CD34+ stromal cells and hyalinized vascular changes in the anal fibroepithelial polyps

AIMS: To elucidate the pathogenesis of the anal fibroepithelial polyp, we examined surgically resected lesions histopathologically. METHODS AND RESULTS: Twenty-seven surgically resected anal fibroepithelial polyps were investigated histologically with an additional immunohistochemical examination using anti-CD34. For a control study, the surgical specimens of the anal canal showing non-polypoid lesions, obtained from haemorrhoidectomy (18 specimens) and rectectomy (five specimens) due to rectal cancer without anal canal involvement, were also analysed. We demonstrated characteristic spindle or stellate cells immunohistochemically positive for CD34 in the anal fibroepithelial polyps (24/27, 89%). The number of CD34+ cells was statistically related to the size of anal fibroepithelial polyps, although CD34+ stromal cells were recognized in the non-polypoid anal submucosa and haemorrhoids. We also found hyalinized vascular changes in the base of six anal fibroepithelial polyps examined. These features were not detected in the non-polypoid anal canal. CONCLUSIONS: An increase in CD34+ stromal cells may play a role in the enlargement of anal fibroepithelial polyps. CD34+ stromal cells are suggested to be distinctive mesenchymal cells with a capability for tissue repair and overgrowth. The vascular impairment could be secondary change associated with localized tissue damage by abnormal traction.     

The Psychological Significance of Task-Induced Tonic Changes in Somatic and Autonomic Activity

Two experiments tested the view that task-induced autonomic-somatic gradient parallelism does exist and that the steeper the physiological gradients, over the course of a task, the more involved the subject and the greater the effort. Thirty-three male subjects performed easy and difficult versions of a continuous reaction time task. In both experiments the difficult task prompted steeper electromyographic (EMG) activity gradients than did the easy version. Scores on heart rate (HR) and skin conductance did not show clear gradients. However, task-dependent effort was positively related to the magnitude of the initial HR acceleration and to the steepness of the EMG gradient. The autonomic-somatic coupling hypothesis of Obrist did not explain the results. Instead, evidence for ventilatory-somatic parallelism was found.     

溴氰菊酯对白纹伊蚊C6／36细胞株的杀伤作用及对其形态影响的研究

本文采用ＭＴＴ微量酶反应比色法，研究了溴氰菊酯对白纹伊蚊Ｃ６／３６细胞的杀伤作用、形态影响以及受损细胞的恢复。结果发现用溴氰菊酯处理２４ｈ后，对Ｃ６／３６细胞的半数毒性浓度（ＩＣ５０）为７４８８μｇ／ｍｌ，且毒性作用强度随着药物浓度增加而增强。溴氰菊酯浓度在２０μｇ／ｍｌ以上时可以诱发Ｃ６／３６细胞形态学改变，表现为细胞呈多形性、细胞间有间隙、胞质内充满颗粒，以后随药物浓度的升高，胞质出现空泡、染色质凝成粗大颗粒或无结构大块、大片细胞脱落、崩解、死亡。高浓度溴氰菊酯（１６０μｇ／ｍｌ）作用于Ｃ６／３６细胞，其受损细胞的恢复与作用时间有关，作用２４ｈ的细胞，在经历一段生长停滞后，可缓慢恢复，而作用４８ｈ的细胞，则不可逆转的死亡     

A scanning electron microscopy study of the interface between ceramics and bone

By use of scanning electron microscopy (SEM), together with energy dispersive chemical analysis, a study has been made of the comparison of an in vitro method of assessing interface reactions between bone and ceramic implants with the naturally occurring changes seen in the rat ear model. Interface reactions between bone and two ceramic materials were examined following 4 wk in culture and 4 wk implantation. In both cases a gradual chemical change occurred at the calcium silicate surface during the fibrous growth onto the ceramic material. Gradual mineralization of the connective fibres was found at the interface of the calcium silicate material, whereas, in the case of alumina ceramic a connective fibrous bond had formed with no associated chemical change at the ceramic surface.     

Quality validation of platelets obtained from the Haemonetics and Trima Accel automated blood-collection systems

BackgroundPlatelet transfusion is required to treat haemo-oncology or trauma patients. Platelet apheresis (PA) performed with apheresis equipment has increased rapidly in recent years. Leucocyte-reduced platelet apheresis (LRPA) can reduce the risk of platelet refractoriness and febrile nonhemolytic transfusion reactions (FNHTRs) for transfusion. Accordingly, this study aimed to investigate and compare the platelet metabolic and functional responses between PA performed with Haemonetics and LRPA performed with Trima Accel cell separator.MethodsThe qualities of platelets collected through PA and LRPA were evaluated in terms of visual appearance, morphology, platelet-aggregation changes, metabolic activities, and bacterium-screening test during 5-day storage. Statistical analyses included two-sample t-test and generalised estimating equation(GEE) method.ResultsDuring 5-day storage in LRPA, residual leucocytes were all <1.0×10⁶, and the parameters of platelet function were as follows: platelet aggregated to agonists such as adenosine 5′-diphosphate (ADP) and collagen, and the extent of shape change and pO₂ showed no statistically significant difference between PA and LRPA. The hypotonic shock reaction (HSR) on days 0, 1, and 3 were significantly higher in LRPA than in PA (71.78±6.92 vs. 64.10±7.42; P=0.002; 71.53±8.98 vs. 62.96±9.84; P=0.007; 68.05±7.28 vs. 57.76±6.80; P<0.0001, respectively). Values of mean platelet volume (MPV) were statistically larger in PA than in LRPA on days 0, 1, and 3. On day 5, the swirling score was higher in LRPA than in PA. The mean lactate levels had no statistically significant difference between PA and LRPA. Moreover, no growth was observed through bacterium-screening test conducted on 40 samples.ConclusionComparison of LRPA and PA products collected from the Trima Accel and Haemonetics automated blood-collection systems, respectively, revealed that both products possessed good platelet qualities even though additional processes are needed to reduce leucocytes. Furthermore, investigating the outcomes of other apheresis instruments with focus on the safety of donors, products, and recipients is necessary.     

