Although no clinical signs of atrophic rhinitis (AR) were recognized in 2- and 5-week-old pigs, approximately 60% of 2- to 6-month-old pigs showed clinical signs of AR in an affected pig farm. None of the pigs had normal turbinate at slaughter. Bordetella bronchiseptica was not isolated from any of the pigs before onset and incipient stage of the outbreak (2-week to 2-month-old). Pasteurella multocida of capsular type D was not isolated from any of those pigs. However, toxigenic P.multocida of capsular type A was isolated from a number of the pigs immediately before onset and incipient stage of the outbreak. Thirty-six-day-old primary specific-pathogen-free pigs were inoculated intranasally with a toxigenic type A P.multocida isolated from a 5-week-old pig. Severe nasal turbinate atrophy was observed in those pigs which were necropsied at 3 weeks post-inoculation. This is the first report on outbreak of severe nasal turbinate atrophy induced by toxigenic type A P.multocida in Japan.

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An immunohistochemical and histopathological study using the ABC technique was carried out to examine time-sequential virus spread in the central nervous system (CNS) of mice after inoculation with the CVS strain of fixed rabies virus by different routes; intracerebral (ic), intraocular (io), intranasal (in), intramuscular (im) and subcutaneous (sc). Only the ic and io inodulations caused fatal infections, so that detailed analysis was conducted on mice inoculated by these two routes. In ic-inoculated mice, viral antigens were detected mainly in neurons in the cerebral cortex and in the pyramidal cells and granular cells of the hippocampus. After io inoculation, viral antigen was first detected in the trigeminal nerve ganglia, following which it spreads to the cerebral cortex and cerebellum. In the hippocampus only a few cells were viral antigen-positive at the early stage after io inoculation. There were no inflammatory lesions or Negri bodies in the CNS of mice infected by either route. This suggests that clinical signs such as ataxia or depression leading to death may be due to the direct effect of the virud on the functions of neural cells, but not to inflammatory reactions. The ABC method will be useful for the early diagnosis of suspected patients or animals to have the disease when conventional histopathological and immunofluorescent antibody techniques can not detect lesions or viral antigens.

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Mitochondrial DNA (mtDNA) polymorphism was studied in 20 mongrel dogs using 14 restriction enzymes. The polymorphism was observed in the cleavage patterns of Apa I, EcoR I, EcoR V, Hinc II and Sty I. Three morphs using EcoR I and Apa I and two morphs using EcoR V, Hinc II and Sry I were found. However, no polymorphism was detected in the cleavage patterns of BamH I, Bgl II, Hae II, Hind III, Pst I, Sal I, Sca I, Stu I and Xba I. The examined dogs were classified in seven types using five restriction endonucleases which recognized six nucleotide sequences. The value of nucleotide diversity was estimated to be 0.0055. A phylogenetid tree constructed by genetic distances among seven restriction types showed at least two clusters of mtDNA.

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In 47 dairy cows with abomasal displacement, 34 (72%) cows were confirmed to have the lipid infiltration in liver by biopsy examinations. The pathological degree of the lipid infiltration was significnatly higher in the cows with left abomasal displacement than in those with right one. The halftime for sulfobromophthalein clearance (BSP-T1/2) was markedly increased in nonrecovered cows with left abomasal displacement. In left abomasal displacement cases, cows with the T1/2 less than 11 min recovered regardless of the degree of liver lipid infiltration, but those with the T1/2 longer than 11 min showed a significantly lower recovery rate (44%). Thereford, it was concluded that the BSP-T1/2 was one of valuable parameters for predicting the prognosis of this disease.

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Numerical changes of insulin-, glucagon- and somatostatin-positive cells in the pancreas of WBN/Kob male rats with spontaneously occurring diabetes were examined. The rats examined were divided into three different age groups: Groups I (12 weeks old) and II (33 weeks old) were clinically prediabetic and group III (60-90 weeks old) was diabetic. Serum glucose value was in the normal range in groups I and II, while it was much higher in group III. B and A cells were markedly decreased in number in groups II and III. In group II, the ratio of B to A cells was normally preserved, though the total endocrine cell number was markedly decreased as compared with that in group I. In group III, the percentage of B cells was decreased significantly. The normal ratio in group II seemed to keep serum glucose within the normal level. In addition to the total endocrine cell reduction, an altered ratio of B and A cells was considered to cause the diabetic condition.

