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2.
PLoS Med ; 11(9): e1001735, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25247995

RESUMO

BACKGROUND: Intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) is recommended for malaria prevention in HIV-negative pregnant women, but it is contraindicated in HIV-infected women taking daily cotrimoxazole prophylaxis (CTXp) because of potential added risk of adverse effects associated with taking two antifolate drugs simultaneously. We studied the safety and efficacy of mefloquine (MQ) in women receiving CTXp and long-lasting insecticide treated nets (LLITNs). METHODS AND FINDINGS: A total of 1,071 HIV-infected women from Kenya, Mozambique, and Tanzania were randomized to receive either three doses of IPTp-MQ (15 mg/kg) or placebo given at least one month apart; all received CTXp and a LLITN. IPTp-MQ was associated with reduced rates of maternal parasitemia (risk ratio [RR], 0.47 [95% CI 0.27-0.82]; p=0.008), placental malaria (RR, 0.52 [95% CI 0.29-0.90]; p=0.021), and reduced incidence of non-obstetric hospital admissions (RR, 0.59 [95% CI 0.37-0.95]; p=0.031) in the intention to treat (ITT) analysis. There were no differences in the prevalence of adverse pregnancy outcomes between groups. Drug tolerability was poorer in the MQ group compared to the control group (29.6% referred dizziness and 23.9% vomiting after the first IPTp-MQ administration). HIV viral load at delivery was higher in the MQ group compared to the control group (p=0.048) in the ATP analysis. The frequency of perinatal mother to child transmission of HIV was increased in women who received MQ (RR, 1.95 [95% CI 1.14-3.33]; p=0.015). The main limitation of the latter finding relates to the exploratory nature of this part of the analysis. CONCLUSIONS: An effective antimalarial added to CTXp and LLITNs in HIV-infected pregnant women can improve malaria prevention, as well as maternal health through reduction in hospital admissions. However, MQ was not well tolerated, limiting its potential for IPTp and indicating the need to find alternatives with better tolerability to reduce malaria in this particularly vulnerable group. MQ was associated with an increased risk of mother to child transmission of HIV, which warrants a better understanding of the pharmacological interactions between antimalarials and antiretroviral drugs. TRIAL REGISTRATION: ClinicalTrials.gov NCT 00811421; Pan African Clinical Trials Registry PACTR 2010020001813440 Please see later in the article for the Editors' Summary.


Assuntos
Antimaláricos/administração & dosagem , Infecções por HIV/tratamento farmacológico , Malária/prevenção & controle , Mefloquina/administração & dosagem , Complicações Infecciosas na Gravidez/prevenção & controle , Combinação Trimetoprima e Sulfametoxazol/administração & dosagem , Adulto , Método Duplo-Cego , Feminino , Seguimentos , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Humanos , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Quênia/epidemiologia , Malária/diagnóstico , Malária/epidemiologia , Moçambique/epidemiologia , Gravidez , Complicações Infecciosas na Gravidez/diagnóstico , Complicações Infecciosas na Gravidez/epidemiologia , Complicações Parasitárias na Gravidez/diagnóstico , Complicações Parasitárias na Gravidez/epidemiologia , Complicações Parasitárias na Gravidez/prevenção & controle , Resultado da Gravidez , Tanzânia/epidemiologia , Resultado do Tratamento , Adulto Jovem
3.
PLoS Med ; 11(9): e1001733, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25247709

RESUMO

BACKGROUND: Intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) is recommended by WHO to prevent malaria in African pregnant women. The spread of SP parasite resistance has raised concerns regarding long-term use for IPT. Mefloquine (MQ) is the most promising of available alternatives to SP based on safety profile, long half-life, and high efficacy in Africa. We evaluated the safety and efficacy of MQ for IPTp compared to those of SP in HIV-negative women. METHODS AND FINDINGS: A total of 4,749 pregnant women were enrolled in an open-label randomized clinical trial conducted in Benin, Gabon, Mozambique, and Tanzania comparing two-dose MQ or SP for IPTp and MQ tolerability of two different regimens. The study arms were: (1) SP, (2) single dose MQ (15 mg/kg), and (3) split-dose MQ in the context of long lasting insecticide treated nets. There was no difference on low birth weight prevalence (primary study outcome) between groups (360/2,778 [13.0%]) for MQ group and 177/1,398 (12.7%) for SP group; risk ratio [RR], 1.02 (95% CI 0.86-1.22; p=0.80 in the ITT analysis). Women receiving MQ had reduced risks of parasitemia (63/1,372 [4.6%] in the SP group and 88/2,737 [3.2%] in the MQ group; RR, 0.70 [95% CI 0.51-0.96]; p=0.03) and anemia at delivery (609/1,380 [44.1%] in the SP group and 1,110/2743 [40.5%] in the MQ group; RR, 0.92 [95% CI 0.85-0.99]; p=0.03), and reduced incidence of clinical malaria (96/551.8 malaria episodes person/year [PYAR] in the SP group and 130/1,103.2 episodes PYAR in the MQ group; RR, 0.67 [95% CI 0.52-0.88]; p=0.004) and all-cause outpatient attendances during pregnancy (850/557.8 outpatients visits PYAR in the SP group and 1,480/1,110.1 visits PYAR in the MQ group; RR, 0.86 [0.78-0.95]; p=0.003). There were no differences in the prevalence of placental infection and adverse pregnancy outcomes between groups. Tolerability was poorer in the two MQ groups compared to SP. The most frequently reported related adverse events were dizziness (ranging from 33.9% to 35.5% after dose 1; and 16.0% to 20.8% after dose 2) and vomiting (30.2% to 31.7%, after dose 1 and 15.3% to 17.4% after dose 2) with similar proportions in the full and split MQ arms. The open-label design is a limitation of the study that affects mainly the safety assessment. CONCLUSIONS: Women taking MQ IPTp (15 mg/kg) in the context of long lasting insecticide treated nets had similar prevalence rates of low birth weight as those taking SP IPTp. MQ recipients had less clinical malaria than SP recipients, and the pregnancy outcomes and safety profile were similar. MQ had poorer tolerability even when splitting the dose over two days. These results do not support a change in the current IPTp policy. TRIAL REGISTRATION: ClinicalTrials.gov NCT 00811421; Pan African Clinical Trials Registry PACTR 2010020001429343 Please see later in the article for the Editors' Summary.


