Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Eur J Obstet Gynecol Reprod Biol ; 297: 86-90, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38598900

RESUMO

BACKGROUND: Human epididymis protein 4 (HE4) is a tumor marker overexpressed in ovarian cancer and is commonly utilized to aid with diagnosis of an adnexal mass. HE4 levels vary based on pregnancy, age, menopausal status, and tobacco use. OBJECTIVE(S): The objective of this study was to evaluate population-based data to examine factors that affect HE4 among adult women in the United States and stratify levels of HE4 by demographic and gynecologic factors. STUDY DESIGN: A retrospective analysis was conducted using data from 2,480 women aged 20 + who participated in the National Health and Nutrition Examination Survey (2001-2002). From these cross-sectional data, serum HE4 and cotinine, a marker of tobacco exposure, were combined with demographic and interview data. Estimated glomerular filtration rates (eGFR) were based on serum creatinine, age, sex, and race. Other variables of interest included menopausal status, pregnancy, and various gynecologic factors. Summary HE4 data are provided as geometric means with associated 95 % confidence intervals. RESULTS: HE4 levels were independently associated with age, renal function, and nicotine use, all p < 0.001. Pre-menopausal women with a history of endometriosis were found to have elevated HE4 levels compared to those without, p < 0.01; however, we found no such difference among post-menopausal women. Adjusting for age, no differences in HE4 were found based on race/ethnicity, p = 0.29. HE4 levels showed statistically significant associations with income level; however, these were small and clinically irrelevant. CONCLUSION: This study provides evaluation of HE4 levels among a data set representative of 98.5 million non-institutionalized women in the United States and gives insight into extraneous factors that may influence these levels.


Assuntos
Inquéritos Nutricionais , Proteína 2 do Domínio Central WAP de Quatro Dissulfetos , Humanos , Feminino , Proteína 2 do Domínio Central WAP de Quatro Dissulfetos/análise , Proteína 2 do Domínio Central WAP de Quatro Dissulfetos/metabolismo , Adulto , Pessoa de Meia-Idade , Estudos Retrospectivos , Estados Unidos/epidemiologia , Estudos Transversais , Proteínas/análise , Proteínas/metabolismo , Adulto Jovem , Gravidez , Idoso , Menopausa/sangue , Fatores Etários
2.
New Phytol ; 242(2): 727-743, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38009920

RESUMO

Poales are one of the most species-rich, ecologically and economically important orders of plants and often characterise open habitats, enabled by unique suites of traits. We test six hypotheses regarding the evolution and assembly of Poales in open and closed habitats throughout the world, and examine whether diversification patterns demonstrate parallel evolution. We sampled 42% of Poales species and obtained taxonomic and biogeographic data from the World Checklist of Vascular Plants database, which was combined with open/closed habitat data scored by taxonomic experts. A dated supertree of Poales was constructed. We integrated spatial phylogenetics with regionalisation analyses, historical biogeography and ancestral state estimations. Diversification in Poales and assembly of open and closed habitats result from dynamic evolutionary processes that vary across lineages, time and space, most prominently in tropical and southern latitudes. Our results reveal parallel and recurrent patterns of habitat and trait transitions in the species-rich families Poaceae and Cyperaceae. Smaller families display unique and often divergent evolutionary trajectories. The Poales have achieved global dominance via parallel evolution in open habitats, with notable, spatially and phylogenetically restricted divergences into strictly closed habitats.


Assuntos
Ecossistema , Poaceae , Filogenia , Evolução Biológica
4.
Ann Bot ; 130(7): 999-1014, 2022 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-36342743

RESUMO

BACKGROUND AND AIMS: While variation in genome size and chromosome numbers and their consequences are often investigated in plants, the biological relevance of variation in chromosome size remains poorly known. Here, we examine genome and mean chromosome size in the cyperid clade (families Cyperaceae, Juncaceae and Thurniaceae), which is the largest vascular plant lineage with predominantly holocentric chromosomes. METHODS: We measured genome size in 436 species of cyperids using flow cytometry, and augment these data with previously published datasets. We then separately compared genome and mean chromosome sizes (2C/2n) amongst the major lineages of cyperids and analysed how these two genomic traits are associated with various environmental factors using phylogenetically informed methods. KEY RESULTS: We show that cyperids have the smallest mean chromosome sizes recorded in seed plants, with a large divergence between the smallest and largest values. We found that cyperid species with smaller chromosomes have larger geographical distributions and that there is a strong inverse association between mean chromosome size and number across this lineage. CONCLUSIONS: The distinct patterns in genome size and mean chromosome size across the cyperids might be explained by holokinetic drive. The numerous small chromosomes might function to increase genetic diversity in this lineage where crossovers are limited during meiosis.


