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Dynamin-related protein 1 (DRP1) is an essential controller of mitochondrial fission whose activity is tightly controlled to ensure balanced mitochondrial dynamics and maintain internal cellular homeostasis. Growing evidence suggests that DRP1-dependent mitochondrial fission plays a role in drug-induced toxicity (DIT). Therefore, understanding the molecular mechanisms underlying DIT and the precise regulation of DRP1 function will inform the development of potential therapeutic treatments for DIT. This review comprehensively summarizes the diverse DITs and their potential mechanism associated with DRP1-dependent mitochondrial fission and discusses in vivo and in vitro model studies of toxicity protection targeting DRP1.
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Dinaminas , Dinâmica Mitocondrial , Dinâmica Mitocondrial/efeitos dos fármacos , Dinaminas/metabolismo , Humanos , Animais , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Efeitos Colaterais e Reações Adversas Relacionados a MedicamentosRESUMO
Breast cancer is the most commonly diagnosed malignancy and benefits from endocrine agents such as tamoxifen. However, the development of drug resistance in cancerous cells often leads to recurrence, thus limiting the therapeutic benefit. Identification of potential biomarkers that can predict response to tamoxifen and recognize patients who will clinically benefit from this therapy is urgently needed. In this study, we report that high collagen type XI alpha 1 (COL11A1) expression was associated with poor therapeutic response and prognosis in breast cancer patients treated with tamoxifen. To confirm the role of COL11A1 in the development of tamoxifen resistance, we established MCF-7/COL11A1 and T47D/COL11A1 cell lines, which stably expressed COL11A1. Compared with parental MCF-7 and T47D, MCF-7/COL11A1 and T47D/COL11A1 cells were more resistant to 4-OHT-induced growth inhibition. Moreover, the level of COL11A1 expression was upregulated in tamoxifen-resistant MCF-7/TamR and T47D/TamR cell lines, and depletion of COL11A1 markedly sensitized the cells to 4-OHT in vitro and in vivo. Interestingly, the level of estrogen receptor α (ERα) expression was elevated, probably due to the increased COL11A1 in TamR cells. In addition, knockdown of COL11A1 decreased the expression of ERα and its downstream target genes. Overall, our findings suggest that overexpressed COL11A1 contributes to tamoxifen resistance, and targeting COL11A1 holds great promise for reversing endocrine resistance.
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BACKGROUND AND OBJECTIVES: Although thromboembolic events (TEEs) have been reported with the use of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), their association remains largely unknown. In this study, we aimed to provide a comprehensive review of TEEs associated with EGFR-TKIs. METHODS: We collected EGFR-TKIs (gefitinib, erlotinib, afatinib, and osimertinib) adverse reaction reports from 2015 Q1 to 2023 Q1 from the US Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) database. Disproportionality analysis was conducted to identify thromboembolic adverse events associated with EGFR-TKIs by comparing them with the overall FAERS database according to the reporting odds ratio (ROR). Associated factors were explored using univariate logistic regression. RESULTS: We identified 1068 reports of TEEs associated with EGFR-TKIs (1.24% accounts for all TEEs). Affected patients were females (49.72%) and those older than 65 years (41.20%). The reported TEE case fatality was 30.24%. The median time to onset (TTO) of all cases was 39 days [interquartile range (IQR) 11-161], and the median TTO of fatalities [31 days (IQR 10-116)] was significantly shorter than that of non-fatal cases [46 days (IQR 12-186)]. CONCLUSION: This study yielded three key findings. Firstly, EGFR-TKIs seem to exhibit prothrombotic effects, elevating the risk of TEEs. Secondly, the clinical outcomes of TEEs associated with EGFR-TKIs were poor. Thirdly, most TEEs occurred within the initial 3 months, and fatal cases occurred earlier than non-fatal cases.
