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Qatar Foundation Annual Research Forum Volume 2013 Issue 1
- Conference date: 24-25 Nov 2013
- Location: Qatar National Convention Center (QNCC), Doha, Qatar
- Volume number: 2013
- Published: 20 November 2013
201 - 250 of 541 results
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Protective role of 4-phenylbutyrate against palmitate-induced endoplasmic reticulum stress and renal cell injury
More LessBackground and Objectives: Obesity is recognized as a significant risk factor for the development of chronic kidney disease (CKD). Emerging studies indicate that endoplasmic reticulum (ER) stress play a major role in obesity-induced renal damage and the development of CKD in obese patients. Therapeutic interventions to ameliorate ER stress using 4-phenylbutyrate (4-PBA), a chemical chaperone, have been shown to prevent obesity-induced organ damage in the liver and pancreas. Thus, the goal of this study was to investigate the protective role of 4-phenylbutyrate (4-PBA) against palmitic acid (PA)-induced ER stress and renal cell injury using normal rat kidney (NRK-52E) cells. Methods: NRK-52E cells were divided into four groups: Control, PA-treated, 4-PBA-treated, and 4-PBA+PA co-treated. Cells were exposed to 250 µM PA with or without 5 mM 4-PBA for 24 hours, and compared against the control. Western blotting was performed to determine the expression of ER stress markers - glucose-regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP) in NRK-52E cells. The cytoprotective effect of 4-PBA on PA-induced NRK-52E cell injury was assessed by cell viability measurements and caspase-3/7 activity assay. Results: PA treatment in NRK-52E cells significantly reduced the cell viability (85% to that of the control; P-value < 0.05), increased caspase-3/7 activity (2-fold increase to that of control; P-value < 0.05), and caused profound ER stress - evidenced by induction of GRP78 and CHOP (1.6 and 2 folds of control respectively; P-value < 0.05). Treatment with 4-PBA significantly protected the cells from PA-induced cell death (93.4% vs. 81.3% cell viability in PA treated group; P-value < 0.05), and normalized the activity of caspase-3/7 and the expression of ER stress markers - GRP78 and CHOP. Conclusion: 4-PBA inhibits ER stress and protects renal cells against PA-induced apoptotic cell injury. Further studies are required to ascertain the clinical utility of 4-PBA to prevent renal injury and the development of CKD in obese patients.
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The Impact Of Viral Evolution And Frequency Of Variant Epitopes On Primary And Memory Hiv-1-Specific Cd8+ T Cell Responses
By Nada MelhemIt is not clear if HIV-1 variants lose the ability to prime naïve CD8+ cytotoxic T lymphocytes (CTL) during progressive, untreated infection. Answering this question is important for developing immunotherapeutic approaches for enhanced control of residual HIV-1 infection in persons on combination antiretroviral therapy (cART). We therefore conducted a comprehensive longitudinal analysis of viral evolution and its impact on primary and memory CD8+ T cell responses pre-seroconversion (SC), post-SC, and during cART. We report the emergence of variant sequences in Gag, Env, and Nef at early (0-3 yr) and late (3.3-7.8 yr) times following SC, and after ART (>8 yr). Memory T cell responses targeting autologous virus variants reached a nadir by 8 yr post-SC along with the development of AIDS. This was followed by a transient enhancement of anti-HIV-1 CTL responses upon initiation of cART. The frequency of epitope variants was clearly associated with the breadth but not the magnitude of memory T cell responses. Our study reveals that the immune system retained its capacity to induce broad and high magnitude, primary T cell responses to late variants in pre-SC T cells, comparable to primary anti-HIV-1 responses induced in T cells from HIV-1 uninfected persons. Consequently, despite evolutionary changes in HIV-1, CD8+ T cells can still be primed to viral variants. Hence, vaccination against late, mutated epitopes could be successful in enhancing primary reactivity of T cells for control of the residual reservoir of HIV-1 in persons on ART.
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Coronary artery bypass graft patients in Qatar: Possibly the youngest with the highest incidence of diabetes in the world
More LessCoronary Artery Disease in Qatar: Coronary artery bypass graft (CABG) - population possibly the youngest with the highest incidence of diabetes in the world. CS Carr, M Abdulsamad, AM Alkhulaifi Objective: Coronary artery disease is a potentially life-threatening condition. At the Heart Hospital we have an internationally established surgical database to collect data on our cardiac surgical patients. We studied our isolated CABG patients in terms of demographics, rate of diabetes, left ventricular function, and percentage of glycosylated haemoglobin (marker of blood sugar control). Methods: Data were collected from isolated CABG patients (September 2011 until March 2013) at the new Heart Centre in Qatar. Data were derived from theatre logs, the 'Dendrite' surgical database and the Hospital Information System, A standard statistical package was used for analysis. Results: There were 314 patients who underwent isolated CABG within the 18 month study period. 287 (91%) were male; the average age was 55.87 years (55 mean, 58 mode, 55 median). 188 (60%) patients were of Indian Subcontinent origin with the overall ethnicity represented in table 1. Table 1: Distribution of ethnic origin of the CABG patients. 213 patients had a diagnosis of diabetes mellitus (68% of the CABG patients). The glycosylated haemoglobin (HbA1C) was measured in 88% (275 out of 314 patients) of the CABG patients (213 of the diabetic patients). The average value was 7.66 (normal value <6%). The range of values for our patients is shown in figure 1. Figure 1: Distribution of HbA1c for the diabetic patients. The ejection fractions for the patients are divided into good, moderate and poor. The proportions of each group are shown in figure 2. Figure 2: Pie chart representation of the distribution of pre-operative ejection fractions of the CABG patients. Conclusions: Our CABG population appears to be very young (compared to the European Association of Cardiothoracic Surgeons, EACTS, 2010 data book, data for 29 countries). Our rate of diabetes is extremely high at 68% and has extremely variable sugar control. Mass screening for diabetes and early tight control may have a considerable impact on our general population in terms of long term health and financial burden on the health services.
