Includes abstract. Includes bibliographical references (leaves 172-196).

Includes bibliographical references. / Respiratory motion of the heart is a problem for high-resolution cardiac MRI. Diaphragmatic navigator gating with a 5mm acceptance window is most commonly used to address this but has an inherently low respiratory efficiency that is further compromised by respiratory drift. A novel method is presented that uses data from multiple navigators prior to the imaging segment as input for a control system to predict the diaphragm position throughout the imaging segment and correct the slice position in real time.

Includes bibliographical references. / South Africa offers unique opportunities for the investigation of genetically determined illnesses in view of the excellent facilities available and the different origins of the various population groups. Huntington's chorea is generally considered to be a very rare disease in South Africa. Evidence in support of this, is the dearth of publications concerning the disorder in this country. By 1977 there had been only two such articles, in marked contrast to the plethora of reports from around the world. This investigation was concerned with the study of many different aspects of Huntington's chorea in South Africa. The primary aims were to determine the history, frequency, clinical presentation and course of Huntington's chorea in the Republic. In the wake of the genealogical and clinical findings, interesting new observations and exploration of the established concepts of the genetics of Huntington's chorea have been undertaken. A major attempt has been made to investigate the hypothesis that dopamine excess is important in the pathophysiology of this condition. Since dopamine has an important regulatory function on anterior pituitary hormone secretion, affected individuals might be expected to have abnormal patterns of hormonal regulation. The disturbances in prolactin, thyrotropin and growth hormone secretion reported in this thesis, support the concept of dopamine predominance. The demonstration of similar neuroendocrine abnormalities in twelve of 23 clinically normal first-generation relatives may have importance for presymptomatic diagnosis. Although not a primary focus of the investigation, it soon became apparent that the social implications of this disorder were extremely important and largely unexplored. The attention of all health professionals is drawn to the tremendous cost of the disorder, and recommendations for improved care are proposed. Huntington's chorea is a far more serious problem in South Africa than was initially suspected. The gene was probably introduced by the first Dutch settlers over 300 years ago, and is found today in all population groups. The South African population of mixed ancestry has amongst the highest frequency of juvenile Huntington's chorea in the world. Even though the present study deals with only one relatively uncommon illness, the concepts presented are pertinent to numerous other unrelated chronic diseases, with which Huntington's chorea has shared concerns and needs.

Gaucher disease is a biochemical genetic disorder of the lipid storage group. It is characterised by an accumulation of a glycosphingolipid, glycosyl ceramide in the reticulo-endothelial system. The condition presents clinically with hepatosplenomegaly, haematologic and orthopaedic problems. Affected individuals suffer from chronic ill-health and debility, with a clinical course of acute exacerbations, remissions and relapses. The basic defect has been shown to be a genetically determined abnormality in the enzyme beta-glucosidase, (Brady et aZ, 1965; Patrick, 1965). The diagnosis can now be accurately confirmed by laboratory procedures, which also enable determination of carrier status. Of particular interest is the high prevalence of the condition in the Ashkenazi-Jews. Fried, (1958), in a survey of cases in Jerusalem, estimated the minimal carrier or heterozygote rate to be 1 in 25. Other studies of Ashkenazi-Jews have revealed carrier frequencies ranging from 1 in 25 to about 1 in 40. This stimulated the investigation which was initially undertaken under the supervision of Professor Beighton in the Department of Human Genetics, University of Cape Town Medical School in 1975 and 1976. Further data has been accumulated by the author as a medical registrar at Groote Schuur Hospital in the ensuing period until 1979.

Includes bibliography. / Despite the fact that the chicken embryo is a model system for developmental biologists, comparatively little is known about the regulation of avian melanogenesis. There has only been one report of the characterisation of the chicken tyrosinase gene promoter, and only one full-length chicken microphthalmia cDNA (cmi9) has been identified to date.

Includes abstract. / Includes bibliographical references (p. 197-215). / The primary aim of this thesis was to identify candidate genes that may be associated with ACL ruptures, and then use a genetic association approach following a case-control study design to identify specific sequence variants (single nucleotide polymorphisms, SNPs) within these candidate genes which may predispose individuals to ACL ruptures. Candidate genes (COL1A1, COL5A1 and COL12A1) were selected based on the biological function of their encoded proteins (type I, type V and type XII collagen respectively) within the basic structural and functional unit of ligaments, namely the collagen microfibril.

