143 research outputs found

    Mitochondrial Function, Oxidative Stress and Parkinson's Disease

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    The loss of the activity of mitochondrial respiratory chain (MRC) complexes, particularly complex I, has been implicated in Parkinson’s disease (PD) pathogenesis. However, it is still uncertain whether altered MRC activity is an early event in the pathophysiology of PD, or a late consequence of cellular stress. Therefore, this thesis contributes differently from other studies as to the ongoing investigations about MRC activity in PD post-mortem brain based on pathological severity. This study demonstrates that loss of complex I activity occurs in regions with both moderate and mild pathology in PD brain. Furthermore, multiple complex defects were noted in the moderate pathology region. However, the activity of complex II which is entirely encoded by nuclear DNA appeared to be preserved. The exact mechanism of multiple complex defects remain elusive. However, the possibility arises that impairment of complex I results in secondary damage to the other complexes. Here, neuroblastoma cells were employed to study the effect of pharmacologically induced MRC complex I deficiency upon the activity of the other complexes. In this model, rotenone-treated (100 nM; 24-48 hours) SH-SY5Y cells induced an inhibition of complex I. At 24 hours no effect was observed on the other complexes. However at 48 hours, multiple complex defects were noted, but the activity of complex II appeared to be preserved. Additionally, bioenergetics and glutathione status were compromised. By utilizing this model, the effectiveness of antioxidants in alleviating the progression of complex I deficiency on other complexes were also evaluated. Furthermore, the use of the Oxygraph-2K® instrument together with a step-wise protocol was developed to assess the integrated mitochondrial function in cultured SH-SY5Y cells. Additionally, the focus of attention was also to validate the fibroblast growth factor-21 ELISA assay. Based on the results, this assay appears to be a useful as a biomarker for mitochondrial dysfunction

    Oxidative Stress: Mechanistic Insights into Inherited Mitochondrial Disorders and Parkinson's Disease

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    Oxidative stress arises when cellular antioxidant defences become overwhelmed by a surplus generation of reactive oxygen species (ROS). Once this occurs, many cellular biomolecules such as DNA, lipids, and proteins become susceptible to free radical-induced oxidative damage, and this may consequently lead to cellular and ultimately tissue and organ dysfunction. Mitochondria, as well as being a source of ROS, are vulnerable to oxidative stress-induced damage with a number of key biomolecules being the target of oxidative damage by free radicals, including membrane phospholipids, respiratory chain complexes, proteins, and mitochondrial DNA (mt DNA). As a result, a deficit in cellular energy status may occur along with increased electron leakage and partial reduction of oxygen. This in turn may lead to a further increase in ROS production. Oxidative damage to certain mitochondrial biomolecules has been associated with, and implicated in the pathophysiology of a number of diseases. It is the purpose of this review to discuss the impact of such oxidative stress and subsequent damage by reviewing our current knowledge of the pathophysiology of several inherited mitochondrial disorders together with our understanding of perturbations observed in the more commonly acquired neurodegenerative disorders such as Parkinson’s disease (PD). Furthermore, the potential use and feasibility of antioxidant therapies as an adjunct to lower the accumulation of damaging oxidative species and hence slow disease progression will also be discussed

    Diagnostic challenge of intestinal obstruction secondary to Henoch–Schonlein purpura

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    Henoch–Schonlein purpura is the most common form of vasculitis in pediatric age group. Gastrointestinal manifestations have been long recognized as part of the disease, but usually preceded by other manifestations. We present a case of a boy whose initial manifestation of the disease was bowel obstruction and ischemia requiring surgical intervention twice with diagnostic dilemma prior to diagnosis of Henoch–Schonlein purpura. Although common surgical diseases prove to be the culprit in most cases, a surgeon should always keep an open mind for possibility beyond surgical diseases. Multidisciplinary approach to situations where ambiguities in diagnosis exist proves to be a valuable tool aiding surgical decision.Keywords: gastrointestinal, henochscholine, intestinal ischemia, intussusception, purpur

    Diagnostic challenge of intestinal obstruction secondary to Henoch–Schonlein purpura

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    Henoch–Schonlein purpura is the most common form of vasculitis in pediatric age group. Gastrointestinal manifestations have been long recognized as part of the disease, but usually preceded by other manifestations. We present a case of a boy whose  initial manifestation of the disease was bowel obstruction and ischemia requiring surgical intervention twice with diagnostic  dilemma prior to diagnosis of Henoch–Schonlein purpura. Although common surgical diseases prove to be the culprit in most cases, a surgeon should always keep an open mind for possibility beyond surgical diseases. Multidisciplinary approach to  situations where ambiguities in diagnosis exist proves to be a valuable tool aiding surgical decision.Keywords: gastrointestinal, henochscholine, intestinal ischemia, intussusception, purpur