Skin Conductance Responses to Stimulus "Energy" Decreases Following Habituation

Two experiments are reported in which a reduction in tone intensity or duration followed habituation. Experiment I, which employed 120 subjects, assessed the effects of type of stimulus change (intensity or duration) and trial of change (trial 5 or trial 22) on orienting response (OR) recovery. Experiment II employed 131 subjects, and examined the effects of reduction of stimulus intensity on trial 22 or after subjects reached a predetermined habituation criterion. Experiment I demonstrated OR reappearance following the offset of a shortened stimulus. The combined findings of Experiments I and II suggest that the effects of reducing stimulus intensity depend on when the change is made. In Experiment I, reducing stimulus intensity on trial 5 led to a significant decrease in OR magnitude. In Experiment II, increases in OR magnitude were produced by reducing stimulus intensity either after reaching a criterion or after 21 habituation trials. These findings suggest a Sokolovian view of the development of the generalization gradient of habituation. Results also revealed large individual differences in responding to the stimulus change in Experiment II. Multiple regression analyses of these data were therefore conducted, which allowed two further conclusions to be drawn: First, initial electrodermal state can be used to predict responding on the stimulus change trial. Second, with long habituation training (21 trials), the role of the initial state variables diminishes while other variables representing change over the experimental session become more prominent in predicting responding to stimulus change.     

Parvalbumin in rat cerebrum, cerebellum and retina during postnatal development

Radioimmunoassay and immunohistochemical studies were performed on the occurrence and distribution of parvalbumin-like immunoreactivity (PA-LI) in developing rat cerebrum, cerebellum and retina. No PA-LI was detected in the nervous tissues of the newborn animals. In the cerebrum, the PA-LI appeared in non-pyramidal neurons at the 2nd postnatal week and increased linearly until the 8th week. In the cerebellum, a rapid increase in the PA-LI took place at the 2nd week, with an enrichment of the antigen to Purkinje neurons. In the retina, amacrine cells contained PA-LI, the levels of which increased from the 2nd to 4th week. Regulation of intracellular Ca²⁺ concentration may be one of the important factors for the maturation of the central nervous system.     

医疗卫生机构气候韧性和环境可持续评价工具研究进展

目的 气候变化给医疗卫生机构带来诸多不确定性威胁,医疗卫生机构亟需提高自身的气候韧性并采取积极的应对措施,如何系统评价医疗卫生机构应对气候变化的能力成为应对气候变化挑战的工作重点。方法 使用范围综述筛选医疗卫生机构气候韧性和环境可持续评价工具相关文献和最新进展,并对密切相关的文献采用引文检索拓展研究范围。结果 借鉴国际经验已开发出适用于我国的《绿色医院建筑评价标准》,但对于医疗卫生机构气候韧性的指南和要求仍在探索中。国际上已经发展了三套较完整的工具包和指南,并已探索性开展了实地应用,包括加拿大的医疗卫生机构气候变化韧性工具包、美国的可持续和气候韧性医疗卫生机构工具包,以及世界卫生组织的气候韧性和环境可持续性的医疗卫生机构指南。结论 医疗卫生机构气候韧性和环境可持续能力评价工具构建是开展脆弱性评估和干预的基础,应积极借鉴国外相关经验开发适宜我国的评价工具,以增强机构和人员应对气候变化的能力。     

政策反馈理论视域：中国医疗卫生政策钟摆式变迁及其逻辑

新中国成立以来,党和国家不断强化医疗卫生建设,70余年来医疗卫生政策演进呈钟摆式变迁的特征,即从公益导向的福利性医疗卫生政策摆向效率导向的市场化政策,再摆向公益为主兼顾效率的民生导向政策,在公益与效率间发生三次摆动。本文借助政策反馈理论分析医疗卫生政策钟摆式变迁的内在逻辑,发现政策变迁过程中原有政策通过资源效应、解释效应、演化效应和学习效应影响新政策的制定,使得新政策留有原政策的烙印,呈现出摆动式变迁而非剧烈或范式变迁。政策反馈理论为医疗卫生政策制定提供新视角,制定医疗卫生政策需注重原政策的历史影响力,以公共价值引领医疗医保医药政策,从多重政策反馈效应视角出发优化卫生政策的制定。