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111.
Dave VP; Keefe R; Berger MA; Drbal K; Punt JA; Wiest DL; Alarcon B; Kappes DJ 《International immunology》1998,10(10):1481-1490
CD3delta-deficient (delta degrees) mice are defective in alphabeta T cell
development. Here we explore the capacity of TCR-CD3 signaling complexes
expressed on delta degrees thymocytes to mediate the following functional
outcomes in response to antibody cross-linking: (i) the transition from the
CD4-CD8- to CD4+CD8+ stage, (ii) the transition from the CD4+CD8+ to
CD4+CD8- or CD4-CD8+ stages and (iii) the induction of apoptosis. We
provide evidence that CD3deltaepsilon complexes are dispensable for
mediating the anti-CD3-mediated CD4-CD8- to CD4+CD8+ transition. On the
other hand, CD3delta is critical at the CD4+CD8+ stage. We demonstrate that
CD4+CD8+ thymocytes from delta degrees mice, unlike delta degrees CD4-CD8-
thymocytes and wild-type CD4+CD8+ thymocytes, require prolonged or
consecutive stimuli to elicit functional responses. Depending on the nature
of the secondary stimulus, delta degrees thymocytes can be induced to
undergo apoptosis or preferential maturation to the CD4-CD8+ stage. Taken
together these results indicate that the signaling capacity of the TCR-CD3
complex is noticeably altered in the absence of CD3delta. The essential
role of CD3delta at the CD4+CD8+ stage of development correlates with the
onset of TCRalpha rearrangement, consistent with a critical structural
and/or functional relationship between CD3delta and TCRalpha.
相似文献
112.
113.
To calculate the centre of pressure using piezoelectric force plates mounted on pads, no net tensile stresses may be imposed on the surface of the plate. This condition is violated when stairs are attached to the plates, unless the plates are preloaded. Typical shear forces encountered when climbing stairs were used to determine required preloads of approximately 16.4 N/cm step height. Vertical and horizontal loads were applied at known locations on the steps, and points of application were calculated. Deviations were within ± 3 mm. The effect of point of application inaccuracy on calculated joint moments is considerable. A 2 cm medial shift in the point of application resulted in calculated peak knee abduction/adduction moment errors of 35%. 相似文献
114.
MR mammographic localization. Work in progress 总被引:1,自引:0,他引:1
Hussman K; Renslo R; Phillips JJ; Fischer HJ; Khalkhali I; Braslau DL; Sinow RM 《Radiology》1993,189(3):915
115.
116.
I. Vercruysse AM Vermeulen FM Belpaire DL Massart and AG Dupont 《Fundamental & clinical pharmacology》1994,8(4):373-378
Summary— The influence of the dihydropyridine calcium entry blockers nicardipine, amlodipine, nifedipine, isradipine and of the dihydropyridine calcium entry promotor BAY K 8644 on the disappearance rate of propranolol by isolated rat hepatocytes was compared to the effect of diltiazem and verapamil, two non-dihydropyridine calcium channel blockers and known inhibitors of hepatic cytochrome P450 mixed function oxidases. All compounds dose-dependently inhibited the disappearance rate of propranolol. Nicardipine and isradipine were more potent in inhibiting the disappearance rate of propranolol than the other dihydropyridines and than diltiazem and verapamil. The inhibitory effect of nicardipine on the disappearance rate of propranolol was not stereoselective and was not influenced by age. 相似文献
117.
118.
Scintigraphy in 3 patients with chondroblastoma showed that the tumors were hyperemic and avidly accumulated the radionuclide. These changes were also present in adjacent normal bone, but to a lesser degree. This suggest that radionuclide uptake in chondroblastoma is a function of the blood supply to the tumor rather than primary matrix extraction. 相似文献
119.
120.
The authors report a case of a hepatic artery aneurysm that simulated a mass in the head of the pancreas. The correct diagnosis was made preoperatively based on several findings: curvilinear calcification within the mass on CT, a well-defined cystic collection on ultrasound, absence of biliary duct dilatation or jaundice, and presence of other aneurysms. 相似文献