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2.
Curr Oncol ; 22(1): 49-59, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25684988

RESUMO

Venous thromboembolism is a common complication in cancer patients, and thromboembolism is the second most common cause of death after cancer progression. A number of clinical practice guidelines provide recommendations for the management of cancer-associated thrombosis. However, the guidelines lack recommendations covering commonly encountered clinical challenges (for example, thrombocytopenia, recurrent venous thromboembolism, etc.) for which little or no evidence exists. Accordingly, recommendations were developed to provide expert guidance to medical oncologists and other health care professionals caring for patients with cancer-associated thrombosis. The current expert consensus was developed by a team of 21 clinical experts. For each identified clinical challenge, the literature in medline, embase, and Evidence Based Medicine Reviews was systematically reviewed. The quality of the evidence was assessed, summarized, and graded. Consensus statements were generated, and the experts voted anonymously using a modified Delphi process on their level of agreement with the various statements. Statements were progressively revised through separate voting iterations and were then finalized. Clinicians using these recommendations and suggestions should tailor patient management according to the risks and benefits of the treatment options, patient values and preferences, and local cost and resource allocations.

4.
Curr Oncol ; 21(2): e241-9, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24764709

RESUMO

BACKGROUND: We used an interview-assisted survey of patients with chronic myeloid leukemia (cml) at a single tertiary care centre to explore patient reactions to and preferences for, and the risk-acceptability of, stopping tyrosine kinase inhibitor (tki) treatment. METHODS: The study included patients with confirmed cml currently being treated with a tki. The survey was conducted by structured interview using a standard form. Patient preferences were explored in a case-based scenario using 0%-100% visual analog scales and 5-point Likert scales. Data were analyzed using proportions for dichotomous variables and medians and interquartile ranges for continuous variables. RESULTS: Of 63 patients approached, 56 completed the survey. Participant responses suggest that the idea of stopping tki use is appealing to many patients if there is a chance of long-term stable disease and a high probability of response upon restarting a tki. Participants were more likely to stop their tki as the risk of relapse decreased. Participants reported loss of disease control and failure of disease to respond to treatment as important concerns if they chose to stop their tki. CONCLUSIONS: Given the current 60% estimated rate of relapse after discontinuation of tki therapy, most patients with cml chose to continue with tki. However, at the lower relapse rates reported with second-generation tkis, participants were more undecided, demonstrating a basic understanding of risk. Contrary to our hypothesis, neither compliance nor occurrence of side effects significantly affected patient willingness to stop their tki.

5.
Phys Rev Lett ; 110(2): 027202, 2013 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-23383936

RESUMO

We investigate the magnetic coupling of Ni centers embedded in two-dimensional metal-coordination networks self-assembled from 7,7,8,8-tetracyanoquinodimethane (TCNQ) molecules on Ag(100) and Au(111) surfaces. X-ray magnetic circular dichroism measurements show that single Ni adatom impurities assume a spin-quenched configuration on both surfaces, while Ni atoms coordinating to TCNQ ligands recover their magnetic moment and exhibit ferromagnetic coupling. The valence state and the ferromagnetic coupling strength of the Ni coordination centers depend crucially on the underlying substrate due to the different charge state of the TCNQ ligands on the two surfaces. The results suggest a superexchange coupling mechanism via the TCNQ ligands.

6.
Nanotechnology ; 23(10): 105303, 2012 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-22361956

RESUMO

We demonstrate the fabrication and analysis of well-ordered high-resolution quasiperiodic nanostructures with feature sizes down to a few tens of nanometers using extreme ultraviolet interference lithography. A well-controlled mask manufacturing process for producing high quality transmission diffraction masks enables simple and fast fabrication of highly ordered 2D quasiperiodic structures using 5- and 8-beam interference setups.

