Evaluation of four elastomeric interocclusal recording materials

Background: The fabrication of dental prosthesis requires the transfer of interocclusal records from patient's mouth to semiadjustable articulators using different kinds of recording media. Any inaccuracy in these interocclusal records leads to occlusal errors in the final prosthesis. This study was conducted to evaluate the dimensional changes occurring in the interocclusal recording material over a given period of time and the material's resistance to compression during the cast mounting on the articulator.     

Single photon emission computerized tomography in childhood hydrocephalus

Single photon emission computerized tomography (SPECT) is now widely used as one of the tools in evaluating cerebral blood flow (CBF). The authors report the CBF changes in childhood hydrocephalus. Five pediatric cases studied by ¹²³I-IM SPECT in children are presented. The authors counted radioactivities both in early and delayed images in each patient, and calculated the reabsorption ratio (RR). Two negative-RR cases and three positive-RR cases were found. All of the negative-RR patients had a poor prognosis, while all of the positive-RR patients had a favorable outcome.     

新加坡亚洲人的基底细胞癌特征及完全与不完全切除肿瘤的比较

背景：大多数已报道的基底细胞癌（BCCs）的特征主要是依据高加索患者。而关于亚洲人中不完全切除BCCs的特征少见报道。目的：本研究调查了新加坡亚洲居民的BCCs特征，并对常规外科切除术后完全切除与不完全切除肿瘤进行了比较。患者和方法：收集1991--1995年间在国家皮肤病中心行肿瘤切除术的原发性BCC患者的病历进行回顾性研究。结果：166例BCC患者（男女比0．95；平均年龄70．9岁）的185个组织病检确诊的BCCs记录在案。发病最高比例（27．1％）在8l～90岁年龄组。与普查资料相比，华人BCCs患者的比例明显增高（P〈0．001）。肿瘤平均直径为12．0mm，且大多数（84．3％）位于头颈部。28处（15．1％）皮损被不完全切除，多位于鼻部及鼻唇沟。不完全切除的基底细胞癌较完全切除的基底细胞癌更多发生于面中部及躯干部（P=0．003），但与肿瘤大小、肿瘤持续时间、患者年龄、种族及性别无显著相关。平均随访74个月，     

Practice of orthokeratology by a group of contact lens practitioners in Hong Kong

Purpose: The aim of the study was to provide information about the characteristics of three main types of orthokeratology (ortho‐k) lenses used in Hong Kong and to report on their performance based on the clinical impressions of a group of ortho‐k practitioners. Method: Twelve ortho‐k practitioners were interviewed between 1 March and 30 June 2001. Results: Most ortho‐k lenses were ordered from three manufacturers: DreimLens, Fargo and Contex. The median maximum myopia reduction reported for DreimLens, Contex and Fargo lenses were 6.25 D, 6.00 D and 4.50 D respectively. The time to reduce myopia by up to 4.00 D could be up to three weeks for Contex and DreimLens and up to four weeks for Fargo. For reduction of myopia by up to 4.00 D, the treatment usually required only one or two lenses per eye for all three types of lenses. The incidence of lens binding and lens tightening after achieving the optimal reduction was reported to be higher with the DreimLens design. Good centration, less lens binding, relatively lower incidence of complications and lens tightening after achieving the optimal reduction were reported with the Fargo lenses. Conclusions: DreimLens tended to be more effective for myopia reduction. However, some practitioners were concerned with the aggressiveness of myopia reduction using this lens design and the higher potential for ocular complications. Selection of the lens design is dependent on various factors, in particular, practitioners need to be comfortable with the design they choose and to consider the needs of their patients and the final goal of the treatment.     

Estrogen-induced transcortin increase and progesterone and cortisol interactions: implications from pregnancy studies

The concentrations of progesterone, cortisol, estradiol, and transcortin binding capacity (TBC) were measured in plasma samples of women during normal pregnancy. Between 10 weeks and 20 weeks gestation, the mean of TBC increased linearly, and the mean increase in TBC for a given estradiol increment was constant until the estradiol concentrations reached approximately 30 nmol per liter. The results were consistent with the increase in TBC having been induced by estradiol; however, there was an inherent upper limit of response. Progesterone and cortisol were each linearly related to TBC, but the ratios of progesterone:TBC and cortisol:TBC showed no systematic trend throughout the period studied, and there was no systematic relationship between TBC and the progesterone:cortisol ratio. There was, however, a linear relationship between TBC and the progesterone + cortisol sum, such that a unit increase in TBC was accompanied by an approximate unit increase in the total concentration of the two main transcortin binding steroids. Some cases of spontaneous abortion or habitual abortion might be due to aberrant metabolic influence on progesterone of binding protein; in the instances studied, no evidence was found for this.