The testis of a greater Indian rhinoceros (Rhinoceros unicornis) was examined by naked eyes and light microscopy. The animal sampled was estimated to be 42 years old. Testis was ellipse-shaped and weighed 1, 300 g. Although a number of elongated spermatids were distinguishable in some seminiferous tubules, the lumen of seminiferous tubules was closed and connective tissues conspicuously increased in amount in the intertubular space. These findings in testicular morphology of the animal may be due to ageing.

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A nested polymerase chain reaction (PCR) was developed to detect porcine reproductive and respiratory syndrome (PRRS) virus. A common primer set for European and North American type isolates of PRRS virus was designed for reverse transctiption PCR, and a specific primer set for each of the 2 type isolates was designed for nested PCR. The PCR that used a specific primer set detected the corresponding type of the virus at a level equivalent to 1 TCID₅₀/100μl, but not the other type of isolates. Therefore, the method clearly differentiated the 2 types of virus from each other. The detection of PRRS virus by the nested PCR was as sensitive as virus isolation in cultures of porcine alveolar macrophages from infected pigs at the acute stages, and was more sensitive from pigs at the convalescent stages. The infecting virus type was determined by use of 2 specific primer sets even when virus isolation was negative in naturally infected pigs. It was concluded that the nested PCR is useful for diagnosis and typing of PRRS virus and studies of persistent infection by the virus.

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The capsular polysaccharide (CPS) of Streptococcus (S.) suis type 2 was isolated from a type strain of S. suis NCTC 10234 by three different preparative methods: (A) lysozyme treatment method, (B) autoclave extraction method, and (C) HCl-extraction method. The structural characteristics of the three CPS (CPS-A, B and C) were examined by gel permeation chromatography, reactivity against rabbit antiserum and proton-nuclear magnetic resonance (¹H-NMR). N-Acetylneuraminic acid (NeuAc) residues as sialic acid in CPS-C were partially dissociated or degraded during preparation with a remarkable decrease in the molecular mass and the antigen activity. Although both methods A and B produced intact CPS without releasing NeuAc residues, method B was considered to be a more suitable procedure for preparing the CPS antigen because of time-saving and safety factors. Sugar analysis by high performance liquid chromatography and gas liquid chromatography showed that CPS-B consisted of five kinds of sugars: Rhamnose (Rha), Glucose (Glc), Galactose (Gal), N-acetylglucosamine (GlcNAc) and NeuAc, in a molar ratio of 1.00:0.95:3.68:0.80:1.31. After complete removal of NeuAc residues by mild acid hydrolysis of CPS-B, the reactivity with anti-type 2 serum was not detected. The NeuAc residue in CPS of S. suis type 2 strain was thought to be the antigen epitope portion.

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In order to clarify the spontaneous occurrence of arrhythmias in chickens, electrocardiograms using standard bipolar limb leads were recorded for 461 chickens of 7 breeds, including 3 pure breeds: Rhode Island Red (RIR, n=125), Japanese Game (JG, n=101), and White Leghom (WL, n=52); and 4 crossbreeds of RIR: the first filial generation (F1) obtained by mating RIR with JG (RIR×JG, n=44), the backcross obtained by mating the F1 of RlR×JG with the parental JG ((RIR×JG)×JG, n=10), the F1 obtained by mating RIR with WL (RIR×WL, n=73), and the F1 obtained by mating RIR with the commercial hybrid chicken, Dekalb Amber Link (DAL)(RIR×DAL, n=56). Nine types of arrhythmias were observed in 107 chickens (23.2%, 107/461): 66 had sinus arrhythmia, 19 had atrial premature contraction, 9 had ventricular preexcitation syndrome, 7 had ventricular premature contraction, 2 had second-degree atrioventricular block, 1 had atrial fibrillation, 1 had aberrant ventricular conduction, 1 had intraventricular conduction disturbance, and 1 had ventricular electrical alternans. Except for sinus arrhythmia, the incidence of other arrhythmias in RIR was significantly high, compared with that in pure breeds other than RIR (p<0.001) and that in crossbreeds of RIR (p<0.01). Arrhythmias other than ventricular premature contraction and sinus arrhythmia will be the first to be described as spontaneously occurring arrhythmias in chicken. Although the reason for both the highest incidence of sinus arrhythmia in WL and the predominance of other arrhythmias in RIR were obscure, the present results suggest the possibility of using chickens, especially RIR which shows a high incidence of arrhythmias, as a relevant animal for studying arrhythmias.

