Comparison of tissue reactions produced by Haemophilus pleuropneumoniae vaccines made with six different adjuvants in swine.

Tissue damage caused by six different adjuvants incorporated in a Haemophilus pleuropneumoniae vaccine was compared in swine. The adjuvants compared were four mineral oil compounds, one peanut oil compound and aluminum hydroxide. Inoculations were given in the neck, quadriceps and semitendinosus muscles. The mineral oil adjuvants were highly irritant and caused extensive areas of granulomatous inflammation that were present at eight weeks after injection. The aluminum hydroxide produced smaller lesions that also persisted for eight weeks. Only the peanut oil adjuvant did not produce significant lesions at the site of injection. At two and four weeks, but not at eight weeks postinoculation, lesions in the quadriceps and semitendinosus muscles were approximately twice as extensive as those in the muscles of the neck.     

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.     

Potentiating effect of adjuvants on humoral immunity to porcine parvovirus vaccines in guinea pigs

Fourteen different adjuvants, given either in single or combined form with another compound were compared in guinea pigs for their ability to potentiate humoral immunity to porcine parvovirus (PPV) antigen after 2 vaccinations. Two injections were given, the second 3 weeks following the initial vaccination. Antibody concentrations to PPV in sera from injected animals were measured over a 5-week period by the hemagglutination inhibition test. At the conclusion of the experiment, guinea pigs injected with the following adjuvants and PPV antigen: CP-20 961 (Avridin), 50% aluminum hydroxide gel, ethylene maleic anhydride (EMA), oil and water emulsion (O/W) and dimethyl-dioctadecyl-ammonium bromide (DDA) immunologically responded with high geometric mean HI titers (380, 224 and 427, 602, 512, 1202 respectively), whereas guinea pigs receiving Emulsan, sodium dodecyl sulfate (SDS), L-121, combinations of Emulsan/aluminum hydroxide, SDS/aluminum hydroxide and B. pertussis/aluminum hydroxide responded with low mean titers (54, 64, 18, 27, 11, 64, 14, 20 respectively). Guinea pigs injected with antigen without adjuvant responded weakly with geometric mean titers of 3.3 and 16 for the 2 groups tested. Prior to booster injection, guinea pigs immunized with 13 of the preparations had low (less than 4) or undetectable antibody titers. Antibody titers from guinea pigs receiving DDA adjuvant continued to rise throughout the duration of the experiment and at the conclusion had the highest mean titers of the groups tested (1202). The 2 groups immunized with 50% aluminum hydroxide gel had high mean titers (224, 427), but in both instances there was a wide range of titers within a group evidenced by high standard deviations. In contrast, guinea pigs receiving either DDA, CP-20 961, O/W or EMA had antibody titers within a narrow range and small standard deviation. The significance of aluminum hydroxide gel concentration on immunogenicity is discussed.     

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.     

Hyperthyroidism in four guinea pigs: clinical manifestations,diagnosis, and treatment

Hyperthyroidism was diagnosed in four guinea pigs by demonstration of an increased serum total thyroxine concentration. The main clinical signs were comparable with those observed in feline hyperthyroidism and included weight loss despite maintenance of appetite and a palpable mass in the ventral cervical region. Three animals were treated successfully with methimazole for between 13 and 28 months. Clinical signs and regular measurement of circulating total thyroxine concentrations appear to be convenient parameters for monitoring response to medical therapy.     

