3. Electronic Theses and Dissertations (ETDs) - All submissions
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Item The viruses of vervet monkeys and of baboons in South Africa(1974) Malherbe, H. H.In this thesis are presented briefly the results of studies extending over the period 1955 to 1974. The use of vervet monkeys in South Africa for the production and testing of poliomyelitis vaccine made acquaintance with their viruses inevitable; and the subsequent introduction of the baboon as a laboratory animal of major importance also necessitates a knowledge of its viral flora. Since 1934 when Sabin and Wright described the B Virus which was recovered from a fatal human infection contracted as the result of a macaque monkey bite, numerous viral agents have been isolated from monkeys and baboons. In the United States of America, Dr. Robert N. Hull initiated the classification of simian viruses in an SV (for Simian Virus) series according to cytopathic effects as seen in unstained infected tissue cultures. In South Africa, viruses recovered from monkeys and baboons were designated numerically in an SA (for Simian Agent) series on the basis of cytopathic changes seen in stained preparations of infected cells. Integration of these two series is in progress. Simian viruses in South Africa have been recovered mainly through the inoculation of tissue cultures with material obtained by means of throat and rectal swabs, and also through the unmasking of latent agents present in kidney cells prepared as tissue cultures. Some evidence concerning viral activity has been derived from serological tests. In this thesis the classification of simian viruses later proposed by Dr. Hull in 1968 has been adopted. This Ill comprises five categories based on nucleic acid type and strandedness, and on' ether sensitivity. It has not been possible to provide conclusive proof for the inclusion of a number of South African viruses in the categories to which they have been assigned under this scheme, but the available evidence suffices to indicate that representatives of the five main categories occur in South Africa. Some viruses found in this country are recognized as prototype strains in the internationally recognized classification of simian viruses, and one vervet adenovirus has been widely distributed and studied for its oncogenic properties. The herpesvirus SA8 is sufficiently closely related to the dangerous B Virus of macaques to warrant extreme care in the handling of non-human primates. This virus has been recovered from baboons as well as vervet monkeys. It is becoming evident that viruses recovered from one species may eventually be found to be more common in another species. In South Africa much remains to be done in the field of simian virology, and in this thesis are indicated techniques which could be further exploited and expanded to increase our knowledge of this group of potentially dangerous viruses.Item A cephalometric study of vervet monkeys with induced hypothyroidism.(1974) Preston, Charles BrianGrowth and development of the skull is influenced by metabolic factors such as the endocrinopathies. The purpose of this study is to examine the effects of induced hypothyroidism on growth and development of the skull of the Vervet monkey. Seven infant monkeys of the subspecies Ceraop-ithecus aethiops cloetei were selected as the experimental animals in this study. Two of the seven monkeys were used as the control group, the remaining five monkeys were given radio-active iodine to depress their thyroid activity. Cephalometric records were taken of the animals for a period of approximately one year, at the end of which time they were sacrificed. At the age of 15 months the radiographs of the hypothyroidic monkeys, when compared to those of the control group, exhibit marked differences in cranial form. However, the most marked changes are seen in the cranial vaults of the experimental animals. Some of the findings are examined in the light of a number of theories which have been proposed for the control of the growth and development of the skull.