7.
J Environ Qual ; 40(1): 83-9, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21488496

RESUMO

This study investigated the degree to which human activities through urbanization influence heavy metal concentrations in a suburban landscape in Ankeny, IA. Residential areas from different years in nine time periods of development were identified from aerial photos. Soil cores were collected from the center of the front yard of 10 randomly selected homes. Cores were subdivided into 0- to 5-, 5- to 10-, and 10- to 20-cm increments from a composite of five cores. The soils were analyzed for organic C, pH, and total Cd, Co, Cr, Cu, Ni, Pb, and Zn. Results showed that organic C increased and pH decreased with time, and that there was a general decreasing trend in heavy metal concentrations from the pre-1939 period until 1983-1990, after which there was a sharp increase in the concentrations of most of the metals. The mean Cu concentration ranged from 21 mg kg(-1) for the pre-1939 time period of development to 14.9 mg kg(-1) for the recent period of development (2003-2005). Nickel concentrations increased significantly with depth with means of 21.3 mg kg(-1) at depth 0 to 5 cm, 22.5 mg kg(-1) at depth 5 to 10 cm, and 23.0 mg kg(-1) at depth 10 to 20 cm. The concentrations of heavy metals were significantly intercorrelated, except Zn, suggesting their coexistence as mineral constituents or common contamination source. The concentrations of Cu and Pb in some locations could be due to anthropogenic inputs or higher organic matter content in soils adjacent to older homes. There appears to have been a source that caused an increase in Cd, Cr, Co, Cu, Pb, and Ni concentrations in soil adjacent to homes built between 1983 and 1990.


Assuntos
Metais Pesados/química , Poluentes do Solo/química , Solo/química , Iowa , População Suburbana , Fatores de Tempo
8.
Data Brief ; 39: 107488, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34729386

RESUMO

Sentinel-2 MSI is one of the core missions of the Copernicus Earth Observation programme of the European Union. This mission shows great potential to map the regional high-resolution spatio-temporal dynamics of land use and land cover. In tropical regions, despite the high revisiting time of 5 days including both Sentinel-2A and 2B satellites, the frequent presence of clouds, cloud-shadows, haze and other atmospheric contaminants are precluding the visibility of the Earth surface up to several months. In this paper we present four annual pan-tropical cloud-free composites computed and exported from Google Earth Engine (GEE) by making use of available Sentinel-2 L1C collection for the period spanning from 2015 to 2020. We furthermore propose empirical approaches to reduce the BRDF effect over tropical forest areas by showing pros and cons of image-based versus swath-based methodologies. Additionally, we provide a dedicated web-platform offering a fast and intuitive way to browse and explore the proposed annual composites as well as layers of potential annual changes as a ready-to-use means to visually identify and verify degradation and deforestation activities as well as other land cover changes.

9.
BMJ Open ; 11(9): e049557, 2021 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-34518263

RESUMO

INTRODUCTION: After deep vein thrombosis, up to 50% of patients develop post-thrombotic syndrome (PTS). PTS is a chronic condition that reduces quality of life (QOL). Cornerstones of PTS treatment include the use of elastic compression stockings but this treatment is usually incompletely effective and is burdensome. Venoactive drugs have been reported to be effective to treat chronic venous insufficiency (CVI). However, the level of evidence supporting their use in CVI in general and in PTS in particular is low. METHODS AND ANALYSIS: The MUFFIN-PTS trial is an academic, publically funded, multicentre randomised placebo-controlled trial assessing the efficacy of micronised purified flavonoid fraction (MPFF, Venixxa), a venoactive drug, to treat PTS. Eighty-six patients with PTS (Villalta score (VS) ≥5) and experiencing at least two of the following PTS manifestations among daily leg heaviness, cramps, pain or oedema will be randomised to receive 1000 mg of oral MPFF or a similar appearing placebo for 6 months, in addition to their usual PTS treatment. Total study follow-up will be 9 months, with visits at inclusion/baseline, 3, 6 and 9 months. Primary outcome is the proportion of patients with improvement in VS in each group, where improvement is defined as a decrease of at least 30% in VS or a VS <5 in the PTS-affected leg. Main secondary outcomes include QOL and patient satisfaction. ETHICS AND DISSEMINATION: Primary ethics approval was received from Centre intégré universitaire de santé et de services sociaux (CIUSSS) West-Central Montreal Research Ethics Board. Results of the study will be disseminated via peer-reviewed publications and presentations at scientific conferences. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Registry (NCT03833024); Pre-results.


