免疫组织化学ABC法观察扁桃酸对小鼠急性弓形虫病肝脏病变的作用

目的用免疫组织化学ABC法观察扁桃酸治疗小鼠急性弓形虫病肝脏的病变，探讨扁桃酸对病变肝脏的保护作用。方法扁桃酸200mg／kg，2次／d，口服和静脉注射治疗弓形虫感染小鼠，同时设立乙胺嘧啶及扁桃酸药物对照组，治疗不同时间后取肝脏组织，常规制作病理切片，免疫组织化学ABC法常规染色。结果阳性对照组可见大量肝细胞坏死区，其内可见形态典型的弓形虫速殖子，扁桃酸治疗组仅见少量散在的黄染肝细胞，乙胺嘧啶对照组小鼠肝组织内也仅见少量散在的黄染肝细胞，但肝细胞受到明显的毒性损害。因而扁桃酸能有效地抑制弓形虫速殖子入侵肝细胞，减轻弓形虫速殖子对肝细胞的破坏程度，且扁桃酸对肝细胞的毒副作用极少。结论扁桃酸对弓形虫感染小鼠的肝脏有明显的保护作用。     

Large granular lymphoma with toxoplasmosis in a cat

A five-year-old domestic cat with generalised toxoplasmosis and severe leukaemia (145 × 10⁹ WBC/1) is described. The liver was necrotic with tissue cysts and a localised lymphoma.Toxoplasma gondii organisms were found in all organs investigated. Tumour cells containing large cytoplasmic, azurophilic granules were observed in the blood. Erythrophagocytosis by tumour cells was also seen.     

Several results of a Toxoplasma survey

A pilot Toxoplasma survey was conduct in Ciego de Avila province during the month of September, 1985, to assess, in practice, the methodologic structure proposed for the National Toxoplasma Survey. Of the 292 listed individuals, 284 were surveyed during the field work phase (97.2%) and the remaining 2.8% of no response was due mainly to the fact that dwellers were not at home during the visit. The best day for this type of survey resulted to be Sunday, in the morning. No difficulty was noted with the used modelling, and results obtained in the application of used techniques and procedures are appropriate for use in the National Toxoplasma Survey. The prevalence rate of anti- Toxoplasma antibodies was 55.9%. There was a significant association between some risk factors such as: living with cats, ingestion of non potable water and ingestion of raw meat.     

刚地弓形虫培养上清对THP-1增殖的影响及可能机制

 利用弓形虫速殖子细胞内寄生的特性和对宿主细胞生物学行为的影响,提取弓形虫体外细胞共培养上清,并研究上清对人急性单核细胞白血病细胞THP-1增殖及细胞周期的影响。方法 取对数生长期的THP-1细胞（浓度为5×105）分别接种于不同细胞培养瓶,对照组加入含10%胎牛血清RPMI-1640,试验组加入相同体积不同数量(2×107mL-1、 4×107mL-1、 8×107 mL-1 )弓形虫速殖子培养上清孵育不同时间后, MTT法检测THP-1细胞增殖抑制率;流式细胞仪检测细胞周期改变;以Western印迹方法分析上清作用48h后细胞核转录因子NF-κB/p65与周期蛋白cyclinD1表达或活性的变化。结果 MTT法检测结果显示弓形虫培养上清抑制THP-1细胞株增殖,且呈时间剂量依赖性。流式细胞仪检测显示处理组细胞周期在G0/G1期产生阻滞; Western印迹方法分析THP-1细胞株的NF-κB/p65、cyclin D1 蛋白表达量下降,结论 刚地弓形虫培养上清能够抑制人急性单核细胞白血病细胞THP-1细胞株增殖并可通过细胞株的NF-κB信号途径来下调cyclin D1蛋白表达引起人急性单核细胞白血病细胞THP-1细胞株G0/G1期阻滞。     

