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61.
G. Fava 《Genetica》1975,45(3):289-305
In order to determine the biotic selective factors affecting the fitness of genotypes in the polymorphic speciesT. clodiensis, five types of experimental populations were utilized:
- Populations started with equal numbers of virgin females and males of the three genotypes (pp, pP, PP) at f(p)=f(P)=0.5 in Hardy-Weinberg proportions;
- Populations started with equal numbers of heterozygous females and males;
- Populations started with equal numbers of recessive homozygous females and dominant homozygous females, each fertilized by males of the same genotype;
- Populations with virgin females and males of the three genotypes at f(p)=0.2, f(P)=0.8 in Hardy-Weinberg proportions;
- One population as in (4) but with f(p)=0.7 and f(P)=0.3.
62.
Histological distribution of the 35-KD protein substrate of the epidermal growth factor receptor/kinase in thymus 总被引:1,自引:0,他引:1
Rat thymus has been identified as a tissue comparatively enriched in a 35-KD substrate of the epidermal growth factor receptor/kinase (lipocortin-1) (J Biol Chem 261:13784, 1986). A polyclonal antiserum prepared against the 35-KD protein was used to determine histological distribution of the protein in thymus. Frozen sections of rat thymus were examined after indirect labeling of the 35-KD protein with a rhodamine conjugate of secondary antibody. The antigen was localized primarily in the reticular network of the thymic epithelium, with no detectable labeling of resident thymocytes. Immunoblotting (Western blots) of cytosol extracts also demonstrated that thymocytes did not contain detectable amounts of the antigen. Cultured thymic epithelial cells (TEC), however, contained an abundance of two immunologically related protein bands with molecular weights similar but not identical to the antigen from the parental cell line (human A-431 carcinoma). Paraffin sections of rat and human thymus were subjected to an immunoperoxidase staining procedure, and it was observed that Hassall's corpuscles (keratinized epithelial cells) and other cortical and medullary TECs were intensely stained. The demonstration that the antigen is primarily associated with TEC in thymus, in conjunction with its distribution in other tissues, will aid in deducing its physiological role. 相似文献
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65.
Degradation and mineralization of 3-chlorobiphenyl by a mixed aerobic bacterial culture 总被引:4,自引:0,他引:4
Summary A mixed bacterial culture obtained from polychlorinated-biphenyl-contaminated river sediments proved capable of degrading 3-chlorobiphenyl (3-CB) under aerobic laboratory conditions. Almost total mineralization of 150 mg/l of 3-CB occurred when, after 3 days of incubation, the mineral medium was supplied with benzoic acid as a carbon source. Two strains of Pseudomonas capable of degrading the substrate to 3-chlorobenzoic acid and a strain of Pseudomonas fluorescens capable of co-metabolizing this metabolite were selected from the mixed culture. A nearly stoichiometric amount of chloride, which defines the percentage of total mineralization, was eliminated during mixed culture growth.
Offprint requests to: F. Fava 相似文献
66.
Intracavernous injection of 20 μg of prostaglandin E1 (PGE1) was carried out in 130 impotent patients. The erectile response was compared to the results of arteriological investigations including nocturnal penile tumescence and rigidity monitoring (NPTR) in 59 patients. The response of 60 patients positively categorized as exclusively psychogenic or vasculogenic was also compared to the pattern of the response to 80 mg of papaverine observed in a previous study by the same authors. The PGE1 test may not discriminate psychogenic from wholly organic patients since its results are not correlated to those of NPTR. It helps for the screening of vasculogenic impotence. Lack of response or a partly rigid response is consistent with this actiology but is not specific for it. A fully response makes it unlikely. Compared to papaverine, PGE1 induces less non rigid responses in psychogenic patients (15% versus 35% with papaverine) and more fully rigid responses in vasculogenic patients (respectively 12% and 5 %). Consequently the specificity of the PGE1 test is higher but its sensitivity lower than that of papaverine so that there is no clear difference in the effectiveness of the tests. Nevertheless the PGE1 test should be preferred, because it is safer. Prolonged erections occured in only 5 patients, and all ceased spontaneously. However 4 presented severely painful erections. 相似文献
67.
Effects of differing salinities on morphological characters have been found in marine and brackish populations of Tisbe holothuriae. The results suggested an active role of salinity as a factor promoting divergence. In order to test if the observed differentiation could be due to the level of heterozygosity, a study was performed in strains with low and high homozygosity. Six quantitative traits, and their respective fluctuating asymmetry, have been measured in outbred (coefficient of consanguineity, F = 0) and inbred (F = 0.5) strains, raised at three salinities; 20, 25 and 35. The analysis of variance was applied to test if the morphological measures were the same, and if the variations induced by decreased salinity had the same trend, in the two strains. Wilcoxon test was applied to the asymmetry, when it was not possible to render the variances homogeneous. The results showed that the measures and the effects of salinity on morphometry differed in the strains with low and high homozygosity. No effect of salinity on asymmetry was found. Length measures showed higher asymmetry in the most homozygous strain. 相似文献
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69.
Obesity is now considered a major public health concern globally as it predisposes to a number of chronic human diseases. Most developed countries have experienced a dramatic and significant rise in obesity since the 1980s, with obesity apparently accompanying, hand in hand, the adoption of "Western"-style diets and low-energy expenditure lifestyles around the world. Recent studies report an aberrant gut microbiota in obese subjects and that gut microbial metabolic activities, especially carbohydrate fermentation and bile acid metabolism, can impact on a number of mammalian physiological functions linked to obesity. The aim of this review is to present the evidence for a characteristic "obese-type" gut microbiota and to discuss studies linking microbial metabolic activities with mammalian regulation of lipid and glucose metabolism, thermogenesis, satiety, and chronic systemic inflammation. We focus in particular on short-chain fatty acids (SCFA) produced upon fiber fermentation in the colon. Although SCFA are reported to be elevated in the feces of obese individuals, they are also, in contradiction, identified as key metabolic regulators of the physiological checks and controls mammals rely upon to regulate energy metabolism. Most studies suggest that the gut microbiota differs in composition between lean and obese individuals and that diet, especially the high-fat low-fiber Western-style diet, dramatically impacts on the gut microbiota. There is currently no consensus as to whether the gut microbiota plays a causative role in obesity or is modulated in response to the obese state itself or the diet in obesity. Further studies, especially on the regulatory role of SCFA in human energy homeostasis, are needed to clarify the physiological consequences of an "obese-style" microbiota and any putative dietary modulation of associated disease risk. 相似文献
70.
Blood AJ Iosifescu DV Makris N Perlis RH Kennedy DN Dougherty DD Kim BW Lee MJ Wu S Lee S Calhoun J Hodge SM Fava M Rosen BR Smoller JW Gasic GP Breiter HC;Phenotype Genotype Project on Addiction Mood Disorders 《PloS one》2010,5(11):e13945