The relationship between protein malnutrition and ethanol consumption as modulating factors of the genetic response to xenobiotics was studied. BALB/c mice of both sexes were fed for three weeks after weaning either with a normal diet containing 25% protein or a hypoproteic diet containing 5% protein. Half of the animals received 20% ethanol in drinking water. Cytogenetic analysis was performed in bone marrow cells. Slides were stained for C-banding in order to assure the accurate scoring of dicentric chromosomes. Results obtained showed an increased frequency of dicentric chromosomes in mice fed with the hypoproteic diet (5.45 dicentrics per 100 cells) in contrast to mice fed with the normal diet (0.61 dicentrics per 100 cells). Ethanol consumption increased the frequency of chromosomal damage, but no differences in the effect of ethanol between mice fed with the normal diet and mice fed with the hypoproteic diet (16.33 and 16.80 dicentrics per 100 cells respectively). The enhanced frequency of dicentric chromosomes in animals fed with the hypoproteic diet might have been originated from the increase or the improper repair of chromosome breaks. The similarity in the response to ethanol consumption in animals fed either with the normal or the hypoproteic diet might have been provoked by a decrease of alcohol dehydrogenase (ADH) level in undernourished mice. The chromosomal damage due to ethanol may be lower in undernourished mice than in mice fed with the normal diet due to the reduced amount of circulating acetaldehyde able to induce chromosomal damage. The results obtained are an evidence of the role played by the diet in the modulation of the genetic response to xenobiotics.

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Our studies indicate the effects of in vivo asbestos exposure on the ability of alveolar macrophages (AM) to elaborate a chemoattractant for fibroblast using a rat model of asbestos inhalation. Two groups of rats were exposed by intermittent inhalation (6 hr/day for 5 days/week over a total period of 4 weeks) to either amphibole (crocidolite) or serpentine (chrysotile) asbestos. A group of control rats were sham-exposed to clean air only. The animals were sacrificed 2-5 months after the cessation of exposure. The AM were obtained from the 3 exposure groups in 2 different rat strains by the bronchoalveolar lavage and the cultured in RPMI-1640 medium for 24-96 hr at 37°C. The supernatants from cultured AM were tested for chemotactic activity towards fetal rat skin fibroblasts in a chemotactic assay using 8 μm pore-size filters. The culture supernatants of AM obtained from crocidolite-exposed rats exhibited a significantly greater chemotactic activity towards rat fibroblasts than similar culture supernatants from sham-exposed control animals (p&0.01) in both rat strains. Significant chemotactic activity was observed after chrysotile exposure (p&0.05) in ACI rats but not in Fischer-344 rats. Maximal chemoattractant release from AM was noted after 48 hr in culture. Preliminary characterization of the chemoattractant has shown that it is a thermolabile and trypsin sensitive factor whose activity was partially reduced after dialysis. Since AM accumulate at sites of intrapulmonary asbestos deposition, these findings may have relevance to the pathologic accumulation of interstitial lung fibroblasts which occurs during asbestos-mediated lung injury.

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The serum hemolytic activity of Babesia gibsoni-infected dogs varied when assayed with nonself red blood cells from different dogs, whereas it did not vary when assayed with red blood cells, irrespective of self or nonself, from a particular dog throughout the experiment. The variety in activity determined with nonself red blood cells was not related to the type of red blood cell by DEA, D and J systems. Serum hemolytic activity with self red blood cells was different in the course of infection from that with nonself red blood cells, especially in the late stage of infection, when the activity with self red blood cells decreased more rapidly than that with nonself red blood cells. The results indicate that the serum hemolytic activity of B. gibsoni-infected dogs determined with self red blood cells probably reflects the in vivo activity, suggesting that the rapid decrease in activity in the late stage of infection is a way of acquired resistances for the host to recover from hemolytic anemia in the infection. The facts that the hemolytic activity increased by heating the serum at 56°C, that the osmotic fragility of red blood cells remained almost on the same during the course of infection and that Coobms' test for red blood cells of the infected animal was negative suggest that the immune-mediated hemolytic anemia is not a possible mechanism for the progressive and severe anemia in B. gibsoni-infection. The present results support the previous notion that the increased serum hemolytic activity is at least one of the causes of anemia in canine B. gibsoni-infection.

