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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
PubMed2001

Perinatal metabolism of dichlorodiphenyldichloroethylene in Nicaraguan mothers.

Umbilical cord and venous blood samples were collected at the time of delivery from 52 mothers living in urban and rural areas of the Atoya River basin, Nicaragua. In a subsample of 24 mothers that delivered by Cesarean section, abdominal adipose tissue samples were also collected, as was breast milk later in lactation. Cord and venous blood sera were analyzed for 13 organochlorine pesticides: 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (pp'-DDT); 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (pp'-DDE); pp'-dichlorophenyldichlorodiene (pp'-DDD); alpha-hexachlorocyclohexane (alpha-HCH); beta-hexachlorocyclohexane (beta-HCH); gamma-hexachlorocyclohexane (gamma-HCH); delta-hexachlorocyclohexane (delta-HCH); toxaphene; dieldrin; endrin; aldrin; heptachlor; and heptachlor epoxide. In venous blood only pp'-DDE (100% of samples), pp'-DDT (1.92%), dieldrin (15.38%), heptachlor (15.38%), gamma-HCH (7.69%), beta-HCH (11.53%), and delta-HCH (1.92%) were found, whereas in cord blood only pp'-DDE (100%), pp'-DDT (3.84%), dieldrin (19.23%), and heptachlor (9.16%), were found. The persistent DDT metabolite pp'-DDE, present in all samples of blood serum, adipose tissue, and breast milk, was studied in relation to maternal characteristics such as body mass index (BMI), age, lactation experience, and fetal pesticide acquisition. Mean venous (7.12 microg/g) and cord (6.39 microg/g) pp'-DDE concentrations were not significantly different but were significantly correlated. pp'-DDE in maternal adipose tissue was positively correlated with pp'-DDE in cord blood (P=0.0001) and breast milk (P<0.0001) and marginally correlated with changes in BMI (r=-0.03088; P=0.06). There was a higher proportion of samples (58%) with a greater concentration of DDE in venous than in cord blood. Although DDE accumulation may be less during fetal development than during breast feeding, exposure during embryogenesis may be more important than during the postnatal period.

Adipose Tissue↗
PubMed2001

Intrauterine device and maternal copper metabolism during lactation.

The effects of intrauterine device (IUD) on maternal copper (Cu) metabolism during breastfeeding was studied in 95 volunteer mothers who chose to use non-hormonal contraceptive methods. They were divided into two groups that were inserted with the IUD-Cu 380A (n = 33), IUD-Cu 200B (n = 29), and a third group that did not use any IUDs served as control (n = 33). Endometrial biopsies, blood, and milk samples were collected before (at 10 weeks postpartum) and 6 weeks after insertion of device for the determination of metabolites associated with copper metabolism, namely, serum ceruloplasmin, and copper concentrations in breast milk and endometrium. Endometrial copper concentration increased in women using IUDs, but was statistically significant (p = 0.001) only in the IUD-Cu 380A group. The increase in endometrial copper concentration did not affect serum ceruloplasmin or milk copper concentrations.

Adult↗
PubMed2001

Gender role attitudes and other determinants of breast feeding intentions in Brazilian women.

This study of 230 Brazilian mothers examined the associations of several sociodemographic variables, maternal attitudes and perceptions with intended breast feeding duration. The usual relationships of sociodemographic variables such as mother's age, education, smoking, parity and infant birth weight with intended breast feeding duration were not found. However, mother's intentions were related to gender role attitudes with both the least and the most traditional women intending to breast feed longer than women with moderately traditional gender role attitudes. Mother's attitude toward breast feeding, help with household tasks, and the attitudes of friends and relatives toward breast feeding were also very significantly related to intended breast feeding duration. Women who did not work outside the home intended to breast feed significantly longer than those who were employed.

Adolescent↗
PubMed2000

Iron and copper in human milk.

The reported concentrations of iron and copper in breast milk show a wide variation. Research published over the past 50 y has reported median values of 0.47 and 0.32 mg/L for iron and copper, respectively. The levels of both metals decrease with the progress of lactation. The calculated iron-to-copper ratio of reported means differs from 0.25 to 6.29 (median = 1.18). Maternal constitutional variables such as undernutrition, iron and copper body reserves, stage of lactation, adolescent motherhood, gestation length, and infection and environmental variables such as iron and copper dietary intake, in addition to supplementation, smoking, vegetarianism, and prolonged use of hormonal contraceptives before and during lactation did not consistently affect the concentrations of iron and copper in breast milk. Extreme cases of either low or high levels of body metal availability or altered metabolism due to chelating therapy or illnesses such as Wilson's disease and infections did not affect metal transfer from blood serum to breast milk. There is no clinical or scientific support for the need of extra iron or copper, besides the quantities provided by milk in the full-term breast-fed infant, at least during the first 6 mo.

Contraceptives, Oral↗
PubMed1999

Dietary intake of selenium and its concentration in breast milk.

