Altaf Khan

National Guard Health Affairs | NGHA · Bioinformatics and Database Section (BDS)

Context Bariatric surgery has been shown to be effective in inducing complete remission of type 2 diabetes in adults with obesity. However, its efficacy in achieving complete diabetes remission remains variable and difficult to predict before surgery. Objectives We aimed to characterize bariatric surgery-induced transcriptome changes associated wi...

Background Ambient temperatures exceeding 40 °C are projected to become common in many temperate climatic zones due to global warming. Therefore, understanding the health effects of continuous exposure to high ambient temperatures on populations living in hot climatic regions can help identify the limits of human tolerance. Objective We studied th...

Background: Although the association between ambient temperature and mortality in local populations is evident, this relationship remains unclear in transient populations (e.g., due to immigration, mass gatherings, or displacement). The holy city of Mecca annually shelters two populations comprising its residents and the transitory Hajj pilgrims (...

An evolutionary heat shock response (HSR) protects most living species, including humans, from heat‐induced macromolecular damage. However, its role in the pathogenesis of heat stroke is unknown. We examined the whole genome transcriptome in peripheral blood mononuclear cells of a cohort of subjects exposed to the same high environmental heat condi...

Objective To assess the efficacy of Zafirlukast as a SARS-CoV-2 Helicase Inhibitor in adult patients with moderate COVID-19 symptoms (hospitalized patients with COVID-19 pneumonia who were not admitted to an intensive care unit). Methods We conducted a randomized, double blind, placebo-controlled, pilot trial with adult patients with moderate COVI...

Video gaming is a popular source of entertainment among children and adolescents. Although the Middle East is home to one of the fastest growing communities of video game users, most of the research established on this topic has been carried out through small scale studies. Our aim in this study is to assess the prevalence of video game use and its...

We reported a gastric anti-ulcerogenic effect of the Nigella sativa (L.)-derived herbal melanin (HM) in rat models. However, the molecular mechanisms underlying the HM gastroprotective effect remain unknown. Cyclooxygenase-2 (COX-2)-catalyzed prostaglandin E2 (PGE2) and toll-like receptor 4 (TLR4)-mediated interleukin-6 (IL-6) production and secret...

This study aimed to verify whether p70S6K1 could be a potential biomarker of invasive breast cancer tissues in T2DM patients and to investigate its role in AGEs-promoted breast cancer progression. Many epidemiological studies reported the increased risk of developing invasive breast cancer in postmenopausal patients with type 2 diabetes mellitus (T...

In this work an attempt has been made to review the current state of arts in epidemiological modeling, assessment of predictive models as well as forecasting of new pathogen. The primary concern is the containment of the outbreak from wide spread of the disease among the whole population. This article also focuses for the development of management...

Aim We aimed to review our experience of managing Wilms tumor in our center over a period of fifteen years with regards to disease characteristics, outcome and see how well we are doing as compared to rest of the world. Methods All children admitted at King Abdullah Specialist Children's Hospital, Riyadh from Jan 2001 to Dec 2015 with the diagnosi...

Background There is currently a lack of information regarding ocular tropism and the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Globally, the cumulative number of coronavirus disease 2019 (COVID-19) cases is increasing daily. Thus the potential for ocular transmission and manifestations of SARS-CoV-2 requires more investigation....

OBJECTIVE: Determine normal reference range of Tc-99m pertechne-tate thyroid uptake for thyroid scintigraphy in Saudi Arabia. DESIGN: Retrospective, cross-sectional. SETTING: Nuclear medicine service at tertiary care center in Riyadh. PATIENTS AND METHODS: We used data from biochemically euthyroid patients who underwent a thyroid Tc-99m pertechneta...

Objectives: To describe the clinical and laboratory characteristic, state the treatment and outcome of patients with juvenile idiopathic arthritis (JIA), and describe temporomandibular joint (TMJ) involvement as observed in a large tertiary center. Methods: A retrospective cross-sectional study of children diagnosed with JIA was assessed at King...

BACKGROUND Thyrotoxicosis is a common medical problem. Thyroid nuclear imaging with either I ¹²³ or technetium-99m (Tc-99m) pertechnetate are used to determine the cause. Although I ¹²³ has been the standard technique, Tc-99m pertechnetate is now commonly used, acceptable and easier to perform. The commonly used normal value of Tc-99m pertechnetate...

Background The primary focus for this study was investigation of prognostic biomarkers in colorectal cancer (CRC), since biomarkers are instrumental in clinical decision making and patient management as well as playing pivotal roles in precision medicine. Methods We analyzed indigenous dataset from colorectal cancer patients. Exon microarray datase...

The disease (COVID-19) novel coronavirus pandemic has so far infected millions resulting in the death of over a million people as of Oct 2020. More than 90% of those infected with COVID-19 show mild or no symptoms but the rest of the infected cases show severe symptoms resulting in significant mortality. Age has emerged as a major factor to predict...

