三氯苯达唑对斯氏狸殖吸虫童虫作用的透射电镜观察

目的探索三氯苯达唑治疗大鼠斯氏狸殖吸虫童虫感染的最适剂量;进一步探讨三氯苯达唑杀灭斯氏狸殖吸虫的机理。方法40只SD大鼠随机分成3组实验组和对照组,每组10只大鼠。将斯氏狸殖吸虫囊蚴经腹腔注射感染各组大鼠。感染后第39d分别用不同剂量三氯苯达唑治疗实验组大鼠,治疗结束后第22d剖杀大鼠,对检获的虫体用透射电镜观察其超微结构的变化。结果三氯苯达唑对童虫体壁和肠壁的超微结构有不同程度的损坏,但低剂量组轻微,中剂量组对虫体的破坏作用比低剂量组强,但尚不能致死虫体,而高剂量组对虫体的破坏是致死性的;对照组大鼠检获的虫体未出现改变。结论三氯苯达唑治疗大鼠斯氏狸殖吸虫童虫感染的最适剂量为200?/?.d,它对斯氏狸殖吸虫的作用机理除了损伤虫体体壁外,还可破坏虫体肠壁的超微结构。     

斯氏狸殖吸虫转换宿主的研究

斯氏狸殖吸虫 195 9年由陈心陶首次报道 ,是中国独有虫种。我们在狸殖吸虫宿主转换的系列研究中 ,对犬与斯氏狸殖吸虫的生物学关系及宿主相容性进行了研究 ,本文报道斯氏狸殖吸虫在犬体内的分布、发育与转换宿主的特点。1　材料与方法从湖北省十堰市采集锯齿华溪蟹 (Sinopotamondenticu latum)中分离斯氏狸殖吸虫囊蚴。囊蚴感染豚鼠 5 0d后 ,用生理盐水逸出法收集各部位的童虫 ,在林格氏液内保存备用。将发育较小和发育较大的童虫分别感染家犬 1只 ,6 0d后剖杀 ,收集虫体观察。2　结　　果斯氏狸殖吸虫在鼠与犬间的宿主转换囊蚴感染豚鼠5 0…     

酶免疫转移印迹试验分析斯氏狸殖吸虫成虫抗原

本文应用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)分离斯氏狸殖吸虫成虫抗原,并通过转移电泳亚硝酸纤维薄膜(NC)上,然后用酶联免疫试验观察成虫抗原蛋白与感染斯氏狸殖吸虫的病人、犬及大鼠血清的反应,检测和识别特异性虫体抗原蛋白。实验结果显示:虫体抗原经SDS-PAGE分离,染色后可显示20余条蛋白区带,分子量分别为22、24、26KD的抗原蛋白对人体和动物的斯氏狸殖吸虫感染具有诊断价值。     

斯氏狸殖吸虫幼虫排泄分泌抗原Dot—ELISA诊断肺吸虫病研究

目的 探索斯氏狸殖吸虫幼虫排泄分泌抗原的免疫诊断价值。方法 采用斯氏狸殖吸虫幼虫排泄分泌抗原Dot-ELISA检测28例斯氏狸殖吸虫病人血清、6份日本血吸虫病人血清、4份华支睾吸虫病人血清、20份健康 人血清中抗斯氏狸殖吸虫幼虫排泄分泌抗原的抗体IgG。结果 斯氏狸殖吸虫幼虫排泄分泌抗原与28例斯氏狸殖吸虫病人血清均呈阳性反应,与其它2种吸虫病和健康人血清未发生反应。结论 斯氏狸殖吸虫幼虫排泄分泌抗原Dot-ELISA为诊断肺吸虫病敏感、特异的诊断方法。     

三氯苯达唑、吡喹酮对斯氏狸殖吸虫作用的透射电镜观察

目的观察三氯苯达唑、吡喹酮对斯氏狸殖吸虫作用后的超微结构改变。方法将30只SD大鼠随机分成三氯苯达唑治疗组、吡喹酮治疗组和对照组,分别用斯氏狸殖吸虫囊蚴经腹腔注射感染。于感染后60 d,两治疗组粪检阳性鼠分别给予三氯苯达唑和吡喹酮治疗,对照组不作治疗。用药后第3 d剖杀各组大鼠,检获虫体,作透射电镜观察。结果三氯苯达唑治疗组的虫体皮层消失,基质膜受破坏,肌肉层坏死;吡喹酮治疗组虫体皮层外质膜及基质层消失,肌层存在但较紊乱;对照组虫体体壁结构完整。结论三氯苯达唑和吡喹酮对斯氏狸殖吸虫体壁均有损伤作用,以三氯苯达唑所致的虫体损伤程度更严重。     