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Farmacovigilância , Feminino , Estados Unidos/epidemiologia , Humanos , Masculino , United States Food and Drug Administration , Afatinib , Receptores ErbB , Inibidores de Proteínas Quinases/efeitos adversosRESUMO
Tripterygium wilfordii Hook F (TwHF) has a long history of use as a traditional Chinese medicine and has been widely administered to treat various inflammatory and autoimmune diseases. MicroRNAs (miRNAs) are endogenous, short, non-coding RNAs that regulate gene expression post-transcriptionally. They participate in the efficacies and even toxicities of the components of TwHF, rendering miRNAs an appealing therapeutic strategy. This review summarizes the recent literature related to the roles and mechanisms of miRNAs in the pharmacological and toxicological effects of main components of TwHF, focusing on two active compounds, triptolide (TP) and celastrol (CEL). Additionally, the prospects for the "You Gu Wu Yun" theory regarding TwHF nephrotoxicity are presented.
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Medicamentos de Ervas Chinesas , MicroRNAs , Medicamentos de Ervas Chinesas/farmacologia , Tripterygium , Medicina Tradicional ChinesaRESUMO
Laser desorption ionization mass spectrometry (LDI-MS) aroused intensive concerns for the merits of label-free and high-throughput analysis. Here, we designed a silver nanoparticles (AgNP)-modified indium vanadate nanosheets with doping samarium (AgNP@InVO4:Sm) nanosheets. The developed AgNP@InVO4:Sm nanosheets (AIVON) were synthesized based on the microemulsion-mediated solvothermal method and ultraviolet-assisted in situ formation of AgNP, then for the first time applied as a matrix in LDI-MS analysis. With the advantages including enhanced MS signal, little matrix-related background, high reproducibility, and good salt tolerance, AIVON exhibited much better prospect than non-modified indium vanadate nanosheets with doping samarium (IVON) and traditional organic matrix, thus allowing sensitive MS detection for a wide range of low-molecular-weight (LMW) molecules. Moreover, by coupling with headspace sampling thin-film microextraction (TFME), a kind of representative pollutant chlorophenols were identified and quantified via AIVON-assisted LDI-MS in environmental and biological samples. Volatile LMW pollutants could be preconcentrated after TFME, hence a sensitive and rapid assay with negligible sample matrix effect was realized by using AIVON-assisted LDI-MS. It is anticipated that this novel nano-matrix AIVON and the proposed TFME coupling detection strategy were of competitive merits for LDI-MS analysis in the fields of environment, biomedicine, and agriculture.
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Poluentes Ambientais , Nanopartículas Metálicas , Vanadatos , Índio , Reprodutibilidade dos Testes , Samário , Prata , Espectrometria de Massas , Lasers , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
This study presents the first-ever synthesis of samarium-doped indium vanadate nanosheets (IVONSs:Sm) via microemulsion-mediated solvothermal method. The nanosheets were subsequently utilized as a nano-matrix in laser desorption/ionization mass spectrometry (LDI-MS). It was discovered that the as-synthesized IVONSs:Sm possessed the following advantages: improved mass spectrometry signal, minimal matrix-related background, and exceptional stability in negative-ion mode. These qualities overcame the limitations of conventional matrices and enabled the sensitive detection of small biomolecules such as fatty acids. The negative-ion LDI mechanism of IVONSs:Sm was examined through the implementation of density functional theory simulation. Using IVONSs:Sm-assisted LDI-MS, fingerprint recognitions based on morphology and chemical profiles of endogenous/exogenous compounds were also achieved. Notably, crucial characteristics such as the age of an individual's fingerprints and their physical state could be assessed through the longitudinal monitoring of particular biomolecules (e.g., ascorbic acid, fatty acid) or the specific biomarker bilirubin glucuronide. Critical information pertinent to the identification of an individual would thus be facilitated by the analysis of the compounds underlying the fingerprint patterns.
