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1.
Anal Chem ; 93(42): 14231-14237, 2021 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-34644048

RESUMO

We studied the diffusion properties of lipophilic vitamin E (VE) through bicontinuous microemulsions (BME) using both electrochemical and fluorescence correlation spectroscopy (FCS) measurements. We investigated the effect of different composition ratios of micro-water and micro-oil phases in BMEs (W/OBME). When we employed the BME with a lower W/OBME value of 40/60 (oil-rich BME) as an electrolyte solution, we obtained a larger current response from VE at a fluorinated nanocarbon film electrode. Further voltammetric studies revealed that a higher VE diffusion coefficient was observed in the oil-rich BME. The FCS results also exhibited faster diffusion through the oil-rich BME, which played a significant role in accelerating the VE diffusion probably due to the widening of the micro-oil phase pathway in the BME. Moreover, the effect of increasing the VE diffusion was pronounced at the interface between the electrode surface and the BME solution. These results indicate that controlling the conditions of the BME as the measurement electrolyte is very effective for achieving superior electrochemical measurements in a BME.


Assuntos
Vitamina E , Água , Difusão , Eletrodos , Emulsões
2.
Anal Chem ; 92(20): 14031-14037, 2020 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-32942844

RESUMO

Bicontinuous microemulsion (BME)-based hydrogel films were integrated with screen-printed electrodes (SPEs) comprising working, counter, and reference electrodes to form stand-alone, semi-solid-state electrochemical systems that do not require an outer electrolyte solution. The gel network of the BME hydrogel only exists in the microaqueous phase and retains the structure of the entire BME gel. Following gelation, a microaqueous phase with sufficient ionic strength ensured effective ionic conductivity, even in thin gel films. This enabled the electrochemical reaction to proceed using a thin gel film as an electrolyte solution. However, an intact micro-oil phase with no gel network enabled efficient extraction from an external oil solution and exhibited rapid electrochemistry that was comparable to that of a BME solution. Cyclic voltammograms of lipophilic redox species in oil using the gel-integrated SPE system demonstrated successfully in the oil itself and in the air with dropped oil onto the system.

3.
J Stroke Cerebrovasc Dis ; 28(1): 70-75, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30268366

RESUMO

BACKGROUND: Intravenous thrombolysis with recombinant tissue plasminogen activator and endovascular mechanical thrombectomy are known to be the most effective treatments in the acute phase of ischemic stroke. However, the safety of intravenous systemic thrombolysis with recombinant tissue plasminogen and endovascular mechanical thrombectomy during pregnancy is not well-confirmed. We describe a case of an uneventful pregnancy and delivery after thrombolysis plus endovascular mechanical thrombectomy for acute ischemic stroke. MATERIALS AND METHODS: The patient's medical records were reviewed retrospectively. A comprehensive systemic literature search of the PubMed database was conducted. CASE PRESENTATION: A 36-year-old woman at 21 weeks gestation presented with a sudden headache, dysarthria, and right hemiparesis. Magnetic resonance angiography revealed occlusion of the left internal carotid artery. Recombinant tissue plasminogen activator was administered intravenously 193 minutes after symptom onset, and endovascular mechanical thrombectomy was started immediately. Recanalization of her left internal carotid artery was achieved. The patient continued to experience mild hemiparesis after the initial treatment and started rehabilitation. The fetus remained in satisfactory condition during the pregnancy and was delivered at 38 weeks without obvious maternal or neonatal complications. No apparent abnormality has been observed in the newborn in the first year of life. CONCLUSIONS: Intravenous recombinant tissue plasminogen and endovascular mechanical thrombectomy could be considered as treatment for acute ischemic stroke during pregnancy unless high risks of hemorrhage or preterm labor are expected.