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Haptoglobin (Hp) was isolated from equine serum by ammonium sulphate precipitation, anion-exchange chromatography and gel filtration. Equine Hp which migrated to the α₂-globulin region in electrophoresis, contained 2 fractions with molecular weights (NW) of 108, 000 and 105, 000, and each fraction consisting of 2 subunits. Quantitative measurement of Hp in equine serum was performed by the single radial immunodiffusion method using anti-equine Hp serum. In clinically normal horses, the highest concentration of serum Hp was found in newborn foals and a high value was maintained until 12 months of age. The concentration then decreased with age. Normal Hp values were 5.25±2.36 mg/ml in foals (≤12 months old), 2.19±1.54 mg/ml in adult horses (≥18 months old) and 3.62±0.81 mg/ml in all horses. Serum Hp concentration in mares during the perinatal period in comparison with the normal adult female was high for 4 months pre-partum, a passing increase at delivery, and then decreased at 2 weeks post-partum returning to normal within 1 month of delivery. In horses with experimentally-induced inflammation, serum Hp concentration began to increase immediately after treatment and reached the highest value, 1.5 to 9 times higher than those of pre-treatment at 2 to 5 days, then decreased within 4 weeks. It was also elevated in most cases of horses with clinically inflammatory signs.

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Vacuole response in HEp-2 cells was induced with culture supernatants of Bacillus cereus strains isolated from outbreaks of vomiting- and diarrheal-type food poisoning grown in rice flour and laboratory media. High vacuole response was obtained with culture supernatants of B.cereus strains isolated from vomiting-type food poisoning grown in cooked rice suspension or on a cooked rice plate, whereas no response was obtained with those of the same strains grown in brain heart infusion and trypto-soya broth media. The vacuole activity appeared only after spore formation of B.cereus. The activity was stable to proteolytic enzymes, heating, and exposing to pH 2.0 and 11.0. Of 124 strains isolated from B.cereus food poisoning that were tested, the vacuole activity was observed by 68 of 110 (61.8%) of the strains isolated from the vomiting-type food poisoning but not by all strains (14 strains) from diarrheal-type ones. Moreover, the vacuole response in the HEp-2 cells was found to be induced by 56 of 76 (73.7%) of the serotype H-1 strains isolated from vomiting-type food poisoning.

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The antigens gII, gIII and gVI were purified from the lysates of the pseudorabies virus (PRV) -infected HmLu-1 cells using Sepharose 4 B coupled with MAbs against these antigens. Mice immunized with either gII, gIII, gVI antigen or a mixture of them were challenged intraperitoneally with 8.5×10³ plaque forming units of PRV. All the mice immunized with 1.5 and 4.5 μg of the mixture and 4.5 μg of the gIII antigen survived. The sera of mice immunized with the mixture had virus neutralizing activity which was independent of complement, hemagglutination inhibition activity, and recognized major (93 kilodaltons) and minor (129, 74, 68 and 50 kilodaltons) PRV proteins under reducing conditions in western blotting. The serological activity levels in the lower survival group were not different from those in the complete survival. These results indicate that the mixture of each glycoprotein is more effective for eliciting of protective immunities in mice and that serological activity do not always correlate with protection.

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A total of 20 cases of disproportionate calves on Japanese Brown cattle were examined morphologically. Investigation of 5 affected calves revealed that the insufficiency of endochondral ossification was confined only to the long bones of the limbs and was not accompanied by other associated changes. On the basis of the histological changes of epiphyseal plate and the affected site, this condition may be called chondrodysplasia of the rhizomelic type. Therefore, this disorder was defined as a bovine dwarfism. From three dimensional image analysis and histological changes of the tibial proximal portion in the other 15 cases, deformity and shortness of the tibia were related to the state of distribution and the degree of damages of the epiphyseal plate. In the affected cartilage matrix, cystoid degeneration, fibrous striation, bone spicule, necrotic foci and rent were found. Inadequate metachromasia suggests the abnormal staining of sulfated glycosaminoglycans and alcian blue stainability may be attributable to the abnormal interactions between proteoglycan and other matrix components. At the interface of cartilage and bone, irregular calcifidation, fibrotic scar and sealing by osseous tissue with relation to vascularity were found. These changes in this study indicated the failure of modeling on the epiphyseal plate, showing disturbance of chondrocytic differentiation and abnormal formation of the matrix.

