完全观察潜伏期估计

潜伏期的估计在流行病学调查和制订疾病防制措施中具有重要的意义和用途。疾病潜伏期是指某病患从感染到最早临床症状出现的这一段时间区间。疾病潜伏期调查的特点是观测的完全性与不完全性混杂。完全观察（complete observations）是指感染日期明确的观察。所谓不完全观察（incomplete observations）是指只能调查到患的感染期区间而不能确定具体感染日期。目前最可靠的潜伏期估算是基于对具有完全观察病例的研究，传统所使用的统计方法大多数是中位数法，即将若干个体的潜伏期从小到大排列，位置居于中问的数字即为该病的平均潜伏期。本讲座主要探讨完全观察病例潜伏期的非参数和参数估计的方法，为疾病潜伏期的估计提供新的统计方法。     

胆囊炎、胆石症合并急性心肌梗死2例临床分析

近年来,随着生活水平的提高及生活方式的改变,冠心病的发病率已呈现明显上升趋势[1].在急诊工作中,不典型的心肌梗死有时易与急腹症相混淆,给诊断与治疗带来困难.本文就我科今年接诊的2例胆囊炎、胆石症合并急性心肌梗死进行回顾性分析.     

沙棘的化学营养成份及其医学保健作用

作为一种重要的经济植物，沙棘含有黄酮类、β-胡萝卜素、多种维生素、不饱和脂肪酸、多种氨基酸和微量元素等生物活性物质，其具有重要的医学保健作用，集中表现为对心血管系统、免疫系统、肝损伤的保护、消化系统及抗肿瘤作用等。     

REML法和MCMC法在数量性状核心家系遗传方差分量模型中参数估计的比较

目的 比较限制性最大似然估计(REML)和马尔可夫链蒙特卡罗(MCMC)方法在数量性状遗传方差分量模型中参数估计的偏差和精度。方法 计算机模拟50个数量性状核心家系数据集，运用SAS软件中的PROC MIXED程序和WinBUGS软件进行参数估计，比较不同样本含量时两法参数估计结果。结果 在本试验参数指定条件下，对固定效应参数，两法估计的相对偏差低于2％；对随机效应，估计偏差较高。小样本时，MCMC法估计结果比REML法更接近真值。结论 在模拟数量性状方差分量模型时，大样本家系资料可根据实际情况选用两法；小样本家系资料，MCMC法可得到比REML法更稳健的估计，推荐使用。     

完全性肺静脉畸形引流的超声诊断与手术结果的对比分析

完全性肺静脉畸形引流的超声诊断与手术结果的对比分析栾姝蓉陈启明韩玲周其文完全性肺静脉畸形引流（ＴＡＰＶＣ）约占先天性心脏病的１．５％～３％〔１〕，由于临床上无特异性杂音，常难与其它心脏疾病鉴别。二维超声心动图虽可提示本病，但确诊仍困难，随着彩色多普勒...     

胸腹联合伤抢救体会(附4例报告)

胸腹联合伤病势凶险,病理生理复杂,病情恶化快,抢救不及时或处理不当常在短时间内死亡。我院自1987年10月至1990年5月抢救4例均获成功,现报告如下: 【例1】患者男,53岁。因被镰刀砍伤左背部6小时,于1987年10月10日急症入院。检查:表情淡漠,面     

经腹膜的腹膜外子宫切除术20例报告

我们在西非几内亚比绍共和国工作期间,发现当地群众患疤痕疙瘩(疤痕瘤)者较多,手术后并发粘连者多;当地黑人也喜在身上用刀划痕刻花,愈后痕疤凸出,花纹显露,似普遍存有粘连素质。此外,当地医疗条件差,设备简陋、器械种类少、护理质量低,还经常缺水。为减少术后腹内粘连的发生,为减少术前术后护理工作,我们因地制宜开展了经腹膜的腹膜外子宫切除术,现报道如下:     

流行病学数学模型

1 概述流行病学数学模型,是把数学方法应用到流行病学学科领域建立起来的数学模型。它是理论流行病学研究的主要方法,所以理论流行病学又称数学流行病学或数量流行病学。所谓建立数学模型,通常是指把疾病的流行过程,用符号、数字组成的数学式表达出来,定量地揭示出其可供分析、解释、预报、控制或决策的内在规律。建立一个流行病学数学模型,一般包括如下几步:     

COA: Bone Morphogenetic Protein 2 Promoted Transforming Growth Factor β3 Induced Chondrogenesis of Human Osteoarthritic Synovium-Derived Stem Cells

Background Synovium-derived stem cells (SDSCs) with greater chondrogenic potential are attracting more considerable attention as a cell source for cartilage regeneration. The aim of this study was to investigate the effect of bone morphogenetic protein-2 (BMP-2) on transforming growth factor-beta3 (TGF-β3)-induced chondrogenesis of SDSCs isolated from human osteoarthritic synovium in a pellet culture system. Methods Nucleated cells isolated from human osteoarthritic synovium were plated at an optimal cell density to allow the selective proliferation of SDSCs. The clonogenicity, stem cell marker expression and multi-differentiation potential were determined by CFU assay, flow cytometry assay and specific staining including alizarin red S staining, Oil red staining and alcian blue staining, respectively. SDSCs pellet was cultured in chondrogenic medium without or with TGF-β3 or/and BMP-2. At day 21, the diameter and the weight of the pellets were measured. Chondrogenic differentiation of SDSCs was evaluated by Safranin O staining, immunohistochemical staining of collagen type II, sulfated glycosaminoglycan (sGAG) synthesis and mRNA expression of collagen type II (COL2A1), aggrecan (ACAN), SOX9, link-protein (HAPLN1), collagen type X (COL10A1) and BMP receptor II (BMPR-II). Results Cells isolated under the optimized culturing density (104/60cm2) showed clonogenicity and multi-differentiation potential. These cells were positive (>99% positive) for CD44, CD90, CD105 and negative (<10% positive) for CD34 and CD71. SDSCs differentiated to a chondrocytic phenotype in chondrogenic medium containing TGF-β3 with or without BMP-2. Metachromatic staining of the extracellular matrix with Safarnin O was positive and the expression of collagen type II was detected. The combination of TGF-β3 and BMP-2 produced cell pellets with larger diameter and weight, produced more sGAGs, expression higher levels of collagen type II and chondrogenic markers, except COL10A1, than medium with TGF-β3 alone. Conclusions SDSCs could be isolated from human osteoarthritic synovium. Supplementation of BMP-2 significantly promoted the in vitro TGF-β3-induced chondrogenic differentiation of SDSCs.