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21.
Activation-induced modification in the CD3 complex of the gammadelta T cell receptor 总被引:2,自引:0,他引:2
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Hayes SM Laky K El-Khoury D Kappes DJ Fowlkes BJ Love PE 《The Journal of experimental medicine》2002,196(10):1355-1361
The T cell antigen receptor complexes expressed on alphabeta and gammadelta T cells differ not only in their respective clonotypic heterodimers but also in the subunit composition of their CD3 complexes. The gammadelta T cell receptors (TCRs) expressed on ex vivo gammadelta T cells lack CD3delta, whereas alphabeta TCRs contain CD3delta. While this result correlates with the phenotype of CD3delta(-/-) mice, in which gammadelta T cell development is unaffected, it is inconsistent with the results of previous studies reporting that CD3delta is a component of the gammadelta TCR. Since earlier studies examined the subunit composition of gammadelta TCRs expressed on activated and expanded peripheral gammadelta T cells or gammadelta TCR(+) intestinal intraepithelial lymphocytes, we hypothesized that activation and expansion may lead to changes in the CD3 subunit composition of the gammadelta TCR. Here, we report that activation and expansion do in fact result in the inclusion of a protein, comparable in mass and mobility to CD3delta, in the gammadelta TCR. Further analyses revealed that this protein is not CD3delta, but instead is a differentially glycosylated form of CD3gamma. These results provide further evidence for a major difference in the subunit composition of alphabeta- and gammadelta TCR complexes and raise the possibility that modification of CD3gamma may have important functional consequences in activated gammadelta T cells. 相似文献
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Reviews of the medical literature have always been an important resource for physicians. Increasingly, qualitative and quantitative "systematic reviews" have replaced the traditional "narrative review" as a means of capturing and summarizing current evidence on a topic or, when possible, answering a specific clinical question. This paper is part one of a two-part series designed to provide emergency physicians with the background necessary to locate, critically evaluate and interpret systematic reviews. The paper provides a brief background on systematic reviews and general principles on locating and critically appraising them. To facilitate readability, examples from the emergency medicine literature have been included for illustrative purposes and technical details have been kept to a minimum. The references, however, are comprehensive and provide a resource for readers seeking further information. 相似文献
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Benoît Mesurolle Laurence Kadoch Mona El-Khoury Andr Lisbona Nandini Dendukuri William D. Foulkes 《Journal of ultrasound in medicine》2007,26(6):817-824
OBJECTIVE: The purpose of this study was to review the sonographic features of breast cancer gene BRCA1- and BRCA2-associated breast carcinomas in comparison with "sporadic" breast carcinomas and benign breast masses. METHODS: Sonograms of 233 breast masses, including 33 BRCA-associated malignant masses (BRCA1, 15; BRCA2, 18), 148 sporadic malignant masses, and 52 benign masses, were reviewed by consensus by 2 radiologists according to American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) terminology. RESULTS: Most of the sporadic and BRCA1-and BRCA2-associated cancers displayed an irregular shape (91.2%, 93.3%, and 83.3%, respectively). BRCA1-associated cancers showed microlobulated margins in 53.3% versus 33.8% (sporadic) and 33.3% (BRCA2). A parallel orientation was most frequently encountered in BRCA1-associated lesions (46.7%) versus sporadic (33.8%) and BRCA2 (33.3%), whereas posterior acoustic shadowing was least frequently seen in BRCA1-associated lesions (13.3%) versus BRCA2 (16.7%) and sporadic (31.1%). Most (73.3%) of the BRCA1-associated lesions were classified as BI-RADS category 4, whereas most of the sporadic and BRCA2-associated lesions were classified as BI-RADS category 5 (66.2% and 72.2%). CONCLUSIONS: Sonographic features of BRCA-associated and sporadic breast carcinomas do not differ substantially. BRCA1-associated breast carcinomas trend toward less malignant sonographic characteristics, but strict application of the BI-RADS categorizations demands that they be classified as category 4 or 5. 相似文献
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Sommers CL Dejarnette JB Huang K Lee J El-Khoury D Shores EW Love PE 《The Journal of experimental medicine》2000,192(6):913-919
The T cell antigen receptor (TCR) and pre-TCR complexes are composed of multiple signal-transducing subunits (CD3 gamma, CD3 delta, CD3 epsilon, and zeta) that each contain one or more copies of a semiconserved functional motif, the immunoreceptor tyrosine-based activation motif (ITAM). Although biochemical studies indicate that individual TCR-ITAMs may bind selectively or with different affinity to various effector molecules, data from other experiments suggest that at least some ITAMs are functionally equivalent. In this study, we examined the role of CD3straightepsilon ITAM-mediated signals in T cell development by genetically reconstituting CD3 epsilon-deficient mice with transgenes encoding either wild-type or ITAM-mutant (signaling defective) forms of the protein. The results demonstrate that signals transduced by CD3 epsilon are not specifically required for T cell maturation but instead contribute quantitatively to TCR signaling in a manner similar to that previously observed for zeta chain. Unexpectedly, analysis of TCR-transgenic/CD3 epsilon-mutant mice reveals a potential role for CD3 epsilon signals in T cell survival. 相似文献
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Bendardaf R Buhmeida A Ristamäki R Syrjänen K Pyrhönen S 《Scandinavian journal of gastroenterology》2007,42(12):1473-1478
OBJECTIVE: The role of MMP-1 (collagenase-1) in the development of a metastatic phenotype in colorectal cancer (CRC) has not been fully studied. The aim of this study was to investigate the mechanisms involved in the dissemination of CRC by examining the expression of MMP-1 in the primary tumours and their metastases, with special reference to standard clinicopathological features and disease outcome. MATERIAL AND METHODS: Surgical specimens from the primary tumours (P) and their metastatic (M) lesions were available from 30 patients with Stage II, III and IV CRC, and were subjected to immunohistochemical (IHC) staining for MMP-1. Both cytoplasmic expression in cancer cells (CC) and stromal (ST) expression were related to pertinent clinical and follow-up data. RESULTS: In a pairwise comparison of P-M pairs, CC expression (but not ST expression) in P and M was significantly different (Wilcoxon rank test, p=0.037). Strong CC expression in P was significantly related to the presence of lymph node involvement at diagnosis (p=0.008). CC expression in M was intense only in metachronous metastases (Stage II/III disease) but never in synchronous metastases (Stage IV) (p=0.034). There was a significant down-regulation of CC (p=0.004) in liver metastasis (n=9) in comparison with all other metastatic sites (n=21). ST expression in P (but not in M) showed a linear decrease in parallel with increasing stage (p=0.028 for linear trend). MMP-1 expression was not significantly associated with any other clinicopathological variables, including age, gender, carcinoembryonic antigen (CEA) or patients' disease-free or overall survival. CONCLUSIONS: These data suggest that MMP-1 may play an important role in tumour invasion and metastasis of CRC. 相似文献
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A single fracture of the ring of a vertebra is a rare injury of the spine. In this report, we present five single fractures
of the posterior ring of the cervical spine below the atlas from four patients after motor vehicle accidents. Initial radiographs
failed to show any of these fractures; all were detected by computed tomography. Single ring fractures are stable and none
of our patients presented with a neurological deficit. Patients were treated conservatively with a cervical collar or a cervicothoracic
brace. They all recovered without any neurological abnormalities. 相似文献
30.
Stringer MD Soloway RD Taylor DR Riyad K Toogood G 《Journal of pediatric surgery》2007,42(10):1677-1682