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Vitamin D Suppresses Hepcidin Expression In Macrophages
More LessBackground: Anemia of chronic disease (ACD) is highly prevalent among subjects with chronic kidney disease (CKD), rheumatoid arthritis, diabetes mellitus, and cancer as well as in elderly subjects. ACD is also highly associated with infections, severe trauma and critical illness. Anemia of chronic disease is immune driven and is associated with decreased quality of life, and increased mortality. Iron is an essential nutrient for erythropoiesis and its metabolism is altered in ACD. Macrophages play a central role in iron homeostasis by engulfing senescent and damaged red blood cells (RBCs), and recycling iron daily in a process known erythrophagocytosis. Hepcidin, a master iron regulating hormone, prevents iron egress from macrophages and thus prevents normal recycling of the iron needed to support erythropoiesis. Hepcidin binds to ferroportin, the only known iron exporter, leading to its internalization and degradation and consequent iron retention in macrophages. Cytokines like IL-1β and IL-6 are commonly elevated in chronic diseases and stimulate hepcidin production from the liver and macrophages. Circulating hepcidin levels are increased in patients with chronic diseases and recently found to be inversely correlated with vitamin D status. Purpose: To investigate whether vitamin D (1,25(OH)2D) regulates the hepcidin-ferropotin axis in macrophages and thus improves iron egress to circulation to ameliorate ACD. Study design and Results: We sought to examine whether 1,25(OH)2D decreased local expression of hepcidin and increased ferroportin expression in human monocyte/macrophage cell line. THP-1 cells were cultured in the presence of increasing concentrations of 1,25(OH)2D prior to incubation with lipopolysaccharide (LPS (20ng/ml)), a known stimulator of hepcidin, to mimic an inflammatory state found in ACD. We performed RT-PCR to quantify the changes in mRNA expression in these cultured cells. We found that 1,25(OH)2D statistically decreased the mRNA expression of hepcidin and increased the expression of ferroportin in a dose dependent manner. These preliminary data strongly suggest that vitamin D plays a crucial role in macrophage recycling of iron by increasing expression of ferroportin. Although the liver is the primary source of hepcidin, we found that vitamin D also inhibited hepcidin expression in THP-1 cells. We performed in silico analysis on hepcidin promoter; however, no vitamin D response element (VDRE) consensus was identified in hepcidin promoter. Therefore, vitamin D indirectly suppresses hepcidin expression. We examined whether vitamin D may decrease inflammatory cytokines that stimulate hepcidin expression. We measured cytokine release from THP-1 cells cultured in the presence of increasing concentrations of 1,25(OH)2D prior to LPS exposure and found a dose dependent decrease in IL-1β and IL-6 release suggesting that vitamin D suppresses hepcidin expression by lowering pro-hepcidin cytokines. Conclusion: Our in vitro studies show that vitamin D regulates hepcidin-ferroportin axis in macrophages which facilitates iron egress. Thus vitamin D deficiency may contribute to the pathogenesis of ACD. To translate our finding, we are currently conducting a double-blind, randomized, placebo-controlled trial, in subjects with early chronic kidney disease supplemented with oral high dose vitamin D or matching placebo for one year.
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Metformin Protects Against Glucose-Induced Mouse Microvascular Endothelial Cell (Mmec) Death
By Hong DingBackground and Objectives: Type 1 and type 2 diabetes are associated with an elevated incidence of cardiovascular disease. An early indicator of cardiovascular disease is endothelial dysfunction wherein there is a blunted blood flow response following activation of the endothelium. The elevated blood glucose associated with diabetes is thought to be a key factor associated with endothelial dysfunction and, in particular, the development of microvascular disease. Elevated blood glucose also has a negative effect on endothelial cell survival and thus enhances the ageing effect of diabetes on cardiovascular function. Clinical data suggests that metformin, a widely used orally effective hypoglycaemic drug, has an endothelial cell protective action. Metformin may also be beneficial in preventing endothelial cell death via a cellular pathway(s) that involves the activation of AMP-activated kinase (AMPK) - a master metabolic sensor for glucose and lipid metabolism. However, a link between metformin and AMPK and a protective action against high glucose-induced microvascular endothelial cell death has not been established. Methods: In the current study, we designed experimental protocols utilizing cell cultures of mouse microvascular endothelial cells (MMECs) that were exposed to high glucose, 40 mM, equivalent to those observed in the db/db mouse model of type 2 diabetes and in the absence and presence of metformin. Results: Exposure of the MMECs to high glucose for 48 h decreased the phosphorylation of AMPK and activated the endoplasmic reticulum (ER) stress and caspase-dependent apoptotic pathways. The presence of metformin (100 micromole/l) enhanced the phosphorylation of AMPK and prevented the activation by high glucose of the ER stress and caspase-dependent apoptotic pathways. Conclusion: Taken together, these data indicate that metformin, in addition to it's well known hypoglycaemic action, may also be beneficial for the improvement of endothelial cell survival via the up-regulation of AMPK and the down-regulation of ER stress and caspase-dependent apoptotic pathways. Further studies are required to fully elucidate the cellular pathways involved and determine the clinical implications. Supported by NPRP 5-149-3-040 and NPRP 4-910—3-244
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Beliefs and values influencing breast cancer screening practices of Arabic-speaking women in Qatar
More LessIntroduction: Similar to many countries in the world, breast cancer is the most common cancer among women in the State of Qatar and the incidence rate is rising. Previous findings indicate women in Qatar are often diagnosed with breast cancer at advanced stages and their awareness of breast cancer screening (BCS) services and participation rates in screening activities are low. Previous studies indicate the need to understand the many complex beliefs, values, and attitudes that influence Arabic women's health seeking behavior for the development of culturally-appropriate awareness and effective intervention strategies to address breast cancer in Qatar. This study investigates beliefs and attitudes about breast cancer and BCS activities in Qatar and how it relates to their screening practices. Methods: A multi-center, cross-sectional quantitative survey of 1,063 (87.5% response rate) female Qatari citizens and Qatari Arabic-speaking residents, 35 years of age or older, was conducted in Qatar from March 2011 to July 2011. Results: In addition to low levels of awareness and participation rates in BCS (13.9% of participants reported performing a monthly BSE, 31.3% had a CBE within the last 1-2 years, and 26.9% of participants 40 years of age or older had a mammogram done within the last 1-2 years), less than half of the women interviewed believed breast cancer can be prevented. The majority of women participants want to know if they have breast cancer and would make an appointment for a mammogram if their HCP suggested it. The main reasons for not planning BCS were fear and embarrassment. Other factors related to BCS practice indicate women with self-perceived good and excellent health, who believe cancer can be prevented, and do not believe cancer is due to God's punishment or bad luck, were more likely to practice BCS. Conclusion: A variety of channels (health care providers, media, breast cancer survivors, and religious leaders) should be utilized to create culturally-appropriate intervention programs to raise awareness of breast cancer, BCS, and the benefits of early detection of breast cancer to help reduce mortality rates amongst Arabic-speaking women living in the State of Qatar. Awareness campaigns must emphasize that cancer can be prevented and treated if detected in its early stages. In addition, including religiously and culturally appropriate messages/teachings as part of awareness campaigns is important components to sustaining intervention strategies that address breast cancer amongst Arabic-speaking Muslim women.
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HIV sero-discordancy can be predictive of HIV infectiousness in sub-Saharan Africa
More LessIntroduction: The majority of the population in reproductive age across sub-Saharan Africa is engaged in stable couples. At least half of the couples affected by HIV are sero-discordant (SDCs), that is couples where one of the partners is HIV infected while the other is not, with potential for HIV within-couple transmission. Countries of sub-Saharan Africa are characterized by varying levels of HIV sero-discordancy. HIV infectiousness also appears to vary across the continent. Understanding the link between the levels of HIV sero-discordancy and HIV infectiousness is important for understanding HIV epidemiology and informing HIV prevention efforts. Methods: We constructed a mathematical model that describes HIV transmission dynamics among a nationally-representative cohort of the population in reproductive age in 23 countries in sub-Saharan Africa. The purpose of the model is to understand analytically the link between HIV sero-discordancy and HIV infectiousness. HIV sero-discordancy was defined as the proportion of SDCs out of all stable couples affected by HIV (Pdiscord) in the population. The model was parameterized using nationally-representative empirical epidemiological and demographic measures derived from the Demographic and Health Survey data for each of the analyzed countries, along with state-of-the art empirical data for HIV natural history. Sensitivity analyses were also incorporated. Results: Our results revealed a strong functional dependence of HIV infectiousness on HIV sero-discordancy. The risk of HIV transmission among SDCs decreased following a non-linear pattern as Pdiscord increased. The non-linear relationship was characterized by a sharp decrease in HIV infectiousness as Pdiscord increased from zero up to nearly 50%. A transitional region followed where the dependence of HIV infectiousness on Pdiscord stabilized. Eventually, HIV infectiousness was slowly varying, with values of Pdiscord exceeding 50% not leading to major declines in infectiousness. Countries of sub-Saharan Africa clustered either in the transitional region around Pdiscord of 50% or in the asymptotic region well above Pdiscord of 50%. We did not identify any country in the highly non-linear region of Pdiscord well below 50%. Our sensitivity analyses with respect to other parameters in the model affirmed these findings. Conclusions: Our findings suggest that the observed levels of HIV sero-discordancy across the African continent can be predictive of HIV infectiousness among stable couples, and suggest that countries fall into two HIV infectiousness domains of high and low infectiousness. Mapping HIV sero-discordancy can inform HIV prevention programs on "hotspot" areas of potentially higher HIV infectiousness.
