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21.
Early iron deficiency in rat does not affect the weight or the protein, DNA, and RNA content but results in a slight reduction in gamma-aminobutyric acid (GABA) (13%, p less than 0.01) and glutamic acid (20%, p less than 0.001) content of the brain. The activities of the two GABA shunt enzymes, glutamate dehydrogenase and GABA-transaminase, and of the NAD+-linked isocitrate dehydrogenase (ICDH) were inhibited whereas the glutamic acid decarboxylase, mitochondrial NADP+-linked ICDH, and succinic dehydrogenase activities remained unaltered in brain. On rehabilitation with the iron-supplemented diet for 1 week, these decreased enzyme activities in brain attained the corresponding control values. However, the hepatic nonheme iron content increased to about 80% of the control, after rehabilitation for 2 weeks. A prolonged iron deficiency resulting in decreased levels of glutamate and GABA may lead to endocrinological, neurological, and behavioral alterations. 相似文献
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A rapid method for preparation of plasma membrane fromAcanthamoeba culbertsoni involving toluene treatment followed by lithium bromide extraction is described. In the plasma membrane preparation,
5′-nucleotidase, Na+ + K+ -ATPase, Mg2+ -ATPase and glucose-6-phosphatase activities were enriched. The membrane preparation was free from nucleic acid, cytochrome
P-450 and cytochrome b5. Amino acid (14C-Ieucine) was not incorporated in the plasma membrane in 2 min. Succinic dehydrogenase was not detectable in the plasma membrane
preparation. The molar ratio of cholesterol and phospholipids was 0.95 which is characteristics for plasma membranes. Under
electronmicroscopy the preparation was homogenous without any other component of the cell. Plasma membrane proteins and glycoproteins
were separated on acrylamide gel electrophoresis 相似文献
24.
The intensitive investigations on the lipid profile of Thiobacillus ferrooxidans at various culture ages suggest some correlations of the lipid constitutents with the membrane-bound iron oxidation system. Phosphatidic acid, phosphatidyl serine and phosphatidyl ethanolamine were the major polar components; hydrocarbon, triglyceride and diglyceride were the main neutral components. Major fatty acids were C16:0, C16:1, C16:3, C18:1, C18:3, C22:1 while C20:1, C20:2, C12:0, C14:2, C18:0, C18:2, C20:0, C22:0 were found in trace amounts which also depended upon the phase of the growth. One lipoamino acid was identified as ornithine lipid in the polar fraction. Each and every component varied to some extent at different growth phasesindicating relationship of these lipids to the iron oxidation system of the strain. 相似文献
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Improved synthesis of oligodeoxyribonucleotide using 3-methoxy-4-phenoxybenzoyl group for amino protection. 总被引:1,自引:1,他引:0 下载免费PDF全文
3-Methoxy-4-phenoxybenzoyl group has been used for the protection of exocyclic amino group of nucleosides. In case of 2'-deoxycytidine it has been found to be highly selective under controlled conditions. The N-protected derivatives of 2'-deoxyadenosine and 2'-deoxyguanosine have been found to be sufficiently stable towards acids minimising depurination under conditions of synthesis of oligodeoxyribonucleotide on solid support via phosphotriester approach. The high lipophilicity of the group and milder deprotection conditions are additional advantages. 相似文献
27.
Summary Organic matter has been found to be closely associated with the retention of manganese in an exchangeable form. The destruction of organic matter or its addition decrease or increase the exchangeable form of manganese respectively.The removal of iron and Fe2O3 addition greatly affect the retention of manganese. An increase in Fe2O3 addition increases the retained, reducible and fixed forms (R, r and F values) of manganese in soils. 相似文献
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Summary The sieve plate pores of Salix caprea in preparations fixed in glutaraldehyde are normally found to be occupied by slime fibrils showing periodic banding such as occur in a number of other species. Arguments are put forward to suggest that the occurence of fibrils in this position is natural and not an artefact of preparation. The sieve tubes further possess prominent and persistent nucleoli showing a radiating structure of tubules. The endoplasmic reticulum often occurs in parietal stacks reminiscent of other species.This evidence is discussed in relation to the electroosmotic theory of translocation.This work formed part of that submitted for the degree of Ph. D. of the University of London by U. Mishra. 相似文献
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Summary The use of paraffin bait technique in the isolation ofNocardia asteroides has been tested in 241 samples of sputa obtained from 235 cases of respiratory diseases.N. asteroides was recovered on 6 occasions from sputum of a patient using the paraffin bait technique. On the other hand cultures of sputa from the same patient on routine agar media such as Sabouraud's agar and Lowenstein Jensen medium yielded only one isolated of the pathogen.This work forms a part of the Ph. D. thesis of P.V.K. submitted to the University of Delhi. 相似文献
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