A 474-base pair segment covering the hypervaible region of VP2 gene from six Korean infectious bursal disease virus(K-IBDV) isolates(K1, K2, SH/92, 225, 269, 310) and one attenuated IBDV(DAE) were amplified using RT-PCR, sequenced, and compared with published sequences for IBDV. K-IBDV isolates(K1, K2, SH/92, 225, 269) and foreigh very virulent(vv) IBDV strains had 94.93-100% amino cid sequence similarity. K-IBDV isolate 310 and other K-IBDV isolates had 84.31%-86.07% amino acid sequence similarity. Attenuated strain(DAE), like other attenuated strain, has substitution at positions 279(D to N) and 284(A to T) as well as in the serine-rich heptapeptide region. Five K-IBDV isolates except 310 isolate share unique amino acid residues at positions 222(A), 256(I), 294(I) which are not present in other standard and attenuated strains. At the two hydrophilic region, K-IBDV isolates except 310 isolate had identical amino cids comparing with Belgium vv IVDV 894VB but had four amino acid substitutions comparing with Chinese vv IBDV F9502. The SWSASGS heptapeptide is conserved in all KIBDV isolates. The sequence of K-IBDV isolate 310 was markedly different from other IBDV strains, evolving from a separate lineage than the others. By phylogenetic analysis, Five K-IBDV isolates except 310 isolate were categorized in one group with foreign vv IBDV isolates but K-IBDV isolate 310 was categorized ina separate group which was differentiated form other compared IBDV strains

The present study was carried out to investigate the pathogenicity and pathogenesis of wild rats(Rattus norvegicus), trapped in nature, intranasally infected Aujeszky's disease virus(ADV/NYJ-1-87) by histopathology, immunohistochemistry and in situ hybridization(ISH). Fifteen rats inoculated intranasally were roughened haircoat, anorexia, listlessness, and depression second day after inoculation, and three rats died in 66-72 hours. Eight rats showed severe pruritus at the fact that was accompanied by frequent face-washing movements of the forelegs, and then became violent and spasmodic for and hour or until they died. Four rats slowly recovered after showing mild clinical signs of the disease. Microscopic lesions in infected rats were characterized by meningitis, perivascular round cell infiltration, focal gliosis, and neuronal degeneration and necrosis. And intranuclear inclusion bodies were frequently detected in the cerebral cortex and medulla. Positive reaction to ADV by immunohistochemistry and ISH were detected in the following areas:trigemimal ganglion, brain, tonsil, nasal mucosa, spleen, lung and liver. The result has suggested that ADV intranasally infected in wild rats is followed by replication in epithelial cells of nasal mucosa and tonsil, then invade local lymph nodes by way of the lymphatics. It is also believed that the virus invades bipolar olfactory cells and trigerminal ganglion, and then spread into central nervous system.

The purpose of this study was to evaluate effect of chitosan-oligosaccharides(CHIOL) on hydrophobicity of pathogenic E coli including a field isolate from suckling piglet with diarrhea, E coli-0157:H7, and E coli-O149:K88ac. E coli field isolate appeared adhesion of 100% to n-hexadecne between 0.00125% and 0.05% CHIOL. E coli-O157:H7 occurred adhesion of 69% and 64% under the level of 0.00125% and 0.025% CHIOL, respectively. E coli-O149:K88ac showed adhesion of 100% in higher than 0.025% CHIOL. For cationic action, the adhesion of E coli isolate and E coli-O149:K88ac to n-hexadecane were inhibited at level of higher than 10mM Ca2+ but did not induce any difference among the concentrations used(p0.01). However,the adhesion of E coli-O157:H7 to n-hexadecane was inhibited at level of higher than 50mM Ca2+. In a field trial, control piglets showed average mortality of up to 58% during 3 days after the onset of diarrhea. In contrast, the prevalence of E coli-induced diarrhea in CHIOL-treated groups without mortality was dropped down to average 34% on the 1st day after the treatment of CHIOL, and average 2% on the 4th day. After then, piglets with diarrhea was not present. In conclusion, the low concentrations of CHIOL were most likely to associate with the enhancement of hydrophobicit to pathogenic E coli. Calcium inhibited the hydrophobicity of E coli by CHIOL. These results suggested that CHIOL could be played an efficient and reliable role in treating enteric colibacillosis of piglets.

