Diagnosis of iron deficiency anemia in children of Northeast Brazil.

OBJECTIVE: To diagnose iron deficiency anemia in children. METHODS: The study was conducted with a sample of 301 children aged six to 30 months attending public daycare centers in the city of Recife, Northeast Brazil, in 2004. The diagnoses of anemia were based on a combination of different hematological and biochemical parameters: hemoglobin, mean corpuscular volume, ferritin, C-reactive protein, transferrin saturation and transferrin receptor. The chi-square test and ANOVA were used in the statistical analysis. RESULTS: Of all children studied, 92.4% had anemia (Hb<110 g/L) and 28.9% had moderate/severe anemia (Hb<90 g/L). Lower levels of hemoglobin were found in children aged 6-17 months. Iron deficiency was found in 51.5% of children using ferritin (<12 microg/L) as parameter. Taking into consideration the combination of hemoglobin level, ferritin and transferrin receptor, 58.1% had anemia with iron deficiency, 34.2% had anemia without iron deficiency and 2.3% had iron deficiency without anemia. Mean ferritin concentration was significantly higher in children with high C-reactive protein when compared with those with normal levels (22.1 vs. 14.8 microg/L). CONCLUSIONS: The use of several biochemical and hematological parameters allowed to diagnosing iron deficiency anemia in two thirds of children, suggesting a need to identify other determinants of anemia without iron deficiency.

Diagnosis of iron deficiency anemia in children of Northeast Brazil / Diagnóstico de anemia por deficiencia de hierro en niños del Noreste de Brasil

OBJETIVO: Diagnosticar anemia por deficiência de ferro em crianças. MÉTODOS: O estudo foi desenvolvido com uma amostra de 301 crianças com idade entre seis e 30 meses, usuárias de creches públicas de Recife, PE, em 2004. Para o diagnóstico da anemia utilizou-se a combinação de diferentes parâmetros hematológicos e bioquímicos: hemoglobina, volume corpuscular médio, ferritina, proteína C-reativa, saturação da transferrina e receptor da transferrina. Para a análise estatística empregou-se o teste do qui-quadrado e ANOVA. RESULTADOS: Do total de crianças, 92,4 por cento tinha anemia (Hb < 110g/L) e 28,9 por cento apresentou anemia moderada/grave (Hb<90g/L). Níveis mais baixos de hemoglobina foram observados em crianças de seis a 17 meses. Encontrou-se deficiência de ferro em 51,5 por cento das crianças, utilizando-se a ferritina (< 12µg/L) como parâmetro. Considerando a combinação da concentração de hemoglobina, ferritina e do receptor de transferrina, 58,1 por cento tinha anemia com deficiência de ferro, 34,2 por cento anemia sem déficit de ferro e 2,3 por cento deficiência de ferro sem anemia. A concentração média de ferritina foi significativamente maior em crianças com proteína C-reativa aumentada quando comparada com aqueles com níveis normais (22,1 versus 14,8 µg/L). CONCLUSÕES: A utilização de diversos parâmetros bioquímicos e hematológicos possibilitou diagnosticar anemia por deficiência de ferro em dois terços das crianças, revelando a necessidade de identificar outros determinantes de anemia sem deficiência de ferro.

OBJETIVO: Diagnosticar anemia por deficiência de ferro em crianças. MÉTODOS: O estudo foi desenvolvido com uma amostra de 301 crianças com idade entre seis e 30 meses, usuárias de creches públicas de Recife, PE, em 2004. Para o diagnóstico da anemia utilizou-se a combinação de diferentes parâmetros hematológicos e bioquímicos: hemoglobina, volume corpuscular médio, ferritina, proteína C-reativa, saturação da transferrina e receptor da transferrina. Para a análise estatística empregou-se o teste do qui-quadrado e ANOVA. RESULTADOS: Do total de crianças, 92,4% tinha anemia (Hb < 110g/L) e 28,9% apresentou anemia moderada/grave (Hb<90g/L). Níveis mais baixos de hemoglobina foram observados em crianças de seis a 17 meses. Encontrou-se deficiência de ferro em 51,5% das crianças, utilizando-se a ferritina (< 12µg/L) como parâmetro. Considerando a combinação da concentração de hemoglobina, ferritina e do receptor de transferrina, 58,1% tinha anemia com deficiência de ferro, 34,2% anemia sem déficit de ferro e 2,3% deficiência de ferro sem anemia. A concentração média de ferritina foi significativamente maior em crianças com proteína C-reativa aumentada quando comparada com aqueles com níveis normais (22,1 versus 14,8 µg/L). CONCLUSÕES: A utilização de diversos parâmetros bioquímicos e hematológicos possibilitou diagnosticar anemia por deficiência de ferro em dois terços das crianças, revelando a necessidade de identificar outros determinantes de anemia sem deficiência de ferro.