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Of 170 cows with ovarian cysts which were detected by palpation of the ovaries per rectum, 88 cows (51.8%) were diagnosed as having follicular cysts on the basis of milk progesterone concentrations. Eighty-three of the 88 cows were used for treatment trials. A group of 56 cows injected subcutaneously with fenprostalene, prostaglandin F₂α analog, 14 days after treatment with fertirelin, an analog of gonadotropin-releasing hormone, compared with another 27 cows treated only with fertirelin (controls), showed a higher pregnancy rate within 100 days after the initial treatment (66.1 vs 48.1%) and shorter intervals from the treatment to conception (30±21 vs 43±27 days). It was concluded that the administration of fenprostalene following fertirelin treatment is effective in shortening the interval from treatment to conception in cows with follicular cysts.

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The present study describes the radiological and histological changes in the canine intervertebral disk after the experimental injection of chymopapain as the chemical reagent, and determines the appropriate dose of the enzyme for treatment of herniated disks. By radiography, narrowing of the disk space was observed within 2 weeks after the injection of chymopapain, and recovered to 74.1% in the 0.1mg group, 61.1% in the 1.0mg group and 71.7% in the 10.0mg group at 12 weeks. The disk space recovery showed a tendency to delay with aging. Microscopically, proteoglycan positive matrix appeared and the nuclear space was reduced in each disk at 2 weeks after chymopapain injection. The nucleus pulposus contained an irregularly-defined mass consisting of clusters of degenerated notochordal cells surrounded by proliferated chondrocytes and collagen matrix. In each disk at 12 weeks after chymopapain injection, the center of the nucleus pulposus was replaced by fibrocartilage tissue. In the disk into which 10.0mg chymopapain was injected, the nuclear space filled with dense fibrocartilage tissue without a regenerated matrix component and narrowing of the disk were maintained. It is suggested that canine chemonucleolysis with 10.0mg of chymopapain reduces the interdiskal pressure. This treatment may therefore relieve the signs and symptoms of herniation of the nucleus pulposus, and may effect chemical disk decompression.

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Hemodynamic effects of nitroglycerin were investigated in dogs with right ventricular failure including engorgement of the pulmonary artery and ascites induced by insertion of adult live heartworms into the pulmonary artery. The mean pulmonary arterial pressure (21.5±6.6mmHg) in heartworm-inserted dogs 4 or 5 weeks after heartworm insertion were higher than that of control (4.2-7.1mmHg). Nitroglycerin administered intravenously at doses of 3 or 10μg/kg decreased pulmonary arterial pressure in these heartworm inserted dogs. This drug also decreased pulmonary vascular resistance and total systemic resistance with no effect on cardiac index and heart rate.

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The in vivo efficacy of nonglycosylated recombinant human granulocyte-macrophage colony stimulating factor (rh GM-CSF) expressed in Escherichia coli was studied in cynomolgus monkeys (Macaca fascicularis). A single intravenous (IV) administration of rh GM-CSF (100μg/kg) resulted in a two-fold increase in peripheral white blood cell (WBC) count with a predominance of neutrophils after 12 hr. The increased WBC count returned to the initial level within 48 hr after administration. In a study with consecutive IV administrations for 10 days, animals treated with 20μg/kg/day rh GM-CSF underwent marked leukocytosis (four fold) and thrombocytosis (two fold). The increase in WBC count was due to increased number of neutrophils, eosinophils, lymphocytes, monocytes and basophils. Red blood cell count was unaffected. The leukocytosis resolved within one week after the termination of administration. A lower mean platelet volume compared to the pre-treatment level was observed in rh GM-CSF treated animals receiving 20μg/kg/day for 20 days. This coincided with the elevation in platelet count.

