·Cover Illustration Investigator puts the finishing touches on a molecular model of a possible deoxyribonucleic acid structure (DNA).

·HIGHLIGHTS OF HEART
PROGRESS-1960
Items of Interest on Research Studies Conducied
and Supported by the National Heart Institute
Most of these tems acte prepared for submission at congressional bestsags on
appropriations for fiscal year 1962
I'S DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
Poble Health, errice
National Institutes of Health

·Public IIcalth Service Publication No. 832
This publication was prepared by the Ileart Information Center
National Heart Institute, Bethesda 1. Maryland
For sale by the Superintendent of thxuments, I's Government Printing Office
Washington 25 DC - Price 25 cents

·CONTENTS Atherosclerosis and Coronary: lleart Disease Past 1 ܕܕ MER-29 Lowers Cholesterol By Blockade of Final Step in Iis Synthesis BX Laxer Grantee Study Evaluates Prognosis of Victims of First Heart Attacks. Hyaluronidase Reduces Edema in Ischemic Ilcart Muscle... Heart Attacks Treated By Coronary Injections of Clor-Dissolving Enzyme. Androsteronc Linked to Fligh Scrum Cholesterol of Thyroid Deficiency New Technique Provides More Sensitasc Measure of Mayma Clot L.) sis...... Clor-Dessolving Enzyme Isolated From Thrombin By NIII Granitos Arachidonic Acid Postiblc Factor in Besistance to Atherosclerosis. Find Serum Cholesterol Not Related to Obesity in Iealthy Young Men... Find Mucopolysacchandes Not Causally Related to Atherosclerotic Lesions... NIIT Findings Support Filtration Theory of Atherosclerosis... 3 4 $ 6 B 8 9 10 Blood Pressure 12 13 New Hypotensise Drugs Slimmize Side Effects By Selective Acyon.... Neurological Disturbances in Catron. Treated Pauents Due to Common Amina Acad. Chronx Renewal Jypertensson Not Dependent on Pressor Substances From hutney Ditt-Induced Hypertension in Rats Similar to Hynian Essential Hypertension.. Studies Demonstrate Value of Renal Resascularization in Selected llyperten 15 5:13 16 Surgery Cardiac Shunts Derected By Ileant In ecu00f of Krypton-85... Supenonty of Butanol Cardioplegia Ronaldo. ... 17 18 19 20 21 ·New Knoicledge and Methods New Dhurctic Is Effective Against Edema of Normal or Toxemic Pregnancy.. Developments Extend Use of Gas Chromatography in Lipid Analysis... Report Gas Chromatography Detector Based on Sound Velocity Variations... Drug Metabolism By Liver Unaltered in Patients with Corrhosis.. Reflexes From Carotid Sinus Important in the Control of Heart Output... Alcohol Causes Deposition of Fat in Liver By Action on Pituitary ... Myocardial Edema Result of ligh Atrial Pressure in Congestive Failure.. Neutral Fat Made in Adipose Tissue By Mechanism Similar to That in Liscr.. Tranquilizer Triggers Prtuslary-Adrenal "Stress" Responses. Rheumatic Fever Studies Reveal Predictability of licart Damage. Lipids Play Major Role in Protein Synthesis, NHI Studies Suggest.- Myosin Moleculc Consists of Three Tightly Coiled Protein Chains. Naturc of Ilormone Control Over Fatty Acid Release Explored By NIII Studies... Active Ion Transport in Red Cell Ghost Powered Ny ATP.. Protein and Fat Fractions of Lipoprotein Molecule Provided By Liver. Observe Accelerated Drug Metabolism in Pretreated Rats.. Prednisone-Aspirin Equally Effective in Preventing Rhumatic lleart Damagc... 28 28 30 31 32 33 31 35 36 37 38 39 40 41 42 44 ·ATHEROSCLEROSIS AND CORONARY HEART DISEASE MER-29 Lovers Cholesterol by Blockade of Final Step in Its Synthesis by Lirer Studies by scientists at the National Institutes of Health have pinpointed the mechanism by which MER-29 lowers serum cholesterol tesels By blocking the conversion of desmosterol to cholesterol, the drug inhibits cholesterol synthesis by the liver at the very last step of the comples sequence of reactions by which the cholesterol moleculc is formed. These studies were made by Drs Joel Avigan and Daniel Steinberg, of the National Heart Institute's Laboratory of Cellular Physiology and letabolism, and Mr Malcolm J. Thompson and Dr. Erich Mosetug of the National Institute of Arthritis and Metabolic Diseases. Their findings are reported in Progress against Cardiovascular Dostase (2 525-530) The scientists observed that the sterol material in the livers of rats treated with MER-29 had properties that differed subtly, but definitely, from those of cholesterol, the major sterol of normal livers. Caserud analysis revealed the presence of large amounts of desmosterol, a compound identical to cholesterol except for two missing hydrogen atoms at one point in the molecule When they injected radioactive acetatc, a cholesterol precursor, into animals pretreated with MER-29, they found that most of the radioactivity accumulated in desmosterol rather than in cholesterol Clinical studies also showed that desmosterol accumulated in high concentrations in the serum of patients receiving the drug These and other findings indicated that NER-29 louers serum cholesterol by inhibiting the destosterol-cholesterol conversion. They also help to clanfy the process of normal cholesterol biosynthesis in man by providing factual esidence that desmosterol is an intermediate in this process CO mm; "WAS ALS, Larvohydrates, or proteins--all of which can give rise to acetate, the primary building block. Thus the possibility of lowering serum cholesterol levels by the use of drugs which inhibit the body's ok n production of cholesterol has attracted increasing attention dusing the past fesy years MER-29 appears 10 be the most promising of the compounds developed thus far ·The synthesis of MER-29 was announced in 1958 by Frank Palopoli and co-workers at the William S. Merrell Company, Cincinnati, and its cholesterol-lowering effects in rats were announced in 1959 by Thomas Blohm and Robert Mackenzie of the same company. The drug, also called "Triparanol," is marketed by the William S Merrell Company, who also made the drug available for clinical research The NIH clinical studies showed that MER-29 reduced serum cha. lesterol levels in patients without producing any observed toxic cliccts. However, the fall in scrum cholesterol was accompanied by a risc in serum desmostcrol, so that total serum sterol levels were not greatly changed, and were actually increased in some patients. The investi. gators suggest that the biologic role of desmosterol warrants more thorough investigation, since information thus gained might be pertinent to the safe long-term use of drugs, such as MER-29, which might lead to the pile-up of compounds normally present in the body only in very low concentrations, Granice Sludy Evaluutes Prognosis of Victims of First Heart Attacks An Nill grant-aided study of survival and factors affecting survival after the acute phase of first heart attacks (myocardial infarction) has shown that morc than half of the 224 patients studied survived for five years or more The five-year outlook was brighter for younger pacients than for older ones, was brighter for men than for women, and was brightest for patients able to resume normal activity after their attacks. The prognosis of patients surviving for more than one month after their first clinically diagnosed heart attack was evaluated by Drs. 3. L Jucrgens, ). E. Edwards, R. W. P Achor, and H. B. Burchell, of the Mayo Clinic, Rochester, Minnesota The scientists determined the rates of survival for 224 patients thrce, five, and ten years after the initial attack. They also evaluated statistically the effects on survival of such factors as age at onsci, sex, pre-existing angina or hypertension; congestive heart failure developing subscquent 10 ihe attack; occupation (active or sedentary); and degree of physical disability result. ing from the attack Their findings are reported in the A 11.A Archives of Internal Medicine (105, 414-450) The average age at time of onset was 62 years (60 years for men, 67 5 years for women) follow-up of these patients showed that 68.8% survived for three years or more after their attacks, 55 4% for five years or more, and 29.2% for ten years or more Not surprisingly, five-year survival rates were fughest among the suffering attacks in these forcies or fifties (78 6% and 62 596), declined moderately among those having attacks during their sixhes (10 56 6%), 2 ·then more sharply among those having attacks in their seventies or cighties (to 25.9% and 20%, respectively) Also no surprise was the finding that pre-existing angina or hypertension, or congestive heart failure deseloping after the attack, made the hve-year prospect bleakerby about 25% on the average. The study also indicated that five-year surxial rates were not sig. nificantly affected by the degree of physical activity involved in the occupations of male patients, were considerably higher for men than for women; and highest for those patients who were able to resume nos mal activity after their attacks The better prognosis enjoyed by the men could not be fully accounted for either by age differences at time of onset or by any other factors observed in the course of the study. The excellent five-year survival rate (73.2%) of patients who were able to resurne normal activity after their attacks has also been obstned in other studies, and appears to be the best index of a good prognosis Necropsy studies on 79 patients who survived their initial attacks but died later revealed that 82% subsequently died from cardiovascular disease. Of these, 31% succumbed to recurrent myocardial infarction Hyaluronidase Reduces Edema in Ischemic Heart Muscle The edematous fluid accumulations in heart muscle which follow coronary artery ligauor in dogs, are markedly reduced by hyaluronidase injections, report Drs. J Mastas de Oliveira, M N. Levy, and Mr Mi Schock, of St Vincent Charity Hospital in Cleveland Ther NHL-supported studies are reported in the American Heart Journal 160 106-109) Dr Martins de Oliveira and co-workers tied off a branch of the left coronary artery in 14 dogs to produce infarction and edema of the posterior papillary muscle (PPNI). Eight of these dogs received hyalurondase intravenously immediately after ligation and at hourly intervals for 5 hours, whereas the remaining 6 dogs received placebo injecuons of saline solution Sus non-ligated dogs sen ed as normal controls, Specimens of the PPM and of anterior superior left ventricular tissue (ASLV) not affected by coronary ligation, were taken from the animals at sacrifice 5 hours after ligation. Differences in tissu na content, measured by the tissues an oven, formation From these studies the scientists found that PPR water content avcraged 17 48 percent in the hyaluronidase-treated group, but increased to an average of 79 92 percent in dogs that received only placebo injections ASLV values in both of these groups, 76 39 and 7621 percon respectacly, approximated normal control values obtained from ·non-ligated dogs The differences between normal and ischemic myocardium in the experimental groups are statistically significant, report the investigators. "In the present study, hyaluronidase significantly reduced the water content of the ischemic myocardial arcas, bringing it to values close to those of the normal regions," conclude the Clevcland scícntists. Ilow. ever, they state, "The practical application of our experiments is still uncertain, since it remains to be proved whether or not it is beneficial to reducc cdema in an ischemic myocardium. It may be postulated, however, that the incrcased tissue pressure caused by this cdema may exert a compressive action upon the collateral vessels, thereby reducing still more the flow of blood to the damaged areas Further insestiga tions are now being carried out in an effort to answer this question Hyaluronidase, or "sprcading factor," is a mucolytic enzyme used by physicians to promote diffusion and absorption of drugs injected subcutaneously. Recent findings by Hungarian scientists, who demon. strated that intravenous hyaluronidase produces a faster diffusion of fluids through extracellular spaces and chances lymphatic drainage, provided the basis for using hyaluronidase in the present study Heart Attacks Treated by Coronary Injections of Clot-Dissolving Enzyme A techniquc using a cardiac catheter to inject the clor-dissolving on. zyme fibrinolysın into the coronary arteries has been used by NHI grantces in the treatment of cight patients with myocardial infarction. The procedure, which was well tolerated by the patients, appears to possess the important advantages over oral or intravenous means of administering fibrinolytic therapy in such cases It provides high con. centrations of clot-lysing enzymes at the site of the clot without unduly clevating whole-system concentrations, and it allows intermittent perfu. sion, a procedure that appears to be more effective in dissolving clots than is continuous perfusion. These studies were conducted by Drs Robert J Boucek and William P. Murphy, Jr, of the University of Miami School of Medicine, Miami, Hlorida Their findings are reported in the American Journal of Cardiology (6 525-533) The technique involves passing a cardiac catheter into the aorta via the brachial artery and, under fluoroscopic guidance, positioning the catheter tip at the root of that great vessc! Thrs brings the catheter orifice in line with the coronary branches, so that fibrinolysın injected through the catheter will be swept into these vessels with their blood supply. To assure th fibrinolysın is delivered at the exact time that the coronaries are filling with blood, the injection is made by a small pump activated by the R wasc of the electrocardiograph. Best > ·results were obtained in this study when injections were made during every founh cardiac cle. The patients selected were treated within 4-12 hours after onset of the attack. Because of its reported enhancement of clot lysis, heparin (an anticoagulant) was perfused with the fibnnolysin (as Thrombolysin: Aferck, Sharp, and Dohme) The effectiveness of therapy was evaluated on the basis of the patients' clinical response, subsequent ECG data; and determinations of serum glutamic oxaloacetic transaminase (GOT), an enzyme released from injured heart tissue and which provides an inder of the extent of heart damage. No attempt was made to evaluate clot lysis by angiol. ogy because it was felt that injections of radiopaque substances, which are somewhat toxic, might be harmful to heart tissue already hyperirritable The evaluation, though limited by available methodology, suggested that most patients were benefited by the therapy. All had an unusually mild clinical course in the hospital All but ino had serum GOT levels considerably lower than those of usperfused controls, indicative of less heart muscle damage. GOT lesels were lowest in patients treated within four hours of the attack, highest in those treated 9-12 hours after This indicates that fibrinolytic therapy, to be effective, must be initiated quickly, since it appeared that heart damage because irreversible about four hours after myocardial infarction. While this study does not offer conclusive proof thar fibrinolytic therapy is beneficial in the treatment of myocardial infarction, the technique used may prove extremely useful for future studies in this important, rapidly descloping research area Androsterone Linked to High Serum Cholesterol of Thyroid Deficiency Androsterone, an important end-product of the metabolism of cortain male sex hormones (androgens), may be an important factor in the high serum cholesterol levels that usually accompany thyroid deficiency NHI grant-aided studies on the role of thyroid hormones in steroid metabolism, have shown that androsterone levels in the blood are below normal in patients with thyroid deficiency and high in those with hyperthyroidism The studies also shoned that injections of androsterone produced a sharp and significant {all 11 the serum cholesterol lesels of normal subjects and those with hypercholesterolemia These findings suggest that androsterone, a metabolite of certain