Includes bibliographical references (p. 182-205). / We investigated the effects of voluntary exercise on neuroprotection after unilateral lesions with 6-hydroxydopamine. Rats were divided into runners (had access to running wheel) and non-runners (their running wheels were immobilised). Two weeks after injection of the neurotoxin, the rats were injected with apomorphine and the number of ipsilateral and contralateral rotations was counted with contralateral rotations of greater than 150 considered to represent striatal dopamine neuron destruction of 70% or above.

Includes bibliographical references. / This main purpose of this thesis was therefore to investigate whether any specific genes on the tip of the long arm of chromosome 9 were associated with Achilles tendon injuries, using a case-control study design. The specific objectives were: (i) to identify all genes located in the 9q32-q34.3 locus in close proximity to the ABO gene, that could be involved in tendon injuries (Chapter 2) and (ii) to investigate the possible association of the identified candidate genes (COL5A1 and TNC with both Achilles tendon rupture and chronic Achilles tendinopathy (Chapter 3 and 4) and (iii) finally to investigate the possible interaction of these two genes with tendon function, namely the muscle-tendon unit flexibility (chapter 5) and structure, namely the morphological changes of the Achilles tendon (Chapter 6).

Includes bibliographical references / Skeletal age is a measure of biological maturation and is based on the stages of formation of bones. As age increases, skeletal maturation progresses and the various hard tissue changes which take place are uniquely identifiable and defining to each stage of development. Age assessment using skeletal maturation is a diagnostic tool used clinically and in forensic investigations. Radiographs of the hand and wrist are frequently used to estimate age (Greulich and Pyle,1959); however studies conducted in South Africa have shown that these methods are not applicable to South Africans since the method over estimates age in the 17 - 22 year olds(Dembetembe and Morris, 2013) and both over and underestimates age in 0 - 13 year old individuals (Speed, 2012). There currently is a lack of comprehensive data and studies on the union of the major joints in South African children despite the need for population specific data in age estimations. The LODOX Statscan system, which emits low dose radiation and full body radiographs in thirteen seconds, was used to assess radiographs of1891 individuals between the ages of 6 - 24 years. Union was classified in four stages ranging from one (non-union) to stage four (complete union). Radiographs were obtained from the Red Cross War Memorial hospital and Groote Schuur hospital in Cape Town and Tygerberg and Salt River mortuaries in Cape Town as well as the Chris Hani Baragwanathand Milpark hospitals in Johannesburg. The standards developed on radiographs were later used to conduct gross analysis of skeletal material obtained from the Raymond Dart Collection. Complete union was classified as the age at which 95% of the both males and females showed stage 4 of union. Complete union of all joints in females occurs by age 21 years and 24 years in males with the iliac crest being the last epiphysis to fuse in both males and females. Ordinal logistic regression found significant differences between males and females in the stages of union and age (p < 0.05). There is however no significant differences in stage of union and age between different ethnic groups and individuals from various socio-economic status backgrounds (p > 0.05).Data for union times in South African children show that maturity in females at the elbow, hip and ankle are achieved at approximately 15 years of age followed by the knee at 16 years, wrist at 18 years, and shoulder at 20 years. The radiographically visible epiphyses the iliac crest are the last epiphyses to complete union at 21 years. Males progress through union in the same sequence with the exception that there is a two year delay in age at maturity. The elbow in males completes union at approximately 17 years followed by the hip and ankle at 18 years, knee at 19 years, wrist at 20 years, and shoulder at 21 years and finally the iliac crest at 22 years. The methodology derived on radiographs was successfully applied to gross observations of skeletal material. It therefore provides a useful diagnostic tool for use in skeletonised forensic cases in the absence of skeletal material from which to derive such standards. The current work provides an alternative to the Greulich and Pyle (1959) method and is specifically tailored toward South African children.

The right to legal representation has been acknowledged as a fundamental right of an accused in a criminal trial. 1 Traditionally, however, this, right has been viewed as a right to retain counsel, rather than a positive right to be provided with legal representation in the case of indigent accused. The importance of legal assistance for accused persons being tried in an adversarial justice system has been recognised in the Anglo-American legal systems. In an adversarial system the duty of a presiding officer is to act as an independent and objective adjudicator of the facts and evidence presented to him or her by the two parties to the trial. The onus is on the litigants to advance their own case. It naturally follows that the strength of a party's case depends on the skill of the litigator.