Feline immunodeficiency virus (FIV) was first isolated in 1986 from a cat with an acquired immunodeficiency syndrome (AIDS)-like disease. This virus has many characteristics in common with human immunodeficiency virus which is an etiological agent of AIDS in human and is classified as a member of the lentivirus genus of the retrovirus family. Since the discovery of FIV, many researchers have studied the virus extensively from clinical, biological, and genetic aspects. In this review, the biological nature of FIV is summarized in four sections, i.e., morphological and biochemical properties of FIV, biological properties of FIV, immunological aspects of FIV infection, and clinical aspects of FIV infection. This review includes some recent, unpublished data from our and other groups.

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Eighty rabbits receiving the square resection (4×4 mm) of both patellar ligaments in full thickness at their center were divided into 4 groups, and each group (20 rabbits) were electromagnetically stimulated with different magnetic intensities, 0(control group), 2, 10, or 50 gauss (G), for 6 hr daily. Pulse frequency and pulse width were 10 Hz and 25 μsec, respectively. Five animals of each group were sacrificed weekly from 1st to 4th week after operation and the defect tissue was collected for biochemical and ultrastructural evaluations. Before sacrificing, the blood flow of the central portion of patellar defects were measured. Significant increases in blood flow at the defect were observed in 50 G group compared to those of other groups from 2 to 4 weeks after operation. The collagen content in PEMFs groups showed a significant increase compared to that of control group. Furthermore, those increases were higher according to the increase in magnetic intensity. Electronmicroscopically, massive developmental rough endoplasmic reticulum was seen in the fibroblasts at 2 weeks after operation in 50 G group compared to other groups, which suggests the more active collagen production in this group. These results suggest that PEMFs enhanced the blood flow and increased the fibroblasts at the defect. At the same time, PEMFs directly stimulated the collagen production from the fibroblasts, thus accelerate the healing process of the ligament.

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Changes in body weight, concentrations of urine glucose, blood glucose, plasma insulin and FFA and hepatic enzyme activities were investigated in KK and C57BL mice treated with monosodium-L-aspartate (MSA). MSA was administered subcutaneously to neonates at a dose of 4 mg/g body weight. The MSA-treated KK and C57BL mice were remarkably obese at 10 weeks of age. The average plasma insulin concentration in the control KK mice was 73.6 μU/ml, over 4 times higher than in the control C57BL mice. In the control KK mice, hepatic glucokinase (GK) activity was quite low, and fructose-1, 6-bisphosphatase (FBP) and acetyl-CoA carboxylase (CBX) activity was much higher than in the control C57BL mice. In the MSA-treated KK and C57BL mice, the plasma insulin concentration increased to 2 to 3 times higher than in the controls. The MSA-treated C57BL mice showed an increase in GK and CBX activity and acceleration of obesity. In the MSA-treated KK mice, GK activity did not change and CBX activity decreased, and only FBP activity increased significantly. Glycosuria was induced and blood glucose and plasma FFA increased remarkably in all MSA-treated KK mice.

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Renin, a key enzyme controlling blood pressure, is mainly synthesized in kidney. To characterize the rat renin promoter, we have constructed a reporter gene containing the 238-bp putative regulatory region linked to a bacterial chloramphenicol acetyltransferase (CAT), and analyzed its promoter activity by in vitro transfection and introduction of the CAT fusion gene into germline of mice. CAT activity was detected in transfected embryonic kidney-derived 293 cells, but not in HeLa cells derived from cervical carcinoma, showing that the putative promoter region of the rat renin gene directs transcription in a cell type-dependent manner. To examine whether the sequence was sufficient to regulate the expression of the CAT chimeric gene in mice, we generated seven transgenic mice carrying the reporter construct. Unexpectedly, the transgene was not expressed in any of the independent transgenic mice examined. These results suggest one possibility that an additional control region may be required for efficient expression of the rat renin promoter in developing mice.

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This study was designed to determine the quantity of functional renal tissue needed to maintain homeostasis of red blood cell production by evaluating the erythropoietin (EPO) production response to phlebotomic stimulation in the 1/2- and 1/4-kidney dogs surgically prepared. The results showed that the reduction in functional renal tissue caused a decrease in EPO production, which led to the delay in recovery from anemia. In the anemic progress stage, the plasma EPO level showed a transition proportional to the quantity of functional renal tissue immediately after the operation for tissue reduction. The 1/2-kidney dog group still kept such proportional relation even in the recovery stage. Thus, the half of the normal renal tissue was considered sufficiently contributory to EPO production needed to maintain homeostasis of red blood cell production. However, the 1/4-kidney dog group precipitously decreased in plasma EPO level in the recovery stage and fell into an extremely unfavorable anemia. This indicated that homeostatic maintenance in erythropoiesis would be impossible more below a quarter of normal renal tissue. These findings disclosed that reduction in functional renal tissue quantity would sensitively influence homeostatic maintenance of red blood cell production through the decrease in EPO production, even if it does not affect renal function concerned with urine production.

