Influenza virus assembly and its defects

The most abundant protein within the influenza virus particles is membrane protein (M protein) which forms an inner virus membrane under a lipid bilayer and plays the role of mediator during the process of assembly of a virus particle on plasma membranes. Ehrlich ascites tumor cells (EAT) when infected with influenza virus, strain WSN, produced virus-like particles containing greatly reduced amounts of M protein. Such particles were extremely fragile and easily lost hemagglutinins. The loss of this glycoprotein was accompanied by a decrease in infectious activity.SDS-PAGE analysis of RNA duplexes formed after hybridization of intracellular labeled mRNAs and unlabeled virion RNA showed that the mRNA for M protein was synthesized in EAT nearly in the same amounts as in productively infected chicken fibroblasts. Accordingly, M protein was readily revealed when the polypeptides of infected EAT were analyzed by SDS-PAGE. Thus, the reduced amount of M protein in virus particles was likely not due to the decrease in its synthesis but rather to its defective structure or to its defective transport and misintegration into plasma membranes of EAT.     

Haemostatic variables associated with diabetes and its complications.

To study the possible role of an "increased thrombotic tendency" in the vascular complications of diabetes several tests of haemostatic function were carried out on 91 men and 63 women with diabetes aged 35-54 years and the results compared with findings in 686 men and 393 women of the same age in the Northwick Park Heart Study. Mean values for factors VII and X, fibrinogen, and platelet adhesiveness were higher in the diabetics, but mean fibrinolytic activity and whole blood platelet counts were lower. Antithrombin III values were also higher in the diabetics, which may have constituted a protective response to other changes favouring the onset of vascular disease. Diabetics with retinopathy had higher factor VII and antithrombin III values, and those with proteinuria had higher values for factor VII, fibrinogen, and platelet adhesiveness than those without these complications. These findings suggest a potentially important association between a thrombogenic tendency and vascular disease in diabetes. Nevertheless, prospective data are needed to clarify whether the haemostatic abnormalities precede the onset of clinically manifest vascular complications or are a consequence of them.