The role of the GATA2 transcription factor in normal and malignant hematopoiesis.

Hematopoiesis involves an elaborate regulatory network of transcription factors that coordinates the expression of multiple downstream genes, and maintains homeostasis within the hematopoietic system through the accurate orchestration of cellular proliferation, differentiation and survival. As a result, defects in the expression levels or the activity of these transcription factors are intimately linked to hematopoietic disorders, including leukemia. The GATA family of nuclear regulatory proteins serves as a prototype for the action of lineage-restricted transcription factors. GATA1 and GATA2 are expressed principally in hematopoietic lineages, and have essential roles in the development of multiple hematopoietic cells, including erythrocytes and megakaryocytes. Moreover, GATA2 is crucial for the proliferation and maintenance of hematopoietic stem cells and multipotential progenitors. In this review, we summarize the current knowledge regarding the biological properties and functions of the GATA2 transcription factor in normal and malignant hematopoiesis.

Óxidos de colesterol en alimentos cocinados con presencia habitual en nuestra dieta / Cholesterol oxidation products in common cooked foods

Los productos de oxidación del colesterol (COPs) poseen demostrados efectostóxicos y están implicados en el desarrollo de aterosclerosis. Pueden estar presentesen organismos animales y por ende, en alimentos de origen animal, siendosusceptibles de ser absorbidos a través de la dieta. Su formación en los alimentosse favorecería, al tratarse de un proceso de oxidación química, por la elevación dela temperatura y la presencia de oxígeno. En este trabajo se presenta una estimaciónde la presencia de COPs en diferentes tipos de alimentos cocinados mediantediferentes tecnologías culinarias y almacenados mediante distintas modalidades deconservación. El análisis se llevó a cabo por cromatografía de gases-espectrometríade masas. Tanto pescados (salmón y langostinos) como carnes (hamburguesas,pechugas de pollo, lomo y salchichas tipo frankfurt) mostraron valores bajos deCOPs en crudo (0.003-0.552 mg/100 g alimento), incrementándose significativamentetras el cocinado (hasta 0.7 mg/100 g alimento). El cocinado con microondassupuso el mayor incremento de COPs en comparación con la fritura, plancha yasado. El almacenamiento a vacío disminuyó drásticamente la formación de COPs respecto al almacenamiento en aerobiosis. La congelación ralentizó más eficazmentela formación de COPs que la refrigeración

Cholesterol oxidation products (COPs) have shown different toxic effects andare involved in the development of atherosclerosis. These compounds can be foundin animal organisms, and inconsequence in animal origin foods, and they aresusceptible to be absorbed from the diet. Their formation in foods would be increasedby high temperatures and the presence of oxygen, as it is a chemicaloxidation process. In this paper, an estimation of the presence of COPs in differenttypes of foods treated by different cooking technologies are shown. Also differentstorage conditions are studied. The analysis was carried out by gas chromatography-mass spectrometry. Both fish (salmon and shrimps) and meat (hamburgers,breast chicken, pork loin and frankfurters) showed low COPs values in raw products(0.003-0.552 mg/100 g food), increasing significantly after the application ofcooking technologies (up to 0.7 mg/100 g food). Microwave treatment leaded to thehighest increase of COPs in comparison to frying, grilling and roasting. Vacuumstorage dramatically decreased COPs formation with regard to aerobic storage.Freezing minimized COPs formation more efficiently than refrigeration

Preliminary study on health-related lipid components of bakery products.

The purpose of this study was to evaluate the presence of health-related lipid components, in particular trans fatty acids and sterol oxidation products, in four bakery products. Both types of components are known for their adverse biological effects, especially the increase of atherogenic risk, and therefore it is advisable to monitor their presence in food products. Trans fatty acids were determined by silver-ion thin-layer chromatography-gas chromatography, whereas sterol oxidation was assessed by gas chromatography and gas chromatography-mass spectrometry determination of 7-keto derivatives (tracers of sterol oxidation). The amount of trans fatty acids (0.02 to 3.13 g/100 g of product), sterols (34.9 to 128.3 mg/100 g of product), and 7-keto derivatives of sterols (1.88 to 3.14 mg/kg of product) varied considerably among samples. The supply of phytosterols (22.5 to 64.0 mg/100 g of product) was not significant, and the extent of oxidation of most phytosterols to its corresponding 7-keto derivative was low (0.29 to 0.84%), except for that of brassicasterol (2.01 to 3.11%). The quality of ingredients and raw materials seems to have greatly influenced the fatty acid profile, stability, safety, and quality of the final product; these ingredients should be chosen with extreme care to decrease their potential negative health effects and to increase safety of these products.

Levels of phytosterol oxides in enriched and nonenriched spreads: application of a thin-layer chromatography-gas chromatography methodology.

The content of phytosterol oxidation products (POPs) in enriched and nonenriched commercial spreads was evaluated by thin-layer chromatography-gas chromatography (TLC-GC). Oxides of beta-sitosterol, campesterol, and stigmasterol were produced by thermo-oxidation (7-hydroxy, 7-keto, and epoxy derivatives) and chemical synthesis (triol derivatives), which were then separated and identified by TLC-GC. Their identification was further confirmed by GC-mass spectrometry (GC-MS). The total amounts of phytosterols found were 6.07 and 0.33 g/100 g of sample in phytosterol-enriched and nonenriched spread, respectively, whereas the total POPs contents were 45.60 and 13.31 mg/kg of sample in the enriched and nonenriched products. The main POPs found were the 7-keto derivatives of all phytosterols analyzed; 7-ketositosterol was the most abundant one (14.96 and 5.93 mg/kg of sample in phytosterol-enriched and nonenriched spread). No beta-epoxy and triol derivatives were detected in both types of samples. The enriched spread presented a lower phytosterol oxidation rate (0.07%) than the nonenriched one (0.41%).

Combined effect of cooking (grilling and roasting) and chilling storage (with and without air) on lipid and cholesterol oxidation in chicken breast.

The oxidation of the lipid fraction and cholesterol in raw and cooked chicken breast samples stored for 0 and 6 days at 4 degrees C under aerobic conditions and in vacuum packaging was studied. The multivariate statistical analysis showed significant effects of both culinary process and storage conditions on the lipid and cholesterol oxidation process, with a significant interaction between the two variables. Aerobic storage increased thiobarbituric acid reactive substances (TBA) from 0.04 to 0.06 ppm for raw samples, from 0.21 to 1.20 ppm for grilled samples, and from 0.24 to 1.62 ppm for roasted samples. During vacuum storage, only roasted samples showed significant increases in TBA. Levels of total cholesterol oxidation products (COP) remained low (2.88 to 4.35 microg/g of lipid) for all raw samples. Cooking increased COP levels to 12.85 and 11.54 microg/ g of lipid for grilled and roasted samples, respectively. Total COP and all individual COP except for cholestanetriol were significantly correlated with TBA and the peroxide index. However, the most extensive effect was attributable to the aerobic storage of cooked samples, which led to COP levels of 92.35 and 88.60 microg/g of lipid in grilled and roasted samples, respectively. Vacuum packaging did not increase COP levels for cooked samples.