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191.
Subtyping of Mycoplasma pneumoniae isolates based on extended genome sequencing and on expression profiles 总被引:1,自引:0,他引:1
Dumke R Catrein I Pirkil E Herrmann R Jacobs E 《International journal of medical microbiology : IJMM》2003,292(7-8):513-525
Mycoplasma pneumoniae isolates from patients, collected over a period of 12 years in Germany, were characterized by various methods (parameters) including multilocus sequence typing, restriction fragment length polymorphisms, Western blotting with mono-specific antibodies directed against selected proteins or with polyspecific antibodies directed against the Triton X-114-soluble protein fraction, and two-dimensional gel electrophoresis. The results for 91 isolates from Germany, which were complemented with 14 isolates from the USA and 10 isolates from France, clearly showed that M. pneumoniae is a highly uniform species and that most of the isolates could be assigned to one of the two subtypes 1 and 2. The members of one subtype differ from the other with respect to the sequence of the P1 gene, the ORF6 gene, the P65 gene, and by a typical DNA restriction fragment pattern. We observed four isolates (variants), which seemed identical by the above mentioned criteria, but did not belong to either one of the two subtypes. They showed most of the subtype 2-specific features, but differed in the sequence of the P1 gene and showed a variation in the restriction fragment pattern. The appearance of subtype 1 or 2 over the last 12 years in Germany showed a dominance of subtype 1 between 1989 and 1996 and a dominance of subtype 2 between 1997 and 1998. The variant (neither subtype 1 nor subtype 2) was only detected in 1991 and 1995 but it had no epidemiological consequences. 相似文献
192.
193.
The morphogenesis of testicular degeneration induced in rats by orally administered 2,5-hexanedione 总被引:5,自引:0,他引:5
The neurotoxic hexacarbon 2,5-hexanedione (2,5-HD) produces testicular atrophy in experimental animals. To examine the morphogenesis of the testicular lesion, 1.0% 2,5-HD was provided in the drinking water of adult F-344 rats for up to 6 weeks. After 3 weeks of administration, there were occasional large vacuoles in the basal region of the germinal epithelium. At 4 weeks, these vacuoles were much larger and more numerous; electron microscopy demonstrated that they were derived from the smooth endoplasmic reticulum. The vacuoles were preferentially associated with stages 12, 13, 14, and 1 of the spermatogenic cycle. Additionally, at 4 weeks there was a significant decrease in the number of tubules in stages 7 and 13, and a concomitant increase in the percentage of tubules in stages 3, 5, and 6. By Week 5, most Golgi-phase and cap-phase spermatids were visibly affected, showing margination of nuclear chromatin, and were becoming dissociated from Sertoli cells. Frequent multinucleated giant cells were seen and electron microscopy of these cells suggested that they were derived from fused spermatocytes or spermatids. After 6 weeks, fewer giant cells were present, most tubules contained cellular debris, and many showed empty lumina encircled by a thin ring of cytoplasm near the basement membrane. Interstitial tissue appeared unaffected. These studies indicate that the Sertoli cell is probably an initial target for 2,5-HD action in the testis. 相似文献
194.
A portable device for the rapid concentration of viruses from large volumes of natural freshwater 总被引:2,自引:0,他引:2
A portable device for the rapid concentration of viruses from natural freshwaters described and its performance in field use is evaluated. The system handled up to 500 litres of water in less than 90 min at a cost of only 2 pounds per sample. Where the samples contained sufficient bacteriophages for detection by direct plating the apparent phage recoveries were greater than 75%. Plant and animal viruses were also concentrated from waters with this system. 相似文献
195.
