热休克蛋白表达对缺血性脑损伤的保护作用

INTRODUCTIONThecytoprotectioneffectofcerebralischemicpreconditioning(CIPhasbeenprovedbymanyfacts,buttheconcretemechanismofitre-maintobesolved.Thelateststudiespointoutthatpreconditioningischemiamaygeneratetheinternalantitraumicprocessinbodycelandinducetheischemicpreconditioningadaptationthuseliminatethbrainischemictrauma犤1,2犦.Heatshockprotein(HSPs)istheseriesoemergentproteinresultingfromthebadstimulation,whichprotectthebodycellfrominjuries.HSPsarethoughttobethebasicmaterialfotheintern…     

骨形态发生蛋白2复合异种脱蛋白骨支架材料修复山羊大段骨缺损

背景：单纯骨形态发生蛋白2修复骨缺损只有骨诱导性，单纯异种脱蛋白骨只有骨传导性。目的：评估异种脱蛋白骨复合骨形态发生蛋白2修复山羊大段长骨缺损的效果。设计、时间及地点：随机分组设计、动物对照观察实验，于2005—03／2007—02在解放军第三军医大学创伤、烧伤与复合伤国家重点实验室完成。材料：山羊24只用于制备大段长骨缺损模型。市售猪股骨用于制备脱蛋白骨。重组骨形态发生蛋白2为美国Biosource公司产品。方法：山羊右侧胫骨中下段截除胫骨总长度20％制备节段性骨缺损模型。24只山羊按植入材料的不同分为3组，单纯异种脱蛋白骨组、自体骨组和异种脱蛋白骨＋重组骨形态发生蛋白2组，每组8只。主要观察指标：植入后4，8，12，16，20，24周X射线评估骨缺损情况。植入后24周取新生骨组织进行双能X射线、组织学、生物力学检测修复效果。结果：植入后12，24周自体骨组和异种脱蛋白骨＋重组骨形态发生蛋白2组X射线评分均高于单纯异种脱蛋白骨组，差异有显著性意义（P〈0．05）。植入后24周自体骨组和异种脱蛋白骨＋重组骨形态发生蛋白2组骨密度和骨矿含量均高于单纯异种脱蛋白骨组，差异有显著性意义（P（0．05）。自体骨组和异种脱蛋白骨＋重组骨形态发生蛋白2组之间比较差异均无显著性意义（P〉0．05）。植入后24周生物力学测试表明，自体骨组〉异种脱蛋白骨＋重组骨形态发生蛋白2组〉单纯异种脱蛋白骨组。植入后24周，自体骨组、异种脱蛋白骨＋重组骨形态发生蛋白2组，新生骨与最初两断端连成一体，新生骨骨小梁排列整齐有序。单纯异种脱蛋白骨组，新生骨与最初两断端部分相连。结论：重组骨形态发生蛋白2复合异种脱蛋白骨修复山羊胫骨大段缺损成骨能力与自体骨相当。     

髋关节置换术后并发症的特征

目的:全髋关节置换术后发生感染、脱位、静脉栓塞等并发症仍是影响术后效果的主要原因,如何治疗和预防这些术后并发症是提高全髋关节置换术远期疗效的重要手段。资料来源:应用计算机检索PubM ed2000-01/2004-12期间相关文章,检索词为“totalhip arthroplasty(replacement),com plication orinfection,ordislocation,or throm boembolism”,限定文章语言种类为“English”。资料选择:对资料进行初审,选择髋关节置换术后与并发症有关的临床论著,排除综述类文章及未提供摘要类文章。资料提炼:共收集到214篇有关髋关节置换术后与并发症有关的论著,通过阅读摘要或全文对文章内容进行分类整理,83篇与本文综述内容有关,排除131篇。资料综合:83篇论著中包括感染、静脉栓塞、脱位、应力遮挡等术后并发症有关的文献。其中感染并发症主要为人类免疫缺陷病毒感染或毒品注射这一特殊人群。结论:随着对全髋关节置换术后各种并发症的认识水平不断提高,可望将其发生控制在最低限度,但对这些并发症的预防和治疗的研究观察,仍需作大量的工作。尤其对特殊人群的关节置换术,仍需继续积累经验。     

Imaging features of small intestinal amyloidosis: a case report

Amyloidosis is a rare disease characterized by forming pathological protein deposits in organs or tissues. The localized form of amyloidosis affecting small intestine is rare. We report a case of small intestine amyloidosis which presented gastrointestinal bleeding and abdominal pain. We also display radiologic features of amyloidosis of the small bowel which will add evidence to accurate diagnosis and management.     

