This study was conducted to isolate etiological agents from the 103 scouring piglets in Kyongnam area and also carried out antimicrobial drug susceptibility test and epidemiogical survey. The incidence of scouring piglet was most prevalent in 81.6% at the age of 2 to 4 weeks after birth, while the rate was less than 10% at the age of 5 to 6 weeks and under 1 week after birth. When comparing the isolation frequency of each etiological agent, enteropathogenic E. coli was most prevalent in 46.6%, thermophilic Campylobacter in 26.2% and Salmonellae was in 8.7% in that order. In the OK serotyping for 117 isolates of enteropathogenic E. coli, type 0141 : K85(20.5%), 0157:K88ac(14.5%), 0138:K81 and 0149:K91 (13.3%) were encountered most frequently. In the biotyping for 27 isolates of thermophilic Campylobacter, most strains of C. jejuni belonged to type I (50.0%) and II (25.0%), and most strains of C. coli belonged to biotype I (78.9%). In the serotyping for 9 strains of Salmonellae, 3 strains were grouped as D, 2 strains as C and 1 strain each was group B and E. The other 2 strains were untypable. The 117 isolates of enteropathogenic E. coli were resistant more than 90% to erythromycin, penicillin, tetracycline and streptomycin, whereas about 90% of the isolates were sensitive to kanamycin and gentamicin. In the case of Salmonellae, all of the isolates were resistant to penicillin, but about 89% of the isolates were sensitive to gentamicin and colistin. All of C. jejuni and C. coli isolates were resistant to cephalothin, but more than 89% of C. jejuni and C. coli were sensitive to kanamycin and gentamicin

This paper deals with the 0 groups of citrate utilizing variants of Escherichia coli (Cit+ E. Coli) isolated from cattle, the production of colicin, hemolysin, K99 antigen, heat stable enterotoxin, and the isolation of plasmid DNA. Among 42 Cit + E. Coli, 12 strains were 020, 9 strains 08, 5 strains 045, 3 strains 0115, 1 strain 064, 1 strain 0139 and remaining strains (11) were untypable. Thirty-nine(81.3%)out of 48 Cit + E. Coli produced colicin and 13(27.0%) produced hemolysin. Of 12 cit + E. coli bearing K99 antigen, 6(50.0%) produced heat stable enterotoxin. In gel electrophoresis for the isolation of plasmid DNA, the number of plasmids varied from 1 to 7 in 10 Cit+ E. Coli. Its molecular weight ranged from 2 to 50 Mdalton, and 50 Mdalton plasmid commonly existed in all strains

Light-microscope studies of the coccidial organisms found in the Bursa fabricii from chickens showing some specific signs were carried out, and the etiological agent was estimated as the parasite belonging to the Family Cryptosporiidae. The specific gross pathological signs were intestinal hemorrhage and atrophy of the Bursa fabricii and hyperplasia was associated with the presence of organisms attached to the epithelial cells lining the plicae of the bursa of Fabricius in the microscopical findings

To establish a laboratory animal model for study on development of diagnostic methods for infectious bovine rhinotracheitis virus(IBRV), experimental infection of the virus to rabbits immunosuppressed with dexamethasone(DX) were carried out. When lymphocyte activity was measured by lymphocyte transformation to phytohaemagglutinin parallel with total and differential leucocyte counting, both groups treated with 2.0mg DX once and 1.0mg DX daily showed marked immunosuppression between 5 to 72 hrs. after administration. The degree of suppression of lymphocyte activities was more remarkable in the latter group. IBRV PQ7 strain at 10** (7.5) TCID50/0.2ml was inoculated into conjunctival sacs of rabbits immunosuppressed with DX and non-treated. During 3 weeks observation, the immunosuppressed groups revealed mild conjunctivitis, viremia and virus recovery by 33.3 to 100%, whereas the DX nontreated group showed viremia and virus recovery with no clinical conjunctivitis in one of three rabbits(33.3%). In conclusion, it was indicated that experimental infection of IBRV PQ7 strain to rabbit was limited in prerequisite to immunologic modification by administration of immunosuppressive drugs

The present study was carried out to investigate C. jejuni and C. coli in chicken. Also were examined the pathogenicity of the isolates in chicks by experimental inoculation. Thermophilic Campylobacter were isolated from 34 (45.9%) of the 74 specimens, and classified as 21.6 % C. jejuni, and 24.3 % C. coli. In the biotyping of 16 strains of C. jejuni isolates, 37.5 % of the strains were grouped as biotype I, 62.5 % as biotype II. In the case of 18 strains of C. coli isolates, 49.9 % of isolates were grouped as biotype I, 55.6 % as biotype II. In oral inoculation with 10** (4)cfu of Capmylobacter isolates into infant chicks (1 to 3 days-old), 17 days-old and 34 days-old chicks, 32.5 % of the chicks developed diarrhea on day 1, 52.5 % on day 3, 70.0 % on day 5, and 27.5% on day 7, and the peak incidence of diarrhea was reached on day 5. The organisms were found to be discharged in feces one day afterwards. C. jejuni and C. coli strains were detected from the feces in 87.5 % of the chicks on day 5.