Assuntos
Cromossomos de Plantas , Evolução Molecular , Filogenia , Cromossomos de Plantas/genética , Tamanho do Genoma , Genoma de Planta/genética
5.
Mol Phylogenet Evol ; 126: 196-209, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29679713

RESUMO

We investigated the monophyly of Costularia (25 species), a genus of tribe Schoeneae (Cyperaceae) that illustrates a remarkable distribution pattern from southeastern Africa, over Madagascar, the Mascarenes and Seychelles, to Malesia and New Caledonia. A further species, Tetraria borneensis, has been suggested to belong to Costularia. Relationships and divergence times were inferred using an existing four marker phylogeny of Cyperaceae tribe Schoeneae expanded with newly generated sequence data mainly for Costularia s.l. species. Phylogenetic reconstruction was executed using Bayesian inference and maximum likelihood approaches. Divergence times were estimated using a relaxed molecular clock model, calibrated with fossil data. Based on our results, Tetraria borneensis is not related to the species of Costularia. Costularia s.l. is composed of four distinct evolutionary lineages. Two lineages, one including the type species, are part of the Oreobolus clade, i.e. a much reduced genus Costularia restricted to southeastern Africa, Madagascar, the Mascarenes and Seychelles, and a small endemic genus from New Caledonia for which a new genus Chamaedendron is erected based on Costularia subgenus Chamaedendron. The other two lineages are part of the Tricostularia clade, i.e. a separate single-species lineage from the Seychelles for which a new genus (Xyroschoenus) is described, and Costularia subgenus Lophoschoenus. For the latter, more research is needed to test whether they are congeneric with the species placed in the reticulate-sheathed Tetraria clade.


Assuntos
Cyperaceae/classificação , Cyperaceae/genética , Filogenia , África , Teorema de Bayes , Biodiversidade , Cyperaceae/anatomia & histologia , Funções Verossimilhança , Madagáscar , Nova Caledônia , Análise de Sequência de DNA , Seicheles , Fatores de Tempo
6.
Am J Obstet Gynecol ; 217(4): 467.e1-467.e6, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28602773

RESUMO

BACKGROUND: Ventricular hypertrophy is a known sequela of long-standing chronic hypertension with associated morbidity and mortality. OBJECTIVE: We sought to assess the frequency and importance of left ventricular hypertrophy in gravidas treated for chronic hypertension during pregnancy. STUDY DESIGN: This was a retrospective study of pregnant women with chronic hypertension who were delivered at our hospital from January 2009 through February 2015. All women who were given antihypertensive therapy underwent maternal echocardiography and were managed in a dedicated, high-risk prenatal clinic. Left ventricular hypertrophy was defined using the criteria of the American Society of Echocardiography as left ventricular mass indexed to maternal body surface area with a value of >95 g/m2. Maternal and infant outcomes were then analyzed according to the presence or absence of left ventricular hypertrophy. RESULTS: Of 253 women who underwent echocardiography, 48 (19%) met criteria for left ventricular hypertrophy. Women in this latter cohort were significantly more likely to be African American (P = .031), but there were no other demographic differences. More than 85% of the entire cohort had a body mass index >30 kg/m2 and a third of all women had class III obesity with a body mass index of >40 kg/m2. Importantly, duration of chronic hypertension (P = .248) and gestational age at time of echocardiography (P = .316) did not differ significantly between the groups. Left ventricular function was preserved in both groups as measured by left ventricular ejection fraction (P = .303). Those with ventricular hypertrophy were at greater risk to be delivered preterm (P = .001), to develop superimposed preeclampsia (P = .028), and to have an infant requiring intensive care (P = .023) when compared with women without ventricular hypertrophy. These findings persisted after adjustment for age, race, and parity. The gestational age at delivery according to measured left ventricular size was also examined and with increasing ventricular mass there was a significant association with the severity of preterm birth (P < .001). CONCLUSION: Left ventricular hypertrophy was identified in 1 in 5 women given antepartum treatment for chronic hypertension. Further analysis showed that these women were at significantly greater risk for superimposed preeclampsia and its attendant perinatal sequelae of preterm birth.


