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81.
82.
视网膜缺血对兔视神经纤维损害的定量研究 总被引:2,自引:0,他引:2
目的:定量研究视网膜缺血对视神经的损害。方法:通过计算机图像分析定量测算视神经纤维数量;通过前房灌注平衡液,造成超高眼压,形成兔视网膜完全缺血模型,观察视神经纤维数量的变化。结果:正常兔眼平均视神经轴突数为109608±14561(n=22);视网膜缺血眼视神经纤维数量明显减少(P〈0.001)。结论:急性高眼压造成的视网膜缺血可使视神经节细胞及轴突的数量明显减少,应用计算机图像分析可定量检测这种 相似文献
83.
超液化碘油混合抗癌药物栓塞治疗中晚期肝癌 总被引:1,自引:0,他引:1
本文报告超液化碘油混合抗癌药物经皮肝动脉栓塞治疗51例中晚期肝癌。术后50例临床病情改善,治疗2次后肿瘤显著缩小(>50%)16例,中度缩小(20~50%)21例,轻度缩小(<20%)7例;5例为弥漫型难以判定肿块大小,另2例未复查。所有肿瘤缩小的病例均可见肿瘤血管减少。治疗后3个月、6个月、9个月和1年以上生存率分别为100%、82.4%、59.8%和23.5%,其中生存期大于9个月者均为团块型或多结节型。 相似文献
84.
壬苯醇醚避孕药膜的临床研究 总被引:3,自引:3,他引:0
894对健康、已育的育龄夫妇,随机分两组:447对使用壬苯醇醚方型膜,447对使用帽型膜,经两年连续观察。按生命表统计法处理数据。总使用妇女月,方型组9601,帽型组9382,随访率100%。累计停用率、妊娠率和续用率,方型组分别为16.8%、15.3%和83.2%,帽型组为18.4%、15.6%和81.6%,两组无显著差异(p>0.05)。临床和实验室资料表明壬苯醇醚药膜是安全、有效、简便、易于推广的避孕药具之一。 相似文献
85.
将昆明小鼠随机分为低(0.025)、中(0.05)、高(0.1)剂量组及生理盐水对照组,以2号海洛因经腹腔注射染毒,20天后,取睾丸组织制成石蜡切片.HE染色,光镜下观察生精小管上皮细胞的形态变化,并应用图像分析系统对初级精母细胞的形态参数进行了分析;结果表明,(1)光镜观察 对照组及低剂量组小鼠睾丸组织未见明显的变化;中剂量组小鼠睾丸曲细精管上皮有不同程度的组织改变;高剂量组小鼠生精管壁细胞明显地出现上皮层次减少,精子细胞和精子减少,并发现曲细精管内有脱落的生精细胞;(2)形态定量分析显示 低剂量组及中剂量组各形态参数(中剂量组圆形度除外)较对照组无显著差异;高剂量组初级精母细胞核面积、核灰度与对照组相比无显著差异,细胞面积、细胞周长及浆面积较对照组明显增大(P<0.05).而核浆比例、圆形度较对照组有减小(P<0.05).结果提示 海洛因可明显改变小鼠生殖细胞的形态结构. 相似文献
86.
目的:评价双盘封堵器介入治疗继发孔型房间隔缺损(ASD)的临床疗效及安全性。方法:在X线透视和经食道超声心动图(TEE;13岁以下儿童经胸超声心动图,TTE)监视下,采用经皮穿刺放置封堵器方法治疗继发孔型ASD16例,术后立刻、24h、1月、3月进行TEE或TTE和X线胸片检查,以评价其疗效。结果:本组16例封堵器置入均获成功。其中9例术后胸闷症状立即消失,第2天即能下床活动,无特殊不适主诉;另7例症状任2周后逐渐好转。1例术后仍有微量分流,3个月后分流才消失;术后1个月有8例右房及右室内径较术前缩小。14例术后3个月TTE显示ASD无残余分流,封堵器位置良好;另2例失访。结论:经皮封堵治疗继发孔型ASD,是一种有效的介入治疗方法,具有安全、有效、操作简便,成功率高的特点。 相似文献
87.
The onset response pattern displayed by octopus cells has been attributed to intrinsic membrane properties, low membrane impedance, and/or synaptic inputs. Although the importance of a low membrane impedance generally is acknowledged as an essential component, views differ on the role that ion channels play in producing the onset response. In this study, we use a computer model to investigate the contributions of ion channels to the responses of octopus cells. Simulations using current ramps indicate that, during the "ramp-up" stage, the membrane depolarizes, activating a low-threshold K(+) channel, K(LT), which increases membrane conductance and dynamically increases the current required to evoke an action potential. As a result, the model is sensitive to the rate that membrane potential changes when initiating an action potential. Results obtained when experimentally recorded spike trains of auditory-nerve fibers served as model inputs (simulating acoustic stimulation) demonstrate that a model with K(LT) conductance as the dominant conductance produces realistic onset response patterns. Systematically replacing the K(LT) conductance by a h-type conductance (which corresponds to a hyperpolarization-activated inward rectifier current, I(h)) or by a leakage conductance reduces the model's sensitivity to rate of change in membrane potential, and the model's response to "acoustic stimulation" becomes more chopper-like. Increasing the h-type conductance while maintaining a large K(LT) conductance causes an increase in threshold to both current steps and acoustic stimulation but does not significantly affect the model's sensitivity to rate of change in membrane potential and the onset response pattern under acoustic stimulation. These findings support the idea that K(LT), which is activated during depolarization, is the primary membrane conductance determining the response properties of octopus cells, and its dynamic role cannot be provided by a static membrane conductance. On the other hand, I(h), which is activated during hyperpolarization, does not play a large role in the basic onset response pattern but may regulate response threshold through its contribution to the membrane conductance. 相似文献
88.