androgens, may be an important determines of scrum cholesterol levels, since these are usually elevated in hypothyroid patients and low in those with hyper. theroidism ·These findings are summarized in Annals of the New York Academy of Sciences (86: 605-611) by Drs. T. F. Gallagher, Leon Hellman, H I.. Bradlow, B. Zumofl, and D. K. Fukushima, of the Sloan-Kettering Institute for Cancer Research, New York, Androsterone is one of tho major end-products from the metabolism of testosterone and certain other androgens; the other, ctiocholanone, is structurally similar but differs sharply from androsterone in its biological activities The scientists found that, in euthyroid patients (normal thyroid function), the ratio of androsteronc to ctiocholanone was 40.60. However, the androsterone fraction was only 15% or even less in pa. tients with hypothyroidism from myxedema; conversely, it was 50% or higher in those with hyperthyroidism from Graves' disease, toxic nodu. lar goiter, or toxic adenoma. The scientists found that the androsterone fraction was sharply in. creased in euthyroid patients when thcy were given thyroid hormonc, and was decreased toward normal in patients whose hyperthyroidism was corrected by therapy. Thc cholesterol-lowering effects of androsterone might seem para. doxical, since thc androgens from which it is derived are normally as. sociated with high scrum lipid levels. However, the scientists point out, hormone metabolites are not necessarily inactive end-products of a spent hormone. They may have their own important physiological functions that arc not related in any way to those of the substances from which they are derived. These findings are the basis for an hypothesis, advanced by the scicntists, that the recognizable cffects of thyroid cxcess or deficiency arc mediated by the availability of androsterone in the body. They also suggest that androsteronc deficiency may be one of the mechanisms involved in the development of hypercholesterolemia and, perhaps, of atherosclerosis Nero Technique Provides More Sensitire Measure of Plasma Clot Lysis Using a sensitive, direct assay technique that closely approximates in Xro conditions, NHI grantees lave nicasured the degree of clot-dessolsing activity in human plasma They report in the Journal of Clinical Investigation (39: 426-434) that such activity depends primarily upon an activator whose concentration in plasma varies widely in response to stress, certain drugs, and discase. For these studies Drs W D Sawyer, A Pfletcher, Norma Alh. jaersig, and Sol Sherry, of the Washington University School of Medicinc, St Louis, prepared clots from aged human plasma enriched with plasminogen and containing traces of bovinc fibrinogen tagged with radioactiic lodine The methods used produced "" labeled clots that were largely free of entrapped human plasma 6 ·The clots were then incubated for two hours at body temperature in samples of unaltered plasma from healthy adults who had been sub jected to stress or pretreated with certain drugs, and from patients with various chronic or infectious discases. The degree of clot lysis was determined by measuring the amount of radioactivity telcased into cach plasma sample as the clot dissolved Thrombolysis 13 a complex process involving many factors whose exact roles have not yet been clarified The major components appear to be plasmin, the enzyme that actually dissolves the clot, plas. minogen, its inactive precursor; and plasminogen activator, which converts plasminogen to plasmin. The circulating blood is thought to contain inhibitors for both actise principles so that, under stormal circumstances, they are present in the circulation in their "neutra!" forms A blood clot also contains plasminogen, which was trapped in the clot during its formation In fibrinolysis, it is thought, plasminogen activator accumulates on the fibrin surface of the clot and proceeds to convert the trapped plasminogen 10 plasmin. The plasmın dissolves the clot from within by digesting its fibrin. Further knowledge of this property of plasma and better means of measuring i have been made essential by recent developments in the field of fibrinolytic drugs However, techniques heretofore available were indirect, were not sufficiently sensitive, or disturbed the complex balance between individual plasma components. The technique used in this study appears to avoid these limitations, and, with it the scienpists have been able to provide experimental confirmation of concepts that formerly were largely inferential. They found that plasma clot-lysing activity was sharply increased by sustained vigorous exercise and was increased by emotional stress or injections of nicotinic acid (a B-vitamin} or a ſever-producing drug. It was also generally elevated in patients with acute infections, hier disease, or leukemia Conversely, clot-lysing activity was commonly observed to be below normal in patients with cancer other than leukemia, congestisc heart failure, or atherosclerosis Thus subnormal acuvity may be causally selated to the thrombo-embolic complications that frequently attend these diseases Plasma clot-lysing activity was found to be due primarily to the plasminogen activator it contained, and upon the plasminogen in the clot rather than that in the plasma. Clot lysis was greatly reduced when clors containing little plasminogen nere incubated in the piasma sam. ples, and was practically pil when plasminogen-free clots were used Clot fysis was also reduced by the addition of E-aminocaproic acid, which in los concentrations effectively inhibits plasminogen activator, but not plasmin ·Clot-Dissolving Enzyme Isolated From Thrombin By NHI Grantees Chemical "dissection" of thrombin has yielded a new clot-dissolving, or fibrinolytic enzyme identified as thrombin-E, report Drs. Walter II Seegers, Ricardo H. Landaburu, and J. Frederic Johnson at Wayne State University in Detroit The scientists observed powerful fibrinalytic effects of the new enzyme following its intravenous infusion in dogs. Their findings published in Science (131 726) stem from an carlier observation that thrombin, long known for its important physiological role in catalyzing the formation of blood clots, has both the power 10 form and subsequently dissolve fibrin clots under certain laboratory conditions In their currently reported studies, the investigators attribute the lytic activity of thrombin to a distinctly different enzyme which they named esterase thrombin, or thrombin-E, to distinguish it from thrombin-C, the parent compound. They produced thrombin-E in pure form by acctylating thrombin-C with acetic anhydride. This destroyed the clothing power of throm bin-C and almost doubled the activity of thrombin-E, which was then stabilized by drying. Dog experiments demonstrated the ability of intravenously infused thrombin-E to dissolve blood clots. In a typical experiment, 15 mg of dried thrombin-E dissolved in 100 ml of physiological saline solution, was slowly injected over a period of 1 hour and blood samples repeatedly withdrawn. Dr Seegers and co-workers report that at the end of the infusion period, blood samples clotted but subsequently lysed within an hour. "Occasionally the lytic phenomenon was so pronounced that the blood would not clot spontaneously upon with drawal or even after thrombin was added," they stated The dogs tolerated the procedure very well; the few physiological effects obserscd, such as lowered platelet and white cell counts, increased blood sugar levels, and lyric phenomena, disappeared within 24 hours. The investigators speculate that thrombin-E may function by activating physiological processes concerned with fibrinolysis and thus the maintenance of blood ſudity. “This opens possibilities for the uscful application of thrombin-E," they said. Arachidonic Acid Possible Factor in Resistance 10 Atherosclerosis Studies by NHI grantees suggest that arachidonic acid--a lughly unsaturated fatty acid found in certain fish oils, dairy products, and ſowi-may be a significant factor in the relatise immunity to athicno. 8 ·sclerosis enjoyed by animals of certain species in these studies the cholesterol fractions of serum from man and from seven other species were analyzed and compared. The arachidonic acid content of scrum cholesterol esters (which comprise about 70% of the total blood choles. terol) was found to be highest in shose species most resistant to atherosclerosis, lowest in the most susceptible species. The largest amounts of arachidonic acid were found in the cholcsterol ester fractions of the rat (50%) and the dog (17%), both highly resistant species Much smaller amounts (1.1-58%) were found in the cholesterol esters of the goose, chicken, rabbit, guinea pig, and pig. Sesere atherosclerosis can be produced in these species by feeding them high-cholesterol diets for only a short period, even ihough they seldom appear to develop the disease spontaneously. Man (7.5%) is susceptible to atherosclerosis, but usually develops sc. iere lessons only after many years on a diet high in fat and cholesterol (although much lower in cholesterol than the atherogenic diets fed laboratory animals). However, the scientists point out, these findings, though in accord with an hypothesis that arachidonic acid dehciency is an important causal factor in atherosclerosis, have not proved that arachidonic acid is the protectie factor not that niore of it in the dict of humans will make them less susceptible Bur the possibility remains that the arachidonic acid content of hu. man lipids may be increased by diets higher in this fatty acid or the clements from which it is synthesized (hnoleic acid plus the co-factor vitamin B.) te would then remain to be seen whether such an increase would confer upon man greater immunity to atherosclerosis These studies were done by Dr Leon Swell, of the Veterans' Ad. ministration Center, Martinsburg, West Virginia; and Drs. Henry Field, 3r, and C R Treadwell, of George Washington University. Their findings are reported in Proceedings of the Society for Experimental Biology and Medicine (104 325-328). Find Serum Cholesterol Not Related to Obesity in Healily Young Men No significant correlation was found between serum cholesterol level and relative obesity in 159 male medical students at Johns Hopkins University, report. Drs Caroline Bedell Thomas, Johns Hopkins Uru. crsity School of Medicine, Baltimore, and Stanley M Carn, Feis Research Institute, Yelloss Springs, Ohio. Findings of their NHI grant. aided study appear in the journal Science (13) 42) Obesitt measured indirectly was expressed in the study as actual weight or weight in selation to skeletal chest-frame diameter as seen in chest X-ray films ·Measurcments of the fat-plus-skin thickness at the level of the tenih rib were also used by thc investigators as a more direct method of de. termining obesity. The fatty layers were seen as shadows on the X-ray films and ranged in thickness from 2 to 15 mm, averaging 7.4 mm. thick Scrum cholesterol values varied in the students from 140 to 386 nig. per 100 mi. of scrum and averaged 225 mg/100 ml. The study revealed an insignificant correlation ("not significantly dilferent from zero at the 5 percent level of confidence") between scrum cholesterol levels and direct and indirect obesity measurements “The lack of relationship between the amount of body fat and the scrum cholesterol level demonstrated in the present study supports the view that the nutritional status of hcalthy young men such as medical students is considerably less important in determining the Cholesterol level than other biologic factors," conclude the investigators. Several of these "biologic factors," which include agc, sci, race, heredity, endocrine patterns, habits of smoking and cxcrcisc, and cmotional stress, have been previously reported by Dr. Thomas and coworkcrs to bear a positive relationshup to high serum cholesterol levels among the Johns Hopkins medical students. Find Mucopolysaccharides Not Causally. Related to Atherosclerotic Lesions Because mucopolysaccharides are often found in increased amounts at the site of atherosclerotic Icsions, they have been suspected of being a causative factor in atheroma development. However, studies of the aortas of cholesterol-fed rabbits suggest that the increased amounts of mucopolysaccharides usually found in arterial tissuc at the sitc of atherosclerotic lcsions are secondary to fat deposition rather than a cause of it. The studies, supported in part by an NHI grant, serc carried out by Drs A. J. Bollet, Wayne State University College of Medicine, Detroit; Chuni Wang, Detroit Receiving Hospital, and David Adlersberg. Mount Sinai Hospital, New York Thcir findings are reported in Circulation Research (8 88-92) Mucopolysaccharides are found in the connective tissues which bind together and support the cellular components of blood essels and many other organs. The supportive function is accomplished by the protein collagen, whose insoluble fibers are embedded in a soluble matrix called the ground substance Mucopolysaccharides are important constituents of the ground substance. In recent years studies on the possible role of the arterial ground substance in atherosclerosis have shown that the development of atherosclerotic lesions appears to be accompanied by increased concentrations of mucopolysacchandes in the affected tissues Animal studies 10 ·also showed that cortisone (which retards mucopolysaccharide metab olism) slowed the development of atherosclerotic lesions while the enzyme hyaluronidase (which breaks down the mucopolysaccharide hyaluronic acid) counteracted the effects of cortisone. These findings sug. gested thar changes in mucopolysaccharides are important in atheroma formation and might eses be a causatke factor. To insestigate this possibility, the scientists induced atherosclerosis in rabbits by feeding them cholesterol for 1-7 months. Animals were sacrificed at tho-week intervals after the first month and their aartas analyzed both for lipids and for mucopolysaccharides Early athero. sclerotic changes were found in the aortas of animals after 5-2 months of cholesterol feeding, and moderate to severe lesions in animals fed cholesterol for three months or more. However, chemical analysis of the mucopolysaccharide content of these vessels showed no significant increases except in the more advanced lesions produced by six months or more of cholesterol ſeeding. The findings suggest that alterations in mucopolysaccharides are in. deed related to lipid changes in the development of atherosclerotic lesions, but are secondary to lipid deposiuon, not a cause of it NAI Findings Support Filtration Theory of Atherosclerosis Evidence supporting the filtration theory of atherosclerosis has fxen obtained from studies on experimental atherosclerosis conducted by Dr. Leroy Duncan, Mirs Katherin Buck, and Mr. Almorris Lynch, of the NHI Laboratory of General Medicine and Experimental Therapeutics The filtration theory assigns the chtel role in the development of atherosclerosis to lipoproteins, fat-protein complexes which sone as the major vehicles of lipid transport in the body. According to this theory, imac lipoproicins carrying cholesterol pass from the plasma into the inner layer of the arterial wall Here, because of the structure of the wall, they are trapped and give rise to atheromatous lesions The studies on experimental atherosclerosis were based on informasion gained in previous studies on the movement of plasma albumin into arterial walls. These studies had disclosed that albumin enters the aorta with a gradient of rates, entering most rapidly in the upper aorta and progressively more slowly down its length The investigators seasoned that plasma albumin and plasma lipoproicin might cnter aortic wall by the same mechanism and thus show the same gradient When combined with the filtration theory, this reasoning led 10 the prediction that there should also be a gradient in the deposition of