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1.
J Psychiatr Res ; 173: 1-5, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38437783

RESUMO

Brain derived neurotrophic factor (BDNF) may play an important role in the success of treatment for posttraumatic stress disorder (PTSD). Pre- and post-treatment blood samples were analyzed for 40 veterans who completed a 3-week intensive outpatient treatment for PTSD. The treatment included Cognitive Processing Therapy, mindfulness, and yoga as core treatment components. PTSD symptoms were assessed at pre-treatment, post-treatment, and 3-month follow-up. Participants reported large decreases in PTSD symptoms from pre-to post-treatment (d = 1.46, p < 0.001) and pre-treatment to 3-month follow-up (d = 0.91, p < 0.001). Unexpectedly, participants demonstrated a decrease in BDNF from pre-to post-treatment (d = 0.64, p < 0.001). Changes in BDNF from pre-to post-treatment were not significantly associated with PTSD symptom improvement. However, higher levels of post-treatment BDNF were significantly associated with lower PTSD symptoms at 3-month follow-up (n = 27, r = -0.57, p = 0.002) and greater improvements in PTSD symptoms from pre-treatment to 3-month follow-up (n = 27, r = 0.50, p = 0.008). Higher levels of post-treatment BDNF may facilitate the long-term success of intensive PTSD treatment. Further research with larger samples is needed to evaluate the processes by which BDNF may affect consolidation of improvements after completion of PTSD treatment.


Assuntos
Terapia Cognitivo-Comportamental , Transtornos de Estresse Pós-Traumáticos , Veteranos , Humanos , Veteranos/psicologia , Transtornos de Estresse Pós-Traumáticos/psicologia , Fator Neurotrófico Derivado do Encéfalo , Resultado do Tratamento
2.
Arch Dis Child ; 109(2): 106-112, 2024 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-37875332

RESUMO

OBJECTIVES: To determine the baseline trends in the total birth prevalence of neural tube defects (NTDs) in England (2000-2019) to enable the impact of folic acid fortification of non-wholemeal wheat flour to be monitored. DESIGN: Population-based, observational study using congenital anomaly (CA) registration data for England curated by the National Congenital Anomaly and Rare Disease Registration Service (NCARDRS). SETTING: Regions of England with active registration in the time period. PARTICIPANTS: Babies that were liveborn or stillborn and pregnancies that resulted in a termination of pregnancy or a late miscarriage (20-23 weeks' gestation) with an NTD. MAIN OUTCOME MEASURES: Total birth prevalence of anencephaly, spina bifida and all NTDs in England. Poisson regression analysis was used to evaluate time trends with regional register as a random effect. The progress of national registration across England was assessed. RESULTS: There were 4541 NTD pregnancies out of 3 637 842 births in England; 1982 anencephaly and 2127 spina bifida. NTD prevalence was 12.5 (95% CI 12.1 to 12.9) per 10 000 total births. NTD prevalence per 10 000 total births was significantly higher in 2015-2019 (13.6, 95% CI 12.9 to 14.4) compared with 2010-2014 (12.1, 95% CI 11.7 to 12.5). An increasing trend in NTDs overall was detected (incidence rate ratio (IRR) 1.01, 1.00 to 1.02), although further analysis determined this effect was confined to 2015-2019 (compared against 2000-2004, IRR 1.14, 1.04 to 1.24). The birth prevalence of anencephaly reflected this pattern. The prevalence of spina bifida remained relatively stable over time. CONCLUSIONS: Baseline NTD prevalence for England has been established. National and standardised CA registration is in place, facilitating the systematic and consistent monitoring of pre-fortification and post-fortification NTD trends and evaluating the impact of fortification on NTD prevalence.


Assuntos
Anencefalia , Defeitos do Tubo Neural , Disrafismo Espinal , Gravidez , Feminino , Humanos , Ácido Fólico , Farinha , Prevalência , Anencefalia/epidemiologia , Anencefalia/prevenção & controle , Estudos de Coortes , Triticum , Alimentos Fortificados , Defeitos do Tubo Neural/epidemiologia , Defeitos do Tubo Neural/prevenção & controle , Disrafismo Espinal/epidemiologia , Disrafismo Espinal/prevenção & controle
3.
Front Pediatr ; 9: 647038, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34249803

