实验大鼠,实验小鼠肠道鞭毛虫种类和检索

我们对普通级SD大鼠和KM小鼠肠道内鞭毛虫分别作了观察,从大鼠检出10种肠道鞭毛虫:鼠唇鞭毛虫(Chilomastixbettencourti)、人肠滴虫(Enteromonashominis)、西蒙氏贾第虫(Giardiasimoni)、鼠六鞭虫(Hexamitamuris)、似单尾滴虫(Monocercomonoidiessp)、人五毛滴虫(Pentatrichomonashominis)、曲滴虫(Retortamonassp)、田鼠四毛滴虫(Tetratrichomonasmicroti)、微小三毛滴虫(Tritrichomonasminuta)和鼠三毛滴虫(Tritrichomonasmuris)。从小鼠检出8种肠道鞭毛虫:鼠唇鞭毛虫(Chilomastixbettencourti)、鼠贾第虫(Giardiamuris)、鼠六鞭毛虫(Hexamitamuris)、鼠八鞭毛虫(Octomituspulcher)、人五毛滴虫(Pentatrichomonashominis)、田鼠四毛滴虫(Tetratrichomonasmicroti)、微小三毛滴虫(Tritrichomonasminuta)、鼠三毛滴虫(Tritrichomonasmuris)。根据大鼠和小鼠肠道鞭毛虫的形态特征分别列出了检索表。     

实验性卡氏肺孢子虫肺炎的病理学研究

Ｗｉｓｔａｒ大鼠皮下注射醋酸考的松诱发卡氏肺孢子虫肺炎，自第６～１２周，每周解剖病鼠２只观察，全部给药鼠均发病。肺部病变表现为：（１）肺印片查见卡氏肺孢子虫包囊和滋养体。（２）组织病理学改变：第６～８周ＨＥ染色切片呈间质性肺炎伴中度淋巴细胞浸润，肺泡内缺乏泡沫样渗出物，第９～１２周肺泡内出现泡沫样渗出物，ＰＡＳ染色该渗出物呈阳性反应，ＧＭＳ染色查见染成黑色的包囊。（３）停用醋酸考的松后４～６周，肺部炎症明显好转，提示大鼠卡氏肺孢子虫肺炎有自愈可能。电镜显示包囊、滋养体及受损肺泡上皮细胞的超微结构。     

梨形鞭毛虫滋养体的单克隆抗体产生及其特性(文摘)

梨形鞭毛虫是一种寄生于鼠小肠中的原生动物寄生虫,梨形鞭毛虫感染鼠可构成人贾第氏虫病的动物模型以及探讨鞭毛虫滋养体抗原的肠免疫应答的实验途径。鼠单克隆抗体(McAb)是由梨形鞭毛虫滋养体表面抗原来生产的,经非肠道免疫后的BALB/c鼠脾淋巴细胞与P3/NS1/1-Ag4-1骨髓瘤细胞融合而得到B-细胞杂交瘤。梨形鞭毛虫     

瑞士兰氏贾第虫株变异性富含半胱氨酸表面蛋白的研究

从羊、牛和人各自分离出的贾第虫株都具有一个大的膜蛋白。用生物素和放射性碘标记后，ＳＤＳ－ＰＡＧＥ显示此膜蛋白分子量的大小，在不同种群之间有着明显的差异。［＾３５Ｓ］半胱氨酸代谢标记及电泳分析表明每个克隆化虫株都有一个主要蛋白，此蛋白的大小与表面标记技术展示的表面蛋白相似。贾第虫株富含半胱氨酸表面蛋白（ＣＲＩＳＰｓ）具有变异能力。虫株在连续体外克隆化培养几代后，在克隆化的群体中自发的出现了一些新的Ｃ     

以30日龄长爪沙鼠为介体建立贾第虫青岛株纯培养

以３０日龄长爪沙鼠为介体建立贾第虫青岛株纯培养祝虹，郭增柱，宫玉香，吴娟，王正仪（北京热带医学研究所，北京１０００５０）卢思奇等（１９９０）以１０日龄长爪沙鼠（Ｍｅｒｉｏｎｅｓｕｎｇｕｉｃｕｌａｔｕｓ）乳鼠为分离蓝氏贾第鞭毛虫（Ｇｉａｒｄｉａｌａｍｂ...     