Assuntos
Hipertensão/epidemiologia , Hipertrofia Ventricular Esquerda/epidemiologia , Pré-Eclâmpsia/epidemiologia , Complicações Cardiovasculares na Gravidez/epidemiologia , Nascimento Prematuro/epidemiologia , Adolescente , Adulto , Índice de Massa Corporal , Ecocardiografia , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Obesidade/epidemiologia , Gravidez , Gravidez de Alto Risco , Estudos Retrospectivos , Volume Sistólico , Texas/epidemiologia , Adulto Jovem
7.
Phytochemistry ; 134: 87-97, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27890584

RESUMO

Propolis samples from Kangaroo Island, South Australia, were investigated for chemical constituents using high-field nuclear magnetic resonance spectral profiling. A type of propolis was found containing a high proportion of prenylated hydroxystilbenes. Subsequently, the botanical origin of this type of propolis was identified using a beehive propolis depletion method and analysis of flora. Ligurian honey bees, Apis mellifera ligustica Spinola, were found to produce propolis from resin exuded by the Australian native sedge plant Lepidosperma sp. Montebello (Cyperaceae). The plants, commonly known as sword sedge, were found to have resin that matched with the propolis samples identified as the most abundant propolis type on the island containing C- and O-prenylated tetrahydroxystilbenes (pTHOS) in addition to a small amount of prenylated p-coumarate. The isolation of five pTHOS not previously characterized are reported: (E)-4-(3-methyl-2-buten-1-yl)-3,4',5-trihydroxy-3'-methoxystilbene, (E)-2,4-bis(3-methyl-2-buten-1-yl)-3,3',4',5-tetrahydroxystilbene, (E)-2-(3-methyl-2-buten-1-yl)-3-(3-methyl-2-butenyloxy)-3',4',5-trihydroxystilbene, (E)-2,6-bis(3-methyl-2-buten-1-yl)-3,3',5,5'-tetrahydroxystilbene and (E)-2,6-bis(3-methyl-2-buten-1-yl)-3,4',5-trihydroxy-3'-methoxystilbene. A National Cancer Institute 60 human cell line anticancer screen of three of these compounds showed growth inhibitory activity. The large Australasian genus Lepidosperma is identified as a valuable resource for the isolation of substances with medicinal potential.


Assuntos
Antineoplásicos/isolamento & purificação , Cyperaceae/química , Própole/química , Estilbenos/isolamento & purificação , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Austrália , Abelhas , Cumarínicos/química , Cumarínicos/isolamento & purificação , Macropodidae , Prenilação , Estilbenos/química
8.
Obstet Gynecol ; 126(3): 569-574, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26244533

RESUMO

OBJECTIVE: To evaluate the association of spousal deployment during the antenatal period on maternal and neonatal outcomes and to estimate whether group prenatal care may be beneficial in reducing adverse outcomes when spouses are deployed. METHODS: Primigravid women who delivered at Womack Army Medical Center, Fort Bragg, North Carolina, were prospectively enrolled and selected for participation on a random basis between January 2013 and January 2014. Women whose spouses were deployed to a combat zone during the entire pregnancy (deployed group) were compared with women whose spouses were not deployed during the pregnancy (nondeployed group). Pregnancy and neonatal outcomes were compared between groups. RESULTS: Three hundred ninety-seven women were enrolled with 183 (46.1%) in the deployed group and 214 (53.9%) in the nondeployed group. Spouse deployment was associated with increased risk of preterm delivery (38 [20.8%] compared with 16 [7.5%], P<.001) and postpartum depression (30 [16.4%] compared with 13 [6.1%], P=.001) when compared with women in the nondeployed group. There were no differences in the incidence of preterm delivery and postpartum depression for women in the deployed group who participated in group prenatal care when compared with women participating in traditional care (preterm delivery 6 [14.6%] compared with 32 [22.5%], P=.38; postpartum depression 4 [9.8%] compared with 26 [18.3%], P=.24). CONCLUSION: Women who have a spouse deployed during their pregnancy are at increased risk for preterm birth and postpartum depression. Larger studies are needed to evaluate whether spouse deployment during pregnancy has other perinatal effects and whether group prenatal care may have a positive effect on adverse perinatal outcomes in this population. LEVEL OF EVIDENCE: II.


