放射性肝纤维化过程的定量研究

经＾６０Ｃｏγ线照射大鼠肝区，通过光镜、电镜和图像分析仪、宣研究了照后１年肝脏的病理改变。结果表明，３０Ｇｙ组在照射后１年内逐渐发生了放射性肝纤维化病变。在肝纤维化发生过程中，肝细胞内糖原颗凿含量进行性减少，间质中胶原纤维含量进行性增加，网状纤维于照射１－３个月呈进行性增加。     

高海拔地区血气正常值范围的探讨

通过西宁地区１１００例正常人血气值的统计，提出在高海拔地区血气ＰＨ不应是硷血症，而是在正常范围内轻度偏硷，关于高海拔地区动脉氧分压的预计。作者提出有海拔系数来计算，并对西宁地区ＰａＣＯ２，ＰＨ，ＨＣＯ＾－３数值的统计处理，得出它们的回归系数，回归方程，为判断各类酸硷紊乱提供参考。     

涎腺腺样囊性癌氩离子激光流式细胞术分析及其临床意义

为探讨流式细胞术对涎腺腺样囊性癌的诊断和预后估计的价值，对４１例腺样囊性癌行流式细胞术分析。结果，平均ＤＮＡ指数为１．１７９，Ｓ期细胞比例为２９．４９％，细胞增殖指数为４２．６７％，均明显高于正常组织。异倍体检出率为７０．７３％。随着肿瘤的增大和恶性程度的增加，其异倍体率、ＤＮＡ指数和Ｓ期细胞比例值也相应增加。流式细胞术为涎腺腺样囊性癌的病理诊断和确定恶性程度提供了有效的辅助诊断措施，但尚不能判断预后。     

顺序节段分析法在先天性右位心合并心内畸形中的诊断价值

目的提高超声心动图对心脏位置异常合并复杂心内畸形的诊断准确率。方法选择近年来在我院经手术或心血管造影证实的先天性右位心合并心内畸形患者42例,对其超声心动图检查结果进行回顾分析。结果手术证实本组先天性右位心分型：镜像右位心13例,右旋心29例;心内畸形：单心室10例,右室双出口8例,法洛四联症6例,完全性大动脉转位5例,矫正性大动脉转位4例,完全性房室间隔缺损4例,永存动脉干3例,肺动脉闭锁2例。超声误诊、漏诊的病例：3例完全性大动脉转位伴巨大室间隔缺损误诊为单心室;2例右室双出口误诊为法洛四联症;1例矫正性大动脉转位误诊为完全性大动脉转位;1例肺动脉闭锁误诊为永存动脉干;1例肺动脉闭锁超声漏诊左肺动脉缺如及多支体肺侧枝。结论超声心动图顺序节段法对绝大多数先天性右位心并心内畸形能作出准确诊断,但对某些极为复杂的病例心导管检查仍是明确诊断和手术条件的重要手段。     

围产儿死亡原因分析

本组对1986年10月1日至1991年9月30日内,在青海省17所医院里分娩的死胎、死产、新生儿死亡均统一填表。分娩总数50509例,围产儿死亡1783例,围产儿死亡率31.55％,死胎748例占41.95％,死产438例占24.57％,新生儿死亡597例占33.48％。围产儿死亡原因:第一胎盘因素占16.43％,第二宫内缺氧占15.37％,第三早产儿占11.95％,第四畸形占9.93％,第五脐带因素占9.7％。本组城市围产儿死亡率25.37‰,农村47.78‰,牧区34.98‰,5年来比较死亡率有下降倾向,但仍处于高死亡率水平。今后需加强妇幼保健、产前检查、产时监护和提高产科质量,以进一步降低围产儿死亡率。     

密闭舱有害气体的分析及初步评价

为对载人密闭舱的有害气体进行分析和评价，本实验模拟飞行状态，对密闭舱内有害所体进行了５ｄ的跟踪检测和分析，定量出８个有机类别共８２种挥发性有机化合物和三种目标无机物，     

Social support and individual styles of coping in the Japanese workplace: an occupational stress model by structural equation analysis

The aim of the present study was to ascertain the role of social support and individual styles of coping on employee well‐being. The subjects were intermediate managers working for a zipper and sash manufacturing company in Japan. Measurements were made of the following: depression using the Self‐rating Depression Scale (SDS), job demand, job control, social support using Karasek's Job Content Questionnaire, and of three coping styles: emotion‐oriented coping, task‐oriented coping and avoidance‐oriented coping using the Coping Inventory for Stressful Situations (CISS). Data was analysed by structural equation modeling. Each coping style had a direct effect on depression. Emotion‐oriented coping had a negative effect. On the other hand, task‐oriented coping and avoidance‐oriented coping had a positive effect. Moreover, there was an indirect effect that coping styles precede and determine the perception of social support as well as job demand and control. Social support showed a direct positive effect on depression. However, the overall impact on employee well‐being was greater for individual coping styles as compared to social support from either supervisors or co‐workers. The present study showed the effectiveness of coping strategies in the workplace. Copyright © 2003 John Wiley & Sons, Ltd.     

