Cardiopathologic and electrocardiographic examinations were carried out on 4-, 8- and 35-week-old DBA/2 and BALB/c mice of both sexes. Both of the electrocardiographic changes (prolongation of QRS duration and PQ-interval, appearance of abnormal P wave and notch in QRS complex, deviation of "ST-segment", and shift of mean electrical heart axis to the left) and pathologic alterations (scatteringly observed small focal myocardial calcification and marked calcification restricted to the myocardium under the right ventricular epicardium) were significantly more frequent and clear in DBA/2 mice than in BALB/c mice, and they became more apparent at 8 weeks of age. Such cardiac disorders as observed in the present study were thought to be free from hypercalcemia because of unchanged serum total calcium concentration.

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A total of 207 strains of Yersinia enterocolitica serotype O3 isolated from human, pig, dog, cat, rat and pork meat during the period between 1972 and 1984 were examined for the 44-megadalton plamid DNA, calcium dependency and autoagglutination. Strains positive for the plasmid, calcium dependency and autoagglutination were counted and found to be 164(79.2%), 152(73.4%) and 149(72.0%) respectively. All the plasmodia harboring strains were either calcium dependent or positive for the autoagglutination. All the strains which lacked the plasmid were calcium independent and negative for the autoagglutination except four strains (1.9%) that were positive for the autoagglutination. Despite different sources of Y. enterocolitica, all the plasmid positive strains harbored a single plasmid of 44-megadalton. These plasmids had identical restriction endonuclease digestion patterns, and the number of digestion fragements by BamHI, EcoRI and HindIII were 9, 10 and 13, respectively. Based on these results, it is suggested that the presence of the 44-megadalton plasmid Y. enterocolitica serotype O3 strains is closely related to calcium dependency and autoagglutination and that this plasmid may be inherent to serotype O3.

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Tyzzer's disease in euthymic mice was aggravated by splenectomy, treatment with carrageenan, India ink or silica. The aggravating effect was more prominent when splenectomy was performed 3 days rather than 7 days before infection. Blocking of the reticuloendothelial system was most effective in increasing the severity of infection when made on the day following the inoculation. Non-treated athymic nude mice did not show enhancement of the infection compared with euthymic mice. In nude mice splenectomy done 6 days before infection combined with carrageenan treatment on 1 day p.i . showed hepatic lesions as severe as seen in cortisone-treated euthymic mice.

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The sciatic nerves of fourteen 104- to 135-week-old rats with spontaneous radiculoneuropathy were examined by light and electron microscopy. The most conspicuous changes were the nerve fiber degeneration indicative of wallerian degeneration and regeneration. Along with these changes, shrinking axons with disproportionally thicker myelin sheaths could sometimes be observed in large myelinated nerve fibers. In these myelinated fibers, there were also demyelinative changes characterized by wide distention of myelin sheaths with shrinkage of axons which are the most prominent changes in the spinal nerve roots in the radiculoneuropathy. Among the nerve fibers showing these demyelinative changes, axonal degradation following shrinkage of axons could be detected in several fibers. Our findings may suggest that shrinking axons in the spinal nerve roots cause axonal degradation and subsequent destruction of nerve fibers in the more distal portion of the peripheral nervous system in aging rats with radiculoneuropathy.

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Effect of partial hepatectomy on experimental Tyzzer's disease was studied. When the 2/3-hepatectomy was performed shortly after infection, severer hepatic lesions were produced in operated mice than sham-operated ones. No effect was observed when mice were hepatectomized three days before infection. Hepatic lesions after the 2/3-hepatectomy were severer as compared with the 1/3-hepatactomy. The results suggested that hepatocellular activation after hepatectomy might enhance the growth of organisms.

