Porcine reproductive and respiratory syndrome (PRRS) viruses were isolated from pig samples obtained from two farms characterized by an increased number of stillbirth and high mortality in new-born piglets (farm A), and respiratory distress with high mortality in weaning and growing pigs (farm B) in 1993, respectively. When primary specific pathogen-free piglets, 5-day-old or 13-day-old, were experimentally inoculated with the isolates, they showed clinical signs of depress, anorexia, pyrexia, diarrhea, sitting posture and periocular edema. Rate of the weight gain was reduced in the inoculated piglets compared with the non-inoculated pig. There were no apparent differences in clinical signs between the piglets inoculated with the virus samples derived from farms A and B. Microscopically, the most prominent changes observed in experimentally inoculated piglets were interstitial pneumonia, nonpurulent myocarditis and catarrhal lymphnoditis post inoculation day (PID) 28. Viruses were recovered from tissues collected from the inoculated piglets on PID 7 or 28. Furthermore, the viruses were continuously recovered from the sera from PID 7 to PID 28. Antibodies measured by indirect immunofluorescence assay to PRRS virus were first detected in sera on PID 14, and the antibody titer rose to 1:1280 on PID 28.

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This study was designed to compare the renal effects of atrial (A-type) natriuretic peptide (ANP) on control (saline-injected) rats and rats with non-oliguric acute renal failure induced by cisplatin. The results obtained here are summarized as follows: (1) In the metabolic cage study, cisplatin-treated rats showed increased in blood urea nitrogen and serum creatinine while creatinine clearance decreased to the lowest levels on day 4. A transient increase in urinary protein was observed at day 4. (2) ANP infusion significantly increased urine flow fate (UFR), creatinine clearance (CCr), fractional excretion rates of sodium (FE_Na) and chloride (FE_Cl), and urinary phosphorus and magnesium (Mg) excretions in a dose-dependent manner without affecting renal plasma flow and fractional excretion rates of potassium and urea in cisplatin-treated : rats. (3) Renal effects of ANP on UFR, CCr, FE_Na, FE_Cl and excretion of Mg were more pronounced in cisplatin-treated rats compared to control rats although markedly blunted responses to ANP have been reported in nephrotic patients and nephrotic animals induced by adriamycin and aminonucleoside. (4) Histological examination showed extensive necrosis of the S₃ segment of the proximal tubule located in the outer stripe of the outer medulla with minimal glomerular abnormalities in the kidney of cisplatin-treated rats. In conclusion, the main mechanism of the increased renal responses to ANP is considered to be due to an increased delivery of sodium, fluid and ANP itself to the inner medullary collecting duct which is the major renal site of action of ANP under the condition of acute proximal tubular necrosis by cisplatin.

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To clarify the resistibility against Theileria sergenti infection in Holstein and Japanese Black cattle under controlled conditions in artificial environmental chambers, those breeds of calves were infected with T. sergenti by infestation with the same number of infected ticks. No apparent differences between the two breeds were observed in the feeding numbers and feeding periods of ticks infested. The level and duration of parasitemia were clearly less and shorter in Japanese Black than those in Holstein calves. With progress of parasitemia, packed cell volume (PCV) and erythrocyte number decreased in both breeds. However, the minimum PCV and erythrocyte number recorded in Japanese Black Were higher than those in Holstein calves. These results suggest that the Japanese Black shows solider resistance to T. sergenti infection than the Holstein breed does under experimentally controlled condition without external factors.

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The rapid inhalation induction of anesthesia (RII) by mask inhalation of halothane, enflurane, isoflurane and sevoflurane at an equianesthetic concentration (2.5 MAC) was evaluated in 24 beagle dogs. The differences in movements, induction and intubation time between anesthetics were mainly associated with the differences in each blood/gas solubility. The most rapid and smoothest induction was observed by sevoflurane inhalation (209.0±44.2 sec), followed by isoflurane inhalation (285.8±34.1 sec). Halothane inhalation took the longest induction time (790.3±75.7 sec). Movements during RII were minimal in sevoflurane group comparing to the other groups. Heart rate, cardiac output and rate pressure product significantly increased after the beginning of inhalation in all the dogs except for those of halothane group. These changes exceeded the physiological level just after the beginning of inhalation, however, rapidly reversed to the meintenante level (1.5 MAC) approximately 10 min after intubation. Consequently, sevoflurane seemed to be the best inhalational anesthetic for RII in (logs without significant problems in respifatory and/or cardiac functions. Isoflurane also induced rapid induction with some degree of the movements.

