Functional elucidation of lactate dehydrogenase in Toxoplasma gondii by double-stranded RNA gene suppression mediation.

Toxoplasma gondii is an intracellular parasite of humans and other mammals which can differentiate between an active and a dormant form. Our primary interest was to modulate gene expression in T. gondii in order to investigate a putative gene function. The capability of double-stranded RNA to down-regulate gene expression has been demonstrated in various organisms but has yet to be demonstrated in intracellular organisms such as T. gondii. Therefore, the effect of in vitro synthesized double-stranded RNA was first investigated for the down-regulation effect of the homologous gene in T. gondii. Three non-essential marker genes which encode the green fluorescent protein, uracil phosphoribosyl transferase and hypoxanthine-xanthine-guanine phosphoribosyltransferase were used in the study. Double-stranded RNA was efficiently electroporated into the parasites and specifically lowered the expression of the homologous marker gene. The down-regulation effects can be observed for three successive propagations of the parasites, suggesting the potential use of double-stranded RNA in T. gondii. Subsequently, the down-regulation effect of double-stranded RNA was further characterized in transgenic T. gondii expressing double-stranded RNA. We constructed a plasmid coding for double-stranded RNA homologous to the uracil phosphoribosyl transferase gene. A stable parasite line with down-regulated uracil phosphoribosyl transferase expression was generated and shown to have lowered levels of the corresponding transcript as compared to wild type parasites. The steady state level of the expressed double-stranded RNA was quantified and correlated to that of the homologous mRNA in order to estimate the copy number of double-stranded RNA which can effectively exhibit the down-regulation effect. Most importantly, the double stranded RNA was used for functional elucidation of lactate dehydrogenase which has long been hypothesized to be essential for parasite metabolism and differentiation. We generated stable transgenic parasite lines in which the expression of lactate dehydrogenase was knocked-down by double-stranded RNA. The differentiation processes of these parasite lines were impaired. In vivo studies in a murine model system revealed that these parasite lines were unable to establish a chronic infection. This study was the first to demonstrate that lactate dehydrogenase expression is essential for parasite differentiation.Dept. of Chemistry and Biochemistry. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2005 .A43. Source: Dissertation Abstracts International, Volume: 66-11, Section: B, page: 5953. Thesis (Ph.D.)--University of Windsor (Canada), 2005

Exploring the Utilization of Non-Invasive Methods for Assessing Health Statusof Patients with Chronic Respiratory Inflammation within the United ArabEmirates

Asthma is defined as the chronic inflammation of the large airways that is characterized by reversible airflow obstruction and airway hyper-responsiveness. On the other hand, Chronic Obstructive Pulmonary Disease (COPD) is a chronic inflammation that is marked by progressive and irreversible airflow obstruction. Both conditions are manifested by symptoms of wheezing, coughing, and shortness of breath. Similarity in symptoms between these two conditions could lead to misdiagnosis and mistreatment. Although inflammation is present in both conditions, there are some marked differences. The main difference is that inflammation in asthma is an IgE mediated and involves the release of histamine while it is absent in the case of COPD. There is now a new trend for measuring the content of exhaled nitric oxide as a marker for assessing airway inflammation and especially for asthma diagnosis and monitoring. This study aimed at utilizing biomarkers to differentiate between the different types of respiratory inflammations. In this study, 23 patients with asthma, 20 with allergic rhinitis, 10 with COPD, and 17 healthy controls were recruited into the study at a local hospital clinic and assessed based on the level of their exhaled nitric oxide (eNO), serum specific IgE antibodies, and relative blood eosinophilia count. The results demonstrated that the many asthmatics (74%) had high eNO levels, while only 25% of patients with allergic rhinitis, 10% of those with COPD, and 6% of the healthy individuals similarly had elevated eNO levels. The results confirmed the fact that exhaled nitric oxide could be an effective parameter for differentiating asthma from other allergic diseases (e.g. allergic rhinitis) and other respiratory inflammations (COPD)