Ernesto Mendes Açucena Raphael Norma G.S. Mota Nelson F. Mendes 《The Journal of allergy and clinical immunology》1974,53(4):223-229
Eighty-nine patients with leprosy, 65 classified as lepromatous and 24 as tuberculoid, were examined in this study. Skin test responses to protein antigens and dinitrochlorobenzene (DNCB) were depressed in lepromatous patients compared to controls. Tuberculoid patients did not exhibit a significant depression to microbial antigens, but they showed a definite depression in the ability to be sensitized with DNCB. The transfer of delayed hypersensitivity reactions to tuberculin, trichophytin, and lepromin (Fernandez and Mitsuda reactions) was accomplished in lepromatous and indeterminate leprosy patients using viable lymphocytes from donors presenting positive reactions to these antigens. The lepromin reaction was also transferred to patients with South American blastomycosis and cutaneous leishmaniasis. The positive reactions of adoptive immunity were confirmed by histologic examination of skin biopsies. 相似文献
196.
Human genes typically contain multiple introns, and in many cases the exons can be joined more than one way to generate multiple rnRNAs, encoding distinct protein isoforms. This process is called alternative splicing. The article summarized the human cytochrome P450 pre-mRNA alternative splicing and their regulatory mechanism and impacts on biological functions. 相似文献
197.
198.
L Léger Y Charnay J A Chayvialle A Bérod F Dray J F Pujol M Jouvet P M Dubois 《Neuroscience》1983,8(3):525-546
The distribution of tyrosine hydroxylase-, substance P- and enkephalin-immunoreactive neurons in the cat dorsolateral pons was studied using the indirect immunofluorescence method of Coons. To allow for the visualization of substance P- and enkephalin-immunoreactive cell bodies, colchicine was injected either in the ventricular space or in the cerebral tissue. The distribution of the tyrosine hydroxylase-immunoreactive cell bodies corresponded with the well-known distribution of catecholamine cells in this area of the brain. The observation of adjacent sections treated separately with tyrosine hydroxylase- and enkephalin-antiserum revealed that most catecholaminergic cells contain enkephalin-immunoreactivity. In addition to this catecholamine-enkephalin cell population, a moderate number of substance P-immunoreactive cell bodies was found in dorsolateral pons. The peribrachial nuclei were found to be densely supplied with substance P- and enkephalin-immunoreactive fibers, whereas the medial subdivisions, which contain the majority of the catecholamine cells in the dorsolateral pons, display a moderate number of immunoreactive fibers. These results are suggestive of interactions between peptide-containing and catecholaminergic neurons and also between-peptide-containing and non-catecholamine-containing neurons in the cat dorsolateral pons. 相似文献
199.
The Thy-1 antigens or rat brain and thymus have been isolated and chemically characterized, but those of mice have not been identified. Moreover, it is uncertain whether the antigens are glycolipids or glycoproteins. This study with highly purified preparations of gangliosides GM1, 1GD1a, GD1b and GT1b from bovine brain and several ganglioside fractions from mouse brain showed that Thy-1 activity does not reside in gangliosides, but rather in the chloroform-methanol-insoluble residue of brain remaining after extraction of gangliosides. The antigen could be solubilized from this residue with a non-ionic detergent. The antigenic activity of the solubilized preparation was heat-labile but resistant to periodate. The chemical properties of the Thy-1 antigen of mouse brain are discussed. 相似文献
200.
Ziganshin AU Zaitsev AP Shamsutdinov AF 《Bulletin of experimental biology and medicine》2002,133(3):255-257
We studied contractile responses of isolated smooth muscles from human uterus induced by P2 receptor agonists. In preparations from pregnant uterus all tested P2 receptor agonists caused smooth muscle contractions. The relative activity of P2 receptor agonists decreased in the following order: a,b-methylene-ATP-uridine triphosphate-ATP. Responses induced by ATP and ADP were similar. The amplitude of contractions induced by alpha,beta-methylene-ATP significantly decreased in the presence of P2 receptor antagonist pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid. None of tested P2 receptor agonists induced contractions of isolated myometrium from nonpregnant women. Our results indicate that pregnant human uterus contains P2 receptors mediating the contractile response. 相似文献