Hypoxia sensing in the fetal chicken femoral artery is mediated by the mitochondrial electron transport chain.

Vascular hypoxia sensing is transduced into vasoconstriction in the pulmonary circulation, whereas systemic arteries dilate. Mitochondrial electron transport chain (mETC), reactive O(2) species (ROS), and K(+) channels have been implicated in the sensing/signaling mechanisms of hypoxic relaxation in mammalian systemic arteries. We aimed to investigate their putative roles in hypoxia-induced relaxation in fetal chicken (19 days of incubation) femoral arteries mounted in a wire myograph.

Intestinal protozoan infections in relation to nutritional status and gastrointestinal morbidity in Colombian school children.

While Giardia duodenalis infection has been consistently associated with nutrient malabsorption and stunting in children, the effects of other protozoans on nutritional status or gastrointestinal morbidity are less clear. We sought to determine whether infection with common intestinal protozoans including Giardia duodenalis, Entamoeba coli and Blastocystis hominis was associated with anthropometric and micronutrient status, gastrointestinal symptoms, visits to the doctor or school absenteeism in children 5-12 years of age from Bogotá, Colombia. We obtained stool samples from 442 children enrolled in primary schools in 2006 and examined the presence of intestinal protozoans in relation to height, body mass index, plasma concentrations of vitamins A and B12, ferritin and zinc and erythrocyte folate.

Evidence for an effect of fetal growth on the risk of tuberculosis.

We examined the risk of tuberculosis in relation to birth weight and ponderal index among 21,596 Swedish twins born from 1926 through 1958. Using a cohort design, tuberculosis risk was 11% lower for every 500 g of birth weight (P = .05) and 8% lower for every 0.

Brain apoptosis and carotid artery reactivity in fetal asphyctic preconditioning.

We aimed to develop a model of fetal hypoxia-ischemia (HI) preconditioning that reflects the pathophysiological conditions of perinatal asphyxia more closely than the existing neonatal stroke models. Fetal asphyxia (FA) was induced by clamping the uterine vasculature on embryonic day E17. At birth (P0), severe perinatal asphyxia (SPA) was induced during cesarean section.

Age-related changes in isoprostane-mediated relaxation of piglet blood vessels.

We studied the putative relaxant effects of several isoprostanes (8-iso-PGE1, and 8-iso-PGE2, 8-iso-PGF1alpha, 8-iso-PGF1beta, 8-iso-PGF2alpha, and 8-iso-PGF2beta) on pulmonary (PA), mesenteric (MA), coronary (CA) arteries and pulmonary veins (PV), from newborn and 2-week-old piglets. Isoprostanes were compared with agonists of the EP (PGE1, PGE2, and misoprostol), DP (PGD2), and IP (iloprost) receptors. Isoprostane-induced relaxation was only observed when TP receptors were occupied (by U46619) or blocked (by SQ 29,548).

Mitochondrial DNA damage analysis in bronchoalveolar lavage cells of preterm infants.

In mechanically ventilated preterm infants, the combination of immaturity, volutrauma, oxidative stress, and inflammatory processes can lead to chronic lung injury. Mitochondrial DNA (mtDNA) is more susceptible to oxidative damage than nuclear DNA. We aimed to investigate the level of mtDNA damage (deletions, mutations and changes in copy number) in bronchoalveolar lavage (BAL) cells from 10 preterm infants (27-30 weeks).

Response of chicken ductus arteriosus to hypercarbic and normocarbic acidosis.

Background: Changes in pH can have profound effects on vascular tone and reactivity, but their influence on the ductus arteriosus (DA) remains unknown.

Objective: To analyzethe effects of hypercarbic and normocarbic acidosis in the reactivity of the chicken DA.

Methods: DA rings from 19-day chicken fetuses (total incubation time, 21 days) were mounted in a wire myograph for isometric tension recording.

The economic and nutrition transition in Equatorial Guinea coincided with a double burden of over- and under nutrition.

We assess trends in children's nutritional status in Equatorial Guinea, a country in socioeconomic transition. Nationally representative samples were conducted in 1997, at the start of the economic take off, and again in 2004. Children aged 0-60 months were included in the surveys (N=436, 552).

A randomized trial to determine the optimal dosage of multivitamin supplements to reduce adverse pregnancy outcomes among HIV-infected women in Tanzania.

