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1.
Eur Rev Med Pharmacol Sci ; 26(6): 1939-1944, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35363343

RESUMO

OBJECTIVE: Although the application of transcranial Doppler (TCD) ultrasonography in clinical diagnosis of cerebral vasospasm is popular in clinical practice in Vietnam, available evidence of the predictive value of vasospasm on TCD in the literature was mostly reported from large institutions in developed countries. Hence, this study was conducted to evaluate the value of TCD ultrasonography in the diagnosis of vasospasm in patients with subarachnoid hemorrhage (SAH) in Vietnam. PATIENTS AND METHODS: This is a prospective observational study of all aneurysmal SAH patients consecutively admitted to a single center between 2008 and December 2011. TCD and 64-slice computed tomographic angiography (CTA) were used to cerebral vasospasm in SAH patients. RESULTS: 316 patients were analyzed (mean age = 52.97±12.27 years, 52.2% males). There were statistically significant difference rates of the cerebral vasospasm by Hunt and Hess Classification and Fisher classification (p <0.01). The proportion of the patients with cerebral vasospasm who were diagnosed exactly by TCD was 95.2%, while the proportion of the patients without cerebral vasospasm diagnosed exactly was 91.5%. TCD predictive diagnostic value was the highest, with the sensitivity of 0.95 (95% CI: 0.91-0.98), specificity of 0.91 (95% CI: 0.85-0.96), positive predictive value of 0.94 (5% CI: 0.90-0.97) and negative predictive value of 0.93 (95 CI: 0.87-0.97). Hemiplegia was the clinical symptom with the highest diagnostic value with the sensitivity of 0.34 (95% CI: 0.27-0.41), specificity of 0.92 (95% CI: 0.86-0.96), positive predictive value of 0.86 (95% CI: 0.76-0.93) and negative predictive value of 0.49 (95% CI: 0.41-0.54). CONCLUSIONS: Evidence of vasospasm diagnosis on TCD ultrasonography was found with high accuracy. Current study enables to suggest the wide application of TCD in Vietnam health facilities from central to grassroots levels instead of the CTA use.


Assuntos
Hemorragia Subaracnóidea , Vasoespasmo Intracraniano , Adulto , Idoso , Angiografia Cerebral , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Hemorragia Subaracnóidea/diagnóstico por imagem , Ultrassonografia Doppler Transcraniana/métodos , Vasoespasmo Intracraniano/diagnóstico por imagem , Vietnã
3.
Int J Tuberc Lung Dis ; 22(11): 1269-1276, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30355405

RESUMO

SETTING: Studies of US populations have produced conflicting findings about the impact of diabetes mellitus (DM) on tuberculosis (TB) treatment outcomes. OBJECTIVE: To investigate the association between DM and all-cause mortality among patients on anti-tuberculosis treatment in California, USA. DESIGN: Using TB surveillance data, we conducted a retrospective analysis of California patients with culture-confirmed TB who started anti-tuberculosis treatment during 2010-2014. We used Cox proportional hazards models to estimate the association of DM with all-cause mortality and conducted a sensitivity analysis to estimate the attenuating effect of unmeasured confounding by body mass index. RESULTS: Among 8461 patients with TB, 2124 (25.1%) had DM and 713 (8.4%) died during anti-tuberculosis treatment. A higher proportion of TB-DM patients died (13.1% vs. 6.8% TB-no DM). After adjusting for confounders, DM was associated with mortality (adjusted hazards ratio [aHR] 1.35, 95%CI 1.15-1.57). There was effect modification by human immunodeficiency virus (HIV) status, with HIV-positive patients having an aHR of 5.33 (95%CI 1.76-16.12). CONCLUSION: TB patients with DM had a greater hazard of death during anti-tuberculosis treatment than those without DM. Further investigation into the impact of HIV on the relation of DM to death is necessary.