Adenovirus-expressed human hyperplasia suppressor gene induces apoptosis in cancer cells

Hyperplasia suppressor gene (HSG), also called human mitofusin 2, is a novel gene that markedly suppresses the cell proliferation of hyperproliferative vascular smooth muscle cells from spontaneously hypertensive rat arteries. This gene encodes a mitochondrial membrane protein that participates in mitochondrial fusion and contributes to the maintenance and operation of the mitochondrial network. In this report, we showed that an adenovirus vector encoding human HSG (Ad5-hHSG) had an antitumor activity in a wide range of cancer cell lines. We further focused on the lung cancer cell line A549 and the colon cancer cell line HT-29 and then observed that Ad5-hHSG induced apoptosis both in vitro and in vivo. Confocal laser scanning microscopy and electron microscopy revealed that cells infected with Ad5-hHSG formed dose-dependent perinuclear clusters of fused mitochondria. Adenovirus-mediated hHSG overexpression induced apoptosis, cell cycle arrest, mitochondrial membrane potential (DeltaPsim) reduction and release of cytochrome c, caspase-3 activation, and cleavage of PARP in vitro. Overexpression of hHSG also significantly suppressed the growth of subcutaneous tumors in nude mice both ex vivo and in vivo. In addition, Ad5-hHSG increased the sensitivity of these cell lines to two chemotherapeutic agents, VP16 and CHX, and radiation. These results suggest that Ad5-hHSG may serve as an effective therapeutic drug against tumors.     

Predicting the success of defibrillation by electrocardiographic analysis

BACKGROUND: We investigated an electrocardiographic signal analysis technique for predicting whether an electrical shock would reverse ventricular fibrillation (VF) in an effort to minimize the damaging effects of repetitive shocks during CPR. METHODS AND RESULTS: An established model of CPR was utilized. VF was electrically induced in anesthetized 40 kg domestic pigs. Defibrillation was attempted after either 4 or 7 min of untreated VF. Failing to reverse VF, a 1 min interval of precordial compression and mechanical ventilation preceded each subsequent defibrillation attempt. The amplitude frequency spectrum of digitally filtered VF wavelets was computed with Fourier analysis during uninterrupted precordial compression from conventional right infraclavicular and left apical electrodes. Of a total of 34 electrical defibrillation attempts, 24 animals were restored to spontaneous circulation (ROSC). An amplitude spectrum analysis (AMSA) value of 21 mV Hz had a negative predictive value of 0.96 and a positive predictive value of 0.78. CONCLUSIONS: AMSA predicted when an electrical shock failed to restore spontaneous circulation during CPR with a high negative predictive value. This method potentially fulfills the need for minimizing ineffective defibrillation attempts and their attendant adverse effects on the myocardium.     

Correlation between the combination of apparent integrated backscatter–spectral centroid shift and bone mineral density

Purpose

To introduce a new diagnostic parameter: the linear combination of apparent integrated backscatter and spectral centroid shift.

Methods

Ultrasonic backscatter measurements were performed at the calcanei of 1262 volunteers in vivo. The hip and spine bone mineral densities of the volunteers were measured using dual X-ray absorptiometry. The apparent integrated backscatter and spectral centroid shift were calculated. A new diagnostic parameter, i.e., the linear combination of apparent integrated backscatter and spectral centroid shift, was introduced and its correlation to bone mineral density was analyzed.

Results

The results show that the combination of apparent integrated backscatter and spectral centroid shift is significantly correlated to bone mineral density (R = 0.73–0.84, n = 1262, p < 0.05), and that this correlation is more significant than the correlation between the apparent integrated backscatter and bone mineral density or the correlation between spectral centroid shift and bone mineral density (R = 0.48–0.69, p < 0.05).

Conclusion

The combination of apparent integrated backscatter and spectral centroid shift can provide the complementary information of attenuation of the two parameters and predict more information about cancellous bone, and may be employed to assess cancellous bone status.

     

Determinants of mitotic catastrophe on abrogation of the G2 DNA damage checkpoint by UCN-01

Genotoxic stress such as ionizing radiation halts entry into mitosis by activation of the G(2) DNA damage checkpoint. The CHK1 inhibitor 7-hydroxystaurosporine (UCN-01) can bypass the checkpoint and induce unscheduled mitosis in irradiated cells. Precisely, how cells behave following checkpoint abrogation remains to be defined. In this study, we tracked the fates of individual cells after checkpoint abrogation, focusing in particular on whether they undergo mitotic catastrophe. Surprisingly, while a subset of UCN-01-treated cells were immediately eliminated during the first mitosis after checkpoint abrogation, about half remained viable and progressed into G(1). Both the delay of mitotic entry and the level of mitotic catastrophe were dependent on the dose of radiation. Although the level of mitotic catastrophe was specific for different cell lines, it could be promoted by extending the mitosis. In supporting this idea, weakening of the spindle-assembly checkpoint, by either depleting MAD2 or overexpressing the MAD2-binding protein p31(comet), suppressed mitotic catastrophe. Conversely, delaying of mitotic exit by depleting either p31(comet) or CDC20 tipped the balance toward mitotic catastrophe. These results underscore the interplay between the level of DNA damage and the effectiveness of the spindle-assembly checkpoint in determining whether checkpoint-abrogated cells are eliminated during mitosis.