cholesterol along the length of the aorta early in the develapment of experimental atherosclerosis Subsequent determinations of the cholesterol concentrations along of rates ·the length of aortas in dogs confirmed the prediction Carly in ex. perimental atherosclerosis there is a striking gradient of cholesterol deposition, and this gradient is very similar to the gradient of rates with which albumin enters the aortic wall. Thc cxperimental demonstration of this consequence of the filtration theory offers strong support for that theory The scientists found that the gradient disappears later in the deselpment of experimental atherosclerosis, and that the cholesterol concentrations eventually become hgher in the lower portion of the aorta This scquence of events suggests that the most severc atheromatous le sions tend to localize eventually in the lower aorta because of the extremely slow removal of cholesterol from that segment. These studies, reported in Circulation Rescarch (8: 1023-1027), also cniphasize that the interplay of the rates of deposition and emoval of cholesterol from the arterial wall are of prime importance in the development of atherosclerosis. Studies on factors influencing these rates are in progress BLOOD PRESSURE New Hypotensive Drugs Minimize Side Effects by: Selective Action Syrosingopine and guancthidine, two new hyposensive drugs synthesized and marketed by CIBA, have been found to be cffective in lowering blood pressure and also specific enough in their modes of action to minimize undesirable side cllects. Scientists of the NHI Laboratory of Chemical Pharmacology have found that both drugs lower blood pressure by depleting the peripheral sympathetic nerve endings of norepinephrine, thereby bloching the transmission of nerve impulscs that trigger blood vessel constriction Drugs that lower blood pressure by peripheral sympathcuc blockade are not new; some have been in use for years Most of these work by inlubiling the action of norepinephrine, an amine that is relcased from sympathetic nerve terminals to transmit their impulscs to the muscles of the arterial wall Reserpine was the first drug found to lower blood pressure by depleting this amine at sympathetic tcrminals, but only slightly larger doscs may also produce undesired sedation and parasy 17). patlıctic effects by depleting brain amincs, and diarrhea by releasing scrotonin in the intestines A major problem in ercating hypertensies with reserpinc lias been the maintenance of dosage schedules that would hold blood pressure down without causing these side effects Syrosingopinc, a compound made by "tailoring" the reserpinc moloculc slightly, resembles reserpine in its effects on blood pressure, but is 12 ·more selective in its site of action. In experiments on animals, Drs Barbara H. Orlans, Kenneth F. Finger, and Bernard B. Brodic compared the effects of reserpine and syrosingopine on peripheral norepincphrine and on brain amine levels Both drugs depleted peripheral norepinephrine in doses that did not affect brain amines; houcier, reserpine exhibited this selectivity only over a narrow dosage range, whereas syrosingopine did not affect brain amines over a wide range. This more selective peripheral action of sytosingopine is a highly desirable clinical feature that provides a greater margin of safety against undesirable side effects Guanethidine, a synthetic drug structurally different from reserpinc, is also far more specific in its action than is reserpine The drug depletes the peripheral sympathetic nerves of norepinephrine, but does not affect brain amine levels (due in part to its limited abilty to penetrate the blood-brain barrier), therefore does not produce sedation It does not release serotonin from peripheral body tissues, thus does not cause diarrhea. The drug is also well suited to oral administration because it is stable in the gut and is more readily absorbed than are ganglionic blocking agents. The work by Drs. Rosemary Cass, Ronald Kuntzman, and Bernard B Brodie did not disclose the precise mechanism by which guaneth idine depletes peripheral norepinephrine, even though the results in. dicate that it does so by a mechanisin different from that of rescrpine, There are two possibilities, both under study the drug may impair storage of the amine or block its synthesis The findings on the two drugs are reported, respectively, in the Journal of Pharmacology and Experimental Therapeulics (128. 131-139) and in Proceedings of the Soculy for Experimental Biology and Mediane (103. 871-872) Neurological Disturbances in Catron-Treated Patients Due to Common Amino Acid Tryptophan is an essential amino acid found in many dietary staples, and which, under normal circumstances, produces no untoward effects on the consumer However, when given to patients receiving monoamine oxidase (MAO) inhibitors, tryptophan us capable of producing pronounced neurological disturbances, some of them strikingly similar to those of alcoholic intoxication These disturbances were obsered by Drs John A. Oates and Albert Sjoerdsma, of the NHI Laboratory of General Medicine and Experimental Therapeutics, after giving tryptophan orally to seven hypertensive patients being treated with Catron, a potent MAO inhibitor. The doses of tryptophan producing these effects were only 1/2-3 times the usual dretary intake of this amino acid This small difference saises the question of whether diets unusually high in this or other 591031 0-61-3 ·amino acids might not modify the clinical effects and side ellects of MAO inhibitors in the treatment of hypertension and especially in the treatment of certain depressed states. In three of these patients, tryptophan produced irregularities of coordination, euphoria, release of inhibitions, slurred specch, and other effects strikingly similar to those of alcoholic intoxication These and other patients also showed signs of drowsiness, a sharp contrast to the psychic cnergizing effects usually produced by MIAO inhibitors Four patients recciving the largest doses of tryptophan also exhibircd crag. gerated reflexes, confined chiefly to the lower extremities, and accom. panied by spasms of the ankle. The fact that tryptophan produced these effects only in patients receiving MAO inhibitors suggests that the cliccts might be due to one or more of the amines produced from this amino acid. The most likely suspects are tryptamine and scrotonin. Animal studies have shown that doses of tryptophan increase the levels of both of these amines in the brain, and that this increase is augmented by MAO inhibitors. These inhibit the destruction of trypa tamine and serotonin by the enzyme monoamine oxidase at the same time that tryptophan is leading to stepped-up amınc production. Increased levels of enther or both amines are accompanied by neurological effects that vary according to the species of animal In man tlic evidence is less direct, but tryptophan has been shown 10 mcrease urinary excretion of tryptamine and an end-product of serotonin metabolism 5-fydroxyindole acetic acid (5-HIAA). Truus it is reasonable to assume that levels of both amines in the nervous system are increased by tryptophan and MAO inhibitors, and that enrher or both amines may be responsible for the observed neurological cffects These findings have been accepted for publication in Neurology Chronic Renal Hypertension Not Dependent on Pressor Substances from Kidney Animal studies on the role of the kidney in hypertension have provided evidence that the chronic elevation of blood pressure that persists in renal hypertension is not dependent on increased blood liels of artery-constricting substances from the kidney. These studies, sus ported in part by as NHI grant, are reported in the American Joumal of Physiology (198. 1148-1152) by Drs, Pedro Blaquier, David F Bohr, and Sibicy W Joobler, of the Diversity of Michigan, The kidney is known to be the villain in several forms of secondary hypertension and has also been suspected of playing a role in the development and/or mainicnance of essential hypertension It has been demonstrated that the kidney releases senin as an acuic response ·to an inadequate renal blood supply; and that renin, in cura, scacts with a serum protein to form angiotensin, a potent artery constrictor. But whether this response is transient or is involved in the majnienance of chronic hypertension has been the subject of much conflict. ing evidence. In the study of this problem, the scientists used a cross-circulation technique in which the femoral arteries and veins of rats with surgi. cally produced renal hypertension were connected by plastic rubing to those of normotensive rats Preliminary work had shows thas (1) cross circulation between pairs of normotersise rats produced no signifirant changes in blood pressure, and (2) clevated blood pressure produced in one of the pair by infusions of renin or angiotensin was followed shortly by elevated blood pressure in the other. Thus, if the hypertension sa the surgically treated rat were due to circulating vasoconstrictors, cross circulation should also produce hypertension in the normotensine rat of each pair. To rule out blood pressure aberrations that might be due to blood volume changes, normal and stable blood volumes were maintained by equalizing the law rates berncen the animals of cach pair by adjustable clamps on the plastic tubing. The animals were arranged on the two pans of a sensitive balance so that any volume variations would be promptly noted and corrected in pre series of experiments the scientists used seven rats whoxe renal asteries kad previously been clamped for four hours. When the clamps were removed, hypertension was produced within minutes, presumably by renin from the ischemic kidney. Cross circulation, immediately initated between these rats and seven normotensives, re. suled in elevated blood pressure in all normotensive rats. However, cross circulation between normotensive rats and those with hyperten. siart of more than one week's durauon had no significant effect on the blood pressure of the normotersives. Thus, it appears from these experiments that circulating artery constricting substances such as renin may play some role in the initiation of renal hypertension, but may not contribute to its maintenance Diet-Induced flypertension in Rats Similar ID Human Essential Hypertension Szudies on rais made hypertensie by dieis deficient in potassium or choline dating carly life suggest than this dietary technique may yuló laboratory animals more suitable for research on the role of the kidney essental hypertension than de commonly used methods in. solving renal artery construction or removal of onc kidney. Renal function studies on rats showed that she dict-induced hypertension in ·these animals, like essential hypertension in humans, was not the result of an inadequate renal blood supply nor was it associated with severe excretory insufficiency. In these experiments, Drs Fred N. White, M. P. Sambhi, and Arthur Grollman, of the University of Texas Southwestern Medical Center, studied renal function in 31 rats: 10 normal controls and 21 with dict-induced chronic hypertension. The NHI grantees compared data from the two groups to determine the effects of the cxperimental hypertension on rates of renal blood flow, plasma filtration by the kidney glomeruli, and excretion of urca. Their findings, reported in the American Journal of Physiology (198 221-222), revealed significant changes from normal only in the glomerular filtration rates, which were somewhat reduced in the hy. pertensive rats The findings suggest certain striking similarities, with respect to renal function, betwecn diet-induced experimental hypertension and the essential hypertension that develops spontaneously in humans, Neither is the primary result of an inadequate renal blood supply and neither is accompanied by severe impairment of excretory capacity These similarities suggest that the dietary technique might yield laboratory animais especially suitable for research on kidney function and hemodynamics in hypertension, especially on more subtle renal changes that might be masked by the severe lesions and renal ischemia usually resulting from drastic surgical procedures Furthermore the dietary procedure is simpler and less subject to failure than are most surgical techniques. The potassium or choline deficient diets need to be fed to the animals for only a short period (usually 1-5 weeks) early in their lives to produce hypertension, after which the disease is sell-maintaining and progress Previous studies by Drs Grollman and White, who developed the technique, indicate that the morphological changes induced in the heart, blood vessels, and kidneys by dict-induced hypertension arc also similar to those of essential hypertension in humans. Thus the techniquc may aid in the accumulation of experimental data that might establish relationships between experimental hypertension in animals and essential fıypertension in man Such relationships might help to clarify many of the puzzling features of this enigmatic discasc Studies Demonstrate Value of Renal Revascularization in Selected Hypertensives Hypertension caused by narrowing of one or both main renal arteries has been relieved in 33 of 40 patients by restoring blood flow to affected kidneys, report NHI grant-aided investigators in Houston, Texas. In renovascular hypertension caused by occlusive discasc of onc or 16 ·both main renal arteries, the affected kidney(s) releases a substance (remin) which acts in the bloodstream to form the hypertensive agent, angiotensin Patients with this kind of hypertension involving only one kidney have been treated by removal of that kidney (nephrectomy). However, because nephrectomy relieved hypertension in only 20 percent of these patients and could not be applied to bilaterallyaffected patients, it was abandoned more than a decade ago In recent years, surgical treatment of renovascular hypertension has been revolutionized by the development of procedures for conserving renal function by removing or bypassing arterial obstructions The value of this modern surgical approach to renovascular hypertension was recently demonstrated in studies conducted by Drs G. C Morris, Jr, M. E. DeBaley, J W Overstreet, and Russell Scott, Jr., of the Baylor University College of Medicine in Houston, Texas They used renal arteriography for the definitive diagnosis of renovascular lesions in 40 hypertensive patients. The lesions, which affected both kidneys in 40 percent of the patients, were then corrected in one of ino ways in most cases the obstructions were bypassed by syn. thetic grafts of Dacron, narrowed artenes were also widened by cutting them longitudinally and inserting a Dacron patch-graft into the Incision Results of surgery, evaluated by physical examination, renal artenography, and tests of renal function, are reported in the American Surgeon (26 745-749) Dr Morris and co-workers found that 33 (82 percent) of these patients became normotensive and have remained so (observation periods at the time of report were up to 3 years' duration) of the remaining 7 patients, 4 showed some improvement in their hyperten- 51on and 1 patient died 5 days postoperatively as the result of a coronary occlusion They also report renal function following revascularization for unilateral involvement is always superior on the side of renal artery narrowing," a finding which emphasizes the value of conserving renal function in unilaterally as well as bilaterally affected patients SURGERY Cardiac Shunts Detected by Heart Injections of Krypton-85 Studies by NHI scientists on 48 patients have shown that radioactise krypton, injected directly into the heart via a cardiac catheter, provides a simple, rapid, and accurate means of detecting and localizing cardiac shunts The small quantities of the isotope needed for the procedure and its short biological half-life make the method safe both for the patient and for laboratory personnel.

