Activation of M1 muscarinic acetylcholine receptors by proline-rich oligopeptide 7a (

Background: The bioactive peptides derived from snake venoms of the Viperidae family species have been promising as therapeutic candidates for neuroprotection due to their ability to prevent neuronal cell loss, injury, and death. Therefore, this study aimed to evaluate the cytoprotective effects of a synthetic proline-rich oligopeptide 7a (PRO-7a; <EDGPIPP) from Bothrops jararaca snake, on oxidative stress-induced toxicity in neuronal PC12 cells and astrocyte-like C6 cells. Methods: Both cells were pre-treated for four hours with different concentrations of PRO-7a, submitted to H2O2-induced damage for 20 h, and then the oxidative stress markers were analyzed. Also, two independent neuroprotective mechanisms were investigated: a) L-arginine metabolite generation via argininosuccinate synthetase (AsS) activity regulation to produce agmatine or polyamines with neuroprotective properties; b) M1 mAChR receptor subtype activation pathway to reduce oxidative stress and neuron injury. Results: PRO-7a was not cytoprotective in C6 cells, but potentiated the H2O2-induced damage to cell integrity at a concentration lower than 0.38 μM. However, PRO-7a at 1.56 µM, on the other hand, modified H2O2-induced toxicity in PC12 cells by restoring cell integrity, mitochondrial metabolism, ROS generation, and arginase indirect activity. The α-Methyl-DL-aspartic acid (MDLA) and L-NΩ-Nitroarginine methyl ester (L-Name), specific inhibitors of AsS and nitric oxide synthase (NOS), which catalyzes the synthesis of polyamines and NO from L-arginine, did not suppress PRO-7a-mediated cytoprotection against oxidative stress. It suggested that its mechanism is independent of the production of L-arginine metabolites with neuroprotective properties by increased AsS activity. On the other hand, the neuroprotective effect of PRO-7a was blocked in the presence of dicyclomine hydrochloride (DCH), an M1 mAChR antagonist. Conclusions: For the first time, this work provides evidence that PRO-7a-induced neuroprotection seems to be mediated through M1 mAChR activation in PC12 cells, which reduces oxidative stress independently of AsS activity and L-arginine bioavailability.(AU)

First-wave protease inhibitors for hepatitis C genotype 1 treatment: a real-life experience in Brazilian patients

Abstract INTRODUCTION: Licensed for chronic hepatitis C treatment in 2011, the protease inhibitors (PIs) telaprevir (TVR) and boceprevir (BOC), which have high sustained viral responses (SVR), ushered a new era characterized by the development of direct-action drugs against the hepatitis C virus (HCV). The aim of this study was to analyze the effectiveness and safety of BOC and TVR administered with pegylated interferon and ribavirin and to share the experience of a Brazilian reference center. METHODS: A retrospective descriptive study was conducted in patients with HCV genotype 1 infection who started treatment between July 2013 and December 2015. Data were collected using a computerized system. RESULTS: A total of 115 subjects were included, of which 58 (50.4 %) had liver cirrhosis and 103 (89.6 %) used TVR. The overall SVR rate was 61.7 % (62.1 % for TVR and 58.3 % for BOC). The presence of cirrhosis was associated with a lower SVR rate, whereas patients who relapsed after prior therapy had a greater chance of showing SVR than did non-responders. The incidence of adverse drug reactions (ADRs) was high. Almost all patients (~100 %) presented with hematologic events. Furthermore, treatment had to be discontinued in 15 subjects (13 %) due to severe ADRs. CONCLUSIONS: In conclusion, the SVR rates in our study were lower than those reported in pre-marketing studies but were comparable to real-life data. ADRs, particularly hematological ADRs, were more common compared to those in previous studies and resulted in a high rate of treatment discontinuity.

