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Mucin overproduction is a common feature of chronic airway diseases such as asthma and chronic obstructive pulmonary disease (COPD), and exacerbates their underlying respiratory condition. Surfactant protein D (SP-D) protects against airway diseases through modulation of immune reactions, but whether it also exerts direct effects on airway epithelial cells has remained unclear. Therefore, we sought to investigate the inhibitory role of SP-D on mucin production in airway epithelial cells. We prepared air-liquid interface (ALI) cultures of human primary bronchial epithelial cells (HBECs), which recapitulated a well-differentiated human airway epithelium. Benzo(a)pyrene (BaP), a key toxicant in cigarette smoke, induced mucin 5AC (MUC5AC) production in ALI-cultured HBECs, airway secretory cell lines, and airway epithelia of mice. Then, the protective effects of SP-D against the BaP-induced mucin overproduction were examined. BaP increased MUC5AC production in ALI cultures of HBECs, and this effect was attenuated by SP-D. SP-D also suppressed the BaP-induced phosphorylation of extracellular signal-regulated kinase (ERK) and MUC5AC expression in NCI-H292 goblet-like cells, but not in NCI-H441 club-like cells. Signal regulatory protein α (SIRPα) was found to be expressed in HBECs and NCI-H292 cells but absent in NCI-H441 cells. In NCI-H292 cells, SP-D activated SH2 domain-containing tyrosine phosphatase-1 (SHP-1), downstream of SIRPα, and knockdown of SIRPα abolished the suppressive effects of SP-D on BaP-induced ERK phosphorylation and MUC5AC production. Consistent with these in vitro findings, intratracheal instillation of SP-D prevented the BaP-induced phosphorylation of ERK and Muc5ac expression in airway epithelial cells in a mouse model. SP-D acts directly on airway epithelial cells to inhibit mucin secretion through ligation of SIRPα and SHP-1-mediated dephosphorylation of ERK. Targeting of SIRPα is therefore a potential new therapeutic approach to suppression of mucin hypersecretion in chronic airway diseases such as COPD and asthma.
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Asma , Doença Pulmonar Obstrutiva Crônica , Animais , Humanos , Camundongos , Células Epiteliais/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Células Caliciformes/metabolismo , Mucina-5AC/genética , Mucinas , Proteína D Associada a Surfactante PulmonarRESUMO
This case study of a patient with BOS after HSCT found increased ST2+CD64+ macrophages in BALF, a potential therapeutic target for treatment-refractory BOS, and reduced CCR2+CD14+ monocytes compared to other lung disorders https://bit.ly/406Uyy9.
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BACKGROUND: Damage-associated molecular pattern (DAMP)-related immunogenic cell death triggers secondary adaptive immune responses. The relationship between DAMP levels and prognosis in patients with non-small cell lung cancer (NSCLC) who undergo a combination therapy of immune checkpoint inhibitors (ICI) and chemotherapy remains unclear. METHODS: Serial plasma samples were prospectively collected from 45 patients treated with ICI combination therapy for advanced NSCLC. Plasma concentrations of high-mobility group box 1 (HMGB1), calreticulin (CRT), annexin A1, and heat shock protein 70 were measured. Associations between increases in plasma DAMP levels and the efficacy of the ICI combination therapy were evaluated. RESULTS: The maximum fold changes in plasma levels differed across individuals but demonstrated a marked increase, especially for CRT (mean ± SEM, 11.61 ± 46.15). Increased plasma DAMP levels were not clearly associated with clinical responses. There was a significant correlation between the maximum fold change in CRT levels and progression-free survival (PFS; r = 0.49, P < 0.001). Median PFS and overall survival (OS) rates were higher in patients with a ≥ 2-fold increase in plasma CRT levels than in those with a < 2-fold increase (PFS, 14.9 versus 6.0 months, hazard ratio (HR), 0.58; P = 0.17; OS, not reached versus 21.6 months, HR, 0.31, P = 0.02). CONCLUSIONS: Plasma CRT level monitoring has the potential to predict the efficacy of ICI combination therapy and shed light on the mechanisms underlying DAMP-related immunogenic cell death.
