A number of 689 Streptococcus suis isolates collected nationwide from diseased and healthy pigs from 1987 to 1996 were surveyed for antibiotic susceptibilities to 11 drugs.No isolates resistant to amoxicillin, chloramphenicol, and sulfamethoxazole/trimethoprim were found.Isolates were highly susceptible to penicillins(penicillin G, ampicillin, and amoxicillin)except cloxacillin.They were not susceptible to tetracycline, streptomycin, and kanamaycin(MIC₉₀ 50μg/ml, ≥100μg/ml, and ≥100μg/ml, respectively).Multiple−resistant isolates(≥3 antimicrobial agents)were found in 20.3% of all isolates tested.

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Mouse monoclonal antibodies(MAbs), raised against the NaOH−extracted antigen of Erysipelothrix rhusiopathiae strain Kyoto(serovar 2), recognized two different epitopes on a single protein of molecular weight 67 kDa.The MAbs were classified as protective or non−protective against strain Fujisawa(serovar 1).In immunoblotting analysis using the MAbs, fifteen wild strains were shown to contain different amounts of 67 kDa protective antigen.Each formalin−killed whole cell vaccine(bacterin)prepared from the fifteen wild strains conferred different levels of protection against strain Fujisawa in mice.Bacterins prepared from wild strains with larger amounts of 67 kDa protective antigen tended to give high levels of antigen−specific antibody and better protection to mice.These results indicate that the amount of 67 kDa protective antigen which influences the induction of protective immune responses may vary substantially among the strains of E.rhusiopathiae(serovar 2).

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A calf having extremely high concentrations of triglycerides, cholesterol and phospholipids, in particular in chylomicrons(CM)and very low−density lipoprotein(VLDL)fraction was found.The purpose of the present study was to determine serum concentration and distribution of apolipoprotein(apo)C−III, a low molecular mass protein mainly distributed in high−density lipoprotein(HDL)fraction in normolipidemic cattle, in the calf with hyperlipidemia.The serum apoC−III concentration in the calf increased to more than 10−fold that of normolipidemic control calves, and apoC−III was distributed more in the CM than in the HDL.The concentration of apoA−I(a predominant apoprotein in the HDL)was also increased to nearly 4−fold that of controls in the serum from the calf, and its major distribution site was the CM.Haptoglobin was detected in the serum from the hyperlipidemic calf, and was distributed in the CM as well as in the HDL.Serum amyloid A was also induced.In contrast to apoC−III, apoA−I and haptoglobin, the majority of apoSAA was found in the HDL fraction, as observed in normolipidemic calves.Increased concentrations in the CM of apoC−III and apoA−I suggest that the two apolipoproteins may be involved in the pathogenesis of calf hyperlipidemia.The presence of haptoglobin in the CM and HDL also implies the relevance of this acute−phase protein in the regulation of lipid metabolism.

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Monoclonal antibodies(Mabs)against bovine α₁−acid glycoprotein(α₁AGP)were prepared from mouse hybridoma cell line.Bovine α₁AGP as antigen was purified by using ion exchange column chromatography and the yield from 500 ml serum was about 10 mg.Immunoglobulin isotypes of 3 Mabs obtained were IgM and light chain types were κ.The Mabs reacted with bovine α₁AGP on immunoblot analysis, but not with α₁AGP digested with N−glycosidase, suggesting that an epitope recognized by these Mabs may be associated with a glycan side chain of bovine α₁AGP.

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A mature form of porcine interleukin−2(IL−2)protein without signal peptides was expressed as glutathione S−transferase(GST)fusion proteins in Escherichia coli using pGEX vector.Since most of GST−IL−2 fusion protein was detected in an insoluble fraction on SDS−PAGE analysis, the insoluble fusion protein was solubilized by refolding procedure using urea.The recombinant IL−2(rIL−2)was purified by a batch method using Glutathione Sepharose 4B and factor Xa digestion and used for preparation of antisera in mice.The antisera reacted with rIL−2 expressed in baculovirus system on immunoblot analysis.In addition, the purified rIL−2 showed a high biological activity on CTLL−2 proliferative response.