选择性肠道清洁法对重症烫伤大鼠肠源性内毒素血症的影响

本实验采用大鼠４０％Ⅲ°烫伤模型，初步观察了选择性肠道清洁法（ＳＤＤ）对肠源性内毒素血症的防治效果。结果发现，防治组动物门、体循环内毒素水平伤后均显著降低（Ｐ＜０．０５～０．０１），各段肠腔内游离内毒素含量较烫伤对照组下降９９．５％以上。且肠道细菌易位率致伤１～５天都明显减少，回肠粘膜二胺氧化酶活性逐渐恢复。防治组大鼠严重烫伤５天存活率提高２６．７％（Ｐ＜０．０５）。本结果提示，该方法对于重症烫伤大鼠肠源性内毒素血症具有显著防护效应，并能抑制肠道细菌的移居与减轻肠粘膜的进一步损害。因此，及早进行ＳＤＤ可能有助于烧伤后肠源性感染及其它并发症的防治。     

蓝氏贾第鞭毛虫PPDK特异性锤头状核酶-GCV重组载体的构建及鉴定

丙酮酸磷酸双激酶（Pyruvatephos phate dikinase,PPDK）可能是蓝氏贾第鞭毛虫能量代谢中具有催化作用的关键酶桩一。为了进一步探讨该酶在贾第虫能量代谢中的作用,本文采用RNA draw软件分析贾第虫编码PPDK的基因序列并设计特异性反义锤头状核酶（Hammerheade ribozyme）,克隆该核酶序列并与犬贾第虫病毒（GCV）连接,构建了载有特异性锤头状核酶的贾第虫病毒重组载体pGCV634/H5/2174。该载体经线性化处理后进行体外转录,转录产物以电击方式转染对数生长期的贾第虫滋养体。提取转染后24h虫体总RNA,并以其为模板进行RT-PCR验证转染效果和对靶mRNA的切割效果。结果初步证实了该载体对虫体细胞内编码PPDK的mRNA具有切割作用。     

感染疟原虫斯氏按蚊血淋巴元素组成的分析

分别从初羽化及吸正常鼠血或感染约氏症原虫（Ｐｈｓｍｏｄｉｕｍｙｏｅｌｉｉｙｏｅｌｉｉ）鼠血后５、７、９ｄ的斯氏按蚊（Ａｎｏｐｈｅｌｅｓｓｔｅｐｈｅｎｓｉ）收集血淋巴，用ＩＣＡＰ－９０００型等离子原子发射光谱仪测定其常量元素和微量元素的含量，并对２０种元素含量变化作比较分析。初羽化蚊与吸血（正常鼠血和感染疟原虫的鼠血）后５ｄ的蚊相比，均有７种元素有非常显著的差异（Ｐ＜０．０１），１种元素有显著性差异（Ｐ＜０．０５）。比较感染与未感染疟原虫的蚊血淋巴元素含量，显示吸血后５ｄ有１２种元素Ｐ＜０．０１．３种元素Ｐ＜０．０５；吸血后７ｄ，７种元素Ｐ＜０．０１，１种元素Ｐ＜０．０５；吸血后９ｄ，６种元素Ｐ＜０．０１，２种元素Ｐ＜０．０５。本研究结果表明，蚊虫血淋巴元素含量与其营养代谢及发育有密切关系。提示疟原虫的寄生可影响蚊媒血淋巴元素含量发生明显变化。     

