Investigation and identification of the antimicrobial component of the drug "Tomatol"]

Antimicrobial activity of Tomatol against laboratory strains of Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 6538-P and Candida albicans ATCC 885-653 as well as against clinical isolates of Enterobacter spp., Streptococcus spp., Staphylococcus spp., Klebsiella spp. and Escherichia spp. was tested. Tomatol was shown to have a broad antimicrobial spectrum including gram-positive and gram-negative organisms and Candida. The TLC investigation demonstrated that the Tomatol antimicrobial component was that of a complex of organic acids such as succinic, citric, tartaric and others.     

Morphology of genital system and reproductive biology of the arctic calanoid copepod Metridia longa

This paper considers features of the external morphology and internal structure of the genital system of adult males and females of Metridia longa Lubbock from the White Sea, as well as related with them features of reproduction biology of this mass Arctic copepod. Males of M. longa are dimorphically asymmetric. In the population, there are two morphotypes, which are mirror images of each other. Asymmetry manifests in them as the presence of a right (males ??righties??) or left (males ??lefties??) geniculate antenna, structure of the fifth pair of swimming legs, and location of an unpaired gonad and genital opening. The relative position of these structures is linked together. In females, there are two widely spaced copulator pores that lead to the two spermathecae not connected to each other. The latter, in turn, are connected to two gonopores, through which shedding of eggs occurs. The vast majority of the females in the studied population M. longa in all seasons of the year had only one filled spermatheca, either the right or the left. The females with bilateral insemination also occurred, but did not exceed 2.7% of all specimens. The ratio of females with the right and left filled spermathecae and ??right-handed?? and ??left-handed?? males suggests that the male morphotype determines in which spermathecae male gonads are most likely to get into. The presence of females with two filled spermathecae implicates insemination by two males of different morphotypes. Since each spermatheca is connected to only one of the two oviducts, it is assumed that a half of the eggs produced by unilateral inseminated females remains not fertilized. The morphology of genital structures and literature data on the egg production of M. longa indicate that almost a half of eggs produced by females is not viable and thus wasted.     

Effect of the bacterial preparation, insectin, on the fleas Xenopsylla cheopis]

The effect of 0.2-2 mg/g of insectine (Bacillus insectus) upon the Ist-IInd stage larvae of X. cheopis is very negligible but it manifests itself in the subsequent low (9 to 30%) development and hatching of imagos. The III stage larvae are more resistent and after the effect of 10 mg/g of the preparation 9% of larvae formed cocoons which later developed into imagos. Adult fleas poorly responded to 0.2-2 mg/g of insectine. However, 10-30 mg/g of insectine caused in four days a mass death of fleas and their population decreased to 70% as compared to control.     

Specific features of digestive function development in larvae of some salmonid fish

We studied the activities of digestive enzymes responsible for the digestion of food carbohydrate and protein components in plant-eating fish at various stages of larval development. The activities of all digestive enzymes tend to rise during larval development. Species specific features of the alimentary canal functioning have been described.     

Two Subtypes of Nicotinic Acetylcholine Receptors in <Emphasis Type="Italic">Lymnaea stagnalis</Emphasis> Neurons Control Chloride Conductance

Giant neurons of the mollusc Lymnaea stagnalis contain heterogeneous population of nicotinic acetylcholine receptors (nAChRs) according to their relative sensitivity to antagonists. All these receptors are involved in the total response to acetylcholine (ACh). To evaluate activity of different pharmacological agents correctly it is necessary to know ionic selectivity of nAChRs which participate in transmembrane ionic current. In this work we studied the influence of ionic composition of the external and intracellular solutions on the current amplitude and current–voltage relation under the action of ACh or other nAChR agonists on the identified neurons of the left and right parietal ganglia of Lymnaea. After non-permeable cation N-methyl-D-glucamine was completely substituted for external Na⁺ ions there were no changes in the current characteristics. After a 10-fold decrease in Cl–concentration in the external solution there was a considerable shift of the current–voltage curve to the right, outward currents at the holding potential (V_h) up to 30 mV were not observed. On the contrary, a 10-fold decrease of Cl^– concentration in the intracellular solution led to a shift of the current–voltage curve to hyperpolarizing direction, the reversal potential shift was in the average –42 mV. When ACh and nicotinic agonists with higher selectivity towards vertebrate α7 neuronal nAChR type and one of the two subtypes of Lymnaea nAChRs were compared, no differences in changes of ionic current characteristics were found. Neurons with distinct relative fraction of one or another nAChR subtype reacted to Cl^– concentration change in the same way. Our results support earlier data on Cl^– mechanism of Lymnaea neuron responses to ACh and evidence identical ionic selectivity of the two nAChR subtypes in identified neurons tested.     

Safety and reactogenicity of a group-A meningoccal polysaccharide vaccine for children 5 to 14

The safety and reactogenicity of group A meningococcal polysaccharide vaccine prepared at the G. N. Gabrichevsky Research Institute for Epidemiology and Microbiology (Moscow) and intended for the immunization of children aged 5-14 years were studied. The data obtained in this study made it possible to characterize the preparation as safe and mildly reactogenic. Shifts in the blood formula registered 24 hours after the injection of the vaccine remained within the limits of physiological fluctuations. Subfebrile temperature persisting for 2 days was registered in some of the children aged 5-8 years. Local reaction in the form of hyperemia at the site of injection was insignificant. The optimum vaccination dose will be determined on the basis of the whole complex of the data presented in this work, as well as the data on the immunological activity of the preparation.     

The role of lipids during exposure of mutant cells of Candida tropicalis D-2 to heterologous DNA after treatment with calcium cations

It was shown that treatment of mutant cells of Candida tropicalis D-2 strain with deficiency for histidine and respiration Ca2+ ions leads to increase in the number of revertants at the action of heterologous DNA. The effect of preliminary treatment with Ca2+ ions depends on the time of their action, the number of intracellular lipids, the nature of DNA and temperature of treatment.