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Auto-Regulation And Cerebral Blood Flow In Tia Patients Attending A Stroke/Tia Clinic: Implications For Stroke Prevention In Qatar
More LessBackground and objectives: Cerebral auto-regulation is an intrinsic protective mechanism guaranteeing hemodynamic integrity of cerebral circulation. It modulates cerebral blood flow (CBF) in order to meet regional perfusion demands despite variations in arterial blood pressure. Impaired cerebral auto-regulation is associated with poor functional and prognostic outcomes in patients with ischemic stroke. The aims of this study are to: (i) correlate CBF and cerebral auto-regulation with microalbuminuria in TIA patients; and (ii) assess the prognostic outcomes of such impairment. Methods: Blood flow in the middle cerebral artery was measured on both sides of the brain, using a trans-cranial Doppler. Cerebral auto-regulation was estimated non-invasively by calculating the correlation coefficient between slow changes of arterial blood pressure, evaluated by finger plethysmograph, and slow changes of cerebral blood flow velocity measured with trans-cranial Doppler. Microalbuminuria was measured first by calculating the Albumin/Creatinine Ratio (ACR). Then 24hr urinary protein was collected to calculate total urine albumin excreted in 24hr. Urine samples with microalbuminuria (30-300mg/24hr) and with normal levels of albumin (<30mg/24hr) were also examined (using SDS-PAGE electrophoresis). Protein bands were identified by their rate of migration in comparison with standard molecular weight markers. The presence of albumin was confirmed further by immuno-blotting (Figure-1). Results: The SDS-gel, revealed the presence of three unknown protein bands (Figure-2). Band (A) is heavily stained, representing albumin. Specimens collected from patients 2, 5, 8 and 9 reveal a particularly dense band, and this is supported by the biochemical assay results, which estimated protein content at 35mg/L for sample 9, 40mg/L for sample 5, and 80mg/L for samples 2 and 8. Band (B) was shown in three of the urine samples, namely from patients 2, 5, and 8. Its position on the gel is roughly equidistant between bands A and C. Band (C), denoting a slower migration band, representing Tamm-Horsfall protein. Tamm-Horsfall protein is suspected since not only is it the most abundant protein in urine after albumin, but also its position is in concordance with the relative molecular weight of Tamm-Horsfall protein (between 85 and 110kDa). The intensity of this band is generally not as great as band A. Conclusions: This study has just started in Qatar and the UK. The outcomes will enable us to answer the following questions: Whether testing for cerebral auto-regulation in Stroke/TIA clinics will help in identifying a subgroup of TIA patients who are at grave risk of developing microvascular and macrovascular diseases, including stroke. Do TIA patients with impaired cerebral auto-regulation and microalbuminuria have more vascular events than TIA patients with normal cerebral auto-regulation without microalbuminuria? Is there any statistically significant difference in the short-term (3-6 months) and long-term (3 years) prognosis (between the two groups of TIA patients? Whether there is any correlation between CBF/auto-regulation and microalbuminuria in TIA patients with microalbuminuria. Whether post TIA stroke is independently affected by impaired cerebral auto-regulation, taking into account other confounding factors that might affect the outcome of this study (such as diabetes, hypertension, age, other cardiovascular co-morbidity).
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HIV Nef expression in an AIDS mouse model favors the accumulation of CD4+ Treg cells which retain important suppressive functions
By Zaher HannaHIV-1 infection causes depletion and/or dysfunction of distinct CD4+ T cell subsets and may affect these differently. Regulatory CD4+ CD25Hi Foxp3+ T cells (Treg) represent a distinct CD4+ T cell subset with suppressor activity. These cells play an important role in the regulation of self-tolerance and autoimmunity, and in the regulation of immune responses against cancerous tumors and pathogens. During HIV infection, several studies have reported abnormalities of CD4+ Treg in blood and/or lymphoid organs. However, it has not been possible to firmly establish whether Treg are beneficial or pathogenic to the host during HIV infection. Because much remains to be learned about Treg in the context of HIV-1 infection, and because the mouse has so far been one of the best models to study the biology of Treg, we hypothesize that a study on Treg in a mouse model of AIDS may facilitate our understanding of their role in this disease. In the present study, we used the CD4C/HIVNef transgenic (Tg) mouse model to investigate Treg disturbances and characteristics. These Tg mice express Nef under the regulation of the upstream elements of the human CD4 gene and develop a very severe AIDS-like disease. In particular, they exhibit abnormal development of thymic CD4+ T cells, loss and enhanced apoptosis of CD4+ T cells and activation of CD4+ and CD8+ T cells. We report that HIV-1 Nef in this Tg mouse model causes depletion of total CD4+ T cells, but preserves and relatively enriches CD4+ Treg. We found that Nef-mediated CD4+ Treg enrichment is the direct result of Nef expression in CD4+ T cells and occurs independently of Nef-induced lymphopenia. Tg CD4+ Treg accumulation likely results from multiple mechanisms: lower apoptosis, enhanced cell division and increased generation from precursors. Interestingly, Tg CD4+ Treg enrichment could be reversed by enhancing Lck activity. Most importantly, we show that, in contrast to Tg helper CD4+ T cells which have lost their function, Nef-expressing CD4+ Treg retain their regulatory function in vitro and also in vivo, under some settings. In particular, we found that Treg prevent expansion of Tg B and non-Treg T cells in vivo. Our study reveals that Nef affects distinct CD4+ T cell subsets differently and uncovers the high proliferative potential of B and non-Treg T cells in this mouse model.