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The effect of cotton type chitosan implantation under the skin on the immunological response mediated by macrophages and whole blood was evaluated by chemiluminescence (CL) in dogs. The number of white blood cells was significantly decreased until 120 hr after operation in the control group (p<0.05), while chitosan implantation increased the number of white blood cells, particularly neutrophils, from 24 to 96 hr after implantation (p<0.05). The CL response of whole blood in the control group seemed to be reduced at 48 and 96 hr after operation (p<0.05), but in the chitosan groups it maintained higher activity until 120 hr after implantation (p<0.05). The macrophage activity measured by CL assay in the control group was markedly decreased from 24 to 120 hr after operation, and that for the 5 mg/kg chitosan group was also decreased at 24 and 48 hr after implantation (p<0.05), although high activity was observed from 72 to 120 hr after implantation (p<0.05). Neither 5 mg/kg nor 10 mg/kg chitosan groups showed any reduction in CL response of macrophages after operation, and the 20 mg/kg chitosan group retained high CL response of macrophages until 120 hr after operation (p<0.05). These findings suggest that chitosan may be an efficacious and useful immunopotentiator for preventation of immunosuppression after surgery.

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Homologues of herpes simplex virus ICP4 are important genes for the activation of many herpesviruses. We detected transcripts of the Marek's disease virus serotype1 homologue of ICP4 (MDV1 ICP4) by in situ hybridization (ISH). Using a digoxigenin-labeled-RNA (DIG-RNA) probe, MDV1 ICP4 transcripts were detected in c.a. 90% of MDV1-infected chicken embryo fibroblasts (CEF) cells when cytopathic effect was reached to 90% of the CEF cells and in 0.35% of MDCC-MSB-1 (MSB-1) cells, at a frequency similar to that for MD antigen-positive MSB-1 cells. Using the same in situ procedure, we detected abundant MDV 1 ICP4 transcripts in the feather follicle epithelium (FFE) and some lymphoid cells in the liver, kidney and peripheral nerve of infected chickens. The subcellular localization of the transcripts appeared to vary: MSB-1 cells had them in the nucleus, infected CEF cells and FFE had them in the nucleus and cytoplasm, and lymphoid cells contained them in the cytoplasm. The MDV1 ICP4 transcripts were also detected in the FFE and lymphoid cells in the liver by reverse-transcriptase polymerase chain reaction (RT-PCR). Detection of MDV1 ICP4 transcripts by RT-PCR indicated the existance of MDV1 ICP4 transcripts-positive cells in these tissues. And these data suggested that DIG-RNA-ISH can detect MDV transcripts on paraffin sections and provide information about their subcellular localization.

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The pectinate ligaments of ten horses, two donkeys, five oxen, five sheep, ten goats, five dogs, five cats, thirty pigs and two rabbits were studied under the stereomicroscope and the scanning electron microscope. In the horse and the donkey, the pectinate ligament was very prominent and was characterized by sturdy interconnected strands and relatively small intertrabecular spaces. The pectinate ligaments of ruminants were composed of shorter strands, separated by relatively larger spaces. Fusion between adjacent strands, resulting in the formation of fenestrated sheets, was regularly observed in these species, in particular in the superior and inferior ocular segments. In the dog and the cat, the pectinate ligament consisted of slender strands that were separated by large intertrabecular spaces. The strands of the pectinate ligaments of the pig and the rabbit were shorter and their diameters were intermediate between those of the herbivores and the carnivores. The clinical relevance of the normal variability in the structure of the pectinate ligament and proposals for a uniform anatomical nomenclature are discussed.

