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Biomedical subjects

J G Dorea

Publications and source records attributed to J G Dorea.

At least 19 recordsLinked to original sources
PubMed1997

Pregnancy-related changes in fat mass and total DDT in breast milk and maternal adipose tissue.

BACKGROUND: Changes in body fat mass during pregnancy and its effects on total DDT concentration i.e. the, sum of pp'-DDT (pp'-dichlorodiphenyltrichloroethane), and pp'-DDE (pp'-dichlorophenyldichloroethylene), in maternal milk and abdominal fat were studied in humans. METHODS: Forty mothers that delivered by Caesarean section and chose to breast feed consented in providing samples (abdominal fat and breast milk) for determination of organochlorine pesticides. Constitutional variables, such as the number of children, and estimators of body fat mass, based on height and body weight (before and after pregnancy), were measured. RESULTS: Body mass index before and after pregnancy, as well as percent change in body weight, showed no significant difference in total DDT concentration in abdominal fat or breast milk. The only variable to significantly affect either body load of pesticides (abdominal fat) or its excretion (milk fat) was the number of children (p = 0.0117 and p = 0.0324, respectively). Correlation coefficients between DDT (in adipose tissue and milk fat) and variables related to body fatness (body mass index) were low and not significant. However, a close relationship was found between total DDT in adipose tissue and milk fat (r = 0.709; p = 0.0001).

Adipose Tissue↗
PubMed1995

Subcutaneous fat changes in low-income lactating mothers and growth of breast-fed infants.

OBJECTIVE: We studied changes in body fat of lactating mothers and its relationship to milk fat and growth of exclusively breast-fed infants during the first 3 months of life. METHOD: Changes in body fat measured by body mass index (BMI) and skinfold thickness (triceps, suprailiac, subscapular, pectoral) of 39 low socioeconomic status women were measured every 15 days during the first 3 months postpartum. Milk fat concentrations and growth of exclusively breast-fed infants were followed at the same intervals. Attained growth (ponderal and linear) of infants was analyzed through multivariate analyses against changes in maternal adiposity (BMI and sum of skinfolds), weight, and milk fat concentrations. RESULTS: There was a decrease in maternal skinfold thickness from the 15th day postpartum. Milk fat concentrations decreased significantly only at the second month of lactation. CONCLUSION: Statistical model adjustments for duration of study, milk fat concentration, and birth weight of infants explained 88% of variance in infant growth (r2 = 0.886, p = 0.0001).

Adipose Tissue↗
PubMed1995

Antimony oxidation states in antileishmanial drugs.

Chemical methods specific for the determination of the levels of trivalent antimony (Sb+3) and pentavalent antimony (Sb+5) were used to investigate proprietary formulas used to treat leishmaniasis. Trivalent antimony was determined by differential pulse polarography, whereas Sb+5 was determined by iodine titration. Proprietary formulas based on N-meglumine antimoniate (Glucantime) were analyzed in detail. The results showed Sb+3 in all ampules of Glucantime. In formulations said to contain either 85 or 100 mg of Sb+5/ml, we found both forms of antimony. The amount of Sb+3 ranged from 10.5 to 15.8% (10.06-18.96 mg of Sb/ml). These findings raise issues on product stability and standardization and may help to clarify resistance to antimonial drugs and the reducing effect of tissue on Sb+5.

Antimony↗
PubMed1992

Zinc reverses the increased sensitivity of lymphocytes from aged subjects to the antiproliferative effect of prostaglandin E2.

To study the effect of zinc on the sensitivity of lymphocytes from aged people to prostaglandin E2 (PGE2), ZnCl2 was added to cultures of peripheral blood mononuclear cells stimulated with phytohemagglutinin (PHA). Mononuclear cells from 11 aged (greater than 65 years old) and 9 control (less than 36 years old) subjects were cultured with PHA and proliferation was measured 72 hr later by the uptake of [3H]thymidine. Lymphocytes from the aged group, whose mean plasma zinc concentration was significantly lower than that of the control group (68 +/- 6 micrograms/dl and 85 +/- 4 micrograms/dl, respectively), showed a decreased proliferation of lymphocytes and an increased sensitivity to the antiproliferative effect of PGE2. The addition of zinc to cultures increased proliferation of cultured cells in both groups, especially in the aged group. Our data indicate that zinc deficiency can act as a causal factor for T-lymphocyte dysfunction in elderly people.