从形态变化,生活史和DNA检测排除泡囊狸殖的独立性研究

目的通过形态观察、生活史循环试验和分子生物学鉴定研究泡囊狸殖吸虫的独立性问题。方法从三元区采集溪蟹分离得到泡囊狸殖吸虫囊蚴和斯氏狸殖吸虫囊蚴,进行形态观察。以泡囊狸殖吸虫虫卵投放到调查过无泡囊狸殖吸虫的疫区中感染螺蛳,继而感染溪蟹,稍后检查蟹体内所获囊蚴是否保持泡囊狸殖吸虫形态还是同斯氏狸殖吸虫囊蚴近似。提取斯氏狸殖吸虫囊蚴和泡囊狸殖吸虫囊蚴的基因组DNA,用特异引物,PCR扩增其ITS2基因并将PCR扩增产物纯化后测序,然后通过GenBank的Blast程序分析基因序列的同源性,并应用MEGA3.0软件中的ME程序构建种系发生树。结果泡囊狸殖吸虫囊蚴与斯氏狸殖吸虫囊蚴形态差异明显,但观察到泡囊狸殖吸虫囊蚴在从蟹体分离后0.5~2 h内有57.14%变成同斯氏狸殖吸虫囊蚴近似的特征。将泡囊狸殖吸虫虫卵投放到自然环境进行生活史循环试验,从收集的溪蟹中只分离到斯氏狸殖吸虫囊蚴而没有发现泡囊狸殖吸虫囊蚴。基因同源性比较结果显示:泡囊狸殖吸虫与斯氏狸殖吸虫的ITS2基因同源性为100%,碱基差异为0,没有基因差异。结论虽然泡囊狸殖吸虫囊蚴和斯氏狸殖吸虫囊蚴的形态特征有较明显的差别,但放置一段时间后,57.14%的泡囊狸殖吸虫囊蚴变成与斯氏狸殖吸虫囊蚴形态相似的特征。从用泡囊狸殖吸虫虫卵进行生活史循环试验中收集的溪蟹体内没有发现泡囊狸殖吸虫囊蚴。ITS2基因序列的同源性比较分析发现斯氏狸殖吸虫和泡囊狸殖吸虫的基因高度同源,而且种系发生树也显示二者之间无明显的遗传分化。因此,斯氏狸殖吸虫和泡囊狸殖吸虫为同一物种,泡囊狸殖吸虫不具有虫种独立性。     

三氯苯达唑对斯氏狸殖吸虫体表及超微结构的影响

目的观察三氯苯达唑对斯氏狸殖吸虫作用后体表及超微结构改变。方法将30只SD大鼠随机分成治疗组和对照组,每组15只,分别用斯氏狸殖吸虫囊蚴经腹腔注射感染。于感染后60 d,治疗组粪检阳性鼠分别给予三氯苯达唑治疗,对照组不作治疗。用药后第3 d剖杀两组大鼠,检获虫体,作扫描和透射电镜观察。结果扫描电镜观察治疗组的虫体体表破坏严重,对照组虫体体表结构完整。透射电镜观察治疗组的虫体皮层消失,基质膜受破坏,肌肉层坏死;对照组虫体体壁结构完整。结论三氯苯达唑对斯氏狸殖吸虫体表及超微结构均能造成损伤。     

斯氏狸殖吸虫半胱氨酸蛋白酶基因克隆及由体定位

目的克隆斯氏狸殖吸虫成虫半胱氨酸蛋白酶cDNA片段,并研究该酶在斯氏狸殖吸虫的表达部位。方法通过RT-PCR方法扩增斯氏狸殖吸虫成虫半胱氨酸蛋白酶cDNA片段,TA克隆入pUCm-T载体,鉴定、测序;利用DNASIS程序推导其编码氨基酸序列,并比较分析与其相关虫种半胱氨酸蛋白酶氨基酸序列同源性。采用地高辛标记原位杂交技术检测该酶基因在斯氏狸殖吸虫成虫的表达及组织定位。结果经RT-PCR和对阳性克隆鉴定、测序后获得一cDNA序列,长495bp;同源性分析结果显示,该序列与相关虫种的半胱氨酸蛋白酶存在较高同源性,组成半胱氨酸催化三联体的半胱氨酸、组胺酸和天冬酰胺残基高度保守。原位杂交结果显示斯氏狸殖吸虫成虫的肠管上皮呈阳性着色。结论克隆获得了斯氏狸殖吸虫成虫半胱氨酸蛋白酶cDNA片段,该片段包含了与半胱氨酸蛋白酶活性和空间结构相关的重要基因位点。斯氏狸殖吸虫成虫半胱氨酸蛋白酶的表达部位主要为肠管上皮。     

