Qatar Foundation Annual Research Forum Volume 2013 Issue 1

It 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.

Background: 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.

Introduction: 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.

Background 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).

Blood 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.

Background 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&#39;-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.

Absorbed 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.

Monitoring 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.

Background: 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.

Background 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.