Background: We previously reported that supplementation with multivitamins (vitamin B complex, vitamin C, and vitamin E) at multiples of the Recommended Dietary Allowance (RDA) significantly decreased the risk of adverse pregnancy outcomes among HIV-infected women. The minimum dosage of multivitamins necessary for optimal benefits is unknown.

Objective: We investigated the efficacy of multivitamin supplements at single compared with multiple RDAs on decreasing the risk of adverse pregnancy outcomes among HIV-infected women.

Role of Rho-kinase in mediating contraction of chicken embryo femoral arteries.

Rho-kinase-dependent Ca2+ sensitization is an essential process for contraction of mammalian vascular smooth muscle but the information about its effects in non-mammalian vessels is scarce. We aimed to investigate, using the Rho-kinase inhibitor hydroxyfasudil, the potential role of the Rho-kinase pathway of Ca2+ sensitization in depolarization- and agonist-mediated contraction of chicken embryo (at day 19 of the 21 days of incubation) femoral arteries. Contraction elicited by KCl (125 mM) comprised two phases (phasic and tonic contraction), both of which were abolished in the absence of extracellular Ca2+.

Relation between vitamin B12 and folate status, and hemoglobin concentration and parasitemia during acute malaria infections in Colombia.

Anemia is a common complication of human malaria. Since micronutrient deficiencies are highly prevalent in malaria-endemic areas and appear to contribute to anemia etiology, we conducted a cross-sectional study in Tumaco, Colombia, to examine the associations between plasma vitamin B12 or erythrocyte folate concentrations and hemoglobin (Hb) among 96 adults with predominantly Plasmodium falciparum malaria. Prevalence of folate and vitamin B12 deficiencies was 26.

Factors associated with mortality in HIV-infected and uninfected patients with pulmonary tuberculosis.

Background: HIV has fuelled the TB epidemic in sub-Saharan Africa. Mortality in patients co-infected with TB and HIV is high. Managing factors influencing mortality in TB patients might help reducing it.

Pulmonary vascular endothelial growth factor expression and disaturated phospholipid content in a chicken model of hypoxia-induced fetal growth restriction.

Background: Prenatal hypoxia is an important cause of intrauterine growth retardation that affects fetal lung maturation, although previous studies have rendered conflicting results. The fetal chicken model allows the study of the isolated effects of hypoxia during development.

Objectives: We hypothesized that prenatal hypoxia would differentially affect surfactant synthesis, depending on timing and duration of hypoxia.

Isoprostanes in fetal and neonatal health and disease.

Isoprostanes are prostaglandin-like bioactive molecules generated via nonenzymatic peroxidation of lipid membrane-derived arachidonic acid by free radicals and reactive oxygen species. Their cognate receptors, biological actions, and signaling pathways are poorly understood. Aside from being sensitive and specific biomarkers of oxidative stress, E- and F-ring isoprostanes have important biological functions and likely mediate many of the disease-related pathological changes for which they are used as indicators.

Nutritional and socio-economic factors associated with Plasmodium falciparum infection in children from Equatorial Guinea: results from a nationally representative survey.

Background: Malaria has traditionally been a major endemic disease in Equatorial Guinea. Although parasitaemia prevalence on the insular region has been substantially reduced by vector control in the past few years, the prevalence in the mainland remains over 50% in children younger than five years. The aim of this study is to investigate the risk factors for parasitaemia and treatment seeking behaviour for febrile illness at country level, in order to provide evidence that will reinforce the EG National Malaria Control Programme.

Nationally representative surveys show recent increases in the prevalence of overweight and obesity among women of reproductive age in Bangladesh, Nepal, and India.

Our aims in this study were to examine trends in the prevalence of overweight-obesity and underweight among women of reproductive age in 3 South Asian countries between 1996 and 2006 and to identify sociodemographic correlates of overweight in the most recent survey. Using nationally representative data from 8 Demographic and Health Surveys conducted in Bangladesh (n = 19,211), Nepal (n = 19,354), and India (n = 161,755), we examined the change in the prevalence rates of overweight-obesity (BMI > or = 25 kg/m(2)) and underweight (BMI < 18.5 kg/m(2)) over a recent 7- to 10-y period among women aged 15-49 y.

Are vitamin A and iron deficiencies re-emerging in urban Latin America? A survey of schoolchildren in Bogota, Colombia.

Background: In Latin America, the burden of vitamin A and iron deficiencies has been documented primarily in preschool-age children. There are few recent reports on the vitamin A and iron status of school-age children.

