Pesticide use and chronic bronchitis among farmers in the Agricultural Health Study.

BACKGROUND: Farmers have increased risk for chronic bronchitis. Few investigators have considered pesticides. METHODS: We evaluated pesticides as risk factors for chronic bronchitis using the Agricultural Health Study enrollment data on lifetime pesticide use and history of doctor-diagnosed chronic bronchitis from 20,908 private pesticide applicators, primarily farmers. RESULTS: A total of 654 farmers (3%) reported chronic bronchitis diagnosed after age 19. After adjustment for correlated pesticides as well as confounders, 11 pesticides were significantly associated with chronic bronchitis. Heptachlor use had the highest odds ratio (OR=1.50, 95% Confidence Interval (CI)=1.19, 1.89). Increased prevalence for chronic bronchitis was also seen for individuals who had a history of a high pesticide exposure event (OR=1.85, 95% CI=1.51, 2.25) and for those who also applied pesticides in off-farm jobs (OR=1.40, 95% CI=1.04, 1.88). Co-morbid asthma and current farm activities did not explain these results. CONCLUSIONS: These results provide preliminary evidence that pesticide use may increase chronic bronchitis prevalence.

Chronic bronchitis among nonsmoking farm women in the agricultural health study.

OBJECTIVE: The purpose of this study was to examine agricultural risk factors for chronic bronchitis among nonsmoking farm women. METHODS: We used self-reported enrollment data from the 21,541 nonsmoking women in the Agricultural Health Study to evaluate occupational risk factors for prevalent chronic bronchitis among farm women. Odds ratios (ORs) for chronic bronchitis for occupational exposures were adjusted for age, state, and related agricultural exposures. RESULTS: Applying manure and driving combines were independently associated with chronic bronchitis. Off-farm job exposures associated with chronic bronchitis were organic dusts, asbestos, gasoline, and solvents. Five pesticides were associated with chronic bronchitis after multivariate adjustment and sensitivity analyses: dichlorvos (OR=1.63, 95% CI=1.01, 2.61), DDT (OR=1.67, 95% CI=1.13, 2.47), cyanazine (OR=1.88, 95% CI=1.00, 3.54), paraquat (OR=1.91, 95% CI=1.02, 3.55), and methyl bromide (OR=1.82, 95% CI=1.02, 3.24). CONCLUSION: Pesticides as well as grain and dust exposures were associated with chronic bronchitis among nonsmoking farm women.

Evaluation of potassium iodide prophylaxis knowledge and nuclear emergency preparedness: New Jersey 2005.

The Nuclear Regulatory Commission requires states to consider including potassium iodide as a protective measure in the unlikely event of a major release of radioactivity from a nuclear power plant. We evaluated emergency preparedness knowledge, including proper potassium iodide use, among the general public and emergency responders located around New Jersey's nuclear power plants. We found that knowledge about responder chain of command, evacuation routes, and some aspects of potassium iodide usage was incomplete among the general public and emergency responders.

Assessment of potassium iodide (KI) distribution program among communities within the emergency planning zones (EPZ) of two nuclear power plants.

The primary objective of this study was to evaluate a joint state and local government-sponsored potassium iodide (KI) distribution program in New Jersey. This program is part of a radiological emergency response system for residents living within the Emergency Planning Zones (EPZs) of nuclear power facilities. KI pills and an informational fact sheet were distributed locally at six different public clinics in the summer of 2002. In this study, a mailed survey was developed, pilot tested, and sent to the general public to assess knowledge about KI use. The survey consisted of two groups of people, those who attended a KI distribution clinic and those that did not attend a clinic. There was a statistically significant difference in knowledge among the two groups of survey respondents regarding KI prophylaxis, with a mean of 46% of survey questions answered correctly by those who attended a clinic vs. 15% by those who did not attend. Certain questions were problematic for the public to answer correctly and included potential low compliance with government instructions for taking KI, confusion regarding where the public can obtain KI pills during an emergency, and the lack of awareness on the proper use of KI for children, pregnant women, and persons over the age of 40 y. Additional outreach in these specific areas is warranted. This study also found that there was a highly variable geographic pattern of homes that have a supply of KI pills, with some areas having 60% of the households supplied with pills from the clinic while other areas had as low as 1% of the homes supplied with KI pills.

Temporally distinct demands for classic cadherins in synapse formation and maturation.

Classic cadherins are synaptic adhesion proteins that have been implicated in synapse formation and targeting. Brief inactivation of classic cadherin function in young neurons appears to abrogate synapse formation when examined acutely. It remains unknown if such abrogation is unique to young neurons, whether it occurs by stalling neuronal maturation or by directly interfering with the process of synapse assembly, or whether synapse targeting is altered. Here we asked if sustained pan-cadherin blockade would prevent or alter the progression of axonal and dendritic outgrowth, synaptogenesis, or the stereotypic distribution of excitatory and inhibitory synapses on cultured hippocampal neurons. While pre- and postsynaptic cadherins are required for synapse assembly in young neurons, we find that in neurons older than 10 days, classic cadherins are entirely dispensable for joining and aligning presynaptic vesicle clusters with molecular markers of the postsynaptic density. Furthermore, we find that the proportion and relative distributions of excitatory and inhibitory terminals on single neurons are not altered. However, synapses that form on neurons in which cadherin function is blocked are smaller; they exhibit decreased synaptic vesicle recycling and a decreased frequency of spontaneous EPSCs. Moreover, they fail to acquire resistance to F-actin depolymerization, a hallmark of mature, stable contacts. These data provide new evidence that cadherins are required to promote synapse stabilization and structural and functional maturation, but dispensable for the correct subcellular distribution of excitatory and inhibitory synapses.

Polymorphisms in the one-carbon metabolic pathway, plasma folate levels and colorectal cancer in a prospective study.

One-carbon (e.g., folate) metabolism plays a pivotal role in the etiology of colorectal cancer (CRC). Cytosolic serine hydroxymethyltransferase (cSHMT), methylenetetrahydrofolate dehydrogenase (MTHFD1) and glutamate carboxypeptidase II (GCPII) are key genes involved in this pathway. Several new polymorphisms have been identified and there is evidence implicating their functionality. We examined whether polymorphisms in these genes, i.e., cSHMT L474F, MTHFD1 R653Q and GCPII H475Y, modify the risk of CRC in the prospective Physicians' Health Study. Among the 270 incident CRC cases and 453 controls, none of the one-carbon polymorphisms were associated with risk of CRC. Compared to the wild-type genotype, the multivariate-adjusted relative risks and 95% confidence intervals were 1.14 [0.68, 1.93] for cSHMT 474FF, 1.04 [0.67, 1.62] for MTHFD1 653QQ and 1.00 [0.55, 1.82] for GCPII 474HY. Furthermore, we examined the associations between one-carbon polymorphisms and folate status in terms of plasma folate and homocysteine levels in this population. No independent gene effect was observed. Although compound homozygous variants at cSHMT and MTHFD1 loci had the lowest plasma folate levels compared to other compound genotypes, no significant gene-gene interactions were observed. Findings from our prospective investigation indicate that these newly identified polymorphisms in one-carbon metabolizing genes have limited functionality in modifying folate status and related CRC risk.