Benzene and its effects on cell signaling pathways related to hematopoiesis and leukemia.

Benzene is an environmental toxicant found in many consumer products. It is an established human carcinogen and is known to cause acute myeloid leukemia in adults. Epidemiological evidence has since shown that benzene can cross the placenta and affect the fetal liver. Animal studies have shown that in utero exposure to benzene can increase tumor incidence in offspring. Although there have been risk factors established for acute myeloid leukemia, they still do not account for many of the cases. Clearly then, current efforts to elucidate the mechanism by which benzene exerts its carcinogenic properties have been superficial. Owing to the critical role of cell signaling pathways in the development of an organism and its various organ systems, it seems plausible to suspect that these pathways may have a role in leukemogenesis. This review article assesses current evidence of the effects of benzene on critical hematopoietic signaling pathways. Pathways discussed included Hedgehog, Notch/Delta, Wingless/Integrated, nuclear factor-kappaB and others. Following a review of the literature, it seems that current evidence about the effects of benzene on these critical signaling pathways remains limited. Given the important role of these pathways in hematopoiesis, more attention should be given to them.

The epidemiological aspects of congenital heart disease in central and southern district of Iran.

BACKGROUND: Congenital heart disease (CHD) is a major health problem and its prevalence is different around the world. The aim of study was determination of the epidemiological aspects of CHD in central and southern district of Iran. MATERIALS AND METHODS: In this descriptive and analytical study, 3714 medical records were evaluated from March 21, 2001 to December 18, 2011. Medical records of inpatients from angiography and outpatients in the Heart Clinic of Afshar hospital (a referral hospital in center and south of Iran) were the source of information. Types of CHD and demographic data including age, sex and residential location are collected. The data were analyzed by SPSS (version 17) software. Chi-square and Fisher's exact tests were used to compare variables between groups. RESULTS: At the study, the mean age of the patients at diagnosis time was 8.8 ± 11.6 year (at the range of one day to 76 years with median of 4 years). The percentage of females and males was 54.2 (n: 2014) and 43.8 (n: 1627), respectively. The chi-square test showed that there was significant difference in frequency of CHDs between females and males (P value < 0.0001). Ventricular septal defect (VSD) was found to be the most frequent of CHDs (27%). Patent ductus arteriosus (PDA) (16.8%), atrial septal defect (ASD) (15.8%), pulmonary stenosis (PS) (11%) and Tetralogy of Fallot (TOF) (8.9%) were more prevalent in CHDs after VSD. CONCLUSIONS: The frequency of CHDs in female was more than male and VSD, PDA, ASD, PS, and TOF were most common in CHDs, respectively.