The clinical usefulness of biodegradable oriented poly-L-lactide (PLLA) screws for experimental Salter-Harris type 4 fracture in the distal femoral condyle of dogs was evaluated. Bony union of the osteotomized fragment of the condyle was almost completed radiographically and histologically within 1 to 2 months after surgery, suggesting that PLLA screws maintained strength long enough to fix the fragment until bone healing. At 4 to 6 months after surgery, minute fissures were histologically confirmed on the surface of the screw thread, suggesting the early stage of biodegradation and absorption of the polymer. During the observational period, no significant difference between the treated femur and the contralateral non-treated femur in either total femoral length or maximum condyle width was observed, indicating no growth disturbance in the treated femur. From these results it was concluded that the PLLA screw might be an ideal implant for the reduction and fixation of epiphyseal plate fractures such as Salter-Harris type 3 or type 4 fractures.

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Phosphorylated protein pp38 is the only protein that is detected in the Marek's disease (MD) lymphoma caused by MD virus serotype 1 (MDV-1) and lymphoblastoid cell lines. In this study, a recombinant protein coded for by the almost entire open reading frame of the MDV-1 pp38 cDNA was produced in E. coli and purified by affinity chromatography. Prior to the expression and purification of the protein, cDNA containing the entire coding region for pp38 was cloned and its nucleotide sequence was determined. Immunoblot analysis indicated that the expressed recombinant protein electrophoresed close to that of the pp38 in infected cells. The difference in mobility of the purified recombinant and the pp38 in infected cells corresponded to a fusion peptide. The recombinant pp38 may be of interest for function analyses and the diagnotic use of pp38.

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We report here distributions of antigens expressed on sporadic bovine leukosis (SBL) cells by a total of 38 monoclonal antibodies (mAbs) directed against three different types of SBL-cell lines, BLT2 (thymic type), BTL-PC3 (calf type) and BLS1 (skin type). Most mAbs had high reactivities with some bovine lymphoma cell lines and less reactivity with normal lymphocytes except for some peripheral blood mononuclear cells (PBM) in cattle and certain other species. They were more reactive with cultured T-cell line BTL-PC3 and B-cell lines, BL312 and KU-1, than naturally occurring lymphoid tumor cells. Among the 38 mAbs, 27 was determined the molecular weights of their recognized antigens in Western blot analyses. A mAb C419 had high reactivity with lymphoma cell lines but no reactivity with normal lymphocytes, indicating that it recognizes tumor-associated antigens of SBL.

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Seasonal changes in spermatogenesis and the ultrastructure of developing spermatids in the Japanese rat snake, Elaphe climacophora, were observed by light and transmission electron microscopy. Spermatogenesis in this species began in August, continued through October and ceased in November. No spermatozoa were found during other periods. Japanese rat snakes mate from May to July, and spermatogenesis occurs after the mating season. Therefore, according to Girons' classification (1982), the reproduction of this spccies was classified as a postnuptial type. Although the morphological changes in developing spermatids during spermiogenesis in these snakes fundamentally resembled those in mammals, some unique features were detected. The most prominent characteristic of the developing spermatids was lipid-like structures. These structures first appeared in early round spermatids, gradually increased in size and number, and, finally, aligned around the nucleus of mature spermatids. Although spermatozoa with lipid-like structures were released from the epithelium, stored spermatozoa in vas deferenses had none of these structures. Lipid-like structures that apparently separated from spermatozoa were scattered in the vas deferens. Prominent elongation of mitochondria was also remarkable in elongated spermatids.

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The changes in ganglioside composition of bovine erythrocytes associated with Theileria sergenti infection were investigated using the erythrocytes before and after the infection. The erythrocytes before infection with T. sergenti had GM3, sialosylparagloboside (SPG), i-active, and I-active ganglioside as predominant gangliosides. After infection with T. sergenti merozoites, the contents of SPG and i-active ganglioside were slightly less, and I-active ganglioside content was much less in the erythrocytes, though GM3 content did not so vary. The decreased I-active ganglioside content showed a recovery as the parasitemia waned to low level in the infected cattle. The total amount of lipid-bound sialic acid also decreased in the erythrocytes after the infection. Similar changes were also caused by the incubation of liposomes containing ganglioside fraction obtained from bovine erythrocytes with T. sergenti piroplasms. These results suggest that the reduction of the contents of SPG, i-active, and I-active ganglioside on the erythrocytes was related to the T. sergenti infection.

