Porcine Proliferative Ebterophthy(PPE) is an infectious enteric disease and a major cause of economic loss in swine industry due to weight loss, poor growth and sudden death in growing and finishing pigs at 6 tp 20 weeks of age. PPE has been diagnosed by clinical sighs, syndrom and lesions in the intestine in Korea. However, the diagnostic method had several problems in the detection of infected or carrier pigs. Therefore, in this study, we established the polymerase chain reaction(PCR) which ws a fast, specific and sensitive method for identification of Lawsonia intracellularis(L intracellularis). We designed and synthesized primer on the 16S rDNA and p78 gene encoding L intracellularis. Specificity of the method was confirmed by comparison of the PCR results using other enteric bacteria and the study has shown that PCR method was sensitive to detect 1ng of genomic DNA as a template. Identity of the PCR products was confirmed by comparison of pattern of restriction endonclease analysis with restriction enzyme HaeIII and PstI. Also, the PCR method was applicable to the naturally affected pigs with PPE. Based on the results from this study, the PCR method could be used as a fast and specific diagnostic tool for PPE.

African swine fever (ASF) is an infectious disease of domestic and wild pigs for which there is no vaccine in the world. A proper surveillance of viral activity and a timely response to ASF outbreaks depend upon the rapid diagnosis of ASF viral infection. Internationally prescribed enzyme-linked immunosorbent assay (ELISA) is a fast, sensitive test routinely used in the diagnosis of the ASF. However, inactivated whole ASF virus antigen used in this test is a tedious to prepare and has a risk of outside exposure of infectious virus by laboratory accident during the preparation.

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.

DNA hybridization assay using probes prepared from liver was carried out to identify species characterization of the domestic animals. Gel electrophoresis showed that the target DNA extracted from raw muscle were 1kb and uniform pattern while fragments size of heated muscle were irrgular. Hybridizatino was performed by adding 200ng/ml probe in hybridization solution and incubating for 12 hours at 68 degrees centigrade. To obtain good discrimination, applied washing buffer and washing step differently depending on the species. The probes of pig, horse and dog formed the specific hybrids with each target DNA respectively. Although cross reaction ws detected in cattle, goat and sheep but signal intensity among these species made the discrimination possible each other. Such pattern was the same in the cases of chicken, turkey and duck. The hybridization pattern of heated muscle was similar to that of raw muscle in general, but the signal intensity was inferior to that of raw muscle. Species identification between closely related animal species, hybridized using the target DNA of such closely related animal species as a blocking agent, remarkable increase of discrimination from the evident decrease of non specific reaction compared with the control group. In addition, in the admixture where certain meat was included in the beef, pork, chicken meat, we colud find whether any unjust meat was admixed or not. In this case, detection limit of certain meat in admixture was 1%.

Swine shipworm(Trichuris suis) is cosmopolitan nematode which can cause serious pathology in immature stage(larva2~larva5) of infected pigs, such as anorexia, diarrhea, anemia, and death in heavy infections. In this larval stages, it is very difficult to diagnose the infection of whipworm and to differentiate from other common swinegstrointestinal disorders such as 21 day scours which are associated with TGE virus, rota virus, coccidium, and the stress of weaning. In this experiment, the isolated antigens of Trichuris spp. were carried out to examine the structure and specificity of antigens and to select the resonable antigens which would be used in serological diagnosis by electrophoresis, Western blotting, ELISA. The results of this experiment were as follews: 1. The common fractions of each Trichuris suis antigen were identified 28,32,45, 80kDa by SDS-PAGE with silver stain and four major fractions could be detected in positive swine sera by Western blot analysis. 2. The OD(optical density) values of somatic and excretory-secretory antigens which were reacted against positive(negative) sera from pigs infected with Trichuris suis by ELISA reader were; 1) OD values(mean+_SD) of adult somatic antigen against positive(negative) sera were O.30+_0.12(0.09+_0.006) and third-stage larva of somatic antigen were 0.28+_0.038(0.10+_0.005). And OD values of excretory-secretory antigens of adult and third-stage larva were 0.24+_0.031(0.11+_0.005) and 0.08+_0.013(0.10+_0.003), respectively. 2) OD values of adult somatic, larval somatic antigen and adult excretory-secretory antigen response to positive sera were significantly (p0.01) associated with negative swine sera. And the Cut-off OD values(minimum positive value) were determined to be mean negative value plus 3 SD that would minimized the risk of false positives. 3. The OD values of somatic antigens of T suis and T vulpis against swine positive(negative) sera were 0.30+_0.120(0.09+_0.006) and 0.25+_0.141(0.09+_0.003). These data mean that the somatic antigens of T suis and T vulpis were able to diagnose T vulpis infection in dogs as well as T suis infection in pigs. These results suggest that somatic antigen of third-stage larva and excretory-secretory antigen of adult T suis could be used the diagnostic antigen by serological test(ELISA) in immature Trichuris spp. infection.

Detection and distribution of bovine biral diarrhea virus(BVDV) was studied in formalin-fixed, paraffin-embedded tissues from two naturally infected cattle by in situ hybridization with a non-radioactive biotinylated probe. A 600 base pair cDNA probe from BVDV B-25 strain ws used for probe. The whole procedure of ISH to diagnose was carried out within 1~2 hours in MicroprobeTM capillary action system. The biotin-labelled probe was demonstrated after hybridization under standard conditions by the application of streptoavidin and biotinylated alkaline phosphatase. Alkaline phosphatase was visualized using a fast red TR/naphthol phosphatase and the sections were counterstained with hematoxylin. We have obtained the result of positive reactions in digestive tract(sm1.all intestine and colon) and epidermis of tongue in the state of the intract tissues. The result suggested that in situ hybridization method can be considered as a useful diagnostic technique for detection of specific nucleic acid sequences of BVDV.

