To determine sex of bovine embryos using hamster histocompatibility Y(H-Y) antibodies, bovine compact morulae were incubated for 6 hours in TCM199 supplemented with 10% hamster H-Y antiserum and the embryos with developmental arrest were diagnosed as male embryos, while the embryos showing development during the incubation as femalle embryos. This presumptive embryo sexing was confirmed by polymerase chain reaction(PCR)method. 1. In the result of hamster sperm cytotoxicity test to measure H-Y antibody titer, the rate of dead sperm was considerably lower in H-Y antiserum absorbed with hamster male splenocytes than in H-Y antiserum absorbed with hamster female splenocytes or H-Y antiserum umabsorbed with splenocytes(p0.01). 2. The rate of oocytes fertilized in vitro and the rate of blastocysts of the fertilized oocytes were 58.5% and 32.4%, respectively. The rate of blastocysts on day 8 was 15.9%, denoting the highest rate during whole culture period posterior to in vitro fertilization(IVF). 3. The bovine 16 cell and compact morulae embryos incubated in the medium supplemented with hamster H-Y antibodies showed 37.1% and 48.9% of developmental arrest which were diagnosed as male, respectively, and rates of redeveloped embryos from the arrested were 24.1% in 16 cell and 44.3% in compact morulae embryos, respectively, denoting higher rater of sex determination and rate of redevelopment in compact morulae than 16 cell embryos. 4. Bovine compact morulae of Korean cattle and Holstein were treated with hamster H-Y antibodies for sex determination and the rates fo developmental arrest(deagnosed as male) were 48.4% for Korean cattle and 47.9% for Holstein, respectively. The rates of redeveloped embryos to blastocyst after treatment were 42.6% for Korean cattle and 41.8% for Holstein, respectively, ahowing no sighificant differences of sex determination and redevelopment between both breed. 5. The sex determination of bovine cmbryos(Korean cattle Holstein) using hamster H-Y antibodies was diagnosed by PCR for confirmation, denoting the rates of 86.1% for Korean cattle and 85.9% for Holstein male embryos, respectively, and the rates of 91.9% for Korean cattle and 90.1% for Holstein female embryos, respectively, with no significant differences of sex determination between both breed. These results indicated that hamster H-Y antibodies can be usable for sex determination of bovine embryos of Korean cattle and Holstein, the viability of bovine embryos was sustained while being cultured in the medium supplemented with hamster H-Y antibodies of appropriate titer and sex determination of bovine embryos by PCR can be feasible for confirmation.

A species-specific 760 base pair(bp) BamHI to EcoRI DNA fragment(fMG-2) of lipoprotein gene was isolated from a Mycoplasma gallisepticum (M gallisepticum) genomic library. Based on the DNA sequence data of fMG-2, a pair of 25bp primers was synthesized. When used in the polymerase chain reaction(PCR), 732bp DNA products were amplified from 6 standard strains and 10 field isolates of M gallisepticum, but not from 2 Mycoplasma synoviae and 7 other Mycoplasma species. The lower detection limit was 100fg of the genomic DNA. Identity of the PCR products was confirmed by comparison of patterns of restriction endonuclease analysis with AseI, DraI, EcoRV and SspI.

Osteoporosis is defined as a decrease in bone mass that leads to an increased risk of fracture. The therapeutic effect of 1alpha,25 dihydroxycholecalciferol, the hormonal form of vitamin D3 that mediates calcium translation in intestine and bone, on the healing process of fracture has still been controversial. These studies were designed to understand the healing process of normal fibular fracture, the osteoporotic changes after ovariectomy, and the theraqeutic effects of 1alpha,25 dihydroxycholecalciferol on the osteoporotic fracture in rats. The simple transverse fractures of rat fibulae were produced with a rotating diamond saw. The changes of the biochemical and mechanical indices of rats were investigated. The mechanical study based on bending test revealed the healing of the fibular fracture in the 5th week after simple transverse fracture. The osteoporosis impaired more the healing of osteoporotic fibular fracture than normal non-osteoporotic fibular fracture. The healing process of osteoporotic fracture was facilitated by the treatment with 1alpha,25 dihydroxycholecalciferol, however was delayed more than the healing process of normal fracture. The bone strength based on the bending test also confirmed this tendency. The bone strengths in the 5th week after fracture of normal bone, osteoporotic bone, and 1alpha,25 dihydroxycholecalciferol-treated osteoporotic bone were 75%, 41% and 67%, respectively, in comparison with those of intact bone. In conclusion, 1alpha,25 dihydroxycholecalciferol was effective in promoting the osteroporotic fracture healing.

