Decreased plasma folate concentration in young and elderly healthy subjects after a short-term supplementation with isotretinoin

Background In the last two decades, there has been an increasing use of isotretinoin (13‐cis‐retinoic acid or 13‐CRA) for treatment of severe, and recently mild and moderate, acne in Westernized populations. Recent human and animal studies emphasized alterations caused by 13‐CRA administration on folate‐dependent, one‐carbon metabolism. Folate deficiency and subsequent hyperhomocysteinemia increase the risk of degenerative diseases. Objectives We determine whether a short‐term supplementation with 13‐CRA alters folate status and homocysteinemia in young and elderly healthy human subjects. Methods Twenty young and 20 elderly (age mean, 26.1 and 65.4 years, respectively) healthy male volunteers were supplemented with ~0.5 mg/kg/day of 13‐CRA for 28 days. Fasting plasma concentrations of 13‐CRA, 5‐methyltetrahydrofolate (5‐mTHF) as the main circulating form of folate, and homocysteine (Hcy), as well as haematologic parameters and biochemical markers of liver and renal function, were measured at baseline and at the end of supplementation. Statistical analyses were carried out using two‐way anova and standard tests. Results In both groups, isotretinoin supplementation caused a dramatic increase in the circulating concentration of 13‐CRA and its derivatives. It also led to significant increases in serum triglyceride (P < 0.0001) and creatinine (P = 0.002) concentrations and γ‐glutamyltranspeptidase activity (P = 0.0001) and decrease in serum level of urea (P = 0.027). However, the latter four parameters remained within normal ranges. These changes were accompanied by a 17.7% and 13.5% decrease in the plasma level of 5‐mTHF (P = 0.001) in the young and elderly volunteers, respectively. Supplementation with 13‐CRA did not cause significant variations in their plasma Hcy concentration. However, the latter parameter seemed to respond differently in each group of age (P = 0.046). Conclusions Our data indicate that a 28‐day supplementation with isotretinoin alters the plasma folate in young and old healthy individuals. This stresses the necessity of studying the long‐term effects of retinoid therapy on folate status and homocysteinemia in acne patients, given that alteration in the latter parameters is known to increase the risk of degenerative diseases.     

Hypoxic hepatitis in children after cardiac surgery

<正>To the Editor: Hypoxic hepatitis(HH), also known as ischemic hepatitis or shock liver, is a liver injury characterized by necrosis of centrilobular hepatocytes with a rapid increase in serum aminotransferase levels. The incidence rate of HH among patients in the intensive care unit(ICU) was found to be 0.9%-11.9% [1]. Occurrence of HH appears to have a significant impact on the clinical outcome.     

人类免疫缺陷病毒感染细胞的Rer蛋白依赖性凋亡引导

目的:以人类免疫缺陷病毒(HIV)调节蛋白Rev与Rev反应区(RRE)的高亲和性建立引导HIV感染细胞凋亡的结构。方法:用分子克隆技术合成含RRE和肿瘤坏死因子受体-1(TNF-R1)的Rev依赖性凋亡引导质粒,流式细胞仪检测质粒表达。结果:新质粒pDM128-TNF-R1(pT128)HindIII内切有3.1、2.7、1.0和0.87kb片段;聚合酶链反应(PCR)法检测示TNF-R1的1360bp片段。DNA测序法确认其准确性。单纯Hup60TNF-R1在pDC302(pT60)转染Hela,TNF-R1表达可明显杀伤Hela(P<0.01),Rev存在时,pT128也能表达TNF-R1杀伤Hela(P<0.01),但不及pT60的作用(P<0.01);无Rev时,pT128不表达TNF-R1,不杀伤Hela(P>0.01)。单纯Rev不杀伤Hela(P>0.01)。pT128与pRev共转,TNF-R1表达较pT60慢(P<0.01),40h后才接近单纯pT60。结论:新质粒具有Rev依赖性表达作用,进而引导Rev表达细胞凋亡。     

尿中麻黄碱类药物的气相色谱检测法

麻黄碱及其类似物有兴奋作用,属体育比赛禁用药。这类化合物的化学结构相似,故有相似的鉴别特征。本文报道了以气相色谱对尿中麻黄碱(ephedrine)、甲基麻黄碱(methylephedrine)、乙基麻黄碱(ethylephedrine)、去甲麻黄碱(norephedrine)及去甲伪麻黄碱(cathine)进行检测,最后以气质联用法进行确证。本法操作简便,灵敏度高,结果可靠。     

河北省4个地区广泛焦虑症的流行病学调查

目的:了解广泛焦虑症的患病率及人口学特点。方法:于2004-10/2005-03随机抽取河北省邯郸、保定、秦皇岛、承德4个地级市18岁以上人口进行全省精神疾病流行病学现场抽样调查工作,总样本24000人。调查筛选工具采用改编后的一般健康问卷12项,以《DSM-Ⅳ-TR轴Ⅰ障碍定式临床检查》病人版为调查的诊断工具。根据被调查者一般健康问卷12项总分,把被调查者分为高危人群、中危人群、低危人群3类。根据预试验调查结果确定三段危险人群的分界分:总分≥4分属于高危人群,高危人群全部进行DSM-Ⅳ-TR轴Ⅰ障碍定式临床检查;总分为2分或3分即属中危人群,中危人群约40%需进行DSM-Ⅳ-TR轴Ⅰ障碍定式临床检查,总分为0分或1分即属低危人群,低危人群中10%需进行DSM-Ⅳ-TR轴Ⅰ障碍定式临床检查。改编后的一般健康问卷12项分数及内容不变,另外增加8个问题均为高危因素,并进行DSM-Ⅳ-TR轴Ⅰ障碍定式临床检查。结果:①实际完成调查20716人,其中男10343人(49.9%),女10373人(50.1%)。共诊断焦虑症患者127例。②按高中低危因素调整后时点患病率为7.69/1000(95%CI6.50/1000～8.88/1000)。城市患病率4.87/1000,农村患病率8.10/1000,两者差异无显著性意义(u=1.78,P>0.05)。女性患病率明显高于男性,差异有显著性意义(分别为10.42/1000,4.97/1000,u=4.49,P<0.01),男女患病率比例为1:2.10。按不同年龄阶段的人口计算出各年龄段的时点患病率,20～29岁患病率较低(3.17/1000),50～59岁患病率较高(15.56/1000)。③通过12个因素的Logistic回归分析发现,影响广泛焦虑症的危险因素有年龄50～59岁(OR=1.713);保护性因素男性(OR=0.431),年龄20～29岁(OR=0.393),收入10001～20000元(OR=0.568),收入20001～40000元(OR=0.117)。结论:广泛焦虑症的流行病学特征为女性、中老年人患病率较高,男性、青年、收入中等者患病率较低。     

