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31.
用51只Wistar大鼠建立了新的大鼠原位肝移植手术模型,手术成功率为92.1%,周存活率为86.27%。手术要点是术前供肝冷灌注;受体肝只建立门静脉血供,静脉吻合分别采用“双袖套”式吻合和“8”字外翻缝合;胆管重建采用单管支架总胆管对端吻合法。移植术后肝细胞超微结构动态观察表明:术后2周是控制免疫排斥反应的关键时期,术后8周实验鼠产生免疫耐受性,移植肝脏成活。 相似文献
32.
Rationale: Although physically aversive stimuli induce functional changes in central noradrenergic neurones, little is known about the
noradrenergic response to environmentally aversive stimuli. Objectives: The first aim was to characterise environmental features that are perceived as stressful by rats. The second was to investigate
whether changes in the concentration of extracellular noradrenaline are induced by these environmental features. Methods: A light/dark shuttle-box was used to test rats’ behavioural response to a range of stimuli (novelty, bright light, and the
presence of an unfamiliar rat), either before or after microdialysis probe implantation. Changes in the concentration of extracellular
noradrenaline in the frontal cortex and hypothalamus in vivo were then evaluated on exposure to these same test conditions. Results: Naive rats spent less time in a brightly-lit test arena than a dark one. However, the behavioural response to the light arena
was attenuated by the presence of an unfamiliar rat. Probe implantation intensified the response to the light arena but did
not affect behaviour in the dark arena. In the microdialysis studies, there was no change in the concentration of extracellular
noradrenaline on transfer of rats to the dark arena but there was an increase in both the frontal cortex (+45%) and hypothalamus
(+75%) on exposure to the light arena. A similar increase was induced in both brain regions when the light arena contained
an unfamiliar rat. Conclusions: Implantation of a microdialysis probe modifies the behavioural responses to certain environmental stimuli. Regardless of
this, the extent to which rats perceive a novel environment as aversive is not the only determinant of the noradrenergic response
to such stimuli. However, differences in stimulus controllability in the microdialysis and the behavioural experiments could
influence the apparent intensity of the stress.
Received: 29 October 1998 / Final version: 19 March 1999 相似文献
33.
The shape of the bladder and the optical characteristics of the tissue within the wall can be shown to play an important role in the amount of light actually received at the wall. The use of estimated doses even assuming spherical geometry, cannot therefore be relied upon. This paper describes some experimental work carried out on a glass model that was used to simulate the bladder. A specially constructed dual detector was used which consisted of an isotropic probe and semiconductor detector. This enabled measurements of irradiance and space irradiance (light energy fluence rate) to be made simultaneously. By changing the optical characteristics of the wall a four-fold increase in space irradiance was measured. Contamination of the water contained within the model by blood was also investigated and has shown that with concentrations as low as 0.5% the delivered light dose reaching the wall can be reduced by up to 50% at a wavelength of 510 nm. Some in vivo measurements are also presented together with some comments on the difficulties that have been encountered when transferring measurements from the model to the patient. 相似文献
34.
W. J. Whitehouse 《Calcified tissue international》1977,23(1):67-76
Summary Calcified tissue in the iliac crest and the adjoining ala of the ilium was investigated by scanning electron micrographs of thick, polished sections from which the marrow had been removed. Some quantitative properties of the trabeculae and of the marrow spaces were obtained from measurements on the images of the polished surfaces. Most of the cortex of the crest was porous, about 25% void, of varying thickness, intruding into the cancellous space in some regions. A structure containing about 35% by volume of bone was found at and near the anterior superior spine. Compact bone of normal appearance began as thin medial and proximal sheets below the crest, and thickened until at 20–30 mm it was substantial. The cancellous bone contained by these structures was varied. Two main zones were distinguished, whose junction ran from just below the anterior superior spine to the lower portion of the iliac fossa. In the lateral zone, adjacent to the crest, there were arch-like structures, commencing from the medial and proximal walls, and meeting, or even crossing, near the centre. The medial zone was distinguished by large marrow cavities and strongly orientated trabeculae. The relative volume of bone was similar in the two zones, falling from a maximum of 15–20% to about 5% in the regions of the anterior inferior spine and the iliac fossa. The average width of the trabeculae was significantly greater in the medial than in the lateral zone (W
b
(m)0.16 mm, Wb(l)0.12 mm). Inclusions of very heavily constructed trabeculae, having average widths of about 0.35 mm, were found in both zones. 相似文献
35.
