published_or_final_version / Zoology / Master / Master of Science

published_or_final_version / Anatomy / Doctoral / Doctor of Philosophy

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Les îles Kerguelen (40°S, 70°E) renferment des écosystèmes d’eau douce parmi les plus isolés du monde des activités anthropiques directes. Le but de ce travail était d’étudier les facteurs bio-écologiques influençant les niveaux de bioaccumulation des contaminants chimiques dans les tissus des salmonidés des îles Kerguelen (truite commune, Salmo trutta et omble de fontaine, Salvelinus fontinalis) et les effets toxiques potentiellement associés. Nos travaux ont permis de démontrer que les teneurs hépatiques et musculaires en Cd et en Cu, mais aussi les teneurs musculaires en PCB étaient élevées et comparables à celles détectées chez des populations de salmonidés de zones géographiques plus anthropisées. Par ailleurs, des différences de contamination selon l’espèce, la saison et le morphotype (lac, rivière et base) ont été mises en évidence. L’analyse histologique des foies des truites a mis en évidence des atteintes hépatiques (fibrose, infiltration des cellules immunitaires, développement de centres mélanomacrophagiques) et hepatocytaires (nécrose, altérations nucléaires) nettes de l’ensemble des poissons étudiés qui révelent un état de stress important en cohérence avec les forts taux de toxiques dans cet organe. D’autre part, les biomarqueurs des défenses anti-oxydantes ont mis en évidence des différences entre les morphotypes étudiés. Par ailleurs, l’analyse de l’activité sérique de lysozyme a montré que ces salmonidés sont caractérisés par des niveaux de compétences immunitaires réduits. Les îles Kerguelen constitue un site atelier pour les études écotoxicologiques. Le suivi sur le long terme, devrait améliorer la connaissance des variations des réponses écophysiologiques des populations de poissons d'eau douce face à la pression chimique globale. / The Kerguelen Islands (40°S, 70°E) contain freshwater ecosystems among the most isolated from human activities in the world. The aim of this work was to study the bio-ecological factors influencing levels of chemical bioaccumulation in Kergueln salmonids tissue (brown trout, Salmo trutta and brook trout, Salvelinus fontinalis) and their potential toxic effects. Our work demonstrated that the hepatic and muscular Cu and Cd levels, and also, the muscular PCB levels were hight and similar to those of salmonids from impacted areas. Moreover, differences in contamination according to species, season and morphotype (lake, river and base) were noted. Histological analysis of trouts livers showed clear damage of liver (fibrosis, infiltration of immune cells, development centers mélanomacrophagiques) and of hepatocytes (necrosis, nuclear alteration) in all studied fish traducing an important level of stress consistently with the high concentration of toxicant in this organ. On the other hand, antioxidant defenses biomarkers revealed differences between the studied morphotypes. Moreover, analysis of serum lysozyme activity showed that these salmonids were characterized by reduced immune competences. Kerguelen Islands constitute a workshop site for ecotoxicological studies. The long-term monitoring should improve the knowledge of changes in eco-physiological responses of freshwater fish populations dealing with the global chemical pressure.

