Microcarrier culture technics were widely used for the massive production of the vertebrate animal cells. In this study, attempt was made to establish the microcarrier cell culture system using Cytodex. Various factors affecting the growth of cells on microcarrier culture were also discussed. In conclusion, the yield of cells in microcarrier culture was several times greater than those in roller bottle and flask culture methods, based on the volume of culture media

An experiment was carried out to measure the cellular immune response in the animals by sensitizing the animals with 2, 4-dinitrochlorobenzene (DNCB). The fowls could be sensitized with primary application of DNCB. The sensitizing and challenge dose was standarized. Heterophils were prominent in the early inflammatory response in the superficial and deep dermal regions with scattering of eosinophils. The histological response in the fowls was characteristic of a delayed hypersensitivity reaction

Sprague-Dawley rats received subcutaneous injections of gentamicin sulfate, 50 and 100mg/kg for 3, 7 and 10 days. The hematological and blood chemical values were determined. Kidneys were examined histologically and ultrastructurally. The serum values of aspartate transaminase, blood urea nitrogen and creatinine in the rats administered gentamicin, 50 and 100mg/kg/day were significantly increased than those in the control. The ratio of kidney weight to body weight was significantly increased in the rats injected gentamicin, 100mg/kg for 10 days than those in the control

The present study was carried out to observe the histopathological changes in the lung of A/J, C57BL/6N, DBA/2 and NIH-GP mice intratracheally instillated with benzo(a)pyrene or urethan. In the group of intratracheal instillation with benzo(a)pyrene and charoal powder, squamous cell carcinomas and adenocarcinomas were induced. Tumors were induced in high incidence in the lung of A/J and C57BL/6N mice. Especially, squamous cell carcinomas were induced in high incidence and were well-differentiated in the lung of A/J mice

The prevalence of diarrhea caused by enterotoxigenic Escherichia coli was surveyed on 445 calves in 6 farms which were located in the central part of Korea. The incidence of enterotoxigenic Escherichia coli in calves with diarrhea was investigated by detecting the K99 and F41 antigens from the isolated strains of Escherichia coli. The incidence of colibacillosis in calves was 23.3%. Of 238 strains of Escherichia coli isolated from calves with diarrhea, 73 strains (30.6%) were proved possessing the K99 antigen by mannose-resistant hemagglutination (MRHA) using horse red blood cells and 79(33.1%) possessing F41 antigens by MRHA using guinea-pig red blood cells

The present study has been carried out to elucidate the antiestrogenic effects of tamoxifen on RNA and protein synthesis in uteri of immature rats. Immature female Sprague-Dawley rats were allocated into 4 groups and injected with 5 micro g of estradiol-17 beta, 50 micro g of tamoxifen, a combination of both, or vehicle only subcutaneously three times with an interval of 24 hrs respectively. The specific activities of 3H-uridine incorporation into uterine RNA and those of 3H-leucine incorporation into uterine protein were measured before and 1, 3, 6, 12, 24, 48 and 72 hrs after the above treatments

Isolation and identification of mycoplasma were performed to clarify mycoplasma infection of mice fed by convectional feeding at two (K1, K2) institutes in Korea. The twenty mice to be tested were randomly samples from each of 10 breeding colonies in respective institute. Identification of the mycoplasma strains isolated from the nasal cavity, lung and synovia of mice was made according to the morphology of colonies, biological and biochemical properties with special reference to M. pulmonis, M. arthritidis and M. neurolyticum

Isolation of Staphylococcus hyicus subsp. hyicus from piglets suffering from exudative epidermitis and healthy pigs was performed, and some properties of the isolates were examined. Twenty-six litters of exudative epidermitis observed in the field were sucking piglets with ages ranging from 1 to 5 weeks and most (73.1%) of these cases occurred in piglets between 2 and 3 weeks of age. Staphylococcus hyicus subsp. hyicus was isolated from 192 (38.9%) of 494 healthy pigs. The rate of isolation of these organism from healthy pigs was found to vary greatly among farms at an isolation rate of 33.3% to 45.5% and this organism was isolated more frequently from sucking piglets below the age of 8 weeks than adult pigs

Progesterone immunogen has been synthesized and its melting point, Rf-value, UV and IR spectrum have been measured to develop the essential step in antisera production against low molecular weight substance. Mixed anhydrid reaction was used to conjugate 11 alpha-hydroxy-progesterone with succinic anhydride. Melting point of one intermediate compound was 156 deg C, and Rf-value was 0.41 in benzene: acetone: methanol (5:5:2).

Endocrine cells were observed in the gastrointestinal tract of the squirrels by light microscopy using Grimelius and Masson-Hamperl silver impregnation, and in the stomach and duodenum by electron microscopy. Light microscopically, argyrophil cell decreased gradually in number in the pyloric region and ileum, stomach, duodenum and jejunum and rectum in the order listed. Argentaffin cells were moderately distributed in the stomach, pyloric region and duodenum, while absent in the jejunum, ileum and rectum