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排序方式: 共有186条查询结果,搜索用时 15 毫秒
91.
Standardization of a broth microdilution susceptibility testing method to determine minimum inhibitory concentrations of aquatic bacteria 总被引:3,自引:0,他引:3
Miller RA Walker RD Carson J Coles M Coyne R Dalsgaard I Gieseker C Hsu HM Mathers JJ Papapetropoulou M Petty B Teitzel C Reimschuessel R 《Diseases of aquatic organisms》2005,64(3):211-222
A multiple laboratory study was conducted in accordance with the standards established by the Clinical and Laboratory Standards Institute (CLSI), formerly the National Committee for Clinical Laboratory Standards (NCCLS), for the development of quality control (QC) ranges using dilution antimicrobial susceptibility testing methods for bacterial isolates from aquatic animal species. QC ranges were established for Escherichia coli ATCC 25922 and Aeromonas salmonicida subsp. salmonicida ATCC 33658 when testing at 22, 28 and 35 degrees C (E. coli only) for 10 different antimicrobial agents (ampicillin, enrofloxacin, erythromycin, florfenicol, flumequine, gentamicin, ormetoprim/sulfadimethoxine, oxolinic acid, oxytetracycline and trimethoprim/sulfamethoxazole). Minimum inhibitory concentration (MIC) QC ranges were determined using dry- and frozen-form 96-well plates and cation-adjusted Mueller-Hinton broth. These QC ranges were accepted by the CLSI/NCCLS Subcommittee on Veterinary Antimicrobial Susceptibility Testing in January 2004. This broth microdilution testing method represents the first standardized method for determining MICs of bacterial isolates whose preferred growth temperatures are below 35 degrees C. Methods and QC ranges defined in this study will enable aquatic animal disease researchers to reliably compare quantitative susceptibility testing data between laboratories, and will be used to ensure both precision and inter-laboratory harmonization. 相似文献
92.
Loss of phylogenetic information in chorion gene families of Bombyx mori gene conversion 总被引:1,自引:0,他引:1
Regier JC; Weigmann BM; Leclerc RF; Friedlander TP 《Molecular biology and evolution》1994,11(1):72-87
The silkmoth chorion has provided a stimulating model for the study of
evolution and developmental regulation of gene families. Previous attempts
at inferring relationships among chorion sequences have been based on
pairwise comparisons of overall similarity, a potentially problematic
approach. To remedy this, we identified the alignable regions of low
sequence variability and then analyzed this restricted database by
parsimony and neighbor-joining methods. At the deepest level, the chorion
sequence tree is split into two branches, called "alpha" and "beta." Within
each branch, early- and late-expressing genes each constitute monophyletic
groups, while the situation with middle-expressing genes remains uncertain.
The HcB gene family appears to be the most basal beta-branch group, but
this conclusion is qualified because the effect of gene conversion on
branching order is unknown. Previous studies by Eickbush and colleagues
have strongly suggested that ErA, HcA, and HcB families undergo gene
conversion within a gene family, whereas the ErB family does not. The
occurrence of conversion correlates with a particular tree structure;
namely, branch lengths are much greater at the base of the family than at
higher internodes and terminal branches. These observations raise the
possibility that chorion gene families are defined by gene conversion
events (reticulate evolution) rather than by descent with modification
(synapomorphy).
相似文献
93.
Sequences sufficient for correct regulation of Sgs-3 lie close to or within the gene. 总被引:11,自引:6,他引:5
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The Drosophila melanogaster 68C chromosomal locus is the site of a prominent polytene chromosome puff that harbors the genes Sgs-3, Sgs-7 and Sgs-8. These genes code for proteins that are part of the salivary glue that Drosophila larvae secrete as a means of fixing themselves to an external substrate for the duration of the pre-pupal and pupal period. The 68C glue genes are regulated by the steroid hormone ecdysterone, with the hormone required for both initiation and cessation of gene expression during the third larval instar. Previous work has defined sequences sufficient for expression of abundant levels of Sgs-3 mRNA at the correct time and in the correct tissue. We show here that sequences sufficient for normal tissue- and stage-specific accumulation of Sgs-3 RNA, but adequate only for low levels of expression, lie within 130 bp of the 5' end of the gene, or within the gene. 相似文献
94.
It is argued that Homo sapiens is a habitual rather than a facultative meat eater. Quantitative similarity of human gut morphology
to guts of carnivorous mammals, preferential absorption of haem rather than iron of plant origin, and the exclusive use of
humans as the definitive host by Taenia saginata and the almost complete human specificity of T. solium are used to support
the argument. 相似文献
95.
Marc BM Bracke Sandra A Edwards Bas Engel Willem G Buist Bo Algers 《Acta veterinaria Scandinavica》2008,50(1):29
Background
Recently, a Risk Assessment methodology was applied to animal welfare issues in a report of the European Food Safety Authority (EFSA) on intensively housed calves. 相似文献96.
97.
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99.
The R-spondin protein family 总被引:1,自引:0,他引:1
The four vertebrate R-spondin proteins are secreted agonists of the canonical Wnt/β-catenin signaling pathway. These proteins are approximately 35 kDa, and are characterized by two amino-terminal furin-like repeats, which are necessary and sufficient for Wnt signal potentiation, and a thrombospondin domain situated more towards the carboxyl terminus that can bind matrix glycosaminoglycans and/or proteoglycans. Although R-spondins are unable to initiate Wnt signaling, they can potently enhance responses to low-dose Wnt proteins. In humans, rare disruptions of the gene encoding R-spondin1 cause a syndrome of XX sex reversal (phenotypic male), palmoplantar keratosis (a thickening of the palms and soles caused by excess keratin formation) and predisposition to squamous cell carcinoma of the skin. Mutations in the gene encoding R-spondin4 cause anonychia (absence or hypoplasia of nails on fingers and toes). Recently, leucine-rich repeat-containing G-protein-coupled receptor (Lgr)4, Lgr5 and Lgr6, three closely related orphans of the leucine-rich repeat family of G-protein-coupled receptors, have been identified as receptors for R-spondins. Lgr5 and Lgr6 are markers for adult stem cells. Because R-spondins are potent stimulators of adult stem cell proliferation in vivo and in vitro, these findings might guide the therapeutic use of R-spondins in regenerative medicine. 相似文献
100.