To elucidate the action of the cholinergic and adrenergic nerve on isolated gastric fundus smooth muscle of rabbit, the effects of electrical transmural stimulation were investigated in the presence of atropine, cholinergic receptor blocker; phentolamine, nonselective alpha-adrenergic receptor blocker; propranolol, nonselective beta-adrenergic receptor blocker and L-arginine from the isometric contraction of physiological recording system. 1. The contractile response induced by electrical transmural stimulation was increased as the frequency(1~32Hz)-dependent manner on the isolated gastric fundus smooth muscle. 2. The contractile response induced by electrical transmural stimulation was markedly inhibited by the pretreatment of atropine(1 microM). 3. The contractile response induced by electrical transmural stimulation was inhibited by the pretreatment of phentolamine(1 microM). 4. The relaxative response induced by electrical transmural stimulation on presence of atropine (1 microM) was inhibited by the pretreatment of propranolol(1 microM). 5. The relaxative responses on precontraction induced by histamine(10 microM) with guanethidine (50 microM) and atropine(1 microM) by electrical transmural stimulation were incresed by L-arginine(1mM). These fingings suggest that it was the exciatory action of cholinergic and alpha-adrenergic nerve, and the inhibitory action of beta-adrenergic nerve and nonadrenergic noncholinergic nerve on the isolated gastric fundus smooth muscle of rabbit.

Since Robert Koch found tubercle bacilli in 1882, the studies on tubercle bacilli of human and animal had been carried out. Being old tuberculin(OT) introduced in 1890, the specificity of the diagnosis of tuberculosis has been improved by continual uses of heat concentrated synthetic medium(HCSM) and purified protein derivatives(PPD) tuberculin. Now, two types of tuberculin test are used worldwidly; the single intradermal test(SIT) using bovine tuberculin and the single intradermal comparative tuberculin test(SICTT) using avian and bovine tuberculins. In the SICTT, each countries have used with different combination of both avain and bovine tuberculins' titers. However, this kinds of studies have not reported in Korea. Therefore, the studies on the combination of their tuberculins' titers were performed through intradermal test of guinea pigs sensitized with either Mycobacterium bovis or M avium and were examined in 10 cattles of SIT positive reactors. Also, IFN-y assay, the latest diagnostic method of bovine tuberculosis, was experimentally applied to SIT positive reactors. For determinint the optimal titers, sensitized guinea pigs with M bovis and M avium were intradermally injected avain and bovine tuverculin. In guinea pigs sensitized with M bovis, bovine tuberculin 50 T.U. showed significant difference from all tested concentrations of avian tuberculin(p0.05). In guinea pigs sensitized with M avium, there is significantly different between bovine tuberculin and avian tuberculin by 25 T.U.(p0.01). Therefore, optimal titers of bovine and avian PPD tuberculins' titers for the SICTT in Korea were 5,000 and 2,500 tuberculin units, respectively, and the swelling differences between bobine and avian site in SIT positive reactors were above 3mm. Also, in IFN-y assay, the 9 SIT positive reactors were showed all the positive reactions.

This study was conducted to examine the outbreak rate and the causative agents of otitis externa in 26 dogs(49 ears; 23 dogs = bilateral, 3 dogs = unilateral), and the normal microfloras of external ear canal in 68 dogs(133 ears; 65 dogs = bilateral, 3 dogs = unilateral) in Taegu, 1997. The breed, living environment, sex, age and season distribution of otitic dogs were as follows: Dogs with erect and hairy ears(42.3%), pendulous and hairy ears(38.5%), indoor(92.3%), female(65.4%) and below one year old(38.5%) were more prevalent. According to season, otitis externa was mainly occurred between July and October. The major causative agents of canine otitis externa were Malassezia pachydermatis(32.7%), Staphylococcus aureus(26.5%) and S intermedius(16.3%). The major causative agents of canine otitis externa were Malasszia pachydermatis(32.7%), Staphylococcus aureus(26.5%) and S intermedius(16.3%). In the microorganism isolated 39 otitic ear canals, single infection was 53.8% and mixed infection was 46.2%. The normal microfloras of canine external ear canal were fungi including M pachydermaits, Aspergillus spp, Microsporum canis, Alternaria spp, Verticillium spp and Yeast, and bacteria including Staphylococcus spp(10 species including S xylosus), Bacillus spp, Corynebacterium spp, Listeria spp, Actinomyces pyogenes and Escherichia coli. No growth was 34.6%.

