Biomedical subjects

A S Moura

Publications and source records attributed to A S Moura.

At least 19 recordsLinked to original sources

PubMed2004

[Nutritional status of children and occupational categories of the family in a rural community of Paraná, Brazil].

The relationship between the occupational category of the family and the nutritional status of children was studied. Participants were 340 children up to 11 years of age, living in a small town of a rural area in Paraná, Brazil. The nutritional status of the children, as measured in 1983, was related to the principal occupational categories of the family in the period 1972- 1983. Occupation of the family was categorized as: migrant farmworkers (bóias-frias) throughout the entire period; renters or sharecroppers that were converted to migrant farmworkers; those who never worked as migrant farmworkers; and salaried urban workers that were converted to migrant farmworkers. Other variables included age and sex of the children, condition of birth (home or hospital), number of children up to 11 years of age in the family, birthweight and school enrollment of the children 5 years old or over. The prevalence of wasting was greatest among children belonging to salaried urban workers that were converted to migrant farmworkers. In contrast, this category showed the lowest prevalence of stunting. Compared with migrant farmworkers during the entire period, the odds ratio of wasting in this category was 2.7 with a 95% confidence interval of 1.3-5.7. Wasting and stunting were also independently associated with the number of children (p<0.05). The larger the family, the lower the risk of wasting, whereas for stunting, the larger the family, the higher the risk. These findings suggest an important role for the occupational category in the determination of the nutritional status in children and indicate that wasting and stunting may have differential risk factors.

English Abstract↗

PubMed2004

Hypothalamic nuclei nitric oxide synthase expression in rats malnourished during early lactation period.

In humans and other animals, it has been shown that protein malnutrition during the prenatal period leads to permanent changes, which in adulthood may cause chronic diseases. Molecules involved in the control of energy metabolism could be targets to alterations caused by nutritional status. Some hypothalamic nuclei as the paraventricular (PVN), ventro-medial and arcuate are related to energy metabolism regulation. Orexigenic and anorexigenic molecules are involved in this regulation. Some studies have showed that these nuclei present nitric oxide synthase (NOS) and that it is increased in obese rats. Recently it had been shown that rats malnourished during the lactation period presented metabolic alterations that persist in adulthood. The aim of this work was to study the expression of NOS in hypothalamic nuclei of rats submitted to malnutrition during the early lactation period. Rats from post-natal day (P10) to P90 were used. Control dams were fed with regular chow pellets and diet dams were fed with protein-free chow pellets during the first 10 days of lactation. NADPH-diaphorase or immunostaining techniques were used to access NOS expression in hypothalamic nuclei. Our results show a delay in NOS expression in the PVN and VMH of malnourished rats. It may affect the development of the hypothalamic circuitry, leading to a metabolic imprinting.

Aging↗

PubMed2003

Combined effect of short stature and socioeconomic status on body mass index and weight gain during reproductive age in Brazilian women.

Short stature, a marker for undernutrition early in life, has been associated with obesity in Brazilian women, but not in men. We tested the hypothesis that weight gain during the reproductive years could explain this gender difference. A national two-stage household survey of mothers with one or more children under five years of age was conducted in Brazil in 1996. The subjects were women aged 20 to 45 years (N = 2297), with last delivery seven months or more prior to the interview. The regions of the country were divided into rural, North/Northeast (urban underdeveloped) and South/Southeast/Midwest (urban developed). The dependent variables were current body mass index (BMI) measured, BMI prior to childbearing (reported), and BMI change. Socioeconomic variables included mother's years of education and family purchasing power score. A secondary analysis was restricted to primiparous women. The prevalence of current overweight and overweight prior to childbearing (BMI > or = 25 kg/m2) was higher among shorter women (<1.50 m) compared to normal stature women only in the urban developed region (P < 0.05). After adjustment for socioeconomic variables, age, parity, BMI prior to childbearing, and age at first birth, current BMI was 2.39 units higher (P = 0.008) for short stature women living in the urban developed area compared with short stature women living in the urban underdeveloped area. For both multiparous and primiparous women, BMI gain compared to the value prior to childbearing was significantly higher among short stature women living in the urban developed region (P <= 0.04). These results provide clear evidence that short stature was associated with a higher BMI and with an increased risk of weight gain/retention with pregnancy in the developed areas of Brazil, but not in the underdeveloped ones.