<p> The purpose of this study was to determine whether there are histological changes in the microvasculature of rat skeletal muscle following chronic spinal cord injury both above and below the level of injury. This study is important because microvascular structure likely impacts muscle performance and cardiovascular health. To the best of our knowledge, this is the only study to investigate microvascular structure within rat skeletal muscle after spinal cord injury. We hypothesized structural remodeling would occur in both the myofibers and microvasculature, which would then manifest in differences in myofiber cross sectional area and microvascular diameter, wall thickness, wall to lumen ratio, and wall cross sectional area.</p><p> Changes in sympathetic tone and reduced muscular activity following spinal cord injury may induce microvascular structural remodeling. Initially after injury, sympathetic activity below the level of injury is diminished. Over time, neuroplasticity results in recovery of sympathetic tone, which increases vascular smooth muscle contraction and may lead to alterations in vasculature structure. In addition, the spinal lesion leads to loss of descending drive, which causes physical deconditioning below the level of injury. Physical deconditioning is known to induce vascular remodeling, and effects may be opposite of those associated with increased sympathetic tone.</p><p> We conducted a test of vascular remodeling in a rat contusion model of spinal cord injury. Ten adult female rats were evenly divided into control and spinal cord injury groups. Severe spinal cord injury was induced using a controlled weight drop onto the spinal cord, resulting in a contusion injury. After a 90 day survival period, the biceps brachii, triceps brachii, tibialis cranialis, and soleus muscles were removed, processed, and stained with Verhoeff van Gieson elastin and hematoxylin and eosin stains for histological analysis. Ultrastructural features of the myofibers and non-capillary microvessels were quantified. There was no significant difference between spinal cord injury and control skeletal muscles with regards to muscle cross sectional area, myofiber cross sectional area, microvascular diameter, wall thickness, wall to lumen ratio, or wall cross sectional area. Results indicated similar myofiber integrity and microvascular structure between control and spinal cord injury groups above and below level of injury.</p><p> While results did not support our original hypothesis, the findings also did not contradict previous studies. Following chronic spinal cord injury, recovery of spontaneous muscle activation and sympathetic activity may maintain integrity of skeletal muscle and associated microvasculature. Future research could assess microvascular function post spinal cord injury and identify an alternate animal model to study effects of spinal cord injury on muscle atrophy and associated microvasculature changes.</p>

This Thesis is submitted to the University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Surgery. The examination for this degree was completed in 1947. / The skull and mandible of the baboon. This is a morphological study of the skulls and mandibles of 102 specimens from known localities in Southern Africa. A detailed reference book on the anatomy of the baboon is particularly important because of the increasing use of this animal in medical science. The skulls and mandibles of captive animals are referred to but are not included in the comparative study since animals in captivity are subject to dietetic disturbances and other factors not yet fully understood. The cranium of an adult male skull is described in all normae. Comparisons are made with the crania of seven adult male baboons from widely separated known localities. This study shows that two main craniofacial types, with intermediate types, occur among the crania of South African baboons. Type 1. crania have small maxillary ridges, shallow maxillary fossae, ventrally directed zygomatic bones, large ventral orbital apertures, well developed superciliary ridges, high temporal lines and sagittal crests. Type 11. crania have large flared maxillary ridges, deep maxillary fossae, ventrolateral ly directed zygomatic bones, small ventral orbital apertures, large supraorbital tori, low temporal lines and no sagittal crests. This apparent1y supports the specific and subspecific claims of some observers. However, a critical examination of the crania of six adult female baboons from the same troop at Bindura, Rhodesia, shows that similar craniofacial types occur among female baboons. It is possible to associate mandibular types with the craniofacial types in adult male baboons. This is not the case with female baboon mandibles. / WHSLYP2017

Dissertation submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in Medicine Johannesburg, 2000 / During the academic year of 1997/98, two randomised groups of second year medical students at Universidade Eduardo Mondlane in Maputo learned gross anatomy of the limbs and the trunk by different teaching approaches. One group (A) dissected the thorax for 5 weeks according to an experimental programme, while the other (group B) worked on the same topic in the traditional way at UEM, which excluded dissection. The groups learned the abdomen by reversing the methods. For the study of the limbs, all the students learned the upper limbs by using the traditional approach while the lower limbs were dissected. Study guides were supplied to the Experimental Group and each of the practical classes started with a ten-minute preparatory tutorial when the structures to be studied were discussed. The same amount of time and the same background were given to both groups. At the end of the semester all students were examined by written and practical tests. The mean differences in the tests were statistically significant (p<0.001) only in the case of the practical test on the anatomy of the limbs, favouring the Experimental Group. Pre-questionnaires and post-questionnaires were completed before and after the experimentation. The combination of lectures, tutorials and dissection was the most preferred teaching approach. The students’ comments indicated that they felt that dissection enhanced the learning despite the short time devoted to it. On the other hand, students felt that dissection can enhance other skills which will be very useful later in pathology and surgery, for example in a way not possible to achieve by means of tutorials, or even prosections. Therefore, these results suggest that dissection could be a useful complementary teaching approach in addition to lectures and tutorials in Anatomy at UEM / IT2017

A collection of papers (D.Sc.1971) from the Dept. of Zoology, Univof Adelaide / 1v. various pagings / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (D.Sc.)--University of Adelaide, 1971