Vitamin D deficiency is common in individuals diagnosed with HIV and is known for its detrimental health effects. Its recognition as a potent immune-modulator with possible immune health implications in HIV disease progression was the main impetus for this study. The association between Vitamin D and CD4 count falls short of being consistent and is too weak to allow conclusions. Similarly, the literature is inconsistent with regard to the impact of Vitamin D supplementation on CD4. This observational, retrospective chart review study aimed to explore the relationship between Vitamin D deficiency and CD4 count/percent, and to evaluate whether changes in Vitamin D levels after supplementation corresponds with significant changes in CD4 count/percent in a cohort of African American, HIV-infected men who attended an HIV clinic in southeast Michigan (N = 70). The conceptual framework was based on the role of Vitamin D in regulating the immune responses through Vitamin D nuclear receptors on the CD4 cells. It postulated that an increase in Vitamin D level might enhance immune function, promote cellular anti-inflammatory state, and decelerate CD4 destruction. Data analysis included descriptive statistics, bivariate correlation, logistic and linear regression, t test, repeated measures ANOVA, and ANCOVA. Findings of the study did not support the hypotheses of significant correlation between Vitamin D and CD4 count (p = 0.458) and percent (p = 0.776), or of any impact of supplementation on CD4 count (p = 0.216) and percent (p = 0.918). Social change implications include providing health professionals, researchers, and policymakers with knowledge to tailor health promotion interventions aiming to reduce Vitamin D deficiency in favor of improving the overall health of HIV patients, especially high-risk groups such as African American HIV-infected patients.

No description available.

This study addresses the importance of studies of human psychoneuroimmunology in understanding the role of psychological factors in cancer. Research trends in psychosocial aspects of cancer are reviewed, exploring the role of distress and the support group as an intervention which potentially reduces distress through enhancing interpersonal relationships, emotional adjustment and communication with health professionals, in these ways helping the patient to cope with the symptoms of treatment. In South Africa, most hospitals which treat cancer patients medically do not simultaneously have support groups for the newly diagnosed patient to join in order to discuss immediate fears and acquire more knowledge about their particular disease. Following an experimental cancer support group involving patients who had recently undergone a bone marrow transplant (some considerable time after their first cancer diagnosis) in Cape Town's Groote Schuur Hospital, the researcher, as one of the participants in the fortnightly meetings convened to dicuss psychosocial issues related to each patient's experience of the cancer and transplant process, transferred the themes, concepts and questions that arose in that scenario, to a cancer clinic in Pretoria where recently diagnosed patients were asked to volunteer to participate in such a group. It was felt that these patients would derive some benefit early in their treatment programme. Psychosocial concerns are left to the individual patient to seek therapy should it be required. Presently, it is reported in the body of knowledge about cancer, that interventions aimed at alleviating the psychosocial distress of cancer patients highlight hypnosis, guided imagery and relaxation therapy. It is contended that a more appropriate intervention for the majority of people with cancer in South Africa would entail a fellow-patient support group meeting on a regular basis. / Psychology / (M.A. (Psychology)