Adult↗

PubMed2003

Syphilitic meningitis in HIV-patients with meningeal syndrome: report of two cases and review.

Few patients with symptomatic neurosyphilis present with signs and symptoms of acute meningitis. Here we report two cases of syphilitic meningitis diagnosed in HIV patients with meningeal syndrome. The first case, a 30-year-old black bisexual male, had concurrent meningeal and ocular syphilis with persistent unusually low CSF glucose levels. He responded well to 21 days of intravenous penicillin therapy. The second case was a 55-year-old female with epilepsy, depression, behavioral disorder and confusion. The diagnosis of HIV infection was made after onset of the syphilitic meningitis. She was treated with 21 days i.v. penicillin with improvement in her clinical condition. The clinical aspects of combined neurosyphilis and HIV infection, plus special features of diagnosis and treatment are discussed.

AIDS-Related Opportunistic Infections↗

PubMed2003

Impairment of inflammatory response in adult rats submitted to maternal undernutrition during early lactation: role of insulin and glucocorticoid.

OBJECTIVE: Early nutritional environment may program permanent metabolic alterations, predisposing to later diseases. We have investigated the interference of maternal malnutrition during lactation with the development of acute inflammation in adult rats. MATERIALS AND METHODS: Adult rats, offspring of dams fed with either protein-free diet (UN group) or 22% protein diet (C group) during the first 10 days of lactation, were submitted to pleurisy with carrageenan (500 microg/cavity). Pleural edema, neutrophil migration and ICAM expression, were evaluated 4 h after and correlated with alterations in plasma insulin and corticosterone. Leukocyte-endothelium interactions were evaluated by intravital microscopy 1 h after inflammation. RESULTS: Compared to controls, UN rats showed a decrease in pleural edema formation (50%), neutrophil migration (50%), endothelial ICAM-1 expression on pulmonary tissue, and impairment in leukocyte adhesion (50%) and migration (80%) through endothelium. Circulating insulin was lower (42%) and corticosterone was higher (34%) in UN, compared to controls. Pre-treatment of UN with insulin (5 IU/day) or RU486 (20 mg/kg/day), inhibitor of glucocorticoid receptor, restored leukocyte functions and ICAM-1 expression. CONCLUSION: Postnatal maternal malnutrition, programming for permanent alterations in insulin and glucocorticoid secretion in progeny, that were unable to properly mount an inflammatory response, probably predisposes to chronic diseases in adult life.

Animals↗

PubMed2002

Malnutrition during lactation as a metabolic imprinting factor inducing the feeding pattern of offspring rats when adults. The role of insulin and leptin.

The aim of the present study was to determine the impact of malnutrition during early postnatal life and the feeding pattern of rat offspring when adults (2 months and 1 year old). In comparison with rats normally fed during lactation, we observed that adult offspring displayed a faster process of feeding reduction when a protein-free diet was offered. In addition, we studied the concentration of insulin and leptin in the lactating pups (10 days) and when these offspring became adult after the onset of a new feeding pattern induced by the protein-free diet. When the diet was changed at 60 days, the offspring malnourished during lactation displayed, after 3 days, a food intake reduction around 41.4 vs 14.2% of the control group. At 10 days of life, plasma leptin and insulin were higher in the malnourished pups when compared with normally fed rats (leptin: 4.6 +/- 0.8 vs 2.25 ng/ml; insulin: 0.73 +/- 0.12 vs 0.22 +/- 0.03 ng/ml) while at 60 days they showed reduction of both hormones when compared with the control group (leptin: 1.03 +/- 0.25 vs 1.43 +/- 0.5 ng/ml; insulin: 0.54 +/- 0.3 vs 0.61 +/- 0.4 ng/ml). Despite the different food intake reductions, the malnourished and control rats displayed a similar reduction of insulin and leptin after 3 days of protein-free diet (from 60 to 63 days). The data suggest that the high concentration of insulin and leptin found at 10 days in the malnourished pups may elicit a sustained long-term and unique feeding pattern.

Animals↗

PubMed2000

Obesity and abdominal fatness associated with undernutrition early in life in a survey in Rio de Janeiro.

