临床试验中应用安慰剂的伦理学争议评价

在有效治疗存在的情况下，对于是否可以在临床试验中应用安慰剂对照组，存在很大争议。当第5版“赫尔辛基宣言”(2000)出台后，此争议更趋激烈。本就此争议进行了回顾，并且调查了香港医学研究人员在此争议中的态度。有关争议的内容主要包括四个方面。第一，从试验方法角度而论，应用安慰剂对照的设计是否在确定疗效方面具有优越性?第二，治疗的真实疗效是否应该包括安慰剂效应?第三，安慰剂对照组的参与是否面对发生更大不良反应事件的机会?第四，有效治疗的标准究竟应该是地区性的，还是国际性的?从初步研究的数据来看，香港研究人员对于在临床试验中有效治疗存在的情况下，是否可以应用安慰剂对照组似乎也存在意见分歧。因此，为减少此争议给香港医学研究人员带来的困惑，有必要进行一定的培训以达成共识。     

海藻酸盐的理化特性及其在组织工程研究和临床中的应用

目的:对藻酸钠和藻酸钙的理化特性及在骨、软骨组织工程研究和临床中的应用作一系统回顾。资料来源:检索2000/2006 Medline与藻酸钠或藻酸钙相关的文献,检索词"sodium alginate,Calcium alginate",并限定文章语言种类为"English";同时检索中国医院数字图书馆1994/2006中国医学核心期刊关于藻酸钠或藻酸钙的相关文献,检索词"藻酸钠,藻酸钙",限定文章语言种类为中文。同时手工检索相关书籍。资料选择:对检索到的与藻酸钠或藻酸钙相关文献212篇进行筛选,并排除综述类文献,符合纳入标准的有71篇。资料提炼:对71篇文献进行分类整理,排除重复性文献,纳入33篇文献,其中22篇关于海藻酸理化特性,11篇为临床应用。资料综合:①藻酸钠水溶液在钙离子的作用下发生侧向交联由液态变为凝胶态,该水凝胶具有很好的亲水性,营养物质易于渗透扩散,其酶解产物对人体无毒害作用。这类凝胶以其良好的生物相容性在骨或软骨组织工程中、在药物缓释系统、创伤修复、治疗返流性食管炎等临床过程和改善水质、净化环境等方面发挥重要作用。②藻酸钙凝胶是藻酸钠的置换物,是一种中性偏碱的基质材料,除机械强度较差外,它在生物相容性、可降解性、细胞-材料界面、三维立体多孔结构和可塑性等方面都有利于种子细胞的接种和生长,是理想的组织工程基质材料,尤其在骨和软骨组织工程中。结论:海藻酸盐主要从海藻中提取,其凝胶具有良好的生物相容性,在组织工程及临床应用方面有巨大的潜力。     

Frequency of platelet-specific antigens among Chinese in Taiwan

The frequencies of six platelet-specific antigens among Chinese in Taiwan are reported, which have not previously been well studied. HPA- 1a (PlA1) antigen was positive in all 1100 Chinese tested. HPA-4b (Yukb) antigen was positive in all 100 persons tested. HPA-2b (Ko(a), Sib(a)) antigen was positive in 9 percent of 100 persons tested, HPA-3a (Bak(a)) in 77 percent, and NAKa in 96 percent. HPA-4a (Yuk(a)) antigen occurred in 0 percent in this study but is estimated to be present in 0.5 percent of the Taiwanese population.     

Association between antidepressant drug use during pregnancy and child healthcare utilisation

Objective  To evaluate healthcare utilisation by children who were exposed to antidepressant drug use during pregnancy and those whose mothers stopped using antidepressants before pregnancy compared with a control group.
Design  Cohort study.
Setting  Health insurance records in the Netherlands.
Population  A total of 38 602 children born between 2000 and 2005.
Methods  Survey of child healthcare utilisation in relation to gestational antidepressant use.
Main outcome measure  Healthcare utilisation rates during the first year of life, with special emphasis to medical care related to cardiac disease.
Results  Children of mothers who used antidepressants during pregnancy showed increased healthcare use during the first year of life, independent of the mother's healthcare use. The relative risk of more than two visits to general practitioners was 1.5 (95% confidence interval, CI: 1.3–1.8) in the continuous antidepressant users group and 1.3 (95% CI: 1.2–1.5) in the group of children whose mothers stopped taking medication. In both study groups there was a trend towards more drug use for infections and inflammation compared with the control group. Children continuously exposed to antidepressants had an increased risk of cardiac interventions such as cardiovascular surgery or heart catheterisation, relative risk of 5.6 (95% CI: 1.8–17.4). The risk of physiotherapy was twice as high in the antidepressant group compared with the control group (relative risk 2.0; 95% CI: 1.5–2.6).
Conclusion  Antidepressant use during pregnancy is associated with increased child healthcare utilisation and increased risk of major cardiac interventions in early childhood.     