Assuntos
Diabetes Mellitus Tipo 1/epidemiologia , Diabetes Mellitus Tipo 2/epidemiologia , Tuberculose/mortalidade , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antituberculosos/uso terapêutico , California/epidemiologia , Causas de Morte , Coinfecção/tratamento farmacológico , Coinfecção/epidemiologia , Coinfecção/mortalidade , Comorbidade , Feminino , Infecções por HIV/epidemiologia , Infecções por HIV/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Sistema de Registros , Estudos Retrospectivos , Fatores de Risco , Tuberculose/tratamento farmacológico , Tuberculose/epidemiologia , Adulto Jovem
4.
Br J Pharmacol ; 170(2): 366-79, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23808942

RESUMO

BACKGROUND AND PURPOSES: Myocardial C-type natriuretic peptide (CNP) levels are increased in heart failure. CNP can induce negative inotropic (NIR) and positive lusitropic responses (LR) in normal hearts, but its effects in failing hearts are not known. We studied the mechanism of CNP-induced NIR and LR in failing hearts and determined whether sarcoplasmatic reticulum Ca(2+) ATPase2 (SERCA2) activity is essential for these responses. EXPERIMENTAL APPROACH: Contractility, cGMP levels, Ca(2+) transient amplitudes and protein phosphorylation were measured in left ventricular muscle strips or ventricular cardiomyocytes from failing hearts of Wistar rats 6 weeks after myocardial infarction. KEY RESULTS: CNP increased cGMP levels, evoked a NIR and LR in muscle strips, and caused phospholamban (PLB) Ser(16) and troponin I (TnI) Ser(23/24) phosphorylation in cardiomyocytes. Both the NIR and LR induced by CNP were reduced in the presence of a PKG blocker/cGMP analogue (Rp-8-Br-Pet-cGMPS) and the SERCA inhibitor thapsigargin. CNP increased the amplitude of the Ca(2+) transient and increased SERCA2 activity in cardiomyocytes. The CNP-elicited NIR and LR were not affected by the L-type Ca(2+) channel activator BAY-K8644, but were abolished in the presence of isoprenaline (induces maximal activation of cAMP pathway). This suggests that phosphorylation of PLB and TnI by CNP causes both a NIR and LR. The NIR to CNP in mouse heart was abolished 8 weeks after cardiomyocyte-specific inactivation of the SERCA2 gene. CONCLUSIONS AND IMPLICATIONS: We conclude that CNP-induced PLB and TnI phosphorylation by PKG in concert mediate both a predictable LR as well as the less expected NIR in failing hearts.


Assuntos
Insuficiência Cardíaca/fisiopatologia , Infarto do Miocárdio/fisiopatologia , Peptídeo Natriurético Tipo C/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Éster Metílico do Ácido 3-Piridinacarboxílico, 1,4-Di-Hidro-2,6-Dimetil-5-Nitro-4-(2-(Trifluormetil)fenil)/farmacologia , Animais , Proteínas de Ligação ao Cálcio/metabolismo , GMP Cíclico/análogos & derivados , GMP Cíclico/farmacologia , Proteínas Quinases Dependentes de GMP Cíclico/metabolismo , Isoproterenol/farmacologia , Masculino , Camundongos , Camundongos Knockout , Miocárdio/patologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Fosforilação , Ratos , Ratos Wistar , Tapsigargina/farmacologia , Tionucleotídeos/farmacologia , Troponina I/metabolismo
5.
Phys Rev Lett ; 107(6): 062504, 2011 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-21902318

RESUMO

We report results from the NEMO-3 experiment based on an exposure of 1275 days with 661 g of (130)Te in the form of enriched and natural tellurium foils. The ßß decay rate of (130)Te is found to be greater than zero with a significance of 7.7 standard deviations and the half-life is measured to be T(½)(2ν) = [7.0 ± 0.9(stat) ± 1.1(syst)] × 10(20) yr. This represents the most precise measurement of this half-life yet published and the first real-time observation of this decay.

