Anaerobic energy provision does not limit Wingate exercise performance in endurance-trained cyclists

[EN] The aim of this study was to evaluate the effects of severe acute hypoxia on exercise performance and metabolism during 30-s Wingate tests. Five endurance- (E) and five sprint- (S) trained track cyclists from the Spanish National Team performed 30-s Wingate tests in normoxia and hypoxia (inspired O(2) fraction = 0.10). Oxygen deficit was estimated from submaximal cycling economy tests by use of a nonlinear model. E cyclists showed higher maximal O(2) uptake than S (72 +/- 1 and 62 +/- 2 ml x kg(-1) x min(-1), P < 0.05). S cyclists achieved higher peak and mean power output, and 33% larger oxygen deficit than E (P < 0.05). During the Wingate test in normoxia, S relied more on anaerobic energy sources than E (P < 0.05); however, S showed a larger fatigue index in both conditions (P < 0.05). Compared with normoxia, hypoxia lowered O(2) uptake by 16% in E and S (P < 0.05). Peak power output, fatigue index, and exercise femoral vein blood lactate concentration were not altered by hypoxia in any group. Endurance cyclists, unlike S, maintained their mean power output in hypoxia by increasing their anaerobic energy production, as shown by 7% greater oxygen deficit and 11% higher postexercise lactate concentration. In conclusion, performance during 30-s Wingate tests in severe acute hypoxia is maintained or barely reduced owing to the enhancement of the anaerobic energy release. The effect of severe acute hypoxia on supramaximal exercise performance depends on training background.

Constitutive gene expression profile segregates toxicity in locally advanced breast cancer patients treated with high-dose hyperfractionated radical radiotherapy

[EN] Breast cancer patients show a wide variation in normal tissue reactions after radiotherapy. The individual sensitivity to x-rays limits the efficiency of the therapy. Prediction of individual sensitivity to radiotherapy could help to select the radiation protocol and to improve treatment results. The aim of this study was to assess the relationship between gene expression profiles of ex vivo un-irradiated and irradiated lymphocytes and the development of toxicity due to high-dose hyperfractionated radiotherapy in patients with locally advanced breast cancer. Raw data from microarray experiments were uploaded to the Gene Expression Omnibus Database http://www.ncbi.nlm.nih.gov/geo/ (GEO accession GSE15341). We obtained a small group of 81 genes significantly regulated by radiotherapy, lumped in 50 relevant pathways. Using ANOVA and t-test statistical tools we found 20 and 26 constitutive genes (0 Gy) that segregate patients with and without acute and late toxicity, respectively. Non-supervised hierarchical clustering was used for the visualization of results. Six and 9 pathways were significantly regulated respectively. Concerning to irradiated lymphocytes (2 Gy), we founded 29 genes that separate patients with acute toxicity and without it. Those genes were gathered in 4 significant pathways. We could not identify a set of genes that segregates patients with and without late toxicity. In conclusion, we have found an association between the constitutive gene expression profile of peripheral blood lymphocytes and the development of acute and late toxicity in consecutive, unselected patients. These observations suggest the possibility of predicting normal tissue response to irradiation in high-dose non-conventional radiation therapy regimens. Prospective studies with higher number of patients are needed to validate these preliminary results.

Determinants of specific food consumption in the Canary Islands (Spain)

[EN]The consumption of specific functional foods (FF) and some determinants of FF item selection were assessed using a questionnaire administered to 1112 individuals in the Canary Islands (Spain). The results indicated that the highest prevalence was fortified drinks (63.6%; 95%CI: 60.7–66.5). Overall FF consumption prevalence was 80.1% (95%CI: 77–83): single FF item consumption being rare. There were significant inter-group relationships, and some group intakes (milk products, cereals and drinks) were related to age but with no overall relationship between consumption and age. The education level was significantly related to the consumption of cereals, drinks, meat products and condiments (c2 test p ¼ 0.04).