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1.
Sensors (Basel) ; 22(12)2022 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35746319

RESUMO

Nowadays, improving the traffic safety of visually impaired people is a topic of widespread concern. To help avoid the risks and hazards of road traffic in their daily life, we propose a wearable device using object detection techniques and a novel tactile display made from shape-memory alloy (SMA) actuators. After detecting obstacles in real-time, the tactile display attached to a user's hands presents different tactile sensations to show the position of the obstacles. To implement the computation-consuming object detection algorithm in a low-memory mobile device, we introduced a slimming compression method to reduce 90% of the redundant structures of the neural network. We also designed a particular driving circuit board that can efficiently drive the SMA-based tactile displays. In addition, we also conducted several experiments to verify our wearable assistive device's performance. The results of the experiments showed that the subject was able to recognize the left or right position of a stationary obstacle with 96% accuracy and also successfully avoided collisions with moving obstacles by using the wearable assistive device.


Assuntos
Pedestres , Tecnologia Assistiva , Pessoas com Deficiência Visual , Dispositivos Eletrônicos Vestíveis , Cegueira , Humanos , Tato
2.
J Neurol Neurosurg Psychiatry ; 89(12): 1332-1340, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30076270

RESUMO

OBJECTIVES: Brain acetylcholine is decreased even in patients with cognitively preserved Parkinson's disease (PD). We investigated whether early and long-term use of donepezil prevents psychosis in non-demented PD patients. METHODS: A double-blinded, placebo-controlled trial was conducted. A total of 145 non-demented PD patients were randomly assigned to receive 5 mg/day donepezil (n=72) or placebo (n=73) for 96 weeks. Medications for PD were not restricted, but antipsychotic drugs were not permitted throughout the study. The primary outcome measure was survival time to psychosis that was predefined by Parkinson's Psychosis Questionnaire (PPQ) B score ≥2 or C score ≥2. Secondary outcome measures included psychosis developing within 48 weeks, total PPQ score, Mini-Mental State Examination (MMSE), Wechsler Memory Scale (WMS) and subgroup analysis by apolipoprotein ε4 genotyping. RESULTS: Kaplan-Meier curves for psychosis development were very similar between the two groups, and the Cox proportional hazard model revealed an adjusted HR of 0.87 (95%CI 0.48 to 1.60). The changes in MMSE and WMS-1 (auditory memory) were significantly better with donepezil than in placebo. In the subgroup analysis, donepezil provided an HR of 0.31 (0.11-0.86) against psychosis in 48 weeks for apolipoprotein ε4 non-carriers. CONCLUSIONS: Although donepezil provided beneficial effects on PPQ, MMSE and auditory WMS score changes in 2 years, it had no prophylactic effect on development of psychosis in PD. Apolipoprotein ε4 may suppress the antipsychotic effect of donepezil. TRIAL REGISTRATION NUMBER: UMIN000005403.


Assuntos
Disfunção Cognitiva/tratamento farmacológico , Donepezila/uso terapêutico , Doença de Parkinson/tratamento farmacológico , Transtornos Psicóticos/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Apolipoproteína E4/genética , Inibidores da Colinesterase/uso terapêutico , Disfunção Cognitiva/complicações , Método Duplo-Cego , Feminino , Genótipo , Humanos , Masculino , Testes de Estado Mental e Demência/estatística & dados numéricos , Pessoa de Meia-Idade , Testes Neuropsicológicos/estatística & dados numéricos , Doença de Parkinson/complicações , Doença de Parkinson/genética , Transtornos Psicóticos/complicações , Resultado do Tratamento
3.
Bioorg Med Chem Lett ; 24(8): 1871-4, 2014 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-24675380

RESUMO

A series of 114 SIRT inhibitor candidates was assembled using 'click chemistry', by reacting two alkynes bearing 2-anilinobenzamide pharmacophore with 57 azide building blocks in the presence of Cu(I) catalyst. Screening identified two SIRT2-selective inhibitors, which were more SIRT2-selective than AGK2, a known SIRT2 inhibitor. These findings will be useful for further development of SIRT2-selective inhibitors.


Assuntos
Química Click , Inibidores Enzimáticos/química , Furanos/química , Quinolinas/química , Sirtuína 2/antagonistas & inibidores , Triazóis/química , Catálise , Cobre/química , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/isolamento & purificação , Inibidores Enzimáticos/farmacologia , Furanos/farmacologia , Concentração Inibidora 50 , Estrutura Molecular , Quinolinas/farmacologia , Triazóis/farmacologia
4.
Biomimetics (Basel) ; 9(3)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38534836

RESUMO

This research introduces an advanced robotic finger designed for future generalist robots, closely mimicking the natural structure of the human finger. The incorporation of rarely discussed anatomical structures, including tendon sheath, ligaments, and palmar plates, combined with the usage of anatomically proven 3D models of the finger, give rise to the highly accurate replication of human-like soft mechanical fingers. Benefiting from the accurate anatomy of muscle insertions with the utilization of Shape Memory Alloy (SMA) wires' muscle-like actuation properties, the bonding in-between the flexor tendons and extensor tendons allows for the realization of the central and lateral band of the finger anatomy. Evaluated using the computer vision method, the proposed robotic finger demonstrates a range of motion (ROM) equivalent to 113%, 87% and 88% of the human dynamic ROM for the DIP, PIP and MCP joints, respectively. The proposed finger possesses a soft nature when relaxed and becomes firm when activated, pioneering a new approach in biomimetic robot design and offering a unique contribution to the future of generalist humanoid robots.