不同佐剂对奶牛乳房炎金黄色葡萄球菌多价毒力因子疫苗免疫效果的影响

为评价佐剂对金黄色葡萄球菌(S.aureus)CP8-FnBPB-ClfA免疫效果的影响,用纯化的S.aureus血清8型荚膜多糖与FnBPB-ClfA蛋白偶联的偶联物配合不同佐剂对健康成年新西兰大耳白母兔进行免疫接种,第1、2、3、4组的佐剂分别为弗氏佐剂、铝盐佐剂、脂质体佐剂及大肠杆菌不耐热肠毒素B(LTB),第5组为对照组用PBS免疫。用间接ELISA法和Western blot对各组兔血清中的抗体进行监测,评价体液免疫效果;通过检测Th1/Th2类细胞因子含量变化评价机体免疫被激活的程度;T淋巴细胞增殖试验评价细胞免疫,并对三免后2周的白兔进行攻毒保护试验。结果显示,以脂质体为佐剂的组7d时开始产生抗体,为产生抗体最早组,14d后抗体水平就开始下降;以LTB为佐剂的组抗体水平最高,持续时间最长。细胞免疫水平检测结果显示,经ConA刺激后,各组T淋巴细胞普遍增殖,无显著差异,刺激指数都在1.0左右;用抗原刺激的组中,以LTB为佐剂的组T淋巴细胞增殖能力最强,刺激指数为2.23,对白兔的攻毒保护率为80%。     

Changes in the visual evoked potentials with different photic conditions in guinea pigs.

Visual evoked potential (VEP) was studied in five adult male guinea pigs weighing 350-750 g. VEPs were recorded with chronically implanted electrodes. Photic stimulation was presented in the following order: binocular, left eye, right eye, and screened binocular. The averages of the responses were made from 140 samples. When a single eye was exposed to photic stimulation, the ipsilateral VEP was different from the contralateral VEP; the peaks N140 and P200 disappeared, and the peak latencies of N75 and P100 were significantly (P less than 0.05) longer than those in the contralateral hemisphere. Peak-to-peak amplitude N40-P55 in the ipsilateral VEP was significantly (P less than 0.05) lower than that in the contralateral VEP. The contralateral VEP by monocular stimulation was generally indistinguishable from the response to binocular stimulation. As described above, when only a single eye was exposed to flashes, the ipsilateral dural VEP was different from the contralateral dural VEP.     

氯化汞对SD大鼠组织损伤的病理学研究

将24只SD大鼠被随机分为4组,即对照组(饮用蒸馏水)、低剂量汞组(HgCl250 mg/L)、中荆量汞组(HgCl2100 mg/L)、高剂量汞组(HgCl2200 mg/L),采用自由饮水染毒,染毒时间为21 d.期间记录大鼠体质量及临床症状,染毒结束后采集心、肝、脾、肺、肾组织,称重并制作石蜡切片观察其病理组织学变化.结果显示,各染毒组大鼠体质量增长均低于对照组,部分组间差异显著(P<0.05);与对照组相比.中、高剂量染毒组大鼠肾脏、脾脏、肺脏和大脑脏器系数差异显著(P<0.05);光学显微镜观察各染毒组大鼠肝细胞肿胀、肝细胞索紊乱、中央静脉淤血;肾小管上皮细胞肿胀、变性,管腔内有脱落的上皮细胞或溶解崩裂的细胞碎片,肾间质有红细胞积聚;心脏、脾脏、肺脏可见大量红细胞积聚,而大脑未见明显异常的病理学变化.结果表明,低剂量汞暴露对SD大鼠生长发育具有明显抑制作用,且能引起机体各组织器官广泛性病理损伤.     

Pathological and aetiological studies of multifocal interstitial nephritis in wasted pigs at slaughter

Multifocal interstitial nephritis in pigs has been associated with several infectious agents. The objective of the present study was to investigate several different potential infectious agents associated with "white-spotted" kidneys in pigs suffering from wasting at slaughter (aged 6-8 months). Twenty-nine case kidneys (with a "white-spotted" gross appearance) classified into 3 macroscopic lesional grades, and 15 control kidneys (lacking gross lesions), were obtained from a pig abattoir. Laboratory analyses to detect potential associations with the aforementioned pathological condition with Leptospira spp., porcine circovirus type 2 (PCV2), porcine parvovirus (PPV), porcine reproductive and respiratory syndrome virus (PRRSV), and bacteria, were carried out. Microscopically, interstitial nephritis with a lymphofollicular inflammatory pattern (follicular nephritis) was observed in both case and control kidneys, with a higher frequency seen in the former ones. No leptospires were identified, although antibodies to the Pomona and Bratislava serovars were detected. Some pyogenic bacteria were also isolated from both case and control kidneys. PCV2 nucleic acid was only detected in 1 case kidney. PRRSV antigen was not found in any tested sample. Some pigs were tested positive for PPV by serology. Apparently, none of the studied agents were specifically associated as being the potential cause of the renal lesions in the studied wasted pigs. The fact that these chronic lesions may have been the consequence of a previous infection with one of these studied microorganisms, or more, and eventually with other non-tested infectious agents during the growing-finishing period, cannot be ruled out.     