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In the Kanto area a total of 245 wild rats were captured. All rats captured in Ikebukuro (110 rats) and 9 out of 41 rats in Yokohama were Rattus rattus, and all other 126 rats were Rattus norvegicus. In Kashima and Ikebukuro, listeria was isolated from 28 rats (77.8%) and 27 rats (24.5%), respectively, but in the other 4 areas listeria was isolated from 0-7% rats. Listeria monocytogenes was isolated from 12 fats (10.9%) captured in Ikebukuro and 2 rats in Kashima and Numazu. The frequent isolation of L.monocytogenes in buildings suggests the possibility of R.rattus as a reservoir of L.monocytogenes and the continual environmental contamination in buildings by L.monocytogenes.

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An oligonucleotide complementary to a leader RNA of positive-stranded mouse hepatitis virus (MHV) was tested for the effect on the viral multiplication in mouse DBT cells. A 14-mer antisense oligonucleotide contained a sequence complementary to the conserved pentanucleotide sequence, UCUAA, of the leader RNA. A treatment of MHV-infected cells with the antisense oligonucleotide at concentrations from 5 to 25 μM had an inhibitory effect on the viral multiplication and reduted the synthesis of viral specific mRNA and proteins. No inhibitory effect was observed when the cells were treated with sense oligonucleotide and oligonucleotide which contained unrelated sequences at concentrations from 1 to 10 μM. These results showed that antisense oligonucleotide against the leader RNA reduced the multiplication of positive-stranded RNA virus, MHV.

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Activation of bovine peripheral blood monocytes and its suppressive effect on parasite growth was examined in Theileria sergenti-infected calves by using a rosette assay that detects changes in Fc receptor expression and by luminol-dependent chemiluminescence response. Monocyte activation preceded the peak of parasitemia but was depressed parallelly with the growth of the parasites. When four calves were treated with prednisolone, three showed a good correlation between the suppression of monocyte activity and an increase of parasitemia.

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The cardiac musculature of cranial and caudal venae cavae and pulmonary vein was examined to clarify its distribution pattern in the fowl using both light and electron microscopies. The musculature was distributed from the heart to the root of subclavian vein in the cranial vena cava, to the cranial margin of the liver in the caudal vena cava, and to the left and right distal pulmonary veins in the pulmonary vein, respectively. Judging from the morphology and distribution pattern in the venous wall, the cardiac musculature in the fowl is thought to share the same phylogenic origin with that in mammals. The ultrastructure of cardiac myocytes including transitional cells in the cranial vena cava and the pulmonary vein resembled that of atrial myocytes. While, the typical specialized myocytes such as Purkinje fiber were found in the caudal vena cava of the fowl.

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Nine cases affected with disseminated mucormycosis (1.3% of all autopsy cases and 20.0% of systemic mycosis) were found among bovine systemic mycosis examined from 1975 to 1985. The disseminated lesions were found in the lungs (3 cattle), heart (2 cattle), liver (2 cattle), spleen (1 beef cattle), kidneys (1 cattle), central nervous system (1 cattle) and lymph node (1 cattle). Histological examination revealed granulomatous lesions, necrotic foci including infarcts, and thromboangiitis with the hyphae of a member of the Zygomycetes and neutrophil reaction. Granulomatous lesions with asteroid bodies were found in the liver. Metastatic foci were established from the primary lesions found in the alimentary organ (4 from the forestomach or abomasum and 1 from the tongue). One case resulted from uterine mucormycosis, and no primary lesion was found in the other 3 cattle. Complicated infection with respiratory aspergillosis occurred in 4 cases with alimentary mucormycosis. All of the 9 cattle had predisposing disorders. Six cattle had been manifested with prolonged debilitating conditions. Anemia was present in 4, luekopenia in 2 and lymphopenia in 1 cattle.

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Chicken pathogenic Escherichia coli strains were found to autoagglutinate in a static culture of trypticase soy broth (TSB). One strain, designated PDI-386, was further studied for its autoagglutinating property. Acidity in the cultured medium caused by glucose degradation induced the autoagglutination. The bacterial cells grown in a glucose-free L-broth could be aggregated by adding acid, which suggests a potentiality of autoagglutination of the strain grown in the L-broth. The autoagglutinating parent (Agg) formed small colonies with irregular edges like rough colonies on the TS agar, whereas its non-autoagglutinating variant (Nag) formed larger smooth colonies with a perfectly round edge. The Nag colony was easily generated from the Agg colony on the TS agar. The autoagglutinating property was very unstable when the bacteria was passed in the TSB, but rather stable in the L-broth. Under electron microscope, the Agg were found to possess pili of more than 20 μm in length. However, the phenotypic expression of autoagglutination did not correlate with that of mannose-sensitive hemagglutination against guinea pig erythrocytes. Incubation of the Nag in the L-broth at room temperature for more than 10 days provoked the reversion of the autoagglutination. There was no difference between the Agg and the Nag in terms of surface hydrophobicity, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns of membrane proteins and LPS, and plasmid profiles. The virulence of the Agg was higher than that of the Nag. The autoagglutinating property is, however, so unstable that the pathogenicity of E. coli isolates from chickens should be carefully evaluated.