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Epidemiology of candidemia in Qatar: Performance of MALDI-TOF MS for identification of candida species, species distribution, outcome and susceptibility pattern
More LessBlood stream infections due to Candida species cause significant morbidity and mortality in health care settings. This surveillance analysis describes the epidemiology, trend in species distribution and outcomes of candidemia in patients at Hamad hospital, Doha, Qatar. From January 2004 to December 2010, a total of 187 patients with 201 episodes of candidemia were identified. C. albicans was the most common species isolated 33.8% (n=68), whereas non-albicans Candida species represented 66.2 % (n=133) of the episodes. The latter consisted of C. glabrata 18.9% (n=38), C. tropicalis 17.9% (n=36), C. parapsilosis 16.9% (n=34), C. orthopsilosis 4% (n=8) and C. dubliniensis 1.5% (n=3). Rare occurring cases of Pichia kudriavzevii , Meyerozyma guilliermondii, Clavispora lusitaniae, Wickerhamomyces anomalus and C. pararugosa (n=2 each) caused (4.9%) of infections. Uncommon yeast species such as C. intermedia, Yarrowia lipolytica, Kluyveromyces lactis , Lidnera fabianii, and Loddermyces elongisporus were found in single cases of candidemia (2.4%). The species distribution and outcome of candidemia showed a difference in crude mortality between patients infected with C. albicans (n=30, 45.5%) and non-albicans Candida species, e.g. C. parapsilosis candidemia was associated with the lowest mortality rate (40.6%), and patients with other non-albicans species had the highest mortality rate (68-71.4%). High mortality rates were observed among pediatric (<1year) and elderly patients (>60 years). All strains showed low MICs (≤ 1%) to isavuconazole. Overall reistance to voriconazole in vitro antifungal activity was 2.5%. Higher resistant rates were only observed for itraconazole (10.9%), C. glabata (n=38) was susceptible dose dependent to fluconazole. Except 0.5%, all isolates were susceptible to anidulafungin and 81.1% to caspofungin. Resistance to anidulafungin was detected in 1/8 (12.5%) isolates of C. orthopsilosis. According to new CLSI breakpoints, C. glabrata n=38 showed 100% resistance, and 37/68 (54.4%) of C. albicans were SDD to caspofungin. Identification by MALDI-MS was 100% in concordance with molecular identification.
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QBB: The first Qatar public biobank: Participant feedback and observations
By Nahla AfifiQatar Biobank (QBB), the first very large scale, long-term public biorepository in Qatar, is designed to build a powerful research infrastructure for future investigations of the lifestyle, metabolic and genetic risk factors for the most frequent medical conditions in Qatar, namely diabetes, cardiovascular and respiratory diseases, obesity and cancer. Qatar Biobank's recruitment approach provides a model for public involvement in biomedical research. Through inviting the public to contribute, Qatar Biobank promotes Qatar as dedicated to raising awareness and committed to engaging the community in shaping the health of their future generations. During the pilot phase, between December 2012 and June 2013, 503 participants have completed their baseline visit at the QBB Center. 67.9% of participants are Qatari nationals, the remaining are Qatar long term residents (> 15 years). There is a balanced participation of males (51.8%) and females (48.2%). Attitudes, perceptions and feedback are captured through a structured post-appointment participant questionnaire. Analysis of the feedback shows that upon giving consent the highest area of concern for participants is providing blood samples (47%), a further (46%) demonstrate concern over the physical measurements and (39%) are uneasy with contributing urine samples. An overwhelming (96%) of participants rate their experience at Qatar Biobank as very positive. A significant proportion (72%) of participants decide to contribute to Qatar Biobank due to word of mouth recommendations from friends (41.4%) and family (30.4%) emphasizing that the majority of participants value and enjoy their experience and are empowered to actively recruit within their communities.
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Estrogen Receptor Α Gene And Vitamin K Epoxide Reductase (Vkorc1) Gene Haplotypes And Low Bmd In Palestinian Postmenopausal Women
More LessBackground Osteoporosis is a common skeletal disorder characterized by low bone mass and microarchetectual deterioration of bone tissue with increased susceptibility to fractures. Osteoporosis is considered a multifactorial polygenic disease. The prevalence of postmenopausal osteoporosis in Palestine, based on of BMD at femoral neck, total hip and spine was 24%, 14% and 29.7% respectively. Previous studies on the effect of genetic polymorphisms on bone mineral density (BMD) showed significant correlation between various haplotypes and mutations in the VDR and MTHFR and low bone mineral density [BMD] among Palestinian postmenopausal subjects. Estrogens are known to play an important role in regulating bone homeostasis. Estrogen act through binding to Estrogen Receptor α (ERα) which is a member of the nuclear receptor superfamily of ligand activated transcription factors. Vitamin K hydrochinon is an important cofactor for gamma carboxylation of osteocalcin, a major bone matrix protein . The reduction of vitamin K to vitamin K hydrochinon depends on the vitamin K epoxide reductase complex subunit 1 (VKORC1). Aim In the present study, correlation between specific XbaI and PvuII polymorphisms in the ERα gene and selected polymorphisms in the VKORC1 gene with low BMD and fractures risk were investigated in 345 postmenopausal Palestinian women including 165 osteoporotic, 93 osteopenic and 86 normal subjects using allele-specific polymerase chain reaction (PCR) and RFLP-PCR technology. Results The data showed significance association between the XX haplotype of the XbaI in ERα gene and lower BMD at the hip (P=0.012). Similarly the PP haplotype of PvuII ER α gene was significantly associated with lower hip BMD ( P=0.03). In addition, the 9041G allele [GG and GA] was significantly more frequent in patients with low BMD (P = 0.012). In our cohort, a genetic variation in the 3'-region of the VKORC1 gene (9041 AG and GG) was significantly associated with low BMD. The data also revealed the +2255 TT haplotype which is linked to lower activity of the enzyme was associated with low BMD while the presence of the C allele [CC or CT], linked to higher activity at this locus, was associated with normal BMD levels [P=0.02]. Conclusions These findings indicate that specific polymorphisms in the ERα gene and VKORC1 gene are correlated with variation in BMD levels among our subjects. These results along with previous data with the VDR and MTHFR genes provide evidence for the strong correlation between genetics and osteoporosis in our population may be significant for treatment decisions and screening of osteoporotic patients. The involvement of other genes variation like the osteoprotegrin and TNF superfamily member genes are underway. The overall data will eventialy be employed for direct correlation and evaluation between the genetic background of patients and the efficacy of selected specific drugs used to treat osteoporosis.