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The primer pheromone is responsible for the “male effects” in goats and produced in the sebaceous glands testosterone−dependently.In the present study, the responses of sebaceous glands obtained from the head and rump regions of castrated goats were examined by our bioassay system after testosterone treatment to demonstrate the presence of regional differences in the pheromone production in male goats.The testosterone treatment resulted in the marked development of sebaceous glands and the induction of pheromone bioactivity in the head region of the goats.On the contrary, this treatment brought neither development of the sebaceous glands nor induction of pheromone bioactivity in the rump region.The treatment increased immunoreactivities to androgen receptors(AR)and 5α−reductase in the sebaceous glands of both regions, although the activities were more apparent in the head region than the rump region.These findings suggest that the primer pheromone of male goats is produced specifically in the sebaceous glands of the head region due partly to regional differences in the expression of AR and 5α−reductase mediating testosterone bioactivities.

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The clonality analysis of the bone marrow cells was carried out by detecting the integrated proviruses of feline leukemia virus(FeLV)to understand the pathogenesis of FeLV−associated hematopoietic disorders in cats.Bone marrow cells from 4 cases with acute myeloid leukemia(AML), 9 cases with myelodysplastic syndromes(MDS), 2 cases with pure red cell aplasia(PRCA)and 3 healthy carriers infected with FeLV were subjected to Southern blot analyses using an exogenous FeLV probe.Clonal hematopoiesis was found in all the cases with AML and in 6 of the 9 cases with MDS, but not in the cases with both PRCA and healthy carriers infected with FeLV.In the 2 cases with MDS, it was thought that the same clones of the hematopoietic cells might proliferate before and after the progression of the disease irrespective of the changes of the hematological diagnoses by cytological examination.This study indicates that MDS in cats is a disease manifestation as a result of clonal proliferation of hematopoietic cells and can be recognized as a pre−leukemic state of AML.

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Spontaneous hydronephrosis in KK−A^y mice was studied using light and electron microscopy and scanning electron microscopy of resin casts to evaluate micro vascular changes in the kidney.The renal parenchyma was extremely thin as a result of tubular atrophy.Histologically, varying degrees of glomerulosclerosis were observed.Ultrastracturally, marked thickenings of the glomerular basal lamina, an increase in mesangial cells and matrix, and marked effacement of foot processes were observed.In resin casts, a marked reduction in number of glomeruli was evident.The capillaries were thin, strangulated and torn−off to varying degrees in severely affected glomeruli.In the medulla, the three−dimensional capillary network running along the tubules was lost and changed to a two−dimensional vascular bed.Despite severe hydronephrosis, the glomerular capillary network was relatively well preserved, being either slightly or moderately injured in approximately 60% of surviving glomeruli.

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A full length cDNA of feline interleukin(IL)−12p35 and p40 subunits was cloned.By transferring the plasmids containing both the subunit genes to mammalian cells, we expressed biologically active feline IL−12.The expressed feline IL−12 has interferon−γ−inducing activity against both human and feline peripheral blood mononuclear cells(PBMC)and stimulates cytotoxic T lymphocyte activity against herpes simplex virus−infected human PBMCs.There were two kinds of molecules(p75, p80)in the purified recombinant feline IL−12, and both molecules exhibited biological activity.The difference between p75 and p80 was the degree of the glycosylation of the p35 chain.Moreover, when we modified the cDNA of p35 by changing some codons and deleted the 5’ and 3’ non−coding regions, the expression level of IL−12 increased about 100 fold.

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Seven monoclonal antibodies(mAbs)were raised against Trypanosoma congolense procyclic form(PCF).Localization of the antigens recognized by the mAbs was determined in bloodstream form(BSF), PCF, epimastigote form(EMF)and metacyclic form(MCF)by confocal laser scanning microscopy(CLSM).Two mAbs(10F9 and 20H12)showed different fluorescent patterns among different life−cycle stages of the parasite.The 10F9 recognized a 76 kDa antigen of all life−cycle stages of the parasite and the antigen localization corresponded with that of a mitochondrion.While the 20H12 recognized 119 and 122 kDa antigens of all the life−cycle stages and the antigen localization corresponded with a flagellum in BSF and MCF, tip of a flagellum in PCF, and part of cytoplasm in EMF.Moreover, the 20H12 did not react to T.brucei gambiense, T.b.rhodesiense and T.evansi antigens in both CLSM and immunoblotting.Therefore, the antigens recognized by the 20H12 seem to be T.congolense specific.Although, further studies will be required for a full characterization of the T.congolense specific 119 and 122 kDa antigens, the mAb 20H12 and the specific antigens may be useful in not only establishment of T.congolense specific diagnosis methods but also studies on molecular mechanisms regulating differentiation of the parasite during life−cycle.

