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1.
Biochem Cell Biol ; 96(2): 107-116, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29112458

RESUMO

In western countries, alcohol consumption is widespread in women of reproductive age, and in binge quantities. These countries also continue to have high incidences of unplanned pregnancies, with women often reported to cease drinking after discovering their pregnancy. This suggests the early embryo may be highly exposed to the detrimental effects of alcohol during the periconception period. The periconception and pre-implantation windows, which include maturation of the oocyte, fertilisation, and morphogenesis of the pre-implantation embryo, are particularly sensitive times of development. Within the oviduct and uterus, the embryo is exposed to a unique nutritional environment to facilitate its development and establish de-novo expression of the genome through epigenetic reprogramming. Alcohol has wide-ranging effects on cellular stress, as well as hormonal, and nutrient signalling pathways, which may affect the development and metabolism of the early embryo. In this review, we summarise the adverse developmental outcomes of early exposure to alcohol (prior to implantation in animal models) and discuss the potential mechanisms for these outcomes that may occur within the protected oviductal and uterine environment. One interesting candidate is reduced retinoic acid synthesis, as it is implicated in the control of epigenetic reprogramming and cell lineage commitment, processes that have adverse consequences for the formation of the placenta, and subsequently, fetal programming.


Assuntos
Consumo de Bebidas Alcoólicas/efeitos adversos , Blastocisto , Desenvolvimento Embrionário , Epigênese Genética , Fertilização , Regulação da Expressão Gênica no Desenvolvimento , Animais , Feminino , Humanos , Masculino
2.
Placenta ; 54: 10-16, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-27979377

RESUMO

Exposure of the embryo or fetus to perturbations in utero can result in intrauterine growth restriction, a primary risk factor for the development of adult disease. However, despite similar exposures, males and females often have altered disease susceptibility or progression from different stages of life. Fetal growth is largely mediated by the placenta, which, like the fetus is genetically XX or XY. The placenta and its associated trophoblast lineages originate from the trophectoderm (TE) of the early embryo. Rodent models (rat, mouse, spiny mouse), have been used extensively to examine placenta development and these have demonstrated the growth trajectory of the placenta in females is generally slower compared to males, and also shows altered adaptive responses to stressful environments. These placental adaptations are likely to depend on the type of stressor, duration, severity and the window of exposure during development. Here we describe the divergent developmental pathways between the male and female placenta contributing to altered differentiation of the TE derived trophoblast subtypes, placental growth, and formation of the placental architecture. Our focus is primarily genetic or environmental perturbations in rodent models which show altered placental responsiveness between sexes. We suggest that perturbations during early placental development may have greater impact on viability and growth of the female fetus whilst those occurring later in gestation may preferentially affect the male fetus. This may be of great relevance to human pregnancies which result from assisted reproductive technologies or complications such as pre-eclampsia and diabetes.


Assuntos
Placenta/fisiologia , Placentação , Caracteres Sexuais , Animais , Feminino , Humanos , Placenta/irrigação sanguínea , Gravidez
3.
Biol Sex Differ ; 8: 17, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28523122

RESUMO

BACKGROUND: A male fetus is suggested to be more susceptible to in utero and birth complications. This may be due in part to altered morphology or function of the XY placenta. We hypothesised that sexual dimorphism begins at the blastocyst stage with sex differences in the progenitor trophectoderm (TE) and its derived trophoblast lineages, as these cells populate the majority of cell types within the placenta. We investigated sex-specific differences in cell allocation in the pre-implantation embryo and further characterised growth and gene expression of the placental compartments from the early stages of the definitive placenta through to late gestation. METHODS: Naturally mated Sprague Dawley dams were used to collect blastocysts at embryonic day (E) 5 to characterise cell allocation; total, TE, and inner cell mass (ICM), and differentiation to downstream trophoblast cell types. Placental tissues were collected at E13, E15, and E20 to characterise volumes of placental compartments, and sex-specific gene expression profiles. RESULTS: Pre-implantation embryos showed no sex differences in cell allocation (total, TE and ICM) or early trophoblast differentiation, assessed by outgrowth area, number and ploidy of trophoblasts and P-TGCs, and expression of markers of trophoblast stem cell state or differentiation. Whilst no changes in placental structures were found in the immature E13 placenta, the definitive E15 placenta from female fetuses had reduced labyrinthine volume, fetal and maternal blood space volume, as well as fetal blood space surface area, when compared to placentas from males. No differences between the sexes in labyrinth trophoblast volume or interhaemal membrane thickness were found. By E20 these sex-specific placental differences were no longer present, but female fetuses weighed less than their male counterparts. Coupled with expression profiles from E13 and E15 placental samples may suggest a developmental delay in placental differentiation. CONCLUSIONS: Although there were no overt differences in blastocyst cell number or early placental development, reduced growth of the female labyrinth in mid gestation is likely to contribute to lower fetal weight in females at E20. These data suggest sex differences in fetal growth trajectories are due at least in part, to differences in placenta growth.