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Antineoplásicos Imunológicos , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Inibidores de Checkpoint Imunológico/uso terapêutico , Calreticulina/uso terapêutico , Antineoplásicos Imunológicos/uso terapêutico , Biomarcadores Tumorais , PrognósticoRESUMO
Immune cells have been implicated in interstitial lung diseases (ILDs), although their phenotypes and effector mechanisms remain poorly understood. To better understand these cells, we conducted an exploratory mass cytometry analysis of immune cell subsets in bronchoalveolar lavage fluid (BALF) from patients with idiopathic pulmonary fibrosis (IPF), connective-tissue disease (CTD)-related ILD, and sarcoidosis, using two panels including 64 markers. Among myeloid cells, we observed the expansion of CD14+ CD36hi CD84hiCCR2- monocyte populations in IPF. These CD14+ CD36hi CD84hi CCR2- subsets were also increased in ILDs with a progressive phenotype, particularly in a case of acute exacerbation (AEx) of IPF. Analysis of B cells revealed the presence of cells at various stages of differentiation in BALF, with a higher percentage of IgG memory B cells in CTD-ILDs and a trend toward more FCRL5+ B cells. These FCRL5+ B cells were also present in the patient with AEx-IPF and sarcoidosis with advanced lung lesions. Among T cells, we found increased levels of IL-2R+ TIGIT+ LAG3+ CD4+ T cells in IPF, increased levels of CXCR3+ CD226+ CD4+ T cells in sarcoidosis, and increased levels of PD1+ TIGIT+ CD57+ CD8+ T cells in CTD-ILDs. Together, these findings underscore the diverse immunopathogenesis of ILDs.
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Doenças do Tecido Conjuntivo , Fibrose Pulmonar Idiopática , Doenças Pulmonares Intersticiais , Sarcoidose , Humanos , Líquido da Lavagem Broncoalveolar , Linfócitos T CD8-Positivos/patologia , Fibrose Pulmonar Idiopática/patologia , Doenças Pulmonares Intersticiais/patologia , Família de Moléculas de Sinalização da Ativação LinfocitáriaRESUMO
To date, various immobilized chiral stationary phases (CSPs) have been developed. The immobilized CSPs have opened up possibilities not only maintaining the high chiral recognition abilities as well as corresponding coated ones but also affording high durability to various mobile phase. This report directed to investigate enantioseparation of recently launched four immobilized CSPs with cellulose and amylose backbones under normal phase liquid chromatography conditions. Their chiral recognition abilities were compared with previously developed six immobilized CSPs. Particularly, we focused on the complementarity for chiral recognitions. Among them, amylose tris(3-chloro-5-methylphenylcarbamate) CSP, namely, CHIRALPAK IG, showed notable chiral recognition abilities to various racemates. As expected, the investigated immobilized CSPs represented remarkable durability to wide range of mobile phases, whereas the corresponding coated CSPs could not be run due to the irreversible degradation. Taking advantage of unrestricted solvent compatibility, chiral separation selectivities were improved for some racemates.
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Amilose , Fenilcarbamatos , Amilose/química , Benzoatos , Celulose/química , Cromatografia Líquida de Alta Pressão/métodos , Fenilcarbamatos/química , EstereoisomerismoRESUMO
Immune-checkpoint inhibitors (ICIs) targeting cytotoxic T-lymphocyte antigen 4 (CTLA-4), programmed cell death-1 (PD-1), and programmed cell death-1-ligand 1 (PD-L1) have become new treatment options for various malignancies. ICIs bind to immune-checkpoint inhibitory receptors or to the foregoing ligands and block inhibitory signals to release the brakes on the immune system, thereby enhancing immune anti-tumor responses. On the other hand, unlike conventional chemotherapies, ICIs can cause specific side effects, called immune-related adverse events (irAEs). These toxicities may affect various organs, including the lungs. ICI-related pneumonitis (ICI-pneumonitis) is not the most frequent adverse event, but it is serious and can be fatal. In this review, we summarize recent findings regarding ICI-pneumonitis, with a focus on potential pathogenesis and treatment.