运动对小脑皮质和脊髓分离突触体膜流动性和突触体内游离Ca~（2＋）的影响

采用超速离心技术分离制备突触体，结合ＤＰＨ荧光偏振方法和ｆｕｒａ－２荧光标记技术分析长期适量运动（跑转笼）对小脑皮质和脊髓分离突触体膜流动性、突触体内游离Ｃａ２＋的影响。以同龄对照组心重／体重比率均值的２倍标准差作为运动有效标准。结果显示，和５月龄鼠比较，１３月龄鼠小脑皮质和脊髓分离突触体膜流动性均无显著性差异，而经８个月运动训练后，突触体膜流动性升高（Ｐ＜０．０５）．在小脑去极化状态（高Ｋ＋）下，１３月龄鼠分离突触体游离Ｃａ２＋高于５月龄鼠（Ｐ＜０．０５），而静息状态下两者间无差异（Ｐ＞０．０５）．在脊髓静息和去极化状态下分离突触体游离Ｃａ２＋在两个年龄对照组间无差异（Ｐ＞０．０５）．经８个月运动训练后，小脑皮质和脊髓分离突触体在静息和去极化状态下的游离Ｃａ２＋均低于同龄对照组，但无显著性差异（Ｐ＞０．０５）．结果表明，从青年开始的长期适量运动对突触体膜功能和Ｃａ２＋调节系统具有一定的保护作用．     

不饱和脂肪酸对花生四烯酸代谢产物的影响

本文用不饱和脂肪酸治疗脓毒症大鼠，观察治疗前、后大鼠血浆ＴＸＢ２、６－酮－ＰＧＦ１α、ＰＧＥ２及肝脏枯否氏细胞膜、红细胞膜花生四烯酸（ＡＡ）水平的变化，并探讨其机理。结果表明脓毒症大鼠血浆三种ＡＡ代谢产物水平明显高于正常组（Ｐ＜０．０１）；枯否氏细胞膜和红细胞膜的ＡＡ含量明显降低（Ｐ分别＜０．０１和＜０．０５）。经富含不饱和脂肪酸的鱼油治疗后，血浆ＴＸＢ２、ＰＧＥ２明显降低，两种细胞膜ＡＡ含量明显升高（Ｐ＜０．０１）。但血浆６－酮－ＰＧＦ１α仍处于高水平状态。提示在炎性反应时细胞膜ＡＡ发生明显变化，而肠道给予不饱和脂肪酸，可以改变膜ＡＡ含量，减少炎症介质的产生。     

Localization of immunoreactive calcitonin gene-related peptide in thyroid C cells from various mammalian species

Localization of immunoreactive calcitonin gene-related peptide (CGRP) in thyroid C cells from various mammalian species was investigated by the immunoperoxidase method. In many animal species including dogs, cats, cattle, monkeys, rats, and rabbits, almost all C cells revealed an intense immunoreactivity for CGRP; the cytoplasm of C cells was filled with reaction products for CGRP. In these animal species, calcitonin and CGRP coexisted in the C cells. However, in some species including pigs, mice, hamsters, and guinea pigs, the CGRP immunoreactivity of C cells was weak or negative. It was concluded that there was a considerable variation in CGRP immunoreactivity of C cells from species to species. In rabbits and guinea pigs, almost all C cells were also intensely immunoreactive to antisomatostatin antiserum, whereas in other animal species including dogs, cats, cattle, monkeys, rats, pigs, mice, and hamsters only a few C cells were immunoreactive to somatostatin. Three peptides--calcitonin, somatostatin, and CGRP--are synthesized alone in rabbit C cells. Thus, there was no relation between CGRP and somatostatin concerning the existence of both peptides in thyroid C cells.     

Variations in pulmonary antibacterial defenses among experimental animals.

Intrapulmonary killing of Staphylococcus aureus proceeded at equal rates in guinea pigs, hamsters, rats, and mice. In the lung of guinea pigs and hamsters, Proteus mirabilis was killed at virtually the same rate as S. aureus as compared with half the rate of inactivation in the lungs of rats and mice.     

Establishment of cutaneous Leishmania enriettii infection in hamsters.

A model of a self-healing type of cutaneous leishmaniasis was established in hamsters using the guinea pig parasite Leishmania enriettii. L. enriettii was passaged several times in hamsters without losing its infectivity for guinea pigs or for hamsters. The course of the infection in hamsters resembled that of guinea pigs, with the exception that the lesion at the site of parasite inoculation did not ulcerate and no metastatic lesions developed spontaneously. Moreover, unlike guinea pigs, infected or recovered hamsters were skin test unresponsive to various preparations of L. enriettii antigens. However, histological examination of draining lymph nodes showed features of a cell-mediated immune response, and in vitro inhibition of macrophage migration was demonstrable using peritoneal exudate cells from recovered animals and specific leishmanial antigen. Antibody was demonstrable by indirect immunofluorescence starting 1 week after infection. Recovered animals were immune to reinfection; however, the passive transfer of peritoneal exudate cells or serum from recovered animals did not confer protection against L. enriettii infection in normal animals.     

