Evaluating how occupational exposure to organophosphates and pyrethroids impacts ADHD severity in Egyptian male adolescents.

BACKGROUND: Attention Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder characterized by deficits in attention and hyperactivity/impulsivity that cause impairments to daily living. An area of long-standing concern is understanding links between environmental toxicants, including pesticides, and the development or worsening of ADHD. OBJECTIVES: The present study evaluated associations between occupational pesticide exposure, specifically organophosphate (OP) pesticides, chlorpyrifos (CPF) and the pyrethroids (PYR) alpha-cypermethrin (αCM) and lambda-cyhalothrin (λCH), and symptoms of ADHD in a longitudinal study among Egyptian adolescent males. METHODS: Participants (N = 226, mean age = 17) were Egyptian adolescent males who either applied pesticides or were non-applicators. Urinary trichloro-2-pyridinol (TCPy) was measured as a specific metabolite biomarker of exposure to chlorpyrifos. Urinary 3-phenoxybenzoic acid (3-PBA) was measured as a general metabolite biomarker of exposure to pyrethroids, while urinary cis-3-(2,2- dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (cis-DCCA) was measured as a specific biomarker of exposure to αCM and lambda cyhalothric acid (λCH acid) measured as a specific biomarker of exposure to λCH. Ordinal logistic regression models controlling for age were used to determine the likelihood of ADHD development (measured via parent-reported ADHD symptoms) as the level of biomarkers of pesticide exposure increased. RESULTS: Cis-DCCA was the only biomarker associated with higher likelihood ADHD symptoms (> 0.60 vs. 0-0.17 µg/g creatinine; OR = 2.82, 95% CI: 1.29-6.14). All participants reported clinical levels of ADHD symptoms when compared to national norms used in the United States. TCPy, trans-DCCA and λCH acid were not associated with risk of ADHD symptoms after controlling for levels of cis-DCCA. No other metabolites were associated with the number of ADHD symptoms. There were no interaction effects found for exposure to both OPs and Pyrethroids. DISCUSSION: The results suggest that exposure to the pyrethroid αCM is associated with more ADHD symptoms. Methodological and cultural considerations in need of further study are discussed.

Evaluation of occupational pesticide exposure on Egyptian male adolescent cognitive and motor functioning.

BACKGROUND: Chronic low-level exposure to organophosphorus pesticides is associated with adverse health effects, including a decline in neurological functioning and long-term impairment. These negative effects may be more detrimental in children and adolescents due to their critical stage in development. Little work has investigated the effects of chronic exposure to pesticides, specifically chlorpyrifos (CPF) during the adolescent period. OBJECTIVES: To examine effects of CPF exposure over a year-long period within a group of male adolescents in Egypt (N = 242, mean age = 17.36), including both pesticide applicators and non-applicators. METHODS: Associations between average CPF exposure (measured via urinary metabolite levels of 3,5,6-trichloro-2-pyridinol [TCPy]) and neurobehavioral functioning were examined in a 1-year longitudinal study. Given previous literature, higher levels of TCPy were expected to be associated with worse neurobehavioral functioning. RESULTS: Using mixed effects linear regression, average TCPy exposure predicted deficits in more complex neurobehavioral tasks (Benton visual retention, digit span reverse, match to sample, serial digit learning, and alternating tapping) with estimates of effects ranging from -0.049 to 0.031. Age (effects ranging from 0.033 to 0.090) and field station (effects ranging from -1.266 to -0.278) were significantly predictive of neurobehavioral functioning over time. An interaction effect was found for field station and TCPy across several neurobehavioral domains. DISCUSSION: Results show that occupational exposure to pesticides may have particularly deleterious effects on complex neurobehavioral domains. Additionally, differences across field stations and the age at which individuals are exposed may be important factors to investigate in future research.

The Circulating Micro-RNAs (-122, -34a and -99a) as Predictive Biomarkers for Non-Alcoholic Fatty Liver Diseases.

