The Limulus test was conducted to detect endotoxin in plasma of 29 cows infected with so-called Gangrenous mastitis. Endotoxin in plasma (0.09-2.88ng/ml) was found in 21 cows in which Gramnegative bacteria were isolated from the milk of affected udders. These cows showed an increase in pulse and respiration rate, watery diarrhea, and swollen udder. The blood test revealed a decrease in blood platelet count and prolonged prothrombin and partial thromboplastin time. decrease in fibrinogen count was more remarkable in the endotoxin-positive cows than the negative ones.
A total of 64 bovine embryos were frozen in plastic straw (0.25ml). The storage medium used was Dulbecco's PBS with addition. Embryos were held at room temperature for 30minutes and cooled at 1.0°C/min to-4.5°C. The storage medium was seeded at-4.5°C by clasping the outside of each ampoule with forceps which had been precooled in liquid N2. After seeding, the straw was cooled to-35°C at 0.3°C/min, followed by 10 minutes' cooling at 0.1°C/min to-3.6°C, and then plunged directly into liquid N2. Of 55 freeze-thawed embryos, 28 (50.9%) were survived.
Over a 5-month period beginning with December, 1979, 17 calves were born on two farms to suffer from yellowish watery diarrhea. Of them, fifteen (88.2%) died in 1-3 days. Autopsy revealed no marked changes. Histologically, the small intestine was affected with catarrhal enteritis. Colibacilli were isolated in a pure form from the brain and other organs. All of them showed a serotype of O101: H-, produced thermostabile enterotoxin, and possessed an immobilized factor, K99 ciliary antigen. Sensitivity was noticed to chloramphenicol, colistin, and oleandomycin. Virological examination gave negative results.
Antigen used was physiological salin extracts from adult flukes of Fasciola sp. When it was allowedto react with sera from 209 cattle, two or three precipitating lines appeared. Specificity ofthese reactions was demonstrated by the immunodiffusion reaction (ID) and a combination of IDand absorption test. By using 0.8% agar in 0.05M veronal-HCL buffer, pH 8.6, counterelectrophoresis (CEP) wascarried out to detect precipitating antibody in the sera of 16 cattle in the pasture. Fasciola eggs werefound 2 months after the appearance of the antibody in the serum. After that, no antibody could befound CEP was more capable of detecting early infection than ID.
A grazing Japanese Blackox died suddenly in Aomori Prefecture. Histopathologically, it wasaffected with fibrionpurulent meningitis. Haemophilus somnus was isolated in pure culture froma brain lesion, although the ox manifested little vascular changes in the central nervous system.This case showed an importance of the differential diagnosis of H. somnus infection.