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Sarcoidosis is a systemic, granulomatous disease caused by unknown immunological abnormalities. The organs most vulnerable to sarcoidosis are the lungs. Patients often resolve spontaneously, but the lungs can also be severely affected. Although details regarding prognostic factors in sarcoidosis patients with lung involvement remain unclear, several reports have suggested that immune checkpoint molecules are involved in the pathogenesis of sarcoidosis. In this study, we divided sarcoidosis patients into two groups based on chest computed tomography (CT) findings and compared immune checkpoint molecules expressed on T cells in bronchoalveolar lavage fluid (BALF) in the two groups, using flow cytometry. We found elevated programmed cell death 1 (PD-1) or T cell immunoglobulin- and mucin-domain-containing molecule-3 (TIM-3) expression on T cells in BALF in patients with spontaneous improvement in CT findings, compared with those in patients without improvement in CT findings. In conclusion, our study implies that PD-1 or TIM-3 expression on T cells in BALF may be a prognostic factor for pulmonary lesions in sarcoidosis.
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BACKGROUND: Immunogenic cell death (ICD) characterized by the release of damage-associated molecular patterns (DAMPs) from dying cancer cells may contribute to the synergistic antitumor effect of cytotoxic chemotherapy combined with an immune checkpoint inhibitor. The kinetics of circulating DAMP levels in cancer patients have remained largely uncharacterized, however. METHODS: We evaluated the possible effects of various systemic anticancer therapy modalities on the kinetics of plasma DAMP concentrations in a prospective observational study of patients with advanced lung cancer. The plasma concentrations of high-mobility group box 1 (HMGB1), calreticulin (CRT), heat shock protein 70 (HSP70), annexin A1, and histone H3 were thus determined in 121 such patients at four time points during the first cycle of treatment. RESULTS: The mean of the maximum fold change in HMGB1, HSP70, or annexin A1 concentration observed during treatment was significantly greater than the corresponding baseline value (P<0.005). The maximum fold changes in HMGB1 and CRT concentrations tended to be associated with clinical response as evaluated by RECIST criteria, although the changes in the levels of these two DAMPs were not correlated, suggestive of differential induction mechanisms. Among the various treatment modalities administered, platinum-based combination or single-agent chemotherapy tended to elicit robust increases in the concentrations of HMGB1 and CRT. CONCLUSIONS: Serial monitoring of plasma revealed that systemic anticancer therapy increased the circulating levels of HMGB1 and CRT and that these changes tended to be associated with clinical response, suggesting that agents capable of releasing these DAMPs into plasma might induce ICD in advanced lung cancer patients.
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An asymptomatic 47-year-old woman was admitted with pleural effusion and pulmonary infiltrates 1 month after ingesting raw wild boar and deer meat. Both her blood and pleural fluid were eosinophilic. Thoracoscopy revealed multiple nodules of the pleura, and biopsy samples of the nodules showed necrosis with epithelioid cell granulomas. An enzyme-linked immunosorbent assay was positive for antibodies against Paragonimus westermani, and the patient was successfully treated with praziquantel. This is the first reported case of pulmonary or pleuropulmonary paragonimiasis where several pleural nodules were observed. The detection of pleural nodules on thoracoscopy can contribute to the prompt and accurate diagnosis of paragonimiasis.
