Is celiac disease due to molecular mimicry between gliadin peptide-HLA class II molecule-T cell interactions and those of some unidentified superantigen?

This paper presents a new hypothesis for the etiology and pathogenesis of celiac disease (CD). It is our contention that CD is triggered by the binding of one or more gliadin peptides to CD-associated HLA class II molecules. Furthermore, we propose that these putative CD peptides bind to oligosaccharide residues on HLA class II molecules distal to the peptide-binding groove invoking recognition and binding by specialized subsets of gamma delta T cell receptor-bearing lymphocytes. The binding of these gamma delta T cells serves as a signal for abrogation of oral tolerance to ingested proteins setting in motion a series of immune responses directed against the small intestinal epithelium of CD patients. CD patients are victimized by this self-distructed immune response because of inheritance of certain combinations of HLA-DQ and DR haplotypes. Dimers encoded by HLA-DR haplotypes may be the primary restriction elements for lectin-like, gliadin peptides while the degree of immune suppression (or lack thereof) to ingested gliadins is governed by inherited HLA-DQ haplotypes. Finally, we speculate that molecular mimicry between one or more gliadin peptides and some, as yet unidentified, bacterial or viral superantigen plays a role in disease pathogenesis.

Development and validation of the Cholesterol-Saturated Fat Index (CSI) Scorecard: a dietary self-monitoring tool.

OBJECTIVE: The Cholesterol-Saturated Fat Index (CSI) Scorecard was developed and tested as a self-monitoring tool for patients consuming a cholesterol-lowering diet. SUBJECTS/DESIGN: Twelve nutritionists used the CSI Scorecard to estimate the CSI score of the same five food records. Subsequently, using a revised tool, 12 subjects with hypercholesterolemia estimated the CSI score of their 4-day food records and 11 participated in evaluation meetings. STATISTICAL ANALYSES: Two-tailed, one-sample t tests and the Spearman rho correlation test were used, respectively, to compare CSI Scorecard estimates of nutritionists and participants to CSI scores obtained from computer calculations. RESULTS: The CSI scores estimated by the nutritionists were close to the computed scores at the 25th and 75th food record percentiles. The correlation of the estimated CSI scores of participants to the computed scores was rs = .8 (P < .05). APPLICATION: The CSI Scorecard is a new, simple, quick, and accurate dietary self-monitoring tool patients can use in research centers and primary care settings. By numerically illustrating the saturated fat and cholesterol content of foods, the CSI Scorecard facilitates dietary self-monitoring and, thus, self-efficacy in the adoption and maintenance of a cholesterol-lowering dietary pattern.

Diet, hormonal, and metabolic factors affecting bone mineral density in adolescent amenorrheic and eumenorrheic female runners.

Seven adolescent female runners with secondary amenorrhea and six adolescent eumenorrheic female runners received dietary supplements of 1200 mg calcium carbonate and 400 IU vitamin D/d for 12 months. Bone mineral density (BMD) of the axial skeleton was measured by dual photon densitometry at the beginning and end of the 12 month period. Plasma estradiol and ionized calcium concentration were also determined. Bone mineral density decreased in two of the amenorrheic subjects, with the lowest estradiol values concurrent with the severest training regimen and highest calcium intake. There was a significant decrease in plasma estradiol concentration in the amenorrheic runners (p less than 0.05). Plasma ionized calcium and estradiol explained 99% of the variation in BMD (r2 = 0.999). A significant inverse relationship between plasma estradiol and miles run/week was observed (r2 = -0.748). Adolescent female runners who train extensively and have low plasma estradiol levels may be adversely affecting BMD despite supplemental calcium and vitamin D intake.

"Dine to Your Heart's Content": an assessment of the program in Virginia.

The "Dine to Your Heart's Content" program in Virginia was examined from the perspectives of both patrons and restaurateurs. Both groups were tested on knowledge of food composition relative to fats and oils. Additionally, restaurateurs responded to questions concerning the need for nutrition education for their personnel. Eighty-eight percent of the 178 patrons expressed an interest in following a heart-healthy diet: 55% maintained that they always or often were motivated by health-related considerations when selecting menu items. The most important characteristics of the menu items (5-point scale, 1 = least important) were reported to be low cholesterol (3.85 +/- 1.01), low saturated fat (3.77 +/- 1.05), low total fat (3.76 +/- 1.03), low sodium (3.69 +/- 1.15), and low calorie (3.57 +/- 1.13). Fifty-seven percent of the patrons were aware of the program, but most of them dined in participating restaurants less than half of the time they dined out. There were no significant differences between the scores of patrons and restaurant personnel regarding knowledge of fat and oil content of foods. The overall mean score for the entire group was 6.09 +/- 3.4 points out of a possible 13 points. Restaurateurs cited nutrition education for waitstaff and assistance in the identification of appropriate menu items as aspects of the program most in need of further development. The major disadvantage of the program cited was potential negative attention drawn to some menu items. Overall, however, restaurateurs concurred that the advantages of participation in the program outweighed the disadvantages. All of them stated that the major advantage of the program was the ease with which a public service could be provided to their patrons while, simultaneously, the image of the restaurant was enhanced.

Role and nature of an interview in the selection of CUP applicants.

The purposes of this research were to study the role of an interview in the selection of applicants in coordinated undergraduate programs (CUPs) in dietetics and to ascertain the nature of the interview in those programs in which it was used. A questionnaire sent to all CUP directors asked why they did or did not use an interview, the criteria used to determine which applicants would be interviewed, and the makeup of the interviewing team. Furthermore, the directors were asked to state the types of questions asked most frequently, the rationale for asking those questions, and the procedure used to evaluate applicants' responses. Finally, the directors were asked to rate the level of influence of selected factors that might be used in the decision regarding admission to CUP. The overall response rate was 81%. Results indicated that an interview is used in 80% of the programs. Difficulty in scheduling and in achieving a standardized method of evaluating an interview were the most frequently cited reasons for not using one. Thirty-seven percent of the respondents ranked an interview as high in influencing the decision regarding admission to CUP. In contrast, 90% of the respondents ranked completion of prerequisite courses and 86% ranked overall GPA as highly influential factors.

Evaluating student performance in clinical dietetics.

The focus of this study was on the development and field-testing of a set of behaviorally anchored rating scales for evaluating the clinical performance of dietetic students. The scales emphasized the application of skills and knowledge. A variation of the Smith-Kendall technique was used to develop the scales. The 42 participants involved in instrument development included dietetic students, didactic and clinical instructors, and dietetic practitioners. The completed instrument contained 8 dimension statements and 70 behavioral anchors. The instrument was field-tested in 16 clinical rotations within 8 dietetic education programs. Evaluators not only rated student performance but also critiqued the format and content of the scales. The mid-to-upper portions of each scale were used most frequently, and little score variation within or across programs was noted. The scales were deemed appropriate for formative evaluation; however, some evaluators who had to grade students' performance expressed a desire for performance standards defined in terms of grades. Because the process used to develop the instrument facilitated the articulation of performance criteria, it is recommended as a practical approach to setting performance standards.