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1.
J Biol Chem ; 300(7): 107465, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38876300

RESUMO

The voltage-gated potassium ion channel KV11.1 plays a critical role in cardiac repolarization. Genetic variants that render Kv11.1 dysfunctional cause long QT syndrome (LQTS), which is associated with fatal arrhythmias. Approximately 90% of LQTS-associated variants cause intracellular protein transport (trafficking) dysfunction, which pharmacological chaperones like E-4031 can rescue. Protein folding and trafficking decisions are regulated by chaperones, protein quality control factors, and trafficking machinery comprising the cellular proteostasis network. Here, we test whether trafficking dysfunction is associated with alterations in the proteostasis network of pathogenic Kv11.1 variants and whether pharmacological chaperones can normalize the proteostasis network of responsive variants. We used affinity-purification coupled with tandem mass tag-based quantitative mass spectrometry to assess protein interaction changes of WT KV11.1 or trafficking-deficient channel variants in the presence or absence of E-4031. We identified 572 core KV11.1 protein interactors. Trafficking-deficient variants KV11.1-G601S and KV11.1-G601S-G965∗ had significantly increased interactions with proteins responsible for folding, trafficking, and degradation compared to WT. We confirmed previous findings that the proteasome is critical for KV11.1 degradation. Our report provides the first comprehensive characterization of protein quality control mechanisms of KV11.1. We find extensive interactome remodeling associated with trafficking-deficient KV11.1 variants and with pharmacological chaperone rescue of KV11.1 cell surface expression. The identified protein interactions could be targeted therapeutically to improve KV11.1 trafficking and treat LQTS.


Assuntos
Síndrome do QT Longo , Transporte Proteico , Proteostase , Humanos , Síndrome do QT Longo/metabolismo , Síndrome do QT Longo/genética , Células HEK293 , Canais de Potássio Éter-A-Go-Go/metabolismo , Canais de Potássio Éter-A-Go-Go/genética , Canal de Potássio ERG1/metabolismo , Canal de Potássio ERG1/genética , Animais
2.
Mol Pharmacol ; 105(3): 194-201, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38253398

RESUMO

Intracellular Ca2+ leak from cardiac ryanodine receptor (RyR2) is an established mechanism of sudden cardiac death (SCD), whereby dysregulated Ca2+ handling causes ventricular arrhythmias. We previously discovered the RyR2-selective inhibitor ent-(+)-verticilide (ent-1), a 24-membered cyclooligomeric depsipeptide that is the enantiomeric form of a natural product (nat-(-)-verticilide). Here, we examined its 18-membered ring-size oligomer (ent-verticilide B1; "ent-B1") in RyR2 single channel and [3H]ryanodine binding assays, and in Casq2 -/- cardiomyocytes and mice, a gene-targeted model of SCD. ent-B1 inhibited RyR2 single channels and RyR2-mediated spontaneous Ca2+ release in Casq2 -/- cardiomyocytes with sub-micromolar potency. ent-B1 was a partial RyR2 inhibitor, with maximal inhibitory efficacy of less than 50%. ent-B1 was stable in plasma, with a peak plasma concentration of 1460 ng/ml at 10 minutes and half-life of 45 minutes after intraperitoneal administration of 3 mg/kg in mice. In vivo, ent-B1 significantly reduced catecholamine-induced ventricular arrhythmias in Casq2 -/- mice in a dose-dependent manner. Hence, we have identified a novel chemical entity - ent-B1 - that preserves the mechanism of action of a hit compound and shows therapeutic efficacy. These findings strengthen RyR2 as an antiarrhythmic drug target and highlight the potential of investigating the mirror-image isomers of natural products to discover new therapeutics. SIGNIFICANCE STATEMENT: The cardiac ryanodine receptor (RyR2) is an untapped target in the stagnant field of antiarrhythmic drug development. We have confirmed RyR2 as an antiarrhythmic target in a mouse model of sudden cardiac death and shown the therapeutic efficacy of a second enantiomeric natural product.


