Sterility of Males Determined by Functional Features of the Mouse Spermatozoa Bearing t-Complex

The mechanisms underlying normal spermatogenesis and its pathology expressed as male sterility determined by t-complex located on chromosome 17 in mice are considered in this review. t-Complex is a very convenient model with diverse markers of expression of the genes involved in development of the functional features of the spermatozoa bearing t-complex. These features include defects of mobility, capacitation, and acrosome reactions, which determine full or partial male sterility. It has been proposed that the defects of capacitation are also inherent in humans and affect male fertility. This homology is confirmed by the presence of the male gene Tcp11 in humans and demonstration of the fact that the protein TCP11 plays a leading role in modulation of the capacitation of murine spermatozoa. Hence it follows that the defects of human genes leading to incomplete binding of the fertilization promoting peptide could play a certain role in a decreased male fertility. All this is essential not only for deeper understanding of the biology of spermatozoa, but also for development of new therapeutic methods of finding and treating the pathology of spermatozoa.     

Changes in surface activity of surfactant and ultrastructure of the air-blood barrier in alcoholic intoxication in experimental animals

In the results of complex investigation of the lungs of 26 white rats, it was established, that there is the suppression of surface active properties of surfactant under influence of ethanol. In acute poisoning this suppression is associated with direct injury of surfactant with ethanol and inactivation of surfactant with serum proteins, which appear in the alveolar space because of the edema of air-haematic barrier. In prolonged influence the suppression of the surface activity of surfactant is due to the increase of its catabolism with alveolar macrophages.     

Surfactant surface activity and ultrastructural changes in the type-II alveolocytes of fetal and neonatal lungs in experimental inflammation of the maternal lungs

The lungs of 19 guinea pigs, born from 8 females in which acute and chronic pneumonia had been modelled by transtracheal introduction of sterile fishing-line were investigated. It was established, that in guinea pigs, born in females with acute and chronic pneumonia, the functional immaturity of pneumocytes of the 2-nd type took place. The functional immaturity of pneumocytes of the 2-nd type results in suppression of the surface active characteristics of surfactant.     

Use of differences in substrate inhibition for determination of the interrelationship between molar fractions of lactate dehydrogenase subunits]

A kinetic method of estimating the ratio of mole quota of H and M human lactate dehydrogenase (LDG) subunits is proposed, based on changes in substrate inhibition of LDG isoenzymes with lactate. Stability of kinetic constants for a long period of time is demonstrated. The dependency of activities ratio under low and high substrate concentration on the contribution of mole quota of LDG M subunits is studied. The correlation of experimental and theoretical values is shown to be: r=0.998 p less than 0.001. A comparison is carried out of the content of LDG subunits molar quotas in artificial mixtures with electrophoretic experimental data, a good coinsidence of these values being registered. The informative importance of the method described with standard methods of the estimation of LDG isoenzyme systems is discussed. No effect of components of human diploid cells homogenate and an insignificant effect of blood serum components on kinetic constants of LDG isoenzymes is registered. A dependency of variation coefficients on the enzyme activity is studied, minimal omegan value being 0.6%. The applicability of the method described for the calculation of quantitative content of both LDG subunits in natural objects (blood serum, diploid cell homogenate etc.) is demonstrated.     

Age-Related Peculiarities of the Control of Respiration and Their Correlation with the Intensity of Free-Radical Processes

We describe the results of a study of the relations between the control of the respiratory function in isocapnic increasing hypoxia and the intensity of free-radical processes in groups of healthy young and aged subjects. It is known that aging is accompanied by some weakening of the response of the respiratory system to hypoxia with no considerable changes in the indices of ventilation in the resting state. Aged subjects, as compared with young tested persons, are characterized by a decrease in the activity of catalase, the absence of significant differences in the activity of superoxide dismutase, and a trend toward an increase in the content of products of lipid peroxidation in the blood. We discuss possible mechanisms mediating age-related modifications in the system of control of respiration and consider shifts in the system of pro/antioxidant balance and intensification of peroxidation processes against the background of a decreased activity of catalase primary changes responsible for the above modifications. These effects lead to modifications of the sensitivity of chemoreceptors responding to a drop in O₂ tension in the blood.     