6.
Nutr Metab Cardiovasc Dis ; 21(2): 94-103, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19939654

RESUMO

BACKGROUND AND AIMS: Studies evaluating the effect of legume consumption on cholesterol have focused on soybeans, however non-soy legumes, such as a variety of beans, peas, and some seeds, are commonly consumed in Western countries. We conducted a meta-analysis of randomized controlled trials evaluating the effects of non-soy legume consumption on blood lipids. METHODS AND RESULTS: Studies were retrieved by searching MEDLINE (from January 1966 through July 2009), EMBASE (from January 1980 to July 2009), and the Cochrane Collaboration's Central Register of Controlled Clinical Trials using the following terms as medical subject headings and keywords: fabaceae not soybeans not isoflavones and diet or dietary fiber and cholesterol or hypercholesterolemia or triglycerides or cardiovascular diseases. Bibliographies of all retrieved articles were also searched. From 140 relevant reports, 10 randomized clinical trials were selected which compared a non-soy legume diet to control, had a minimum duration of 3 weeks, and reported blood lipid changes during intervention and control. Data on sample size, participant characteristics, study design, intervention methods, duration, and treatment results were independently abstracted by 2 investigators using a standardized protocol. Data from 10 trials representing 268 participants were examined using a random-effects model. Pooled mean net change in total cholesterol for those treated with a legume diet compared to control was -11.8 mg/dL (95% confidence interval [CI], -16.1 to -7.5); mean net change in low-density lipoprotein cholesterol was -8.0mg/dL (95% CI, -11.4 to -4.6). CONCLUSION: These results indicate that a diet rich in legumes other than soy decreases total and LDL cholesterol.


Assuntos
HDL-Colesterol/sangue , LDL-Colesterol/sangue , Fabaceae/química , Proteínas de Vegetais Comestíveis/administração & dosagem , Adolescente , Adulto , Idoso , Doenças Cardiovasculares/dietoterapia , Intervalos de Confiança , Dieta , Feminino , Humanos , Hipercolesterolemia/dietoterapia , Isoflavonas/farmacologia , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Ensaios Clínicos Controlados Aleatórios como Assunto , Triglicerídeos/sangue , Adulto Jovem
7.
Cancer ; 91(5): 928-39, 2001 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-11251944

RESUMO

BACKGROUND: Cervical carcinoma is the leading cause of cancer-related death among women in the developing world. The absence of cervical screening in Vietnam and other developing countries is due in large part to the perceived expense of implementing Papanicolaou cytology screening services, although, to the authors' knowledge, the cost-effectiveness of establishing such services has never been studied in a developing country. METHODS: Using decision analytic methods, the authors assessed cost-effectiveness of Pap screening from a societal perspective in Vietnam, the world's 9th most populous developing country (estimated 1999 population, 79 million). Outcomes measured included life expectancy, cervical carcinoma incidence, cost per woman, and cost-effectiveness. RESULTS: Total costs to establish a nationwide 5-year interval Pap screening program in Vietnam will average less than $148,400 annually during the 10-year time period assumed necessary to develop the program and may be considerably lower if only high risk geographic areas are targeted. Maintenance costs will average less than $0.092 annually per woman in the target screening population. Assuming 70% program participation, cervical carcinoma incidence will decrease from 26 in 100,000 to 14.8 in 100,000, and cost-effectiveness will be $725 per discounted life-year. Several assumptions used in this analysis constitute biases against the effectiveness of Pap screening, which in reality may be significantly more cost-effective than reported here. CONCLUSIONS: Contrary to widespread belief, Pap screening in developing countries such as Vietnam is extraordinarily inexpensive and appears to be cost-effective. Because prospects are uncertain regarding useful alternatives to the Pap test, the evidence-based argument for establishing conventional Pap screening services in developing countries such as Vietnam is compelling. Population-based conventional Pap screening services have been established de novo in Vietnam and are now operational.


Assuntos
Países em Desenvolvimento , Programas de Rastreamento/economia , Teste de Papanicolaou , Neoplasias do Colo do Útero/diagnóstico , Esfregaço Vaginal/economia , Adulto , Idoso , Análise Custo-Benefício , Feminino , Humanos , Expectativa de Vida , Pessoa de Meia-Idade , Neoplasias do Colo do Útero/economia , Neoplasias do Colo do Útero/patologia , Vietnã
8.
J Nutr Educ ; 33(6): 341-6, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-12031172

RESUMO

In response to welfare reform and the Food Stamp Nutrition Education Program's (FSNEP) goal of increasing clients' self-sufficiency, a literature review and small exploratory study were conducted to gain insight into a potential approach that would go beyond current nutrition education methods. Interviews with 17 FSNEP participants showed a widespread willingness to share food-related skills that others wanted to learn, some interest in cooperating on food-related projects, and frequent cases of social and geographic isolation. Based on these preliminary findings, we suggest the development and evaluation of nutrition education programs that appreciate and build on existing abilities of participants, provide opportunities for self-directed learning and activities, and build social support, social networks, and trust among participants while linking them to the broader community.