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In an investigation aimed to identify Toxoplasma gondii antigens expressed in feline enteroepithelial−stages parasites, a cDNA library was constructed and fourteen positive clones were isolated by immunoscreening using sera from cats immunized with feline enteroepithelial−stages parasites.By DNA sequence homology analysis, these fourteen isolated clones were classified into four groups:hypoxanthine−guanine phosphoribosyl transferase(HGPRT)cDNA, heat shock protein 70(HSP70)cDNA, 14−3−3 protein homologue cDNA, and cDNA encoding an unknown product.In an indirect immunofluorescence antibody test, sera from mice immunized with the recombinant protein encoded by the cDNA for HGPRT, HSP70, 14−3−3 protein, or the unknown product each showed a relatively high level of immunoreactivity with feline enteroepithelial−stages parasites.

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A direct competitive enzyme−linked immunosorbent assay(ELISA)for screening sulfamethazine(SMZ)in pork tissues was developed.The assay was made with the affinity−purified polyclonal antibody−coated microtiter plate.A cross reactivity of IgG was observed at 3.5 μg/g of sulfamerazine among nine kinds of sulfonamide tested.Pork tissues fortified with SMZ was mixed with octadecyl silica(C₁₈), and extracted with dichloromethane.The extracted SMZ was measured by homemade ELISA, commercial ELISA, and HPLC.The results were correlated(r=0.993, p<0.01).The homemade ELISA was sensitive to determine SMZ at the maximum residue level(MRL)as commercial one.During stability test of the IgG coated microtiter plate performed at 40°C for 14 days, no difference in sensitivity was observed.We developed homemade ELISA with a detection limit of 10 ng of SMZ per g of pork tissues, and it could be used to screen SMZ in pork tissues.

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The cardiovascular effects of medetomidine, detomidine, and xylazine in horses were studied.Fifteen horses, whose right carotid arteries had previously been surgically raised to a subcutaneous position during general anesthesia were used.Five horses each were given the following 8 treatments:an intravenous injection of 4 doses of medetomidine(3, 5, 7.5, and 10 μg/kg), 3 doses of detomidine(10, 20, and 40 μg/kg), and one dose of xylazine(1 mg/kg).Heart rate decreased, but not statistically significant.Atrio−ventricular block was observed following all treatments and prolonged with detomidine.Cardiac index(CI)and stroke volume(SV)were decreased with all treatments.The CI decreased to about 50% of baseline values for 5 min after 7.5 and 10 μg/kg medetomidine and 1 mg/kg xylazine, for 20 min after 20 μg/kg detomidine, and for 50 min after 40 μg/kg detomidine.All treatments produced an initial hypertension within 2 min of drug administration followed by a significant decrease in arterial blood pressure(ABP)in horses administered 3 to 7.5 μg/kg medetomidine and 1 mg/kg xylazine.Hypertension was significantly prolonged in 20 and 40 μg/kg detomidine.The hypotensive phase was not observed in 10 μg/kg medetomidine or detomidine.The changes in ABP were associated with an increase in peripheral vascular resistance.Respiratory rate was decreased for 40 to 120 min in 5, 7.5, and 10 μg/kg medetomidine and detomidine.The partial pressure of arterial oxygen decreased significantly in 10 μg/kg medetomidine and detomidine, while the partial pressure of arterial carbon dioxide did not change significantly.Medetomidine induced dose−dependent cardiovascular depression similar to detomidine.The cardiovascular effects of medetomidine and xylazine were not as prolonged as that of detomidine.

