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Influence of Corn Farming on the Immune System

8. září 2020 aktualizováno: National Cancer Institute (NCI)

This study will look for links between corn farming practices and short-term changes in immune function in farmers throughout the growing season. It will examine biologic effects associated with specific pesticide exposures and general planting activities, such as tillage. Farmers have an increased risk of non-Hodgkin s lymphoma and certain other blood cancers such as multiple myeloma and leukemia, but the reasons for this increase have not been identified. Findings of this study may contribute to learning the causes of cancers such as non-Hodgkin s lymphoma.

Farmers enrolled in the Agricultural Health Study (a study of pesticide applicators and their spouses in Iowa and North Carolina) and a group of control subjects selected from agricultural extension workers in Iowa may participate in this study.

The study involves six home visits to farmers and four visits to farmers to individuals in the control group. All participants will complete the following tests and procedures:

  • Questionnaires and diaries During the first visit, all participants will have a medical history review, including questions about smoking and other health habits. Farmers will be asked about their farming practices, and controls will be asked about their occupations. Farmers will fill out daily diaries during short time periods of interest around certain pesticide applications to describe farming activities that day. At other times during the growing season before harvest, farmers will fill out weekly diaries describing farming activities; controls, meanwhile, will fill out weekly diaries describing their health and work activities. At home visits during the farmers growing season, all participants will fill out questionnaires about their health. Finally, farmers and controls will complete a more extensive questionnaire in the off-season, during the last home visit, to learn about their activities and exposures in the final part of the year (post-harvest for farmers).
  • Urine samples: At the time of each home visit, controls will provide a urine sample that the interviewer will take that day. Farmers, too, will provide urine samples at the time of home visits, but they will also collect urine samples for a period of 4 days each during short time periods of interest after certain pesticide applications. The interviewer will collect these samples immediately at the end of these periods.
  • Blood samples: At the time of each home visit, the interviewer will draw 50 ml (3.5 tablespoons) of blood.
  • Telephone calls: Farmers will be called frequently from once every 2 weeks to every other day to schedule visits at the times of interest. Control subjects will also be called frequently to schedule their visits closely to those of the farmers.

Přehled studie

Postavení

Dokončeno

Podmínky

Detailní popis

When compared to the general population, farmers have an increased risk of non-Hodgkin's lymphoma (NHL) and certain other hematopoeitic cancers (i.e., multiple myeloma, leukemia). Factors that contribute to this excess risk have not been discerned. While several epidemiologic studies have observed an increased risk of NHL among farmers who are exposed to certain pesticides (i.e., phenoxyacetic acids, organophosphates, organochlorines, and triazines), these studies have not been conclusive. In addition, a clear mechanistic association between farming or pesticide exposure and subsequent development of cancer has not been identified. Given that immunocompromised individuals are at increased risk for NHL, it has been hypothesized that altered immune function may be an indicator of increased potential for the development of immunologically based diseases such as NHL. Therefore, research into early immunologic effects of farming exposures holds some promise in discerning disease mechanisms and in identifying specific etiologic agents for lymphatic cancers such as NHL. Few such studies have been conducted.

This protocol outlines a study of immune effects among corn farmers within Agricultural Health Study (AHS) cohort. The main objective is to evaluate the changes in immune parameters in farmers throughout the growing season, as well as effects of specific pesticide exposures including atrazine and organophosphate (OP) insecticides. Farmers and control subjects were contacted just prior to planting (February-March) to be enrolled in the study. Biological sampling before and after planting and application of preemergent pesticides (likely to include atrazine and possibly Ops or carbamates) allowed examination of short-term biologic effects associated with specific pesticide exposures and general planting activities (e.g., tillage). The first post-emergent application of organophosphate insecticide will also be monitored, in order to evaluate short-term biologic effects associated with this OP exposture. Post-harvest and off-season samples also were collected to allow evaluation of overall immune effects of farming activities. Pesticide exposures (e.g., atrazine, OPs, and potentially 2,4-D or carbamates) are being assessed primarily by measurement of the parent compound or its metabolites in urine, and additional information on farming activities and work practices will be obtained by questionnaire. Farmers serve as their own self-controls, and a selected control group will provide a means for external comparison.

