IgG response in guinea pigs to Trichinella spiralis infection

An enzyme-linked immunosorbent assay (ELISA) using excretory-secretory antigens was developed to study the dynamics of the IgG antibody response to varying levels of Trichinella spiralis infection in the guinea pig. Four groups of four Hartley guinea pigs each were infected with 1250, 250, 50 or 10 T. spiralis infective muscle larvae. They were bled every 15 days for 6 months and the IgG antibody response determined by ELISA. The time of seroconversion was dose dependent as the larger the dose, the earlier the response occurred. Significant differences in antibody response between the dose groups were evident at 30 days post-infection (P less than 0.05). Beyond 60 days post-infection, the response was similar in the four groups. The antibody response in the groups infected with 250 and 50 infective larvae was similar, but was significantly different from that of the high (1250) and low (10) dose groups from 30 days post-infection (P less than 0.01). Once seroconversion occurred, the antibody titer rose to the same level, irrespective of the initial dose. To compare the antibody response according to muscle larvae recovered, the guinea pigs were grouped into four categories: less than 10 larvae; 10-25 larvae, 50-80 larvae, greater than 100 larvae. A significant positive correlation (P less than 0.05) was observed at 60 days post-infection when these groups were compared.     

Induction of systemic and local basophil and eosinophil responses in guinea pigs by the feeding of the tsetse fly Glossina morsitans

Guinea pigs infested with Glossina morsitans weekly for 5 weeks exhibited marked peripheral blood basophil and eosinophil responses to each infestation, with a dominant cutaneous basophil response to challenge infestation. G. morsitans feeding was completed within 3--10 min, depending upon prior exposure, and flies were reluctant to feed and probed longer on hyperexposed animals. Blood basophil responses exhibited the greatest increases over controls (up to 12-fold) compared to eosinophils (up to 3-fold). After the first and third infestations, both basophil and eosinophil levels increased, whereas after the second and fourth infestations both cell types declined. Greatest blood basophil responses developed after the first infestation with levels ranging from 0 to 14 +/- 9 cells/mm3 in infested animals to 0 and 2 +/- 2 cells/mm3 in uninfested controls. Eosinophilia increased with each infestation where levels ranged from 57 +/- 23 cells/mm3 after the first tsetse feeding to 110 +/- 20 cells/mm3 after the fourth infestation; compared to 11 +/- 11 to 50 +/- 12 cells/mm3 in uninfested controls. Fly-feeding sites were marked by hemorrhages, and probing behavior resulted in a line of small hemorrhages when the underside of the skin was examined. Histologically, G. morsitans feeding sites in naive guinea pigs 24 h post-infestation were dominated by mononuclear cells (93% of the infiltrate) with a weak granulocyte component, of which eosinophils were dominant (1.3%). Tsetse feeding sites in guinea pigs exposed 3 times previously were again dominated by mononuclear cells (57% of the infiltrate), but granulocytes comprised a significant part of the response (43% of the infiltrate) where basophils were dominant (25%).     

The hemolytic activity of bracken extracts in guinea pigs

This study was conducted to elucidate the hemolytic activity of a new toxic substance in bracken fern. A crude extract (CE) was prepared from the methanol extracts of bracken by the column chromatography. When the CE was injected subcutaneously in guinea pigs, the hemoglobinuria and hemolysis were observed within 6 hr, and 3 days later edema and hemorrhages in the urinary bladder were observed. The CE was then fractionated by high performance liquid chromatography (HPLC), and three (HF, BF and CF) of the fractions showed the toxic activities in guinea pigs. The HF caused the hemolysis, whereas both the BF and the CF caused the hemorrhagic cystitis without any hemolytic activities. The HF was further fractionated by the HPLC, resulting of the 3 fractions (HF-I, II and III). The hemolysis was caused only with the HF-II, and HF-II as well as HF did not cause the hemorrhagic cystitis. HPLC analysis revealed that both BF and CF contains braxin B and braxin C, respectively, and both HF and HF-II do not contain braxin A, B or C. These facts suggest that bracken fern contains a new toxic substance (hemolysin) which induces the acute hemolysis in guinea pigs.     

