Lipids and Coagulation

S 797 plasma was llSCCl and in the high fat series when undiluted plasma was used. The experiInental results were submitted to detailed sh’.tistical analysis, and it was considered that in measurement of coagulation time the spread of readings within samples had far less effect on the experiments than the uncontrolled variability between samples. Variables that have to be considered include degrees of perfection in venepuncture, the time of the day, the weather and the taking of a meal as distinct from its fat content. The measurement of the stypven time is affected by the presence of saturated or sinsaturated fat in tile plasma, and the evidence at present seems insufficient to indict either variety of fat as a cause of accelerated coagulation.-R. H. G. METHODS FOR COMPARING EFFECTS OF VARIOUS FATS ON FIUmN0LYsIs. R. F. Scott and W. A. Thomas. From Washington University Scllool of Medicine, St. Louis, Mo. Proc. Soc. Exper. Biol. & Med. 96:24-29, 1957. Previous studies by this group have shown that butter and oleomargarine meals inhibit lysis of injected clots in rabbits. The present study provides in vitro extension of these findings. Rabbits were given intragastric infusions of butter or of other oils. After 3 hours, blood was collected in oxalate, then clotted in a mixture of bovine thrombin and streptokinase. The clot lysis tulle was measured. Clots from animals fed water, corn oil, or coconut oil lysed in about 15 minutes; clots from lmtter-fed animals ilad the time lengthened to about 22 minutes. Similar prolongation of clot lysis time was observed wilen oxalated rabbit plasma was mixed in vitro with butter; and tile other oils gave a considerably lesser effect in this system.-T. H. S. AmsasosCLERoSIs SN A HAEMOPHILIAC. J. W. Stewart and E. D. Aciwson. From Middlesex Hospital, London, England. Lancet 1:1121-1 122, 1957. A 73-year-old hemophiliac with angina pectoris died following melena. He had atheroma of the coronary arteries and aorta. Unless the deposition of fibrin takes place independently of the ordinary coagulation processes, it is difficult to believe that a thronlbogenic influence was an important factor in narrowing his coronary arteries.-R. H. G. THE EFFECT OF FAsTINo NORMAL SERUM ON IIEPARIN-INDUCED CLEARING REACTION. G. S. Getz and B. P4. Bloomberg. From tile Department of Pathology and Microbiology, University of the Witwatersrand, Johannesburg. S. Afr.J. Med.Sc. 22:129-136, 1957. Fasting normal human serum ( F.S. ) as a source of tile co-factors of the heparin clearing reaction was studied in an in vitro system using as substrate a coconut-oil suspension. The results showed that F.S. contains sonic substance, which, if preincubated with the substrate, will retard the clearing reaction temporarily. The retardation was dependent upon the time of preincubation with F.S. and the amount of F.S. used. The authors suggest that the data indicate the need for “activation” of the circulating lipoproteins onto whlcil the fat is to be hound, before the lipoproteins can act as substrates for the heparin-clearing reaction. The lag in clearance would then be due to a competitive binding of fat by lipoproteins unsuitable for substrate activation. As the clearing reaction proceeds, the accelerating rate of clearing may follow a conversion of unsuitable lipoprotein to a suitai)le, substrate-activating lipoprotein, and this process itself may be catalyzed by heparin-clearing factor.-T. II. B.