Occupational exposure to pesticides and endotoxin and Parkinson disease in the Netherlands.

OBJECTIVES: Previous research has indicated that occupational exposure to pesticides and possibly airborne endotoxin may increase the risk of developing Parkinson disease (PD). We studied the associations of PD with occupational exposure to pesticides, specifically to the functional subclasses insecticides, herbicides and fungicides, and to airborne endotoxin. In addition we evaluated specific pesticides (active ingredients) previously associated with PD. METHODS: We used data from a hospital-based case-control study, including 444 patients with PD and 876 age and sex matched controls. Exposures to pesticides from application and re-entry work were estimated with the ALOHA+job-exposure matrix and with an exposure algorithm based on self-reported information on pesticide use. To assess exposure to specific active ingredients a crop-exposure matrix was developed. Endotoxin exposure was estimated with the DOM job-exposure matrix. RESULTS: The results showed almost no significant associations. However, ORs were elevated in the higher exposure categories for pesticides in general, insecticides, herbicides and fungicides, and below unity for endotoxin exposure. The analyses on specific active ingredients showed a significant association of PD risk with the fungicide benomyl. CONCLUSIONS: This study did not provide evidence for a relation between pesticide exposure and PD. However, the consistently elevated ORs in the higher exposure categories suggest that a positive association may exist. The possible association with the active ingredient benomyl requires follow-up in other studies. This study did not provide support for a possible association between endotoxin exposure and PD.

Statistical inference of the time-varying structure of gene-regulation networks.

BACKGROUND: Biological networks are highly dynamic in response to environmental and physiological cues. This variability is in contrast to conventional analyses of biological networks, which have overwhelmingly employed static graph models which stay constant over time to describe biological systems and their underlying molecular interactions. METHODS: To overcome these limitations, we propose here a new statistical modelling framework, the ARTIVA formalism (Auto Regressive TIme VArying models), and an associated inferential procedure that allows us to learn temporally varying gene-regulation networks from biological time-course expression data. ARTIVA simultaneously infers the topology of a regulatory network and how it changes over time. It allows us to recover the chronology of regulatory associations for individual genes involved in a specific biological process (development, stress response, etc.). RESULTS: We demonstrate that the ARTIVA approach generates detailed insights into the function and dynamics of complex biological systems and exploits efficiently time-course data in systems biology. In particular, two biological scenarios are analyzed: the developmental stages of Drosophila melanogaster and the response of Saccharomyces cerevisiae to benomyl poisoning. CONCLUSIONS: ARTIVA does recover essential temporal dependencies in biological systems from transcriptional data, and provide a natural starting point to learn and investigate their dynamics in greater detail.

Investigation of deaths in an area of groundnut plantations in Casamance, South of Senegal after exposure to Carbofuran, Thiram and Benomyl.

Between May and October 2000, the Regional Health Office of Kolda Region in the south of Senegal, West Africa, reported an epidemic of an unknown illness characterized by thoracic pain, dyspnea and edemas of limb and face. The epidemic covered a radius of approximately 40 km (24 miles) between the districts of Kolda and Sedhiou in Kolda Region. Cases were mostly men whose age ranged between 12 and 60 years old. Investigation revealed that they had been exposed to pesticides distributed by the government to groundnut farmers. The signs and symptoms suggested intoxication with carbamates, carbofurans, and possibly thiram, contained in the pesticides distributed with the groundnut seeds. Government distribution created an excessive use of pesticides in the farms, and consequently an overexposure of the subjects who handled the seeders, especially young males but also a small proportion of women who worked in the groundnut fields. Many of these subjects, not accustomed to handle pesticides, came to overestimate the quantity of product to fill the seeder. It should be noted that the policy of distribution of pesticides in Senegal, which presents risk of poisoning, was not systematically accompanied by sufficient information on the danger of the products and of certain precautions that should be taken during their use.

[Ovarian activity of Drosophila melanogaster Meigen (Diptera), during a chronic intoxication with four fungicides: anatomical and cytological study]. / [Ovarian activity of Drosophila melanogaster Meigen (Diptera), during a chronic intoxication with four fungicides: anatomical and cytological study]

Two types of reactions were observed on the alteration of Drosophila vitellogenesis by the four fungicides used in this study. Dithane M45 resulted in stimulation associated with egg retention. However, the other three fungicides (Benlate, Bouillie bordelaise and Euparène) resulted in inhibition to a varying degree. Although the inhibition was comparatively limited due to Benlate it induced an egg retention. The inhibition was very high due to Bouillie bordelaise and Euparène. With Bouillie bordelaise an egg retention occured together with the reduction of vitellogenesis and caused an increase in the rate of the follicle resorption. The latter depended on the duration of treatment. With Euparène, no egg retention was observed and the toxicity was only noticed on vitellogenesis.

Benlate. A medical and scientific controversy.

Benlate, a fungicide, has been used for over 20 years in Florida to treat agricultural crops and ornamentals. In the past few years, there have been reports of crop damage and health effects from exposure. Physicians should be aware of research findings regarding these effects.