RESUMO

Objective: Thirty years ago it was demonstrated that folic acid taken before pregnancy and in early pregnancy reduced the risk of a neural tube defect (NTD). Despite Public Health Initiatives across Europe recommending that women take 0.4 mg folic acid before becoming pregnant and during the first trimester, the prevalence of NTD pregnancies has not materially decreased in the EU since 1998, in contrast to the dramatic fall observed in the USA. This study aimed to estimate the number of NTD pregnancies that would have been prevented if flour had been fortified with folic acid in Europe from 1998 as it had been in the USA. Design and Setting: The number of NTD pregnancies from 1998 to 2017 that would have been prevented if folic acid fortification had been implemented in the 28 countries who were members of the European Union in 2019 was predicted was predicted using data on NTD prevalence from 35 EUROCAT congenital anomaly registries and literature searches for population serum folate levels and folic acid supplementation. Results: From 1998 to 2017 an estimated 95,213 NTD pregnancies occurred amongst 104 million births in the 28 countries in the EU, a prevalence of 0.92 per 1,000 births. The median serum folate level in Europe over this time period was estimated to be 14.1 µg/L. There is a lack of information about women taking folic acid supplements before becoming pregnant and during the first trimester of pregnancy, with one meta-analysis indicating that around 25% of women did so. An estimated 14,600 NTD pregnancies may have been prevented if the European countries had implemented fortification at the level adopted by the USA in 1998 and 25% of women took folic acid supplements. An estimated 19,500 NTD pregnancies would have been prevented if no women took folic acid supplements. Conclusions: This study suggests that failure to implement mandatory folic acid fortification in the 28 European countries has caused, and continues to cause, neural tube defects to occur in almost 1,000 pregnancies every year.

4.
PLoS One ; 15(12): e0240338, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33306682

RESUMO

Thyroid hormones are important modulators of metabolic activity in mammals and alter cholesterol and fatty acid levels through activation of the nuclear thyroid hormone receptor (THR). Currently, there are several THRß agonists in clinical trials for the treatment of non-alcoholic steatohepatitis (NASH) that have demonstrated the potential to reduce liver fat and restore liver function. In this study, we tested three THRß-agonism-based NASH treatment candidates, GC-1 (sobetirome), MGL-3196 (resmetirom), and VK2809, and compared their selectivity for THRß and their ability to modulate the expression of genes specific to cholesterol and fatty acid biosynthesis and metabolism in vitro using human hepatic cells and in vivo using a rat model. Treatment with GC-1 upregulated the transcription of CPT1A in the human hepatocyte-derived Huh-7 cell line with a dose-response comparable to that of the native THR ligand, triiodothyronine (T3). VK2809A (active parent of VK2809), MGL-3196, and VK2809 were approximately 30-fold, 1,000-fold, and 2,000-fold less potent than T3, respectively. Additionally, these relative potencies were confirmed by quantification of other direct gene targets of THR, namely, ANGPTL4 and DIO1. In primary human hepatocytes, potencies were conserved for every compound except for VK2809, which showed significantly increased potency that was comparable to that of its active counterpart, VK2809A. In high-fat diet fed rats, a single dose of T3 significantly reduced total cholesterol levels and concurrently increased liver Dio1 and Me1 RNA expression. MGL-3196 treatment resulted in concentration-dependent decreases in total and low-density lipoprotein cholesterol with corresponding increases in liver gene expression, but the compound was significantly less potent than T3. In conclusion, we have implemented a strategy to rank the efficacy of THRß agonists by quantifying changes in the transcription of genes that lead to metabolic alterations, an effect that is directly downstream of THR binding and activation.


Assuntos
Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Receptores beta dos Hormônios Tireóideos/agonistas , Transcrição Gênica/efeitos dos fármacos , Acetatos/farmacologia , Acetatos/uso terapêutico , Proteína 4 Semelhante a Angiopoietina/metabolismo , Animais , Linhagem Celular Tumoral , LDL-Colesterol/sangue , LDL-Colesterol/metabolismo , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Hepatócitos , Humanos , Iodeto Peroxidase/genética , Iodeto Peroxidase/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Malato Desidrogenase/genética , Malato Desidrogenase/metabolismo , Masculino , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/patologia , Organofosfonatos/farmacologia , Organofosfonatos/uso terapêutico , Fenóis/farmacologia , Fenóis/uso terapêutico , Cultura Primária de Células , Piridazinas/farmacologia , Piridazinas/uso terapêutico , Ratos , Uracila/análogos & derivados , Uracila/farmacologia , Uracila/uso terapêutico
5.
BMC Med ; 16(1): 229, 2018 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-30567539