Assuntos
Produtos Biológicos , Depsipeptídeos , Camundongos , Animais , Antiarrítmicos/farmacologia , Antiarrítmicos/uso terapêutico , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Arritmias Cardíacas/tratamento farmacológico , Arritmias Cardíacas/metabolismo , Depsipeptídeos/metabolismo , Depsipeptídeos/uso terapêutico , Morte Súbita Cardíaca/etiologia , Miócitos Cardíacos/metabolismo , Cálcio/metabolismo
3.
J Pharmacol Exp Ther ; 385(3): 205-213, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36894328

RESUMO

The unnatural verticilide enantiomer (ent-verticilide) is a selective and potent inhibitor of cardiac ryanodine receptor (RyR2) calcium release channels and exhibits antiarrhythmic activity in a murine model of catecholaminergic polymorphic ventricular tachycardia (CPVT). To determine verticilide's pharmacokinetic and pharmacodynamic properties in vivo, we developed a bioassay to measure nat- and ent-verticilide in murine plasma and correlated plasma concentrations with antiarrhythmic efficacy in a mouse model of CPVT. nat-Verticilide rapidly degraded in plasma in vitro, showing >95% degradation within 5 minutes, whereas ent-verticilide showed <1% degradation over 6 hours. Plasma was collected from mice following intraperitoneal administration of ent-verticilide at two doses (3 mg/kg, 30 mg/kg). Peak C max and area under the plasma-concentration time curve (AUC) scaled proportionally to dose, and the half-life was 6.9 hours for the 3-mg/kg dose and 6.4 hours for the 30-mg/kg dose. Antiarrhythmic efficacy was examined using a catecholamine challenge protocol at time points ranging from 5 to 1440 minutes after intraperitoneal dosing. ent-Verticilide inhibited ventricular arrhythmias as early as 7 minutes after administration in a concentration-dependent manner, with an estimated potency (IC50) of 266 ng/ml (312 nM) and an estimated maximum inhibitory effect of 93.5%. Unlike the US Food and Drug Administration-approved pan-RyR blocker dantrolene, the RyR2-selective blocker ent-verticilide (30 mg/kg) did not reduce skeletal muscle strength in vivo. We conclude that ent-verticilide has favorable pharmacokinetic properties and reduces ventricular arrhythmias with an estimated potency in the nanomolar range, warranting further drug development. SIGNIFICANCE STATEMENT: ent-Verticilide has therapeutic potential to treat cardiac arrhythmias, but little is known about its pharmacological profile in vivo. The primary purpose of this study is to determine the systemic exposure and pharmacokinetics of ent-verticilide in mice and estimate its efficacy and potency in vivo. The current work suggests ent-verticilide has favorable pharmacokinetic properties and reduces ventricular arrhythmias with an estimated potency in the nanomolar range, warranting further drug development.


Assuntos
Canal de Liberação de Cálcio do Receptor de Rianodina , Taquicardia Ventricular , Camundongos , Animais , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Antiarrítmicos/farmacologia , Antiarrítmicos/uso terapêutico , Arritmias Cardíacas/tratamento farmacológico , Taquicardia Ventricular/tratamento farmacológico , Taquicardia Ventricular/metabolismo , Miócitos Cardíacos/metabolismo
4.
Drug Metab Dispos ; 51(6): 782-791, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36921993

RESUMO

The anti-hypertensive agent hydralazine is a time-dependent inhibitor of the cytosolic drug-metabolizing enzyme aldehyde oxidase (AO). Glutathione (GSH) was found to suppress the inhibition of AO by hydralazine in multiple enzyme sources (human liver and kidney cytosol, human liver S9, rat liver S9, and recombinant human AO) and with different AO substrates (zoniporide, O6 -benzylguanine, and dantrolene). Hydralazine-induced AO inactivation was unaffected when GSH was added to the incubation mixture after pre-incubation of hydralazine with AO (rather than during the pre-incubation), suggesting that GSH traps a hydralazine reactive intermediate prior to enzyme inactivation. Consistent with previous reports of 1-phthalazylmercapturic acid formation when hydralazine was incubated with N-acetylcysteine, we detected a metabolite producing an MS/MS spectrum consistent with a 1-phthalazyl-GSH conjugate. O6 -Benzylguanine, an AO substrate, did not protect against hydralazine-induced AO inactivation, implying that hydralazine does not compete with O6 -benzylguanine for binding to the AO active site. Catalase also failed to protect AO from hydralazine-induced inactivation, suggesting that hydrogen peroxide is not involved. However, an allosteric AO inhibitor (thioridazine) offered some protection, indicating a catalytic role for AO in the bioactivation of hydralazine. AO inhibition by phthalazine (a substrate and inhibitor of AO and a metabolite of hydralazine) was unaffected by the presence of GSH. GSH also prevented hydralazine from inhibiting the nitro-reduction of dantrolene by AO. Furthermore, the GSH-hydralazine combination stimulated dantrolene reduction. Phthalazine inhibited only oxidation reactions, not reduction of dantrolene. Together, these results support the hypothesis that hydralazine is converted to a reactive intermediate that inactivates AO. SIGNIFICANCE STATEMENT: These studies suggest that a reactive intermediate of hydralazine plays a primary role in the mechanism of aldehyde oxidase (AO) inactivation. Inactivation was attenuated by glutathione and unaffected by catalase. Phthalazine (hydralazine metabolite) inhibited AO regardless of the presence of glutathione; however, phthalazine inhibited only oxidation reactions, while hydralazine inhibited both oxidation and reduction reactions. This report advances our mechanistic understanding of hydralazine as an AO inhibitor and provides information to facilitate appropriate use of hydralazine when probing AO metabolism.


