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1.
Plant Biol (Stuttg) ; 23(4): 556-563, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33550673

RESUMO

Floral structures, such as stamen appendages, play crucial roles in pollinator attraction, pollen release dynamics and, ultimately, the reproductive success of plants. The pollen-rewarding, bee buzz-pollinated flowers of Melastomataceae often bear conspicuous staminal appendages. Surprisingly, their functional role in the pollination process remains largely unclear. We use Huberia bradeana Bochorny & R. Goldenb. (Melastomataceae) with conspicuously elongated, twisted stamen appendages to investigate their functional role in the pollination process. We studied the effect of stamen appendages on pollinator behaviour and reproductive success by comparing manipulated flowers (appendages removed) with unmanipulated flowers. To assess bee pollinator behaviour, we measured three properties of buzzes (vibrations) produced by bees on Huberia flowers: frequency, duration and number of buzzes per flower visit. We measured male and female reproductive success by monitoring pollen release and deposition after single bee visits. Finally, we used artificial vibrations and laser vibrometry to assess how flower vibrational properties change with the removal of stamen appendages. Our results show that the absence of staminal appendages does not modify bee buzzing behaviour. Pollen release was higher in unmanipulated flowers, but stigmatic pollen loads differ only marginally between the two treatments. We also detected lower vibration amplitudes in intact flowers as compared to manipulated flowers in artificial vibration experiments. The presence of connective appendages are crucial in transmitting vibrations and assuring optimal pollen release. Therefore, we propose that the high diversity of colours, shapes and sizes of connective appendages in buzz-pollinated flowers may have evolved by selection through male fitness.


Assuntos
Melastomataceae , Polinização , Animais , Abelhas , Flores , Pólen , Reprodução
2.
Plant Biol (Stuttg) ; 18(4): 585-93, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26789333

RESUMO

Most species in Melastomataceae have poricidal anthers related to specialised bee buzz-pollination, while some have anthers with large openings associated to non-bee pollination systems. We tracked the evolution of anther morphology and seed number on the Miconieae phylogenetic tree to understand the evolutionary shifts in such pollination systems. Anther morphometric data and seed number were recorded for 54 taxa. Pollinators (bees, flies, wasps) were recorded for 20 available species. Ancestral state reconstruction was made using Maximum Likelihood from nrITS sequences. We used phylogenetic eigenvector regressions to estimate phylogenetic signal and the adaptive component for these traits. Species pollinated by bees or bees and wasps tend to have smaller pores and fruits with more seeds. Species pollinated by flies or flies and bees and/or wasps tend to have larger pores and fruits with less seeds. Independent evolution occurred three times for anthers with large pores and twice for fruits with few seeds. We detected a phylogenetic signal in both traits, and negative correlated evolution between them. In actinomorphic small-flowered Miconieae, changes in anther morphology can be related to generalisation in the pollination system incorporating flies and wasps as pollinators and lessening the importance of buzzing bees in such process. Differences in pollen removal and deposition may explain differences in anther morphology and seed number in Miconieae.


Assuntos
Melastomataceae/fisiologia , Polinização , Animais , Abelhas/fisiologia , Evolução Biológica , Análise por Conglomerados , Dípteros/fisiologia , Flores/anatomia & histologia , Flores/genética , Flores/crescimento & desenvolvimento , Flores/fisiologia , Melastomataceae/anatomia & histologia , Melastomataceae/genética , Melastomataceae/crescimento & desenvolvimento , Fenótipo , Pólen/anatomia & histologia , Pólen/genética , Pólen/crescimento & desenvolvimento , Pólen/fisiologia , Sementes/anatomia & histologia , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/fisiologia , Vespas/fisiologia
3.
Plant Biol (Stuttg) ; 18(1): 132-8, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26152277

RESUMO

Apomixis is an asexual seed reproduction mechanism thorough which embryos are originated from material tissues inside the ovules, without precedent fertilisation. It allows plants to colonise new habitats, even in places where flower visitors are scarce or where plants are isolate. Apomixis seems to be related to pollen sterility and, in species with flowers that offer pollen as a reward for pollinators, the amount or quality of the pollen offered by these species may influence the amount of the visits and specific composition of the visitors. In order to test this hypothesis, we studied breeding systems of 16 species of Melastomataceae and their flower visitors, evaluating composition and abundance of the visits to apomictic and sexual species. Apomictic plants with no viable pollen or with pollen with low viability did not receive visits from pollinators, and consequently probably produce strictly apomictic fruits. On the other hand, apomictic and sexual plants with high pollen viability do receive visits; in this case, apomictic plants may produce fruits and seeds through both sexual and apomictic methods. The species composition of insects visiting Melastomataceae with high pollen viability was similar, regardless of whether the plants were apomictic or not. It seems that pollen viability levels are important to determine visits to the flowers irrespective of breeding system.