金钗石斛光合作用特征的初步研究 总被引:9,自引:0,他引:9
利用LiCor-6400光合测定系统测定了不同天气条件下,金钗石斛叶片24hCO2吸收的动态变化,以及CO2吸收对有效光合辐射的响应。结果表明:晴天,白天和夜间金钗石斛都能吸收CO2,中午有光下呼吸现象,CO2的交换方式具景天酸代谢途径(CAM)的特点;阴雨天,中午没有光下呼吸现象,白天都在吸收CO2,夜间21:00仍有CO2吸收,23:00以后至次日凌晨处于暗呼吸状态。金钗石斛叶片CO2吸收对光照强度的效应表现出强光抑制现象,饱和光照强度为1000μmol/m^2s。叶片受到强光照射后,光合饱和点降低,CO2吸收速率下降,说明金钗石现象,饱和光照强度为1000μmol/m^2s。叶片受到强光照射后,光合饱和点降低,CO2吸收速率下降。说明金钗石斛是兼性景天酸代谢植物,随着环境条件变化,光合作用可在CAM途径与C3途径间变化,这一光合特性可能是金钗石斛适应需荫环境和生物缓慢,稀少的主要原因之一。 相似文献
36.
37.
目的 建立应用扫描激光检眼镜 (scanninglaserophthalmoscope ,SLO )测定微视野的方法 ,并测定不同年龄正常人中心 10°视网膜光敏感度 ,计算年龄与平均光敏感度的相关关系。方法 用德国RodenstockSLO对 80例 160眼 17~ 85岁正常眼进行中心 10°微视野检测。结果 SLO可清晰观察后极部眼底情况。正常人各年龄组中心 10°平均光敏感度与性别、眼别、象限别无关 (P >0 0 5 )。平均视网膜光敏感度随年龄增加呈直线下降 ,年龄 (x)每增加 10岁 ,平均光敏感度 (y)下降 0 0 5 5dB ,即y =3 0 9-0 0 5 5x。结论 SLO微视野检查将眼底解剖部位与光敏感度相对应 ,具有直观、准确的优点。正常值的测定为进一步研究黄斑部病变时光敏感度的变化提供依据 相似文献
38.
To date qualitative studies of IgA in the cerebrospinal fluid in neurological disease, particularly multiple sclerosis, have been few and given mixed results. The aim of this study was to identify local synthesis of IgA by detection of clonal IgA bands, in a large cohort of patients with a variety of neurological disorders, using polyacrylamide gel electrophoresis, transfer of protein to nitrocellulose membranes and specific staining. Of 2,097 sequentially analysed patients with suspected neurological disease 54 (2.6%) had locally synthesised IgA; most notably, IgA was present in 39 of 291 (13%) patients with suspected multiple sclerosis. The latter group also had a significant excess of light-chain production, particularly free kappa, when compared to multiple sclerosis patients without local synthesis of IgA. Locally synthesised IgA was also demonstrated in inflammatory, infectious and autoimmune diseases of the central nervous system. This qualitative technique is simple and suitable for routine analysis of cerebrospinal fluid, and further qualitative studies of IgA may be useful in investigating the pathophysiology of certain neurological disorders. 相似文献
39.
中医色诊研究及光子学技术在色诊中的应用 总被引:6,自引:0,他引:6
简要地阐述了中医色及色诊的基本概念及其临床意义,以及目前中医色诊的主要研究方向及其进展,探讨了光子学技术在中医色诊中的应用及其主要研究内容,以期光子学技术促使色诊技术向微量化、自动化和快速化的方向发展,提供中医诊断的新手段、新方法和新仪器,为中医药学的现代化探求新的方向与前景. 相似文献
40.
