Astrocyte hypertrophy in the dentate gyrus of young male rats reflects variation of individual stress rather than group environmental complexity manipulations

Glial hypertrophy is associated with synaptogenesis in visual cortex and with stress-induced damage in the hippocampus. This study examined astrocytes in the dentate gyrus of male weanling rats exposed to complex or standard laboratory environments. No group differences in astrocytic surface density were observed, as expected in this brain region where group differences in synaptogenesis in male rats are reportedly minimal. Similarly, no group differences in adrenal weight were observed. Across all treatment groups, however, a significant positive correlation (r = 0.57) between adrenal weight and surface density of astrocytic processes was found. Considerable variation in responses of individual rats to their environments occurs in both the complex and the laboratory cage environments, and animals responding poorly may have had heavier adrenals and greater astrocyte reactivity in the dentate gyrus. Thus astrocyte hypertrophy in the dentate gyrus reflects the stress history of the individual rat and not any differential effects of rearing in a complex or a laboratory cage environment.     

Day-case conventional discectomy: a randomised controlled trial

A prospective randomised trial compared the results of conventional lumbar discectomy performed as day cases with those performed on an in-patient basis. The aim of the study was to investigate whether conventional discectomy can be performed safely on a day-case basis. Thirty-one patients were included in the study; 18 were randomised to day-case treatment and 13 to in-patient stay. Day patients mobilised more quickly immediately following surgery and were better able to walk at 2 weeks. The rate of complications was unchanged. It is concluded that conventional discectomy can be undertaken safely as day-case surgery and may indeed speed up the recovery process.     

抗甲状腺药物诱导的狼疮样综合征循证诊断与治疗的个案分析

狼疮样综合征和抗中性粒细胞胞浆抗体(ANCA)阳性的血管炎合并甲亢在临床中十分罕见.为了找出这三种疾病之间的关系,作者借助循证医学的方法,根据患者病情,提出临床问题,从PubMed(1966～2003年)、中国生物医学文献数据库(CBM)(1978～2003年)、荷兰医学文摘数据库(EMBase)(1974～2003年)查找相关信息.结果发现抗甲状腺药物的副反应是对该病例的最好解释,并据此采取了相应治疗措施,使患者病情获得明显好转.     

雪灵芝对二乙基亚硝胺诱导大鼠肝癌组织细胞的抑制作用

目的：验证雪灵芝是否具有抑制大鼠肝癌的功效。方法：实验于2003—09/2004—08在广西疾病预防控制中心SPF级动物实验室完成。选用健康成年SD大鼠160只。按体质量分层随机分为5组：空白对照组、模型组、雪灵芝高剂量组、雪灵芝中剂量组和雪灵芝低剂量组，每组32只。雪灵芝高、中、低剂量组大鼠分别灌胃2．500，1．250，0．625mL/kg雪灵芝溶液，阴性对照组和模型组灌胃等量蒸馏水，1次／d，连续60d。第61天开始雪灵芝高、中、低剂量组和模型组灌胃二乙基亚硝胺溶液，对照组灌胃等量的生理盐水。于停止灌胃90d后各组处死一半受试大鼠（雌雄各半），检测血常规及血清主要生化指标，观察各脏器大体形态改变、脏器的癌变程度。1周后给剩余大鼠灌胃雪灵芝溶液（不含二乙基亚硝胺）。7周后处死余下的一半雄性大鼠，进行相同操作。8周后处死余下的全部大鼠，操作及检测方法同前。结果：纳入的160只SD大鼠，145只进入结果分析，15只脱落。①病理切片检查结果：除阴性对照组，其他各组大鼠肝组织均发生癌变或癌前病变。雪灵芝高、中、低剂量组的癌前病变发生率与模型组相近（P〉0．05）；癌变的发生率均低于模型组，差异有显著性意义（P〈0．05，0．01）。②大体标本检查结果：阴性对照组大鼠肝脏的大体标本均无异常改变，其他各组大鼠的肝脏有些可见表面粗糙等病理改变。模型组大体标本病理改变的阳性率高于雪灵芝高、中、低剂量组，差异有显著性意义（P〈0．05）。肉眼观模型组癌变发生率高于其他各组。③其他脏器检查结果：模型组2只大鼠有肝癌肺转移。结论：以较大剂量的二乙基亚硝胺连续灌胃30d可以复制大鼠肝癌模型；雪灵芝对二乙基亚硝胺诱导的大鼠肝癌具有预防和抑制的作用。     