Assuntos
Placenta/embriologia , Placentação , Caracteres Sexuais , Animais , Contagem de Células , Diferenciação Celular , Vilosidades Coriônicas/embriologia , Vilosidades Coriônicas/metabolismo , Implantação do Embrião , Feminino , Idade Gestacional , Masculino , Placenta/citologia , Placenta/metabolismo , Gravidez , RNA Mensageiro/metabolismo , Ratos Sprague-Dawley
4.
Placenta ; 46: 87-91, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27697226

RESUMO

Maternal alcohol consumption is common prior to pregnancy recognition and in the rat results in altered placental development and fetal growth restriction. To assess the effect of ethanol (EtOH) exposure on the differentiation of trophoblast stem (TS) cells, mouse TS lines were differentiated in vitro for 6 days in 0%, 0.2% or 1% EtOH. This reduced both trophoblast survival and expression of labyrinth and junctional zone trophoblast subtype-specific genes. This suggests that fetal growth restriction and altered placental development associated with maternal alcohol consumption in the periconceptional period could be mediated in part by direct effects on trophoblast development.


Assuntos
Depressores do Sistema Nervoso Central/toxicidade , Etanol/toxicidade , Proteínas da Gravidez/metabolismo , Trofoblastos/efeitos dos fármacos , Animais , Biomarcadores/metabolismo , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Camundongos , Trofoblastos/metabolismo
5.
Thromb Haemost ; 68(5): 526-33, 1992 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-1455399

RESUMO

To determine if rhesus monkeys (Macaca mulatta) could serve as a model for studying the role of the contact system in the pathophysiology of human infections, we compared structural, kinetic, and functional characteristics of plasma prekallikrein and its activation products in rhesus and humans. Three prekallikrein variants (85-, 89- and 93-kDa) were revealed in rhesus plasma as compared with the two variants (85- and 88-kDa) in human plasma by immunoblotting with the monoclonal antibody MAb 13G11. The prekallikrein concentration in rhesus plasma was 1.5-fold that in human plasma as determined by computerized immunoblot analyses (CIBA) and amidolytic activity. The electrophoretic mobility of prekallikrein from plasma of both species increased after deglycosylation. Inhibition of prekallikrein activation by MAb 13G11 was 55% (rhesus plasma) and 76% (human plasma), with similar inhibition curves. Immunoblots of activated rhesus plasma showed prekallikrein, complexes of kallikrein with C1 inhibitor, alpha 2-macroglobulin and approximately 60-kDa inhibitor(s) (viz. antithrombin III), and 45-kDa fragments, like those in activated human plasma. Concentrations and molecular masses of factor XII and high molecular weight kininogen were similar in rhesus and human plasma. The activated partial thromboplastin time (APTT) and prothrombin time were 20.1 +/- 1.6 and 9.7 +/- 0.3 s for rhesus and 32.0 +/- 5.6 and 12 +/- 0.5 s for human plasma. Human and rhesus APTTs were similar when prekallikrein concentrations in human and rhesus plasma became alike by adding human purified prekallikrein.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Pré-Calicreína/química , Animais , Fator XII/metabolismo , Fibrinogênio/metabolismo , Glicosilação , Humanos , Calicreínas/antagonistas & inibidores , Cinética , Cininogênios/metabolismo , Macaca mulatta , Estrutura Molecular , Tempo de Tromboplastina Parcial , Pré-Calicreína/metabolismo , Pré-Calicreína/farmacologia , Tempo de Protrombina , Especificidade da Espécie , Temperatura
6.
Pediatr Infect Dis J ; 6(2): 170-6, 1987 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-3031575