Objective: We aimed to determine the prevalence and predictors of vitamin A and iron deficiencies in Colombian schoolchildren.

Correlates of obesity and body image in Colombian women.

Objective: To examine the sociodemographic correlates of overweight and obesity as well as body shape perception in women from Bogotá, Colombia.

Methods: The sample (n = 671) represented low-income and middle-income women, aged 21-55 years, living in Bogotá, who had children in the public school system. We measured height and weight to calculate body mass index (BMI, kg/m(2)) and defined two dichotomous outcomes: overweight/obesity (BMI >or=25) and obesity (BMI >or=30).

Maturation of O2 sensing and signaling in the chicken ductus arteriosus.

The increase in O(2) tension after birth is a major factor stimulating ductus arteriosus (DA) constriction and closure. Here we studied the role of the mitochondrial electron transport chain (ETC) as sensor, H(2)O(2) as mediator, and voltage-gated potassium (K(V)) channels and Rho kinase as effectors of O(2)-induced contraction in the chicken DA during fetal development. Switching from 0% to 21% O(2) contracted the pulmonary side of the mature DA (mature pDA) but had no effect in immature pDA and relaxed the aortic side of the mature DA (mature aDA).

Provision of a school snack is associated with vitamin B-12 status, linear growth, and morbidity in children from Bogota, Colombia.

In 2004, Bogotá's Secretary of Education (SED) initiated a snack program in public primary schools. A midmorning food ration was provided free of charge to children to supplement 30 and 50% of their daily requirements of energy and iron, respectively. The purpose of this study, an observational investigation of 3202 children ages 5-12 y, was to examine whether the snack program improved children's nutritional and health status.

Endotoxin induced chorioamnionitis prevents intestinal development during gestation in fetal sheep.

Chorioamnionitis is the most significant source of prenatal inflammation and preterm delivery. Prematurity and prenatal inflammation are associated with compromised postnatal developmental outcomes, of the intestinal immune defence, gut barrier function and the vascular system. We developed a sheep model to study how the antenatal development of the gut was affected by gestation and/or by endotoxin induced chorioamnionitis.

Effects of prenatal hypoxia on pulmonary vascular reactivity in chickens prone to pulmonary hypertension.

Among chickens, meat-producing broiler strains are highly prone to develop severe pulmonary hypertension (PH) that is accompanied by endothelial dysfunction in the conduit extrapulmonary arteries. We hypothesized that exposure to chronic prenatal mild hypoxia would accelerate PH and endothelial dysfunction in smaller intrapulmonary arteries from broiler chickens. Fertilized broiler and layer (White Leghorn, WL) eggs were incubated under normoxic or hypoxic conditions.

Growing up under generalized violence: an ecological study of homicide rates and secular trends in age at menarche in Colombia, 1940s-1980s.

We examined secular changes in mean age at menarche among 5577 Colombian women born between 1941 and 1989, and correlated those changes with nation-wide rates of homicide and real gross domestic product per capita (GDP) at the year of birth and at the year at age 5, within predefined historical periods. The mean (standard error) rate of change in age at menarche by year of birth was -0.55 (0.

Is the association between low birth weight and asthma independent of genetic and shared environmental factors?

Epidemiologic evidence linking birth weight and asthma is inconsistent. The authors examined the association between birth weight and asthma during childhood and adult life in twins. Using prospectively collected data on 21,588 like-sexed Swedish twins of known zygosity born in 1928-1952, they first conducted a cohort study to examine the risk of asthma in relation to birth weight.

Assessing the impact of the introduction of the World Health Organization growth standards and weight-for-height z-score criterion on the response to treatment of severe acute malnutrition in children: secondary data analysis.

Objective: The objective of our study was to assess the impact of adopting the World Health Organization growth standards and weight-for-height z-score criterion on the response to treatment of severe acute malnutrition in children compared with the use of the National Center for Health Statistics growth reference.

Methods: We used data from children aged 6 to 59 months with acute malnutrition who were admitted to the Médecins sans Frontières nutrition program in Maradi, Niger, during 2006 (N = 56214). Differences in weight gain, duration of treatment, recovery from malnutrition, mortality, loss to follow-up, and need for inpatient care were compared for severely malnourished children identified according to the National Center for Health Statistics reference and weight-for-height <70% of the median criterion versus the World Health Organization standards and the weight-for-height less than -3 z-score criterion.