Pathological studies on systemic mycoses in calves.

Systemic mycoses were found in 19 (4.7%) of 406 calves less than 6 months old which were autopsied during the past 10 years. Alimentary mycosis occurred in 12 (63.2%) of 19 cases. In alimentary mycosis, mucormycosis showed the highest rate of occurrence (91.7%, 11/12 calves) followed by aspergillosis 41.7% and candidiasis was 9.3%. Mucormycosis and aspergillosis were characterized by focal hemorrhagic necroses with hyphal proliferation and thrombi in the mucosa and muscular layers of the forestomach, abomasum, and small intestine. Candidiasis was characterized by hyperkeratosis with pseudohyphae and microconidia in the mucosa of the omasum. Four of 12 calves (33.3%) had mixed infections of the alimentary tract consisting of Mucorales and Aspergillus species. Pulmonary aspergillosis was found in 10 (52.6%) of 19 calves. There were micro-abscesses with hyphal proliferation or asteroid bodies in the lungs. Infections involving both the alimentary tract and respiratory organs were noted in 3 (10.5%) of 19 calves. Disseminated mycosis was found only in one calf. In alimentary mycosis, administration of antibiotics for the treatment of diarrhea and early weaning were thought to be an important predisposing factor.     

甘肃棘豆对SD大鼠组织损伤的病理学

为探讨不同剂量甘肃棘豆对大鼠不同组织的病理学损伤,试验将1 6只SD大鼠随机分为44组,每组4只,分别标记为对照组、试验Ⅰ～Ⅲ组,分笼饲养,自由采食和饮水.对照组饲喂全价饲料,试验J～Ⅱ组分别饲喂含15％,30％,45％甘肃棘豆的混合日粮,期间记录各组大鼠体质量及临床症状,染毒结束后采集脑、肝脏、肾脏、脾脏,制作石蜡切片观察其病理组织学变化.结果显示,甘肃棘豆能引起SD大鼠脑组织部分神经细胞肿胀、树突变短或消失、胞浆空泡化、且HE染色变淡;小脑浦肯野细胞、脑干网状结构、肾脏、肝脏、脾脏等多种组织出现以空泡变性为特征的病理变化.结果表明,甘肃棘豆对SD大鼠生长发育具有明显抑制作用,且能引起机体各组织器官广泛性病理损伤.     

Isometamidium in pigs: disposition kinetics, tissue residues and adverse reactions

The disposition and adverse effects of the anti-trypanosomal drug isometamidium in pigs were evaluated. Following intramuscular administration of the drug at doses of 0.5, 15 and 35 mg kg-1, the drug was rapidly absorbed within 15 to 30 minutes to reach maximum plasma concentrations of 12 to 477 (n = 6), 302 to 655 (n = 4) and 1620 (n = 1) ng ml-1, respectively. No drug was detectable in plasma (less than 5 ng ml-1) 24 hours after drug administration at the three doses used. The half-lives of disappearance of the drug from plasma during the terminal phase were 7.12 h for the pigs given a dose of 15 mg kg-1, and 7.20 h for the pig which received a dose of 35 mg kg-1. At all the intramuscular injection sites, high drug concentrations were found six weeks after administration. The most dramatic adverse reactions observed were: one death after intramuscular administration at a dose of 35 mg kg-1 to two animals, and two deaths after intravenous administration at a dose of 2 mg kg-1 to two animals. For all these cases, the immediate cause of death was acute cardiovascular collapse. Biochemical analyses and gross and histological examinations showed that the animals that tolerated the high doses of 15 and 35 mg kg-1 given intramuscularly had extensive and severe tissue damage at the injection sites. Significant increases in plasma gamma-glutamyltransferase and alanine aminotransferase following drug administration suggested a degree of hepatobiliary damage.