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Gamma-globulin fraction was obtained from the blood serum of a steer and colostrum wheys of cows vaccinated against bovine rotavirus (BRV) and bovine coronavirus (BCV), and emulsified with vegetative oil and other ingredients to reconstitute artificial colostrum (AC). The efficacy of AC was studied for protection of colostrum-deprived calves against experimental exposure to BRV and BCV at 22 or 25 hr of age. Calves Nos. 1 and 2 were orally challenged with the cell cultures of BRV and BCV, and Nos. 3, 4 and 5 with BCV; all the inocula were in combination with Escherichia coli K99(+) Ent(+). Calves Nos. 1 and 3, fed no AC, developed severe diarrhea. On the contrary, No. 2, fed AC several times before and after the challenge, and No. 5, once fed AC within 30 min after the challenge, developed no diarrhea. No. 4, once fed AC 4 hr after the challenge, showed only transient diearrhea. The severity and prevention of diarrhea related generally with immunoglobulin levels and antiviral antibody titers, derived from the administered AC, in the serum of the animals at about 100 hr of age. The results obtained indicated that AC has protective effects in calves against the exposure with BRV and/or BCV.

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The ependyma of the lateral ventricle in the N-methylnitrosourea (MNU)-induced dysgenetic hydromicrocephalic rat offsprings was examined morphologically at the ages of 1, 3, 12 and 27 weeks. Hydromicrocephalus became more severe with advancing age, and a slignt dilation of the lateral ventricle was already observed at the age of 1 week, and at the age of 27 weeks the desquamation and depression of the ependymal cells were the most severe. Ultrastructurally the changes of the ependymal cells and subependyma were relatively slight at the age of 3 weeks. At the age of 12 weeks degenerated ependymal cells had irregular distribution of nuclear chromatin and various sized vacuoles characterized by dilation of the endoplasmic reticulum and Golgi sac. Most of the mitochondria were condensed and the microfilaments were decreased or destroyed. In ependymal cells adjacent to chroidal cells there were a large number of altered rough endoplasmic reticula showing short tubular structures. At the luminal surface the cilia and microvilli were severely disrupted and the ependymal intercellular space was obviously dilated. In the subependyma vacuoles varied in size were formed by distention of the astrocytic and neuronal processes and extracellular space. These findings were considered to suggest insufficient function of ependymal cells to allow subependymal exudation of a large amount of cerebrospinal fluid (CSF) from the ventricle in the present hydromicrocephalus.

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Ten strains of canine distemper virus consisting of seven attenuated and three virulent ones were compared for their biological properties, i.e. pock-forming capacity on the chorioallantoic membranes of chicken embryos, neurovirulence in suckling mice, growth patterns in Vero cells including type of CPE, plaque size and inclusion-body formation, as well as their molecular properties including viral proteins and RNAs. Marked difference among strains was found in these biological properties, especially in pock-forming capacity, neurovirulence in suckling mice, and plaque size. All the virulent strains showed low pock-forming capacity compared with relatively high capacity in most of the attenuated strains, suggesting that this property might be associated with a decrease of virulence in dogs. Correlation between plaque size and neurovirulence in mice was also suggested. On the other hand, only slight difference in the electrophoretic mobility of viral proteins and RNAs was noticed in some strains. These findings may serve as basic data for further establishment of strain marker as well as of attenuation marker.

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Vibrio parahaemolyticus strains with different abilities to produce Kanagawa hemolysin were observed for persistence in a brackish water clam, Corbicula japonica, held in aquariums with artificial seawater diluted to 60% (60% seawater) and sand bed at 25°C for 28 days. The hemolysin producer persisted at a level of 10³ cfu/g in the molluscs held in 30-60% seawater, while it was the highest in 60% seawater followed by 50, 40 and 30% seawater in order at the 14th day. The producer was detected from digestive organs in the highest level since the second day. Three V. parahaemolyticus strains with different productivities for Kanagawa hemolysin persisted in a level of 10³ cfu/g while an Escherichia coli strain decreased to non-detectable level in 60% seawater.