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A cell line was established from a Mongolian gerbil's (Meriones unguiculatus) homotransplantable malignant melanoma. Ascitic tumor cells detected in a gerbil when transplanted intraperitoneally were adapted to culture. In primary culture, cells were divided into 2 types, multipolar and polygonal cells. Cell masses which adhered to polygonal cells were observed after the 6th passage. The adhering cells were removed and transferred into another flasks. The cells showed multipolar and possessed projections. Then after, the cells increased in number vigorously and formed acinous structures. At early passages, abundant melanin granules in some of the cells were demonstrated by light and electron microscopical observations. Most of the cells were positive by DOPA reaction. Melanin pigments were gradually decreased through the 20th to 30th passage and most of cells became amelanotic. The doubling time of the cell line was 32 hr. Chromosome number of the cell line ranged from 68 to 82. Whitish tumors were produced in the abdominal cavity within 30 days when intraperitoneally inoculated the cells to gerbils. This cell line, designated as MGM-A, has been subcultured for more than 100 passages during 2 years.

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A new procedure was developed for the assay of the hog cholera virus (HCV) and anti-HCV antibody. Initially, the suppression effect of HCV on interferon (IFN) by HCV production was confirmed. Swine kidney cell cultures preinfected with HCV produced no IFN, even following the addition of IFN inducers. However the sensitivity of the cell to IFN was not influenced by the Infection with this virus. Based on these results, a new method, named reverse interference method, was established. In this method, infective titer of HCV was determined by the appearance of cell pathogenic effects (CPE) induced by vesicular stomatitis virus (VSV), which is caused by the suppression effect on the heterologous interference of GPE^- strain of HCV against VSV infection in swine kidney cell cultures. This method showed nearly the same sensitivity as the END method. There was no difference in the infective titer of HCV and antibody titer against HCV as estimated by this method and the END method. The reverse interference method had advantages in rapidity and objectivity compared with the END method.0

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The object of this study was to determine whether several washings with trypsin affected the survival and development of in vitro fertilized (IVF) bovine embryos. The embryos developed to blastocysts 7-8 days after insemination, were washed 12 times in washing medium (modified Dulbecco's phosphate-buffered saline (mPBS) containing 20% fetal bovine serum (FBS): 25 mM Hepes TCM199 with Earle's salts=1:1), or in a series of three washes in the washing medium, two in mPBS containing 0.3% bovine serum albumin (BSA), two in 0.25% trypsin in Hank's solution (without Ca⁺⁺ and Mg⁺⁺) for a total time in the trypsin of 60 to 90 sec and five in the washing medium. After washing, the embryos were either cultured in vitro or cryopreserved. The fresh and frozen-thawed embryos were either cultured for 72 hr in vitro for evaluating development or transferred nonsurgically to recipient cows. Development of fresh and frozen-thawed embryos in vitro in control-washed and trypsin-washed embryos did not differ. Pregnancy rates did not differ (P>0.05) among recipient cows receiving control-washed or trypsin-washed embryos, and transferring fresh or frozen-thawed embryos. These results indicate that the treatment of bovine IVF embryos with trypsin during washing did not have a positive effect on embryonic development.

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Four primary histiogenic tumors of the epididymis were discovered in 110 male B6C3F₁ mice used in a carcinogenicity study in our laboratory. From the results, all these tumors were considered to be spontaneous. Histologically, the tumors were characterized by compact growth of spindle to oval shaped histiocytic cells with or without a cleaved nucleus. Focal hemorrhage was present in three cases, and erythrophagocytosis occurred in such lesions. The tumors had some similar histological features of histiocytic sarcomas, which had been observed with high malignancy in other male and female animals. However, systemic growth and atypism of neoplastic cells found in the histiocytic sarcomas were not observed in these epididymal tumors. On the other hand, four histiogenic tumors of the uterus, with features characteristic of epididymal tumors, were observed in 106 female mice. The uterine histiogenic tumors were regarded as benign or precursor lesions of histiocytic sarcoma. Furthermore, it is suspected that histiocytic sarcoma arises from the epididymis.