This study investigated factors associated with two mortality events: avian botulism in waterfowl and mortality associated with hatching asynchrony in prefledgling Franklins gulls (Larus pipixcan). The initial focus of my research was on the spatiotemporal relationship between mortality of Franklins gulls and the onset of botulism outbreaks in waterfowl, and the suitability of gull carcasses for proliferation and toxigenesis of Clostridium botulinum. From 1999 to 2001, dead hatch-year Franklins gulls were by far the most abundant carcasses, and the only source of toxin-laden maggots found on transects prior to the occurrence of avian botulism in waterfowl. Nest density was a significant predictor of hatch-year gull carcass density. High density of toxic material from gull carcasses prior to the onset of botulism in waterfowl coincided with high densities of susceptible birds; hence, mortality of Franklins gulls has the potential to be a major initiating factor for botulism outbreaks at Eyebrow Lake, Saskatchewan. The causes of gull mortality were conditions or diseases associated with starvation, stress, or immunosuppression, and most mortality occurred in third-hatched chicks. To separate effects of laying order from effects of hatching asynchrony on prefledgling survival, a cross-fostering experiment was conducted to create clutches containing asynchronously hatching eggs of the same laying order, and of similar egg mass, egg volume, and female quality. Hatching order, independent of laying order, significantly affected survival to fledging, whereas laying order had no observable effect, indicating that intraclutch variation in egg quality does not predetermine the fate of prefledglings, and may be less important than hatching asynchrony for survival of prefledgling Franklins gulls. Relationships among hatching asynchrony, laying order, mass, corticosterone, immune function, growth, and survival at two stages of development were complex. Hatching asynchrony significantly affected early and late prefledgling survival, and was directly or indirectly associated with mass, corticosterone level, and cell-mediated immune responses at early and later stages of development. Both hatching asynchrony and mass appeared to play key roles in mediating life history trade-offs among cell-mediated immune function, growth, and survival. In contrast to cell-mediated immune responses, primary humoral immune response was not directly affected by hatching order or mass, nor was it associated with survival to fledging. Rather, it was associated with laying order, neonatal testosterone, corticosterone at 2 weeks, growth of leg length, and clutch initiation date, illustrating the importance of examining more than one branch of the immune system in studies of life history trade-offs. This study is a step toward using a multipronged and multidisciplinary approach to demonstrate interactions and trade-offs among life history traits, the physiological mechanisms that produce these relationships, and how these relationships may change depending on stage of development.

This study investigated factors associated with two mortality events: avian botulism in waterfowl and mortality associated with hatching asynchrony in prefledgling Franklins gulls (Larus pipixcan). The initial focus of my research was on the spatiotemporal relationship between mortality of Franklins gulls and the onset of botulism outbreaks in waterfowl, and the suitability of gull carcasses for proliferation and toxigenesis of Clostridium botulinum. From 1999 to 2001, dead hatch-year Franklins gulls were by far the most abundant carcasses, and the only source of toxin-laden maggots found on transects prior to the occurrence of avian botulism in waterfowl. Nest density was a significant predictor of hatch-year gull carcass density. High density of toxic material from gull carcasses prior to the onset of botulism in waterfowl coincided with high densities of susceptible birds; hence, mortality of Franklins gulls has the potential to be a major initiating factor for botulism outbreaks at Eyebrow Lake, Saskatchewan. The causes of gull mortality were conditions or diseases associated with starvation, stress, or immunosuppression, and most mortality occurred in third-hatched chicks. To separate effects of laying order from effects of hatching asynchrony on prefledgling survival, a cross-fostering experiment was conducted to create clutches containing asynchronously hatching eggs of the same laying order, and of similar egg mass, egg volume, and female quality. Hatching order, independent of laying order, significantly affected survival to fledging, whereas laying order had no observable effect, indicating that intraclutch variation in egg quality does not predetermine the fate of prefledglings, and may be less important than hatching asynchrony for survival of prefledgling Franklins gulls. Relationships among hatching asynchrony, laying order, mass, corticosterone, immune function, growth, and survival at two stages of development were complex. Hatching asynchrony significantly affected early and late prefledgling survival, and was directly or indirectly associated with mass, corticosterone level, and cell-mediated immune responses at early and later stages of development. Both hatching asynchrony and mass appeared to play key roles in mediating life history trade-offs among cell-mediated immune function, growth, and survival. In contrast to cell-mediated immune responses, primary humoral immune response was not directly affected by hatching order or mass, nor was it associated with survival to fledging. Rather, it was associated with laying order, neonatal testosterone, corticosterone at 2 weeks, growth of leg length, and clutch initiation date, illustrating the importance of examining more than one branch of the immune system in studies of life history trade-offs. This study is a step toward using a multipronged and multidisciplinary approach to demonstrate interactions and trade-offs among life history traits, the physiological mechanisms that produce these relationships, and how these relationships may change depending on stage of development.

