SARS: ventilatory and intensive care

Severe acute respiratory syndrome (SARS) is an emerging infection caused by a novel coronavirus. It is characterised by a highly infectious syndrome of fever and respiratory symptoms, and is usually associated with bilateral lung infiltrates. The clinical syndrome of SARS often progresses to varying degrees of respiratory failure, with about 20% of patients requiring intensive care. Despite concern about potential aerosol generation, non-invasive ventilation (NIV) has been reported to be efficacious in the treatment of SARS-related ARF without posing infection risks to health care workers (HCW). Spontaneous pneumomediastinum and pneumothorax in SARS is common. The incidence of NIV-associated barotrauma ranged from 6.6% to 15%. Patients who fail to tolerate NIV or fail NIV with progressive dyspnoea, tachypnoea and hypoxaemia should be intubated and mechanically ventilated. Mortality rates in intensive care units for SARS patients were high: 34–53% at 28 days, when some patients were still being ventilated. Strict adherence to infection control measures including isolation, use of appropriate personal protective equipment and negative pressure environment had been reported to eliminate cross-infection to HCW.     

Malignancy may adversely influence the quality and behaviour of oocytes

A case series of eight cycles of in-vitro fertilization (IVF) in five women diagnosed with malignant disorders is presented. These patients chose to defer definitive treatment for a chance for preservation of potential fertility. The response of these patients to ovarian stimulation, and the outcome, was compared with 17 IVF cycles in 12 age- matched patients with isolated tubal infertility. An apparent adverse influence of malignant disease on the quality and behaviour of oocytes was observed. Despite a comparable total number of oocytes per cycle in the two groups, a significantly reduced percentage of mature oocytes was retrieved per cycle from patients with malignant diseases. The oocytes from patients with malignant disorders were of a poorer quality and exhibited a significantly impaired fertilization rate compared to the controls. We propose that neoplastic processes, irrespective of the site or cell of origin, may have a detrimental impact on the biology of oocytes, an effect akin to that seen on spermatozoa in men with certain malignancies.      

L-精氨酸对糖尿病大鼠心肌缺血再灌注损伤的影响

目的:观察糖尿病大鼠心肌缺血再灌注时血管紧张素Ⅱ、胰岛素样生长因子1、醛固酮、细胞间黏附分子1和自由基代谢的变化及L-精氨酸对其的影响。方法:实验于2005-02/2006-06在江苏大学医学院机能学实验室完成。①实验分组:腹腔注射链脲佐菌素制作糖尿病大鼠模型,30只大鼠造模成功。按随机数字表法分为3组(n=10):心肌缺血再灌注组:开胸结扎冠脉,造成心肌缺血,60min后放松再灌注60min;L-精氨酸治疗组:于手术前4周灌胃L-精氨酸250mg/(kg·d),然后重复心肌缺血再灌注组操作;假手术组:完成操作后只穿线不结扎,观察2h作为对照。实验结束时心室取血6mL,摘取心脏,留取左心室心肌组织。②实验评估:检测大鼠血浆血管紧张素Ⅱ、醛固酮和血清胰岛素样生长因子1含量及心肌细胞间黏附分子1蛋白表达。检测大鼠血清、心肌组织超氧化物歧化酶、谷胱甘肽-过氧化物酶活性、丙二醛含量及心肌线粒体Na ,K -ATP酶、Mg2 -ATP酶、Ca2 -ATP酶活性。结果:30只大鼠全部进入结果分析。①与假手术组相比,心肌缺血再灌注组血浆血管紧张素Ⅱ、醛固酮含量明显升高(P<0.05～0.01),血清胰岛素样生长因子1含量降低(P<0.05);L-精氨酸治疗4周后血浆血管紧张素Ⅱ、醛固酮含量低于心肌缺血再灌注组(P<0.05～0.01),血清胰岛素样生长因子1含量高于心肌缺血再灌注组(P<0.05)。②与假手术组相比,心肌缺血再灌注组血清、心肌丙二醛含量明显升高(P<0.05),血清、心肌超氧化物歧化酶和谷胱甘肽-过氧化物酶活性明显降低(P<0.05￣0.01);用L-精氨酸治疗4周后血清、心肌丙二醛含量低于心肌缺血再灌注组(P<0.05￣0.01),血清、心肌超氧化物歧化酶和谷胱甘肽-过氧化物酶活性高于心肌缺血再灌注组(P<0.05～0.01)。③与假手术组相比,心肌缺血再灌注组心肌线粒体Na ,K -ATP酶、Mg2 -ATP酶、Ca2 -ATP酶活性明显降低(P<0.05),心肌细胞间黏附分子1蛋白表达明显升高(P<0.01);用L-精氨酸治疗4周后心肌线粒体Na ,K -ATP酶、Mg2 -ATP酶、Ca2 -ATP酶活性明显高于心肌缺血再灌注组(P<0.05),心肌细胞间黏附分子1蛋白表达低于心肌缺血再灌注组(P<0.05)。结论:血管紧张素Ⅱ、醛固酮和胰岛素样生长因子1可能共同参与了糖尿病心肌缺血再灌注的发生,细胞间黏附分子1蛋白表达与糖尿病心肌损伤关系密切。L-精氨酸通过减少细胞间黏附分子1蛋白表达,起心肌保护作用。糖尿病心肌缺血再灌注时存在自由基代谢异常,补充L-精氨酸后,可通过提高超氧化物歧化酶、谷胱甘肽-过氧化物酶和ATP酶活性,降低丙二醛水平,减轻自由基损伤,改善心肌组织功能。     