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Mimicking A Postprandial Increase In Glucose Has A Biphasic Action On Microvascular Function
More LessBackground and Objectives: The high morbidity and mortality associated with both type 1 and type 2 diabetes are closely associated with an elevated incidence of cardiovascular disease. The importance of good glycaemic control for the reduction of risk, notably of microvascular disease, has been emphasised by the results from clinical trials such as the DCCT for type 1 diabetes and UKPDS for type 2 diabetes. Data from clinical studies also indicate that an oral glucose load results in a reduction in the forearm flow-mediated dilatation (FMD) that coordinates and sustains local blood flow. The reduction was greater and more prolonged in patients with diabetes, probably reflecting uncoupling of endothelial nitric oxide synthase secondary to glucose metabolism and elevated oxidative stress. These data suggested that the hyperglycaemia associated with poor glycaemic control may reduce blood flow as a result of an endothelium-dependent reduction in FMD. However, the mechanisms whereby glucose may alter this and other aspects of microvascular function are unknown. In the current study, we designed protocols that allowed us acutely to change glucose concentration and compare endothelium-dependent and endothelium-independent vasodilation in mouse and rat microvessels from the mesenteric and gracilis circulation. Methods: Small mesenteric and rat gracilis arteries with resting lumen diameters of approximately 200-250 µm and 110-120 µm were used in the study. The vessels were mounted in a pressure myograph, pressurised to 60 mmHg and endothelium-dependent vasodilatation (EDV) was assessed against agonist-mediated or myogenic tone. EDV was compared under normoglycaemic (11.0 mM for mouse and 5.5 mM for rat) versus hyperglycaemic conditions (25 or 40 mM - as based on rodent models of diabetes) with mannitol used as the osmotic control. Results: A short (10-15 minute) exposure to hyperglycaemia increased EDV in gracilis but reduced EDV in mesenteric arteries, whereas after 60-120 minutes EDV was reduced in both tissues, as indicated by both a reduced maximal response (EMAX) and reduced sensitivity (EC50) to agonist. Further analysis revealed that a 60-minute exposure to hyperglycaemia reduced both nitric oxide and non-nitric oxide-mediated EDV. Conclusion: These data indicate that an increase in glucose concentration has a biphasic effect on EDV and hence blood flow. Further studies are underway to determine the cellular mechanisms involved as well as the long-term effects hyperglycaemia on the regulation of microvascular function. Supported by NPRP 4-910-3-244
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The Application of Experimental Microdosimetry to Mixed-Field Neutron-Gamma Dosimetry
More LessAbsorbed Dose Distributions In Lineal Energy For Neutrons And Gamma Rays Were Measured Using Both A Tissue-Equivalent Walled Counter (Tepc) And A Graphite-Walled Low Pressure Proportional Counter (Gpc) In The Am-Be Neutron Source Facility At Uoit. A Series Of Measurements Were Performed With The Counters Filled With Propane-Based Te Gas (55.1% C3H8, 39.5% Co2 And 5.4% N2) At Operating Gas Pressures Corresponding To Tissue Spheres 2.0 , 4.0 And 8.0 ?m In Diameter. The Results Of These Measurements Indicated Satisfactory Performance Of The Counters To Measure Microdosimetric Spectra Extending Down To Event-Sizes That Cover The Gamma Component Of A Mixed Field. An Assessment Of The Performance Of Different Size Tepc Has Been Done And Excellent Agreement Between Their Event Size Spectra Was Found With Differences In The Microdosimetric Parameters Yf And Yd Not Exceeding 3%, Which Is In The Region Of Counting Statistics. To Separate Neutron Dose From Gamma Dose A Simple Lineal Energy Threshold Technique Has Been Used In Addition To More Sophisticated Methods Using G-Fitting And Graphite-Walled Counter Measurements. The Results Of This Study Showed That The Absorbed Dose Gamma Fraction Of The Am-Be Source Was 34.5% As Determined By Gamma Fitting And Dual Chamber Methods. The Simple Threshold Technique Gave A Value Of The Gamma Fraction Of 48% Which Is Acceptable For Radiation Protection Monitoring, However, For Radiation Biology And Neutron Metrology The More Sophisticated Methods Of Determining The Gamma Fraction Of The Total Dose Should Be Used.
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Do Qatar Community Pharmacists Prescribe And Dispense Acute Community-Acquired Gastroenteritis Medications Rationally To Patrons? A Mystery Patient Study
More LessDo Qatar Community Pharmacists Prescribe and Dispense Acute Community-Acquired Gastroenteritis Medications Rationally to Patrons? A Mystery Patient Study
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Low-Complexity Wireless Monitoring Of Respiratory Movements Using Ultra-Wideband Impulse Response Estimation
By Furrukh SanaMonitoring of respiratory rate and amplitudes of a human being has important medical applications such as in health monitoring as well as in diagnosis of respiratory illnesses and disorders such as the sleep apnea disorder. Currently used techniques for respiratory monitoring require patients to wear sensors and electrodes across the chest to measure the respiratory effort. Such techniques not only cause discomfort to the patient but also require expert supervision. It is desirable to have a low-cost wireless monitoring equipment that is able to measure the respiratory rate and amplitudes through a non-contact and non-invasive methodology. Ultra-wideband (UWB) technology offers promising features for wireless monitoring in medical environments. However, there are several challenges that need to be addressed to enable development of a cost effective and reliable product capable of operating in realistic environments. Such challenges include low signal-to-noise ratios (SNR), interference from moving background objects (clutters) and the need for expensive sampling equipment. We propose a comprehensive scheme for wireless monitoring of the respiratory movements using UWB technology. Our scheme overcomes all the three challenges mentioned above. The proposed scheme is based on the estimation of the ultra-wideband channel impulse response. We exploit the sparsity inherent in the UWB channel to estimate the respiratory movements while operating in a Bayesian framework. We suggest techniques for dealing with background clutter in situations when it might be time variant. We also present a novel methodology for reducing the required sampling rate of the system significantly while achieving the accuracy offered by the Nyquist rate. Results from simulations conducted with pre-recorded respiratory signals demonstrate the robustness of our scheme for tackling the above challenges and providing a low-complexity solution for the monitoring of respiratory movements in harsh operating environments. Equipment based on our technique will be particularly useful to hospitals for clinical diagnosis purposes and also for commercial household usage by people in need of continuous monitoring of their health status. Measurements acquired through the equipment can potentially be communicated to a remote terminal/station for analysis by physicians. The equipment will also be useful in search and rescue scenarios for detecting and monitoring the vital signs of survivors trapped under debris and rubble in disaster management scenarios as well as in surveillance operations such as detecting people behind a wall.
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Continuous And Noninvasive Hemoglobin Monitoring Reduces Red Blood Cell Transfusion During Neurosurgery: A Prospective Cohort Study
By Wael AwadaContext: Continuous, noninvasive hemoglobin (SpHb) monitoring provides clinicians with real-time trending of changes or lack of changes in hemoglobin, which has the potential to alter red blood cell transfusion decision making. Objective: The objective was to evaluate the impact of SpHb monitoring on blood transfusions in high blood loss surgery. Design: Prospective cohort study. Setting: Tertiary academic hospital in Cairo, Egypt from February to August, 2012 Patients: Convenience sample of adult neurosurgical patients were enrolled (n=111) with 106 completing the study. Exclusion criteria included significant liver or renal disease, coagulopathy, pregnancy, anemia, and patients scheduled for procedures with excepted low blood loss. Interventions: Patients were enrolled into either a Control Group or a SpHb Group. The Control Group received standard anesthesia care including intraoperative blood sampling when estimated blood loss was ≥15% of total blood volume and transfusion when hemoglobin was ≤10 g/dL. In the SpHb Group, the anesthesiologist was guided by the addition of SpHb monitoring. Main Outcome Measures: The effect of SpHb on transfusion practice and absolute and trend accuracy of SpHb compared to laboratory hemoglobin were evaluated. Potential cost savings from reduced red blood cell utilization were estimated. Results: Compared to the Control Group, the SpHb Group had fewer of units of blood transfused (1.0 vs 1.9 units for all patients; p≤0.001, and 2.3 vs 3.9 units in patients receiving transfusions; p≤0.01), fewer patients receiving >3 units (32 vs 73%; p≤0.01) and a shorter time to transfusion after the need was established (9.2±1.7 vs 50.2±7.9 min; p≤0.001). The absolute accuracy of SpHb was 0.0±0.8 g/dL and trend accuracy yielded a coefficient of determination of 0.93. SpHb monitoring could save $470,000 to $1,065,000 per 1,000 surgeries performed. Conclusions: SpHb monitoring resulted in decreased blood utilization and decreased transfusion costs in high blood loss neurosurgery, while facilitating earlier transfusions.