Assuntos
Serviços de Alimentação/organização & administração , Ciências da Nutrição/educação , Humanos , Grupos de Autoajuda , Apoio Social , Seguridade Social
9.
Expert Opin Emerg Drugs ; 6(2): 225-38, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15989523

RESUMO

In this overview, the antiviral properties of the Curie-pyridinone compounds, a new class of non-nucleoside reverse transcriptase inhibitors (NNRTIs) developed as anti-HIV agents, are described. These compounds are hybrids between hydroxyethoxymethyl-phenylthiothymine (HEPT) and Merck pyridinones. Several structure-activity relationships (SAR) studies between HIV-1 reverse transcriptase (RT) and the Curie-pyridinones are described. The Curie-pyridinones are potent inhibitors of both HIV-1 replication in cell culture and of HIV-1 RT activity in vitro. They are specific to HIV-1 and do not inhibit the replication of HIV-2. The mechanism of inhibition is non-competitive with respect to the natural substrate dGTP. For these reasons, the Curie-pyridinones can be considered as non-nucleoside inhibitors of HIV-1 RT. Moreover, they have the unusual ability to reach the reverse transcription complex inside the extracellular virions and may therefore be useful as retrovirucides. This might lead to the design and synthesis of new drugs able to interact with the retroviral enzyme inside the viral core.

10.
Am J Respir Crit Care Med ; 162(6): 2033-8, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11112109

RESUMO

The objective of this study was to describe outcomes of tuberculosis (TB) contact investigations, factors correlated with those outcomes, and current successes and ways to improve TB contact investigations. We abstracted clinic records of a representative U.S. urban sample of 1,080 pulmonary, sputum-smear(+) TB patients reported to CDC July 1996 through June 1997 and the cohort of their 6,225 close contacts. We found a median of four close contacts per patient. Fewer contacts were identified for homeless patients. A visit to the patient's residence resulted in two additional (especially child) contacts identified. Eighty-eight percent of eligible contacts received tuberculin skin tests (TSTs). Recording the last exposure date to the infectious patient facilitated follow-up TST provision. Thirty-six percent of contacts were TST(+). Household contacts and contacts to highly smear(+) or cavitary TB patients were most likely to be TST(+). Seventy-four percent of TST(+) contacts started treatment for latent TB infection (LTBI), of whom 56% completed. Sites using public health nurses (PHNs) started more high-risk TST(-) contacts on presumptive treatment for LTBI. Using directly observed treatment (DOT) increased the likelihood of treatment completion. We documented outcomes of contact investigation efforts by urban TB programs. We identified several successful practices, as well as suggestions for improvements, that will help TB programs target policies and procedures to enhance contact investigation effectiveness.


Assuntos
Busca de Comunicante , Tuberculose Pulmonar/transmissão , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Busca de Comunicante/métodos , Busca de Comunicante/estatística & dados numéricos , Feminino , Humanos , Lactente , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Radiografia Torácica/estatística & dados numéricos , Fatores Socioeconômicos , Escarro/microbiologia , Resultado do Tratamento , Teste Tuberculínico/estatística & dados numéricos , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/tratamento farmacológico , Estados Unidos , População Urbana/estatística & dados numéricos
11.
J Med Chem ; 43(21): 3949-62, 2000 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-11052800

RESUMO

Several 4-benzyl analogues of 5-ethyl-6-methyl-4-(phenylthio)pyridin-2(1H)-ones were synthesized and evaluated for their anti-HIV-l activities. Key transformations include metalation at the 4-C-position of 5-ethyl-2-methoxy-6-methyl-3-pivaloylaminopyridine (5) and its coupling with benzyl bromide or benzaldehyde derivatives. Biological studies revealed that some of the new 4-benzylpyridinones show potent HIV-1 specific reverse transcriptase inhibitory properties. Compounds 14, 19, and 27, which inhibit the replication of HIV-1 in CEM-SS cells, with IC(50) values ranging from 0.2 to 6 nM are the most active compounds in this series. Biochemical studies showed that compound 27 strongly inhibited the activity of a recombinant HIV-1 RT. Moreover, the infectivity of isolated HIV-1 particles was severely decreased after exposure to compound 27. Although cross resistance is frequently observed between non-nucleoside reverse transcriptase inhibitors, compound 27 was capable of inhibiting a virus resistant to nevirapine with an IC(50) of 40 nM.