Assuntos
Síndrome Pós-Trombótica , Trombose Venosa , Flavonoides/uso terapêutico , Humanos , Estudos Multicêntricos como Assunto , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Meias de Compressão
10.
Thromb Res ; 162: 88-92, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28416213

RESUMO

INTRODUCTION: Patients with cancer are at increased risk of thrombosis, particularly those with central venous catheter (CVC) placement, which may predispose to the development of upper extremity deep vein thrombosis (UEDVT). Standard treatment includes low molecular weight heparin (LMWH) or LMWH bridged to warfarin. The direct oral anticoagulants (DOACs) have become standard of care for uncomplicated venous thromboembolism (VTE), but research in patients with cancer is ongoing. OBJECTIVES: To assess rivaroxaban monotherapy in patients with cancer who develop UEDVT due to CVC for preservation of line function, and safety outcomes of VTE recurrence, bleeding risk and death. MATERIALS AND METHODS: Patients ≥18years of age with active malignancy and symptomatic proximal UEDVT with or without pulmonary embolism (PE), associated with a CVC, were eligible. Treatment included rivaroxaban 15mg oral twice daily for 3weeks, followed by 20mg oral daily for 9weeks. Patients were followed clinically for 12weeks to assess for line function, recurrent VTE and bleeding. RESULTS: Seventy patients (47 women) were included, with mean age 54.1years. The most common malignancy was breast cancer (41%). Preservation of line function was 100% at 12weeks. The risk of recurrent VTE at 12weeks was 1.43%, with one episode of fatal PE. 9 patients (12.9%) experienced 11 total bleeding episodes. CONCLUSIONS: Rivaroxaban showed promise in treating CVC-UEDVT in cancer patients, resulting in preserved line function. However, bleeding rates and a fatal pulmonary embolism on treatment are concerning safety outcomes necessitating further study before rivaroxaban can be recommended.


Assuntos
Cateteres Venosos Centrais/efeitos adversos , Inibidores do Fator Xa/uso terapêutico , Neoplasias/complicações , Rivaroxabana/uso terapêutico , Trombose Venosa Profunda de Membros Superiores/tratamento farmacológico , Inibidores do Fator Xa/farmacologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/patologia , Estudos Prospectivos , Rivaroxabana/farmacologia , Trombose Venosa Profunda de Membros Superiores/etiologia , Trombose Venosa Profunda de Membros Superiores/patologia
11.
Curr Oncol ; 25(2): e139-e145, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29719438

RESUMO

Background: A twice-weekly galactomannan (gm) screening protocol was implemented in high-risk hematology inpatients. Study objectives were to determine adherence to the protocol, use of selected resources, and patient outcomes. Methods: This retrospective cohort study compared outcomes of interest before and after implementation of gm screening. Adults undergoing matched related allogeneic hematopoietic stem-cell transplantation or induction chemotherapy for acute leukemia were eligible. Patients could be enrolled more than once and were evaluated as episodes. Adherence to the gm protocol was assessed in post-implementation episodes. Use of broad-spectrum antifungals (bsafs), consultations (infectious diseases, respirology), and diagnostic procedures (computed tomography imaging, bronchoalveolar lavage) were compared between phases, as were the patient outcomes of all-cause mortality and clinical success (alive and not taking a bsaf). Results: Of 182 episodes consecutively screened, 70 per phase were enrolled. Clinical characteristics and duration of assessment were similar for the phases. Full or partial adherence to the protocol was observed in 61 post-implementation episodes (87%), with full adherence in 40 episodes (57%). More episodes in the pre-implementation phase than in the post-implementation phase involved receipt of bsafs, consultations, and diagnostics (27% vs. 7%, p = 0.02; 46% vs. 26%, p = 0.014; and 46% vs. 31%, p = 0.083 respectively). Although mortality was similar in the two phases, clinical success at the final assessment was observed in fewer pre-implementation than post-implementation episodes (79% vs. 98%, p < 0.001). Conclusions: Implementation of a gm screening protocol was feasible and associated with significantly fewer episodes involving receipt of bsafs and consultations, and with significantly more episodes showing clinical success.