RESUMO

BACKGROUND: The UK's National Health Service (NHS) is currently subject to unprecedented financial strain. The identification of unnecessary healthcare resource use has been suggested to reduce spending. However, there is little very research quantifying wasteful test use, despite the £3 billion annual expenditure. Geographical variation has been suggested as one metric in which to quantify inappropriate use. We set out to identify tests ordered from UK primary care that are subject to the greatest between-practice variation in their use. METHODS: We used data from 444 general practices within the Clinical Practice Research Datalink to calculate a coefficient of variation (CoV) for the ordering of 44 specific tests from UK general practices. The coefficient of variation was calculated after adjusting for differences between practice populations. We also determined the tests that had both a higher-than-average CoV and a higher-than-average rate of use. RESULTS: In total, 16,496,218 tests were ordered for 4,078,091 patients over 3,311,050 person-years from April 1, 2015, to March 31, 2016. The tests subject to the greatest variation were drug monitoring 158% (95%CI 153 to 163%), urine microalbumin (52% (95%CI 49.9 to 53.2%)), pelvic CT (51% (95%CI 50 to 53%)) and Pap smear (49% (95%CI 48 to 51%). Seven tests were classified as high variability and high rate (clotting, vitamin D, urine albumin, prostate-specific antigen (PSA), bone profile, urine MCS and C-reactive protein (CRP)). CONCLUSIONS: There are wide variations in the use of common tests, which is unlikely to be explained by clinical indications. Since £3 billion annually are spent on tests, this represents considerable variation in the use of resources and inefficient management in the NHS. Our results can be of value to policy makers, researchers, patients and clinicians as the NHS strives towards identifying overuse and underuse of tests.


Assuntos
Testes Diagnósticos de Rotina/estatística & dados numéricos , Padrões de Prática Médica , Atenção Primária à Saúde , Adulto , Testes Diagnósticos de Rotina/economia , Feminino , Política de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Programas Nacionais de Saúde , Padrões de Prática Médica/economia , Atenção Primária à Saúde/economia , Estudos Retrospectivos , Reino Unido
6.
Antivir Chem Chemother ; 26: 2040206618764483, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29562753

RESUMO

Influenza virus, respiratory syncytial virus, human metapneumovirus, parainfluenza virus, coronaviruses, and rhinoviruses are among the most common viruses causing mild seasonal colds. These RNA viruses can also cause lower respiratory tract infections leading to bronchiolitis and pneumonia. Young children, the elderly, and patients with compromised cardiac, pulmonary, or immune systems are at greatest risk for serious disease associated with these RNA virus respiratory infections. In addition, swine and avian influenza viruses, together with severe acute respiratory syndrome-associated and Middle Eastern respiratory syndrome coronaviruses, represent significant pandemic threats to the general population. In this review, we describe the current medical need resulting from respiratory infections caused by RNA viruses, which justifies drug discovery efforts to identify new therapeutic agents. The RNA polymerase of respiratory viruses represents an attractive target for nucleoside and nucleotide analogs acting as inhibitors of RNA chain synthesis. Here, we present the molecular, biochemical, and structural fundamentals of the polymerase of the four major families of RNA respiratory viruses: Orthomyxoviridae, Pneumoviridae/Paramyxoviridae, Coronaviridae, and Picornaviridae. We summarize past and current efforts to develop nucleoside and nucleotide analogs as antiviral agents against respiratory virus infections. This includes molecules with very broad antiviral spectrum such as ribavirin and T-705 (favipiravir), and others targeting more specifically one or a few virus families. Recent advances in our understanding of the structure(s) and function(s) of respiratory virus polymerases will likely support the discovery and development of novel nucleoside analogs.


