Medical education change: a detailed study of six medical schools

This article reports a comparative case study of six selected USA medical schools, undertaken to identify factors that facilitate or obstruct innovation in medical education. The findings suggest that the culture of each medical school results from a combination of intra-institutional and external factors. Together these forces influence substantially the fate of educational innovations. The institutional culture influences critical elements such as educational philosophy, leadership and resources provided in support of innovation. Equally important, the culture shapes the level and type of change a school considers and implements. The findings also suggest that the availability of resources and the creative impetus present in schools giving priority to research can benefit the educational goals and facilitate educational change.     

The direct effect of graft compliance mismatch per se on development of host arterial intimal hyperplasia at the anastomotic interface

To study the direct and sole effect of compliance mismatch on anastomotic intimal hyperplasia of the host arterial wall and to minimize possible confounding factors, dogs with a low thrombotic potential were selected as experimental subjects. Externally supported 6 cm x 5 mm Dacron grafts with a compliance value of approximately 1/300 of the host artery were implanted into the carotid arteries with end-to-end anastomoses on one side and end-to-side anastomoses on the other. The control graft was an autogenous carotid artery segment 4 cm in length transplanted into the femoral artery. Eight cases (24 grafts) were studied for 1 year and three (nine grafts) for 6 months. All were patent throughout the study period except for two noncompliant grafts with end-to-end anastomoses; thrombosis was the documented cause of occlusion. For the patent grafts, follow-up arteriograms showed no progressive narrowing of noncompliant anastomoses. Whether compliant or noncompliant, light microscopy studies showed slight intimal thickening within 1 to 2 mm of the anastomotic line, possibly the result of the normal healing response to stitch and surgical trauma. Quantitatively, 22 measurements representing longitudinal and circumferential thickness of the neointima were taken at each of the 40 patent noncompliant and 22 patent compliant control anastomoses. There was no statistically significant difference in anastomotic neointimal thickness in compliant and noncompliant grafts or for the different implantation periods. These data suggest that graft/host artery compliance mismatch does not cause arterial intimal hyperplasia at the anastomotic interface.     

Temporal patterns of clonality and parasitism in a population of freshwater bryozoans

Clonal reproduction is commonly incorporated into the life cycles of many metazoans. However, whether and how such highly clonal animals persist in the face of natural enemies remains poorly understood. Here we report the first temporal genetic study of a clonal population, the freshwater bryozoan Cristatella mucedo, and the associated prevalence of a myxozoan parasite. High levels of both clonality and parasitism persisted over a 3 year period. Random amplified polymorphic DNA markers revealed four distinct clones of C. mucedo. The two most common clones varied in abundance with the significantly more common clone in the first year becoming the significantly less common by the third year. There was no evidence that the most common clone was disproportionately infected. These results are discussed in relation to predictions of the Red Queen and the metapopulation dynamics of clonal organisms.     

Ecological and psychocultural mediators in the delivery of services for urban, culturally diverse Hispanic clients.

Influences on underuse of mental health services by the urban, low-income Latino subgroup are analyzed through a systems-cultural framework. Results of a review of over 100 applied, empirical, and theoretical published works in the last 14–26 yrs strongly suggest that when social-ecological and psychocultural perspectives are used by service providers, their therapeutic relationship, techniques, and treatment plan become more clinically and culturally compatible with the presenting problems of the urban Latino client. Accuracy of assessment and effectiveness of treatment also have been found to increase. Recommendations for the overlapping domains of clinical practice, graduate training, and program and policy development are offered. By augmenting assessment and intervention models to encompass a psychocultural and socioecological view, professionals move toward a greater concordance with the life problems, phenomenology, and value orientation of urban, culturally diverse Hispanic families. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Measuring heart patients' willingness to pay for changes in angina symptoms

Willingness-to-pay (WTP) measures of the effects of changes in health on a person's welfare are more comprehensive than traditional cost-of-illness (COI) measures, but they are sometimes difficult to obtain. The authors investigated two approaches for measuring heart patients' WTP for changes in their angina symptoms. First, actual expenditures and perceived angina episodes avoided were used to infer an averting-behavior measurement of WTP. Second, a contingent-valuation approach was used to ask direct WTP questions regarding a hypothetical medical treatment that could be purchased to avoid additional angina episodes. The results indicated that although negligible COI changes were expected with small changes in angina frequency, the subjects had significant WTP to avoid increases in angina. The average WTP to avoid additional angina episodes revealed by the averting-behavior questions was comparable to the directly-elicited WTP, providing a test of the validity of the contingent-valuation approach.     

Sexual partner change and condom use among urban factory workers in northwest Tanzania

High resolution, magnetic resonance imaging was used to quantitatively study the morphometry of the superior oblique muscles of two patients with superior oblique myokymia, as well as 18 superior oblique muscles of 14 patients with normal superior oblique function. The cross sectional area of each superior oblique muscle was measured at 3-millimeter intervals along the entire muscle length. In both cases of myokymia, the affected superior oblique muscles were significantly smaller than normal (P < .05). These anatomical changes in the superior oblique muscle of patients with myokymia suggest that an antecedent injury to the trochlear nerve has occurred. This injury, even if clinically unapparent, may be the initial event which leads to subsequent development of superior oblique myokymia.     

Comparison of analytic models for estimating the effect of clinical factors on the cost of coronary artery bypass graft surgery

The cost of treating disease depends on patient characteristics, but standard tools for analyzing the clinical predictors of cost have deficiencies. To explore whether survival analysis techniques might overcome some of these deficiencies in the analysis of cost data, we compared ordinary least square (OLS) linear regression (with and without transformation of the data) and binary logistic regression with two survival models: the Cox proportional hazards model and a parametric model assuming a Weibull distribution. Each model was applied to data from 155 patients undergoing coronary artery bypass grafting. We examined the effects of age, sex, ejection fraction, unstable angina, and number of diseased vessels on univariable and multivariable predictions of costs. The significant univariable predictors of cost were consistent in all models: ejection fraction was significant in all five models, and age and number of diseased vessels were each significant in all but the OLS model, while sex and angina type were significant in none of the models. The significant multivariable predictors of cost, however, differed according to model: ejection fraction was a significant multivariable predictor of cost in all five models, age was significant in three models, and number of diseased vessels was significant in one model. All five models were also used to predict the costs for an average patient undergoing surgery. The Cox model provided the most accurate predictions of mean cost, median cost, and the proportion of patients with high cost. This study shows: (1) lower ejection fraction and older age are independent clinical predictors of increased cost of CABG, and (2) the Cox proportional hazards model shows considerable promise for the analysis of the impact of clinical factors upon cost.