本研究采用牛房实验小屋,加装不透光百叶窗和透光门廊,从而全面观察药帘对侵入实验小屋蚊虫毒杀情况,包括蚊虫入屋前接触药帘时和屋内蚊虫外逸出屋外后的死亡情况。结果表明,澳氰菊酯、二氯苯醚菊酯毒效强和持效长,浸泡门窗帘后6个月18次试验,对侵入屋内蚊虫毒杀,平均死亡率分别为89.4%和90.6%。两药对入屋内蚊虫的吸血率均没有明显减少,可能与诱饵动物的吸引力有关。二氯苯醚菊酯有明显驱避作用,其减少蚊虫入屋率,按蚊为70.6%,库蚊为75.2%均没有明显减少,阿蚊却没有效应。 相似文献
89.
The hypothalamus regulates many aspects of energy homeostasis, adjusting both the drive to eat and the expenditure of energy in response to a wide range of nutritional and other signals. It is becoming clear that various neural circuits operate to different degrees and probably serve specific functions under particular conditions of altered feeding behaviour. This review will discuss this functional diversity by illustrating hypothalamic neurones that express neuropeptide Y (NPY), the melanocortin-4 receptor (MC4-R) and the orexins. NPY neurones in the arcuate nucleus (ARC) release NPY, a powerful inducer of feeding and obesity, in the paraventricular nucleus (PVN) and the lateral hypothalamic area (LHA). ARC-NPY neurones are inhibited by leptin and insulin and become overactive when levels of these hormones fall during undernutrition. They may function physiologically to protect against starvation. With disruption of the inhibitory leptin signals due to gene mutations, the NPY neurones are overactive, which contributes to hyperphagia and obesity in the ob/ob and db/db mice and fa/fa Zucker rat. The MC4-R is activated by alpha-melanocyte-stimulating hormone [alpha-MSH; a cleavage product of pro-opiomelanocortin (POMC), which is expressed in the other ARC neurones] and inhibits feeding. This effect is antagonised by agouti gene-related peptide (AGRP), which is coexpressed by the ARC-NPY neurones only. Activation of MC4-R, possibly mediated by blockade of AGRP release, appears to restrain overeating of a palatable diet. This response may be programmed by a transient rise in leptin soon after presentation of palatable food, and rats that fail to do this will overeat and become obese. Orexin-A and -B (corresponding to hypocretins 1 and 2) are expressed in specific LHA neurones. These have extensive reciprocal connections with many areas involved in appetite control, including the nucleus of the solitary tracts (NTS), which relays vagal afferent satiety signals from the viscera. Orexin neurones also have close anatomical connections with LHA glucose-sensitive neurones. Orexin-A induces acute feeding but does not cause obesity. Orexin neurones are stimulated by hypoglycaemia partly via the NTS and inhibited by food ingestion. These neurones may therefore be involved in the severe hyperphagia of hypoglycaemia and short-term control of feeding. 相似文献
90.
Cai Guoping Lian Jie Shapiro Sandor S. Beacham Dorothy A. 《Methods in Cell Science》2000,22(2-3):107-114
In this study we introduce a novel in vitro 'oil-drop' assay system for the measurement of endothelial cell (EC) migration, based on the original concept of the Teflon fence assay (Pratt et al., 1984; Am. J. Pathol. 117: 349–354). An aliquot of 15–20,000 human umbilical vein EC (HUVEC) is pipetted through a layer of mineral oil. The cells readily attach, spread and migrate on the surface of a matrix-coated tissue culture dish as a confluent circular monolayer. Migration is measured as the net increase in the total area covered at 24 hours. We have used this system to quantify EC migration on matrices composed of a mixture of type I collagen and either von Willebrand factor (vWF) or fibronectin (FN) in the presence or absence of tumor necrosis factor (TNF). Plating efficiency on both vWF/collagen and FN/collagen, measured by counting cells after attachment and spreading, is about 80%. With this method, migration on vWF/collagen was about 6.4 mm2 and 5.3 mm2 for TNF-treated and untreated HUVEC, respectively. HUVEC migration on FN/collagen was slightly greater – 6.4 mm2 and 6.5 mm2 with and without TNF treatment, respectively. During the 24 hour time period, HUVEC numbers increased 30–40% on vWF/collagen, and 60–80% on FN/collagen, with increased proliferation observed with TNF- treatment. EC proliferation could be completely inhibited by 2 mM hydroxyurea. This assay system has proven useful in our studies to quantify cell migration and proliferation. 相似文献