碳酸氢钠预防造影剂肾病——一项随机对照研究

背景：造影剂肾病仍是放射影像学检查的一种常见并发症。在动物急性缺血性肾衰竭模型中，预先使用碳酸氢钠比氯化钠的肾脏保护作用更佳。缺血和造影剂引发的急性肾衰竭均被认为是自由基损伤所致。但是，在人或动物至今尚无评价碳酸氢钠预防造影剂肾病有效性的研究。 目的：在使用放射性造影剂前后用碳酸氢钠或氯化钠进行预防性水化，比较二者的有效性。 设计、地点和病人：一项于2002年9月16日至2003年6月17日进行的前瞻性、单中心、随机试验。119例血清肌酐稳定在≥1．1mg／dL（t≥97．2μmol／L）水平的病人，在应用碘帕醇（370mg碘／mL）造影前后，随机接受了氯化钠静脉滴注（n=59）或碳酸氢钠静脉滴注（n=60），剂量均为154mEq／L。在造影前及造影后第1、2天进行了血清肌酐检测。 干预：病人接受154mEq／L的氯化钠或碳酸氢钠，造影前以每小时3mL／kg的速度静脉滴注1小时，造影后以每小时1mL／kg的速度滴注上述药物6小时。 主要观察指标：造影剂肾病，其定义为在造影后2天内血清肌酐升高tμ25％。 结果：两组病人在年龄、性别、糖尿病发生、种族以及造影剂用量方面无显著差异。碳酸氢钠治疗组病人基线血清肌酐水平稍高于氯化钠治疗组，但亦无显著差异（氯化钠组均值[sD]为1．71[0．42]mg／dL[151．2{37．1}μmol／L]，碳酸氢钠组为1．89[0．69]mg／dL[167．1{61．0}μmol／L]；P=0．09）。氯化钠组8例（13．6％），发生造影剂肾病一级终点，而碳酸氢钠组仅1例（1．7％）（均值差别，11．9％；95％可信区间[CI]，2．6％～21．2％；P=0．02）。随后，又对191例符合研究纳入标准的病人给予了碳酸氢钠治疗并进行随访登记，结果有3例出现了造影剂肾病（1．6％；95％CI，0％～3．4％）。 结论：对于造影剂引发的肾衰竭，在造影前采用碳酸氢钠进行水化治疗比采用氯化钠水化治疗更为有效。     

EFFECT OF HIGH ALTITUDE ON PREVALENCE OF CONGENITAL HEART DISEASE

The prevalence of congenital heart disease (CHD7at high altitude was determined by st.trveying 1116children at 4 study sites, ranging from sea level to4 300 M. Children were screened by physical exami-nation, and echocardiogram and electrocardiogramwere done on those suspected of having CHD. Ahigh prevalence of patent ductus arteriosus (PDA)and atrial septal defect (ASD) was found at highaltitude sites and the effect of altitude was progres-sivc. At 4300 M, a combined prevalence of 5.2%was found. PDA is thought to result from failureof low atmospheric p02 to constrict ductal muscle.We speculate that the persistence of high pulmonaryvascular resistance and right heart pressure inhibits early closure of the patent foramen ovale (PFO) andthat the flap becomes incompetent with growth, re-sulting in ASD. The high prevalence of ASD/PFOin tetralogy of Fallot may be analogous and related to high right ventricular pressurc present from birth.     

头颈部恶性肿瘤诊断治疗指南

恶性肿瘤是威胁人类生存的第一杀手,就头颈肿瘤来说虽然发病率在我国并不高,但由于我国人口众多,发病率的绝对数字也是不可忽视的。当今提倡晚期头颈肿瘤的综合序列治疗,患者的生存率及生存质量已有很大的提高,由于我国的地域差异和医学发展水平的不平衡,对于头颈肿瘤的治疗难以形成统一的治疗标准,目前国内也缺少头颈肿瘤的诊断治疗指南,客观存在着肿瘤的诊断治疗欠规范,延误诊治、过度治疗、治疗不够等现状,这不仅导致医疗资源的浪费和国家及个人的经济负担加重,而且由此导致的医患纠纷时有发生。鉴于此,本期刊出由上海交通大学医学院附属第九人民医院·口腔医学院郭伟等医师编译的2005年美国国立癌症综合信息网(National Comprehensive Cancer Network,NCCN)公布的由NCCN头颈肿瘤专家组31位专家撰写的关于头颈部恶性肿瘤诊断治疗指南的有关内容,旨在结合我国实际情况供专业人员参考。     

美国职业病控制

在美国,与职业有关的损伤和疾病是一重要的公共卫生问题,每年约有1/11的工人因接触作业环境中的有害因素而患病或受到损伤(Bureau ofLabour Statistics.1980)。全美在雇工11人以上的工场工作的工人中,至少有4,500例死亡与工作有关,550万人致残,工伤缺勤每年达3,600万工作日,非创伤性职业病及其死亡的确切资料较难获得,据七十年代初的估计,每年约有1万人因职业接触死亡,40万人患病(总统报告,1972)。 第二次产业革命以来,由于某些重大职业病的发生,使人们认识到作业环境对健康影响的重要性。包括:     

成纤维细胞的力学生物学(下)