Pituitary adenomas in patients with Cushing disease: initial experience with Gd-DTPA-enhanced MR imaging

To assess the role of magnetic resonance imaging in the evaluation of adrenocorticotropic-hormone (ACTH)-producing pituitary adenomas, and the effect of intravenously administered gadolinium-diethylenetriaminepentaacetic acid (DTPA) on lesion/pituitary contrast, imaging was performed in 13 patients with clinical and chemical evidence of Cushing disease. Images were obtained at 0.5 T before and after the injection of Gd-DTPA (0.1 mmol/kg). Lesions were identified in eight of 12 precontrast and ten of 12 postcontrast studies. In these 12 patients adenomas were found at transsphenoidal surgery. The other patient, with normal images, was found to have an ectopic source of ACTH. Coronal images corresponded remarkably well with the neurosurgeon's intraoperative findings. Serial T1-weighted images disclosed early enhancement of the pituitary gland and delayed enhancement of the cystic adenomas. The discrepancy in times to peak enhancement accounted for improved lesion/pituitary contrast in some early images and for reversal or diminution of lesion/pituitary contrast in later images.     

Binding characteristics of ortho-toluidine to rat hemoglobin and albumin

The binding characteristics of [14C]ortho-toluidine (OT), a suspect human carcinogen, were investigated in male Sprague-Dawley rats. Rats were administered [14C]OT i.p. at 10, 20, 40, 50, or 100 mg/kg body weight, then sacrificed at 2, 4, 8, 18, 24, 48, or 72 h, or 7, 14, or 28 days. Hemoglobin (Hb) and albumin (Alb) were isolated from blood, and OT binding was determined by liquid scintillation counting. For Alb, peak binding occurred at 50 mg/kg at the 4-h time point (15.6 ng OT/mg Alb), while for Hb peak binding was observed at 24 h at the 100 mg/kg dose (23.0 +/- 5.1 ng OT/mg Hb). OT-Alb binding was not linear; however, OT-Hb binding appeared to increase linearly in a dose-dependent manner. Biological half-lives of OT bound to Alb or Hb were observed to be 2.6 and 12.3 days, respectively, after rats were administered a single dose of [14C]OT and sacrificed after 4 h to 28 days. The effect of route of administration on OT-Hb adduct formation was investigated, and approximately a two-fold increase in radioactivity bound to Hb was observed after i.p. administration of 100 mg/kg [14C]OT versus oral intubation. Additional studies were carried out to investigate the effect of microsomal enzyme induction. An increase in OT-Hb binding was seen in rats pretreated with phenobarbital compared to rats pretreated with beta-naphthoflavone or without pretreatment; however, this increase was not statistically significant. These results suggest that OT-Hb and OT-Alb adduct formation may be a valuable biomarker for assessing workplace exposure.     

Hepatic haemangioendothelioma presenting with early heart failure in a newborn: treatment with hepatic artery embolization and interferon

We report our management of a newborn presenting in utero with congestive heart failure secondary to a giant hepatic haemangioendothelioma. Control of heart failure was achieved by transcalheter hepatic artery embolization, and rapid regression of the tumour was observed after a course of α₁ interferon. The combination of hepatic artery embolization and interferon may be a useful approach in the management of this rare, potentially fatal condition.     

四川轮环藤根中两种新双苄基异喹啉生物碱的分离鉴定

从中国特有植物四川轮环藤(Cyclea sutchuenensis Gagnep.)根中除分得已知的轮环藤碱(Ⅰ)和异粒枝碱(Ⅱ)外,还分离得到两种新双苄基异喹啉生物碱,分别命名为异轮环藤碱(Ⅲ)和四川轮环藤辛碱(Ⅳ)。经物理常数和波谱数据分析鉴定,证明Ⅲ为轮环藤碱的差向异构体,Ⅳ系一种新型的8-12′,12-7′首尾双氧桥双苄基异喹啉生物碱。     

Normal penile anatomy and abnormal penile conditions: evaluation with MR imaging

The appearance of the normal penis and of a variety of penile abnormalities on magnetic resonance (MR) images was studied in 55 patients with either medium (0.35 T) or high (1.5 T) magnetic field strengths. Penile morphologic characteristics with anatomic detail of the corpora cavernosa and corpus spongiosum were demonstrated in each patient. MR images clearly displayed congenital anomalies (n = 6), penile prostheses (n = 7), fibrous tissue or hematoma due to trauma (n = 8), and fibrous plaque in Peyronie disease (n = 3). MR imaging also demonstrated urethral (n = 6) and penile (n = 5) neoplasms and allowed tumor staging, thus facilitating the surgical approach.