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Circadian variations of N-acetyl-β-D-glucosamidase (NAG, EC 3. 2. 1. 30) and γ-glutamyl transpeptidase (γ-GTP, EC 2. 3. 2. 2) were examined in dogs. Urine and blood were collected at 4-hr intervals from adult mongrel dogs (11 males, 11 females) weighing between 7 and 13 kg. The collected urine and blood were used to measure creatinine, NAG and γ-GTP. The amount of urine was significantly higher (p<0.05) during the period from 12:00 to 16:00. Creatinine clearance did not show any characteristic variations and creatinine excretion was significantly higher (p<0.05) during the period from 8:00 to 16:00. No characteristic variations were observed in the amounts excreted, activity, or NAG and γ-GTP creatinine index. There were high correlations between creatinine excretion and creatinine clearance (r=0.693), γ-GTP excretion and γ-GTP creatinine index (r=0.724), NAG excretion and NAG creatinine index (r=0.878), and between the NAG and γ-GTP creatinine index of each 4-hr specimen and the NAG and γ-GTP excretion of the 24-hr specimens. These results suggest the diagnostic usefulness measuring enzyme activity in non-periodically collected urine.

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We measured crania and mandibles of Ryukyu wild pigs from Iriomote Island. Sex and age were determined by observation of lower teeth. From the present data, the growth pattern was established for some items. For several parts of the cranium and mandible, the relative growth coefficient was compared. The results obtained here are summarized as follows: (1) Although sexual dimorphism was already shown in the younger group, a significant difference in profile length and length from the angle was not seen in the adult group. (2) As the animal grew, the proportion of length to width became larger in the skull. (3) The visceral cranium grew more rapidly in length than the cerebral cranium. On the other hand, growth of the cerebral cranium contributed to width in cranial development. (4) The body of the mandible was shown to grow more rapidly in length than the ramus of the mandible. (5) The growth pattern of some items was related to that of their associated muscles. These basic data are expected to be compared with data from other populations of the same subspecies and Japanese wild pig. The comparisons will contribute to the establishment of origin and phylogeny of this animal.

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Blood gases and cardiopulmonary function were analyzed in 67 dogs with heartworm (HW) caval syndrome (CS) and 19HW-free dogs. Arterial oxygen tension (PaO₂) was 91.5±7.3 mmHg in the HW-free dogs, 74.9±14.3 mmHg in 46 dogs that subsequently survived surgical HW removal (surviving dogs) and 64.6±14.7 mmHg in 21 dogs which later died or were euthanatized following surgical treatment (nonsurviving dogs). PaO₂ levels less than 60 mmHg were detected in 30.4% and 38.1% dogs in the surviving and nonsurviving groups, respectively. Arterial carbon dioxide tension (PaCO₂) was 35.8±4.9 mmHg in the HW-free dogs, 30.7±5.6 mmHg in the surviving dogs, and 28.8±6.2 mmHg in nonsurviving dogs. PaO₂ (p<0.01) and PaCO₂ were lower (p<0.01) and the alveolar-arterial oxygen difference (AaDO₂) was higher (p<0.01) in CS dogs than in HW-free dogs. PaO₂ was lower (p<0.01) and AaDO₂ was larger (p<0.01) in the nonsurviving dogs than in the surviving dogs. Arterial blood pH and bicarbonate concentration were lower (p<0.01) and the anion gap was larger (p<0.01) in CS dogs than in the HW-free dogs. Serum lactic acid level in nonsurviving dogs (13.2±3.9 mmol/l) was higher (p<0.01) than in the HW-free (1.7±0.8 mmol/l) and surviving dogs (2.7±1.8 mmol/l). The PaO₂ correlated significantly with mean pulmonary arterial pressure (r=-0.65, p<0.01), cardiac index (r=0.44, p<0.05) and total pulmonary resistance (r=-0.70, p<0.01). Blood gas analysis was repeated 1 week after HW removal in 21 dogs that survived and 10 dogs that did not survive. PaO₂ (p<0.05) and PaCO₂ (p<0.01) increased, and AaDO₂ (p<0.01) decreased in the surviving dogs, but not in the nonsurviving dogs. Blood gas values reflecting circulatory disturbance and ventilation insufficiency are predictors of survival following surgical HW removal in dogs with CS.

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Thirty-one base pairs (bp) containing putative AP-1 and AP-4 binding sequences in the U3 region of feline immunodeficiency virus (FIV) long terminal repeat (LTR) were deleted from an infectious molecular clone of FIV for construction of a mutant virus, and the replication rate and the cytopathogenic activity of the virus were compared with those of the wild type virus in concanavalin-A (Con-A) stimulated primary feline peripheral blood mononuclear cells (fPBMCs). It was found that the replication rate and cytopathogenic activity of the mutant were almost the same as those of the wild type. The deletion of the mutant virus was stable during the infection experiments. From these data, we concluded that the 31 bp fragment in the LTR is not required for the replication of FIV in Con-A stimulated primary fPBMC.