Assuntos
Aldeído Oxidase , Espectrometria de Massas em Tandem , Ratos , Animais , Humanos , Aldeído Oxidase/metabolismo , Catalase , Dantroleno , Hidralazina/farmacologia , Ftalazinas/metabolismo , Glutationa
5.
Cancer Control ; 26(1): 1073274819864641, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31327239

RESUMO

Anxiety, a condition which is commonly found in patients with cancer, has negative impacts on their quality of life and treatment outcome. This study aimed to determine the level of anxiety in patients with cancer and explore sociodemographic, disease-related, and hospital-related factors associated with anxiety in those patients. A cross-sectional study was conducted on 510 inpatients with cancer at Thanh Hoa Oncology Hospital, Vietnam. Data were collected from self-administered questionnaire forms on hospital depression anxiety-A, interviews with patients, and patient medical records. The univariate and multivariate linear regression analyses were performed using STATA ver. 14.0. Our finding that the patients' mean anxiety score (standard deviation) was 7.22 (3.8); 27.6% of the patients had an anxiety score between 8 and 10 points, and 15.5% had an anxiety score of ≥11 points. In the multivariate model, in more advanced stages of cancer, and patients with metastasis were more likely to have higher levels of anxiety than those who presented no sign of metastasis. The longer the patients had cancer, the less anxious they became. Lower levels of anxiety were observed in patients who stated that hospital facilities were adequate or had trust in health workers. Patients with cancer need to be provided with psychological support in the early stage of cancer detection and when metastases form. A strong patient-health-care provider relationship after diagnosis may help reduce distress among patients with cancer with higher levels of medical mistrust.


Assuntos
Ansiedade/diagnóstico , Pacientes Internados/psicologia , Neoplasias/psicologia , Relações Médico-Paciente , Qualidade de Vida , Adulto , Idoso , Ansiedade/prevenção & controle , Ansiedade/psicologia , Institutos de Câncer , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/terapia , Questionário de Saúde do Paciente/estatística & dados numéricos , Vietnã
6.
Sex Transm Dis ; 45(5): e25-e28, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29465694

RESUMO

Among men who have sex with men traveling internationally, self-reported hepatitis B virus (HBV) vaccination prevalence was 77% and less prevalent among older men and those with HBV infection. The HBV infection prevalence was 25% and was associated with older age and HIV infection. Testing for chronic infection, universal vaccination, and treatment for populations with multiple risks is needed.


Assuntos
Vacinas contra Hepatite B/administração & dosagem , Hepatite B/epidemiologia , Hepatite B/prevenção & controle , Homossexualidade Masculina , Viagem , Vacinação/estatística & dados numéricos , Adolescente , Adulto , Fatores Etários , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Humanos , Internacionalidade , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Minorias Sexuais e de Gênero , Estados Unidos/epidemiologia , Adulto Jovem
7.
Sex Transm Infect ; 93(1): 62-64, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26944344

RESUMO

OBJECTIVES: Men who have sex with men (MSM) are disproportionately impacted by HIV. Criminalisation of homosexuality may impede access to HIV services. We evaluated the effect of the enforcement of laws criminalising homosexuality on access to services. METHODS: Using data from a 2012 global online survey that was published in a prior paper, we conducted a secondary analysis evaluating differences in perceived accessibility to health services (ie, 'how accessible are ____' services) between MSM who responded 'yes'/'no' to: 'have you ever been arrested or convicted for being gay/MSM?' RESULTS: Of the 4020 participants who completed the study and were included in the analysis, 8% reported ever being arrested or convicted under laws relevant to being MSM. Arrests and convictions were most common in sub-Saharan Africa (23.6% (58/246)), Eastern Europe/Central Asia (18.1% (123/680)), the Caribbean (15% (15/100)), Middle East/North Africa (13.2% (10/76)) and Latin America (9.7% (58/599)). Those arrested or convicted had significantly lower access to sexually transmitted infection treatment (adjusted OR (aOR)=0.81; 95% CI 0.67 to 0.97), condoms (aOR=0.77; 95% CI 0.61 to 0.99) and medical care (aOR=0.70; 95% CI 0.54 to 0.90), compared with other MSM, while accounting for clustering by country and adjusting for age, HIV status, education and country-level income. CONCLUSIONS: Arrests and convictions under laws relevant to being MSM have a strong negative association with access to HIV prevention and care services. Creating an enabling legal and policy environment, and increasing efforts to mitigate antihomosexuality stigma to ensure equitable access to HIV services are needed, along with decriminalisation of homosexuality, to effectively address the public health needs of this population.