<Emphasis Type="Italic">In-Situ</Emphasis> Visualization and Quantification of Mineralization of Cultured Osteogenetic Cells

An osteoblastic cell line (HOS cells) produces a prominent osteoid matrix with mineralization. Fibroblasts, on the other hand, do not exhibit this mineralization. To evaluate the degree of mineralization, we added calcein to the culture medium and then observed the culture wells by using an image analyzer. The calcein uptake into the cell/matrix layer was detected in the HOS cells but not in the fibroblasts. The calcein uptake was also quantified in situ by using an image analyzer, which revealed high levels in the HOS cells, which correlated well with the calcium content of the mineralized matrix. Rat marrow cells were also cultured in media containing calcein, fetal bovine serum, -glycerophosphate, L-ascorbic acid 2-phosphate, and with or without dexamethasone. With the dexamethasone, the cells exhibited osteogenic differentiation that resulted in mineralized matrix formation after about 10 days. The matrix formation coincided with the appearance of calcein uptake into the cell/matrix layer, with the amount of calcein uptake increasing with time. By contrast, the culture without the dexamethasone did not exhibit matrix formation and the calcein uptake was negligible. In the case of both HOS cell and rat marrow cell cultures in vitro, calcein did not affect expressions of their alkaline phosphatase activity or osteocalcin production. Furthermore, histologic observation revealed that rat marrow cells subcultured with calcein could show osteogenic ability after in vivo implantation. These results suggest that the current method of detecting calcein uptake in a culture allows the monitoring of the osteogenic capacity of cultured cells, as well as the measurement of the amount of mineralization produced by the osteogenic cells. Given that osteogenic cultured cells/mineralized matrices are used in bone reconstruction surgery, the in situ monitoring method is invaluable in that it allows us to evaluate the osteogenic capacity of in vitro constructs.     

July 2003

The effect of the Prandtl number (Pr) and the Reynolds number (Re) on the behaviour of weak laminar axisymmetric and plane fountains has been studied using dimensional and scaling analyses and direct numerical simulation. For Fr 1.0 and assuming viscous effects are important, the analysis shows that for both the axisymmetric and plane fountains, y_mFrRe^–1/2, where Fr is the Froude number defined at the fountain source and y_m is the non-dimensionalized fountain height. These scalings are also valid for the non-dimensionalized fountain width. The analyses also shows _msFr², where _ms is the non-dimensionalized time scale for the fountain flow in the fountain core to reach steady state, and using this time scale y_TFr(RePr)^–1/2, where y_T is the non-dimensionalized thickness of the temperature layer on the symmetry axis over which the fountain fluid temperature changes from the inlet value to that of the ambient fluid. All these scalings have been quantified by the direct numerical simulations, hence confirming in certain ranges the phenomenological scaling obtained in this paper. The financial supports from the National Natural Science Foundation (grant numbers 19872059 and 10262003) and Yunnan Province of the People's Republic of China to W. Lin and the Australian Research Council are gratefully acknowledged.     

Heat stress and strain in exercise and sport

Heat stress arising from the thermal environment is of concern to sports medicine and to sports administration because of the perceived risk of heat casualties, in particular heat stroke. Many sports organizations recommend environmental indices such as the WBGT for assessing risk and setting environmental limits for training and competition. But the limits are not justified by evidence. This article describes the nature of heat stress in sport and how it may be assessed objectively. Heat stress and the principal human responses to exercise heat stress are reviewed briefly. Metabolic heat production and the thermal environment provoke separate and largely independent physiological strains. Metabolic heat production drives body core temperature, and the thermal environment drives skin temperature; the combined stresses are integrated to drive sweat rate. Control of core temperature depends on adequate sweat production and the capacity of the environment to evaporate the sweat. The nature of exercise heat stress is demonstrated by rational analysis of the physical heat exchanges between the body and the environment. The principles of this analysis are applied to critical review of current practice in the assessment of heat stress in sport. The article concludes with discussion of research to establish methods for objective sport-specific assessment of heat stress.