广东地区散发克罗恩病患者β防御素2启动子区基因突变检测

目的:对广东地区散发克罗恩病患者β防御素2启动子区基因突变进行筛查,探讨该基因在克罗恩病发病中的作用。方法:克罗恩病组为2002-01/2006-10于南方医院消化科确诊的克罗恩病患者45例,对照组为门诊健康志愿者50例。签定知情同意书后分别取静脉血5mL,提取基因组DNA,并根据设计好的引物序列及PCR反应条件进行目的片段的扩增,阴性对照使用蒸馏水代替DNA。扩增成功的目的基因片段用DNA纯化试剂盒进行纯化,并由上海英俊公司完成测序工作。利用DNAMAN软件将患者测序结果与正常对照结果进行比对,并与基因库数据对照(http://www.ncbi.nlm.nih.gov/BLAST/),SPSS13.0进行统计学分析。并根据结果分析其与克罗恩病患者病变特点的相关性。结果:①纳入的45例克罗恩病患者与50例健康志愿者在性别和年龄上无统计学意义,并全部进入实验分析。②45例克罗恩病患者中有4例在β防御素2启动子区第-233(G→C)位发现基因突变,密码子由AGG变成AGC,编码氨基酸由精氨酸变成丝氨酸,而50例对照组未发现此改变,二者比较具有统计学意义(χ2=4.34,P<0.05)。③4例突变的患者病变均位于小肠(χ2=10.81,P<0.01)且病情较重。结论:在克罗恩患者中存在着β防御素2启动子区基因突变携带者,与患者发病年龄、病变部位、病变程度明显相关,有必要对其功能进行进一步探讨。     

Plasma antioxidant vitamins, chronic hepatitis B virus infection and urinary aflatoxin B1-DNA adducts in healthy males

Epidemiological evidence indicates that aflatoxin B1 (AFB1) intake is associated with an increased risk of hepatocellular carcinoma (HCC). The hepatocarcinogenesis is initiated by covalent binding of AFB1 to cellular DNA. To determine whether nutritional factors and hormonal status may influence the binding of AFB1 to hepatic DNA, a cross- sectional study was performed on a total of 42 male asymptomatic hepatitis B surface antigen (HBsAg) carriers and 43 male non-carriers in a cohort study on the multistage development of HCC in Taiwan. The major AFB1-DNA adduct in vivo, AFB1-N7-guanine, was measured by high- performance liquid chromatography in urine. Urinary AFB1-N7-guanine was detectable in 40% of the subjects. HBsAg carriers had a higher detection rate of urinary AFB1-DNA adducts than non-carriers and the difference was statistically significant after multivariate adjustment. After taking into account the total AFB1 urinary metabolite level, chronic HBsAg carrier status, and other potential confounders, plasma levels of cholesterol, alpha-tocopherol, and alpha- and beta-carotene were positively associated with the detection rate of the AFB1-DNA adducts in a dose-dependent manner, whereas plasma lycopene level was inversely related to the presence of the adducts in urine. The association of urinary AFB1-DNA adducts with the plasma levels of cholesterol, alpha-tocopherol, lycopene, and alpha- and beta-carotene was observed at both low and high exposure levels of AFB1. There was a synergistic interaction of plasma alpha-tocopherol with alpha- and beta- carotene on the adduct levels. No association with the adducts was found for plasma levels of retinol and testosterone. This study demonstrated different associations of antioxidant vitamins with AFB1- DNA adduct formation. The data consistent with our previous finding in cultured woodchuck hepatocytes that alpha-tocopherol and beta-carotene enhanced AFB1-DNA adduct formation suggest that prospective investigation of the relationship between plasma micronutrients and risk of AFB1-related HCC is warranted.      

