Ecological study of socio-economic indicators and prevalence of asthma in schoolchildren in urban Brazil

BACKGROUND: There is evidence of higher prevalence of asthma in populations of lower socio-economic status in affluent societies, and the prevalence of asthma is also very high in some Latin American countries, where societies are characterized by a marked inequality in wealth. This study aimed to examine the relationship between estimates of asthma prevalence based on surveys conducted in children in Brazilian cities and health and socioeconomic indicators measured at the population level in the same cities. METHODS: We searched the literature in the medical databases and in the annals of scientific meeting, retrieving population-based surveys of asthma that were conducted in Brazil using the methodology defined by the International Study of Asthma and Allergies in Childhood. We performed separate analyses for the age groups 6-7 years and 13-14 years. We examined the association between asthma prevalence rates and eleven health and socio-economic indicators by visual inspection and using linear regression models weighed by the inverse of the variance of each survey. RESULTS: Six health and socioeconomic variables showed a clear pattern of association with asthma. The prevalence of asthma increased with poorer sanitation and with higher infant mortality at birth and at survey year, GINI index and external mortality. In contrast, asthma prevalence decreased with higher illiteracy rates. CONCLUSION: The prevalence of asthma in urban areas of Brazil, a middle income country, appears to be higher in cities with more marked poverty or inequality

Early diagnosis of HIV-1: Infected infants in Brazil using nested-PCR

The polymerase chain reaction (PCR) has been the most promising test for HIV-1 early diagnosis in infants suspected of perinatal transmission. The first and second reactions of the amplification in 41 infants (under 18 months old) suspected of HIV-1 perinatal infection, were standardized and carried out in the present study. The first and the second PCR were carried out with the sets of primers JA4-JA7, JA9-JA12, JA13-JA16, and JA17-JA20 for the first reaction of amplification (outer primers) and JA5-JA6, JA10-JA11, JA14-JA15, and JA18-JA19 for the second reaction of amplification (inner primers), resulting in amplification of 131, 341, 172, and 129 pb, respectively. From 41 patients analysed, 12 patients presented positive to HIV-1 infection by PCR. The gag, env (region 1), and pol regions presented a greater sensitivity. The first and the second reactions of the amplification were performed with the same concentration of MgCl2 for all sets of primers. The results agree with several studies that affirm that the PCR is the indicated method for HIV-1 early diagnosis in infants suspected of perinatal infection.50210711

Relationship between physiologic deadspace/tidal volume ratio and gas exchange in infants with acute bronchiolitis on invasive mechanical ventilation

Objectives. To evaluate the association between deadspace/ tidal volume ratio (V-D/V-T) and gas exchange variables: PaO2, PacO(2), PaO2/FIO2, arterial/alveolar oxygen tension ratio (PaO2/PAO(2)), alveolar-arterial oxygen tension difference/arterial oxygen tension ratio (P(A-a)O-2/PaO2), carbon dioxide production (VCO2), ventilation index ([PaCO2 x peak inspiratory pressure x mechanical respiratory rate]/1000), and oxygenation index ([mean airway pressure x FIO2 x 100]/PaO2), all measured at an early stage in children with obstructive acute respiratory failure. Design: Prospective, cross-sectional, observational study. Setting: Pediatric intensive care unit, university hospital. Patients: Twenty-nine infants with acute bronchiolitis, defined according to clinical and radiologic criteria, Children with chronic pulmonary disease, neuromuscular disease, congenital cardiopathies, or hemodynamic instability were excluded. Interventions: Measurements were made between 24 and 72 hrs of mechanical ventilation using volumetric capnography and arterial blood gas analysis. Measurements and Main Results: The following variables significantly correlated with V-D/V-T, calculated using Spearman's correlation coefficient (r(s)): PaO2 (r(s) = -0.63, p < .001), PaO2/FIO2 (r(s) = -0.56, p = .002), PaO2/PAO(2) (r(s) = -0.46, p = .012), P(A-a)O-2/PaO2 (r(s) = 0.46, p =.012), PaCO2 (r(s) = 0.51, p = .005), VCO2 (r(s) = -0,62, p < .01), oxygenation index (r(s) = 0.48, p = .009), and ventilation index (r(s) = -0.53, p =.003). A statistically significant association was found between an increase in V-D/V-T and severity of lung injury, defined as PaO2/FIO2 < 200 (p =.03, Mann-Whitney). Conclusions: In the study population, V-D/V-T not only reflected ventilatory disorders, as is well recognized, but also was associated with disturbances of oxygenation. These results warrant further evaluation of the usefulness of serial measurement of V-D/V-T as a marker of disease severity in severe acute bronchiolitis and other causes of respiratory failure.8437237

Bone marrow features in children with HIV infection and peripheral blood cytopenias

HIV infection is associated with numerous abnormalities affecting both the myeloid and lymphoid lineages. We studied the features associated with peripheral cytopenias as the first sign of HIV infection in children. Peripheral blood (PB) counts, PB and bone marrow (BM) lymphocyte subsets, as well as viral load and serum levels of ferritin, vitamin B12, and folic acid were determined. Five children were naive of treatment (Group 1) and three were under HAART (Group 2). In Group 1 all patients had anemia of chronic disease. One had a bone marrow culture positive for Mycobacterium avium intracellulare and pancytopenia. Besides this, neutropenia and thrombocytopenia were seen in one patient each. In Group 2 anemia was found in all, neutropenia in one, and thrombocytopenia in two patients. Peripheral blood cytopenias were due to HAART toxicity in one patient. In the other two they were due to iron or folate deficiency. Bone marrow cytology showed cell abnormalities mainly in granulocytic precursors and megakaryocytes. All except two (taking HAART) patients had a high viral load. There was a straight correlation between viral load in PB and bone marrow. Viral load was correlated with peripheral CD4 but not with CD8 lymphocytes. A decrease in bone marrow B lymphocytes was seen in all patients. The introduction of HAART improved peripheral cytopenias. Bone marrow examination was useful for determining the etiology of the cytopenias and for detection of opportunistic infection. Hemopoietic cell abnormalities were similar to those seen in adults and indicative of HIV infection.51211411