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Experiments were performed in 17 adult cats spinalized at T10-11. Thc effects of electrical stimulation of the central pad (CP) and toe pads (TP-2, 3, 4, 5) on the monosynaptic reflex (MR) in lumbar spinal segments were studied. The conditioning stimulation had different effects on the MRs of the various motoneurons except the posterior biceps and semitendinosus, depending on the footpad stimulated. Lateral gastroenemius and soleus, and medial gastrocnemius (MG) MR were inhibited by footpad stimulation. The effect of TP-2 (medial footpad) stimulation on MG-MR was weak. The popliteus (Pop) and tibialis anterior muscles (TA) are inward and lateral rotators of the knee joint, respectively. Pop- and TA-MR were excited by stimulation of lateral and medial TPs, respectively. Plantaris MR was enhanced and inhibited by stimulation of the CP and TPs, respectively. There were remarkable differences in the effects of TP conditioning stimulation on the flexor digitorum longus, extensor digitorum longus, peroneus brevis and teritius, and peroneus longus-MRs, depending on the toe pads stimulated. These results suggest that afferent inputs from footpads modulate the activity of motoneurons, stabilize the foot and help maintain body balance.

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In a previous paper we reported that we constructed a recombinant baculovirus named BmFeIFN1 which produced recombinant feline interferon (FeIFN) in silkworm after infection. High purification of FeIFN in body fluid from the larvae revealed that two kinds of FeIFN were produced by the BmFeIFN1. The difference between the two in the NH₂-terminal amino acid sequence was clarified, and two kinds of processing at different sites in FeIFN precursor were suggested. Changing one residue of the amino acid sequence in deduced signal peptide by site directed mutagenesis of encoding cDNA led to the production of homogeneous FeIFN whose NH₂-terminal three amino acid sequence was identical to the conserved sequence of human interferon-α. We designated the FeIFN produced as rFeIFN. Amino acid sequence analysis revealed that rFeIFN consisted of 170 amino acid residues. The COOH-terminal amino acid of the rFeIFN is Glu which is located at one amino acid residue upstream to the COOH-terminal amino acid deduced from the nucleotide sequence. Positive periodic acid Schiff reaction, undetectability of Asn at position 79 by automated protein sequencer, and detectability of N-acetylglucosamine not N-acetylgalactosamine suggested that rFeIFN was N-glycosylated. rFeIFN was stable at pH 1.5 at 4°C for at least 50 days, and had an antiviral action on feline calicivirus or feline herpesvirus in vitro. Its isoelectric point was pI 6.5. Comparing the structure and biosynthesis of rFeIFN with those of HuIFNs, rFeIFN may be classified as ω-type.

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The effects of an active egg white product (AEWP) on neutrophil function in calves were investigated. Calves were administered AEWP orally at doses of 250 mg and 500 mg/kg either once or twice, with an interval of 5 days between doses in the latter case. The peripheral blood neutrophils of calves receiving a single 500 mg/kg dose displayed increased nitroblue tetrazolium reducing activity and increased intracellular killing of Staphylococcus aureus from 1 day after administration, with maximum levels being attained on the 3rd day. However, no such increase of these activities was observed after administration of 250 mg/kg. Calves receiving two doses of 500 mg/kg displayed the same changes as seen in the corresponding one-dose group, while the neutrophil activity of calves receiving 250 mg/kg also increased after the second dose. However, no increase in the peripheral blood neutrophil count was observed after AEWP administration. Thus, AEWP enhanced the nonspecific antibacterial activity of neutrophils when given to calves by the oral route.

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Suspected uremic substances contained in four fractions, which had been selected as the suspected canine uremic peaks in the previous study, were isolated by two stages of preparative liquid chromatography (PLC) from plasma of uremic dogs treated with the ligation of the ureter, and then their physicochemical properties were examined. The primary separation of the suspected uremic peaks were performed with the same anion exchange resin as used in the analytical HPLC in the previous study. Analytical reverse phase HPLC showed that three of 4 suspected uremic peaks almost consisted of single substances, but the other contained several substances. Main subtractions of these peaks were successfully isolated by the secondary stage reverse phase PLC. By means of thin layer chromatography, ultraviolet absorption spectrometry and proton-nuclear magnetic resonance spectroscopy, components of 4 main peaks were confirmed to be small molecules such as a pyridine derivative, uric acid, hippuric acid and kynurenic acid, respectively.