BACKGROUND: Undernutrition early in life has been associated with chronic diseases and obesity among adults. Our study tested the hypothesis by examining the association between low stature, a marker of early poor nutrition, with obesity and abdominal fatness among adults. METHODS: A population-based survey was conducted in 1996, among 2040 households, with a non-response rate of 11.2%. Weight, height, waist and hip circumference, and skinfolds were measured at home. RESULTS: Age-adjusted prevalence of body mass index (BMI) greater than 25 kg/m2 was 32% more frequent among adult men, and 60% more frequent among adult women, comparing the first to the fourth quintile of height. A J-shaped curve describes the association between weight and the sum of skinfolds with stature after adjusting for confounding by age, energy intake, physical activity, smoking, age at menarche, and race. The adjusted odds ratio of obesity (BMI>30 kg/m2) for short stature, compared to normal stature, was 1.57 with a 95% confidence interval (CI) = 0.90-2.71 among men and 1.84 with a 95% CI=1.10-3.06 among women. Short stature was associated with the risk of abdominal fatness only among women, with an odds ratio=1.77; 95% CI=1.10-2.83. CONCLUSIONS: Increased risk of obesity and abdominal fatness among women of short stature, a marker for undernutrition early in life, was not explained by racial and socio-economic conditions, energy intake or age at menarche.

Abdomen↗

PubMed2000

Bradykinin enhances membrane electrical activity of pancreatic beta cells in the presence of low glucose concentrations.

In most of cells bradykinin (BK) induces intracellular calcium mobilization. In pancreatic beta cells intracellular calcium is a major signal for insulin secretion. In these cells, glucose metabolism yields intracellular ATP which blocks membrane potassium channels. The membrane depolarizes, voltage-dependent Ca2+ channels are activated and the intracellular calcium load allows insulin secretion. Repolarization occurs due to activation of the Ca2+-dependent K+ channel. The insulin secretion depends on the integrity of this oscillatory process (bursts). Therefore, we decided to determine whether BK (100 nM) induces bursts in the presence of a non-stimulatory glucose concentration (5.6 mM). During continuous membrane voltage recording, our results showed that bursts were obtained with 11 mM glucose, blocked with 5.6 mM glucose and recovered with 5.6 mM glucose plus 100 nM BK. Thus, the stimulatory process obtained in the presence of BK and of a non-stimulatory concentration of glucose in the present study suggests that BK may facilitate the action of glucose on beta cell secretion.

Animals↗

PubMed2000

Undernutrition during early lactation period induces metabolic imprinting leading to glucose homeostasis alteration in aged rats.

This study examines the effects of early postnatal undernutrition on the glucose homeostasis of rats at one year of age, comparing the effects of a free protein diet (FPD) and a normal diet containing 25% of protein (NPD) supplied during the first 10 days of lactation. The insulin secretion and the insulin sensitivity, using the glucose clamp technique, were studied in these rats. The analysis of the integrated area of insulin secreted by isolated islets stimulated with 16.7 mM glucose was reduced in the FPD group when compared with the NPD (FPD = 5.07 +/- 1.6 ng/ml/50 min.; NPD = 35.8 +/- 12 ng/ml/50 min., p < or = 0.001). Using the glucose clamp technique the plasma glucose concentration was raised by continuous glucose stimulation with 10 mg/Kg(-1) x min(-1). After 30 minutes the NPD displayed a lower level of plasma glucose concentration (FPD = 220.8 +/- 8 mg/dl.; NPD = 185 +/- 3 mg/dl., p < or = 0.01). Afterwards, the hyperglycemia of the NPD increased and in both groups was, subsequently, similarly maintained and, after 90 minutes of continuously glucose infusion, there was no difference between the groups (FPD = 191.6 +/- 8 mg/dl.; NPD = 189.3 +/- 17 mg/dl). In order to test the peripheral sensitivity to glucose, insulin 1.67 mU x Kg(-1) min(-1) was administered together with glucose 10 mg x kg(-1) x min(-1) (50 minutes after the beginning of the clamping). The glycemia after the insulin administration compared to glycemia 90 minutes of FPD was significantly reduced and the NPD maintained the same glycemic level ( FPD from 220.7 +/- 8 mg/dl to 170.6 +/- 5 mg/dl, p < or = 0.001; NPD from 195.3 +/- 10 mg/dl to 185.2 +/- 6 mg/dl.). Also, after the insulin administration the plasmatic insulin was raised but after 90 minutes the FPD group displayed a lower insulin concentration when compared to the same point of time for the NPD group (FPD = 0.8 +/- 0.01 ng/ml; NPD = 1.8 +/- 0.03 ng/ml., p < or = 0.01). The data suggest that undernutrition during early postnatal may cause a metabolic imprinting which leads to a decreasing action of the insulin secretory apparatus and increased insulin sensitivity as an adaptive response.