Diabetogenic effects of N-nitrosomethylurea with special regard to species variations.

The effect of N-nitrosomethylurea on the blood-glucose and the pancreatic islet light microscopic picture was studied in the Chinese hamsters, golden hamsters, guinea pigs, mice, rats and sand rats. The Chinese hamsters were most susceptible. Only in this species did a dose of 50 mg/kg body weight cause blood-glucose elevations and pancreatic islet damage. At a dose of 100 mg/kg body weight of N-nitrosomethylurea, blood-glucose elevations were recorded in the golden hamster together with damage to the islets and the exocrine pancreatic parenchyma. A toxic dose of 200 mg/kg body weight resulted in hyperglycemia and islet cell destruction in the rat and in slight alterations in the islets of mice. N-nitrosomethylurea was non-diabetogenic to guinea pigs and sand rats. The ethyl derivate of nitrosourea was less toxic and diabetogenic to the Chinese hamsters in comparison with the methyl derivate.     

Antibody response to Giardia muris trophozoites in mouse intestine.

The protozoan parasite Giardia muris colonizes the mouse small intestinal lumen. This parasite is cleared immunologically from the intestine of normal mice. In contrast, T-lymphocyte-deficient (nude) mice have an impaired immunological response to G. muris and become chronically infected. In the present study, trophozoites were harvested from the intestinal lumen of immunocompetent BALB/c mice and nude mice and examined for surface-bound mouse immunoglobulins by immunofluorescence microscopy. Immunoglobulin A (IgA) and IgG, but not IgM, were detected on trophozoites obtained from BALB/c mice, from day 10 of the infection onwards. Trophozoites from nude mice showed very little evidence of surface-bound mouse immunoglobulin at any time during the 5-week period immediately following infection of these animals with G. muris cysts. Intestinal G. muris infection was cleared by the BALB/c mice but not by the nude animals. The data suggest that parasite-specific IgA and IgG bind to G. muris trophozoites in the intestinal lumen of immunocompetent BALB/c mice. Intestinal antibodies that bind to trophozoite surfaces are likely to play an important part in the clearance of G. muris infection by immunocompetent mice. The inability of nude mice to clear this infection at a normal rate is likely to be due to impairment of Giardia-specific intestinal antibody production.     

On the transplacental induction of tumours by N-ethyl--N-nitrosourea in different species (author's transl)]

The transplacental activity of N-ethyl-N-nitrosourea (ENU) was tested in rats, rabbits, Syrian golden hamsters, Dzungarian dwarf hamsters, guinea pigs, dogs, and rhesus monkeys. In the offspring of rats, multiple tumours of the central and peripheral nervous system were found in 100 per cent, whereas in rabbits kidney tumours developed. In Syrian golden hamsters, the application led mostly to neoplasms of the thyroid gland. Dzungarian dwarf hamsters and monkeys prooved to be resistant. 9 out of 15 dogs died shortly after birth. In two dogs a carcinoma of the thyreoid gland and one of an ovary were found. Because of an infection, the experiments with guinea pigs were to be interrupted untimely. Therefore, a final answer is impossible. Own results were compared with the findings of other authors. The significance of the different susceptibility in distinct species is discussed.     

Host specificity of enteropathogenic Escherichia coli from rabbits: lack of correlation between adherence in vitro and pathogenicity for laboratory animals.