Assuntos
Depressão Pós-Parto/epidemiologia , Depressão Pós-Parto/psicologia , Militares/estatística & dados numéricos , Resultado da Gravidez , Nascimento Prematuro/epidemiologia , Cônjuges/psicologia , Guerra , Adulto , Distribuição de Qui-Quadrado , Estudos de Coortes , Depressão Pós-Parto/diagnóstico , Feminino , Humanos , Incidência , Recém-Nascido , Masculino , Análise Multivariada , Gravidez , Nascimento Prematuro/psicologia , Cuidado Pré-Natal/métodos , Cuidado Pré-Natal/psicologia , Estudos Prospectivos , Valores de Referência , Medição de Risco , Estados Unidos , Adulto Jovem
9.
Am J Obstet Gynecol ; 211(2): 132.e1-6, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24593936

RESUMO

OBJECTIVE: The aims were to establish a gestational-age specific curve for serum total thyroxine (T4) levels and to compare pregnancy outcomes of euthyroid women with those identified to have subclinical hypothyroidism (SCH) defined by an elevated thyroid-stimulating hormone (TSH) level in conjunction with either total T4 or free T4 determinations. STUDY DESIGN: Over a 2.5 year period, serum thyroid analytes were measured in all women presenting for prenatal care. After exclusion of women with overt thyroid disorders, the normal distribution of serum total T4 levels were determined by quantile curves for those screened in the first 20 weeks and who were delivered of a singleton infant weighing at least 500 g. Pregnancy outcomes for women with an elevated TSH and normal total T4 concentrations were analyzed and compared with those of women identified to have SCH defined by normal free T4 levels. RESULTS: Of 17,298 women tested, serum total T4 increased into the second trimester and plateaued around 16 weeks. The upper threshold for total T4 ranged from 12.6 to 16.4 µg/dL, and the lower threshold ranged from 5.3 to 8.0 µg/dL. Women identified to have SCH defined by serum free T4, total T4, or both were at risk for preterm delivery (P = .007) and placental abruption (P = .013) when compared with euthyroid women. CONCLUSION: When combined with elevated TSH levels, free or total T4 determinations are equally sensitive to identify women with SCH who are at increased risk for preterm birth and placental abruption when compared with euthyroid women.


Assuntos
Hipotireoidismo/diagnóstico , Complicações na Gravidez/diagnóstico , Tiroxina/sangue , Descolamento Prematuro da Placenta/sangue , Adulto , Feminino , Idade Gestacional , Humanos , Hipotireoidismo/sangue , Gravidez/sangue , Complicações na Gravidez/sangue , Trimestres da Gravidez/sangue , Nascimento Prematuro/sangue , Cuidado Pré-Natal
10.
Am J Bot ; 100(12): 2494-508, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24302693

RESUMO

PREMISE OF THE STUDY: The broad austral distribution of Schoeneae is almost certainly a product of long-distance dispersal. Owing to the inadequacies of existing phylogenetic data and a lack of rigorous biogeographic analysis, relationships within the tribe remain poorly resolved and its pattern of radiation and dispersal uncertain. We employed an expanded sampling of taxa and markers and a rigorous analytic approach to address these limitations. We evaluated the roles of geography and ecology in stimulating the initial radiation of the group and its subsequent dispersal across the southern hemisphere. METHODS: A dated tree was reconstructed using reversible-jump Markov chain Monte Carlo (MCMC) with a polytomy prior and molecular dating, applied to data from two nuclear and three cpDNA regions. Ancestral areas and habitats were inferred using dispersal-extinction-cladogenesis models. KEY RESULTS: Schoeneae originated in Australia in the Paleocene. The existence of a "hard" polytomy at the base of the clade reflects the rapid divergence of six principal lineages ca. 50 Ma, within Australia. From this ancestral area, Schoeneae have traversed the austral oceans with remarkable frequency, a total of 29 distinct dispersal events being reported here. Dispersal rates between landmasses are not explicable in terms of the geographical distances separating them. Transoceanic dispersal generally involved habitat stasis. CONCLUSIONS: Although the role of dispersal in explaining global distribution patterns is now widely accepted, the apparent ease with which such dispersal may occur has perhaps been under-appreciated. In Schoeneae, transoceanic dispersal has been remarkably frequent, with ecological opportunity, rather than geography, being most important in dictating dispersal patterns.


