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851.
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Summary It was shown by experiments with staining reactions performed in situ in blood smears of adults and children, in sections prepared by various procedures, in spot tests, and by chromatographic examination of extracted lipids that haemoglobin is responsible entirely for the staining of red blood cells in the acid haematein test and for the greater part for the staining in the OTAN reaction. The acid haematein test is from the point of view of lipid histochemistry neither specific nor sensitive. On the other hand the OTAN reaction is sensitive although it is not specific. It is concluded that the extraction test with chloroform-methanol must always be performed when the lipidic nature of the demonstrated substance(s) is to be proved unequivocally and that the non-lipidic nature of the residual staining must be always considered. 相似文献
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Abstract— 5-HT was injected intravenously in rats (10 mg/kg) and a marked increase in brain 5-HT and 5-HIAA was observed. For the first 10 min after injection the penetration of 5-HT into the brain and formation of 5-HIAA is evident. After 10 min degradation of exogenous 5-HT and elimination of 5-HIAA are prominent. Metabolism of exogenous 5-HT in the brain is very fast (half-life between 5 and 10 min; completely metabolized in approximately 80 min). The importance of these results in explaining the permeability of blood-brain barrier to 5-HT is discussed. Experiments on brain slices show that 5-HT is more readily metabolized in brain tissue than eliminated into incubation medium. In contrast, 5-HIAA very easily leaves brain tissue. 相似文献
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858.
1. The reactions of beta-propiolactone with amino acids were investigated under various conditions of pH and temperature to find those under which the reagent acted with specificity. 2. At pH9.0 and 22 degrees , after 15min. of reaction, at least 85% of each amino acid had reacted, methionine and cystine being the most reactive. 3. At pH7.0 and 22 degrees most amino acids reacted; methionine, cystine and histidine reacted almost entirely, and proline and lysine to a significantly smaller extent. 4. At pH3.0 and 22 degrees further specificity was obtained; methionine and cystine were the only reactive amino acids. 5. Reaction at pH3.0 and 0 degrees was specific for methionine; it was the only amino acid modified even after 145hr. of reaction. 相似文献
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860.