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Índio , Vanadatos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Ácidos Graxos , LasersRESUMO
As an integral organelle in the eukaryote, the lysosome is the degradation center and metabolic signal center in living cells, and partakes in significant physiological processes such as autophagy, cell death and cellular senescence. Fluorescent probe has become a favorite tool for studying organelles and their chemical microenvironments because of its high specificity and non-destructive merits. Over recent years, it has been reported that increasingly new lysosome-targeted probes play a major role in the diagnosis and monitor of diseases, in particular cancer and neurodegenerative diseases. In order to deepen the relevant research on lysosome, it is challenging and inevitability to design novel lysosomal targeting probes. This review first introduces the concepts of lysosome and its closely related biological activities, and then introduces the fluorescent probes for lysosome in detail according to different detection targets, including targeting mechanism, biological imaging, and application in diseases. Finally, we summarize the specific challenges and discuss the future development direction facing the current lysosome-targeted fluorescent probes. We hope that this review can help biologists grasp the application of fluorescent probes and broaden the research ideas of researchers targeting fluorescent probes so as to design more accurate and functional probes for application in diseases.
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Corantes Fluorescentes , Lisossomos , Autofagia , Morte CelularRESUMO
With the continuous cognition of the relationship between tumor cells and tumor immune microenvironment, immunotherapy based on the immune checkpoint blockade has achieved great breakthroughs, led to improved clinical outcomes, and prolonged survival for cancer patients in recent years. Nevertheless, the de novo or acquired resistance to immunotherapy has greatly counteracted the efficacy, leading to a 20%-40% overall response rate. Thus, further in-depth understanding of the regulation of the tumor microenvironment and antitumor immunity is urgently warranted. Ubiquitination-mediated protein degradation plays vital roles in protein stabilization, activation, and dynamics as well as in cellular homeostasis modulation. The dysregulated ubiquitination and deubiquitination are closely related to the changes in physiological and pathological processes, which subsequently result in a variety of diseases including cancer. In this review, the authors first summarize the current knowledge about the involvement of the ubiquitin-proteasome system in tumor development with the ubiquitin conjugation-regulated stability of p53, phosphatase and tensin homolog, and Myc protein as examples, then dissect the potential implications of ubiquitination-mediated immune checkpoints degradation in tumor microenvironment and immune responses, and finally discuss the effects of therapeutically targeting the ubiquitin-proteasome pathway on immunotherapy, with the goal of providing deep insights into the exploitation of more precise and effective combinational therapy against cancer.
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Neoplasias , Ubiquitina , Humanos , Ubiquitina/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Imunoterapia , Ubiquitinação , Neoplasias/patologia , Microambiente TumoralRESUMO
Purpose: Parathyroid hormone (PTH) can induce the downregulation of CYP3A in chronic kidney disease (CKD). Nevertheless, the effect of PTH on CYP3A-mediated clearance pathways from a clinical perspective remains unclear. Methods: This study employed population pharmacokinetic (PopPK) modeling to delineate potential changes in CYP3A activity in patients with CKD. Pharmacokinetic data for nifedipine, a typical CYP3A substrate, as well as covariate information, were prospectively collected from 157 patients with a total of 612 concentrations. PopPK data analysis was performed using a nonlinear mixed-effects model. Results: The pharmacokinetics of nifedipine were optimally described according to a one-compartment model with zero-order absorption and first-order elimination. The estimated population parameters (and interindividual variability) were apparent clearance (CL/F) 49.61 L/h (58.33%) and apparent volume of distribution (V/F) 2300.26 L (45.62%), and the PTH level negatively correlated with CL/F. In comparison with the reference level, it was observed that the dosage of nifedipine should be reduced with the maximum boundary value of PTH, after a Monte Carlo simulation. Conclusion: This study provides insight into the effects of PTH on CYP3A-mediated clearance pathways. Moreover, PTH could be used as a guide for the appropriate administration of CYP3A eliminated drugs in patients with CKD.