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Monotherapy Versus Combination Gram Negative Empiric Antibiotic Therapy For Febrile Neutropenia In Children With Cancer
By Shane PawlukBackground: Children with cancer who are treated with intensive myelosuppressive chemotherapy or radiation therapy and develop neutropenia are at risk of developing life-threatening infections. In adult cancer patients with febrile neutropenia, some evidence suggests that there is no difference in efficacy between monotherapy and combination gram negative empiric antibiotic regimens. Outcomes of these different antibiotic regimens have not been compared in the pediatric population in North America. The objectives of this study were to compare the effectiveness and safety of a combination gram negative antibiotic regimen versus monotherapy in pediatric cancer patients with cancer and febrile neutropenia, and to describe the use of additional antimicrobial agents for those patients who did not respond to initial empiric therapy. Methods: A retrospective review of medical records of cancer patients who received empiric treatment for febrile neutropenia with piperacillin-tazobactam and gentamicin, and those who received monotherapy for febrile neutropenia with pipercillin-tazobactam was performed. Demographic information, drug therapy for febrile neutropenia, measures of renal function, daily peak temperature, other medications received (including antibiotics and antipyretics), and bacterial and fungal cultures were obtained from the patient's medical records using a standardized data collection form. Descriptive statistics were used to describe the study patient's demographic information. Difference in duration of fever and change in serum creatinine were assessed using the Wilcoxon Rank-Sum Test. Results: A total of 60 patients were included in this study. Mean duration of fever was 3.5 days in the combination treatment group and 3.1 days in the monotherapy group (p = 0.5). Both the combination and monotherapy groups had similar rates of adding vancomycin (17% vs. 13%). The monotherapy group received additional gram-negative coverage antibiotics more often (10%) than the combination group (0%). Antibiotics added included: gentamicin (0 combination group, 7% combination group), and ciprofloxacin (0 combination group, 3% monotherapy group). Piperacillin-tazobactam was changed to meropenem in 3% of the patients in the combination group and 7% of the monotherapy group, while 3% of the combination group patients were switched from piperacillin-tazobactam to ceftriaxone. Mean percent increase in serum creatinine was 25% in the combination group and 10% in the monotherapy group (p = 0.03). Conclusion: Empiric treatment of febrile neutropenia in children with cancer using a monotherapy regimen with piperacillin-tazobactam is as effective as the combination of piperacillin-tazobactam and gentamicin for reducing duration of fever. This therapeutic option however must be evaluated against local microbial resistance patterns and patient risk factors. Although statistically significant, the difference in change in serum creatinine between the two groups was not clinically significant.
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Analyzing Electrocardiograms Via Smartphone To Detect Cardiovascular Abnormalities
More LessCardiovascular diseases (CVD) are the leading cause of death globally. According to the World Health Organization, around 17.3 million people died from CVD in 2008, which is estimated to increase to 23 million annually by 2030. This calls for the exploitation of the latest technology to analyze and detect heart diseases in a timely fashion. Electrocardiogram (ECG) records the electrical activity of heart, and any irregularities in the heart rhythm are used as indicators of possible heart diseases. However, the process of acquiring an ECG and visually inspecting it is laboursome and time consuming. It is in this context that developing a mobile ECG monitoring system based on smart phones and automated diagnostic algorithms prove significant. The ECG acquiring system being developed by our team transmits ECG from the human body to the patient's smart phone in real-time via Bluetooth. This is completed by an application running on the phone. Two approaches are being developed to process the data received. The first is to send the data from the phone to a Webserver where the data will be analyzed and processed and lastly send the results back; this can be done through Wi-fi or a 3G connection. The second approach is to run the algorithm within the application on the smart phone itself. This way, the data can be processed locally, and the results can be displayed in case of no network. Both approaches are being compared for pros and cons. In the first approach, the Webserver can be updated frequently without modifying the application. Moreover, the usage of RAM memory will be efficient, and the code can be preserved from corruption. Nevertheless, this process will not succeed if the server fails or if the network interrupts. The second approach can process the data without network connectivity. However, it is more demanding on the phone, more susceptible to bugs and more difficult to update and debug the C code. The necessary hardware to acquire ECG and transmit it to the smart phone has been developed. Also, a robust diagnostic algorithm and an interactive smart phone application are being built. On integration, the system will be capable of analyzing ECG in real time and providing early warning to patients under cardiac risk saving valuable time and effort in their treatment.
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How Do Pharmacists Advise Diabetes Patient Self-Management During The Holy Month Of Ramadan?
More LessBackground Many diabetes patients choose to participate in the Ramadan fast despite medical and religious advice to the contrary. Pharmacists, especially in ambulatory care, are considered the most easily and readily accessible health care providers whose guidance can help ensure safe fasting for these patients. Objective The aim of this novel study is to describe Qatar pharmacists' current practice, knowledge, and attitudes towards diabetes medication management during Ramadan. Methodology This cross-sectional descriptive study was performed among a convenience sample of 500 pharmacists in various practice settings in Qatar. A web-based, 30-items questionnaire was systematically developed following comprehensive literature review. The volume and nature of pharmacist interactions with diabetes patients was explored. Pharmacists' awareness and knowledge of relevant resources, endorsed by international medical and religious bodies, were evaluated. In addition, their attitudes regarding pharmacist role in diabetes care during Ramadan were assessed. Data was entered and analyzed using SPSS Version 19. Results: The survey was completed by 166 (33%) pharmacists during May and June 2012. Eighty-eight (53%) were based in ambulatory care and reported somewhat more interaction (at least weekly) with diabetes patients during Ramadan than hospital pharmacists (70.4%, vs. 55.8%, p=0.08). Three-quarter of respondents had never read recommended diabetes Ramadan guidelines with 62% using Internet resources as their primary reference to answer fasting-related diabetes questions. Two-thirds of respondents correctly identified how to modify oral diabetes therapy dosing during Ramadan, but just 20 (12%) did so for insulin. Despite stated barriers of workload, insufficient access to patient medical records and private counseling areas, pharmacists overwhelmingly expressed willingness to assume greater roles in diabetes patient education during Ramadan. Conclusion Qatar pharmacists frequently interact with diabetes patients, but application of recommended medical guidelines for care and medication dosing for fasting patients is not optimal. While there are various barriers limiting pharmacist participation in diabetes management during Ramadan, they are motivated to assume a greater role in developing this service.