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The methemoglobin formation and methemoglobin reduction in canine erythrocytes characterized by inherited high potassium (K⁺) and normal reduced glutathione concentrations (HK-low GSH cells) were compared with those in canine erythrocytes with inherited high K⁺ and high GSH concentrations (HK-high GSH cells) and normal canine erythrocytes with low K⁺ and low (= normal) GSH concentrations (LK-low GSH cells). The rate of methemoglobin formation induced by sodium nitrite (NaNO₂) was in the order; LK-low GSH > HK-low GSH > HK-high GSH cells, and the difference among groups was significant at 7 and 15 min. Methemoglobin reduction in a medium containing glucose occurred rapidly in both HK-high GSH and HK-low GSH cells, and the rate of reduction was 1.7-fold higher than in LK-low GSH cells. Accumulation of pyruvate equivalent to the amount of methemoglobin reduced indicated that methemoglobin was predominantly reduced by NADH-methemoglobin reductase coupled to glycolysis. HK-low GSH cells showed an increased glycolytic rate and high pyruvate kinase activity similar to the levels in HK-high GSH cells. It is therefore evident that HK-low GSH cells offer greater protection against oxidation of hemoglobin to methemoglobin than LK-low GSH cells because of the increased glycolytic rate in HK-low GSH cells attributable to high pyruvate kinase activity in these cells.

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In mice infected with MHV-2, histopathological changes of the thymus was studied. Extensive cell lysis with pyknotic nuclear debris appeared at 48 hr postinfection, and cortico-medullary border was indistinguishable. Electron microscopy revealed vacuolation and shrinkage of the cytoplasm of lymphoid cells, margination of nuclear chromatin, and fragmentation of nuclei. Virus Particles were detectable in the lymphoid and reticular epithelial cells, being immunohistochemically positive for viral antigen. By DNA electrophoresis thymocytes showed DNA fragmentation with a laddering pattern characteristic of apoptosis.

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Long-Evans Cinnamon (LEC) mutant rats were reported to exhibit a deficiency in the serum immunoglobulin (Ig) G1. The phenotype determining the basal level of IgG1 was tentatively designated as immunoglobulin subclass regulator-1 (Igsr-1), and normal rats and LEC rats were categorized into Igsr-1A (normal expression of IgG1) and Igsr-1B (low expression of IgG1), respectively. In this report we examined genetic trait of this phenotype in LEC rats. The serum IgG1 levels in F₁ hybrids produced by mating LEC rats (Igsr-1B) with normal rats (Igsr-1A) were intermediate level, indicating that Igsr-1 behaves as a co-dominant genetic trait. When backcross rats were examined, serum IgG1 levels varied between those in normal and LEC rats without clear segregation, indicating that Igsr-1 is controlled by multiple genes. Furthermore, the serum IgG1 level in each backcross rat did not correlate to another recessive mutant genotype, thid (T-helper immunodeficiency). These data suggest that the deficiency in serum IgG in LEC rats is independent of the deficiency in helper T cell function, but might be due to the multiple deficiency in as-yet-unidentified mechanisms.

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DNA fingerprinting employing a minisatellite Myo probe was used for individual identification and paternity determination in Hokkaido brown bears (Ursus arctos yesoensis). We used two restriction enzymes, HinfI and HaeIII to make DNA fingerprints. Band patterns obtained from randomly selected bears were compared with each other, and the probability x that fragment in an individual was also present in the other was 0.69 for HinfI and 0.83 for HaeIII. The value for HinfI (0.69) was similar to that obtained from other species, such as dog and domestic animals, and the mean probability of all fragments was calculated to be 2.5×10^-2. The results suggest that DNA fingerprinting applying the combination of HinfI and Myo is available for individual identification. On the other hand, the ability to determine paternity seemed to be insufficient owing to the lack of paternal fragments, although the band patterns reflected the correct relationships between child and father.

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Three porcine reproductive and respiratory syndrome viruses (PRRSVs) were successfully isolated from stillborn piglets and fattening pigs derived from diffelent herds affected either with an epizootic reproductive failure or a severe chronic respiratory distress in Japan. The isolates were reacted with antisera against both European (Lelystad virus) and American (strain 46448) PRRSVs in indirect immunofluorescence (IIF). However, cross immunoperoxidase monolayer assay revealed the close serological relationships between the Japanese isolates and American PRRSV, but not between the Japanese isolates and the European PRRSV. The data of preliminary serological survey with IIF technique showed a high frequency of antibody positive pigs against both Japanese isolate and the American PRRSV, whereas a low frequcncy of antibody positive pigs against the European PRRSV, on herds which have had clinical episodes of PRRS-like diseases. These results indicate that PRRSVs are prevalent in Japan, and suggest that the antigenicities of the prevalent PRRSVs are more closely related to those of the American than the European PRRSVs.