RESUMO

During 29 months of prospective longitudinal study of diarrhea in the home, human rotaviruses (HRVs) infected one or more members in 51% of 65 families, 35 of 126 children (28%) and 16 of 124 adults (13%). Within the 33 affected families, 57% of 62 children and 25% of 65 adults were infected. HRV gastroenteritis peaked at 40/100 person years at ages 12 to 23 months and decreased to 5 episodes/100 person years in adults. Among 25 children 0 through 36 months of age who had HRV infection, 88% were symptomatic. Of the 22 children with symptomatic HRV infection, 1 required hospitalization and 8 were seen by their physician for supportive care. HRVs were found in 12% of 216 stools obtained during gastrointestinal illness, but in only 0.2% of 1238 non-illness stools tested. HRV infections were noted as early as October and as late as April. Of 33 families who were studied for 2 seasons, at least 1 individual in each of 3 families experienced HRV infections in both years, but only one, an adult, shed virus and had symptoms in both seasons.


Assuntos
Gastroenterite/genética , Infecções por Rotavirus/genética , Adolescente , Adulto , Criança , Pré-Escolar , Infecções por Enterovirus , Ensaio de Imunoadsorção Enzimática , Fezes/microbiologia , Feminino , Gastroenterite/diagnóstico , Gastroenterite/epidemiologia , Gastroenterite/terapia , Humanos , Lactente , Estudos Longitudinais , Masculino , Microscopia Eletrônica , Estudos Prospectivos , Rotavirus/isolamento & purificação , Infecções por Rotavirus/diagnóstico , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/terapia , Virginia
7.
Am J Trop Med Hyg ; 36(2): 416-23, 1987 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-3030150

RESUMO

Significant coagulation abnormalities were associated with experimental infection of strain 13 guinea pigs with Pichinde virus, an arenavirus related to the virulent human pathogens Junin, Machupo, and Lassa viruses. Infected animals developed decreased activity of multiple coagulation factors, decreased antithrombin III levels, high levels of fibrin-fibrinogen degradation products, impaired platelet function, and thrombocytopenia. Testing for the presence of a coagulation inhibitor revealed a pattern consistent with factor deficiency. Fibrin thrombi were not found at necropsy. The findings of high fibrin-fibrinogen degradation product levels and decreased antithrombin III levels, in association with decreased activity of multiple coagulation factors and thrombocytopenia, suggest that intravascular coagulation is a feature of this experimental infection. The demonstration of abnormal platelet function is also significant, as this could contribute to defective hemostasis despite the moderate thrombocytopenia which usually occurs in arenaviral disease.


Assuntos
Infecções por Arenaviridae/sangue , Transtornos da Coagulação Sanguínea/microbiologia , Febre Hemorrágica Americana/sangue , Animais , Testes de Coagulação Sanguínea , Feminino , Cobaias , Testes de Inibição da Hemaglutinação , Hematócrito , Contagem de Leucócitos , Masculino , Agregação Plaquetária , Contagem de Plaquetas
8.
Chin Med J (Engl) ; 106(8): 608-10, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7900974

RESUMO

We analysed the early viremia and clinical tests in 82 patients with epidemic hemorrhagic fever (EHF). The results showed that the changes in viremia and clinical tests are related to the severity of the disease and prognosis. Higher concentrations of the virus in infected patients might cause a more unfavourable prognosis and more abnormalities in clinical tests. CK-MB, SGOT, SGPT, serum creatinine and urea nitrogen contents increased markedly, while serum total protein, albumin and calcium contents decreased markedly, indicating that the heart, liver and kidney in EHF patients were severely damaged. Markedly increased WBC and monocytes showed that the patients were seriously infected. Platelet count, antithrombin-III and plasminogen decreased markedly, demonstrating that there were marked changes in the coagulation-anticoagulation and fibrinolytic system of the EHF patients. Changes in RBC, Hb and HCT contents indicated that the blood in the EHF patients had a higher concentration. This study gives further evidence that EHFV plays an important role in the pathogenesis of EHF.