Aging↗

PubMed1999

Direct and correlated responses to selection for efficiency of lean gain in mice.

Improvement in feed efficiency when selection is based on gain:feed ratio has often been accompanied by a reduction in feed intake. The following four criteria were used in mass selection for improved lean gain efficiency in mice with an objective of evaluating changes in lean gain and intake: 1) gain deviation, animals selected had the greatest gain in fat-free mass (FFM) after adjustment to a constant intake; 2) intake deviation, mice selected had the least feed intake after adjustment to a constant gain in FFM; 3) intrinsic efficiency, similar to the second criterion except that adjustment was also made for average weight maintained during the period; and 4) a positive control that used the ratio of gain in FFM: feed intake as the selection criterion. A fifth line, in which a male and a female were selected at random from each litter, served as a negative control. Experimental animals were outbred mice of the CF1 strain. Two replicates of the five lines were included in the study. Twelve males and females were pair-mated within each line-replicate combination each generation. Feed disappearance was measured from 25 to 42 d. Mice were scanned to obtain an electrical conductivity measurement for prediction of FFM. After six generations of selection, realized heritabilities for gain:feed, gain deviation, intake deviation, and intrinsic efficiency were .00 +/- .04, .04 +/- .29, .35 +/- .08, and .28 +/- .06, respectively. There were no differences among lines for gain:feed ratio. The correlated response in feed intake reduction was significant in the intake deviation and intrinsic efficiency lines (-.17 +/- .05 and -.21 +/- .04 g x d(-1) x generation(-1), respectively). The realized genetic correlations between the ratio and gain deviation, intake deviation, and intrinsic efficiency were .83 +/- .15, .01 +/- .04, and .21 +/- .12, respectively. Litter size was depressed in all selected lines.

Animals↗

PubMed1999

Components of growth in mice hemizygous for a MT/bGH transgene.

The objective of this study was to determine the effects of a metallothionein/bovine GH transgene on duration and rate of growth of lean and fat in mice. Mice were produced by mating hemizygous transgenic males to nontransgenic females. Ten weights and six measurements of total body electrical conductivity to estimate body composition were taken on 147 progeny between birth and 84 d of age. Growth traits for fat-free mass (FFM) and body fat mass (FM) were obtained by fitting FFM and FM to a logistic curve y = A/(1 + exp(k(b - t))), where y is FFM or FM, A is asymptotic mass, k and b are curve parameters, and t is time in days. The function and its first, second, and third derivatives for FFM and FM were used to model growth. A mixed model was used with animal and litter as random effects and trans-genotype, sex, and transgenotype x sex as fixed effects in analyses of growth traits. Estimates of transgeno-type and transgenotype x sex interaction were tested by using their corresponding standard errors. Males had greater response to the transgene than females in final FFM and growth rate during the entire growth period. Transgenic males and females had greater duration of lean growth than nontransgenics. Transgenic males began to accumulate fat later, but they eventually gained more fat than transgenic females.

Adipose Tissue↗

PubMed1998

Thermogenic activity of growth hormone transgenic mice.

The objective was to determine the effect of a mouse metallothionein/bovine growth hormone transgene on resting metabolic rate (RMR), cold-induced thermogenesis, and beta-agonist stimulated nonshivering thermogenesis in mice. Non-transgenic littermates were used as controls. Open-circuit indirect calorimetry was used to assess RMR and cold-induced thermogenesis in 64 mice. Air temperature in the chamber was set at 31 degrees C for RMR and was decreased to 28, 25, 21, or 17 degrees C to determine cold-induced thermogenesis. Response to the beta-agonist isoproterenol was evaluated by monitoring changes in colonic temperature of 34 mice upon injection of the drug or saline. Despite the fact that RMR tended to be lower in transgenics than in nontransgenics, at 31 degrees C transgenic mice were able to regulate colonic temperature at the same level as nontransgenics, but colonic temperature decreased in transgenics relative to nontransgenics as air temperature was reduced. For each degree decrease in air temperature between 31 and 17 degrees C, nontransgenic mice increased heat production by 1.03 +/- .10 watt/kg, whereas transgenic mice increased it by only .56 +/- .08 watt/kg, indicating that the thermogenic response of transgenics to cold was inferior. The magnitude of the maximal increase in colonic temperature after isoproterenol injection was similar for both groups, but the response was slower in transgenics. We suggest that lean body mass and substrate availability for shivering thermogenesis are reduced in transgenics relative to total body weight, and that they allow colonic temperature to decrease to conserve energy.