Assuntos
Fármacos Anti-HIV/síntese química , Piridonas/síntese química , Inibidores da Transcriptase Reversa/síntese química , Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacologia , Linhagem Celular , Células Cultivadas , Resistência Microbiana a Medicamentos , HIV-1/efeitos dos fármacos , Humanos , Piridonas/química , Piridonas/farmacologia , DNA Polimerase Dirigida por RNA/metabolismo , Proteínas Recombinantes/antagonistas & inibidores , Inibidores da Transcriptase Reversa/química , Inibidores da Transcriptase Reversa/farmacologia , Relação Estrutura-Atividade , Vírion/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos
12.
Paediatr Perinat Epidemiol ; 14(3): 240-7, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10949216

RESUMO

Incidence rates of childhood cancer for the city of Ho Chi Minh are presented for the first time. For the 3-year period 1995-97, a total of 302 cancer cases were registered in children under 15 years of age, with a male to female ratio of 1.1. The overall crude rate was 78.8 and the age-standardised incidence rate was 88.4 per million person-years, which was low in comparison with other countries in eastern Asia and with the predominantly white population of Australia. Leukaemia (principally acute lymphocytic), brain tumours and lymphomas were the most common childhood neoplasms, which is consistent with the pattern observed in other registries of the region. The rate of retinoblastoma was higher than in the other regional registries. On the other hand, no cases of hepatocellular carcinoma were registered.


Assuntos
Neoplasias/epidemiologia , Adolescente , Idade de Início , Criança , Pré-Escolar , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Neoplasias/classificação , Vigilância da População , Vietnã/epidemiologia
13.
Chemistry ; 6(9): 1559-63, 2000 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-10839173

RESUMO

Sequence-specific DNA recognition can be achieved by oligonucleotides that bind to the major groove of oligopyrimidine x oligopurine sequences. These intermolecular structures could be used to modulate gene expression and to create new tools for molecular biology. Here we report the synthesis and biochemical characterization of triple helix-specific DNA cleaving reagents. It is based on the previously reported triplex-specific ligands, benzo[e]pyridoindole (BePI) and benzo[g]pyridoindole (BgPI), covalently attached to ethylenediaminotetraacetic acid (EDTA). In the presence of iron, a reducing agent and molecular oxygen, BgPI-EDTA x FeII but not BePI-EDTA x FeII induced a double-stranded cut in a plasmid DNA at the single site where a triplex-forming oligonucleotide binds. At single nucleotide resolution, it was found that upon triplex formation BePI-EDTA x FeII led to cleavage of the pyrimidine strand and protection of the purine strand. BgPI-EDTA x FeII cleaved both strands with similar efficiency. The difference in cleavage efficiency between the two conjugates was rationalized by the location of the EDTA x FeII moiety with respect to the grooves of DNA (major groove: BePI-EDTA x FeII, minor groove: BgPI-EDTA x FeII). This work paves the way to the development of a new class of triple helix directed DNA cleaving reagents. Such molecules will be of interest for sequence-specific DNA cleavage and for investigating triple-helical structures, such as H-DNA, which could play an important role in the control of gene expression in vivo.


