丙泊酚对大鼠局灶性脑缺血-再灌注低氧诱导因子-1和热休克蛋白70的影响

目的 观察丙泊酚对大鼠局灶性脑缺血-再灌注后低氧诱导因子(HIF-1)和热休克蛋白70(HSP70)的影响,探讨丙泊酚脑保护作用机制.方法 32只雄性sD大鼠,随机均分为四组,采用可逆性大脑中动脉内线栓法建立局灶性脑缺血-再灌注模型,缺血2 h再灌注24 h后断头取脑,采用免疫组化法检测HIF-1和HSP70.HE染色,光镜观察细胞形态学改变.结果 大鼠局灶性脑缺血-再灌注后大脑皮质和海马区出现神经细胞的坏死和凋亡改变,HIF-1和HSP70的表达均增加,给丙泊酚后神经细胞的肿胀、坏死、凋亡明显减少,HIF-1和HSP70蛋白的表达受到明显抑制.结论 丙泊酚对大鼠局灶性脑缺血-再灌注损伤的保护机制与减少HIFll、HSP70的表达有关.     

丙泊酚对大鼠局灶性脑缺血-再灌注时脑组织热休克蛋白70基因和蛋白表达的影响

目的观察丙泊酚对大鼠局灶性脑缺血-再灌注时脑组织热休克蛋白(HSP)70 mRNA和HSP70蛋白表达的影响,以探讨其脑保护的机制。方法采用大脑中动脉线栓法建立大鼠局灶性脑缺血-再灌注模型。60只雄性Wistar大鼠,随机分为假手术组(Sham组)、缺血-再灌注组(I-R组)和丙泊酚组(P组),每组20只。大鼠脑缺血2 h,然后进行再灌注。在再灌注3、6、24、72 h断头取脑组织,采用原位杂交法和免疫组织化学染色检测大鼠脑组织HSP70 mRNA和HSP70蛋白的表达。结果局灶性脑缺血-再灌注后,HSP70 mRNA和HSP70蛋白的表达增加(P<0.01),但HSP70 mRNA表达较早,分布范围较广泛,而HSP70蛋白表达以半暗带区为主。应用丙泊酚能显著地促进脑缺血-再灌注后脑组织中HSP70 mRNA和HSP70蛋白的表达(P<0.01),与脑缺血-再灌注组相比较,HSP70 mRNA和HSP70蛋白不仅表达增多、范围增加,而且还能延缓下降(P<0.05)。结论丙泊酚能促进大鼠局灶性脑缺血-再灌注时HSP70的表达,这可能是其脑保护作用的部分机制。     

p38 MAPK在沙土鼠前脑缺血再灌注损伤及缺血预处理中的作用

目的 研究p38 MAPK在沙土鼠前脑缺血再灌注损伤及缺血预处理中的作用。方法 雄性蒙古沙土鼠384只，体重50-80 g，随机分为6组，每组64只。假手术组（SH组）：仅游离双侧颈总动脉但不阻断;缺血再灌注组（I／R组）：夹闭双侧颈总动脉，前脑缺血5min后恢复灌注;缺血预处理组（IP组）：前脑缺血3 min后恢复灌注，24 h后再行前脑缺血5 min;P组：于前脑缺血前20 min侧脑室内注射0．8μg p38 MAPK特异性激动剂P79350;SB组：于前脑缺血前20 min侧脑室内注射0．4μg p38 MAPK特异性抑制剂SB202190;溶剂对照组（VE组）：于前脑缺血前20min侧脑室内注射1％二甲基亚砜4μl。各组于再灌注15min、2h、4h、6h分别取8只沙土鼠，测定海马CA1区p-p38 MAPK的表达，再灌注1、3、5、7d分别取8只沙土鼠，采用开阔法观察行为学，然后测定海马CA1区存活神经元计数、凋亡神经元计数及p-p38 MAPK、HSP27、Bcl-2、Bax的表达。结果 I／R组再灌注期p-p38 MAPK表达上调，IP组及SB组再灌注各时点p-p38 MAPK表达水平低于I／R组，P组再灌注各时点高于I／R组、IP组及SB组（P〈0．05）;IP组、SB组较I／R组及vE组沙土鼠探索活动减少，CA1区再灌注期凋亡神经元数减少，HSP27、Bax表达下调，存活神经元数增加，Bcl-2表达上调（P〈0．05）;P组再灌注1 d探索活动增加，再灌注各时点p38 MAPK及HSP27表达均较I／R组上调（P〈0．05）。结论 沙土鼠脑缺血再灌注损伤及神经元凋亡与p38 MAPK的激活有关;缺血预处理可通过抑制p38 MAPK的激活，下调HSP27及Bax的表达、上调Bcl-2的表达。     