Assuntos
Antimaláricos/administração & dosagem , Infecções por HIV , Mosquiteiros Tratados com Inseticida/estatística & dados numéricos , Malária/prevenção & controle , Mefloquina/administração & dosagem , Complicações Parasitárias na Gravidez/prevenção & controle , Adolescente , Adulto , África Subsaariana/epidemiologia , Estudos de Coortes , Feminino , Seguimentos , Humanos , Recém-Nascido de Baixo Peso , Malária/diagnóstico , Malária/epidemiologia , Gravidez , Complicações Parasitárias na Gravidez/diagnóstico , Complicações Parasitárias na Gravidez/epidemiologia , Serviços Preventivos de Saúde/estatística & dados numéricos , Resultado do Tratamento , Adulto Jovem
4.
Development ; 131(7): 1543-52, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-14985258

RESUMO

During oogenesis, the Xenopus oocyte is blocked in prophase of meiosis I. It becomes competent to resume meiosis in response to progesterone at the end of its growing period (stage VI of oogenesis). Stage IV oocytes contain a store of inactive pre-MPF (Tyr15-phosphorylated Cdc2 bound to cyclin B2); the Cdc25 phosphatase that catalyzes Tyr15 dephosphorylation of Cdc2 is also present. However, the positive feedback loop that allows MPF autoamplification is not functional at this stage of oocyte growth. We report that when cyclin B is overexpressed in stage IV oocytes, MPF autoamplification does not occur and the newly formed cyclin B-Cdc2 complexes are inactivated by Tyr15 phosphorylation, indicating that Myt1 kinase remains active and that Cdc25 is prevented to be activated. Plx1 kinase (or polo-like kinase), which is required for Cdc25 activation and MPF autoamplification in full grown oocytes is not expressed at the protein level in small stage IV oocytes. In order to determine if Plx1 could be the missing regulator that prevents MPF autoamplification, polo kinase was overexpressed in stage IV oocytes. Under these conditions, the MPF-positive feedback loop was restored. Moreover, we show that acquisition of autoamplification competence does not require the Mos/MAPK pathway.


Assuntos
Retroalimentação Fisiológica , Fator Promotor de Maturação/metabolismo , Oócitos/fisiologia , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas de Xenopus , Xenopus laevis/fisiologia , Animais , Proteína Quinase CDC2/metabolismo , Proteínas de Ciclo Celular , Extratos Celulares , Ciclina A/metabolismo , Ciclina B/metabolismo , Ciclina B1 , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Feminino , Humanos , Meiose/fisiologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Ácido Okadáico/farmacologia , Oócitos/citologia , Oócitos/efeitos dos fármacos , Oogênese/fisiologia , Progesterona/farmacologia , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas c-mos/metabolismo , Transdução de Sinais/fisiologia , Fosfatases cdc25/metabolismo
5.
Toxicol Sci ; 73(1): 141-8, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12700411

RESUMO

Methoxychlor, lindane, and dieldrin are organochlorine pesticides that have been described as altering different reproductive functions in mammals and in invertebrates. However, few data have been published concerning the effects these pesticides have on oocyte maturation and fertilization. The aim of this study was to determine whether these compounds could affect maturation of mouse and starfish oocytes. We observed that germinal vesicle breakdown (GVBD) in starfish oocytes was significantly inhibited by the pesticides. Furthermore, formation of the first meiotic spindle and extrusion of the first polar body were also altered in mouse as well as in starfish. Our results suggest that the three pesticides act on common intracellular targets in invertebrates as well as in vertebrates.


Assuntos
Inseticidas/toxicidade , Oócitos/crescimento & desenvolvimento , Estrelas-do-Mar/crescimento & desenvolvimento , Animais , Dieldrin/toxicidade , Feminino , Imunofluorescência , Hexaclorocicloexano/toxicidade , Técnicas In Vitro , Meiose/efeitos dos fármacos , Metoxicloro/toxicidade , Camundongos , Oócitos/efeitos dos fármacos , Fuso Acromático/efeitos dos fármacos , Fixação de Tecidos
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