Predictors of early treatment discontinuation and severe anemia in a Brazilian cohort of hepatitis C patients treated with first-generation protease inhibitors

The aim of this study was to determine risk factors for adverse events (AE)-related treatment discontinuation and severe anemia among patients with chronic hepatitis C virus (HCV) genotype 1 infection, treated with first-generation protease inhibitor (PI)-based therapy. We included all patients who initiated treatment with PI-based therapy at a Brazilian university hospital between November 2013 and December 2014. We prospectively collected data from medical records using standardized questionnaires and used Epi Info 6.0 for analysis. Severe anemia was defined as hemoglobin ≤8.5 mg/dL. We included 203 patients: 132 treated with telaprevir (TVR) and 71 treated with boceprevir (BOC). AE-related treatment discontinuation rate was 19.2% and anemia was the main reason (38.5%). Risk factors for treatment discontinuation were higher comorbidity index (OR=1.85, CI=1.05-3.25) for BOC, and higher bilirubin count (OR=1.02, CI=1.01-1.04) and lower BMI (OR=0.98, CI=0.96-0.99) for TVR. Severe anemia occurred in 35 (17.2%) patients. Risk factors for this outcome were lower estimated glomerular filtration rate (eGFR; OR=0.95, CI=0.91-0.98) for patients treated with TVR, and higher comorbidity index (OR=2.21, CI=1.04-4.67) and ribavirin dosage (OR=0.84, CI=0.72-0.99) for those treated with BOC. Fifty-five (57.3%) patients treated with TVR and 15 (27.3%) patients treated with BOC achieved sustained virological response (SVR). Among patients who received TVR and interrupted treatment due to AE (n=19), only 26.3% (n=5) achieved SVR (P=0.003). Higher number of comorbidities, lower eGFR and advanced liver disease are associated with severe anemia and early treatment cessation, which may compromise SVR achievement.

TRIPLE THERAPY IN CHRONIC HEPATITIS C: initial series in a public health program in the South of Brazil / Terapia tripla em pacientes com hepatite C: experiência inicial em um pólo de aplicação do Sul do Brasil

Background Chronic hepatitis C has great impact on world’s health. Current therapy for genotype 1 hepatitis C virus includes protease inhibitors boceprevir and telaprevir, associated to standard therapy - peginterferon alfa + ribavirin. There are no published data in Brazil on the results of this new therapy, and it is interesting an evaluation of what was accomplished up to this moment. Objectives To evaluate virologic response to triple therapy, as well as the safety profile and tolerability. Method This study is a clinical series of patients receiving triple therapy for C hepatitis in a single center of a Public Health System of South Brasil. Out of the 121 patients that initiated the triple therapy, the first patients that finished the treatment and evaluated the sustained virological response (24 weeks after the end of treatment) were included. Results Twenty four genotype 1 chronic hepatitis C monoinfected patients were included. Nineteen (79.2%) patients had been previously treated. Thirteen (54.2%) patients were cirrhotic. Nineteen (79.2%) patients completed the planned therapy. By the end of the treatment, 14 (58.3%) out of 24 patients had undetectable viral load. Sustained virologic response occurred in 12 (50.0%) out of 24 patients, 07 (58.3%) in telaprevir group and 05 (41.7%) in boceprevir group. Out of 24 patients under triple therapy, 58% (n=14) presented anemia. Conclusions In conclusion, despite the small number of patients treated with triple therapy evaluated in the current study, it possibly reflects the population under this therapy in real-life. .