大鼠骨骼肌缺血再灌注损伤的细胞凋亡及相关基因表达

目的研究缺血性损伤和缺血再灌注损伤的发生情况和病理改变，探讨细胞凋亡及相关基因p53、p21、Bax、Bcl-2的表达规律。方法建立大鼠后肢缺血和缺血再灌注实验模型，光镜下观察缺血和缺血再灌注早期的骨骼肌组织病理学变化，检测缺血和缺血再灌注过程中细胞凋亡现象的发生及相关基因p53、p21、Bax、Bcl-2的表达。结果缺血5h的大鼠骨骼肌全部存活，而缺血9h者未获存活。缺血和缺血再灌注损伤引起骨骼肌细胞水肿、坏死和细胞凋亡，并于再灌注过程观察到微循环障碍和中性粒细胞趋化浸润现象。缺血7h细胞凋亡率最高，相关基因p53、p21、Bax表达与缺血时间成正比，而Bcl-2表达与缺血时间成反比。结论细胞凋亡是缺血和缺血再灌注损伤的重要病理学改变。微循环障碍和中性粒细胞趋化浸润是缺血再灌注损伤的重要原因之一。相关基因表达与凋亡的发生关系密切。     

脑缺血／再灌注后神经元Ku蛋白的表达与DNA双链损伤的变化

目的：探讨脑缺血／再灌注后早期神经元Ku蛋白的表达与DNA双链损伤的变化及其与神经元转归的关系。方法：56只大鼠随机分为脑缺血／再灌注组（大脑中动脉线栓法制备缺血／再灌注模型）和假手术组,分别于术后1、6、12、24、48、72h6个时相点取脑组织,免疫组化法测定缺血／再灌注区Ku异二聚体的成分之一Ku70的表达,原位末端标记法（TUNEL法）观察脑缺血／再灌注后不同时相点缺血／再灌注区神经元DNA双链损伤的变化,DNA琼脂糖凝胶电泳检测缺血／再灌注区细胞凋亡。结果：脑缺血／再灌注1h时,缺血侧Ku70阳性细胞数即开始减少,缺血／再灌注24h降至最低水平;缺血／再灌注6h,缺血区TUNEL细胞数量开始升高,于24hTUNEL阳性细胞数均达到高峰,其后逐渐减少;24h后细胞DNA琼脂糖凝胶电泳始见凋亡特有的阶梯状（Ladder）条带。结论：脑缺血／再灌注早期,神经元Ku蛋白表达下降,可能是导致双链断裂的DNA无法得到修复造成神经元DNA不可逆性损伤,进而引起神经元死亡的原因。     

肝缺血再灌注细胞凋亡现象及Fas蛋白、PCNA 、p53、bcl-2 mRNA表达

目的：探讨肝缺血再灌注肝细胞凋亡发生的时空分布、基因表达特点及意义。方法：在观察SD大鼠（n=40）肝缺血0,30,45,60min再灌注3,6,24h存活率及病理形态基础上,重点观察大鼠（n=100)全肝血流阻断30min再灌注0,0.5,1,3,6,12,24,48,72,96h凋亡细胞分布（原位末端标记术,TUNEL）,G0-G1期细胞、凋亡细胞、增殖细胞指数分布（流式细胞术）,肝细胞显微及超微结构（光镜、电镜技术）,Fas蛋白、PCNA蛋白（免疫组化）及p53、bcl-2基因mRNA表达（原位杂交）。结果：缺血30min组多见细胞凋亡,细胞应答反应主要为三期：①急性期：再灌注0.5h Fas蛋白首先在血管周围高表达;②亚急期（3-24h):TUNEL阳性细胞在血管周围高分布,并向周围扩展;病理形态可见严重变性、细胞皱缩、细胞增殖三种变化;G1期细胞数大量减少,凋亡峰逐渐升高,12h后出现增殖峰,相关基因表达增强;③恢复早期（24-96h)：G1期细胞指数回升,凋亡峰和增殖峰持续并缓慢下降;相关基因表达陆续减弱。结论：肝缺血30min再灌注期机体可能通过下述基因调控途径影响细胞损伤应答反应：①Fas死亡基因与bcl-2存活基因的双重调控;②细胞凋亡与增殖双重调控;③经p53基因实现的细胞周期调控。     