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Basal promoter activities of various lentiviral long terminal repeats (LTRs) in a human colon carcinoma cell line (SW480 cells) and a feline renal cell line (CRFK cells) were examined by the chloramphenicol acetyltransferase (CAT) assay using the LTR-CAT reporter plasmids. In SW480 cells, the basal promoter activities induced by LTRs of visna virus, caprine arthritis-encephalitis virus (CAEV), and simian immunodeficiency virus (SIV_AGM) were moderate, and those induced by LTRs of human immunodeficiency virus (HIV) type 1 (HIV-1) and HIV type 2 (HIV-2) were low. However, the activity induced by the LTR of feline immunodeficiency virus (FIV) was extremely low. In CRFK cells, the basal promoter activities induced by LTRs of visna virus, CAEV and SIV_AGM were relatively high, and those induced by LTRs of HIV-1, HlV-2 and FIV were moderate. From these data, although the structure of the LTR of FIV is reported to be similar to that of visna virus and CAEV, the function of the LTR of FIV is rather quite different from that of the LTR of these viruses.

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An emerging swine disease principally involving periweaning piglets was examined. The disease was clinically characterized by lethargy, fever, emaciation, coughing, and severe abdominal breathing, hence colloquially named "Heko-heko" disease. The consistent lesions in affected piglets were diffuse interstitial pneumonia with pronounced type II pneumocytic proliferation, meningoencephalitis, and regression of the lymphoid tissues. The causal virus was isolated in primary porcine lung cell (PLC) cultures from various organs of affected piglets and showed serological relatedness to the European porcine reproductive and respiratory syndrome (PRRS) virus. Numerous virus particles, measured about 49 nm in diameter, were detected in the cytoplasm of alveolar epithelial cells and pulmonary macrophages in PLC cultures infected with the isolate. The condition could be experimentally reproduced in conventional piglets by intranasal inoculation with the isolate and the virus was reisolated from the infected animals.

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To establish which monoamines are elaborated in the pancreatic islet cells of cats, the pancreatic tissue was studied by immunohistochemistry on serial or mirror tissue sections. Glucagon-containing A-cells reacted immunohistochemically with antisera directed against serotonin and aromatic L-amino acid decarboxylase, though the half of A-cells immunostained with glucagon antiserum did not show the colocalization with serotonin. Pancreatic polypeptide-containing PP-cells also showed immunoreactivity for antisera directed against serotonin and aromatic L-amino acid decarboxylase. However, PP-cells exhibiting immunoreactivity for serotonin were very few in number. The overlapping areas of the two types of cell represented only a small proportion of the PP-cells. Immunoreactivity for aromatic L-amino acid decarboxylase was observed within almost all A- and PP-cells. Since aromatic L-amino acid decarboxylase is an enzyme involved in the synthesis of serotonin, it is concluded that pancreatic islet A- and PP-cells in cats have the ability to elaborate serotonin. Contrarily, islet B- and D-cells showing immunoreactivity for insulin and somatostatin antisera, respectively, did not react with antisera directed against serotonin and aromatic L-amino acid decarboxylase.

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Sixty one strains of Pasteurella multocida and 35 strains of Actinobacillus pleuropneumoniae isolated from pneumonic lesions of porcine lungs during the period from 1985 to 1989 in Japan were tested for antibiotic susceptibility to chlortetracycline (CTC), thiamphenicol (TP), tylosin (TS), acetylisovaleryl-tylosin (AIV-TS), tilmicosin (TMS), mirosamycin (MRM). Most strains of both species were sensitive to CTC, TP and TMS. Growth of fifty-one strains (83.6%) and forty-six strains (75.4%) of P. multocida were inhibited with 3.13μg/ml of CTC and 0.78μg/ml of TP, respectively. TS showed low activity against almost all strains (MIC ≥ 6.25μg/ml). Fifty-eight (95.1%), twenty-three (37.7%) and fifty (82%) of P. multocida showed MICs of ≥ 6.25μg/ml against AIV-TS, TMS and MRM, respectively. The MICs of A. pleuropneumoniae against CTC were less than 1.56μg/ml. Thirty-two strains (91.4%) and 33 strains (94.3%) of A. pleuropneumoniae were inhibited with 3.13μg/ml of TP and TMS respectively. However, TS, AIV-TS and MRM showed low activity against all of A. pleuropneumoniae (MIC ≥ 6.25μg/ml). Three different resistance patterns were observed in P. multocida and two in A. pleuropneumoniae isolates, respectively.