斯氏狸殖吸虫半胱氨酸蛋白酶基因克隆及由体定位

目的 克隆斯氏狸殖吸虫成虫半胱氨酸蛋白酶cDNA片段,并研究该酶在斯氏狸殖吸虫的表达部位。方法 通过RT-PCR方法扩增斯氏狸殖吸虫成虫半胱氨酸蛋白酶cDNA片段,TA克隆入pUCm-T载体,鉴定、测序;利用DNASIS程序推导其编码氨基酸序列,并比较分析与其相关虫种半胱氨酸蛋白酶氨基酸序列同源性。采用地高辛标记原位杂交技术检测该酶基因在斯氏狸殖吸虫成虫的表达及组织定位。结果 经RT-PCR和对阳性克隆鉴定、测序后获得一cDNA序列,长495bp;同源性分析结果显示,该序列与相关虫种的半胱氨酸蛋白酶存在较高同源性,组成半胱氨酸催化三联体的半胱氨酸、组胺酸和天冬酰胺残基高度保守。原位杂交结果显示斯氏狸殖吸虫成虫的肠管上皮呈阳性着色。结论 克隆获得了斯氏狸殖吸虫成虫半胱氨酸蛋白酶cDNA片段,该片段包含了与半胱氨酸蛋白酶活性和空间结构相关的重要基因位点。斯氏狸殖吸虫成虫半胱氨酸蛋白酶的表达部位主要为肠管上皮。     

印度殖盘吸虫神经系统的乙酰胆碱酯酶定位观察

采用乙酰胆碱酯酶组织化学方法对印度殖盘吸虫进行染色,观察并描绘其神经结构。结果显示,该吸虫脑神经节与神经连合位于口吸盘和生殖吸盘之间、虫体的背侧。脑神经节向前发出4对神经干,与口吸盘内神经网相连;向后发出3对神经干,其中腹主神经干最粗大,3对神经干在虫体后端各分出几条神经分支进入腹吸盘。生殖吸盘上分布有发达的神经网。虫体表面神经纤维成对并行,斜行交叉,构成表面神经网。分布于前体部的神经细胞分为3种类型。说明印度殖盘吸虫神经结构符合复殖类吸虫的基本特征,其生殖吸盘内具有独特、复杂的神经结构。     

贝居腹盾吸虫神经纤维分布及神经细胞形态观察

目的　了解贝居腹盾吸虫神经纤维分布及神经细胞类型。方法　采用硝酸银染色法、组织化学技术和HE染色法,对贝居腹盾吸虫神经系统进行观察。结果　贝居腹盾吸虫前端脑神经节附近存在单极、双极、多极3类神经细胞,形态上可分为7种不同类型;该吸虫消化器官咽和肠道以及生殖器官睾丸、卵巢、子宫末段、阴茎囊表面均有神经网分布,由环形和纵向神经纤维组成;围绕口腔的神经网与中枢神经结构相似。结论　贝居腹盾吸虫神经系统结构非常复杂,这些神经可能与吸虫生理活动相关,不同神经细胞可能承担不同功能。     

Immunoreactive corticotropin-releasing hormone in the hypothalamoinfundibular tract

Ovine corticotropin-releasing hormone (CRF)-like immunoreactivity has been examined in the rat hypothalamus by light microscopy. Immunoreactivity was found in nerve fibers of the median eminence, mainly in the external zone around the portal vessels. In rats pretreated with colchicine or with hypothalamic knife cuts, small to moderate sized cells with two (bipolar) or rarely more (multipolar) dendrites, showing CRF-like immunoreactivity were present in the anterior and medial parvocellular subdivisions of the paraventricular nucleus. Scattered CRF-like immunopositive cells were found in the periventricular and medial preoptic nuclei. CRF-like immunoreactivity was clearly enhanced in the median eminence and paraventricular nucleus 8-10 days after bilateral adrenalectomy. A variety of hypothalamic transections had to be performed to determine reliably the topography of CRF-like nerve fibers projecting to the stalk-median eminence. Axons left the paraventricular nucleus in a lateral direction, turned ventrally in the lateral hypothalamus then medially as they approached the base of the hypothalamus above and behind the optic chiasm (lateral retrochiasmatic area). Fibers reached the median eminence by traveling caudally and medially from the rostral half of the lateral retrochiasmatic area. Scattered fibers were present in the retroinfundibular (posterior) portion of the median eminence. No immunoreactive fibers remained in the stalk-median eminence 1 or 4 weeks after transection of that loop-like pathway of CRF-containing fibers in the lateral retrochiasmatic area.     

