DNA methylation regulates lineage-specifying genes in primary lymphatic and blood endothelial cells

During embryonic development, the lymphatic system emerges by transdifferentiation from the cardinal vein. Although lymphatic and blood vasculature share a close molecular and developmental relationship, they display distinct features and functions. However, even after terminal differentiation, transitions between blood endothelial cells (BEC) and lymphatic endothelial cells (LEC) have been reported. Since phenotypic plasticity and cellular differentiation processes frequently involve epigenetic mechanisms, we hypothesized that DNA methylation might play a role in regulating cell type-specific expression in endothelial cells. By analyzing global gene expression and methylation patterns of primary human dermal LEC and BEC, we identified a highly significant set of genes, which were differentially methylated and expressed. Pathway analyses of the differentially methylated and upregulated genes in LEC revealed involvement in developmental and transdifferentiation processes. We further identified a set of novel genes, which might be implicated in regulating BEC-LEC plasticity and could serve as therapeutic targets and/or biomarkers in vascular diseases associated with alterations in the endothelial phenotype.     

单侧腰-硬联合麻醉用于高龄患者髋关节手术的效果

【摘要】 目的 探讨80岁以上高龄患者髋关节置换手术采用单侧腰硬联合麻醉的临床效果。 方法 我院2009年至2011年择期行髋关节置换手术病例130例,年龄在80~96岁,ASA Ⅱ~Ⅲ级。将130例随机分为对照组和观察组,每组各65例,观察组于L3-L4穿刺采用单侧腰硬联合麻醉;对照组于L2-L3穿刺采用硬膜外麻醉。两组患者一般资料无明显差异,具有可比性。观察两组麻醉效果。 结果 观察组患者在麻醉起效时间和麻醉阻滞完善时间明显较对照组快,(P<0.05)。两组患者麻醉前后心率无明显变化,对照组的收缩压、舒张压、平均动脉压麻醉后与术前比较波动较大(P<0.05)。两组患者麻醉效果比较,观察组麻醉效果好于对照组。 结论 单侧腰硬联合麻醉具有起效快、镇痛和肌松效果好、麻醉平面可控性强、呼吸循环影响小等优点,可安全有效地用于高龄患者的手术麻醉。     

影响胫骨平台骨折预后因素的研究

【摘要】 目的 探讨影响胫骨平台骨折预后的因素,为临床治疗及康复提供依据。方法 收集2006年1月~2011年12月收治的62例胫骨平台骨折病例,其中非手术治疗19例,方法为抽取关节腔积血,加压包扎,石膏托外固定;手术治疗43例,方法为切开复位内固定。结果 临床治疗后均获得随访,随访平均时间2.8年。参照Lysolm评分标准,非手术治疗组优良率73.7%,手术治疗组优良率88.4%。SchatzkerⅠ、Ⅱ、Ⅲ型骨折优良率高于Ⅳ、Ⅴ、Ⅵ型(P<0.05);男性患者优良率稍高于女性患者,但差异无统计学意义;8小时内治疗的患者预后优良率高于8小时后治疗的患者(P<0.05);60岁以上患者预后优良率不及60岁以下患者。3例患者术后出现创伤性关节炎,2例患者术后出现不同程度的关节面塌陷。结论 手术是胫骨平台骨折的有效治疗方法。胫骨平台骨折类型,治疗方法和治疗时机的选择,患者年龄,早期功能锻炼可以影响胫骨平台骨折的预后。     

Influence of electrode misplacement on the electrocardiographic signs of inferior myocardial ischemia

Electrocardiographic (ECG) artifacts resulting from misplacements of electrodes are frequent, difficult to detect, and can become of clinical importance. We investigated 2 healthy volunteers and 3 patients with ECG signs of inferior myocardial scars. We exchanged the peripheral electrodes in a defined manner and investigated the resulting ECG for morphology and possible diagnostic errors. In the volunteers, ECG signs of inferior ischemia could be produced. In the patients with ischemic heart disease, normal ECG without signs of ischemia resulted by placing the electrode of the left leg to the left arm. The automatic ECG analyzer was not helpful in detecting artifacts by misplaced electrodes. A very low amplitude of the QRS complex in lead I, II, or III was pathognomonic for electrode misplacement in half of the cases. ECG artifacts must also be suspected when abnormal QRS- or P-axis occur or when QRS morphology does not match with the clinical presentation of the patient.     