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Comparisons were made of body weights, survivals, and pathological changes between CRJ:CD-1 (ICR) and B6C3F₁ mice dying in the course of the study as well as those survived for 104 weeks. The mean body weight curves of both sexes of B6C3F₁ crossed between 65 to 70 weeks of age and thereafter the mean body weight of females was heavier than that of males. No such a finding was observed in ICR mice. At 104 weeks of age, survival was better in B6C3F₁ than in ICR mice. The incidences of liver tumors were higher in both sexes of B6C3F₁ than in ICR mice. Pulmonary tumors occurred more frequently in ICR males than in B6C3F₁ males, whereas malignant lymphomas were more common in B6C3F₁ females than in ICR females. The incidences of pelvic dilatation and cerebral mineralization were higher in ICR males than in B6C3F₁ males. On the contrary, foci or areas of hepatocellular alteration, lithogeny in the renal tubules, spindle-cell proliferation in the adrenal cortex, and pancreatic islet-cell hyperplasia occurred more frequently in B6C3F₁ males than in ICR males. In females, systemic amyloidosis, proteinaceous casts, cysts, pelvic dilatation and epithelial yellow pigment deposition in the kidney, and ovarian cysts were more common in ICR than in B6C3F₁ mice, while hyperplasia of lymphatic follicles in the spleen, spindle-cell proliferation in the adrenal cortex, focal necrosis in the abdominal adipose tissue, and endometrial cystic hyperplasia in the uterus occurred more frequently in B6C3F₁ mice.

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A study was undertaken to evaluate the effects of 1, 24(R)-dihydroxyvitamin D₃(1, 24(R) (OH)₂D₃) and 1, 25-dihydroxyvitamin D₃(1, 25(OH)₂D₃) on the metabolic bone disorder developed in forced swimming rats. Serum 1, 25(OH)₂D concentration was significantly lower in the swimming group than in the intact group. Neither serum levels of calcium, phosphorus and immunoreactive parathyroid hormone(iPTH) nor urinary excretions of calcium and phosphorus are significantly different between the intact and the swimming groups. The ash content of the tibia significantly decreased in the swimming rats, and histological changes in longitudinal sections of the tibia from the swimming rats were quite similar to the osteoporosis. The oral administration of 1, 24(R)(OH)₂D₃ and 1, 25(OH)₂D₃(0.10μg/kg/day, from the 49th to the 81st days of forced swimming) increased the ash content of the tibia and partially prevented development of osteoporosis in the swimming rats. These results might indicate that these vitamin D₃ therapy is effective for the osteoporosis caused by the severe exercise.

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When the 90HS strain of procine parvovirus (PPV) was subjected to passages in embryonic swine kidney cell line (ESK cells), the low virulent HT^- strain was obtained. When it was subjected continually to passages in primary swine kidney cultured (SK) cells at low temperature, attenuated HT^-/SK strain as live virus vaccine was established. The ability of the HT^-/SK strain to multiply in vitro was the highest at 32°C. The strain which multiplied at this temperature showed more than 3000 times as high an infective titer as that which multiplied at incubation of 37°C or 40°C. To examine the safety of the HT^-/SK strain, 4-months-old piglets and pregnant sows negative for antibody were inoculated with this strain. No piglets or sows presented any abnormal clinical sign, viremia, or discharge of virus, or involved in contact infection. These swines showed complete ability of defense against challenge by intranasal inoculation with PPV of field strain. The pregnant sows immunized with the HT^-/SK strain were challenged with PPV field strain to examine an effect of preventing fetal infection. They gave birth, however, to normal piglets, which were negative for serum antibody against PPV before sucking of colostrum. Therefore, no fetal infection was induced by high virulent field virus. On the other hand, abnormal young were born from a nonimmunized control sow. Virus was recovered from stillborn fetuses from this sow. Thus, it was considered that this strain could be used as attenuated live vaccine for prevention of PPV.

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Changes of the heart rate and ECG to twitching were examined using 5 Thoroughbred foals at various ages and their mares. The effect of the heart rate decrease to twitching was significantly greater in the foals than in the mares. The decreased heart rate in the foals continued during and after the twitching. Changes of the T wave in the A-B lead ECG shown as enhancement of the negative ingredient of the T wave were observed both in the foals and in the mares, accompanied by a decrease in the heart rate during and/or after the twitching. Two out of the five foals showed second-degree A-V block following a decrease in the heart rate during and/or after the twitching at the 3.5 and 4 months of age and thereafter.

