The purpose of this study was to establish a rapid, reliable diagnostic method detecting Encephalomyocarditis virus(EMCV) RNA in formalin-fixed, paraffin-embedded tissues of EMCV naturally infected pigs by cDNA probe of EMC K3, the EMCV strain isolated from Korea. Using a biotin-labelled nick translated probe for the cDNA marker. We made up for some defects of radiolabeled method. In situ hybridization(ISH) technique, differently from theother nucleic acid hybridization methods, is able to detect the virus genome specifically in the state of the intact shapes of cells and/or tissues. We succeeded in performing the experiment to detect the EMCV within 1~2 hours usign the MicroProbeTM capaillary action system. In this study, we ovserved highly specific positive sighals of red color by staining the paraffinembedded tissue sections of naturally EMCV-infected pig organs or tissues, including brain, heart, kidney and lacrimal gland with the Fast Red TR salt/Naphtol phosphate chromogen. The results suggested that this ISH method is considered as a highly sensitive and reliable tool for molecular biologic diagnosis of the EMC viral disease.

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.

A nation wide sero-epidemiological survery of porcine reproductive and respiratory syndrome(PRRS) was carried out to analyze the current status of the PRRS virus infections in the field using the indirectr immunofluorescent antibody assay(IFA) with the field isolate PL96-1. Since the first report of the antibody detection to PRRSV in 1993, the prevalence of seropositive pigs has increased dramatically and the data indicate that over 21% of the pigs and around 60% of the farms showed seropositives to the PRRS virus. A slightly higher positive rate was recognized in breeders than fattenings and it might be due to the higher age at the time of testings. No significant regionl defferences were detected in the sero-epidemiological survey. Higher sero-positive rate in growers indicatesthat PRRSV infection in the field was common after weaning(around 40 days). However, the number of seropositive pigs were declined in fattening pigs. Sows showed around 26% of sero-positive rate that there is a higher chance of continuous virus circulation in the infected farms. Low rate of sero-positivity in boars(9.8%) implies that there is high demand in proper controlmeasures to prevent virus spreading through breeding procedures such as natural or artificial insemination Therefore it was concluded that PRRSV infection in domestic swine herds is endemic and the positive rate and economic loses will be increased by spontaeous infections in naive farms.

The 2,078 blood samples from 148 swine farms were collected and tested by IFA for porcine reproductive and respiratory syndrome(PRRS) virus antibody to know what type of PRRS prevails by the area. Clnically reproductive form of PRRS occurred in swine farms of 3/27, 3/87, and 2/34 in estern, central and western areas, but the seroprevalence of those areas ws different as 6.5%, 23.3%, and 17.6%, respectively. However, respiratory form of PRRS occurred more frequently, and the number of farms manifested with the respiratory form of PRRS in the eastern, central and western areas was 22/27, 71/87, and 30/34, respectively. The seroprevalence of that form of PRRS in the eastern, central and western areas was 52.2%m 67.1%, and 51.6%, respectively. Sybsequently mixed form of PRRS ocurred more frequently in the central area and the number of farms of eastern, central and western areas was 2/27, 13/87, and 2/34, respectively. The PRRS seroprevalence of the eastern, central and western areas was 58.6%, 54.0%, and 19.2%, respectively. Collectively the PRRS seroprevalence of eastern, central and western areas was 43.8%, 59.3%, and 38.2%, respectively. Overall seroprevalence of PRRS in Korea was 51.8%. In conclusion, the reproductive or the respiratory form of PRRS has been still in trouble inthe Korean swine industry and PRRS control measures have to be taken in consideration.

Previous studies suggested that the inhibition of thyroxine (T4) release by alpha1-adrenoceptor and muscarinic receptor stimulation results in activated protein kinase C (PKC) from mouse and guinea pig thyroids. In the present study, the effect of carbachol, methoxamine, phorbol myristate acetate (PMA), and R59022 on the release of T4 from the mouse, rat, and guinea pig thyroids was compared to clarify the role of PKC in the regulation of the release of T4. The thyroids were incubated in the medium containing the test agents, samples of the medium were assayed for T4 by EIA kits. Forskolin, an adenylate cyclase activator, chlorophenylthio-cAMP sodium, a membrane permeable analoge of cAMP, and isobutyl-methylxanthine, a phospho-diesterase inhibitor, like TSH (thyroid stimulating hormone), enhaced the release of T4 from the mouse, rat, and guinea pig thyroids. Methoxamine, an alpha1-adrenoceptor agonist, inhibited the TSH-stimulated release of T4 in mouse, but not rat and guinea pig thyroids. In contrast, carbachol, a muscarinic receptor agonist, inhibited the release of T4 in guinea pig, but not mouse and rat thyroids. These inhibition were reversed by prazosin, an alpha1-adrenoceptor antagonist or atropine, a muscarinic antagonist or M1- and M3- muscarinic antagonists, in mouse or guinea pig thyroids. In addition, staurosporine, a PKC inhibitor, reversed methoxamine or carbachol inhibition of TSH stimulation. Furthermore, PMA, a PKC activator, and R59022, a diacylglycerol (DAG) kinase inhibitor, inhibited the TSH-stimulated release of T4 in mouse, rat, and guinea pig thyroids. These inhibition were blocked by staurosporine. these findings suggest that the activation of receptor or DAG inhibits TSH-stimulated T4 release through a PKC-dependent mechanism in thyroid gland.

The present experiments were performed to examine the effects of acetylcholine (ACh) and carbachol (CC) on thyroxine (T4) release and any possible relation between inhibition of T4 relese and sighaling pathway in guinea pig thyroids. The thyroids were incubated in the medium containing the test agents, samples of the medium wer assayed for T4 by EIA kits. ACh and CC inhibited the TSH-stimulated T4 release. These inhibition were reversed by atropine, but not by d-tubocurarine. The ingibitory effects of ACh on T4 release were prevented by M1- and M3-muscarinic antagonists and its inhibition was also slightly reversed by M2- and M4- muscarinic antagonists. R59022, like ACh and CC, also inhibited the TSH-stimulated T4 release. This inhibition was reversed by protein kinase C inhibitor and Ca2+ channel blocker. The present study suggests that cholinergic inhibition of T4 release from thyroids can be induced mainly by ctivation of the M1- or M3-receptors and that it is mediated throught the muscarinic receptor-stimulated protein kinase C activation