RESUMO
The recent use of organophosphate nerve agents in Syria, Malaysia, Russia, and the United Kingdom has reinforced the potential threat of their intentional release. These agents act through their ability to inhibit human acetylcholinesterase (hAChE; E.C. 3.1.1.7), an enzyme vital for survival. The toxicity of hAChE inhibition via G-series nerve agents has been demonstrated to vary widely depending on the G-agent used. To gain insight into this issue, the structures of hAChE inhibited by tabun, sarin, cyclosarin, soman, and GP were obtained along with the inhibition kinetics for these agents. Through this information, the role of hAChE active site plasticity in agent selectivity is revealed. With reports indicating that the efficacy of reactivators can vary based on the nerve agent inhibiting hAChE, human recombinatorially expressed hAChE was utilized to define these variations for HI-6 among various G-agents. To identify the structural underpinnings of this phenomenon, the structures of tabun, sarin, and soman-inhibited hAChE in complex with HI-6 were determined. This revealed how the presence of G-agent adducts impacts reactivator access and placement within the active site. These insights will contribute toward a path of next-generation reactivators and an improved understanding of the innate issues with the current reactivators.
Assuntos
Acetilcolinesterase/metabolismo , Inibidores da Colinesterase/efeitos adversos , Agentes Neurotóxicos/efeitos adversos , Oximas/efeitos adversos , Compostos de Piridínio/efeitos adversos , Acetilcolinesterase/química , Acetilcolinesterase/isolamento & purificação , Inibidores da Colinesterase/química , Humanos , Estrutura Molecular , Agentes Neurotóxicos/química , Oximas/química , Compostos de Piridínio/químicaRESUMO
Although distigmine is known to sometimes cause severe adverse drug reactions (ADRs), such as cholinergic crisis, there are limited data on the risk factors for these ADRs. In this study, we defined a serum cholinesterase (sChE) cutoff level for early detection of ADRs to distigmine and sought to identify risk factors for these ADRs based on this value. This retrospective cohort study included all patients who were prescribed distigmine and underwent measurement of sChE over a period of 8 years at Kaetsu Hospital. Ninety-three patients were included. The sChE cutoff level below which there was an increase in risk of ADRs was defined as 129 U/L based on the levels in patients who had ADRs by receiver operating characteristic analysis. The percentage of ADRs tended to increase with advancing chronic kidney disease (CKD) stage. Multivariate logistic regression analyses showed that a distigmine dose >0.1 mg/kg/d (odds ratio 3.19, 95% confidence interval 1.24-8.19) and age >85 years (odds ratio 3.04, 95% confidence interval 1.18-7.82) were positively associated with an sChE level ≤129 U/L. An sChE cutoff level of 129 U/L is a useful predictor of the risk of an ADR to distigmine, and dose per body weight, age, and CKD progression may pose potential risk of an ADR to distigmine. Therefore, for patients taking distigmine who have these risk factors, the risk of a severe ADR to distigmine can be reduced by decreasing the dose of distigmine and close monitoring of the sChE level.
Assuntos
Inibidores da Colinesterase/efeitos adversos , Compostos de Piridínio/efeitos adversos , Insuficiência Renal Crônica/complicações , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Colinesterases/sangue , Relação Dose-Resposta a Droga , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de RiscoRESUMO
A 54-year-old female experienced rapid respiratory failure while being transported in an ambulance to our emergency department for evaluation and management of constipation and abdominal pain. The patient was on treatment with distigmine bromide for postoperative urination disorder and magnesium oxide for constipation. Increased salivary secretions, diminished respiratory excursion, type 2 respiratory failure (PaCO2 : 65 mmHg), low serum cholinesterase, and hypermagnesemia were detected. Imaging studies revealed that the patient had bilateral aspiration pneumonia, fecal impaction in the rectum, and a distended colon causing ileus. The patient was mechanically ventilated and was weaned off the ventilator on day 3. Therapeutic drug monitoring after discharge revealed that the serum level of distigmine bromide on admission was markedly elevated (377.8 ng/mL vs. the normal therapeutic level of 5-10 ng/mL). Distigmine bromide induced a cholinergic crisis with a resultant increase in airway secretions and respiratory failure. In this particular case, orally administered distigmine bromide was excessively absorbed because of prolonged intestinal transit time secondary to fecal impaction and sluggish bowel movement; this caused a cholinergic crisis and hypermagnesemia contributing to respiratory failure. Clinicians should be aware that bowel obstruction in a patient treated with distigmine bromide can increase the risk of a cholinergic crisis.