Sterility of males determined by functional features of the mouse spermatozoa bearing t-complex

The mechanisms underlying normal spermatogenesis and its pathology expressed as male sterility determined by t-complex located on chromosome 17 in mice are considered in this review. t-Complex is a very convenient model with diverse markers of expression of the genes involved in development of the functional features of the spermatozoa bearing t-complex. These features include defects of mobility, capacitation, and acrosome reactions, which determine full or partial male sterility. It has been proposed that the defects of capacitation are also inherent in humans and affect male fertility. This homology is confirmed by the presence of the male gene Tcp11 in humans and demonstration of the fact that the protein TCP11 plays a leading role in modulation of the capacitation of murine spermatozoa. Hence it follows that the defects of human genes leading to incomplete binding of the fertilization promoting peptide could play a certain role in a decreased male fertility. All this is essential not only for deeper understanding of the biology of spermatozoa, but also for development of new therapeutic methods of finding and treating the semen pathology.     

Dynamics of the dominance of identified cardioregulatory neurons in the snail Achatina fulica]

9 cardioregulating neurones belonging to 5 different functional groups were studied in visceral and right parietal ganglia of the Giant African snail Achatina fulica. The neuronal network included multimodal and multifunctional cells exerting short- or long-lasting chronoionotropic effects on the cardiac electro- and mechanograms. Mechanisms of the differences in the cardioregulating effectiveness of these groups were discussed.     

Pseudomonas brassicacearum strain Am3 containing 1-aminocyclopropane-1-carboxylate deaminase can show both pathogenic and growth-promoting properties in its interaction with tomato

The role of bacterial 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity in the interaction between tomato (Lycopersicon esculentum=Solanum lycopersicum) and Pseudomonas brassicacearum was studied in different strains. The phytopathogenic strain 520-1 possesses ACC deaminase activity, an important trait of plant growth-promoting rhizobacteria (PGPR) that stimulates root growth. The ACC-utilizing PGPR strain Am3 increased in vitro root elongation and root biomass of soil-grown tomato cv. Ailsa Craig at low bacterial concentrations (10(6) cells ml-1 in vitro and 10(6) cells g-1 soil) but had negative effects on in vitro root elongation at higher bacterial concentrations. A mutant strain of Am3 (designated T8-1) that was engineered to be ACC deaminase deficient failed to promote tomato root growth in vitro and in soil. Although strains T8-1 and 520-1 inhibited root growth in vitro at higher bacterial concentrations (>10(6) cells ml-1), they did not cause disease symptoms in vitro after seed inoculation, or in soil supplemented with bacteria. All the P. brassicacearum strains studied caused pith necrosis when stems or fruits were inoculated with a bacterial suspension, as did the causal organism of this disease (P. corrugata 176), but the non-pathogenic strain Pseudomonas sp. Dp2 did not. Strains Am3 and T8-1 were marked with antibiotic resistance and fluorescence to show that bacteria introduced to the nutrient solution or on seeds in vitro, or in soil were capable of colonizing the root surface, but were not detected inside root tissues. Both strains showed similar colonization ability either on root surfaces or in wounded stems. The results suggest that bacterial ACC deaminase of P. brassicacearum Am3 can promote growth in tomato by masking the phytopathogenic properties of this bacterium.     

First Philippine record of the parasitoid,Comperiella sp. (Hymenoptera: Encyrtidae): a potential biocontrol agent against Aspidiotus rigidus (Hemiptera: Diaspididae)

The encyrtid genus Comperiella Howard has so far not been reported in the Philippines, where there is currently an outbreak of the coconut scale insect Aspidiotus rigidus Reyne particularly in the southern parts of the island of Luzon and in some areas in Mindanao. Among Comperiella species, only C. unifasciata Ishii has been reported as a parasitoid of A. rigidus. We report not only new sightings of this parasitoid genus in the Philippines from surveys conducted in parts of the provinces of Laguna and Batangas, but also the discovery of a possibly new species that, like C. unifasciata, has been found to parasitize A. rigidus at a high rate. These findings have presented a potential of biological control against the coconut scale insect problem that has threatened the coconut industry in the country.