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91.
Kajsa Sjöholm Björn Carlsson Lena MS Carlsson 《Central European Journal of Biology》2006,1(2):221-234
The leptin system regulates body fat mass through a feedback loop between adipose tissue and the hypothalamus. To test if
leptin responsiveness may be regulated we assayed hypothalamic response to leptin during the estrous cycle; when changes in
food intake are known to occur. Immature rats were treated with pregnant mare’s serum gonadotropin (PMSG) to induce synchronized
follicular development, ovulation and corpus luteum formation. Leptin response was estimated by measuring the in vitro induction of tis11, a primary response gene activated by STAT3-dependent cytokines in hypothalamic explants after leptin stimulation. In addition,
mRNA levels of the suppressor cytokine signaling-3 (SOCS-3), a possible mediator of leptin resistance, were analyzed. Serum
leptin levels did not change between days 2 and day 3 (corresponding to proestrus and estrus, respectively) but the response
to leptin was higher on day 2 than on day 3 (p=0.05). Food intake displayed a tendency towards downregulation between day
1 and day 2 (p=0.057), and a tendency towards upregulation between day 2 and day 3 (p=0.072), although the body weight increased
on day of the study (p<0.0001). There was no significant difference in hypothalamic expression of SOCS-3 between day 2 and
day 3. In conclusion, we have shown that leptin responsiveness changes during a hormonally induced estrous cycle in rats.
Our data suggest that a change in the hypothalamic response to leptin may cause the cyclic feeding behavior seen in rats. 相似文献
92.
Gotsman M Dusa C Nassar H Hasin Y Lotan C Rozenman Y 《International journal of cardiovascular interventions》1999,2(3):187-190
The Cutting Balloon consists of a standard balloon dilatation catheter with four microtome-sharp blades that incise the plaque and minimize arterial wall trauma. It was used in 31 patients; nine had calcified arteries, ten had non-compliant lesions, three had in-stent restenosis and nine had aorto-ostial lesions. Seventeen lesions were predilated, 28 were post-dilated and 18 required stent implantation. The procedure was very effective in aorto-ostial lesions, non-compliant lesions that were not responsive to high-pressure balloon dilatation, and was partially successful in calcified arteries. It has a very specific niche in selected lesions. 相似文献
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95.
North NN Dollhopf SL Petrie L Istok JD Balkwill DL Kostka JE 《Applied and environmental microbiology》2004,70(8):4911-4920
Previous studies have demonstrated that metal-reducing microorganisms can effectively promote the precipitation and removal of uranium from contaminated groundwater. Microbial communities were stimulated in the acidic subsurface by pH neutralization and addition of an electron donor to wells. In single-well push-pull tests at a number of treated sites, nitrate, Fe(III), and uranium were extensively reduced and electron donors (glucose, ethanol) were consumed. Examination of sediment chemistry in cores sampled immediately adjacent to treated wells 3.5 months after treatment revealed that sediment pH increased substantially (by 1 to 2 pH units) while nitrate was largely depleted. A large diversity of 16S rRNA gene sequences were retrieved from subsurface sediments, including species from the alpha, beta, delta, and gamma subdivisions of the class Proteobacteria, as well as low- and high-G+C gram-positive species. Following in situ biostimulation of microbial communities within contaminated sediments, sequences related to previously cultured metal-reducing delta-Proteobacteria increased from 5% to nearly 40% of the clone libraries. Quantitative PCR revealed that Geobacter-type 16S rRNA gene sequences increased in biostimulated sediments by 1 to 2 orders of magnitude at two of the four sites tested. Evidence from the quantitative PCR analysis corroborated information obtained from 16S rRNA gene clone libraries, indicating that members of the delta-Proteobacteria subdivision, including Anaeromyxobacter dehalogenans-related and Geobacter-related sequences, are important metal-reducing organisms in acidic subsurface sediments. This study provides the first cultivation-independent analysis of the change in metal-reducing microbial communities in subsurface sediments during an in situ bioremediation experiment. 相似文献
96.
Critical role for CXCR4 signaling in progenitor localization and T cell differentiation in the postnatal thymus 总被引:11,自引:0,他引:11
Plotkin J Prockop SE Lepique A Petrie HT 《Journal of immunology (Baltimore, Md. : 1950)》2003,171(9):4521-4527
T cell differentiation in the thymus depends on sequential interactions between lymphoid progenitors and stromal cells in discrete regions of the cortex. Here we show that CXCL12/CXCR4 signaling is absolutely required for proper localization of early progenitors into the cortex and thus for successful steady state differentiation. All early progenitors in the thymus express CXCR4, and its ligand (CXCL12) is expressed only by stromal cells in the cortex, where early progenitors are found. Early progenitors migrate in response to CXCL12 in vitro, while thymus-specific deletion of CXCR4 in vivo results in failed cortical localization and developmental arrest. These findings indicate a crucial and nonredundant role for CXCR4 in facilitating localization of early lymphoid progenitors to tissue regions of the thymus, where lineage commitment and proliferation are controlled. 相似文献
97.
Stuempfle KJ Katch FI Petrie DF 《Journal of strength and conditioning research / National Strength & Conditioning Association》2003,17(2):238-244
We assessed body composition (height, body mass, body mass index, body fat by densitometry, fat mass, fat-free mass, and lean/fat ratio) and performance (10- and 40-yd sprints, pro shuttle run, vertical jump, sit and reach, and bench press) in 77 National Collegiate Athletic Association Division III football players. Data were analyzed by position and playing status. Significant differences (p = 0.05) were found between positions for all body composition measurements and all performance tests except the sit and reach. Starters outperformed nonstarters in all performance tests except the 10-yd sprint and sit and reach (p = 0.05). Correlations (r) for percent body fat and performance tests ranged from 0.52 to 0.70, and common variance with the effects of body mass removed ranged from 8 to 23%. Percent body fat is not closely correlated with results of commonly administered performance tests in Division III football players. 相似文献
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Lucotte GL;French MS Consortium 《Genetic counseling (Geneva, Switzerland)》2002,13(2):133-138
To identify the chromosomal localizations of the multiple sclerosis (MS) genes, we conducted a genomewide linkage analysis using eighteen affected families. A MS gene is linked to markers located in the 19q13.3 region (multipoint lod-score = 2.1). Apolipoprotein E (ApoE) gene, located in this region, is an excellent candidate gene for MS because the ApoEe4 allele is acting as a severity allele in the disease. 相似文献
100.