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The attachment of horse cecal bacteria to forage or grass cell walls and the degradation of the various plant tissues were investigated with transmission electron microscopy. Differences were observed in the manner of attachment with different morphological types of cecal bacteria degrading plant cell walls. Cocci appeared to be attached to plant walls via capsule-like substances. Many bacilli and cocci appeared to be attached via small amount of extracellular fibrous or slime material, but some bacilli dit not possess extracellular substance. Other bacilli appeared to be adhering by conforming their bacterial shape to the shape of the plant bell walls. The cecal bacteria degraded leaves of Trifolium or Agropirum and straw material obtained from the horse cecum, in different manners. Bacteria colonized extensively mesophyll cells and intercellular spaces between these cells. The bacteria were also attached to lignified thick walls of schlerenchyma cells and of the vascular tissue of xylem. Location of the bacteria (cocci and bacilli) attached or near to the erosion areas suggested the action of extracellular enzymes. The presence of cecal bacteria with the capability of degrading lignified tissue represents an important biochemical function previously unknown in the cecal ecosystem.

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The snail host of Fasciola sp. was experimentally defined to be Lymnaea truncatula in the Tempoku district of Hokkaido. This species of snails from the district was exposed to miracidia of liver flukes from the same district. Sporocysts recovered on day 4 after exposure were 107.1-203.1×44.8-97.6μm, and rediae were 302.9-306.8×38.5-86.8μm on day 9 and 363.0-1, 550.9×82.5-265.5μm on days 24 to 28. Rediae contained 1 to 5 cercariae. The duration from the exposure of snails to miracidia to cercarial shedding was 45 days at a water temperature of 21°C to 31°C and 38 days at 28°C. Metacercariae were 196.9-307.3×192.6-213.4μm in size. The prepatent period was 64 to 71 days in goats and worm recovery was 70.0% and 22.2% on days 133 and 172 after infection, respectively. L. auricularia from the district showed total resistance to the infection with the liver fluke.

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Pregnant rats were treated with N-methylnitrosourea (MNU), and dysgenetic hydromicrocephalic offsprings was morphologically examined at the ages of 1, 3, 12 and 27 weeks. The changes of the pia-arachnoid became more severe with advanced age, and partial destruction of the arachnoideal trabeculae was observed at 1 week of age. At 27 weeks remarkable dilation of the subarachnoid space with extremely thin arachnoid was characteristic. In the subpial parenchyma spongy degeneration accompanied with slight infiltration of mononuclear cells was seen. Ultrastructurally, the arachnoideal cells were polyhedral showing irregular interdigitation with each other at 3 weeks of age. Most of the cells had scanty chromatin in the nuclei and a large number of swollen or condensed mitochnodria, vesiculated or aqueous humor-containing rough endoplasmic reticulum (RER) and increased microfilaments in the cytoplasm. At 12 weeks, the arachnoid was extremely thin, showing short tubular RER, condensed mitochondria and some altered subcellular organelles in the cytoplasm. Changes of the pia mater and subpial parenchyma was prominent with advanced age. At 12 weeks, irregularly arranged pial cells processed marginated or decreased nuclear chromatin, condensed mitochondria and altered RER. In the subpial parenchyma the remarkable concavo-convex appearance of the basal lamina and may swollen astrocytic processes with a few macrophages were observed. From the results, it was considered that dysfunction of the arachnoid may be closely associated with pathogenesis of the MNU-induced hydrocephalus.