Assuntos
Apomixia/fisiologia , Melastomataceae/fisiologia , Infertilidade das Plantas/fisiologia , Polinização/fisiologia , Animais , Brasil , Flores , Insetos , Pólen , Sementes
4.
Obstet Gynecol ; 110(5): 977-85, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17978107

RESUMO

OBJECTIVE: To assess tolerance and safety of 0.6% chlorhexidine vaginal and neonatal wipes to improve perinatal outcomes in home deliveries in Pakistan and the ability of traditional birth attendants and project staff to perform a randomized trial of this intervention. METHODS: Focus groups of pregnant and nonpregnant women and in-depth interviews of traditional birth attendants explored barriers to the use of chlorhexidine wipes. Then, a study was performed of women delivering at home attended by traditional birth attendants. Consenting women were randomly assigned to receive either 0.6% chlorhexidine or saline vaginal and neonatal wipes. Women and their infants were followed up on postpartum days 7, 14, and 28. Acceptability and tolerance of vaginal and neonatal wipes, as well as maternal and neonatal outcomes, were assessed. RESULTS: The focus groups and interviews indicated that the chlorhexidine intervention would be acceptable to women and their providers. Of the 213 eligible pregnant women approached, 203 (95%) gave informed consent and were enrolled and allocated to groups. Traditional birth attendants had no difficulty administering chlorhexidine vaginal and neonatal wipes in a home setting. Of the 203 births, 103 (51%) of whom received 0.6% chlorhexidine, there were no allergic reactions, vaginal itching, burning, or requests for study termination. Follow-up at 28 days postpartum was more than 95%. Although this study was not powered to show significant differences in neonatal outcomes between treatment groups, the lower rates of some neonatal adverse clinical outcomes in the chlorhexidine group were encouraging. CONCLUSION: Use of 0.6% chlorhexidine vaginal and neonatal wipes for the prevention of neonatal infection is well-tolerated and seems safe. A trial of this intervention by traditional birth attendants in a home-delivery setting is feasible. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00121394 LEVEL OF EVIDENCE: I.


Assuntos
Anti-Infecciosos Locais/uso terapêutico , Clorexidina/uso terapêutico , Parto Domiciliar/métodos , Adulto , Estudos de Viabilidade , Feminino , Grupos Focais , Humanos , Mortalidade Infantil , Recém-Nascido , Doenças do Recém-Nascido/prevenção & controle , Infecções/transmissão , Masculino , Tocologia , Paquistão/epidemiologia , Cooperação do Paciente , Projetos Piloto , Gravidez
5.
Biol Trace Elem Res ; 80(2): 107-13, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11437176

RESUMO

We hypothesized that plasma extracellular superoxide dismutase (EC-SOD) activity reflects the zinc nutriture of healthy pregnant women. Sixty-three women were selected from 580 African-American women who participated in a clinical trial to evaluate the effect of prenatal zinc supplementation on pregnancy outcome. Half of the women received zinc (25 mg/d) and the other half was given a placebo from about 19 wk gestation to delivery. In the trial, a positive effect of zinc supplementation on birthweight was observed, indicating that the population as a whole had suboptimal zinc nutriture. Using plasma samples obtained during the trial, EC-SOD activities were measured and the values were compared with plasma zinc concentrations and plasma alkaline phosphatase activities. Plasma EC-SOD activities in our subjects were lower than previously published values for healthy adults in Korea. Although plasma EC-SOD activity may reflect severe zinc deficiency, it is not a sensitive marker for marginal deficiency status. Plasma EC-SOD activities did not prove to be a better indicator of zinc nutriture of pregnant women than either plasma zinc or plasma alkaline phosphatase activities.


