Chemoreceptor function and metabolism of the carotid body in the rat

Using fluorimetric and polarographic determination of cell respiration, metabolic reactions of the carotid body of rats to adequate stimulation have been revealed. Functional relationships of the dose--effect type, which were found for these reactions, may be approximated by equations which are similar to those describing the unconditioned reflexes from the carotid chemoreceptors. However, reactions of the metabolics systems of the carotid body account for the perception of not all chemical stimuli, but only of acids and some alkaloids. These data reveal the heteregeneity of the carotid chemosensory system not only in the amphibians (which was known earlier), but in mammals as well.     

The combined action of microwave radiation and hydrogen peroxide on the viability and ultrastructure of Pseudomonas aeruginosa cells

The comparative study of the action of microwave radiation and hydrogen peroxide, as well as their combined action, on the viability and ultrastructure of P. aeruginosa cells has been made. The combined use of microwave radiation and hydrogen peroxide has been shown to decrease the viability of P. aeruginosa 1.5-2 times in comparison with the isolated action of each factor. The electron microscopic study of the ultrastructure of cells have shown the deterioration of the surface structures, nuclear and ribosomal apparatus of the cells under the isolated action of each of the above-mentioned factors or under their combined action. The morphological picture of these changes has proved to be different. The maximum changes in the ultrastructure of P. aeruginosa cells have been registered after the combined action of these bactericidal factors.     

Reference values for feeding parameters of isopods (Porcellio scaber,Isopoda, Crustacea)

The advantage of using terrestrial isopods in toxicity studies is that a battery of parameters can be tested at different levels of biological complexity. Feeding parameters for example link organism level response to potential ecological consequences but a problem with using feeding parameters in toxicity tests with terrestrial isopods is their high variability. The aim of our study was to set benchmark values for feeding parameters for isopod Porcellio scaber (Isopoda, Crustacea) in laboratory-controlled experiments. In the work presented here, the daily feeding rate of the central 50% of the control population of Porcellio scaber and a correlation between feeding rate and isopod weight were set. Values outside these ranges need additional evaluation to increase the relevance of test outcomes. We suggest using benchmark values for feeding parameters as well as the coefficient of variation (a) to identify animals with altered feeding parameters with respect to controls, and (b) to assess the data quality in each experiment.     

Antibiotic prophylaxis, antibiotic therapy and microbiological situation in surgical unit]

The clinical and economic efficacies of antibiotic prophylaxis in the surgical unit of the Hospital were confirmed by the results of the analysis of 1313 case records of the patients operated during a year for acute appendicitis and acute cholecystitis. At the same time it was shown advisable to use antibiotic therapy in the patients with various pathological processes. The dynamics of the microbial dissemination in the surgical unit and some other units of the Hospital, as well as the dynamics of antibiotic resistance of the microflora, its interrelation with the volume of the antibacterials used and their rotation are described.     

Changes in the Activity of the Maturation-Promoting Factor Are Correlated with Those of a Major Cyclic AMP and Calcium-Independent Protein Kinase During the First Mitotic Cell Cycles in the Early Starfish Embryo

Many studies suggest that MPF activation depends on protein phosphorylation or that MPF is itself a protein kinase. In the present report, cyclic variations of MPF activity have been correlated in vivo with changes in the extent of protein phosphorylation or in vitro with changes of a major protein kinase during the first cell cycles of fertilized starfish eggs. This cycling protein kinase neither requires cAMP nor Ca²⁺. Neither colchicine nor aphidicoline, which inhibits cleavage and chromosome replication respectively, was found to suppress the synchronous and cyclic variations of both MPF and protein kinase activities. Protein synthesis was found to be required for both MPF and protein kinase activities to reappear after their simultaneous drop at the time of mitotic or meiotic cleavages. Production of either MPF or protein kinase activities is not the immediate result of protein synthesis since there is a delay at each cell cycle between the time when protein synthesis is required and the time when both MPF and protein kinase activities are produced. This suggests that both MPF and protein kinase activities might involve some post-translational modification of a precursor protein synthesized during the preceeding cell cycle.     

中国平脉树螽属五新种记述：直翅目：螽斯科：树螽亚科

本文报道中国平脉树螽属5个新种。每个新种皆有详细的形态描述和形态特征图。所有模式标本存于北京农业大学昆虫标本室。