A Community-Based Approach to the Promotion of Breastfeeding in Mexico

A comprehensive education strategy is presented that links training, community education, research, and mass-media efforts to enhance breastfeeding practices. Breastfeeding promotion models, an administrative system, and lessons learned during the project are described. The keys to effective breastfeeding promotion are shown to be accurate information; appropriate education, training, and follow-up; and a supportive administrative system.     

The validity of clerkship performance evaluations

The validity of narrative evaluations of clinical performance in medical school was investigated for three successive classes of medical school graduates. The criteria were ratings obtained from residency supervisors one year after entering the programme. Bivariate correlational analysis, multiple regression analysis and canonical redundancy analysis were performed to examine the associations between the evaluations by teachers of competence in medical school clerkships and the subsequent ratings by residency supervisors. The results, best summarized in the canonical analysis, showed two relationships between the two sets of measures (lambda 1 = 0.54 and lambda 2 = 0.47). The first relationship revealed an overall-competence-in-medicine dimension; the second suggested an interpersonal-skills/professional-maturity dimension. Overall, knowledge of clerkship performance accounted for 15% of the variance in residency ratings. The findings suggest the need to improve the assessment of professional maturity and behaviour during medical school.     

Left ventricular mass in hypertensive patients with mild‐to‐moderate reduction of renal function

Aim: Left ventricular hypertrophy (LVH) is an independent predictor of cardiovascular (CV) morbidity and mortality. The aim of the present study was to evaluate the relationship between LV mass and mild‐to‐moderate renal dysfunction in a group of non‐diabetic hypertensives, free of CV diseases, participating in the Renal Dysfunction in Hypertension (REDHY) study. Methods: Patients with diabetes, a body mass index (BMI) of more than 35 kg/m², secondary hypertension, CV diseases and a glomerular filtration rate (GFR) of less than 30 mL/min per 1.73 m² were excluded. The final sample included 455 patients, who underwent echocardiographic examination and ambulatory blood pressure monitoring. Results: There was a significant trend for a stepwise increase in LV mass, indexed by both body surface area (LVMI) and height elevated to 2.7 (LVMH^2.7), with the declining renal function, that remained statistically significant after correction for potential confounders. The prevalence of LVH, defined either as LVMI of 125 g/m² or more or as LVMH^2.7 of 51 g/m^2.7 or more, was higher in subjects with lower values of GFR than in those with normal renal function (P < 0.001 in both cases). The multiple regression analysis confirmed that the inverse association between GFR and LVM was independent of confounding factors. Conclusion: The present study confirms the high prevalence of LVH in patients with mild or moderate renal dysfunction. In the patients studied (all with a GFR of 30 mL/min per 1.73 m²), the association between LVM and GFR was independent of potential confounders, including 24 h blood pressure load. Taking into account the negative prognostic impact of LVH, further studies focusing on a deeper comprehension of the mechanisms underlying the development of LVH in chronic kidney disease patients are needed.     

Development and suppression of a population of late-adhering macrophages in mouse malaria

Changes in phagocytic and adherent cell numbers were compared during the course of infections of mice with Plasmodium yoelii (Py) and P. berghei (Pb) and in vaccinated mice challenged with homologous parasites. Nucleated cells in the spleen increased in number in Py-infected mice and were maximal at the time of recovery. The number of phagocytic cells increased in parallel, as did the number of blood leucocytes. Rates of increase were accelerated in vaccinated mice. Changes in Pb-infected mice resembled controls and blood leucocytes showed no consistent increase. In infected mice, the number of spleen and bone marrow cells which adhered to plastic rose above normal. At some stages of infection, cells which did not adhere in 24 h did so in 72 h. Such late-adhering cells, which resembled macrophages in morphology, were most numerous at the time of recovery. They appeared to be derived from monocyte precursors which matured in culture. Sometimes cells adherent at 24 h suppressed the development of the late-adhering population. Silica invactivated these suppressive macrophages but did not affect the precursors which developed into late-adhering cells. It is concluded that malarial infection stimulates the production of precursors of the macrophage-monocyte series and that their development is regulated by the presence of mature macrophages.     

Suppressor T cells and soluble suppressor factors in allergy: effect of immunotherapy

Suppressor-cell activity of Concanavalin-A-stimulated lymphocytes was studied in allergic patients by inhibition of one-way mixed lymphocyte culture reactions before and after allergy immunotherapy. This activity was compared with twelve healthy controls. In preliminary experiments, six out of eight allergic patients had no detectable T suppressor activity. In the second prospective group, eight out of eleven patients had much reduced suppressor-cell activity before immunotherapy, and seven out of eleven patients had much reduced activity after immunotherapy. The data suggest that non-specific T suppressor-cell activity is reduced in allergic patients but immunotherapy does not restore such activity.