Experimental Tonsillophilus suis granuloma in rats and guinea pigs.

Rats and guinea pigs were experimentally infected by intradermal and intraperitoneal inoculation of T. suis. These animals were observed for pathologic changes at various stages. Macroscopic observation disclosed visible grayish white soft nodules at the injection site in those inoculated intradermally and many grayish white nodules in the peritoneum of those inoculated intraperitoneally. Histopathological examination revealed the presence of characteristic microbial elements in the centre of the lesions. Various stages of the lesions were recognized; the early stage being abscess, the advanced stage being pus-forming granuloma and the final stage being residual granuloma. The microbial elements were composed of spores, thalli and multilocular tubers. Clubs were formed around microbial elements in rats inoculated intradermally and in guinea pigs inoculated intraperitoneally. The characteristic T. suis lesions in pigs were reproduced by experimental infection of this organisms in rats and guinea pigs, and thus the pathogenicity of T. suis was confirmed.     

Cytology of bone marrow.

Cytologic examination of bone marrow aspirates can provide a wealth of diagnostic information. Practitioners should not hesitate to perform bone marrow aspirates when indicated. This article is designed to assist the practitioner in the evaluation of bone marrow aspiration biopsies. The indications for marrow evaluation, methods of sample collection, sample preparation, and cytologic examination of bone marrow are discussed. Cases are provided to demonstrate accurate interpretation of bone marrow aspirates.     

Clinical and pharmacological properties of ivermectin in rabbits and guinea pigs.

When 400 micrograms ivermectin/kg was administered subcutaneously to rabbits infected with the ear mite Psoroptes cuniculi it significantly reduced the clinical score, and when 500 micrograms ivermectin/kg was administered subcutaneously to guinea pigs with mange due to Trixacaurus caviae it resulted in a clinical cure. In rabbits a subcutaneous dose of 400 micrograms/kg produced high and sustained concentrations of ivermectin in the tissues and body fluids for at least 13 days and its rate of depletion from tissues was similar to that observed in sheep and rats. The mean (+/- sem) maximum concentration in plasma was 42.0 +/- 9.7 ng/ml 37.2 +/- 5.0 hours after administration and the area under the concentration-time curve was 3543 +/- 580 ng/ml hours. After the administration of 500 micrograms ivermectin/kg to guinea pigs orally, subcutaneously or topically the drug could be detected in the plasma only after subcutaneous administration. The mean concentration 72 hours after its administration to four guinea pigs was 0.7 +/- 0.3 ng/ml.     

Experimental infection by Vibrio anguillarum in mice and guinea pigs.

The fish pathogen Vibrio anguillarum causes a lethal infection in farmed fish characterized by hemorrhagic septicemia. There are no reports of experimental laboratory infections in warm-blooded animals. We investigated the effects of an intraperitoneal infection with different doses of a V. anguillarum suspension in mice and guinea pigs. The infection caused a 95-100% of mortality in 24-48 h. Hemorrhagic septicemia was observed at necropsy and confirmed by histological and hematological examination. Immunohistochemically positive bacterial clumps were detected exclusively in vessel lumen in all examined organs, including brain, and V. anguillarum was reisolated in pure culture from all organs, particularly from the kidney. Blood analysis showed erythropenia and leukopenia with granulocytosis in mice, platelet reduction and leukopenia with lymphocytosis in guinea pigs.     

Sequential morphological and quantitative changes in blood and bone marrow neutrophils in dogs with acute inflammation.