Assuntos
DNA/química , Ácido Edético/química , Indóis/química , Regulação da Expressão Gênica/efeitos dos fármacos , Ferro/química , Modelos Moleculares , Conformação de Ácido Nucleico , Oligodesoxirribonucleotídeos/química , Plasmídeos/química
14.
J Med Chem ; 43(10): 1927-39, 2000 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-10821705

RESUMO

To test the concept that HIV reverse transcriptase could be effectively inhibited by "mixed site inhibitors", a series of seven conjugates containing both a nucleoside analogue component (AZT 1, ddC 2) and a nonnucleoside type inhibitor (HEPT analogue 12, pyridinone 27) were synthesized and evaluated for their ability to block HIV replication. The (N-3 and C-5)AZT-HEPT conjugates 15, 22, and 23 displayed 2-5 microM anti-HIV activity, but they had no effect on the replication of HIV-2 or the HIV-1 strain with the Y181C mutation. The (C-5)AZT-pyridinone conjugates 34-37 were found to be inactive. In marked contrast, the ddC-HEPT molecule 26 displayed the same potency (EC(50) = 0.45 microM) against HIV-1 (wild type and the Y181C nevirapine-resistant strain) and HIV-2 in cell culture. No synergistic effect was observed for these bis-substrate inhibitors, suggesting that the two individual inhibitor components in these molecules do not bind simultaneously in their respective sites. Interestingly, however, the results indicate that the AZT-HEPT conjugates and the ddC-HEPT derivative 26 inhibit reverse transcriptase (RT) in an opposite manner. One explanation for this difference is that the former compounds interact preferentially with the hydrophobic pocket in RT, whereas 26 (after supposed triphosphorylation) inhibits RT through binding in the catalytic site.


Assuntos
Fármacos Anti-HIV/síntese química , Transcriptase Reversa do HIV/antagonistas & inibidores , Piridonas/síntese química , Uracila/análogos & derivados , Zalcitabina/química , Zidovudina/química , Fármacos Anti-HIV/farmacologia , Citidina/análogos & derivados , Citidina/síntese química , Citidina/farmacologia , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , HIV-1/efeitos dos fármacos , HIV-2/efeitos dos fármacos , Estrutura Molecular , Piridonas/farmacologia , Relação Estrutura-Atividade , Uracila/síntese química , Uracila/farmacologia , Zidovudina/análogos & derivados , Zidovudina/síntese química , Zidovudina/farmacologia
15.
Chem Biol ; 6(11): 771-7, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10574778

RESUMO

BACKGROUND: Double-helical DNA can be recognized sequence specifically by oligonucleotides that bind in the major groove, forming a local triple helix. Triplex-forming oligonucleotides are new tools in molecular and cellular biology and their development as gene-targeting drugs is under intensive study. Intramolecular triple-helical structures (H-DNA) are expected to play an important role in the control of gene expression. There are currently no good probes available for investigating triple-helical structures. We previously reported that a pentacyclic benzoquinoquinoxaline derivative (BQQ) can strongly stabilize triple helices. RESULTS: We have designed and synthesized the first triple-helix-specific DNA cleaving reagent by covalently attaching BQQ to ethylenediaminetetraacetic acid (EDTA). The intercalative binding of BQQ should position EDTA in the minor groove of the triple helix. In the presence of Fe(2+) and a reducing agent, the BQQ-EDTA conjugate can selectively cleave an 80 base pair (bp) DNA fragment at the site where an oligonucleotide binds to form a local triple helix. The selectivity of the BQQ-EDTA conjugate for a triplex structure was sufficiently high to induce oligonucleotide-directed DNA cleavage at a single site on a 2718 bp plasmid DNA. CONCLUSIONS: This new class of structure-directed DNA cleaving reagents could be useful for cleaving DNA at specific sequences in the presence of a site-specific, triple-helix-forming oligonucleotide and also for investigating triple-helical structures, such as H-DNA, which could play an important role in the control of gene expression in vivo.


Assuntos
DNA/química , DNA/efeitos dos fármacos , Ácido Edético/síntese química , Conformação de Ácido Nucleico , Oligodesoxirribonucleotídeos/química , Quinoxalinas/síntese química , Pareamento de Bases , Sequência de Bases , Desenho de Fármacos , Ácido Edético/farmacologia , Hidrólise , Modelos Moleculares , Dados de Sequência Molecular , Plasmídeos/efeitos dos fármacos , Quinoxalinas/farmacologia
16.
Arch Virol ; 144(3): 513-23, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10226617