Assuntos
Cyperaceae/genética , Ecossistema , Evolução Molecular , Especiação Genética , Oceanos e Mares , Filogenia , Dispersão Vegetal , Austrália , DNA de Plantas , Geografia , Modelos Genéticos
11.
Obstet Gynecol Clin North Am ; 40(1): 89-101, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23466139

RESUMO

Hypertension is commonly encountered in pregnancy and has both maternal and fetal effects. Acute hypertensive crisis most commonly occurs in severe preeclampsia and is associated with maternal stroke, cardiopulmonary decompensation, fetal decompensation due to decreased uterine perfusion, abruption, and stillbirth. Immediate stabilization of the mother including the use of intervenous antihypertensives is required and often delivery is indicated. With appropriate management, maternal and fetal outcomes can be excellent.


Assuntos
Anti-Hipertensivos/uso terapêutico , Hidralazina/uso terapêutico , Pré-Eclâmpsia/diagnóstico , Complicações Cardiovasculares na Gravidez/diagnóstico , Bloqueadores dos Canais de Cálcio/uso terapêutico , Creatina/urina , Diuréticos/uso terapêutico , Medicina de Emergência , Feminino , Monitorização Fetal/métodos , Humanos , Infusões Intravenosas , Labetalol/uso terapêutico , Metildopa/uso terapêutico , Nifedipino/uso terapêutico , Nitroprussiato/uso terapêutico , América do Norte/epidemiologia , Oligúria/urina , Pré-Eclâmpsia/tratamento farmacológico , Pré-Eclâmpsia/mortalidade , Pré-Eclâmpsia/urina , Gravidez , Complicações Cardiovasculares na Gravidez/tratamento farmacológico , Complicações Cardiovasculares na Gravidez/mortalidade , Complicações Cardiovasculares na Gravidez/urina , Proteinúria/urina
12.
Obstet Gynecol Clin North Am ; 40(1): 103-20, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23466140

RESUMO

Seizures and intracranial hemorrhage are possible medical diseases that any obstetrician may encounter. This article reviews the cause, treatment, and medical management in pregnancy for seizures and intracranial hemorrhage, and how the two can overlap into preeclampsia or eclampsia. This article also highlights some challenging management issues from the obstetrician's perspective.


Assuntos
Anticonvulsivantes/administração & dosagem , Anormalidades Congênitas/etiologia , Eclampsia/diagnóstico , Epilepsia/complicações , Hemorragias Intracranianas/diagnóstico , Convulsões/etiologia , Anticonvulsivantes/efeitos adversos , Carbamazepina/administração & dosagem , Eclampsia/tratamento farmacológico , Eclampsia/mortalidade , Epilepsia/tratamento farmacológico , Epilepsia/mortalidade , Feminino , Ácido Fólico/uso terapêutico , Heparina/administração & dosagem , Humanos , Recém-Nascido , Hemorragias Intracranianas/tratamento farmacológico , Hemorragias Intracranianas/mortalidade , Lamotrigina , Monitorização Fisiológica , América do Norte/epidemiologia , Fenobarbital/administração & dosagem , Fenobarbital/efeitos adversos , Fenitoína/administração & dosagem , Fenitoína/efeitos adversos , Gravidez , Fatores de Risco , Convulsões/tratamento farmacológico , Convulsões/mortalidade , Hemorragia Subaracnóidea/diagnóstico , Triazinas/administração & dosagem , Ácido Valproico/administração & dosagem , Ácido Valproico/efeitos adversos , Vitamina K/uso terapêutico
13.
PhytoKeys ; (28): 19-59, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24399891

