Texte remanié : Thèse : Théologie : Friedrich-Wilhems Universität : 1994. / Bibliogr. p.[427]-448. Index.

In recent years, there have been several proposals for large-scale human genotyping projects in the developing world. The dissertation presented here explores the motivations, opportunities and challenges of initiating locally led, large-scale genotyping projects documenting human genomic variation in the developing world. I analyze two case studies: the Indian Genome Variation Consortium in India and the University of Cape Town, Department of Human Genetics and the African Genomics Education Initiative in South Africa. These case studies, together with similar projects in Mexico and Thailand provide compelling reasons for pursuing these projects: the potential to address local health needs and reduce health care costs; the opportunity to stimulate economic development through investments in genomic sciences, and the availability of unique population resources. In an effort to capture the value of these investments and promote an equal stake in international collaborations, Mexico and India have developed guidelines and laws to protect local human genetic material as a sovereign resource, referred to here as ‘genomic sovereignty’. Critics have suggested that it can impede international collaborations and reduce access to external funding. I provide an in depth analysis of genomic sovereignty and how it may contribute to each country’s aim of achieving health equity through investments in genomics, its relation to heritage and patrimony, and its potential limitations. The debate is critical, as the knowledge generated from large-scale human genomic research will need to be interpreted in larger international collaborative efforts before it can lead to health benefits. Qualitative case study methodology is employed and the primary data source consists of interviews conducted with key informants. The research described here provides a source of empirical description and analysis that is informing the framing of policies, principles and practices on how research infrastructure and capacity are being established for human genomic sciences in developing countries.

This research examines the activation of the Rapid Response Team (RRT) through the Early Warning Score (EWS) model as a system of predicting adverse event outcomes. Modeling the input parameters of this system concluded that although conventional parameters associated with EWSs were predictive,the most predictive clinical and laboratory parameters are those of hematological and nephritic function, related to the model of multi-organ system decompensation. Upon examining different EWSs, the Modified Early Warning Score exhibited superior operating characteristics, however, it was not statistically different than other common EWSs from literature. Accounting for temporal features of the dataset shows that the International Normalized Ratio is the most predictive parameter, however, the hazard model exhibits poor discriminative ability. Therefore, clinically, parameters outside the EWS models are predictive of the outcomes in question, and their incorporation into future policy would serve to better inform the prevention of adverse events.

This study examined the effects of 30 minutes of cycle exercise at 65% V̇O2max on the pharmacokinetics of the S.S.R.I. sertraline. Blood samples were taken over 48 hours from 14 healthy males (23.9±2.5 years, 80.3±12.6 kilograms) following oral ingestion of a single 100 mg dose of sertraline. Participants completed two sertraline trials separated by at least two weeks; one trial while resting and the other trial with exercise as described above. With exercise, the absorption rate constant and volume of sertraline in the central compartment decreased, while the elimination half-life increased. Maximum concentration, time of maximum concentration, and area under the curve were unchanged. Fitness level had little impact on the concentration of sertraline, as compartmental modeling was unchanged when relative V̇O2max was added as a covariate. However, controlling for participant body weight improved the model estimate. These results indicate that acute aerobic exercise has the potential to change the concentration of sertraline in vivo.