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To compare the cardiovascular effects of dibutyryl cyclic AMP (DBcAMP) and milrinone, we used the right heart bypass method in intact anesthetized dogs. The preload of the left ventricle was maintained constant throughout the experiment. Therefore, the effects of DBcAMP and milrinone on cardiac contractility and afterload of the left ventricle were investigated respectively without preload influence. DBcAMP and milrinone exhibited marked positive chronotropic-, positive inotropic-, vasodilative- and diuretic-activity. DBcAMP expressed these effects gradually and continuously, whereas milrinone expressed its pharmacological actions rapidly, but for a short duration of time. Both the afterload-reducing and the cardiac contractile force-enhancing activities of DBcAMP were longer lasting than those of milrinone. Mean arterial pressure was not altered by DBcAMP infusion, whereas it was increased significantly (p < 0.05) by milrinone infusion. The results of this study suggested that DBcAMP appeared to be indicated when there is a need to increase cardiac output by reducing afterload and increasing cardiac contractile force gradually and continuously. On the other hand, milrinone would seem to be indicated when the goal is to raise blood pressure rapidly and to increase cardiac output simultaneously.

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Cattle in Peninsular Malaysia were examined for evidence of infection with Babesia ovata, B. bigemina and B. bovis by an enzyme-linked immunosorbent assay for detection of antibody to the three Babesia species. All of the test samples when assayed with B. ovata antigen, resulted in low value indicating low probability of cattle infected with B. bigemina, 74.4% were positive for B. bovis and 72.6% were positive for both Babesia species. In addition, a serological survey with regard to age difference was carried out on a milk production farm. High reactivity antibody to B. bigemina and B. bovis was detected in calves less than 1 month of the age. The reactivity decreased in calves 1-3 months of the age. Then, the reactivity increased for both Babesia species in 6 months old calves. These results suggested that cattle infected with B. bigemina and B. bovis were widespread throughout Peninsular Malaysia and that both parasites might exist as an enzootical parasite.

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Using a homemade MR imaging probe (Helmholtz coil), MR images of brains of 5-week-old and 23- or 24-month-old Wistar rats were taken under a magnetic field of 7.05 T (Tesla). The probe was designed to fit the rat head and made by winding thin copper film round an acrylic tube with a 5-cm i.d., 10-cm length and 2-mm thickness. This was adjusted to resonate with the 300 MHz radiofrequency corresponding to the resonance frequency of ¹H under a magnetic field of 7.05 T. MR images were obtained by T₁-weighted and two-dimensional Fourier transformation techniques. The sagittal and coronal sections were imaged in 1-mm-thick slices. The size of the data matrix was 128 phase-encoded steps. Each image was obtained through eight acquisitions. A comparison of the MR images with those semi-microscopically taken at the same position of the coronal section revealed that the cerebral cortex, hippocampus, hypothalamus and thalamus were clearly imaged by this probe. With aging, MR images of cerebral cortices were observed with decreased signal intensities. Enlargement of the third ventricles and hypertrophy of cranical parietal bones were also recognized in sagittal MR images of aged rats. These observations were more marked in males than in females. From these observations it was concluded that this probe was applicable for MR imaging of rat brains under a magnetic field of 7.05 T.

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We designed and constructed two hammerhead ribozymes targeted against the Polymerase gene of mouse hepatitis virus (MHV). They consisted of a 22-nucleotide (nt) ribozyme core sequence and antisense sequences of different lengths, 243-nt (S-ribozyme) and 926-nt (L-ribozyme). In cell-free reactions, the constructed ribozymes cleaved the target RNA at a specific site. Vectors that directed the expression of ribozymes by a Promoter of human elongation factor 1α were introduced into DBT cells, and the resulting several cell lines constitutively expressing the ribozymes were selected by Northern blot analysis and examined for intracellular multiplication of MHV. The production of infectious progeny virus particles was significantly reduced in the transfected cell lines expressing either S-ribozyme or L-ribozyme. Although the in vitro cleavage process of L-ribozyme was slower than that of S-ribozyme, no difference was observed in inhibitory effects on MHV multiplication between S- and L-ribozymes in the transfected cells.