Assuntos
Antivirais/farmacologia , Nucleosídeos/farmacologia , Infecções por Vírus de RNA/tratamento farmacológico , Vírus de RNA/efeitos dos fármacos , Infecções Respiratórias/tratamento farmacológico , Infecções Respiratórias/virologia , Antivirais/química , Humanos , Testes de Sensibilidade Microbiana , Modelos Moleculares , Estrutura Molecular , Nucleosídeos/química , Infecções por Vírus de RNA/virologia
7.
Undersea Hyperb Med ; 43(4): 427-435, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28763172

RESUMO

OBJECTIVE: To describe the implementation of a quality improvement (QI) project that aimed at improving and standardizing glucose checks on patients with diabetes undergoing hyperbaric oxygen (HBO2) therapy. METHODS: This is a prospective cohort study. Following the Model for Improvement, nurses and physicians ran several Plan-Do-Study-Act (PDSA) cycles over a four-month period, with multiple iteration and testing changes. They developed and implemented a nurse-led protocol that was tested prospectively. RESULTS: Compared to the pre-protocol baseline (N = 332), glucose checks per session guided by the protocol decreased by 37.7% (2.84 vs. 1.77 per session, P⟨0.001). Compliance with the new protocol was higher than compliance with the existing protocol (97.3% to 84.2%, P⟨0.001). There were no cases of a symptomatic hypoglycemic event after the implementation of the protocol. CONCLUSIONS: A quality improvement project implemented by a multidisciplinary team in a hyperbaric practice was feasible and has improved the management of diabetic patients undergoing HBO2 therapy. Considering how the hyperbaric community values the culture of safety and considering the feasibility of this project, more QI training and projects in hyperbaric programs should be performed.


Assuntos
Glicemia/análise , Protocolos Clínicos/normas , Diabetes Mellitus/sangue , Oxigenoterapia Hiperbárica , Melhoria de Qualidade , Estudos de Viabilidade , Humanos , Oxigenoterapia Hiperbárica/estatística & dados numéricos , Hipoglicemia/sangue , Hipoglicemia/diagnóstico , Hipoglicemia/etiologia , Equipe de Assistência ao Paciente/organização & administração , Padrões de Prática em Enfermagem , Estudos Prospectivos , Qualidade da Assistência à Saúde/normas , Fatores de Tempo , Procedimentos Desnecessários
8.
Undersea Hyperb Med ; 42(3): 191-6, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26152103

RESUMO

BACKGROUND: Hypoglycemia is concerning in patients with diabetes undergoing hyperbaric oxygen (HBO2) therapy. We aimed to estimate the incidence, risk factors and a pretreatment glucose threshold of HBO2-associated hypoglycemia. METHODS: We retrospectively evaluated a patient cohort undergoing HBO2 therapy. We calculated the area under the curve (AUC) and odds ratio (OR) with 95% confidence interval (CI) adjusting for patients' age, gender, diabetes type, insulin use, body mass index, hemoglobin A1c and HBO2 treatment time. RESULTS: During 77 months, 3,136 HBO2 sessions were performed on patients with diabetes. In-chamber glucose was higher than pre-HBO2 glucose in 1,708/3,136 sessions (54%). The incidence of hypoglycemia (defined as ≤ 70 mg/dL) during or immediately after HBO2 treatment was 1.5% (0.8-2.1%). Hypoglycemia that was symptomatic or severe was rare. A glucose value pre-HBO2 of 150 mg/dL best predicted the risk of subsequent hypoglycemia (AUC 0.80; 95% CI, 0.75-0.86). Type 1 diabetes was independently associated with increased risk of hypoglycemia (OR 3.69; 95% CI, 1.67, 8.19) whereas insulin use was not. CONCLUSIONS: In patients with diabetes undergoing HBO2, severe hypoglycemia is rare and occurs more frequently in Type 1 diabetes. Pre-HBO2 glucose values may be used to predict subsequent hypoglycemia and reduce the need for routine glucose monitoring during and after HBO2.


Assuntos
Diabetes Mellitus/terapia , Hemoglobinas Glicadas/análise , Oxigenoterapia Hiperbárica/efeitos adversos , Hipoglicemia/sangue , Hipoglicemia/epidemiologia , Adulto , Fatores Etários , Idoso , Área Sob a Curva , Pressão Atmosférica , Biomarcadores/sangue , Intervalos de Confiança , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/terapia , Feminino , Humanos , Hipoglicemia/etiologia , Hipoglicemiantes/uso terapêutico , Incidência , Insulina/uso terapêutico , Masculino , Pessoa de Meia-Idade , Razão de Chances , Estudos Retrospectivos , Fatores de Risco , Fatores Sexuais
9.
J Mol Cell Cardiol ; 85: 37-47, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25988231