Assuntos
Leucemia/terapia , Mananas/sangue , Micoses/diagnóstico , Infecções Oportunistas/diagnóstico , Adulto , Idoso , Antifúngicos/uso terapêutico , Biomarcadores/sangue , Estudos de Viabilidade , Feminino , Galactose/análogos & derivados , Fidelidade a Diretrizes/estatística & dados numéricos , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Hospedeiro Imunocomprometido , Leucemia/imunologia , Masculino , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Micoses/tratamento farmacológico , Micoses/imunologia , Neutropenia/etiologia , Neutropenia/imunologia , Infecções Oportunistas/tratamento farmacológico , Infecções Oportunistas/imunologia , Guias de Prática Clínica como Assunto , Estudos Retrospectivos , Resultado do Tratamento
12.
J Thromb Haemost ; 5(4): 729-37, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17408406

RESUMO

BACKGROUND: Low-molecular-weight heparins (LMWH) have an antitumor effect in vitro and in experimental animal models of malignancy. Retrospective data suggest that it might improve survival in cancer patients. OBJECTIVES: To evaluate the effect of LMWH compared to placebo or no anticoagulant intervention on the survival of cancer patients. METHODS: We conducted a systematic review of randomized trials specifically evaluating the impact of LMWH on the survival of cancer patients. DATA SOURCES WERE: MEDLINE, EMBASE, HealthSTAR, Cochrane library, gray literature and cross-referencing from reference lists. Data extraction was performed by one reviewer, and accuracy was independently verified by a second reviewer. Meta-analysis was conducted using: (i) odds ratio (OR) and relative risk (RR); (ii) survival rates using censored endpoints; and (iii) hazard ratios (HR). RESULTS: The pooled HR in all patients was 0.83 (95% CI 0.70-0.99; P = 0.03), and in patients with advanced disease it was 0.86 (95% CI 0.74-0.99; P = 0.04), both in favor of the LMWH group. The results of the OR, RR and survival meta-analysis consistently favored the LMWH group. Sensitivity analyses according to tumor type were not conducted, because of a lack of information. CONCLUSIONS: LMWH improves overall survival in cancer patients, even in those with advanced disease. Additional trials are required to define the tumor types, disease stages and dosing schedules most likely to provide the greatest survival benefit.


Assuntos
Heparina de Baixo Peso Molecular/uso terapêutico , Neoplasias/tratamento farmacológico , Neoplasias/mortalidade , Anticoagulantes/uso terapêutico , Bases de Dados Bibliográficas , Humanos , Razão de Chances , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
13.
J Thromb Haemost ; 5(8): 1600-6, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17663731

RESUMO

BACKGROUND: The risk of decreased bone mineral density (BMD) with prophylactic dose long-term low-molecular-weight heparin (LMWH) is unknown. OBJECTIVES: We sought to determine whether long-term prophylactic dalteparin in pregnancy leads to loss of BMD. PATIENTS/METHODS: Patients in a substudy of an ongoing multicenter randomized trial investigating the effect of antepartum dalteparin prophylaxis on pregnancy outcomes in thrombophilic pregnant women were randomized to either dalteparin 5000 U s.c. daily until 20 weeks and then 5,000 U s.c. q12 h until >37 weeks or to the control group. The primary outcome was absolute spine BMD at six weeks postpartum. RESULTS: Of 77 patients eligible for the BMD substudy, 62 were analyzed. 33 patients received a mean of 212 days of dalteparin in the intervention group. 29 patients received a mean of 38 days of postpartum dalteparin in the control group. There was no difference in mean BMD between the intervention (1.11 g cm(-2)) and the control groups (1.14 g cm(-2)). Similarly, there was no difference in T-scores; the difference of -0.34 (95% confidence interval -0.93 to +0.25) in favor of the control group excludes a clinically important increase in fracture risk. CONCLUSIONS: Our results suggest that the use of long-term prophylactic dalteparin in pregnancy is not associated with a significant decrease in BMD. CLINICAL TRIAL REGISTRATION: ISRCTN87441504 at http://www.controlled-trials.com.


