No Adverse Effect of Genetically Modified Antifungal Wheat on Decomposition Dynamics and the Soil Fauna Community – A Field Study

The cultivation of genetically modified (GM) plants has raised several environmental concerns. One of these concerns regards non-target soil fauna organisms, which play an important role in the decomposition of organic matter and hence are largely exposed to GM plant residues. Soil fauna may be directly affected by transgene products or indirectly by pleiotropic effects such as a modified plant metabolism. Thus, ecosystem services and functioning might be affected negatively. In a litterbag experiment in the field we analysed the decomposition process and the soil fauna community involved. Therefore, we used four experimental GM wheat varieties, two with a race-specific antifungal resistance against powdery mildew (Pm3b) and two with an unspecific antifungal resistance based on the expression of chitinase and glucanase. We compared them with two non-GM isolines and six conventional cereal varieties. To elucidate the mechanisms that cause differences in plant decomposition, structural plant components (i.e. C∶N ratio, lignin, cellulose, hemicellulose) were examined and soil properties, temperature and precipitation were monitored. The most frequent taxa extracted from decaying plant material were mites (Cryptostigmata, Gamasina and Uropodina), springtails (Isotomidae), annelids (Enchytraeidae) and Diptera (Cecidomyiidae larvae). Despite a single significant transgenic/month interaction for Cecidomyiidae larvae, which is probably random, we detected no impact of the GM wheat on the soil fauna community. However, soil fauna differences among conventional cereal varieties were more pronounced than between GM and non-GM wheat. While leaf residue decomposition in GM and non-GM wheat was similar, differences among conventional cereals were evident. Furthermore, sampling date and location were found to greatly influence soil fauna community and decomposition processes. The results give no indication of ecologically relevant adverse effects of antifungal GM wheat on the composition and the activity of the soil fauna community

Comparison of human and porcine insulin therapies in children with newly diagnosed diabetes mellitus.

A multicenter, longitudinal study of children below the age of 16 years with newly diagnosed Type 1 (insulin-dependent) diabetes treated either with porcine monocomponent insulin (n = 26) or semisynthetic human monocomponent insulin (n = 26) was performed during the first 24 months after onset of diabetes. The two groups were carefully matched for age, duration of disease symptoms, initial metabolic values, islet cell antibodies and HLA-DR antigens. During the 24-month observation period there was no significant difference between the two groups in respect to the clinical course, insulin dosage, HbA1 and residual B-cell activity. No child in either group had a real remission without necessitating insulin therapy. The prevalence of insulin antibodies increased slowly and was 62% in the group treated by human insulin and 52% in the porcine insulin-treated group after 24 months. The titres were generally low and there was no statistical difference between the two groups in respect to insulin antibody formation