Epiedmiologic significance of the distribution of corynephages in different collectives]

Corynephage distribution was studied in the nasopharyngeal washings of 252 persons infected with C. diphtheriae of gravis type, toxigenic (21 patients and 147 carriers) and non-toxigenic ones (84 carriers), and in 468 uninfected persons in collective bodies under different epidemic conditions. Corynephages were isolated from the nasopharyngeal washings only in persons infected with toxigenic C. diphtheriae--in 4 (of 21) patients, and in 21% (of 147) carriers. Phages tox+ (4--6.2%) were revealed only in carriers of toxigenic C. diphtheriae with numerous bacteria in the nasopharynx and in diphtheria patients. Carriers of nontoxigenic diphtheria bacilli can become infected with phage tox+ only together with the toxigenic strains (reinfection). The data obtained indicated that toxigenic and nontoxigenic C. diphtheriae strains were individual variants.     

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.     

The Growth,Population Size Structure,Physiological Changes,and Ultrastructure of the Microalga Picochlorum maculatum (Chlorophyta) under Sublethal Copper Concentrations

Russian Journal of Marine Biology - This study examines the effect of copper (100 and 200 μg/L) on the cell number dynamics, cell size and ultrastructure, chlorophyll a fluorescence,...     

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.     

Specific features of humoral immunity in cryptogenic fibrosing alveolitis patients

Cryptogenic fibrosing alveolitis (CFA) is a severe autoimmune disease of unclear etiology and prognostically unfavorable. The complexity of the diagnostics of this disease makes it necessary to search for new methods; for this reason immunity in CFA patients must be studied. The study of humoral organ-specific, organ-unspecific and antibacterial immunity of CFA patients revealed that the latter differed from the members of the groups used for comparison by a higher frequency of positive reactions in EIA determinations of IgG antibodies to cytokeratin-8 and Moraxella catarrhalis antigens. In addition, only in CFA patients a high degree of correlation (r=0.88) between these results was established. This made it possible to propose to use these reactions for confirming the diagnosis of CFA and suggested the probable role of M. catarrhalis in triggering autoimmune reactions characteristic of this disease.     

The influence of neonatal ketamine injection on pain sensitivity and audiogenic seizures in adult rats

The remote effects of neonatal (on the 3d-to-9th postnatal days) ketamine injections (10 and 50 mg/kg in 20 microliters of distilled water, s.c.) were analyzed in adult Wistar, WAG/Rij, and KM (a strain with high audiogenic sensitivity) rats. Both ketamine and water injections increased pain sensitivity in adult rats. Neonatally injected water increased the mean score of seizures in Wistar and WAG/Rij, whereas ketamine water solution injected in the dose of 50 mg/kg did not change the seizure intensity (as compared to the intact control). Consequently, ketamine significantly reduced the mean score of the audiogenic seizure fit without change in its latency. In highly sensitive KM rats the neonatally injected ketamine (50 mg/kg) significantly shortened the mean latency of the fit onset, and fit stages developed faster. Thus, the neonatal ketamine injection increased the audiogenic seizure susceptibility of brain structures in KM rats.     

Influence of changes in sea water salinity on the growth,photosynthetic pigment content,and cell size of the benthic alga <Emphasis Type="Italic">Attheya ussurensis</Emphasis> Stonik,Orlova et Crawford, 2006 (Bacillariophyta)

The study deals with the effect of changes in salinity from 32 to 4‰ (at an interval of 4‰) on the growth, chlorophyll a and carotenoid contents, and cell size of the benthic alga Attheya ussurensis (Bacillariophyta). A. ussurensis showed high tolerance to reduced salinity and ability to adapt to salinity changes from 16 to 12‰. In this salinity range, the cells restored their shapes, sizes, and physiological functions. The number of cells and photosynthetic pigment content were highest at a salinity reduction to 24‰. At 8‰, algal cells remained alive, but the process of cell division was inhibited; as a result, the number of cells was significantly lower than in the control, the cells did not restore their sizes and shapes and remained deformed until the end of the experiment. A drop in salinity to 4‰ caused a complete loss of cell viability of A. ussurensis within a day of exposure to this factor.     

Neonatal injections of pharmacological agents and their remote genotype-dependent effects in mice and rats

Experimental data were reviewed which demonstrated that the neonatal injection effects of certain biologically active drugs (ACTH_4?C10 fragment and its analogue Semax, piracetam, caffeine, levetiracetam, busperone, etc.) could be detected in adult animals as changes in physiological and behavioral reactions and in several morphological traits as well. Audiogenic seizures proneness, anxiety-fear and exploration behavior as well as pain sensitivity were analyzed. The remote effects discovered were either similar in direction to those applied to an adult organism, or opposite to it. Pharmacological treatments of such type presumably interfere the CNS development during early postnatal ontogeny and change the normal pattern of brain development. These modulatory influences could be due to changes in neurotransmitter system development and are presumably capable to induce CNS morphological deviations (numbers of neurons, adult neurogenesis).