Assuntos
Inibidores da Colinesterase/efeitos adversos , Colinesterases/sangue , Íleus/complicações , Compostos de Piridínio/efeitos adversos , Insuficiência Respiratória/etiologia , Administração Oral , Inibidores da Colinesterase/administração & dosagem , Feminino , Humanos , Absorção Intestinal , Óxido de Magnésio/efeitos adversos , Óxido de Magnésio/sangue , Óxido de Magnésio/metabolismo , Pessoa de Meia-Idade , Compostos de Piridínio/administração & dosagem , Compostos de Piridínio/metabolismoRESUMO
PURPOSE: Low molecular weight cyclin E (LMW-E) isoforms, overexpressed in a majority (~70 %) of triple-negative breast cancers (TNBC), were found in preclinical models to mediate tumorigenesis through binding and activation of CDK2. CDK1/CDK2 inhibitors, such as dinaciclib, combined with anthracyclines, were synergistic in decreasing viability of TNBC cell lines. Based on this data, a phase 1 study was conducted to determine the maximum tolerated dose of dinaciclib in combination with epirubicin in patients with metastatic TNBC. METHODS: Cohorts of at least 2 patients were treated with escalating doses of dinaciclib given on day 1 followed by standard dose of epirubicin given on day 2 of a 21 day cycle. No intra-patient dose escalation was allowed. An adaptive accrual design based upon toxicity during cycle 1 determined entry into therapy cohorts. The target acceptable dose limiting toxicity (DLT) to advance to the next treatment level was 30 %. RESULTS: Between 9/18/2012 and 7/18/2013, 9 patients were enrolled and treated at MD Anderson Cancer Center. DLTs included febrile neutropenia (grade 3, n = 2), syncope (grade 3, n = 2) and vomiting (grade 3, n = 1). Dose escalation did not proceed past the second cohort due to toxicity. After further accrual, the first dose level was also found to be too toxic. No treatment responses were noted, median time to progression was 5.5 weeks (range 3-12 weeks). Thus, accrual was stopped rather than explore the -1 dose level. CONCLUSION: The combination of dinaciclib and epirubicin is associated with substantial toxicities and does not appear to be an effective treatment option for TNBC.
Assuntos
Antibióticos Antineoplásicos/uso terapêutico , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Epirubicina/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Compostos de Piridínio/uso terapêutico , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Adulto , Idoso , Antibióticos Antineoplásicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Compostos Bicíclicos Heterocíclicos com Pontes/efeitos adversos , Óxidos N-Cíclicos , Quinases Ciclina-Dependentes/antagonistas & inibidores , Epirubicina/efeitos adversos , Feminino , Humanos , Indolizinas , Dose Máxima Tolerável , Pessoa de Meia-Idade , Inibidores de Proteínas Quinases/efeitos adversos , Compostos de Piridínio/efeitos adversos , Resultado do TratamentoAssuntos
Anticorpos Monoclonais/administração & dosagem , Compostos Bicíclicos Heterocíclicos com Pontes/administração & dosagem , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Compostos de Piridínio/administração & dosagem , Idoso , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais Humanizados , Compostos Bicíclicos Heterocíclicos com Pontes/efeitos adversos , Óxidos N-Cíclicos , Feminino , Humanos , Indolizinas , Leucemia Linfocítica Crônica de Células B/mortalidade , Masculino , Pessoa de Meia-Idade , Compostos de Piridínio/efeitos adversos , RecidivaRESUMO
The currently fielded pre-hospital therapeutic regimen for the treatment of organophosphorus (OP) poisoning in the United States (U.S.) is the administration of atropine in combination with an oxime antidote (2-PAM Cl) to reactivate inhibited acetylcholinesterase (AChE). Depending on clinical symptoms, an anticonvulsant, e.g., diazepam, may also be administered. Unfortunately, 2-PAM Cl does not offer sufficient protection across the range of OP threat agents, and there is some question as to whether it is the most effective oxime compound available. The objective of the present study is to identify an oxime antidote, under standardized and comparable conditions, that offers protection at the FDA approved human equivalent dose (HED) of 2-PAM Cl against tabun (GA), sarin (GB), soman (GD), cyclosarin (GF), and VX, and the pesticides paraoxon, chlorpyrifos oxon, and phorate oxon. Male Hartley guinea pigs were subcutaneously challenged with a lethal level of OP and treated at approximately 1 min post challenge with atropine followed by equimolar oxime therapy (2-PAM Cl, HI-6 DMS, obidoxime Cl2, TMB-4, MMB4-DMS, HLö-7 DMS, MINA, and RS194B) or therapeutic-index (TI) level therapy (HI-6 DMS, MMB4-DMS, MINA, and RS194B). Clinical signs of toxicity were observed for 24 h post challenge and blood cholinesterase [AChE and butyrylcholinesterase (BChE)] activity was analyzed utilizing a modified Ellman's method. When the oxime is standardized against the HED of 2-PAM Cl for guinea pigs, the evidence from clinical observations, lethality, quality of life (QOL) scores, and cholinesterase reactivation rates across all OPs indicated that MMB4 DMS and HLö-7 DMS were the two most consistently efficacious oximes.