Adult↗
PubMed1992

Concentration of zinc, copper and metallocalorie ratio in bottle-milks prepared by poor urban families.

The concentration of zinc and copper and metallocalorie ratios were measured in samples of bottle-milks fed to infants from a poor urban settlement in Brasilia, Brazil. The bottle-milks fed to infants under 1 year of age from a sample of 40 families were analysed for zinc and copper. Zinc and copper concentrations ranged from 0.7 to 11.5 mg/l (mean 3.37) and from 0.09 to 1.47 mg/l (mean 0.43), respectively. The mean metallocalorie ratio was 1.26 mg/MJ (5.29 mg/1000 kcal) for zinc and 0.17 mg/MJ (0.73 mg/1000 kcal) for copper. Based on minimum recommendations for formulae, 55% of the bottle-milks had both zinc and copper concentrations below 3.2 and 0.4 mg/l, respectively. However, owing to added sugar and high caloric concentrations in the milk preparations, metal:calorie ratios were below the minimum recommendations in 72.5 and 62.5% of cases for zinc and copper, respectively. The variation in zinc and copper concentrations in the milks prepared by mothers/infant caretakers under unsupervized home conditions is wide. Owing to the low availability of zinc in cow's milk preparations, it is of concern that more than half the bottle preparations had zinc and copper concentrations/ratios below the minimum recommendations.

Animals↗
PubMed1992

Concentration of fat, protein, lactose and energy in milk of mothers using hormonal contraceptives.

Energy, protein, lactose and fat were studied in the milk of mothers who were using different types of contraceptives. One hundred and eleven mothers made up the following groups. C: control (barrier and natural methods, or sterilization), n = 22; combined pill: LDP (low dose pill (levonorgestrel 0.15 mg + ethinylestradiol 0.03 mg)), n = 12 and MDP (medium dose pill (levonorgestrel 0.25 mg + ethinylestradiol 0.05 mg)), n = 13; MP (minipill (norethindrone 0.35 mg)), n = 37; DMPA (injectable progesterone (depot medroxiprogesterone acetate 150 mg)), n = 17; and IUD (plastic or copper intrauterine device), n = 10. The mean stages of lactation were, respectively, 15, 17, 5, 9, 5 and 9 weeks. The mean duration of observation for the study groups ranged from 2 to 4 weeks. Milk samples were collected before and after initiation of treatment (mean = 20 days; range = 14-103 days). The stage of lactation and the interval of nursing before sampling were recorded so that statistical account could be taken of these uncontrollable sources of variability. When incorporated as covariates, they showed that no significant differences existed between the groups tested, either before or after treatment.

Adult↗
PubMed1992

Infant feeding practices among poor families of an urban squatter community.

We studied the types of food, time of introduction, frequency and nutrient intake among 133 infants during the 1st year of life. A 24-hour dietary recall indicated that 42 different types of food, including mothers' milk, were offered directly or in suitable preparations. Breast- and mixed-fed infants were likely to receive more milk feedings than non-breast-fed infants. Sugar and liquids such as tea, fruit juices and soft drinks were introduced at a very early age. The breast-fed babies were offered only teas before the 3rd month. Solid food was offered as early as at 4 months, regardless of breast or bottle feeding. Fe and vitamin A were estimated to be below the recommended dietary allowance in the group that was not receiving breast milk.

Animals↗
PubMed1990

Retention of antimony in skin biopsies of leishmaniasis patients after treatment with N-methylglucamine antimoniate.

Leishmaniasis patients were treated with N-methylglucamine antimoniate by intravenous injections of 10 or 20 mg of Sb per kilogram of body weight per day for 10 or 20 days. Digests of skin biopsies taken from the site of lesion before and after treatment were analyzed for antimony by instrumental neutron activation (INAA). The detection limit of the assay was 20 ng, and no Sb could be measured in digests of samples (less than 2.45 mg) taken before treatment. Biopsies taken after injections of Sb showed concentrations in the range of 8.32 to 70.68 ng/g skin. We discuss the usefulness of INAA in the study of Sb in small samples of tissues.