刚地弓形虫培养上清抑制肺癌A549细胞系增殖

目的研究刚地弓形虫(Toxoplasma gondii)培养上清对体外培养的肺癌细胞A549增殖及细胞周期的影响。方法取对数生长期的A549细胞(浓度为5×104mL-1)分别接种于不同细胞培养板,对照组加入RPMI-1640孵育,试验组加入相同体积不同数量(4×107mL-1、8×107mL-1、16×107mL-1)弓形虫速殖子培养上清孵育不同时间后,四甲基氮噻唑蓝(MTT)法检测吸光度(A490值);PI染色后检测细胞周期;以Western blot检测细胞周期蛋白cyclinB1、cdc2表达或活性。结果弓形虫培养上清呈时间剂量依赖性抑制A549细胞系增殖,处理组细胞周期在G2/M期产生阻滞;A549细胞系的cyclinB1、cdc2蛋白表达量下降。结论刚地弓形虫培养上清能够抑制肺癌A549细胞系增殖,并通过调节cyclinB1、cdc2等蛋白表达或活性改变引起肺癌A549细胞系G2/M期阻滞。     

Pituitary pathology in acquired immunodeficiency syndrome

Pituitary morphology was studied in 49 autopsied patients with acquired immunodeficiency syndrome. Direct infectious involvement was noted in six adenohypophyses (12%), including five cases by cytomegalovirus and one by Pneumocystis carinii. Two cases with neurohypophysial lesions presumably caused by cytomegalovirus and one questionable case of Toxoplasma gondii were also observed. In all instances these changes were associated with generalized and/or cerebral infection by these same agents. Neither Kaposi's sarcoma nor malignant lymphoma was encountered in the pituitary glands. Acute necrotic foci, presumably due to infarction, were noted in four cases. Four pituitary microadenomas (8%) and four hyperplastic nodules were identified. The incidence of such noninfectious lesions, as well as the prevalence and distribution of the various immunoreactive adenohypophysial cell types, were similar to those seen in the pituitary glands of age-matched male control patients.     

Isotypic profiles of antibody responses to Toxoplasma gondii infection in rats and mice: kinetic study and characterization of target antigens of immunoglobulin A antibodies.

The antibody responses to Toxoplasma gondii were investigated in rat and mouse experimental models. The immunoglobulin A (IgA) antibody response was of particular interest because acquisition of Toxoplasma gondii is usually by the oral route. The rat model was used because the natural resistance of rats to the parasite is similar to the natural resistance exhibited by adult humans. There was an early and simultaneous rise in IgA and IgM antibody responses. The IgA antibody response was maximal around day 40. IgA antibodies from Fischer rats were mainly directed against soluble and membrane antigens of 28.5, 29, 30, 35, and 38 kilodaltons (kDa). In mice, however, a major antigen of 29 kDa was recognized by IgA antibodies. Moreover, in orally infected rats, an intense IgE antibody response against the major surface antigen, P30, was observed. An IgA antibody response was also observed in rats and mice immunized with Toxoplasma excreted-secreted antigens, even without adjuvant. This response was mainly directed against 28.5- and 34-kDa antigens in rats. Serum IgA from infected rats tested against the excreted-secreted antigens bound to 28.5- 34-, and 39-kDa antigens, whereas sera from infected mice recognized only the 34-kDa antigen.     

Cerebellar anomalies in congenital murine toxoplasmosis

Gravid Nya:NYLAR mice, infected with Toxoplasma gondii on gestation day 7, experienced embryo resorptions, abortions, stillbirths, and a reduction in average litter size by one-third. Postnatally, all congenitally infected pups showed growth retardation, cachexia, and hind limb weakness. Some pups developed necrotic petechiae on the ears and tail, and a blood-tinged nasal discharge. Coronal sections of the cerebellum at age 1 month revealed developmental abnormalities including: persistence of remnants of an external granular layer; fragmented and disoriented Bergmann glial foot processes; numerous ectopic granule cells stranded in the molecular layer; focal disorganization and edema of the Purkinje cell layer; and thinning of the internal granular layer. Our working hypothesis is that the cerebellar anomalies originated with parasite invasion of the fetal vascular endothelium leading to vasculitis and microcirculatory dysfunction, perivascular edema, perfusion impairment, and tissue anoxia. In the cerebellar folia, the cellular migration defects are attributed to edema-induced swelling and fragmentation of the Bergmann glial foot processes that guide migrating neurons, whereas the focal loss of Purkinje and granule cells is ascribed to hypoxia-ischemia. Although Toxoplasma cysts were detected in the cerebellum, morphologic evidence of parasite association with neuropathology was not obtained.     