Assuntos
Isquemia Encefálica/terapia , Complicações Cardiovasculares na Gravidez/terapia , Acidente Vascular Cerebral/terapia , Trombectomia , Terapia Trombolítica , Adulto , Isquemia Encefálica/diagnóstico por imagem , Feminino , Humanos , Nascido Vivo , Gravidez , Complicações Cardiovasculares na Gravidez/diagnóstico por imagem , Acidente Vascular Cerebral/diagnóstico por imagem
4.
Gan To Kagaku Ryoho ; 46(7): 1165-1170, 2019 Jul.
Artigo em Japonês | MEDLINE | ID: mdl-31296823

RESUMO

Hiccups are occasionally experienced by most individuals, and although not life-threatening, they may leadto a decline in quality of life. Shitei extract(shitei, persimmon calyx)may be usedfor the treatment of hiccups. The effects of shitei extract were investigatedin patients admittedto the Japanese RedCross Musashino Hospital between October 2011 andM ay 2016. Numerous prescriptions for shitei extract were reportedin the Department of Respiratory Organs andNeurosurgery. The primary causes of hiccups were chemotherapy andbrain disease. Of 149 patients, 107(71.8%)sufferedfrom hiccups. None of the patients reported adverse events related to the administration of shitei extract. The incidence of hiccups was significantly higher in patients with brain disease(p=0.0075), treatedwith chemotherapy for cancer(p=0.0402), or requiring the insertion of a gastric tube(p=0.0065). Among those treatedwith chemotherapy for cancer, shitei extract was effective against hiccups in 82.0% patients(45 of 55). Furthermore, four patients receivedprophylaxis with shitei extract for the prevention of hiccups after chemotherapy. In conclusion, these results indicate that shitei extract is an effective and safe therapeutic drug for the treatment of hiccups. In particular, shitei extract was effective in the prevention of hiccups after chemotherapy.


Assuntos
Soluço , Neoplasias , Humanos , Medicina Tradicional Chinesa , Qualidade de Vida
5.
Europace ; 20(10): 1591-1597, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-29244081

RESUMO

Aims: Some studies have shown that the type of atrial fibrillation (AF), whether paroxysmal AF (PAF) or persistent or permanent AF (PeAF), affects the incidence of ischaemic stroke. This study sought to determine the relationship between the AF pattern and the severity and brain volume of infarction in an AF population including transient ischaemic attack (TIA) patients. Methods and results: This was a retrospective observational study. We studied 161 consecutive patients who were admitted to our stroke care unit with cardiogenic embolism or TIA related to non-valvular AF (age 79 ± 9.5, 78 females, and 87 PAF patients). We evaluated the differences in severity and infarct volume between the types of AF. Additionally, we divided the patients into three groups according to severe stroke (n = 38), TIA (n = 28), and those who were neither (stroke, n = 95) for the assessment of the predictors of severe stroke and TIA. Persistent or permanent atrial fibrillation patients with acute cardiogenic stroke or TIA had worse peak National Institute of Health Stroke Scale (NIHSS) scores [PAF median 4 (range 3-14), PeAF 17 (5.8-25); P < 0.0001] and worse NIHSS scores at discharge [PAF 2.0 (1-7), PeAF 11 (3-22); P < 0.0001]. Their infarct brain volume assessed by computed tomography or magnetic resonance imaging was also larger [PAF 4.4 (1.1-32) mL, PeAF 64 (6.9-170) mL; P < 0.0001]. Multivariate analysis of severe stroke vs. non-severe stroke patients showed that having PeAF was the only independent predictor of severe stroke [odds ratio (OR) 4.27, 95% confidence interval (CI) 1.91-10.2; P = 0.0003]. Comparison of TIA vs. non-TIA patients showed that PeAF (OR 0.120, 95% CI 0.0230-0.444; P = 0.0008) and anticoagulant use (OR 8.24, 95% CI 2.15-40.8; P = 0.0018) were independent predictors of TIA. Conclusion: Cardiogenic emboli due to non-valvular PeAF are associated with a worse acute clinical course and greater volume of infarction than those due to PAF.