·Shunts result from holes in the partition separating the right hear from the left heart. The right heart receives oxygen-poor blood from the body and pumps it to the lungs; the left heart receives the freshly oxygenated blood from the lungs and pumps it to the body. By allowing the mixing of oxygen-poor blood with oxygenated blood in the heart, shunts can seriously impair the efficiency of the heart in delivering oxygen to the tissues. To detect left-10-right shunts, a catheter is positioned in the left hcart and 3-5 ml. of saline containing dissolved krypton-85 injected. If no shunts exist, the gas will be pumped throughout the system and largely dissipated before making a much-delayed appearance in the lungs via the right heart. But a left-lo-righe shunt will allow same of the gas to cross to the right heart, where it is pumped directly to the lungs Thus, shortly after injection the gas will appear in high concentration in the air exhaled by the patient. The radiation of the expired air is monitored by a count-rate meter and recorded continuously on a dircct-writing Oscillograph To detect right-to-left shunts. the krypton-85 is injected into the right heart and arterial blood samples drawn at a constant rate for he next 15 seconds In the absence of a shunt, all of the gas is pumped to the lungs where about 95% of it is eliminated in the expered air helore cheering the arterial circulation. Thus, high concentrations of the isotope in the arterial samples mean that the gas bypassed the lungs by crossing directly to the left heart Repeated injections of krypton-85 with the catheter tip stationed at different points makes it possible to localize shunts with a considerabic degree of accuracy The method also permits estimation of the magnitude of right-to-left shunts by relatively simple calculations In every patient in which this techmque indicated the presence or absence of a shunt, its accuracy was subsequently verificd by findings at operation or autopsy, or by the use of other established cechniques for diagnosing shunts These included selective angiography, dye durion curves, and kryptan-35 or nigrous oxide inhalanon 12815. The method proved to be convenient, simple to apply during heart catheterization, and sensuive enough to permut the detection and localization of even very small shunis These clinical studics were conducted by Drs RTL Long, Eugene Braunwald, and AG Morrow, of the NHI Surgery Branch Their findings are reported in Circulation (8 1121-1133) Superiority of Butanol Cardioplegia Revealed by Animal Studies The frequently obscrved depression of heart action in paticas fol lowing clective cardiac arrest has stimulated the quest for bener ·methods of stilling the heart Chemical methods (aortic injections of potassium atrate or acetyicholine) have been largely abandoned in inor of the anoxic method which involves clamping the aorta to restrict blood flow to the heart. Now evidence that butanol-induced cardioplegia has certain advantages over the anoxic method is reported in the Transactions of the American Society for Artificial Internal Organs (6. 323-337) by Drs H. H McGuire, Jr., L. H. Bosher, Jr, and R W. Ramsey, of the Medical College of Virginia, Richmond. Their studies were supported by a National Heart Institute grant, The scientists divided 21 dogs into four groups according to type and duration of cardioplegia butanol arrest of 15 or 30 minutes duration, and 15 or 30 minutes anoxic arrest Control ventricular function data was obtained for each group prior to arrest for comparison with simular data obtained 15 and 30 minutes after cessation of arrest. Comparison of the post-arrest venincular function curves showed that recovery following 15-minute arrest was much more rapid in the butanoltreated animals than in the anoxic arrest group At 15 minutes post arrest, for example, ventricular function had returned 10 85% of normal in the butanol-arrested animals, but to only 49% of normal in the others Recovery after 30-minute butanol arrest was less satisfactory, but was still much more rapid than that after 30-minute anoxic arrest Although the protection conferred by butanol appears to diminish if cardioplegia is maintained for longer than 15 minutes, the scientists feel that this protection might be extended for longer periods by the use of hypothermia or auxiliary metabolic or cardioplegic agents New Catheter Design Permits Selectire Visualization of Coronary Arteries A new coronary artenography procedure, involving the use of a special loop-end catheter, 15 reported in The New England Journal of Medicine (262 325-333) by NHI grant-aided scientists in Boston Their studies in dogs and humans show that the technique permits sale, selecuve X-ray visualization of the coronaries with smaller amounts of radiopaque dye than is usually required by other procedures Further application of this technique may improve X-ray diagnosis of coronary artery disease The Boston scientists are Drs Sven Bellman, H A. Frank, P B Lambert, David Littmann, J H Hall, and J A. Williams of Beth Israel Hospital, West Rosbury Veterans Administration Hospital, and Harvard Medical School In coronary arteriography, a radiopaque substance is injected through a catheter into the base of the aorta where the coronary 19 ·arteries branch out into the heart. As contrast substance flows into the coronaries, rapid-sequence X-ray pictures are taken to reveal the extent and location of atherosclerotic deposits. Success of the proces dure depends upon an adequate flow of contrast medium into the coronaries, and has been accomplished in the past by either injecting large quantities of medium or by diverting more contrast material into the coronaries through aortic occlusion or temporary heart arrest. While the procedure is usually safe and reliable, adverse reactions have been observed in some patients receiving large dye injections. The new technique employs a different principle of injection whereby dye is injected through holes in the catheter loop and directed toward the coronary openings, thus eliminating the necessity for large amounts of dye. The loop-end catheter was developed by the scien. tists after their dog studies had shown that ordinary, straight-tipped catheters recou from the coronary openings as dye is injected The catheter loop is held straight by a wire guide while being inserted into the aorta and regains its circular shape upon withdrawal of the guide. The synchronous injection of dye and rapid-scquence exposure of X-ray plates may be repeated for a second sct of films, The Boston workers report that coronary arteriography with the loop-end catheter was well tolerated by both dogs and humans, and that good coronary visualization was regularly obtained They expressed the behef that this method is inherently safer than other methyods currently available, and concluded, "This approach to the problems of angiographic diagnosis of coronary artery diseasc shows considerable promise The loop-end catheter method is one of several recent developments in coronary arteriography and illustrates progress being made in this ficld Technique Increases Safety of Surgery To Unblock Small Arteries A new technique that permits surgical removal of atherosclerotic deposits, clots, or other lesions obstructing blood flow in small arteries has been developed by Drs Es Crawford, AC Beall, P R Eles, Jr., and M E DeBahey of the Baylor University College of Medicine The new method overcomes the problem formerly posed by the constriction of the inner diameter of the artery at the site of the incision during the healing process This is done by inserting a knitted Dacron patch at the incision site (following removal of the arterial obstruction), then suturing the wound edges to this patch rather than to one another After being tested on laboratory animals, the technique was used in 93 patients suffering from lesions impeding arterial blood flow At the 20 ·site of arterial blockade a longitudinal incision was made through the artery wall, cutting through all of the diseased portion plus a short undiseased arterial segment at either end. A piece of plastic tubing was inserted to detour blood around the site while the obstruction was removed The Dacron patch was then inserted and the wound edges sutured to its circumference, the plastic tubing "detour" being withdrawn just before the final suture was drawn taut. None of these patients deseloped recurrent arterial obstruction dusing their convalescence, and only two had recurrences during the next 30 months This is in sharp contrast to the results of animal studies in which incisions, made in arteries of comparable diameter, were repaired by suturing the wound edges together Every artery repaired in this way subsequently became constructed Endarterectomy, the direct surgical removal of lesions obstructing blood flow, has been used successfully to restorc normal circulation in such large arteries as the aorta and iliac Theoretically, the same technique should be even better suited for obsiructed small aricries, such as the coronary, renal, or vertebral arteries, since lesions tend to be confined to short segments of such vessels. However, its application had previously been sharply limited by the constriction that often developed in such vessels after surgical repair--a factor of great importance in small vessels because of the attendant danger of clot formation By overcoming this problem, the new technique greatly extends the use of surgery for the correction or improvement of arterial insufficiency resulting from atherosclerosis or other cardiovascular diseases. It may also make possible the safe and effectise use of surgery in the treatment of coronary heart disease, heretofore attended by high risk and low probability of success This work, which was supported in part by an NHI grant, is reported in Surgical Forurn (10 671-675) Combat Heart Arrest by Massage Through Unopened Chest A new method of closed-chest cardiac massage which may be used by "anyone, anywhere" to restore blood flow in patients with cardiac arrest, is described in The Journal of the American Ifedical Association (173 1061-1067) by Drs W. B Kouwenhoven, J R Jude, and Nir GG. Knickerbocker of the Johns Hopkins University School of Medicine at Baltimore The method, which they developed through extensive experimentation on more than 100 dogs, has been used with notable success on patients with cardiac arrest The new technique is casily applied and, unlike direct cardiac massage, it eliminates the necessity for surgieal.esposure of the heart. To TEDIOAL CO 591031 0-61-7 ·effect massage, the operator places both hands, one above the other, with the heel of the lower hand resting on the lower third of the patient's sternum and presses vertically downward about 60 times per minute. With each pressure stroke the sternum is moved 3 or 4 ccntimeters toward the spinc, thus compressing thc heart and forcing out blood Relaxation at the end of the stroke allows the hicart to fill again Artificial respiration should be given simultaneously. "When cardiac arrest occurs," the scientists point out, "the circulation must be restored promptly, otherwise anoxia will result in irreversible damage." They found that closed-chest cardiac massage, combined with artificial respiration, maintains a flow of oxygenated blood to the heart and central nervous system until normal heart action returns spontaneously or, in cases of ventricular fibrillation, until a closed-chest defibrillator can be brought to the scene of the cmergency. According to the investigators' experience, hearts in fibrillation for longer than 3 minutes usually do not respond to defibrillation procedures. Closed. chest cardiac massage, however, greatly extended this time limit: "Adequate circulation for periods as long as 30 minutes was easily maintained with the dog in ventricular fibrillation. A closed-chest defibrillating shock would result in the immediate return of normal sinus rhythm in such animals," they explain In the 10 months preceding their report, Dr. Kouwenhoven and coworkers applied closed-chest cardiac massage to 20 patients who were from 2 months to 80 years of age. In addition to cardiac massage, which varied from less than 1 minute to 65 minutes in duration, 3 patients required defibrillation and 13 required artificial respiration The scientists report that all 20 patients were successfully resuscitated and, at the time of this report, 14 patients were alive without central nervous sysem damage; an over-all permanent survival ratc of 70 per- Although their data was obtained from hospitalized patients, Dr Kouwenhoven and co-workers conclude, "The rcal value of the method lies in the fact that it can be used wherever the emergency arises, whether that is in or out of the hospital." cent Portable Pacemaker dids Patients Tith Complete Heart Block Electrical stimulation of the heart with a transistorized portable pacemaker is reported to be an effective method of treating complete hcart block in patients A description of thc apparatus and its ersc in 66 patients is reported in The Journal of the American Medical Issociation (172 2006-2010) by Drs CW Lillehei, V L Gott, PC Hodçcs, Jr, DM Long, and Mr E E Bakken of the University of Minnesota Medical School at Minneapolis 22 ·In complete heart bloch, disease or operative injury of the heart's conduction tissue blocks nerse impulse conduction from the sinoatrial node (the heart's "pacemaker" located in the right atrium) to the ventricles. The ventricles thus lose their normal rhythm and frequently cease beating entirely, The artificial pacemaker des eloped by the Minnesota workers is de. signed to maintain the heartbeat for days, seeks or even monthsuniil diseased or injured tissue regenerates and the heart's own pacemaker can resume maintenance of normal heart phythm The device consists of a transistorized transformer powered by a self-contained long-life battery, and is connected to the heart by one or two thin wire electrodes inserted into the heart muscle. open Electrode(s) may be inserted either through the chest in or, nonsurgical patients, by piercing the chest wall with a hollow needle, through which an electrode is passed and the needle subsequently withdrawn. The small pacemaker (slightly larger than a package of cigarettes) is completely portable and is worn strapped to the patient's chest The NHI grant-aided scientists report that artificial paccrnaker slimulauon has proved to be the most effective method of managing complete heart block in surgical patients, and that 2 to 5 of these pa. tients required less than 2 or 3 weeks of continuous stimulation. Most of the remaining surgical patients were "weaned" from the pacemaker by progressively lowering the rate of stimulation and administering isoprotererol hydrochloride, a drug which increases cardiac rhythmicity and rate Most of the patients treated in this series had descloped heart block subsequent to cardiac surgery However, the pacemaker has also been used successfully in the treatment of Stokes-Adams syndromc-heart block due to atherosclerosis, inſection, or certain drugs-restoring many of its victims to useful activity The investigators point out that, not only has the threat of sudden death in these patients been removed, but that their physical and emotional rehabilitation has been dranatic At the time of their report, one patient with Stokes-Adams syndrome had been maintained under continuous stimulation for 15 months Neic Aortic l'alre Prostheses Reported by NHI Grantees Unis ersity of Minnesota surgeons David L Long, Jr., Laurence P Sterns, Robert H De Reimer, Herbert E Warden, and C. Walton Lillehet, described in Surgical Forum (10 660-665) two different types of plastic sales which they developed for the replacement of itrepa. rably damaged aortic vales They report that one type of vahe has been used with success in patients 23 ·Both valvesma flap valve and a bicuspid valve-are constructed of silastic (a rubbery silicone plastic) bonded to a polyvinyl sponge (Ivalon) base. They are inserted through a slit in the aorta and se cured by sutures at the site of the natural aortic valve. Both valves have been tried in dogs They were also tested in human cadaver hearts which were made to "beat" in a mechanical pulso duplicating apparatus. rlap valves were successfully inscried by the Minnesota surgeons in tho paticnts, with subsequent restoration of valvular function in cach case. The investigators report that the first patient wiis sell and active at the time of their report, eleven months after surgery, and that the sccond patient was well and active following the operation but died two months later of an unrelated cause. Autopsy rcvcaled a properly positioned, functional valve with no abnormal blood clots present. Function and durability tests of the bicuspid valve in a pulse dupli. cating machine have been cry encouraging but complications that occurred upon installation of the value in dogs delayed clinical trials Difficulties encountered included leakage of blood between the vale and aortic wall in same aniinals before a suitablc mcthod was devised for securing the valve. Completc hcart black also developed in some animals as a result of damage to heart impulse-conduction tissuc by sutures or internal bleeding The investigators bcheve that, in the human hcart, the larger size of the structures may make it possible to avoid this complication. Results of the Minnesota studies suggest, conclude the investigators, "that substantial progress has been achieved in the resolution of many of the very significant problems concerned in the use of artificial cardiac valves Moreover, this same progress, culminating in successful clinical application, has served to point the way for numerous further improvements in choice of materials, design, and surgical technique." Artificial Ileart Prototypes Designed and Tested by NIU Grantecs The design and preliminary trials of two prosthetic hearts are re. ported in the American Ilean Journal (59 723-736) by Drs C S Hous ton, Tetsuzo Akutsu, and W J Kollf, at the Cleveland Clinic Coundation and the Frank E. Bunts Educational Institute in Cleu cland Studies of the mechanical hearts in dogs and in a mock circulatory system indicate that progress is being made toward replacing irreparably damaged human hearts with mechanical pumps implanted within the chest Tliesc pumps, however, are not sufliciently developed to warrant their installation in humans Each of the new prostheses--a pendulum-lype pump and a rollertype pump--contains an clectric motor and two clastic pumping cham.

