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Thesis (MSCMedSc (Pathology. Medical Virology))--University of Stellenbosch, 2005. / There is an urgent need for a safe, effective, affordable human immunodeficiency virus type 1 (HIV-1) vaccine that induces both cellular and humoral immunity. A popular strategy for vaccine design is the use of plasmid DNA encoding HIV-1 genes for priming vaccinations followed by either viral vector or recombinant protein boosting. DNA-based vaccines are attractive because they are safe, easily administered and can induce both cellular and humoral immune responses. In order for DNA vaccination to induce a potent immune response it is necessary for plasmid-encoded genes to be targeted to dendritic cells (DCs) as these are the key antigen presenting cells in natural HIV infection. The immunogenicity of all potential vaccine candidates needs to be assessed in animal models prior to entry into human trials. Nonhuman primates are the best alternative to humans for assessment of vaccine immunogenicity and protective efficacy. In order to clearly understand how DNA vaccines interact with DCs, suitable in vitro DC culture systems for nonhuman primates need to be developed. This study investigated the culture and characterisation of chacma baboon DCs in vitro, and was the first to assess the effect of various transfection methods on baboon DC maturation and function. The study also evaluated the efficacy of a candidate HIV-1 subtype C DNA vaccine at the level of baboon DC transfection, gene transcription and antigen presentation. Generation of immature DCs (iDCs) in the presence of interleukin-4 (IL-4) and granulocyte-macrophage colony stimulating factor (GM-CSF) was accompanied by a loss in the monocyte marker CD14. Expression of the markers CD80 and CD83 was observed on a minority of iDCs, whereas CD86 was expressed on almost all iDCs. Following maturation, all these markers were expressed on an increased number of cells, a pattern of marker expression and upregulation that is similar to that observed in both human and macaque DCs. Transfection of baboon DCs by passive pulsing, lipofection and electroporation was evaluated and compared in several ways. Transfection efficiency, cytotoxicity, the effect of the transfection on DC maturation and subsequent presentation of plasmidencoded antigen to memory T lymphocytes was examined. Baboon DCs lipofected with pDNA efficiently took up HIV-1 subtype C plasmid DNA, transcribed plasmid-encoded genes into mRNA, translated the mRNA into protein, processed the protein and presented peptide antigens to antigen-specific memory T cells. The other methods of transfection were less effective than lipofection due to either decreased transfection efficiency or increased cell cytotoxicity. However, neither lipofection nor passive pulsing in any way negatively impacted on DC marker, CD83, or costimulatory molecule, CD80 and CD86, upregulation. Both methods were found to be as effective as a standard cytokine maturation cocktail in inducing DC maturation. Transfected DCs were also found to be more potent inducers of allogeneic T cell stimulation than their untransfected counterparts, which would appear to indicate enhanced major histocompatibility complex (MHC) expression concurrent with DC maturation marker expression. Lipofection with candidate HIV-1 subtype C vaccine plasmid DNA constructs led to antigen-specific expansion of autologous memory T cells, a finding which indicates the effective expression of plasmid-encoded HIV genes in baboon DCs. This study highlights the functional activity of in vitro generated baboon DCs and provides the groundwork for future studies addressing targeting of plasmid DNA to DCs and enhancement of expression of plasmid-encoded antigens in DCs. A more detailed evaluation of baboon DC interaction with simian immunodeficiency viruses/chimeric simian human immunodeficiency viruses (SIVs/SHIVs) may also reveal how the course of infection in this primate differs from that seen in the macaque or chimpanzee and also how it relates to HIV-1 infection in humans.

