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2B4 is a cell surface glycoprotein of the immunoglobulin superfamily structurally related to CD2-like molecules. It was originally identified in the mouse as a receptor that mediates non-MHC-restricted cytotoxicity by NK cells and CD8+ T cells. Recently, 2B4 was shown to bind CD48 by molecular binding assays and surface plasmon resonance. Here, we have investigated the cell surface expression, biochemical characteristics and function of human 2B4. Our results show that 2B4 is expressed not only on NK cells and CD8+ T cells, but also on monocytes and basophils, indicating a broader role for 2B4 in leukocyte activation. In NK cells, engagement of 2B4 with a specific monoclonal antibody or with CD48 can trigger NK cell-mediated cytotoxicity. The contribution of 2B4-CD48 interaction to target cell lysis by different NK cell clones varies, probably dependent on the relative contribution of other receptor-ligand interactions. In T cells and monocytes, ligation of 2B4 does not lead to T cell or monocyte activation. Thus, it appears that the primary function of 2B4 is to modulate other receptor-ligand interactions to enhance leukocyte activation.  相似文献   
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Tricuspid valve regurgitation was assessed quantitatively by measuring blood flow velocity in the vena cava using a pulsed Doppler velocimeter. A non-invasive index of regurgitation was obtained by calculating the ratio between the maximum amplitudes of the systolic and diastolic components of the velocity curves. The index was compared with the angiographic grading of regurgitation in 70 patients after right heart catheterisation; the results were closely correlated. Using the Doppler index the differences between the groups defined according to their angiographic grade were significant. Thus measurement of blood flow velocity in the vena cava appears to quantify accurately the severity of tricuspid regurgitation.  相似文献   
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A case of challenging microsurgical reconstruction of a difficult defect in a radiated upper limb is reported. A difficult wound, with tendon and bone exposition, developed on the dorsum of the forearm in a 76‐year‐old patient; she had been radiated since almost 50 years and her left hand had also been revascularized twice with venous grafts between the humeral artery and the superficial palmar arch. After failure of a local flap, an anterior‐lateral thigh perforator flap was successfully transferred with end‐to‐side anastomoses on the arterialized venous graft. Up to date follow‐up shows a good outcome. The Authors discuss the case and review the indications for microsurgical reconstruction in difficult wounds after radiation and ischemic limb conditions. © 2009 Wiley‐Liss, Inc. Microsurgery, 2009.  相似文献   
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Post-coma persons in an apparent condition of vegetative state and pervasive motor impairment pose serious problems in terms of assessment and intervention options. A technology-based learning assessment procedure might serve for them as a diagnostic supplement with possible implications for rehabilitation intervention. The learning assessment procedure adopted in this study relied on hand-closure and eye-blinking responses and on microswitch technology to detect such responses and to present stimuli. Three participants were involved in the study. The technology consisted of a touch/pressure sensor fixed on the hand or an optic sensor mounted on an eyeglasses’ frame, which were combined with a control system linked to stimulus sources. The study adopted an ABABCB sequence, in which A represented baseline periods, B intervention periods with stimuli contingent on the responses, and C a control condition with stimuli presented non-contingently. Data showed that the level of responding during the B phases was significantly higher than the levels observed during the A phases as well as the C phase for two of the three participants (i.e., indicating clear signs of learning by them). Learning might be deemed to represent basic levels of knowledge/consciousness. Thus, detecting signs of learning might help one revise a previous diagnosis of vegetative state with wide implications for rehabilitation perspectives.  相似文献   
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The purpose of the study was to describe the trend in the incidence of breast cancer in women under 40 in France for the period 1983-2002 and compare it with the trend observed in other age groups. Data from seven cancer registries were analysed. Annual percentage changes were estimated in different age groups using Poisson regression. During the period 1983-2002, breast cancer incidence in women under 40 increased regularly, with an estimated annual percentage change of 0.65 (95% CI: 0.03-1.26). In women aged over 40, the increase is more significant, particularly among women aged 50-74 (2.93% per year). The increase in breast cancer incidence in women under 40 was low and steady over the 20-year period considered. Even though young women did not experience such a major change in diagnostic practices as the development of screening among women aged 50-74, it is difficult to distinguish the effects of possible changes in risk factors and in diagnostic practices in the slight increase observed.  相似文献   
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