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To investigate the effect of the decrease in the number of embryonic cells on the development and morphogenesis of mouse embryos at the peri-implantation stage, half embryos which developed from bisected morulae were morphologically classified into eu-blastocysts (eu-blasts), pseudo-blastocysts (pseudo-blasts), trophectodermal vesicles (TVs) and non-integrated forms (NIFS) and then cultured on plastic substratum, uterine-epithelial-cell monolayer and type I collagen gel. When half embryos were cultured on plastic substratum and cell monolayer, the rates of attachment and trophoblast outgrowth in the eu- and pseudo-blasts were not significantly different from those of the controls. The TVs and NIFs showed significantly lower rates of outgrowth than the controls (P<0.01). When half embryos were cultured on type I collagen gel, no significant difference was observed in the rate of primitive endoderm formation between the eu-blasts and controls after 36 hr of culture. In the eu-blasts, however, the developmental rate to the egg cylinder at stage 8 was significantly lower than in the controls after 72 hr (P<0.05). The pseudo-blasts revealed significantly lower rates of endoderm formation and development to the egg cylinder than the controls after 36 and 72 hr, respectively (P<0.05). In the TVs and NIFs, the rates of outgrowth were significantly lower than those of the controls (P<0.05) and no egg cylinder was observed. The invasion of type I collagen gel by the cytoplasmic protrusions of trophoblast cells was observed regardless of the type and developmental stage of the embryos. The results show that a decrease in the number of embryonic cells affects the formation of the primitive endoderm and the development to the egg cylinder in vitro.

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Three strains of influenza A virus (H3N2) were isolated from pigs in Hokkaido, Japan in 1993. The hemagglutinin (HA) antigen of the three isolates was related to that of recent H3N2 viruses of human origin. The reactivity patterns of two of the isolates (A/sw/Obihiro/1/93 and A/sw/Obihiro/2/93) with monoclonal antibodies to the hemagglutinin of A/Bangkok/1/79 strain were similar to that of the human H3N2 strain isolated in Hokkaido in 1988, while that of the other one (A/sw/Obihiro/3/93) was similar to human H3N2 strains of 1993. In the phylogenetic analysis based on the nucleotide sequences of the HA1 regions, the HA genes of the two isolates were shown to be closely related to those of human H3N2 viruses isolated between 1986 and 1988. The remaining one isolate was shown to be closely related to those of current human H3N2 viruses. We have also found serological evidence that the A/sw/Obihiro/1/93 virus is circulating extensively in Obihiro swine. It is clear from these findings that pigs were infected with the recent H3N2 influenza virus during the human epidemic and that the virus has been maintained in pigs for at least five years.

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Corpora lutea of the sika deer (Cervus nippon, Cervidae) were histologically examined in order to elucidate their retrograding processes after parturition. They showed a remarkable regression within one month as luteal cells decreased in number and, by nine months after parturition, turned into masses of blood vessels containing many arterioles with a diameter of 30μm or less. In retrograde corpora lutea (RCL), older than 1.5 years after parturition, arterioles of these dimensions decreased markedly, while those measuring 50μm or more became dominant. These findings indicate that an examination of RCL can distinguish females less than nine months after parturition from those mote than 1.5 years after parturition. Based on the findings of RCL from the ovaries of a 10.5-year-old female, it is suggested that RCL remain in the ovaries for at least 8.5 years after parturition. It was, however, difficult to distinguish RCL of pregnancy from retrograde accessory corpora lutea (RACL). In order to arrive at a complete count of RCL, the ovaries should be examined at thicknesses of 0.5 mm. To check the presence/absence of RCL of pregnancy within nine months or less after parturition, sectioning at thicknesses of 2 mm is sufficient.