Attempts of these studies were made to investigate the nonspecific congenital focal accumulation of etcodermal glial cells in the brain of normal piglets. The brain samples were taken from 1-, 10-, 20-, 35-, 45- and 70-day-old piglets from a SPF-pig farm and three model pig farms. Occurrences of neuroglial cell foci(NCF) on the brain were observed with light microscope. Appearance degrees of the congenital NCF on 10 to 16 cross section slides per a piglets brain were tentatively designed on a scale from deg. + to +++ by NCF number: +, less than 20 of NCF number; , 21-40 of NCF number: +++ , more than 41 of NCF number. NCF in the brain were obseved mainly on the cerebrum. Regions of higher frequencies on the cerebrum were ordered as subependymal layers of the lateral ventricles, peripheral regions of lateral ventricles in the white matter and some neuron layers under the molecular layer of the gray matter. But NCF were not observed in the cerebellum, pons, medulla oblongata and spinal cords. On the subependymal layers of the lateral ventricles, NCF were observed in 100% of 27 piglets, and appearance degree of was observed in 10 piglets (37.0%), ++ in 10 piglets (37.0%) and + in 7 piglets (26.0%) of 27 piglets, respectively. On the white matter of the cerebrum, NCF were observed in 25 piglets (92.6%) of 27 piglets, and appearance degree of +++ was observed in 3 piglets (11.1%), in 13 piglets(48.2%), + in 9 piglets (33.3%) and- in 2 piglets (7.4%) of 27 piglets, respectively. On the gray matter of the cerebum, NCF were observed in 21 piglets (77.8%) of 27 piglets, and appearance degree of +++ was not observed, appearance degree of ++ was obseved in 6 piglets (22.2 %), + in 15 piglets (55.6%) and - in 6 piglets (22.2%) of 27 piglets, respectively. NCF tended to be converged appearance on some regions and tended to be decreased markedly from 35th day after birth, and the shapes of NCF were global or oval forms crowded by analogous shaped and stained cells in the empty spaces of the brain substrate or on one side of the blood vessels

For the laboratory diagnosis of Sarcocystis infections especially in domesticated food animals, several antificial digestion techniques were applied for the musculature specimens and several staining techniques wes applied for the bradyzoites of Sarcocystis species isolated. The digestion technique using trypsin (0.5%) and sodium chloride (0.85%) mixed solution was regarded as the most valuable for the detection of asexual stages of Sarcocystis in bovine musculature specimens. Optimal time for digestion was approximately one to four hours. The trypsin digestion technique with Giemsa's stain could be helpful for the detection of Sarcocystis proliferative forms and for the observation of the nucleus of the parasite. A systematic detection was also performed in an autopsy for a bovine carcass naturally infected with Sarcocystis species, and the asexual stages such as metrocytes and bradyzoites were observed in the specific organs, respectively

This study was performed to investigate the effect of gestation on the histological and histochemical changes of the uterine cervix of the native Korean cattle. A total of 110 cows obtained from the chonbuk abattoir were divided into six groups. The 1st group was of 9 non-pregnant cows and 101 singleton pregnant cows were grouped into 5 groups from pregnant I to pregnant V according to gestation periods by means of crown rump length measures. For light microscopy the tissues were fixed in 10% neutral formalin and processed routinely for paraffin sections. The 6um sections were taken and stained with H-E, Alcian blue pH 1.0, Alcian blue pH 2.5, Alcian blue pH 2.5/PAS, PAS reaction, toluidin blue, and trichrome. The cervical lengths and widths were increased in relation to advancing gestation. The cervical mucosubstance was composed of mixed mucopolysaccharides; the acid mucus was increased from the early pregnant state but the neutral mucus was found after pregnant IV, and the mucus was stained deeply in each staining in the fold cavity in according to gestation state.

Regional distribution and relative frequency of endocrine cells in ten portions of the gastrointestinal tract of the Korean native cattle were observed by immunocytochemical methods using specific antisera against chromogranin, serotonin, somatostatin, glucagon, bovine pancreatic polypeptide (BPP), motilin, gastric inhibitory polypetide (GIP), neurotensin, secretin, gastrin and substance P. In the abomasum, chromograin-, serotonin-, somatostatin-, motilin-, glucagon-, gastrin-, and substance P-immunoreactive cells were found. Chromogranin- and serotonin- and serotonin-immunoreactive cells were more numerous in the fundic region than pyloric region. Somatostatin- and gastrin- immunoreactive cells were numerous in the pyloric region than in the fundic region. In the large intestine, chromogranin-, serotonin- and BPP-immunoreactive cells were widely distributed and most numerous in the rectum. Somatostatin-, glucagon- and substance P-immunoreactive cells were rarely seen in the large intestine

This study was designed to elucidate the effects of iron, a well known catalyst of lipid peroxidation, on the contents of phospholipids, unsaturated fatty acids composed in phospholipid molecules and their derivatives, prostaglandins, and the composition changes of fatty acids contained in phospholipids. Iron decreased the contents of phospholipids and its components of unsaturated fatty acids. Catalytic action of iron decreased the composition rates of linoleate and linolenate composed in phospholipid molecules, while that of arachidonate was inclined to increase. The content of arachidonate was increased and that of prostaglandins was decreased without regard to increase the precursor of prostaglandins. It may be concluded that the decreases of the activities of prostaglandins and the increase of arachidonate are due to inhibition of the activities of enzyme systems responsible for prostaglandin synthesis by lipid peroxides produced by the catalyst of iron