Assuntos
Antídotos/uso terapêutico , Substâncias para a Guerra Química/química , Inibidores da Colinesterase/química , Reativadores da Colinesterase/uso terapêutico , Intoxicação por Organofosfatos/tratamento farmacológico , Oximas/uso terapêutico , Praguicidas/antagonistas & inibidores , Animais , Antídotos/administração & dosagem , Antídotos/efeitos adversos , Atropina/administração & dosagem , Atropina/efeitos adversos , Atropina/uso terapêutico , Substâncias para a Guerra Química/toxicidade , Inibidores da Colinesterase/administração & dosagem , Inibidores da Colinesterase/toxicidade , Reativadores da Colinesterase/administração & dosagem , Reativadores da Colinesterase/efeitos adversos , Colinesterases/sangue , Esquema de Medicação , Monitoramento de Medicamentos , Quimioterapia Combinada/efeitos adversos , Cobaias , Injeções Intramusculares , Injeções Subcutâneas , Masculino , Antagonistas Muscarínicos/administração & dosagem , Antagonistas Muscarínicos/efeitos adversos , Antagonistas Muscarínicos/uso terapêutico , Intoxicação por Organofosfatos/sangue , Intoxicação por Organofosfatos/fisiopatologia , Oximas/administração & dosagem , Oximas/efeitos adversos , Praguicidas/toxicidade , Compostos de Piridínio/administração & dosagem , Compostos de Piridínio/efeitos adversos , Compostos de Piridínio/uso terapêutico , Distribuição AleatóriaRESUMO
OBJECTIVES: Oxime HI-6 DMS (dimethanesulfonate) is an asymmetric bis-pyridinium aldoxime and essential acetylcholinesterase (AChE) reactivator. The high effectiveness is due to its wide spectrum of therapeutic activity against different structures of nerve agents. Aim of this study was to compare plasma time profiles and tissue distribution (to delimitation of potential toxicity risks) after its intramuscular (i.m.) and intragastric (i.g.) administration to experimental pigs. METHODS: The study entered female Landrace pigs (Sus scrofa f. domestica), 4-5 months old animals, 29 ± 3.2 kg of body weight. Before the HI-6 DMS administration (i.m. injection or i.g. using a gastric tube), vena auricularis was cannulated (under general anaesthesia) for collection of blood samples. The tissue distribution study was carried out at expected t-max. Concentrations of HI-6 DMS in blood plasma and other tissue samples were detected by means of HPLC method. RESULTS: Fast absorption after i.m. administration, relatively slow absorption and no even elimination after i.g. administration were found. Tissue distribution showed low accumulation in the liver, but a higher content in the kidneys and high concentrations in the brain and gastrointestinal wall. CONCLUSIONS: Plasma time profiles after i.g. administration has a prolonged pharmacokinetics. Tissue distribution study showed potential side effects to the stomach due to a higher accumulation of HI-6 in this tissue after i.g. administration but not after a standard i.m. administration. Higher content of HI-6 in the kidneys after i.m. administration suggests the main way of the oxime elimination.