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Endothelium-dependent modulation of vascular tone was investigated in isolated porcine and bovine basilar arteries. L-Nitro-arginine (NO synthase inhibitor) and methylene blue (soluble guanylate cyclase inhibitor) increased, but indomethacin (cyclooxygenase inhibitor) decreased the vascular tone in the basilar arteries from both species. Bradykinin evoked relaxation of precontracted porcine basilar artery, but not bovine basilar artery. Sodium fluoride (endothelial G-protein activator) produced relaxation of precontracted basilar arteries from both species. The effects of bradykinin and sodium fluoride were completely abolished by endothelial denudation and markedly inhibited by L-nitro-arginine and methylene blue, but not by indomethacin. Sodium nitroprusside (guanylate cyclase activator) evoked relaxation of precontracted endothelium-denuded basilar arteries from both species. These results suggest that there is species variation in endothelium-dependent modulation of vascular tone in the basilar artery.

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Sedative effects of combinations of medetomidine at 20μg/kg-midazolam at 0.3mg/kg (Me-Mi) and medetomidine at 20μg/kg-butorphanol at 0.1mg/kg (Me-B) were evaluated comparing with those of medetomidine alone (20, 40 and 80μ/kg). All dogs given Me-Mi or Me-B were smoothly and rapidly induced to more profound and longer sedation than those by medetomidine alone. Especially, Me-Mi produced desirable sedation with moderate reflex depression, analgesia, excellent muscle relaxation and immobilization without further side effects. This potent effect of this combination seemed to be induced by a synergistic interaction between medetomidine and midazolam. This combination is available and valuable as a chemical restraint agent in dogs for various diagnostic or therapeutic procedures accompanied by light pain.

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Influences of 38 monoclonal antibodies (mAbs) on the growth of bovine T lymphoma cells (BTL-27) were examined. One of them, S37, inhibited the cell growth strikingly when it was added to the cultures. S37-treated cells showed DNA fragmentation containing∼200-base pair multiple patterns and chromatin condensation. This evidence suggested that mAb S37 induced apoptosis in BTL-27 cells.

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Comparative analysis of nucleotide sequences in the 5' non-coding region (NCR) of pestivirus RNA detected from live porcine and human virus vaccines indicated that the contaminants are of bovine viral diarrhea virus (BVDV), and that there are at least three genotypes, which are distinct from hog cholera virus, among the BVDV strains. Most of the nucleotide changes in variable regions of the 5' NCR were covariant, with complementary substitutions at other positions for secondary structures. The proposed secondary structure in the 5' NCR was similar to the prokaryotic ρ independent terminator. Short open reading frames in the 5' NCR were well conserved among pestiviruses.

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In order to determine relationships between the number of small follicles Prior to superovulatory treatment and superovulatory response, a total of 55 superovulations were induced in Holstein cows. The ovaries were examined ultrasonographically once 0-1.5 days before the initiation of superovulatory treatment. The number of small follicles 3-6mm in diameter on both ovaries before superovulatory treatment was found to be significantly correlated with the numbers of corpora lutea after superovulation (r=0.440, P < 0.001), total ova recovered (r=0.503, P < 0.001) and transferable embryos recovered (r=0.482, P < 0.001). These results indicate that a single ultrasonographic examination of follicles 3-6mm in diameter prior to superovulatory treatment can be utilized to Predict superovulatory response.

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A 10-month-old, female Holstein-Friesian cow with tetralogy of Fallot died during surgery for ameliorating pulmonary stenosis. Necropsy revealed no fracture of bones. Microscopically, fat emboli in the capillaries were detected in the brain, kidney, lung, adrenal gland and pituitary. In the kidney, many fat emboli were present in the glomeruli. No significant changes of the neurons were found throughout the brain, and perivascular hemorrhage and/or necrosis were rarely seen accompanying with fat emboli in the cerebral cortex. The trigger for fat embolism might be costectomy, and right-to-left shunt due to heart malformation might be attributed to crossed and systemic distribution of the fat emboli.

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We examined the prevalence and characteristics of valvular regurgitation in 20 normal beagle dogs with no cardiac murmur by color Doppler echocardiography. The prevalence of pulmonary, mitral, aortic and tricuspid valvular regurgitation was 75%, 15%, 10%, and 0%, respectively. The peak flow velocity of pulmonary, mitral and aortic regurgitation was 57.1±18.5 cm/sec (mean ± SD), 89.8 cm/sec (mean) and 96.5 cm/sec, respectively. The peak velocity of regurgitant flow was considered characteristically low, as the calculated pressure gradient derived from the modified Bernoulli equation (pressure gradient = 4 × velocity²) was not as high as the normal pressure gradient existing across each valve. We consider that, in the evaluation of the characteristics of regurgitation in dogs, regurgitant signals having low peak velocity can be Tegarded as being physiological or trivial regurgitation.

