Assessment of ochratoxin A stability following gamma irradiation: experimental approaches for feed detoxification perspectives

The present study evaluated the effect of gamma irradiation on the stability of ochratoxin A (OTA) under various conditions. The effects of the physical state of OTA (solid vs aqueous), initial OTA concentration, irradiation dose and dose rate as well as the presence of model substances simulating food matrix compounds on OTA radiostability were investigated. First, pure OTA with and without food model compounds including α-D-glucose (monosaccharide), Methyl α-D-glucopyranoside (starch) and the amino acid derivatives N-α-acetyl-L-lysine methyl ester and N-α-acetyl-L-cysteine methyl ester (protein models) were irradiated with doses of 2, 4 and 8 kGy applied at 15.117 and 108.24 Gy/min. Secondly, artificially OTA-contaminated wheat with different moisture content (11, 14 and 16%) was irradiated with doses of 2, 4 and 8 kGy applied at 63.39 Gy/min. Residual OTA levels were analysed using ultra-high performance liquid chromatography coupled with tandem mass spectrometry. Solid OTA (50 and 3,200 ng/ml)showed great irradiation stability, even with irradiation doses up to 8 kGy. Under dry conditions, the presence of food model components did not affect OTA radiostability. However, in an aqueous solution, complete reduction was achieved at the initial OTA concentration of 50 ng/ml and irradiation dose of 2 kGy. Applying gamma irradiation to cereal-based food model systems produced a significant OTA reduction (5,000 µg/kg) of 47.2% in moistened wheat kernels (16%) with an absorbed dose of 8 kGy but failed to reduce the OTA content of low moisture content wheat (11%). These model experiments offered a useful tool to assess the main key factors affecting gamma irradiation-induced OTA reduction. Gamma irradiation is promising since the irradiation doses applied could partially reduce OTA contamination. Nevertheless, its efficacy was largely affected by initial moisture content and could be dangerous if toxic by-products are produced or nutritive quality is lost and needs further study.

Fractional laser for vitiligo treated by 10,600 nm ablative fractional carbon dioxide laser followed by sun exposure

BACKGROUND

Vitiligo is an acquired disorder of the skin and mucous membranes. Many patients with vitiligo remain in the refractory state despite the availability of numerous potential treatments. To the best of our knowledge, only one trial considers ablative fractional CO2 laser in the treatment of vitiligo.

OBJECTIVE

To investigate the effects of fractional CO2 laser followed by systemic sun exposure on non-segmental vitiligo (NSV).

METHODS

Ten patients presenting refractory NSV were enrolled in this study. The patients underwent three sessions, one month apart, of fractional CO2 laser therapy on the affected areas of the skin (L-group). Five days after each laser treatment, patients were asked to expose themselves to the sun for 2 hours on a daily basis. Objective and subjective clinical assessments were performed at the beginning and at the end of the treatment. The L-group was then compared to a control group (C-group) that consisted of vitiligo lesions in the same patients but with sun exposure as the exclusive therapy.

RESULTS

Compared to the C-group, the L-group showed better improvement in both objective and subjective assessments. There were no noticeable adverse events in terms of scarring and Koebner phenomenon among others.

CONCLUSIONS

All patients treated with both, laser sessions and sun exposure, improved their chronic NSV lesions. Improvement was less significant in patients who exhibited vitiligo lesions over articular surfaces such as elbows and underarms. The best results were observed in vitiligo plaques located on the face, neck and legs. Consequently, fractional CO2 laser followed by sun exposure could be considered as an alternative modality for the treatment of refractory vitiligo, especially in sunny regions.

The origins of the condom

We know little about the origins of one of the oldest forms of contraception in medicine, the condom. Condoms were initially recognised as being useful for the prevention of sexually transmissible infections. Later on, they were used as contraceptives. We present here a short presentation of the condom’s history.