BACKGROUND: It remains essential for patient safety to develop non-invasive diagnostic tools to diagnose non-alcoholic fatty liver rather than invasive techniques. AIM: Our case-control study was to address the value of circulating miRNAs as a potential non-invasive biomarker for the diagnosis of non-alcoholic fatty acid diseases (NAFLD) and monitoring of disease progression. METHODS: Routine clinical assessment, laboratory tests, anthropometric study, and liver biopsy results reported for 210 patients with NAFLD (124 patients of simple steatosis (SS) and 86 of non-alcoholic steatohepatitis (NASH)). Apparently matched for age and gender, healthy participants (n= 90) were enrolled as a control group. Serum samples were tested for micro-RNAs (-122, -34a and -99a) by quantitative-PCR. RESULTS: By histopathology, 124 of the NAFLD group were of SS and 86 patients were of NASH. Compared with the control subjects, both mi-RNA-122 and -34a levels were increased in NAFLD (p< 001) and at a cut-off = 1.261, mi-RNA-122 had 92% sensitivity, 85% specificity to differentiate NAFLD from healthy controls, while mi-RNA-99a were significantly decreased in NAFLD patients with an observed decrease in disease severity, and at a cut-off = 0.46, miRNA-99a had 94% sensitivity and 96% specificity to discriminate SS from NASH. CONCLUSION: The integration of a circulating mi-RNA panel to diagnose NAFLD cases and to discriminate between SS and NASH. Large-scale study is still needed to verify the other mi-RNA profiles and their role in NAFLD pathogenesis and targeting therapy.

Evaluation of circulating zonulin as a potential marker in the pathogenesis of nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) is a spectrum of liver disorders ranging from simple hepatic steatosis up to nonalcoholic steatohepatitis (NASH) evolving to cirrhosis and hepatocellular carcinoma (HCC). Liver biopsy is still the gold standard modality for diagnosing and staging NAFLD. The linkage between intestinal microbiota and NAFLD, might suggest a potential role of serum zonulin in NAFLD diagnosis. To appraise the role of circulating zonulin in NAFLD pathogenesis, 56 subjects with proved NAFLD by ultrasonography and liver biopsy, as well as 20 healthy controls were tested. Liver function tests, serum glucose, fasting insulin, C peptide, lipid profile, homeostasis model assessment of insulin resistance (HOMA-IR), IL-6, and circulating zonulin were performed to all subjects. Aspartate transaminase (AST), alanine transaminase (ALT), gamma-glutamyl transferase (GGT), triglycerides, HDL-c, fasting insulin, C peptide, HOMA-IR, IL-6, and serum zonulin were higher in NAFLD group than in controls (p < 0.05), and in NASH patients than those with simple steatosis (p < 0.05). Zonulin was positively correlated with body mass index (BMI), ALT, triglycerides, fasting insulin, HOMA-IR, liver histopathology, and serum IL-6 (p < 0.05), with inverse correlation to HDL-C (p < 0.05). At cut off 8.3 pc/mL, serum zonulin was found to be of diagnostic value of NASH occurrence with 100% sensitivity and specificity (AUR = 1.000, p-value = <0.001). The increasing zonulin levels in NAFLD patients with steep rise in NASH group denotes a possible role in pathogenesis of NAFLD occurrence and progression. This could open a new avenue of implicating zonulin antagonists as targeted therapies in NAFLD prevention.

Hepcidin levels and iron status in beta-thalassemia major patients with hepatitis C virus infection.