低氧暴露对运动性贫血大鼠抗氧化能力的影响

目的:观察低氧暴露对运动性贫血大鼠某些抗氧化酶的影响,探讨低氧条件下抗氧化系统的反应是否有利于改善运动性贫血。方法:实验于2005-07/09在广东省高等学校运动生物化学教学重点实验室完成。选择6周龄健康雄性SD大鼠40只,均为运动性贫血动物模型,大鼠适应环境1周后采用6周递增负荷跑台运动方式建立。按随机数字表法分为1h低氧暴露组、2h低氧暴露组和间歇性低氧暴露组、常氧恢复组,每组10只。采用人工常压低氧环境,低氧浓度控制在14.5%左右,按分组每天在常压低氧舱进行1,2h和间歇性低氧暴露(低氧暴露1h,中间间歇3h,再低氧暴露1h),其余时间在舱外常氧中自由活动,每周6d,持续3周。常氧恢复组大鼠在常氧中自由活动。3周后测试运动性贫血大鼠血清丙二醛含量、超氧化物歧化酶活性和血浆过氧化氢酶、谷胱甘肽过氧化酶活性。结果:纳入动物40只,均进入结果分析。①低氧暴露3周后1h低氧暴露组、2h低氧暴露组、间歇性低氧暴露组血清丙二醛含量均显著低于常氧恢复组[分别为(2.62±0.16),(2.60±0.22),(2.55±0.06),(3.36±0.34)μmol/L,P<0.05]。②低氧暴露3周后血清超氧化物歧化酶和血浆谷胱甘肽过氧化酶、过氧化氢酶活性均高于常氧恢复组,2h低氧暴露组与常氧恢复组比较差异有显著性意义[分别为(4239.68±169.53),(3190.30±339.40)μkat/L;(20622.46±2002.07),(15556.44±607.79)μkat/L;(50.01±6.67),(35.17±4.50)μkat/L,P<0.05]。③各低氧暴露组间除2h低氧暴露组血清超氧化物歧化酶活性显著高于1h低氧暴露组外[分别为(4239.68±169.53),(2126.41±161.20)μkat/L,P<0.05],其他指标组间差异无显著性意义(P>0.05)。结论:低氧暴露可提高运动性贫血大鼠机体的抗氧化能力,有利于促进运动性贫血的恢复。     

全层软骨缺损合并深部“微骨折”兔软骨修复情况

目的:观察在全层软骨缺损深部制造“微骨折”对兔软骨修复的影响。方法:实验于2003-04/10在同济医学院矫形外科实验室完成。实验用自制“微骨折”骨刀由管形不锈钢制作而成,分微骨刀内芯和外置套筒两部分。微骨刀近端配有可拆卸的螺帽,其远端为4枚锋利的钢钉,孔距为4mm,其连线呈正方形,孔隙深4mm,可深达松质骨内。取20只大白兔随机分2组,每组10只。用尖刀片在兔股骨内髁处切除6mm×6mm软骨组织造成全层关节软骨缺损,建立实验动物模型。实验组在缺损局部应用特制骨刀造成“微骨折”,对照组缺损局部不予特殊处理。分别在4周和8周每组各处死5只实验兔,作大体观察以及组织病理学检查。结果:①两组兔缺损修复处大体观察:在缺损处对照组只有肉芽组织和瘢痕组织生长,仅边缘有少量软骨组织生长,实验组在4周时大部分为软骨组织生长,而8周已全部被软骨组织修复。②组织病理学观察:实验组在4周时修复组织以纤维软骨为主,还有大量幼稚的透明软细胞,排列较紊乱,内混有一些纤维组织,与正常的关节软骨组织有一定的差异。而对照组修复组织均为红染的肉芽组织和纤维瘢痕组织,8周时,仅为瘢痕组织。③关节活动度的变化:术后各组动物关节活动度良好。结论:采用特制骨刀在全层软骨缺损的情况下合并“微骨折”,能使全层缺损的软骨组织得以修复。     