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Immunoperoxidase antibody (IPA) method as a titrating method of feline infectious peritonitis (FIP) virus (FIPV) was developed for titrating antibody to FIPV (IPA-titer). By this method, the immune responses of the cats that had been infected with FIPV, were traced. The infected cats could be grouped into three types by their immune responses to FIPV and clinical appearances. Type I cats lived for a long time, formed a major group among infected cats, had 160 to 1×10⁴ IPA-titers, and showed healthy appearances without any changes both on autopsy and histopathologically. From among type I cats, type II cats appeared sporadically with rapid elevation of IPA titers to 3.2×10⁵ and showing clinical signs of FIP, and died. Type III cats lived healthily for a long time with gradual elevation of IPA-titers to a plateau of about 1×10⁵, then showed neuronal disorder of hind leg paralysis with the descending IPA-titers to 2×10⁴, and died. Thus, typical FIP appeared as a hyper-immune disease. Other related problems are discussed.

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An immunohistochemical analysis of Rhodococcus equi-induced pneumonia in 10 foals was performed by biotin-streptavidin system. The detection of R.equi was more sensitive in immuno-stain using anti-R.equi serum than in Gram's stain. This bacteria also reacted to anti-BCG serum. Lysozyme and α₁-antitrypsin were detectable in macrophages. A particularly intense staining was observed in association with intracellular bacteria. Though a degree of reaction for α₁-antichymotrypsin was very low in comparison with lysozyme and α₁-antitrypsin, it was also demonstrated in macrophages ingesting R.equi. These bacteria were almost intact under an electron microscope. Therefore, the surface components of R. equi may play important roles of protection from intracellular enzymes of macrophages. The cells containing intracytoplasmic IgM, IgG or IgA were a few in number and scattered predominantly around the pneumonic lesion. It is considered that the bactericidal activity by immunoglobulins may be weak in comparison with phagocytosis by macrophages.

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Expression of CD4, CD8, IL-2 receptor α chain (IL-2Rα), and MHC class II (MHC-II) on peripheral blood mononuclear cells were examined in cats infected with feline immunodeficiency virus (FIV). CD4/CD8 T cell ratio in FIV-infected cats was slightly decreased, as compared with that in specific-pathogen-free (SPF) cats. However, there was no statistical differences between them. The number of circulating IL-2Rα⁺ cells in FIV-infected cats was higher than that in healthy cats, whereas induction of IL-2Rα expression by concanavalin A (Con A) stimulation was depressed in FIV-infected cats. By using two-color cytofluorometry, Con A-induced enhancement of IL-2Rα expression was found to be reduced in both CD4⁺ and CD8⁺ populations in PBMC from FIV-infected cats. The circulating MHC-II⁺ cells were also increased in FIV-infected cats. Furthermore, the induction of IL-2Rα expression on PBMC after Con A-stimulation significantly depressed by FIV inoculation in vitro. These results suggest that FIV activates PBMC in vivo via direct and/or indirect mechanisms, leading to the unresponsive state of T cells to further stimuli in vitro.

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Twenty four cloned isolates of Aujeszky's disease virus collected from outbreaks of Aujeszky's disease from 1981 through 1989 in Japan were characterized by their restriction endonuclease (RE) cleavage patterns, virulence for mice and thymidine kinase (TK) activity. All of the isolates belonged to Type II of the four types classified by Herrmann et al. (1984). Based on the number and migration rate of the restriction fragments, the isolates were divided into 7 groups with Bam HI, 9 groups with Kpn I, 3 groups with BstE II and 2 groups with Sal I. The results indicate that the RE analysis, especially with Bam HI and Kpn I, provides useful epidemiological information about field isolates of Aujeszky's disease virus. All of the isolates showed virulence for mice ranging from 6.9 to 63.0 (PFU/LD₅₀). It was interesting that the Nagano S87 strain, which had the highest virulence for the mouse, showed unique RE cleavage patterns with four enzymes. On the other hand, ara-T-resistant, TK-negative strain, was avirulent for mice (>10^6.4PFU/LD₅₀). AlI of the isolates investigated in this study showed TK activity by the thymidine plaque autoradiography.