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A retrobulbar abscess/cellulitis occurred in a Yorkshire Terrier dog.The clinical signs were exophthalmos, prolapsed nictitating membrane and purulent ocular discharge.Ultrasonography showed a marked soft tissue swelling of the retrobulbar tissues as well as echogenic parallel lines between the globe and the medial orbital rim.Surgical exploration of the orbit was performed and no foreign body was found.The pterygopalatine fossa was incised and therapeutic retrobulbar drainage attempted.A drain was placed to encourage ventral drainage of the abscess.Anaerobic cultures revealed heavy growth of gram negative rods(prevotella bivia and prevotella buccae were isolated).Recovery was successful but subsequent treatment for keratoconjunctivitis sicca was necessary.A full recovery of tear production occurred after several weeks.

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Superovulation of female rabbits was induced by subcutaneous injection(s)of porcine FSH.Zygotes were recovered 17 to 19 hr after hCG injection and were classified into two categories under a microscope equipped with Nomarski interference−contrast optics at ×200 magnification:(A)zygotes with clearly visible pronuclei, or(B)zygotes with visualized pronuclei after 10 min centrifugation at 12, 000×g.No significant difference between strains was found in the proportion of category−A zygotes(JW 72.6% vs NZW 79.3%).Pronuclei of category−A zygotes were located in the center of the cytoplasm, and the pronuclei of category−B zygotes were slightly moved by centrifugation toward the mass of cytoplasmic lipid droplets.Exogenous DNA solution(5 μg/ml of fusion gene composed of bovine αS₁−casein promoter and human growth hormone structural gene)was microinjected into the pronucleus of the JW zygotes.The pronucleus of category−A zygotes with a mean volume of 7.4 pl swelled up to 16.6 pl(132% increase), while that of category−B zygotes with a mean volume of 6.1 pl swelled up to 15.9 pl(148% increase).Nevertheless, similar proportions of category−A and category−B zygotes developed into offspring after transfer to recipient females(11.1 and 11.2%, respectively).The efficiency to produce hGH−carrying transgenic rabbits was 0.9%(2/235)from category−A zygotes and 0.5%(1/215)from category−B zygotes(P>0.05).To date, transgenic rabbits have been produced without centrifugation of pronuclear zygotes.However approximately 25% of fertilized rabbit zygotes can be used for DNA microinjection after they have been centrifuged to visualize their pronuclei.

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A quick method for sex determination of horses was developed.Simultaneous amplification of the equine sex−determining region of the Y chromosome gene(SRY)and amelogenin gene(AMEL)accomplished the determination of the presence of both the Y chromosome and SRY gene.In agarose gel electrophoresis, a normal stallion showed 1 SRY band and 3 AMEL(AMELX, AMELY, and AMELX/AMELY heteroduplex)bands, and a normal mare showed a single AMELX band.In XY−mares, 3 AMEL bands were detected as in a normal stallion, but no SRY band.The present method enables a quick diagnosis for XY−mare prior to cytogenetic analysis.

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The effect of linoleic acid−albumin(LAA)supplementation to the media for IVM, enucleation, and activation on the developmental potential of bovine embryos produced by nuclear transfer(NT)into frozen−thawed cytoplasts was investigated.Blastomeres derived from morulae was placed in the perivitelline space of frozen−thawed cytoplasts, which were then fused by a DC pulse.The proportion of fused embryos was similar between groups with and without LAA(87 vs.90%).The proportion of development to blastocysts of NT embryos derived from the media with LAA(14%)was higher than that without LAA(4%), indicating that LAA treatment of bovine oocytes during IVM, enucleation and activation can improve the ability of such cytoplasts after freezing and thawing to develop into blastocysts after NT.

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The prostatic regression effect of oral administration of a new steroidal anti−androgen, osaterone acetate, was investigated in dogs with prostatic hypertrophy.To dogs with prostatic hypertrophy, 0.1−1.0 mg/kg of osaterone acetate was orally administered for one week, and the regression rate was observed.It was shown that administration of osaterone acetate at 0.2 mg/kg or higher, sharply regressed prostatic hypertrophy during the early stage.Therefore, this agent may be clinically applicable as a therapeutic agent for benign prostatic hypertrophy.

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