ABSTRACT
OBJECTIVES: Glutathione S-transferase pi (GSTP1) is a candidate enzyme that may be involved in colorectal cancer susceptibility. Polymorphism of GSTP1 gene may cause changes in expression or structure which lead to alteration in the efficiency of catalytic function of the enzyme variants, i.e., deficient detoxification of carcinogens and consequently influences coloreActal cancer development. The present report examined the possible impact of GSTP1 (Ilel05Val) polymorphism and the risk of colorectal cancer. METHODS: Samples of paraffin embedded tissues from 83 patients with colorectal cancer as well as thirty five non-cancerous colon tissues were collected from the archive of the pathology department at King Abdulaziz University in Saudi Arabia. All cancer and control samples were subjects to DNA extraction then amplification. DNA genetic analyzer from Applied Biosystems was used to sequence the product of amplification for genotypes determination. RESULTS: None of the genotypes of GSTP1 was associated with the risk of colorectal cancer development. There were no statistical differences in the frequencies of GSTP1 genotypes between colorectal cancer cases and controls. CONCLUSION: The incidence of (Val/Val) genotype in colorectal cancer cases was three folds higher than controls. This finding is not statistically significant, but it could be of clinical consequence that it may increase the risk of colorectal cancer in Saudi Arabia.
Subject(s)
Colorectal Neoplasms/genetics , Genetic Predisposition to Disease , Glutathione S-Transferase pi/genetics , Adult , Aged , Aged, 80 and over , Amino Acid Substitution/genetics , Case-Control Studies , Colorectal Neoplasms/epidemiology , Female , Gene Frequency , Genotype , Humans , Male , Middle Aged , Polymorphism, Single Nucleotide , Saudi Arabia/epidemiology , Valine/geneticsABSTRACT
BACKGROUND AND OBJECTIVES: Few studies have been conducted in Saudi Arabia to estimate the prevalence of visual impairment and its causes. The objective of this study was to estimate the prevalence of visual impairment, and identify its causes and associated factors among the adult population attending primary health care (PHC) centers in Aljouf province, in northern Saudi Arabia. DESIGN AND SETTING: A cross-sectional study during the year 2005 in PHC centers in Aljouf province in northern Saudi Arabia. PATIENTS AND METHODS: A sample of 620 Saudi adults, of age 18 years and older, from the catchment area of the Aljouf PHC centers, were randomly selected through a multistage random sampling technique. Data were collected using a questionnaire about socioeconomic and related information and a visual acuity test was performed using the Snellen chart (E). Diagnosis was established according to World Health Organization (WHO) criteria. Visual impairment was categorized into blindness for a visual acuity of less than 3/60 (20/400, 0.05) in the better eye with the best correction and low vision for a best corrected visual acuity of less than 6/18 (20/60, 0.3) but not less than 3/60 (20/400, 0.05) in the better eye. Regression analysis was used to identify the predictors of visual impairment. RESULTS: Of 617 adult Saudis interviewed and examined, 269 (43.6%) were females. The mean (SD) age was 38.6 (16.2) years. The overall prevalence of visual impairment was 13.9% (95% CI: 11.4%-16.9%). The main medical causes of visual impairments were refractive errors (36.0%) followed by cataract (29.1%) and diabetic retinopathy (20.9%), and the least leading cause was glaucoma (5.8%). The most prominent determinants of visual impairment were age (P<.05), sex (P<.001), and a history of previous eye injury (P<.05). CONCLUSION: Prevalence of visual impairment in the study population from the Aljouf area is high. It is recommended that regular checks of visual acuity be conducted for all Saudis of age 50+ years, who attend the PHC centers.
