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排序方式: 共有1334条查询结果,搜索用时 171 毫秒
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Ouédraogo Dieu-Donné Tiendrébéogo Wendlassida Joelle Stéphanie Kaboré Fulgence Ntsiba Honoré 《Clinical rheumatology》2020,39(7):2069-2075
Clinical Rheumatology - Since December 2019, the pandemic caused by coronavirus disease 2019 (COVID-19) raises a real public health problem. COVID-19 appeared in Wuhan (Hubei province) in China.... 相似文献
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Gresham T Richter Jacob E Smith Horace J Spencer Chun Y Fan Emre Vural 《Otolaryngology--head and neck surgery》2007,137(2):239-242
OBJECTIVES: Histological comparison of human-based (AlloDerm) and porcine-based (ENDURAGen) dermal matrices regarding tissue incorporation and neovascularization as potential soft tissue augmentation materials. STUDY DESIGN: In vivo, rat model. METHODS: Subcutaneous implantation of 1-mm thick, 1 cm x 1 cm pieces of AlloDerm, ENDURAGen, and meshed ENDURAGen was performed in 24 Sprague Dawley rats. Implant materials were harvested at 4 (n = 12) and 8 weeks (n = 12). Histological quantification of soft tissue ingrowth and microvascular density was performed following hematoxylin-eosin staining and CD34 immunohistochemistry, respectively. RESULTS: AlloDerm showed significantly greater soft tissue ingrowth and microvascular density compared with both ENDURAGen and meshed ENDURAGen at 4 and 8 weeks (P < 0.001). CONCLUSIONS: Although these results may differ in human host tissues, AlloDerm seems to be a more suitable dermal matrix implant than ENDURAGen for cases in which tissue incorporation and neovascularization are sought for the optimal outcome based on this animal model. 相似文献
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Ludwig Wilkens Joelle Tchinda Dagmar Burkhardt Hans Heinrich Kreipe 《Pathobiology》2002,70(4):204-208
OBJECTIVE: Comparative genomic hybridization (CGH) has been established as an informative technique in genetic analysis. However, differences in the ratio of hybridization intensities were reported for particular chromosomes, which may affect CGH results. The aim of this study was to define these differences in more detail. For this purpose, CGH results of 70 samples of bone marrow cells (BMC) with normal karyotype in conventional cytogenetics (CC) were evaluated using seven different reference DNAs and two different DNA labeling systems. METHODS AND RESULTS: CGH using fluorochrome-conjugated nucleotides for DNA labeling indicated signal deviations in 21/70 BMC samples. Deviations affected chromosomes 1 (n = 21), 2 (n = 11), 4 (n = 11), 5 (n = 9), 6 (n = 7), 7 (n = 2), 8 (n = 2), 12 (n = 5), 13 (n = 15), 14 (n = 1), 16 (n = 17), 17 (n = 11), 19 (n = 21), 20 (n = 12), and/or 22 (n = 17). None of the imbalances were confirmed by fluorescence in situ hybridization (FISH). Using digoxigenin and biotin-conjugated nucleotides in exemplary cases (n = 5) led to the disappearance of the signal deviations. Repeated CGH experiments using seven different reference DNAs showed remarkable variations in the signal deviations. CONCLUSION: Hybridization differences depend not only on the hapten or fluorochrome-labeled nucleotides used for DNA labeling, but also on the reference DNA chosen. Therefore, close control of CGH experiments is mandatory, and additional techniques such as FISH should be performed to confirm the results obtained by CGH. 相似文献
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We have investigated the density of peptides required to elicit different biological responses in cytotoxic T lymphocytes (CTL), including trogocytosis (i.e., the phenomenon whereby the lymphocytes actively capture fragments of plasma membrane from those cells with which they establish an immune synapse). We have used two separate mouse models of CTL recognising defined peptides presented by MHC class I molecules. In both systems, triggering of cytotoxicity and capture of membrane components reached saturation with low densities of ligand. On the other hand, down-modulation of cell-surface levels of TCR, induction of IFN-gamma production and detection of peptide captured required much higher ligand densities. Interestingly, fratricide (i.e., killing between CTL sharing the same specificity), a mechanism proposed to account for CTL exhaustion, was detected only at antigen concentrations still well above that second threshold leading to full blown activation. Taken together, our results show that the different thresholds that govern the elicitation of different CTL functions correlate with different proportions of antigen among the target cell components being captured via trogocytosis. 相似文献
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Expression of CD138 (Syndecan-1) in renal cell carcinoma is reduced with increasing nuclear grade. 总被引:1,自引:0,他引:1
Neriman G?kden Graham F Greene Ilene B Bayer-Garner Horace J Spencer Ralph D Sanderson Murat G?kden 《Applied immunohistochemistry & molecular morphology》2006,14(2):173-177
CD138/Syndecan-1 is a cell-surface heparan sulfate proteoglycan expressed on most epithelial cells, and decreased CD138 expression is associated with increased invasive and metastatic potential in carcinomas. CD138 expression has not been investigated previously in renal neoplasms. Formalin-fixed, paraffin-embedded tissue sections of 50 renal cell carcinomas (RCCs) (40 clear-cell RCCs of various nuclear grades, 10 of which harbored metastases; 6 papillary RCCs, 4 chromophobe RCCs) and 4 oncocytomas were stained immunohistochemically for CD138 using the monoclonal antibody B-B4 (CD138). Staining intensity and distribution were scored and results related to histologic type, nuclear grade, and local stage (pT). Immunoreactivity was membranous in all clear-cell RCCs, chromophobe RCCs, and oncocytomas and was located at the basal aspect of cytoplasm in papillary RCCs. In clear-cell RCCs, the extent of CD138 immunoreactivity decreased with increasing nuclear grade (P<0.001). No significant correlation was found between CD138 immunoreactivity and histologic type (P=0.2) or local stage (P=0.7). Metastatic foci showed a mild to moderate decrease in intensity compared with primary tumor. Decreased expression of CD138 may have a role in more aggressive behavior of clear-cell RCC. 相似文献
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Roger A. Williamson Michael A. Donlan Cynthia R. Dolan Horace C. Thuline Mary T. Harrison Judith G. Hall John M. Opitz 《American journal of medical genetics. Part A》1981,9(2):105-111
The use of elongated prophase and prometaphase chromosome preparations has allowed detection of an insertion of a small segment of 3q into 11q in a kindred with 4 balanced carriers and 8 unbalanced offspring. Those with partial 3q deletion have a true multiple congenital anomalies/mental retardation (MCA/MR) syndrome with an appearance suggestive of the Schwartz-Jampel syndrome. 相似文献