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In this study transgenic mice which expressed antisense RNA against the nucleocapsid protein gene of mouse hepatitis virus (MHV) under the control of RSV LTR were produced. These transgenic mice were able to transmit the foreign gene to their progeny in a Mendelian fashion. Antisense RNA was detected in various tissues from the transgenic mice including liver and brain, the target organs of MHV infection. One strain of transgenic mice derived from founder mouse No.19 was more resistant to the lethal challenge of MHV than non-transgenic mice. The results of the present study show the ability of antisense RNA against the viral gene to protect against viral infection in vivo.

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To define the species of Campylobacter harboring in the intestine of calves and adult cattle and to examine their distribution among different age groups and farms, 34 calves and 60 adult cattle raised in 6 farms in 3 different areas were studied. Campylobacters were detected in the feces obtained from healthy calves (97.1%) less than 1-year-old but were much less frequently found in adult cattle (46.7%). Young calves harbored more species of Campylobacter than adult cattle. The isolation rate of campylobacters in adult cattle differed depending upon the farms examined. C. jejuni, C. hyointestinalis and C. fetus subsp. fetus were isolated from 61.8, 26.5, and 26.5% of calves, respectively. However, these 3 species were detected at the lower rates of 11.7 to 15.0% in adult cattle. C. coli, C. lari, C. fetus subsp. venerialis, C. fecalis, and other Campylobacter spp. were also detected in a few calves and adults. These results indicate that campylobacter colonization in the intestine is very common in young calves but not in adult cattle.

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It is known that blood and plasma volume increase during lactation. The present paper examines whether an increase in plasma volume is accompanied by the change in plasma composition or attributed to hydro-dilution. Six dam-nursed pups and six dam-removed pups housed individually were designated as lactating rats and control rats, respectively. The plasma osmotic pressure and hematocrit value (Ht) were measured in the rats on days 3, 5, 7, 10, 13 and 18 of lactation. The total plasma protein (TP) and serum sodium concentration were also measured as they are factors affecting the plasma osmotic pressure. In addition, milk yield was estimated by the Morag technique. On day 5 and after day 10, the osmotic pressure of the lactating rats was found to be significantly lower than that of the control rats. The serum sodium concentration (days 5 and after day 10) and Tp values (days 3, 10 and 18) of the lactating rats were significantly lower than those of the control rats. Except on day 5, the Ht values of the lactating rats were significantly lower than those of the controls. During the period between days 3 and 10, milk yield was increased and it become steady (18g/12hr) on days 10 and 18. On and after day 10 when rats secreted a large amount of milk, it is considered that a decrease in the plasma osmotic pressure was mainly attributed to the reduction of sodium concentration by hydro-dilution. The Ht values indicate that an increase in blood volume is mainly through plasma volume rather than blood cell volume in lactating rats.

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Changes in bone metabolism throughout pregnancy and lactation in female beagle dogs were examined by histomorphometry and measurement of serum biochemical constituents related to bone. A total of eight dogs, including one dog observed repeatedly from 1 year and 8 months to 4 years and 7 months of age, were used. For double bone labeling to obtain the bone dynamic parameters, dogs were each injected twice, at an interval of 7 days, with fluorochromes such as tetracycline or calcein at the time just after mating, just after delivery, and before weaning. At the time just after weaning, the iliac bone was biopsied. Histomorphometric analysis of trabecular bone area of undecalcified iliac bone sections was performed using a semiautomatic image analyzer. Serum biochemical parameters related to bone such as parathyroid hormone, calcitonin, calcium, phosphorus and alkaline phosphatase activity were periodically measured. Bone histomorphometric analysis revealed significant increases in the mean values of osteoid volume and mineral apposition rate as compared with those of age-matched no pregnancy dogs. The mineral apposition rate measured with the passage of time was increased after delivery and was further increased before weaning compared with that at the time of mating. There were no significant changes in mean values of bone volume, mean trabecular thickness, bone formation rate and mineralizing lag time. Histological examination showed that the osteoid accumulated during the late stage of pregnancy and lactation. All histomorphometric values were significantly correlated to the age of the dam and the number of pups. Mean values of all serum biochemical parameters did not change. These results indicate that bone mineral loss occurs due to high turnover of bone metabolism during the late stage of pregnancy and lactation and is related to the age of the dam and the number of pups in dogs, in addition to the fetus mineralization and milk production.