This study was designed to evaluate the effect of cyclophospaide(CY) on dietynitrosamine(DEN)-induced hepatic tumors in rats. Thirty five male of femal Sprague Dawley rats were continiously given water containing O.01% DEN for 10 weeks and then were give with CY 25mg/rat/day in water for 3, 5, 7 or 9 days. The livers of rats were removed and fixed in 10% buffered neutral formalin. The appearances of positive cells by immunohistochemical methods using proliferating cell nuclear antigen (PCNA) antibody, p53 antibody and apoptotic kit were investigated. The livers of rats given with CY were grossly brilliant, red-brown color, flexible, and thin border, and stainability of the liver cells were restored microscopically, and the vaccuolated and degenerated regions were differentiated from restored regions. These restored findings also were advanced in control group becouse of no DEN treatment but tended to be less avanced. In immunohistochemistry, positive cells to PCNA antibody appeared more numerous in control groups than that of CY treated groups. Appearance of positive cells in CY-treated group for 7 days and for 9 days were more numerous than those of CY-treated groups for 3 days and for 5 days, respectively. So these findings suggested that CY suppressed cell proliferations and effects of these action were decreased with CY-treated days. The numbers of positive cells to PCNA antibody were more prominent in hepatocelular carcinoma regions and cholangiocarcinoma regions, and then were ranked as order of large liver cell regions and normal liver cell regions. Also the numbers of the positive cells by apoptotic kit tended to be higher in hepatocelular carcinoma regions and cholangiocarcinoma regions but not uniformly in order in all regions nd were much less numbers than those of OCNA positive cells. So immunohistochemical methods using PCNA antibody together than using apoptotic kit alone when anti-carcinogen experiments. Rats with positive cells by p53 antibody were 11 of 15 rats(73.4%) in control groups and 12 of 18 rats(66.7%) in CY treated group, respectively. These positive cells appeared focally in early vacuole-occurring regions and were low in numbers.

Although it has been reported that hormones or chemicals, which increse in intracellular cAMP, produced Mg2+ release from the heart, it is not well characterized whether a specific Mg2+ exchanger is involved in cAMP-induced Mg2+ efflux in themammalian hearts In this work, we studied the relationship between the increase in intracellular cAMP and ion transport system on Mg2+ regulation in the perfused rat heart and isolated myocytes. The Mg2+ content in the perfusate and supernatant were measured by atomic absorption spectrophotometer. The addition of membrane permeable cAMP analogue to the perfused hearts and myocytes. cAMP-induced Mg2+ efflux was ingibited by H7, benzamil or imipramine in the perfused hearts and myocytes, but not by EIPA. We confirmed that a significant Mg2+ efflux was induced by an increase in intracellular cAMP in the hearts and myocytes. The cAMP-induced increase of Mg2+ efflux in the hearts may be involved in ion transport system(Na+-Ca2+ and Na+-Mg2+ exchanger)

The purpose of the present study was to investigate the effect of bovine amniotic membrane grafts on healing of full-thickness skin wound in dogs. Two 3cm*3cm area-matched full-thickness skin wounds were induced bilaterally on the dorsolateral aspect of the trunk of 15 dogs Chlorhexidine-treated amnion, dried amnion, silver sulfadiazine and 0.9% sterile saline solution were applied on the wound area and examined grossly and histopathologically. Begining 14 days after wounding, amnion applied group had appreciably less amount of inflammatory exudate and hemorrhage than sulfadiazine and saline treated groups. From 14 days after wounding, the degree of wound contraction in amnion groups, especially in the dried amnion group was greater than that of the sulfadiazine and saline treated groups. The percentages of wounds completely healed on 28 days after wounding in saline treated group, chlorhexidine-treated amnion group, dried amnion group and sulfadiazine treated group were 33%, 50%, 83% and 50%, respectively. Microscopically neovascularization and fibrosis were first noticed on 5 days after wounding in the dried amnion group and sulfadiazie treated group, on 7 days in the chlorhexidine-treated amnion group and on 14 days in the saline treated group. Epithlialization in thedried amion and sulfadizine treated groups ws first noticed on 9 days after wounding, which was faster than that in the other groups. The present study suggests that bovine amniotic membrane, especially dried bovine amnion is effective on healing of full-thickness skin wound in dogs through both wound contraction and epithelialization.

Swine plasminogen is not activated by staphylokinase of Staphylococcus aureus. In this study, the activation of swine plasminogen by staphylokinase of Staph hyicus subsp. hyicus was investigated and the effect of EDTA(disodium) on plasminogen activation was also studied. When the activation of swine plasminogen by staphylokinase of Staph hyicus subsp. hyicus was examined in fresh swine plasma, swine plasminogen could be weakly activated. However, when EDTA was added to the swine plasma, plasminogen activation was markedly enhanced, but this enhancement was not observed on bovine fibrin-dog plasminogen agar plate containing EDTA. Chicken and bovine plasminogens were not activated by staphylokinase of Staph hyicus subsp. hyicus. Using fresh swine plasma agar containing 0.07% EDTA, staphylokinase activity was detected in 96.3% of Staph hyicus subsp. hyicus strains isolated from pigs and in none of the chicken and bovine strains.