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Citocromo P-450 CYP3A , Insuficiência Renal Crônica , Citocromo P-450 CYP3A/metabolismo , Humanos , Modelos Biológicos , Nifedipino , Hormônio Paratireóideo , Insuficiência Renal Crônica/tratamento farmacológicoRESUMO
The simultaneous analysis of diversified biomarkers with high sensitivity and in a point-of-care (POC) manner is of great significance for facile and early cancer diagnosis. Herein, we develop a target amplification-assisted ratiometric fluorescence assay (TARFA) platform integrating the dual-amplification strategy and colorimetric readout technology for sensitive and specific detection of two malignancy-associated biomarkers. Meanwhile, the NIR-excited alkaline-earth sulfide nanodots (ASNDs) with an ultrasmall (<10 nm) diameter and tunable emission wavelength are employed to replace commonly UV/visible light-excited fluorescent labels to minimize background interference from the sample matrix. Unique advantages of the ASNDs, together with superiority of consecutive signal amplification of enzymatic target recycling (ETR) and hybridization chain reaction (HCR), realize the pg/mL-range detection limit in specifically recognizing the vascular endothelial growth factor (VEGF) and soluble interleukin-6 receptors (sIL-6R). The combination detection of the dual analyte exhibits an improved sensitivity for cancer diagnosis. The addition of the target biomarkers leads to an increasingly ratiometric RGB signal, and quantification based on the ratio-dependent signal is more reliable rather than measuring the absolute RGB signals. Moreover, perceptible color transformation makes the TARFA platform competent for visual analysis of the target analytes as convenient as reading the pH indicator strip, and hue-based image analysis also improves the method with fine precision by quantitatively identifying the visual color. This work provides a new kind of NIR-excited aptasensing platform with a low detection limit, high throughput, and great portability, which also highlights the potential of the ASNDs in biomolecular fluorescent labeling.
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Técnicas Biossensoriais , Neoplasias , Biomarcadores Tumorais , Corantes , Humanos , Limite de Detecção , Neoplasias/diagnóstico , Hibridização de Ácido Nucleico , Fator A de Crescimento do Endotélio VascularRESUMO
Nasopharyngeal carcinoma (NPC) is a kind of malignancy generated from the nasopharyngeal epithelium. Recently, long noncoding RNA (lncRNA) has been shown to be involved in the regulation of many signaling pathways and is closely associated with carcinogenesis and tumor progression. However, the precise role of lncRNA Opa-interacting protein 5 antisense RNA 1 (OIP5-AS1) in NPC is not well understood. Here, we find that OIP5-AS1 is overexpressed in NPC patient specimens and NPC cell lines. Further investigations reveal that knockdown of OIP5-AS1 significantly inhibits the proliferation, migration, and invasion and accelerates the apoptosis of NPC cells in vitro. Consistent with these findings, NPC progression is significantly slowed in mice when OIP5-AS1 is knocked down. Interestingly, there is a functional link between OIP5-AS1 and microRNA-203 (miR-203), a tumor suppressor, in NPC cells. In conclusion, our data demonstrate that OIP5-AS1 plays an important role in the development and progression of NPC by targeting miR-203 and therefore provide a promising target for the treatment of NPC.
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Regulação Neoplásica da Expressão Gênica , MicroRNAs/biossíntese , Carcinoma Nasofaríngeo/metabolismo , Neoplasias Nasofaríngeas/metabolismo , RNA Longo não Codificante/biossíntese , RNA Neoplásico/biossíntese , Animais , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , MicroRNAs/genética , Carcinoma Nasofaríngeo/genética , Carcinoma Nasofaríngeo/patologia , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/patologia , RNA Longo não Codificante/genética , RNA Neoplásico/genéticaRESUMO
BACKGROUND: Diabetic nephropathy serves as one of the most regular microvascular complications of diabetes mellitus and is the main factor that causes end-stage renal disease and incident mortality. As the beneficial effect and minute adverse influence of Celastrol on the renal system requires further elucidation, the renoprotective function of Celastrol in early diabetic nephropathy was investigated. METHODS: In high-fat and high-glucose diet/streptozotocin-induced diabetic rats which is the early diabetic nephropathy model, ALT, AST, 24 h urinary protein, blood urea nitrogen, and serum creatinine content were observed. Periodic acid-Schiff staining, enzyme-linked immunosorbent assay, immunohistochemical analysis, reverse transcription-polymerase chain reaction, and western blot analysis were used to explore the renoprotective effect of Celastrol to diabetic nephropathy rats and the underlying mechanism. RESULTS: High dose of Celastrol (1.5 mg/kg/d) not only improved the kidney function of diabetic nephropathy (DN) rats, and decreased the blood glucose and 24 h urinary albumin, but also increased the expression of LC3II and nephrin, and downregulated the expression of PI3K, p-AKT, and the mRNA level of NF-κB and mTOR. CONCLUSION: Celastrol functions as a potential therapeutic substance, acting via the PI3K/AKT pathway to attenuate renal injury, inhibit glomerular basement membrane thickening, and achieve podocyte homeostasis in diabetic nephropathy.
