Ultrastructural changes in the liver in experimental diffuse peritonitis

Experiments were performed to detect "alkali" and "acid" carboxypeptidases in 39 enzymic preparations from fungi, yeast, actinomyces, bacteria and algae. Distribution of both types of carboxypeptidases is different: they are absent in the six of the studied sources, there are no "acid" carboxypeptidases in 11 sources and no "alkali" in nine ones. The largest amount of carboxypeptidases is in the objects from fungi and actinomycetes, the least, in those from bacteria and algae. There is no correlation between synthesis of these enzymes by one microorganism. Thus, fungi produce mainly "acid" enzymes, and actinomycetes only "alkali" ones. Asp. oryzae and Asp. flavus are powerful producers of the former, Streptomyces griseus of the latter. Specific activities 15-20 times as high as all the already studied ones are obtained for the preparations isolated from Str. griseus (protezym, proteinase-1, proteinase-3, crystal line complex of proteases). Carboxypeptidase of Str. griseus is relatively stable in comparison with "acid" ones in purification and concentration.     

Body temperature changes during combined inhalational and epidural anesthesia

Glycation of basement membrane collagen IV has been implicated as a major pathogenetic process leading to diabetic microvascular complications. To evaluate the relevance of carbohydrate-induced modifications on collagen IV in diabetic nephropathy, we isolated the cross-linking domains 7S and NC1 from the glomerular basement membrane (GBM) of patients with diabetes mellitus. Modifications characteristic for glycated proteins were identified when the domains from diabetic kidney were compared with the same domains from human placenta as an unmodified control. In both domains a marked formation of inter-and intramolecular cross links could be demonstrated by SDS-PAGE. Furthermore circular dichroism studies showed a decrease in helicity of the 7S domain from human diabetic kidneys of 13%, indicating denaturation already at room temperature. Thermal transition profiles, showing a shift of the denaturation temperature towards a lower temperature, with loss of a distinct second melting point, confirmed this observation. Our data provide further evidence for a possible role of protein-modification by glycoxidative reactions in the onset of diabetic nephropathy in vivo.     

Ultrastructural and biochemical enzymatic properties of right ventricular muscles during hindlimb suspension in rats

As a result of exposure to microgravitational forces, the body fluids are shifted from lower part of the body to upper part with a volume of about 2 liters. Many reports on the hemodynamic, humoral, and other biomedical aspects of the body exposed by weightlessness have been reported. A 45 degree head-down tail suspension was introduced to examine ultrastructure and biochemical analyses on the right and left ventricles in rats. Increases in oxydative enzyme activities and relatively increase in m-CK(mitochondrial creatine kinase) were recognized in the right ventricle after suspension for 2 weeks. Mitochondrial volume and density of mitochondrial cristae were also increased. Direct measurement of right ventricular systolic pressure of suspended rats were significantly higher (28.99 +/- 3.11 mmHg) than that of control rats (20.99 +/- 2.94 mmHg), (p < 0.01).     

Volatile anesthetics in general anesthesia with mechanical ventilation. Statistical comparison of fluothane and ethrane

Spleen cells collected from mice bearing transplanted chemically induced syngeneic fibrosarcomas non-specifically inhibited DNA synthesis of sarcoma and lymphoma target cells in vitro. Splenocytes from mice hyper-immunized against a syngeneic sarcoma specifically inhibited DNA synthesis of the tumour used for immunization. The impairment of tumour-cell DNA synthesis was associated in vitro with cytostasis, and lysis of the target cells was not seen. Since treatment with anti-theta serum and complement did not impair cytostatic action of the spleen cells, and since thymus-deprived animals showed similar activity to normal mice, T lymphocytes were not involved in non-specific cytostasis. Removal of phagocytic adherent cells by carbonyl iron markedly inhibited the cytostatic activity of the spleen cells, suggesting a role in this reaction for cells of the monocyte-macrophage series. The presence of an actively growing sarcoma was a prerequisite for the expression of non-specific cytostasis, since surgical excision resulted in complete disappearance of this activity of spleen cells.     