Assuntos
Creatina Quinase/sangue , Febre Hemorrágica com Síndrome Renal/microbiologia , Viremia/sangue , Adolescente , Adulto , Alanina Transaminase/sangue , Aspartato Aminotransferases/sangue , Nitrogênio da Ureia Sanguínea , Feminino , Hematócrito , Febre Hemorrágica com Síndrome Renal/sangue , Humanos , Isoenzimas , Masculino , Pessoa de Meia-Idade , Prognóstico
9.
Chin Med J (Engl) ; 104(2): 149-53, 1991 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1678691

RESUMO

Kinetic changes of viremia were observed in 287 cases of hemorrhagic fever with renal syndrome (HFRS) in whom ribavirin was administered with double blind random control studied by means of virus isolation, indirect immunofluorescence assay and enzyme-linked immunosorbent assay. The positive rate of viremia was 79.7% (Sp = 3%) and positive rate of HERS IgM was 85% (Sp = 3.1%) before treatment. Viremia could be interrupted by ribavirin as in the ribavirin treated group, the viremia positive rate decreased, duration of viremia was shortened, viral antigen products, virus titer and HFRS IgG antibody level were reduced as compared with the control group. This showed that viremia was very frequent in patients in the febrile phase and ribavirin is an effective antiviral drug in HFRS during the febrile phase. Dosage and course of treatment of this drug are discussed.


Assuntos
Febre Hemorrágica com Síndrome Renal/tratamento farmacológico , Ribavirina/uso terapêutico , Viremia/tratamento farmacológico , Método Duplo-Cego , Febre , Humanos
10.
W V Med J ; 89(10): 442-4, 1993 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8266681

RESUMO

To gauge the impact of screening mammography and the results of clinical trials on the pattern of primary surgical care of early breast cancer, tumor registry data from the Charleston Area Medical Center for 1980-81 was compared to tumor registry data at the hospital for 1990-91. Over the course of 10 years, there was a significant increase in the proportion of patients with T1 tumors (52% vs. 66%, p = .004), a significant increase of cases diagnosed by mammography alone (6% vs. 34%, p < .001), a significant decrease in the proportion of patients with positive axillary nodes (41% vs. 28%, p = .016), and a significant increase in the proportion of patients undergoing breast-sparing procedures (4% vs. 16%, p = .003). However, the percentage of breast-sparing operations at CAMC from 1990-91 was lower than the number reported in the National Cancer Data Base of 1988 (16% vs. 29%). A future study to assess reasons for patient selection of mastectomy or local excision is being planned.


Assuntos
Neoplasias da Mama/epidemiologia , Mamografia , Programas de Rastreamento , Lesões Pré-Cancerosas/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/patologia , Neoplasias da Mama/prevenção & controle , Feminino , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Lesões Pré-Cancerosas/patologia , Lesões Pré-Cancerosas/prevenção & controle , Sistema de Registros/estatística & dados numéricos , West Virginia/epidemiologia
11.
Hospitals ; 50(8): 83-5, 1976 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-939511

RESUMO

There is increasing emphasis on continuing education of hospital personnel, who need and want access to information in order to be aware of advances in health care. Small hospitals cannot afford to duplicate extensive collections. Personnel of hospitals that are remote from urban centers often do not have opportunities to visit a resource library on a regular basis and do not have experience in searching the medical literature through the use of reference tools. It is increasingly evident that the circuit librarian program has served as a catalyst in establishing relationships between the hospitals and the university health sciences center. The director of the CHSL has consulted with the deans of the nursing and the medical schools and with various professors. They have promised that the schools will try to address identifiable continuing education needs or requests from the hospitals. Moreover, the circuit librarian meets with individual hospital personnel and then obtains information for them from the CHSL and its staff. The circuit librarian program is one way to meet community hospitals' needs for access to health sciences literature and to initiate peer interaction for information exchange.


Assuntos
Serviços Hospitalares Compartilhados , Serviços de Biblioteca , Educação Continuada , Serviços de Biblioteca/provisão & distribuição , Ohio , Recursos Humanos em Hospital/educação
12.
Immunopharmacology ; 43(2-3): 265-71, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10596862