Animals↗

PubMed1997

Two-way selection for daily gain and feed conversion in a composite rabbit population.

We conducted a two-way selection experiment in a composite rabbit population to investigate the responses to selection for postweaning ADG and feed conversion (FC). Two generations of crossing, followed by four generations of random pair matings, preceded three generations of selection. Selection was practiced within four lines: high-feed conversion (HFC), low-feed conversion (LFC), high gain (HG), and low gain (LG). Data on 1,446 rabbits from the random mating and selection generations were fitted to an animal model to estimate heritabilities of and the genetic correlation between ADG and FC. The two-trait model included rabbit and common litter random effects and line, generation, and sex fixed effects. Estimates of heritability of ADG and FC were .48 and .29, respectively, and the genetic correlation between them was -.82. Common litter environmental effects accounted for a proportion of .11 and .13 of the phenotypic variation of the two traits, respectively. For ADG (in g/d) the regressions of mean breeding values on generation number during the selection period were 1.23 +/- .12 (P < .01) in the HG line and -.86 +/- .12 (P < .01) in the LG line; the regressions for FC (in g feed/g gain) were -.07 +/- .01 (P < .01) in the HFC line and .03 +/- .01 (P < .05) in the LFC line. Selection for ADG was effective in improving ADG and FC.

Animals↗

PubMed1997

Insulin secretion impairment and insulin sensitivity improvement in adult rats undernourished during early lactation.

In order to study the effect of undernutrition on the onset of disturbances in insulin secretion and insulin resistance, we compared the effects of a low protein diet containing 4% of protein (LPD) and a normal diet containing 25% of protein (NPD) supplied to the dams during the first 10 days of lactation when the pups turn into adults (90 days). We studies, in these rats, the insulin secretion, the glucose tolerance test (GTT) and, using the glucose clamp technique, the insulin resistance. The GTT showed a delay of the response of LPD group to the glucose challenge (1 mg/kg body weight) at 10 minutes (NPD = 450 +/- 27 mg/dl; LPD = 650 +/- 32 mg/dl, p < 0.01). The insulin secretion, four minutes after stimulation was found reduced in the LPD group (LPD = 1.1 +/- 0.08 microU/islet/min; NPD = 1.85 +/- 0.02 microU/islet/min, p < 0.01). Using the glucose clamp technique the plasma glucose concentration was raised during the first 20 minutes after the glucose stimulation with 10 mg/Kg-1.min-1 (NPD = 200 +/- 32 mg/dl and; LPD = 160 +/- 14 mg/dl., p < 0.01). Afterwards, the hyperglycemia was subsequently maintained (NPD = 154 +/- 9 mg/dl; LPD = 149 +/- 12 mg/dl) and the insulinemia was unchanged by infusion of glucose in the LPD group. In a similar experiment, the administration of glucose (10 mg/Kg-1. min-1) plus insulin (1.67 mU/Kg-1. min-1), the LPD group when compared with the NPD group, displayed an accentuated decreasing of glucose concentration level (LPD = 90 +/- 7 mg/dl; NPD = 130 +/- mg/dl., p < 0.01), 30 minutes after the infusion. The data suggest that undernutrition induces an adaptive process of insulin sensitivity which occurs together with an insulin secretion first phase blockage.

Animals↗

PubMed1996

Undernutrition during early lactation as an alternative model to study the onset of diabetes mellitus type II.