Assuntos
Fibrilação Atrial/fisiopatologia , Infarto Encefálico/fisiopatologia , Embolia Intracraniana/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Fibrilação Atrial/complicações , Infarto Encefálico/diagnóstico por imagem , Infarto Encefálico/etiologia , Feminino , Humanos , Embolia Intracraniana/diagnóstico por imagem , Embolia Intracraniana/etiologia , Ataque Isquêmico Transitório/diagnóstico por imagem , Ataque Isquêmico Transitório/etiologia , Ataque Isquêmico Transitório/fisiopatologia , Imageamento por Ressonância Magnética , Masculino , Estudos Retrospectivos , Índice de Gravidade de Doença , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/fisiopatologia
6.
Neurol Sci ; 39(10): 1713-1716, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29974307

RESUMO

No evidence of disease activity-3 (NEDA-3), defined as absence of clinical relapse, disability progression, and brain magnetic resonance imaging (MRI) activity, has emerged as the therapeutic target of disease-modifying therapy for multiple sclerosis (MS). However, recent studies have revealed that NEDA-3 might not be sufficient to prevent cognitive deterioration and predict long-term disability. In addition to NEDA-3, brain atrophy has recently been recognized as a pivotal biomarker that is closely associated to disability in patients with MS. This retrospective observational study included 22 Japanese MS patients with relatively mild disease (median expanded disability status scale = 1.75). Fifteen patients (68%) received disease-modifying therapy (DMT), including interferon (IFN)-ß (n = 6), IFN-ß, or azathioprine followed by fingolimod (n = 4), fingolimod (n = 4), and IFN-ß followed by natalizumab (n = 1). It revealed that 14 (64.6%) patients achieved NEDA-3 in the 2-year observational period. However, nine (64.3%) of the patients with NEDA-3 were revealed to have a significant BVL, defined as ≥ 0.4% per year. Importantly, these nine patients included all patients receiving IFN-ß therapy (n = 6), whereas patients without BVL included none of these patients. Conversely, patients treated with fingolimod following IFN-ß did not have significant BVL. These results indicate that evaluation of NEDA-4 is encouraged especially in patients with IFN-ß therapy in MS clinical practice in Japan although Japanese MS patients have generally been thought to possess a milder disease including brain atrophy compared to their Western counterparts.


Assuntos
Encéfalo/patologia , Esclerose Múltipla/diagnóstico por imagem , Esclerose Múltipla/fisiopatologia , Adulto , Encéfalo/diagnóstico por imagem , Encéfalo/efeitos dos fármacos , Avaliação da Deficiência , Progressão da Doença , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Fatores Imunológicos/uso terapêutico , Japão , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/tratamento farmacológico , Estudos Retrospectivos
7.
J Stroke Cerebrovasc Dis ; 27(7): 1914-1920, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29602617

RESUMO

PURPOSE: Medication is an important risk factor for delirium; however, the association between delirium and prehospitalization medication is unclear. We investigated the association between prestroke medication and poststroke delirium. MATERIALS AND METHODS: All patients hospitalized in the stroke care unit from September 2011 to September 2012 were selected, and their delirium symptoms, patient information, and pre- and poststroke medications were analyzed. Delirium was defined as a score of 4 or higher on the Intensive Care Delirium Screening Checklist. Factors that were related to delirium were extracted using univariate analysis, and the independent risk factors were determined using multivariate analysis. RESULTS: Of the 269 patients analyzed, 97 (36%) experienced delirium. Univariate analysis revealed significant differences between the delirium and nondelirium groups in age, dementia, previous cerebrovascular disease, craniotomy, all insertion-tube types, and 6 categories of prestroke medication. Prestroke polypharmacy was associated with poststroke delirium (P = .002). Multivariate analysis showed that taking antianxiety agents or sleep aids was an independent risk factor for delirium (odds ratio: 3.17, 95% confidence interval: 1.16-8.82). CONCLUSIONS: The present study suggests that prestroke medication affects the onset of poststroke delirium. These findings can contribute to the prediction and prevention of this condition.