丙泊酚对脑缺血-再灌注后海马组织热休克蛋白70和c-fos基因表达的影响

目的观察丙泊酚对脑缺血一再灌注后海马组织热休克蛋白70(HSP70)与c-fos基因表达的影响。方法雄性Wistar大鼠40只,随机分为假手术组、缺血一再灌注对照组和缺血一再灌注丙泊酚处理组,后者按丙泊酚用量又分为50、100和150mg／kg三个亚组。采用大鼠全脑缺血一再灌注损伤模型。全脑缺血10min再灌注60min时,断头取脑,采用免疫组织化学和半定量RT-PCR方法,对脑内HSP70与c-fos蛋白及其mRNA在海马组织的表达水平进行检测。结果缺血一再灌注后皮层、海马、纹状体及边缘区等脑区均有大量的HSP70和c-fos阳性蛋白表达,海马组织HSP70及c-fos基因mRNA的表达水平明显增高,其中以缺血一再灌注对照组表达最为显著;假手术组仅有少量阳性蛋白的表达,海马组织mRNA的表达水平极低;麻醉相关剂量的丙泊酚可显著抑制HSP70与c-fos蛋白在各脑区的表达,尤以海马CA1区最为显著,亦可明显下调HSP70和c-fos mRNA在海马组织的表达水平。结论缺血一再灌注损伤可明显诱导HSP70与c-fos基因的表达,丙泊酚的脑保护作用可能与其下调HSP70与c-fos基因的异常表达有关。     

脑缺血再灌注损伤时细胞凋亡的相关基因调控

脑缺血再灌注损伤与细胞凋亡密切相关，细胞凋亡是基因调控的。本文综述了脑缺血再灌注损伤时细胞凋亡的相关基因（bcl-2、IEGs、p53、ICE、Fas等）的结构、功能及其在细胞凋亡中的作用、机制和表达情况。     

细胞周期调控基因Chk1在脑缺血再灌注损伤中的作用

目的 研究缺血再灌液时大脑细胞Chk1基因表达及其调控机制。方法 从正常及不同缺血再灌注时点大鼠的大脑提取RNA,采用半定量RT－PCR法,图象经分析测出正常及各缺血再灌注时点大脑Chk1基因mRNA的相对水平。结果 在正常成年大鼠大脑皮质中,有一定量的Chk1基因的表达,约为GAPDH表达量的一半左右;脑缺血再灌注损伤对Chk1mＲＮＡ的表达有影响。在缺血６０min再灌注６h,Chk1 mRNA表达明显下降,与对照组及其它组比较有显著差异。结论 提示Ｃhk1基因可能参与成年大鼠脑缺血再灌注损伤后细胞存活和细胞凋亡的调控。     

参附注射液预处理对大鼠脑缺血-再灌注损伤后HSP70和HSP90表达的影响

目的探讨参附注射液(SF)单次预处理对大鼠脑缺血-再灌注损伤的保护作用。方法30只雄性SD大鼠随机均分为单纯缺血-再灌注组(MCAO组)、SF预处理组(SF组,缺血前30 min经腹腔注射SF 10 ml/kg)和假手术组(Sham组)。MCAO组和SF组采用颈内动脉尼龙线线栓法致右侧大脑中动脉栓塞120 min。观察再灌注后24 h时脑组织病理学改变,检测热休克蛋白(HSP)70和HSP90表达。结果再灌注24 h后,SF组脑组织病理学损害轻于MCAO组。Sham组未见HSP70及HSP90表达。MCAO组可见到较多的HSP70免疫阳性细胞,明显高于Sham组(P<0.01);SF组HSP70免疫阳性细胞分布较MCAO组广泛,数量明显增多,胞浆及胞核都可见HSP70免疫阳性细胞[(1.341±0.464)vs.(0.856±0.574)](P<0.05),而SF组HSP90的表达与MCAO组相仿[(0.006±0.013)vs.(0.005±0.007)]。结论SF预处理可通过增加HSP70表达而对大鼠脑缺血-再灌注损伤起保护作用。     