Assuntos
Gravidez/sangue , Superóxido Dismutase/sangue , Zinco/administração & dosagem , Fosfatase Alcalina/sangue , Cobre/sangue , Método Duplo-Cego , Espaço Extracelular/enzimologia , Feminino , Humanos , Micronutrientes/administração & dosagem , Necessidades Nutricionais , Resultado da Gravidez , Zinco/sangue
6.
Am J Obstet Gynecol ; 183(4): 805-9, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11035317

RESUMO

OBJECTIVE: The purpose of this study was to determine whether second-trimester plasma homocysteine levels are elevated among women whose pregnancies are subsequently complicated by pregnancy-induced hypertension, preeclampsia, or intrauterine growth restriction. STUDY DESIGN: Women with normal but relatively low plasma zinc levels were randomly assigned to receive zinc supplementation or placebo from 19 weeks' gestation until delivery. Plasma homocysteine concentration and plasma and erythrocyte folate levels were determined for all available stored samples (zinc group, 231/294; placebo group, 206/286) at 26 and 37 weeks' gestation. Among all women with available samples, pregnancy-induced hypertension (n = 12) or preeclampsia (n = 4) developed in 16 women, and 22 pregnancies were complicated by intrauterine growth restriction. RESULTS: Mean homocysteine levels in women with pregnancy-induced hypertension and preeclampsia were similar to those of control subjects at 26 weeks' gestation but were significantly higher at 37 weeks' gestation. Homocysteine levels were similar between women with pregnancies complicated by intrauterine growth restriction and control subjects at both time points. CONCLUSION: Second-trimester plasma homocysteine concentrations do not predict the subsequent development of pregnancy-induced hypertension, preeclampsia, and intrauterine growth restriction.


Assuntos
Retardo do Crescimento Fetal/sangue , Homocisteína/sangue , Hipertensão/sangue , Pré-Eclâmpsia/sangue , Complicações Cardiovasculares na Gravidez/sangue , Adulto , Eritrócitos/metabolismo , Feminino , Retardo do Crescimento Fetal/tratamento farmacológico , Ácido Fólico/sangue , Humanos , Hipertensão/tratamento farmacológico , Concentração Osmolar , Pré-Eclâmpsia/tratamento farmacológico , Gravidez , Complicações Cardiovasculares na Gravidez/tratamento farmacológico , Segundo Trimestre da Gravidez , Valores de Referência , Zinco/uso terapêutico
7.
Am J Clin Nutr ; 71(1): 109-13, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10617954

RESUMO

BACKGROUND: There is no consensus in the literature as to whether maternal zinc nutriture is associated with pregnancy outcome or fetal growth. OBJECTIVE: We evaluated the associations between plasma zinc concentrations during pregnancy and various measures of pregnancy outcome and neonatal conditions at birth. DESIGN: We measured zinc concentrations in plasma samples obtained at a mean of 16 wk of gestation (range: 6-34 wk) from 3448 women who were screened for a trial designed to evaluate the effect of zinc supplementation on fetal growth. Subjects were from low socioeconomic backgrounds and attended a public health clinic for their prenatal care. Plasma zinc concentrations were compared with pregnancy outcome, including complications during pregnancy and delivery, and anthropometric measures and Apgar scores of neonates. RESULTS: Plasma zinc concentrations declined as gestation progressed. After plasma zinc concentrations were adjusted for gestational age, they were not significantly associated with any measure of pregnancy outcome or neonatal condition. CONCLUSION: We conclude that plasma zinc concentrations during the late first trimester to the early third trimester do not predict pregnancy outcomes in women of a low socioeconomic background.


Assuntos
Resultado da Gravidez , Gravidez/sangue , Zinco/sangue , Adulto , Alabama , Antropometria , Índice de Apgar , Peso ao Nascer , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Pobreza , Valor Preditivo dos Testes , Complicações na Gravidez
8.
Obstet Gynecol ; 92(3): 446-9, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9721787