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Dogs raised in the open air were used in this study. Metallothionein (MT) immunoreactivity was observed in the nucleus and/or cytoplasm of sustentacular cells of the olfactory epithelium in the nasal mucosa, whereas there was few MT-positive cells in the respiratory epithelium. MT immunoreactivity was also observed in astrocytes in all layers of the the olfactory bulb cortex; glial cells surrounding the glomeruli in the olfactory bulb showed prominent immunoreactivity for MT. Adult dogs exhibited stronger immunoreactivity for MT than young. Northem blot analysis demonstrated substantial levels of MT mRNA in the olfactory mucosa and olfactory bulb. Physiological roles of MT localized in the olfactory pathway of dogs were discussed.

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A cDNA (1555 bp) (DNA database accession number; D61396) having a homology with human vitronectin (Vn) was isolated from a porcine liver cDNA library, and its sequence was determined. The open reading frame in the cDNA was found to code a protein with 388 amino acids, then the amino acid sequence of the protein (porcine putative Vn) was aligned to the other mammalian (mouse, rabbit, and human) Vns previously reported. The alignment revealed that the functional amino acid sequences reported as the cell attachment site, the heparin binding site, the region involved in glycosylation, and plasminogen activator inhibitor I-binding domain were conserved in the porcine putative Vn. These findings together with the fact that the calculated molecular weight and the N-terminal amino acid sequence of the putative Vn agreed with those reported by biochemical analysis on porcine Vn, led us to conclude that the cDNA isolated in the present study coded for the porcine Vn. Then, a time course study was performed to examine whether the administration of growth hormone (GH) affects Vn mRNA expression in liver and skeletal muscle, since the level of Vn mRNA was reported to be affected by inflammation, and since GH was reported to be involved in inflammation. This revealed that GH has no effect on the level of liver Vn mRNA, and that Vn mRNA level in skeletal muscle seemed to be affected following GH-injection.

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Pregnant Wistar rats were divided into 3 groups, non-operated control, adrenalectomized, and adrenalectomized and corticosterone-treated. Maternal adrenalectomy was performed on day 6 of gestation. Corticosterone therapy was made from the day at operation to the day at observation. The growth pattern of insulin-producing B-cells was observed immunohistochemically and histometrically from days 12 to 16. The results obtained were as follows: From day 12 to day 15, maternal adrenalectomy resulted in a significant retardation of the growth of insulin-positive B-cells in terms of the collective volume of the cells. Maternal corticosterone therapy prevented this retardation. On day 16, however, the growth of B-cells in collective volume overcame the suppressive effect of maternal adrenalectomy. These results suggest that the lack of adrenocortical hormones causes a retardation of B-cell growth in early development, and that, when once developed well, B-cells can grow independently of the hormones.

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Immature B lymphocytes in the chicken bursa of Fabricius have previously been reported to undergo apoptosis by low doses of ionizing radiation. In the present study, newly hatched chickens were subjected to whole-body X-irradiation, and the bursa of Fabricius was examined at various postirradiation times by light and electron microscopy to obtain information on the change of ultrastructure of irradiated bursal cells as well as on the time course and dose-response for the induction of apoptosis. Histological examination by light microscopy showed that pyknotic cells started to increase in the bursa within a few hours after irradiation and the frequency of occurrence reached a maximum at 6 hr. An evident increase of the pyknotic cells in number was observed at a dose of as little as 1 Gy, and the frequency increased with increases in the dose, rcaching over 90% at 15 Gy. Electron microscopy of the irradiated bursa revealed typical apoptotic morphology such as chromatin condensation, nuclear fragmentation, formation of apoptotic bodies and phagocytosis of pyknotic cells. Induction of apoptosis was also confirmed by the appearance of a typical DNA ladder pattern on agarose gel. Thus, the present results demonstrate that the chicken bursal cells are hypersensitive to X-irradiation with regard to induction of apoptosis, and that the apoptotic bursal cells exhibit most of the ultrastructural features known to be typical of apoptosis.