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The anesthetic effects of tricaine methanesulfonate (MS-222), eugenol (FA-100) and thiopental sodium (RABONAL) on adult carp (Cyprinus carpio) were examined with the recovery process. For this purpose, behavioral response and changes in respiratory rates during anesthesia and recovery were determined. All anesthetic agents were applied to carp by immersing it in the solution of the agent. Effects of water temperature (10 and 20°C) on anesthetic and recovery process were also tested. FA-100 (25 to 100ppm) and RABONAL (200 to 300ppm) shortened the time required to induce each anesthetic stage and delayed recovery with dose depended manner. Higher dosage of MS-222 (50 to 200ppm) also hastened induction of anesthesia. There was no difference in recovery times between the used concentrations of MS-222, and recovery was quicker than those observed in the cases with other agents. MS-222 caused the increase in respiratory rates. On the contrary, FA-100 and RABONAL decreased respiratory rates. The high water temperature (20°C) augmented the anesthetic effects of agents and facilitated the recovery. These results reveal the quick recovery of carp when it is anesthetized with MS-222 and indicate that the criterion of anesthesia and recovery determined in this study is useful for analysing the effect of anesthetic in adult carp.

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Eleven monoclonal antibodies to the HN protein of NDV strain Sato were established and used to elucidate the functions and antigenic structure of the HN molecule. Seven of these antibodies showed various patterns of inhibition against biological functions of the virus; whereas, 4 antibodies did not inhibit any viral function tested. The differences in the inhibition patterns of the antibodies were not apparently due to differences in avidity for viral antigen. One antibody inhibited viral neuraminidase but not hemagglutination, thus supporting the concept of spatially distinct active sites for hemagglutination and neuraminidase on the HN protein molecule of paramyxoviruses. This anti-neuraminidase antibody did not show neutralization activity unless it was reacted with virus before attachment of the virus to the cells, indicating that neuraminidase may play a role at the initial stage of infection. One antibody inhibited hemagglutination, neuraminidase and hemolysis but not infectivity of the virus; whereas, another antibody inhibited neither hemagglutination nor neuraminidase but inhibited hemolysis and infectivity. These findings may suggest possible differences in the cellular receptors or membrane structure between erythrocyte and host cell, or alternative mechanism of viral neutralization by anti-HN antibodies which may not involve inhibition of viral attachment or neuraminidase.

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The occurrence of various red blood cell groups and corresponding genes was studied with dogs of various breeds reared in Japan. Thirteen antisera were used to determine the red blood cell groups. The frequency of the red blood cell groups of the DEA1, DEA3, DEA6, D, and J1 systems had distince tendency towards certain canine breeds. In particular, there was a pronounced difference in the frequency of D gene system between indigenous Japanese and European and American breeds. The Japanese breeds, Akita and Shiba, had a high frequency in the D¹ gene, while the European and American breeds showed a high frequency in the D² gene. There was no other deviations in the frequency of genes in any other system of red blood cell groups that might characterize the indigenous Japanese breeds. There was no relationship between sex and the frequency of genes in any system of the red blood cell groups.

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Adhesive capacities of Yersinia strains to L-929 cells were compared in respect to the presence of virulence plasmid and the effects of temperature (25°C and 37°C) for bacterial cultivation and for adsorption with L-929 cells. Yersinia pseudotuberculosis IB carrying virulence plasmid adhered remarkably to L-929 cells when the organisms were cultivated at 37°C and adsorbed on L-929 cells at 37°C. Low degree of adherence was observed in the same organisms with three other combinations of cultivation- and adsorption-temperatures (37°C vs 25°C, 25°C vs 37°C and 25°C vs 25°C). Adhesive capacity to L-929 cells was low in Y. pseudotuberculosis IB mutant lacking virulence plasmid as compared with that in the parent strain. Y. pseudotuberculosis strains showed higher adhesive capacities than Y. enterocolitica strains. Furthermore, formalin-inactivated Y. pseudotuberculosis IB, both cultivated and adsorbed at 37°C, showed as high adhesive capacity as the live organism. The results suggested that the adhesive factor of Yersinia depended greatly on plasmid and was expressed more efficiently when the organisms were cultivated at 37°C and adsorbed with L-929 cells at 37°C.