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Intravenous administration of the lethal dose of diazinon or fenthion, P=S type organophosphates, to urethan anesthetized rats induced bradycardia and transient apnea followed by a decline of blood pressure, and death. We investigated the mechanisms of the lethal action of these organophosphates in rats through measurements of blood pressure, heart rate, and respiratory pattern. We compared their cardiorespiratory effects in the five different conditions under anesthesia; 1)normal (without treatment), 2)artificially ventilated, 3)vagotomized, 4)atropinized, 5)pithed, vagotomized and atropinized. It was found that the administration of 200 mg/kg of fenthion and 100 mg/kg of diazinon, caused sudden bradycardia, transient apnea and gradual decline of blood pressure in the anesthetized normal rat, and the rat died. The rats in other conditions also died except the artificially ventilated rats, in which 400 mg/kg of fenthion was administered to cause hypotension and subsequent death. Hypotension was observed consistently even after the cardiac effect such as bradycardia was eliminated by atropine treatment. In the pithed rats which were further vagotomized and atropinized, these organophosphates also caused hypotension. These results may indicate that hypotension is the main cause of death which resulted from intravenous administration of the P=S types. Hypotension may be caused by peripheral cardiovasculaf effect of the P=S types, which is unrelated to cholinergic mechanisms.

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The present paper described the immunohistochemical distributions of carbonic anhydrase (CA) isozymes. CA-I, CA-II and CA-III, in the epithelium lining the rat gastrointestinal tract, with rabbit antibodies to equine CA-I, CA-II and CA-III. Prior to the immunohistochemical examinations, the crossreactivities of these antibodies to the rat-antigens were confirmed in this study. In the stomach, surface epithelial cells and parietal cells of the glandular region showed an immunoreactivity only to CA-II. In the large intestine, each immunoreactivity to CA isozyme (CA-I, CA-II and CA-1lI) was localized in the upper portion of intestinal glands, and decreased toward the distal digestive tract, but absent in the small intestine. The present histological findings suggested that the CA isozymes might play a role in the ion-transportation during the water absorption in the rat large intestine.

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A total of 148 Japanese isolates of pseudorabies virus (PrV) collected in 1987 to 1990 were examined for the cleavage patterns of their genomes by a restriction endonuclease (RE) assay using Bam HI and Kpn I. Basically, there was no large difference in the cleavage patterns of viruses recently isoalted in Japan. All of them were considered as belonging to Bam HI cleavage pattern type II as well as strain Yamagata-S81 that is the first isolate of PrV in Japan, suggesting that no remarkable variations occurred in PrVs spreading in Japan since the first outbreak in 1981. However, considerable variations that are probably due to the gain and/or loss of cleavage sites, and to the addition and/or deletion of nucleotide sequences were detected in the repeat, conjunction and left end regions of genome. Some of those variations were similar to one another among the viruses isolated in the same geographical areas or farms at the same times, and from the epidemiologically related outbreaks, indicating that the RE assay on PrV genome is one of useful tools for the epidemiological studies on Aujeszky's disease.

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Testis size, seminiferous tubules and plasma testosterone concentrations showed conspicuous annual changes in Sika deer of Hokkaido, Japan. The onset of the spermatogenic process occurred in July or August. Spermatogenic activity had already reached its height in late October, at the beginning of the rutting season, and had begun to decline in late December. Spermatogenesis had stopped in February or March. Plasma testosterone concentrations showed very high levels in late October and early November, but was almost at the basal level in February, March, June and December. The wide individual variation of the plasma levels in October suggest pulsatile secretions of testoster-one.

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The types of feline coronaviruses that are prevalent throughout Japan were determined by competitive enzyme-linked immunosorbent assay (ELISA) using a monoclonal antibody (MAb) to feline infectious peritonitis virus (FIPV) Type II and neutralizing test using Type II FIPV as challenge virus. A total of 1, 079 cat serum samples were tested by indirect fluorescent antibody (IFA) assay for FIPV Type II antigen, all 42 sample from natural cases of FIP, 138 of 647(21.3%) from cases with some chronic diseases and 57 of 390 (14.6%) from apparently non-diseased cases were positive. Of the 42 cases with FIP, 29 (69%) and 13 (31%) were found to have infection with FIPV Types I and II, respectively. Of the cases with chronic diseases, 111 (80.4%) were shown to have infection with FIPV or FECV Type I, while 14 (10.1%) with FIPV or FECV Type II. All of the 57 apparently non-diseased cases seemed to have been infected with FIPV or FECV Type I. These results indicated that feline coronavirus Type I is more high prevalent in Japan.

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