Typ studie

Pozorovací

Zápis (Aktuální)

40

Kontakty a umístění

Tato část poskytuje kontaktní údaje pro ty, kteří studii provádějí, a informace o tom, kde se tato studie provádí.

Studijní místa

    • Iowa
      • Iowa City, Iowa, Spojené státy, 52242
        • University of Iowa

Kritéria účasti

Výzkumníci hledají lidi, kteří odpovídají určitému popisu, kterému se říká kritéria způsobilosti. Některé příklady těchto kritérií jsou celkový zdravotní stav osoby nebo předchozí léčba.

Kritéria způsobilosti

Věk způsobilý ke studiu

18 let až 100 let (Dospělý, Starší dospělý)

Přijímá zdravé dobrovolníky

Ne

Pohlaví způsobilá ke studiu

Mužský

Metoda odběru vzorků

Vzorek nepravděpodobnosti

Studijní populace

Farmers enrolled in the Agricultural Health Study and a group of control subjects selected from agricultural extension workers in Iowa may participate in this study. Specifically, male corm farmers in the AHS who plan to apply specific pesticides. Only non-smokers are included in the study.@@@

Popis

  • INCLUSION CRITERIA:

Male corm farmers in the AHS who plan to apply specific pesticides.

Any ethnicity or race groups are included.

Limit the age criteria for inclusion to 40 to 60 years.

Only non-smokers are included in the study.

Studijní plán

Tato část poskytuje podrobnosti o studijním plánu, včetně toho, jak je studie navržena a co studie měří.

Jak je studie koncipována?

Detaily designu

Kohorty a intervence

Skupina / kohorta
1
Corn farmers enrolled in the Agricultural Health Study who are non-smokers, and who plan to apply specific pesticides.
2
Control subjects selected from agricultural extension workers in Iowa who are non-smokers

Co je měření studie?

Primární výstupní opatření

Měření výsledku
Popis opatření
Časové okno
Immunilogical effects of farming exposues
Časové okno: Before and after application of pesticies
Evaluate the changes in immune parameters in farmers throughout the growing season, as well as effects of specific pesticide exposures including atrazine and organophosphate (OP) insecticides. Pesticide exposures (e.g., atrazine, OPs, and potentially 2,4-D or carbamates) are being assessed primarily by measurement of the parent compound or its metabolites in urine, and additional information on farming activities and work practices will be obtained by questionnaire. Farmers serve as their own self-controls, and a selected control group will provide a means for external comparison.
Before and after application of pesticies

Spolupracovníci a vyšetřovatelé

Zde najdete lidi a organizace zapojené do této studie.

Sponzor

Termíny studijních záznamů

Tato data sledují průběh záznamů studie a předkládání souhrnných výsledků na ClinicalTrials.gov. Záznamy ze studií a hlášené výsledky jsou před zveřejněním na veřejné webové stránce přezkoumány Národní lékařskou knihovnou (NLM), aby se ujistily, že splňují specifické standardy kontroly kvality.

Hlavní termíny studia

Začátek studia

3. května 2002

Primární dokončení (Aktuální)

31. ledna 2004

Dokončení studie (Aktuální)

5. února 2008

Termíny zápisu do studia

První předloženo

19. června 2006

První předloženo, které splnilo kritéria kontroly kvality

19. června 2006

První zveřejněno (Odhad)

21. června 2006

Aktualizace studijních záznamů

Poslední zveřejněná aktualizace (Aktuální)

10. září 2020

Odeslaná poslední aktualizace, která splnila kritéria kontroly kvality

8. září 2020

Naposledy ověřeno

1. září 2020

Více informací

Termíny související s touto studií

Další identifikační čísla studie

  • 999902197
  • 02-C-N197

Informace o lécích a zařízeních, studijní dokumenty

Studuje lékový produkt regulovaný americkým FDA

Ne

Studuje produkt zařízení regulovaný americkým úřadem FDA

Ne

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