Ultrastructural changes in the supraoptic nucleus and posterior lobe of the pituitary following experimental burns

The dynamics of the ultrastructure of the neurosecretory system in the postburn period is characterized by phasic of organells of neurosecretory cells and synapses on their bodies and processes. Immediately after burn there appear pronounced signs of an increased formation of secretion synchronous to a considerably increased functional activity of synaptic structures. Of the opposite character are fine structures in neurocytes in the subsequent period (1-1,5 hour after burn). Phenomena of disintegration and degeneration of organells are developing in the cells. In the posiologically active neurohormones and degeneration of membrane structures gradually increase at all the observed stages of the burn trauma. All the elements of the supraoptic nucleus and the posterior lobe of the hypophysis early responding to the effect of such a powerful extreme factor are involved in the response of the organism to burn. It should be noted that immediately after burn there appears an increased permeability of capillaries followed by extravasation of formed elements and liquid blood. It steadily increases with the development of the process.     

Morphological changes of clefts in Plasmodium-infected erythrocytes under adverse conditions

Blood infected with human or rodent malaria parasites, Plasmodium falciparum or Plasmodium berghei, was exposed to higher pH, higher PO2, and lower temperature than those used in standard cultivation conditions. Parasitized blood was incubated for 20, 25, and 30 min with RPMI 1640 medium, 10% (vol/vol) serum, pH 8.0, at 20 degrees C in the air, conditions which are ultimately lethal to the asexual stages of malarial parasites. Markedly dilated clefts were observed in the cytoplasm of the malaria-infected erythrocytes so treated. These clefts can take up colloidal gold particles and macromolecules such as Protein A, rhodamine-dextran, and lucifer yellow-dextran. Such dilated clefts were not seen in the cytoplasm of infected erythrocytes that were incubated under normal cultivation conditions before fixation. These had slender clefts of the usual sort that did not take up colloidal gold particles and macromolecules.     

Ultrastructural changes in the cell center during enterocyte differentiation in the mouse

Centrioles in the enterocytes of murine small intestine are located far away from the nuclei and close to the apical surface of cells (1-3 microns from the brush border). Centrioles never form a primary cilium and are not attached to the plasma membrane. Centrosomes (cell center) in enterocytes undergo subsequent involution in respect to the position of cell in the crypt-villus system. Five zones were studied separately: the bottom of the crypt (approx. 1/3 of the appendix), the upper part of the crypt (before its transition into the villus), the basal part, the middle and top of the villus. A centrosome in the crypt contains two centrioles (maternal and daughter) located close to each other. In 10 of 27 cells studied centrioles were replicating. A maternal centriole has 2-3 pericentriolar satellites and appendages. Several cytoplasmic microtubules run towards mother centrioles. Centrioles at the upper part of the crypt split at a distance up to 1.5 microns from each other. The average number of cytoplasmic microtubules and pericentriolar satellites decreases. At the basal part of the villus, centrioles split a distance up to 5 microns from each other; seldom microtubules may be found in a radius of 1 micron around centrioles and none of them is attached to centrioles or satellites. Starting from the middle of the villus, centrioles sometimes may have incomplete triplets of microtubules at the distal and (or) the proximal end. At the upper part of the villus there is only one centriole per cell, that was found in 10 of 50 cells studied on a complete series of 0.2 micron thick sections.     

The adaptive characteristics of the small intestine under chronic experimental conditions

The influence of local substrate loads, both monomeric (glucose) and dimeric (saccharose) ones, on the interrelations between the hydrolysis and transport processes was studied under conditions of a chronic experiment on rats with isolated portions of the small intestine. The use of different substrate loads (glucose, saccharose) made it possible to reveal a difference in the response of various portions of the small intestine. The distal portions are more sensitive to loading than the proximal ones.     

Perceptual reactivity to threat and neutral words under varying experimental conditions.

30 male and 30 female introductory psychology student volunteers were randomly assigned by sex to one of 3 experimental groups and were tested for perceptual reactivity to threat and neutral words matched for word frequency. The experimental groups differed only in terms of induced strength of expectation for threat words from 0% to 100%. Findings support the prediction that the discrepancy between threat and neutral word thresholds decreases as strength of set for threat stimuli increases. However threat words were found to have higher report thresholds than neutral words in all conditions. 18 references. (PsycINFO Database Record (c) 2010 APA, all rights reserved)