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Carne/parasitologia , Paragonimíase/patologia , Infecções Respiratórias/patologia , Animais , Cervos , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Pessoa de Meia-Idade , Paragonimíase/complicações , Paragonimíase/tratamento farmacológico , Paragonimus westermani , Pleura/parasitologia , Pleura/patologia , Derrame Pleural/etiologia , Praziquantel/uso terapêutico , Infecções Respiratórias/complicações , Infecções Respiratórias/tratamento farmacológico , Sus scrofa , ToracoscopiaRESUMO
INTRODUCTION: The use of multi-electrode arrays (MEA) in combination with human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) provides a promising method to predict comprehensive cardiotoxicity, including drug-induced QT prolongation and arrhythmia. We previously demonstrated that MEA in combination with hiPSC-CMs could provide a generalizable platform by using 7 reference drugs at 10 testing facilities. Using this approach, we evaluated responses to reference drugs that modulate a range of cardiac ion currents and have a range of arrhythmogenic effects. METHODS: We used the MEA system (MED64) and commercially available hiPSC-CMs (iCell cardiomyocytes) to evaluate drug effects on the beat rate, field potential duration (FPD), FPD corrected by Fridericia's formula (FPDc), and the incidence of arrhythmia-like waveforms. RESULTS: This assay detected the repolarization effects of Bay K8644, mibefradil, NS1643, levcromakalim, and ouabain; and the chronotropic effects of isoproterenol, ZD7288, and BaCl2. Chronotropy was also affected by K+ and Ca2+ current modulation. This system detected repolarization delays and the arrhythmogenic effects of quinidine, cisapride, thioridazine, astemizole, bepridil, and pimozide more sensitively than the established guinea pig papillary muscle action potential assay. It also predicted clinical QT prolongation by drugs with multiple ion channel effects (fluoxetine, amiodarone, tolterodine, vanoxerine, alfuzosin, and ranolazine). DISCUSSION: MEA in combination with hiPSC-CMs may provide a powerful method to detect various cardiac electrophysiological effects, QT prolongation, and arrhythmia during drug discovery. However, the data require careful interpretation to predict chronotropic effects and arrhythmogenic effects of candidate drugs with multiple ion channel effects.
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Arritmias Cardíacas/induzido quimicamente , Cardiotoxinas/farmacologia , Frequência Cardíaca/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Canais Iônicos , Miócitos Cardíacos/efeitos dos fármacos , Arritmias Cardíacas/fisiopatologia , Cardiotônicos/farmacologia , Células Cultivadas , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos/métodos , Frequência Cardíaca/fisiologia , Humanos , Células-Tronco Pluripotentes Induzidas/fisiologia , Canais Iônicos/agonistas , Canais Iônicos/antagonistas & inibidores , Canais Iônicos/fisiologia , Miócitos Cardíacos/fisiologiaRESUMO
INTRODUCTION: Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are anticipated to be a useful tool for conducting proarrhythmia risk assessments of drug candidates. However, a torsadogenic risk prediction paradigm using hiPSC-CMs has not yet been fully established. METHODS: Extracellular field potentials (FPs) were recorded from hiPSC-CMs using the multi-electrode array (MEA) system. The effects on FPs were evaluated with 60 drugs, including 57 with various clinical torsadogenic risks. Actual drug concentrations in medium were measured using the equilibrium dialysis method with a Rapid Equilibrium Dialysis device. Relative torsade de pointes (TdP) scores were determined for each drug according to the degree of FP duration prolongation and early afterdepolarization occurrence. The margins were calculated from the free concentration in medium and free effective therapeutic plasma concentration. Each drug's results were plotted on a two-dimensional map of relative TdP risk scores versus margins. RESULTS: Each drug was categorised as high, intermediate, or low risk based on its location within predefined areas of the two-dimensional map. We categorised 19 drugs as high risk; 18 as intermediate risk; and 17 as low risk. We examined the concordance between our categorisation of high and low risk drugs against the torsadogenic risk categorisation in CredibleMeds®. Our system demonstrated high concordance, as reflected in a sensitivity of 81%, specificity of 87%, and accuracy of 83%. DISCUSSION: These results indicate that our torsadogenic risk assessment is reliable and has a potential to replace the hERG assay for torsadogenic risk prediction, however, this system needs to be improved for the accurate of prediction of clinical TdP risk. Here, we propose a novel drug induced torsadogenic risk categorising system using hiPSC-CMs and the MEA system.
