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81.
The possibility of producing toxic effects in day-old chicks with mycotoxins from Phomopsis sp. or Diaporthe phaseolorum var. sojae isolates was studied. Evidence was found that Phomopsis sp., but not Diaporthe, produces hepatic necrosis with high mortality in chicks. Enzymatically, the hepatotoxin produced by Phomopsis sp. caused an increase in the level of liver glucose-6-P dehydrogenase. Mycotoxicosis caused by Phomopsis sp. was compared with lupinosis.  相似文献   
82.
Microorganisms actively participate in the transformation of metals and metalloids by various processes including adsorption, absorption, alkylation, oxidation and reduction reactions. Bacteria of the genera Thiobacillus and Sulfolobus have a chemolithotrophic mode of metabolism and catalyze various metal transformations. These bacteria are primarily involved in oxidation-reduction reactions of metals. Metal sulfides can be either directly oxidized by the microbes or oxidized by ferric iron, an end-product of microbial metabolism. These processes result in solubilization of iron, copper, molybdenum, uranium, and many other metals as well. Bacteria capable of these reactions are found, and they function in a variety of environments. Conditions which favor their growth are acidic pH (1.5 to 3.5) and temperatures which can be as high as 75 degrees C for Sulfolobus. The microbes have potential for mobilization of pollutants, or toxic elements, during resource extraction processes. In the absence of oxygen, iron, molybdenum and chromium may be reduced by microbes.  相似文献   
83.
Phospholipase A2 (PLA2) was analysed in seminal plasma of fertile, subfertile, and vasectomized men as well as in prostatic secretion and tissue. Immunological cross-reactivity was observed between synovial-type PLA2 antiserum and the enzyme present in seminal plasma. There was a highly significant correlation between the concentration of the synovial-type PLA2, as measured by a time-resolved fluoroimmunoassay and the catalytic activity of the PLA2. The results show that the PLA2 content in human seminal plasma is very high (approximately 1000 times of that present in blood plasma) and that the enzyme belongs to the synovial-type group II phospholipase A2. The results also indicate that the enzyme is secreted by the prostate.  相似文献   
84.
The mucociliary transport system is usually an important defense system which protects the body against a variety of noxious agents. Reactions of the bronchial mucosa to chronic infections are seen in the ciliated cells, the amount of globlet cells, in modifications of the basement membrane underlying the bronchial epithelium and an altered percentage of inflammatory cells. In ciliated cells the following atypia can be seen: thickening of the ciliar membrane, swollen cilia, formation of compound cilia, disarrangement of microtubules. Common alterations of the basement membrane are: increased diameter of the basement membrane zone, inhomogeneous staining pattern of the basement membrane zone, formation of cytoplasmatic protrusions, formation of double layers of the basement membrane and increased number of cytoplasmatic bound vesicles. Structural abnormalities of the basement membrane will lead to disturbances of the zone of transition and have to be interpreted as a sign of disregulation in the process of diffusion and resorption. The inflammatory response of the epithelium during chronic bronchitis and asthma shows many similarities. The bronchial epithelium has a specific reaction pattern which supports the response against different noxious agents. So all findings have to be interpreted as unspecific pathological changes. All alterations may show different degrees of severity and are dependent on individual pattern and the severity of chronic process. Electronmicroscopical examinations in combination with lightmicroscopical findings and immuno-histochemistry and seen in context with clinical data help to understand the mechanism of the inflammatory process.  相似文献   
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86.
Children grieve differently than adults. Although the unit of care in hospice is the patient and family, emphasis is often on the grown members of the family and the anticipatory grief and bereavement needs of children and adolescents are sometimes not met adequately. In this paper, hands-on strategies for working with children both before and after a significant death are presented, as well as appropriate context information on the grieving process for youth under age 18.  相似文献   
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The yellow-pigmented bacterium isolated from a ditch was a gram negative rod with a G+C content of 63 mol%, and was classified in the genus Sphingomonas. Electron microscopy revealed that the bacterial cell surface was covered with many large plaits. When grown in a medium containing a polysaccharide as an essential nutrient, a pit of 0.02-0.1 micrometers in diameter was formed on the cell surface, and a thin section showed the rearrangement of the plaits and the presence of a region where the cell membrane sinks into the cytosol. The dependence of the pit formation on the presence of macromolecule may predict the existence of a direct uptake mechanism for macromolecules through a mouth-like pit, possibly in endocytosis fashion. The confirmation of the pit structure is the first such finding in the history of microbiology and may provide a new insight into the cell morphology and biochemistry of macromolecule transport in microbial cell system.  相似文献   
90.
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