Dissertation (PhD)--University of Stellenbosch, 2007. / ENGLISH ABSTRACT: This study: 1. Describes the localization of CYP11B1 in the Cape baboon adrenal gland using Western blot analysis. CYP11B1 was localized to the adrenal cortex and medulla. 2. Describes the catalytic activity of CYP11B1 towards 11-deoxycorticosterone and corticosterone in adrenal cortical- and medullary tissue homogenates. Aldosterone formation in the adrenal medulla was identified using an atmospheric pressure chemical ionization-mass spectrometry method, which was developed in our department. 3. Compares the catalytic activity of three recombinant Cape baboon CYP11B1 cDNAs, expressed in COS-1 cells, towards 11-deoxycorticosterone and 11-deoxycortisol. 4. Describes the determination of the Michaelis-Menten constants and maximum reaction rates of 11-deoxycorticosterone and 11-deoxycortisol utilization by two functional recombinant Cape baboon CYP11B1 cDNAs, respectively. 11-Deoxycorticosterone metabolites were quantified using an enzyme immunoassay kit. 11-Deoxycortisol metabolites were quantified using a liquid chromatography-mass spectrometry method, which was developed in our department. 5. Describes the homology modeling of two isoforms of Cape baboon CYP11B1 using CYP102 and CYP2C5 as structural templates. The influence of three amino acid residue substitutions, located in the predicted D-E helix, on the catalytic activity of the two CYP11B1 isoforms was examined. / AFRIKAANSE OPSOMMING: Hierdie studie: 1. Beskryf die lokalisering van CYP11B1 in die bynier van die Kaapse bobbejaan deur gebruik te maak van die Western kladtegniek. CYP11B1 is gelokaliseer tot die adrenale korteks en medulla. 2. Beskryf die metabolisme van 11-deoksikortikosteroon en kortikosteroon in adrenale korteks- and medulla weefsel preparate, onderskeidelik. Die produksie van aldosteroon in die medulla is geïdentifiseer deur gebruik te maak van ‘n atmosferiese druk chemiese ionisasie-massa spektrometrie metode wat in ons departement ontwikkel is. 3. Vergelyk die katalitiese aktiwiteit van drie rekombinante Kaapse bobbejaan CYP11B1 cDNAs, getransfekteer in COS-1 selle, ten opsigte van 11-deoksikortikosteroon en 11- deoksikortisol metabolisme. 4. Beskryf die bepaling van die Michaelis-Menten konstantes en maksimum snelhede van twee funksionele rekombinante Kaapse bobbejaan CYP11B1 cDNAs, getransfekteer in COS-1 selle, ten opsigte van 11-deoksikortikosteroon en 11-deoksikortisol metabolisme. 11-Deoksikortikosteroon metaboliete is gekwantifiseer deur gebruik te maak van ‘n ensiem immunotoets. 11-Deoksikortisol metaboliete is gekwantifiseer deur middel van ‘n vloeistofchromatografie-massaspektrometrie metode, ontwikkel in ons departement. 5. Beskryf die modelering van drie-dimensionele strukture van twee funksionele Kaapse bobbejaan CYP11B1 isoensieme deur CYP102 en CYP2C5 as template te gebruik. Die effek van drie aminosuurresiduveranderinge in die voorspelde D-E heliks op die katalitiese aktiwiteit van die twee CYP11B1 isoforme is bepaal.

The focus of this study is the effect of environmental conditions on the social relationships among females in a free-ranging troop of chacma baboons (Papio cynocephalus ursinus), in a southern woodland habitat. The female dominance hierarchy, rank related differential costs and benefits to individuals, and the nature of special relationships between females, were followed. The study was conducted for a total of 18 months during three years, at Mkuzi Game Reserve, Zululand, South-Africa. The study troop occupy a rich woodland habitat with abundant food resources. Visibility under these conditions is poor and the baboons are subjected to leopard predation. Intra-troop competition for food among female primates and its effect on lifetime reproductive success, has been widely stressed to be a major cost for low ranking females. No evidence of competition for food was found among females at Mkuzi. It is suggested that the main cause for mortality may be predation by leopards, and that females compete mainly over a safe spatial position. The following characteristics of female sociality at Mkuzi may support this suggestion: 1. While no indication of rank related feeding behaviour, reproductive success, or 'attractiveness' to others was found, the higher ranking females had more access to central, and thus better protected, spatial positions in the troop. 2. The importance of social associations among females at Mkuzi seems to lie in mutual grooming and protection from predation by the vicinity to each other, and not in coalitionary support. Female associates were thus not necessarily adjacent ranking and probably not kin. 3. Although female dominance hierarchy was usually stable, the lowest ranking adult female has promoted her rank independently, following the disappearance of her only female associate and during her pregnancy, when she was probably subjected to high risk of predation. 4. Following troop fission, most females chose to improve their own rank position by adopting the AYS strategy (Abandon Your immediate Superior in rank), rather than joining associates. It is suggested that the resident males were responsible for the initiation of troop fission, in order to decrease the high cost of sexual competition to them, by reducing the number of males in each daughter troop. High intensity of competition between males was the result of the high female reproductive success. Risk of predation, and therefore the cost to individual females, increased after fission. This study may present an additional accumulating behavioural evidence on adaptations environmental conditions. the of flexibility primates example to of social and to various environmental conditions. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1993.