Assuntos
Infecções por HIV/prevenção & controle , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Disparidades em Assistência à Saúde/legislação & jurisprudência , Homossexualidade Masculina/estatística & dados numéricos , África do Norte , Região do Caribe , Europa (Continente) , Europa Oriental , Infecções por HIV/epidemiologia , Pesquisas sobre Atenção à Saúde , Humanos , Aplicação da Lei , Masculino , Oriente Médio , Estigma Social
8.
AIDS Behav ; 19(2): 227-34, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25086670

RESUMO

Globally, HIV disproportionately affects men who have sex with men (MSM). This study explored associations between access to HIV services and (1) individual-level perceived sexual stigma; (2) country-level criminalization of homosexuality; and (3) country-level investment in HIV services for MSM. 3,340 MSM completed an online survey assessing access to HIV services. MSM from over 115 countries were categorized according to criminalization of homosexuality policy and investment in HIV services targeting MSM. Lower access to condoms, lubricants, and HIV testing were each associated with greater perceived sexual stigma, existence of homosexuality criminalization policies, and less investment in HIV services. Lower access to HIV treatment was associated with greater perceived sexual stigma and criminalization. Criminalization of homosexuality and low investment in HIV services were both associated with greater perceived sexual stigma. Efforts to prevent and treat HIV among MSM should be coupled with structural interventions to reduce stigma, overturn homosexuality criminalization policies, and increase investment in MSM-specific HIV services.


Assuntos
Infecções por HIV/psicologia , Acessibilidade aos Serviços de Saúde , Homossexualidade Masculina/psicologia , Investimentos em Saúde , Estigma Social , Preservativos/estatística & dados numéricos , Discriminação Psicológica , Infecções por HIV/diagnóstico , Infecções por HIV/tratamento farmacológico , Infecções por HIV/prevenção & controle , Pesquisas sobre Atenção à Saúde , Disparidades em Assistência à Saúde , Humanos , Lubrificantes , Masculino , Atenção Primária à Saúde/organização & administração , Comportamento Sexual , Inquéritos e Questionários , Adulto Jovem
9.
Sex Transm Infect ; 90(3): 250-3, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24431183

RESUMO

OBJECTIVE: We evaluated the relationship among syndemic conditions (defined as a cluster of interconnected psychosocial health conditions), sexual behaviours and self-reported HIV infection in a global sample of men who have sex with men (MSM). METHODS: We used generalised estimating equations logistic regression models with robust SEs to assess the relationships among cumulative number of syndemic conditions--including depression, substance use, violence, sexual stigma and homelessness--and unprotected anal intercourse (UAI) and HIV infection, while accounting for clustering within-country in a global cross-sectional survey of 3934 MSM across 151 countries. RESULTS: We observed parallel, significant dose-response associations between the number of syndemic conditions and UAI, as well as number of syndemic conditions and HIV infection. Compared with participants without syndemics, the adjusted OR (aOR) for UAI among those with 1, 2 and 3 or more syndemic conditions were 1.44 (Bonferroni-adjusted 95% CI 1.23 to 1.68), 1.89 (1.51 to 2.36) and 2.03 (1.43 to 2.89), respectively. Compared with participants without syndemics, the aOR for HIV infection among those with 1, 2 and 3 or more syndemic conditions were 1.67 (1.24 to 2.26), 2.02 (1.44 to 2.85) and 2.35 (1.31 to 4.21), respectively. CONCLUSIONS: This analysis provides evidence of intertwining syndemics that may operate synergistically to increase HIV risk among MSM globally. To curb HIV effectively and advance the health of MSM, multiple conditions must be addressed concurrently using multi-level approaches that target both individual and structural risk factors.