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Diabetes Mellitus Experimental/tratamento farmacológico , Nefropatias Diabéticas/tratamento farmacológico , Triterpenos Pentacíclicos/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Modelos Animais de Doenças , Glomérulos Renais/efeitos dos fármacos , Masculino , Estrutura Molecular , Triterpenos Pentacíclicos/química , Podócitos/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , EstreptozocinaRESUMO
To thoroughly evaluate the quality of Citri Sarcodactylis Fructus (CSF) and acquire knowledge of the lipophilic components of CSF from different origins, a simple and efficient approach based on supercritical fluid extraction (SFE) combined with ultraperformance liquid chromatography plus Q-Exactive Orbitrap tandem mass spectrometry (UPLC-Q-Exactive Orbitrap/MS) detection for the discrimination of components from CSF was set up for the first time in this work. Eight batches of CSF samples from five main producing areas were extracted by SFE under optimized conditions, and then SFE extracts were dissected via UPLC-Q-Exactive Orbitrap/MS. The results indicated that 39 lipophilic compounds were successfully separated and unambiguously or tentatively identified, where 4 coumarins, 6 polymethoxyflavones, 3 phthalides, 6 terpenes, and 4 phenolics were not reported formerly. It was illustrated that CSF may be abundant in polymethoxyflavones, as in coumarins. Moreover, there were significant differences in the components of CSF from different origins. Especially, coumarin, dehydrocostus lactone, atractylenolide II, and atractylenolide I were exclusively found in CSF from the Guangdong province; isopsoralen was almost exclusively found in CSF from the Guangxi province; and ferulic acid was exclusively found in CSF from the Zhejiang province. These observations indicated that SFE joint with UPLC-Q-Exactive Orbitrap/MS owing to the potential of characterizing the lipophilic components could be used to promote quality assessment and chemotaxonomic investigation in phytology sciences of CSF.
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PURPOSE: (R,R)-penehyclidine fumarate (R2PHF) is a highly selective muscarinic receptor antagonist used to suppress glandular secretions before general anesthesia or tracheal intubation and to treat organophosphorus poisoning. This is the first-in-human study to evaluate the safety, tolerability, and pharmacokinetics of R2PHF in healthy subjects. MATERIALS AND METHODS: In this single-center, double-blind, randomized study, 23 subjects received escalation doses of R2PHF (0.0625 mg, 0.25 mg, 0.50 mg, and 1.0 mg), 4 received the parent drug penehyclidine hydrochloride (PHC, 1.0 mg) as a reference, and 4 received a placebo. The pharmacokinetic parameters of R2PHF were determined. Tolerability was assessed based on adverse events and clinical laboratory tests. RESULTS: Single doses of 0.0625 mg, 0.25 mg, and 0.50 mg R2PHF were well-tolerated by healthy subjects. Delirium was set as the termination outcome and appeared in 1 case receiving 1.0 mg. For this reason, the escalation experiment was cut off. The mean half-life (T1/2) ranged from 30.57 to 32.27 hours. CONCLUSION: R2PHF was safe and well-tolerated at doses ranging from 0.0625 to 0.50 mg. A single administration of 0.50 mg was determined to be the maximum tolerated dose of R2PHF. Further pharmacodynamics, safety, and efficacy testing is required to advance R2PHF to the next stage of clinical development and application.