The pathogenicity of four attaching and effacing strains of enteropathogenic Escherichia coli originally isolated from diarrheic rabbits was investigated by inoculating them perorally into rabbits, guinea pigs, and mice. The ability of the four strains to adhere to cultured epithelial cells, erythrocytes, and intestinal brush borders from various animal species, including rabbits, guinea pigs, and mice, varied considerably. Only one strain carried AF/R1 fimbriae, which are believed to determine the host specificity of these bacteria. Despite these differences, the pattern of behavior of the four strains in experimentally infected animals was similar. Each strain caused fatal diarrhea in rabbits (although the virulence of individual strains for rabbits differed significantly), and none was virulent for guinea pigs or mice. None of the strains colonized the intestinal tract of guinea pigs, but all were able to cause attaching-effacing lesions in ligated loops of guinea pig small intestine. By contrast, all four strains colonized mice, in particular the distal intestine, but none induced attaching-effacing lesions in mouse intestinal loops. These findings suggest that there may be previously unrecognized host-restricted adhesins in enteropathogenic E. coli and indicate that adherence to erythrocytes or intestinal brush borders in vitro does not necessarily reflect colonizing ability or pathogenicity in vivo.     

Somatostatin immunoreactive C cells in thyroid glands from various mammalia species

The relative distribution of somatostatin- and calcitonin-containing cells in thyroid glands from various mammalian species was investigated by immunoperoxidase staining, and the concentration of immunoreactive somatostatin by radioimmunoassay. In the thyroid glands of guinea pigs and rabbits, most of the calcitonin cells were also immunoreactive to the somatostatin antiserum, and high concentration of immunoreactive somatostatin was obtained. On the other hand, in the thyroids of other animal species—rats, dogs, pigs, cows, goats, cats, monkeys, mice, and hamsters—only a few C cells revealed the immunoreaction for somatostatin, and the concentration of somatostatin was low. In all animal species studied, the somatostatin was present in the same cells that contain calcitonin, though in guinea pigs and rats there were some C cells containing a large number of reaction products for somatostatin but very few for calcitonin. Thus, it was concluded that there was a considerable variation in somatostatin immunoreactivity of thyroid C cells from species to species.     

Changes in intestinal fluid and mucosal immune responses to cholera toxin in Giardia muris infection and binding of cholera toxin to Giardia muris trophozoites.

The effect of Giardia muris infection on the diarrheal response and gut mucosal antibody response to cholera toxin was examined in mice. The results obtained showed that the fluid accumulation in intestinal loops exposed to cholera toxin was increased in mice infected with a low number (5 X 10(4) ) of G. muris cysts compared with the response in noninfected mice. This effect was associated with a marked reduction in absorption of oral rehydration fluid from the intestine. In contrast, mice infected with a high dose (2 X 10(5) ) of cysts showed a marked decrease in fluid accumulation in response to the toxin. This decrease might be related to the finding that both G. muris and Giardia lamblia trophozoites can bind significant amounts of cholera toxin. Evidence is presented which suggests that the gut mucosal antibody response, mainly immunoglobulin A but also immunoglobulin G, to an immunization course with perorally administered cholera toxin was depressed in mice infected with G. muris. The reduction in antibody levels was particularly evident when the primary immunization was made very early after infection. The serum antitoxin antibodies to the oral immunization with cholera toxin were, however, not affected. Likewise, the delayed-type hypersensitivity response against sheep erythrocytes in animals primed subcutaneously with sheep erythrocytes was not modified during the course of G. muris infection.     

Reovirus-like agent associated with fatal diarrhea in neonatal pigs.

Large numbers of a reovirus-like agent were visualized with electron microscopy in bacteria-free gut homogenates obtained from piglets with a fatal diarrhea resembling transmissible gastroenteritis. The syndrome, of vomiting, diarrhea, dehydration, and death, was reproduced in piglets artificially infected with these bacteria-free gut homogenates. Reovirus-like particles persisted in serial piglet passage and none was seen in uninfected, asymptomatic controls. Hyperimmune sera (made in recovered piglets) aggregated the reovirus-like particles, as judged by immunoelectron microscopy, and neutralized the infectious agent. The cytoplasm in enterocytes on infected intestinal epithelium fluoresced when this hyperimmune sera was used in an indirect fluorescent antibody test. Feeding cow colostrum or diets containing porcine gamma globulin protected infected piglets. No cytopathogenic effect was noted in infected tissue cultures, nor did this agent affect neonatal guinea pigs, hamsters, mice, and rats. The agent did not agglutinate human O or A erythrocytes.