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Histological observations were performed on the schizonts of Japanese Theileria sergenti in three calves necropsied 8 and 10 days after application of nymphal Haemaphysalis longicornis infected with T. sergenti. In all the three calves, schizonts were observed in the cytoplasm of huge cells formed in the drainage lymph nodes, liver and spleen. The huge cells were 50 to 200 μm in diameter. Schizonts had granular appearance and an irregular shape and were 1 to 7 μm in diameter. Ultrastructurally, schizonts had more than on nuclei and were formed in the unit enlarged cell. Schizonts showed a specific reaction against anti-T. sergenti anti serum, therefore, it was concluded that the schizonts were those of T. sergenti histologically.

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Experimental infections were induced out to examine whether Aujeszky's disease virus (ADV) infection in pigs results in a severe pneumonia by Actinobacillus pleuropneumoniae. Intranasal inoculation of ADV (10^6.9 median tissue culture infective dose/head) in 4-month-old primary specific-pathogen-free pigs was followed by the inoculation of A. pleuropneumoniae type 1 (10^3.1 or 10^5.1 colony-forming-units/head). The pigs inoculated with ADV alone developed clinical signs of Aujeszky's disease but not pneumonia, and those inoculated with A. pleuropneumoniae (10^3.1 CFU/head) alone did not develop clinical symptoms and lung lesions. Whereas all the pigs inoculated dually with ADV and A. pleuropneumoniae (10^3.1 CFU/head) showed severe or very severe clinical symptoms and moderate or severe pneumonia and one of them died. The pigs inoculated with A. pleuropneumoniae (10^5.1 CFU/head) alone had severe clinical symptoms and one of the 2 pigs died acutely. Furthermore, all of the 3 pigs inoculated with ADV and A. pleuropneumoniae (10^5.1 CFU/head) showed clinical symptoms and moderate or severe pneumonic lesions and one pig died of disease. It was concluded that the clinical symptoms of A. pleuropneumoniae became severer by concomitant infection with ADV.

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To define the relationship between the immunologic reaction and the pathogenesis of cerebral vasospasm (VS) following experimental subarachnoid hemorrhage (SAH), we examined the effect of a cell mediated immunosuppressive agent, FK-506, isolated from Streptomyces tsukubaensis, by using the canine SAH model. There was a significant vasoconstriction in the basilar artery in the control group after SAH. This constriction, however was not successfully prevented by FK-506 or combination of FK-506 and steroid, since there was no significant difference in the vessel caliber size among these groups. The pathologic approach, accompanied by immunohistochemistry, could not discriminate the differences in the nature of the lesion between the untreated group and FK-506 treated groups, except for slight lymphocytic infiltrations present around the basilar artery of untreated group. Histopathologically, inflammatory reactions consisting of neutrophils, that were not suppressed by FK-506 treatment, were clearly seen around the spastic vessels in the subarachnoid space. Furthermore, several constrictive changes or degenerative alterations were also observed in the spastic vascular wall. Immunohistochemically, the deposition of IgG, IgM and C₃ was present in the intima and the luminal side of the smooth muscle layer, and capillary vessels of the brain stem. It is considered that this deposition was caused by increased vascular permeability in VS. On the basis of the above findings that the cell mediated immunosuppressive agent, FK-506 failed to prevent vasoconstriction or pathologic lesions but lymphocytic infiltrations, it is considered that the cell mediated immunopathogenesis may play little role in producing VS following SAH.

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Protective response against Babesia microti was studied in Isospora felis-infected mice. Isospora felis-infected mice which were exposed to B. microti on the 28th day post-infection showed absolute resistance against Babesia microti. Interestingly, these mice showed no anti-B. microti antibodies. Mice that received spleen cells from I. felis-infected donors that were subsequently exposed to B. microti showed lower peak parasitemia (10.3%±2.6) compared to those mice that received normal spleen cells (60.9%±15.0), and no spleen cells at all (47.3%±8.5). Treatment of I. felis-infected mice with monoclonal antibodies against L3T4⁺ cells resulted to a depression of their resistance to B. microti, as clearly manifested by high levels of parasitemia. Findings of the present study demonstrate the role of cell mediated immunity, specifically by L3T4⁺ T-cells induced by I. felis infection, in providing mice protection against B. microti.

