Cattle In Africa Research Articles

Comment on "Exchange of Cattle in Africa"

Comment on "Exchange of Cattle in Africa"

Exchange of Cattle in Africa

Exchange of Cattle in Africa

Bovine Herpes Mammillitis Virus: III. Observations on experimental infection

SUMMARY Day-old rats, mice and Chinese hamsters were susceptible to infection with bovine herpes mammillitis virus, though older animals were not. In rabbits and guinea-pigs, which were of lower susceptibility, no difference in age susceptibility was observed. Experimental infection of cattle of various age groups has shown only local reaction to occur except where very large doses of virus are given intravenously. The histological changes associated with skin lesions are described, and in the discussion the pathogenesis of BHM virus is compared with that of Allerton virus, a herpes virus associated with lumpy skin disease of cattle in Africa.

Cattle in Africa: Distribution, Types, and Problems

dence of an extinct long-hored, straight-backed Bos primigenius, but its contribution to present breeds is not well established. Cattle, mostly Bos indicus, have existed in Africa for thousands of years.' The major groups appear to have been introduced into Egypt from Southwest Asia and to have spread from Egypt south across the Sahara, probably through the Nile corridor. Some groups then branched south to the Cape of Good Hope, while others spread west to the Atlantic.

Observations on the development of Setaria labiatopapillosa using new techniques for infecting Aedes aegypti with this nematode.

1.The common filarial parasite of cattle in Africa,Setaria labiatopapillosa, has been shown to develop in the mosquitoAedes aegypti. Third stage larvae reached maturity between the 8th and 10th days.2.To avoid feeding mosquitoes on cattle new techniques were developed. Monkeys and rabbits were infected by transplanting adult livingSetariainto then peritoneal cavities. Monkeys, rabbits and rats were also infected by either intraperitoneal or intravenous injections of suspensions of microfilariae extracted from the uteri of adult worms.3.Mosquitoes fed on these substitute hosts were readily infected with theSetaria.4.Mosquitoes were also infected by feeding them on a suspension of microfilariae through membranes of guineapig omentum; the microfilariae were extracted from the uteri of adult worms and suspended in fresh defibrinated rabbit's blood.A few mosquitoes were infected by intrathoracic injections of uterine microfilariae.

Inhibition of Ascites Tumour Growth by the Trypanocide, Ethidium Bromide, in Combination with Azaserine

ETHIDIUM bromide (3,8-diamino-5-ethyl-6-phenyl-phenanthridinium bromide) has been used to treat trypanosome infections of cattle in Africa for some time1,2. (This chemical was kindly supplied by Dr. M. R. Gurd, Boots Pure Drug Co., Ltd., Nottingham. Its alternative name is 2,7-diamino-9-phenyl-10-ethyl-phenanthridinium bromide.) Recently we have examined the biochemical effects of this compound on Ehrlich ascites tumour cells, and have found that it inhibits completely the incorporation of preformed purines (adenine, guanine and hypoxanthine) into nucleic acids3. The possible application of this biochemical effect to cancer chemotherapy was immediately considered. It was believed, however, that ethidium bromide, if used alone, would at best be only moderately carcinostatic because it does not appreciably impair the de novo pathway of purine biosynthesis3. Because the antibiotic azaserine is well known to inhibit completely the de novo synthesis of purines, it was therefore believed that if these two compounds could be used in combination without undue host toxicity, the conditions for a complete concurrent blockade4 of the purine nucleotide supply for nucleic acid synthesis could be effected. Because both drugs maintain their inhibitory effects for less than 24 hr.3,5, for more nearly maximal effect it was felt that both should be administered more often than in the daily treatment schedule usually used in tests of carcinostatic efficacy.

114. Mythical Origin of Cattle in Africa.

114. Mythical Origin of Cattle in Africa.