·bers, of sentricles, of polyurethane plastic. Polyurethane valves and connecting tubes maintain vn directional blood flow through the hearts, and plastic coated wires supply current from an externally located battery pack or wall sockel 10 power the hearts. In the pendulum pump, a motor suspended on pisots (the "pendulum") swings back and forth within a ngid outer housing, alternately compressing cach ventricle against the housing. To-and-fro excursions of the mosos-pendulum are caused by an eccentrically mounted, adjustable lever arm which connects the motor shaft with the outer housing Tests of the pendulum pump in a mock circulatory system showed that as much as 1800 ml of blood per minute is ejected from each ventricle and that hemolysis of red blood cells by the pump is not excessive, report the Cleveland scientists. Encouraged by these tests, shey installed a pendulum pump at the anatomical site of the natural heart in a 30-kilogram dos, which was maincained by a heart-lung machine during removal of its own heart, The investigators report that the dog's circulation was sustained for S hours by the pump, but that several infusions of norepinephrine were required to maintain blood pressure The pump had been adjusted to deliver 2000 ml per minute which, they explain, was inadequate for a dog of this size The pendulum pump, however, "scemed promising enough to serve as a model for a more durablc pump, which is under construction," they report The second type of pump designed by the Cleveland group employs a small, motor-drnen roller to compress the senuicles against a rigid outer housing Polyurethane foam inserted between the sentricles and housing, provides a yelding surface wluch minimizes hemolyses lo mack circulation tests of this pump, venincular outputs increased (in the left sentncle, from 200 to 2.200 ml per minute) as atrial presures were increased Thus, the ouput on both sides are sell-regulat. {RS, If one side pumps more blood than the other, the increased atrial pressure on the other side leads to an increased output by shat side In a single animal experiment, che coller pump sustained a dog for 2 hours Although the pump was not sufficientls streamlined to allow closure of the dog's chest, there was evidence of spontaneous breathing and of excellent blood oxygenation, pressure tracings indicated good functioning of the pump Report First Snccessful Kidney Transplant Berceen Nonidentical Twins Transplantation of a healthy kidney from a 24-year-old man to his fraternal twin brother has saved the life of the recipient, whose own incurably diseased kidneys were subsequently semarad This operation, ·the first successful renal transplant between nonidentical twins, was reported in the New England Journal of Medicine (262. 1251-1260) by Drs J. P. Merrill, J E. Murray, J. H. Harrison, E. A. Friedman, J. B. Dealy, Jr., and G. J. Dammin, of Peter Bent Brigham Ilospital and Harvard Medical School in Boston. Their success follows 5 years of pioneering experience in transplanting kidneys between identical twins. In the currently reported case, the brothers were believed to be fraternal rather than identical twins because of differences in their physical appearance. Proof of this, and of the tissue incompatibility that exists between individuals of different genetic background, ucre demon. strated by slow rejection of skin grafted from the donor to his brother and by accelerated rejection of a second graft. With the failure of these grafts, the Boston scientists realized that transplanted kidney tissue would be subject to the same fate unless the patient's immune response were modified in some way Knowing that the rejection of tissues foreign to the body is a function of the antibody-forming system (blood-forming and lymphatic tissues) and that this system is depressed by X-rays, the scicntists believed that immunological tolerance could be produced by the use of sub. lethal, whole-body irradiation that would temporarily impair, but not destroy the antibody-forming system. They postulaied: "A kidney transplanted immediately after the administration of such irradiation would then constitute an antigen to which antibody production was impaired, if not destroyed.” The slow recovery of antibody-forming capacity in the presence of foreign kidney tissue might correspond to the development of immunological tolerance in animals that have been injected with foreign cells during embryonic or neonatal life before the antibody-forming system is fully matured and capable of "recognizing" foreign tissue Tolerance thus acquired persists in adult life and enables acceptance of subsequent tissue grafts from the same donor, On this theoretical basis, irradiation totalhng 450 r was administered to the patient prior to kidney transplantation The kidney functioned 207>mediately afier sessoration of its blood supply (11 had been ischemic for a period of 52 minutes) and excreted 32 liters of urinc during the first 36 hours. Cleven days later the patient's own diseascd kidneys were removed, and within 2 months he was completely well The patient continued to feel well despite the onset of graft rejection which was detected by urinary abnormalities and renal biopsy findmys 10 months after operation, This beginning rejection was aborted by large doses of cortisone and small doses of irradiation, the patient quickly regained normal renal function, report the scientists They conclude: "Partai tolerance for a renal homograft has been produced, and this tolerance is consistent with normal renal function and clinical well-being" 26 ·Thermal Dilution Curres Used Crncally Dingnose Cardiac Shunis Thermal dilution curses have been used successfully by scientists of the SHI Surgery Branch for the diagnostic evaluation of circulatory shunts in patients with congenital heart disease. The basic technique 1135 not developed at NIH, but was modified here and new insinmentation des eloped for its application 10 clinical diagnosis. The tech. nique is a substantial improvement over standard dye dilution methods because, while retaining the accuracy of these methods, it eliminates the necessity of withdrawing large blood samples and also the prob. lems of skin discoloration and allergic reaction that occasionally follow mulúple dye injections These studies are reported in the American Journal of Cardiology (6. 1065-1069) by Drs. Theodore Cooper, Eugene Braunu ald, and Andrew H. Morton, of the NHI Surgery Branch, and GC Riggle, of the Disision of Research Services Dye dilution curves are widely used to diagnose, localize, and rsti. mate the magnitude of cardiac shunts, the abnormal flow of blood through holes in the partition that separates the two sides of the hean. In this technique dye is injected into the appropriate side of the heart and its concentration subsequently measured in blood withdrawn from a Wessel located downstream from the injection site. As the blood is withdrawn at a constant rate into a special syringe, its dye concentra- LOR es continuously measured by a densitometer. If no shunt is prese ent, the dye concentration plots as a cure with a sharp upslase fal. lowed by a smooth gradual dowaslapa Honcet, a shunt causes a break in the curse or a second peak resulting from the appearance of dye detoured by the shunt Though accurate and safe, this method requires the withdrawal of large blood samples, and frequently necessitates blood transfusions, especially in young children Muluple de terminations, frequently needed for precise diagnosis are also limited with this technique because of decreasing accuracy and increasing danger of allergic responses The new technique uses cold salıne as the indicator and measures 123 concentration as a function of blood temperature in a sessel down. Stream from the point of injection by means of a heat-sensing clement called a thermistor Since the thermistor can be introduced directly into the sesse} with a special needle or short catheter, no blood samples need be withdrawn The comparson by the NHI scientists of the sea technique with standard dye dilution methods showed that the thermal dilution curies are strictly analogous to dye dilulion curves and appear to be equally sensitate and accurate for the diagnoslic evaluation of shunts Repeated determinations can be made with this technique without any decrease in accuracy and without any danger of toxicity, Teatures which make possible the more precise diagnosis of shunts as well as immediate evaluation of surgical measures to correct them. 27 ·NEW KNOWLEDGE AND METHODS New Diuretic Is Effective Against Edema of Normal or Toremic Pregnancy Hydrochlorothiazide, a new diuretic drug derived from chlorothiazide, has been found highly effective against the cdema of normal or toxemic pregnancy. In NHI grant-supported studies at the University of California Medical Center, Dr. N. S Assali used hydrochlorothiazide, as Esidrer (CIBA) and Hydro Diuril (Mierck, Sharp & Dohme), to treat 33 plu tients with edema accompanying normal pregnancy and 25 edematous patients with toxemia of pregnancy. His findings, reported in Clinical Pharmacology and Therapeutics (1: 48-52), indicate that the diuretic action of the new drug closely resembles that of chlorothiazide, but appcars to be cffective at one-tenth the dose Edema is the accumulation of fluid in the extracellular tissuc spaces its most common cause in normal pregnancy is too much salt in the diet or salt retention by the hidneys Edema in toxemia of pregnancy is also associated with salt retention, and may be abetted by the loss of protein in the urine that also characterizes this disorder. Although slight or moderate edema is more unsightly than clinically dangerous, severe edema can lead to fluid accumulation in the abdonunal cavity (ascites) or in the chest, where it can seriously interfere with respiration. Like chlorothiazide, hydrochlorothiazide rcduced edema by increasing renal excretion of salt, potassium, and water, but 100-150 mg. seemed to produce effects comparable to those produced by 1000-1500 mg of chlorothiazide in a previous study the drug appears to increase salt and water excretion by inhibiting their reabsorption in the kidney tubules, since it produced no significant effects on renal plasma flow or filtration rates The drug produced no observed adverse effects, did not noticeably alter serum electrolyte levels in most patients, and produced most marked diuresis in patients whose edema was most severe As cdema diminished, the effects of the drug were reduced This is a very desirable feature of the drug because it provides a margin of safety to protect against the possibly serious consequences of electrolytc deplction. Developments Extend Use of Gas Chromatography In Lipid Analysis Important new contributions by NHI scientists have made possible the use of gas chromatography for the radioassay of farty acids labeled 28 ·with radioactie carbon and for the analysis of steroids These develop. ments should greatly facilitate research on lipids and lipid metabolism and the possibie roles of these factors in atherosclerosis. Ongnally deseloped in England in 1952, gas chromatography has bciped solve many problems of lipid analysis formerly posed by analynical methods that were complex, slow, and insufficiently accurate for the assay of small samples. In gas chromatography, a small sample of the lipid mirrure to be analyzed is injecied into an analytical column, vaporized, and swept through the column on a stream of inest carrier gas (argon or helium) In transit through the column the lipid vapors are brought into repeated contact with a non-volatile liquid, present as a thin coaling ether on the inner surface of the column or on small incrt particics with which the column is packed All of the lipids are soluble in thuis liquid, but the extent varies with their structure and chemical properties This variation affords the means of separating the lipid compancats (the more soluble the lipid, the slower its transit and vice Versa) and also for identifying cach component as it emerges. As it emerges from the column the lipid rapor enters a special detector which senses its passage, measures its concentration, and records these data against time on a strip chari. The system for the radioissay of carbon-14 labeled farty acids by gas chromatography was worked out by Drs. Arthur Karmen and Harold R. Tritch, of the Laboratory of Technical Development The system, described in Vature (185 350-151), uses a short column contating anthracene crystals coated with silicone oil to trap the fattyacid vapors emerging from the analytical column. The radioactive vapor dissolves in this on, thereby coming in close proximity to the anthracene crystals The radiaron emitted causes small Bashes (scuitillations) in the crystals These scintillations are detected by photolubes and counted by an automatic scintillation counter The system allows the collection of individual fatty acid esters in separate trapping columns or for continuous monitoring of a single column In the latter method, a deuce measures the rate at which scinullauions are occurring and plots this against time on a strip chart As eath new component enters the grapping calumn, this rate increases sharply from this data can be determined the time that each com. ponent entered the column and how much radioactivity it conjained The use of gas chromatography for the analysis of sıcroids as made possible by a special analytical column designed by Drs J A Vanden Heuvel, CC Suceley, and E C Horning, of the NRI Laboratory of the Chemistry of Natural Products Steroids, the subject of intense scientific study in recent years, are members of a large family of compounds which include cholesterol, many important adrenal hormones, seseral vitamins, and the male and ·NEW KNOWLEDGE AND DIETHODS New Diuretic Is Effcctire Against Edema of Normal or Toxemic Pregnancy Hydrochlorothiazide, a new diuretic drug derived from chlorothiazidc, has been found highly effective against the cdema of normal or toicmic pregnancy. In NHI grant-supported studies at the University of California Medical Center, Dr. N, S. Assali uscd lıydrochlorothiazide, aus Esidres (CIBA) and Hydro Diuril (Merck, Sharp & Dohme), to treat 33 px tients with cdema accompanying normal pregnancy and 25 edcntalous patients with toucmia of pregnancy. His findings, reported in Clinical Pharmacologr and Therapeutis (1. 48-52), indicate that the diuretic action of the new drug closely icscmbles that of chlorothiazide, but appcars to be cffccrive at onc-tenth thic dose Edema is the accumulation of fluid in the extracellular tissue spaces Its most common causc in normal pregnancy is too much salt in the diet or salt retention by the kidneys. Edema in toucmia of pregnancy is also associated with salt retention, and may be aberred by the less of protein in the urme that also characterizes this disorder Although slight or maderate edema is more unsightly than clinically dangerous, severe cdema can lead to fluid accumulation in the abdominal cavity (ascites) or in the chest, where it can scriously interfere with respiration Like chlorothiazide, hydrochlorothazide reduced cdema by increasing renal cxcretion of salt, potassium, and water, but 100-150 mg soomed to produce effects comparable to those produced by 1000-1500 mg. of chlorothiazide in a previous study. The drug appears to increasc salt and water excretion by indubiting their reabsorption in the hidney tubules, since it produced no significant cffects on renal plasma Row or filtration rates. The drug produced no observed adverse effects, did not noticeably alter serum electrolyte levels in most patients, and produced most marked diuresis in patients whose edema was most severe Is calcm. diminished, the effects of the drug were reduced This is a very desirable feature of the drug because it proudes a margin of safety ( protect against the possibly serious consequences of clectralve depletion Developments Extend Use of Gas Chromatography In Lipid Analysis Important new contributions by Nill scientists have made possible the use of gas clyromatography for the radioassay of lartı acids labeled 28 ·according to the physical properties of the gas, such as its molecular keight With the equipment described, soltage is applied to a sound. transmitting crystal at one end of a wobe containing the sample, and recorded by a recewing crystal at the other end. Phase differences induced by particular samples between the isso sollages are sufliciently definitive to imply analytical usefulness for the principle The actual value of the sound velocity principle as used in the equipment Atr, Noble described remains to be demonstrated in an plied research Drug Metabolism by Lirer Unaltered in Patients Tith Cirrhosis Preliminary studies at NHI and New York Umersury suggest that normal rates of drug metabolism are not allered by cirrhosis, despite sesere loss of functioning liver, wherein are located the special enzyme susiems that inactivate drugs. Thus, the presumed sensuavity 10 cet ta'n drugs of patients with liver disease may require some other explanation, if these indications are borne out by morc cxiended studies Conversion of certain fat soluble foreign compounds, such as drugs, into inacılıe derivatives is an important function of the lises, without which the action of many drugs would persist for a dangerously lone time The uver disposes of such compounds by converting them to derantes such arc less fat soluble, thus barring them from yeabsorption into the body through the faz-like membrane lining the hidney tubules Recently Dr Bernard B Brodie and Dr John Burns of NHI, and Dr Murray Werner of New York University Research Service compared the inactivation of various drugs in patients with sesere Larnnec's cirrhosis and in normal subjects. The drugs studird (phenylbuta- Forte, aminopyrine, antipyrine, salicy kc acid. and dicumarol) had pre- Tously been shown to be metabolized in the body through the action of lyser enzymes The biologic hall-life of these drugs was not sigmficantly different in the cirrhotics and controls, indicanng that the activity of the enzyme systems involved was not appreciably affected by the liver-damaging disease. Special precautions are usually advised in the adminisiration of certain other drugs to patients with liver disease, for it is commonly believed that drug metabolism is generally impaired in the discased Iner The present studies should be extended to patients with ncher itpes of liver disease as well as to other compounds that are me. tabolized along other similar pathways I indications of the present findings are borne out by further study, some other explanation should 31 ·female sex hormoncs, Previous attempts had been made to separate and analyze steroids by gas chromatography, but had been