Complement activation by necrotic cells in normal plasma environment compares to that by late apoptotic cells and involves predominantly IgM

Necrotic cells are generally considered to stimulate inflammation, whereas apoptotic cells should not. However, apoptotic cells have pro-inflammatory properties since they can activate complement. To what extent this activation compares to that by necrotic cells is not known. We compared complement activation by necrotic cells and apoptotic cells in plasma. Jurkat cells were made apoptotic or necrotic by incubation with etoposide or by heat shock, respectively. Cells incubated in recalcified plasma were tested for C3 and C4 fixation and fluid phase generation of complement activation products. Fixation of C3 and C4 to necrotic cells occurred mainly via the classical pathway, independent from the method of necrosis induction and the cell type. Depletion of IgM from plasma almost completely abrogated complement fixation by necrotic cells, which was restored by supplementation with purified IgM. Complement activation by late apoptotic cells was comparable to that by necrotic cells regarding the extent and dependence on IgM. Moreover, incubation of plasma with necrotic or late apoptotic cells led to the generation of comparable amounts of complement activation products. These results indicate that late apoptotic and necrotic cells employ similar complement activation mechanisms in the plasma environment.     

Experimental animal studies for the detection of circulating Toxoplasma antigens

Rabbits and mice were infected by Toxoplasma gondii (RH and HanR) and Hammondia hammondi. An enzyme immunoassay with monoclonal antibodies was used to reveal circulating Toxoplasma antigens. They were found only in mice and rabbits that had been infected by the cyst-forming strain Toxoplasma HanR. In mice infected by Hammondia hammondi low antibodies titres were found that showed a cross-reaction with Toxoplasma. The enzyme immunoassay for evidence of Toxoplasma antigens demonstrated a negative reaction in these animals.     

孕期弓形虫感染对胎盘的入侵和病理损害的研究

目的探讨孕期弓形虫感染对胎盘的入侵和病理损害情况。方法孕8dBALB/c小鼠经腹腔接种弓形虫速殖子,在孕10、12、14、16和18d剖腹取胎鼠,分离胎盘并精确称重。采用HE染色观察胎盘的病理损害情况,RNA原位杂交检测胎盘组织弓形虫速殖子的动态入侵。结果在孕10、12d,感染组胎盘重量与对照组比较无明显差别。而在孕14、16、18d,感染组的胎盘重量明显低于对照组（P〈0.01）。随着感染时间的延长,胎盘组织切片可见有大量淋巴细胞、单核细胞、嗜酸性粒细胞浸润,绒毛血管减少,显示有炎症表现;滋养层细胞破坏明显,可见凋亡小体形成。感染组小鼠在孕10d未检测到虫体,感染孕12d偶见虫体。孕14、16、18d虫体数目明显增多（P〈0.01）,虫体主要位于滋养层细胞内、细胞间质和血管中,并有假包囊形成。结论孕期弓形虫感染可影响胎盘生长,胎盘出现炎症反应和凋亡等病理损害。虫体可侵入胎盘组织细胞间质和血管中,并侵入滋养层细胞内增殖,跨越胎盘屏障传播给胎儿。     

Immunoglobulin M-immunosorbent agglutination assay for diagnosis of infectious diseases: diagnosis of acute congenital and acquired Toxoplasma infections.

An immunoglobulin M (IgM)-immunosorbent agglutination assay (IgM-IS-AGA) was negative in all sera from individuals negative in the Sabin-Feldman dye test, in sera from individuals with chronic Toxoplasma infection, and in cord blood samples from uninfected infants. In contrast, all sera that were obtained from individuals with a recent history of acute Toxoplasma infection and from infants with congenital Toxoplasma infection and that were positive in both the dye test and the IgM-indirect fluorescent-antibody (IgM-IFA) test were positive in IgM-ISAGA. A total of 21 (67.7%) of 31 sera that were negative in the IgM-IFA test, despite being obtained from individuals with recently acquired Toxoplasma infection, and 8 (72.7%) of 11 sera that were negative in the IgM-IFA test and obtained from infants with congenital Toxoplasma infection were positive in IgM-ISAGA. The presence of rheumatoid factor, antinuclear antibodies, or both did not cause false-positive results in the IgM-ISAGA but did so in the IgM-IFA test. Thus, IgM-ISAGA in both more sensitive and more specific than the IgM-IFA test for detection of IgM antibodies to Toxoplasma gondii and, therefore, for the diagnosis of acute congenital and acquired Toxoplasma infections.     