RESUMO

The status of a putative new species of Lepidosperma from the mountains of south-western Tasmania, Australia, was investigated. Phenetic analysis (Flexible UPGMA Agglomerative Hierarchical Fusion and semi-strong hybrid multidimensional scaling) was conducted on a database derived from morphological and anatomical characters scored from herbarium material, culm anatomy slides and scanning electron micrographs of fruit. The results of the analysis support the recognition of a new species, here described as Lepidosperma monticola G.T.Plunkett & J.J.Bruhl. The distribution, habitat and conservation status are discussed.

14.
Obstet Gynecol ; 119(2 Pt 1): 315-20, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22270283

RESUMO

OBJECTIVE: To estimate the possibility of long-term effects of subclinical thyroid dysfunction on hypertension and other cardiovascular-related conditions during pregnancy. METHODS: This is a secondary analysis of a prospective prenatal population-based study in which serum thyroid-function analytes were measured from November 2000 through April 2003. Women with evidence of overt thyroid disease were excluded. The remaining women were classified as being euthyroid, having subclinical hyperthyroid, or having subclinical hypothyroid, and the frequency of pregnancy-associated hypertensive disorders was compared between these groups. RESULTS: Pregnancy outcomes in 24,883 women were analyzed for pregnancy hypertension, classified as gestational hypertension, mild preeclampsia, or severe preeclampsia. The incidence of hypertensive disorders were compared between the three cohorts. The overall incidences of hypertension in pregnancy were 6.2%, 8.5%, and 10.9% in the subclinical hyperthyroid, euthyroid, and subclinical hypothyroid groups, respectively, and were found to be significant when unadjusted (P=.016). After adjusting for confounding factors, there was a significant association between subclinical hypothyroidism and severe preeclampsia (adjusted odds ratio 1.6, 95% confidence interval 1.1-2.4; P=.03). CONCLUSION: Women with subclinical hypothyroidism identified during pregnancy have an increased risk for severe preeclampsia when compared with euthyroid women. LEVEL OF EVIDENCE: II.


Assuntos
Hipertensão Induzida pela Gravidez/epidemiologia , Hipertireoidismo/complicações , Hipotireoidismo/complicações , Adulto , Análise de Variância , Eclampsia/epidemiologia , Feminino , Humanos , Hipertireoidismo/sangue , Hipotireoidismo/sangue , Incidência , Modelos Logísticos , Análise Multivariada , Pré-Eclâmpsia/epidemiologia , Gravidez , Fatores de Risco , Índice de Gravidade de Doença , Tireotropina/sangue , Tiroxina/sangue , Adulto Jovem
15.
Am J Perinatol ; 28(1): 19-24, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20607643

RESUMO

We sought to determine if maternal use of selective serotonin reuptake inhibitors (SSRIs) in the second half of pregnancy is associated with persistent pulmonary hypertension of the newborn (PPHN). We performed a case-controlled study (1:6 ratio) of infants delivered at Madigan Army Medical Center with primary PPHN from 2003 through 2009. Study and control patients were compared for the following clinical factors: SSRI use after 20 weeks gestation, mode of delivery, maternal disease, body mass index, tobacco use, fetal gender, maternal age, and parity. We identified 20 cases of primary PPHN out of 11,923 births for an incidence of 0.17%. Mode of delivery was the only factor we found to be associated with PPHN. Specifically, cesarean delivery (CD) prior to the onset of labor increased the risk for PPHN: odds ratio (OR) = 4.9, confidence interval (CI) 1.7 to 14.0. Importantly, use of SSRIs in the second half of pregnancy was identified in 5% of the controls but none of the cases (OR = 0, CI 0 to 3). PPHN is associated with CD prior to the onset of labor but not with SSRI use in the second half of pregnancy. Previous studies linking PPHN to SSRI use relied on after-the-fact patient interviews and incomplete records. Additional studies are needed to verify these results.


