Bovine fibroblast interferon (BoF-IFN), produced in primary bovine embryonic kidney cell cultures after priming and infection with bluetongue virus, was purified by controlled pore glass (CPG) chromatography to a specific activity of 10(6) U/mg of protein, with 40% recovery of the original activity. The crude IFN was concentrated more than sevenfold during purification. This proved to be a relatively simple, practical method of obtaining sufficient quantities of partially purified natural BoF-IFN for further studies. The CPG-purified BoF-IFN was further concentrated by sequential ultrafiltration and was analyzed by sodium dodecyl sulfate/polyacrylamide-gel electrophoresis (SDS-PAGE). Interferon, recovered from denaturing conditions either by dialysis against phosphate-buffered saline solution or by dilution in cell culture medium containing 10% fetal bovine serum, migrated as a single stainable protein with molecular weight of 21,000 on analytic SDS-PAGE gels. Recovered IFN activity from preparative SDS-PAGE totalled 8.7% of that applied. Attempts to further purify CPG-purified BoF-IFN by zinc chelate affinity chromatography were unsuccessful.

Studies were conducted to ascertain in vitro effects and effects of percutaneous application (in vivo) of dichlorvos (2,2-dichlorovinyl dimethyl phosphate; DDVP) on cholinesterase activities in bovine erythrocytes and plasma. Treatment in vitro of erythrocytes and plasma with DDVP resulted in concentration- and time-dependent inhibition of erythrocyte acetylcholinesterase (AChE) and plasma cholinesterase (ChE) activities. Mean (+/- SD) DDVP concentrations required to cause 50% enzyme inhibition were 15.7 +/- 3.3 muM and 43.1 +/- 5.7 muM for AChE and ChE, respectively; however, these values required to achieve this inhibition were markedly decreased with increasing incubation time. The inhibited AChE activity failed to be reactivated after incubation of erythrocytes with 2-pyridine aldoxime methiodide (2-PAM); however, limited reactivation of inhibited AChE and ChE activities was observed with excess concentration of 2-PAM. Percutaneous application of a DDVP-containing livestock spray on cattle also caused a marked decrease in the in vivo activities of AChE and ChE; however, the inhibited enzyme activities were reactivated rapidly after incubation with 2-PAM.

Each of twenty blood samples taken from apparently healthy Korean cows was used to produce five different mixtures of autologous plasma and blood corpuscles such that their values of packed cell volume(PCV) lay between 10 to 50ml/100ml. The measurement of erythrocyte sedimentation rate(ESR) using 45 degree-angled Wintrobe hematocrit tube, 3mm bore, (45deg C-Wintrobe-ESR) was practised for the blood of various levels of PCV lowered. Correlation of the ESR to PCV showed curvilinear regression each in three levels of PCV under the ambient temperature of 10deg C, 20deg C and 30deg C. Correlation of the ESR to the ambient temperature showed linear regression each in five levels of PCV. The ESR increased with ascending ambient temperature, and magnitude of the increase of the ESR became greater as the level of PCV lowered. Correlation of the ESR to PCV showed curvilinear regression each in three levels of the ambient temperature, and the ESR was increased with decreasing PCV. The data were statistically analysed and a list of relative anticipated 45deg C-Wintrobe-ESR values for PCV and ambient temperature was presented.

For the comparison of surface fine structures in the proliferative forms of two major protozoan parasites, Toxoplasma gondii and Sarcocystis species in mammalian hosts, isolated from the artificially infected mice and from the naturally infected cattle, respectively, an SEM(Hitachi S-570) was applied to the fixed, dried and coated with gold ion on the microslide glasses. The tachyzoites of T. gondii from the peritoneal cavity of the mouse showed the crescent-like feature and measured as 5.57 micro m in length and 2.33 micro m in width, while the bradyzoites of Sarcocystis species from the heart muscle of slaughtered cattle was banana-shaped and measured 14.18 micro m in length and 2.85 micro m in width. On the surface of Sarcocystis species bradyzoite, a distinct elliptical micropore was identified in the high magnification observation of 60,000X, and it measured as 0.35 micro m in length and 0.18 micro m in width.

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

A total of 593 mastitic pathogens was isolated from the clinical mastitic milk of dairy cattle in Kyonggi area from March 1984 to February 1988. The mastitic pathogens were further studied bacteriologically and examined for susceptibility patterns to 10 antibiotics. 173 pathogens were isolated in the first year of studies, 205 pathogens in the second year, 122 pathogens in the third year and 93 pathogens in the last year. The pathogens isolated from clinical mastitis were more in summer than other seasons. Staphylococcus spp (50%) and Streptococcus spp (18%) were the main pathogens in the first year of studies but coliforms (15%) and other bacteria (40%) were the main pathogens in the last year of studies. Coliform mastitis occurred only in summer and autumn. Antibiotic susceptibility patterns of the same genuses from clinical mastitis infections in different herds and in different years varied greatly. Therefore, treatment should be selected on the basis of susceptibility test results

A preliminary survey of Sarcocystis species in the slaughtered cattle in Seoul was undertaken during October through December 1987, using digestion diagnostic technique for the heart muscle specimens digested in 0.5 % trypsin solution. Results indicated that 41.5 % of 159 bovine hearts were infected with Sarcocystis proliferative forms. High frequencies in the exotic dairy cattle (42.2%) and the Korean native cattle (41.7%) were noticed in comparison with low frequency in the cross breed (25.0%). No differences were indicated between the sexes of the host animals, although an age difference was noticed as 48.9 % in cattle older than four years in comparison with 39.0 % and 37.1 % in younger than two years and in two to four years, respectively