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Fumaratos/administração & dosagem , Antagonistas Muscarínicos/administração & dosagem , Quinuclidinas/administração & dosagem , Administração Oral , Adulto , Área Sob a Curva , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Fumaratos/farmacocinética , Humanos , Infusões Intravenosas , Masculino , Antagonistas Muscarínicos/farmacocinética , Quinuclidinas/farmacocinética , Adulto JovemRESUMO
Clopidogrel is an antiplatelet drug whose performance at a low dose (25 mg) have not been evaluated in Chinese patients, who may be subject to different effects from Caucasians. We carried out this evaluation and compared a generic (Taijia) and a reference drug (Plavix®). We evaluated Taijia and Plavix® in 128 subjects, with 64 in a fasted state and 64 receiving a high-fat diet, and computed Cmax, AUC0-∞, and AUC0-t. Reference-scaled average bioequivalence (RSABE) methods and average bioequivalence (ABE) methods were used, and adverse events were assessed. Average maximum plasma concentrations (Cmax) of clopidogrel were significantly greater after 25 mg dose under fed conditions compared to fasted. Reference-scaled Cmax, AUC0-t, and AUC0-∞ were higher than the 0.294 cutoff during fasted, meeting RSABE criteria. Under fed conditions, SWR for AUC0-t and AUC0-∞ were lower than 0.294, permitting use of ABE. The 90% confidence intervals for AUC0-t and AUC0-∞ indicated bioequivalence. Pharmacokinetic parameters differed between fasted and fed states. The generic product was bioequivalent to the reference drug, and was safe and well tolerated. This suggests that they can be used interchangeably in a clinical setting.
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Clopidogrel/farmacocinética , Dieta Hiperlipídica , Jejum , Inibidores da Agregação Plaquetária/farmacocinética , Administração Oral , Adolescente , Adulto , China , Clopidogrel/administração & dosagem , Clopidogrel/sangue , Relação Dose-Resposta a Droga , Feminino , Voluntários Saudáveis , Humanos , Masculino , Estrutura Molecular , Inibidores da Agregação Plaquetária/administração & dosagem , Inibidores da Agregação Plaquetária/sangue , Equivalência Terapêutica , Adulto JovemRESUMO
PURPOSE: To determine the pharmacokinetic properties of the common tablet of roflumilast administered in single and multiple oral doses in Chinese subjects. SUBJECTS AND METHODS: Both the single- and multiple-dose studies included 12 adults (6 males and 6 females). In this single-center, open-label study, single doses of 0.25, 0.375, and 0.5 mg were administered using a randomized, three-way crossover design, and then, the 0.375 mg dose was continued for 11 days once daily. The pharmacokinetic parameters for roflumilast and roflumilast N-oxide were determined and the safety evaluation included adverse events assessed by monitoring, physical examination, vital sign tests, and clinical laboratory tests. RESULTS: After every single dose, the time to the maximum concentration (C max) of roflumilast (T max) was 0.25-2.0 hours; thereafter, the concentration declined, with a mean half-life (t 1/2) of 19.7-20.9 hours over the range of 0.25-0.50 mg. As for roflumilast N-oxide, the mean t 1/2 was 23.2-26.2 hours. The area under curve from the beginning to 24 hours (AUC0-24 h), the AUC until infinity (AUCinf), and the C max of roflumilast and roflumilast N-oxide increased in a dose-proportional manner. After multiple doses, the accumulation index (Rac) on the 11th day of the steady state was ~1.63 for roflumilast and 3.20 for roflumilast N-oxide. No significant sex differences were observed in the pharmacokinetic parameters of roflumilast and roflumilast N-oxide. In addition, there were no serious adverse events across the trial. CONCLUSION: Roflumilast was safe and well-tolerated in healthy volunteers, and a linear increase in its C max and AUC values was observed at doses ranging from 0.25 to 0.50 mg.
