RESUMO
Experiments linking neonicotinoids and declining bee health have been criticized for not simulating realistic exposure. Here we quantified the duration and magnitude of neonicotinoid exposure in Canada's corn-growing regions and used these data to design realistic experiments to investigate the effect of such insecticides on honey bees. Colonies near corn were naturally exposed to neonicotinoids for up to 4 months-the majority of the honey bee's active season. Realistic experiments showed that neonicotinoids increased worker mortality and were associated with declines in social immunity and increased queenlessness over time. We also discovered that the acute toxicity of neonicotinoids to honey bees doubles in the presence of a commonly encountered fungicide. Our work demonstrates that field-realistic exposure to neonicotinoids can reduce honey bee health in corn-growing regions.
Assuntos
Abelhas/efeitos dos fármacos , Colapso da Colônia , Animais , Abelhas/crescimento & desenvolvimento , Canadá , Produtos Agrícolas , Inseticidas/toxicidade , Larva/efeitos dos fármacos , Nitrocompostos/toxicidade , Pólen/química , Zea maysRESUMO
CombAT (Combination of Avodart and Tamsulosin) was a randomised, double-blind study in men (n=4844) aged ≥ 50 years with a clinical diagnosis of BPH. Patients were randomised to daily tamsulosin 0.4 mg, dutasteride 0.5 mg or both for 4 years. The primary endpoint was time to acute urinary retention (AUR) or BPH-related surgery. Secondary endpoints included BPH clinical progression, symptoms and maximum urinary flow rate. A post hoc analysis of data from the European subgroup was conducted. A total of 2925 men were randomised to treatment in Europe as part of CombAT (tamsulosin, n=972; dutasteride, n=970; combination, n=983). Combination therapy significantly reduced the relative risk of AUR or BPH-related surgery compared with either monotherapy at 4 years, and also significantly reduced the risk of BPH clinical progression. Combination therapy also provided significantly greater symptom improvement than either monotherapy at 4 years. Safety and tolerability of dutasteride plus tamsulosin was consistent with previous experience of this combination and with the monotherapies. These data provide further evidence to support the use of long-term combination therapy (dutasteride plus tamsulosin) in men with moderate-to-severe lower urinary tract symptoms because of BPH and prostatic enlargement. The results in the European subgroup are generally consistent with those in the overall study population.