RESUMO

OBJECTIVE: Matrix metalloproteinase-9, a zinc-dependent proteinase, may be important in initiating labor or rupture of membranes. We determined plasma levels of this enzyme in nonpregnant and pregnant women and evaluated whether they predict spontaneous preterm delivery. METHODS: A sandwich enzyme-linked immunosorbent assay (ELISA) was used to measure matrix metalloproteinase-9 levels in plasma samples from 25 nonpregnant women (mean age 39+/-9 years) and in stored plasma samples obtained during a randomized trial of zinc supplementation in pregnancy. Women were selected who delivered following spontaneous labor or premature rupture of membranes at 24-32 weeks (n = 20), 33-36 weeks (n = 29), and greater than 37 weeks (n = 30). Plasma samples were obtained sequentially at 19, 26, 31, and 36 weeks if undelivered and at presentation for delivery. RESULTS: Plasma matrix metalloproteinase-9 levels for non-pregnant women averaged 18.6+/-11.2 (mean +/- standard deviation) ng/mL. Prenatal values averaged 298+/-227 ng/mL from 19 weeks until 36 weeks (not including presentation for delivery) and did not change significantly as the gestational age increased, regardless of whether women ultimately delivered at 24-32, 33-36, or after 37 weeks. Values obtained prior to, but within 1 week of, presentation for delivery (n = 7, 281+/-103 ng/mL) were not significantly different than those obtained earlier in pregnancy (n = 71, 309+/-307 ng/mL, [P = .60]). Plasma matrix metalloproteinase-9 levels for women in spontaneous labor were similar regardless of gestational age and were increased three-fold (852+/-301 ng/mL) compared with those drawn at each prenatal visit (for example, 26 week values = 285+/-144 ng/mL [P < .001]). CONCLUSION: Plasma matrix metalloproteinase-9 levels remain unchanged throughout pregnancy until the onset of spontaneous labor when there is a three-fold increase. Plasma matrix metalloproteinase-9 levels obtained prior to presentation for delivery do not appear to predict spontaneous preterm birth.


Assuntos
Colagenases/sangue , Trabalho de Parto Prematuro/diagnóstico , Adulto , Feminino , Humanos , Metaloproteinase 9 da Matriz , Valor Preditivo dos Testes , Gravidez
9.
Am J Epidemiol ; 147(2): 127-35, 1998 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-9457001

RESUMO

Associations between maternal cigarette smoking and accelerated placental maturation measured as tissue calcification have been reported. The authors sought to address whether intakes of the dietary antioxidants, vitamin C, alpha-tocopherol, and beta-carotene, were related to placental calcification of the maternal surface and villi in a cohort of smokers and nonsmokers at risk for delivering small-for-gestational age infants. Gross and histologic examination of placentas were used to determine calcification at the surface (n = 1,213) and villus sites (n = 730), respectively, in a prospective study of black and white women who delivered singleton births between December 1985 and October 1988 at the University of Alabama at Birmingham Hospital in Birmingham, Alabama. Controlling for race and gestational age, likelihood of surface and villus calcification increased as smoking levels increased. Significant reductions in villus calcification were related to alpha-tocopherol intake after controlling for smoking and gestation while intakes of beta-carotene and vitamin C were related to significant reductions in calcification for black but not white women. Surface calcification was not found to be related to antioxidant intake. The authors' findings confirm a pathologic relation between smoking and placental calcification and suggest that dietary antioxidants may reduce villus calcification.


Assuntos
Antioxidantes/administração & dosagem , Calcificação Fisiológica/efeitos dos fármacos , Vilosidades Coriônicas/efeitos dos fármacos , Placenta/efeitos dos fármacos , Complicações na Gravidez/induzido quimicamente , Fumar/efeitos adversos , beta Caroteno/administração & dosagem , Antioxidantes/farmacologia , Ácido Ascórbico/administração & dosagem , Ácido Ascórbico/farmacologia , Suplementos Nutricionais , Feminino , Humanos , Recém-Nascido Pequeno para a Idade Gestacional , Gravidez , Vitamina E/administração & dosagem , Vitamina E/fisiologia , beta Caroteno/farmacologia
10.
Am J Obstet Gynecol ; 177(5): 1003-10, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9396883

RESUMO

OBJECTIVE: Our goal was to identify risk factors for the development of preeclampsia in nulliparous women enrolled in a multicenter trial comparing calcium supplementation to a placebo. STUDY DESIGN: A total of 4589 women from five centers was studied. Analysis of risk factors for preeclampsia was performed in 4314 who carried the pregnancy to > 20 weeks. Baseline systolic and diastolic blood pressure, demographic characteristics, and findings after randomization were examined for the prediction of preeclampsia. Preeclampsia was defined as hypertension (diastolic blood pressure > or = 90 mm Hg on two occasions 4 hours to 1 week apart) and proteinuria (> or = 300 mg/24 hours, a protein/creatinine ratio > or = 0.35, one dipstick measurement > or = 2+ or two dipstick measurements > or = 1+ at an interval as specified for diastolic blood pressure). RESULTS: Preeclampsia developed in 326 women (7.6%). The first analysis treated each risk factor as a categoric variable in a univariate regression. Maternal age, blood group and Rh factor, alcohol use, previous abortion or miscarriage, private insurance, and calcium supplementation were not statistically significant. Risk factors initially found to be significant were body mass index, systolic blood pressure, diastolic blood pressure, non-white race (African-American and other), clinical center, and smoking. Adjusted odds ratios computed with a logistic regression model revealed that body mass index (odds ratio 3.22 for > or = 35 kg/m2 vs < 19.8 kg/m2), systolic blood pressure (odds ratio 2.66 for > or = 120 vs < 101 mm Hg), diastolic blood pressure (odds ratio 1.72 for > or = 61 mm Hg vs < 60 mm Hg), and clinical center (odds ratio 1.85 for Memphis vs the other clinical centers) were statistically significant predictors of preeclampsia. Results of the final model fit revealed that preeclampsia risk increases significantly (p < 0.0001) with increased body mass index at randomization, as well as with increased systolic and diastolic blood pressure at randomization. Calcium supplementation had no effect on the risks posed by body mass index and blood pressure. Among risk factors developing after randomization, an abnormal results of a glucose screen (plasma glucose > or = 140 mg/dl 1 hour after a 50 gm glucose challenge) was not found to be associated with a significant risk of preeclampsia. CONCLUSION: These risk factors should be of value in counseling women regarding preeclampsia and should aid in understanding the pathophysiologic characteristics of this syndrome.