一、肌腱内成纤维细胞的力学生物学反应 肌腱内的成纤维细胞可以合成胶原蛋白及其他一些大分子。成纤维细胞可以将这些分子排列成组织性较高的单元，并使纤维的方向与张力方向平行。无论是培养的肌腱还是独立的成纤维细胞都可以对力做出相应的反应。     

IL-6–174G/C genotype is associated with the bone mineral density response to oestrogen replacement therapy in post-menopausal women

A reduction in interleukin-6 (IL-6) activity may contribute to the beneficial effects of hormone replacement therapy (HRT) on the menopausal decline in bone mineral density (BMD). We have examined this hypothesis using a genetic strategy. The –174C (rather than G) IL-6 gene variant is associated with lower IL-6 expression. As such, we might anticipate the C allele to be associated with a greater response to HRT. We have tested this hypothesis. Mean three-site [spine (L1-L4), neck of femur, and Wards triangle] BMD was measured in 65 women in a 1-year randomised controlled trial of HRT with 0.625 mg oestrogen/day and 0.15 mg norgestrel (n=30). Baseline BMD was genotype-independent for both the control and HRT group. In the control group, the percentage change in BMD after 1 year was similar between genotypes (P=0.45). In contrast, in the HRT group, the rise was genotype-dependent. Those homozygous for the G allele showed a 3.62 (2.14)% increase in BMD compared with 10.44 (4.68)% for the C-homozygous group. Heterozygotes had an intermediate BMD increase of 5.6 (2.82)% [P=0.006 (P value for interaction between HRT and genotype was 0.04)] Although the study was limited by its small sample size, these are the first data to demonstrate the importance of IL-6 genotype in determining response to oestrogen therapy, rather than its physiological withdrawal.     

Human papilloma virus infection in Indian nasopharyngeal carcinomas in relation to the histology of tumour

Nasopharyngeal carcinoma (NPC) is a rare malignancy world-wide. It shows an increasing trend in the southern parts of India. Genetic alterations brought about by environmental factors, HPV and EBV are thought to be crucial for NPC carcinogenesis. This study reports for the first time the incidence of HPV infection in NPC in Southern India. Detection of HPV was carried out in 36 NPC and 10 adenoid lesions by immunohistochemical analysis. 38.8% of NPC were positive for HPV with higher positivity in WHO Type I and WHO Type II cancers. One among 10 adenoid lesions also showed presence of HPV. The patients belonged to low socio-economic status and had exposure to either tobacco or alcohol alone or in combination or kitchen smoke.     

Quality assurance of a helical tomotherapy machine

Helical tomotherapy has been developed at the University of Wisconsin, and 'Hi-Art II' clinical machines are now commercially manufactured. At the core of each machine lies a ring-gantry-mounted short linear accelerator which generates x-rays that are collimated into a fan beam of intensity-modulated radiation by a binary multileaf, the modulation being variable with gantry angle. Patients are treated lying on a couch which is translated continuously through the bore of the machine as the gantry rotates. Highly conformal dose-distributions can be delivered using this technique, which is the therapy equivalent of spiral computed tomography. The approach requires synchrony of gantry rotation, couch translation, accelerator pulsing and the opening and closing of the leaves of the binary multileaf collimator used to modulate the radiation beam. In the course of clinically implementing helical tomotherapy, we have developed a quality assurance (QA) system for our machine. The system is analogous to that recommended for conventional clinical linear accelerator QA by AAPM Task Group 40 but contains some novel components, reflecting differences between the Hi-Art devices and conventional clinical accelerators. Here the design and dosimetric characteristics of Hi-Art machines are summarized and the QA system is set out along with experimental details of its implementation. Connections between this machine-based QA work, pre-treatment patient-specific delivery QA and fraction-by-fraction dose verification are discussed.     

Use of a repetitive DNA probe to type clinical and environmental isolates of Aspergillus flavus from a cluster of cutaneous infections in a neonatal intensive care unit

Aspergillus flavus is second to A. fumigatus as a cause of invasive aspergillosis, but no standard method exists for molecular typing of strains from human sources. A repetitive DNA sequence cloned from A. flavus and subcloned into a pUC19 vector, pAF28, was used to type 18 isolates from diverse clinical, environmental, and geographic sources. The restriction fragment length polymorphisms generated with EcoRI- or PstI-digested genomic DNA and probed with digoxigenin-labeled pAF28 revealed complete concordance between patterns. Eighteen distinct fingerprints were observed. The probe was used to investigate two cases of cutaneous A. flavus infection in low-birth-weight infants in a neonatal intensive care unit (NICU). Both infants were transported by the same ambulance and crew to the NICU on the same day. A. flavus strains of the same genotype were isolated from both infants, from a roll of tape used to fasten their umbilical catheters, from a canvas bag used to store the tape in the ambulance, and from the tape tray in the ambulance isolette. These cases highlight the need to consider exposures in critically ill neonates that might occur during their transport to the NICU and for stringent infection control practices. The hybridization profiles of strains from a second cluster of invasive A. flavus infections in two pediatric hematology-oncology patients revealed a genotype common to strains from a definite case patient and a health care worker. A probable case patient was infected with a strain with a genotype different from that of the strain from the definite case patient but highly related to that of an environmental isolate. The high degree of discrimination and reproducibility obtained with the pAF28 probe underscores its utility for typing clinical and environmental isolates of A. flavus.