Assuntos
Delírio/epidemiologia , Delírio/etiologia , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/epidemiologia , Idoso , Ansiolíticos/efeitos adversos , Ansiolíticos/uso terapêutico , Feminino , Humanos , Hipnóticos e Sedativos/efeitos adversos , Hipnóticos e Sedativos/uso terapêutico , Incidência , Modelos Logísticos , Masculino , Análise Multivariada , Polimedicação , Estudos Retrospectivos , Fatores de Risco
8.
Anal Chem ; 89(11): 5976-5982, 2017 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-28466637

RESUMO

This paper reports an on-chip electrochemical assessment of the DNA methylation status in genomic DNA on a conductive nanocarbon film electrode realized with combined bisulfite restriction analysis (COBRA). The film electrode consists of sp2 and sp3 hybrid bonds and is fabricated with an unbalanced magnetron (UBM) sputtering method. First, we studied the effect of the sp2/sp3 ratio of the UBM nanocarbon film electrode with p-aminophenol, which is a major electro-active product of the labeling enzyme from p-aminophenol phosphate. The signal current for p-aminophenol increases as the sp2 content in the UBM nanocarbon film electrode increases because of the π-π interaction between aromatic p-aminophenol and the graphene-like sp2 structure. Furthermore, the capacitative current at the UBM nanocarbon film electrode was successfully reduced by about 1 order of magnitude thanks to the angstrom-level surface flatness. Therefore, a high signal-to-noise ratio was achieved compared with that of conventional electrodes. Then, after performing an ELISA-like hybridization assay with a restriction enzyme, we undertook an electrochemical evaluation of the cytosine methylation status in DNA by measuring the oxidation current derived from p-aminophenol. When the target cytosine in the analyte sequence is methylated (unmethylated), the restriction enzyme of HpyCH4IV is able (unable) to cleave the sequence, that is, the detection probe cannot (can) hybridize. We succeeded in estimating the methylation ratio at a site-specific CpG site from the peak current of a cyclic voltammogram obtained from a PCR product solution ranging from 0.01 to 1 nM.


Assuntos
Metilação de DNA , Enzimas de Restrição do DNA/metabolismo , Aminofenóis/química , Carbono/química , Citosina/metabolismo , Técnicas Eletroquímicas , Eletrodos , Nanopartículas/química
9.
Anal Chem ; 88(5): 2944-51, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26829010

RESUMO

Au nanoparticle (AuNP)-embedded carbon films were formed with a one-step reproducible process by using unbalanced magnetron (UBM) cosputtering to make it possible to detect As(3+) in water. The sputtered Au components formed NPs (typically 5 nm in diameter) spontaneously in the carbon films, owing to the poor intermiscibility of Au with carbon. The surface contents of embedded AuNPs in the carbon film were widely controllable (Au = 13-21 at %) by regulating the target powers of Au and carbon individually. The obtained film had a flat surface (Ra = 0.1 nm) despite the fact the AuNPs were partially exposed at the surface. By anodic stripping voltammetry (ASV) As(3+) detection, a limit of detection of 0.55 ppb and linear dynamic range of 1-100 ppb were obtained with our electrode. These values meet the requirements imposed by international regulation. Moreover, our electrode structure realized good electrode stability for repetitive ASV measurements (relative standard deviation (RSD) = 11.7%, n = 15) because the partially embedded AuNP structures prevented the AuNPs from detaching from the surface. This result was achieved by the electrode recovery only by a potential scan from 0.1 to 1.5 V. Our electrodes can be stocked for a long time (2 years) with maintaining the electrode performance, which is very attractive for practical electrode. Selectivity test by using Tsukuba tap water added 10 ppb As(3+) and 1000 ppb Cu(2+) was successfully achieved with existence of 0.1 M EDTA (RSD = 2.6%, n = 3). The ASV results with tap water samples agreed well with those by the conventional ICPMS method.

