空气喷磨和酸蚀与树脂突超微结构的关系

目的 体外评价５种处理方法对树脂突超微结构的影响。方法 对照组：对１颗离体磨牙常规预防性树脂充填。其余４颗磨牙用空气喷磨处理,分别用５０μ和２７μ氧化铝微粒,酸处理其中２颗磨牙。窝洞用复合树脂充填后,用１０％盐酸溶解牙釉质,扫描电镜观测树脂突超微结构。结果 对照组呈典型窝状结构。空气喷磨的树脂突呈不规则结构,结合酸蚀的树脂突表面更加粗糙。结论 空气喷磨具有一定的蚀刻作用但不如酸蚀作用强。     

Molecular characteristics of two esophageal carcinosarcomas: a hint for theclonality of carcinomatic and sarcomatic tumor components

AIM To study the clonality of the esophageal carcinosarcoma by using molecular approaches.METHODS Two esophageal carcinosarcomas were included in the study. Tumor area from dysplasticlesion, squamout cell carcinoma, basaloid cell carcinoma and spindle cell elements were microdissectedseparately. Each element was analyzed with 14 microsatellite markers and direct sequenced for p53 gene andras gene mutation.RESULTS Both tumors displayed a typical histologic feature of carcinosarcoma. Both cases showed thedivergent differentiation by immunohistochemistry study. In case 1 the identical LOH at p53 and hMLH1 lociwas detected. The heterogenous LOH was detected only in carcinosarcoma at RB1 and BRCA1 loci, whilethe LOH at ACTC locus was seen only in sarcoma. The same mutation of the splice site of exon 6-intron 6displayed in the two tumor elements. In case 2, a coordinate LOH at RB locus was demonstrated in threetypes of tumor elements: sqamous carcinoma, basaloid carcinoma and spindle cell element. A heterogenousLOH was seen only in spindle cells at TAP1 locus. No mutation in exon 5-8 of p53 gene has been found incase 2. No mutation of K-ras gene was found.CONCLUSION Although the different differentiation, the two elements of esophageal carcinosarcoma mayhave a single clonality. The p53 gene mutation occurred before the two differentiation directions switched.The distinct molecular genotype can be determined through molecular biological analysis. The microsatelliteprofiling can serve as an approach to find out which genetic alteration occurs before or after thedifferentiation is determines.     

冠状动脉狭窄的16层螺旋CT造影检查

目的以常规X线冠状动脉造影为标准,评价16层螺旋CT（MSCT）无创性检查冠状动脉及诊断冠状动脉狭窄的价值。资料与方法65例临床初诊为冠心病,无冠状动脉成形术和搭桥术史的患者,在冠状动脉16层MSCT造影检查后,回顾性重建心电门控轴位图像,并采用容积成像（VR）、多平面重建（MPR）、曲面MPR、最大密度投影（MIP）等后处理方法,对所有冠状动脉及其分支进行重建,统计可供临床评价的、管径≥1．5mm的冠状动脉段,以选择性冠状动脉造影（SCA）为标准,对比分析MSCT诊断冠状动脉显著性狭窄（管腔平均直径缩小超过50％）的准确性。其中8例在检查前心率超过80次／min的患者使用了B受体阻滞剂。结果93％的冠状动脉节段和94％的冠状动脉主干可供评价,不能评价的主要原因分别为：心脏运动伪影（58％）,致密钙化（28％）和管腔显影不良（14％）。除外不能评价的冠状动脉,按节段和主干分类,MSCT诊断冠状动脉显著性狭窄的敏感性和特异性分别达到92％、98％和95％、97％。结论无需常规使用B受体阻滞剂,16层MSCT冠状动脉造影即可获得较好的图像质量用于诊断冠状动脉狭窄,是一种值得临床医师信赖的检查冠状动脉有无狭窄的非创伤性方法。     

LDL-receptor gene mutations and the hypocholesterolemic response to statin therapy

Studies of the cholesterol lowering effect of statin therapy as a function of low-density lipoprotein (LDL)-receptor mutation type have not produced a clear picture, possibly because they included patients with several different kinds of LDL-receptor mutations. We studied the response to treatment with fluvastatin in 28 patients with heterozygous familial hypercholesterolemia as a result of a receptor-negative mutation (Trp23-stop) and in 30 patients with a receptor-binding defective mutation (Trp66-Gly) to test the hypothesis that response to treatment depends on the type of mutation. Patients were randomized to 12 weeks of treatment with fluvastatin 40 mg daily and 12 weeks of placebo treatment, preceded by a placebo run-in period of 8 weeks in a double-blind, cross-over design. Untreated plasma concentrations of lipids and lipoproteins were similar in the two groups of patients. Plasma cholesterol and LDL cholesterol response to therapy tended to be less marked in receptor-binding defective patients, but the differences were not statistically significant. A tabulation of the results of the present and earlier studies suggests that differences in treatment response as an apparent function of LDL-receptor gene mutational type occur mainly in populations with recent genetic admixture (<400 years). In such populations, persons with the same mutation in the LDL-receptor gene are more likely to share other but undetermined genetic variations affecting the pharmacology of statins.     

Oral lesions of HIV infection in developing countries

HIV infection has spread rapidly within developing countries since it was first recognized in the early 1980s. The purpose of this paper is to review the prevalence of oral lesions associated with HIV infection (oral HIV) in the developing world, and to identify additional factors that may complicate the presentation of these lesions. Direct comparison of regional and local prevalence studies within Africa, India and Thailand is speculative because there are few reports available. Furthermore, inherent differences in study design, data collection, standardization and calibration of health workers make any inferences inconclusive. Additional prevalence studies of oral HIV lesions associated with systemic disease or social conditions, such as poverty or malnutrition, are needed. In order to provide a basis for the diagnosis and treatment of HIV-associated oral lesions in the developing world, it is important to recognize any confounding factors that may impact on their presentation and management. Elucidation of these various factors may provide a basis for treatment within the developing and developed world.