轻稀土化合物抑癌作用及机制的研究 总被引:9,自引:0,他引:9
目的在探讨稀土与肿瘤关系的基础上进一步证明稀土的抑癌作用及探讨作用机制,最终的目标是为稀土在医药保健事业方面开创一个新领域.提供确定、可靠的科学依据.方法通过动物实验及细胞培养,采用生化、免疫、分子生物学等方面的规范方法及高新技术的应用,如用电子顺磁共振(FSR)自旋扑获技术测定自由基、Northern杂交技术分析稀土元素对抑癌基因的表达等.此外,还对接触稀土人群进行了10年的动态观察和肿瘤流行病学回顾性的队列调查等.结果①整体抑癌实验按卫生部颁发的药效实验规程,给小鼠腋下种瘤株,腹腔注射ReNO3、ReCl3等,剂量在32及64 mg/kg时对S180肉瘤生长的抑制率分别为39.87%及27.34%、Lewis肺癌生长抑制率分别为36.82%及29.55%均有明显的统计学意义.给AMAE小鼠腹腔注射氨基甲酸乙酯的肺癌剂同时饮用ReCl3(0.062 5%、0.25%、1.0%)120 d时其肿瘤发生率分别为75%、61.8%、79.6%,而未给稀土组为90.0%,表明稀土对化学致肺腺癌小鼠亦具有明显抑制作用.②体外抑癌试验对人白血病细胞(K562)在ReNO3浓度为0.032~0.5 mg/ml时,生长的抑制率为15.8%~34%,在ReCl3浓度为0.01~0.5 mmol/L时其细胞生长抑制率为18%~68%,而对正常人羊膜细胞(FL)起促生长作用;对胃癌细胞(PAMC82)经ReCl31 mmol/L处理14~28 d时,其细胞形态发生明显变化,用免疫荧光染色观察细胞骨架微管和微丝的结构,多数癌细胞内出现近似正常细胞的微管网架;PAMC82细胞在软琼脂中生长良好,经ReCl3处理后,细胞生长极慢,平均每皿集落数由18.7降至4.以上结果表明,癌细胞经稀土处理后,其恶性程度降低,分化程度升高.③抑癌机制研究从免疫、生化及分子生物学等方面探讨其作用机制.A对正常小鼠腹腔隔日注射(共5次)的ReNO3(32 mg/kg)及给化学致癌剂(氨基甲酸乙酯)后饮ReCl3水溶液120 d的小鼠,取其脾脏测定NK细胞活力(%).结果均有明显激活作用.B.采用Balb/c小鼠腹腔巨噬细胞(MΦ)培养及孔雀绿显色法,以ReNO3浓度为16~250 μg/ml与MΦ培养,测得其吞噬强度范围(1.12~1.35),明显地高于非稀土培养的吞噬强度(0.88),表明稀土有促进巨噬细胞特异的吞噬功能.C利用电子顺磁共振技术EPR 300型波谱仪测得20 mg温石棉在磷酸盐缓冲液中产生的羟自由基(*OH)信号谱峰高为4.6 cm,当其分别给与2~20 mg ReCl3或ReNO3混合后,产生的*OH信号几乎消失或明显减弱;经温石棉诱导,用ReCl3处理的肺巨噬细胞,其*OH强度和超氧阴离子(O-*)2)的浓度明显受抑制;经氨基甲酸乙酯诱癌的小鼠,饮ReCl3溶液120 d后,其体内超氧化物歧化酶(SOD)显著高于未饮稀土组,脂质过氧化物代谢产物丙二醛(MDA)明显低于饮稀土组.以上结果表明稀土可抑制温石棉产生*OH和O-)/(*)2,增强SOD活性,降低膜脂质过氧化.D对肿瘤相关基因表达的研究;用Northern杂交分析方法,结果表明抑癌基因P53和P21表达水平低下的人胃癌细胞PAMC82,经1.5 mmol/L laCl3或0.75 mmol/L的CaeCl3(ReCl3)处理后,其P53和P16基因表达明显增强;而变化最明显的是抑癌基因P21的表达.④肿瘤流行病学调查对我国最大的甘肃稀土公司,进行了肿瘤回顾性的队列调查,其结果稀土组和对照组死亡率分别为19.675 2/105和87.948 4/105,RR为0.223 7(P<0.05),稀土组和对照组的肺癌死亡率分别为0/105与40.923 0/105(P<0.05),此结果表明稀土有控制肿瘤发生的趋势.结论从微观到宏观,从动物实验到人群流调,均证明了稀土有抑癌作用.从抑癌机制的研究表明,经稀土处理的人胃癌细胞P21、P16、P53的基因表达均有明显增强,提示其抑癌作用可能是通过稀土使癌细胞恶性程度降低,分化程度升高,增强抑癌基因表达实现的.还表明稀土在直接作用于细胞的同时,还能改善和提高机体的抗肿瘤免疫及清除体内垃圾的抗氧化功能等方面的综合性防癌作用. 相似文献