Assuntos
Cesárea/efeitos adversos , Parto Obstétrico/efeitos adversos , Trabalho de Parto/fisiologia , Síndrome da Persistência do Padrão de Circulação Fetal/etiologia , Inibidores Seletivos de Recaptação de Serotonina/efeitos adversos , Adulto , Estudos de Casos e Controles , Intervalos de Confiança , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Razão de Chances , Gravidez , Inibidores Seletivos de Recaptação de Serotonina/farmacologia
16.
J Pept Sci ; 16(9): 465-72, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20629115

RESUMO

A helical, prehairpin trimer covering the majority of the HR1 region of human immunodeficiency virus gp41 was achieved by chemically coupling three identical 51 amino acid peptides. A 1,3,5-tris(aminomethyl)-2,4,6-triethylbenzene pinwheel 'cap' was used to trimerize the peptides by taking advantage of the unique property of triacyl fluoride and orthogonal protection and deprotection. The resulting protein is fully helical, highly thermostable and soluble.


Assuntos
Proteína gp41 do Envelope de HIV/química , Fragmentos de Peptídeos/síntese química , Multimerização Proteica , Estrutura Secundária de Proteína
17.
Biochemistry ; 47(25): 6662-70, 2008 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-18507398

RESUMO

Enfuvirtide (ENF), the first human immunodeficiency virus type 1 (HIV-1) fusion inhibitor approved for clinical use, acts by binding to gp41 heptad repeat 1 (HR1) and preventing its interaction with the viral HR2 region. Treatment-emergent resistance to ENF has been mapped to residues within HR1, and these mutations decrease its susceptibility to ENF and may reduce viral fitness and pathogenesis, although the mechanism for these effects is not clear. N43D, a common ENF resistance mutation, was found in in vitro assays to cause a 5-50-fold in antiviral activity. We introduced this mutation into peptide models and determined the impact of this mutation by circular dichroism and X-ray crystallography. We find that the mutation results in a decrease in the thermal stability of the six-helix bundle and causes a significant change in the HR1-HR2 interface, including a loss of HR2 helicity. These data form a mechanistic basis for the decrease in ENF sensitivity and six-helix bundle stability. The E137K polymorphism, generally present at baseline in patients who develop N43D, partially compensates for the loss of stability, and we show that these residues likely form an ion pair. These data form a framework for understanding the impact of resistance mutations on viral fitness and pathogenesis and provide a pathway for the development of novel fusion inhibitor peptides.


Assuntos
Farmacorresistência Viral/genética , Proteína gp41 do Envelope de HIV/farmacologia , HIV-1/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Sítios de Ligação , Dicroísmo Circular , Cristalografia por Raios X , Enfuvirtida , Proteína gp41 do Envelope de HIV/química , Proteína gp41 do Envelope de HIV/genética , Inibidores da Fusão de HIV/farmacologia , HIV-1/genética , Humanos , Ligação de Hidrogênio , Concentração Inibidora 50 , Modelos Moleculares , Mutação , Polimorfismo Genético , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína
18.
Protein Sci ; 17(4): 633-43, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18359857

RESUMO

HIV fusion is mediated by a conformational transition in which the C-terminal region (HR2) of gp41 interacts with the N-terminal region (HR1) to form a six-helix bundle. Peptides derived from the HR1 form a well-characterized, trimeric coiled-coil bundle in the presence of HR2 peptides, but there is little structural information on the isolated HR1 trimer. Using protein design, we have designed synthetic HR1 peptides that form soluble, thermostable HR1 trimers. In vitro binding of HR2 peptides to the engineered trimer suggests that the design strategy has not significantly impacted the ability to form the six-helix bundle. The peptides have enhanced antiviral activity compared to wild type, with up to 30-fold greater potency against certain viral isolates. In vitro passaging was used to generate HR1-resistant virus and the observed resistance mutations map to the HR2 region of gp41, demonstrating that the peptides block the fusion process by binding to the viral HR2 domain. Interestingly, the activity of the HR2 fusion inhibitor, enfuvirtide (ENF), against these resistant viruses is maintained or improved up to fivefold. The 1.5 A crystal structure of one of these designs has been determined, and we show that the isolated HR1 is very similar to the conformation of the HR1 in the six-helix bundle. These results provide an initial model of the pre-fusogenic state, are attractive starting points for identifying novel fusion inhibitors, and offer new opportunities for developing HIV therapeutics based on HR1 peptides.