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Potenciais de Ação/efeitos dos fármacos , Cardiotoxinas/toxicidade , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Torsades de Pointes/induzido quimicamente , Potenciais de Ação/fisiologia , Células Cultivadas , Humanos , Células-Tronco Pluripotentes Induzidas/fisiologia , Miócitos Cardíacos/fisiologia , Medição de Risco , Torsades de Pointes/patologia , Torsades de Pointes/fisiopatologiaRESUMO
Recent increasing evidence suggests that the currently-used platforms in vitro IKr and APD, and/or in vivo QT assays are not fully predictive for TdP, and do not address potential arrhythmia (VT and/or VF) induced by diverse mechanisms of action. In addition, other cardiac safety liabilities such as functional dysfunction of excitation-contraction coupling (contractility) and structural damage (morphological damage to cardiomyocytes) are also major causes of drug attrition, but current in vitro assays do not cover all these liabilities. We organized the Consortium for Safety Assessment using Human iPS cells (CSAHi; http://csahi.org/en/), based on the Japan Pharmaceutical Manufacturers Association (JPMA), to verify the application of human iPS/ES cell-derived cardiomyocytes in drug safety evaluation. The main goal of the CSAHi HEART team has been to propose comprehensive screening strategies to predict a diverse range of cardiotoxicities by using recently introduced platforms (multi-electrode array (MEA), patch clamp, cellular impedance, motion field imaging [MFI], and Ca transient systems) while identifying the strengths and weaknesses of each. Our study shows that hiPS-CMs used in these platforms have pharmacological responses more relevant to humans in comparison with existent hERG, APD or Langendorff (MAPD/contraction) assays, and not only MEA but also other methods such as impedance, MFI, and Ca transient systems would offer paradigm changes of platforms for predicting drug-induced QT risk and/or arrhythmia or contractile dysfunctions. Furthermore, we propose a potential multi-parametric platform in which field potential (MEA)-Ca transient-contraction (MFI) could be evaluated simultaneously as an ideal novel platform for predicting a diversity of cardiac toxicities, namely whole effects on the excitation-contraction cascade.
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Potenciais de Ação/efeitos dos fármacos , Arritmias Cardíacas/induzido quimicamente , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Modelos Cardiovasculares , Miócitos Cardíacos/efeitos dos fármacos , Cardiotoxicidade , Técnicas de Cultura de Células , Células Cultivadas , Relação Dose-Resposta a Droga , Humanos , Células-Tronco Pluripotentes Induzidas/fisiologia , Microeletrodos , Miócitos Cardíacos/fisiologia , Preparações Farmacêuticas/administração & dosagemRESUMO
The aims of this study were to (1) characterize basic electrophysiological elements of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) that correspond to clinical properties such as QT-RR relationship, (2) determine the applicability of QT correction and analysis methods, and (3) determine if and how these in-vitro parameters could be used in risk assessment for adverse drug-induced effects such as Torsades de pointes (TdP). Field potential recordings were obtained from commercially available hiPSC-CMs using multi-electrode array (MEA) platform with and without ion channel antagonists in the recording solution. Under control conditions, MEA-measured interspike interval and field potential duration (FPD) ranged widely from 1049 to 1635 ms and from 334 to 527 ms, respectively and provided positive linear regression coefficients similar to native QT-RR plots obtained from human electrocardiogram (ECG) analyses in the ongoing cardiovascular-based Framingham Heart Study. Similar to minimizing the effect of heart rate on the QT interval, Fridericia's and Bazett's corrections reduced the influence of beat rate on hiPSC-CM FPD. In the presence of E-4031 and cisapride, inhibitors of the rapid delayed rectifier potassium current, hiPSC-CMs showed reverse use-dependent FPD prolongation. Categorical analysis, which is usually applied to clinical QT studies, was applicable to hiPSC-CMs for evaluating torsadogenic risks with FPD and/or corrected FPD. Together, this results of this study links hiPSC-CM electrophysiological endpoints to native ECG endpoints, demonstrates the appropriateness of clinical analytical practices as applied to hiPSC-CMs, and suggests that hiPSC-CMs are a reliable models for assessing the arrhythmogenic potential of drug candidates in human.