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To clarify the normal value of ventricular wall thickness we directly measured the ventricular wall thickness of 50 normal mongrel dogs of one year old. Because of a wide range in body weight from 6.0 to 16.0 kg of these 50 dogs, we selected 34 dogs weighing 8 to 12 kg to calculate the mean ventricular wall thickness as normal value of one year old. The results obtained were as follows; (1) The mean and standard deviation of the left ventricular wall thickness was 7.1±1.2 mm at anterior, 6.3±1.6 mm at posterior, 7.1±1.3 mm at lateral, 10.3±1.8 mm at the interventricular septum, and that of the right ventricular wall thickness was 3.4±1.0 mm. (2) Although any site of the ventricular wall thickness correlated significantly to heart weight, only the anterior left ventricular wall and interventricular septum barely correlated to body weight. (3) There was no significant correlation between arterial blood pressure and the ventricular wall thickness. Further study should be necessary to clarify influences of aging on the ventricular thickness and to determine the criteria of ventricular hypertrophy.

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Two acriflavine-fast attenuated Erysipelothrix rhusiopathiae strains Koganei 65-0.15 of serotype 1a (strain Kg-1a) and 2 (strain Kg-2) were comparatively characterized. Biochemical characterization showed the similar reactions with slight variation between the strains. Strain Kg-2 was more resistant to acriflavine dye than strain Kg-1a. Pathogenicity of strain Kg-2 was higher than strain Kg-1a in mice of strains ddY, C3H/He and A/J. Significant differences of clinical signs between strains Kg-1a and Kg-2 were observed in occurrence of arthritis (P<0.05) and systemic signs (P<0.01) of only ddY mice. C3H/He mice was more resistant than ddY and A/J mice to the infection of strains Kg-1a and Kg-2. Three culture fractions, whole culture: WC, culture filtrate: CF and killed cells: KC, of strain Kg-2 were more protective than those of strain Kg-1a in ddY mice. CF of strain Kg-2 was most protective in all fractions. Heating at 56°C and 100°C or treatment with trypsin completely reduced the protective activity of WC of the two strains, indicating that major protective antigens of WC were protein. The present results demonstrated that immunogenicity and pathogenicity for mice were different between the two attenuated strains.

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We studied the effects of chemicals which induce liver enlargement and can induce hepatic protein synthesis on experimental Tyzzer's disease in rats. Plasma transaminase values were evaluated as an indicator of the severity of the disease. Chemicals used were phenobarbital sodium and 3-methylcholanthrene as hepatic enzyme inducers, and lead nitrate and ethylene dibromide as mitogens of hepatocytes. In rats non infected with Tyzzer's organism, liver weight in those treated with these chemicals was higher than that in rats without chemical treatment. Tyzzer's disease-infected rats treated with these chemicals showed higher plasma transaminase values and more severe histopathologic liver lesions than infected rats without chemical treatment. The results indicated that the growth of Tyzzer's organisms in hepatocytes was accelerated in the course of hepatocytic metabolic changes during liver enlargement, and that protein synthesized in the hepatocyte may play an important role in the nutritive requirements of the organism.

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A shock model was experimentally produced by intravenous injection of a lethal dose (3 mg/kg) of endotoxin under general anesthesia induced by pentobarbital sodium using 7 beagles. The effect of this endotoxic shock on the reticuloendothelial function was investigated. The blood endotoxin concentration peaked immediately after administration and decreased subsequently. However, the value still remained on an increased level (1, 051 pg/ml) even at 360 min after endotoxin treatment. The lipid emulsion test as an index of reticuloendothelial phagocytotic activity and the arterial ketone body ratio as an index of the energy charge in the liver decreased after endotoxin treatment and failed to recover during the experiment. Fibronectin, one of opsonic proteins, tended to decrease after injection of the endotoxin and was significantly (p<0.01) low at 180 and 360 min compared with the value before injection of the endotoxin. These results suggested the depression of the reticuloendothelial function during endotoxin-induced shock.

