脂质比值与代谢综合征的关联及预测价值评价：基于多阶段横断面研究

背景 随着代谢性疾病发病率的上升,代谢综合征(MS)的预防与控制引起广泛的关注。而脂质比值是重要的筛查指标之一,与MS之间的关系成为热点研究话题。目的 基于贵州省多阶段横断面研究人群分析三酰甘油/高密度脂蛋白胆固醇(TG/HDL-C)、总胆固醇/HDL-C(TC/HDL-C)、低密度脂蛋白胆固醇/HDL-C(LDL-C/HDL-C)及非高密度脂蛋白胆固醇(non-HDL-C)与MS发病风险的关联及预测价值评价。方法 回顾性选取贵州省参与2010年全国疾病监测地区慢性病及危险因素调查、2013年中国慢性病及其危险因素监测、2015年中国成人慢性病与营养监测和2018年中国成人慢性病与营养监测的21 727例自然人群为研究对象,收集研究对象的基线资料,根据是否患有MS将研究对象分为MS组(n=4 981)和非MS组(n=16 746)。绘制受试者工作特征曲线(ROC曲线)分别评价男性和女性TG/HDL-C、TC/HDL-C、LDL-C/HDL-C和non-HDL-C对MS的预测价值。通过Delong检验比较脂质比值预测MS发生的ROC曲线下面积(AUC)的差异。采用多因素Logistic回...     

Calcineurin B1 is essential for positive but not negative selection during thymocyte development

During development, discrete cell fates often result from variation in the intensity of a particular signal. The mechanisms underlying these seemingly analog-to-digital switches are not understood. In developing T lymphocytes, low-intensity signals through the antigen receptor result in positive selection while more intense signals give rise to negative selection. By deleting the genetic locus encoding the regulatory B1 subunit of calcineurin specifically in thymocytes, we found an absolute requirement for calcineurin in positive selection. In contrast, calcineurin activity was dispensable in several models of negative selection. Unexpectedly, we found that removal of calcineurin activity from thymocytes results in inefficient ERK activation at the double-positive stage of thymocyte development, when selection occurs. These studies clarify the mechanism by which graded signals are converted to discrete outcomes in T cell development and further indicate that the developmental roles of calcineurin likely contribute to immunosuppression by calcineurin inhibitors.     

Circulating inflammatory mediators during start of fever in differential diagnosis of gram-negative and gram-positive infections in leukopenic rats

Gram-negative and gram-positive infections have been considered the most important causes of morbidity and mortality in patients with leukopenia following chemotherapy. However, discrimination between bacterial infections and harmless fever episodes is difficult. Because classical inflammatory signs of infection are often absent and fever is frequently the only sign of infection, the aim of this study was to assess the significance of serum interleukin-6 (IL-6), IL-10, macrophage inflammatory protein-2 (MIP-2), procalcitonin (PCT), and C-reactive protein (CRP) patterns in identifying bacterial infections during start of fever in normal and cyclophosphamide-treated (leukopenic) rats following an injection of lipopolysaccharide (LPS) or muramyl dipeptide (MDP) as a model for gram-negative and gram-positive bacterial infections. We found that, compared to normal rats, immunosuppressed animals exhibited significantly higher fevers and lesser production of all mediators, except IL-6, after toxin challenge. Moreover, compared to rats that received MDP, both groups of animals that received an equivalent dose of LPS showed significantly higher fevers and greater increase in serum cytokine levels. Furthermore, in contrast to those in immunocompetent rats, serum levels of IL-6 and MIP-2 were not significantly changed in leukopenic animals after MDP injection. Other serum markers such as PCT and CRP failed to discriminate between bacterial stimuli in both groups of animals. These results suggest that the use of the analyzed serum markers at an early stage of fever could give useful information for the clinician for excluding gram-negative from gram-positive infections.     

Combined high resolution linkage and association mapping of quantitative trait loci

In this paper, we investigate variance component models of both linkage analysis and high resolution linkage disequilibrium (LD) mapping for quantitative trait loci (QTL). The models are based on both family pedigree and population data. We consider likelihoods which utilize flanking marker information, and carry out an analysis of model building and parameter estimations. The likelihoods jointly include recombination fractions, LD coefficients, the average allele substitution effect and allele dominant effect as parameters. Hence, the model simultaneously takes care of the linkage, LD or association and the effects of the putative trait locus. The models clearly demonstrate that linkage analysis and LD mapping are complementary, not exclusive, methods for QTL mapping. By power calculations and comparisons, we show the advantages of the proposed method: (1) population data can provide information for LD mapping, and family pedigree data can provide information for both linkage analysis and LD mapping; (2) using family pedigree data and a sparse marker map, one may investigate the prior suggestive linkage between trait locus and markers to obtain low resolution of the trait loci, because linkage analysis can locate a broad candidate region; (3) with the prior knowledge of suggestive linkage from linkage analysis, both population and family pedigree data can be used simultaneously in high resolution LD mapping based on a dense marker map, since LD mapping can increase the resolution for candidate regions; (4) models of high resolution LD mappings using two flanking markers have higher power than that of models of using only one marker in the analysis; (5) excluding the dominant variance from the analysis when it does exist would lose power; (6) by performing linkage interval mappings, one may get higher power than by using only one marker in the analysis.     

