TGFβ1诱导的肝脏前体细胞上皮-间质转换在逆转过程中可影响星状细胞活化

目的通过收集TGFβ1刺激过的前体细胞条件培养基,观察其对HSC的影响。方法收集TGFβ1预处理的前体细胞条件培养基,培养HSC细胞48 h,观察HSC活化程度及细胞外基质相关指标的变化。结果经TGFβ1刺激后的前体细胞形态明显变大变圆,胞质比例明显增加,核质比减少。去除TGFβ1刺激后,发现TGFβ1刺激超过24 h,前体细胞的上皮-间质转换发生逆转,表现为α-平滑肌肌动蛋白(α-smooth muscle actin,α-SMA)蛋白表达量下降,24 h、36 h及48h分别为对照组的1.31倍(P0.05)、0.97倍(P=0.027)、1.08倍(P=0.058)。与对照组相比,TGFβ1刺激后前体细胞的条件培养基对HSCs的细胞形态无明显差别。进一步分析发现,TGFβ1刺激前体细胞6h后,其条件培养基促使星状细胞α-SMA及细胞外基质标志物金属蛋白酶组织抑制剂-1(tissue inhibitor of metalloproteinase,TIMP-1)在蛋白及基因水平上(分别为对照组的4.12倍及2.64倍)的表达;然而刺激超过24h上述作用相反,在蛋白水平表现为α-SMA表达降低而TIMP-1的表达无明显变化,在基因水平α-SMA及TIMP-1均呈降低趋势(24 h、36 h、48 h分别为对照组0.81倍及0.98倍、0.96倍及0.61倍、0.63倍及0.76倍)。结论去除TGFβ1的刺激后,其诱导的上皮-间质转换可发生逆转,并在逆转过程中可影响星状细胞的活化。     

Clinical factors influencing the efficacy of pooled platelet transfusions

To determine the relative importance of clinical factors on the efficacy of platelet transfusions, 941 pooled platelet transfusions from HLA-unmatched donors were studied prospectively in 133 patients with bone marrow failure. Multiple linear regression analyses identified the major factors influencing one-hour-corrected increments (CI) as prior splenectomy, bone marrow transplantation, disseminated intravascular coagulation, concurrent intravenous amphotericin B, splenomegaly, and HLA antibody grade. The relative impact of these factors on CI has been quantitated by using a formula developed from these data. A linear relationship was demonstrated between increasing percentage of HLA antibody grade and decreasing CI. A number of other factors were less important in the linear regression model than the aforementioned major factors. These included platelet-specific antibodies, concurrent antibacterial antibiotics, clinical bleeding grade, and temperature. Factors that did not influence CI included the number of prior platelet transfusions, prior granulocyte transfusions, prior red cell transfusions, infection, age, blood group, diagnosis, sex, pretransfusion platelet count, prior pregnancies, and concurrent antineoplastic drugs. This study identified major clinical factors that significantly influenced CI and were major causes of refractoriness to pooled platelet transfusions.     

Overweight and obesity trends in Copenhagen schoolchildren from 2002 to 2007

Aim: The purpose of this study is to monitor the prevalence trend in overweight and obesity among Copenhagen schoolchildren from the school years 2002 to 2007. Methods: Copenhagen community health service doctors conducted routine examinations at school entry (ages 5–8 years) and exit (ages 14–16 years). Body mass index (kg/m²) of 33 245 schoolchildren was calculated. The prevalence of overweight (including obesity) and obesity was classified using the International Obesity Task Force definitions. Results: From 2002 to 2007, although the prevalence of overweight (including obesity) in young girls decreased from 17.8 to 15.9%, the trend was non‐significant. In young boys, the trend slightly decreased, and the prevalence fell from 14.0 to 11.6%. In adolescent girls, the prevalence varied considerably and increased from 22.7 to 25.4% without a discernable trend. In adolescent boys, the trend slightly increased, and the prevalence rose from 15.8 to 18.9%. There were no significant changes in the prevalence of obesity. Conclusion: In contrast to the preceding decades, we identified a potential stagnation in the obesity epidemic among children but a continuing increase among adolescents. It remains critical to continue monitoring and to increase preventive measures to reduce the prevalence of overweight and obesity.     

L-蛋氨酸驱铅对小鼠体内微量元素的影响

目的　探讨L 蛋氨酸 (L Met)驱铅对小鼠体内微量元素Zn、Cu、Mn、Fe的影响。方法　分别给小鼠蒸馏水 (样本数 =1 0 ,正常对照组 )或 40 0 μg/ml(以Pb2 + 计 )的醋酸铅溶液 (样本数 =2 0 )作为饮用水 ,持续 1 0d,然后 ,停止喂铅 ;将染铅小鼠再随机均分为 2组 ,一组改用蒸馏水 (样本数 =1 0 ,Pb对照组 ) ,另一组改用 0 .5mg/mlL Met溶液 (样本数 =1 0 ,Pb +L Met组 )作为饮用水 ,持续进行 4周。实验开始和结束时 ,分别称取小鼠的体重。 4周后的第 1天 ,杀死所有动物 ,取出各组小鼠的肝、脑、脾、肾 ,用电感耦合等离子体发射光谱法 (ICP)测定其中的Pb、Zn、Cu、Mn、Fe含量 ,并与正常对照组和Pb对照组进行比较。结果　Pb对照组小鼠肝、脑、脾、肾中Pb含量 [(1 .490± 1 .654)、(3 .470±2 .757)、(4.975± 2 .993)、(0 .0 66± 0 .0 0 1 ) μg/g]明显高于正常对照组 [(0 .0 1 5± 0 .0 0 1 )、(0 .0 0 9±0 .0 0 7)、(0 .0 2 7± 0 .0 0 2 )、(0 .0 0 6± 0 .0 1 5) μg/g] ,差异有显著性 (P <0 .0 5) ;肝、脑、脾中Zn含量 ,肝、脑、脾、肾中Fe含量及Mn含量均明显低于正常对照组 ,差异有显著性 (P <0 .0 5)。L Met组小鼠脑、脾中的Pb含量和肾Cu含量明显高于正常对照组 ,差异有显著性 (P <0 .0 5) ;肝、脑、