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The viability of the bovine embryo was monitored by measuring the early pregnancy factor (EPF). The EPF activity was measured by the rosette inhibition test before and after artificial insemination (AI) at natural estrus (n=14), and after superovulatory treatment followed by embryo removal on day 7 after AI (n=5). In the cows inseminated artificially at natural estrus, there were significant differences (p<0.01) in the rosette inhibition titer (RIT) between pregnant and non-pregnant cows on day 13-16 and day 20-25 after AI. In the 8 pregnant cows, the RIT remained more than 5 from day 6-9 after AI. In the 6 non-pregnant cows, two patterns were observed. In one pattern, RIT rose transiently to more than 5 and decreased to less than 4 thereafter. In the other pattern, RIT remained less than 4 throughout the experimental period. The former pattern suggested early embryonic death, while the latter suggested that fertilization had not taken place or that early embryonic death had occurred before the first blood collection on day 6-9 after AI. In the cows superovulated followed by embryo removal on day 7 after AI, the RIT values were all less than 4 on the day of AI (day 0), rose to more than 5 on day 3 and thereafter then until the day of embryo removal on day 7. In 4 cows, the RIT decreased to less than 4 by 3 days after embryo removal, and in the remaining one cow, the RIT decreased to less than 4 by 7 days after embryo removal. These findings suggest that the measurement of EPF activity is useful for monitoring the viability of bovine embryos.

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Blood gases were analyzed in dogs with pulmonary heartworm (HW) disease. The arterial oxygen tension (Pa_O2) in dogs with mild signs of dirofilariasis (mildly affected group, n=48, 85.7±8.2 mmHg) and in dogs with signs of right heart failure (severely affected group, n=13, 76.4±11.6 mmHg) was lower (p<0.01) than in dogs without HW infection (HW-free group, n=19, 91.5±7.3 mmHg). Only 2 dogs in the severely affected group had a Pa_O2 less than 60 mmHg. The arterial carbon dioxide tension (Pa_CO2, p<0.01) and mixed venous O₂ (p<0.01) and CO₂ (p<0.01) tensions were lower, and alveolar-arterial oxygen difference (AaD_O2, p<0.01) was greater in the severely affected group than in the HW-free and mildly affected groups. Arterial pH and bicarbonate (HCO₃^-) concentrations were lower (p<0.01) in both affected groups than in the HW-free group. The anion gap level was not different among the 3 groups. Serum lactic acid level in the severely affected group was higher (p<0.01) than in the HW-free and mildly affected groups. However, a slightly higher serum lactic acid concentration was found only in 2 dogs of the severely affected group (3.84 mmol/l and 3.82 mmol/l). The Pa_O2 (r=-0.62) and AaD_O2 (r=0.66) correlated significantly (p<0.01) with mean pulmonary arterial pressure. One week after HW removal, blood gases, pH and HCO₃^- concentration remained unchanged in the mildly affected group. In the severely affected group, blood gas values were the same, but pH and HCO₃^- concentration improved slightly.

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This report describes a unique response of the anion transporter in equine erythrocytes to the fluorescent substrate N-(2-aminoethyl sulfonate)-7-nitrobenz-2-oxa-3-diazole (NBD-taurine). Equine erythrocytes showed fluxes of NBD-taurine both inward and outward at rates considerably slower than those in human cells. These fluxes were completely abolished by a typical anion transport inhibitor, 4, 4'-diisothiocyanostilbene-2, 2'-disulfonate. Furthermore, NBD-taurine competitively inhibited the uptake of phosphate in equine red cells with an inhibition constant of phosphate that was slightly higher than the Michaelis constant of phosphate uptake. These results demonstrate that the anion transporter (band 3) in equine red cells binds NBD-taurine but does not prefer it as the substrate for transport, suggesting a structural difference between equine and human anion transporters at the polypeptide portion which is implicated in anion transport.