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Aminopiridinas/farmacocinética , Benzamidas/farmacocinética , Adolescente , Adulto , Aminopiridinas/administração & dosagem , Aminopiridinas/química , Benzamidas/administração & dosagem , Benzamidas/química , China , Estudos Cross-Over , Ciclopropanos/administração & dosagem , Ciclopropanos/química , Ciclopropanos/farmacocinética , Relação Dose-Resposta a Droga , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Estrutura Molecular , Comprimidos , Adulto JovemRESUMO
Pyragrel is a novel thromboxane A2-synthetase inhibitor for the treatment of cerebral infarction, and it is currently being investigated in phase I clinical trials. This paper reports the first reliable LC-MS/MS method for the simultaneous determination of Pyragrel and its two main metabolites, M1 and M2, in human plasma. All analytes were extracted from human serum using liquid-phase extraction and separated on a Zorbax EcLipse XDB C18 column using isocratic elution with a mobile phase composed of methanol, water and formic acid (65:35:0.1, v/v/v). Determination of the analytes was achieved by tandem-mass spectrometry with positive electrospray ionization. The multiple reaction monitoring transitions under positive electrospray ionization were performed at m/z 329.0â¯ââ¯m/z 135.9 for Pyragrel, m/z 303.1â¯ââ¯m/z 135.0 for M1, m/z 331.2â¯ââ¯m/z 135.0 for M2, and 482.2â¯ââ¯m/z 258.0 for IS, respectively. The following parameters were validated: specificity, recovery, matrix effects, carry-over, linearity, sample stability under a variety of storage and handling conditions, and stock solution stability. The validated method has been successfully applied to an initial pharmacokinetic study in healthy volunteers following intravenous administrations of 60â¯mg of Pyragrel, and this method will facilitate further studies involving more comprehensive identification of the metabolic profile of Pyragrel and the appropriate dosage regimen.
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Fibrinolíticos/sangue , Pirazinas/sangue , Tromboxano-A Sintase/antagonistas & inibidores , Infarto Cerebral/tratamento farmacológico , Cromatografia Líquida de Alta Pressão/métodos , Ensaios Clínicos Fase I como Assunto , Feminino , Fibrinolíticos/farmacocinética , Fibrinolíticos/uso terapêutico , Voluntários Saudáveis , Humanos , Masculino , Pirazinas/farmacocinética , Pirazinas/uso terapêutico , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Fatores Sexuais , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodosRESUMO
The aim of this study is to explore the effect of timing of initiation of pulsed electromagnetic field (PEMF) therapy on bone mass, microarchitecture, and biomechanical properties, and to investigate receptor activator of NF-kB (RANK) expression in ovariectomized (OVX) rats. Sixty female Sprague-Dawley rats were randomly divided into two equal batches of three groups each (10 rats in each group). The first batch comprised of sham-operated (Sham-0 group), ovariectomized (OVX-0 group), and ovariectomized plus treated with PEMF starting from the day of OVX (Early PEMF group). The second batch comprised of sham-operated (Sham-12 group), ovariectomized (OVX-12 group), and ovariectomized plus treated with PEMF starting 12 weeks after OVX (Late PEMF group). Rats (whole body) in the early and late PEMF groups were exposed to PEMF (3.8 mT peak, 8 Hz pulse burst repetition rate). After 12 weeks of PEMF therapy, Early PEMF prevented OVX-induced deterioration in bone mineral density (BMD) and mechanical properties in lumbar vertebral body and femur, and deterioration in bone microarchitecture in lumbar vertebral body and proximal tibia. Late PEMF intervention only inhibited deterioration of BMD, bone microarchitecture, and mechanical properties in lumbar vertebral body. Both early and late PEMF therapy suppressed RANK protein expression in OVX rats without a concomitant effect on RANK mRNA expression. These results demonstrate that timing of initiation of PEMF therapy plays an important role in achieving optimal beneficial effects. The specific PEMF parameters may exert these favorable biological responses, at least partially, via inhibition of protein expression of RANK. Bioelectromagnetics. 38:456-465, 2017. © 2017 Wiley Periodicals, Inc.