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Two strains (Strains 39 & B) of Haemophilus paragallinarum were isolated and identified as serotype C by dot-blotting analysis in Taiwan in 1994. To identify their virulence and pathogenicity in Taiwanese local chickens, local chickens were inoculated via nostril with the isolates, and examined for 14 days. Clinical signs of swollen face, and nasal discharge were first seen at 24 hr after inoculation, and the infectivity of Strains 39 and B at 14 days after inoculation among the inoculated chickens was 50.0-71.4% and 55.6-77.8%, respectively. From the results, we concluded that the two bacterial isolates were pathogenic to local chickens with a maximum morbidity of 77.8%.

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Isolation of very virulent Marek's disease virus (vvMDV) was carried out by inoculating blood and spleen samples of Marek's disease (MD) chickens onto chicken embryo fibroblast cell cultures and into the peritoneal cavity of one-day-old chicks. Seven isolates of MDV were isolated in this experiment. By the results of cytopathic effect and fluorescent antibody tests, the 7 isolates were divided into 3 serotypes: serotype 1 of strains LTB-1, -2, -3, LTS-1, and -2; serotype 2 of strain LTB-4; and serotype 3 of strain LTB-5. Strain LTB-1 was used to inoculate experimental chickens of both layers and broilers. Early phase mortality and markedly atrophied lymphoid organs were observed during 0-2nd week post-inoculation (PI) and at 5th week PI, respectively, but were not found in uninoculated chickens. In addition, experimental chickens vaccinated with (HVT) vaccine at 1 day old and challenged with strain LTB-1 at 10th day post-vaccination, revealed early phase death before 2nd week post-challenged (PC), and lymphomatous lesions before 10th week PC. From these results of this in vivo experiment, strain LTB-1 showed the same pathogenicity as that of vvMDV, and this is the first report of vvMDV being isolated and identified in Taiwan.

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To investigate a possible phenotypic modulation, MT-8L and MT-9L cells were induced by in vitro culture of undifferentiated MT-8 and fibrohistiocytic MT-9 cells, which had been established from a rat malignant fibrous histiocytoma (MFH), in the medium containing 10 μg lipopolysaccharide (LPS)/ml. MT-8L and MT-9L gave greater positive reactions for histiocytic lysosomal markers and showed ultrastructures of histiocytic natures. In MT-8L, α-smooth muscle actin-positive myofibroblastic cells also significantly increased in number. MT-8L expressed both histiocytic and myofibroblastic phenotypes. MT-8L-induced tumors consisted mainly of storiform type MFH, differing from undifferentiated sarcoma type induced by MT-8. MT-9L and MT-9 tumors showed a storiform pattern. A phenotypic modulation of MFH cells was easily induced by LPS treatment.

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Two groups of White Leghorns were inoculated with Salmonella Typhimurium in the breast muscle. One group was injected with amikacin every 9 hr (8 times) from 24 to 96 hr after the bacterial inoculation and the other group was given no amikacin. In both groups, a significant increase in the levels of aspartate aminotransferase and creatine kinase, and a significant decrease in the levels of alkaline phosphatase, total cholesterol and glucose were found 96 hr after inoculation. There were, however, no significant differences in the blood chemical values between the amikacin-treated group and non-treated group. The results from the present study may provide basic data for further investigation of blood chemical values during Salmonella infection and amikacin therapy in fowls.

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The telomere in the cat chromosome was detected by the fluorescence in situ hybridization method using all human telomere, as a probe. In the metaphase chromosomes of cultured peripheral lymphocytes, telomere spots were observed in the terminal portions of the chromosomes. Although telomeres were confirmed in all chromosomes, the fluorescence intensity varied between the two homologues in some chromosomes.