RESUMO

This study is part of a project aimed at understanding individual responses to acute endotoxemia in a catheter-free rhesus (Macaca mulatta) model of inflammation. In the previous study [J. Endotoxin Res. 2 (1995) 411-420.], we showed that of 14 endotoxin 0111:B4 (ETX)-infused monkeys, only three died at < 13.5 h and one at 6 days postinfusion. Doses of ETX correlated neither with the magnitude of hypotension nor with rhesus outcome. Survival (and death at 6 days) or death at < 13.5 h was rather associated with controllable or uncontrollable rise of plasma levels of proinflammatory cytokines and reversible or irreversible shock. In the current study, we used plasmas of 5 survivors and of one of the monkeys that died at < 13.5 h (each infused with 3 X 10(6) EU ETX/kg), and of two saline control monkeys of the previous study. We analyzed changes in parameters of coagulation and contact systems. After ETX infusion, activated partial thromboplastin time (APTT) and prothrombin time (PT) values increased modestly in survivors but markedly in the nonsurvivor; responses of platelet counts and levels of fibrinogen, antithrombin, alpha2-macroglobulin (alpha2M), Cl-inhibitor (C1INH) and alpha1 -antitrypsin were similar in survivors and the nonsurvivor; the rate of plasma prekallikrein (PK) activation measured by hydrolysis of the kallikrein (KAL) substrate D-Pro-Phe-Arg-p-nitroanilide was not altered by ETX infusion; and the distribution of PK activation products, analyzed by MAb 13G11/immunoblotting in plasmas with or without artificial activation, was similar in survivors and the nonsurvivor. Responses in controls were relatively stable. Since we used defined experimental conditions, this primate model has the potential to be useful to study further correlation of inflammatory parameters with differential outcome.


Assuntos
Endotoxinas/toxicidade , Inflamação/sangue , Pré-Calicreína/metabolismo , Animais , Macaca mulatta , Tempo de Tromboplastina Parcial , Tempo de Protrombina , Fator de Necrose Tumoral alfa/análise
13.
Infect Immun ; 58(9): 3056-60, 1990 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2387633

RESUMO

There appears to be a particular association between Helicobacter pylori and the gastric antrum, but the mechanisms by which the organism adheres to and colonizes the gastric mucosa are unclear. Surface hydrophobicity and surface charge mediate the adherence of other bacterial pathogens to mucosal epithelial cell surfaces. Therefore, in this study we characterized both the surface hydrophobicity and the surface charge of 10 H. pylori strains grown in broth culture. Four complementary methods were used to determine hydrophobicity: hydrophobic interaction chromatography, the salt aggregation test, comparison of bacterial adherence to polystyrene with adherence to sulfonated polystyrene, and measurement of contact angle with droplets of water. Three of the methods (salt aggregation test, adherence to polystyrene, and contact angles) indicated that each of the 10 strains expressed a relatively hydrophilic cell surface. In contrast, hydrophobic interaction chromatography determinations with both phenyl- and octyl-Sepharose suggested that the H. pylori strains were relatively hydrophobic. However, tetramethyl urea (0.4 M) did not reduce the binding of H. pylori to phenyl-Sepharose columns. DEAE-cellulose ion-exchange chromatography showed that each of the 10 strains of H. pylori had a surface which, overall, was highly negatively charged. We conclude that H. pylori expresses an overall relatively hydrophilic and negatively charged surface in vitro.


Assuntos
Aderência Bacteriana , Campylobacter/fisiologia , Mucosa Gástrica/microbiologia , Propriedades de Superfície , Epitélio/microbiologia , Humanos
14.
Planta Med ; 53(5): 470-4, 1987 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17269070

RESUMO

When added to suspension cultures of CATHARANTHUS ROSEUS, abscisic acid (ABA) stimulated intracellular accumulation of the indole alkaloids catharanthine and ajmalicine in both flask and 30 litre fermenter-scale systems. The response varied, and depended upon the cell line, the concentration and source of the ABA, and the growth phase at which the cells were treated. Precise timing of ABA addition to cells in a 301 fermenter resulted in a catharanthine yield of 85.25 mg/l after 10 days of cultivation. We propose that ABA may be useful for increasing the yield and reducing the production time for commercially useful secondary plant metabolites.

15.
Plant Cell Rep ; 3(4): 161-4, 1984 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24253477

RESUMO

Pre-existing methods for measuring cell or organelle volume based on the selective permeability of biological membranes have been modified to make them suitable for determining the intracellular volume of immoblised cells. When a freely permeable substance (e.g. tritiated water) and an impermeable substance ((14)C labelled mannitol is often suitable) are mixed with an immobilised cell culture, the two substances are diluted to different degrees. The extent of the difference allows the total intracellular volume of intact cells to be calculated. This volume is shown to be a useful parameter for assessing cell growth. The application of the method to follow membrane integrity and cell viability is also discussed.