Assuntos
Cálcio/administração & dosagem , Pré-Eclâmpsia/etiologia , Adolescente , Adulto , Pressão Sanguínea , Índice de Massa Corporal , Feminino , Humanos , Idade Materna , Gravidez , Fatores de Risco
11.
J Am Diet Assoc ; 97(11): 1269-74, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9366865

RESUMO

OBJECTIVE: To evaluate the effects of usual dietary intake of zinc and of zinc supplementation during pregnancy on plasma and erythrocyte zinc concentrations. DESIGN: A randomized, double-blind, placebo-controlled trial. SUBJECTS: Low-income African-American women (n = 580) assigned randomly to groups at 19 weeks of gestation. INTERVENTION: A daily dose of zinc (25 mg) or a placebo until delivery. MAIN OUTCOME MEASURES: Plasma, erythrocyte, and dietary zinc levels. STATISTICAL ANALYSES: Multiple regression and repeated measures analysis of variance. RESULTS: In both the placebo and the supplemented groups, when all subjects were grouped by usual dietary zinc intake above or below the median (12 mg/day), results were the same: Women with high dietary zinc intake had higher erythrocyte zinc levels at the time of randomization and at all subsequent measurements during pregnancy than those who had low dietary zinc intake (P < or = .06; difference not significant for zinc-supplemented group); no difference was observed for plasma zinc levels. On the other hand, when the subjects were stratified at the median by total daily zinc intake (usual dietary zinc + 25 mg zinc supplement) during pregnancy, a significant difference in plasma zinc levels (P < .005) was found between women with high total zinc intake (mean = 38 mg/day) and low total intake (mean = 13 mg/day) at 26, 32, and 38 weeks of gestation; however, no such differences were found in erythrocyte zinc levels. APPLICATIONS: These results should help dietitians and other health professionals better understand the expected changes in plasma and erythrocyte zinc levels during pregnancy, and the relationship between dietary and supplemental zinc and zinc nutriture.


Assuntos
População Negra , Dieta , Gravidez/etnologia , Zinco/administração & dosagem , Zinco/sangue , Adulto , Suplementos Nutricionais , Método Duplo-Cego , Eritrócitos/química , Feminino , Humanos , Pobreza , Gravidez/sangue
12.
Obstet Gynecol ; 88(4 Pt 1): 497-502, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8841206

RESUMO

OBJECTIVE: To evaluate the effect of angiotensin-converting enzyme (ACE) genotypes on pregnancy outcome, the incidence of pregnancy-induced hypertension, and changes in blood pressure (BP) during pregnancy; and the relationship between plasma ACE activities and plasma and erythrocyte zinc concentrations in each genotype. METHODS: The subjects (n = 191) were selected from 580 indigent African-American pregnant women who enrolled toward the end of a trial to evaluate the effect of zinc supplementation on pregnancy outcome. This selection resulted in 93 subjects who received zinc and 98 who received placebo. Sample size was calculated with a 0.50 correlation coefficient between plasma ACE activities and zinc levels and a power of 80%. This calculation indicated that the sample size in each ACE genotype should be more than 28. Angiotensin-converting enzyme genotypes were identified using polymerase chain reaction. Blood pressure, plasma ACE activities, and plasma and erythrocyte zinc concentrations were measured at each prenatal clinical visit. RESULTS: Pregnancy outcome, the incidence of pregnancy-induced hypertension, and BP were not different among the three ACE genotypes. There was no significant correlation between plasma ACE activities and zinc concentrations. Zinc supplementation did not have a significant effect on either plasma ACE activities or zinc concentrations, probably because of the small sample size in our study. CONCLUSION: There was no effect of ACE gene polymorphism on pregnancy outcome, the incidence of pregnancy-induced hypertension, or changes in BP during pregnancy. Among each ACE genotype, plasma ACE activities did not correlate significantly with plasma zinc concentrations.