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Cromanos/farmacologia , Cisaprida/farmacologia , Células-Tronco Pluripotentes Induzidas/fisiologia , Miócitos Cardíacos/citologia , Piperidinas/farmacologia , Piridinas/farmacologia , Sulfonamidas/farmacologia , Células Cultivadas , Fenômenos Eletrofisiológicos/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Modelos Lineares , Modelos Cardiovasculares , Torsades de Pointes/induzido quimicamente , Torsades de Pointes/fisiopatologiaRESUMO
ABA is a phytohormone that is synthesized in response to abiotic stresses and other environmental changes, inducing various physiological responses. While ABA has been found in unicellular photosynthetic organisms, such as cyanobacteria and eukaryotic algae, its function in these organisms is poorly understood. Here, we found that ABA accumulated in the unicellular red alga Cyanidioschyzon merolae under conditions of salt stress and that the cell cycle G1/S transition was inhibited when ABA was added to the culture medium. A gene encoding heme-scavenging tryptophan-rich sensory protein-related protein (CmTSPO; CMS231C) was positively regulated by ABA, as in Arabidopsis, and CmTSPO bound heme in vitro. The intracellular content of total heme was increased by addition of ABA, but unfettered heme decreased, presumably due to scavenging by CmTSPO. The inhibition of DNA replication by ABA was negated by addition of heme to the culture medium. Thus, we propose a regulatory role for ABA and heme in algal cell cycle initiation. Finally, we found that a C. merolae mutant that is defective in ABA production was more susceptible to salt stress, indicating the importance of ABA to stress resistance in red algae.
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Ácido Abscísico/metabolismo , Ciclo Celular , Homeostase , Fotossíntese , Reguladores de Crescimento de Plantas/metabolismo , Rodófitas/fisiologia , Replicação do DNA , Heme/metabolismo , Rodófitas/genéticaRESUMO
INTRODUCTION: Drug-induced QT prolongation is a major safety issue during drug development because it may lead to lethal ventricular arrhythmias. In this study, we evaluated the utility of multi-electrode arrays (MEA) with human induced pluripotent stem cell-derived cardiomyocytes (hiPS-CMs) to predict drug-induced QT prolongation and arrhythmia. METHODS: Ten facilities evaluated the effects of 7 reference drugs (E-4031, moxifloxacin, flecainide, terfenadine, chromanol 293B, verapamil, and aspirin) using a MED64 MEA system with commercially available hiPS-CMs. Field potential duration (FPD), beat rate, FPD corrected by Fridericia's formula (FPDc), concentration inducing FPDc prolongation by 10% (FPDc10), and incidence of arrhythmia-like waveform were evaluated. RESULTS: The inter-facility variability of absolute values before drug application was similar to the intra-facility variability for FPD, beat rate, and FPDc. The inter-facility variability of FPDc10 for 5 reference drugs ranged from 1.8- to 5.8-fold. At all 10 facilities, E-4031, moxifloxacin, and flecainide prolonged FPDc and induced arrhythmia-like waveforms at concentrations 1.8- to 6.1-fold higher than their FPDc10. Terfenadine prolonged FPDc and induced beating arrest at 8.0 times the FPDc10. The average FPDc10 values for E-4031, moxifloxacin, and terfenadine were comparable to reported plasma concentrations that caused QT prolongation or Torsade de Pointes in humans. Chromanol 293B, a IKs blocker, also prolonged FPDc but did not induce arrhythmia-like waveforms, even at 7.4 times the FPDc10. In contrast, verapamil shortened FPDc and aspirin did not affect FPDc or FP waveforms. DISCUSSION: MEA with hiPS-CMs can be a generalizable method for accurately predicting both QT prolongation and arrhythmogenic liability in humans.
