Very little is known about why and how the Parkinson's disease (PD) neurodegenerative process begins and progresses. In the course of developments for treatment of PD, the discovery of the inhibition of monoamine oxidase (MAO B) was a conceptual breakthrough, and has now been firmly established. MAO B has also been implicated in the neurodegenerative processes resulting from exposure to xenobiotic amines. For example, MAO B catalyzes the first step of the bioactivation of the parkinsonian inducing pro-neurotoxin, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Additional insight into the mechanism of catalysis of MAO B and the mechanism of neurotoxicity by MPTP is therefore very valuable in the pursuit of the treatment of PD. / Thesis (Ph.D. (Pharmaceutical Chemistry))--North-West University, Potchefstroom Campus, 2008.

Background: Anthracyclines, in particular Doxorubicin (DOX), are highly effective chemotherapeutic agents in the breast cancer setting, which are limited by their cardiotoxic side effects. Recently, the introduction of Trastuzumab (TRZ), a novel monoclonal antibody against the HER2 receptor, in the breast cancer setting compounds the issue of DOX mediated cardiac dysfunction. Amongst the potential mechanisms for the deleterious effects of this drug-induced cardiomyopathy, the relationship between nitric oxide synthase 3 (NOS3) and oxidative stress has gained recent attention. Objective: To determine the role of NOS3 in a clinically relevant female murine model of DOX+TRZ induced heart failure. Methods: A total of 120 C57Bl/6 female mice [60 wild type (WT) and 60 NOS3 knockout (NOS3-/-)] were treated with either 0.9% saline, DOX (20 mg/kg), TRZ (10 mg/kg), or DOX+TRZ. Serial echocardiography was performed daily for a total of 10 days, after which the mice were euthanized for histological and biochemical analyses. Results: As compared to WT, NOS3-/- mice demonstrated increased cardiotoxicity following treatment with DOX. This effect was potentiated with DOX+TRZ combination therapy. In WT female mice receiving DOX+TRZ, left ventricular ejection fraction (LVEF) decreased from 75±3% at baseline to 46±2% at day 10 (p<0.05). In the NOS3-/- group, LVEF decreased from 72±3% at baseline to 35±2% at day 10 (p<0.05). LVEF was significantly lower in NOS3-/- mice than WT at day 10 in those receiving DOX+TRZ (p<0.05). As compared to WT, NOS3-/- mice also demonstrated increased mortality following treatment with DOX+TRZ, corroborating the echocardiographic findings. Histological analysis using light and electron microscopy demonstrated increased loss of cell integrity including myofibrillar degradation, cytoplasmic vacuolization, and enlargement of the smooth endoplasmic reticulum in both the WT and NOS3-/- mice treated with DOX+TRZ. There was no significant difference, however, in the degree of cardiac remodeling between the WT and NOS3-/- groups. There was an increasing trend in the degree of cardiac apoptosis in both WT and NOS3-/- mice treated with DOX+TRZ therapy. Conclusion: Congenital absence of NOS3 potentiates the cardiotoxic effects of DOX+TRZ in an acute female murine model of chemotherapy-induced cardiomyopathy.

Very little is known about why and how the Parkinson's disease (PD) neurodegenerative process begins and progresses. In the course of developments for treatment of PD, the discovery of the inhibition of monoamine oxidase (MAO B) was a conceptual breakthrough, and has now been firmly established. MAO B has also been implicated in the neurodegenerative processes resulting from exposure to xenobiotic amines. For example, MAO B catalyzes the first step of the bioactivation of the parkinsonian inducing pro-neurotoxin, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Additional insight into the mechanism of catalysis of MAO B and the mechanism of neurotoxicity by MPTP is therefore very valuable in the pursuit of the treatment of PD. / Thesis (Ph.D. (Pharmaceutical Chemistry))--North-West University, Potchefstroom Campus, 2008.

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Aquesta investigació examina el succeit al panorama de les producciones televisives de ficció nortamericanes nascudes al nou segle a través de l’anàlisi en profunditat de l’estat de la ficció actual i l’aplicació d’aquest model a una serie de ciència-ficció paradigmàtica del moment, Battlestar Galactica. Així, intentarem demostrar que existeixen noves formes de pensar, fer i consumir el drama, que el criteri de qualitat ha quedat diluit en el context actual fent necessària una nova aproximació a aquest i que Battlestar Galactica és un producte singular de l’època que ha permès incloure els gèneres marginals als nous discursos de qualitat, per finalment poder legitimar l’existència de la Tercera Edat Daurada de la Televisió. / La presente investigación examina lo ocurrido en el panorama de las producciones televisivas de ficción norteamericanas nacidas en el nuevo siglo a través del análisis en profundidad del estado de la ficción actual y la aplicación de dicho modelo a una serie de ciencia-ficción paradigmática de la época, Battlestar Galactica. Así, intentaremos demostrar que existen nuevas formas de pensar, hacer y consumir el drama, que el criterio de calidad ha quedado diluido en el contexto actual haciendo necesaria una nueva aproximación a éste y que Battlestar Galactica es un producto singular de la época que ha permitido incluir los géneros marginales en los nuevos discursos de calidad, para finalmente poder legitimar la existencia de la Tercera Edad Dorada de la Televisión. / This research examines the changes in the landscape of American fiction television productions born in the new century through the in-depth analysis of the current state of the new drama model and by applying this model to a paradigmatic science-fiction series of the time, Battlestar Galactica. Thus, we will try to demonstrate that there are new ways of thinking, making and consuming the television series, that the quality concept has been diluted by a wide and unifying new approach, and that Battestar Galactica is a unique product of its time that has allowed to bring marginal television genres to the new quality discourses, to finally legitimize the existence of the Third Golden Age of Television.

