Umbilical cord blood transplantation is clinically limited by its low progenitor cell content. Ex vivo expansion has become an alternative to increase the cell dose available for transplants. Expansion has been evaluated in several ways such as static cultures combining growth factors or mimicking the natural microenvironment using co-culture systems. However, static cultures have a small volume capacity and therefore large-scale expansion has been addressed using bioreactors. These and other biotechnological approaches for the expansion of hematopoietic progenitors and their utility to study several aspects of hematopoietic stem cell biology are discussed here.

The objective of this study was to compare the chemical composition and ruminal degradation of whole pod, exomesocarp, endocarp and seed fractions of red and white mesquite pods. The pods contained on average 220 g free sugars, 78 g crude protein, 21 g fat per kg dry matter (DM), and a potential DM degradation of 163 g/kg. Contaminant fungi (mostly Aspegillus spp.) count was low. Unsaturated fatty acids, mainly linoleic acid, were the predominant (~50%) fatty acids in whole pods and seeds. Sucrose was the largest free sugar proportion. The highest fibre content was found in the endocarp, the highest free sugar was found in the exomesocarp, and the highest crude protein content was found in the seeds. Tannins were more abundant in red pods (0.4 mg/100 g DM) than in white ones. Some differences in nutritional values were found between red and white pods and their components (exomesocarp, endocarp and seeds), although both have a potentially high nutritive value. Whole pods and the endocarp can be used by ruminants; seeds can be used by simple stomach animals; and the exomesocarp can be used in human nutrition because of its low glycaemic index properties.

In this work, we evaluated the expansion of human hematopoietic stem cells from umbilical cord blood in roller bottles. The Iscove's modified Dulbecco's medium, the Stem Pro 34-SFM medium, and the L-15 Leibovitz's medium for cultures in CO(2)-free atmosphere were assessed. At day 5 of culture, total colony forming unit expansions of 14.44 ± 3.74, 11.20 ± 6.37, and 17.25 ± 3.65-folds were attained, respectively. The expansion reached using L-15 medium in roller bottles was around 10 times higher than that achieved in the static control cultures. To our knowledge, this is the first report of cultures in CO(2)-free atmosphere to expand cord blood human hematopoietic stem cells and it opens a new branch of possibilities for culturing and clinical applications.

Colon cancer is a world concerning disease; it shows a high mortality rate and may be related to eating habits. Studies using inulin-like fructans, which are produced as energy supplies by several plants, have demonstrated a chemo-protective effect of these fructans in colon cancer. However, agavins a structurally different type of fructans from the Agave genus with demonstrated prebiotic effects, have been poorly studied for their possible protective effects in cancer. The aim of the present study was to evaluate the effect of Agave fructan-rich diets in colon cancer progress using a rat model and "Agave mezcalero potosino" A. salmiana Otto ex Salm Dick, which is widely distributed in Mexico. Results showed a significant decrease (p<0.05) in early lesions of colon cancer (aberrant crypt foci) compared with the control group. These data suggest that fructans from A. salmiana may contribute to a reduction in the risk of colon cancer as well as inulin-like compounds.