Assuntos
Reativadores da Colinesterase/farmacocinética , Oximas/farmacocinética , Compostos de Piridínio/farmacocinética , Sus scrofa/metabolismo , Animais , Reativadores da Colinesterase/administração & dosagem , Reativadores da Colinesterase/efeitos adversos , Feminino , Oximas/administração & dosagem , Oximas/efeitos adversos , Compostos de Piridínio/administração & dosagem , Compostos de Piridínio/efeitos adversos , Sus scrofa/sangue , Distribuição TecidualRESUMO
BACKGROUND: Dinaciclib, a small-molecule, cyclin-dependent kinase inhibitor, inhibits cell cycle progression and proliferation in various tumor cell lines in vitro. We conducted an open-label, dose-escalation study to determine the safety, tolerability, and bioactivity of dinaciclib in adults with advanced malignancies. METHODS: Dinaciclib was administered starting at a dose of 0.33 mg/m2, as a 2-hour intravenous infusion once weekly for 3 weeks (on days 1, 8, and 15 of a 28-day cycle), to determine the maximum administered dose (MAD), dose-limiting toxicities (DLTs), recommended phase 2 dose (RP2D), and safety and tolerability. Pharmacodynamics of dinaciclib were assessed using an ex vivo phytohemagglutinin lymphocyte stimulation assay and immunohistochemistry staining for retinoblastoma protein phosphorylation in skin biopsies. Evidence of antitumor activity was assessed by sequential computed tomography imaging after every 2 treatment cycles. RESULTS: Forty-eight subjects with solid tumors were treated. The MAD was found to be 14 mg/m2 and the RP2D was determined to be 12 mg/m2; DLTs at the MAD included orthostatic hypotension and elevated uric acid. Forty-seven (98%) subjects reported adverse events (AEs) across all dose levels; the most common AEs were nausea, anemia, decreased appetite, and fatigue. Dinaciclib administered at the RP2D significantly inhibited lymphocyte proliferation, demonstrating a pharmacodynamic effect. Ten subjects treated at a variety of doses achieved prolonged stable disease for at least 4 treatment cycles. CONCLUSIONS: Dinaciclib administered every week for 3 weeks (on days 1, 8, and 15 of a 28-day cycle) was generally safe and well tolerated. Initial bioactivity and observed disease stabilization support further evaluation of dinaciclib as a treatment option for patients with advanced solid malignancies. TRIAL REGISTRATION: ClinicalTrials.gov # NCT00871663.
Assuntos
Antineoplásicos/uso terapêutico , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Quinases Ciclina-Dependentes/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Compostos de Piridínio/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/efeitos adversos , Antineoplásicos/farmacocinética , Compostos Bicíclicos Heterocíclicos com Pontes/efeitos adversos , Compostos Bicíclicos Heterocíclicos com Pontes/farmacocinética , Óxidos N-Cíclicos , Relação Dose-Resposta a Droga , Feminino , Humanos , Indolizinas , Masculino , Pessoa de Meia-Idade , Inibidores de Proteínas Quinases/efeitos adversos , Inibidores de Proteínas Quinases/farmacocinética , Compostos de Piridínio/efeitos adversos , Compostos de Piridínio/farmacocinéticaRESUMO
The dysferlinopathies (e.g. LGMD2b, Myoshi myopathy) are progressive, adult-onset muscle wasting syndromes caused by mutations in the gene coding for dysferlin. Dysferlin is a large (~200kDa) membrane-anchored protein, required for maintenance of plasmalemmal integrity in muscle fibers. To facilitate analysis of dysferlin function in muscle cells, we have established a dysferlin-deficient myogenic cell line (GREG cells) from the A/J mouse, a genetic model for dysferlinopathy. GREG cells have no detectable dysferlin expression, but proliferate normally in growth medium and fuse into functional myotubes in differentiation medium. GREG myotubes exhibit deficiencies in plasma membrane repair, as measured by laser wounding in the presence of FM1-43 dye. Under the wounding conditions used, the majority (~66%) of GREG myotubes lack membrane repair capacity, while no membrane repair deficiency was observed in dysferlin-normal C2C12 myotubes, assayed under the same conditions. We discuss the possibility that the observed heterogeneity in membrane resealing represents genetic compensation for dysferlin deficiency.
Assuntos
Linhagem Celular , Proteínas de Membrana/metabolismo , Distrofia Muscular do Cíngulo dos Membros/genética , Mioblastos/metabolismo , Animais , Proliferação de Células , Disferlina , Lasers/efeitos adversos , Proteínas de Membrana/genética , Camundongos , Desenvolvimento Muscular/genética , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/lesões , Músculo Esquelético/metabolismo , Compostos de Piridínio/efeitos adversos , Compostos de Amônio Quaternário/efeitos adversos , Ferimentos e Lesões/genéticaRESUMO
Nicotinamide adenine dinucleotide (NAD) replenishment therapy using nicotinamide riboside (NR) shows promise for Parkinson's disease (PD) and other neurodegenerative disorders. However, the optimal dose of NR remains unknown, and doses exceeding 2000 mg daily have not been tested in humans. To evaluate the safety of high-dose NR therapy, we conducted a single-center, randomized, placebo-controlled, double-blind, phase I trial on 20 individuals with PD, randomized 1:1 on NR 1500 mg twice daily (n = 10) or placebo (n = 10) for four weeks. The trial was conducted at the Department of Neurology, Haukeland University Hospital, Bergen, Norway. The primary outcome was safety, defined as the frequency of moderate and severe adverse events. Secondary outcomes were tolerability defined as frequency of mild adverse events, change in the whole blood and urine NAD metabolome, and change in the clinical severity of PD, measured by MDS-UPDRS. All 20 participants completed the trial. The trial met all prespecified outcomes. NR therapy was well tolerated with no moderate or severe adverse events, and no significant difference in mild adverse events. NR therapy was associated with clinical improvement of total MDS-UPDRS scores. However, this change was also associated with a shorter interval since the last levodopa dose. NR greatly augmented the blood NAD metabolome with up to 5-fold increase in blood NAD+ levels. While NR-recipients exhibited a slight initial rise in serum homocysteine levels, the integrity of the methyl donor pool remained intact. Our results support extending the dose range of NR in phase II clinical trials to 3000 mg per day, with appropriate safety monitoring. Clinicaltrials.gov identifier: NCT05344404.