Selenium concentration was measured in the breast milk of 30 mothers at different stages of lactation and various body mass indices (BMI). For a maternal mean selenium intake meeting 100% of the Recommended Daily Allowance, mean milk selenium concentration was 14.06 ng/mL (range: 10.0-24.7 ng/mL). No significant correlation was found between the concentration of milk selenium with the stage of lactation, BMI, or dietary selenium intake.

Adult↗
PubMed1999

The effects of oral contraceptive use on iron and copper concentrations in breast milk.

OBJECTIVE: To determine the effects of oral contraceptive (OC) treatment on maternal iron and copper metabolism during lactation. DESIGN: Observational study. SETTING: Private and public clinics in Brazil. PATIENT(S): Lactating mothers attending the family planning clinic of the University of Brasilia. INTERVENTION(S): The OCs used were a combination pill (0.15 mg of levonorgestrel and 0.03 mg of ethinyl estradiol) and a minipill (0.35 mg of norethidrone). Blood and breast milk samples were collected before and after a measured period of OC treatment. MAIN OUTCOME MEASURE(S): Iron and copper concentrations were studied in the serum and breast milk of 54 breast-feeding mothers who had been advised by their physicians to use an OC, and in a control group. RESULT(S): Regression analysis was performed using a model that took into consideration socioeconomic status, number of children, duration of previous lactation, type of OC, length of treatment, and age. Repeated measurements (before and after OC treatment) showed that only copper concentrations in breast milk were significantly affected by stage of lactation. During the study period, which varied from 2-15 weeks, the decline in iron concentrations in breast milk was negligible, whereas copper concentrations decreased by 50%. CONCLUSION(S): The use of OCs does not appear to affect significantly the secretion of iron and copper in breast milk during the first 6 months of lactation.

Adolescent↗
PubMed1998

Selenium and mercury concentrations in some fish species of the Madeira River, Amazon Basin, Brazil.

Samples of 7 species of piscivorous, omnivorous, and herbivorous fish caught at 12 different sites on the Madeira River, Amazon Basin, were analyzed for selenium and mercury. Selenium was determined by anodic stripping voltammetry and mercury by cold vapor atomic absorption spectrophotometry. The means for selenium concentrations ranged from 0.49 to 3.11 nmol/g and for mercury from 0.41 to 6.66 nmol/g depending on the fish species. The molar ratios of Hg:Se increased according to the fish trophic level. Piscivorous species had the highest mean ratio (4.0) and herbivorous species the lowest (0.9). There was a positive and statistically significant correlation between selenium and mercury concentrations for the herbivorous species (r = 0.716; p = 0.0088) not seen for omnivororus and piscivorous species (r = -0.2032; p = 0.3407). These findings are significant for the fish-eating population of the Madeira River because the ingestion of mercury would always be in excess of selenium.

Animals↗
PubMed1998

Calcium and phosphorus in milk of Brazilian mothers using oral contraceptives.

OBJECTIVE: Oral contraceptives (OC) are the most efficient method of contraception and it is the most prescribed by doctors in developing countries. Therefore we studied the effects of combination pill and mini-pill on calcium and phosphorus in milk of breast-feeding mothers at different stages of lactation. METHODS: Fifty-four breast-feeding mothers made up three study groups: 33 mothers who had been advised by their doctors to use either combination pill (12), or mini-pill (21), as well as a control group of 21 mothers that used no hormonal contraceptives. All mothers completed a questionnaire and provided samples of milk before and after a measured period of observation. Mean duration of study was 76, 120, and 101 days, respectively for users of mini-pill, combination pill, and controls. Determination of calcium and phosphorus was done by inductively coupled plasma-atomic absorption spectrometry. RESULTS: Overall the decrease in milk concentrations of phosphorus (6%) and calcium (26.3%) during the study period was not influenced by OC treatment. Regression analyses which took into consideration length of treatment, socioeconomic status, number of children, duration of previous lactation, type of contraceptive, and age of mothers and repeated measurements (before and after OC) showed that milk calcium was significantly affected by stage of lactation (p=0.0013). CONCLUSION: The use of hormonal contraceptive such as the combination pill (levonorgestrel 0.15 mg+ethynilestradiol 0.03 mg) and mini-pill (norethindone 0.35 mg) does not seem to affect the secretion of calcium and phosphorus in milk of mothers.

Adolescent↗
PubMed1997

Multielement determination in small samples of human milk by inductively coupled plasma atomic emission spectrometry.

Inductively coupled plasma atomic emission spectroscopy (ICP-AES) was used for routine analysis of small samples of human milk. The concentrations of calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), phosphorus (P), and zinc (Zn) were determined in 203 milk samples from postpartum women at different stages of lactation after stepwise digestion in HNO3, HClO4, and H2O2 under heat. Validation of the procedure was achieved using certified reference material of bovine liver (NBS 1577) with mean recoveries of 103.5%. The concentrations of the above elements in milk matrix were comparable with previously reported values. The analytical results from breast milk will provide reference information for mineral studies of Brazilian mothers and breast-fed infants.

Animals↗
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↗