10.
J Neurol Neurosurg Psychiatry ; 85(1): 85-91, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24027298

RESUMO

OBJECTIVE: To investigate whether or not the lesions in sporadic amyotrophic lateral sclerosis (ALS) originate from a single focal onset site and spread contiguously by prion-like cell-to-cell propagation in the rostrocaudal direction along the spinal cord, as has been hypothesised (the 'single seed and simple propagation' hypothesis). METHODS: Subjects included 36 patients with sporadic ALS and initial symptoms in the bulbar, respiratory or upper limb regions. Abnormal spontaneous activities in needle electromyography (nEMG)-that is, fibrillation potentials, positive sharp waves (Fib/PSWs) or fasciculation potentials (FPs)-were compared among the unilateral muscles innervated by different spinal segments, especially between the T10 and L5 paraspinal muscles, and between the vastus medialis and biceps femoris. Axon length and the proportion of muscle fibre types, which are both related to motoneuronal vulnerability in ALS, are similar in the paired muscles. RESULTS: Fourteen of 36 patients showed a non-contiguous distribution of nEMG abnormalities from the onset site, with skipping of intermediate segments. In eight of them, the non-contiguous pattern was evident between paired muscles with the same motoneuronal vulnerability. The non-contiguously affected lumbosacral lesions involved motoneuron columns horizontally or radially proximate to one another, appearing to form a cluster in four of the eight patients. FPs, known to precede Fib/PSWs, were shown more frequently than Fib/PSWs in all the lumbosacral segments but L5, suggesting that 2nd hits occur at L5 and then spread to other lumbosacral segments. CONCLUSIONS: In sporadic ALS, the distribution of lower motoneuron involvement cannot be explained by the 'single seed and simple propagation' hypothesis alone. We propose a 'multifocal hits and local propagation' hypothesis instead.


Assuntos
Esclerose Lateral Amiotrófica/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Interpretação Estatística de Dados , Progressão da Doença , Eletromiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neurônios Motores/fisiologia , Músculo Esquelético/patologia
11.
Stroke ; 44(2): 512-5, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23192760

RESUMO

BACKGROUND AND PURPOSE: Prominent posterior cerebral artery (PCA) laterality upon 3-dimensional time-of-flight magnetic resonance angiography is often encountered in patients with middle cerebral artery occlusion. We hypothesized that this sign is correlated with improved functional outcome in patients with middle cerebral artery occlusion treated with intravenous recombinant tissue plasminogen activator. METHODS: Fifty acute ischemic stroke patients with middle cerebral artery occlusion were treated with intravenous recombinant tissue plasminogen activator from April 2007 to October 2009. All patients routinely underwent initial (first 3 hours) magnetic resonance scans on admission, and additional follow-up (14-21 days after stroke onset) computed tomography scans. Two film readers blinded to all clinical information assessed the presence or absence of PCA laterality on magnetic resonance angiography. We retrospectively analyzed the clinical and radiologic data on all patients. RESULTS: Out of 50 patients, 20 showed PCA laterality on magnetic resonance angiography. National Institute of Health Stroke Scale score 7 days after stroke onset was significantly lower (P=0.007), and infarct volume on follow-up computed tomography was significantly smaller (P=0.009) in patients with PCA laterality than in patients without this sign. Multivariate logistic regression analyses showed an adjusted odds ratio of 8.49 for a favorable outcome (modified Rankin Scale score 0-1 at 6 months) in patients with PCA laterality (95% CI: 1.82 to 55.8, P=0.005). CONCLUSIONS: The presence of PCA laterality on magnetic resonance angiography before intravenous recombinant tissue plasminogen activator can be used as a predictor of favorable functional outcome in patients with middle cerebral artery occlusion, probably due to improvement of recanalization rate.


Assuntos
Infarto da Artéria Cerebral Média/diagnóstico , Angiografia por Ressonância Magnética , Artéria Cerebral Posterior/patologia , Recuperação de Função Fisiológica , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Seguimentos , Humanos , Infarto da Artéria Cerebral Média/tratamento farmacológico , Infarto da Artéria Cerebral Média/fisiopatologia , Angiografia por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Recuperação de Função Fisiológica/fisiologia , Estudos Retrospectivos , Método Simples-Cego , Fatores de Tempo , Ativador de Plasminogênio Tecidual/uso terapêutico , Resultado do Tratamento
12.
Anal Chem ; 85(20): 9845-51, 2013 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-24053755