Adolescent↗
PubMed1988

Osmolalities of bottle- and breast-milk fed to poor urban Brazilian infants.

Feeding practices related to osmotic strength of bottle-milk and breast-milk were studied in 133 families with infants less than 1 year of age in a poor urban settlement in Brasilia, Brazil. Osmolality [mean (SEM)] of breast-milk [318.8 (4.46) mOsm/kg water] was significantly less than that of bottle-milk [568.7 (29.9) mOsm/kg water]. The wide range of osmotic strength (253.7-1,380.0 mOsm/kg water) found in bottle-milk was partly due to the predominant use (82%) of powdered cow's milk among non-breastfeeders and its improper reconstitution. Diarrhoea and feeding management are also discussed.

Animals↗
PubMed1988

Making sense of the hair zinc literature: where do we go from here?

The authors make a critical review on the hair zinc literature, discussing the main contributions in this field. Certain explanations, as well as some solutions aimed to put an end to the confusion which exists on this matter are suggested. As a first step, it is recommended that only endogenous zinc in hair be reliably measured. Therefore, the zinc metabolic status should be operationally defined in function of the zinc detected in hair. Each one of the variables should thus be identified, quantified and controlled. It must be added that these variables would have to include differences in zinc metabolism. Only then would it be possible to see the real baseline reference value of hair zinc. At present researchers should begin looking for a functional relation and not just a statistical significant association between hair zinc concentration and zinc metabolic status. At the same time, it would be necessary to ratify and prove findings of the great number of studies reported in the paper, through the replication of studies with experimental animals.

Hair↗
PubMed1987

Concentration of copper and zinc in liver of fetuses and infants.

Hepatic concentrations of copper (Cu) and zinc (Zn) were studied in 38 fetuses and infants, who died of various causes, from 26 weeks of gestation up to 16 weeks post-natally. The six fetuses of 28-32 weeks gestation had median and mean hepatic Cu concentrations micrograms/g fresh tissue) comparable to those found in the 21 born at term, but the range of values was much narrower: all of the Cu values for those born prematurely were at or below 40 micrograms/g. Values at 10 micrograms/g and below were found in five infants at term and five who died at 1-4 months of age. There was a comparable range of Zn values for both pre-term and term babies (10 to 300 micrograms/g fresh tissue). The value of 10 micrograms/g was found only in one 4-month-old infant. The accumulation of both Cu and Zn occurs independently in the fetuses. The socioeconomic status did not influence significantly the concentration of liver Cu or Zn in babies born at term. However, size of babies as measured by liver weight showed that larger babies had significantly higher mean Cu concentration (37 +/- 24 micrograms/g) than smaller babies (21 +/- 14 micrograms/g. The same trend, but without significant difference, was observed for hepatic Zn between larger (104 +/- 78 micrograms/g) and smaller (74 +/- 59 micrograms/g babies.

Copper↗
PubMed1987

Antimony accumulation in hair during treatment of leishmaniasis.

We used instrumental neutron activation analysis (INAA) to determine antimony in small quantities of hair from individuals living in an area of endemic leishmaniasis. The groups studied were 12 patients undergoing treatment with N-methylglucamine antimoniate, 34 patients who had received such treatment a year ago, and 17 control subjects (untreated) who were living in the same area. Patients receiving treatment showed mean and median (12.13, 2.9 micrograms/g) values for antimony in hair that significantly exceeded those in either controls (1.01, 0.4 microgram/g) or patients one year after treatment (1.54, 1.0 microgram/g). We conclude that INAA can be useful in monitoring and differentiating such exposure to antimony in patients under treatment.

Antimony↗
PubMed1986

The rate of rhodopsin regeneration in the bleached eyes of zinc-deficient rats in the dark.