6.
Bioorg Med Chem Lett ; 23(17): 4907-10, 2013 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-23876989

RESUMO

Syntheses and biological evaluation of novel SRT1720 derivatives are described in search for new candidates of SIRT1 activator. Several parts of the SRT1720 structure, including piperazine moiety, quinoxaline ring on the amide group, and position of the amide function, were modified, and the assay results indicated that transfer of the ortho amide-substituent regarding to the imidazo[1,2-b]thiazole core onto the meta position resulted in improvement of SIRT1 activation ability. Modeling analyses of SRT1720 and the most potent derivative bound to model complex of SIRT1 with peptide substrate were also performed.


Assuntos
Ativação Enzimática/efeitos dos fármacos , Compostos Heterocíclicos de 4 ou mais Anéis/química , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Sirtuína 1/metabolismo , Humanos , Simulação de Acoplamento Molecular , Tiazóis/química , Tiazóis/farmacologia
7.
BMC Neurol ; 13: 145, 2013 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-24119306

RESUMO

BACKGROUND: Psychoses such as hallucinations are a frequent non-motor problem in patients with Parkinson disease (PD) and serious psychosis requires anti-psychotic medications that worsen Parkinsonism. Although psychosis could be associated with patient-related or biological factors such as cognition, age, and severity of PD, it can also be associated with medications.Therefore we aimed to investigate patient-related and medication-related risks of psychosis requiring anti-psychotic medications (serious psychosis). METHODS: A retrospective cohort of 331 PD patients was followed for 2 years. Patient-related factors associated with risk of psychosis were identified by a survival time analysis. In patients who developed psychosis, medications during the hazard period (1-14 days before psychosis) were contrasted with those during the control periods (1 and 3 months before psychosis) using a case-crossover analysis to identify medication-related risks of psychosis. RESULTS: Serious psychosis was detected in 52 patients and the incidence was estimated to be 116 (95% confidence interval [CI], 85-148) per 1,000 person-years. Analyses of baseline characteristics revealed the risk to be higher in patients with a modified Hoehn-Yahr stage of ≥4 (hazard ratio [HR], 2.22; 95% CI, 1.11-4.40), those with a longer duration of PD (HR, 1.25; 95% CI, 1.00-1.55, per 5 years) and those with Mini-Mental State Examination scores of ≤24 (HR, 2.66; 95% CI, 1.37-5.16). The case-crossover analysis revealed that anti-cholinergics use (HR, 19.7; 95% CI, 2.39-162) elevated the risk, while donepezil use reduced it (HR, 0.48; 95% CI, 0.27-0.85). CONCLUSIONS: Risk of psychosis was elevated by increasing severity of PD, cognitive dysfunction and duration of the disease. It was elevated by use of anti-cholinergic drugs and reduced by use of donepezil. The medication-related risk was higher in patients aged ≥ 70 years. In contrast, there was no significant medication-related risk in younger patients, suggesting different pathomechanisms between young and old patients.


Assuntos
Doença de Parkinson/complicações , Doença de Parkinson/psicologia , Transtornos Psicóticos/complicações , Transtornos Psicóticos/tratamento farmacológico , Adulto , Idoso , Antipsicóticos/uso terapêutico , Transtornos Cognitivos/epidemiologia , Transtornos Cognitivos/etiologia , Estudos de Coortes , Estudos Cross-Over , Relação Dose-Resposta a Droga , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/epidemiologia , Modelos de Riscos Proporcionais , Escalas de Graduação Psiquiátrica , Transtornos Psicóticos/mortalidade , Fatores de Tempo
8.
Materials (Basel) ; 16(3)2023 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-36770021

RESUMO

The authors have developed a micro-vibration actuator using filiform SMA wire electrically driven by periodic electric current. While applying the SMA actuators to tactile displays, we discovered a phenomenon that the deformation caused by a given stress to an SMA wire generated a change in the electrical resistance. With this characteristic, the SMA wire works as a micro-force sensor with high sensitivity, while generating micro-vibration. In this paper, the micro-force sensing ability of an SMA transducer is described and discussed. Experiments are conducted by sliding the SMA sensor on the surface of different objects with different speeds, and the sensing ability is evaluated to be related with human tactile sensation.