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Moxibustion on 12 specific points (Keiketsu in Japanese) was applied for treatment of delayed uterine involution in 16 cows that were diagnosed on the basis of rectal palpation and vaginoscopic examination 21 to 35 days after parturition. The treatment was continued for three consecutive days. Other 32 cows with the delayed uterine involution were either injected intramuscularly with 25 mg PGF₂α (17 cows) or infused in utero with 500 mg ampicillin (15 cows). The uterine involution following the treatment was monitored by rectal palpation and vaginoscopic examination. Milk samples were collected three times weekly and used for milk progesterone assay to monitor the ovarian function. No significant difference was observed in the uterine involution among the groups treated with moxibustion, PGF₂α or ampicillin. Percentages of cows with abnormal cervical mucus and bacterial isolation from cervical swab decreased remarkably in all groups during 4 weeks after treatment. Forty-six percent of cows with delayed uterine involution was diagnosed as having inactive ovaries. Percentage of cows that responded with ovulation and corpus luteum formation after moxibustion was 67 percent, slightly higher than those in cows treated with PGF₂α or ampicillin. Reproductive performance after the moxibustion was well-comparable to those after PGF₂α or ampicillin treatment. Result indicates that the moxibustion could be used as the alternative to PGF₂α and antibiotics for treating delayed uterine involution in cows.

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The dynamics of toxigenic Bordetella bronchiseptica and Pasteurella multocida infection and the B. bronchiseptica specific antibody content of the blood and nasal secretion were studied in three Hungarian and three Dutch pig herds. In both countries, the studies involved young sows that had farrowed once or twice (YS), old sows that had farrowed more than four times (OS), and their piglets. The results indicate that Dutch sows are characterized by a lower prevalence of B. bronchiseptica and P. multocida infection than Hungarian sows. In Dutch sows and in their piglets, the rate of P. multocida infection was higher than that of B. bronchiseptica infection. The opposite was found for the Hungarian sows and their piglets. B. bronchiseptica infection commenced at 3 and 4 weeks of age in piglets of young and old Dutch sows, respectively, followed by the emergence of P. multocida infection at 5 (YS) and 6 weeks of age (OS). In Hungarian piglets, B. bronchiseptica infection was first demonstrable at 1 (YS) and 3 (OS) while P. multocida infection at 3 (YS) and 5 (OS) weeks of age. The serological tests demonstrated higher B. bronchiseptica specific antibody levels in the Dutch sows and piglets as compared to the Hungarian ones. According to the ELISA results, the levels of IgA and IgG in the serum and those of sIgA, IgA and IgG in the nasal secretion of Dutch sows were significantly (p<0.001) higher in the Dutch than in the Hungarian piglets up to 3 and 4 weeks of age, respectively.

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The epidemiological studies of S. suis infections in Japan were carried out between 1987 to 1991. A total of 380 S. suis strains isolated from pigs, cattle and a horse were serotyped by using antisera against S. suis types 1 to 22. A total of 318(83.7%) of S. suis isolates were serologically typable. Serotype 2 was the most prevalent with 28.2%, followed by type 7(10.8%), 1/2(8.4%), 3(7.4%) and 4(5.5%). Of twenty S. suis strains isolated from cattle, eight were type 9, one was type 10, five were type 18, one was type 20 and five were untypable. One out of all the strains was also isolated from a racing horse with pneumonia. The majority of the isolates were originated from meningitis (38.2%), followed by from pneumonia (33.4%) and endocarditis (9.2%). Of all of the S. suis isolates, 333 isolates (87.6%) were identified correctly by API STREP 20 system.

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We investigated the effects of dihydroheptaprenol (DHP) on resistance of guinea pigs and pigs inoculated with Actinobacillus pleuropneumoniae (Apn) vaccine to subsequent challenge with Apn. Guinea pigs with complement-fixation (CF) antibody titers of 1:8 and 1:16 after intramuscular (i.m.) inoculation with inactivated Apn vaccine showed enhanced resistance to intraperitoneal (i.p.) infection with a homologous Apn strain (5×10¹⁰ CFU/animal) when injected with DHP (20 mg/kg, i.m.) on the day before infection. The survival rates of the control, vehicle (lecithin solution without DHP), and DHP groups were 33%, 37%, and 63%, respectively, and that of the DHP group was significantly higher than the rates of the other groups (P<0.05). Pigs with CF antibody titers of 1:8 and 1:16 after i.m. inoculation with inactivated Apn vaccine showed enhanced resistance to intratracheal infection with 5×10¹⁰ CFU of Apn when injected with DHP (1, 2.5, or 5 mg/kg, i.m.) on the day before infection. The survival rates of the control, vehicle, DHP 1 mg/kg, DHP 2.5 mg/kg, and DHP 5 mg/kg groups were 37%, 38%, 47%, 60%, and 73%, respectively, and pigs given DHP at a dose of 5 mg/kg showed a significantly higher survival rate than the vaccinated control pigs (P<0.05). The protective effect of DHP in vaccinated guinea pigs and pigs suggests that phagocytosis and bactericidal activity may be enhanced by this agent, depending on some opsonification effect on Apn antibody.