16.
Plant Cell Rep ; 6(2): 142-5, 1987 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24248497

RESUMO

Vanadyl sulphate (10-500 mg/l), when added to cell suspension cultures of Catharanthus roseus stimulated increased intracellular accumulation of catharanthine and ajmalicine. This response was demonstrated in both flask and fermenter (30 litre) systems. The response varied, and depended upon cell line, concentration of vanadyl sulphate and the stage of the growth phase at which the cells were treated. This process has the potential to increase the yield and reduce the production time for commercially useful secondary plant metabolites.

17.
Lancet ; 1(8629): 68-71, 1989 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-2462660

RESUMO

A rapid diagnostic test for malaria based on acridine orange staining of centrifuged parasites in a microhaematocrit tube ('QBC' tube) was compared with the thick blood smear in 12 volunteers experimentally infected with Plasmodium falciparum, 408 residents of a malaria endemic area, and 180 hospital patients with suspected malaria. In the experimentally infected volunteers, the QBC tube test and the thick blood smear were comparable and the QBC tube could detect as few as 4 parasites/microliter blood. When used for mass screening in the field study, the test had a sensitivity of 70% for the diagnosis of malaria compared with 92% for a single thick blood smear. However, when used to diagnose malaria in hospital patients, the test detected as few as 3 parasites/microliter in 91 of 92 patients with asexual parasitaemia. For the three studies, the QBC tube was highly specific (98.4%), indicating malaria in only 8 of 487 subjects with negative blood films. The species of parasite was correctly identified in 77% of species. Processing the QBC tube was easier and much more rapid than was processing a thick blood smear, taking only 5 min for centrifugation and 5 min for examination. The QBC tube is not a substitute for the blood smear, but its speed and ease of use make it an important new tool for the diagnosis of malaria.


Assuntos
Laranja de Acridina , Malária/diagnóstico , Parasitologia/métodos , Plasmodium falciparum/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Centrifugação , Criança , Pré-Escolar , Estudos de Avaliação como Assunto , Humanos , Lactente , Malária/sangue , Pessoa de Meia-Idade , Parasitologia/instrumentação , Valor Preditivo dos Testes , Coloração e Rotulagem/métodos , Fatores de Tempo
18.
Ann Intern Med ; 120(4): 294-9, 1994 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-8291822

RESUMO

OBJECTIVE: To determine whether doxycycline, 100 mg administered as a single daily oral dose, is effective as a causal prophylactic agent, an agent active against the pre-erythrocytic liver stage of Plasmodium falciparum malaria parasites, in healthy nonimmune persons. If effective, the recommendation by the Centers for Disease Control and Prevention (CDC) that doxycycline be continued for 4 weeks after returning from malaria-endemic areas could be shortened to 1 week. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: Medical ward at the U.S. Army Research Institute of Infectious Diseases, Fort Detrick, Maryland. PARTICIPANTS: 18 nonimmune, healthy, adult male volunteers, age 21.7 +/- 2.9 (SD) years, were enrolled in two groups, one of 8 persons and one of 10 persons. Six participants in the first group and 7 in the second group received doxycycline. The remaining participants received placebo. Two volunteers were dropped from the study, leaving 16 participants for analysis. INTERVENTION: Each participant received doxycycline, 100 mg, or placebo in a single daily oral dose starting 3 days before exposure to P. falciparum-infected mosquitoes and ending 6 days after exposure. MEASUREMENTS: Monitoring for parasitemia, plasma doxycycline concentrations, and mosquitoes' salivary-gland sporozoite grade. RESULTS: 6 of 6 (100% [95% Cl, 54% to 100%]) participants on doxycycline in the first group and 2 of 6 (33% [Cl, 4% to 78%]) in the second group were protected from malaria. No differences were found between protected and nonprotected participants in the doxycycline elimination half-life (T1/2) (20.8 +/- 5.0 h compared with 21.9 +/- 5.2 h), the steady-state average plasma concentration (1626 +/- 469 ng/mL compared with 1698 +/- 651 ng/mL), or other pharmacokinetic parameter estimates. The mean mosquito salivary-gland sporozoite grade was significantly higher (P = 0.02) in protected (3.5 +/- 0.3) than in nonprotected persons (3.1 +/- 0.1). Overall, 8 of 12 persons on doxycycline were protected from malaria, yielding a causal prophylactic efficacy rate of 67% (Cl, 35% to 90%). CONCLUSIONS: A dosing regimen of doxycycline, 100 mg once daily, administered as a causal prophylactic agent against P. falciparum malaria in healthy, nonimmune volunteers, had an unacceptably high failure rate. Therefore, the CDC recommendation that doxycycline should be taken daily starting 1 to 2 days before travel, during travel, and for 4 weeks after travel should still be followed.