RESUMO

Reverse transcription takes place in the cytoplasm of infected cells, although it has been demonstrated that retroviruses can also initiate reverse transcription prior to infection of target cells. In addition to partial reverse transcripts, full-length proviral molecules have been detected in the plasma and seminal fluid of HIV-1 seropositive patients. Intravirion endogenous reverse transcription appears to be directly correlated with an increased level of infectivity. Therefore, the ability of an inhibitor to reach and inhibit the replication complex in the core of the free-virion may constitute an important part of its capacity to suppress viral infection. In this work we tested the ability of some reverse transcriptase inhibitors to decrease viral infectivity in pretreated highly purified virions. Our results showed that Curie pyridinone [Dollé et al. (1995), J Med Chem 38: 4,679-4,686], a non nucleoside RT inhibitor, strongly inhibited the infectivity of extracellular HIV-1 particles. Other non nucleoside inhibitors (TIBO R82913, HEPT, nevirapine) tested in these conditions were unable to do so. Our data indicate that the effect of Curie pyridinone on intact virions may be related to its capacity to tightly bind the target RT. This approach may lead to the design and synthesis of new drugs able to interact with the retroviral enzyme inside the viral core.


Assuntos
Fármacos Anti-HIV/farmacologia , Transcriptase Reversa do HIV/antagonistas & inibidores , HIV-1/efeitos dos fármacos , Nucleosídeos/farmacologia , Inibidores da Transcriptase Reversa/farmacologia , Linhagem Celular Transformada , HIV-1/enzimologia , HIV-1/fisiologia , Humanos , Vírion/efeitos dos fármacos , Vírion/fisiologia
17.
Am J Trop Med Hyg ; 59(5): 823-7, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9840605

RESUMO

To investigate the pharmacokinetic and pharmacodynamic properties of artesunate (ARTS) and its active metabolite dihydroartemisinin (DHA) in Plasmodium vivax infections, 12 male Vietnamese adults with slide-positive vivax malaria received either intravenous ARTS (120 mg; group 1) or oral ARTS (100 mg; group 2) with the alternative preparation given 8 hr later in a randomized, open, cross-over study. Following intravenous injection, ARTS had a peak plasma drug concentration (Cmax) of 35.6 microM (13.7 mg/L), an elimination half-life (t1/2) of 2.2 min, a clearance (CL) of 3.0 L/hr/kg, and a volume of distribution (V) of 0.16 L/kg. Dihydroartemisinin had a Cmax of 7.7 microM (2.2 mg/L), a tmax of 8 min, a t1/2 of 37 min, an apparent CL of 1.1 L/hr/kg, and an apparent V of 0.9 L/kg. Following oral ARTS, the mean relative bioavailability of DHA was 85%, the Cmax was 3.0 microM (0.85 mg/L), the tmax was 75 min, and t1/2 was 40 min. The mean time to 50% reduction in the parasite count (PCT50) and median fever clearance time were 3 hr and 16 hr, respectively. Following intravenous ARTS (group 1), the PCT50 for total parasites, rings, trophozoites, and gametocytes was 3.3 hr, 3.2 hr, 4.0 hr, and 3.6 hr, respectively. This study confirms that ARTS is effective against P. vivax, with rapid clearance of sexual and asexual forms of the parasite. Artesunate is a suitable initial treatment for vivax malaria, or when the plasmodial species cannot be reliably identified.


Assuntos
Antimaláricos/farmacologia , Antimaláricos/farmacocinética , Artemisininas , Malária Vivax/tratamento farmacológico , Malária Vivax/metabolismo , Sesquiterpenos/farmacologia , Sesquiterpenos/farmacocinética , Administração Oral , Adulto , Animais , Antimaláricos/administração & dosagem , Artesunato , Disponibilidade Biológica , Estudos Cross-Over , Meia-Vida , Humanos , Injeções Intravenosas , Malária Vivax/parasitologia , Masculino , Parasitemia/tratamento farmacológico , Parasitemia/metabolismo , Parasitemia/parasitologia , Plasmodium vivax/efeitos dos fármacos , Plasmodium vivax/crescimento & desenvolvimento , Plasmodium vivax/isolamento & purificação , Sesquiterpenos/administração & dosagem , Vietnã
18.
Anticancer Drug Des ; 13(4): 361-72, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9627673

RESUMO

The title compounds were synthesized in 9-10 steps in order to compare their cytotoxic properties to that for 1-(3-dimethylaminopropyl)-amino-4,5-dimethyl- 8-hydroxy-5H-pyrido[4,3-b]indole. Whereas the latter is a potent cytotoxic agent, displaying significant antitumour activity, the corresponding 9-propyl (and 7,9-dimethyl) derivatives were found to be > 10-fold less cytotoxic.