Assuntos
Doença de Parkinson , Humanos , Doença de Parkinson/tratamento farmacológico , NAD , Niacinamida , Compostos de Piridínio/efeitos adversos , Método Duplo-CegoRESUMO
Distigmine sometimes causes severe adverse events, and the serum butyrylcholinesterase (BChE) level is reduced by distigmine. However, limited data are available on the association between serum BChE level and the risk of distigmine-induced adverse events. To clarify the association between the risk of distigmine-induced adverse events and serum BChE level, we retrospectively reviewed 371 patients with 2199 measurements of serum BChE levels at three hospitals, of whom 24 (6.5%) had adverse events. Multivariate logistic regression analysis was performed to identify risk factors associated with adverse events of distigmine. The risk of adverse events was associated with distigmine dose>0.15 mg/kg/d [odds ratio (OR) 3.55, 95% confidence interval (CI) 1.07-11.70, p=0.04], serum BChE level 80-112 U/L (OR 3.13, 95% CI 1.03-9.52, p=0.04), and serum BChE level <80 U/L (OR 13.70, 95% CI 5.14-36.50, p<0.01). Serum BChE might be a useful biomarker for estimating the risk of distigmine-induced adverse events. The risk of adverse events might be decreased by closely monitoring serum BChE and assessing distigmine dose in patients with high risk factors.
Assuntos
Butirilcolinesterase , Compostos de Piridínio , Biomarcadores , Humanos , Compostos de Piridínio/efeitos adversos , Estudos RetrospectivosRESUMO
Distigmine bromide is a cholinesterase inhibitor widely used for the treatment of hypotonic neurogenic bladder. However, this drug is also known to cause cholinergic crisis, a rare but serious adverse reaction. Cholinergic crisis is an excessive amount of acetylcholine due to the systemic inhibition of cholinesterase activity, characterized by parasympathetic symptoms such as sweating, salivation, miosis, bradycardia, diarrhea and circulatory and respiratory failure. The incidence of cholinergic crisis has been estimated at approximately 0.2%, and the majority of the patients are elderly with underlying conditions such as cerebrovascular disease. Since 2004, we have encountered 5 cases of acute respiratory failure associated with cholinergic crisis induced by the administration of a normal oral dose of distigmine. We present these cases here and review an additional 23 cases from the literature in Japan. In these 28 cases, mechanical ventilation was required for 57%, with a mean duration of 5.1 days and a mortality rate of 11%. Pneumonia was observed in half of the cases in the acute phase, and relapse due to the readministration of distigmine was reported in 20% of cases. It is important to remember that cholinergic crisis in the elderly is often misdiagnosed and is occasionally treated as simple aspiration pneumonia.
Assuntos
Inibidores da Colinesterase/efeitos adversos , Compostos de Piridínio/efeitos adversos , Insuficiência Respiratória/induzido quimicamente , Doença Aguda , Idoso , Idoso de 80 Anos ou mais , Doenças do Sistema Nervoso Autônomo/induzido quimicamente , Feminino , Humanos , MasculinoRESUMO
Poly(ADP-ribose) polymerase (PARP) enzymes initiate (mt)DNA repair mechanisms and use nicotinamide adenine dinucleotide (NAD+) as energy source. Prolonged PARP activity can drain cellular NAD+ reserves, leading to de-regulation of important molecular processes. Here, we provide evidence of a pathophysiological mechanism that connects mtDNA damage to cardiac dysfunction via reduced NAD+ levels and loss of mitochondrial function and communication. Using a transgenic model, we demonstrate that high levels of mice cardiomyocyte mtDNA damage cause a reduction in NAD+ levels due to extreme DNA repair activity, causing impaired activation of NAD+-dependent SIRT3. In addition, we show that myocardial mtDNA damage in combination with high dosages of nicotinamideriboside (NR) causes an inhibition of sirtuin activity due to accumulation of nicotinamide (NAM), in addition to irregular cardiac mitochondrial morphology. Consequently, high doses of NR should be used with caution, especially when cardiomyopathic symptoms are caused by mitochondrial dysfunction and instability of mtDNA.
