A comparative study of the biological properties of pyelonephritogenic Escherichia coli isolated at different times in the infectious process

The comparative study of the biological properties of E. coli cultures, isolated from the urine of 7 patients two times during the first 11 days from the beginning of clinical manifestations of the exacerbation of chronic pyelonephritis, was conducted. In most cases the strains obtained as the result of the inoculations of the first and second urine samples belonged to the same serological and enzymatic variants. Still bacteria isolated in the second investigation, in contrast to E. coli obtained by the earlier inoculation of urine samples, often had no hemagglutinins and showed low adhesive capacity with respect to uroepithelium. Only in one out of 4 patient E. coli with antigen K1+ could be detected not only after the first inoculation, but also after the second one. In 4 patients E. coli cultures obtained as the result of the second isolation of these bacteria had lower content of sialic acid. Besides, differences in the sensitivity of E. coli strains isolated from the same patients in the course of the infectious process to the action of nonspecific protection factors of the body were established. The results obtained in the course of this study give more precise understanding of the existing conception of the pathogenesis of pyelonephritis.     

Elemental distribution in striated muscle and the effects of hypertonicity: Electron probe analysis of cryo sections

A method of rapid freezing in supercooled Freon 22 (monochlorodifluoromethane) followed by cryoultramicrotomy is described and shown to yield ultrathin sections in which both the cellular ultrastructure and the distribution of diffusible ions across the cell membrane are preserved and intracellular compartmentalization of diffusabler ions can be quantitated. Quantitative electron probe analysis (Shuman, H., A.V. Somlyo, and A.P. Somlyo. 1976. Ultramicros. 1:317-339.) of freeze-dried ultrathin cryto sections was found to provide a valid measure of the composition of cells and cellular organelles and was used to determine the ionic composition of the in situ terminal cisternae of the sarcoplasmic reticulum (SR), the distribution of CI in skeletal muscle, and the effects of hypertonic solutions on the subcellular composition if striated muscle. There was no evidence of sequestered CI in the terminal cisternae of resting muscles, although calcium (66mmol/kg dry wt +/- 4.6 SE) was detected. The values of [C1](i) determined with small (50-100 nm) diameter probes over cytoplasm excluding organelles over nuclei or terminal cisternae were not significantly different. Mitochondria partially excluded C1, with a cytoplasmic/ mitochondrial Ci ratio of 2.4 +/- 0.88 SD. The elemental concentrations (mmol/kg dry wt +/- SD) of muscle fibers measured with 0.5-9-μm diameter electron probes in normal frog striated muscle were: P, 302 +/- 4.3; S, 189 +/- 2.9;C1, 24 +/- 1.1;K, 404 +/- 4.3, and Mg, 39 +/- 2.1. It is concluded that: (a) in normal muscle the "excess CI" measured with previous bulk chemical analyses and flux studies is not compartmentalized in the SR or in other cellular organelles, and (b) the cytoplasmic C1 in low [K](0) solutions exceeds that predicted by a passive electrochemical distribution. Hypertonic 2.2 X NaCl, 2.5 X sucrose, or 2.2 X Na isethionate produced: (a) swollen vacuoles, frequently paired, adjacent to the Z lines and containing significantly higher than cytoplasmic concentrations of Na and Cl or S (isethionate), but no detectable Ca, and (b) granules of Ca, Mg, and P = approximately (6 Ca + 1 Mg)/6P in the longitudinal SR. It is concluded that hypertonicity produces compartmentalized domains of extracellular solutes within the muscle fibers and translocates Ca into the longitudinal tubules.     

Caudate-cortical connections in the cat brain

By means of optical and electron microscopic methods, the cortical fields from the ipsilateral hemisphere was analysed in the cat after electrocoagulation of the dorsal part in the nucleus caudatus (NC). Degenerating axonal preterminals and terminals were detected in the preparations impregnated after Nauta--Gygax and Wiitanen's methods and in electronograms. To exclude degeneration of cortical and projective thalamic fibrillae from the great number of regenerated conductors, additional operations were performed on the same cats--thalamic and ventral NC nuclei were damaged and coagulative electrode was inserted into the dorsal NC a month before the last operation.     