Assuntos
Doxiciclina/administração & dosagem , Malária Falciparum/prevenção & controle , Administração Oral , Adulto , Animais , Método Duplo-Cego , Doxiciclina/farmacocinética , Esquema de Medicação , Humanos , Imunocompetência , Masculino
19.
Rev Infect Dis ; 5(4): 723-36, 1983.
Artigo em Inglês | MEDLINE | ID: mdl-6353529

RESUMO

This report summarizes the clinical trials of the A/USSR/77 (H1N1) influenza vaccines performed in 1978. A total of 2,091 subjects participated in these trials. The results of these clinical trials indicated that two doses of H1N1 viral antigen were necessary to produce serum titers of hemagglutinin-inhibiting (HAI) antibody of greater than 1:40 in 80% or more of the test subjects younger than 25 years of age, who were unlikely to have experienced natural infection during the earlier period of prevalence of H1N1 virus (1947-1957). Only one dose of the A/Texas/77 (H3N2) or B/Hong Kong/72 antigen was necessary to stimulate equivalent titers of HAI antibody in serum. Thus, previous natural exposure to H1N1 viruses primed individuals 26 years of age or older to respond to H1N1 antigens. No major differences in antigenicity were noted between whole-virus and split-virus vaccines. No differences in reaction indexes measuring systemic reactions were noted when vaccine types were compared. Only one vaccine was associated with a reaction index appreciably higher than that of placebo. The relatively uniform antibody responses observed were attributed to the newer methods of vaccine standardization introduced after the clinical trials in 1976. No cases of vaccine-related neurological problems, including Guillain-Barré syndrome, were found during these trials. Vaccines containing 7-21 micrograms of each viral antigen were antigenic and were well tolerated.


Assuntos
Vacinas contra Influenza/farmacologia , Adolescente , Adulto , Criança , Pré-Escolar , Ensaios Clínicos como Assunto , Feminino , Testes de Inibição da Hemaglutinação , Hemaglutinação por Vírus , Humanos , Lactente , Recém-Nascido , Vacinas contra Influenza/imunologia , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários
20.
J Infect Dis ; 164(6): 1119-27, 1991 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1683355

RESUMO

A prospective, randomized, double-blind, concurrent, placebo-controlled clinical trial of intravenous ribavirin (loading dose of 33 mg/kg, 16 mg/kg every 6 h for 4 days, and 8 mg/kg every 8 h for 3 days) was conducted in 242 patients with serologically confirmed hemorrhagic fever with renal syndrome (HFRS) in the People's Republic of China. Mortality was significantly reduced (sevenfold decrease in risk) among ribavirin-treated patients, when comparisons were adjusted for baseline risk estimators of mortality (P = .01; two-tailed). HFRS typically consists of five consecutive but frequently overlapping clinical phases. Only occurrence of oliguric phase and hemorrhage was associated with severity of clinical disease in the placebo group. Ribavirin therapy also resulted in a significant reduction in the risk of entering the oliguric phase and experiencing hemorrhage. The only ribavirin-related side effect was a well-recognized, fully reversible anemia after completion of therapy.


Assuntos
Febre Hemorrágica com Síndrome Renal/tratamento farmacológico , Ribavirina/uso terapêutico , Anemia Hemolítica/induzido quimicamente , Método Duplo-Cego , Feminino , Febre/tratamento farmacológico , Febre/etiologia , Seguimentos , Orthohantavírus/imunologia , Febre Hemorrágica com Síndrome Renal/complicações , Febre Hemorrágica com Síndrome Renal/mortalidade , Humanos , Hipotensão/tratamento farmacológico , Hipotensão/etiologia , Imunoglobulina M/sangue , Injeções Intravenosas , Tábuas de Vida , Masculino , Oligúria/tratamento farmacológico , Oligúria/etiologia , Poliúria/tratamento farmacológico , Poliúria/etiologia , Prognóstico , Estudos Prospectivos , Análise de Regressão , Ribavirina/administração & dosagem , Ribavirina/efeitos adversos
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