Ganglioside composition of differentiated caco-2 cells resembles human colostrum and neonatal rat intestine.
| Related Articles |
Ganglioside composition of differentiated Caco-2 cells resembles human colostrum and neonatal rat intestine.
Br J Nutr. 2008 Aug 20;:1-7
Authors: Schnabl KL, Field C, Clandinin MT
Gangliosides are glycosphingolipids found in cell membranes and human milk with important roles in cell proliferation, differentiation, growth, adhesion, migration, signalling and apoptosis. Similar changes in ganglioside composition occur during embryonic development, lactation and cancer cell differentiation. It is not known, however, whether ganglioside compositional changes that occur in differentiating colon cancer cells reflect changes that occur during intestinal development. The Caco-2 cell line is commonly used to study physiological and pathophysiological processes in the small intestine and colon. Therefore, to examine this question, undifferentiated and differentiated Caco-2 cells were grown and total lipid was extracted from cell supernatant fractions using the Folch method. The upper aqueous phase containing gangliosides was collected and purified. Total gangliosides were measured as ganglioside-bound N-acetyl neuraminic acid, while individual ganglioside content was quantified via a colorimetric assay for sialic acid and scanning densitometry. The total ganglioside content of differentiated Caco-2 cells was 2.5 times higher compared with undifferentiated cells. Differentiated Caco-2 cells had significantly more (N-acetylneuraminyl) 2-galactosylglucosyl ceramide (GD3) and polar gangliosides, and a lower N-acetylneuraminylgalactosylglucosylceramide (GM3):GD3 ratio than undifferentiated cells. The present study demonstrates that the total ganglioside content and individual ganglioside composition of differentiated Caco-2 cells are similar to those of human colostrum and neonatal rat intestine. Differentiated Caco-2 cells may therefore be an alternative model for studying physiological and pathological processes in the small intestine and colon, and may help to elucidate possible functions for specific gangliosides in development and differentiation. Further research using more sensitive techniques of ganglioside analysis is needed to confirm these findings.
PMID: 18713482 [PubMed - as supplied by publisher]
(Source: The British Journal of Nutrition)
MedWorm Sponsored Message: Find out how you can get your message across here by sponsoring this MedWorm news feed.
Effects of food energy on cognitive performance: no support from event-related potentials (yet?).
| Related Articles |
Effects of food energy on cognitive performance: no support from event-related potentials (yet?).
Br J Nutr. 2008 Aug 20;:1-5
Authors: de Bruin EA, Gilsenan MB
Several reviews of behavioural studies have concluded that some foods may have beneficial effects on cognitive performance. The present review summarises findings from studies using event-related potentials to investigate the food effects on brain activity underlying cognition. Despite initial positive indications from observational studies, subsequent studies with a within-subject design have not consistently confirmed these effects. This could be due to several factors, e.g. the use of attention tests (in contrast to memory tests employed in behavioural studies) and the lack of a control condition in some instances. Future studies could benefit from measuring cognitive performance with more difficult tests that tap into cognitive domains other than attention, using an appropriately controlled cross-over design, and a more systematic variation and complete description and characterisation of the food intervention.
PMID: 18713483 [PubMed - as supplied by publisher]
(Source: The British Journal of Nutrition)Soybean allergen detection methods - a comparison study
Soybean containing products are widely consumed, thus reliable methods for detection of soy in foods are needed in order to make appropriate risk assessment studies to adequately protect soy allergic patients. Six methods were compared using eight food products with a declared content of soy: a direct sandwich ELISA based on polyclonal rabbit antibody (ab) to raw soy flakes, a commercial and an in-house competitive ELISA both based on ab to denatured, 'renatured' soy protein, an enzyme-allergosorbent test (EAST) inhibition based on two sera from soy allergic patients, histamine release (HR) using basophils passively sensitized with patient serum and a PCR method detecting soy DNA. Eight food products were selected as model foods to test the performance of the methods. There was an overall good agreement between the methods in terms of ranks of soy content but not the quantity. The sandwich ELISA aimed at native soy proteins had the lowest detection limit of 0.05 ppm, but only identified soy in 5/8 products, and generally in lower amounts compared to other methods. The competitive ELISA had a higher detection limit of 21 ppm, but seemed more successful in detecting processed soy. Only HR, EAST inhibition and PCR detected soy in all eight products. In spite of a general good correlation in terms of ranks of soy content, more than a single method may be necessary to confirm the presence of soy in foods. (Source: Molecular Nutrition)