Chemiluminescence of human lymphocytes in reactions with Staphylococcus aureus peptidoglycan

The capacity of S. aureus peptidoglycan (PG) for inducing the luminol-dependent chemiluminescence of human lymphocytes has been studied. Lymphocytes taken from adult donors have been found to give dose-dependent reaction to S. aureus PG, while lymphocytes from newborn infants have been inert under the same conditions. Essential differences in the kinetics of response to PG (the maximum intensity of chemiluminescence occurs in 25-30 minutes) and to phytohemagglutinin (the maximum intensity is reached in 1 minute) were observed. These results are considered as the manifestation of specific sensitization to bacterial peptidoglycans, which may be rapidly detected by reactive chemiluminescence.     

Red-breasted goose colonies on the Taimyr Peninsula: Factors responsible for the proximity of goose nests to nests of peregrine falcons,rough-legged buzzards,and snowy owls

Red-breasted goose colonies have been studied near Medusa Bay (73°21′N, 80°32′E), on the northwestern Taimyr Peninsula, and along the Agapa River (70°11′N, 86°15′E) down to its mouth (71°26′N, 89° 13′E), in the central Taimyr Peninsula. Red-breasted geese nesting near peregrine falcons are protected by the falcons from arctic foxes; however, they are sometimes attacked by the falcons themselves. In the colonies near peregrine falcon nests, the vast majority of goose nests were situated no farther than 100 m from the falcon nest. When food is abundant, falcons protect a larger area around their nest. The distance between the falcon nest and the surrounding goose nests is inversely related to the falcon’s activity. In years of higher falcon activity, falcons prevent red-breasted geese from nesting as close to their nest as in years of lower falcon activity. Additional stimuli are required for red-breasted geese to form colonies near rough-legged buzzard nests. The distance between snowy owl nests and red-breasted goose nests was smaller when arctic foxes were abundant than when they were scarce.     

Characteristics of blastolysin preparations in their ability to inhibit hemagglutination caused by bacteria of the genus Lactobacillus

Anabol and blastolysin preparations obtained from L. bulgaricus may contain surface structural components of the initial strain with adhesion activity; of these, one is similar in specificity to L. casei adhesin and the other, to L. plantarum adhesin. The antigenic activity of anabol and blastolysin, evaluated in the immunodiffusion test, does not correlate with their capacity for binding the receptors of susceptible bacterial cells, determined in the Lactobacillus-induced hemagglutination inhibition test.     

Activation of parathyroid hormone by heparin in vitro]

Heparin proved to be essential component in bone resorption. In vitro heparin activated the effects of parathyroid hormone in respect to bone resorption, but heparin alone was incapable of causing the resorption.     

Electrophoresis and electrofocusing of rhodopsin solubilized by triton X-100]

Detergent-rhodopsin micells (component I) were separated from other fast and slow migrating protein components under electrophoresis of triton X-100 solubilized bovine rod outer segments (ROS). Treatment of ROS by alum caused a complete disappearance of non-rhodopsin proteins and the appearance of slow migrating band (component II). Preliminary bleaching of dark extracts did not affect the migration rate of the component I. The addition of urea to solubilizing mixture caused the increase of component I content and the diffusity components I and II bands. The rate of electrophoretic migration and the content of components I and II sharply decreased together with the appearance of fast migrating pink-brown band after the addition of 2-mercaptoethanol. The extracts from alum-treated ROS were separated into 15-20 protein bands under acrylamide gel isoelectric focusing. Such protein heterogeneity probably depended on the ability of triton X-100 to form micells with different isoelectric points during the interaction with ampholines in the electric field. These micells, having different isoelectric points, are shown to contain one and the same protein--opsin.     

Assessment of the effects of methylmercury and copper ions on primary processes of photosynthesis in green microalga Chlamydomonas moewusii by analysis of the kinetic curves of variable chlorophyll fluorescence

The effect of methylmercury and copper ions on the kinetics of light induction and dark relaxation of the variable fluorescence of chlorophyll a has been studied on cultures of unicellular alga Chlamydomonas moewusii. Methylmercury was effective at much lower levels. The toxicants at concentrations that did not decrease the photochemical activity of PS II (F _v/F _m) did affect the electron transport on the acceptor side of PS II, nonphotochemical quenching of excitation in the antenna, and reoxidation of the quinone pool. Our results indicate that this approach can be used for detecting the changes in plant cells at the early stages of toxicant action.     

Effects of long-term fixation on histological quality of undecalcified murine bones embedded in methylmethacrylate

While long-term fixation and storage of specimens is common and useful for many research projects, it is particularly important for space flight investigations where samples may not be returned to Earth for several months (International Space Station) or years (manned mission to Mars). We examined two critical challenges of space flight experimentation: the effect of long-term fixation on the quality of mouse bone preservation and the preservation of antigens and enzymes for both histochemical and immunohistochemical analyses, and how the animal/sample processing affects the preservation. We show that long-term fixation minimally affects standard histological staining, but that enzyme histochemistry and immunolabeling are greatly compromised. Further, we demonstrate that whole animal preservation is not as suitable as whole leg or stripped leg preservation for long-term fixation and all histological analyses. Overall, we recommend whole leg processing for long-term storage of bone specimens in fixative prior to embedding in plastic for histological examination.