Salicylate enables cochlear arachidonic-acid-sensitive NMDA receptor responses.

Currently, many millions of people treated for various ailments receive high doses of salicylate. Consequently, understanding the mechanisms by which salicylate induces tinnitus is an important issue for the research community. Behavioral testing in rats have shown that tinnitus induced by salicylate or mefenamate (both cyclooxygenase blockers) are mediated by cochlear NMDA receptors. Here we report that the synapses between the sensory inner hair cells and the dendrites of the cochlear spiral ganglion neurons express NMDA receptors. Patch-clamp recordings and two-photon calcium imaging demonstrated that salicylate and arachidonate (a substrate of cyclooxygenase) enabled the calcium flux and the neural excitatory effects of NMDA on cochlear spiral ganglion neurons. Salicylate also increased the arachidonate content of the whole cochlea in vivo. Single-unit recordings of auditory nerve fibers in adult guinea pig confirmed the neural excitatory effect of salicylate and the blockade of this effect by NMDA antagonist. These results suggest that salicylate inhibits cochlear cyclooxygenase, which increased levels of arachidonate. The increased levels of arachidonate then act on NMDA receptors to enable NMDA responses to glutamate that inner hair cells spontaneously release. This new pharmacological profile of salicylate provides a molecular mechanism for the generation of tinnitus at the periphery of the auditory system.

Peroxynitrite mild nitration of albumin and LDL-albumin complex naturally present in plasma and tyrosine nitration rate-albumin impairs LDL nitration.

In blood, peroxynitrite (ONOO- ) and CO2 react to form NO2* and CO3* through the short-lived adduct ONOOCO2-, leading to protein-bound tyrosine nitration. ONOO(-) -modified LDL is atherogenic. Oxidatively modified LDL generally appears in the vessel wall surrounded by antioxidants. Human serum albumin (HSA) is one of them, partly associated to LDL as a LDL-albumin complex (LAC). The purpose was to study the effect of a mild nitration on LAC and whether albumin may interfere with LDL nitration. To do so, SIN-1 was used as ONOO- generator in the presence or absence of 25 mM HCO3-. The human serum albumin (HSA)-bound tyrosine nitration rate was found to be 4.4 x 10(-3) mol/mol in the presence of HCO3-. HSA decreased the LAC-tyrosine nitration rate from 2.5 x 10(-3) to 0.6 x 10(-3) mol/mol. It was concluded that HSA impaired the apoB-bound tyrosine nitration. These findings raise the question of the patho-physiological significance of these nitrations and their interactions which may potentially prevent both atheromatous plaque formation and endothelium dysfunction in particular and appear to be beneficial in terms of atherogenic risk.

Saúde e nutrição de crianças de áreas urbanas da Zona da Mata Meridional de Pernambuco: resultados preliminares de um estudo de coorte / Child health and nutrition in urban areas in the South of Pernambuco: preliminary results of a cohort study

OBJETIVOS: apresentar as características socioeconômicas e demográficas, o perfil nutricional de crianças ao nascer e aos 12 meses de vida, além dos dados longitudinais sobre aleitamento, diarréia e situação vacinal durante o primeiro ano de vida. MÉTODOS: uma amostra de 652 recém-nascidos foi recrutada de setembro de 1997 a agosto de 1998 e acompanhada durante os primeiros 18 meses de vida. Essas crianças residiam nas áreas urbanas de quatro municípios da zona da mata meridional de Pernambuco. A coleta de dados foi realizada através de visitas domiciliares. RESULTADOS: cerca de 60 por cento das famílias tinham uma renda per capita ú ® salário mínimo e 41 por cento das mães referiam menos de quatro anos de escolaridade. A mediana do aleitamento materno exclusivo e total foi de 0 dias e 94 dias, respectivamente. A incidência da diarréia foi de dois episódios/criança/ano nos primeiros 12 meses de vida e a prevalência de déficit peso/idade e comprimento/idade (<-2 escores z) aos 12 meses foram de 6,8 por cento e 11 por cento, respectivamente. Apenas 66 por cento das crianças aos 12 meses tinham completado o esquema vacinal. CONCLUSÕES: o desenvolvimento desta pesquisa prospectiva contribuirá para uma maior compreensão dos problemas de saúde e nutrição da população infantil e para o adequado planejamento de intervenções na área.

New insight on the relationship between LDL composition, associated proteins, oxidative resistance and preparation procedure.