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Seven of the 25 dogs (4 to 15 years old) with benign prostatic hypertrophy (BPH) at the teaching hospital of Nippon Veterinary and Animal Science University from 1989 through 1990 were treated orally with chlormadinone acetate (CMA), a synthetic anti-androgen, 2 mg/kg/day, twice a day for 3 or 4 weeks. Prostatic size was measured by radiography and ultrasonography before and after CMA treatment, and prostatic volume was calculated from the images. Semen quality was examined in 3 of the dogs with BPH. Peripheral blood simples were collected and plasma levels of LH, 4-androstenedione, 5α-dihydrotestosterone, testosterone and estradiol-17β were measured. Clinical signs disappeared within 10 days after the start of CMA treatment. The mean (±S.E.) prostatic volume 3 or 4 weeks after treatment decreased to 39±4% of the pretreatment volume. The mean level of plasma testosterone in the dogs with BPH before treatment was significantly lower than that in the normal dogs (P<0.01). In 6 of the CMA-treated dogs the levels of all hormones examined, except LH, were significantly lower after CMA treatment than before (P<0.05). The sperm count and motility decreased and the percentage of abnormal sperms increased after CMA treatment. These results demonstrate that, although CMA treatment in dogs with BPH inhibits testicular function, the prostatic volume is markedly reduced and clinical signs disappear in a short period after the therapy. However, a relapse of BPH was observed approximately 6 months after oral CMA treatment in some dogs.

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The relationship of senile plaques to neuronal cells, neurites, glial cells, or capillaries was examined using double labeling-immunostaining methods on the Bouin's solution-fixed serial brain sections from dogs. Compact deposits of beta protein (amyloid plaques) in the cerebral cortex always contained microvessels labeled by anti-collagen type IV antibody and some of them might be formed as the result of fusion of several perivascular beta amyloid deposits. In the periphery of those plaques swollen neurites recognized with anti-neurofilament antibody were sometimes present, but the relation between such plaques and neuronal cells or glial cells were unclear. Diffuse deposition of beta protein (diffuse plaques) was frequently developed beside neuronal cells, while most plaques did not contain glial cells. Some of those plaques were closely contact with microvessels, but some had no relation. Intact or irregularly arranged neurites were present in diffuse plaques. Such irregularity of the neurites were obvious in the plaques in the hippocampus as compared with those in the cerebral cortex. These results indicate the possibility that canine amyloid plaques would be formed as the result of amyloid degeneration of cortical capillaries, and diffuse parenchymal deposition of beta protein would originate from neuronal or neurotic processes.

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Postpartum resumption of ovarian activity in 40 Holstein cows was monitored by ultrasonography twice weekly until artificial insemination. The accuracy of ultrasonography for assessments of ovarian structures was examined by comparing results of in vivo ultrasonography with macroscopic findings of the same ovaries after slaughter. Correlation coefficients were 0.71 and 0.85 for number of follicles 10-14 mm and &ge;15 mm, and 0.99 for diameters of the largest follicle. Follicular profiles prior to first ovulation were characterized by single dominant follicle (DF&ge;10 mm) in 25 cows, two in 10, three in 4, and four in one, respectively. However, after first ovulation, two waves of DF prevailed. The total number of DF (7.2) or time of ovulation (3.6) before conception was positively correlated with postpartum intervals to conception (74.0 days). Profiles of the volume of corpus luteum estimated by ultrasonography paralleled with the variations of plasma progesterone levels. The volume of corpus luteum and the peak progesterone level were smaller after the first ovulation as compared with after the second or third ovulations. In the ultrasound images of uterus, two elliptical lines indicated cross section of endometrium and stratum vascularis. Uterine involution assessed by reaching the nadir of endometrium was completed by 41.5 days postpartum. Results indicated that the number of DF before the first ovulation and the volume of corpus luteum after the ovulation were smaller compared with those of the second and third ovulation.