Assuntos
Anticoagulantes/efeitos adversos , Densidade Óssea/efeitos dos fármacos , Dalteparina/efeitos adversos , Trombofilia/tratamento farmacológico , Adulto , Doenças Ósseas Metabólicas , Feminino , Humanos , Pessoa de Meia-Idade , Osteoporose , Gravidez , Complicações Hematológicas na Gravidez , Resultado da Gravidez , Resultado do Tratamento
14.
Colloids Surf B Biointerfaces ; 40(1): 51-9, 2005 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-15620840

RESUMO

The phase and miscibility behavior of a triple-chain phosphatidylcholine (TPHPC) and a single-chain surfactant (CTAB) were investigated in aqueous dispersions and in monolayers at the air/water interface. CTAB can be incorporated in the TPHPC monolayer because of its complementary molecule shape and reduces the tilt angle of TPHPC. The type of phases and the phase sequence (L2 - LS) are the same in the pure TPHPC monolayer and in the TPHPC/CTAB (80:20 mol:mol) mixture. No indication of any ordering of adsorbed DNA was observed. In the aqueous dispersions, TPHPC exhibits an inverted hexagonal phase above the chain melting. The addition of 30 mol% CTAB leads to the appearance of a lamellar Lalpha phase. The binding of DNA to the mixture is obvious but this is accompanied by a separation of the two lipids what is supported by monolayer experiments. The system has no long-term stability. The main reason seems to be not only the stronger interaction of DNA with CTAB, but also especially the unexpected weak interaction between CTAB and TPHPC. The transfection efficiency is lower compared with lipofectamine. The main disadvantage of this system is the cytotoxicity of CTAB, which could not be lowered by incorporation of CTAB in the TPHPC bilayer.


Assuntos
DNA/química , Técnicas de Transferência de Genes , Lipídeos/química , Fosfatidilcolinas/química , Transfecção , Animais , Materiais Biocompatíveis/química , Cátions , DNA/metabolismo , Lipossomos/química , Substâncias Macromoleculares , Camundongos , Microscopia de Fluorescência , Células NIH 3T3 , Plasmídeos/metabolismo , Pressão , Espalhamento de Radiação , Propriedades de Superfície , Tensoativos , Sais de Tetrazólio/farmacologia , Tiazóis/farmacologia , Raios X , beta-Galactosidase/metabolismo
15.
J Thromb Haemost ; 13(3): 398-408, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25495610

RESUMO

BACKGROUND: Post-thrombotic syndrome (PTS) is a frequent chronic complication of deep vein thrombosis (DVT). OBJECTIVE: In the BioSOX study, we investigated whether inflammation markers predict the risk of PTS after DVT. METHODS: We measured C-reactive protein (CRP), ICAM-1, interleukin (IL)-6, and IL-10, at baseline, and 1 month and 6 months after a first proximal DVT, among 803 participants in the SOX trial. Participants were prospectively followed for 24 months for development of PTS. RESULTS: Median CRP levels at 1 month, ICAM-1 levels at baseline, 1 month and 6 months, IL-6 levels at 1 month and 6 months and IL-10 levels at 6 months were higher in patients who developed PTS than in those who did not. Multivariable regression with the median as a cutoff showed risk ratios (RRs) for PTS of 1.23 (95% confidence interval [CI] 1.05-1.45) and 1.25 (95% CI 1.05-1.48) for ICAM-1 at 1 month and 6 months, respectively, and 1.27 (95% CI 1.07-1.51) for IL-10 at 6 months. Quartile-based analysis demonstrated a dose-response association between ICAM-1 and PTS. ICAM-1 and IL-10 were also associated with PTS severity. Analysis of biomarker trajectories after DVT demonstrated an association between the highest-trajectory group of ICAM-1 and PTS. CONCLUSIONS: In this prospective study, ICAM-1 over time was most consistently associated with the risk of PTS. Further study is required to confirm these findings and assess their potential clinical relevance.