Oxidized low density lipoprotein (LDL) plays an important role in atherogenesis. It is generally thought that LDL is mainly oxidized in the intima of vessel walls, surrounded by hydrophilic antioxidants and proteins such as albumin. The aim of this study was to investigate the possible interrelationships between oxidation resistance of LDL and its protein and lipid moieties. Proteins and to a lesser extent lipids, appeared to be the major determinants in the LDL Cu2+-oxidation resistance, which in turn depend on the ultracentrifugation (UC) procedure used. Comparing high speed/short time (HS/ST, 4 h), high speed/long time (HS/LT, 6-16h) and low speed/long time (LS/LT, 24h) conditions of UC, HS with the shortest time (4h) led to prepare LDL (named LDL.HS-4 h) with higher total protein and triglyceride contents, unchanged total cholesterol, phospholipids and Vitamin E, and higher Cu2+-oxidation resistance. Among proteins, only albumin allows to explain changes. PAF acetyl hydrolase appeared to be unaffected, whereas its pro-oxidant role was established and found only in the absence of albumin. In contrast the pro-oxidant role of caeruloplasmin took place regardless of the albumin content of LDL. The antioxidant effect of albumin (the oxidation lag time was doubled for 20mol/mol albumin per LDL) is assumed to be due to its capacity at decreasing LDL affinity for Cu2+. Interestingly, the LDL.HS-4 h albumin content mirrored the intrinsic characteristics of LDL in the plasma and was not affected by added free albumin. Moreover, it has been verified that in 121 healthy subjects albumin was the best resistance predictor of the Cu2+-oxidation of LDL.HS-4 h, with a multiple regression equation: lag time (min) = 62.1 + 0.67(HSA/apoB) + 0.02(TG/apoB)-0.01(TC/apoB); r = 0.54, P < 0.0001. Accounted for by lag time, the oxidation resistance did not correlate with alpha-tocopherol and ubiquinol contents of LDL. The mean albumin content was about 10mol/mol, and highly variable (0-58 mol/mol) with subjects. The LDL.HS-4h may account for the status of LDL in its natural environment more adequately than LDL resulting from other conditions of UC.

Convective and diffusive losses of vitamin C during haemodiafiltration session: a contributive factor to oxidative stress in haemodialysis patients.

BACKGROUND: Enhanced oxidative stress in haemodialysis (HD) patients may be considered as a risk factor for accelerated atherosclerosis. Reduced antioxidant defences include impairment in enzyme activities and decreased plasma levels of hydrophilic vitamin C (vit C), and cellular levels of lipophilic vitamin E (vit E). METHODS: We investigated plasma levels of vit C in 19 patients undergoing regular haemodiafiltration (HDF) (mean age 62+/-7 years) and in 1846 healthy elderly subjects (HS) (mean age 69+/-5 years). The contribution of convection and diffusion was determined using paired filtration dialysis (PFD), a modified HDF technique which physically separates convective from diffusive fluxes. Blood samples were collected before and after the HDF session; in addition at 60 min of HDF, samples were drawn from arterial lines (AL) and venous lines (VL), dialysate (D) and ultrafiltrate (UF). Blood levels of total vit C were determined using an HPLC fluorescence method. Markers of oxidative stress were also assessed in both populations as follows: levels of malondialdehyde (MDA) were determined by fluorometric assay, measurements of advanced oxidation protein products (AOPP) and glutathione peroxidase (GSH-Px) activity were performed by spectrophotometric assay, and plasma vit E content was obtained by an HPLC procedure. RESULTS: A significant reduction in plasma vit C level was observed in HDF patients when compared with HS (1.6+/-1.4 microg/ml in HDF vs 6.6+/-3.7 microg/ml in HS; P<0.01). The HDF session was associated with a dramatic reduction in vit C levels (1.87+/-1.57 microg/ml before HDF and 0.98+/-0.68 microg/ml after HDF); at 60 min of HDF, concentrations were as follows: AL=1.35+/-1.27 microg/ml; VL=0.37+/-0.31 microg/ml, D=0.40+/-0.34 microg/ml, UF=1.24+/-1.18 microg/ml; corresponding to a diffusive flux of 271 microg/min and a convective flux of 126 microg/min. Total loss of vit C could be assessed at 66 mg/session (8--230 mg/session). According to this loss of vit C, presence of an oxidative stress was demonstrated in HD population as shown by a significant increase in MDA (1.66+/-0.27 microM in HD vs 0.89+/-0.25 microM in HS; P<0.01) and AOPP (77.5+/-29.3 microM in HD vs 23.5+/-13.2 microM in HS; P<0.01) levels, and a decrease in GSH-Px activity (259.2+/-106.3 U/l in HD vs 661.2+/-92.2 U/l in HS; P<0.01). No change in plasma vit E between both populations (30.7+/-9.1 microM in HD vs 35.3+/-7.34 microM in HS) was observed. CONCLUSIONS: These results suggest that HDF with highly permeable membranes is associated with a significant loss of vit C. Diffusive transport is responsible for two-thirds whereas convective phenomenon accounts for only one-third of this loss.