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Cardiat myocytes of an Asian elephant (Elephas maximus) were observed transmission electron microscopy. Typical ultrastructural features of cardiac myocytes are exhibited in the musculature of both the left and right atria, and left ventricle of the heart. Myofibrils, mitochondria, T-system and sarcoplasmic reticulum are well-developed within the cytoplasm. Many mitochondria are characteristically concentrated is some myocytes. Cardiac musculature is also distributed in the root of the caudal vena cava. Many atrial granules are detected not only in atrial myocytes; but also in the myocytes of the caudal vena cava. Atrial natriuretic polypeptide may be secreted from the caval venous wall in the elephant.

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The present study was aimed at the establishment of an experimental model for the numerical assessment of sick animal behavior. Four goats were given bolus injections of 200 ng/kg of lipopolysaccharide (LPS) or vehicle (0 hr) under non-restrained conditions, and observed for behavioral changes and clinical symptoms during the period between -1 and 10 hr. The apparent clinical symptoms of miosis and shivering were observed during the period from 39.5±3.1 to 296.5±9.9 min and from 46.0±2.3 to 251.0±15.5min after the LPS administration, respectively. As to the general behaviors, the total length for standing and sternum lying during the period from 0 to 5 hr after LPS administration showed no change, however, that for feeding and rumination, and the cumulative number of grooming episode were significantly reduced as compared to the control period. On the other hand, the cumulative numbers of urination, defecation and yawning showed a tendency to increase but not significantly. These results suggest that stereotyped behavioral responses, which are typically seen in acute phase of sickness, can be transiently induced in goats by treating them with LPS.

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In order to clarify the relationship between heart morphology and blood pressure, I examined the mutual correlation between the ventricular wall thicknesses of heart and body weight, heart weight, and arterial blood pressure in 15 normal male cynomolgus monkeys. The results obtained were as follows; (1) The mean and standard deviation of the arterial blood pressure was 68±8 mmHg at diastolic time and 124±12 mmHg at systolic time, respectively, and that of pulse rate was 227±17 beats per min under non-anesthesia. In addition, the mean and standard deviation of the arterial blood pressure was 55±11 mmHg at diastolic time and 102±18 mmHg at systolic time, respectively, and that of pulse rate was 197±17 beats per min under general anesthesia. (2) The mean and standard deviation of the left ventricular wall thickness was 6.6±1.1 mm at anterior, 5.3±1.0 mm at posterior. 5.9±0.9 mm at lateral, 5.4±1.2mm at the interventricular septum, and that of the right ventricular wall thickness was 2.4±0.5 mm at anterior. (3) The mean and standard deviation of body weight was 4.1±0.7 kg, and that of heart weight was 16.5±3.1g. (4) The heart weight and interventricular septum thickness correlated significantly to body weight, respectively. (5) There was no significant correlation between arterial blood pressure and the ventricular wall thickness. Further study should be necessary in more normal monkeys, together with abnormal ones with hypertension or cardiac hypertrophy, in order to evaluate the relationship between heart morphology and blood pressure.

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The extract from Sarcocystis cruzi cysts in bovine muscle was subcutaneously injected to mice, guinea pigs, chickens, and rabbits to detect its toxicity. Only rabbits showed reactions after administration of the extract at a dose of 25 μg. The main clinical signs of the rabbits were depression, reduction in body temperature and intermittent diarrhea and the hematological findings observed were elevation in WBC, RBC, PCV, TP, BUN, AST, AUT and creatinine values and reduction in glucose, K⁺ and pH of blood. The extract, crude toxin, was a water soluble, acid-alkali stable and thermolabile protein and estimated to be a molecular mass of 15-16 kd.

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We established a mouse antiserum by immunizing BALB/c mice with sexually undifferentiated 6-day chick embryonic gonads. The antiserum had a higher affinity to the plasma membrane and cytoplasm of primordial germ cells (PGCs) than to the somatic cells in 6-day chick gonads. PGCs at this stage appear to have a higher specificity with more antigenic capacity than gonadal somatic cells; thus, the antiserum should be useful as a cell marker of chick PGCs. Subsequently, an immunohistochemical examination of PGCs settling in the genital ridges of chick embryos wad carried out by the use of the antiserum. The reaction was clearly detected in the plasma membrane and cytoplasm of 5-day PGCs. After sexual differentiation, the reaction changed in distribution in females. At 8 days, it was limited to the perinuclear region of PGCs; In males, although the reaction persisted for longer period than in females, only a weak reaction was detectable at 9 days. These results suggest that the occurrence of periodic molecular changes may be different between male and female PGCs.