A research report submitted to the Faculty of Arts, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the Degree of Master of Arts in the F'ield of Psychology by Course Work arid Research Report: 1996 ..7 Johannesburg, 1997 / This research project set out to explore the racial identities of a selected group of South African whites who were Afrikaans-speaking, Unstructured, in-depth interview techniques were employed, in which the conversations with the participnnts were recorded and transcribed, These transcripts were then subjected tr) a discourse analysis, whereby any possible effeci s and functions of the talk were examined, A number of theoretical approaches informed this task. These included Foucault's concept of discourse and his account of the functioning of disciplinary power in modern societies. Adorno and Horkheimer's ideas 011 prejudice and racism were also found to be of t;!C,lt relevance to this research, as well i1S Altlmsser's formulation of the concept of ideology, ideological state apparatuses, incerpellation and subject positioning. The relationship between psychic and social structures was also explored in the light of Adorno and Horkhelmer's fermulation of prejudice M ,\ defence mechanism. Within this broad framework, it was shown that aside from its overt content, racise talk could be described as having important ideological effects. These included normalisation. legitimation and j\lstificatioll of the existing unequal relations ill. society. The discourse analytic striitcgy facilitated an ,111;11Y5is of the conditions under which the participants were constructed .\S subjects, and the manner In which the terms they used (such I\S race, culture and nation) were imbricated with broader discursive and ideological formations, The influence of social class, gender and uge variables in the interview settings were also evaluated.

The evolutionary history of the South African papionins is a useful analog for the emergence of hominids in South Africa. However, the taxonomic relationships of the papionins are unclear. This study uses low-magnification stereomicroscopy to examine dental microwear and uses the microwear signals to explore the existing classification of these papionins. The results from the species and site level analyses are equivocal. However, the genera and time period results show clear evidence for a dietary change between the extinct and extant forms of Papio and Parapapio. This adds an additional tool for distinguishing these two groups. The dietary changes witnessed in the papionins are likely found in the hominids from the Plio-Pleistocene. Using the papionin analog, hominid dietary evolution may be explored.

Die vorliegende Arbeit soll dazu beitragen, Unstimmigkeiten in den Verwandtschaftsverhältnissen innerhalb der Papionini, einem Stamm innerhalb der Altweltaffen (Cercopithecidae), zu klären. Die Papionini, die zusammen mit den Cercopithecini die Unterfamilie der Cercopithecinae bilden, beinhalten sieben Gattungen (Macaca, Cercocebus, Mandrillus, Lophocebus, Papio, Theropithecus, Rungwecebus) und 45 Arten. Sechs der sieben Gattungen kommen heute hauptsächlich in Afrika vor. Eine Ausnahme ist die Gattung Papio, die mit einer Art (P. hamadryas) auch in Südwest-Arabien vorkommt. Im Gegensatz zu den sechs hauptsächlich afrikanischen Gattungen hat die siebte Gattung (Macaca) nur ein kleines Verbreitungsgebiet im Norden Afrikas und kommt sonst hauptsächlich in Asien vor. Fossilfunde belegen allerdings, dass während des Plio- und Pleistozäns die Gattungen Macaca und Theropithecus auch in Europa vorkamen. Von der Gattung Theropithecus, die heute ausschließlich in Afrika beheimatet ist, wurden zudem auch Fossilien aus dem Pliozän im Norden Indiens gefunden. Die Verwandtschaftsbeziehungen innerhalb der Papionini wurden bisher mit Hilfe morphologischer und genetischer Merkmale untersucht, allerdings waren die Ergebnisse nicht immer übereinstimmend und es gibt immer noch viele Unklarheiten. Zum einen ist nicht eindeutig geklärt, wie die Gattungen Papio, Lophocebus und Theropithecus zu einander in Beziehung stehen. Zum anderen ist auch unklar, wie die einzelnen Pavianarten innerhalb der Gattung Papio mit einander verwandt sind. Außerdem sind auch die Verwandtschaftsverhältnisse zwischen und innerhalb der Artgruppen der Makaken nicht eindeutig geklärt. Um mehr Klarheit in die Evolution der Papionini zu bringen, habe ich im Rahmen dieser Arbeit drei Studien durchgeführt (Kapitel 2-4). Ziel dabei war es, Verwandtschaftsbeziehungen auf unterschiedlichen taxonomischen Ebenen (zwischen und innerhalb von Gattungen, sowie innerhalb einer Art) zu untersuchen. Dazu wurden komplette mitochondriale Genome von Vertretern der Papionini sequenziert und damit Phylogenien und Aufspaltungszeiten berechnet. Die Ergebnisse meiner Arbeit zeigen unter anderem drei Hauptkladen innerhalb der Papionini (Kapitel 2): 1) Papio, Theropithecus, Lophocebus; 2) Mandrillus, Cercocebus; 3) Macaca, wobei Macaca in der mitochondrialen Phylogenie näher mit Mandrillus und Cercocebus verwandt zu seien scheint und nicht wie erwartet, als Schwestergruppe der afrikanischen Papionini abgebildet wird; ein Ergebnis, das im Widerspruch zu nukleären und morphologischen Studien steht. Meine Arbeit zeigt auch, dass komplette mitochondriale Genome in manchen Fällen nicht ausreichen, um phylogenetische Beziehungen vollständig zu rekonstruieren. So bleibt weiterhin unklar wie die Gattungen Papio, Theropithecus und Lophocebus zueinander stehen (Kapitel 2). Außerdem zeigen die Ergebnisse Paraphylien für Mandrillus und Cercocebus (Kapitel 2), sowie innerhalb der Paviane (Kapitel 3). Die Paviane werden dabei gemäß ihrer geographischen Verbreitung und nicht nach ihrer taxonomischen Zugehörigkeit abgebildet, wodurch die meisten Pavian-Arten paraphyletisch sind. Der Grund für diese Baumtopologie ist sehr wahrscheinlich sekundärer Genfluss zwischen parapatrisch vorkommenden Pavian-Arten. In der dritten Studie (Kapitel 4), in der innerartliche Verwandtschaftsverhältnisse innerhalb einer südostasiatischen Makaken-Artgruppe (Macaca fascicularis) untersucht wurden, zeigt sich eine klare Unterteilung in eine kontinentale und eine insulare Klade. Sowohl die kontinentale, als auch die insulare Linie sind auf Sumatra zu finden, was für einen sekundären genetischen Austausch zwischen beiden Populationen spricht. Generell kann man sagen, dass komplette mitochondriale Genome robuste Phylogenien mit hoher statistischer Unterstützung ergeben, die eine gute Grundlage für künftige vergleichende Studien bilden. Die berechneten Aufspaltungszeiten stimmen weitestgehend mit vorherigen Studien überein, wobei sich die ermittelten Konfidenzintervalle verkleinert haben. Allerdings zeigt die Arbeit auch, dass Phylogenien basierend auf mitochondrialen Genomen keine hohe Auflösung erzielen wenn sich Taxa innerhalb kurzer Zeit voneinander trennten. Die hier gezeigten Paraphylien und die abweichenden Ergebnisse zu nukleären Studien wurden höchstwahrscheinlich durch sekundären genetischen Austausch hervorgerufen. Um Verwandtschaftsverhältnisse möglichst exakt rekonstruieren zu können, müssen neben der maternal-vererbten, mitochondrialen Linie noch paternal- und biparentalvererbte Merkmale in Betracht gezogen werden. Zu beachten ist in diesem Zusammenhang, dass ein bestimmter molekularer Marker immer nur eine mögliche Phylogenie von vielen wiedergibt.