Contexto A hepatite crônica pelo vírus C tem grande impacto na saúde mundial. A terapia atual do genótipo 1 inclui os inibidores de protease (IP) boceprevir e telaprevir, associados à terapia padrão - alfapeginterferona + ribavirina (PR). No Brasil ainda não há estudos publicados sobre os resultados dessa nova terapia, sendo de interesse uma avaliação do que foi realizado até o momento. Objetivos Avaliar a resposta virológica ao tratamento triplo, bem como o perfil de segurança e tolerabilidade. Métodos O estudo consta de série de casos dos pacientes em uso de terapia tripla para o tratamento da hepatite C em um polo de tratamento da Secretaria Estadual da Saúde do Estado do Rio Grande do Sul, Brasil. Dentre os 121 pacientes que estão em uso de terapia tripla (PR e IP) foram apresentados os dados referentes aos primeiros que finalizaram o tratamento e realizaram avaliação da resposta virológica sustentada na semana 24 pós-tratamento. Resultados Foram incluídos 24 pacientes monoinfectados por hepatite C crônica genótipo 1. Dezenove (79%) pacientes eram previamente experimentados. Treze (54,2%) pacientes apresentavam cirrose. Dezenove (79,2%) pacientes completaram o tratamento planejado. Ao final do tratamento, 14 (58,3%) dos 24 pacientes apresentaram carga viral indetectável. Resposta virológica sustentada ocorreu em 12 (50%) dos 24 pacientes, sendo 07 (58,3%) no grupo telaprevir e 05 (41,7%) no grupo boceprevir. Dos 24 pacientes submetidos à terapia tripla, 58% (n=14) apresentaram anemia. Conclusões Embora o presente estudo tenha avaliado um pequeno número de casos, possivelmente reflete a população submetida à terapia tripla na vida real, despida das restrições dos estudos de registro. .

Safety aspects of protease inhibitors for chronic hepatitis C: adverse events and drug-to-drug interactions

The standard of care therapy of chronic hepatitis C with the combination of pegylated interferon and ribavirin for 24 or 48 weeks was a remarkable accomplishment of the past decade. However, sustained virological responses rates of about 80% (genotypes 2-3) and 50% (geno 3 type 1) were not satisfactory especially for patients infected with genotype 1. Important advances in the biology of HCV have made possible the development of the direct-acting antiviral agents boceprevir and telaprevir with substantial increase in the rates of sustained virological response with shorter duration of therapy for a large number of patients. However, the complexity of triple therapy is higher and several new side effects are expected suggesting greater expertise in the patient management. Anemia and disgeusia are frequent with boceprevir while cutaneous rash, ranging from mild to severe, is expected with telaprevir. Higher risk of drug-drug interactions demand further clinical consideration of the previous well-known adverse events of pegylated interferon and ribavirin. Identification and prompt management of these potential new problems with boceprevir and telaprevir are crucial in clinical practice for optimizing treatment and assuring safety outcomes to HCV-genotype 1 patients.

Incidence of Atazanavir-associated Hyperbilirubinemia in Korean HIV Patients: 30 Months Follow-up Results in a Population with Low UDP-glucuronosyltransferase1A1*28 Allele Frequency

Hyperbilirubinemia is frequently observed in Caucasian HIV patients treated with atazanavir. UDP-glucuronosyltransferase 1A1 polymorphism, UGT1A1*28, which is associated with atazanavir-induced hyperbilirubinemia, is less common in Asians than in Caucasians. However, little is known about the incidence of atazanavir-associated hyperbilirubinemia in Asian populations. Our objective was to investigate the incidence of and tolerability of atazanavir-associated hyperbilirubinemia in Korean HIV patients. The prevalence and cumulative incidence of atazanavir-associated hyperbilirubinemia and UGT1A1*28 allele frequency was investigated in 190 Korean HIV-infected patients treated with atazanavir 400 mg per day. The UGT1A1*28 were examined by direct sequencing of DNA from peripheral whole blood. The UGT1A1*28 allele frequency was 11%. The cumulative incidence of any grade of hyperbilirubinemia was 77%, 89%, 98%, and 100%, at 3, 12, 24, and 30 months, respectively. The cumulative incidence of severe (grade 3-4) hyperbilirubinemia was 21%, 41%, 66%, and 75%, at 3, 12, 24, and 30 months, respectively. However, the point prevalence of severe hyperbilirubinemia did not increase with time and remained around 25%. Our data suggest that atazanavir-associated hyperbilirubinemia is common but transient in a population with low UGT1A1*28 allele frequency.