Rats fed a zinc-deficient, phytate-containing diet (ZD rats) for 4 wk showed typical signs of zinc deficiency: reduced food intake, slow weight gain, a poor food efficiency ratio and subnormal zinc concentrations in the serum, femur and eye. Pair-fed, weight-matched rats fed a zinc-sufficient diet (PF rats) showed normal serum zinc values, intermediate femur zinc levels and eye zinc concentrations similar to those in ZD rats. The vitamin A status of all three groups, expressed as the concentration of vitamin A in the liver, was comparable. After extensive bleaching, the initial rate of rhodopsin regeneration in ad libitum-fed, zinc-sufficient rats (AL rats), ZD rats and PF rats was the same, whereas the extent of rhodopsin regeneration in AL rats kept in the dark for 120 min was almost twice that found in ZD and PF rats. These results are not consistent with the hypothesis that zinc deficiency primarily affects dark adaptation by reducing the activity of alcohol dehydrogenase in the eye. Rather, zinc deficiency and the generalized malnutrition that results from markedly reduced food intake seem to depress the synthesis of opsin, and probably other proteins as well, in the rod cells of the eye.

Adaptation, Physiological↗
PubMed1985

Lacteal zinc and copper in relation to volume, total ash and energy during the first three months of lactation of Brazilian women.

The concentrations of zinc and copper were longitudinally studied during the first three months of self-determined lactation periods of nine Brazilian women. Both elements were studied in relation to volume, energy and total ash of milk. During the six bi-weekly intervals, zinc showed a significant difference between the high initial value (as mass/volume), mass/g of ash and mass/kcal) and later values toward the end of the third month, but no significant difference was observed for copper. With respect to all three of those parameters, regression analysis of zinc against length of lactation (six bi-weekly intervals) showed a significant and inverse correlation. Only when expressed as mass/g of ash was copper significantly and directly correlated with length of lactation. The data indicate that zinc secretion into human milk occurs independently of copper and mineral mass and also follows a previously identified physiological pattern.

Brazil↗
PubMed1984

Concentration of vitamin A in the liver of foetuses and infants dying of various causes in Brasilia, Brazil.

The vitamin A concentration in liver samples taken at autopsy from the central portion of the right lobe of 57 infants 0-1 year old was determined by a dual spectrophotometric and colorimetric assay. Death was due to respiratory disease (30%), complications of premature birth (16%), infections (14%), hemorrhage (14%), pneumonia (10%), cerebral edema (7%), and miscellaneous causes (9%). Gross malnutrition was noted in only 2 of these children. The median vitamin A concentration was 61 micrograms of retinol/g liver, with a range of 6-293 micrograms/g. The percent distribution of liver vitamin A levels in micrograms/g was: less than 5 (0%); 5-10 (7%); 10-20 (5%); 20-40 (16%); 40-80 (42%); 80-120 (14%); greater than 120 (16%). The mean liver level in 9 stillborn full-term infants (60 micrograms/g) was markedly lower than in 7 stillborn premature infants (125 micrograms/g). The median value for 22 infants from indigent families (54 micrograms/g) was lower than that of 35 infants from non-indigent families (65 micrograms/g). By applying the criteria that liver reserves of vitamin A less than or equal to 5 micrograms retinol/g of liver indicate a high risk of vitamin A deficiency and those less than 20 micrograms retinol/g of liver denote an inadequate reserve, no infant was at high risk but 12% had insufficient reserves.

Brain Edema↗
PubMed1983

Serum albumin and gamma globulin in Trypanosoma cruzi infections.

This paper examines the association between serum protein levels and infection with Trypanosoma cruzi in a region of Central Brazil. 148 people 6 to 78 years of age, were included in this study. There were no statistically significant difference in albumin levels between those with positive T. cruzi serology (2.94 +/- 0.74 g/100 ml) and those with negative serology (3.04 +/- 0.61 g/100 ml). Thus the null hypothesis of no association between infection with T. cruzi and serum albumin is accepted. Gamma-globulin levels were elevated in both groups and were significantly greater (p less than 0.05) in the group with positive T. cruzi serology (1.91 +/- 0.41 g/100 ml) than in the group with negative serology (1.75 +/- 0.41 g/100 ml). The serum albumin levels suggest that malnutrition (either associated with low protein intake or increased loss due to hookworm) is a major problem and unlikely to change if T. cruzi transmission was controlled.

Adolescent↗