Assuntos
Mediadores da Inflamação/sangue , Molécula 1 de Adesão Intercelular/sangue , Síndrome Pós-Trombótica/etiologia , Trombose Venosa/sangue , Adulto , Idoso , Biomarcadores/sangue , Proteína C-Reativa/metabolismo , Canadá , Distribuição de Qui-Quadrado , Feminino , Seguimentos , Humanos , Interleucina-10/sangue , Interleucina-6/sangue , Modelos Lineares , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Síndrome Pós-Trombótica/diagnóstico , Síndrome Pós-Trombótica/prevenção & controle , Estudos Prospectivos , Medição de Risco , Fatores de Risco , Índice de Gravidade de Doença , Meias de Compressão , Fatores de Tempo , Resultado do Tratamento , Estados Unidos , Trombose Venosa/complicações , Trombose Venosa/diagnóstico , Trombose Venosa/terapia
16.
J Invest Dermatol ; 70(2): 105-10, 1978 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-304465

RESUMO

The distribution of thymus-derived (T) and bone marrow-derived (B) lymphocytes in 100 patients with psoriasis were studied by the rosetting techniques. Depression of the number of T lymphocytes forming spontaneous rosettes with sheep erythrocytes (E rosettes) occurred in 66% of patients, whereas no difference in B lymphocytes bearing C3 receptor (EAC rosettes) was observed between psoriatics and normals. The decrease in E rosettes was associated with the active phase of the disease. This disappeared 4-6 wk after onset of remission, which suggested that the abnormality in T-cell marker distribution is transitional. Lymphocytes forming neither E nor EAC rosettes, which were found to be significantly increased in active psoriasis, were identified as T lymphocytes since they reacquired normal E rosette function during short-term preincubation with concanavalin A (Con A). A serum factor was also demonstrated which inhibited E rosette formation by normal peripheral blood lymphocytes. Its activity increased linearly within 2 mo from the onset of skin lesions. The data suggest that in active psoriasis serum factors may be coated on the lymphocyte surface membrane which may be responsible for blocking of specific receptor for sheep erythrocytes and/or interfere with T lymphocyte function.


Assuntos
Psoríase/imunologia , Linfócitos T/imunologia , Animais , Linfócitos B/imunologia , Sítios de Ligação de Anticorpos , Membrana Celular/imunologia , Complemento C3 , Concanavalina A , Eritrócitos/imunologia , Feminino , Humanos , Masculino , Formação de Roseta , Ovinos/imunologia
17.
J Invest Dermatol ; 69(5): 451-7, 1977 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-908844

RESUMO

Hairless mice were administered various amounts of 8-methoxypsoralen (8-MOP) by gavage, followed by irradiation with ultraviolet light (UVA) two or more times per week for periods ranging from 1 to 12 months. The minimum phototoxic dose was 20 mg/kg body weight by this route of administration and potential for serious organ toxicity in long-term exposures was investigated. No histologic features of cutaneous malignancy were encountered under test conditions which produced prolonged phototoxicity, deep ulceration, cicatrization, and other deformities. Repeated daily gavaged doses of 20 mg psoralen/kg body weight in conjunction with twice weekly irradiation for 10 min with UVA elicited an erythematous phototoxic reaction, but did not give rise to subsequent skin lesions. 8-MOP in repeated daily gavage doses of 30 mg and 40 mg/kg body weight combined with twice weekly UVA irradiation for 10 min caused severe burning with subsequent scarring, but did not induce malignant tumors in experiments lasting lasting 8 months. No organ toxicity was seen except for toxic liver changes when severe cutaneous burn and pronounced ulcerations were produced. Limited immunologic studies disclosed no abnormalities in this system.


