Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Environ Sci Pollut Res Int ; 30(7): 16878-16904, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36602729

RESUMO

Geotechnical infrastructures, like slopes and embankments, retaining walls, foundations, engineered landfills, overburden dumps, and pavements, get continuously exposed to various environmental factors which are climate dependent. Fate/stability of these infrastructures due to extreme and abrupt change in precipitation, temperatures, humidity, and wind/airflow is quite questionable. Some of the issues related to climate change on soils include increase in infiltration rate, high pore-water pressure, decrease in effective stress, soil liquefaction, seepage failures, frost heaving, changes in soil suction potential, swelling and shrinkage in fine-grained soils, differential settlement, and damage to vegetation cover and thereby causing slope failures, waterlogged conditions, floods, soil erosion and/or internal erosion of fines, damage to landfill liners and soil covers, desertification, desiccation cracks on the ground surface, and groundwater table pollution due to contaminant migration. Therefore, studies on the impact of climate change on geotechnical infrastructures have gained attention of many researchers in the recent times. In present study, an up-to-date review of the works related to the influence of various climatic factors on geotechnical properties and thereby on geotechnical projects is carried out. Topics related to climate data downscaling using global climate models (GCM), climate change-induced slope instability, acid rains, desiccation cracking in soils with changing temperatures, impacts of dry-wet cycles and freeze-thaw cycles, and vegetation effects on soils are emphasized in this paper. Furthermore, to address the challenges, need-based research related to resilient infrastructures, thermo-hydro-mechanical models, bioremediation methods, innovative sustainable composite materials, and incorporation of climatic factors in design is highlighted and discussed.


Assuntos
Mudança Climática , Solo , Solo/química , Instalações de Eliminação de Resíduos , Temperatura , Congelamento
2.
Lancet Oncol ; 23(6): 781-792, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35576957

RESUMO

BACKGROUND: Targeted inhibition of the PD-L1-PD-1 pathway might be further amplified through combination of PD-1 or PD-L1 inhibitors with novel anti-TIGIT inhibitory immune checkpoint agents, such as tiragolumab. In the CITYSCAPE trial, we aimed to assess the preliminary efficacy and safety of tiragolumab plus atezolizumab (anti-PD-L1) therapy as first-line treatment for non-small-cell lung cancer (NSCLC). METHODS: CITYSCAPE is a phase 2, randomised, double-blind, placebo-controlled trial. Patients with chemotherapy-naive, PD-L1-positive (defined as a tumour proportion score of ≥1% by 22C3 immunohistochemistry pharmDx assay; Dako, Agilent Technologies, Santa Clara, CA, USA) recurrent or metastatic NSCLC with measurable disease, Eastern Cooperative Oncology Group performance status of 0 or 1, and no EGFR or ALK alterations were enrolled from 41 clinics in Europe, Asia, and the USA. Patients were randomly assigned (1:1), via an interactive voice or web-based response system, to receive tiragolumab (600 mg) plus atezolizumab (1200 mg) or placebo plus atezolizumab intravenously once every 3 weeks. Investigators and patients were masked to treatment assignment. The co-primary endpoints were investigator-assessed objective response rate and progression-free survival as per Response Evaluation Criteria in Solid Tumors version 1.1 in the intention-to-treat population, analysed after approximately 80 progression-free survival events had been observed in the primary population. Safety was assessed in all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov, NCT03563716, and is ongoing. FINDINGS: Patients were enrolled between Aug 10, 2018, and March 20, 2019. At data cutoff for the primary analysis (June 30, 2019), 135 of 275 patients assessed for eligibility were randomly assigned to receive tiragolumab plus atezolizumab (67 [50%]) or placebo plus atezolizumab (68 [50%]). In this primary analysis, after a median follow-up of 5·9 months (4·6-7·6, in the intention-to-treat population, 21 patients (31·3% [95% CI 19·5-43·2]) in the tiragolumab plus atezolizumab group versus 11 patients (16·2% [6·7-25·7]) in the placebo plus atezolizumab group had an objective response (p=0·031). Median progression-free survival was 5·4 months (95% CI 4·2-not estimable) in the tiragolumab plus atezolizumab group versus 3·6 months (2·7-4·4) in the placebo plus atezolizumab group (stratified hazard ratio 0·57 [95% CI 0·37-0·90], p=0·015). 14 (21%) patients receiving tiragolumab plus atezolizumab and 12 (18%) patients receiving placebo plus atezolizumab had serious treatment-related adverse events. The most frequently reported grade 3 or worse treatment-related adverse event was lipase increase (in six [9%] patients in the tiragolumab plus atezolizumab group vs two [3%] in the placebo plus atezolizumab group). Two treatment-related deaths (of pyrexia and infection) occurred in the tiragolumab plus atezolizumab group. INTERPRETATION: Tiragolumab plus atezolizumab showed a clinically meaningful improvement in objective response rate and progression-free survival compared with placebo plus atezolizumab in patients with chemotherapy-naive, PD-L1-positive, recurrent or metastatic NSCLC. Tiragolumab plus atezolizumab was well tolerated, with a safety profile generally similar to that of atezolizumab alone. These findings demonstrate that tiragolumab plus atezolizumab is a promising immunotherapy combination for the treatment of previously untreated, locally advanced unresectable or metastatic NSCLC. FUNDING: F Hoffmann-La Roche and Genentech.


