Assessing the Validity of a Multidisciplinary Mini-Clinical Evaluation Exercise.

Construct: The purpose of this study was to provide validity evidence for the mini-clinical evaluation exercise (mini-CEX) as an assessment tool for clinical skills in the workplace. BACKGROUND: Previous research has demonstrated validity evidence for the mini-CEX, but most studies were carried out in internal medicine or single disciplines, therefore limiting generalizability of the findings. If the mini-CEX is to be used in multidisciplinary contexts, then validity evidence should be gathered in similar settings. The purpose of this study was to gather further validity evidence for the mini-CEX but in a broader context. Specifically we sought to explore the effects of discipline and rater type on mini-CEX scores, internal structure, and the relationship between mini-CEXs and OSCEs in a multidisciplinary context. APPROACH: During clerkship, medical students completed eight different rotations (family medicine, internal medicine, surgery, psychiatry, pediatrics, emergency, anesthesiology and obstetrics and gynecology). During each rotation, mini-CEX forms and a written examination were completed. Two multidisciplinary OSCEs (in Clerkship Year 3 and start of Year 4) assessed clinical skills. The reliability of the mini-CEX was assessed using Generalizability analyses. To assess the influence of discipline and rater type, mean scores were analyzed using a factorial analysis of variance. The total mini-CEX score was correlated to scores from the students' respective OSCEs and corresponding written exams. RESULTS: Eighty-two students met inclusion criteria for a total of 781 ratings (average of 9.82 mini-CEX forms per student). There was a significant effect of discipline (p < .001, = .16), and faculty provided lower scores than nonfaculty raters (7.12 vs. 7.41; p = .002, = .02). The g-coefficient was .53 when discipline was included as a facet and .23 when rater type was a facet. There were low, but statistically significant correlations between the mini-CEX and scores for the 4th-year OSCE Total Score and the OSCE communication scores, r(80) = .40, p < .001 and r(80) = .29, p = .009. The mini-CEX was not correlated with the written examination scores for any of the disciplines. CONCLUSIONS: Our results provide conflicting findings for validity evidence for the mini-CEX. Mini-CEX ratings were correlated to multidisciplinary OSCEs but not written examinations, supporting the validity argument. However, reliability of the mini-CEX was low to moderate, and error accounted for the greatest amount of variability in scores. There was variation in scores due to discipline and resident raters gave higher scores than faculty. These results should be considered when considering the use of the mini-CEX in different contexts.

Extracellular matrix and hormones modulate DAX-1 localization in the human fetal adrenal gland.

CONTEXT: The orphan nuclear receptor DAX-1 is essential for human adrenal cortex development and functions as a transcriptional repressor of multiple genes implicated in steroidogenic pathways. OBJECTIVE: The aim of this study was to investigate the localization of the DAX-1 protein in human fetal adrenal glands and to assess whether this protein can be modulated by the extracellular matrix and hormones. RESULTS: DAX-1 is localized mainly in the nucleus in the outer definitive zone and in the cytoplasm in the fetal zone, whereas the number of DAX-1 positive cells decreases from the external to the internal portion of the gland. When cultured on a collagen or a fibronectin matrix, DAX-1 is localized in the nucleus of the definitive cells and exhibits a nucleocytoplasmic distribution in the fetal cells. ACTH stimulation induces nuclear localization of DAX-1 in fetal cells cultured on collagen without modifying nucleocytoplasmic localization on fibronectin. In contrast, angiotensin II induces the protein to be localized only in the cytoplasm in fetal cells cultured on either collagen or fibronectin. CONCLUSIONS: The localization of DAX-1 is compatible with the known functional properties of DAX-1 regarding the steroidogenic activity of adrenal cells. Moreover, this study suggests that modulation of DAX-1 localization in the fetal adrenal gland by hormones and components of the extracellular matrix may represent a mechanism for controlling the expression of steroidogenic enzymes in the definitive and fetal zones.

Connection between integrins and cell activation in rat adrenal glomerulosa cells: a role for Arg-Gly-Asp peptide in the activation of the p42/p44(mapk) pathway and intracellular calcium.

Integrins are responsible for adhesion and activation of several intracellular cascades. The present study was aimed at determining whether the interaction between fibronectin and integrins could generate pathways involved in physiological functions of rat adrenal glomerulosa cells. Immunofluorescence studies and adhesion assays showed that fibronectin was the best matrix in promoting the formation of focal adhesion. Binding of glomerulosa cells to fibronectin, but not to collagen I or poly-L-lysine, involved the integrin-binding sequence Arg-Gly-Asp (RGD). Activation of glomerulosa cells with Arg-Gly-Asp-Ser (RGDS) induced an increase in [Ca(2+)](i), whereas fibronectin triggered a release of Ca(2+) from InsP(3)-sensitive Ca(2+) stores. Aldosterone secretion induced by ACTH, angiotensin II, and RGDS and proliferation were improved on fibronectin, compared with poly-L-lysine. The RGDS peptide induced a transient increase in the activity of the p42/p44(mapk), independent of phosphatidylinositol-3 kinase and protein kinase C. Integrins alpha(5) and alpha(V) as well as their fibronectin receptor partners beta(1) and beta(3), were identified. These results suggest that in rat adrenal glomerulosa cells, binding of the alpha(5)beta(1), alpha(v)beta(1), or alpha(v)beta(3) integrins to fibronectin is involved in the generation of two important signaling events, increase in intracellular calcium, and activation of the p42/p44(mapk) cascade, leading to cell proliferation and aldosterone secretion.

Hormone-sensitive lipase deficiency in mice causes lipid storage in the adrenal cortex and impaired corticosterone response to corticotropin stimulation.

Hormone-sensitive lipase (HSL, E.C.3.1.1.3, gene designation Lipe) is reportedly the major cholesteryl esterase of adrenal cortex. Because of the potential importance of cholesteryl ester hydrolysis in steroidogenesis, gene-targeted HSL-deficient mice were assessed for adrenal cortical morphology and function. Compared with control animals, HSL deficiency results in a marked accumulation of lipid droplets both in zona glomerulosa and zona fasciculata. In the zona fasciculata, lipid accumulation was observed progressively from the outer to the inner regions, culminating near the corticomedullary junction with the formation of syncytial-lipoid structures having the appearance of degenerative cells. These morphological changes did not significantly alter the basal levels of circulating corticosterone, but following ACTH stimulation, corticosterone levels were decreased (P < 0.001). The observation of normal basal corticosterone and aldosterone levels demonstrates that some free cholesterol for steroid synthesis can be produced independently of HSL. Taken together, these results indicate that HSL-deficient mice accumulate lipid droplets in such a way as to impair acute ACTH stimulation of corticosterone secretion. Such observations are also found in some forms of congenital adrenal hyperplasia. By extension, HSL deficiency may be a cause of hereditary adrenocortical hypofunction in humans.