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Specific-pathogen-free (SPF) neonatal pigs were intranasally inoculated with serotype D strains of Pasteurella multocida and/or strain L3 of Bordetella bronchiseptica, and their lesions were studied. Marked inflammatory changes were observed only after the infection with B. bronchiseptica. Both organisms were constantly recovered from the nasal cavities of the pigs during the experimental period; B. bronchiseptica was recovered in higher numbers than P. multocida. Degeneration and resorption of trabeculae in varying grades were observed in all the inoculated pigs. The turbinate bone lesions induced by P. multocida were characterized by the following changes: slight resorption of trabeculae by osteocytic osteolysis, active osteoid synthesis near trabeculae and periosteum due to increase of osteoblasts, and enhanced new bone formation. In many areas of the trabeculae, the trabeculae had been replaced by the proliferative osteoblasts and osteoids, thus, none of the pigs showed gross signs of swine atrophic rhinitis (AR). In contrast, the lesions induced by B. bronchiseptica were severe resorption of trabeculae by osteoclastic osteolysis, perforating resorption, increase of fibrous tissue near trabeculae, and impaired osteogenesis due to the damage to the osteoblasts. Thus, all the pigs showed severe gross signs of AR. Hence, quality and severity of the lesions observed between the 2 species of the bacteria were apparently different. Co-infection of the pigs with the 2 spites of the bacteria apparently enhanced the turbinate lesion formation. Our observations are consistent with the hypothesis that B. bronchiseptica alone is responsible for pathogenesis of swine AR. The different mechanisms in pathogenesis by the 2 species of the bacteria in relation to the production of characteristic turbinate lesions are discussed.

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Non-neoplastic nodular lesions of the pancreas were histopathologically and immunocytochemically investigated with forty three 85 to 114 week-old F344 rats. Similar lesions were also studied by autoradiography with 10 Sprague-Dawley rats. Microscopically, the pancreatic lesion essentially was replacement of the exocrine tissue by proliferated duct-like structures. The often enlarged nuclei of epithelial cells lining these duct-like structures showed mitotic figures and active synthesis of DNA by autoradiography. Single acinus or small aggregates of endocrine cells were seen among these duct-like structures. There were also many transitional type cells between immature cubic cells resembling ductual epithelium and mature exocrine cells. These transitional type cells also revealed active DNA synthesis. The results indicate that the nodular lesions under study are involved with the regenerating change of the pancreatic tissue. Immature epithelial cells of duct-like structure appear to have the potential to differentiate into both ductual and endocrine cells. The possible morphogenesis of these regenerating nodules was discussed.

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A granular cell tumor was found in the leptomeninges of the cerebellar vermis of a male 21-month-old Wistar rat. Histologically, the neoplastic cells which proliferated in sheet and nest fashions frequently showed pleomorphic contour and contained PAS-positive granules in their cytoplasm. Ultrastructurally, the tumor cells had the characteristics of a granular cell tumor. Electron-dense bodies in the cytoplasm of the tumor cells sometimes contained a few rough endoplasmic reticula and ribosomes. Some junctional complexes were present between two adjacent cells.

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Equine neutrophil function was studied in 24 newborn foals, 10 adult horses, and a foal infected with R. equi by the quantitative nitroblue tetrazolium (NBT) reduction test. There was no difference between results in newborn foals and adult horses. A foal naturally infected with R. equi showed normal values of NBT reduction test at birth, and after the initial clinical signs, the spontaneous reduction of NBT by neutrophils was found to be remarkably increased until a week before death.

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A primary cerebellar tumor found in a 14-week-old Sprague-Dawley rat, was noted to be extremely cellular and consist of small undifferentiated cells with hyperchromatic or vesicular nuclei and scanty cytoplasm. Mitotic figures were frequently observed. Solid masses of neoplastic cells were often separated by thin fibro-vascular septa, and a few pseudorossets were present. Many myoblasts were seen in a certain portion of the tumor. The tumor was diagnosed as medullomyoblastoma, a variant of medulloblastoma.

