Diet-induced changes in membrane gangliosides in rat intestinal mucosa, plasma and brain.

OBJECTIVES: The objective of this study was to determine if dietary gangliosides induce changes in the ganglioside content of intestinal mucosa, plasma and brain and to identify where GM3 and GD3 are localized in the enterocyte membrane. METHODS: Male 18-day-old Sprague-Dawley rats were fed a semipurified diet containing 20% (w/w) fat. The control diet contained triglyceride, reflecting the fat formulation of an existing infant formula. Two experimental diets were formulated by adding sphingomyelin (1% w/w of total fat) or a ganglioside-enriched lipid (0.1% w/w of total fat) to the control diet fat. The ganglioside fraction of ganglioside-enriched lipid diet contained more than 80% GD3. After 2 weeks of feeding, the total and individual ganglioside and cholesterol content was measured in small intestinal mucosa, plasma and brain. RESULTS: The ganglioside-enriched lipid diet significantly increased total gangliosides in the intestinal mucosa, plasma and brain compared with the control diet. The ganglioside-enriched lipid diet significantly increased the level of GD3 (7.5% w/w) in the intestine compared with control (3.2% w/w) while decreasing the level of GM3, the major ganglioside in the intestine. The ratio of cholesterol to ganglioside in the intestinal mucosa, plasma and brain decreased significantly in rats fed the ganglioside-enriched lipid diet compared with controls. Confocal microscopy showed that GM3 is exclusively localized in the apical membrane of the enterocyte whereas GD3 is primarily localized in the basolateral membrane. CONCLUSIONS: : The authors conclude that dietary ganglioside is absorbed in the small intestine and transported to different membrane sites, altering ganglioside levels in the intestinal mucosa, plasma and brain and thus possibly having the potential to change developing enterocyte function (and possibly that of other cell lines).

Do patients and expert doctors agree on the assessment of consultation skills? A comparison of two patient consultation assessment scales with the video component of the MRCGP.

OBJECTIVE: The purpose of this study was to determine whether patient ratings of general practice Registrars' consulting skills are associated with 'expert' scoring using the MRCGP video assessment protocol. METHODS: A cross-sectional observational study of general practice Registrars' consultation skills was carried out in 23 practices in South East Scotland using two types of patient assessment compared with expert assessment of video consultation. The main outcome measures were rank correlation of Registrars' overall level of attainment on the Royal College of General Practitioner (RCGP) video assessment with mean score on the Patient Enablement Instrument (PEI) and mean score on the Consultation Satisfaction Questionnaire (CSQ). RESULTS: The rank correlation of Registrars' mean PEI scores with marks on the RCGP video component was 0.01 (P = 0.97, n = 19) and mean CSQ score 0.05 (P = 0.83, n = 19). There were no adverse comments from patients, but Registrars and trainers found the process onerous. CONCLUSION: No meaningful association was identified between Registrars' score on the RCGP video examination and patient assessment via either the PEI or the CSQ. This suggests that, with regard to measuring quality in the consultation, one or more of the assessments are invalid or that they are measuring different attributes. Further research to elucidate the reasons for the lack of correlation is required.

Using web-based animations to teach histology.

We have been experimenting with the use of animations to teach histology as part of an interactive multimedia program we are developing to replace the traditional lecture/laboratory-based histology course in our medical and dental curricula. This program, called HistoQuest, uses animations to illustrate basic histologic principles, explain dynamic processes, integrate histologic structure with physiological function, and assist students in forming mental models with which to organize and integrate new information into their learning. With this article, we first briefly discuss the theory of mental modeling, principles of visual presentation, and how mental modeling and visual presentation can be integrated to create effective animations. We then discuss the major Web-based animation technologies that are currently available and their suitability for different visual styles and navigational structures. Finally, we describe the process we use to produce animations for our program. The approach described in this study can be used by other developers to create animations for delivery over the Internet for the teaching of histology.