Evidence of neutralizing activity against T3 coliphage in oyster Crassostrea gigas hemolymph

To investigate defense reactions of bivalve molluscs against viruses, experimental in vitro assays have been developed using T3 coliphage as a test virus. A native neutralizing factor in oyster Crassostrea gigas serum showed high individual variability and was enhanced significantly by repeated sampling of hemolymph from the same oysters. The responsible factor is apparently thermolabile and sensitive to EDTA treatment. Because of an inhibitory effect by the enzymatic inhibitor, phenylmethylsulphonyl fluoride (PMSF), the T3-neutralizing factor may be related to serine protease.     

Epidemiology of chronic hepatitis B infection in France: risk factors for significant fibrosis--results of a nationwide survey

BACKGROUND: Epidemiological data concerning hepatitis B are scarce in France. AIM: To describe epidemiological, clinical, virological and histological features of HBsAg-positive patients followed at non-academic hospitals in France. METHODS: Clinical, biological, virological and histological data of all HBsAg-positive consecutive patients observed from April 1, 2001 to May 31, 2002 in participating centres were recorded prospectively. Multivariate analyses of factors associated with significant fibrosis and cirrhosis were performed. RESULTS: Nearly 1166 HBsAg-positive patients were seen in the 58 centres: 671 males and 495 females from metropolitan France (32%) and from outside metropolitan France (68%); mean age 41 +/- 15 years. Twenty-nine percent of patients were probable HBsAg inactive carriers, while 50% had chronic hepatitis; 43% of these were HBeAg-positive and 57% HBeAg-negative. Liver biopsy had been performed in 558 (51%) patients; 205 (17.6%) patients had cirrhosis. By multivariate analysis, factors associated with significant fibrosis were: age >40 years (P < 0.05), HBeAg-negative status (P < 0.02) and histological activity (P < 0.0001). Factors associated with cirrhosis: age (P < 0.0001), platelet count <150 000/mm(3) (P < 0.0001) and viral co-infection (P < 0.03). CONCLUSION: HBV infection represents a significant workload for hepatogastroenterologists at non-academic hospitals in France.     

Does apolipoprotein(a) heterogeneity influence lipoprotein(a) effects on fibrinolysis?

High plasma levels of lipoprotein(a) [Lp(a)] are considered to be an independent risk factor for premature cardiovascular disease and are inversely associated with apolipoprotein(a) [apo(a)] isoform sizes. The contribution of apo(a) polymorphism to the inhibition of fibrinolysis, a mechanism that may favor thrombus development, was therefore evaluated by measuring the ability of Lp(a) particles of distinct apo(a) isoform content to compete with plasminogen for fibrin binding during plasminogen activation by fibrin-bound tissue-type plasminogen activator. The rate of plasmin generation was most efficiently inhibited by an isoform with a molecular weight (M(r)) of approximately 540 Kd. An isoform with M(r) approximately 590 Kd produced a less pronounced effect, whereas the isoform with M(r) approximately 610 Kd failed to inhibit plasminogen activation. These effects were directly proportional to the amount of Lp(a) bound to the carboxy-terminal lysine residues of degraded fibrin. The relative affinity of the binding (kd range, 16 to 180 nmol/L) reflected the ability of individual Lp(a) isoforms to inhibit the binding of plasminogen (kd, 600 nmol/L). The question of the influence of kringle sequence variability on the binding to fibrin was not addressed by the present work. These data suggest that apo(a) isoform types with high affinity for fibrin may influence the ability of Lp(a) to interfere with fibrinolysis and contribute thereby to the association of elevated levels of Lp(a) with atherosclerotic and thrombotic risks.