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101.
Annette AM Gerritsen Rob JPM Scholten Willem JJ Assendelft Herman Kuiper Henrica CW de Vet Lex M Bouter 《BMC neurology》2001,1(1):8-7
Background
Carpal tunnel syndrome is a common disorder, which can be treated with surgery or conservative options. However, there is insufficient evidence and no consensus among physicians with regard to the preferred treatment for carpal tunnel syndrome. Therefore, a randomized controlled trial is conducted to compare the short- and long-term efficacy of surgery and splinting in patients with carpal tunnel syndrome. An attempt is also made to avoid the (methodological) limitations encountered in earlier trials on the efficacy of various treatment options for carpal tunnel syndrome. 相似文献102.
Genetic manipulation of carotenoid biosynthesis in the green sulfur bacterium Chlorobium tepidum 总被引:3,自引:0,他引:3
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The green sulfur bacterium Chlorobium tepidum is a strict anaerobe and an obligate photoautotroph. On the basis of sequence similarity with known enzymes or sequence motifs, nine open reading frames encoding putative enzymes of carotenoid biosynthesis were identified in the genome sequence of C. tepidum, and all nine genes were inactivated. Analysis of the carotenoid composition in the resulting mutants allowed the genes encoding the following six enzymes to be identified: phytoene synthase (crtB/CT1386), phytoene desaturase (crtP/CT0807), zeta-carotene desaturase (crtQ/CT1414), gamma-carotene desaturase (crtU/CT0323), carotenoid 1',2'-hydratase (crtC/CT0301), and carotenoid cis-trans isomerase (crtH/CT0649). Three mutants (CT0180, CT1357, and CT1416 mutants) did not exhibit a discernible phenotype. The carotenoid biosynthetic pathway in C. tepidum is similar to that in cyanobacteria and plants by converting phytoene into lycopene using two plant-like desaturases (CrtP and CrtQ) and a plant-like cis-trans isomerase (CrtH) and thus differs from the pathway known in all other bacteria. In contrast to the situation in cyanobacteria and plants, the construction of a crtB mutant completely lacking carotenoids demonstrates that carotenoids are not essential for photosynthetic growth of green sulfur bacteria. However, the bacteriochlorophyll a contents of mutants lacking colored carotenoids (crtB, crtP, and crtQ mutants) were decreased from that of the wild type, and these mutants exhibited a significant growth rate defect under all light intensities tested. Therefore, colored carotenoids may have both structural and photoprotection roles in green sulfur bacteria. The ability to manipulate the carotenoid composition so dramatically in C. tepidum offers excellent possibilities for studying the roles of carotenoids in the light-harvesting chlorosome antenna and iron-sulfur-type (photosystem I-like) reaction center. The phylogeny of carotenogenic enzymes in green sulfur bacteria and green filamentous bacteria is also discussed. 相似文献
103.
Forbes SH; Hogg JT; Buchanan FC; Crawford AM; Allendorf FW 《Molecular biology and evolution》1995,12(6):1106-1113
We compared genotypes at eight (AC)n microsatellite loci in domestic sheep
(Ovis aries) and wild Rocky Mountain bighorn sheep (O. canadensis). The
domestic sheep had greater genetic variation, higher allele-size variances,
and larger allele sizes than the wild sheep. Accumulating evidence from
higher taxonomic comparisons shows that these parameters are biased if
microsatellite loci are selected in one taxon and used in another. Our
results demonstrate similar biases between congeneric species. We compared
standard measures of genetic variation, differentiation, and distance
within and between species (H, D, FST) to newer measures based on
allele-size variance (SW, SB, RST). The size-based distances better
detected species-level divergence, but standard measures better
distinguished allopatric populations. Empirical calibration of these
measures at the subspecies level is needed to establish their useful
ranges.
相似文献
104.
A plasmid library of Acinetobacter calcoaceticus HindIII fragments was
constructed, and clones that complemented an Escherichia coli pabA mutant
were selected. Plasmids containing a 3.9-kb fragment of A. calcoaceticus
DNA that also complemented E. coli trpD and trpC-(trpF+) mutants were
obtained. We infer that complementation of E. coli pabA mutants was the
result of the expression of the amphibolic anthranilate-
synthase/p-aminobenzoate-synthase glutamine-amidotransferase gene and that
the plasmid insert carried the entire trpGDC gene cluster. In E. coli
minicells, the plasmid insert directed the synthesis of polypeptides of
44,000, 33,000, and 20,000 daltons, molecular masses that are consistent
with the reported molecular masses of phosphoribosylanthranilate
transferase, indoleglycerol-phosphate synthase, and anthranilate-synthase
component II, respectively. A 3,105- bp nucleotide sequence was determined.
Comparison of the A. calcoaceticus trpGDC sequences with other known trp
gene sequences has allowed insight into (1) the evolution of the amphibolic
trpG gene, (2) varied strategies for coordinate expression of trp genes,
and (3) mechanisms of gene fusions in the trp operon.
相似文献
105.