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Uncovering The Mechanisms Of Soft Tissue Injuries Associated With Acl Tear
More LessUncovering the Mechanisms of Soft Tissue Injuries Associated with ACL Tear
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Comparison Of Different Assays To Measure Antioxidant Capacity In Qatari Grown Food
More LessComparison of different assays to measure antioxidant capacity in Qatari grown food
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Synthesis And Pharmacological Screening Of Novel Piperine Derivatives As Potential Therapeutic Agents To Treat Chronic Kidney Disease
By Ayat HammadSynthesis and pharmacological screening of novel piperine derivatives as potential therapeutic agents to treat chronic kidney disease
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Bioinformatics applications for Bacteriophages and their pathogenic bacteria proteins Analysis
More LessIntroduction: E. coli is usually harmless to the host, sometimes causes diarrhoeal and other diseases in humans. In the meantime, S. aureus is the cause of a wide range of different kinds of major and minor pyogenic infections. Rational : The mechanical action of the bacteriophage on the selected bacteria species depend on their receptors that adsorb them to their hosts, some proteins of the bacterial outer membrane acts as the receptor for phage infection, to isolate the phages and identify their species through electron microscopy analysis and/or DNA hybridization assays, the relationship between bacteriophages and bacteria proteins could be found by the protein profiles analysis Methods: The proteins of the Escherichia .coli phage and the E. coli bacteria were separated by Sodium Dodecyl Sulphate Poly Acrylamide Gel Electrophoresis (SDS-PAGE) to estimate their molecular weights; the migration of each band was compared to the standards of known weights in the molecular ladder. Results: The mobilised proteins of the phage showed three major bands with molecular weights of 46, 35 and 24 kDa. Meanwhile, the bacteria showed clear nine bands with molecular weight ranged between 96 and 14 kDa. This was analysed by the programme ImageJ136b which showed molecular masses of 47, 34 and 16 kDa, The analysed data showed the protein bands distance migration and plot area of the phage and the bacteria, the results in size from 47.7 to 34.3 kDa resembles 43.3% of total phage protein which formed the capsid head and the coil, while the molecular weight mass of 22.5 formed the tail proteins, we found that the band of 34 kDa was the common shared peak between them. Conclusion The bacterial host E. coli protein profile showed more bands and more peaks than the bacteriophages ones, this is related to the lytic cycle of the bacteriophages and their phenomenon in utilizing the bacterial DNA in proteins manufacturing during their multiplication inside the host.
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Epidemiological Study Of Patients Presenting With The First Seizure In Qatar.
More LessEpidemiological study of patients presenting with the first seizure in Qatar.
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Real-Time Gpu Implementation Of Correlation-Based Dense Matching Of Stereo Endoscopic Images For Surface Reconstruction
More LessReal-Time GPU Implementation of Correlation-Based Dense Matching of Stereo Endoscopic Images for Surface Reconstruction
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Patient-Specific Anatomy And Tissue Texture Models For Surgical Simulations
More LessPatient-Specific Anatomy and Tissue Texture Models for Surgical Simulations
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The Polyamine Binding Protein, Potd, Is Needed For Intracellular Establishment Of The Waterborne Pathogen Legionella Pneumophila
More LessThe Polyamine Binding Protein, PotD, Is Needed for Intracellular Establishment of the Waterborne Pathogen Legionella pneumophila
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Non-Motor Manifestations In Parkinson'S Disease: The Link Between Sense Of Smell, Subjective Visual Vertical (Svv) Perception And Micrographia
By Ali KhattabNon-motor manifestations in Parkinson's disease: The link between Sense of smell, subjective visual vertical (SVV) perception and micrographia
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Notch-Mediated Crosstalk Between Breast Cancer Cells And Endothelial Cells Induces A Transitional Endmt Phenotype Participating To An Endothelial Pro-Tumoral Niche
By Pegah GhiabiNotch-Mediated Crosstalk between Breast Cancer Cells and Endothelial Cells Induces a Transitional EndMT Phenotype Participating to an Endothelial Pro-tumoral Niche
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Sanad: Cognitive Behavioral Therapy For Smart Mobile Diabetes Management System Embedding Social Networking Platform
By Turki AlanziSANAD: Cognitive Behavioral Therapy for Smart Mobile Diabetes Management System Embedding Social Networking Platform
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Cross-Sectional Study Of Total And Central Body Fatness And C-Reactive Protein Among Qatari Men And Women: The Qatar Biobank Project
More LessCross-sectional study of total and central body fatness and c-reactive protein among Qatari men and women: The Qatar Biobank Project
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A Novel Bace-1 Inhibitor, F70Hab16 Reduces Oxidative Stress In Brain Tissues Of Scopolamine-Induced Amnesia In Mice
More LessA Novel Bace-1 Inhibitor, F70Hab16 Reduces Oxidative Stress In Brain Tissues Of Scopolamine-Induced Amnesia In Mice
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Running Mechanics And Spring-Mass Behaviour During Treadmill Repeated Sprints Are Different In Hypoxia And In Normoxia
More LessRunning mechanics and spring-mass behaviour during treadmill repeated sprints are different in hypoxia and in normoxia
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The comparison of Muscle strength and short-term endurance in the different periods of type 2 diabetes
By Boshra HatefBackground: patients with type 2 diabetes (T2DM) are subjected to reduction in the quality and oxidative capacity of muscles. The effect of duration of diabetes on the muscle endurance response is not clear and strength as well .The aim of this study was the assessment of strength and endurance of knee extensor and flexor in the patients with T2DM<10 and T2DM>10 years in comparison with age, sex, BMI, ABI and PAI-matched health control subjects. Methods: isometric maximal peak torque (MPT) of knee extensor and flexor before and after 40 isokinetic repetitions with velocity of 150 degree/s were recorded in 18 patients with T2DM<10 Y , 12 patients with T2DM>10 Y and 20 matched health control (HC) groups. Results: both diabetic patient groups had significant lower isometric and isotonic knee extensor and flexor strength than HC (Table 1). The endurance indices indicated that whereas the isometric MPT of flexor movement was reduced after isokinetic protocol in the both patient groups in comparison with HC, the less decline was seen in the isotonic torque and work during isokinetic protocol in the T2DM>10 Y group in comparison with two other groups (figure 1). The HbA1c and FBS were significantly correlated with strength not with endurance indices. Conclusions: it seems the progression of diabetes accompanied with vascular, neural and muscular deficits activate, some adaptive and compensatory processes which can maintain muscle performance.