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The infectivity of Fasciola spp. to Wistar rats was evaluated with the recovery rate and development of flukes. The recovery rate from the liver parenchyma and bile duct was 20.0-30.0% in F. hepatica, 36.6-47.5% in Japanese Fasciola sp. and 0-5.0% in F. gigantica. Mature flukes were first recovered at week 8 in F. hepatica and week 12 in Japanese Fasciola sp., however, F. gigantica did not mature in the rats examined until 12 weeks after infection. These results suggest that F. hepatica and Japanese Fasciola sp. are high in infectivity to Wistar rats, whereas F. gigantica is low.

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A 3-month-old female collie was diagnosed as having atrioventricular septal defect with ostium primum atrial septal defect (PASD). The diagnosis was made by echocardiographic observation of the PASD and goose-neck deformity on left ventriculogram. The PASD was treated surgically with a patch graft under cross-circulation cardiopulmonary bypass (CC). The PASD was identified above the ventricular septum after right atriotomy. The patch graft was sutured along the fibrous tissue of the tricuspid annulus on the ventricular side of the PASD to avoid injuring the conduction system. After the operation, cardiac function and renal output were well preserved, but the dog died 33 hr later. At postmortem examination, a mitral cleft was identified.

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Genomes of four Argentine isolates of Aujeszky's disease virus (ADV) (Rio Cuarto/79, Mercedes, Chanar Ladeado-7 and Chanar Ladeado-15) from pigs were characterized and compared with four ADV strains obtained from U.S.A. (Indiana-S), Sweden (Sweden 66), France (Alfort) and Japan (Yamagata-S81) by restriction endonuclbase (RE) analysis. Although three Argentine isolates were classified into type I of BamHI cleavage pattern, one isolate, Mercedes, belonged to type II, according to the classification by Herrmann et al. [6]. Since this type II virus was first isolated in 1981, no outbreak of ADV infection by this type has so far been reported in Argentina. This may imply that the immediate measures by total slaughter of pigs in the farm led successful eradication of the type II ADV infection in Argentina. This report is the first epidemiological study using RE analysis on ADV strains in this country.

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Hydropic change of follicular epithelial cells in the thyroid was observed in a female Fischer 344 rat. Microscopically follicular epithelial cells were characterized by edematous swelling with weakly eosinophilic and homogeneous cytoplasm. The cytoplasm was negative for periodic acid-Schiff reaction, and thyroxine- and thyroglobulin-immunohistochemical reactions. Electron-microscopically, a small amount of amorphous substance was noted in remarkably dilated rough-surfaced endoplasmic reticulum (r-ER), and slight regressive changes of cytoplasmic organella were also observed. These morphological changes may indicate that focal intracytoplasmic edema was occurred in r-ER, and that the change belonged to hydropic degeneration of the thyroid follicular cells in the thyroid.

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Six Holstein-Friesian cows suffering from recurrent rumenal tympany were pathologically investigated. Macroscopical lesions associated with the clinical symptoms were confined to the diaphragmatic muscles which were pale, and stiff on palpation. Histopathological examination revealed various degenerative changes in diaphragmatic muscles as follows: variation in muscle fiber diameter, vacuolar and hyalinized degeneration of muscle fibers, fiber splitting, central core-like structures, sarcoplasmic masses and ring fibers. These characteristic features in the present cases were consistent with dystrophy of the diaphragmatic muscles in Meuse-Rhine-Yssel cattle. From these observations, it is confirmed that musculaf dystrophy of the diaphragmatic muscles dose occur in Holstein-Friesian cows, although a genetic mode was not proven.

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Estradiol benzoate (E₂B) was intramuscularly injected in 3 groups of weaned sows at a dose of 0.2mg/head on day 0 and on day 2 and at a dose of 0.4 mg/head on day 2, respectively. The blood concentration of LH rose to a peak 60-66 hr after E₂B injection. The rates of the occurrence of estrus after E₂B treatment in these groups were 85.7, 89.5 and 87.5%, respectively, with no significant differences compared to the control except for the second group. The farrowing rates in the 3 treated groups were l00, 86.8 and 61.9%, respectively, and the value in the third group was significantly lower compared to the control (p < 0.05). There were no significant differences in average litter size between the control and any of the treated groups.