Assuntos
Reparo do DNA , DNA Mitocondrial/metabolismo , Cardiopatias/fisiopatologia , Coração/fisiopatologia , Miocárdio/metabolismo , NAD/metabolismo , Animais , Dano ao DNA , Células HeLa , Humanos , Camundongos , Mitocôndrias/metabolismo , Niacinamida/efeitos adversos , Niacinamida/análogos & derivados , Niacinamida/metabolismo , Compostos de Piridínio/efeitos adversos , Sirtuínas/antagonistas & inibidoresRESUMO
Previous studies have shown that short-wavelength blue visible light induces retinal injury and may be a risk factor for age related macular degeneration. A2E is a blue light absorbing retinal chromophore that accumulates with age. Our previous in vitro studies have determined that, although A2E itself has a low phototoxic efficiency, the oxidation products of A2E that are formed in the presence of visible light can contribute to observed retinal pigment epithelial photodamage. The purpose of this study was to investigate the effects of blue light on retinal phototoxicity and its relationship to A2E, oxidized A2E and its isomers. Sprague-Dawley albino rats were dark adapted for 24 h. Control rats remained in the dark while experimental rats were exposed to blue light (λ = 450 nm, 3.1 mW cm(-2)) for 6 h. Isolated retinas were homogenized in Folch extraction mixture and then in chloroform. The dried extracts were reconstituted and divided for determination of organic soluble compound. Esters of fatty acids were determined with GC-MS, A2E and other chromophores using HPLC, and A2E oxidation products with LC-MS. Exposure of rat eyes to blue light did not significantly change the fatty acid composition of the retina. The A2E concentration (normalized to fatty acid content) in blue light exposed animals was found to be lower than the A2E concentration in control rats. The concentrations of all-trans-retinal-ethanolamine adduct and iso-A2E a precursor and an isomer of A2E respectively, were also lower after blue-light exposure than in the retinas of rats housed in the dark. On the other hand, the amount of oxidized forms of A2E was higher in the animals exposed to blue light. We conclude that in the rat eye, blue-light exposure promotes oxidation of A2E and iso-A2E to the products that are toxic to retinal tissue. Although high concentrations of A2E may be cytotoxic to the retina, the phototoxicity associated with blue light damage to the retina is in part a result of the formation of toxic A2E oxides. This effect may partially explain the association between blue light induced retinal injury and macular degeneration.
Assuntos
Modelos Animais de Doenças , Luz/efeitos adversos , Degeneração Macular/etiologia , Compostos de Piridínio/efeitos adversos , Retinoides/efeitos adversos , Animais , Colesterol/metabolismo , Ácidos Graxos/metabolismo , Degeneração Macular/patologia , Masculino , Oxirredução , Compostos de Piridínio/metabolismo , Ratos , Ratos Sprague-Dawley , Retina/patologia , Retina/efeitos da radiação , Retinoides/metabolismoRESUMO
Disclosed herein is a counterion additive-switched rhodium-catalyzed cascade triple C-H annulation of 4-hydroxy-1-naphthaldehydes with alkynes, in which six chemical bonds are formed in one-pot. This reaction enables the rapid assembly of diverse polycyclic pyrylium and pyridinium fluorophores, which leads to two specific mitochondria-labeling reagents with low cytotoxicity and superior photostability.