Introduction Endoscopic retrograde cholangiopancreatography (ERCP) is a relatively new endoscopic procedure combined with fluoroscopy that is performed for multiple diagnostic and therapeutic indications. It carries a known risk of radiation exposure to patients and staff. We aimed to examine radiation administration techniques and to measure the r...

Objective: To determine the frequency, risk factors, and outcomes of patients with brainstem hemorrhage in stroke center at King Abdulaziz Medical City, Riyadh. Methods: A retrospective, observational cohort study including all patients with brainstem hemorrhage from January 2014 to December 2017. The clinical presentation, location of hemorrhag...

Objectives Ginger extracts gingerol and paradol exhibit anti-platelet aggregation properties. Prior studies have shown a reduction in platelet aggregation; however, results remain inconclusive due to heterogeneity of the used methods i.e. different dose regimen, ginger formulation, and study participants. The main aim of the study was to evaluate t...

Objective: To determine the frequency, risk factors, and outcomes of significant carotid artery disease (CAD) in patients with ischemic stroke. Methods: The frequency of significant CAD in patients admitted to the Stroke Unit between January 2014 and December 2015 was determined from radiological data. Outcomes were determined clinically and rad...

‬ Objectives: To determine the frequency, risk factors, and outcomes of significant carotid artery disease)CAD(in patients with ischemic stroke. Methods: The frequency of significant CAD in patients admitted to the Stroke Unit between January 2014 and December 2015 was determined from radiological data. Outcomes were determined clinically and radio...

Aim Several factors determine the perioperative outcome besides the nature of the congenital heart defect. Prolonged mechanical ventilation (PMV) is a major factor that determines mortality, length of stay (LOS), residual disability, and other functional outcomes. We aim to determine the clinical variables predicting PMV and LOS in hospital, and sp...

Background: In the current study, we investigated the effect of physical activity (PA) on the risk of coronary heart disease (CHD). Methods: In total, 146 cases of CHD and 157 matched controls were included in the study. Data on sociodemographics, lifestyle, and medical history factors were collected using an interviewer-administered questionnaire....

Immune thrombocytopenic purpura (ITP) is a common hematological disease treated primarily by corticosteroids. The aim of the present study was to compare response rate between patients, underwent splenectomy vs. rituximab as second-line therapy. Adult patients diagnosed with ITP who did not respond to corticosteroids or relapsed during the period 1...

To assess the mathematical and statistical issues related with acquired images, and to make inferences in diagnostic detection based on general linear models (GLM) for each and every pixel/voxel of the tomograms, in addition multiple comparison as well as sample size and power issues will be outlined. The steps involved range from tomographics imag...

This paper discusses a novel approach to approximate quadrature integrals that arise in the estimation of likelihood parameters for the generalized linear mixed models (GLMM) as well as Bayesian methodology also requires computation of multidimensional integrals with respect to the posterior distributions in which computation are not only tedious a...

Background: Wake-up Stroke (WUS) doesn't have distinctive clinical characteristics. Physiological changes in circadian rhythm (cerebral autoregulation, vascular tone, blood pressure, coagulation profile) are thought to predispose to WUS. Aim: Our objective is to identify the characteristics WUS amongst the Arab population. Methods: We retrospe...

The investigation is concerned first with reconstruction of the density function of an object from computed tomography data. The projection (Fourier Slice) theorem is discussed for fan-beam geometry. A rebinning algorithm, based on the slant stacking approach, is introduced in order to transform fan-beam geometry data into its parallel-beam counter...

Liver abscess (LA) is a well-described disease in the medical literature; however, information about its characteristics and outcome in the Middle East is lacking. We compared the mode of presentation, risk factors, management and outcome of LA patients in Saudi Arabia with cases from the United Kingdom (UK). Retrospective review of LA patients fro...

The investigation is concerned with reconstruction of the density function of an object from computed tomography data. The projection (Fourier slice) theorem is discussed for fan-beam geometry. A rebinning algorithm, based on the slant stacking approach, is introduced to transform fan-beam geometry data into the parallel-beam geometry. The density...

Predicting the outcome of kidney transplantation is clinically important and computationally challenging. The goal of this project was to develop the models predicting probability of kidney allograft survival at 1, 3, 5, 7, and 10 years. Kidney transplant data from the United States Renal Data System (January 1, 1990, to December 31, 1999, with the...

The surface of fractures and pore volumes in rocks affect many of the physico-chemical processes important to geothermal reservoirs and provides a record of the evolution of reservoir rock. Its geometric characterization is important. Computer tomographic imaging is developed into a technique for characterizing multiscale and fractal surfaces of po...

The surface of fractures and pore volumes in rocks affect many of the physico-chemical processes important to geothermal reservoirs and provides a record of the evolution of reservoir rock. Its geometric characterization is important. Computer tomographic imaging is developed into a technique for characterizing multiscale and fractal surfaces of po...

A semi-analytical iterative approach for enhancing the existing two-dimensional quasi-continuous axisymmetric stress field for a brittle matrix micro-composite (e.g., a single fiber surrounded by a concentric matrix cylinder), is presented. The existing solution due to Pagano employs Reissner’s variational theorem in conjunction with an equilibrium...