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Reactivity of anti-erythrocyte membrane (RBCm) antibody in sera of B. gibsoni-infected dogs on native RBCm and erythrocyte surface (RBCs) was examined using an enzyme linked immunosorbent assay. Anti-RBCm antibody attached to native RBCm and the surface of erythrocytes (RBC) treated with phenylhydrazine or neuraminidase, but not to the surface of non-treated RBC. Based on these results, anti-cytoskeletal protein antibody in sera of B. gibsoni-infected dogs is considered to attach to native RBCm, and furthermore free radical-induced oxidative stress imposed on RBC and sialic acid removal from glycoproteins of RBC are considered necessary for anti-transmembrane protein antibody in sera of B. gibsoni-infected dogs to be bound to RBCs. These are important to elucidating the mechanism of the marked increase in RBCs-bound IgG value and anemia in B. gibsoni infection.

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The stable expression of the alpha chain of the feline cytotoxic T cell differentiation antigen (fCD8α) on Crandell feline kidney cells (CRFK) was carried out by using an expression vector which contains the Rous sarcoma virus long terminal repeat and a neo resistant gene. After three rounds of cloning under G418 selection for over two months, the expression of the feline polypeptide was detected by human monoclonal antibody OKT8.

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Pathogenicity of Strongyloides papillosus to rabbits was investigated by monitoring of food intake, body weight and electrocardiogram. No abnormalities were observed in rabbits infected with 10⁴ infective larvae (L₃)/kg. Rabbits given 10⁵ L₃/kg exhibited anorexia after the establishment of patent infections. Four of them died on Days 19-33 having lost 32-44% of initial body weight. The other one animal regained appetite and body weight as fecal egg output decreased. Cardiac rhythms remained normal even in the emaciation state. In lethal cases, cardiac activities finally disappeared through escape beats preceded by sinus arrhythmia as in a fasted control. These results suggest that heavy S. papillosus infection produces a wasting condition in rabbits resulting from anorexia under normal cardiac functions.

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Antagonistic effect of atipamezole (80μg/kg) on medetomidine (20μg/kg)-midazolam (0.3 mg/kg) induced sedation was evaluated in dogs. Atipamezole effectively reversed sedation and significantly shortened arousal time and total recovery time without apparent side effects. Atipamezole also effectively reversed changes in heart rate, respiratory rate and body temperature produced by medetomidine-midazolam. The possible use of atipamezole as a reversal agent might enhance the value and availability of medetomidine-midazolam for a chemical restraint agent in dogs.

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Two additional small RNAs, named mRNA8 and 9, are transcribed from mouse hepatitis virus (MHV) in virus-infected mouse DBT cells. This report shows that the small mRNAs (mRNA8 and 9) were observed at 3 hr post infection (p. i. ) in DBT cells infected with the JHM strain of MHV. This result suggested that products from mRNA8 and 9 may play a role in the early stage of the viral replication cycle in the infected DBT cells. The mRNA8 is initiated from a perfectly conserved intergenic site, but mRNA9 is from an imperfectly conserved intergenic sequence. Since mRNA8 and 9 were found in the liver flnd brain of an infected mouse, it was suggested that the imperfect intergenic sequence of MHV may serve as an initiation site for leader-primed transcription in vivo.

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In 1989 and 1990, we isolated five strains of Haemophilus paragallinarum in the Philippines. Serological studies were done on three of these isolates. The results of haemagglutination, reactability to monoclonal antibodies and cross immunization with standard strains showed that they belonged to serotypes A, B and C respectively. This is the first report on the isolation of H. paragallinarum and on a related serological study in the Philippines.

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Cross reactivity of serum antibodies from chicken immunized with E. tenella, E. necatrix and E. acervulina was observed. The enzyme linked immunosorbent assay (ELISA) using soluble antigen prepared from oocysts of each species showed the cross reactivity among chicken serum immunized with the three species of protozoa, especially between E. tenella and E. necatrix. In immunoblot analysis with E. tenella oocyst antigen, 7 major bands were detected by homologous E. tenella antiserum and 10 and 6 bands were reacted by E. necatrix and E. acervulina antiserum respectively. In these antigens, the band of 33 kDa was regarded as cross reactive agent between E. tenella and E. necatrix because of high reactivity to both of the antiserum. In addition, the 130 kDa antigen that reacted with every antiserum was regarded as common antigen among these three species.

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Protein compositions of Anaplasma marginale and A. centrale were analyzed by two-dimensional gel electrophoresis. Both species had a major protein which was composed of 3-4 spots. The molecular weights of these two proteins were approximately 39 kDa. However, the position of these proteins in the gels were slightly different when 2 gel maps were superimposed. Five other protein spots were shared by A. marginale and A. centrale, whereas all the other protein spots were appeared to be unique to each of the species.

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