Assuntos
Hipertensão/fisiopatologia , Peptidil Dipeptidase A/sangue , Peptidil Dipeptidase A/genética , Polimorfismo Genético , Complicações Cardiovasculares na Gravidez/fisiopatologia , Zinco/sangue , Adolescente , Adulto , População Negra/genética , Pressão Sanguínea , Método Duplo-Cego , Feminino , Genótipo , Humanos , Hipertensão/sangue , Hipertensão/enzimologia , Hipertensão/etiologia , Pobreza , Pré-Eclâmpsia/sangue , Pré-Eclâmpsia/enzimologia , Pré-Eclâmpsia/fisiopatologia , Gravidez , Complicações Cardiovasculares na Gravidez/sangue , Complicações Cardiovasculares na Gravidez/enzimologia , Zinco/administração & dosagem
13.
Control Clin Trials ; 17(5): 442-69, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8932976

RESUMO

The results of ten clinical trials suggest that supplemental calcium may prevent preeclampsia. However, methodologic problems and differences in study design limit the acceptance of the results and their relevance to other patient populations. Many of the trials were conducted in countries where, unlike the United States, the usual daily diet contained little calcium. Moreover, none of the trials has reported the outcome of systematic surveillance for urolithiasis, a potential complication of calcium supplementation. In response to the need for a thorough evaluation of the effects of calcium supplementation for the prevention of preeclampsia in the United States, the trial of Calcium for Preeclampsia Prevention (CPEP) was undertaken at five university medical centers. Healthy nulliparous patients were randomly assigned to receive either 2 g supplemental calcium daily (n = 2295) or placebo (n = 2294) in a double-blind study. Study tablets were administered beginning from 13 to 21 completed weeks of gestation and continued until the termination of pregnancy. CPEP employed detailed diagnostic criteria, standardized techniques of measurement, and systematic surveillance for the major study endpoints and for urolithiasis. The nutrient intake of each patient was assessed at randomization and at 32-33 weeks gestation. This report describes the study rationale, design, and methods.


Assuntos
Cálcio/uso terapêutico , Estudos Multicêntricos como Assunto/métodos , Pré-Eclâmpsia/prevenção & controle , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Projetos de Pesquisa , Cálcio/efeitos adversos , Método Duplo-Cego , Feminino , Humanos , Hipertensão/diagnóstico , Sistemas de Informação Administrativa , Estudos Multicêntricos como Assunto/estatística & dados numéricos , Avaliação Nutricional , Cooperação do Paciente , Seleção de Pacientes , Placebos , Pré-Eclâmpsia/diagnóstico , Gravidez , Complicações Cardiovasculares na Gravidez/diagnóstico , Controle de Qualidade , Distribuição Aleatória , Ensaios Clínicos Controlados Aleatórios como Assunto/estatística & dados numéricos , Tamanho da Amostra , Índice de Gravidade de Doença , Estatística como Assunto , Estados Unidos , Cálculos Urinários/diagnóstico , Cálculos Urinários/etiologia , Cálculos Urinários/prevenção & controle
14.
JAMA ; 274(6): 463-8, 1995 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-7629954

RESUMO

OBJECTIVE: To evaluate whether zinc supplementation during pregnancy is associated with an increase in birth weight. DESIGN: A randomized double-blind placebo-controlled trial. SETTING: Outpatient clinic and delivery service at the University of Alabama at Birmingham. PATIENTS: Five hundred eighty medically indigent but otherwise healthy African-American pregnant women with plasma zinc levels below the median at enrollment in prenatal care, randomized at 19 weeks' gestational age. Women were subdivided by the population median body mass index of 26 kg/m2 into two groups for additional analyses. INTERVENTION: Women who were taking a non-zinc-containing prenatal multivitamin/mineral tablet were randomized to receive either a daily dose of 25 mg of zinc or a placebo until delivery. MAIN OUTCOME MEASURES: Birth weight, gestational age at birth, and head circumference at birth. RESULTS: In all women, infants in the zinc supplement group had a significantly greater birth weight (126 g, P = .03) and head circumference (0.4 cm, P = .02) than infants in the placebo group. In women with a body mass index less than 26 kg/m2, zinc supplementation was associated with a 248-g higher infant birth weight (P = .005) and a 0.7-cm larger infant head circumference (P = .007). Plasma zinc concentrations were significantly higher in the zinc supplement group. CONCLUSIONS: Daily zinc supplementation in women with relatively low plasma zinc concentrations in early pregnancy is associated with greater infant birth weights and head circumferences, with the effect occurring predominantly in women with a body mass index less than 26 kg/m2.


