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11.
A computer program and accompanying data matrix have been prepared for bacteria of medical interest, to assist the assignment of an unidentified bacterium to the most likely genus. The results on a set of relatively simple tests are entered. The program prints the more likely genera, followed by a list of diagnostic tables in Cowan & Steel (1974) and Buchanan & Gibbons (1974). Where available, identification matrices for further computer-assisted study, are presented. This program may be of particular help in laboratories where a wide range of bacteria have to be identified. 相似文献
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Summary The ultrastructure of the nerves forming the submucous plexus of cervical and thoracic parts of the trachea was studied in the guinea-pig. Specimens were obtained from 6 animals perfused with warm fixative and from 6 animals in which pieces of trachea were incubated in buffer containing 5-hydroxydopamine before being immersed in cold fixative. Of the two types of axonal terminal identified in the nerves, one contained mainly large dense-cored vesicles, and the second contained numerous small vesicles. In specimens incubated in 5-hydroxydopamine, the small vesicles of the latter terminals exhibited the electron-dense cores which are characteristic of adrenergic axonal terminals. Counts made on perfused specimens showed that, in both the thoracic and cervical parts of the trachea, the density of adrenergic terminals was higher than that of terminals containing mainly large dense-cored vesicles. Overall terminal density was, however, higher in the thoracic than in the cervical part of the trachea, and estimates of nerve size showed that this was associated with the presence in the thoracic plexus of a substantially greater proportion of nerves with less than 6 axons. The possible function of the nerves in the control of the calibre of the submucous blood vessels was discussed. 相似文献
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Elizabeth J. Cartwright Pauline Harrington Louise Norbury Gareth Leeming Paul T. Sharpe 《Bioscience reports》1992,12(1):57-67
Rat sperm isolated from the caput and caudal epididymis and the vas deferens were subjected to multiple partition in aqueous two-phase systems. The technique was used to reveal heterogeneity of a sperm population with respect to particular surface properties. Sperm from all three regions gave broad distributions indicative of heterogeneous cell populations. Greatest heterogeneity was observed for cauda sperm with caput and was sperm producing similar distributions.Following multiple partition sperm from different regions of the distribution profiles were immunostained with three antibodies known to recognise maturation antigens. The results show that some antigens are acquired during epididymal transit whilst others are present throughout.The partition (surface heterogeneity) seen cannot therefore be explained solely by the distribution of the antigens recognised by 2D6, 6B2 and 3D5. 相似文献
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Androgens classified as nonaromatizable in placental assay systems typically do not mimic testosterone's effects on sexual behavior in rats. 6α-Fluorotestosterone is an exception. To pursue this challenge to the aromatization hypothesis, we compared several behavioral and neuroendocrine effects of 6α-fluorotestosterone propionate (6α-fluoro-TP) with those of testosterone propionate (TP). Even at a very low dose (6.25 μg/100 g/day), 6α-fluoro-TP maintained most aspects of male sexual behavior as well as TP. It was slightly less potent than TP for inhibiting gonadotropin secretion (testicular development) in prepubertal males. Given neonatally, these androgens were equally likely to induce anovulatory sterility. 6α-Fluoro-TP defeminized sexual development in females and neonatally castrated males half as effectively as TP based on lordosis:mount ratios following estrogen and progesterone therapy in adulthood. Neither androgen masculinized sexual behavior. The behavioral effects of 6α-fluoro-TP correspond to its ability to inhibit cell nuclear accumulation of 17β-[3H]estradiol in the hypothalamuspreoptic area. When injected on a schedule like that used to activate male sexual behavior, the two androgens reduced estrogen uptake equally. When injected into adult castrates on a schedule like that used to defeminize sexual development, 6α-fluoro-TP blocked estrogen uptake half as well as TP. 6α-Fluorotestosterone did not alter estrogen uptake when injected simultaneously with 17β-[3H]estradiol. These data suggest that 6α-fluorotestosterone activates male behavior and defeminizes development because it translocates estrogen receptors in the brain, probably via an aromatized metabolite. Hence androgen aromatizability in the placenta may not reflect neural metabolism and cannot predict the behavioral or neuroendocrine effects of androgens. 相似文献
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Vorobjeva L Leverrier P Zinchenko A Boyaval P Khodjaev E Varioukhina S Ponomareva G Gordeeva E Jan G 《Antonie van Leeuwenhoek》2004,85(1):53-62
Propionibacterium freudenreichii subsp. shermanii is known to prevent mutations caused by various agents such as N-methyl-N'-nitro-N-nitrosoguanidine, 9-aminoacridine, 4-nitro-quinoline-1-oxide and by UV radiation in both prokaryotic and eukaryotic cells. It was also shown to prevent or repair damage caused by H(2)O(2) or UV radiation in Salmonella typhimurium and Escherichia coli, a characteristic previously designated as reactivative effect. In order to characterise this effect at the molecular level, we have purified the active component from a P. freudenreichii cell-free extract using a combination of ammonium sulfate precipitation, anion-exchange and size-exclusion chromatography. The isolated 35 kDa protein was then identified using both N-terminal and internal peptide sequencing as a cysteine synthase. The latter was localised in the P. freudenreichii proteomic map. It is constitutively expressed but also clearly induced during adaptation to detergent and heat, but not acid, stresses. The biological meaning of cysteine synthase in the context of adaptation to oxidative and non-oxidative stresses is discussed. 相似文献
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Jaing C Gardner S McLoughlin K Mulakken N Alegria-Hartman M Banda P Williams P Gu P Wagner M Manohar C Slezak T 《PloS one》2008,3(5):e2163
Emerging known and unknown pathogens create profound threats to public health. Platforms for rapid detection and characterization of microbial agents are critically needed to prevent and respond to disease outbreaks. Available detection technologies cannot provide broad functional information about known or novel organisms. As a step toward developing such a system, we have produced and tested a series of high-density functional gene arrays to detect elements of virulence and antibiotic resistance mechanisms. Our first generation array targets genes from Escherichia coli strains K12 and CFT073, Enterococcus faecalis and Staphylococcus aureus. We determined optimal probe design parameters for gene family detection and discrimination. When tested with organisms at varying phylogenetic distances from the four target strains, the array detected orthologs for the majority of targeted gene families present in bacteria belonging to the same taxonomic family. In combination with whole-genome amplification, the array detects femtogram concentrations of purified DNA, either spiked in to an aerosol sample background, or in combinations from one or more of the four target organisms. This is the first report of a high density NimbleGen microarray system targeting microbial antibiotic resistance and virulence mechanisms. By targeting virulence gene families as well as genes unique to specific biothreat agents, these arrays will provide important data about the pathogenic potential and drug resistance profiles of unknown organisms in environmental samples. 相似文献
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