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The nematocidal effect of doramectin was assessed by subcutaneous injection of 200 μg/kg (single dosage) in cattle with naturally acquired gastrointestinal nematode infection in Japan. This study consisted of two experiments. In experiment l, animals were randomly divided into a doramectin group (n=21) and a non-treated control group (n=21) by fecal egg count. In experiment 2, another group of ivermectin treatment (n=12) was prepared in addition to doramectin (n=23) and control (n=10) groups, by random assignment as in study 1. After doramectin or ivermectin treatment, the egg count/5 g of feces was measured by the sucrose centrifugal flotation method at intervals of 7 days until Day 21 in experiment 1 and at Days 7, 14, 21, 35, 42, 49 and 63 in experiment 2. Coproculture was also carried out using some of the fecal samples. In the 2 doramectin-treated groups, 96.1% -100% egg reduction rates were obtained for Haemonchus, Cooperia, Mecistocirrus, Trichostrongylus, Ostertagia, Bunobtomum, Strongyloides and Trichuris from the 7th day until the 49th day after treatment. Thus doramectin was confirmed to be highly effective against those species of adult nematoda. The effect against Mecistocirrus has not been previously determined. The nematocidal effect against Nematodirus was lower (egg reduction rate approximately 50%) than other species. No adverse reactions to treatment were seen in any animal during either study.

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A serological surveillance was carried out to detect antibody against influenza A virus in chicken sera. A total of 8, 850 field samples were collected from 47 prefectures in Japan. Initially, all the sera were screened by agar gel immunodiffusion and those sera showing positive reaction were investigated for haemagglutination-inhibition (HI) and neuraminidase-inhibition antibodies against influenza viruses. Only 6 samples had antibodies; 4 sera had antibodies against human subtype H1N1 virus; with HI activity against strain A/PR/34; three sera had strong HI activity to strain A/Tottori/4/87, which by haemagglutination test is closely related to A/Yamagata/120/86. The remaining two chicken sera had antibodies against avian subtypes H10N4 and H3N6 viruses respectively.

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Muscarinic receptor subtypes mediating catecholamine secretion and increase in the intracellular concentration of Ca²⁺ ([Ca²⁺]_i) were examined using muscarinic agonists and antagonists in dispersed adrenal chromaffin cells of the guinea pig. All muscarinic agonists (1-1, 000μM) tested caused increases in adrenaline secretion in a dose-dependent manner. Muscarine and methacholine were more effective than bethanechol, oxotremorine and pilocarpine. Muscarine and oxotremorine caused a small increase in adrenaline secretion even in the absence of extracellular Ca²⁺. Both 4-DAMP (0.1μM) and pirenzepine (0.1μM), but not methoctramine (0.1μM), shifted the dose-response curve for muscarine-induced adrenaline secretion to the right. These muscarinic agonists also caused increase in [Ca²⁺]_i in the presence of extralcellular Ca²⁺. Muscarine-induced [Ca²⁺]_i rises were reduced, but not abolished, by removal of extracellular Ca²⁺. These results suggest that catecholamine secretion induced by muscarinic agonists is mediated through M₁, or M₁ and M₃ muscarinic receptor subtypes in adrenal chromaffin cells of the guinea pig.

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Antibody responses to the hapten dinitropbenyl (DNP) and the concentration of catecholamine in chickens received a single injection of 6-Hydroxydopamine (6-OHDA) into the chorioallantoic cavity at the embryonal stage were evaluated. A significantly enhanced anti-DNP IgA response and a markedly decreased level of noradrenaline in the peripheral blood were observed in chickens treated with 400 μg of 6-OHDA at 14 days of incubation. These results suggested the immunomodulatory influence of the sympathetic nervous system.

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The concentration of serum C3 in quails bearing tumors induced by Rous sarcoma virus (RSV) was elevated in parallel with tumor growth, whereas serum C3 levels in quails inoculated with avian leukosis virus, which lacks transforming activity, showed a pattern similar to that in mock-infected quails. C3 deposition was also observed in almost all tumor cells at the tumor developing stage. These findings obtained in vivo suggest that the cells transformed by RSV activated the C3 on their surfaces.