RESUMO

A nitrogen-doped nanocarbon film electrode with mixed sp(2) and sp(3) bonds formed using the electron cyclotron resonance (ECR) sputtering method was studied with respect to the relationship between nitrogen concentration and electrochemical performance. The film (N-ECR) has a nanocrystalline structure, and the sp(3) content increases with increasing nitrogen concentration unlike the recently reported nitrogen-containing tetrahedral amorphous carbon film.1 The film has a very smooth surface with an average roughness of 0.1 to 0.2 nm, which is almost independent of nitrogen concentration. In contrast, the ratio of nitrogen-containing graphite-like bonding is high at low nitrogen concentrations, and then pyridine-like bonding increases as the nitrogen concentration increases. These variations in the chemical structures and the sp(2) and sp(3) content greatly change the electrochemical performance. The N-ECR electrode shows a wider potential window (∼3.8 V) than a pure nanocarbon electrode (∼3.1 V) due to its higher sp(3) content. The N-ECR electrode (N = 9.0 at. %) shows improved electrochemical activity because the lowest peak separation of Fe(CN)6(3-/4-) was observed at this nitrogen concentration. The oxygen and hydrogen peroxide (H2O2) reduction potentials at the N-ECR electrode shifted about 0.3 and 0.15 V, respectively, and the peak height of H2O2 is greatly increased. As a result, a linear relationship was obtained from 0.2 to 17 mM for the reductive current detection of H2O2. The N-ECR electrode also shows better activity for oxidizing certain biomolecules. The oxidation potentials of guanosine and adenosine decreased about 0.1 V, suggesting that the N-ECR electrode is suitable for use as a biosensing platform.


Assuntos
Carbono/química , Ciclotrons , Elétrons , Nitrogênio/química , Eletroquímica , Eletrodos , Peróxido de Hidrogênio/química , Oxirredução , Oxigênio/química
13.
Anal Chem ; 85(21): 9996-9, 2013 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-24117377

RESUMO

The development of a biocatalytic electrode consisting of cytochrome P450 (CYP) proteins would be a key technology with which to establish simple drug metabolizing biosensors or screening devices for drug inhibitors. We have successfully detected the direct electron transfer (DET) from a human CYP layer or a CYP microsome adsorbed on a bare indium tin oxide (ITO) film electrode without any modification layers and applied it to drug metabolism evaluation. We compared the electrocatalytic properties of the two ITO films with different surface nanostructures (polycrystalline or amorphous). CYP on polycrystalline ITO film enhanced the electron transfer rate of oxygen reduction about fifteen times more than with amorphous film. The polycrystalline ITO film was a suitable electrode for the adsorption of CYP proteins while maintaining efficient DET and enzymatic activity, probably because of its larger surface area and negatively charged surface. The oxygen reduction current at the polycrystalline ITO film electrodes had increased 3- to 4-fold, specifically coupled with the oxidation of drugs (testosterone and quinidine) by the monooxygenase activity of CYP. In contrast, the oxygen reduction current completely disappeared in the presence of the CYP inhibitor (ketoconazole). Similar results could be obtained from the CYP microsome with sufficiently clear responses. These results indicate that the CYP modified polycrystalline ITO electrode offers the potential for electrochemically evaluating CYP activity for drug metabolism with a simple configuration.


Assuntos
Técnicas Biossensoriais , Sistema Enzimático do Citocromo P-450/química , Eletroquímica/métodos , Enzimas Imobilizadas/química , Compostos de Estanho/química , Cristalização
14.
Analyst ; 138(21): 6463-8, 2013 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-24027778

RESUMO

Electrochemical biosensors consisting of cytochrome P450 enzyme modified electrodes have been developed to provide a simple method for screening the metabolism of a drug and its inhibitor. Here, we report a very simple electrochemically driven biosensor for detecting drug metabolism and its inhibition based on cytochrome P450 3A4 (CYP3A4) and a carbon nanofiber (CNF) modified film electrode without any other modified layers such as mediator films. Direct electron transfer (DET) between CYP3A4 and CNFs was observed at a formal potential of -0.302 V. The electrocatalytic reduction current increased with the addition of drugs including testosterone and quinidine. In contrast, the reduction current was greatly suppressed in the presence of ketoconazole, which is a CYP3A4 inhibitor. CNFs with high conductivity, a large surface area and sufficient edge planes provide a suitable microenvironment for achieving excellent DET and biocatalysis properties, which could not be observed when we used other carbon materials such as carbon nanotube (CNT) and carbon black (CB) modified electrodes, indicating that our system is promising as a new bioelectronic platform for electrochemical biosensing.