Beta-thalassemia is an inherited anemia in which synthesis of the hemoglobin beta-chain is decreased. Clinical features of beta-thalassemia include variably severe anemia and iron overload due to increased intestinal iron absorption, which may result in damage to vital organs. The hepatic peptide; hepcidin is a key regulator of iron metabolism in mammals. The present study aimed to determine the relationship between hepcidin expression and iron status in beta-thalassemia patients with hepatitis C virus infection. The study included 50 patients diagnosed as beta-thalassemia major (21 of them were HCV infected and 29 were HCV negative), in addition, 20 healthy subjects were enrolled in the study. The hepatic iron and hepcidin mRNA concentration in liver biopsy samples were measured, as well as serum ferritin, serum iron, hemoglobin and levels and serum hepcidin. Result showed remarkable decrease of serum and liver hepcidin mRNA expression in thalassemic patients as compared to controls, and showed a positive correlation with hemoglobin concentration, but negatively correlated with serum ferritin level and hepatic iron index (HII). In HCV infected patients, serum and liver hepcidin mRNA were markedly depressed in HCV positive beta-thalassemia cases, and positively correlated serum albumin and prothrombin concentrations, but inversely correlated with HII and fibrosis score. In HCV positive beta-thalassemia major patients, the hepcidin mRNA level was positively correlated with the synthetic function of the liver (namely serum albumin and prothrombin concentration) and with serum hepcidin level. While, both serum and hepcidin mRNA level was inversely correlated with HII and fibrosis score in these patients. These results suggest a possible role of hepcidin expression in iron overload in beta-thalassemia major, consequent disease progression and development of liver fibrosis.

Frequency and prognostic significance of murine double minute protein-2 overexpression and p53 gene mutations in childhood acute lymphoblastic leukemia.

AIM: Determination of frequency and prognostic significance of murine double minute protein-2 (MDM-2) over expression and its association with p53 status in children with acute lymphoblastic leukemia (ALL). METHODS: MDM-2 expression by flow cytometry and p53 gene status by PCR were determined in peripheral blood or bone marrow of 46 ALL children (at initial diagnosis) and control group. RESULTS: MDM-2 was significantly overexpressed in 15 patients (32.6%). p53 mutation was detected in six out of 46 patients at initial diagnosis, three of them were out of 29 cases achieving complete remission (CR) and the other three cases were out of 17 of relapsed patients, which is significantly higher than CR group (P<0.05). Positive correlation was found between the MDM-2 overexpression and initial WBCs count, peripheral blast cell count and presence of CNS blasts (P<0.05, <0.05 and <0.05 respectively). CONCLUSION: MDM-2 is overexpressed in a significant number of childhood ALL, and more often observed in the poor outcome group and its frequency is not related to p53 status. Measurement of MDM-2 as a bad prognostic marker even in cases with non-mutant p53 is very important. Moreover, MDM-2 may be a potential molecular target for production of new cancer therapy.

Effects of occupational pesticide exposure on children applying pesticides.

Nearly 40% of the Egyptian workforce is employed in agriculture. The cotton industry relies on children and adolescents, who work seasonally, to apply pesticides to the cotton crops. Although previous research has examined adult pesticide exposures in this workforce in Egypt, no research has examined the health effects in adolescents. This study attempts to systematically replicate findings examining the impact of organophosphate pesticide (OP) exposure in adults on Arabic speaking children working as applicators. The aim of this study was to examine the impact of pesticide exposure on children and adolescents spraying cotton fields. Male children currently applying pesticides between the ages of 9 and 15 (Younger, n=30) and 16 and 19 (Older, n=20) were recruited for the study. They completed a neurobehavioral test battery; personality inventory; work, health, and exposure questionnaires; and medical and neurological screening exams. Blood samples were collected to measure acetylcholinesterase. Children not working in agriculture, matched on age and education, served as controls. Both Younger and Older applicator groups, performed significantly worse than the controls on the majority of neurobehavioral tests controlling for age and years of education. The applicators reported significantly more neurological symptoms than the controls and had lower acetylcholinesterase activity. A dose-effect relationship demonstrated that increased years of exposure to organophosphate pesticides is associated with cognitive deficits. This is one of the several studies demonstrating that functional cognitive effects are positively correlated with increased years of exposure to OP pesticides, though primarily in adult populations, building confidence in the association. Since children around the world are exposed to OP pesticides, these studies suggest that the need to evaluate this potential problem is urgent.

Prevalence and prognostic significance of murine double minute protein-2 overexpression and P53 gene mutations in childhood acute lymphoblastic leukemia.