Assuntos
Peso ao Nascer , Gravidez de Alto Risco , Cuidado Pré-Natal , Zinco/administração & dosagem , Adulto , Negro ou Afro-Americano , Antropometria , Método Duplo-Cego , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Modelos Lineares , Idade Materna , Gravidez , Resultado da Gravidez , Vitaminas/administração & dosagem , Zinco/fisiologia
15.
J Natl Med Assoc ; 85(2): 130-4, 1993 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8441188

RESUMO

Racial differences in hematocrit levels and the relationship between low and high hematocrit, intrauterine growth retardation, and preterm delivery were studied in a population of 17,149 low-income, iron- and folate-supplemented pregnant women. Hematocrit levels drawn during four gestational periods were considered. Evaluating pregnancy outcome in regard to hematocrit values at specific gestational ages eliminated the bias resulting in the previously reported association between a low hematocrit and preterm delivery in blacks. In contrast, in this study, in blacks, hematocrits of 27% to 30% were associated with lower but not significant reductions in the rates of intrauterine growth retardation and preterm delivery. Our major finding was that at 31 to 34 weeks, hematocrits > or = 40% were associated with significantly higher odds ratios for intrauterine growth retardation for both blacks and whites. These findings should prompt more attention to women who have high hematocrits in pregnancy while reducing concern for women of either race with low hematocrits.


Assuntos
População Negra , Retardo do Crescimento Fetal/sangue , Hematócrito , Trabalho de Parto Prematuro/sangue , População Branca , Adulto , Alabama , Feminino , Retardo do Crescimento Fetal/prevenção & controle , Ácido Fólico/administração & dosagem , Idade Gestacional , Humanos , Recém-Nascido , Ferro/administração & dosagem , Trabalho de Parto Prematuro/prevenção & controle , Razão de Chances , Gravidez
16.
Am J Clin Nutr ; 56(2): 365-70, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1636615

RESUMO

To evaluate the relationship between folate and zinc, and its effect on pregnancy outcome, maternal serum folate and zinc concentrations were determined at 18 and 30 wk gestation in a defined population of 285 pregnant women as part of a large-scale study to identify risk factors for fetal growth retardation (FGR). These results were correlated with birth weight and Apgar scores of newborn infants and with maternal infections during the perinatal period. A weak linear relationship was observed between maternal serum folate and zinc concentrations at 30 wk gestation. Folic acid supplementation had favorable effects on birth weight and Apgar scores of newborns, and reduced prevalence of FGR and maternal infections. No significant correlation was found between serum zinc concentration and birth weight of infants. The concept that folic acid supplementation has an adverse effect on maternal zinc nutriture and pregnancy outcome was not supported.


Assuntos
Ácido Fólico/sangue , Resultado da Gravidez , Gravidez/sangue , Zinco/sangue , Adulto , Índice de Apgar , Peso ao Nascer , Feminino , Retardo do Crescimento Fetal/etiologia , Ácido Fólico/administração & dosagem , Humanos , Recém-Nascido , Complicações Infecciosas na Gravidez/epidemiologia , Prevalência , Fatores de Risco , Zinco/administração & dosagem
17.
Obstet Gynecol ; 79(5 ( Pt 1)): 719-22, 1992 May.
Artigo em Inglês | MEDLINE | ID: mdl-1565355

RESUMO

Serum folate levels were measured at 30 weeks' gestational age in 289 pregnant women, each of whom had been provided with folate supplementation at enrollment in prenatal care. There was a significant association between low serum folate levels and fetal growth retardation. High folate levels were most likely explained by recent folic acid intake. Therefore, we were concerned that the decreased fetal growth associated with low folate levels may have been related to a combination of psychological and behavioral characteristics for which low serum folate levels were only a surrogate measure. A profile of maternal psychosocial status was created, which included measures of depression, anxiety, self-esteem, mastery, stress, and social support. Poorer psychological scores were significantly related to lower serum folate levels. However, in women with both good and poor psychosocial scores, high folate levels were significantly associated with increased birth weight, a relationship that persisted even after adjusting for maternal race, body mass index, smoking, history of a low birth weight infant, and infant gender. Our findings suggest that women with good psychosocial scores are more likely to take folate, but that the use of folate itself is related to a lower risk of fetal growth retardation and increased birth weight.