Assuntos
Depressão/epidemiologia , Infecções por HIV/epidemiologia , Infecções por HIV/psicologia , Homossexualidade Masculina , Pessoas Mal Alojadas/estatística & dados numéricos , Parceiros Sexuais , Violência/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Estudos Transversais , Saúde Global , Infecções por HIV/prevenção & controle , Pessoas Mal Alojadas/psicologia , Humanos , Relações Interpessoais , Masculino , Pessoa de Meia-Idade , Assunção de Riscos , Parceiros Sexuais/psicologia , Meio Social , Estigma Social , Sexo sem Proteção , Violência/psicologia
10.
Sensors (Basel) ; 14(5): 8037-56, 2014 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-24803194

RESUMO

In this paper, we propose cooperative spectrum sensing schemes, called decode-and-forward cooperative spectrum sensing (DF-CSS) scheme and amplify-and-forward cooperative spectrum sensing (AF-CSS) scheme, in cognitive radio networks. The main goals and features of the proposed cooperative spectrum sensing schemes are as follows: first, we solve the problem of high demand for bandwidth in a soft decision scheme using in our proposed schemes. Furthermore, the impact of transmission power of relaying users which is determined by the interference constraint on sensing performance of cooperative spectrum sensing schemes is also investigated. Second, we analyze the sensing performance of our proposed cooperative spectrum sensing schemes in terms of detection probability and interference probability, respectively. We take into account the interference caused by secondary user (SU) to primary user (PU) in the case that the transmission power of the relaying users exceeds a predefined interference constraint assigned by the primary user. The simulation results show that in cooperative spectrum sensing schemes the total sensing performance depends not only on the interference tolerance level, but also on the relay protocols used. We also prove that high transmission power of relaying users increases the interference between the secondary networks and the primary network.

11.
J Infect Dis ; 208(1): 50-6, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23089590

RESUMO

BACKGROUND: Studies aimed at defining the association between host immune responses and human immunodeficiency virus (HIV) persistence during therapy are necessary to develop new strategies for cure. METHODS: We performed a comprehensive assessment of ultrasensitive plasma HIV RNA levels, cell-associated HIV RNA levels, proviral HIV DNA levels, and T cell immunophenotyping in a cohort of 190 subjects in whom HIV levels were suppressed by highly active antiretroviral therapy. RESULTS: The median CD4(+) T cell count was 523 cells/mm(3), and the median duration of viral suppression was 31 months. Cell-associated RNA and proviral DNA levels (but not ultrasensitive plasma HIV RNA levels) were positively correlated with frequencies of CD4(+) and CD8(+) T cells expressing markers of T-cell activation/dysfunction (CD38, HLA-DR, CCR5, and/or programmed cell death protein 1 [PD-1]) (P < .05). Having a low CD4(+) T-cell count despite receipt of virologically suppressive therapy was associated with high cell-associated RNA and proviral DNA levels (P < .01) and higher frequencies of CD4(+) T cells expressing CD38, HLA-DR, CCR5, and/or PD-1 (P < .0001). CONCLUSIONS: Cell-based measurements of viral persistence were consistently associated with markers of immune activation and the frequency of PD-1-expressing CD4(+) T cells. Treated patients with a low CD4(+) T-cell count had higher frequencies of PD-1-expressing CD4(+) T cells and cell-based measures of viral persistence, suggesting that HIV infection in these individuals may be more difficult to cure and may require unique interventions.


Assuntos
Terapia Antirretroviral de Alta Atividade , Linfócitos T CD4-Positivos/imunologia , HIV/efeitos dos fármacos , Receptor de Morte Celular Programada 1/sangue , Adulto , Contagem de Linfócito CD4 , DNA Viral/efeitos dos fármacos , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Infecções por HIV/virologia , Humanos , Imunidade Celular/efeitos dos fármacos , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/imunologia , Masculino , Pessoa de Meia-Idade , Provírus/efeitos dos fármacos , RNA Viral/sangue
12.
bioRxiv ; 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38352392

RESUMO

Introduction: The voltage gated potassium ion channel K V 11.1 plays a critical role in cardiac repolarization. Genetic variants that render Kv11.1 dysfunctional cause Long QT Syndrome (LQTS), which is associated with fatal arrhythmias. Approximately 90% of LQTS-associated variants cause intracellular protein transport (trafficking) dysfunction, which can be rescued by pharmacological chaperones like E-4031. Protein folding and trafficking decisions are regulated by chaperones, protein quality control factors, and trafficking machinery, comprising the cellular proteostasis network. Here, we test whether trafficking dysfunction is associated with alterations in the proteostasis network of pathogenic Kv11.1 variants, and whether pharmacological chaperones can normalize the proteostasis network of responsive variants. Methods: We used affinity-purification coupled with tandem mass tag-based quantitative mass spectrometry to assess protein interaction changes in human embryonic kidney (HEK293) cells expressing wild-type (WT) K V 11.1 or trafficking-deficient channel variants in the presence or absence of E-4031. Resultsa: We identified 573 core K V 11.1 protein interactors. Both variants K V 11.1-G601S and K V 11.1-G601S-G965* had significantly increased interactions with proteins responsible for folding, trafficking, and degradation compared to WT. We found that proteasomal degradation is a key component for K V 11.1 degradation and that the K V 11.1-G601S-G965* variant was more responsive to E-4031 treatment. This suggests a role in the C-terminal domain and the ER retention motif of K V 11.1 in regulating trafficking. Conclusion: Our report characterizes the proteostasis network of K V 11.1, two trafficking deficient K V 11.1 variants, and variants treated with a pharmacological chaperone. The identified protein interactions could be targeted therapeutically to improve K V 11.1 trafficking and treat Long QT Syndrome.

