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1.
Role of Natural Killer Cell Subsets in Cardiac Allograft Rejection   总被引:2,自引:0,他引:2  
To achieve donor-specific immune tolerance to allogeneic organ transplants, it is imperative to understand the cell types involved in acute allograft rejection. In wild-type mice, CD4(+) T cells are necessary and sufficient for acute rejection of cardiac allografts. However, when T-cell responses are suboptimal, such as in mice treated with costimulation-targeting agents or in CD28-deficient mice, and perhaps in transplanted patients taking immunosuppressive drugs, the participation of other lymphocytes such as CD8(+) T cells and NK1.1(+) cells becomes apparent. We found that host NK but not NKT cells were required for cardiac rejection. Ly49G2(+) NK cells suppressed rejection, whereas a subset of NK cells lacking inhibitory Ly49 receptors for donor MHC class I molecules was sufficient to promote rejection. Notably, rejection was independent of the activating receptors Ly49D and NKG2D. Finally, our experiments supported a mechanism by which NK cells promote expansion and effector function of alloreactive T cells. Thus, therapies aimed at specific subsets of NK cells may facilitate transplantation tolerance in settings of impaired T-cell function.  相似文献   
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We've studied the prognostic significance of the electrocardiographic coronary reserve, evaluated by seried effort tests, in patients with stable angina and proved coronary disease. Seventy-three patients with stable angina, who performed 2 exercise tests (basal and after vasodilator therapy) were included. It's considered variable reserve when in the second test the ST-descent improves greater than or equal to 1 mm for equal or higher double product (43 patients) and fixed reserve when it doesn't (30 patients). All of them underwent to coronariography study. The exercise test was seried each term during the first year. Clinical follow-up lasted 3 years and we considered cardiac events: myocardial infarction, unstable angina, surgery, PTCA or death. Patients with fixed reserve had higher maximal ST-descent (2.5 +/- 0.7 vs 1.9 +/- 0.6; p less than 0.05), lesser effort-time (359 +/- 144 vs 430 +/- 112; p less than 0.05), and more severe coronary disease (score: 3.5 +/- 1.5 vs 2.4 +/- 0.8; p less than 0.01) as compared with variable reserve group. Unfavorable clinic evolution was similar in both groups (44.3% in the fixed reserve group and 34.8% in the variable reserve group). We verified that 92.3% of patients with variable reserve who didn't modify its character in a year had good evolution; 76.4% of patients who changed to fixed reserve had unfavorable evolution (significant association, p less than 0.01). We conclude that in patients with variable reserve, the periodic evaluation of the reserve character has important prognostic implication.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
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Three unusual cases of basal cell carcinoma showing matrical differentiation as evidenced by the focal presence of "shadow cells" within basaloid islands are described. The term basal cell tumor with matrical differentiation seems to be appropriate for this type of tumor. Its differentiation from other tumors, particularly malignant pilomatricoma, is also discussed.  相似文献   
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Metallothionein-III is a low molecular weight, heavy-metal binding protein expressed mainly in the central nervous system. First identified as a growth inhibitory factor (GIF) of rat cortical neurons in vitro, it has subsequently been shown to be a member of the metallothionein (MT) gene family and renamed as MT-III. In this study we have raised polyclonal antibodies in rabbits against recombinant rat MT-III (rMT-III). The sera obtained reacted specifically against recombinant zinc-and cadmium-saturated rMT-III, and did not cross-react with native rat MT-I and MT-II purified from the liver of zinc injected rats. The specificity of the antibody was also demonstrated in immunocytochemical studies by the elimination of the immunostaining by preincubation of the antibody with brain (but not liver) extracts, and by the results obtained in MT-III null mice. The antibody was used to characterize the putative differences between the rat brain MT isoforms, namely MT-I+II and MT-III, in the freeze lesion model of brain damage, and for developing an ELISA for MT-III suitable for brain samples. In the normal rat brain, MT-III was mostly present primarily in astrocytes. However, lectin staining indicated that MT-III immunoreactivity was also present in microglia, monocytes and/or macrophages in the leptomeninges and lying adjacent to major vessels. In freeze lesioned rats, both MT-I+II and MT-III immunoreactivities increased in the ipsilateral cortex. The pattern of MT-III immunoreactivity significantly differed from that of MT-I+II, since the latter was evident in both the vicinity of the lesioned tissue and deeper cortical layers, whereas that of the former was located only in the deeper cortical layers. This suggests different roles for these MT isoforms, and indeed in a new bioassay measuring astrocyte migration in vitro, rMT-III promoted migration to a higher extent than MT-I+II. Thus, MT-III could not only affect neuronal sprouting as previously suggested, but also astrocyte function. Finally, MT-III protein levels of patients with Alzheimer's disease (AD) were, if anything, increased when compared with similarly aged control brains, which was in agreement with the significantly increased MT-III mRNA levels of AD brains.  相似文献   
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Objective

To compare the effects of classic progressive resistance training (PRT) versus eccentric strength-enhanced training (EST) on the performance of functional tests and different strength manifestations in the lower limb of people with multiple sclerosis (PwMS).

Design

Experimental trial.

Setting

Strength training program.

Participants

PwMS (N=52; 19 men, 33 women) belonging to MS associations from the Castilla y León, Spain.

Interventions

Participants were assigned to 1 of 2 groups: a control group that performed PRT or an experimental group that performed EST. In both groups, the knee extensor muscles were trained for 12 weeks.

Main Outcome Measures

Before and after 12 weeks of training, maximal voluntary isometric contraction and 1 repetition maximum (1RM) of the knee extensors were evaluated, as were the Chair Stand Test (CST) and Timed 8-Foot Up and Go (TUG) functional tests.

Results

No differences were found between the groups in the initial values for different tests. Intragroup comparisons found significant differences in CST (F=69.4; P<.001), TUG (F=40.0; P<.001), and 1RM (F=57.8; P<.001). For intergroup comparisons, EST presented better results than PRT in the CST (EST, 4.7%±2.8%; PRT, 1.9%±2.8%; F=13.1; P=.001) and TUG (EST, ?2.9±4.7; PRT, ?.41±5.6; F=5.6; P=.022).

Conclusions

In PwMS, EST leads to improvements in 1RM, TUG, and CST that are similar to those of PRT. However, for patients who participated in this study, the EST seems to promote a better transfer of strength adaptations to the functional tests, which are closer to daily-living activities.  相似文献   
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