Detection of rabbit haemorrhagic disease virus particles in the rabbit liver tissues.

Liver tissues from rabbits experimentally infected with rabbit haemorrhagic disease virus (RHDV) were studied electron microscopically. The earliest change in hepatocytes of the rabbits infected with RHDV was hydropic degeneration. Rough endoplasmic reticulum was dilated with a mild increase in polysomes and cytoplasmic cisternae in degenerated hepatocytes. Characteristic cytopathological changes of necrotic hepatocytes included shrinkage of the cell body, formation of cytoplasmic vesicles, vacuoles or cisternae and karyolysis. A large number of viral particles resembling a calicivirus in size and morphology was demonstrated in the cytoplasm of many necrotic hepatocytes. The particles had accumulated mainly in the membrane-bound cisternae or scattered around the membrane-bound vacuoles of the necrotic hepatocytes. Western blot analysis demonstrated that RHDV antigen was present in the infected hepatocytes. RHDV particles were also detected by immunoelectron microscopy. Replicating patterns of RHDV particles and subsequent cytopathology resembled those in other calicivirus infections.     

Some microcirculatory and metabolic changes of rat myocardium following coronary artery occlusion

The experiments conducted on 50 albino male rats have shown that the increase of capillary metabolic surface area and capillary bed capacity detected 1-15 days after the coronary artery occlusion in the zones distant from necrotic focus, and resulting mainly from capillary dilation, correlated with the progressive reduction of lipid peroxidation intensity, decline in the necrotic focus area and in the activity of necrotic marker enzymes in blood serum. These changes were accompanied by a gradual increase in the activity of some enzymes and substrate content that characterize the myocardial energy supply. The changes detected could be regarded as a result of improvement of microcirculatory blood supply to the myocardium. while a prolonged (lasting for 15 days) increase of myocardial lipid peroxide content could reflect the natural reoxygenation arising from a collateral circulation development.     

Detection of antigens in urine during acute toxoplasmosis.

Toxoplasma antigens were detected in sera and urine of mice acutely infected with Toxoplasma gondii. The concentrations of antigens in the urine samples measured by enzyme-linked immunosorbent assay were similar to those detected in the sera of the corresponding mice. The major antigens were not dialyzable and were largely destroyed by treatment with trichloroacetic acid and heat (100 degrees C for 1 h). Toxoplasma antigens were demonstrable on Western blots (immunoblots) of the urine samples.     

Spinal pencil-shaped softening. Report of an autopsy case studied using a three-dimensional model

The pathologic features of a case of spinal pencil-shaped softening (PS) were studied by detailed step-sectioning and reconstruction using a three-dimensional (3D) model. The spinal cord was obtained at autopsy from a patient who had developed paraplegia due to extradural involvement of lung cancer. Above and below the area of transverse necrosis were PSs containing necrotic debris. They compressed the surrounding tissue and extended longitudinally over several segments. The PS was continuous with the area of transverse necrosis. These findings support the hypothesis that PS is formed by penetration of necrotic debris. The 3D model revealed that the PS was cylindrical to spindle-shaped. It showed a remarkable change in width along its course, with an unusual expanding shape. The PS was mainly located in the ventral part of the posterior column but was also observed in other locations in the segment near the transverse necrosis. Detailed step-sectioning showed that the PS changed in width mainly in response to intrapial pressure, and that it occurred where the parenchymal tissue was fragile. The expansion produced by penetration of necrotic debris may thus play an important role in the morphogenesis of this unusual lesion. Furthermore, the condition of the surrounding tissue may also be an important factor influencing the width and location of PS.     

Spinal Pencil-shaped Softening: Report of an Autopsy Case Studied Using a Three-dimensional Model

The pathologic features of a case of spinal pencil-shaped softening (PS) were studied by detailed step-sectioning and reconstruction using a three-dimensional (3D) model. The spinal cord was obtained at autopsy from a patient who had developed paraplegia due to extradural involvement of lung cancer. Above and below the area of transverse necrosis were PSs containing necrotic debris. They compressed the surrounding tissue and extended longitudinally over several segments. The PS was continuous with the area of transverse necrosis. These findings support the hypothesis that PS is formed by penetration of necrotic debris. The 3D model revealed that the PS was cylindrical to spindle-shaped. It showed a remarkable change in width along its course, with an unusual expanding shape. The PS was mainly located in the ventral part of the posterior column but was also observed in other locations in the segment near the transverse necrosis. Detailed stepsectioning showed that the PS changed in width mainly in response to intrapial pressure, and that it occurred where the parenchymal tissue was fragile. The expansion produced by penetration of necrotic debris may thus play an important role in the morphogenesis of this unusual lesion. Furthermore, the condition of the surrounding tissue may also be an important factor influencing the width and location of PS.     