RESUMO

UNLABELLED: Fatigue and muscle wasting are common symptoms experienced by cancer patients. Data from animal models demonstrate that angiotensin is involved in tumor-induced muscle wasting, and that tumor growth can independently affect myocardial function, which could contribute to fatigue in cancer patients. In clinical studies, inhibitors of angiotensin converting enzyme (ACE) can prevent the development of chemotherapy-induced cardiovascular dysfunction, suggesting a mechanistic role for the renin-angiotensin-aldosterone system (RAAS). In the present study, we investigated whether an angiotensin (AT) 1-receptor antagonist could prevent the development of tumor-associated myocardial dysfunction. METHODS AND RESULTS: Colon26 adenocarcinoma (c26) cells were implanted into female CD2F1 mice at 8weeks of age. Simultaneously, mice were administered Losartan (10mg/kg) daily via their drinking water. In vivo echocardiography, blood pressure, in vitro cardiomyocyte function, cell proliferation assays, and measures of systemic inflammation and myocardial protein degradation were performed 19days following tumor cell injection. Losartan treatment prevented tumor-induced loss of muscle mass and in vitro c26 cell proliferation, decreased tumor weight, and attenuated myocardial expression of interleukin-6. Furthermore, Losartan treatment mitigated tumor-associated alterations in calcium signaling in cardiomyocytes, which was associated with improved myocyte contraction velocity, systolic function, and blood pressures in the hearts of tumor-bearing mice. CONCLUSIONS: These data suggest that Losartan may mitigate tumor-induced myocardial dysfunction and inflammation.


Assuntos
Adenocarcinoma/complicações , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Cardiotônicos/farmacologia , Doenças Cardiovasculares/prevenção & controle , Neoplasias do Colo/complicações , Losartan/farmacologia , Adenocarcinoma/patologia , Angiotensina II/sangue , Bloqueadores do Receptor Tipo 1 de Angiotensina II/uso terapêutico , Animais , Sinalização do Cálcio , Cardiotônicos/uso terapêutico , Doenças Cardiovasculares/etiologia , Linhagem Celular Tumoral , Neoplasias do Colo/patologia , Citocinas/sangue , Avaliação Pré-Clínica de Medicamentos , Feminino , Glutationa/metabolismo , Losartan/uso terapêutico , Camundongos , Miocárdio/metabolismo , Miocárdio/patologia , Transplante de Neoplasias , Carga Tumoral , Remodelação Ventricular/efeitos dos fármacos
10.
BMJ ; 345: e6698, 2012 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-23112118

RESUMO

OBJECTIVE: To clarify associations of fish consumption and long chain omega 3 fatty acids with risk of cerebrovascular disease for primary and secondary prevention. DESIGN: Systematic review and meta-analysis. DATA SOURCES: Studies published before September 2012 identified through electronic searches using Medline, Embase, BIOSIS, and Science Citation Index databases. ELIGIBILITY CRITERIA: Prospective cohort studies and randomised controlled trials reporting on associations of fish consumption and long chain omega 3 fatty acids (based on dietary self report), omega 3 fatty acids biomarkers, or supplementations with cerebrovascular disease (defined as any fatal or non-fatal ischaemic stroke, haemorrhagic stroke, cerebrovascular accident, or transient ischaemic attack). Both primary and secondary prevention studies (comprising participants with or without cardiovascular disease at baseline) were eligible. RESULTS: 26 prospective cohort studies and 12 randomised controlled trials with aggregate data on 794,000 non-overlapping people and 34,817 cerebrovascular outcomes were included. In cohort studies comparing categories of fish intake the pooled relative risk for cerebrovascular disease for 2-4 servings a week versus ≤ 1 servings a week was 0.94 (95% confidence intervals 0.90 to 0.98) and for ≥ 5 servings a week versus 1 serving a week was 0.88 (0.81 to 0.96). The relative risk for cerebrovascular disease comparing the top thirds of baseline long chain omega 3 fatty acids with the bottom thirds for circulating biomarkers was 1.04 (0.90 to 1.20) and for dietary exposures was 0.90 (0.80 to 1.01). In the randomised controlled trials the relative risk for cerebrovascular disease in the long chain omega 3 supplement compared with the control group in primary prevention trials was 0.98 (0.89 to 1.08) and in secondary prevention trials was 1.17 (0.99 to 1.38). For fish or omega 3 fatty acids the estimates for ischaemic and haemorrhagic cerebrovascular events were broadly similar. Evidence was lacking of heterogeneity and publication bias across studies or within subgroups. CONCLUSIONS: Available observational data indicate moderate, inverse associations of fish consumption and long chain omega 3 fatty acids with cerebrovascular risk. Long chain omega 3 fatty acids measured as circulating biomarkers in observational studies or supplements in primary and secondary prevention trials were not associated with cerebrovascular disease. The beneficial effect of fish intake on cerebrovascular risk is likely to be mediated through the interplay of a wide range of nutrients abundant in fish.