13.
Clin Infect Dis ; 56(11): 1546-53, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23418272

RESUMO

BACKGROUND: Cytomegalovirus (CMV) load measurement is used to assess the efficacy of treatment of CMV disease, but lacks standardization. Using the World Health Organization (WHO) international standard for reporting, we correlated viral load with CMV disease resolution. METHODS: CMV load was quantified in plasma using a test calibrated to the WHO standard. Three predictive rules were predefined to determine association between CMV DNAemia and outcome: (1) pretreatment CMV DNA of <18,200 (4.3 log(10)) IU/mL; (2) viral load declines of 1.0, 1.5, 2.0, and 2.5 log(10) IU/mL from baseline to days 7, 14, and 21 of treatment, respectively; and (3) viral suppression <137 (2.1 log(10)) IU/mL at days 7, 14, and 21. Analysis was performed using Cox proportional hazard models. RESULTS: Of 267 patients, 251 had CMV disease resolution by day 49 of treatment. Patients with pretreatment CMV DNA of <18,200 (4.3 log(10)) IU/mL had faster time to disease resolution (adjusted hazard ratio [AHR], 1.56; P = .001). Patients with CMV load suppression (<137 IU/mL [<2.1 log(10)]) at days 7, 14, and 21 had faster times to clinical disease resolution (AHRs, 1.61, 1.73, and 1.64, and P = .005, <.001, and <.001, respectively). Relative CMV load reductions from baseline were not significantly associated with faster resolution of CMV disease. CONCLUSIONS: Patients with pretreatment CMV DNA of <18,200 (4.3 log(10)) IU/mL are 1.5 times more likely to have CMV disease resolution. CMV suppression (<137 [2.1 log(10)] IU/mL), as measured by a test calibrated to the WHO Standard, is predictive of clinical response to antiviral treatment. CLINICAL TRIALS REGISTRATION: NCT00431353.


Assuntos
Antivirais/uso terapêutico , Infecções por Citomegalovirus/tratamento farmacológico , Infecções por Citomegalovirus/virologia , Citomegalovirus/isolamento & purificação , Adolescente , Adulto , Citomegalovirus/genética , Infecções por Citomegalovirus/sangue , DNA Viral/sangue , Ganciclovir/análogos & derivados , Ganciclovir/uso terapêutico , Humanos , Estimativa de Kaplan-Meier , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Valor Preditivo dos Testes , Modelos de Riscos Proporcionais , Ensaios Clínicos Controlados Aleatórios como Assunto , Valores de Referência , Estudos Retrospectivos , Resultado do Tratamento , Valganciclovir , Carga Viral/efeitos dos fármacos , Organização Mundial da Saúde
14.
Int J Syst Evol Microbiol ; 63(Pt 12): 4777-4783, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23996834

RESUMO

As part of an undergraduate microbiology course, a yellow-orange-pigmented, Gram-staining negative, rod-shaped, non-motile bacterial strain was isolated from a glass tank housing several red-spotted newts (Notophthalmus viridescens). The sequence of the 16S rRNA gene of this strain, designated KM(T), was 97.4-98.0 % similar to those of the type strains of Chryseobacterium luteum, C. shigense and C. vrystaatense, while the similarity levels for protein-coding genes were less than 94.7 % for rpoB, less than 92.1 % for groEL and less than 87.1 % for gyrB. These values are lower than for many other established distinct species. Polyphasic characterization and comparison to these relatives revealed that strain KM(T) was similar to other Chryseobacterium strains in that it contained MK-6 as its major respiratory quinone and phosphatidylethanolamine as the most abundant polar lipid, produced flexirubin-type pigments, oxidase and catalase and primarily contained the fatty acids iso-C15 : 0, iso-C17 : 1ω9c, iso-C17 : 0 3-OH and summed feature 3 (comprising C16 : 1ω6c and/or C16 : 1ω7c). Based on the results of this study, strain KM(T) represents a novel species, for which the name Chryseobacterium angstadtii sp. nov. is proposed. The type strain is KM(T) ( = ATCC BAA-2160(T) = NRRL B-59516(T) = KCTC 23297(T)).