Introduction: One potential new therapy for epilepsy involves the omega-3 polyunsaturated fatty acids (PUFAs), and more specifically docosahexaenoic acid (DHA).   Methods: The anticonvulsant properties of the n-3 PUFAs were assessed in a series of different experiments. Subjects received chronic dietary supplementation, sub-chronic and acute injections of either fish oil (chronic) or DHA (sub-chronic, acute). Animals were tested in the electrical afterdischarge thresholds (ADTs) model in the amygdale and the maximal pentylenetetrazol (PTZ) model.   Results: Chronic, sub-chronic, and acute administrations of n-3 PUFAs were anticonvulsant in both the electrical stimulation and maximal PTZ models. In chronic experiments, amygala ADTs increased following 3 months of fish oil administration. Fourteen days of DHA i.p. injections increased latencies to maximal PTZ seizures. Acute injection of DHA s.c. and i.v. increased unesterified serum DHA and seizure latency. Conclusions: The present research suggests that n-3 PUFAs, and more specifically DHA, have anticonvulsant effects in vivo.

The Tim-3+ T cells in HIV infection are dysfunctional in proliferation or cytokine production. Here, we evaluated the effects of Tim-3 expression on the cytotoxicity of CD8+ T cells in HIV infection by examining 1) the ability of Tim-3+ CD8+ T cells to make perforin and 2) the direct ability of Tim-3+ CD8+ T cells to kill HIV infected CD4+ target cells. Tim-3+ CD8+ T cells maintained higher levels of perforin. However, these cells were defective in their ability to degranulate. Blocking the Tim-3 signalling pathway enhanced the cytotoxic capabilities of HIV specific CD8+ T cells by increasing: their degranulation capacity, their ability to release perforin, their ability to target activated granzyme B to HIV antigen expressing CD4+ T cells and their ability to suppress HIV infection of CD4+ T cells. Thus, the Tim-3 receptor can down-regulate the CD8+ T cell cytotoxicity through inhibition of degranulation and perforin/granzyme secretion.

Introduction: One potential new therapy for epilepsy involves the omega-3 polyunsaturated fatty acids (PUFAs), and more specifically docosahexaenoic acid (DHA).   Methods: The anticonvulsant properties of the n-3 PUFAs were assessed in a series of different experiments. Subjects received chronic dietary supplementation, sub-chronic and acute injections of either fish oil (chronic) or DHA (sub-chronic, acute). Animals were tested in the electrical afterdischarge thresholds (ADTs) model in the amygdale and the maximal pentylenetetrazol (PTZ) model.   Results: Chronic, sub-chronic, and acute administrations of n-3 PUFAs were anticonvulsant in both the electrical stimulation and maximal PTZ models. In chronic experiments, amygala ADTs increased following 3 months of fish oil administration. Fourteen days of DHA i.p. injections increased latencies to maximal PTZ seizures. Acute injection of DHA s.c. and i.v. increased unesterified serum DHA and seizure latency. Conclusions: The present research suggests that n-3 PUFAs, and more specifically DHA, have anticonvulsant effects in vivo.

The Tim-3+ T cells in HIV infection are dysfunctional in proliferation or cytokine production. Here, we evaluated the effects of Tim-3 expression on the cytotoxicity of CD8+ T cells in HIV infection by examining 1) the ability of Tim-3+ CD8+ T cells to make perforin and 2) the direct ability of Tim-3+ CD8+ T cells to kill HIV infected CD4+ target cells. Tim-3+ CD8+ T cells maintained higher levels of perforin. However, these cells were defective in their ability to degranulate. Blocking the Tim-3 signalling pathway enhanced the cytotoxic capabilities of HIV specific CD8+ T cells by increasing: their degranulation capacity, their ability to release perforin, their ability to target activated granzyme B to HIV antigen expressing CD4+ T cells and their ability to suppress HIV infection of CD4+ T cells. Thus, the Tim-3 receptor can down-regulate the CD8+ T cell cytotoxicity through inhibition of degranulation and perforin/granzyme secretion.

It has been demonstrated that EGCG and caffeine, naturally present in green tea, have thermogenic properties in thermoneutral conditions. The purpose of this study was to quantify the effect of the combined ingestion of EGCG/caffeine on thermogenic responses during a 3h mild cold exposure. Eight healthy males (22± 1 y) were exposed in a randomized, cross over, single blinded fashion to the cold (liquid conditioned suit perfused with 15°C water), after ingesting either a placebo (CON) or an extract of 1600mg of EGCG and 600mg of caffeine (EXP). Thermic, metabolic and electromyographic measurements were monitored at baseline and during cold exposure. After 180min of cold exposure, shivering intensity was significantly reduced by ~32% in EXP condition compared to CON. Area under the curve calculations for total shivering intensity was also reduced by ~21% in EXP (457±99 %MVC.min) compared to CON (361±81 %MVC.min; p=0.007). In contrast, the total area under curve of VO2 was ~25% higher in EXP (33.3±5.5 L O2) compared to CON (25.3±5.1 L O2; p=0.03). Total Heat production (Hprod) also increased by about 11% in the EXP condition (1535±112 kJ) compared to control (1372 ±106 kJ; p=0.002). The decrease in shivering activity combined with an increase in VO2 and Hprod, following the ingestion of EGCG and caffeine in the cold, indicates that nonshivering thermogenesis pathways can be significantly stimulated in adult humans.