Background: Traumatic spinal cord injury (SCI) results in vascular disruption which appears to contribute to the pathobiology of SCI. Vascular endothelial growth factor (VEGF) is known for vascular development and repair, and more recently for its neuroprotective properties. Given this, I investigated the temporal-spatial changes to the spinal vasculature, as well as examined the role of VEGF as a therapeutic approach for SCI. Hypothesis: It is hypothesized that clip-compression injury will result in significant vascular changes, and that ZFP-VEGF gene therapy will enhance molecular and functional recovery following spinal cord injury. Methods: Briefly, female Wistar rats received a two-level laminectomy and a 35g clip-compression injury at T6-T7 for 1 minute. Control animals received a laminectomy only. AdV-ZFP-VEGF or AdV-eGFP was administered 24 hour post-injury by intraspinal injection. For molecular and vascular analysis, tissues were extracted at various time points between 1 hour and 14 days post-SCI. For behavioural experiments animals were studied for 8 consecutive weeks. Results: I have shown that vasculature undergoes structural and functional changes, which occur as early as 1 hour following SCI. Although endogenous improvement is observed, SCI results in permanent vascular damage. Animals receiving AdV-ZFP-VEGF treatment had increased levels of VEGF mRNA and protein. AdV-ZFP-VEGF resulted in neuroprotection, as observed by increased NF200 protein and NeuN counts, and decreased TUNEL staining. Animals treated with AdV-ZFP-VEGF also showed an increased number of newly formed vessels (angiogenesis), as well as an increase in total number of vessels. Moreover, animals treated with AdV-ZFP-VEGF showed significant increases in hindlimb weight support and reduction neuropathic pain. Conclusions: I have characterized the dramatic temporal-spatial changes which occur in the spinal vasculature following SCI. Additionally, I have demonstrated that AdV-ZFP-VEGF administration results in beneficial molecular and functional outcomes. Overall, the results of this study indicate that AdV-ZFP-VEGF administration can be delivered in a clinically relevant time-window following SCI (24 hours) and provide significant molecular and neurobehavioural benefits, by acting through angiogenic and neuroprotective mechanisms.

Background: Traumatic spinal cord injury (SCI) results in vascular disruption which appears to contribute to the pathobiology of SCI. Vascular endothelial growth factor (VEGF) is known for vascular development and repair, and more recently for its neuroprotective properties. Given this, I investigated the temporal-spatial changes to the spinal vasculature, as well as examined the role of VEGF as a therapeutic approach for SCI. Hypothesis: It is hypothesized that clip-compression injury will result in significant vascular changes, and that ZFP-VEGF gene therapy will enhance molecular and functional recovery following spinal cord injury. Methods: Briefly, female Wistar rats received a two-level laminectomy and a 35g clip-compression injury at T6-T7 for 1 minute. Control animals received a laminectomy only. AdV-ZFP-VEGF or AdV-eGFP was administered 24 hour post-injury by intraspinal injection. For molecular and vascular analysis, tissues were extracted at various time points between 1 hour and 14 days post-SCI. For behavioural experiments animals were studied for 8 consecutive weeks. Results: I have shown that vasculature undergoes structural and functional changes, which occur as early as 1 hour following SCI. Although endogenous improvement is observed, SCI results in permanent vascular damage. Animals receiving AdV-ZFP-VEGF treatment had increased levels of VEGF mRNA and protein. AdV-ZFP-VEGF resulted in neuroprotection, as observed by increased NF200 protein and NeuN counts, and decreased TUNEL staining. Animals treated with AdV-ZFP-VEGF also showed an increased number of newly formed vessels (angiogenesis), as well as an increase in total number of vessels. Moreover, animals treated with AdV-ZFP-VEGF showed significant increases in hindlimb weight support and reduction neuropathic pain. Conclusions: I have characterized the dramatic temporal-spatial changes which occur in the spinal vasculature following SCI. Additionally, I have demonstrated that AdV-ZFP-VEGF administration results in beneficial molecular and functional outcomes. Overall, the results of this study indicate that AdV-ZFP-VEGF administration can be delivered in a clinically relevant time-window following SCI (24 hours) and provide significant molecular and neurobehavioural benefits, by acting through angiogenic and neuroprotective mechanisms.