In order to characterize an alternative animal model for the study of diabetes mellitus type II onset, we compared the effects of a diet containing 8% of protein (LPD) and a normal diet containing 25% of protein supplied to the dams during the first 12 days of lactation. We studied in the pups the growth evolution and, when they develop into adults (60 days), the glucose tolerance test (GTT) and the insulin secretion, in response to stimulatory concentrations of glucose. The weight of the two groups were significantly different at 60 days of age (LPD = 179 +/- 19 g; NPD = 186 +/- 18 g). The GTT ten minutes after iv glucose administration showed a significant increase of blood glucose concentration of the LPD group (LPD = 550 +/- 17 mg/dl; NPD = 425 +/- 13 mg/dl, p < 0.001). The insulin secretion, four minutes after stimulation was found reduced in the LPD group (LPD = 1.1 +/- 0.08 muU/islet/min; NPD = 1.85 +/- 0.2 muU/islet/min.). The present study indicates insulin secretory and/or resistance impairment due to early undernutrition. Also, the data taken together suggest that undernutrition during early lactation can be used as an alternative model to study particular characteristics of the onset of diabetes mellitus type II.

Animals↗

PubMed1995

Membrane potential and intercellular calcium during glucose challenge in mouse islet of Langerhans.

The present work was undertaken to study the effects of the addition and removal of glucose on the calcium concentration of the intercellular space [Ca2+]o of islets of Langerhans. The removal of glucose hyperpolarize the beta-cell membrane to near- 60 mV and induced a biphasic response in [Ca2+]o. On the other hand, the addition of glucose (11 mM) depolarized beta-cell, inducing a biphasic electrical activity and concomitant changes in the [Ca2+]o. During the continuous membrane electrical activity, which characterized the first phase of glucose evoked biphasic response, the [Ca2+]o decreased. In the second phase, the [Ca2+]o displayed an oscillatory behavior concomitantly with the membrane potential.

Animals↗

PubMed1994

The diabetogenic agent alloxan increases K+ permeability by a mechanism involving activation of ATP-sensitive K(+)-channels in mouse pancreatic beta-cells.

The effects of the diabetogenic agent, alloxan, on membrane potential, input resistance and electrical activity of normal mouse pancreatic beta-cells were studied. Tetraethylammonium (TEA), quinine and Glyburide were used to block K(+)-channels and to elucidate the mechanisms underlying alloxan's effects on beta-cell membrane potential. Exposure of the islet to alloxan (75-100 microM) in the presence of glucose (11 mM), produced a rapid (15 sec), transient inhibition of electrical activity, often accompanied by hyperpolarization of the membrane, and this was followed by recovery of the burst pattern. This early effect of alloxan was followed after approximately 15 min by a complete inhibition of electrical activity and hyperpolarization. The inhibition accompanied by hyperpolarization was associated with a decrease in input resistance, indicating increased K(+)-conductance. Both the transient and delayed effects of alloxan were blocked by glucose (33 mM), quinine and glyburide but not by other conditions which induce continuous electrical activity such as elevated external [K+] (10 mM), ouabain, K+ removal, or TEA (20 mM). The transient inhibition induced by alloxan may be due to a direct competition with glucose transport/metabolism since it did not occur when alpha-keto isocaproic acid (KIC) was used to induce electrical activity. The delayed inhibition may reflect indirect effects of accumulation of this agent or its metabolites within the cell. Since both effects of alloxan are blocked by glyburide they appear to involve activation of the ATP-sensitive K(+)-channel (K-ATP).

Alloxan↗

PubMed1994

Ascorbic acid and insulin secretion in pancreatic islets.

The effect of ascorbic acid on glucose-induced insulin release from single pancreatic islets was measured using a new, ultra-sensitive enzyme-linked immunosorbent insulin assay. Within 20 s ascorbic acid inhibited insulin secretion; inhibition was dose dependent and completely reversible. There was a 50% inhibition of the secretory response with 200 microM ascorbic acid and 90% inhibition with 400 microM ascorbic acid. The decrease in insulin secretion was recorded as a reduction of the amplitudes of the fast insulin transients, which give rise to the oscillatory nature of insulin secretion. The inhibition of glucose-induced insulin release by ascorbic acid was associated with hyperpolarization of the pancreatic beta-cell. Suppression of glucose-induced membrane depolarization was evident after 20 s, was dose dependent, and was completely reversible. The data here may provide the first explanation of why plasma ascorbate concentrations are tightly controlled.

Animals↗