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Rifampicin-resistant mutant of Salmonella Enteritidis was used for the experiment of long-term excretion in chickens. Thirty-five specific pathogen free chicks within 24 hrs of hatching were placed in contact with 18 chicks inoculated orally with 4×10² CFU of S. Enteritidis HY-1 Rif within 12 hrs of hatching. After 7 weeks of the contact exposure, samples of cecal droppings were examined for the isolation of S. Enteritidis weekly or biweekly. Twenty-five out of 35 chicks (71%) survived. S. Enteritidis was isolated intermittently at lease until 28 weeks after the contact exposure for male chickens and 21 weeks for female chickens although this strain could be isolated only for one or two months from cecal droppings or internal organs of young chickens and laying hens. In order to prevent S. Enteritidis infection in poultry, it was concluded that (1) the contact exposure within 24 hrs of hatching or transovarian infection should be avoided because infection of chicks within 24 hrs of hatching with S. Enteritidis causes the prolonged cecal shedding, and that (2) the isolation of S. Enteritidis from cecal droppings should be repeated because of its intermittent shedding.

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Five MAbs, which showed neutralizing (NT) activity and recognized S (previously designated E2) glycoprotein of TGE virus TO-163, inhibited cell fusion by TGE virus in IB-RS-2 cells. Other S-specific MAbs with no NT activity did not inhibit the cell fusion. The results indicated that a neutralization epitope is same or very close to a fusion active site. The kinetics of membrane fusion following a reduction in pH were also investigated. The cell fusion appeared between 2 and 6 hr after the binding medium was added.

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A lymphosarcoma originating from kidneys, which metastasized to the ovaries, oviducts, heart and pancreas, was pathologically diagnosed in a 3-year-old female Japanese dog (Shiba dog). Clinically, the dog exhibited vomiting, diarrhea, oliguria and abdominal enlargement, associated with hypoglycemia. Grossly, the kidneys were enlarged and neoplastic masses were also seen in the ovaries and heart. Histologically, a majority of glomeruli and renal tubules were obliterated due to diffuse invasion by tumor cells. There were no metastatic lesions in the mesenteric and tracheobronchial lymph nodes, spleen and bone marrow. Most of the tumor cells were small- to medium- sized lymphoid cells with a large nucleus and scanty cytoplasm.

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An epizootic of foal diarrhea due to serotype 3 rotavirus (RV) was observed in 89 of 168 cases (53%) during the period from March to July in 1987. A total of 51 strains of RV were isolated from the 62 diarrheal feces examined, and one isolate (CH-3) showed a unique electropherotype of viral RNA which differed from the others that widely prevailed on this farm. No positive reaction was observed between strain CH-3 and each of the antisera against serotypes 1 to 12 of human and animal RV in neutralization tests. However, dsRNAs of the CH-3 virus were hybridized with a probe prepared from a strain of equine serotype 3 RV.

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Two familial scrapie cases successively occurred in 29-month-old and 30-month-old Corriedale dams and in three of their offspring as early as 10-19 months of age in a small flock. They showed ataxy but no pruritus. Histopathological and immunochemical examinations of those sheep revealed vacuolation of nerve cells in brain tissue and presence of PrP^sc, a component of scrapie-associated fibrils, in brain, spleen and lymph node tissues. We discuss about shortened incubation periods and lacking pruritus in the present scrapie cases.

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In the California sea lion (Zalophus californianus), the position of the tracheal bifurcation is fairly cranial compared with those of mammals in general. The right lung has the dorsal, ventral, medial and lateral bronchiole systems. The cranial lobe is formed by the first bronchiole of the dorsal bronchiole system. The middle lobe is formed by the first bronchiole of the lateral bronchiole system. The accessory lobe is formed by the first bronchiole of the ventral bronchiole system. The caudal lobe is formed by the remaining bronchioles of the dorsal and lateral bronchiole systems and all bronchioles of the medial bronchiole system. The left lung has the dorsal and lateral bronchiole systems. The middle lobe is formed by the first bronchiole of the lateral bronchiole system. The caudal lobe is formed by the remaining bronchioles of the lateral bronchiole system and all bronchioles of the dorsal bronchiole system.

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Thc investigation of biochemical markers in wild rats (Rattus norvegicus) is thought to be useful in the efficient establishment of inbred strains with a wide range of genetic variability of wild rats. In this study, 21 marker proteins were analyzed by electrophoresis in nine wild rats captured in Oita city. It was found that eleven marker samples in six animals were heterogeneous. We further found that the investigated wild rat population possessed the interesting polymorphisms of esterase-4 (ES-4) with high frequency, which are very rare in laboratory rats.

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A thoroughbred horse, gelding, gray color, aged 19 years old had cutaneous melanomas from the root to the middle of the tail, and throughout the connective tissues of the whole body. Histologically, the tumors were diagnosed as mature melanotic melanomas characteristically deposited with abundant melanin pigment. Examined with an electron microscope, melanosomes were electron opaque without internal structure (stage IV), or as mature granular and lamellar types. Most of them were fused with each other, and formed compound melanosomes, which was similar to internal melanin aggregates in shape. The internal melanin aggregates gradually disintegrated, and compound melanosomes grew spherical. The compound melanosomes changed into autophagosomes.