The murine double minute protein-2 (MDM-2) oncogene is a determinant of embryogenesis, tumorigenesis, and cell cycle progression. The effects of MDM-2 on these processes depend, in part, on its ability to inactivate the p53 tumor suppressor gene. Our goal was to determine whether MDM-2 protein overexpressions or p53 gene mutations are a frequent event in poor outcome pediatric acute lymphoblastic leukemia (ALL). This work was conducted on 46 children with ALL (31 males and 15 females) with age range 2-18 years, 18 children with matched age and sex were enrolled in the study as a control group. The MDM-2 expression by flowcytometry and p53 gene status by PCR were determined in peripheral blood or bone marrow of ALL children (at initial diagnosis) and also of control group. The ALL children were treated by the modified BFM 76179 protocol of therapy, 29 patients (63%) achieved complete remission, while 17 patients (37%) were subsequently failed to achieve complete remission or relapsed within 6 months of achieving complete remission (CR). MDM-2 was significantly overexpressed in 15 ALL patients (32.6%), compared to that of healthy controls, 4 of them (4/15), were out of 29 cases of CR (13.8%), and the other 11 cases were out of 17 relapsed cases (64.7%). In contrast to overexpression of MDM-2, the mutation of p53 was detected in 6 (13%) out of 46 ALL patients at the initial time of diagnosis, 3 of them (10.3%) were out of 29 cases of CR and the other 3 cases (17.6%) were out of 17 of relapsed group, which is significantly higher than CR group (P < 0.05). In relapsed group, 2 patients out of 3 cases with p53 mutation were MDM-2 negative, also, all 3 cases of mutant P53 among patients in CR were negative MDM2. A positive correlation was found between the MDM-2 overexpression and initial WBCs count, blast cell counts in peripheral blood and presence of CNS blasts (p < 0.05, p < 0.05 and p < 0.05 respectively). These results indicate that MDM-2 is overexpressed in a significant number of childhood ALL, it is more frequent in relapsed cases and its frequency is not related to p53 status. Thus measuring of MDM-2 as a bad prognostic marker even in cases with non mutant P53 is very important. Moreover, MDM-2 may be a potential molecular target for production of new cancer therapy.

Significance of zeta-associated protein (ZAP-70) and CD38 expression in chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) is a disease with a highly variable clinical course; some patients never need treatment, while others require intensive treatment early after diagnosis. Some new prognostic factors, such as immunoglobulin variable heavy chain (IgVH) mutational status, zeta-associated protein (ZAP-70) and CD38 expression in leukemic cells were introduced to identify attenuated versus progressive types of CLL bearing the potential to facilitate risk-adapted treatment strategies. So, the aim of this work is to evaluate the clinical value of ZAP-70 and CD38 as predictors of disease progression. We assessed the expression of these markers by flowcytometry in 38 patients with CLL and correlated their levels with genetic abnormalities detected by fluorescence in situ hybridization (FISH) and the clinical outcome. We found that 18 patients (47.4 %) were positive for ZAP-70 (> or = 20%) and 16 patients (42.1%) were positive for CD38 (> or = 20%). Positive ZAP-70 and CD38 status were associated with an unfavorable clinical course including high leukocytic count, lymphocytosis, high lactate dehydrogenase (LDH) serum level, advanced disease stage, trisomy 12 and del (11q); negative ZAP-70 and CD38 status were correlated with del (13q). The treatment-free survival time was 30 months for ZAP-70-positive patients and 18 months for ZAP-70-nagative patients (p < 0.01). Combined analysis of ZAP-70 and CD38 yielded discordant results in 10 patients (26.3 %), whereas 16 patients (42.1%) were concordantly negative and 12 patients (31.6%) were concordantly positive for ZAP-70 and CD38 expression. Median treatment-free survival times in patients whose leukemic cells were ZAP-70+CD38+ was 27 months as compared to 100 months in patients with a ZAP-70(-)CD38(-) status. In patients with discordant ZAP-70/CD38 results, the median treatment-free survival time was 40 months. Thus, ZAP-70 and CD38 expression analyses provide complementary prognostic information and allow distinguishing the patients groups with the most favorable prognosis as well as those with the worst. The current findings suggest that both ZAP-70 and CD38 protein expression should be assessed in patients with CLL for the definition of prognostic subgroups.