Assuntos
Metoxaleno/toxicidade , Pele/efeitos dos fármacos , Raios Ultravioleta , Animais , Metoxaleno/administração & dosagem , Camundongos , Camundongos Nus , Pele/efeitos da radiação
18.
Free Radic Biol Med ; 26(7-8): 850-7, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10232828

RESUMO

Metabolism of different nitroxides with piperidine structure used as spin labels in electron spin resonance (ESR) studies in vitro and in vivo was investigated in human keratinocytes of the cell line HaCaT by GC and GC-MS technique combined with S-band ESR. Besides the well known reduction of the nitroxyl radicals to the ESR silent hydroxylamines as primary products our results indicate the formation of the corresponding secondary amines. These reductions are inhibited by the thiol blocking agent N-ethylmaleimide and by the strong inhibitors of the thioredoxin reductase (TR) 2-chloro-2,4-nitrobenzene and 2,6-dichloroindophenol. The competitive inhibitor TR inhibitor azelaic acid and the cytochrome P-450 inhibitor metyrapone lack any effects. The rates of reduction to the hydroxylamines and secondary amines were dependent on the lipid solubility of the nitroxides. Therefore, it can be assumed that the nitroxides must enter the cells for their bioreduction. The mostly discussed intracellular nitroxide reducing substances ascorbic acid and glutathione were unable to form the secondary amines. In conclusion, our results suggest that the secondary amine represents one of the major metabolites of nitroxides besides the hydroxylamine inside keratinocytes formed via the flavoenzyme thioredoxin reductase most probably. Further metabolic conversions were detected with 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxyl and the benzoate of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl as substrates.


Assuntos
Queratinócitos/metabolismo , Óxidos de Nitrogênio/metabolismo , Óxidos de Nitrogênio/toxicidade , Piperidinas/metabolismo , Piperidinas/toxicidade , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Óxidos N-Cíclicos/metabolismo , Óxidos N-Cíclicos/toxicidade , Espectroscopia de Ressonância de Spin Eletrônica , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Queratinócitos/efeitos dos fármacos , Estrutura Molecular , Óxidos de Nitrogênio/química , Piperidinas/química , Marcadores de Spin , Relação Estrutura-Atividade
19.
Arch Dermatol ; 124(3): 387-91, 1988 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-3125794

RESUMO

Concentrations of arachidonic acid ranging from 0.1% to 2% were applied under occlusive dressings to psoriatic plaques in 45 patients. Alleviation of the clinical symptoms of psoriasis including complete clearing in some cases was obtained with the use of 0.5% to 2% arachidonic acid applied under occlusion every 24 to 48 hours five to seven times. Histologic examination showed polymorphonuclear leukocytes penetrating into the stratum corneum and formation of microabscesses or wide-spread accumulations of polymorphonuclear leukocytes in the stratum corneum, with its eventual destruction. The parakeratotic horny layer became detached; this was followed by restoration of the granular layer and an apparently normal stratum corneum. While arachidonic acid metabolites can be proinflammatory and proproliferative, they may also be important in the healing process for psoriasis.


Assuntos
Ácidos Araquidônicos/uso terapêutico , Psoríase/tratamento farmacológico , Administração Tópica , Ácido Araquidônico , Ácidos Araquidônicos/administração & dosagem , Ácidos Araquidônicos/efeitos adversos , Humanos , Psoríase/patologia , Pele/patologia
20.
Fundam Clin Pharmacol ; 3(3): 193-7, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2767604

RESUMO

A neurogenic inflammation was induced by electrical stimulation of the exposed saphenous or sciatic nerve of male rats. The increase in paw weight of the stimulated leg was used as parameter for degree of inflammation. The content of substance P decreased significantly in the skin supplied by the antidromic stimulated nerves. Substances were tested whose effectivity in neurogenic inflammation is as yet unknown. Inhibition of the angiotensin converting enzyme by the inhibitor captopril did not yield an indirect reference for a causative role of substance P in neurogenic inflammation. The activity of catecholamines refers to the possible importance of blood vessel and/or cyclic nucleotide level alteration in this special type of inflammation.


Assuntos
Anti-Inflamatórios/farmacologia , Inflamação/fisiopatologia , Fenômenos Fisiológicos do Sistema Nervoso , Animais , Edema/induzido quimicamente , Edema/patologia , Estimulação Elétrica , Masculino , Ratos , Ratos Endogâmicos
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