This study was undertaken to detemine the normal appearance of the postpartum uterine involution. Postpartum changes in uterine shape, architecture, echogenicity and diameter were monitored with ultrasonography in 11 Korea Jin-do dogs. Serial ultrasonographic examination was done daily during the first week, 3 days interval from 8 to 30 days, and weekly from 31 to 100 days postpartum, respectively. Of 11 postpartum bitches, 10 bitches(90.9%) had normal involution and 1 bitch (9.1%) had subinvolution of the placental sites (SIPS) by gross findings, vaginal discharges, and by ultrasographic findings, uterine shape and echogenicity. The excretory period of vaginal discharges in 10 normal bitches of uterine involution was finished completely at 20.2+_4.6 days(Mean+_SD) postpartum, but in 1 SIPS at 50 days postpartum. The short axis shape of the uterus was initially often flaccid-appearing. It varied from circular to crescent shaped to polygonal.This lasted until 16.5+_3.7 days postpartum, during which time the short axis uterine shape gradually changed to circular. Also, the long axis shape of the uterus was created a beaded appearance of the horns until 29.9+_3.2 days postpartum. After 30 days, it was appeared as tubular shape without distinguished between placental and interplacental sites. The ultrasonographic image of the postpartum uterus consisted of four echogenicity distinct layers. Ulterine wall was represented the very hyperechoic serosa, hypoechoic mycomtrium, hyperechoic endometrium and anechoic structures of fluid in the uterine cavity until 7 days postpartum. The individual uterine layers were most prominent during the first weeek postpartum,and they became progressively less distinct throughout the course of uterine involution. Anechoic structrues of fluid inthe uterinecavity was detected until 25.0+_6.4 days prostpartum, after which time it was not reliably detected. The uterine diameter was decreased not only in the placental sites from 24.1+_2.5mm at 1 day to 15.4+_1.4mm at 7 days postpartum, but also in the interplacental sites 14.9+_1.5mm at 1 day, 10.6+_0.8mm at 7 days postpartum. There was a general trend of decresing uterine diameter, whichoccurred more rapidly at the placental sites. At 31 days postpartum, these diameter reached almost same size, after that time, they could be not distinguished between placental and interplacental sites. At 87 days postpartum, the uterine diameter was 5.6+_0.6mm both placental and interplacental sites, and the uterine horns were uniform hypoechoic, tubular structures without enlargement. Therefore, complete involution of the uterus occurred at that time. It was concluded that normal postpartum uterine involution in Korea Jin-do bitches appeared to be completed around 87 days postpartum by gross findings such as vaginal discharges, and by ultrasonographic findings, uterine shape and echogenicity. Also ultrasonographic characteristics of the postpartum uterine involution were described. Therefore, these result suggest that ultrasonographic assessment is a reliable method for diagnosing the SIPS and uterine dysfunction, such as pyometra in bitch.

Digital color doppler ultrasonographic system(DCDUS) has a lot of diagnostic functions. One of these is a detection of low velocity vessels in the organs of abdominal cavity. The purpose of study was to determine the clinical usefulness of DCDUS. Interlobar artery resistive index(RI), pulsatility index(PI) and systolic diastolic ratio(SDr) were measured for diagnosis of obstructed urinary tract. RI, PI and SDr were a measure of intrarenal blood flow impedance. This study was consisted of 2 groups. The normal group was studied in 16 normal adult dogs and the study group was studied 7 dogs with surgically induced, unilateral ureateral obstruction. In the study group, parameters were checked in nirmal condition and on 1, 2, 3, 5, 7 and 10th day after ligation. The result were summarized as follows. In the normal group, RI, PI and SDr of the left kidney was 0.65+_0.04, 1.25+_0.12 and 292.45+_29.40, respectively. RI, PI and SDr of the right kidney were 0.64+_0.05, 1.28+_0.20 and 282.25+_37.26, respectively. In the study group, RI of the left kidney induced ligation was increased sighificantly on 1, 2, 3, 5, 7 and 10th day. RI of the left kidney on 1, 2, 3, 5, 7 and 10th day wee 0.75+_0.05, 0.71+_0.03, 0.74+_0.04, 0.74+_0.02, 0.73+_0.02 and 0.73+_0.04, respectively. PI of the left kidney was increased significantly on 1, 3, 5 and 7th day. PI of the left kidney on 1, 3, 5 and 7th day were 1. 57+_0.21, 1.54+_0.24, 1.60+_0.15 and 1.60+_0.26, respectively. SDr of the left kidney increased significantly on 1, 2, 3, 5 and 7th day. SDr of the left kidney on 1, 2, 3, 5 and 7th day were 412.18+_86.69, 352.14+_47.05, 399.77+_65.54, 369.43+_48.34 and 365.57+_22.46, respectively(p0.05). In the study group, RI of the left kidney was more increased than that of the right kidney on 1, 2, 3, 5, 7 and 10th day. PI of the left kidney was more increased than that of the right kidney on 1, 3, 5, and 7th day. SDr of the left kidney was more increased than that of the right kidney on 1, 2, 3, 5 and 7th day(p0.05). RI was effective in the diagnosis of an acute unilateral ureteral obstruction. PI and SDr were insufficient in the diagnosis of an acute unilateral ureteral obstruction.