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Arritmias Cardíacas/induzido quimicamente , Técnicas de Cultura de Células/métodos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Síndrome do QT Longo/induzido quimicamente , Miócitos Cardíacos/efeitos dos fármacos , Arritmias Cardíacas/diagnóstico , Congressos como Assunto , Criopreservação/métodos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/diagnóstico , Humanos , Células-Tronco Pluripotentes Induzidas/fisiologia , Síndrome do QT Longo/diagnóstico , Miócitos Cardíacos/fisiologia , Preparações Farmacêuticas/administração & dosagem , Valor Preditivo dos TestesRESUMO
INTRODUCTION: Multi-electrode array (MEA) systems and human induced pluripotent stem (iPS) cell-derived cardiomyocytes are frequently used to characterize the electrophysiological effects of drug candidates for the prediction of QT prolongation and proarrhythmic potential. However, the optimal experimental conditions for obtaining reliable experimental data, such as high-pass filter (HPF) frequency and cell plating density, remain to be determined. METHODS: Extracellular field potentials (FPs) were recorded from iPS cell-derived cardiomyocyte sheets by using the MED64 and MEA2100 multi-electrode array systems. Effects of HPF frequency (0.1 or 1Hz) on FP duration (FPD) were assessed in the presence and absence of moxifloxacin, terfenadine, and aspirin. The influence of cell density on FP characteristics recorded through a 0.1-Hz HPF was examined. The relationship between FP and action potential (AP) was elucidated by simultaneous recording of FP and AP using a membrane potential dye. RESULTS: Many of the FP waveforms recorded through a 1-Hz HPF were markedly deformed and appeared differentiated compared with those recorded through a 0.1-Hz HPF. The concentration-response curves for FPD in the presence of terfenadine reached a steady state at concentrations of 0.1 and 0.3µM when a 0.1-Hz HPF was used. In contrast, FPD decreased at a concentration of 0.3µM with a characteristic bell-shaped concentration-response curve when a 1-Hz HPF was used. The amplitude of the first and second peaks in the FP waveform increased with increasing cell plating density. The second peak of the FP waveform roughly coincided with AP signal at 50% repolarization, and the negative deflection at the second peak of the FP waveform in the presence of E-4031 corresponded to early afterdepolarization and triggered activity. DISCUSSION: FP can be used to assess the QT prolongation and proarrhythmic potential of drug candidates; however, experimental conditions such as HPF frequency are important for obtaining reliable data.