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Phosphorothioate oligodeoxynucleotides (PS-oligo) complementary to a leader RNA of mouse hepatitis virus (MHV) were more effective inhibitors of MHV multiplication than natural oligodeoxynucleotides (PO-oligo). Sequence-dependent inhibition of viral multiplication was shown at low concentrations (0.001-0.1μM) of antisense PS-oligo. Phosphorothioate oligodeoxycytidine, PS-(dC)₂₀ and PS-oligo, which has no significant homology to the MHV sequence, showed inhibitory effects on MHV multiplication at concentrations higher than 0.5μM. These results showed that PS-oligo was more potent than PO-oligo in inhibition of MHV multiplication and that PS-oligo may inhibit MHV multiplication by two different mechanisms, that is, in sequence-dependent and -independent manners.

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The charcol-cefazolin-sodium deoxycholate agar (CCDA) was compared with Butzler agar for selectivity of campylobacters from fecal samples. A total of 279 samples of cecal contents from 176 cattle and 103 pigs slaughtered in Saitama were examined. Fifty-five (31.3%) cattle were found to contain campylobacters by the direct plating culture on CCDA plates, compared with 29 (16.5%) on Butzler agar plates. The positive rates of pig samples on CCDA and Butzler agar were very high, being 96 (93.2%) and 86 (83.5%), respectively. After enrichment culture of 107 cattle specimens in Preston, CEM or Bu 10 broth, the isolation rate on CCDA was also higher (p<0.01) than that on Butzler agar after enrichment in any medium. These results indicate that CCDA medium is easy to handle without blood and, as to this study shows, is superior to Butzler agar for isolation of Campylobacter species from fecal samples.

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Intramuscular injection of 0.1 mg/kg of Escherichia coli lipopolysaccharide (LPS) mixed with Freund's complete adjuvant (LPS+FCA) in piglets mititated the leukopenia and TNF-α and cortisol levels in the serum compared with that of LPS suspended in LPS-free saline. The endotoxin level in the serum of the LPS+FCA was remarkably reduced. These results suggest that the addition of oil adjuvant mitigate the systemic toxicity of LPS.

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With goose parvovirus (GPV) strain IH, an inactivated vaccine was prepared from allantoic fluid of embryonating Muscovy duck eggs inoculated with GPV. The response to vaccination was measured by virus neutralizing antibody titer against GPV. Offsprings from the vaccinated flock were introduced in a farm in which GPV infection had been experienced and examined for resistance to exposure to GPV. The results showed that the intramuscular vaccination to Muscovy ducks at any age stimulated significant virus neutralizing antibody levels, and that more than 90% Muscovy ducklings from the vaccinated parent flock survived after the exposure to GPV. Muscovy ducklings that passively possessed high level virus neutralizing antibodies also could respond to the vaccination and the induced antibodies remained for more than 2 months.

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A nine-year-old Shetland sheepdog was diagnosed as discoid lupus erythematosus by clinical features, histopathologic findings, positive direct immunofluorescence, negative antinuclear antigen test and the absence of multisystemic diseases. The indirect immunofluorescence test of this patient dog with the salt split skin showed the deposition at the bottom of the cleft at basement membrane zone (BMZ). Western immunoblotting revealed the 120 kDa and the 85 kDa proteins targeted by the autoantibody. These proteins did not correspond with the known BMZ component.

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An 8-month-old cat with bilateral hindlimb paresis was admitted. Radiography revealed a curvature of the thoracic spine and a partial deformation of thoracolumbar vertebrae (dorsal extrusion of the cranial and caudal edges). Compression of the spinal cord (T9-L1 and L6-7) was found by myelography. Medicinal treatment did not yield the desired result. Hemilaminectomy and laminectomy were done to relieve pressure on the spinal cord leading to improved gait. It is, however, not clear whether this syndrome was primarily caused by metabolic or genetic factors.

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The relationship between plasma insulin-like growth factor-I (IGF-I) level and body weight was studied in six breeds of horse. The correlation coefficients between plasma IGF-I and body weight in males and females of 1 year old heavy horses (Percheron and Breton breeds) were 0.62 and 0.12 respectively. The mean plasma IGF-I of males was higher than that of females (p%lt;0.01). However, the plasma IGF-I levels of heavy horses did not exceed those of light horses (Thoroughbred) or ponies (Shetland and Falabella). These data suggest that IGF-I is at least related to the difference of body weights between sexes in heavy horses.

