Development and application of analytical methods for the determination of mycotoxins in organic and conventional wheat.

The aim of this study was to develop a multicomponent analytical method for the determination of deoxynivalenol (DON), ochratoxin A (OTA) and zearalenone (ZEN), nivalenol (NIV), 3-acetyl-DON (3-acDON), 15-acetyl-DON (15-acDON), zearalenol (ZOL) and citrinin (CIT) in wheat. It also aimed to survey the presence and amounts of DON, OTA and ZEN in Belgian conventionally and organically produced wheat grain and in wholemeal wheat flours. After solvent extraction, an anion-exchange column (SAX) was used to fix the acidic mycotoxins (OTA, CIT), whilst the neutral mycotoxins flowing through the SAX column were further purified by filtration on a MycoSep cartridge. OTA and CIT were then analysed by high-performance liquid chromatography (HPLC) using an isocratic flow and fluorescence detection, while the neutral mycotoxins were separated by a linear gradient and detected by double-mode (ultraviolet light fluorescence) detection. The average DON, ZEN and OTA recovery rates from spiked blank wheat flour were 92, 83 and 73% (RSDR = 12, 10 and 9%), respectively. Moreover, this method offered the respective detection limits of 50, 1.5 and 0.05 microg kg-1 and good agreement with reference methods and inter-laboratory comparison exercises. Organic and conventional wheat samples harvested in 2002 and 2003 in Belgium were analysed for DON, OTA and ZEN, while wholemeal wheat flour samples were taken from Belgian retail shops and analysed for OTA and DON. Conventional wheat tended to be more frequently contaminated with DON and ZEN than organic samples, the difference being more significant for ZEN in samples harvested in 2002. The mean OTA, DON and ZEA concentrations were 0.067, 675 and 75 microg kg-1 in conventional samples against 0.063, 285 and 19 microg kg-1 in organically produced wheat in 2002, respectively. Wheat samples collected in 2003 were less affected by DON and ZEN than the 2002 harvest. Organic wholemeal wheat flours were more frequently contaminated by OTA than conventional samples (p < 0.10). The opposite pattern was shown for DON, organic samples being more frequently contaminated than conventional flours (p < 0.10).

[Quantity of foods, weight of anatomic structures and body weight in the muskrat (Ondatra zibethicus, L., 1766)]. / Quantités comestibles, poids des structures anatomiques et poids corporel chez le rat musqué (Ondatra zibethicus, L., 1766).

Weights of skeletons, several viscera (heart, lungs, empty stomach and intestine, liver, spleen, kidneys) and muscles of 80 muskrats were taken. The data were analyzed and compared versus four classes of ages and sexes: adult males, adult females, sub-adult males and sub-adult females. The weight of the muscles is 47 to 50% of the live-weight in the four classes studied. The weight of the viscera is approximately 10 to 12% of the live-weight. Thus, the weight of edible matters varies, in the muskrat between 57 and 62% of the live-weight. The spleen of adult females is relatively heavier than that of adult males or sub-adult females.

[Andrews' pustular bacterids of hands and feet; Sachs' acrodermatitis pustulosa perstans. Histological study (author's transl)]. / La pustulose palmo-plantaire chronique et récidivante (pustular bacterids of hands and feet d'Andrews) (acrodermatitis pustulosa perstans de Sachs). Etude histologique.

Pustulosis palmaris et plantaris chronica et recidivans (pustular bacterid of Andrews) is not an exceptional disease. Its characteristic histological structure is to be considered as a major element of the diagnosis. The fully developed pustule is an oval cavity with transverse long axis, entirely situated within a loca-ly hyperplastic epidermis. Its formation goes through several stages. The first one is spongiosis appearing in the epidermis above the top of a dermal papilla. This gives rise to a vesicle filled with fluid and mononuclear leucocytes. In the next stage, the roof consisting of the malpighian layers is disrupted, and the vesicular fluid comes into contact with the horny layer. There is massive invasion of the cavity by polymorphonuclear leucocytes which penetrate into the intercellular spaces of the vesicle wall, where pictures of spongiform pustules are seen. The initial vesicle, and the late, secundary appearance of the spongiform aspects demonstrate that the mechanism of formation of the lesion of pustulosis palmaris et plantaris chronica et recidivans is different from the one of psoriasis pustulosa palmo-plantaris and that, consequently, these are two different diseases.