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Arritmias Cardíacas/induzido quimicamente , Células-Tronco Pluripotentes Induzidas/citologia , Síndrome do QT Longo/induzido quimicamente , Miócitos Cardíacos/efeitos dos fármacos , Potenciais de Ação/efeitos dos fármacos , Arritmias Cardíacas/diagnóstico , Aspirina/administração & dosagem , Aspirina/toxicidade , Relação Dose-Resposta a Droga , Fluoroquinolonas/administração & dosagem , Fluoroquinolonas/toxicidade , Humanos , Síndrome do QT Longo/diagnóstico , Moxifloxacina , Piperidinas/administração & dosagem , Piperidinas/toxicidade , Piridinas/administração & dosagem , Piridinas/toxicidade , Terfenadina/administração & dosagem , Terfenadina/toxicidadeRESUMO
To elucidate how the nylon oligomer hydrolase (NylB) acquires its peculiar degradation activity towards non-biological amide bonds, we inspected the underlying enzymatic processes going from the induced-fit upon substrate binding to acylation. Specifically we investigated the mutational effects of two mutants, Y170F and D181G, indicated in former experiments as crucial systems because of their specific amino acid residues. Therefore, by adopting first-principles molecular dynamics complemented with metadynamics we provide a detailed insight into the underlying acylation mechanism. Our results show that while in the wild type (WT) the Tyr170 residue points the NH group towards the proton-acceptor site of an artificial amide bond, hence ready to react, in the Y170F this does not occur. The reason is ascribed to the absence of Tyr170 in the mutant, which is replaced by phenylalanine, which is unable to form hydrogen bond with the amide bond; thus, resulting in an increase in the activation barrier of more than 10 kcal mol(-1). Nonetheless, despite the lack of hydrogen bonding between the Y170F and the substrate, the highest free energy barrier for the induced-fit is similar to that of WT. This seems to suggest that in the induced-fit process, kinetics is little affected by the mutation. On the basis of additional structural homology analyses on the enzymes of the same family, we suggest that natural selection is responsible for the development of the peculiar hydrolytic activity of Arthrobacter sp. KI72.
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Amidoidrolases/química , Acilação , Amidoidrolases/genética , Hidrólise , Modelos Moleculares , Simulação de Dinâmica Molecular , Mutação , Nylons/química , Conformação Proteica , Teoria Quântica , TermodinâmicaRESUMO
PURPOSE: Surgical site infections (SSI) are a common complication of gastrointestinal tract surgery. In this study, we explored the correlation between the anastomosis method and the incidence of SSI. METHODS: A total of 110 patients underwent ileocecal resection or right hemicolectomy for the excision of colon cancer. Two methods (open and closed, 28 and 82 patients, respectively) of functional end-to-end anastomosis were adopted. RESULTS: Increased perioperative blood loss (p = 0.029214), a longer hospital stay (p = 0.026668) and the development of SSI (p = 0.000181) were significantly correlated with the open method. There was no correlation between SSI and the body mass index, or between SSI and the length of the surgery or diabetes mellitus. However, patients that developed SSI tended to be obese. CONCLUSION: The open method was associated with a higher incidence of SSI. Therefore, it is necessary to consider potential contamination of the surgical field at the time of anastomosis to reduce the incidence of SSI.
Assuntos
Anastomose Cirúrgica/métodos , Neoplasias do Colo/cirurgia , Infecção da Ferida Cirúrgica/epidemiologia , Infecção da Ferida Cirúrgica/etiologia , Idoso , Anastomose Cirúrgica/instrumentação , Perda Sanguínea Cirúrgica/estatística & dados numéricos , Procedimentos Cirúrgicos do Sistema Digestório/métodos , Contaminação de Equipamentos/prevenção & controle , Feminino , Humanos , Incidência , Masculino , Obesidade , Estudos Retrospectivos , Infecção da Ferida Cirúrgica/prevenção & controleRESUMO
PURPOSE: To describe our initial experiences with the standardized introducer technique for percutaneous endoscopic gastrostomy and to compare clinical outcomes and complications with the pull technique. METHODS: The introducer technique was used on 91 patients. The clinical outcomes of procedures were retrospectively collected and compared with those of 22 patients who had procedures using the pull technique. RESULTS: Mean operation time was significantly longer in the introducer technique group as compared with the pull technique group. Increased inflammation markers (body temperature, white blood cell count, and C-reactive protein) were observed in the pull technique group as compared with the introducer technique group. Incidences of peristomal infection and pneumonia were lower in the introducer method group than in the pull method group. CONCLUSIONS: The introducer technique is a useful and safe method for percutaneous endoscopic gastrostomy in terms of reduced incidences of peristomal infection, pneumonia, pain, and discomfort.