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排序方式: 共有10000条查询结果,搜索用时 15 毫秒
211.
Julia K. Archbold Whitney A. Macdonald Stephanie Gras Lauren K. Ely John J. Miles Melissa J. Bell Rebekah M. Brennan Travis Beddoe Matthew C.J. Wilce Craig S. Clements Anthony W. Purcell James McCluskey Scott R. Burrows Jamie Rossjohn 《The Journal of experimental medicine》2009,206(1):209-219
Human leukocyte antigen (HLA) gene polymorphism plays a critical role in protective immunity, disease susceptibility, autoimmunity, and drug hypersensitivity, yet the basis of how HLA polymorphism influences T cell receptor (TCR) recognition is unclear. We examined how a natural micropolymorphism in HLA-B44, an important and large HLA allelic family, affected antigen recognition. T cell–mediated immunity to an Epstein-Barr virus determinant (EENLLDFVRF) is enhanced when HLA-B*4405 was the presenting allotype compared with HLA-B*4402 or HLA-B*4403, each of which differ by just one amino acid. The micropolymorphism in these HLA-B44 allotypes altered the mode of binding and dynamics of the bound viral epitope. The structure of the TCR–HLA-B*4405EENLLDFVRF complex revealed that peptide flexibility was a critical parameter in enabling preferential engagement with HLA-B*4405 in comparison to HLA-B*4402/03. Accordingly, major histocompatibility complex (MHC) polymorphism can alter the dynamics of the peptide-MHC landscape, resulting in fine-tuning of T cell responses between closely related allotypes. 相似文献
212.
In November 2008, BMC Medicine passed the landmark of its first 5 years of publishing. When we launched the journal with the aim of publishing high quality
research of general interest and special importance, we had no idea what the future would bring. To mark the occasion of our
5th anniversary, we consider the achievements of the last 5 years and discuss our plans for the future. 相似文献
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214.
Guido Germano Paul B Kavanagh Piotr J Slomka Serge D Van Kriekinge Geoff Pollard Daniel S Berman 《Journal of nuclear cardiology》2007,14(4):433-454
Cedars-Sinai's approach to the automation of gated perfusion single photon emission computed tomography (SPECT) imaging is based on the identification of key procedural steps (processing, quantitation, reporting), each of which is then implemented, in completely automated fashion, by use of mathematic algorithms and logical rules combined into expert systems. Our current suite of software applications has been designed to be platform- and operating system-independent, and every algorithm is based on the same 3-dimensional sampling scheme for the myocardium. The widespread acceptance of quantitative software by the nuclear cardiology community (QGS alone is used at over 20,000 locations) has provided the opportunity for extensive validation of quantitative measurements of myocardial perfusion and function, in our opinion, helping to make nuclear cardiology the most accurate and reproducible modality available for the assessment of the human heart. 相似文献
215.
Objectives Hypovitaminosis D (HD) and secondary hyperparathyroidism (SHP) are common in elders, and many factors could contribute to
them. The objectives of this study were to estimate the prevalence of HD, SHP, and its associated factors, in individuals
living in nonprofit homes for elders in south Brazil. Design Cross-sectional study. Methods Serum 25-hydroxyvitamin D 25(OH)D, intact parathyroid hormone (PTH), total calcium, phosphorus, alkaline phosphatase, magnesium,
creatinine, and albumin levels were measured in late spring, November, 2005. The presence of factors potentially related with
HD and SHP—age, sex, weight, height, skin phototype, sun exposure, exercise, smoking, use of ≤5 medications or diuretics or
alcohol, and daily calcium ingestion. Results 102 subjects age 77.8 ± 9.0 were included in the study. HD was found in 85.7% and SHP in 53% of the subjects. The estimated
daily calcium ingestion was 720 mg. There was no association between serum 25(OH)D levels and any of the risk factors evaluated.
Serum 25(OH)D levels were correlated with serum PTH (r = −0.358, P = 0.000), calcium (r = 0.306, P = 0.002), and albumin (r = 0.253, P = 0.011) levels. In univariate analysis, SHP was positively associated with age (P = 0.006), and female sex (0.007); and negatively associated with sunlight exposure (P = 0.020), GFR (P = 0.000), Ln25(OH)D (P = 0.002), and total serum calcium (P = 0.024). After multivariate model adjustment, age [OR 1.09 (CI 1.01–1.18); P = 0.024], Ln25(OH)D [OR 0.92 (CI 0.08–0.74); P = 0.013], GFR [OR 0.96 (CI 0.92–0.99); P = 0.013], and hydrochlorothiazide treatment [OR 7.63 (CI 1.67–34.9); P = 0.008] were independently associated with SHP. Conclusions HD and SHP are highly prevalent in elders living in old-age homes. No associations were established between common risk factors
and low serum levels of 25(OH)D levels; however, SHP was independently related with age, 25(OH)D, GFR, and hydrochlorothiazide
use. 相似文献
216.
217.
José Wellington Alves dos Santos Fabiani Palagi Machado Felipe Schaich Douglas Zaione Nascimento Tiago Teixeira Simon Luis Fernando Cibin Keli Cristina Mann Vinícius André Guerra Mateus Correa Marcos Ferreira Gazzoni Marta Pires da Rocha Melissa Daubermann Falster Ronaldo Manfredini Vassoler 《Respiratory Medicine Extra》2007,3(4):186-188
218.
219.