Neuro-allergology: Mast cell–nerve cross-talk

Mast cells (MCs) are derived from hematopoietic stem cells in the bone marrow, and their maturation is regulated by the tissue environment, such as the skin, lung and gut, leading to host defense. Peripheral nerve fibers located in various tissues are involved in diverse physiological and pathological processes. Anatomical relationships between MCs and nerve fibers were reported to have been observed in various organs. Moreover, MCs are positive for a large number of receptors for classical neurotransmitters (e.g., acetylcholine and corticotropin-releasing hormone) and neuropeptides (e.g., substance P, calcitonin gene-related peptides and hemokinin), and MC's functions are regulated by those nerve-derived factors. Also, histamine and proteases produced and released by MCs modulate nerve fiber functions. This functional cross-talk between MCs and nerve fibers can play physiological and pathological roles. MCs are key effector cells of allergic inflammation, such as atopic dermatitis, airway inflammation and food allergy. Here, we summarize and discuss the molecular mechanisms underlying the functional and anatomical cross-talk between MCs and nerve fibers in allergic inflamed tissues.     

美托洛尔对急性心肌梗死大鼠心肌神经生长因子表达和神经重构的影响

目的 探讨β受体阻滞剂美托洛尔对大鼠急性心肌梗死(AMI)后心肌神经生长因子(NGF)表达和交感神经再生的影响.方法 结扎大鼠左前降支,建立AMI模型,存活者随机分为美托洛尔治疗组(MI-B组,n=10)和梗死对照组(MI-C组,n=10),另设假手术组(S组,n=8).MI-B组给予4周美托洛尔治疗,MI-C组和S组给予同体积生理盐水静脉注射和灌胃,4周后检测梗死周边区和梗死远端心脏神经纤维分布和密度以及心肌NGF基因和蛋白表达的变化.结果 与S组相比,MI-C组梗死周边和梗死远端心肌组织中NGF基因和蛋白表达明显升高(P＜0.05),梗死周边和梗死远端神经支配密度增高(P＜0.01).与MI-C组比较,MI-B组心肌细胞内NGF表达明显下降(P＜0.05),神经支配密度亦明显下降(P＜0.01).结论 早期美托洛尔治疗AMI可以改善心肌NGF表达和交感神经再生.美托洛尔改善交感神经再生的作用机制至少部分与其降低神经生长因子的表达和释放作用有关.     

丝胶对糖尿病大鼠脊髓及脊神经节细胞神经生长因子表达的作用

目的 探讨丝胶对2型糖尿病大鼠脊髓及脊神经节细胞神经生长因子(NGF)表达的作用.方法 36只雄性SD大鼠,随机分为正常对照组、糖尿病模型组和丝胶治疗组(n=12).采用SP法观察坐骨神经对应脊髓节段(L4～6)和脊神经节细胞NGF蛋白的表达.结果 NGF蛋白免疫阳性产物为棕黄色细腻颗粒状,位于脊神经节细胞和脊髓前角细胞的胞质和胞核,以胞质为主.与正常对照组大鼠比较,糖尿病模型组大鼠脊髓前角细胞和脊神经节细胞NGF蛋白的表达明显降低(P＜0.01);与糖尿病模型组大鼠比较,丝胶治疗组大鼠脊髓前角细胞、脊神经节细胞NGF蛋白的表达明显升高(P＜0.01).结论 丝胶上调脊髓前角细胞和脊神经节细胞NGF的表达,保护糖尿病坐骨神经相关神经元胞体.     

Selective damage of intrinsic calcitonin gene-related peptide-like immunoreactive enteric nerve fibers in streptozotocin-induced diabetic rats

The distribution of calcitonin gene-related peptidelike immunoreactive (CGRP-LI) nerve fibers in the myenteric plexus of ileum and proximal colon of rats 8 wk after induction of diabetes with streptozotocin was studied using immunohistochemical techniques. A marked decrease in CGRP-LI nerve fibers mainly around the ganglion cells of the myenteric plexus of both ileum and proximal colon was observed in diabetic rats. The sparsely located immunoreactive nerve cell bodies in the control rats were absent in the diabetic preparations. There were, however, intensely stained CGRP-LI varicose nerve fibers that ran through the internodal strands and over the myenteric ganglia of the diabetic intestines. These findings indicate the presence of CGRP-LI nerve fibers of dual origin in the intestinal wall. The absence of positive cell bodies and diminished CGRP-LI nerve fibers around the ganglion cells in the diabetic tissues suggest that the state of diabetes selectively affects CGRP-LI nerve fibers of intrinsic rather than extrinsic origin. Furthermore, the absence of change in substance P-like immunoreactivity in the enteric system of rats with streptozotocin-induced diabetes of the same duration suggests that calcitonin gene-related peptide and substance P are contained in different populations of intrinsic nerve fibers in the gastrointestinal tract of the rat.     