Assuntos
Antineoplásicos , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais Humanizados , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Antígeno B7-H1/metabolismo , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Método Duplo-Cego , Seguimentos , Humanos , Neoplasias Pulmonares/patologia , Receptor de Morte Celular Programada 1
3.
J Oncol Pharm Pract ; 26(1): 13-22, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30832554

RESUMO

PURPOSE: To describe the outcomes of a pharmacist-led multi-center, collaborative patient education and proactive adverse event management program in a community-based oncology setting. METHODS: Patients with EGFR mutation-positive (EGFRm+) non-small cell lung cancer, newly prescribed with oral afatinib, and monitored as part of the Florida Cancer Specialists patient management program, were included in a retrospective, observational analysis. During follow-up, data were collected on adverse event frequency, and changes in afatinib dosing. Data analyses were descriptive and exploratory in nature. RESULTS: The mean age of the 123 patients included in the analysis was 69 years, and 78% were female. At the time of the analysis, 3 patients had discontinued before receiving treatment, 89 patients had discontinued afatinib treatment, and 31 patients were continuing to receive afatinib treatment. The most common afatinib-related adverse events were diarrhea (85%), rash/skin reactions (58%), stomatitis/mucositis (19%), and paronychia (16%). Overall, 13% of patients discontinued due to afatinib-related adverse events. The median duration of treatment was 4 months in patients who discontinued due to adverse events, 6 months in those who discontinued for other reasons, and 18 months in those who were continuing to receive therapy. Afatinib dose-reductions were more frequent in patients continuing treatment versus those who discontinued due to adverse events (77% vs. 42%, respectively). CONCLUSIONS: Findings suggest that adverse events in patients with EGFRm + non-small cell lung cancer receiving afatinib can be successfully managed in a community-based, real-world setting with the help of collaborative pharmacist-led patient education, adverse event monitoring, and continuous support.


Assuntos
Afatinib/efeitos adversos , Antineoplásicos/efeitos adversos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Educação de Pacientes como Assunto/tendências , Farmacêuticos/tendências , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/genética , Serviços Comunitários de Farmácia/tendências , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/diagnóstico , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/terapia , Receptores ErbB/genética , Feminino , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Masculino , Pessoa de Meia-Idade , Educação de Pacientes como Assunto/métodos , Relações Profissional-Paciente , Estudos Retrospectivos
4.
Cureus ; 11(7): e5054, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31516768

RESUMO

Thrombotic thrombocytopenic purpura (TTP) is a coagulation disorder caused by a deficiency in ADAMTS13. Patients classically present with symptoms of end-organ damage as well as anemia and thrombocytopenia. Treatment is therapeutic plasma exchange (TPE) in the acute setting, with systemic immunosuppression for refractory cases. A 48-year-old female diagnosed with TTP at age 42 presented initially with altered mental status (AMS), severe anemia, and thrombocytopenia requiring intensive care unit (ICU) admission. The patient was treated acutely and discharged from the hospital. During subsequent years, multiple relapses requiring hospitalization prompted scheduled maintenance with rituximab. Since maintenance therapy, the patient remained relapse-free while ADAMTS13 levels escalated. Untreated, TTP is fatal. The treatment goal in the acute setting is the repletion of ADAMTS13 coupled with immunosuppression in refractory cases. Rituximab typically is reserved for patients who do not improve with initial TPE. Albeit unusual in TTP, rituximab maintenance in our patient induced remission. Maintenance therapy with rituximab in patients with a history of relapsing TTP can blunt or obviate the frequency of relapses and hospital admissions. More research is required to establish the effectiveness of rituximab in the chronic treatment of TTP.