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To study the effects of insulin and insulin-like growth factor-I (IGF-I) on early development of bovine embryos, one-cell embryos were cultured in a chemically defined, protein-free medium: modified synthetic oviduct fluid. The addition of 10 μg/ml insulin or 20 ng/ml IGF-I increased the percentage of morulae at Day 5 (5 days after insemination). The cell number of blastocysts which developed after 2 days culture of morulae obtained at Day 5 was increased by supplementation with insulin or IGF-I. The combination of insulin and IGF-I had neither additive nor synergistic effect on the embryonic development. These results clearly show that insulin and IGF-I improve the in vitro development of bovine embryos.

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Sixty-four Japanese Black parous cows were divided into 5 dosage groups (I, II, III, IV, V) and administered either human menopausal gonadotrophin (hMG) or FSH by intramuscular injection. No significant differences were observed between the hMG-treated groups. The average number of recovered ova/embryos in cows treated with 900 IU was significantly greater (P<0.05) than in cows treated with FSH. The percentage of high-quality transferable embryos was highest in the 600 IU hMG-treated group. Also, FSH-treated cows produced a significantly larger number of unfertilized ova compared to hMG-treated cows. The results suggest that hMG treatment is sufficient for Japanese Black Cattle at a dose of 600 IU for 3 days, and that a 2-day treatment regime is also possible.

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A new cell line, designated NB-YK, was established from a transplantable rat nephroblastoma (NB-Y) which was derived from a spontaneous nephroblastoma in an aged Fischer 344 rat. NB-YK grew in a piling-up and noncohesive pattern on the plastic surface and formed colonies in a soft agar. The main cell type of NB-YK represented morphology of mesenchymal phenotype and most of the cells contained several secretory granules in their cytoplasm. Immunocytochemically the cells were positive for vimentin, cytokeratin, and laminin. Coexpression of vimentin and cytokeratin in the cells was confirmed by the one-dimensional gel electrophoresis and immunoblotting for intermediate filament proteins. NB-YK cells were tumorigenic and produced fibrosarcoma-like tumor when inoculated subcutaneously or intraperitoneally into syngeneic rats and nude mice. NB-YK seems to be a useful model for studying biological properties of nephroblastoma.

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Clinical usefulness of rapid inhalation induction of anesthesia (RII) using 5.O vol.% isoflurane (GOI) and sevoflurane (GOS) with N₂O was evaluated in 124 canine patients. Induction times, loss of various reflexes and movement times were significantly faster in GOI group than in GOS group. Scores for the easiness of intubation and the degree of movements were also significantly less in GOI group than in GOS group. Positive correlation between body weight and degree of movements was observed in both induction groups. Thus, RII using GOI is a practically useful and safe induction modality in small-to medium-sized dogs.

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Cell-free-antigens prepared from a concentrated culture supernatant of Actinobacillus pleuropneumoniae (A. pleuropneumoniae) serotypes 1, 2 and 5 were mixed and emulsified with oil adjuvant. The combined vaccine of these 3 serotypes of A. pleuropneumoniae was tested for its ability to confer protection. Pigs immunized with the combined vaccine survived and showed no clinical signs against an intratracheal challenge with A. pleuropneumoniae. In contrast, control pigs inoculated with concentrated culture media emulsified with oil adjuvant developed typical symptoms of pleuropneumonia after challenge inoculation.

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We investigated effects of feline herpesvirus type 1 (FHV-1) ICP4 on feline immunodeficiency virus (FIV) long terminal repeat (LTR)-directed gene expression by transient transfection assay in Crandell feline kidney cells. We demonstrated that FHV-1 ICP4 significantly stimulates the FIV LTR after introduction of site-specific mutation of the C/EBP site in the LTR, and the C/EBP site is sufficient to confer inhibitory effects by FHV-1 ICP4 on a heterologous promoter. These results indicate that FHV-1 ICP4 possesses both ability to transactivate FIV LTR-directed gene expression and to down-regulate the FIV LTR via the C/EBP site.

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