Assuntos
Transtornos Cerebrovasculares/prevenção & controle , Ácidos Graxos Ômega-3/administração & dosagem , Peixes , Animais , Transtornos Cerebrovasculares/dietoterapia , Dieta , Suplementos Nutricionais , Humanos , Estudos Prospectivos , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Risco
11.
Anal Biochem ; 394(1): 138-40, 2009 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-19591800

RESUMO

The hepatitis C virus (HCV) nonstructural protein 3 (NS3) is known to possess multiple enzymatic activities. In addition to its well-characterized protease activity, HCV NS3 also has ATP hydrolase (ATPase) and nucleic acid unwinding (helicase) activities. We systematically studied the effect of common reagents on all three enzymatic activities with a view to improving assay sensitivity for compound screening and profiling. Inclusion of the detergent lauryl dimethylamine oxide (LDAO) improves protease and helicase activities significantly, allowing robust assays at much lower NS3 concentrations. These conditions enable a particularly sensitive protease assay that uses picomolar concentrations of NS3.


Assuntos
Hepacivirus/enzimologia , Proteínas não Estruturais Virais/metabolismo , Detergentes/farmacologia , Dimetilaminas/farmacologia , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/farmacologia , Cinética , Proteínas não Estruturais Virais/antagonistas & inibidores
12.
Antimicrob Agents Chemother ; 52(12): 4432-41, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18824605

RESUMO

Future treatments for chronic hepatitis C virus (HCV) infection are likely to include agents that target viral components directly. Here, the preclinical characteristics of ITMN-191, a peptidomimetic inhibitor of the NS3/4A protease of HCV, are described. ITMN-191 inhibited a reference genotype 1 NS3/4A protein in a time-dependent fashion, a hallmark of an inhibitor with a two-step binding mechanism and a low dissociation rate. Under preequilibrium conditions, 290 pM ITMN-191 half-maximally inhibited the reference NS3/4A protease, but a 35,000-fold-higher concentration did not appreciably inhibit a panel of 79 proteases, ion channels, transporters, and cell surface receptors. Subnanomolar biochemical potency was maintained against NS3/4A derived from HCV genotypes 4, 5, and 6, while single-digit nanomolar potency was observed against NS3/4A from genotypes 2b and 3a. Dilution of a preformed enzyme inhibitor complex indicated ITMN-191 remained bound to and inhibited NS3/4A for more than 5 h after its initial association. In cell-based potency assays, half-maximal reduction of genotype 1b HCV replicon RNA was afforded by 1.8 nM; 45 nM eliminated the HCV replicon from cells. Peginterferon alfa-2a displayed a significant degree of antiviral synergy with ITMN-191 and reduced the concentration of ITMN-191 required for HCV replicon elimination. A 30-mg/kg of body weight oral dose administered to rats or monkeys yielded liver concentrations 12 h after dosing that exceeded the ITMN-191 concentration required to eliminate replicon RNA from cells. These preclinical characteristics compare favorably to those of other inhibitors of NS3/4A in clinical development and therefore support the clinical investigation of ITMN-191 for the treatment of chronic hepatitis C.


Assuntos
Antivirais , Proteínas de Transporte/antagonistas & inibidores , Hepacivirus/efeitos dos fármacos , Hepacivirus/enzimologia , Inibidores de Proteases , Proteínas não Estruturais Virais/antagonistas & inibidores , Proteínas Virais/antagonistas & inibidores , Animais , Antivirais/química , Antivirais/metabolismo , Antivirais/farmacologia , Linhagem Celular Tumoral , Avaliação Pré-Clínica de Medicamentos , Sinergismo Farmacológico , Hepacivirus/genética , Hepacivirus/fisiologia , Humanos , Interferon alfa-2 , Interferon-alfa/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular , Fígado/metabolismo , Macaca fascicularis , Polietilenoglicóis/farmacologia , Inibidores de Proteases/química , Inibidores de Proteases/metabolismo , Inibidores de Proteases/farmacologia , Ratos , Proteínas Recombinantes , Replicação Viral/efeitos dos fármacos
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