Effects of Cholera Toxin on In Vitro Models of Immediate and Delayed Hypersensitivity. FURTHER EVIDENCE FOR THE ROLE OF CYCLIC ADENOSINE 3′,5′-MONOPHOSPHATE

Cholera enterotoxin inhibits the antigen-induced. IgE-mediated release of histamine from human leukocytes and the lysis of allogeneic mastocytoma cells by splenic lymphocytes from specifically immunized mice. This effect requires a prolonged preincubation time of the toxin with the lymphocyte/leukocyte preparations: a demonstrable inhibition requires about 30 min of pre-incubation and the toxin activity is still increasing at 90-180 min. Cholera enterotoxin also stimulates adenyl cyclase and leads to increased levels of cyclic AMP in the lymphocyte/leukocyte preparations. The concentration of toxin required for both cyclic AMP accumulation and inhibition of the biologic responses is about the same (ca. 1 ng/ml), and the time course of cyclic AMP accumulation parallels the development of inhibitory activity. Both activities, inhibition of the in vitro hypersensitivity reactions and cyclic AMP accumulation, are blocked by cholera antitoxin and by a toxoid prepared from the toxin (choleragenoid). These are specific antagonists in that they do not block the inhibiting activity or rise in cyclic AMP levels caused by other adenyl cyclase stimulators. Because cholera enterotoxin has no known activity other than the stimulation of adenyl cyclase and because of its unusual time course and the availability of specific antagonists, this data considerably strengthens the hypothesis that the cyclic AMP system influences the expression of these two forms of hypersensitivity phenomena.     

Congenital diaphragmatic hernia: prognostic indices in the fetal endoluminal tracheal occlusion era

Introduction

Management of congenital diaphragmatic hernia (CDH) in the UK now includes the possibility of fetal endoluminal tracheal occlusion (FETO) for poor prognosis fetuses. The objective of this study was to investigate the value of variables previously thought prognostic in the FETO era.

Methods

A retrospective single-centre study was performed of all infants with CDH born between January 1994 and December 2007. Fetal endoluminal tracheal occlusion was available and had been used with parental consent for fetuses with lung-to-head ratio (LHR) of 1.0 or less and a liver-up position from 2002. Univariate analysis was used to predict survival (to leave hospital) using both prenatal (eg, polyhydramnios) and perinatal variables [eg, best oxygenation index on day 1, or BOI (d1)] and their dependence tested in a logistic regression model. Data were quoted as medians (range). P < .05 was regarded as significant.

Results

Eighty-six infants with CDH (1994-2002, n = 35 and 2002-2007, n = 51 “FETO era”) were studied. Successful FETO intervention was performed in 31 infants.Univariate analysis showed liver position, birth weight, LHR, and BOI (d1) were significant prognostic predictors (all P < .05); however, only BOI (d1) retained significance using logistic regression analysis (odds ratio, 21; 95% confidence interval, 6-74; P < .001). Best oxygenation index on day 1 was then used as a surrogate marker for outcome to test the relationship with LHR (available since 2002) and showed a significant inverse correlation (r_s = −0.5; P < .001). There was no difference in median BOI (d1) between the FETO group and all those treated expectantly (40 [34-1046] vs 59 (23-581); P = .3].

Conclusion

Best oxygenation index on day 1 is the best early postnatal predictor of survival. The more recently evaluated prenatal index, LHR, has an observable relationship with BOI (d1) when it is used as a surrogate marker of outcome.