Assuntos
Corantes Fluorescentes/síntese química , Compostos Heterocíclicos com 3 Anéis/síntese química , Mitocôndrias/metabolismo , Compostos de Piridínio/síntese química , Alcinos/química , Catálise , Linhagem Celular , Corantes Fluorescentes/efeitos adversos , Células Hep G2 , Compostos Heterocíclicos com 3 Anéis/efeitos adversos , Humanos , Mitocôndrias/ultraestrutura , Imagem Óptica , Óxidos/química , Compostos de Piridínio/efeitos adversos , Ródio/química , Coloração e RotulagemRESUMO
BACKGROUND AND OBJECTIVE: Advanced glycation end-products (AGEs) have been implicated in the pathogenesis of diabetic complications through a variety of mechanisms including endothelial dysfunction and structural abnormalities in the vasculature and myocardium. Reducing the AGEs burden and their ensuing pro-inflammatory, pro-oxidative and pro-coagulant effect with associated dysfunctional proteins in various target tissues may retard the progression of and even reverse diabetic macro- and microvascular complications. Pyridinium, 3-[[2-(methylsulfonyl) hydrazino] carbonyl]-1-[2-oxo-2-2-thienyl) ethyl]-chloride (TRC4186) has demonstrated AGE-breaking activities in in vitro experiments and improvement in the endothelial and myocardial function in animal models of diabetes mellitus with reduction of AGEs accumulation in tissues over time. The safety of TRC4186 has been established in in vitro and in vivo preclinical studies. Thus, this drug is being developed for the treatment of complications associated with diabetes. This investigation set out to evaluate the safety, tolerability and pharmacokinetics of TRC4186 in healthy human subjects after single and multiple ascending doses, fixed doses in elderly male and female subjects, and with food and different formulations of the compound. METHODS: Four studies were conducted during phase I clinical development of TRC4186. These were: (i) a randomized, double-blind, placebo-controlled, single-dose, dose-ascending study in healthy male subjects with doses of TRC4186 ranging from 250 to 2500 mg administered as an oral solution (total six doses); (ii) a randomized, double-blind, placebo-controlled, multiple-dose, dose-ascending study in healthy male subjects with three doses of TRC4186 ranging from 500 to 2000 mg twice daily for 6 days with a final single dose on day 7; (iii) a randomized, open-label, three-way crossover study to assess the effect of food (fasted vs fed) and formulation (solution vs tablet) with TRC4186 500 mg; (iv) a randomized, double-blind, placebo-controlled, single-dose, dose-ascending study in elderly male and female subjects at a dose of TRC4186 500 mg followed by TRC4186 1000 mg after a 7-day washout period. The safety and tolerability of TRC4186 were assessed by considering adverse events (AEs), ECG findings, vital signs and laboratory investigation results. RESULTS: TRC4186 was rapidly absorbed, with maximum plasma concentrations (C(max)) attained within 1-4 hours. C(max) and area under the plasma concentration-time curve (AUC) were dose proportional over the range 250-2500 mg for a single dose and 500-2000 mg for multiple doses with twice-daily administration. Steady-state conditions were attained within 6 days at different dose levels. C(max) and AUC were not affected by age, sex, race or type of formulation. The tablet formulation of TRC4186 was bioequivalent with the solution form of the drug under fasting conditions and systemic availability of the tablet formulation was reduced by 40% when administered under fed conditions. Terminal elimination and renal clearance in the elderly male (age 69.1 +/- 6.0 years) were not significantly different compared with younger subjects (age 31 +/- 8.6 years). CONCLUSION: TRC4186 was safe and well tolerated when administered orally with either a single or multiple doses across the different ages, sexes, races and formulations studied. A dose-proportional increase in plasma TRC4186 concentration was seen, with steady state being achieved within 6 days.
Assuntos
Produtos Finais de Glicação Avançada/antagonistas & inibidores , Compostos de Piridínio/administração & dosagem , Sulfonamidas/administração & dosagem , Adolescente , Adulto , Fatores Etários , Idoso , Formas de Dosagem , Relação Dose-Resposta a Droga , Esquema de Medicação , Avaliação de Medicamentos , Eletrocardiografia/efeitos dos fármacos , Feminino , Interações Alimento-Droga , Humanos , Masculino , Pessoa de Meia-Idade , Compostos de Piridínio/efeitos adversos , Compostos de Piridínio/farmacocinética , Sulfonamidas/efeitos adversos , Sulfonamidas/farmacocinética , Equivalência TerapêuticaRESUMO
We propose a 2,5-Bis[1-(4-N-methylpyridinium)ethen-2-yl)]-N-methylpyrrole ditriflate (PEPEP) as a novel nontoxic, nonpotentiometric mitochondrial probe for confocal fluorescence microscopy. PEPEP is a representative chromophore of a large family of heterocyclic fluorescent dyes that show fluorescence emission in aqueous media and great DNA affinity. We check its cytotoxicity and intracellular localization in mammalian and yeast cell cultures. We demonstrate that PEPEP is a very efficient dye for fluorescence confocal microscopy and a valuable alternative to the most frequently used mitochondrial stains.