Control of Clostridium perfringens-induced necrotic enteritis in broilers by target-released butyric acid,fatty acids and essential oils

The efficacy of target-released butyric acid, medium-chain fatty acids (C₆ to C₁₂ but mainly lauric acid) and essential oils (thymol, cinnamaldehyde, essential oil of eucalyptus) micro-encapsulated in a poly-sugar matrix to control necrotic enteritis was investigated. The minimal inhibitory concentrations of the different additives were determined in vitro, showing that lauric acid, thymol, and cinnamaldehyde are very effective in inhibiting the growth of Clostridium perfringens. The in vivo effects were studied in two trials in an experimental necrotic enteritis model in broiler chickens. In the first trial, four groups of chickens were fed a diet supplemented with butyric acid, with essential oils, with butyric acid in combination with medium-chain fatty acids, or with butyric acid in combination with medium-chain fatty acids and essential oils. In all groups except for the group receiving only butyric acid, a significant decrease in the number of birds with necrotic lesions was found compared with the infected, untreated control group. In the second trial the same products were tested but at a higher concentration. An additional group was fed a diet supplemented with only medium-chain fatty acids. In all groups except for that receiving butyric acid in combination with medium-chain fatty acids and essential oils, a significant decrease in the number of birds with necrotic lesions was found compared with the infected, untreated control group. These results suggest that butyric acid, medium-chain fatty acids and/or essential oils may contribute to the prevention of necrotic enteritis in broilers.     

神经干细胞球在生物反应器内培养的模拟计算

采用元胞自动机技术建立的模拟神经球生长的动态模型，结合反应器中培养的神经球内部养分的扩散传递模型，求解了神经干细胞球内出现坏死细胞核的临界神经球尺寸和坏死细胞核的扩大规律，以及反应器内养分浓度的变化情况。计算结果表明，坏死细胞核的出现与体外培养条件有一定关系：神经球培养密度、培养基养分浓度和培养基与神经球之间的传质情况等都有一定程度的影响；但是坏死细胞核的出现主要取决于神经球的尺寸，过大的神经球内必定会出现坏死细胞核，即使在生物反应器中良好的外部培养条件下也不可能抑制它的出现。此外，神经球内由于氧缺乏而形成的坏死细胞核的出现要早于由于葡萄糖缺乏时的情况，并且坏死细胞核一旦出现，其增长速度就非常快，有可能很快使整个神经球成为坏死细胞球。本文所建立的元胞自动机（Cellular automata，CA）模型及各种生物反应器培养条件下神经球内的传质模型可以很好的模拟神经球的生长过程。     

Spontaneous toxoplasmosis in canaries (serinus canaria) and other small passerine cage birds

An outbreak of spontaneous Toxoplasma gondii infection on an Italian bird-farm is described. Small passerine birds (Serinus canaria, Carduelis chloris, Carduelis carduelis, Carduelis spinus, Carduelis cannabina, Pyrrhula pyrrhula) showed clinical signs consisting of anorexia, prostration, weight loss, diarrhoea and dyspnoea accompanied by a high mortality rate. Clinical, pathological, biological and serological investigations were performed. Characteristic lesions and Toxoplasma gondii specimens were identified in several tissues by histopathological examinations. The detection of antibodies against Toxoplasma gondii was constant in dead and sacrificed animals with macroscopic lesions. A therapy based on the administration of sulphadimethoxine and diaveridine was successful in limiting the mortality rate. Four months later some surviving birds developed ocular atrophy. Toxoplasma gondii cysts were observed in the brain and cerebral and ocular lesions described. Sera obtained from these animals were positive (>1:64) for antibodies against Toxoplasma gondii. The authors conclude with some observations on the spread of toxo-plasmosis among cage birds.