Assuntos
Citocromo P-450 CYP3A/química , Citocromo P-450 CYP3A/metabolismo , Técnicas Eletroquímicas/métodos , Nanotubos de Carbono/química , Preparações Farmacêuticas/metabolismo , Avaliação Pré-Clínica de Medicamentos/métodos , Eletrodos , Humanos , Preparações Farmacêuticas/análise
15.
Intern Med ; 62(11): 1653-1657, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-36288992

RESUMO

Neuromyelitis optica spectrum disorders have been previously reported in a paraneoplastic context, although there is no clear consensus on their pathogenesis. We herein report a case of aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder in a 64-year-old woman with colorectal cancer. She underwent tumor resection, resulting in serum aquaporin-4 antibody titers subsequently becoming negative. Serum samples were also positive for glucose-regulated protein 78 antibody, which has recently been suggested to be a novel factor in the disruption of the blood-brain barrier. Serological and pathological investigations in this case highlight the role and involvement of aquaporin-4 and glucose-regulated protein 78 antibodies in paraneoplastic conditions.


Assuntos
Neoplasias Colorretais Hereditárias sem Polipose , Neuromielite Óptica , Feminino , Humanos , Pessoa de Meia-Idade , Autoanticorpos , Chaperona BiP do Retículo Endoplasmático , Neoplasias Colorretais Hereditárias sem Polipose/complicações , Aquaporina 4
16.
J Colloid Interface Sci ; 641: 348-358, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36940591

RESUMO

HYPOTHESES: Bicontinuous microemulsions (BMEs) have attracted attention as unique heterogeneous mixture for electrochemistry. An interface between two immiscible electrolyte solutions (ITIES) is an electrochemical system that straddles the interface between a saline and an organic solvent with a lipophilic electrolyte. Although most BMEs have been reported with nonpolar oils, such as toluene and fatty acids, it should be possible to construct a sponge-like three-dimensionally expanded ITIES comprising a BME phase. EXPERIMENTS: Dichloromethane (DCM)-water microemulsions stabilized by a surfactant were investigated in terms of the concentrations of co-surfactants and hydrophilic/lipophilic salts. A Winsor III microemulsion three-layer system, consisting of an upper saline phase, a middle BME phase, and a lower DCM phase, was prepared, and electrochemistry was conducted in each phase. FINDINGS: We found the conditions for ITIES-BME phases. Regardless of where the three electrodes were placed in the macroscopically heterogeneous three-layer system, electrochemistry was possible, as in a homogeneous electrolyte solution. This indicates that the anodic and cathodic reactions can be divided into two immiscible solution phases. A redox flow battery comprising a three-layer system with a BME as the middle phase was demonstrated, paving the way for applications such as electrolysis synthesis and secondary batteries.

17.
ACS Nano ; 16(7): 10589-10599, 2022 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-35758937

RESUMO

General synthesis of a highly oriented metallic heterodimer array based on a selective electrodeposition technique onto a metal nanoparticle-embedded carbon film is proposed, which enables the preparation of heterodimers with a wide variety of metal combinations. This method requires no surfactant, capping agent, organic solvent, or heat treatment. As a representative metal combination, a nickel (Ni)/palladium (Pd) heterodimer array was prepared by selective electrodeposition of Ni nanoparticles (Ni NPs) on top of partially exposed Pd NPs embedded in carbon film electrodes fabricated by a cosputtering technique. Such a selective electrodeposition becomes possible by utilizing the difference in electrodeposition overpotentials between carbon and Pd NP surfaces. X-ray photoelectron spectroscopy revealed a charge transfer from Ni NPs to Pd NPs, implying that the catalytic and optical properties can be expected to be controllable. The formed heterodimer array structure was mechanically stable against ultrasonication in ethanol for over 1 h because most parts of the Pd NPs were tightly embedded in the carbon film. After conversion from Ni to nickel hydroxide (Ni(OH)2), the electrode showed high electrocatalytic activity toward glucose oxidation, with a higher turnover rate and lower overpotential compared to Ni(OH)2 electrodeposited on pure carbon film electrodes.