急诊科临床分离细菌耐药性分析

目的了解北京大学第一医院急诊科2012年至2015年临床分离细菌的分布及抗菌药物耐药情况。方法收集急诊科2012年至2015年临床分离的非重复细菌,用纸片扩散法或自动化仪器法进行抗菌药物敏感性试验,按照美国临床和实验室标准协会(CLSI)2015标准判定药物敏感结果,用WHONET5.6软件进行统计分析。结果临床共分离1283株细菌,其中革兰氏阳性菌占30.6%,革兰氏阴性菌占69.4%。分离最多的前5位细菌分别是大肠埃希菌(18.4%),鲍曼不动杆菌(15.2%),金黄色葡萄球菌(13.3%),铜绿假单胞菌(12.7%)和肺炎克雷伯菌(8.8%)。耐甲氧西林金黄色葡萄球菌(MRSA)的平均检出率为75.6%,耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)的平均检出率为83.1%,葡萄球菌中未发现对利奈唑胺、万古霉素耐药菌株。粪肠球菌对所测试的大多数抗菌药物的耐药率均明显低于屎肠球菌。超广谱β内酰胺酶(ESBLs)阳性大肠埃希菌的检出率为64.8%,克雷伯菌属细菌为40.5%。铜绿假单胞菌对亚胺培南、美罗培南耐药率分别为30.1%,28.4%,鲍曼不动杆菌对亚胺培南、美罗培南耐药率分别为83.5和83.0%。结论临床分离细菌对抗菌药物耐药性较高,MRSA、耐万古霉素肠球菌、泛耐药肠杆菌科细菌、泛耐药鲍曼不动杆菌、泛耐药铜绿假单胞菌的检出率较高,给临床治疗带来一定挑战。     

红芪不同提取物对环磷酰胺所致免疫低下小鼠的影响及相关成分含量研究

目的对比研究红芪不同提取物对环磷酰胺(CTX)所致免疫低下小鼠的影响及相关化学成分含量。方法按照体重将昆明种小鼠随机分为空白组、模型组、对照组、醇提物组、水提物组、醇沉物组、残留物组。用CTX 40 mg·kg^-1造成免疫低下模型。对照组灌胃参芪颗粒5 g·kg^-1,其他各组灌胃相应受试样品2 g·kg^-1,正常组和模型组灌胃等量0.9%Na Cl,每天给药1次,连续15 d。称重计算小鼠脏器指数,腹腔注射5%鸡红细胞悬液(CRBC)测定腹腔巨噬细胞吞噬百分率及吞噬指数,用50%二硝基氯苯(DNCB)丙酮溶液致迟发型超敏反应测定OD值,用5%CRBC致敏测定血清溶血素OD值,尾静脉注射印度墨汁测定网状内皮系统吞噬指数及吞噬系数。用UV法测定多糖、总皂苷含量。结果模型组各指标与正常组比较,差异均有统计学意义(均P<0.01)。给药后,正常组、模型组与醇提物组、水提物组、醇沉物组、残留物组的胸腺指数(g·kg^-1)分别为2.55±0.88,1.04±0.74,1.24±0.79,1.81±0.62,1.97±0.83,1.09±0.75,水提物组、醇沉物组与模型组比较,差异均有统计学意义(均P<0.05);水提物组、醇沉物组与残留物组比较,差异均有统计学意义(P<0.05)。这6组的腹腔巨噬细胞吞噬百分率(%)分别为48.58±5.51,28.54±3.15,35.28±6.03,36.99±6.78,39.89±8.33,27.91±8.02,醇提物组、水提物组、醇沉物组的吞噬百分率与模型组比较,差异均有统计学意义(P<0.05或P<0.01);水提物组、醇沉物组与残留物组比较,差异均有统计学意义(P<0.05或P<0.01)。这6组的迟发型超敏反应OD值分别为0.53±0.16,0.23±0.09,0.30±0.10,0.37±0.10,0.36±0.11,0.28±0.14,水提物组、醇沉物组与模型组比较,差异均有统计学意义(P<0.05或P<0.01)。各提取物中多糖和总皂苷含量:醇提物(6.35%;6.57%),水提物(22.64%;7.68%),醇沉物(42.15%;1.86%),残留物(4.33%;5.37%)。结论红芪水提物和醇沉物均能对抗CTX的免疫抑制作用,有一定的增强体液免疫和细胞免疫作用,可增强机体的非特异性免疫和特异性细胞免疫功能。推测多糖是其对抗CTX免疫抑制作用的主要活性部位。