7.
Ann Pharmacother ; 49(3): 270-7, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25515864

RESUMO

BACKGROUND: Fondaparinux has an increased bleeding risk in patients with a CrCl ≤ 50 mL/min and is contraindicated if CrCl < 30 mL/min. Data regarding dosing and anti-Xa monitoring are lacking in this population. OBJECTIVE: To describe dosing, monitoring, and safety outcomes of prophylactic fondaparinux in critically ill patients with moderate to severe renal impairment, including renal replacement therapy (RRT). METHODS: Retrospective analysis from October 2006 to November 2012 of patients ≥ 18 years old who received fondaparinux for ≥ 72 hours with ≥ 1 dose in an intensive care unit and a CrCl ≤ 50 mL/min or RRT during therapy. Participants were divided into 4 cohorts: moderate impairment (CrCl = 30-50 mL/min), severe impairment (CrCl < 30 mL/min), hemodialysis (HD), or continuous venovenous hemofiltration (CVVH). Outcomes included the incidence of clinically significant bleeding and thromboembolic events. Fondaparinux dose, dosing frequency, and anti-Xa level monitoring are described. Pharmacokinetic modeling was performed to assess drug accumulation. RESULTS: In all, 95 patients met inclusion criteria: 64 (67.4%) with moderate impairment, 10 (10.5%) with severe impairment, 5 (5.3%) with HD, and 16 (16.8%) with CVVH. The median defined daily doses in the moderate, severe, HD, and CVVH cohorts were 2.5, 2.5, 0.9, and 1.9 mg. Anti-Xa monitoring occurred in 19 (20%) patients, although few concentrations were peaks. Clinically significant bleeding occurred in 4 (4.2%) patients. A pharmacokinetic model demonstrated drug accumulation. CONCLUSIONS: Empirical dose adjustments may be prudent in critically ill patients with renal dysfunction; however, the optimal fondaparinux dosage in this population remains unknown. Peak anti-Xa concentrations may help guide therapy.


Assuntos
Anticoagulantes/uso terapêutico , Estado Terminal/terapia , Polissacarídeos/uso terapêutico , Insuficiência Renal/tratamento farmacológico , Insuficiência Renal/cirurgia , Terapia de Substituição Renal , Adulto , Idoso , Idoso de 80 Anos ou mais , Quimioprevenção , Feminino , Fondaparinux , Hemofiltração , Hemorragia/induzido quimicamente , Hemorragia/epidemiologia , Heparina de Baixo Peso Molecular/sangue , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica/métodos , Diálise Renal , Insuficiência Renal/sangue , Insuficiência Renal/epidemiologia , Estudos Retrospectivos , Índice de Gravidade de Doença , Adulto Jovem
8.
Bioorg Med Chem ; 22(2): 684-91, 2014 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-24393721

RESUMO

Tocopherols (TOH) are lipophilic antioxidants which require the phenolic OH group for their redox activity. In contrast, non-redox active esters of α-TOH with succinate (α-TOS) were shown to possess proapoptotic activity in cancer cells. It was suggested that this activity is mediated via mitochondrial inhibition with subsequent O2(-) production triggering apoptosis and that the modification of the linker between the succinate and the lipophilic chroman may modulate this activity. However, the specific mechanism and the influence of the linker are not clear yet on the level of the mitochondrial respiratory chain. Therefore, this study systematically compared the effects of α-TOH acetate (α-TOA), α-TOS and α-tocopheramine succinate (α-TNS) in cells and submitochondrial particles (SMP). The results showed that not all cancer cell lines are highly sensitive to α-TOS and α-TNS. In HeLa cells α-TNS did more effectively reduce cell viability than α-TOS. The complex I activity of SMP was little affected by α-TNS and α-TOS while the complex II activity was much more inhibited (IC50=42±8µM α-TOS, 106±8µM α-TNS, respectively) than by α-TOA (IC50 >1000µM). Also the complex III activity was inhibited by α-TNS (IC50=137±6µM) and α-TOS (IC50=315±23µM). Oxygen consumption of NADH- or succinate-respiring SMP, involving the whole electron transfer machinery, was dose-dependently decreased by α-TOS and α-TNS, but only marginal effects were observed in the presence of α-TOA. In contrast to the similar inhibition pattern of α-TOS and α-TNS, only α-TOS triggered O2(-) formation in succinate- and NADH-respiring SMP. Inhibitor studies excluded complex I as O2(-) source and suggested an involvement of complex III in O2(-) production. In cancer cells only α-TOS was reproducibly able to increase O2(-) levels above the background level but neither α-TNS nor α-TOA. Furthermore, the stability of α-TNS in liver homogenates was significantly lower than that of α-TOS. In conclusion, this suggests that α-TNS although it has a structure similar to α-TOS is not acting via the same mechanism and that for α-TOS not only complex II but also complex III interactions are involved.