18.
Anal Sci ; 38(2): 401-408, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35314987

RESUMO

We evaluated the dispersion and diffusion of fluorescent-labeled lipophilic vitamin E (VE) in microemulsions (MEs) including water-in-oil (W/O) type ME, oil-in-water (O/W) type ME, and bicontinuous ME (BME), using fluorescence correlation spectroscopy (FCS). We prepared a fluorescent ATTO 488 or BODIPY group labeled VE (VE-ATTO or VE-BODIPY). VE-ATTO possesses lipophilic and hydrophilic parts, while VE-BODIPY consists solely of the lipophilic part. The VE-ATTO dissolved in heptane solution as an oil phase appeared hot pink in color due to the solvatochromism effect under room light and almost no fluorescent signal, which was unlike the VE-ATTO dissolved in ME solutions and all the VE-BODIPY solutions (typical fluorescent green color). The FCS measurement proved that VE-BODIPY diffuses faster than VE-ATTO. This is presumably because the "surfactant-like" VE-ATTO is localized and trapped at the micro-water/micro-oil interface of the MEs, while the VE-BODIPY exists in the ME phase and macro-oil phase with good dispersion. These results demonstrate that FCS is a powerful tool for the rapid evaluation of the lipophilic probe behavior in heterogeneous ME solutions.


Assuntos
Tensoativos , Vitamina E , Emulsões/química , Interações Hidrofóbicas e Hidrofílicas , Espectrometria de Fluorescência/métodos , Tensoativos/química
19.
Intern Med ; 61(10): 1599-1602, 2022 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-34707043

RESUMO

A 70-year-old woman undergoing glucocorticoid therapy for cardiac sarcoidosis was brought to our hospital with the sudden onset of right hemiplegia and aphasia. Brain magnetic resonance imaging showed a high diffusion-weighted imaging signal in the left frontotemporal lobe and disruption of blood flow in the M1 segment of the left middle cerebral artery. Hence, she underwent thrombolysis and mechanical thrombectomy, resulting in marked improvement in her neurological symptoms. A pathologic evaluation of the thrombus suggested its cardiogenicity, and the absence of any obvious abnormality other than a left ventricular aneurysm indicated stroke due to a cardioembolic etiology secondary to cardiac sarcoidosis.


Assuntos
AVC Embólico , Sarcoidose , Acidente Vascular Cerebral , Trombose , Idoso , Imagem de Difusão por Ressonância Magnética , Feminino , Humanos , Sarcoidose/diagnóstico , Sarcoidose/diagnóstico por imagem , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/etiologia , Trombectomia/métodos , Trombose/complicações , Trombose/diagnóstico por imagem
20.
J Am Chem Soc ; 133(13): 4840-6, 2011 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-21384894

RESUMO

We have developed a new carbon film electrode material with thornlike surface nanostructures to realize efficient direct electron transfer (DET) with enzymes, which is very important for various enzyme biosensors and for anodes or cathodes used in biofuel cells. The nanostructures were fabricated using UV/ozone treatment without a mask, and the obtained nanostructures were typically 2-3.5 nm high as confirmed by atomic force microscopy measurements. X-ray photoelectron spectroscopy and transmission electron microscopy revealed that these nanostructures could be formed by employing significantly different etching rates depending on nanometer-order differences in the local sp(3) content of the nanocarbon film, which we fabricated with the electron cyclotron resonance sputtering method. These structures could not be realized using other carbon films such as boron-doped diamond, glassy carbon, pyrolyzed polymers based on spin-coated polyimide or vacuum-deposited phthalocyanine films, or diamond-like carbon films because those carbon films have relatively homogeneous structures or micrometer-order crystalline structures. With physically adsorbed bilirubin oxidase on the nanostructured carbon surface, the DET catalytic current amplification was 30 times greater than that obtained with the original carbon film with a flat surface. This efficient DET of an enzyme could not be achieved by changing the hydrophilicity of the flat carbon surface, suggesting that DET was accelerated by the formation of nanostructures with a hydrophilic surface. Efficient DET was also observed using cytochrome c.


Assuntos
Nanotubos de Carbono/química , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/química , Ozônio/química , Raios Ultravioleta , Adsorção , Biocatálise , Transporte de Elétrons , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Tamanho da Partícula , Propriedades de Superfície
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