SummaryFour different heparin preparations - sodium and calcium salts of the same batch of heparin (mean molecular weight 15,000), low molecular weight sodium heparin (mean m. w. 9,000) and high molecular weight sodium heparin (mean m. w. 22,000) were injected subcutaneously on different days each into 6 healthy young volunteers in a randomized trial. Plasma heparin levels were measured using the anti-Xa assay at 1 hour, 3-4 hours and 6-7 hours after the injection. The highest anti-Xa potentiating effect was obtained after the injection of the low molecular weight sodium heparin (mean 0.381 i. u./ml) at 3-4 hours after the injection. With sodium heparin (m. w. 15,000) the highest values (0.135 i. u./ml) were found at 1 hour. Significantly lower anti-Xa potentiating effect was obtained 1 hour after the injection of calcium heparin and in particular after the injection of high molecular weight heparin (mean values 0. 072 i. u./ml and 0.043 i. u./ml respectively). Both these preparations showed an increase from 1 hour after injection to 3-4 hours after injection (mean values 0.082 i. u./ml and 0.057 1. u./ml at 3-4 hours after injection).These results indicate that the salt and the molecular weight of the preparation may strongly influence the degree of anticoagulation achieved after subcutaneous injection.

SummaryA relapsing clinical syndrome of skin lesions and disseminated intravascular coagulation (DIC) that showed remission with the infusion of fresh frozen plasma is described in a newborn infant with homozygous deficiency of protein C antigen.This patient presented since birth a recurrent clinical picture of DIC and ecchymotic skin lesions that resembled typical ecchymosis except for the fact that they showed immediate improvement with the administration of fresh frozen plasma. Using an enzyme linked immunosorbent assay method, the determination of protein C antigen levels in the patient, without ingestion of coumarin drugs, showed very low values (<1%).No other deficiencies in the vitamin-K-dependent factors or in anti thrombin III, antiplasmin, and plasminogen were found. Seven relatives of the infant had heterozygous deficiency in protein C antigen (values between 40-55%), without clinical history of venous thrombosis. The pedigree analysis of this family suggests an autosomal recessive pattern of inheritance for the clinical phenotype, although an autosomal dominant pattern has been postulated until now in other reported families.We conclude that our patient has a homozygous deficiency in protein C and this homozygous state may be compatible with survival beyond the neonatal period.

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An Aa-arginine-141 to serine substitution has been identified in a homozygous dysfibrinogen, fibrinogen Lima, associated with impaired fibrin polymerization. The point mutation created an asparagine-X-serine-type glycosylation sequence, and indeed, extra, mainly disialylated biantennary oligosaccharides have been isolated from Aa asparagine-139 of the patient's fibrinogen. This type of glycosylation sequence is unique for human fibrinogen, because the sequences shown for normal and abnormal fibrinogens are all asparagine-X-threonine types. The terminal sialic acids of the extra oligosaccharides seem to have largely contributed to the impaired fibrin gel formation, as evidenced by its correction to a near normal level by desialylation. Nevertheless, the polymerizing fibrin facilitated tissuetype plasminogen activator-catalyzed plasmin formation in a normal fashion, indicating that the initial two-stranded fibrin protofibrils had been constructed normally. Thus the impaired fibrin gel formation could be attributed to the delay in their subsequent lateral association, most probably because of the repulsive forces generated by the negative electric charge of the extra sialic acids. The substitution of a basic residue arginine to a noncharged residue serine may also have contributed to the impaired function in a similar manner or by steric hindrance in association with bulky extra oligosaccharide chains. (J. Clin. Invest. 1992. 90:67-76.) Key words: amino acid substitutioncongenital homozygous dysfibrinogen * extra asparagine-linked oligosaccharide * fibrin-facilitated plasminogen activation * lateral association of fibrin protofibrils

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