Iloprost对内皮细胞抗血栓功能的影响

以体外培养的猪主动脉内皮细胞（ＥＣ）为模型研究Ｉｌｏｐｏｓｔ对ＥＣ抗血栓功能的影响。用放免法、发色底物法测定培养液中６－酮－ＰＧＦ１α（６－ｋｅｔｏ－ＰＧＦ１α），血栓素Ｂ２（ＴＸＢ２）含量，纤溶酶原激活物（ＰＡ），纤溶酶原激活物抑制物（ＰＡＩ）活性及ＥＣ环磷酸腺苷（ｃＡＭＰ）含量。结果表明：Ｉｌｏｐｒｏｓｔ中以使ＥＣ生成６－ｋｅｔｏ－ＰＧＦ１α，ｃＡＭＰ含量显著增多，ＴＸＢ２含量显著减少，并使Ｐ     

Linkage and association of adrenergic and dopamine receptor genes in the distal portion of the long arm of chromosome 5 with systolic blood pressure variation

Elevated blood pressure is an important risk factor for renal-, cerebro- and cardiovascular diseases. We used an efficient discordant sib-pair ascertainment scheme to investigate the impact of the distal end of the long arm of human chromosome 5 (chromosomal region 5q31.1-qter) containing genes for the alpha1B and beta2 adrenergic receptors and the dopamine receptor type 1A on variation of systolic blood pressure in young Caucasians. We measured eight highly polymorphic markers spanning this positional candidate gene-rich region in 427 individuals from 55 three-generation pedigrees containing 69 discordant sibling pairs, and calculated multipoint identity by descent (MIBD) probabilities. The results of genetic linkage and association tests indicate that the region between markers D5S2093 and D5S462 is significantly linked to one or more polymorphic genes influencing interindividual variation in systolic blood pressure levels. Since the alpha1B adrenergic receptor and dopamine receptor type 1A genes are located close to these markers, these data suggest that genetic variation in one or both of these G protein-coupled receptors, which participate in the control of vascular tone, plays an important role in influencing interindividual variation in systolic blood pressure levels.      

FD-1冷冻干燥机的研制及生物材料的冷冻干燥

观察自制冷冻干燥机冷冻干燥生物材料的效果。采用 R5 0 2压缩机和制冷剂制成 FD- 1冷冻干燥机。本实验冷冻干燥了胶原海绵、菌种及去纤酶。在冻干箱负载或空载情况下蒸发冷凝器温度均可达到 - 4 5℃ ,小冰箱可达到 - 30℃ ,冻干的胶原海绵具有许多孔洞的结构 ,冻干的菌种和去纤酶性能保持良好。 FD- 1冷冻干燥机适用于生物样品中小批量的冷冻干燥     

氧离子注入增强人工关节软骨材料-UHMWPE的耐磨性

用高能离子注入机对超高分子量聚乙烯 (U HMWPE)进行了 O+注入改性 ,注入能量为 4 5 0 ke V和 10 0ke V,剂量分别为 1× 10 1 5/cm2 ,5× 10 1 5/cm2和 1× 10 1 6 /cm2。以 Si3N4 球为上销样 ,UHMWPE为下盘样组成摩擦副 ,在销盘摩擦试验机上评价它们在干摩擦和蒸馏水润滑条件下的磨损性能。结果表明 ,几种注入工艺均增强了UHMWPE的耐磨性 ,但提高了其摩擦系数 ,其中以能量为 4 5 0 Ke V,剂量为 5× 10 1 5/cm2的注入样品耐磨性最好。未注入 U HMWPE的磨损主要表现为黏着、塑性变形和犁沟 ,注入 U HMWPE的磨损主要为表面硬化层疲劳裂纹的萌生、扩展、剥落及磨粒磨损     

绞股蓝总皂甙对正常人及麻醉犬缺氧性肺血管收缩反应的影响

本文研究绞股蓝总皂甙对血流动力学及缺氧性肺血管收缩反应的影响。１４名男性志愿者口服２０日后，基础血流动力学指标无显著变化，但ＨＰＶ显著降低。服药后血小板活化程度，血浆血管紧张素Ⅰ、Ⅱ含量都明显降低。     

用噬菌体表面展示技术筛选与肝癌细胞系结合的抗体模拟肽

目的:从噬菌体展示肽库中,筛选可与肝癌细胞特异性结合的抗体模拟肽。方法:通过生物淘选使噬菌体富集。利用ELISA法,鉴定噬菌体单克隆原种的亲和性,并进行统计学分析。通过竞争ELISA,分析筛选所得抗体模拟肽的结合位点,并进一步分析抗体模拟肽的序列组成。结果:随着淘选次数的增加,出现噬菌体的富集。ELISA的结果显示,相对于正常肝细胞,筛选所得环状7肽对肝癌细胞系SMMC7721和BEL7402均有良好的结合活性(P<0.05),且与SMMC7721细胞的结合活性明显优于与BEL7402细胞的亲和性(P<0.05)。在α=0.01的水平上,7肽单克隆噬菌体原种可明显与scFv竞争结合SMMC7721细胞(0.005相似文献