Savannah baboons (Papio cynocephalus) have been studied in numerous sites throughout Africa. They have been found to display a wide variety of foraging and feeding behaviours. The aim of this study was to describe and quantify these for a troop in a southern woodland habitat and to determine what factors influence these in order to understand the choices made by baboons. This was done within an optimal foraging framework. The study included the development of random walk and optimal foraging simulation models of day journeys and a comparison of feeding and foraging before and after the troop divided into two daughter troops. The troop lived in a complex mosaic of habitat types with a high tree density. The troop's foraging strategies were found to be consistent with being time minimizers. Distance from the centre of the home range and distance from the nearest sleeping site had the most significant effect on utilisation of the home range. The effect of food availability on habitat use could only be distinguished by the use of simulation models. Comparison of food encountered by the troop and that encountered in the simulations demonstrated that the troop did better than could be expected if the day journey routes were random. The troop's results approximated those of a stochastic short-term optimisation model. The troop's diet consisted of a higher proportion of fruit than previous studies. The troop distinguished between commonly utilised foods and those only occasionally used on the basis of protein/fibre ratio, however food preference between main foods was not correlated with protein/fibre ratio. Any combination of the main foods would fulfil their protein requirement. Evidence is given that, without protein being limmiting, the troop's selection amongst the main foods is based on carbohydrate content. After troop fission the daughter troops had shorter day journeys, spent less time walking, more time socialising resting. They also spent more time in food-rich habitats and were more selective in their diet. These results reinforce the important influence in group size and suggest that troop fission may be seen as a time-minimising strategy. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1994.

Thesis (MScMed)--University of Stellenbosch, 2005. / Bibliography. Also available via the Internet.

Thesis (Ph. D.)--University of Chicago, Dept. of Psychology. / Includes bibliographical references. Also available on the Internet.