William R. Lusby Daniel E. Sonenshine Conrad E. Yunker R. Andrew Norval Michael J. Burridge 《Experimental & applied acarology》1991,13(2):143-152
Three low molecular weight compounds were found in hexane: diethyl ether extracts of fed males of the African ticks,Amblyomma variegatum (tropical bont tick) andA. hebraeum (bont tick), namely,o-nitrophenol, methyl salicylate and 2,6-dichlorophenol. These same compounds were also found in a rinse of fedA. variegatum males, but were absent or present in only trace amounts in a rinse of fedA. hebraeum males.o-Nitrophenol and methyl salicylate were present in much higher concentrations (i.e., amounts/tick) inA. variegatum than inA. hebraeum. 2,6-Dichlorophenol was also more abundant inA. variegatum than inA. hebraeum, but the differences were not as great as with the former two compounds. Extraction in hexane over a 3-week period revealed four additional compounds, benzaldehyde, benzyl alcohol, benzothiazole and nonanoic acid. The first three compounds were found in males of both species; nonanoic acid was found only inA. hebraeum males. Published reports consistently show strong attraction byo-nitrophenol and methyl salicylate for both sexes of the two bont tick species; 2,6-dichlorophenol and benzaldehyde have been reported to be attractive to both sexes ofA. hebraeum. The possible roles of these compounds, as well as others occasionally reported fromA. hebraeum andA. variegatum, as components of the aggregation/attachment pheromone or other pheromones is discussed.Supported by Cooperative Agreement No. AFR-0435A-00-9084-00 with the U.S. Agency for International Development to the Department of Infectious Diseases, College of Veterinary Medicine, University of Florida, Gainesville, FL. 相似文献
106.
M. T. R. Subbiah D. Deitemeyer R. Yunker 《Virchows Archiv. B, Cell pathology including molecular pathology》1981,36(1):41-46
In spontaneously atherosclerosis-susceptible White Carneau pigeons intimal cushions are noted consistently at the coeliac branch of aorta at birth. While these cushions do not progress into atherosclerotic lesions, the area across from the cushion (so called "lesion area") develop a classic atherosclerotic plaque by three years of age. In order to explain this regional aortic susceptibility to atherosclerosis, cholesterol and cholesteryl ester concentrations and prostaglandin biosynthesis in the two aortic regions were examined. It was found that the concentration of free and esterified cholesterol was higher in the intimal cushion area. Examination of the formation of various prostaglandins from C14-arachidonic acid indicates a striking increase in PGE2 synthesis in the lesion area with no difference in the formation of 6-keto PGF1 alpha (stable product of PGI2). These studies suggest that one of the earliest changes noted in the "lesion area" that differs from the intimal cushion is the enhanced formation of PGE2. 相似文献
107.
We report plaquing tests of 124 virus strains, mostly arboviruses of 21 serological groups, in Singh's line of Aedes albopictus cells. Thirty of these plaqued: all were arboviruses of six groups and were known or presumed to be mosquito borne. Failing to plaque were 86 strains of arboviruses, mostly tick borne, two strains of insect pathogens, and six animal viruses not classified as arboviruses. Among mosquito-borne agents, plaquing ability appeared related to serological classification. California group and most A-group viruses failed to plaque, but nearly all members of B and Bunyamwera groups readily plaqued. Within serological group B, 14 of 16 mosquito-borne agents plaqued, but none of 13 tick-borne or vector-unassociated viruses did so. Some implications of these results for recognition and classification of arboviruses are discussed. 相似文献
108.
Z Rymaszewski D J Sprinkle R L Yunker M T Subbiah 《Biochemical and biophysical research communications》1985,131(2):707-711
The activity of Acyl CoA-cholesterol acyl transferase was markedly high in fetal aortas when compared to maternal and adult male rabbits. This activity dropped by 50% at 1 week of age. This high activity in fetal aorta a) did not appear to be due to changes in plasma cholesterol levels or to the later development of endogenous inhibitor in the aorta, but rather b) due to stimulatory factor(s) present in amniotic fluid. 相似文献
109.
Bellis M; Jubier-Maurin V; Dod B; Vanlerberghe F; Laurent AM; Senglat C; Bonhomme F; Roizes G 《Molecular biology and evolution》1987,4(4):351-363
The presence of the L1 sequences, L1Md4 next to the pseudogene beta h3 and
I12 found in the twelfth intron of the albumin gene, in certain strains of
laboratory mice but not of others has led to the suggestion that these
sequences were recent insertions into the Mus mus domesticus genome. To be
sure that they are really recent insertions and not relics of an ancestral
chromosome, we investigated the presence or absence of these sequences in
populations of wild mice belonging to the semispecies M. m. domesticus and
M. m. musculus as well as in other species of the genus Mus and in related
murids. The sequence I12 in the albumin gene was found in 34% of the
chromosomes of the wild mice belonging to M. m. domesticus and to a lesser
extent (6%) in M. m. musculus. Of 114 M. m. domesticus chromosomes, L1Md4
was found in only nine, seven of which came from the same locality. Its
presence was associated with the haplotype Hbbp, which is relatively rare
in European populations of M. musculus. Since there was no evidence for the
presence of these two L1 sequences in more distantly related species, we
conclude that they are recent insertions in the M. musculus genome.
相似文献
110.
B Chevassus JM Blanc P Bergot L Casenave AM Escaffre F Hérioux N Kaushik R Lanneberre 《遗传、选种与进化》1979,11(1):79-92