Concerns Regarding Food Biotechnology: An Ongoing Debate

The development of agricultural biotechnology has led to the production of numerous types of genetically modified crops with improved traits. The prevalence of genetically modified food is increasing globally. The Rapid progress in the development of genetically modified food has significantly however increased public concern about food safety in recent years. The appearance of such foods in the global market has lately resulted in debate and scientific discussion. This debate is likely to continue, probably in the broader context of other uses of biotechnology and their consequences for human societies. To date, regulations and policies which mandate the labeling of genetically modified food are strictly adhered to in many countries to allow consumers both right for knowledge and freedom of choice. Nonetheless, several countries have not yet implemented policies that would oblige food producers to label modified food products. Main concerns about the safety of genetically modified food include allergenicity, emergence of antibiotic resistance and out-crossing of wild type crop. On the other hand, genetically modified crops can successfully reduce maturation time and improve quality by increasing tolerance to stress and some plant diseases. In fact many debate and believe that genetically modified food is the solution of world hunger because it increases food security every day and guarantees adequate nutrition. The debate would likely continue in the future but until clear evidence is provided, all concerns can be considered relative and dealt with transparency and objectivity to reveal both the good and evil side of biotechnology

Sun Exposure and Behavioral Activation for Hypovitaminosis D and Depression: A Controlled Pilot Study

© 2017, Springer Science+Business Media, LLC, part of Springer Nature. Several independent meta-analytic reviews suggest a relationship between vitamin D (VTD) deficiency and depressive symptoms. Theoretically, behavioural withdrawal (staying home, discontinuing outdoor activities etc.) is likely to exacerbate VTD deficiency. This pilot study assessed the efficacy of a modified form of behavioral therapy designed to simultaneously target VTD deficiency and depressive symptoms. College women (N = 114), all citizens of the United Arab Emirates, were screened for depressive symptoms and VTD deficiency. Those participants who were severely VTD deficient and experiencing clinically significant depressive symptoms, were randomly allocated to either a 12-week program of behavioral activation, emphasizing safe-sun exposure (N = 10), or a waiting list control group (N = 10). At time 2 the sun exposure and behavioral activation (SEBA) group showed a significant increases in 25-hydroxyvitamin D and were, on average, no longer VTD deficient, whereas the control group deteriorated in terms of VTD. Similarly positive results were observed for depressive symptoms. Sun exposure and behavioral activation (SEBA) may be an effective approach to improving VTD status and alleviating depressive symptoms

Comparative Internal Pressure Evolution at Interfaces of Activated Carbon for Supercapacitors Containing Electrolytes Based on Linear and Cyclic Ammonium Tetrafluoroborate Salts in Acetonitrile

In this study, the real-time increase in pressure of the accumulated gases at the electrode/electrolyte interface serves as a safety criterion for four conductive electrolytes comprising acetonitrile (ACN) and organic salts. They include tetrafluoroborate as an anion and cyclic 1,1-dimethylpyrrolidinium (Pyr11+), spiro-(1,1′)-bipyrrolidinium (SBP+), acyclic methyl triethyl ammonium (Et3MeN+) or standard tetraethylammonium (Et4N+) as cations. The main focus lies on the SPBF4/ACN system. While the concentrated Pyr11BF4/ACN exhibits a minimal pressure evolution (≈25 Pa) under ambient conditions at 3.0 V, its electrochemical stability is inferior to SPBF4 at high operating voltage. The electrolytes with acyclic tetrafluoroborate salts (1.0 mol L−1) reveal a 20-fold increase in pressure due to the weak salt-ACN interactions and the subsequent high solvent evaporation. The pressure evolution at the interface of activated carbon/electrolyte in electrochemical double layer capacitor (EDLCs) is merely related to the operating voltage and cation nature, viz. Pyr11+ < SBP+ < Et4N+ < Et3MeN+. The fixed specific capacity of 109 F g−1, volumetric capacity of 76 F cm−3, and moderate gas generation (≈190 Pa at 3.0 V, that shifts to ≈400 Pa at 3.4 V) confirm the safe character of the SPBF4/ACN electrolyte for such energy storage devices

Adolescent Mental Health in the Middle East and North Africa (MENA): Where Are We and Where Do We Go from Here?