Assuntos
Chryseobacterium/classificação , Filogenia , Salamandridae , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , Chaperonina 60/genética , Chryseobacterium/genética , Chryseobacterium/isolamento & purificação , DNA Girase/genética , DNA Bacteriano/genética , Ácidos Graxos/química , Dados de Sequência Molecular , Fosfatidiletanolaminas/química , Polienos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
15.
bioRxiv ; 2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37461611

RESUMO

Ca 2+ leak from cardiac ryanodine receptor (RyR2) is an established mechanism of sudden cardiac death (SCD), whereby dysregulated Ca 2+ handling causes ventricular arrhythmias. We previously discovered the RyR2-selective inhibitor ent- (+)-verticilide ( ent -1), a 24-membered cyclooligomeric depsipeptide that is the enantiomeric form of a natural product ( nat -(-)-verticilide). Here, we examined its 18-membered ring-size oligomer ( ent -verticilide B1; " ent -B1") in single RyR2 channel assays, [ 3 H]ryanodine binding assays, and in Casq2 -/- cardiomyocytes and mice, a gene-targeted model of SCD. ent -B1 inhibited RyR2 single-channels and [ 3 H]ryanodine binding with low micromolar potency, and RyR2-mediated spontaneous Ca 2+ release in Casq2-/- cardiomyocytes with sub-micromolar potency. ent -B1 was a partial RyR2 inhibitor, with maximal inhibitory efficacy of less than 50%. ent -B1 was stable in plasma, with a peak plasma concentration of 1460 ng/ml at 10 min and half-life of 45 min after intraperitoneal administration of 3 mg/kg in mice. Both 3 mg/kg and 30 mg/kg ent -B1 significantly reduced catecholamine-induced ventricular arrhythmia in Casq2-/- mice. Hence, we have identified a novel chemical entity - ent -B1 - that preserves the mechanism of action of a hit compound and shows therapeutic efficacy. These findings strengthen RyR2 as an antiarrhythmic drug target and highlight the potential of investigating the mirror-image isomers of natural products to discover new therapeutics. Significance statement: The cardiac ryanodine receptor (RyR2) is an untapped target in the stagnant field of antiarrhythmic drug development. We have confirmed RyR2 as an antiarrhythmic target in a mouse model of sudden cardiac death and shown the therapeutic efficacy of a second enantiomeric natural product.

16.
Antimicrob Agents Chemother ; 56(11): 5998-6000, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22890763

RESUMO

HIV-1 resistance testing was performed in 47 antiretroviral (ARV)-treated subjects with low-level viremia (LLV) of <1,000 copies/ml. The median viral load was 267 copies/ml. In those with ≥2 LLV episodes, 44% accumulated additional resistance mutations. Fewer active ARVs and longer elapsed time were associated with an increased risk of resistance accumulation after controlling for adherence and viral load. Virologic failure followed 16% of LLV time points. Strategies for early intervention after LLV episodes should be further studied.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Farmacorresistência Viral/efeitos dos fármacos , Infecções por HIV/tratamento farmacológico , HIV-1/efeitos dos fármacos , HIV-1/genética , Viremia/tratamento farmacológico , Adulto , Fármacos Anti-HIV/farmacologia , Terapia Antirretroviral de Alta Atividade , Farmacorresistência Viral/genética , Feminino , Infecções por HIV/virologia , HIV-1/patogenicidade , Humanos , Masculino , Pessoa de Meia-Idade , Taxa de Mutação , Carga Viral/efeitos dos fármacos , Viremia/virologia
17.
Sensors (Basel) ; 12(2): 1594-611, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22438727

RESUMO

In this paper, a gait analysis system which estimates step length and foot angles is proposed. A measurement unit, which consists of a camera and inertial sensors, is installed on a shoe. When the foot touches the floor, markers are recognized by the camera to obtain the current position and attitude. A simple planar marker with 4,096 different codes is used. These markers printed on paper are placed on the floor. When the foot is moving off the floor, the position and attitude are estimated using an inertial navigation algorithm. For accurate estimation, a smoother is proposed, where vision information and inertial sensor data are combined. Through experiments, it is shown that the proposed system can both track foot motion and estimate step length.