To elucidate the involvement of interleukin-1beta converting enzyme (ICE) in the courseof experimental autoimmune encephalomyelitis (EAE), we induced EAE by immunizing rats with an emulsion of rat spinal cord homogenate with complete Freund's adjuvant supplemented with Mycobacterium tuberculosis(H37Ra, 5mg/ml) and then examined the expression of ICE in the spinal cord of rats with EAE. In normal rate spinal cords, ICE is constitutively, but weakly, expressed in ependmal cells, neurons, and some neuroglial cells. In EAE, many inflammatory cells are positive for ICE, and the majority of ICE+ cells were identified as ED1+ macrophages. During this stage of EAE, the number of ICE+ cells in brain cells, including neurons and astrocytes, increased and these cells also had incresed ICE immunoreactivity. These findings suggest that the upregulation of ICE in both brain cells and invading hematogenous cells is stimulated by a secretory product from inflammatory cells, and that this enzyme is involved in the pathogenesis of EAE via the production of IL-1 beta.

The present work was conducted to investigate the drug susceptibility of microorganisms isolated form canine external ear canals. Antifungal susceptibility test of M pachydermatis(17 strains) was performed by agar dilution method, using 11 antifungal drugs including amphotericin B(A), nystatin(N), pimaricin(P), griseofulvin(G), gifonazole(B), clotrimazole(C), miconazole(M), econazole(E), ketoconazole(K), tolnaftate(T), 5-fluorocytosine(F). All isolates were highly sensitive to K, M, T(geometric mean MIC;GM MIC_0.16 micro gram/ml). Antibacterial susceptibility test against 119 isolates of bacteria was performed by agar dilution method, using 9 antibacterial drugs including erythromycin(ET), chloramphenicol(CP), gentamycin(G), vancomycin(V), ampicillin(AP), amoxacillin(AX), chlortetracycline(CT), ciprofloxacin(CF), enrofloxacine(EF). All isolates of Staphylococcus spp(101 strains) were highly sensitive to EF, CF, G(GM MIC 0.33~1.47 micro gram/ml). In other gram positive cocci(4 strains), they were highly sensitive to EF, CF, V(GM MIC 1~4.76 micro gram/ml) and CT(GM MIC 1 UFL unit/ml). In gram positive rods(13 strains), they were highly sensitive to EF, CF, G(GM MIC_0.19~1 micro gram/ml). In Pseudomonas aeruginosa(1 strain), it was highly sensitive to AX, EF, ET, CF(GM MIC 0.06~1 micro gram/ml) and CT(GM MIC 1 UFL unit/ml). All isolates weren't sensitive to AP(GM MIC 16~32 micro gram/ml).

This study was carried out to nvestigate the NPY-immunohistochemical characteristics of the olfactory bulb in the striped field mouse(Apodemus agrarius). The animals were anesthesized with thiopental sodium and perfused with 4% paraformaldehyde through left ventricle and aorta. Brains were removed and tranfered 10%, 20% and 30% sucrose. Sections were then cut on a cryostat into 40 micro meter-thick. The tissue immunostained with avidin-biotinylated complex method. The main olfactory bulb consisted of seven circumferential laminae: and olfactory nerve fiber layer, a glomerular layer with glomeruli surrounding by periglomerular cells, an external plexiform layer having granule and tufted cells, a mitral cell layer, a narrow internal plexiform layer, a granule cell layer forming several cell rows and alayer of white matter. The accessory olfactory bulb had four layers: an olfactory or vomeronasal nerve fiber layer, a glomerular layer consisting of small glomeruli, a mixed layer not distinguishing the external plexiform/mitral cell/granule cell layers and a granule cell layer. Most of NPY-immunoreactive(NPY-IR) neurons in main olfactory bulb were localized in the deeper portion of granule cell layer, white matter and anterior olfactory nucleus. In addition, some NPY-IR neurons were identified in the external plexiform layer. The shape of NPY-IR neurons of all olfactory bulb were predominant round or oval, sometime multipolar in shape. And most NPY-IR processes were parallel to long axis of white matter. In accessory olfactory bulb, NPY-IR neurons were not found in all region.

We have developed in situ hybridization(ISH) technique for rapid diagnosis of canine distemper(CD) which is the major infectious disease in dogs. In our experiment, we rapidly detected distribution of the specific canine distemper viral genome without disrupting morphology of tissues of cells. Two oligonucleotide probes for ISH were synthesized chemically and labelled 5' end with nonisotopic biotin by DNA synthesizer. The whole procedures of ISH was completed within 1~2 hours using the Microcapillary action system. On histological study, typical cytoplasmic or intranuclear inclusion bodies wer observed in the trachea, bronchiole, brain, and urinary bladder with the presence of prominent red positive signals on ISH, indicating specific CDV genome from the paraffin-embedded tissues of infected 13 cases. The results showed ISH can be used as a rapid and effective diagnostic method for diagnosis of CD.