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The spontaneously occurring pulmonary foam cells were detected in 97 of 989 Fischer 344 rats of both sexes ranging in age from 13 to 150 weeks. The cells were first detected in the lungs of 52 weeks old rats. An increase in number of the lungs with foam cells and degrees of pulmonary accumulation of the cells were associated with age, the highest incidence (28.8%) being observed in rats over 120 weeks of age. The foam cells, being most frequent in the alveoli, were generally round and had an abundant, foamy cytoplasm and a relatively small nucleus. The cells contained various lipids in their cytoplasm. The plasma cholesterol levels increased with advancing age, seemingly correlated with the incidence of the pulmonary foam cells.

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Secretory responses of insulin, glucagon and cortisol were investigated in Holstein calves moderately exposed to cold (2°C). Plasma insulin, glucagon and cortisol showed a prompt increase at 30 min of cold exposure. With regard to delayed responses, plasma cortisol presented a gradual rise with a maximum level at 4 days of cold exposure. Plasma insulin and glucagon also kept high levels for 8 days in the cold environment.

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A survey of viruses associated with feline respiratory diseases was conducted by virus isolation from swabs collected from cats visiting the University Veterinary Hospital and from apparently healthy laboratory cats in a medical school animal center. Twenty-nine caliciviruses and 2 herpesviruses were isolated from 29 of 65 cats with respiratory disease and 2 caliciviruses were from 2 of 49 cats with other diseases. From 50 laboratory cats 2 caliciviruses were also isolated.

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Histopathological observations were made on pleomorphic liposarcoma found in the omentum and mesentery of a 68-week-old rat. The tumor consisted of two types of tumor cells; round cells that had abundant cytoplasm with a clear large nucleus and spindle-shaped, slender cells with dark oval nuclei. Some round cells contained features suggesting ongoing lipid synthesis in the dilatated cistern of the rough endoplasmic reticulum. Both types of cells had various sizes of lipid droplets with no limited membrane.

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Isospora bigemina large type of cats was compared with Besnoitia wallacei. B. wallacei was slightly infective to hamsters as well as I. bigemina large type. The former was not different to the latter in size of schizonts. Both protozoa were coincident serologically and immunologically. They were found to be identical.

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Spontaneous respiratory disease with wheezing was observed in a 3-month-old Wistar/Ms rat. The gross lesions were enlargement of the lungs with focal atelectasis and bronchiectasis. Histologically, there were tracheitis, bronchitis and bronchiolitis with peribronchial and peribronchiolar cuffs. Numerous argentaffine filamentous organisms, morphologically identified as CAR bacillus were demonstrated in the ciliary borders of epithelial cells in the affected respiratory tracts.

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Bovine myoglobin (Mb) was purified and specific antiserum was prepared. Myoglobin was purified from bovine skeletal muscle by fractionation with ammonium sulfate and two cycles of crystallization. Reasonably pure crystals of bovine metmyoglobin were obtained. Anti-bovine Mb serum, prepared with the purified Mb, was useful in detecting Mb in blood and urine of a calf with nutritional myopathy.

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The prevalences of Rhodococcus (Corynebacterium) equi and mycobacteria in the submaxillary and mesenteric lymph nodes of apparently healthy pigs were studied. R. equi and atypical mycobacteria were isolated from 11 (7.4%) and 7 (4.7%), respectively, of 148 submaxillary lymph nodes, and 0 (0%) and 17 (18.9%), respectively, of 90 mesenteric lymph nodes. R. equi was isolated from 3(2.0%) pigs with atypical mycobacteria, and from 8 (5.4%) pigs without atypical mycobacteria. Atypical mycobacteria was isolated from 4 (2.4%) pigs without R. equi. It seems likely, that lymph nodes of pigs are a suitable environment for R. equi and atypical mycobacteria to harbour.

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Leg-weakness was observed in a field flock of 82-day-old chickens, and a mesogenic Newcastle disease (ND) virus (TY-1 strain) was isolated from the brain of one affected chicken which revealed non-purulent encephalomyelitis characterized by necrosis of motor never cells in the brain and spinal cord. Clinical signs and lesions were reproduced in 6-month-old specific-pathogen-free chickens by an experimental infection with the TY-1 strain. These results indicate the existence of ND virus infection, which induces leg-weakness and obvious pathological changes in the central nervous system in the field.

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