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The relationship between the number of fetuses and the blood constituents in late pregnant beagles was examined. The red blood cell count, hemoglobin concentration and hematocrit values in late pregnancy were found to be negatively correlated to the number of fetuses.

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By using nuclear magnetic resonance (NMR), the aged testis of Chinese hamster was studied by measuring relaxation times of tissue water protons. Spin-spin relaxation time (T₂) was significantly prolonged compared to young testis when edema was apparent in the interstitial space of the aged testis. When edema was experimentally induced in the young testis by ligation of a subcapsular vein, T₂ was prolonged to the similar extent as in the aged testis. Spin-lattice relaxation time (T₁) and water content of the tissue were essentially the same in the testes of the young and aged animals. It is concluded that T₂ can serve as a sensitive parameter for assessing the age-dependent histological changes in the testis of Chinese hamster.

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The sedative and analgesic/anesthetic effects of medetomidine, acepromazine, azaperone, droperidol and midazolam were compared in laboratory pigs. In these sedatives, medetomidine produced the most profound degree of sedation with greater drowsiness than was achieved by other sedatives tested. Medetomidine induced sedation accompanied with weak analgesia and muscle relaxation smoothly and quickly and depressed arousal reaction deeply as compared with other sedatives. Pigs given medetomidine were not aroused easily even by moderately rough stimulation for approximately 60 min after injection.

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Anti-Corynebacterium pseudotuberculosis toxin titers were examined by an enzyme-linked immunosorbent assay (ELISA) at 3 to 5 month intervals in sheep of three age groups (lambs, 1- and 2-year-old sheep). A significant increase in the ELISA-positive ratio was found only in July, 3 months after shearing, in 1- and 2-year-old sheep. A decrease in the positive ratio was found in the same month in lambs, possibly due to a decrease in maternal antibodies. Since the 1- and 2-year-old sheep had been sheared in April, it was considered that the increase in the positive ratio in July might be closely related to the shearing in April.

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To examine the prophylactic efficacy of milbemycin oxime against Dirofilaria immitis infection, 42 filaria-free beagles were inoculated with 100 ineffective larvae of the parasite. Milbemycin oxime was administered orally at doses of 0.05 to 1.0 mg/kg body weight one month after inoculation, and at a single dose of 0.25 mg/kg body weight on days 1 to 90 after inoculation. All dogs were euthanetized and autopsied to evaluate the prophylactic effect of the drug against D. immitis infection 6 months after inoculation. It was confirmed that a dose of 0.25 mg/kg of milbemycin oxime completely-protected the infection 15 to 60 days after infection.

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Virulence of bovid herpesvirus 1 (BHV-1) for C57BL suckling mice was compared among respiratory, genital and attenuated vaccine strains. The 50% mouse lethal dose of the respiratory strain was approximately 1, 000-fold lower than that of the vaccine strain. The genital strain showed intermediate virulence. The kinetic studies suggested that the respiratory strain appeared to multiply in the brain of the animals, and that the genital and vaccine strains were eradicated from the animals.

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The calorimetric assay used 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) was compared with the ³H-thymidine incorporation assay in swine lymphocyte blastogenesis induced by phytohemagglutinin-P (PHA) and concanavalin A (ConA). The correlation coefficients were 0.70 (n=18, p<0.01) in PHA and 0.82 (n=18, p<0.01) in ConA. The maximal responses were observed in cultures of 2.0×10⁶ cells/ml with the final concentration of 2.5-10.0 μg/ml in PHA or 2.5-5.0 μg/ml in ConA for 72 hr. The stimulation index of peripheral blood lymphocytes from clinically healthy pigs aged 6 months were 1.77±0.10 (n=10) in PHA and 1.96±0.18 (n=10) in ConA, respectively.

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A 72-day-old, female, Golden Retriever dog showed anorexia, coughing, nasal discharge, diarrhea and hematochezia, and died on the 15th clinical day. Pathological examination revealed dual infection with canine distemper virus (CDV) and canine adenovirus (CAV). CAV inclusion bodies occurred only in the liver, and biliary and respiratory system, whereas CDV inclusions were demonstrated in the visceral organs systematically. The CAV inclusions were associated with multifocal hepatocellular necrosis and edematous swelling of the wall of the gall bladder, suggesting infectious canine hepatitis virus (canine adenovirus type 1) infection.

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