Childhood and adolescence are time periods for human brain development and growth. Neuroimaging studies show that white matter volume and integrity increases throughout childhood and adolescence, with the frontal and temporal regions of the brain undergoing pronounced changes in adolescence (Tamnes et al. 2010). Decreases in frontal and temporal gray matter volume during adolescence result from environmental influences, as well as increasing white matter, the latter being essential as a transport mechanism of vital brain connections (Giedd et al. 1999). In parallel to these physiologic changes, marked cognitive changes include increases in abstract thought and reasoning (Piaget et al. 1977), improvements in IQ and working memory (Ostby et al. 2011), better problem solving and planning (Squeglia et al. 2013), and maturation of perspective taking (Sebastian et al. 2012). These changes suggest that the human brain exhibits heightened neural plasticity during adolescence, defined as the brain ability to adapt to internal or external changes. Environmental exposures and influences during adolescence determine these changes. For example, contextual neighborhood features such as the absence of opportunities for physical activity or an abundance of vaping stores influence adolescents to exhibit health risk behaviors such as sedentary lifestyles and drug use, which in turn influence the development of health outcomes, such as obesity and mental disorders. Fuhrmann et al. (2015) highlighted adolescence as a sensitive period of development where brain changes may be particularly susceptible to environmental influences, such as drugs, social stress, or cognitive training

The Environmental Impact of Urbanization within Abu Dhabi on the Microbial Profile of Man-Made Beaches

The United Arab Emirates (UAE) is witnessing a significant development in several areas. Many new construction projects are currently underway. One of the main project aims at establishing new beaches around the coastal areas of the UAE. Particularly, in Abu Dhabi the capital of UAE, a new man-made beach has been recently developed in the north coast of the city. The urbanization of this newly developed beach might have a significant impact on the environment. This study aims to investigate the effects of urban development of beaches within Abu Dhabi on the microbial profile of the soil. It is hypothesized that microbial growth would be higher in man-made beaches as compared to natural beaches. Methodology involved collection of 16 soil samples from two different beaches with emphasis on two elements: water content in soil and depth of soil. Subsequently, samples were processed and used for microbial cultivation using selective and differential growth media for the identification of some commonly encountered microorganisms namely yeast, faecal coliforms, Escherichia coli and Staphylococcus aureus . Polymerase Chain Reaction (PCR) and electrophoresis were also used for further analysis. Results of the study revealed the existence of Staphylococcus aureus, Escherichia. coli and coliforms in the soil samples isolated from the man-made beach. Moreover, the hypothesis was supported by the results which showed higher microbial growth (CFU/g) for both factors: (depth of the soil and water content) for man-made beaches as compared to natural beaches

Deep Eutectic Mn(NO3)2−H2O Binary System as a Safe, Cost-Effective, and Efficient Electrolyte for Supercapacitor Applications

Deep eutectic solvents (DESs) have proved to be an effective substitute for conventional electrolytes for energy storage applications because of their unique properties and ability to adapt them to specific applications. In this regard, this study examines an easy-to-produce, widely available and cheap manganese nitrate concentrated electrolyte that holds DES traits. The electrolyte (i. e., manganese nitrate; (Mn(NO3)2 ⋅ 6H2O with a weight composition of 42 %) revealed its eutectic behaviour by benchmarking the eutectic distance (53 °C), thermal expansion coefficient (3.9×10−4 K), activation energy for conductivity (∼2.45 kJ mol−1), and viscosity (14 kJ mol−1). What's more, it was successfully incorporated into a two-electrode symmetric supercapacitor comprising activated carbon electrodes and demonstrated specific capacitance retention of 93 % (170 F g−1) through 2000 consecutive galvanostatic charge-discharge cycles at 25 and −20 °C

Knowledge about Vitamin D among Women in the United Arab Emirates

Vitamin D deficiency is a significant public health issue as it affects almost 90% of the United Arab Emirates (UAE) population. A bigger portion of this percentage is women due to the physiological changes throughout their life cycle. This study aims to assess the knowledge about vitamin D among women in the UAE. This is a quantitative cross-sectional study. Using snowball sampling, an electronic questionnaire was sent to women aged 18 years and above. Overall, 1537 women completed the questionnaire. The participants had mean scores of 49.4 ± 10.7 and 59.6 ± 14.6 for general and nutritional knowledge, respectively. Factors associated with higher scores included older age, marriage, higher educational level, and having tested their vitamin D levels. Factors associated with lower scores included the history of a chronic illness and being employed. Findings indicate that women in this study showed a low level of vitamin D knowledge specifically regarding the non-skeletal benefits of vitamin D and factors that affect vitamin D synthesis. Therefore, health education and promotion programs must be implemented across the UAE to improve overall awareness about vitamin D