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201.
Using monoclonal antibodies as probes, we have characterized three antigens with respect to localization in the nucleolus, molecular weight and solubility. Two proteins, of 110,000 and 94,000 apparent molecular weight, were found associated with the ribonucleoprotein fibers. A third protein, with a molecular weight of 40,000, was accumulated at the nucleolar periphery, was present in the nucleoplasm, and may be involved in pre-ribosome maturation and transport. 相似文献
202.
Pleiotropic effects of a butyrolactone-type autoregulator on mutants of Streptomyces griseus blocked in cytodifferentiation 总被引:1,自引:0,他引:1
U Gr?fe G Reinhardt D Krebs I Eritt W F Fleck 《Journal of general microbiology》1984,130(5):1237-1245
Mutants of Streptomyces griseus blocked in cytodifferentiation regained their capacity to form differentiated mycelia and/or anthracycline pigments in the presence of butyrolactone-type autoregulatory effectors such as trans-2-(6'-methylheptanol-1'-yl)-3-hydroxymethyl-4-butanolide+ ++. In the pertinent indicator strains, the effect has been correlated with the increase of lipid synthesis, with changes in the composition of lipid fraction and with the restoration of the production of neutral proteinases. The results suggest that autoregulatory butyrolactones from streptomycetes stimulate cytodifferentiation of their producers at an early stage of development. 相似文献
203.
Typhlopolycystis rubra, a new species of the taxon Polycystididae (Plathelminthes, Kalyptorhynchia), is described. The red species is characterized
by copulatory hard structures which consist of a proximal girdle and 2 similar sized stylets.T. rubra occurs in intertidal sand near the island of Sylt in the North Sea. Here, it is virtually confined to the lowest parts of
lugworm (Arenicola marina) burrows, where it aggregates in the coarse grained sand around the feeding pocket areas. This is an extremely narrow spatial
niche within the sulfide layer of sediment. Population size over a period of 7 years is the most constant one among all species
of Plathelminthes living on the tidal flat. The ability ofT. rubra to endure unsuitable conditions inside a cyst may contribute to this remarkably low population variability. 相似文献
204.
A superiorly based rectus abdominis muscle flap was successfully used to reconstruct an infected elbow wound with exposed bone and metal screws. We could find no previous report describing the use of this muscle to cover elbow defects. 相似文献
205.
206.
207.
The uptake of nutrients was investigated in the renal cortical brush border membrane (BBM) vesicles at different stages of ascending pyelonephritis. There was significant difference (p less than 0.05) in the uptake of D-glucose, L-alanine, L-aspartate, L-lysine and L-proline 3 days postinfection and onwards in both right unobstructed and left obstructed experimental kidneys as compared to the sham operated control. The uptake of D-glucose, L-lysine and L-proline was found to be significantly decreased (p less than 0.05) during the course of infection. While uptake of L-alanine and L-aspartate increased (p less than 0.05) in early stages and decreased (p less than 0.05) in later stages of infection. The differential effect was attributed to the compensatory measure and different kinds of transport systems for different types of amino acids. 相似文献
208.
Summary A new species of Rhynchoidomonas Patton was observed in a single adult male winter moth, Operophtera brumata (L.) from England. Intracellular amastigotes, and extracellular epimastigotes and trypomastigotes with an undulating membrane and free flagellum, were present. All stages had a large, reniform kinetoplast. As transmission of the flagellate between generations of winter moths by ingestion of infected faeces is a virtual impossibility, it is suggested that the flagellate's true host may have been a dipteran parasitoid and that an egg, surface-contaminated with the flagellate, was oviposited into or ingested by a winter moth larva. If the parasitoid had died, this flagellate infection could have been carried over to the adult moth. ac]19830601 相似文献
209.
F S Larin V U Buko T I Zimatkina D O Oparin Iu M Ostrovski? 《Ukrainski? biokhimicheski? zhurnal》1986,58(5):89-91
Thiochrome caproate modified by the oxyethyl radical of the thiochrome derivative was studied for its effect on different indices of lipid metabolism in the liver and blood of albino rats. It was shown that when animals were fed on a standard laboratory diet, thiochrome caproate changed the amount of total and free fatty acids in the studied tissues and the fatty acid composition in the liver to a greater extent than thiochrome and hydroxythiamine. 相似文献
210.
Promoters of Escherichia coli: a hierarchy of in vivo strength indicates alternate structures. 总被引:41,自引:5,他引:36 下载免费PDF全文
The strength in vivo of 14 promoters was determined in a system which permits the quantitation of RNA synthesis with high accuracy. Up to 75-fold differences in promoter strength were measured and the most efficient signals are promoters from coliphages T7 and T5. Their activity approaches the strength of fully induced promoters of the rRNA operons which may be close to the functional optimum of a single sequence. By contrast, a synthetic 'consensus promoter' belongs to the less efficient signals. Our data show that optimal promoter function can be achieved by alternate structures and strongly suggest that information outside of the 'classical' promoter region contributes to promoter activity. 相似文献