Contribution of whole-cell optimization via cell body rolling to polarization of T cells

Directed secretion of cytotoxins or cytokines by T cells during immune response depends on migration of the centrosome in the T cell to the interface with the target cell. The mechanism of the centrosome translocation has been elusive. The presented computational analysis demonstrates that the centrosome should be positioned at the interface if the T cell attempts simultaneously (a) to minimize its surface area, (b) to maximize the interface area, (c) to maintain the cell volume and (d) to straighten the microtubules. Live three-dimensional microscopy and measurements show that the optimal position of the centrosome is achieved in large part (by about 40%) via rolling of the entire T cell body on the target surface; this movement appears to entrain the centrosome. The theoretical and experimental results draw attention to the previously unrecognized role of the whole-cell structure and whole-cell movements in the T cell polarization.     

Energy balance in the interaction of intense high-temperature plasma flows with solid targets

The energy balance in the interaction of intense (W≈7 MW/cm², Q≈130 J/cm²) flows of a high-temperature (T _e+T _i≈0.7 keV deuterium plasma with targets made of different materials (graphite, tungsten, copper, etc.) is studied experimentally. It is shown that radiation plays a decisive role in the interaction energy balance: a plasma layer arising near the surface of the eroded target reemits most of the plasma-flow energy into the surrounding space. No more than 50 J/cm² reaches the surface. Then, this energy is expended primarily on the target heating and only a small fraction (less than 3 J/cm²) is spent on the evaporation of the target surface layer. It is shown that, for targets made of high-Z materials, the energy reaching the surface is transferred predominantly by radiation.     

Cell-mediated and humoral immunity in HBS-Ag carriers]

The presence of HBs--Ag in the blood was established in 1.8% of practically healthy persons, in 29.7% of virus hepatitis patients and in 86.0% of serum hepatitis patients. The immunological study of clinically healthy HBs--Ag carriers revealed a statistically significant decrease in the number of T and B lymphocytes and an increased level of serum IgA, IgM and IgG in the blood. Among donors, 7.6% were found to have lymphocytes sensitized to HBs--Ag and 15.4% were found to have lymphocytes sensitized to liver antigen, while for HBs--Ag carriers these data were 62.5% and 50%, respectively.     

Clinical case of tandem translocation between chromosomes 13 and 15

Cytogenetic and clinical examination of a patient (girl) with tandem translocation between chromosomes 13 and 15 was carried out. Translocation resulted in a partial loss of the genetic material between chromosomes 15 and 13. The problem on karyotype and phenotype relations with the loss of the respective chromosome regions is discussed.