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Phosphomannosyl receptors of lysosomal enzymes in cardiac and skeletal muscles of young and old mice 总被引:1,自引:0,他引:1
A Salminen V Marjom?ki 《Comparative biochemistry and physiology. B, Comparative biochemistry》1985,82(2):259-262
The endogenous activity and the binding of high-uptake beta-N-acetylglucosaminidase were assayed in the membranes of heart and skeletal muscles of young (2 months) and old (15 months) NMRI-mice (Mus musculus) to evaluate the age-related changes in the phosphomannosyl receptors of lysosomal enzymes in muscular membranes. The total activities of beta-N-acetylglucosaminidase were significantly higher in cardiac and skeletal muscles of old than young mice. The total and the specific (inhibited by mannose-6-phosphate) binding of beta-N-acetylglucosaminidase to the membranes of cardiac muscle, but not to those of skeletal muscle, were higher in old mice than in young ones. The endogenous activity of beta-N-acetylglucosaminidase was significantly higher in the membranes of skeletal muscles of old mice than in those of young mice. The membranes of heart muscles did not show any difference in the endogenous activities. The saturation properties of the binding of beta-N-acetylglucosaminidase to the phosphomannosyl receptors were very similar in the membranes of heart and skeletal muscles of both age groups. We conclude that during aging the number of phosphomannosyl receptors of lysosomal enzymes increases in the membranes of heart muscle while the occupancy of phosphomannosyl receptors with endogenous ligands increases in the membranes of skeletal muscle. 相似文献
3.
Comparative studies of effect of auxin and ethylene on permeability and synthesis of RNA and protein 总被引:2,自引:2,他引:0 下载免费PDF全文
The effects of ethylene on permeability and RNA and protein synthesis were assayed over a 6 to 26 hr period in tissue sections from avocado (Persea gratissima Gaertn. F., var. Fuerte), both pulp and peel of banana (Musa sapientum L., var. Gros Michel), bean endocarp (Phaseolus vulgaris L., var. Kentucky Wonder Pole beans) and leaves of Rhoeo discolor. Ethylene had no effect on permeability in 4 of the 5 tissues, but sometimes enhanced solute uptake in banana peel; it had either no effect or an inhibitory effect on synthesis of RNA and protein in sections from fruits of avocado and banana. Auxin (α-naphthalene acetic acid) stimulated synthesis of RNA and protein in bean endocarp and Rhoeo leaf sections, whereas ethylene inhibited both basal and auxin-induced synthesis. It is concluded that in these tissues the auxin effect is not an ethylene effect. 相似文献
4.
The effect of household smoking, as carried out with three commercially available smoke boxes, on the infestiveness of Diphyllo-bothrium latum was investigated. The temperature changes in fish during the smoking were measured and the effect on tapeworm larvae estimated on the basis of a lethal temperature/time exposure of 56°C/5 min. For all the boxes smoking treatments sufficient to destroy the tapeworm larvae are suggested. The obtained results confirm the conclusion, made in previous studies on other heat preparation methods of fish, that well cooked fish in which all the parts have been subjected to a 56°C/5 min. exposure is safe with regard to the risk of Diphyllobothrium latum infestation. 相似文献
5.
Formation of Novel Polysaccharides by Bradyrhizobium japonicum Bacteroids in Soybean Nodules 总被引:2,自引:1,他引:1 下载免费PDF全文
John G. Streeter Seppo O. Salminen Robert E. Whitmoyer Russell W. Carlson 《Applied microbiology》1992,58(2):607-613
Certain strains of Bradyrhizobium japonicum form a previously unknown polysaccharide in the root nodules of soybean plants (Glycine max (L.) Merr.). The polysaccharide accumulates inside of the symbiosome membrane—the plant-derived membrane enclosing the bacteroids. In older nodules (60 days after planting), the polysaccharide occupies most of the symbiosome volume and symbiosomes become enlarged so that there is little host cytoplasm in infected cells. The two different groups of B. japonicum which produce different types of polysaccharide in culture produce polysaccharides of similar composition in nodules. Polysaccharide formed by group I strains (e.g., USDA 5 and USDA 123) is composed of rhamnose, galactose, and 2-O-methylglucuronic acid, while polysaccharide formed by group II strains (e.g., USDA 31 and USDA 39) is composed of rhamnose and 4-O-methylglucuronic acid. That the polysaccharide is a bacterial product is indicated by its composition plus the fact that polysaccharide formation is independent of host genotype but is dependent on the bacterial genotype. Polysaccharide formation in nodules is common among strains in serogroups 123, 127, 129, and 31, with 27 of 39 strains (69%) testing positive. Polysaccharide formation in nodules is uncommon among other B. japonicum serogroups, with only 1 strain in 18 (6%) testing positive. 相似文献
6.