Assuntos
Retardo do Crescimento Fetal/sangue , Ácido Fólico/sangue , Cooperação do Paciente , Sintomas Afetivos , Peso ao Nascer , Feminino , Retardo do Crescimento Fetal/etiologia , Retardo do Crescimento Fetal/psicologia , Ácido Fólico/administração & dosagem , Humanos , Recém-Nascido , Controle Interno-Externo , Gravidez , Apoio Social , Estresse Psicológico
18.
Obstet Gynecol ; 77(2): 190-4, 1991 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1988879

RESUMO

The relationship between maternal hematocrit and pregnancy outcome at various times in pregnancy was studied in 17,149 iron- and folate-supplemented pregnant women. On univariate analysis, early-pregnancy hematocrits below 37% were associated with preterm delivery. However, this relationship was not confirmed by multivariate analysis controlling for other risk factors. On both univariate and multivariate analyses, both early and later in pregnancy, hematocrits above 40% were associated with preterm delivery. In every gestational time period, at least part of the excess of preterm births was explained by an increase in indicated preterm deliveries. In both early and late pregnancy, and in both the univariate and multivariate analyses, only high hematocrits were associated with fetal growth retardation. The strongest association (odds ratio above 2) between high hematocrit and both fetal growth retardation and preterm delivery occurred with hematocrits at or above 43% at 31-34 weeks' gestation.


Assuntos
Retardo do Crescimento Fetal/sangue , Hematócrito/estatística & dados numéricos , Trabalho de Parto Prematuro/sangue , Feminino , Humanos , Razão de Chances , Gravidez , Primeiro Trimestre da Gravidez , Segundo Trimestre da Gravidez , Terceiro Trimestre da Gravidez
19.
Antimicrob Agents Chemother ; 24(6): 841-6, 1983 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-6581755

RESUMO

Imipenem (formerly imipemide, N-formimidoyl thienamycin, or MK0787) was compared to moxalactam in a randomized therapeutic trial involving 39 evaluable patients with serious bacterial infections. Of those treated with imipenem, 89% were cured or improved versus 60% for moxalactam (P = 0.06). Although mucocutaneous fungal infections occurred in both groups (25 and 10%, respectively), Streptococcus faecalis superinfection was seen in two patients in the moxalactam group only. Adverse drug reactions occurred with both drugs, although bleeding occurred in three patients treated with moxalactam.


Assuntos
Infecções Bacterianas/tratamento farmacológico , Moxalactam/uso terapêutico , Tienamicinas/uso terapêutico , Adulto , Idoso , Infecções Bacterianas/microbiologia , Feminino , Humanos , Imipenem , Inflamação/tratamento farmacológico , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Moxalactam/efeitos adversos , Tienamicinas/efeitos adversos
20.
Am J Obstet Gynecol ; 147(6): 687-93, 1983 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-6638115

RESUMO

Out-of-hospital births in Alabama are characterized with special emphasis on the period from 1970 to 1980. Women having an out-of-hospital birth were more likely to be nonwhite, aged greater than or equal to 35, and multiparous and to have little or no prenatal care. However, within the group of women having out-of-hospital delivery, characteristics which predicted neonatal death included being white, aged less than 20, primiparous, and unmarried and having little or no prenatal care. Both the risk factors for and outcomes of out-of-hospital birth differed markedly by race. In all, out-of-hospital births, which declined from 25% to 0.5% of all births from 1940 to 1980, were associated with a twofold increase in neonatal mortality. The major care provider for out-of-hospital births, the "granny" midwife, was found to have little knowledge about, or ability to provide, modern obstetric care. High-risk status of the patients, limited capability of the care-givers, and lack of appropriate medical resources are suggested as the likely reasons for the excess neonatal mortality in out-of-hospital births.


Assuntos
Parto Obstétrico , Parto Domiciliar , Mortalidade Infantil , Adulto , Fatores Etários , Alabama , Métodos Epidemiológicos , Feminino , Humanos , Recém-Nascido , Tocologia , Paridade , Gravidez , Cuidado Pré-Natal , Fatores de Tempo
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