Preferential expression of insulin-like growth factor binding proteins-1, -3, and -5 during early diabetic renal hypertrophy in rats

The renal insulin-like growth factor-I (IGF-I) system has been implicated in the pathogenesis of renal hypertrophy, altered hemodynamics, and extracellular matrix expansion associated with early diabetes. The relative abundance of IGF binding proteins (IGFBPs) in the renal microenvironment may modulate IGF-I actions. However, the precise IGFBPs expressed in the glomerular and tubulointerstitial compartments during diabetic renal growth have not been characterized. In the present study, in situ hybridization studies were performed to examine the expression of IGFBP-1 to -6 messenger RNAs (mRNAs) 3, 7, and 14 days after streptozotocin (STZ) injection in rats. In control, nondiabetic kidneys, all six IGFBP mRNAs were differentially expressed with a predominance of IGFBP-5. The onset of renal hypertrophy in STZ-induced diabetes was associated with a rapid and site-specific induction of IGFBP-1, -3, and -5 mRNAs. In contrast, basal expression of IGFBP-2, -4, and -6 mRNAs was not altered in diabetic rats. IGFBP-5 mRNA expression increased in diabetic glomeruli, cortical, and inner medullary peritubular interstitial cells at days 3, 7, and 14. Although normal glomeruli failed to express IGFBP-3, it was induced concomitantly with IGFBP-5 in diabetic glomeruli and cortical peritubular interstitial cells. IGFBP-1 mRNA levels also increased in cortical tubular cells at each time point tested. Peak induction of IGFBP-3 and -5 was observed at day 3, whereas IGFBP-1 was delayed until day 7. IGFBP-1, -3, and -5 mRNA levels declined by day 14, but remained persistently elevated above control. By immunoperoxidase staining, similar alterations in the pattern of IGFBP-3 and -5 protein expression were observed at each time point. The preferential and site-specific increase in IGFBP-1, -3, and -5 suggest that these IGFBPs may regulate the local autocrine and/or paracrine actions of IGF-I and contribute to the pathogenesis of the early manifestations of diabetic nephropathy.     

长鞭红景天化学成分的研究

长鞭红景天化学成分的研究彭江南，葛永潮，李晓晖（军事医学科学院放射医学研究所，北京１００８５０）红景天是滋补强壮药物，目前正引起人们极大的兴趣，现已有一些产品上市。我们曾对数种红景天的化学成分进行过研究［１～４］。长鞭红景天（Ｒｈｏｄｉｏｌａｆａｓｔ...     

大网膜脂肪组织中胰岛素受体底物1、葡萄糖转运蛋白4和抵抗素mRNA表达水平与代谢综合征的关系

目的:分析代谢综合征患者大网膜脂肪组织胰岛素受体底物1、葡萄糖转运蛋白4和抵抗素mRNA表达水平及其与代谢综合征相关指标的关系。方法:选择2003-02/08在青岛大学医学院附属医院普通外科及妇科择期手术的患者53例,均知情同意。根据代谢综合征的诊断标准分为两组:①代谢综合征组28例,分为两个亚组:2型糖尿病组13例,非糖尿病组15例。②对照组25例。手术前当天抽取患者空腹血,测定空腹血糖、三酰甘油、空腹胰岛素。手术中取大网膜脂肪组织约200mg,用于RNA提取。采用一步法半定量反转录聚合酶链反应技术,测定患者大网膜脂肪组织中胰岛素受体底物1、葡萄糖转运蛋白4以及抵抗素的mRNA表达水平。结果:代谢综合征组28例,对照组25例患者全部进入结果分析,无脱落。①代谢综合征组患者大网膜脂肪组织胰岛素受体底物1、葡萄糖转运蛋白4mRNA表达均显著低于对照组(P<0.01)。2型糖尿病患者的胰岛素受体底物1mRNA、葡萄糖转运蛋白4mRNA表达显著低于非糖尿病患者(P<0.01)。②代谢综合征组与对照组患者胰岛素受体底物1与葡萄糖转运蛋白4的mRNA表达呈显著正相关(r=0.661,0.621,P<0.01)。③多因素逐步回归分析显示腰臀比与胰岛素抵抗指数及胰岛素受体底物1、葡萄糖转运蛋白4mRNA表达均有明显的相关性。④抵抗素mRNA表达阳性率和表达量在2型糖尿病代谢综合征患者、非糖尿病代谢综合征患者与对照组之间差异均无显著性意义(P=0.121,P=0.228),与腰臀比、体质量指数、胰岛素抵抗指数、空腹血糖、空腹胰岛素、三酰甘油以及血压均无相关性(P>0.05)。结论:代谢综合征患者大网膜脂肪组织胰岛素受体底物1与葡萄糖转运蛋白4mRNA表达明显降低,其中以2型糖尿病患者表现最为显著。大网膜脂肪组织抵抗素mRNA表达与代谢综合征及2型糖尿病无关。胰岛素受体底物1、葡萄糖转运蛋白4的mRNA表达和腰臀比可联合预测胰岛素抵抗的程度。