at best only partly successful. Unfortunately, with ordinary liquid phases and column temperatures, most steroids were so soluble in the liquid phase that they would be retained too long in the column. As a result, many heat-sensitive steroids wouid decompose before entering the detector. The scientists overcame these problems with a column whose inert particles were coated with a very thin film of methyl silicone gum The column could be used at low temperatures and gave rapid transit times, a combination which solved the steroid heat-sensitivity problem. At the same time it provided high sensitivity-being able to analyze samples weighing as little as one millionth of a gram-and could sep.trate components differing only very slightly in their molecular structure, In addition to offering a unique combination of spccd, sensitivity, and high resolution, the column has proved to be versatile as well It has been used successfully to separate and analyze a large numnlser of alkaloids, an enormous family of plant substances which has yielded many valuable drugs over the years The column and its uses were reporied at the Afilan Symposium on Drugs Affecting Lipid Metabolism and in The Journal of the Imerican Chemical Society (82 3181, 3791). Report Gas Chromatography Dercctor Based on Sound Velocity Variations An engineer in the NHI Laboratory of Technical Development has designed detccting cquipment utilizing measurement of sound velocity i gases for characterizing the conscituents of samples separated by gas chromatography For maximum usefulness as an analytical tool in the biologic sciences, the principle of gas chromatography as introduced from England has required the design and incorporation of more sensitne and versatile systems for detecting the constituents of comple samples once thic chromatograph had separated them Investigators in the NHI Laboratory of Technical Development harc attacked this problem on screrai fronts with notable success, designing and developing detecting systems which permit extension of cas chromatography to many new research areas New detecting cquipment using variations of measured sound clocity was described by Frank 1 Noble at the Thirteenth Annual Conference on Electrical Techniques in Mcdicine and Biology held in Waslungton, D.C The velocity of sound passing through a gas varios 30 ·according to the physical properties of the gas, such as its molecular meight. With the equipment described, voltage is applied to a sound. transmitting crystal at one end of a tube containing the sample, and recorded by a receiving crystal at the other end. Phase differences induced by particular samples between the two voltages are sulficiently definitne to imply analytical usefulness for the principle. The actual value of the sound velocity principle as used in the equipment Mr. Noble described remains to be demonstrated in applied research Drug Metabolism by Lirer Unaltered in Patients IT'ith Cirrhosis Preliminary studies at NHI and New York University suggest that normal rates of drug metabol are not altered by cirrhosis, despite sex ere loss of functioning liver, wherein are located the special enzyme systems that inactivate drugs Thus, the presumed sensitivity to cer. carn drugs of patients with liver disease may require some other explanation, of these indications are borne out by more extended studies Conversion of certain fat soluble foreign compounds, such as drugs, into inactive derivatives is an important ſunction of the liver, without which the action of many drugs would persist for a dangerously long time. The her disposes of such compounds by converting them to derivatives which are less fat soluble, thus barring them from reabsorptron into the body through the fat-like membrane lining the kidney tubules. Recently Dr Bernard B Brodie and Dr John Burns of NHI, and Dr Murray Weiner of New York University Research Service compared the inactivation of Sarious drugs in patients with severc Lacnnec's cirrhosis and in normal subjects The drugs studıcd (phenylbutazone, aminopy rine, antipyrine, salicylic acid, and dicumarol) had prevousiy been shown to be metabolized in the body through the action of ver enzymes The biologic hall-life of these drugs was not significantly different in the cirrhotics and controls, indicating that the activity of the en. zyme systems insoked was not appreciably affected by the liver-dam. aging disease Special precautions are usually advised in the administration of certain other drugs to patients with liver disease, for it is commonly believed that drug metabolism is generally impaired in the diseased laser. The present studies should be extended to patients with other types of fier disease as well as to other compounds that are me. tabolized along other similar pathways If indications of the present findings are borne out by further study, some other explanation should ·be sought for the presumed sensitivity to certain drugs of patients with impaired liver function, These findings were published in Medicina Experimentalis (1: 290-292). Reflexes From Carotid Sinus Important in the Control of Heart Output Reflexes originating in the carotid sinus have been shown by NHI scientists to control the vigor with which the heart's receiving chambers (atria) pump blood into the ventricles This, in turn, important. ly affects ventricular performance and cardiac output. The carotid sinus has long been known to be sensitive to changes in blood pressure and to initiate nervous reflexes to compensate those changes. However, it was formerly thought that this was accomplished primarily by bringing about changes in peripheral resistance to blood flow and by reflexly changing heart rate. Now studies at the NHI Laboratory of Cardiovascular Physiology have revealed that when arterial pressure falls, the carotid sinus, in addition to reflexly increasing peripheral arteriolar and venous tone and heart rate, also increases the force of atrial contraction This is done by diminishing the activity of the vagus nerve (which normally restrains the atrial pulse) while simultaneously increasing the activity of the cardiac sympathetic nerves Sympathetic stimulation increases the vigor of atrial contraction, presumably by increasing heart levels of catechol amines These increase the excitability of the atrial muscle fibers and also the synchronization with which they contract The increased vigor of atrial contraction pumps more blood into the ventricle, distending it and elongating its muscle fibers more than usual Since muscle fibers contract more forcefully from longer fiber lengths than from shorter ones (provided that the chemical environment of the fibers is not altered), the result is a more vigorous contraction of the ventricle and hence increased heart output The opposite takes place when arterial pressure is high The carotid sinus reflexly increases vagus activity while decreasing sympathetic activity This suppresses the atrial pulse, reducing ventricular filling pressure and decreasing heart output These reflexes, called the carotido-sympatho-atrial and carotidovago-atrial reflexes, are held to be of substantial importance in the regulation of the circulation in changing states They are particularly important at high heart rates, which give the ventricles less time to relax and the atria less time to fill them adequately between pumping strokes. Ry causing the atria to deliver more blood to the ventricies more rapidly under these conditions, these reflexes help to maintain the heart output at appropriate levels at high heart rates 32 ·The work leading to the discovery of the carotido-atrial reflexes was done by Drs Stanley J. Sarnoff, J. P. Gilmore, and J. H Mitchell. Their findings were reported at the Federation Mectings in Chicago. Alcohol Causes Deposition of Fat in Lirer by dction on Pituitary NHI scientists have found that large singic doses of alcohol in rats interfere with pituitary control over the fat transport system. As a result, excessive amounts of tnglycerides (neutral (at) are mobilized from adipose tissue as free fatty acids and carried by the plasma to the liver, where they are recombined with glycerol and deposited in this organ This derangement of fat transport may be important in the desclopment of the cirrhosis often found in alcoholics, in which the chronic deposition of excessise fat in the liver is thought to lead eventually to necrosis Single orally administered doses of 4.8 grams of alcohol per kilogram of body weight (equivalent in humans to about six double martinus) resulted 18 hours later in a threefold increase in liver triglycerides in female rats Larger doses increased liver triglycerides almost fivefold That these effects were due to the mobilization of fatty acids from adipose tissue rather than to an increased synthesis of fatty acids by the liver was shown by the hnoleic acid content of the deposited fat. This unsaturated fatis acid cannot be synthesized by the rat, but is of dietary origen When assayed by gas chromatography, the liver fat deposited by action of the alcohol was found to have virtually the same linolesc content as adipose tissue Similar results were obtained when the oleic acid content was assayed Since the concentrations of both fatty acids in laer reflect that in adipose tissue, little if any of the fat deposited as a result of the alcohol could have come from fatty acids synthesized by the Iner The finding that akohol did not produce these effects in cats whose pitustasies had been removed suggested that the effects of alcohol in ſat transport were mediated through hormones from this master gland Investigation of the effects of alcohol on the pituitary-adrenal axis indicated that alcohol causes the pituitary to relcase ACTH and perhaps other hormones important in fat mobilization However, the mechanism by which alcohol does so 25 nat known The scientists found that pretreaung rats with certain adrenergic blocking agents presented the alcohol-induced fat deposition in hver, suggesting that the catechol amines may also be involved in the proc- I is not yet clear whether the protection conferred by these agents is due to their blocking the action of amines at nerve endings cas ·which innervate fat cells or to their blocking the release of pituitary hormones. Studies of the mechanism or mechanisms involved are underway in the hope that these might lead to drugs that can prevent or ameliorate Laennec's cirrhosis. The experiments were conducted by Drs. B. B. Brodie, H M. Mal ing, W. M. Butler, Jr. and R. P. Maickel, of the Laboratory of Chemical Pharmacology, and by Dr. M. G Horning, of the Laboratory of Cellular Physiology and Metabolism. Their findings were reported at the Symposium on Neurological and Hepatic Complications of Alcoholism held in New York, Myocardial Edema Result of High Atrial Pressure in Congestire Failure Studies on the mechanism of myocardial edema--the accumulation of water and electrolytes in the heart muscle that often accompanies congestive heart failure-indicate that the major pathogenic factor is the elevated right atrial pressure also frequently found in this condition Excessive serum levels of aldosterone, a hormone which promotes water and salt retention, and low serum protein levels may also play a role in the process The studies were performed on 46 dogs--21 normals and 25 with experimentally produced lesions causing chronic congestive heart fail. ure or chronic ascites (accumulation of fluid in the abdominal cavity) After periods ranging from 6 to 189 days, the animals were ancsthetized, sacrificed, and samples of heart tissue immediately taken for determination of water, fat and electrolyte content. The experimental data were then analyzed to evaluate the importance of the following factors in myocardial edema the duration of heart failure, enlargement of the ventricles, serum aldosterone and protein levels, and clevation of right atrial pressure All of the experimental lesions produced moderate to marked increases in heart muscle content of water, sodium, and chloride The observed increases in myocardial chloride suggested that the cdema was the result of accumulation of extraceilular fund Comparison of data from dogs dying from heart failure within 6 days with the data from another group surviving for 3-6 months ruled out duration of heart failure and sentricular enlargement as significant factors in myocardial edema Other data suggested that mgh serum aldosterone and low serum protein levels, while not determining factors in themselves, do play supporting roles in the process The factor that appeared to be most important in myocardial cdema was elevation of right atral pressure The degree of increase cortelated well with the severity of the edema Increased right atrial pres. sure appears to result in passive venous congestion, which, when 34 ·combined with high serum aldosierone and low serum protein levels, leads to the accumulation of water, sodium, and chloride in heart muscle that constitutes myocardial edema. These etperiments were performed by Drs. N. A. Yanlopoulos, J. O. Davis, Ernest Cotove, and Blary Trapasso of the Laboratory of Kid. ney and Electrolyte Metabolism Their findings were reported in the American Journal of Physiologt (193. 603-608) Neutral Fat Made in Adipose Tissue by Mechanism Similar to That in Lirer NHI scientists have found that fatty acids are converted to their neutral storage form (Triglycerides) in adipose tissue by a mechanism very similar to that reported by others for triglyceride synthesis in liver. The studies also indicate that the release of free fatty acids from adipose tissue may be impostantly influenced by factors affecting the rate of triglyceride synthesis In these studies Drs Daniel Steinberg, Alartha Vaughan, and Sicon A largolss, of the Laboratory of Cellular Physiology and Alctabolism, and Dr. Arthur Karmen, of the Laboratory of Technical Desclopment, measured the conversion of a radioactive fatty acid (palmutic acid) to triglycerides and other neutral fat in rat adipose tissue. This tissut was ground up and the honagenized extract divided into IMO portions One portion was then fortified with substances known to favor triglyceride formation, the other portion, unfortified, was used as the control tissue The incorporation of radioactive palmitic acid into neutral fat * 38 observed only in the fornified lussue and was almost exclusively in the form of diglycerides and triglicerides knowing what substances kad been added to the fortified tissue, the scientists were able to determine the probable sequence of biochemical steps by which triglycerides are formed in adipose tissue. This was found to be sery similar to the sequence presiously reported by others for triglyceride synthesis in liver Triglycerides, the form in which most fats are stored in the body, are neutral esters resulting from the combination of three farty acid molecules with one molecule of glycerol. However, under the biochemical conditions of the body, this combination cannot occur di- Tectly Instead, the fatty acids must first be combined with coenzyme A, which serves as a "carrier" in the process Two of the combined molecules (fatty acyl-CoA) then Itact with glycerol, forming a diglycende and regenerating coenzyme A With coenzyme A again the "earner," the third farty acid is added to the diglyceride to form the triglycende The triglyceride thus formed can in turn de broken down to yield its fatty acids to meet the body's energy requirements during the fasting state ·which innervate fat cells or to their blocking the release of pituitary hormones. Studies of the mechanism or mechanisms involved arc underway in the hope that these might lead to drugs that can prevent or amcliorate Laennec's cirrhosis, The experiments were conducted by Drs. B. B. Brodie, II. M. Ma). ing, W.M. Butler, Jr. and R. P. Maichel, of the Laboratory of Chemical Pharmacology, and by Dr. M. G. Horning, of the Laboratory of Cellular Physiology and Metabolism. Their findings were reported at the Symposium on Neurological and Hepatic Complications of Alcoholism held in New York. Myocardial Edema Result of High Atrial Pressure in Congestive Failure Studies on the mechanism of myocardial edema--the accumulation of water and electrolytes in tlie heart muscle that often accompanies congestive heart failure-indicate that the major pathogenic factor is the clevated right atrial pressure also frequently found in this condition. Excessive serum levels of aldosterone, a hormone which promotes water and salt retention, and low serım protein levels may also play a role in the process. The studies were performed on 46 dogs-21 normals and 25 with experimentally produced lesions causing chronic congestive heart fail. ure or chronic ascites (accumulation of fluid in the abdominal cavity) After periods ranging from 6 to 189 days, the animals were anesthetized, sacrificed, and samples of heart tissue immediately taken for determination of water, fat and electrolyte content The experimental data were then analyzed 10 evaluate the impor. tance of the following factors in myocardial edema the duration of heart failure, enlargement of the ventricles, serum aldosteronc and protein levels, and clevation of right atrial pressure. All of the experimental lesions produced moderate to marked increases in heart muscle content of water, sodium, and chloride The obsercd increases in myocardial chloride suggested that the edema was the result of accumulation of extracellular fuid. Comparison of data from dogs dying from heart failure within 6 days with the data from another group surviving for 3-6 months ruled out duration of heart failure and ventricular enlargement as significant faccors in myocardial edema Other data suggested that high scrum aldosterone and low serum protein levels, while not determining fac. tors in themselıes, do play supporting roles in the process The factor that appeared to be most important in myocardial edema was elevation of right atrial pressure The degree of increase cortelated well with the severity of the edema Increased right atrial pressure appears 10 result in passive venous congestion, which, when 34 ·The scientists found that doses of reserpine which depleted brain stores of norepinephrine and serotonin, producing marked scdation, also proloked a sustained activation of the pituitary-adrenal system This activation was manifested in rats by: (1) a fall in adrenal ascorbic acid, accompanied by a rise in plasma corticosterone; (2) increased activity of tryptophan peroxidase (TPO), a liver enzyme whose activity is an indicator of pituitary-adrenal stimulation; and (3) increased mobiliza. tion of free fatty acids from adipose tissue. These responses are similar to those produced by the stress of prolonged exposure to cold, and were not produced by