Assuntos
Antineoplásicos/farmacologia , Mitocôndrias/efeitos dos fármacos , Succinatos/farmacologia , Superóxidos/metabolismo , Vitamina E/análogos & derivados , alfa-Tocoferol/farmacologia , Antineoplásicos/química , Antineoplásicos/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Complexo I de Transporte de Elétrons/antagonistas & inibidores , Complexo I de Transporte de Elétrons/metabolismo , Complexo II de Transporte de Elétrons/antagonistas & inibidores , Complexo II de Transporte de Elétrons/metabolismo , Complexo III da Cadeia de Transporte de Elétrons/antagonistas & inibidores , Complexo III da Cadeia de Transporte de Elétrons/metabolismo , Radicais Livres/metabolismo , Células HeLa , Humanos , Mitocôndrias/metabolismo , Estrutura Molecular , Relação Estrutura-Atividade , Partículas Submitocôndricas/efeitos dos fármacos , Partículas Submitocôndricas/metabolismo , Succinatos/química , Succinatos/metabolismo , Células Tumorais Cultivadas , Vitamina E/química , Vitamina E/metabolismo , Vitamina E/farmacologia , alfa-Tocoferol/química , alfa-Tocoferol/metabolismo
9.
Bioorg Med Chem ; 19(24): 7643-52, 2011 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-22094277

RESUMO

The syntheses, analytical properties, and spin trapping behavior of four novel EMPO derivatives, namely 5-ethoxycarbonyl-4-hydroxymethyl-5-methyl-pyrroline N-oxide (EHMPO), 5-ethoxycarbonyl-5-ethyl-4-hydroxymethyl-pyrroline N-oxide (EEHPO), 4-hydroxymethyl-5-methyl-5-propoxycarbonyl-pyrroline N-oxide (HMPPO), and 4-hydroxymethyl-5-methyl-5-iso-propoxycarbonyl-pyrroline N-oxide (HMiPPO), towards different oxygen- and carbon-centered radicals are described.


Assuntos
Óxidos N-Cíclicos/química , Marcadores de Spin/síntese química , Óxidos N-Cíclicos/síntese química , Etanol/química , Formiatos/química , Radical Hidroxila/química , Metano/análogos & derivados , Metano/química , Metanol/química , Oxirredução , Superóxidos/química
10.
Tetrahedron ; 67(34): 6181-6185, 2011 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-22031788

RESUMO

While bromination of γ-tocopherol (2) with elemental bromine affords 5-bromo-γ-tocopherol quantitatively (3), the analogous reaction of its truncated model compound, 2,2,7,8-tetramethylchromanol (2a) is known to be accompanied by side reactions and to produce hitherto unknown byproducts. These compounds originate from pyrano[3,2-f]chromene (6), a byproduct in the synthesis of model compound 2a, which affords bromochromene 7 as the major product. The reaction mechanism was shown to proceed via chromene 8 and its 1,2-dibromo addition compound 9, which eliminates HBr in an E1 process to finally afford 7. Analytical data including crystal structures of both 6 and 7 are reported.

11.
Bioorg Med Chem ; 19(2): 985-93, 2011 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-21211983

RESUMO

Synthesis and spin trapping behavior of three novel DMPO derivatives, namely 5-hydroxymethyl-5-methyl-pyrroline N-oxide (HMMPO), 5-(2-furanyl)-oxymethyl-5-methyl-pyrroline N-oxide (FMMPO), and 5-(2-pyranyl)-oxymethyl-5-methyl-pyrroline N-oxide (PMMPO) towards different oxygen- and carbon-centered radicals are described. The stabilizing effect of a series of cyclodextrins on the superoxide adducts was tested.