Assuntos
Antineoplásicos/síntese química , Indóis/síntese química , Animais , Antineoplásicos/farmacologia , Divisão Celular/efeitos dos fármacos , Indóis/farmacologia , Camundongos , Relação Estrutura-Atividade , Células Tumorais Cultivadas/efeitos dos fármacos
19.
Anticancer Drug Des ; 13(4): 373-86, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9627674

RESUMO

Furo[3,2-e]- and pyrano[3,2-e]pyrido[4,3-b] indoles were synthesized from 1,4,5-trisubstituted 8-hydroxy-5H-pyrido[4,3-b]indoles. The intermediates, 10-chloro-6H-furo[3,2-e]pyrido[4,3-b]indole (11), 10-chloro-2,6-dihydro-1H-furo[3,2-e]pyrido-[4,3-b]indole (10) and 11-chloro-2,3-dihydro-3H,7H-pyrano[3,2-e]pyrido[4,3-b]indole (15), were substituted by diamines under thermal conditions (180 degrees C). In contrast, 11-chloro-3H,7H-pyrano[3,2-e]pyrido[4,3-b]indole (14), 9-allyl-1-chloro-4,5-dimethyl-5H-pyrido[4,3-b]indole (9a) and 8-propargyloxy-4,5-dimethyl-5H-pyrido[4,3-b]indole (8) led mainly to 1-aminosubstituted 8-hydroxy-5H-pyrido[4,3-b]indole derivatives resulting from an unexpected C3 unit elimination. When examined in three tumour cell lines (L1210 leukaemia, the B16 melanoma and the MCF7 breast adenocarcinoma) the new amino substituted furo[3,2-e]-, dihydrofuro[3,2-e]- and dihydropyrano[3,2-e]-pyrido[4,3-b]indole derivatives revealed cytotoxic properties, especially important for the 2,6-dihydro-1H-furo[3,2-e]pyrido[4,3-b]indole series. The most active compound (12b) significantly inhibits both DNA topoisomerases I and II, and is as potent as Adriamycin at inhibiting cell proliferation and inducing a massive accumulation of L1210 cells in the G2 + M phase of the cell cycle. However, 12b was less active than Adriamycin when tested in vivo against P388 leukaemia or the B16 melanoma tumour models.


Assuntos
Antineoplásicos/síntese química , Indóis/síntese química , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Humanos , Indóis/farmacologia , Indóis/uso terapêutico , Isomerases/antagonistas & inibidores , Camundongos , Neoplasias Experimentais/tratamento farmacológico , Células Tumorais Cultivadas/efeitos dos fármacos
20.
Nucleic Acids Res ; 26(9): 2179-83, 1998 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-9547278

RESUMO

Oligonucleotide-directed triple helix formation is mostly restricted to oligopyrimidine*oligopurine sequences of double helical DNA. An interruption of one or two pyrimidines in the oligopurine target strand leads to a strong triplex destabilisation. We have investigated the effect of nucleotide analogues introduced in the third strand at the site opposite the base pair inversion(s). We show that a 3-nitropyrrole derivative (M) discriminates G*C from C*G, A*T and T*A in the presence of a triplex-specific ligand (a benzo[e]pyridoindole derivative, BePI). N6-methoxy-2,6-diaminopurine (K) binds to an A*T base pair better than a T*A, G*C or C*G base pair. Some discrimination is still observed in the presence of BePI and triplex stability is markedly increased. These findings should help in designing BePI-oligonucleotide conjugates to extend the range of DNA sequences available for triplex formation.


Assuntos
DNA/química , Conformação de Ácido Nucleico , Inversão Cromossômica , DNA/efeitos dos fármacos , Ligação de Hidrogênio , Indóis/farmacologia , Ligantes , Oligonucleotídeos , Purinas , Piridinas/farmacologia , Pirimidinas
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