Assuntos
Aceleração , Marcadores Fiduciais , Marcha/fisiologia , Interpretação de Imagem Assistida por Computador/instrumentação , Monitorização Ambulatorial/instrumentação , Fotografação/instrumentação , Transdutores , Actigrafia/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Fotografação/métodos , Sapatos
18.
Artigo em Inglês | MEDLINE | ID: mdl-31100981

RESUMO

Despite the availability of effective and safe rubella vaccines for women of childbearing age, prevention and control of congenital rubella syndrome in children remains challenging in Vietnam. In order to examine this issue, we conducted a cross-sectional study, examining the current coverage of rubella vaccination before pregnancy among 807 pregnant women and women with children under 12 months of age in urban and rural districts, Dong Da and Ba Vi, in Hanoi, Vietnam. In this population, we observed an alarming non-compliance rate with rubella vaccination before pregnancy in both localities. Among the 82.0% of participants who remained unvaccinated against this contagious viral infection, 95.8% of them were in Ba Vi district, compared to 68.0% in Dong Da district (p < 0.001). Besides the differences in age, number of children, education levels, primary occupations and monthly incomes among the participants between the two districts, other reasons for noncompliance with rubella vaccination includeddisinterest in rubella vaccination, the high cost and long distance to vaccination sites as well as unawareness of vaccination locations. In addition to addressing the unique socio-economicchallenges behind one's accessibility to vaccination services in urban and rural areas, our study supports a continued effort in ensuring proper access to and education about pre-pregnancy vaccines and vaccination among women of childbearing age in order to achieve and sustain sufficient immunization coverage of rubella and other vaccine-preventable diseases in both settings.


Assuntos
Vacina contra Rubéola , Cobertura Vacinal , Adulto , Estudos Transversais , Escolaridade , Feminino , Humanos , Ocupações , Paridade , Gravidez , Complicações Infecciosas na Gravidez/prevenção & controle , Gestantes , Rubéola (Sarampo Alemão)/imunologia , Síndrome da Rubéola Congênita/prevenção & controle , População Rural , População Urbana , Vietnã
19.
Protein Expr Purif ; 60(2): 147-50, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18538581

RESUMO

Biolayer interferometry is a novel method for quantifying macromolecules, such as proteins, in solution. The presence of other, non-binding molecules does not interfere with quantification, which allows one to measure the concentration of the molecule of interest in a crude mixture. Here we apply this method to determining the dynamic binding capacity of affinity resins.


Assuntos
Proteínas/isolamento & purificação , Animais , Células CHO , Cromatografia Líquida de Alta Pressão , Cricetinae , Cricetulus , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Ligação Proteica , Proteínas/metabolismo
20.
Int J Radiat Oncol Biol Phys ; 64(3): 771-5, 2006 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-16246496

RESUMO

PURPOSE: Metaplastic carcinoma of the breast represents a rare and heterogeneous group of malignancies that accounts for less than 1% of all breast cancers. The purpose of this study is to better characterize the clinical management of this disease including the role of radiation therapy after surgery. We compared patients that have been treated with either modified radical mastectomy (MRM) or breast-conserving surgery (BCS). METHODS AND MATERIALS: We performed a retrospective review of 43 patients with metaplastic breast cancer who were evaluated in our regional radiation oncology department between 1987 and 2002. Twenty-one patients were treated with an MRM and 22 with BCS. Five patients from the MRM group received adjuvant radiation, as did 19 patients from the BCS group. Univariate and multivariate analysis of pathologic and treatment-related factors was performed. Local control, disease-free, and overall survival rates were calculated by the Kaplan-Meier method and compared for the two groups. RESULTS: Mean follow-up for all patients was 44.2 months. Mean tumor size was 3.4 cm. Four patients (9%) had positive estrogen receptors and 20 (25%) had positive nodes. The overall 5-year projected local recurrence-free (88% vs. 85%, p = 0.86), disease-free (55% vs. 84%, p = 0.13), and overall survivals (80% vs. 89%, p = 0.58) were not significantly different for both groups. The only tumor parameter significantly associated with overall survival was nodal status. CONCLUSION: Our study suggests that breast conservation appears to be a reasonable treatment option for women with metaplastic breast cancer, achieving equal survival to mastectomy. The use of adjuvant radiation seems essential for achieving high local control rates after conservation therapy. Further studies will be needed to determine the impact of chemotherapy on survival outcomes.


Assuntos
Neoplasias da Mama/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Neoplasias da Mama/mortalidade , Neoplasias da Mama/radioterapia , Neoplasias da Mama/cirurgia , Intervalo Livre de Doença , Feminino , Humanos , Mastectomia Radical Modificada , Mastectomia Segmentar , Metaplasia/mortalidade , Metaplasia/patologia , Metaplasia/radioterapia , Metaplasia/cirurgia , Pessoa de Meia-Idade , Radioterapia Adjuvante , Estudos Retrospectivos
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