Full-length sequence and mosaic structure of a human immunodeficiency virus type 1 isolate from Thailand. 总被引:15,自引:9,他引:6 下载免费PDF全文
J K Carr M O Salminen C Koch D Gotte A W Artenstein P A Hegerich D St Louis D S Burke F E McCutchan 《Journal of virology》1996,70(9):5935-5943
Human immunodeficiency virus type 1 isolates of envelope genotype E are contributing substantially to the global pandemic. These strains appear to be mosaics, with the gag gene from clade A and the envelope from clade E; the parental clade E strain has not been found. Here we report the first full genomic sequence of one such mosaic virus, isolate CM240 from Thailand. Multiple breakpoints between the two parental genotypes have been found in a CM240 virus. The entire gag-pol region and most, if not all, of the accessory genes vif, vpr, tat, rev, and vpu appear to derive from clade A. The genotype switches to E shortly after the signal peptide of the envelope and back to clade A near the middle of gp41; thus, the portion of the envelope that lies on the cytoplasmic side of the membrane appears to be principally derived not from clade E, as previously thought, but from clade A. Another small segment not belonging to any recognized clade and presumably also contributed by the parental E strain has been found in the long terminal repeat. It may be significant that the implied virion structure resembles a pseudotype virus with the matrix and core from one clade and the outer envelope from another. In the long terminal repeat, differences were observed between CM240 and other clades in the number of NF-kappa B binding sites, the sequence of the TATA box, and the putative secondary structure of the transactivation response region stem-loop. The mosaic structure of a CM240 virion is suggestive of phenotypic differences which might have contributed to the emergence of this variant. 相似文献
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Evolution and probable transmission of intersubtype recombinant human immunodeficiency virus type 1 in a Zambian couple. 总被引:5,自引:3,他引:2 下载免费PDF全文
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Summary Adult, untrained NMRI mice were exhausted on a motor-driven treadmill by an intermittent-type running programme. Serial cryostate sections for the staining of NADH-tetrazolium reductase, -glucuronidase, -N-acetylglucosaminidase, and -glycerophosphatase activities and for making hematoxylin-eosin staining were cut from m. quadriceps femoris 1, 2, 3, 5, 7, and 15 days after physical exhaustion. A strong increase in the activities of -glucuronidase and -N-acetylglucosaminidase, was observed 7 days after exhaustion and the activity changes, which were similar for the both glycosidases, were more prominent in the highly oxidative red compared to less oxidative white fibres. Activity granules were more numerous in the perinuclear than the interfibrillar area of red fibres. Spots were arranged like longitudinal chains between myofibrils. Activity in connective tissue was usually observed only in animals exhausted 3–7 days earlier. Simultaneous activity in fibres exceeded that in connective tissue -Glycerophosphatase activity was not, by the method used, seen in histologically healthy or normal-looking fibres. in samples taken 2–5 days after exhaustion some degenerating and necrotic fibres were observed. Inflammatory reaction was also observed being at its strongest five days after loading when mononuclear cells were seen inside necrotic fibres. The number of regenerating muscle cells was most abundant 7 days after exhaustion. It is suggested that temporary hypoxia, which accompanies exhaustive physical exercise in skeletal muscle, upsets the energy metabolism and homeostasis of fibres and causes the observed histological and histochemical alterations, which posses features typical of both lethal and sublethal acute cell injury. 相似文献