Cystic fibrosis is caused primarily by deletion of Phe508. An exciting discovery was that CFTR’s sister protein, the P-glycoprotein (P-gp) containing the equivalent mutation (ΔY490), could be repaired by a drug-rescue approach. Drug substrates showed specificity, and their mechanism involves direct binding to the transmembrane domains (TMDs) since arginine suppressor mutations were identified in TMDs that mimicked drug-rescue to promote maturation. We tested the possibility of rescuing CFTR processing mutants with a drug-rescue approach. 1) Arginine mutagenesis was performed on TM6, 8, and 12. 2) Correctors were tested for specificity. 3) Truncation mutants were used to map the VX-809 rescue site. Correctors 5a, 5c, and VX-809 were specific for CFTR. VX-809 appeared to specifically rescue CFTR by stabilizing TMD1. Therefore, the TMDs are potential targets to rescue CFTR. Rescue of P-gp and CFTR appeared to occur by different mechanisms since no arginine suppressor mutations were identified in CFTR.

In recent years, there have been several proposals for large-scale human genotyping projects in the developing world. The dissertation presented here explores the motivations, opportunities and challenges of initiating locally led, large-scale genotyping projects documenting human genomic variation in the developing world. I analyze two case studies: the Indian Genome Variation Consortium in India and the University of Cape Town, Department of Human Genetics and the African Genomics Education Initiative in South Africa. These case studies, together with similar projects in Mexico and Thailand provide compelling reasons for pursuing these projects: the potential to address local health needs and reduce health care costs; the opportunity to stimulate economic development through investments in genomic sciences, and the availability of unique population resources. In an effort to capture the value of these investments and promote an equal stake in international collaborations, Mexico and India have developed guidelines and laws to protect local human genetic material as a sovereign resource, referred to here as ‘genomic sovereignty’. Critics have suggested that it can impede international collaborations and reduce access to external funding. I provide an in depth analysis of genomic sovereignty and how it may contribute to each country’s aim of achieving health equity through investments in genomics, its relation to heritage and patrimony, and its potential limitations. The debate is critical, as the knowledge generated from large-scale human genomic research will need to be interpreted in larger international collaborative efforts before it can lead to health benefits. Qualitative case study methodology is employed and the primary data source consists of interviews conducted with key informants. The research described here provides a source of empirical description and analysis that is informing the framing of policies, principles and practices on how research infrastructure and capacity are being established for human genomic sciences in developing countries.

Cystic fibrosis is caused primarily by deletion of Phe508. An exciting discovery was that CFTR’s sister protein, the P-glycoprotein (P-gp) containing the equivalent mutation (ΔY490), could be repaired by a drug-rescue approach. Drug substrates showed specificity, and their mechanism involves direct binding to the transmembrane domains (TMDs) since arginine suppressor mutations were identified in TMDs that mimicked drug-rescue to promote maturation. We tested the possibility of rescuing CFTR processing mutants with a drug-rescue approach. 1) Arginine mutagenesis was performed on TM6, 8, and 12. 2) Correctors were tested for specificity. 3) Truncation mutants were used to map the VX-809 rescue site. Correctors 5a, 5c, and VX-809 were specific for CFTR. VX-809 appeared to specifically rescue CFTR by stabilizing TMD1. Therefore, the TMDs are potential targets to rescue CFTR. Rescue of P-gp and CFTR appeared to occur by different mechanisms since no arginine suppressor mutations were identified in CFTR.

This study examined the effects of 30 minutes of cycle exercise at 65% V̇O2max on the pharmacokinetics of the S.S.R.I. sertraline. Blood samples were taken over 48 hours from 14 healthy males (23.9±2.5 years, 80.3±12.6 kilograms) following oral ingestion of a single 100 mg dose of sertraline. Participants completed two sertraline trials separated by at least two weeks; one trial while resting and the other trial with exercise as described above. With exercise, the absorption rate constant and volume of sertraline in the central compartment decreased, while the elimination half-life increased. Maximum concentration, time of maximum concentration, and area under the curve were unchanged. Fitness level had little impact on the concentration of sertraline, as compartmental modeling was unchanged when relative V̇O2max was added as a covariate. However, controlling for participant body weight improved the model estimate. These results indicate that acute aerobic exercise has the potential to change the concentration of sertraline in vivo.