Presenteeism and Absenteeism Before and After Total Hip and Knee Arthroplasty

BackgroundAbsenteeism is costly, yet evidence suggests that presenteeism—illness-related reduced productivity at work—is costlier. We quantified employed patients’ presenteeism and absenteeism before and after total joint arthroplasty (TJA).MethodsWe measured presenteeism (0-100 scale, 100 full performance) and absenteeism using the World Health Organization’s Health and Work Performance Questionnaire before and after TJA among a convenience sample of employed patients. We captured detailed information about employment and job characteristics and evaluated how and among whom presenteeism and absenteeism improved.ResultsIn total, 636 primary, unilateral TJA patients responded to an enrollment email, confirmed employment, and completed a preoperative survey (mean age: 62.1 years, 55.3% women). Full at-work performance was reported by 19.7%. Among 520 (81.8%) who responded to a 1-year follow-up, 473 (91.0%) were still employed, and 461 (88.7%) had resumed working. Among patients reporting at baseline and 1 year, average at-work performance improved from 80.7 to 89.4. A Wilcoxon signed-rank test indicated that postoperative performance was significantly higher than preoperative performance (P < .0001). The percentage of patients who reported full at-work performance increased from 20.9% to 36.8% (delta = 15.9%, 95% confidence interval = [10.0%, 21.9%], P < .0001). Presenteeism gains were concentrated among patients who reported declining work performance leading up to surgery. Average changes in absences were relatively small. Combined, the average monthly value lost by employers to presenteeism declined from 15.3% to 8.3% and to absenteeism from 16.9% to 15.5% (ie, mitigated loss of 8.4% of monthly value).ConclusionAmong employed patients before TJA, presenteeism and absenteeism were similarly costly. After, employed patients reported increased performance, concentrated among those with declining performance leading up to surgery.     

The German emergency and disaster medicine and management systemdhistory and present

As well for optimized emergency management in individual cases as for optimized mass medicine in disaster management, the principle of the medical doctors approaching the patient directly and timely, even close to the site of the incident, is a long-standing marker for quality of care and patient survival in Germany. Professional rescue and emergency forces, including medical services, are the “Golden Standard” of emergency management systems. Regulative laws, proper organization of resources, equipment, training and adequate delivery of medical measures are key factors in systematic approaches to manage emergencies and disasters alike and thus save lives. During disasters command, communication, coordination and cooperation are essential to cope with extreme situations, even more so in a globalized world. In this article, we describe the major historical milestones, the current state of the German system in emergency and disaster management and its integration into the broader European approach.     

Differences in Osteocyte Density and Bone Histomorphometry Between Men and Women and Between Healthy and Osteoporotic Subjects

Bone defects related to osteoporosis develop with increasing age and differ between males and females. It is currently thought that the bone remodeling process is supervised by osteocytes in a strain-dependent manner. We have shown an altered response of osteocytes from osteoporotic patients to mechanical loading, and osteocyte density is reduced in osteoporotic patients, which might relate to imperfect bone remodeling, leading to lack of bone mass and strength. Hence, information on osteocyte density will contribute to a better understanding of bone biology in males and females and to the assessment of osteoporosis. Osteocyte density as well as conventional histomorphometric parameters of trabecular bone were determined in cancellous iliac crest bone of healthy postmenopausal women and men and of osteoporotic women and men. Osteocyte density was higher in healthy females than in healthy males and lower in osteoporotic females than in healthy females. Bone mass was reduced in osteoporotic patients, both male and female. In females, trabecular number was reduced, whereas in males, trabecular thickness was reduced and eroded surface was increased. There were no correlations between the parameter groups bone architecture, bone formation, bone resorption, and osteocyte density. These results are consistent with impaired osteoblast function in osteoporotic patients and with a different mechanism of bone loss between men and women, in which osteocyte density might play a role. The reduced osteocyte numbers in female osteoporotic patients might relate to imperfect bone remodeling leading to lack of bone mass and strength. M. G. Mullender and S. D. Tan contributed equally to this work.     

肝内胆管囊腺瘤和囊腺癌的CT、MRI及病理表现

目的探讨肝内胆管囊腺瘤和囊腺癌的CT、MRI和病理特点。方法回顾性分析经手术病理证实的6例肝内胆管囊腺瘤和2例肝内胆管囊腺癌的影像及临床病理资料，将病变的影像表现与其病理大体形态及组织学表现作对照分析。结果6例肝内胆管囊腺瘤，女4例、男2例；2例肝内胆管囊腺癌均为女性病人；8例病人平均年龄55岁。所有病灶均表现为多房囊性肿块，肿瘤囊腔各分房内常为多种液体成分，在CT上可表现为不同密度、在MRI上可表现为不同信号强度。囊内出现多发大小不等的壁结节在胆管囊腺癌内更常见，囊内有分隔但无壁结节只见于胆管囊腺瘤。在7例CT扫描中，4例胆管囊腺瘤和1例胆管囊腺癌可见囊壁或分隔上钙化，囊壁、囊内分隔及囊内结节均为轻、中度延迟增强。肿瘤中出现卵巢样间质见于3例胆管囊腺瘤和1例胆管囊腺癌，且均为女性病人。结论肝内胆管囊腺瘤和囊腺癌是肝脏不常见的囊性肿瘤，影像上多房、囊内有分隔且各分房囊内密度或信号不一致，高度提示肝内胆管囊腺瘤或囊腺癌的诊断，如囊内伴有多发大小不等的结节，则进一步提示囊腺癌的可能。但影像学表现不能区分肿瘤中有无卵巢样间质。