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Hemocytes of two marine molluscs, Nerita albicilla (gastropod) and Mytilus edulis (bivalve), were stimulated in vitro with zymosan and live cells of Vibrio parahaemolyticus and Escherichia coli as determined by luminol-dependent chemiluminescence (CL). The CL response was enhanced in the presence of the respective molluscan plasma. Hemocytes of an estuarine gastropod, Clithon retropictus, showed low CL response to zymosan and V. parahaemolyticus, which was slightly enhanced in the presence of C. retropictus plasma. Hemocytes of an estuarine bivalve, Corbicula japonica, showed no CL response. CL response of hemocytes might be a useful tool to analyze defense mechanisms of estuarine molluscs.

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The effects of lactosucrose (4^G-β-D-galactosylsucrose) on fecal flora and fecal putrefactive products were studied in 3 Himalayan and 5 Persian cats fed 175 mg of lactosutrose/each/day for 2 weeks. During lactosucrose administration, the counts of lactobacilli increased significantly (p<0.05), whereas the counts of clostridia, including Clostridium perfringens and Enterobacteriaceace decreased significantly (p<0.05). The levels of fusobacteria and staphylococci were decreased significantly (p<0.01) on day 7 of lactosucrose administration, while the counts of bacteroides increased significantly (<0.05) on day 14 of lactosucrose administration compared to pre-administration. In frequency of occurrence, bifidobacteria increased significantly (p<0.001) during lactosucrose administration, while Spirochaetaceae and lecithinase-negative clostridia decreased significantly (p<0.05) on day 14 of lactosucrose administration compared to pre-administration. No detectable change occurred in the counts of other organisms throughout the experimental periods. Fecal concentrations of ammonia, indole, ethylphenol, and urinary ammonia were reduced significantly (p<0.05) on day 14 of lactosucrose administration. The water content and weight of the feces increased slightly during lactosucrose administration, but the pH values decreased slightly. The environmental ammonia and the fecal odor also decreased remarkably (<0.01) during administration.

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Fifty-eight Staphylococcus aureus strains isolated from bovine mastitic milk at 27 dairy farms in Japan during the period from November 1988 to May 1989 were examined for their productivity of virulence associated factors. The positive rates of the total isolates for various virulence factors were as follows: toxic shock syndrome toxin-1 (TSST-1, 27.6%), staphylococcal enterotoxins (SEs, 34.5%), α-haemolysin (74.1%), β-haemolysin (65.5%), δ-haemolysin (12.1%), DNase (100%), egg-yolk factor (25.9%), clumping factor (70.7%) and protein A (58.6%). All of S. aureus isolates from peracute mastitis produced TSST-1, SEC, α-haemolysin and β-haemolysin. While none of clumping factor and protein A were detected among peracute isolates, these factors were produced at a relatively high frequency by isolates from chronic mastitis. In coagulase typing, the most predominant type was VI (36.2%), and types IV, V and VIII were not observed. TSST-1 positive isolates showed interesting characteristics which all of the isolates produce both SEC and coagulase type VI but lack egg-yolk factor, clumping factor and protein A except for one isolate. We could infer that TSST-1 and SEC contribute to bovine mastitis, especially to peracute mastitis from the present study.

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The morphology of the testis of the mutant As (aspermia) strain rat with severely interrupted spermatogenesis was investigated in the present study. The most advanced development in spermatogenesis was observed at the step 8 at which spermatids had basally-oriented acrosomes. Multinucleate giant cells derived from round spermatids were frequently encountered within the seminiferous tubules. The functionally normal status of the blood-testis barrier between adjacent Sertoli cells was confirmed by morphological and lanthanum tracer studies. By light microscopy, a peculiar structure was found within the pachytene spermatocyte, consisting of numerous particles of approximately 25 nm in diameter. By histochemical and electron microscopic studies, this structure was identified as an aggregate of ribosomes. Neither immature spermatogenic cells up to the pachytene phase, nor Sertoli cells nor interstitial regions showed a recognizable abnormality. It seems that the testicular disruption in the As mutant rat is due to the abnormality in the protein synthetic pathway in pachytene spermatocytes.

