Synergy between callous-unemotional traits and aggression in preschool children: Cross-informant and cross-cultural replication in the UK Wirral Child Health and Development Study, and the Colombian La Sabana Parent-Child Study.

Incremental prediction of aggression from callous-unemotional (CU) traits is well established, but cross-cultural replication and studies of young children are needed. Little is understood about the contribution of CU traits in children who are already aggressive. We addressed these issues in prospective studies in the United Kingdom and Colombia. In a UK epidemiological cohort, CU traits and aggression were assessed at age 3.5 years, and aggression at 5.0 years by mothers (N = 687) and partners (N = 397). In a Colombian general population sample, CU traits were assessed at age 3.5 years and aggression at 3.5 and 5.0 years by mother report (N = 220). Analyses consistently showed prediction of age-5.0 aggression by age-3.5 CU traits controlling for age-3.5 aggression. Associations between age-3.5 CU traits and age-5.0 aggression were moderated by aggression at 3.5 years, with UK interaction terms, same informant, ß = .07 p = .014 cross-informant, ß = .14 p = .002, and in Colombia, ß = .09 p = .128. The interactions arose from stronger associations between CU traits and later aggression in those already aggressive. Our findings with preschoolers replicated across culturally diverse settings imply a major role for CU traits in the maintenance and amplification of already established aggression, and cast doubt on their contribution to its origins.

Aplicación del examen clínico, objetivo estructurado, OSCE, en la evaluación final del internado de pediatría en dos escuelas de medicina / Objetive structured clinical examination for a pediatric internship assessment in 2 medical schools

Background: The Objective Structured Clinical Examination (OSCE) has become a respected and widely used tool for the assessment of clinical competence in medical education. Aim: To describe the first experience of an OSCE as a summative assessment in undergraduate Pediatric Internship, in two universities. Material and Methods: The OSCE was structured by a committee of faculty members of the 5 campi of University of Chile and I campus of the Catholic University. A 21 station OSCE was administered simultaneously to 124 Pediatric Interns (University of Chile =104, Catholic University=20), in 3 centers. A total of 50 faculty members participated in the examination. The OSCE consisted of 20 clinical problems, including videotape recordings, photographs, x-rays and laboratory exams, phantoms and 7 simulated standardized parents. Results: The average total OSCE score was 67.3 percent (range: 84.5 percent-43.5 percent). The maximum theoretic score was achieved in 19 stations. A significant correlation between station and total score, was found for 18 of the 20 clinical problems. Conclusions: The experience of using OSCE has been a success. The OSCE was an adequate procedure to assess a large number of interns simultaneously and it allowed us to measure the main objectives in all domains and a wide range of clinical competence of Pediatric Internship Programs

Mejoría en el desempeño académico de estudiantes de medicina en tiempos de reforma curricular / Improvement of medical studentïs academic performances in times of curricular reform

Background: During the last decade, academic life at the medical school of the Pontificia Universidad Cat-lica de Chile has been thoroughly affected by a curricular reform process. Changes started in 1993 and have continued up until now. This reform did not have an experimental design to allow for a scientific evaluation of its effects. However, it seems interesting to study the evolution of indices of academic performance of our students during this period. Aim: To evaluate the academic performance of medical students between 1989 and 1999. Subjects and Methods: All undergraduate students enrolled between 1989 and 1999. Academic performance was evaluated by 1) failure to pass one or more courses, 2) delay to complete the third year of studies, 3) withdrawal from school and 4) medical school grades. Results: All indices of academic performance changed during the period of study. Failure to pass, delay and withdrawal from school significantly decreased, whereas medical school grades improved, particularly in basic and pre-clinical subjects. Conclusions: Academic performance of medical students improved consistently between 1989 and 1999. While specific causal relationships cannot be established, we believe that this improvement is likely related to the curricular reform. This reform included horizontal and vertical integration of academic contents, greater emphasis in problem-based learning and additional instances of evaluation such as the repetition exam

Landscape features associated with infection by a malaria parasite (Plasmodium mexicanum) and the importance of multiple scale studies.

In a 3-year study, we examined landscape features (aspect, slope, sun exposure, canopy cover, type of ground cover, and nearest water source) that were potentially related to prevalence of infection with Plasmodium mexicanum in fence lizards (Sceloporus occidentalis) within a 4.5 ha study area in northern California, USA. Logistic regression analysis showed that ground cover type was the primary mediator of the probability of P. mexicanum infection. Infected lizards were captured more often in rock and/or leaf litter locations than in grassy ones. In another experiment, the study area was divided into 9 sites (0.07-0.33 ha), and infection prevalence was calculated for each. Three sites with high (> 30%) infection prevalence had significantly more rocky outcrops and leaf litter than those with low (< 20%) or moderate (20-30%) infection prevalence (N = 3 sites each). We conclude that lizard site selection may influence the probability of exposure to infected vectors and thus the likelihood of P. mexicanum infection. We also demonstrate that studies at different spatial scales may be required to understand fully the relationship between landscape features and parasite distribution.

Suppression and recovery of the neonatal hypothalamic-pituitary-adrenal axis after prolonged dexamethasone therapy.

OBJECTIVE: To evaluate the duration and level of hypothalamic-pituitary-adrenal (HPA) axis suppression in premature infants treated with a prolonged course of glucocorticoids for chronic lung disease. STUDY DESIGN: We evaluated HPA axis function in nine very low birth weight (VLBW) infants before and 48 hours after a prolonged (14 to 42 days) dexamethasone (Dex) course. Seven of these infants underwent serial testing in the Clinical Research Center to evaluate the time course of HPA axis recovery. Adrenal function was assessed directly with synthetic adrenocorticotropic hormone (ACTH) stimulation, pituitary function with ovine corticotrophin releasing hormone (oCRH) stimulation, and combined axis function with 3-hour metyrapone testing. RESULTS: Baseline cortisol values were higher before Dex therapy (18.6 +/- 3.9 microg/dl; mean +/- SEM) than after (5.77 +/- 1.45 microg/dl; p < 0.01), as were ACTH-stimulated cortisol levels (24.8 +/- 1.7 microg/dl vs 12.0 +/- 2.2 microg/dl; p < 0.001). ACTH response to oCRH decreased after Dex treatment (22.8 +/- 7.6 pg/ml vs 11.5 +/- pg/ml), but this was not statistically significant (p = 0.18). 11-Deoxycortisol (11-DOC) response to metyrapone dropped from 11.1 +/- 0.5 microg/dl to 4.7 +/- 1.0 microg/dl after Dex therapy (p < 0.0001). Longitudinal testing reveals that adrenal suppression may be short-lived, while recovery of higher centers is more delayed. CONCLUSIONS: Basal cortisol levels may be used as a screening test, but if the level is less than 15 microg/dl, more definitive testing should be performed. The sluggish recovery of higher HPA axis centers is most reliably evaluated by using 11-DOC response to a single dose of metyrapone in VLBW infants after prolonged Dex therapy.