排序方式: 共有16条查询结果,搜索用时 171 毫秒
1.
2.
Complement is one of primary defense mechanisms against intravascular microorganisms and could play a role in the immune response
to malignancy and hence its clinical behavior. We evaluated if the sole coding polymorphism of C1qA associates with outcome
in patients with breast carcinoma. Genotyping for C1qA[276A/G] was performed in 63 breast cancer subjects with localized tumor and compared with that in 38 breast cancer subjects with
metastasis. Established risk factors for clinical outcome were considered and evaluated in multivariable analysis. Breast
cancer subjects with heterozygous or homozygous C1qA[276G] genotype had a higher rate of metastasis than subjects with the homozygous C1qA[276A] genotype [hazard ratio (HR) 2.4, 95% confidence interval (CI) 1.1–4.1]. This association was stronger when only metastatic
sites associated with hematogenous spread, i.e., to the bone, liver, and brain, were considered (HR 3.5, 95% CI 1.4–5.6) and
remained statistically significant after adjustment for the number of positive lymph nodes, estrogen receptor status, and
progesterone receptor status. There was no statistical difference in the C1qA[276A/G] allelic distribution between all subjects with breast cancer and controls. These results suggest there could be an association
of a single nucleotide polymorphism at position 276 of the C1qA component of complement with breast cancer metastasis to sites
linked to hematogenous spread of disease. The C1qA polymorphism associated with decreased distant metastasis has also been
correlated with an increased incidence of subcutaneous systemic lupus and C1q deficiencies, suggesting that an altered immune
response may play a role in the observed association.
Supported in part by National Institute of Health grant R21-CA90822, Friends You Can Count On! grant 1-87093-00, and the Woody and Louise White Cancer Research Fund. 相似文献
3.
T. A. Misharina M. B. Terenina N. I. Krikunova I. A. Mihailov 《Applied Biochemistry and Microbiology》2018,54(1):89-97
A comparative study was performed by solid phase microextraction and capillary gas chromatography to establish the ability of four polymer sorbents of different compositions to extract and concentrate volatile organic compounds from the gas phase above an aqueous solution. All polymer sorbents sorbed nonpolar monoterpene hydrocarbons via a cooperative mechanism with almost equal and high efficiency. Sorbents based on polymethyl disiloxane and its mixture with divinylbenzene were more effective in extracting acetates and sesquiterpenes. As the concentration of these compounds in the gas phase increased, their binding by sorbents decreased. It was found that the determination of polar compounds depended on the presence of a solvent in the system. Compounds that are highly soluble in water (alcohols, ketones, etc.) had low coefficients of distribution between gas and water phases. Consequently, their sorption to any of the polymer sorbents was negligible. In the absence of the solvent, the degree of their extraction from the gas phase above the sample was high. It was shown that the actual composition of compounds in the initial mixture of essential oils could significantly differ from their composition in the gas phase. This method is convenient and informative for the purpose of studying the composition of volatile compounds in the gas phase that determine the flavor of the product. 相似文献
4.
Hopcraft JG Anderson TM Pérez-Vila S Mayemba E Olff H 《The Journal of animal ecology》2012,81(1):201-213
1. Theory predicts that small grazers are regulated by the digestive quality of grass, while large grazers extract sufficient nutrients from low-quality forage and are regulated by its abundance instead. In addition, predation potentially affects populations of small grazers more than large grazers, because predators have difficulty capturing and handling large prey. 2. We analyse the spatial distribution of five grazer species of different body size in relation to gradients of food availability and predation risk. Specifically, we investigate how the quality of grass, the abundance of grass biomass and the associated risks of predation affect the habitat use of small, intermediate and large savanna grazers at a landscape level. 3. Resource selection functions of five mammalian grazer species surveyed over a 21-year period in Serengeti are calculated using logistic regressions. Variables included in the analyses are grass nitrogen, rainfall, topographic wetness index, woody cover, drainage lines, landscape curvature, water and human habitation. Structural equation modelling (SEM) is used to aggregate predictor variables into 'composites' representing food quality, food abundance and predation risk. Subsequently, SEM is used to investigate species' habitat use, defined as their recurrence in 5 × 5 km cells across repeated censuses. 4. The distribution of small grazers is constrained by predation and food quality, whereas the distribution of large grazers is relatively unconstrained. The distribution of the largest grazer (African buffalo) is primarily associated with forage abundance but not predation risk, while the distributions of the smallest grazers (Thomson's gazelle and Grant's gazelle) are associated with high grass quality and negatively with the risk of predation. The distributions of intermediate sized grazers (Coke's hartebeest and topi) suggest they optimize access to grass biomass of sufficient quality in relatively predator-safe areas. 5. The results illustrate how top-down (vegetation-mediated predation risk) and bottom-up factors (biomass and nutrient content of vegetation) predictably contribute to the division of niche space for herbivores that vary in body size. Furthermore, diverse grazing assemblages are composed of herbivores of many body sizes (rather than similar body sizes), because these herbivores best exploit the resources of different habitat types. 相似文献
5.