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The pulmonary artery blood flow was determined in 40 dogs by pulsed Doppler echocardiography as a non-invasive means for estimating pulmonary artery pressure. Most of these dogs had become infected with heartworm disease which has been known to often cause pulmonary artery hypertension. From the flow velocity profile, four parameters, i.e., the Doppler tracing pattern, right ventricular ejection acceleration time (AT), and the ratios of AT to heart rate (AT/HR) and right ventricular ejection time (AT/ET), were obtained and their correlations with the pulmonary artery pressure determined invasively were investigated. Although the morphological pattern of flow velocity hardly allowed quantitative estimation of the pulmonary artery pressure, a relatively good negative correlation (P<0.01) was obtained between the systolic pulmonary artery pressure and AT (r=-0.71), AT/HR (r=-0.67) or AT/ET (r=-0.84). The present results indicate that pulsed Doppler echocardiography is applicable to the estimation of pulmonary artery pressure and that AT/ET has the closest correlation with directly measured pulmonary artery pressure.

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Mitochondrial DNA (mtDNA) polymorphism was studied in 21 Jindo dogs inhabiting Jin Island off the Korean peninsula. The polymorphism was analyzed with 10 restriction endonucleases that recognize six base pairs. The sizes of the mtDNA fragments produced by digestion using each endonucleases were separated by agarose gel electrophoresis, and the polymorphisms were detected with Japanese mongrel dog mtDNA as a probe. The mtDNA polymorphism in Jindo dogs was observed with four restriction endonucleases, Apa I, EcoR V, Hinc II, and Sty I. However, no polymorphism was detected with BamH I, BglII, EcoR I, Hind III, Pst I, or Xba I. The observed restriction endonuclease morphs were classified into 4 types of distinct cleavage patterns. The average number of nucleotide substitutions per nucleotide site in Jindo dogs was estimated to be 0.0086. By UPG phylogenetic analysis, the 4 mtDNA types showed only one cluster. This suggests that Jindo dogs have not diverged from the other cluster up to the present and the species is considerably pure.

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Genomic DNAs of cattle, horses, pigs, dogs, cats and chickens were surveyed using Southern blot hybridization analysis, with a human EGFR cDNA fragment. Several bands with different numbers and molecular weights were observed under the condition of low stringency in the individual animal species. The bands showing DNA polymorphism were observed among bovine genomic PstI-digested DNAs from 4 individuals and EcoRI-digested genomic DNAs from 4 chickens. These results may provide basic data which are useful for analysis of tumorigenetic mechanisms in domestic animals.

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Attempts were made to isolate mycoplasmas from respiratory and urogenital tracts of 35 apparently healthy wild rodents comprising 7 species under 4 genera. Mycoplasmas were isolated from nasal and oral cavities, tracheas, vaginas and penises of the wild rats: ricefield rats (Rattus argentiventer), roof rats (R. rattus) and Polynesian rats (R. exulans), but none was isolated from brown rats (R. norvegicus), house mice (Mus musculus), smithi's voles (Eothenomys smithi) and soft-furred field rats (Millardia meltada). These mycoplasma strains were identified as Mycoplasma pulmonis and M. arthritidis on the basis of their biological and serological properties.

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Among the sera from 9 rabbits spontaneously infected with Encephalitozoon cuniculi, a serum which revealed a high titer for E. cuniculi by indirect protein A-gold (IPAG) immunohistochemistry and reacted with the outer layer of the shell of E. cuniculi spores on immunoelectron microscopical examination, was biotinylated. The biotinylated rabbit anti-E. cuniculi IgG reacted immunohistoche-mically with E. cuniculi, but not with other protozoa tested, namely Neospora caninum, Toxoplasma gondii and sarcocystis. The direct avidin-biotin-peroxidase complex (ABC) immunohistochemistry using biotinylated rabbit anti-E. cuniculi IgG in this study is a useful tool for the diagnosis and study of encephalitozoonosis.