A Lipidomic Approach to the Study of Biodiversity of Symbiotic Dinoflagellates in Millepora Hydrocorals from Vietnam Coral Reefs

Russian Journal of Marine Biology - To assess the biodiversity of symbiotic dinoflagellates (SD) in hydrocorals, we compared the molecular species compositions of four SD lipid classes such as...     

Plant virus infection development as affected by heavy metal stress

The work was focused on the investigation of possible dependencies between the development of viral infection in plants and the presence of high heavy metal concentrations in soil. Field experiments have been conducted in order to study the development of systemic tobacco mosaic virus (TMV) infection in Lycopersicon esculentum L. cv. Miliana plants under effect of separate salts of heavy metals Cu, Zn and Pb deposited in soil. As it is shown, simultaneous effect of viral infection and heavy metals in tenfold maximum permissible concentration leads to decrease of total chlorophyll content in experiment plants mainly due to the degradation of chlorophyll a. The reduction of chlorophyll concentration under the combined influence of both stress factors was more serious comparing to the separate effect of every single factor. Plants' treatment with toxic concentrations of lead and zinc leaded to slight delay in the development of systemic TMV infection together with more than twofold increase of virus content in plants that may be an evidence of synergism between these heavy metal's and virus' effects. Contrary, copper although decreased total chlorophyll content but showed protective properties and significantly reduced amount of virus in plants.     

Parasite fauna from loaches (Cobitidae) of the water basins in Primor'e region

Parasite fauna from loaches was examined in the period 1985-1999 in water basins of different parts of the Primorsk Territory: south (rivers Pojma and Razdolnaya, lake Bol'shoye Mramornoye), north-east (river Yedinka), west (rivers Komissarovka, Ilistaya, Mel'gunovka), center (upper part of the river Ussuri, river Arsen'evka). The 159 specimens of five loache species have been examined. The parasite fauna is represented by 96 species, including 37 protozoan species (flagellates--4, coccidians--2, myxosporidians--10, infusorians--21), plathelminthes--45 (monogeneans--18, trematodes--18, cestodes--9), acanthocephalans--2, nematodes--8, arthropods (crustaceans)--1, mollusks--3 species.     

Contribution of surface salt bridges to protein stability: guidelines for protein engineering

The small globular protein, ubiquitin, contains a pair of oppositely charged residues, K11 and E34, that according to the three-dimensional structure are located on the surface of this protein with a spatial orientation characteristic of a salt bridge. We investigated the strength of this salt bridge and its contribution to the global stability of the ubiquitin molecule. Using the "double mutant cycle" analysis, the strength of the pairwise interactions between K11 and E34 was estimated to be favorable by 3.6kJ/mol. Further, the salt bridge of the reverse orientation, i.e. E11/K34, can be formed and is found to have a strength (3.8kJ/mol) similar to that of the K11/E34 pair. However, the global stability of the K11/E34 variant of ubiquitin is 2.2kJ/mol higher than that of the E11/K34 variant. The difference in the contribution of the opposing salt bridge orientations to the overall stability of the ubiquitin molecule is attributed to the difference in the charge-charge interactions between residues forming the salt bridge and the rest of the ionizable groups in this protein. On the basis of these results, we concluded that surface salt bridges are stabilizing, but their contribution to the overall protein stability is strongly context-dependent, with charge-charge interactions being the largest determinant. Analysis of 16 salt bridges from six different proteins, for which detailed experimental data on energetics have been reported, support the conclusions made from the analysis of the salt bridge in ubiquitin. Implications of these findings for engineering proteins with enhanced thermostability are discussed.     

Parasite fauna of the amur sickleback Pungitius sinensis ( Gasterosteidae) from the Primor'e region

An ecological analysis of parasite fauna occurring in the Amur sickleback in different water basins of the Maritime Territory is carried out. Possible pathways of distribution of this fish within the Maritime Territory is discussed.