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Several previous observations indicate a role for the immune system in the pathogenesis of insulin-dependent diabetes mellitus (IDDM) in non-obese diabetic (NOD) mice. In order to assess the status of the immune system in this model of spontaneous diabetes we studied the phenotype of circulating lymphocytes and the humoral autoimmunity to islet cells in non-diabetic NOD mice at various ages. Lymphocyte numbers were low in young NOD mice (age less than 160 days) as compared with other strains of mice and increased later to reach values in or above the range of controls. The percentages of circulating T lymphocytes and their L3T4+ and Lyt2+ subsets were higher in NOD mice of all ages and both sexes than in controls; however, no imbalance of the L3T4+ and Lyt2+ subpopulations was found. Anti-insulin autoantibodies were detected by an ELISA assay in all the NOD mice studied throughout the entire period of observation. Autoantibodies reacting with the cytoplasm of islet cells in Bouin's fixed pancreas sections, likely to be anti-insulin antibodies, were found in 47 to 58% of the samples from NOD mice aged 75 to 150 days. Antibodies to surface antigens of rat insulinoma cells were virtually absent in young NOD mice (75-100 days) and appeared in 33 to 43% of the samples from 150 to 185 days old NOD mice. The autoantibodies and the quantitative lymphocyte abnormalities reported here, although not predictive of the appearance of overt diabetes, are likely to be involved in the pathogenesis of the disease and therefore may indicate directions for future investigations.  相似文献   
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Migraine is common in children, but few specific drugs are available. We performed an open-label comparison of effects of two nutraceutical preparations (ginkgolide B vs. Griffonia simplicifolia extract) on outcomes in 374 school-age children (mean 10.7?years) with migraine without aura. Half of them received ginkgolide B; and half, Griffonia simplicifolia. Both preparations were given orally twice a day for 6?months. Patients kept a headache diary. Outcomes at the beginning and end of treatment were compared. Both preparations reduced all outcome measures after 6?months of treatment. However, reductions in headache frequency, duration and intensity, PedMIDAS score and behavioural reactions to headache were significantly greater in the ginkgolide B group. Both nutraceutical treatments appear promising in paediatric migraine without aura, particularly because of their lack of side effects. However, the ginkgolide B preparation was significantly more effective in the medium-term (6?months).  相似文献   
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Accuracy of evolutionary analysis of populations within a species requires the testing of a large number of genetic polymorphisms belonging to many loci. We report here a reconstruction of human differentiation based on 100 DNA polymorphisms tested in five populations from four continents. The results agree with earlier conclusions based on other classes of genetic markers but reveal that Europeans do not fit a simple model of independently evolving populations with equal evolutionary rates. Evolutionary models involving early admixture are compatible with the data. Taking one such model into account, we examined through simulation whether random genetic drift alone might explain the variation among gene frequencies across populations and genes. A measure of variation among populations was calculated for each polymorphism, and its distribution for the 100 polymorphisms was compared with that expected for a drift-only hypothesis. At least two-thirds of the polymorphisms appear to be selectively neutral, but there are significant deviations at the two ends of the observed distribution of the measure of variation: a slight excess of polymorphisms with low variation and a greater excess with high variation. This indicates that a few DNA polymorphisms are affected by natural selection, rarely heterotic, and more often disruptive, while most are selectively neutral.  相似文献   
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Concurrence of distinct genetic conditions in the same patient is not rare. Several cases involving neurofibromatosis type 1 (NF1) have recently been reported, indicating the need for more extensive molecular analysis when phenotypic features cannot be explained by a single gene mutation. Here, we describe the clinical presentation of a boy with a typical NF1 microdeletion syndrome complicated by cleft palate and other dysmorphic features, hypoplasia of corpus callosum, and partial bicoronal craniosynostosis caused by a novel 2bp deletion in exon 2 of Meis homeobox 2 gene (MEIS2) inherited from the mildly affected father. This is only the second case of an inherited MEIS2 intragenic mutation reported to date. MEIS2 is known to be associated with cleft palate, intellectual disability, heart defects, and dysmorphic features. Our clinical report suggests that this gene may also have a role in cranial morphogenesis in humans, as previously observed in animal models.  相似文献   
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One hundred consecutive patients with severe aplastic anemia (SAA) received horse antilymphocyte globulin (ALG), cyclosporin A (CyA), 6-methylprednisolone (6Mpred), and granulocyte colony-stimulating factor (G-CSF) as first-line therapy. The median age was 16 years (range, 1-72 years) and median neutrophil count was 0.2 x 10(9)/L (range, 0-0.5 x 10(9)/L). Trilineage hematologic recovery (at a median interval of 96 days from treatment) was seen in 77 patients (48 complete, 29 partial) after 1 (n = 50) or more courses of ALG (n = 27). Of the 23 nonresponders, 11 patients died at a median interval of 83 days (range, 16-1132 days), 6 were considered treatment failures and underwent transplantation, and 6 were pancytopenic. Cytogenetic abnormalities were seen in 11% of patients, clonal hematologic disease in 8%, and relapse of marrow aplasia in 9%. The actuarial survival at 5 years was 87% (median follow-up 1424 days): 76% versus 98% for patients with neutrophil counts less than versus greater than 0.2 x 10(9)/L (P =.001) and 88% versus 87% for patients aged less than versus more than 16 years (P =.8). The actuarial probability of discontinuing CyA was 38%. Patients who did not achieve a white blood cell (WBC) count of 5 x 10(9)/L during G-CSF treatment have a low probability of responding (37%) and a high mortality rate (42%). This update confirms a high probability for SAA patients of becoming transfusion independent and of surviving after treatment with ALG, CyA, 6Mpred, and G-CSF, with a significant effect of neutrophil counts on outcome. Problems still remain, such as absent or incomplete responses, clonal evolution, relapse of the original disease, and cyclosporine dependence. Early transplantation, also from alternative donors, may be warranted in patients with poor WBC response to G-CSF. (Blood. 2000;95:1931-1934)  相似文献   
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