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Feline tooth resorptive lesions were studied using contact microradiographic analysis of ground sections. Contact microdiagram films were developed with a PIAS-imaging device, and decalcification patterns were evaluated, revealing a clear boundary between normal tissue and the resorptive area, which was different from the image of dental caries in humans. By contrasting analysis, decalcification signs appearing in human caries were not observed in feline resorptive lesions.

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To investigate the overall prevalance of chlamydial infections in light (i.e. non-draught) horses in Japan, 599 sera obtained from 12 1ocalities in 1991 were tested for complement fixation antibodies. The mean antibody positive rates of the all sera were 15.2% (91/599) and the regional positive rates were higher in Honshu (19.1%, 48/251) and Kyushu (20.0%, 20/100) than in Hokkaido (9.3%, 23/248). In Honshu, the highest rate (56.0%, 28/50) was observed in Utsunomiya. Analysis of the positive rate in different age groups showed that the 2-5 years age-group had the highest prevalance of chlamydial infections. This indicates that chlamydial infection is prevalant in light horses in Japan.

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A Pomeranian puppy which died from diarrhea and nasal discharge showed catarrhal pneumonia, acute enteritis and focal liver necrosis. Slender bacilli were detected within ileal enterocytes and hepatocytes. A double infection with a distemper virus and Tyzzer's organism at a cellular level was seen within the ileal enterocytes.

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The present study was performed to examine the influence of EMC-D virus on water-maze task performance in DBA/2 mice inoculated with 10³ PFU/ml and BALB/c mice inoculated with 10⁵ PFU/ml of EMC-D virus. In both strains, the latency to accomplish the task was shortened during successive 8 days of testing. However, the shortening of latency in the inoculated group was significantly smaller than that in the control group. Pathological studies showed that in both studies St. pyramidale hippocampi was commonly degenerated, but the degeneration of the spinal cord was shown only in DBA/2 mice. Therefore, the disturbance of water-maze task performance in mice infected with EMC-D virus might be partially due to the dysfunction of memory for working process or cognition of orientation other than underlying decreased ability in locomotion.

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Trichophyton verrucosum, a causative agent of bovine dermatophytosis in Japan is considered to transfer easily from infected cattle to other healthy ones. No studies have ever tried to elucidate the distribution of T. verrucosum in breeding environment. In this study, we investigated the distribution of T. verrucosum in infected young calf skin and healthy skin. Hairs or scale samples were collected from 29 lesional skin, and 46 non-lesional skin of the 19 and 34 infected calves, respectively, both varying in age 2 to 6 months old, and 35 hair samples from the 29 healthy ones. They were directly inoculated on medium. The detection rates of T. verrucosum-positive were 58.6% from the lesional parts, 34.8% from the non-lesional parts and 17.1% from the healthy parts. The isolation of T. verrucosum from the calves with no skin lesion due to dermatophytosis implied that this infection might be easily transmitted by the contact with the infected calves. T. verrucosum infection in cattle poses a serious problem in animal husbandry. It is also important for public health to take preventive measures against the infection.

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The third and fourth stage larvae of Angiostrongylus cantonensis were cultured in various media. When the third stage larvae were cultured in RPMI 1640 supplemented with 20% fetal calf serum for four weeks, about 30% developed to the late third stage. On the other hand, when the fourth stage larvae recovered from rat brains were cultured in Waymouth's chemically defined medium (MB 752/1) for one week, the worms grew rapidly and 74% developed into young adults. The mean body length of the worms in Waymouth's medium showed a 1.4-fold increase in size compared with that before culture.

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Forty-three strains of Erysipelothrix rhusiopathiae, isolated from pigs with chronic swine erysipelas, were examined for the presence of plasmid DNA by agarose gel electrophoresis and electron microscopy. Seven of these strains were found to contain plasmids of which number were varied from 1 to 6. The plasmids ranged from 1.4 to 86 kb in size. This is the first reported evidence for plasmid DNA in E. rhusiopathiae. The functions of the plasmids are unknown at present.

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