Nervous system of Clonorchis sinensis as revealed by acetylcholinesterase activity.

The gross neuroanatomy of Clonorchis sinensis has been revealed by the localization of acetylcholinesterase, well known to be associated with the nervous system. The central nervous system is composed of two cerebral ganglia situated postero-dorsally to the pharynx and connected by a transverse commissure. These ganglia give off four pairs of nerves anteriorly and three pairs posteriorly. The anterior nerves contribute to the pharynx and to the formation of the circum-oral ring located in the oral sucker. The posterior nerves, of which the postero-ventral nerve cords are the most prominent, contribute to the innervation of the acetabulum, the gut, the reproductive organs and the excretory bladder. All the posterior nerve cords are connected by a number of transverse connections throughout their course forming a complicated nerve net. At least two types of nerve cells, bipolar and multipolar ones, were observed.     

Density of substance P, vasoactive intestinal polypeptide and somatostatin-containing nerve fibers in the ageing small intestine of the rats

Immunoelectron microscopic investigations were carried out to study the substance P, vasoactive intestinal polypeptide (VIP) and somatostatin immunoreactive nerve elements in the wall of the small intestine. In young and old animals a large number of immunoreactive nerve fibers were found in all layers of the small intestine. They were observed closely to the epithelial cells, to the blood vessel basement membrane and to the smooth muscle cells and in some cases they were observed in a synapse with other unlabelled nerve fibers. On the other hand, in the senile animals very few immunoreactive nerve fibers were observed, calculated for a 100 micron2 tissue area. In the senile animals the overall number of nerve fibers was decreased in comparison to the young and old animals and most of them were in degeneration. This change could be the cause of the changes in the senescence-related epithelial transport processes and furthermore, of the modifications of the overall intestinal motility of the gastrointestinal tract, resulting in the age-dependent transit rates.     

An alternative nerve conduction study method to evaluate early diabetic neuropathy: Ratio of different diameter nerve fibers in peroneal nerve

Different nerve fibers may have disparate conduction parameters even though they are in the same peripheral nerve. Hyperglycemia can have differential effects on nerve fibers, depending on diameter. In diabetes, conventional nerve conduction studies have allowed us to classify a peripheral nerve as normal or not. But, there may be differential involvement in disparate nerve fibers of the same peripheral nerve. This study evaluated the effects of hyperglycemia on nerve fibers of peroneal nerve by diameter. Thirty-five diabetic patients with normal nerve conduction studies and thirty-two healthy controls were included to the study. The peroneal nerve was stimulated from two points (upper and below the fibula head) and recorded from the tibialis anterior (TA) and extensor digitorum brevis (EDB) muscles. Then the ratios of conduction velocity parameters recorded in these sides were compared between the diabetic and control groups. The conduction velocity recorded from EDB seemed to be faster in both groups. But there were no significant differences among the ratios between the groups. Our study has demonstrated the conduction parameters of two nerve fibers with different diameters in the peroneal nerve. The ratios of conduction parameters were similar in both groups, suggesting that fibers in the peroneal nerve are similarly affected by hyperglycemia.

     

Substance P-, VIP-, and enkephalin-like immunoreactivity in the human vagus nerve.

The human vagus nerve has been investigated for the presence of substance P (SP), vasoactive intestinal polypeptide (VIP), and enkephalin (ENK) using immunohistochemistry. After 0.5-4 hr of nerve ligation during surgical operations two right thoracic main truncs, two anterior subdiaphragmal trunks, and four anterior nerves of Latarjet were found to contain accumulation of immunoreactive material in nerve fibers above the ligation. Very high numbers of SP-, medium numbers of ENK-, and low number of VIP-immunoreactive fibers were seen. The relative proportions were similar at all levels studied. These data thus indicate the presence and axonal transport of SP-, ENK-, and VIP-like peptides in the human vagus nerve. Our observations in humans correlate well with results obtained from other species. Thus gastrointestinal vagal sensory mechanisms may be mediated by SP (and possibly VIP) and some motor mechanisms by ENK.