reserpine or cold in animals whose pituitaries or adrenals had been removed This provided further evidence that these responses to reserpinc result from pituitary-adrena) activation and are mediated by ACTH hypersecretion. Hypersecretion of ACTH does not result from the action of reserpine fw se, but is selated to its depletion of brain serotonin stores. Doses of reserpine that deplete brain serotonin by less than 50% do not clicit noticeable sedation nor hypersecrecion of ACTH; slightly larger doses cicit both responses, which become more marked with increasing doses unul a maximum is reached with the complete depletion of brain serotonin stores That ACTH hypersecretion is related specifically to serotonin depletion has been shown by experiments using alpha-methylm-tyrosine Doses of this amino acid that depleted brain norepinc. phrine stores with very little effect on brain serotonin elicited neither sedation por ACTH hypersecretion This indirect action of reserpine also explains why the "stress" responses, like the drug's sedative effects, persist long after the admıms. tered reserpine has disappeared Apparently, reserpine us a "huc-andrun" drug which depletes the brain of amines by inactivating or destroying their storage sites The bram amines remain depleted until the storage sues recover, when brain amines slowly return to normal. The "stress" responses will persist until brain serotonin again reaches 50% of normal These studies point out the potential value of pharmacological tools in clanſsing how the brain directs biochemical mechanists, and that the interacuon of drugs with these mechanssms may be an important aspect of drug action Rheumatic Ferer Studies Rereal Predictability of Heart Damage NHI grant-aided studies of theumatic fever recurrences at a rheumatic fever prophylaxs cline indicate that. () signs of heart valve damage in susceptible patients usually appear during the initial attack of rheumatic lever, and (2) patients free from valvular involvement during the first attack usually remain free from theumatic heart disease despite recurrent attacks ·The scientists observed that the release of free fatty acids (IFA) from adipose tissue appeared to be influenced by the rate of triglyc. eride synthesis. In the fortified tissue, where biochemical conditions favored triglyceride synthesis, there was a net uptake of FFA; however, in the unfortified tissue there was a net release of FFA. A number of hormones are known to stimulate FFA release, and these obscrvations suggested that their actions might be due in part at least to their effects on triglyceride synthesis In experiments following up this lead, Drs. Steinberg, Vaughan, and Margolis determined the effects of glucose, ACTH, epincphrine, and serotonin on triglyceride synthesis in intact adipose tissue incubated in a medium containing radioactive palmitic acid. When glucose, an inhibitor of FFA release, was added to the incubation medium, the incorporation of the radioactive palmitic acid into triglycerides was more than doubled in the tissue sample. However, the addition of ACTH or cpinephrine, hormones which stimulate FFA release, reduced triglyceride synthesis by 50% or more The reduction in triglyceride synthesis was accompanied by increased FFA concentrations both in the tissue samples and in their incubation media Scrotonin, a hormone which does not affect FFA release, also did not affect the rate of triglyceride synthesis These data thus lend support to the hypothesis that hormonal control over FFA release is exerted, at least in part, over the rate of triglyceride synthesis These findings were reported in Federation Proceedings (19 227) and in the Journal of Brological Chemistry (235 38-39). Tranquilizer Triggers Pituitary-Adrenal "Stress" Responses Reserpine, a drug in wide clinical use as a hypotensive and tranquil izing agent, has been found to trigger certain body responses usually associated with stress hypersecretion of ACTH, increased serum levels of glucocorticoids from the adrenal cortex, and excessive mobilization of free fatty acids from adipose tissue The paradox Implicit in these actions of reserpine is heightened by experimental evidence that these "stress responses" (1) are produced only by doses of rescrpine sufficiently large to produce overt sedation, and (2) are the indirect result of the same action of the drug believed responsible for its tranquilizing cffects-depletion of brain serotonin stores These findings were made by Drs Bernard B Brodie, Erik O. Westermann, and Roger P Machel, of the NHI Laboratory of Chemical Pharmacology, as part of a series of animal studies on the role of the liypothalmo-pituutary-adrenocortical system in biochemical adaptation They were presented by Dr. Brodie at the Fourth International Neurochemical Symposium, held at Varenna, Italy 36 ·storehouse for these master plans. RNA, located out in the microsomal structures of the cell, is widely regarded as a template, or "die in which the protein is cast. Dr. Hendler turned instead to the lipids, which he notes, art cith more abundant ihan RNA in some of the microsomal stuciUTES thought to be sites of protein synthesis. (The ribosomes, sichest of all in RNA, have been reported to contain about five times as much lipid as RNA) From studies of synthesis of the egg protein, albumin, by the hen asiduct, Dr. Hendler has gained evidence that the basic amino acid structural units of proteins combine with lipids sery early in the protein asserably process to form more complex units (amino acid complexes) So far eleven albumin amino acids have repeatedly bcen seen to combine with the lipids in these complexes The findings suggest the possibility that the lipid-associated amino acid groups may actually represent primitive precursors of the natural protein molecule. From the evidence accumulated, Dr Hendler speculates that the basıc building blocks of the protein (the amino acids), arruing at the cell 172 the watery fluds of the body, are made fat soluble, entering into the lipid mechanism very early in the protein assembly process It is in this lipid medium that their first orderly grouping seems to occur—perhaps the first step in the precise forging of the complex links (polypeptides) that will make up the great chains of the finished protein Dr Hendler is also considering the possibility that the whole assembly process-genetic "master plan" to emergence of the finished molecule 13 a hpd process, the study of which might fill major gaps that remain in current understanding of how proteins are made with this as a working hypothesis, he is continwng in his attempts to sift out recognizable protein precursors in new lipid-associated amino acid complexes He is also hoping to find the chemical procesu by which the individual amino acids are made far soluble, for this might be the key step which introduces the raw materials of the protein--the amino acids-- into the cell's machinery for making the protein. Myosin Molecule Consists of Three Tightly Coiled Protein Chains Recent advances in protein chemistry at NHI and elsewhere permit the conclusion that we myosin molecule is made up of three identical chains, cach wound in a ughe corl and all three (wisted together as a long rope The protein myosin is of interest in terms of cardiovascular functions because it is believed to be the predominant component of the contractile tem of muscle A program of research on myosin at NHI has the ·These findings were reported in The New England Journal of afedicine (262: 533-540) by Drs. Alvan R. Feinstein and Mario Spagnuolo of Irvington House, Irvington-on-Hudson, New York, and the New York University College of Medicine in New York City. Their results are based on analyses of 370 documented attacks of rheumatic fever in 161 patients at Irvington House. Only those patients whose attacks fulfilled the modified Jones criteria for the diagnosis of rheumatic fever werc included in the study. The New York scientists found that valvulitis, as determined by carcful stethoscopic examination, was a feature of the initial attack in 30 of these 161 patients. With subsequent attacks, the valvultis remained unchanged or became worse and in some cases was accompanied by cardiac enlargement, pericarditis, or congestive heart failure. Valvular involvement was not found in the initial rheumatic episodes of 71 patients. With subsequent attacks, all but 10 of these patients remained free of valvulitis and other symptoms of heart disease. Al though 10 patients were found to have a significant diastolic murmur at a subsequent attack, the investigators speculate that in at least 8 of these 10 patients, the murmur was present but not recognized at the first attack "The results suggest that the rheumatic host has a specific and persistent susceptibility to get or to avoid valvular involvement If it does not occur with the first attack, it does not occur (with dubrous cxccptions) in the subsequent attacks. In most cases in which rheuniatic heart disease develops, the valvular involvement is manifested in the very first attack," conclude Drs Feinstein and Spagnuolo Their findings, which should be of considerable interest to the parents of rheumatic children, may enable a reduction in the duration of rheu. matic fover prophylaxis for valvulitis-free patients However, "Prophylaxis should not be stopped in this group without careful auscultatory confirmation of cardiac status and unul further studies confirm the present conclusions," state the scientists Lipids Play Major Role in Protein Synthesis, NHI Studies Suggest Evidence for a major role of sntracellular lipids in protein synthesis has been gained from studies by Dr Richard Hendler of the NIXI Laboratory of Cellular Physiology and Metabolism He reported these findings at the Federation Miceungs In the search for the intermediate through which the stored genetic master plans for each protein molds and binds its amino acid structural units into the finished molecule, protein chemists in many counfries are concentrating on variants of the nucleic acids, DNA and RNA Genetic DNA, in the nucleus of the cell, is widely regarded as the 38 ·tasnung albumain and glucose, Dr. Vaughan found that hormonal stim. vlation of UFA release was accompanied by increased uptake of glucose by the tissue and by stepped up phosphorylase activity. Phosphorylase is an enzyme which breaks down glycogen, the form in which carbohydrates are stored in the body, to yield glucose, an important energy source. In the liver, the resulting glucose can be released into the blood by action of the enzyme phosphatase Howexct, the phosphatase is not present in adipose tissue, so that the imal? amounts of glucose resulting from phosphorylase activity must be used locally, esther as a source of energy or for conversion into fatty acids and triglycerides The fact that all four hormones stepped up phosphory lase activity at the same time that they stimulared UFA release suggested that the hormones might control UFA release by a common mechanism, Phos. phorylase is not the common denominator, however, since previous work at this laboratory had shown that serotonin, a hormone which increased phosphorylase activity, did not stimulait UFA release. But the increased phosphorylase activity produced by ACTH in adrenal tissue and by epinephrine and glucagon in liver does have a common denominator --Cyclic 3,5 adenylic monophosphoric acid. The homones have been shown by others to stimulate the accumulation of this compound, which in turn increases active phosphorylase it is probable that the compound may play a similar role in adipose tissue in the intact animal, even though the compound produced no demonstrable effects on phosphorylase in the in ritso studies It is also possible that 3,5 AMP may play a role in hormone-stimulated UFA release, perhaps by affecting reactions in addition to that producing increased phosphorylase These findings were reported at the meeung of the American Society of Biological Chemists, Actire Ion Transport in Red Cell Ghost Porrered by ATP Studies by Dr Joseph Hoffman, of the NHI Laboratory of Kidney and Electrolyte Metabolism, have shown that adenosine triphosphate, a compound thai powers many of the body's energy consuming proce esses, is also the direct energy source for active ion transport in the red blood cell His findings were reported at the Federauon Meetings. Adrive ion transport is the prxcess whereby the cell can actively and sclectively transport electrically charged substances (ions) across the cell membrane against opposing electrochemical forces In this process, the "ton pump maintains normal electrolyte balance within the cell by using ATP generated by cell metabolism to offset the loss of ions across the cell membranc by passive diffusion ·immediate objective of interpreting some of the properties of myosin on the basis of its molecular structure, and is ultimately aimed at untderstanding its role in the contraction of muscle. Like other proteins the myosin molecule is made of amino acid groups, bound together as links in the long chains which constitute its primary structure Although myosin is known to be a comparatively long slens der moleculc (1600 x 22 Angstrom units), is has not been known how many polypeptide chains are held together by secondary bonds to form the molecule and, if more than one chain, whether or not they dillos from one another. Drs. W. Wayne Kiellcy and William F. Harrington, in the NHI Laboratory of Cellular Physiology, have approached this problem using guanidine hydrochloride to break the secondary bonds holding the chains together, while leaving intact the primary bands holding together the polypeptide links of each chain. Examining the products of this dissociating process by sedimentation in the ultracentrifuge, together with observations of their diffusion rates, viscosities, oprical rotation properties, and other data, the investigators have concluded that the myosin molecule consists of three identical polypeptide chains, each wound into a tight helical coil, the threc chains themselves being wound together in the form of a long rope. These findings were published in Brackımıca et Brophysica dda (17: 101-42). Nature of Hormone Control Over Fatty Acid Release Explored by NHI Studies Recent studies at the National Heart Institute have explored the mechanisms whereby Pally acids are stored in the body's fat depois as triglycerides (neutral fat) or are released from these depois as uncsteri: fied fatty acids (UFA) to meet the body's energy requirements The studies sought to clarify the mechanism or mechanisms by which fous hormones---epinephrine, norepinephrine, ACTH, and glucagon-stimu. late UFA release from adipose tissue Triglycerides, the form in which most fats are storcd in the body, are neutral esters formed by the combination of three molecules of fatty acid with one molecule of glycerol The triglyceride can in urn be broken down to yield three molecules of UFA, an important mean bolic fuei during the fasting state The latter process is known to be subject to a number of hormonal controls. Seeking clarify the nature of these hormonal controls, Dr. Martha Vaughan, of the Laboratory of Cellular Physiology and Alciabolism, studied the effects on adipose tissue of four hormones shown by others to stimulate the release of UFA epinephrinc, norepinephrine, ACTA, and glucagon Using rat adipose tissue sacubated ss a medium con- 40 ·Presumably because one ion cannot replace the metabolic functions of another, the cell must maintain the proper concentrations of the proper ions both for the regulation of its volume and for its mctabolic operations. This would be impossible but for the delicalc balance struck between passise loss on the one hand and active transport on the other. Previous work on intact red blood cells by Dr. E. T. Dunham, formerly of the same laboratory, had indicated that ATP might be the fuel for the ion pump. In studies following this Icad, Dr. Hoffman used red cell "ghosts" whose normal contents had been considerably reduced by hemolysis. The ghosts not only retained the membranc characteristics of the intact cell, but could also be reconstituted containing known substances whose metabolism could subscqucntiy be observed without the interference that might result from other metabo. lites and metabolic processes in the intact cell. Dr. Hoffman's studies showed that ATP was the specific fuel for the ion pump in the ghost system; however, if no ATP was incorporated into the ghost, the pump would still work (though less cflicicntly) if other substances that would generate ATP were incorporated. These findings suggest that the ion pump requires the presence of an enzyme (an ATPase) in order to use ATP. Such an enzyme has been characterized in membranes isolated from rcd blood cells by Dr. R L. Post of Vanderbilt, and appears to possess the same activation characteristics as docs active ion transport in both red cells and other ghosts. Thus the evidence is strong that the ion pump erthier is an ATPasc, or else has an ATPase as an intimate component. Protein and Fat Fractions of Lipoprotein Molecule Provided by Liver Scientists at NHI have found that the incr, previously shown to be the source of the lipid portion of lipoproteins, is also the source of the protein of this complex molecule, the form in which fats are transported in the blood Experiments conducted by Drs. Charles Radding and Daniel Steinberg, of the Laboratory of Cellular Physiology and Metabolism, have demonstrated that rat liver slices, incubated in nutro, synthesize and secrete high-density lipoproteins identical with those found in normal rat serum. Their findings are reported in The Journal of Clinical Investigation The liver slices were incubated in rat serum with a complete mixture of amino acids labeled with carbon-1} After incubation periods ranging up to four hours, the slices were removed and samples of the media ultracentrifuged to separate the lipoprotem fractions These were then analyzed by the "fingerprint" technique When broken down by the proteolytic enzymes trypsin or chymo. 