The two main goals of my thesis were to further our understanding of how parental effort is related to life-history trade-offs and to see how parental investment is reflected in various potential measures of nestling quality. I looked at how fitness is maximized by examining (1) the trade-off between current and future reproduction, and (2) the trade-off between quantity and quality of offspring. To see how parents responded to energetic demands and whether each sex reacted in a similar way, I experimentally manipulated brood sizes and quantified provisioning rates. Both male and female parents with enlarged broods increased their feeding rates, but provisioning on a per nestling basis declined, so that parents fledged lighter nestlings with shorter wings. Although the incidence of mortality did not differ between control and enlarged broods, nestlings from enlarged broods were lighter than those from control broods with the same brood size, suggesting that clutch size may be individually optimized. I also looked at how nestlings responded to different levels of nutritional stress in the manipulated broods by quantifying size and body condition, plumage colouration, and the physiological measures of T-cell mediated immune responses, and corticosterone levels in nestling feathers as a long-term integrated measure of stress physiology. The size of melanin ornaments on feathers and the saturation and brightness of carotenoid colouration was associated with nestling mass in such a way that suggested that plumage characteristics reflect nestling quality. The immune function of nestlings was negatively related to brood size and nestlings in better body condition could mount greater immune responses to foreign antigens suggesting that immune responses are energetically costly. Corticosterone levels in the feathers were not related to nestling body condition and were unaffected by the experimental brood manipulation. The ii mass of male nestlings, which are the larger sex, was more compromised by brood size than female mass was. I also found sex-specific relationships between plumage characteristics and measures of physiological performance. These findings help to explain optimal clutch size and the classic trade-off between quality and quantity of offspring. They also offer new insights into the reliability of putative measures of quality in nestlings and relationships between physiological and morphological traits.

This study addresses the importance of studies of human psychoneuroimmunology in understanding the role of psychological factors in cancer. Research trends in psychosocial aspects of cancer are reviewed, exploring the role of distress and the support group as an intervention which potentially reduces distress through enhancing interpersonal relationships, emotional adjustment and communication with health professionals, in these ways helping the patient to cope with the symptoms of treatment. In South Africa, most hospitals which treat cancer patients medically do not simultaneously have support groups for the newly diagnosed patient to join in order to discuss immediate fears and acquire more knowledge about their particular disease. Following an experimental cancer support group involving patients who had recently undergone a bone marrow transplant (some considerable time after their first cancer diagnosis) in Cape Town's Groote Schuur Hospital, the researcher, as one of the participants in the fortnightly meetings convened to dicuss psychosocial issues related to each patient's experience of the cancer and transplant process, transferred the themes, concepts and questions that arose in that scenario, to a cancer clinic in Pretoria where recently diagnosed patients were asked to volunteer to participate in such a group. It was felt that these patients would derive some benefit early in their treatment programme. Psychosocial concerns are left to the individual patient to seek therapy should it be required. Presently, it is reported in the body of knowledge about cancer, that interventions aimed at alleviating the psychosocial distress of cancer patients highlight hypnosis, guided imagery and relaxation therapy. It is contended that a more appropriate intervention for the majority of people with cancer in South Africa would entail a fellow-patient support group meeting on a regular basis. / Psychology / (M.A. (Psychology)

Many athletes incorporate high training volumes and limited recovery periods into their training regimes. This may disrupt the fragile balance and the accumulation of exercise stress may exceed an athlete's finite capacity of resistance. A state of elevated fatigue, increased mood disturbance and decreased exercise performance can result. This is commonly known as overreaching and if increased training and limited recovery is continued, it is believed that the more serious state of overtraining may develop. This is relatively commonly experienced in athletes, however little scientific investigation has been conducted to determine the characteristics and underlying mechanisms. The overall aim of this thesis was to gain a greater understanding of the state of overreaching and to specifically provide new information on potential markers of this state as well as possible mechanisms. To study the cumulative effects of exercise stress and subsequent recovery on performance changes, fatigue indicators and possible mechanisms, the training of endurance cyclists was systematically controlled and monitored in two separate investigations. A number of variables were assessed including performance, physiological, biochemical, psychological, immunological and hormonal variables. In addition heart rate variability and serotonergic responsiveness were also assessed. Some of the more pertinent effects of overreaching included an increase in heart rate variability, a reduction in carbohydrate oxidation, an increase in serotonergic responsiveness and a reduction in stress hormone concentrations. These results suggest that autonomic imbalance in combination with decreased hormonal release appears to be related to the decline in performance and elevated fatigue apparent in overreached athletes. Additionally it also appears that alterations in the hypothalamic-pituitary adrenal axis may occur in overreached athletes.

No description available.