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Characterization Of Growth Factor Receptor Signaling Upon Loss Of Endoplasmic Reticulum Chaperones
More LessCharacterization of growth factor receptor signaling upon loss of endoplasmic reticulum chaperones
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Development And Characterization Of Poly (Diol-Co-Tricarballylate) Biodegradable Matrices For Implantable Controlled Drug Delivery, Tissue Engineering And Other Biomedical Applications
More LessDevelopment and characterization of poly (diol-co-tricarballylate) biodegradable matrices for implantable controlled drug delivery, tissue engineering and other biomedical applications
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Standardization Of An In Vitro Model Of Diabetic Nephropathy Using Madin-Darby Canine Kidney Cells
More LessStandardization of an in vitro model of diabetic nephropathy using Madin-Darby Canine Kidney cells
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Development, Implementation, And Evaluation Of A Novel Medication Safety Health Promotion Program For Schoolchildren In Qatar
By Kyle WilbyDevelopment, Implementation, and Evaluation of a Novel Medication Safety Health Promotion Program for Schoolchildren in Qatar
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Etiologic Studies On Equine Motor Neuron Disease: A Natural Model For Als
More LessEtiologic Studies on Equine Motor Neuron Disease: A natural model for ALS
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Associations Of Single Nucleotide Polymorphisms(Rs2383207) On Chromosome 9P21 With Coronary Artery Diseases In Qatar
More LessAssociations of single nucleotide polymorphisms(rs2383207) on chromosome 9p21 with coronary artery diseases in Qatar
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Mechanism Of Regulation Of Extracellular Matrix Upon Endoplasmic Reticulum Stress
More LessMechanism of regulation of extracellular matrix upon endoplasmic reticulum stress
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Assessment Of Parylene C Thin Films For Heart Valve Tissue Engineering
By Isra MareiAssessment of Parylene C Thin Films for Heart Valve Tissue Engineering
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Nanotechnology Approaches To The Treatment Of Pulmonary Hypertension: Gold Nanoparticles And No-Release
By Nura MohamedNanotechnology approaches to the treatment of pulmonary hypertension: Gold nanoparticles and NO-release
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Ultra-Wideband Mimo Channel Characterization For Healthcare Applications
By Marwa QaraqeThe idea of deploying multiple wireless sensors around the human body to enable ubiquitous healthcare by measuring continuously all the physiological data of interest has received considerable attention. Ultra-wideband (UWB) is a promising communication technology for short-range communication scenarios like body-centric wireless network (BCWN) (i.e, in the area of medical healthcare). UWB is characterized by low-power which makes it suitable for human body exposure and extends the life of the system. UWB is a high data rate technology that provides immunity to multipath interference, which facilitates the compatibility of such technology in body-centric applications. High data-rate wireless communications, nearing 1 Gb/s transmission rates, are of greater interest in emerging wireless technologies. The demand for higher data rate is increasing with the passage of time. To achieve higher data rates, greater than 50 Mb/s, multiple transmit and multiple receive antennas (MIMO) is recommended in IEEE 802.11n. To reach the target of 1 Gb/s, more advanced techniques like Ultra-wideband (UWB) technology combined with MIMO is an attractive research area now-a-days [1]. For BCWN, the use of multiple antennas at transmitter and receiver can simply be considered as a tool to further increase the signal to noise/interference ratio and additional diversity against fading. BCWN mainly experience fading due to relative movements of body parts, polarisation mismatch, shadowing, diffraction, and scattering from the body parts and surrounding environments. Multiple antennas can be used to combat fading and multipath effects. There has been an increasing interest in diversity and multiple-input, multiple output (MIMO) techniques for enhanced mobile and wireless communications in recent years. There are some studies presented in the open literature, where the benefits of multiple antenna techniques for body-centric communications in narrow-band systems have been investigated. The aim of this work is to investigate channel characterization (i.e having comprehensive radio channel knowledge and accurate channel model) and improve channel capacity provided by a UWB MIMO antenna system in body centric communication systems. The work will specifically investigate how UWB radio signals are affected by body shadowing and what kind for of improvement can be achieved in terms of channel capacity by using MIMO technology for BCWN. This is done by incorporating two different models on the measured data in an indoor environment (Fig. 1 shows the MIMO antenna position during measurements), and calculating various parameters like Rician factor, average received power, shadowing deviation, polarization loss for each spatial sub-channel. In addition, water filling is used in place of uniform distribution which provides higher capacity even at low SNR.
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Knowledge of Risk Factors for Spontaneous Abortion among Qatari Arab Women
By Nish PatelSpontaneous abortion affects one in four of all pregnancies (Crenin, 2001). The rate of spontaneous abortion among Qatari Arab women presenting to Women's Hospital, Doha, Qatar is 34% (Women's Hospital, 2012) compared to the next highest ethnic minority (Egyptian Arab women) at 18%. Understanding and modifying risk factors for spontaneous abortion may prevent future miscarriages. Purpose: To assess the level of knowledge of risk factors for spontaneous abortion among Qatari Arab women. Methods: A cross-sectional self-administered survey was completed by 290 Qatari Arab women. The questionnaire assessed knowledge of modifiable lifestyle risk factors of spontaneous abortion. Univariate and bivariate analysis of the data was conducted. Odds ratios were used as a measure of association between categorical variables; confidence intervals and the chi-square test were used to determine whether or not the association was statistically significant. All tests were 2-sided and findings considered significant at p < 0.05. Results: Only 2.6% of the participants were aware of all 11 modifiable lifestyle risk factors. Most women (56%) had knowledge of only 5 or fewer risk factors of spontaneous abortion. Women who had a high school education and were younger than 25 years were two times more likely to know 5 or fewer risk factors than college educated women over 26 years of age (OR=2; CI: 1.2 - 3.3, p<.05). Conclusion: There is a significant lack of knowledge of the risk factors of spontaneous abortion among Qatari Arab women who attended the Antenatal Clinic at Women's Hospital, Doha, Qatar. Targeted and repeated health education during regular clinic visits may increase awareness. This may lead to a behavioral change preventing future spontaneous abortions.
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Analysis Of Whole Genome Sequencing Data Of The Arabian, Percheron And Miniature Horse
More LessWhole genome sequencing provides a rich and unprecedented collection of the existing genetic variation in a genome. The development of next generation sequencing (NGS) technologies has enabled a rapid and relatively inexpensive method for whole genome sequencing. The current archive of genetic variations in the horse is mostly based on the Thoroughbred mare used to generate the reference sequence (EquCab2.0). Therefore, we have used Illumina paired-end NGS technology to sequence three horse genomes from diverse breeds; an Arabian, a Percheron and an American Miniature Horse. Our objective is to catalog newly identified variations within these three individuals and in comparison to the reference. After filtering the reads, we used BWA to align them to the reference and the Genome Analysis Tool Kit (GATK) HaplotypeCaller to call Single Nucleotide Polymorphisms (SNPs) and insertion/deletion polymorphisms (In/Dels). We also used ControlFreec to obtain regions predicted to contain copy number variations on each of the three genomes. Finally, we used BreakDancer to detect structural variations like inversions and translocations. These newly detected variations will enrich the database of genetic variations in the horse and could potentially have a phenotypic impact related to the biology of each of the three horse breeds. Here we will be presenting preliminary findings on our analysis and highlight the important steps in our pipeline.
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Design And Synthesis Of New Monoamine Oxidase Inhibitors As Potential Neuroprotective Agents
More LessBackground and Objectives: Monoamine oxidase (MAO) catalyzes the biodegradation of biogenic amine neurotransmitters and a variety of xenobiotic amines. Selective MAO B inhibitors are used in the treatment of Parkinson's disease and other neurodegenerative diseases while selective MAO A inhibitors are known antidepressants. Piperazine and pyrazole rings are common moieties in several MAO inhibitors. The chronic nature of these diseases raises a compelling need for new MAO inhibitors with improved pharmacokinetics and safety profiles. Therefore, the aim of this project is to design, synthesize, purify and elucidate the structure of a series of new piperazine and pyrazole derivatives with potential MAO inhibitory activity. Methods: Based on the literature review, a series of compounds was proposed for their potential MAO inhibitory activity. Different piperazine and pyrazole derivatives were chemically synthesized by conventional method or by the use of microwave initiator. The reactions were monitored with TLC and purified by liquid-liquid extraction and column chromatography. The structures were confirmed by FTIR and GC/MS. Results: The microwave-assisted synthesis gave a better yield comparing to the conventional synthesis. The structures of the new compounds were confirmed by FTIR and GCMS. All the data will be presented. Conclusions: Microwave assisted synthesis of the proposed compounds improved the obtained yield. FTIR confirmed the formation of new products and the disappearance of the starting materials while the GCMS confirmed the molecular weight of the obtained products. More compounds will be prepared and evaluated for their MAO inhibitory activity.
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Investigating The Function And Substrate Specificity Of Histone Deacetylase Enzymes:New Synthetic Tools To Investigate The Role Of Hdacs In Cancer
More LessInvestigating the Function and Substrate Specificity of Histone Deacetylase Enzymes:New Synthetic Tools to Investigate the Role of HDACs in Cancer
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