Blood and bone marrow morphology were studied sequentially in dogs during experimental inflammation induced by intramuscular injection of turpentine. Depletion of the bone marrow storage pool of mature neutrophils and an increase in mitotic activity and number of early granulocyte precursors were evident within 24 hours. During the next three days, intense granulocytic hyperplasia resulted in replenishment of the bone marrow storage pool. Neutrophils with foamy vacuolation and increased basophilia of the cytoplasm (toxic neutrophils) were present in the blood by eight hours postinjection. The number of toxic neutrophils paralleled the intensity of clinical signs and changes in rectal temperature but not the number of band neutrophils. This indicates that changes in number of toxic neutrophils in sequential leukograms can be a prognostic indicator in dogs with severe inflammation.     

Electron microscopy of a spiral-shaped bacterium in the blood and bone marrow of a rhinoceros iguana.

Spiral shaped bacteria present in blood smears and bone marrow of a sick rhinoceros iguana were examined by light and electron microscopy. The organisms averaged 10 micron in length and had at least three spiral turns. The cell contained nuclear areas, vacuoles and ribosomes, except at the poles where there was a virtual absence of organelles. The bacterium was found by a cell membrane, cell wall and enveloping sheath. "Blebs" were present with regularity on the cell surface. About 14 flagella were present at each pole, and at these sites there was a specialized thickening of the cell membrane. Organisms were present within a phagocytic vacuole of macrophages in the blood and bone marrow, and often these engulfed organisms were degenerated. The taxonomic position of the bacterium is unknown.     

Visual evoked potentials in guinea pigs with brain lesion.

Visual evoked potentials (VEPs) were recorded in 10 adult male guinea pigs with brain lesion. Lesions were produced in 5 animals by superficial suction of the occipital lobe. The other 5 animals were orally administered with hexachlorophene (about 35 mg/kg/day) for 28 days. In the VEP following the ablation of the occipital lobe, the peaks P10, N20, P55, N75, N140 and P200 disappeared in many cases. The amplitude of the peak N40 decreased to approximately one half its control VEP. In the VEP obtained from the animals administered with hexachlorophene, the peak latencies of N20, P30, P55, N75 and P100 were slightly prolonged after the 7th day following the first administration. On the other hand, there was no change in the latency of N40 during the whole period of administration. The peak-to-peak amplitude showed some variability in different peaks. Histologically, diffuse status spongiosis were found in the white matter of the cerebrum, cerebellum, and brain stem. As described above, the ablation of the occipital lobe caused markedly depressed VEPs, however, the responses to the photic stimulation persisted after the injury. On the other hand, the VEPs of animals administered with hexachlorophene showed a high probability of peak appearance, and a decrease in amplitude was not marked.     

Malocclusions in guinea pigs,chinchillas and rabbits

The types of malocclusions encountered in rodents and lagomorphs are classified. Diagnosis, treatment, and prognosis are reviewed. Some malocclusions are curable, whereas others can only be controlled. The need to perform a complete oral examination and to find a cause for the condition is stressed, as it will seriously affect the prognosis.     

布鲁菌在豚鼠和奶牛体内诱导的抗体水平和变态反应强度的相关性

为探索布鲁菌在豚鼠和奶牛体内所引起的抗体水平和变态反应强度的相关性,分别用1×104,3×104CFU牛种布鲁菌强毒2308株各感染12只豚鼠,30 d后测定抗体滴度和变态反应强度。感染后35 d,扑杀豚鼠,取脾脏测定每克脾脏含菌量。用布鲁菌A19疫苗,以5×1010CFU皮下注射布病阴性荷斯坦奶牛50头,分别于免疫后15,30,60 d测定抗体滴度,并于免疫后45 d测定变态反应强度。运用SPSS 17.0-Analyze-Correlate-Bivariate Corre-lations程序分析试验数据,结果显示,不同剂量布鲁菌2308感染豚鼠后30 d所诱导的抗体水平、变态反应强度和克脾脏含菌量三者之间均无相关性。A19疫苗免疫奶牛后60 d的抗体水平与免疫45 d的变态反应强度呈正相关,免疫15 d和30 d的抗体水平和变态反应强度无相关性。豚鼠试验结果表明,抗体水平、变态反应强度与个体对布病的抵抗力均无相关性。