Assuntos
DNA Mitocondrial/metabolismo , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Mitocôndrias/ultraestrutura , Compostos de Piridínio , Pirróis , Animais , DNA Mitocondrial/análise , Corantes Fluorescentes , Haplorrinos , Humanos , Mitocôndrias/efeitos dos fármacos , Compostos de Piridínio/efeitos adversos , Pirróis/efeitos adversosRESUMO
A 74-year-old man became unable to walk two days following the initiation of administration of oral distigmine bromide, 10 mg per day, for his constipation. Neurological examination revealed bradykinesia, rigidity and fine postural tremor without laterality. T2 weighted MRI showed mild front-temporal atrophy and multiple hyperintensities in both deep white matters. His symptoms fully improved one week after discontinuance of distigmine bromide. This is the first case report of distigmine bromide induced Parkinsonism.
Assuntos
Doença de Parkinson Secundária/induzido quimicamente , Compostos de Piridínio/efeitos adversos , Idoso , Constipação Intestinal/tratamento farmacológico , Humanos , MasculinoRESUMO
Sepsis and organ failure remain the main cause of death on the ICU. Sepsis is characterized by a severe inflammatory response, in which platelet-activating factor (PAF) is considered to play an important role. This study investigated whether treatment with the PAF-antagonist TCV-309 reduces morbidity and mortality in patients with septic shock. The study was conducted as a double-blind, randomized, placebo controlled multicenter study. The included patients had to fulfill the SIRS criteria with a clinical suspicion of infection, an admission APACHE II score greater than 15, and shock, defined as a mean arterial pressure <70 mmHg and/or a decrease > or =40 mmHg despite adequate fluid resuscitation. Patients received 1.0 mg/kg TCV-309 or placebo, twice daily, intravenously during 14 days. The prospectively set goals were MOF score, recovery from shock, mortality, and assessment of the safety of the medication. A total of 98 patients were included of which 97 were analyzed on an intention-to-treat basis. The overall survival at day 56 of TCV-309 treated patients was similar compared to placebo treated patients (51.0% vs. 41.7%, P = 0.47). In contrast, the mean percentage of failed organs per patient present after 14 days in the TCV-309 treated patients was significantly lower compared to the placebo treated patients (11.9% vs. 25.1%, P = 0.04), leading to a reduced need for vasopressors, dialysis, and ventilatory support. Furthermore, the mean APACHE-II score during treatment with TCV-309 was significantly lower and the number of patients recovered from shock after day 14 was significantly higher in the TCV-309 treated patient group (2/32 vs. 9/29, P = 0.01). The number of adverse events was not significantly different between the TCV-309 and placebo treated patients. TCV-309 did not change overall mortality of septic shock, however a substantial reduction in organ dysfunction and morbidity, frequently associated with septic shock was achieved, without significant adverse events.
Assuntos
Isoquinolinas/uso terapêutico , Insuficiência de Múltiplos Órgãos/prevenção & controle , Fator de Ativação de Plaquetas/antagonistas & inibidores , Compostos de Piridínio/uso terapêutico , Choque Séptico/tratamento farmacológico , Síndrome de Resposta Inflamatória Sistêmica/tratamento farmacológico , Tetra-Hidroisoquinolinas , APACHE , Adulto , Idoso , Método Duplo-Cego , Feminino , Humanos , Mediadores da Inflamação/sangue , Isoquinolinas/efeitos adversos , Masculino , Pessoa de Meia-Idade , Inibidores da Agregação Plaquetária/efeitos adversos , Inibidores da Agregação Plaquetária/uso terapêutico , Estudos Prospectivos , Compostos de Piridínio/efeitos adversos , Choque Séptico/mortalidade , Choque Séptico/fisiopatologia , Síndrome de Resposta Inflamatória Sistêmica/mortalidade , Síndrome de Resposta Inflamatória Sistêmica/fisiopatologiaRESUMO
The possible side effects of therapeutic drugs against organophosphate poisoning were investigated. First, dose-effect curves were obtained with atropine sulphate (AS), P2S, obidoxime, aprophen, N-methylatropine nitrate and HI-6. The first three drugs are currently used in the therapy of organophosphate poisoning, the others are potentially useful candidates. Automated tests measuring open field behavior, motor coordination and shuttlebox performance, as well as neurophysiological techniques such as the quantified EEG (qEEG) and visual evoked responses were used. The sign-free doses of these compounds were determined; it appeared that open field behavior and the qEEG were the most sensitive methods for these drugs. Subsequently, these two methods were used to investigate the effects of the combinations of AS and P2S, AS and obidoxime or AS and HI-6, each compound given in a sign-free dose. Synergistic or additive effects were found with the combination of AS and P2S, which were smaller with the combination of AS and obidoxime and absent with the combination of AS and HI-6. These results indicate that the untimely use (false alarm, panic) of the current drug combinations may cause undesirable side effects.