Activation of thymic B cells by signals of CD40 molecules plus interleukin-10

We have previously found that thymic B cells, particularly thymic CD5+ B cells, show low responsiveness to the usual B cell stimulants such as lipopolysaccharide or anti-IgM plus interleukin (IL)-4, although they proliferate and produce antibodies after direct interaction with major histocompatibility complex class II-restricted T blasts. These findings raise the possibility that a CD40-CD40 ligand (L) interaction is involved in the activation of thymic B cells. In the present study, we therefore examine this possibility using CD40L-transfected Chinese hamster ovary (CHO) cells or anti-CD40 monoclonal antibody (mAb). When B cells in the spleen and peritoneal cavity were stimulated, they proliferated and produced immunoglobulin (Ig) in the presence of CD40L-CHO cells or anti-CD40 mAb alone. However, another signal delivered by IL-10 in addition to CD40L-CHO cells or anti-CD40 mAb was found to be necessary for thymic B cells to proliferate and secrete Ig. Other interleukins acting on B cells, such as IL-4, IL-5, and IL-6, had no effect on the activation of thymic B cells, which thus have unique characteristics not found in peripheral B cells. This report discusses the physiological significance of IL-10- and CD40-driven signals in the activation of thymic B cells.     

Technology for high-alumina mortar in the Belokamensk Refractory Plant

Materials proposed for the production of a high-alumina mortar are investigated, namely, waste of melting of secondary aluminum, polishing powder of normal electrocorundum, and sintered corundum. A technology for the production of high-alumina mortars of three compositions has been developed for these materials. An experimental industrial batch of mortar composed of ShKN chamotte, polishing powder of normal electrocorundum, and DN2 clay has been manufactured and tested with a positive result. Production of the mortar has been introduced in the Belokamensk Refractory Plant.Translated from Ogneupory, No. 1, pp. 27 – 28, January, 1996.     

Dynamic thermal methods and microprocessing units for measuring the rates and properties of material flows

A multifunctional measurement system utilizing a noncontacting, thermal-tracer primary detector is described. It provides for the automatic acquisition of information on volumetric and mass flow rates and the properties of fluid flows.Translated from Izmeritel'naya Tekhnika, No. 8, pp. 10–11, August, 1994.     

Effects of growth with ethanol on fermentation and membrane fluidity of Saccharomyces cerevisiae

Saccharomyces cerevisiae HSc was grown with ethanol at concentrations up to 10% (v/v). The immediate effects of additions of externally added ethanol on CO₂ production and O₂ consumption of washed organisms were studied by stopped-flow membrane inlet quadrupole mass spectrometry. Fermentative activities of organisms grown with ethanol (0–5% v/v) showed similar sensitivities to inhibition by ethanol, whereas those grown with 10% (v/v) ethanol had become protected and were markedly less sensitive. The fluidity of subcellular membrane fractions was measured by determination of the temperature dependence of the rotational order parameter of the spin label 5-doxyl stearic acid (free radical) by electron spin resonance. Mitochondria prepared from yeasts grown with 0, 7 and 9% (v/v) ethanol showed similar overall fluidity, although differences in temperature-dependent behaviour indicate altered lipid composition or lateral phase separations. On the other hand the microsomal fraction from organisms grown with 9% ethanol showed a remarkable increase in fluidity. These data suggest that the protective effects of growth with ethanol near the limit of tolerance on fermentative activities may arise from altered plasma membrane fluidity properties.     

A preprocessor for geotomographic imaging of irregular geometricscans

An algorithm that acts as a preprocessor to the straight ray algebraic reconstruction technique (ART) algorithm, for the purpose of dealing with nonrectangular scanning geometries, is described. The mathematics of ART in its elementary form is reviewed, showing how the discretization of the rectangular scanning space defines quantities in the projection matrix of the algorithm. A triangular discretization approach for the scanning space that allows nonrectangular or twisted plane geometries to be addressed is proposed, and the effect of this approach on the projection matrix is discussed. An algorithm for determining the projection matrix under these discretization conditions is described, followed by some commentary on its computer implementation. The performance of this preprocessor algorithm, working with standard ART, in reconstructing various synthetic images is demonstrated