丁基苯酞对局部脑缺血大鼠神经元迟发性损伤及细胞内钙的影响

观察了丁基苯酞(NBP)对局部脑缺血迟发性脑梗塞和神经功能缺损的影响。结果表明,大鼠大脑中动脉阻断(MCAO)后2h分别poNBP80,160和240mg·kg^-1,均能明显降低脑梗塞面积,抑制率分别为49.0%,69.5%及85.1%,并明显改善神经功能缺失。在MCAO前1h予防给NBP(160mg·kg^-1po),也可明显缩小脑梗塞面积和改善神经功能缺失;在MCAO前连续口服7d,NBP剂量为80mg·kg^-1·d^-1,对上述指标均有改善作用。NBP对高K⁺引起大鼠脑突触体内Ca²⁺含量升高无影响。以上结果提示NBP对迟发性神经元损伤有保护作用。     

小檗碱对局灶性脑缺血大鼠血小板聚集及血浆TXB2和6-keto-PGF1a水平的影响

以大鼠可逆性大脑中动脉梗塞(MCAO)致局灶性脑缺血为模型,观察小檗碱对大鼠MCAO24h后血小板粘附、聚集、血栓形成及血浆TXB2和PGI₂生成的影响。结果表明,小檗碱20mg·kg^-1·d^-1ipl,3或5d,明显降低MCAo24h后血小板粘附性及ADP、胶原和花生四烯酸诱导的血小板聚集率,抑制血浆TXB₂水平。同剂量ip3或5d,则抑制血栓形成。提示小檗碱可能通过其抗血小板粘附和聚集及影响花生四烯酸代谢而发挥抗脑缺血作用。     

The changing clinical pattern of Reye's syndrome 1982-1990

OBJECTIVE: To describe trends in the clinical pattern of Reye's syndrome in the British Isles between 1982 and 1990; and to determine the relation between any changes and the June 1986 warnings against the use of aspirin in children. DESIGN: Development, and application to reported cases, of a scoring system designed such that patients showing the typical clinical and pathological features of 'classical' Reye's syndrome scored highly. The relations between 'Reye scores' and a number of explanatory variables were explored using multivariable analysis. SETTING: British Isles. SUBJECTS: 445 cases fulfilling the Reye's syndrome case definition reported to the surveillance scheme between January 1982 and December 1990. MAIN OUTCOME MEASURE: Individual 'Reye score'. RESULTS: Cases with high scores were more likely to have occurred in the 4 1/2 year period before June 1986 compared with the subsequent period (p < 0.006). Numbers of cases in the low and intermediate score categories declined by about 50% after June 1986, whereas those in the high category fell by 79%. High scorers were more likely to have received aspirin (p < 0.0001) and were older than intermediate and low scorers (p < 0.008). No relation was identified between score and season of onset. CONCLUSIONS: The decline in Reye's syndrome after the aspirin warnings cannot be explained entirely, as has been proposed, by improved diagnosis of 'Reye-like' inherited metabolic and other disorders: this would not account for the greater decline of the high scoring subgroup which also contained those cases most likely to resemble 'classical' Reye's syndrome and to have received aspirin. This study provides further evidence for the role of aspirin in a subset of cases meeting the standard diagnostic criteria for Reye's syndrome and supports the need to consider this disorder as a heterogeneous group of conditions including Reye-like inherited metabolic disorders.     

缺血后适应的研究与进展

目的:缺血后适应即冠状动脉再灌注开始时对冠脉进行短暂、重复的开通及再闭过程,随后恢复冠状动脉血流,对缺血再灌注心脏有显著保护作用。总结并分析缺血后适应对缺血再灌注心脏的保护作用及其机制。资料来源:应用计算机检索Medline1986-01/2006-05关于缺血后适应的文章。检索词“myocardial protection,Ischemic postconditioning,Ischemia-reperfusion injury”并限定文章的语种类为English。资料选择:对资料进行初审,纳入标准:关于缺血后适应机制及心脏保护作用的研究。排除标准:重复性研究。资料提炼:共收集到符合上述要求的文献51篇,排除21篇重复性研究。30篇符合纳入标准:其中26篇关于缺血后适应的研究,4篇关于缺血后适应的综述。资料综合:缺血后适应对心脏的保护作用包括缩小心肌梗死面积、对抗心律失常等。缺血后适应对心脏的保护作用的机制涉及腺苷、一氧化氮、线粒体ATP敏感K通道、再灌注损伤存活激酶通路、线粒体可渗透转运孔隙等许多方面和信号传导途径。结论:缺血后适应现象已经被许多独立的实验室应用大、小动物在体和体外模型及细胞培养模型所观察。与缺血预适应相比,缺血后适应可能会有更广阔的临床应用前景,其机制需进一步研究。