    Simulation of ion behavior in an open three-dimensional Paul trap using a power series method

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    Simulations of the dynamics of ions trapped in a Paul trap with terms in the potential up to the order 10 have been carried out. The power series method is used to solve numerically the equations of motion of the ions. The stability diagram has been studied and the buffer gas cooling has been implemented by a Monte Carlo method. The dipole excitation was also included. The method has been applied to an existing trap and it has shown good agreement with the experimental results and previous simulations using other methods

    Perception of Faculty Members of Regional Medical School Toward Faculty Development Program

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    Introduction: Any types or process of activities that are performed by a group or an individual to enhance, promote, and improve the performance, competencies or skills of a health professional at an institute level are defined as faculty development which has many other names like staff development, academic development, and educational development. The importance of faculty development stressed by Harden is equivalent to curriculum development, which is a very difficult assignment. Objectives: To determine the pattern of faculty members’ perception toward their weekly faculty development program. Methodology: Enrolling the faculty members of the College of Medicine, University of Bisha, Kingdom of Saudi Arabia ( COM/UB,KSA). COM/UB adopting the innovative curriculum (problem-based learning, team-based learning, interactive lectures, and case-based learning and seminars. Each Tuesday, faculty members gather in the faculty development academic program (FDAP) room to discuss issues related to medical education and quality. Usually, there is a presentation on the selected topic over 25 min, followed by a discussion and workshop, and finally, a recommendation is drawn. The inclusion criterion is those staying in the college for a period of more than one year. New joiners and those staying for a period of less than one year were excluded. Faculty members were enrolled optionally and requested to fill a validated questionnaire. Results: The response rate was 92% of total staff. More than 89%, 87%, 86% and 74% thought that the FDAP is useful to them, helps them in addressing academic issues in the faculty, is an enriching experience, and thought that it helps them in constructing high-quality multiple choice questions (MCQs). Finally, 84% were interested in presenting topics in FDP. Conclusion: FDAP was positively perceived by the faculty members of the University Bisha/College of Medicine, since it enriches their experience and satisfies their academic job. Keywords: faculty, development, academic, program, MCQ

    Effect of Admission Type on the Risk of Bloodstream Infections among Critically Ill Patients with Peripherally Inserted Central Catheters in a Tertiary Center in Saudi Arabia

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    The purpose of the study was to evaluate the association between type of admission (medical versus surgical) with risk of central line associated bloodstream infection (CLABSI) in a university hospital setting. A retrospective analysis was performed on critically ill patients who had peripherally inserted central catheters (PICC) during the period between January 2010 and October 2012. Demographic data, duration of catheterization and type of admission were obtained from patien

    Benchmarking techno-economic performance of greenhouses with different technology levels in a hot humid climate

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    Greenhouse agriculture is expected to play a critical role in sustainable crop production in the coming decades, opening new markets in climate zones that have been traditionally unproductive for agriculture. Extreme hot and humid conditions, prevalent in rapidly growing economies including the Arabian Peninsula, present unique design and operational challenges to effective greenhouse climate control. These challenges are often poorly understood by local operators and inadequately researched in the literature. This study addresses this knowledge gap by presenting, for the first time, a comprehensive set of benchmarks for water and energy usage, CO2 emissions (CO2e) contribution, and economic performance for low-, mid-, and high-tech greenhouse designs in such climates. Utilising a practical and adaptable model-based framework, the analysis reveals the high-tech design generated the best results for economic return, achieving a 4.9-year payback period with superior water efficiency compared to 5.8 years for low-tech and 7.0 years for mid-tech; however, the high-tech design used significantly more energy to operate its mechanical cooling system, corresponding with higher CO2e per unit area (8.3 and 4.0 times higher than the low- and mid-tech, respectively). These benchmarks provide new insights for greenhouse operators, researchers, and other stakeholders, facilitating the development of effective greenhouse design and operational strategies tailored to meet the challenges of hot and humid climates

    Isolation and Genetic Characterization of Rift Valley fever virus from Aedes vexans arabiensis, Kingdom of Saudi Arabia

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    An outbreak of Rift Valley fever in the Kingdom of Saudi Arabia and Yemen in 2000 was the first recognized occurrence of the illness outside of Africa and Madagascar. An assessment of potential mosquito vectors in the region yielded an isolate from Aedes vexans arabiensis, most closely related to strains from Madagascar (1991) and Kenya (1997)
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