The proteome of cytosolic lipid droplets isolated from differentiated Caco-2/TC7 enterocytes reveals cell-specific characteristics

Background information. Intestinal absorption of alimentary lipids is a complex process ensured by enterocytes and leading to TRL [TAG (triacylglycerol)-rich lipoprotein] assembly and secretion. The accumulation of circulating intestine-derived TRL is associated with atherosclerosis, stressing the importance of the control of postprandial hypertriglyceridaemia. During the postprandial period, TAGs are also transiently stored as CLDs (cytosolic lipid droplets) in enterocytes. As a first step for determining whether CLDs could play a role in the control of enterocyte TRL secretion, we analysed the protein endowment of CLDs isolated by sucrose-gradient centrifugation from differentiated Caco-2/TC7 enterocytes, the only human model able to secrete TRL in culture and to store transiently TAGs as CLDs when supplied with lipids. Cells were analysed after a 24 h incubation with lipid micelles and thus in a state of CLD-associated TAG mobilization

Academic and social integration of Master students: a cross-institutional comparison between Dutch and international students

In Europe there is a growing concern among educators and policy makers that students are not well-prepared to start a Master programme. This study draws on longitudinal research conducted at four universities in the Netherlands and a follow-up exploratory purposively chosen from one of the study sites. In Study 1, differences in academic performance between 146 Dutch and 215 international students were identified by focussing on their levels of academic and social integration. Afterwards, students from 53 countries were clustered into ten geographical clusters using Hofstede culture difference scores. In Study 2, a questionnaire about perceived transitional barriers was completed by 159 Master students at one of the four institutes. The results of Study 1 indicate that academic and social integration scores of Western European and domestic students were comparable. Eastern European, non-European and in particular Southern Asian and Confucian Asian Master students had significantly lower academic and social integration scores. Follow-up regressions showed that academic adjustment is the main predictor of study- performance, irrespective of cultural differences. Study 2 indicates that half of the Master students experienced a substantial change in their learning strategies, language and research methods. We encourage UK higher educational institutes to conduct more research on whether the specific needs of international Master students are sufficiently supported

Peer development as an alternative to peer observation: a tool to enhance professional development

Many Higher Education institutions worldwide require that all academic staff undergo a peer observation of teaching each academic year. Within one department in a university in the South of England, questions have arisen about the value and purpose of the traditional 'peer observation' process, and as a result a new voluntary system of 'peer development' has been introduced. This paper explains the rationale underpinning the new peer development process, and explores its worth and value to those who have participated in it as a mechanism for professional development. Reflections on the process are considered, along with what can be done to improve the new system

Structural domain of apolipoprotein A-I involved in its interaction with cells

Apolipoprotein A-I (apo A-I) is the major protein constituent of high-density lipoprotein (HDL), the lipoprotein fraction which mediates the reverse cholesterol transport. This apolipoprotein plays an important role in the binding of HDL to cells and participates in the efflux of cellular cholesterol. We have recently compared six different genetic variants of apo A-I and found that the apo A-I (Pro 165 → Arg) mutant is defective in promoting cellular cholesterol efflux from murine adipocytes and peritoneal macrophages and we have proposed that this region of apo A-I may be involved in their interaction with cells. To confirm this hypothesis, four monoclonal antibodies (mAbs) specific for apo A-I were used to study the inhibition of the interaction of palmitoyloleoylphosphatidylcholine(POPC) :apoA-I complexes with HeLa cells and adipocytes. Among these antibodies, the apo A-I epitope recognized by the A44 mAb lies in the COOH terminal region (amino acid residues 149-186) including the proposed region. The antibodies A05, and A03 react with residues 25-82, 135-140, respectively and the All mAb corresponds to a discontinuous epitope at residues 99-105 and 126-132. Our results show clearly that the A44 and A05 mAbs reduce both the binding to HeLa cells and the cholesterol efflux from adipocytes. The inhibition of POPC :apoA-I complexes binding to both cell types is more strictly observed with the Fab fragments of monoclonal antibodies A44 and A05. Partial cotitration curves of these mAbs in a solid phase assay (RIA), indicated partial competition between these two antibodies. We propose a structural model for the POPC :apoA-I complexes where the N-terminal domain of one apo A-I molecule is in close spatial relationship with the C-terminal domain of the adjacent apo A-I molecule. We therefore suggest that the domain around amino acid 165 of apo A-I and which is recognized by mAb A44 (149-186) forms or contains some specific regions which mediate selectively the interaction with the binding site of cells and is involved in the efflux of cellular cholesterol. © 1994.SCOPUS: ar.jinfo:eu-repo/semantics/publishe