Contractile Fibers and Catch-Bond Clusters: a Biological Force Sensor?

Catch bonds are cellular receptor-ligand pairs whose lifetime, counterintuitively, increases with increasing load. Although their existence was initially pure theoretical speculation, recent years have seen several experimental demonstrations of catch-bond behavior in biologically relevant and functional protein-protein bonds. Particularly notable among these established catch-bond formers is the integrin α₅β₁, the primary receptor for fibronectin and, as such, a crucial determinant for the characteristics of the mechanical coupling between cell and matrix. In this work, we explore the implications of single catch-bond characteristics for the behavior of a load-sharing cluster of such bonds: These clusters are shown to possess a regime of strengthening with increasing applied force, similar to the manner in which focal adhesions become selectively reinforced. Our results may shed new light on the fundamental processes that allow cells to sense and respond to the mechanical properties of their environment and in particular show how single focal adhesions may act, autonomously, as local rigidity sensors.     

The Seventeenth International Conference on Plant Growth Substances (Brno,Czech Republic,July 1–6, 2001)

Russian Journal of Plant Physiology -     

Use of the polymerase chain reaction for analysis of rotaviruses. Nucleotide sequence of a gene, coding for the basic neutralizing antigen VR7 of a human rotavirus with a new G-serotype

A procedure based on polymerase chain reaction use for the detection of rotavirus has been developed. Full length cDNA copy of the VP7 gene coding for the major neutralization glycoprotein of the human rotavirus RK9 with an unusual "wide" electrophoretype is cloned and sequenced. Glycoprotein VP7 of RK9 has a unique amino acid composition in A and C antigenic regions. It shows that strain RK9 represents a new (12) rotavirus serotype.     

Use of cefoperazone in clinical practice]

The bacteriological and clinical efficacy and side effects of cefoperazone were studied in 45 patients with severe and moderate purulent inflammatory diseases. The study showed that its bacteriological and clinical efficacy was high in cases with peritonitis, cholecystitis, respiratory and urinary infections, as well as those of the eye and soft tissues. The general clinical efficacy amounted to 95.6 per cent. The number of the side effects was insignificant. This made it possible to recommend the use of cefoperazone in the therapy of many purulent inflammatory diseases, as well as in empirical therapy.