The morphological studies on the cecal development in the 60-, 90-, and 120-day-old fetuses and the newborns of Korean native goats were investigated by scanning and transmission electron microscopy. The results were summarized as follows; Scanning electron microscopic studies: 1. In the 60-day-old fetuses, fold-like shpaes protrusion oon the cecal mucosa surface appeared. In the 90-day-old fetuses, the cecal villi appeared to be columnar shpaes. In the 120-day-old fetuses, the cecal villi showed variou tongue-like or columnar shpaes. In the newborns, only the rudimental trace of the villi and the intestinal glands were observed. 2. In the 60-day-old fetuses, the cecal epithelia were simple columnar in some areas and stratified columnar in others, and the epithelial cells contained nuclei, nucleoli, ER, mitochondria, Golgi complexes, zonula occuludens, desmosomes, digitiform intercellular junctions, and large masses of the glycogen granules. 3. In the 90-day-old fetuses, the cecal epithelia were simple columnar in some area and stratified columnar in other. The microvilli of the cecal epithelia became much larger and longer than those in the 60-day-old fetuses, and intercellular junctions were developed, and increased numbers of ER, mitochondria, Golgi complexes were observed and the goblet cells contained a lot of the secretory granules. 4. In the 120-day-old fetuses, the cecal epithelia were only columnar in all areas. Microvilli and cytoplasmic organelles were well developed and the irregular annular nuclei were observed. 5. In the newborns, the cecal epithelia were covered with extensive microvilli, and the goblet cells with secretory granules were protruded into lumen. And some goblet cells secreted the secretory granules into the lumen.

The fatty acid composition of muscle were investigated to compare muscle composition among the 9 domestic animals including cattle. In major domestic animals, analyzed the effects of age, part and sex of the animal on their fatty acid composition. The content of 4 types of major fatty acids of muscle was determined and calculated their ratio. Myristic acid and palmitic acid levels were high in chicken and sheep. Besides dog muscle contained a lot of stearic acid. Linoleic acid content showed evident difference in the content depending on the animal species. The ratios of linoleic acid/palmitic acid (L/P ratio) and linoleic acid/stearic acid(L/S ratio) were characteristically high in horse and pig, whereas the ratio of palmitic acid/stearic acid(P/S ratio) was 0.7+_0.17, showing very low level in dog. As for the content of steric acid, in cattle and chicken it was higher in young animal than adults. In duck, the contents of all fatty acids and ratio were increased by the age. As for the content of fatty acids according to the part of chicken, high level was shown in thigh than in breast and wing, while there was no remarkable variation by the part in other animal. The differences in the content of myristic acid, palmitic acid and linoleic acid among some animal could be verified in muscle lipid composition. The L/P ratio which maintained certain level regardless of age, part, sex shown distinctive pattern between the species.

To establish the protocol of a standardized exercise test for evaluating exercise intolerance and degree of fitness in Thoroughbred racehorses, we examined serum lactate concentrations related to exercise intensities using the high speed tradmill. Twelve clinically healthy Thoroughbred racehorses with or without previous training or racing history were assigned to two groups, fit and unfit group, respectively. The protocol used for the standardized exercise test was consisted of two stages:stage ofwarm-up and that of acceleration. During the warm-up, the horses exercised 5 min at 1.8m/s and 3 min 3.4m/s without inclination. At the acceleration stage, exercise test was performed at 10% slope and the speed was increased from the initial 5m/s to the maximal speed which each tested horse could keep up with. The speed was increased with incremental steps of 1 m/s every minute. During the last 15 sec of each step, blood samples were collected for serum lactate determination. V max (masimal treadmill speed which tested horses could keep up with) of the fit group (10.93+_0.33m/s, mean+_SE, n=6) was higher than that of the unfit group (9.52+_0.23m/s, mean+_SE, n=6). Serum lactate concentrations increased exponentially according to exercise intensities. V la4 (speed producing a serum lactate concentration of 4mmol/l) of the fit group, 6.45+_0.26m/s, was higher than that of the unfit group, 5.45+_0.23m/s. La peak (peak plasma lactate concentration during the exercise test) was lower in the fit group (20.34+_1.62mmol/l at 1 min after maximal intensity exercise) than in the unfit group (24.78+_1.09mmol/l at 2 min after maximal exercise step). t50% (time required for the recovery of lactate concentration to be one-half of La peak after maximal exercise) of the unfit group and the fit group were 40.0 and 18.0 min, respectively. Therefore, the protocol of the incremental standardized exercise test utilized in this study seems to be reliable for the assessment of fitness and exercise intolerance for the Thoroughbred racehorses.