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The HEp-2 vacuolation factor (or cereulide) produced by Bacillus cereus isolated from vomiting-type food poisoning, which is supposed to induce emesis, was found to give mouse and suncus lethality after intravenous and intraperitoneal administration. The emetic activity of the factor was also found to be resistant to heating at 121°C for 15 min, exposure to pH 2 and 11, and to digestion with proteolytic enzymes such as pepsin and trypsin. These findings suggest that the cereulide produced by B. cereus is stable in the digestive tracts, induce emesis, and show lethal activity leading to cellular damage.

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Forty-eight digits of 8 dairy cows, which had been diagnosed as sole ulcers in one or two hooves, were examined histopathologically and classified into 5 grades on the basis of the severity of the circulatory disturbances and of keratogenesis. All the cows had significantly higher grades than normal cows. Although hind lateral digits were most severely damaged, there were no significant differences in the grades among claw positions except hind lateral digits. From these results, it is suggested that the cows affected with sole ulcers had some systemic factors predisposing all the digits to digital dosorders.

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A one-year-old male mongrel dog was referred to the Veterinary Clinic with a several-week history of lameness and pain of the right front leg. Radiological examination of the right humerus revealed a cystic lesion at the distal end of the bone; the lesion was nodular in a gross appearance. Histologically, the nodular lesion consisted of large areas of haemorrhage and thick fibrous trabeculae mixed with a variably dilated cavernous structure of blood vessels attributed to haemangiosarcoma. Based on these findings, aneurysmal bone cyst secondary to the tumour was diagnosed.

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The pharmacokinetics of norfloxacin-glycine acetate (NFXGA), a newly formulated norfloxacin, was investigated in healthy flounders at two different seawater temperature (at 12°C and 20°C) varying concentrations (100 ppm and 10 ppm), using dipping administration. It was shown that the elimination half-life (T_1/2) of norfloxacin at 20°C (10 ppm: 13.95±1.18 hr, 100 ppm: 11.71±1.32hr) was significantly shorter than that at 12°C (10 ppm: 16.61±1.47 hr, 100 ppm: 16.32±1.19 hr) in flounders. Mean residence time (MRT) was calculated at 12°C (10 ppm: 194.87±29.88 hr, 100 ppm: 1, 222.37±161.45 hr) and 20°C (10 ppm: 168.42±25.85, 100 ppm: 606.14±122.75 hr). Meanwhile, in the flounder tissue distribution of norfloxacin. It was shown that serum, muscle, kidney, and liver exhibited different elimination half-lives of norfloxacin.

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A CPE-producing agent was recovered in feline cell cultures from feces of a male dog suffering from intermittent watery diarrhea. Antigenic analysis of this isolate, Sapporo/283, was performed using the plaque reduction neutralization and complement fixation assays and it was neutralized by antisera against feline calicivirus (FCV) but not against canine calicivirus (CaCV). Likewise, it showed common CF antigenicity with the other FCV strains included in the experiments. These findings revealed that the isolate was more closely related antigenically to FCV than CaCV, indicating the possibility of interspecies transmission. It was also suggested that the isolate was a respiratory type calicivirus. Epizootiological results suggested, however, that FCV seldom infects dogs under natural condition.

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We examined bovine, porcine, canine, feline, avian and mink veterinary live vaccines for the presence of mycoplasma DNA by the polymerase chain reaction including nested-pair primers. Mycoplasma DNA was detected in 22 of the 61 commercial veterinary vaccines (36.1%), although these vaccines did not contain any viable mycoplasma cells.

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The antagonistic effects of atipamezole (20, 40, 60, 80, and 100μg/kg IV) on medetomidine (10 μg/kg IV)-induced sedation were evaluated in horses. Although 20 and 40μg/kg of atipamezole were not sufficient to reverse the sedation, 60μg/kg did effectively reverse the sedation. Atipamezole at 80μg/kg was more potent, and significantly shortened the duration of sedation without any apparent side effects, but a higher dose of 100μg/kg was not more effective than 80μg/kg. The possible use of atipamezole as a reversal agent may enhance the value and availability of medetomidine as a chemical restraint agent in horses.

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