Assuntos
Óxidos N-Cíclicos/química , Pirróis/química , Óxidos N-Cíclicos/síntese química , Óxidos N-Cíclicos/farmacologia , Radical Hidroxila/química , Metano/análogos & derivados , Metano/química , Espectrometria de Fluorescência , Espectroscopia de Infravermelho com Transformada de Fourier
12.
Chem Res Toxicol ; 23(1): 193-202, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20014750

RESUMO

Tocopherols (alpha-, beta-, gamma-, and delta-Toc) and tocopheryl quinones (alpha-, beta-, gamma-, and delta-TQ) were recently suggested to modulate mitochondrial electron transfer in mammals. Intriguingly, Tocs and stigmatellin, a potent inhibitor of the mitochondrial cytochrome (cyt) bc(1) complex, possess a common structural feature: the chroman core. Therefore, we studied the interference of Tocs as well as synthetic model compounds (low molecular weight TQ analogues and tetramethyl chromanones) at the mitochondrial cyt bc(1) complex. Enzymatic experiments revealed that besides the inhibitor stigmatellin, among natural vitamin E-related derivatives, gamma-TQ/delta-TQ and, among synthetic compounds, TMC2O (6-hydroxy-4,4,7,8-tetramethyl-chroman-2-one) were most effective in decreasing the cyt bc(1) activities. Stopped-flow photometric and low-temperature electron paramagnetic resonance spectroscopic experiments showed for TMC2O an inhibition of electron transfer to cyt c(1) and a modulation of the environment of the Rieske iron-sulfur protein (ISP). Docking experiments suggest a binding interaction of the 6-OH group and 1-O atom/2-C( horizontal lineO) group of TMC2O with Glu-271 (cyt b) and His-161 (ISP) in the cyt bc(1) complex, respectively. This binding pose is similar but not identical to the potent inhibitor stigmatellin. The data suggest that chroman-2-ones are possible templates for modulatory molecules for the cyt bc(1) target.


Assuntos
Antioxidantes/química , Complexo III da Cadeia de Transporte de Elétrons/metabolismo , Tocoferóis/química , Animais , Antioxidantes/toxicidade , Sítios de Ligação , Bovinos , Simulação por Computador , Espectroscopia de Ressonância de Spin Eletrônica , Transporte de Elétrons/efeitos dos fármacos , Complexo III da Cadeia de Transporte de Elétrons/antagonistas & inibidores , Tocoferóis/toxicidade , Vitamina E/análogos & derivados , Vitamina E/química , Vitamina E/toxicidade
13.
Chem Phys Lipids ; 161(1): 32-7, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19580794

RESUMO

Stable cationic carotenoid aggregates - predominantly of the J-type - develop when the hydrochlorides of carotenoid aldoximes and ketoximes are exposed to water. The oxime hydrochlorides are obtained by simple syntheses from commercially available food color carotenoids. Bluish-purple, unstable transient compounds were observed during hydrochlorination performed at liquid nitrogen temperature.


Assuntos
Carotenoides/química , Oximas/química , Carotenoides/síntese química , Oximas/síntese química , Tensão Superficial , Tensoativos , Água/química
14.
J Org Chem ; 72(17): 6504-12, 2007 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-17636958

RESUMO

In contrast to the alpha-form permethylated at the aromatic ring, non-alpha-tocopherols possess free aromatic ring positions which enable them to act as potent scavengers of electrophiles in vivo and in vitro. In preparation of enzymatic studies involving peroxynitrite and other nitrating systems, the behavior of non-alpha-tocopherols under nitration conditions was studied. The nitration products of beta-, gamma-, and delta-tocopherol were identified, comprehensively analytically characterized, and their structure was supported by X-ray crystal structure analysis on truncated model compounds. Even under more drastic nitration conditions, no erosion of the stereochemistry at 2-C occurred. The nitrosation of gamma-tocopherol and delta-tocopherol was re-examined, showing the slow oxidation of the initial nitroso products to the corresponding nitro derivatives by air to be superimposed by a fast equilibrium with the tautomeric ortho-quinone monoxime, which only in the case of gamma-tocopherol released hydroxyl amine at elevated temperatures to afford the stable ortho-quinone. Mononitration of delta-tocopherol selectively proceeded at position 5. This selectivity can be explained by the theory of strain-induced bond localization (SIBL) to the quinoid nitration intermediates. Bisnitration was only insignificantly disfavored by the first nitro group, so that under normal nitration conditions offering an excess of nitrating species only the bisnitration product was found.


Assuntos
Nitratos/química , Vitamina E/química , Cristalografia por Raios X , Espectroscopia de Ressonância Magnética , Modelos Moleculares
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...