12 ·. trypsin, each prolain yields its own characteristic pepude degradation products. These can be spotted on filter paper and separated on the vertical axis by descending paper chromatography, then on the harizonual axis by electrophoresis to form a characteristic peptide paltersi. When this pattern is developed by ninhydrin staining, the result is a destsscine "Gingerprint" which idenufies the protein. The ninh, dnn fingerprints of high-density lipoproteins from the incubation medium utre compared with fingerprints of lipoproteins of the same density class from normal sat serum and found to be identi. cal. Avtoradiograms (made by placing the media fingerprint strips in contact with X-ray film for 1-2 months, then der cloping the film) showed the presence of radioacusity is all of the minhydrin spots of the fingerprint These comparisons showed that the lipoproteins synthesized by the Iner slices were identical to those of normal scrum, and, since labeled 41980 acids had been incorporated into all of the newly synthesized lipoproteins, that the liner was the source of the protein as well as thic hipid portions of those lipoproteins To determine whether the sale af lipoprotein synthesis is affected by the sale of cholesterol synthesis, the scientists pretscaled rats to speed up or slow down their cholesterol production Liver slices from these rag were then incubated ah acetate (a cholesterol precursor) and an amino acid, both tagged with radioactivity so that the rates of cho lesterol and lipoprotein synthesis could bc mcasured simultancously Lipoprotein synthesis was not noticeably affecicd erch by wide vana. lions in the rate of cholesterol synthesis in these experiments, which suggested that the two rates were independent of one another This was not proved conclusively, koucier, because of the possibility that enough cholesterol might already have been formed in the tissue before incubation was begun to support normal rates of lipoprotein synthesis dising the short period of experimental observation, but not oues extended periods Other experiments showed that inter slices from scphrotic rats syathesized both lipoproteins and other serum proteins more rapidly than did those from normal rats This suggests that aterproduction of Sipoproteins may be an important factor in the hyperlipema of nephross Obserce Accelerated Drug Metabolism in Pretrealed Rats Pretreating rats with a sariety of drugs has been found by NIN sienusis to increase the activity of drug-metabolizing enzyme systems in the loses, thus decrtasing the duration of drug action in the body The findings were seported in the Federation Proceedings (19 390) by ·Presumably because one ion cannot replace the metabolic function of another, the cell must maintain the proper concentrations of the proper ions both for the regulation of its volume and for its metabolic operations. This would be impossibic but for the delicate balance struck between passive loss on the one hand and actic transport on the other. Previous work on intact red blood cells by Dr. E. T. Dunhani, formerly of the same laboratory, had indicated that ATP might be the fuel for the ion pump. In studies following this Icad, Dr. Hotlinan used red cell "ghosts" whose normal contents had been considerably reduced by hemolysis. The ghosts not only retained thc membranc characteristics of the intact cell, but could also be reconstituted con. taining known substances whose metabolism could subscquently be observed without the interference that might result from other metabo. lites and metabolic processes in the intact cell. Dr. Hoffman's studies showed that ATP was the specific fuel for the ion pump in the ghost system, however, if no ATP was incorporated into the ghost, the pump would still work (though less cfficiently) if other substances that would generate ATP were incorporatcd. These findings suggest that the ion pump requires the presence of an chizyt! (an ATPase) in order to use ATP. Such an enzyme has been characterized in membrancs isolated from red blood cells by Dr. R. L. Post of Vanderbilt, and appears to possess the same activation characteristics as docs active ion transport in both red cells and other ghosts. Thus the evidence is strong that the ion pump either is an ATPasc, or else has an ATPase as an intimate component. Protein and Fat Fractions of Lipoprotein Molecule Provided by Liver Scientists at NHI have found that the liver, previously shown to be the source of the lipid portion of lipoproteins, is also the source of the protein of this complex molecule, the form in which fars arc transported in the blood Experiments conducted by Drs Charles Radding and Daniel Steinberg, of the Laboratory of Cellular Physiology and Metabolism, have demonstrated that rat liver slices, incubated in tro, synthesize and secretC high-density lipoproteins identical with those found in normal rat seruni. Tlıcır findings are reported in The Journal of Clinical Inrestigation The liver slices were incubated in rat serum with a complete max. ture of amino acids labcled with carbon-14 After incubation ļxcriods ranging up to four hours, the slices were removed and samples of the mcdia ultracentrifuged to separate the lipoprotein fractions. These were then analyzed by the "fingerprine" technique, When broken down by thc protcolytic enzymes trypsin or chymo- 12 ·acid (aspirin) in preventing residual rheumatic heart disease. The NHI grant-aided studies were conducted by the combined Rheumatic Feser Study Group which consists of 12 liestigators in Children's Car. diac Senices of 8 hospitals. 4 in New York City, ? in Baltimore, and I each in Boston and Cleseland The intestigators, coordinated by D. A G Kurtner of New York Universny-Bellevue lledical Center, report their combined findings in the New England Journal of Viednine (262 895-902). Their findings are similar to those of an earlier cooperative study of aspirin is steroid therapy, sponsored joinly by the Rescarch Council of Great Britain and the American Heart Association. In the priesent study, however, steroids were given in larger doses and over a longer period of time. Admitted to the study were 57 patients who met the following criteria. (1) they were 12 years of age or younger, (2) had suffered theis first attack of rheumatic fever not more than 28 days prestously, and (3) had moderate to seiere carditis as evidenced by pericardial rub or eflusion, cardiac enlargement, congestise heart failure, and/or signifi. cant heart murmurs About half of these patients received large daily doses of prednisone which totalled 3 grams over a 12-ucch treatment period, the remaining patients were given doses of acctylsalicylic acid sufficient to maintain blood levels at 25 to 35 mg./100 cc, also for a 12-week period. Three weeks after termination of therapy and again 1 year later all patients were re-examined and the incidence of residual heart disease in each group compared The study group found that both predtusone and aspirin controlled acute rheumatic symptoms in most patients, and, during the ensuing year, all patients remained free of rheumatic recurrences. Of those patients atailable for study at the end of the year, 12 in the prednisone group and 16 in the aspirin group recovered completely with no signs of residual rheumatic heart disease, whereas 16 prednisone and 7 aspirin-treated patients had residual heart discase at this time or 3 patients originally allocated to the aspirin group but later switched to prednisone, I recovered completely and 2 were left with residual heart disease Thus, "large doses of prednisone giren for 12 weeks were not found to be superior to acelylsalicylic acid in presenting residual rheumatic heart disease," conclude the unrestigators. “The chief action of both prednisone and salicylates appears to be to suppress the inflammatory reaction caused by this disease in many patients, however, even if the acute symptoms are promptly and well controlled, cardiac damage is not presented," they state In yew of these findings, all but one of the insestigators felt the risk of prolonged steroid therapy was unwarranted, although no serious side effects of prednisone were noted US GOVEDADES Mint 14 OT-59103 45 ·Drs. A. H. Conney, I. A. Alichaelson, and J. J. Burns of the NHI's Laboratory of Chemical Pharmacology. This laboratory is conducting a broad programı of basic studies alined ai clucidating the factors ieg. ulating duration of drug action. Previous studies in this laboratory had shown that special enzyme systems in liver microsomcs, tiny particles in liver cells, inactivate many drugs as well as other compounds foreign to the body by converting them into compounds which the kidney can excrete. In the currently reported studies, Dr. Conney and co-workers inics. tigated the ability of microsomal enzyme systems in rat livers to metabolize several commonly used drugs following repeated doses of the same or another drug Rats were pretreated for four days and their livers incubated with test drugs to determinc microsomal enzyme activity. The scientists also tested enzyme activity in livc, pretreated rats by measuring the duration of action of test drugs Drugs used in the study included barbiturates, muscle relaxing drugs, analgesics, antirheumatic agents, a carcinogenic hydrocarbon, and an antihistamine. Results of the liver incubation studies showed that pretreatment with phenobarbital, barbital, phenylbutazone, orpliancdrinc, or aminopyrine caused "several-fold increases" in the ability of liver mcrosomes lo metabolize hexobarbital, zoxazolanune, phenylbutazone, and aminopyrine, report the ini cstigators They obtained cudence of accelerated drug metabolism in living, pretreated rats by demonstrating a shortened duration of action of hexobarbital, zoxazolamine, meprobamate, and carısoprodal in animals that had received repeated doses of these drugs. In other in vitro studies, the investigators observed that pretreatment with the hydrocarbon, 3,4-benzpyrene, stimulated the mucrosomal cu zyme system that metabolizes zo\azolamine, but not the hciobarbital. metabolizing system. "In accord with thus, 3, t-benzpyrene administrauon shortens the duration of zolazolamine paralysis from 730 minutes to 17 minutes but does not shorten the duration of hcıobarbital bypnosis," they report Interestingly, the duration of action of both zoxazolamine and hexobarbital was shortened in rats pretreated with the antihistaminic drug, chiorcyclizine "The findings that pretreatment of animals with one drug c.in spccd up the metabolism of the same or another drug may be of considerable importance when evaluating the pharmacological activity of drugs that are given repeatedly, cither alone or in combination," stated the Heart Institutc scientists Prednisone- /spirin Equally Effectire in Preventing Rheumatic lleart Damage Cooperative clinical studics have shown that large doses of the stor. old, prednisonc, are not superior to therapeutic doses of acetylsalicylic ·aad (aspirin) in presenting residual rheumatic heart disease. The NHI grant-aided studies were conducted by the Combined Rheumatic Fener Study Group which consists of 12 jasestigators in Children's Cardiac Services of 8 hospitals: # in New York City, 2 in Baltimorc, and I cach in Boston and Cleveland The investigators, coordinated by Dr. A. G Kuttner of New York University-Bellevue Medical Center, report their combined findings in the View England Journal of Medicine (352 893-902). Their findings are similar to those of an earlier cooperative study of aspirn vs steroid therapy, sponsored jointly by the Research Counal of Great Britain and the American Heart Association. In the pres. ent study, however, steroids were given in larger doses and over a longer penod of ume. Admitted to the study were 57 patients who met the following criteria. (1) they were 12 years of age or younger, (2) had suffered their first attack of rheumatic fever not more than 28 days previously, and (3) had moderate to severe cardius as evidenced by pericardial rub or effusion, cardiac crlargement, congestive heart failure, and/or signifi. cant hcart murmurs. About half of these patients received large daily doses of prednisone which totalled 3 grams over a 12-weck treatment period, the remaining patients were given doses of acetylsalicylic acid sufficient to maintain blood levels at 25 to 35 mg/100 cc., also for a 12-week period Three weeks after termination of therapy and again Iscar later all patients were re-examined and the incidence of residual heart disease in each group compared. The study group found that both prednisone and aspirin controlled acute sheumatic symptoms in most patients, and, during the ensuing y car, a patients remained free of rheumatic recurrences Of those patients available for study at the end of the car, 12 in the prednisone group and 16 to the aspırın group recovered completely with no signs of residual rheumatic heart disease, whereas 16 prednísome and 7 aspinn-treated patients had residual heart disease at this ume Of 3 patients originally allocated to the aspirin group but later switched to prednisone, 1 recovered completely and 2 were left wilk residual heart disease Thus, "large doses of prednisone given for 12 weeks were not found ļo be superior to acetylsalicylic acid in preventing residual rheumatic heart disease," conclude the invesugators "The chief action of both prednisone and salicy lates appears to be to suppress the infiammatory reaction caused by this disease the acute symptoms are promptly and sell controlled, cardiac damage In many patients, however, even if is not presented," they state In view of these findings, all but one of the investigators felt the riske of prolonged steroid thesapy was unwarranted, although no serious side effects of prednisone were noted no OS COTEAREN FUNTING OFFICE 1351 OP-1035 15 ·Drs. A. H. Conney, I. A. Michaelson, and J. J. Burns of the NHI's Laboratory of Chemical Pharmacology. This laboratory is conducting a broad program of basic studies aimed at elucidating the factors rego ulating duration of drug action. Previous studies in this laboratory had shown that special enzyme systems in liver microsomes, tiny particles in liver cells, inactivate many drugs as well as other compounds foreign to the body by converting them into compounds which the kidney can excrete. In the currently reported studies, Dr. Conney and co-workers investigated the ability of microsomal enzyme systems in rat livers to metabolize several commonly used drugs following repeated doses of the same or another drug. Rats were pretreated for four days and their livers incubated with test drugs to determine microsomal enzyme acrivity. The scientists also tested enzyme activity in live, pretreated rats by measuring the duration of action of test drugs. Drugs used in the study included barbiturates, muscle relaxing drugs, analgesics, antirheumatic agents, a carcinogenic hydrocarbon, and an antihistamine. Results of the liver incubation studies showed that pretreatment with phenobarbital, barbital, phenylbutazone, orphanedrine, or aminopyrine caused "several-fold increases" in the ability of liver microsomes to metabolize hexobarbital, zoxazolamine, phenylbutazonc, and aminopyrine, report the investigators They obtained evidence of accelerated drug metabolism in living, pretreated rats by demonstrating a shortened duration of action of hexobarbital, zoxazolamine, meprobamate, and carisoprodol in animals that had received repeated doses of these drugs In other in vitro studies, the investigators observed that pretreatment with the hydrocarbon, 3,4-benzpyrene, stimulated the microsomal en. zyme system that metabolizes zoxazolamine, but not the hexobarbital. metabolizing system "In accord with this, 3,4-benzpyrene administralion shortens the duration of zoxazolamine paralysis from 730 minutes to 17 minutes but does not shorten the duration of hexobarbital hypnosis," they report Interestingly, the duration of action of both zoxazolamine and hexobarbital was shortened in rats pretreated with the antihistaminic drug, chlorcyclızınc. "The findings that pretreatment of animals with one drug can speed up the metabolism of the same or another drug may be of considerable importance when evaluating the pharmacological activity of drugs that are given repeatedly, either alone or in combination," stated the Heart Institute scientists Prednisone-Aspirin Equally Effective in Prerenting Rheumatic Ileart Damage Cooperative clinical studies have shown that large doses of the stor. oid, prednisone, are not superior to therapeutic doses of acetylsalıcylic ·arid (aspirin) in presenting residual sheumatic heart disease. The NHI grant-aided studies were conducted by the Combined Rheumatic Foyer Study Group which consists of 12 in estigators in Children's Cardiac Services of 8 hospitals. * in New York City, ? in Baltimore, and I each in Boston and Cle cland. The intestigators, coordinaced by Dr. A. G. Kunner of New York University-Bellevue Aledical Center, report their combined findings in the Veiv England Journal of Medicine (262 895-902). Their findings are similar to those of an carlier couperative study of aspinn is. steroid therapy, sponsored jointly by the Research Coun. cil of Great Britain and the American Heart Association in the preserit study, however, steroids were gren in larger doses and over a longer period of time. Admitted to the study were 57 patienis who mct the following cri. tena: (1) they were 12 years of age of younger, (2) had suffered their first attack of theumatic fever not more than 28 days previously, and (3) had moderate to sei ere cardusis as evidenced by pericardial rub or effusion, cardiac enlargement, congestive heart failure, and/or significant heart murmurs About half of thtse patients received large daily doses of prednisone which totalled 3 grams over a 12-weck treatment period, the remaining patients were given doses of acetylsalicylic acid sufficient to maintain blood levels at 25 to 35 mg/100 cc., also for a 12-week penod. Three weeks after termination of therapy and again 1 year later all patients were re-examined and the incidence of residual heart disease in cach group compared The study group found that both prednisone and aspirín controlled acute rheumatic symptoms in most patients, and, during the ensuing ycar, all patients remained free of rheumatic recurrences. Of those patients available for study at the end of the year, 12 in the prednisone group and 16 in the aspının group recovered completely with no signs of residual rheumatic heart discase, whereas 16 predni. sone and 7 aspirin-treated patients had residual heart disease at this of 3 patients originally allocated to the aspirin group but latcr switched to prednisone, 1 recovered completely and 2 were left with residual heart disease Thus, "large doses of prednisone given for 12 ccks were not found to be superior to acetylsalicylic acid in prezenting residual rheumatic heart disease," conclude the investigators "The chief action of both prednisone and salicylates appears to be to suppress the inflamniatory reaction caused by this discase. In many patients, houdscr, csen of the acute symptoms are promptly and well controlled, cardiac damage is not prevented." they state In vew of these findings, all put one of the investigators fele the risk of prolonged stcrosd therapy was unwarranted, although no serious side cffects of prednisone were noted io tore time e ATA OFFICE 1OR-1011

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