Associations between PRLR/AluI gene polymorphism with reproductive,growth, and meat traits in pigs 总被引:1,自引:0,他引:1
N. V. Mihailov A. V. Usatov L. V. Getmantseva S. U. Bakoev 《Cytology and Genetics》2014,48(5):323-326
The aim of this study was to determine the associations between genotypes of the prolactin receptor gene (PRLR) and reproductive, growth, and meat traits in pigs. Genetic groups of sows were used: Large White (LW), Danish Landrace (LD), and Landrace × Yorkshire × Duroc hybrids (L × Y × D). Reproductive traits studied were the total number of born (TNB) and the number born alive (NBA). The growth traits were the number of days to 100 kg and the average daily gains (ADG). The meat traits were the average backfat thickness (BFT), half carcass weight (HCW), area of M. longissimus dorsi (MLT), and lean meat content (LM). The polymorphism was detected using the polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) method. It was found that the genotype BB is associated with the best NBA. In sows LD, the AB genotype is associated with best number of days to 100 kg; in hybrids L × Y × D, the AA genotype is associated with better meat traits as compared to the genotype BB. 相似文献
6.
Frequency of the F508 deletion in cystic fibrosis patients from the European part of the USSR 总被引:1,自引:0,他引:1
V. S. Baranov T. E. Ivaschenko V. N. Gorbunova L. A. Livshitz M. T. Venozinskis S. A. Gembovskaya V. N. Kalinin O. P. Romanenko T. E. Gembitzkaya A. V. Orlov N. N. Kapranov V. M. Lebedev A. V. Mihailov T. V. Pigina N. Y. Shwed 《Human genetics》1991,87(1):61-64
Summary The frequency of the F508 deletion (F508) has been analyzed in 189 cystic fibrosis (CF) patients from the European part of the USSR, viz. 127 nothern Slavonians (Leningrad region), 30 southern Slavonians (the Ukraine), 10 central Slavonians (Moscow region), 14 Moldavians (Kishenev region) and 8 Lithuanians (Vilnius region). The distribution of CF+ chromosomes with and without F508 varied significantly in the different ethnic groups studied and correlated with the clinical manifestation of CF. The overall frequency of F508 in Slavonian patients is equal to 62.5%, approximately 90% of them being heterozygous or homozygous for this mutation. The frequency of the deletion among 99 Slavonian patients with severe disease manifestation (pancreatic insufficiency, PI) is equal to 67.5%, only 12 patients having pancreatic sufficiency (PS, 17.5%). The highest value of F508 (77.4%) is registered in PI/CF patients of the southern Slavonian group; it is much less frequent (about 57%) in relevant groups of Slavonians from the northern and central parts of the country. Unusually low frequencies (24% and 26%) of F508 are detected in a few samples of Lithuanian and Moldavian CF patients, respectively. All F508+CF-chromosomes of Slavonian origin are associated with haplotypes 2.2.2. defined by the restriction fragment length polymorphism sites KM19/PstI, CS.7/Hin6I and MP6d-9/MspI, although a high proportion (about 25%) of unknown mutations is associated with the same haplotype. Haplotype B (allele 1XV2c/TaqI; allele 2 KM19/PstI) accounts for 91% of F508+CF chromosomes. Our data are consistent with the hypothesis of a single origin and subsequent diffusion of this major CF mutation; however, its interpopulational dissemination in Eastern Europe does not follow the suggested south-east to north-west gradient in Western Europe. The significance of these data for prenatal diagnosis and carrier screening of CF mutations is briefly discussed. 相似文献
7.
S. Daskalov L. Mihailov 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1988,76(4):530-532
Summary A new improved method for hybrid seed production was successfully tested. This method is based on using a cytoplasmic male sterile line possessing a lethal gene with action that can be easily inhibited and a female sterile pollenizer. The lethal gene ensures 100% purity of the F1 crop. The female sterile pollenizer provides a permanent abundant flowering with excess of pollen grains that leads to increased hybrid seed production without additional labour expenses. The described scheme is applicable for other crops as well. 相似文献
8.
This paper complements our recent survey [1] of experimental and theoretical work on the optical spectra of high-temperature superconductors. The emphasis is laid on experiments involving single crystals and good textured ceramic samples. Data have been collected on chemically doped samples, as well as on samples in which carriers are created by photodoping. One of the most remarkable consequences is the observation of a photoinduced superconductivity and a phase separation of photoexcited carriers. The theory has offered a few main suggestions but they have all failed to produce the magic formula for understanding the optical response. Nevertheless, bipolaron models seem somewhat closer to reality. Future experimental, theoretical, and practical developments are considered. 相似文献
9.
Katharina Schramm Carola Marzi Claudia Schurmann Maren Carstensen Eva Reinmaa Reiner Biffar Gertrud Eckstein Christian Gieger Hans-J?rgen Grabe Georg Homuth Gabriele Kastenmüller Reedik M?gi Andres Metspalu Evelin Mihailov Annette Peters Astrid Petersmann Michael Roden Konstantin Strauch Karsten Suhre Alexander Teumer Uwe V?lker Henry V?lzke Rui Wang-Sattler Melanie Waldenberger Thomas Meitinger Thomas Illig Christian Herder Harald Grallert Holger Prokisch 《PloS one》2014,9(4)
10.
Cristina?Munteanu Daniel?PiriciEmail author Alex?Emilian?Stepan Adrian?Camen Claudiu?Margaritescu 《Diagnostic pathology》2016,11(1):134