Assuntos
Proteína gp41 do Envelope de HIV/química , Engenharia de Proteínas/métodos , Estrutura Quaternária de Proteína , Células Cultivadas , Cristalização , Cristalografia por Raios X , Farmacorresistência Viral , Enfuvirtida , Proteína gp41 do Envelope de HIV/genética , Proteína gp41 do Envelope de HIV/farmacologia , Inibidores da Fusão de HIV/farmacologia , HIV-1/efeitos dos fármacos , Humanos , Modelos Moleculares , Fragmentos de Peptídeos/farmacologia , Dobramento de Proteína
19.
Proc Natl Acad Sci U S A ; 104(31): 12772-7, 2007 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-17640899

RESUMO

Enfuvirtide (ENF), the first approved fusion inhibitor (FI) for HIV, is a 36-aa peptide that acts by binding to the heptad repeat 1 (HR1) region of gp41 and preventing the interaction of the HR1 and HR2 domains, which is required for virus-cell fusion. Treatment-acquired resistance to ENF highlights the need to create FI therapeutics with activity against ENF-resistant viruses and improved durability. Using rational design, we have made a series of oligomeric HR2 peptides with increased helical structure and with exceptionally high HR1/HR2 bundle stability. The engineered peptides are found to be as much as 3,600-fold more active than ENF against viruses that are resistant to the HR2 peptides ENF, T-1249, or T-651. Passaging experiments using one of these peptides could not generate virus with decreased sensitivity, even after >70 days in culture, suggesting superior durability as compared with ENF. In addition, the pharmacokinetic properties of the engineered peptides were improved up to 100-fold. The potent antiviral activity against resistant viruses, the difficulty in generating resistant virus, and the extended half-life in vivo make this class of fusion inhibitor peptide attractive for further development.


Assuntos
Desenho de Fármacos , Farmacorresistência Viral/efeitos dos fármacos , Inibidores da Fusão de HIV/química , Inibidores da Fusão de HIV/uso terapêutico , HIV-1/efeitos dos fármacos , Peptídeos/química , Peptídeos/uso terapêutico , Sequência de Aminoácidos , Animais , Fenômenos Biofísicos , Biofísica , Enfuvirtida , Proteína gp41 do Envelope de HIV/farmacologia , Inibidores da Fusão de HIV/metabolismo , Inibidores da Fusão de HIV/farmacocinética , Infecções por HIV/tratamento farmacológico , Infecções por HIV/patologia , Infecções por HIV/virologia , Macaca fascicularis , Dados de Sequência Molecular , Fragmentos de Peptídeos/farmacologia , Peptídeos/metabolismo , Peptídeos/farmacocinética , Desnaturação Proteica , Dobramento de Proteína , Estrutura Secundária de Proteína , Temperatura
20.
Am J Bot ; 93(9): 1241-50, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21642188

RESUMO

Fundamental questions of floral morphology remain unresolved in the grasslike monocots in order Poales, including what constitutes a flower and what constitutes a spikelet. The mapaniid sedges have particularly complex spikeletlike structures, variously interpreted as clusters of flowers or spikelets. Recent phylogenetic studies of Cyperaceae have identified the mapaniid clade as sister to the rest of the family, but the homology of mapaniid reproductive units (RUs) and spikeletlike units (SLUs) to other sedge flowers and spikelets is unclear. We examined reproductive development in the mapaniid Exocarya sclerioides. Inflorescence branches terminated in a SLU with bracts and 1-4 RUs. RUs had four small leaflike structures (LLSs): two lateral LLSs, each associated with a stamen, an abaxial LLS associated with a stamen, and an adaxial LLS. The gynoecium terminated the RU. All RUs were axillary to bracts, and unexpanded bracts and RUs were produced beyond expanded RUs, so SLUs were racemose. RUs developed from a single primordium that initiated two lateral LLSs, then two lateral stamens, then the gynoecium. Initiation of the abaxial LLS and stamen and the adaxial LLS followed. We hypothesize that the RU is a sympodial branch that terminates in a hermaphroditic flower with two stamens and a gynoecium; the two lateral LLSs are halves of a deeply divided prophyll.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...