9.
RSC Adv ; 12(29): 18354-18362, 2022 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-35799924

RESUMO

This study aims to investigate electrical effects in self-propelled oil droplets and analyze the motion caused by electrical interactions between two droplets. We examine the motion of self-propelled oil droplets in terms of electrical effects; no similar analyses have been reported to date. When an oleic acid droplet is introduced into a surfactant solution, oleic acid is adsorbed at the droplet surface; as a result, the surface becomes negatively charged. However, the electrostatic interaction between oil droplets has not been studied so far. We focus on the chargeability of self-propelled oil droplets, and propose that their motion can be controlled by changing the charge state at the oil/water interface. This is realized by controlling the pH of the surfactant solution. We prepared several aqueous solutions with slightly different pH values, and introduced two oil droplets into each solution to investigate the relationship between the pH value and the correlated motion of the oil droplets. In an aqueous solution at pH 12.00, the two oil droplets showed two types of motion (follow-up and parallel motion), while in an aqueous solution at pH 12.10 they exhibited only one type of motion, i.e., repulsive motion. In order to analyze the three types of motion, we investigated electrical effects on the surface of the oil droplets. First, we measured the zeta potentials of aqueous solutions at pH 12.00 and 12.10, and analyzed the relationship between pH and charge. Furthermore, we calculated the amount of charge and the repulsive force generated on the surface of the oil droplets. For the pH 12.10 solution, the charge of one oil droplet and the repulsive force generated by the charge were found to be -30.79 pC and 282 nN, respectively. Taking into account the driving forces controlling the motion of oil droplets reported in previous studies, this repulsive force could be the driving force of the observed repulsive motion. Based on the experimental results, we inferred that the three types of self-propulsive motion were controlled by electrical effects at the oil/water interface. To further examine these motions, we analyzed the time dependences of the total distance traveled by a droplet and of the distance between oil droplets, as well as the droplet velocities and images of internal convection of oil droplets.

10.
Mult Scler Relat Disord ; 60: 103730, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35287025

RESUMO

OBJECTIVE: The aim of the RIN-2 study was a compassionate use of rituximab (RTX) for patients who completed the RIN-1 study, a multicentre, randomised, double-blind, placebo-controlled trial of RTX. We also investigated the long-term safety and efficacy of RTX. METHODS: A study design was a prospective open-label extension study following the RIN-1 study. RTX was infused repeatedly under monthly monitoring of CD19-positive and CD 20-positive B cell lymphocyte subsets from 24 weeks after an infusion. RESULTS: Thirty-three (87%) of 38 patients of the RIN-1 study were enrolled from February 2016 to March 2019 at six sites in Japan. In RIN-2, RTX was administered three times (median, range 1-5 times), and the interval of RTX administrations were 9.5 [2.5] months (mean [SD]). The observation period was 20.5 [10.1] months. During the trial, three patients dropped out due to two withdrawals and one adverse event. During the study, 28 (90%) of 31 patients were treated with RTX monotherapy. Neuromyelitis optica (NMO) relapses were observed in two patients. The annualized relapse rate (ARR) was 0.035 counts per person-years, ∼1/10th compared with 0.321 in the placebo arm of the RIN-1 study. We observed 14 severe adverse events in six (18%) and 156 adverse events, of which 135 were grade 1, 11 were grade 2 and 10 were grade 3. CONCLUSIONS: Under B cell monitoring, the interval of RTX re-infusion was elongated to nine months, and NMO relapses were suppressed with 0.035 of ARR.


Assuntos
Neuromielite Óptica , Ensaios de Uso Compassivo , Humanos , Fatores Imunológicos/uso terapêutico , Recidiva Local de Neoplasia/tratamento farmacológico , Neuromielite Óptica/induzido quimicamente , Neuromielite Óptica/tratamento farmacológico , Estudos Prospectivos , Rituximab/efeitos adversos , Resultado do Tratamento
11.
BMJ Case Rep ; 14(5)2021 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-33962918

RESUMO

Pterin species participate in dopamine biosynthesis, and abnormal pteridine metabolism contributes to reduced dopamine. GTP cyclohydrolase 1 (GCH-1) deficiency, which triggers pteridine hypometabolism and normally develops in childhood, can mediate an adult-onset decrease in levodopa production and dopa-responsive dystonia (DRD), with normal dopamine transporter single-photon emission computed tomography (DAT-SPECT). A recent study described normal DAT-SPECT in adult-onset cases with GCH-1 mutations, clinically diagnosed with Parkinson's disease, which raises the possibility that the abnormal metabolism of pteridine may be a differential diagnosis for adult-onset parkinsonism. We report an older patient with levodopa-responsive parkinsonism with normal DAT-SPECT, or scans without evidence of dopamine deficit (SWEDD), whose biochemical analysis showed pterin hypometabolism, which occurs in GCH-1-deficient DRD. Surprisingly, this patient presented no dystonia or GCH-1 gene mutation or deletion. This case suggests that low pterin metabolism should be considered in older-onset levodopa-responsive parkinsonism with normal DAT-SPECT, even without GCH-1 mutations or deletions.


Assuntos
Levodopa , Transtornos Parkinsonianos , Adulto , Idoso , Proteínas da Membrana Plasmática de Transporte de Dopamina/genética , GTP Cicloidrolase , Humanos , Levodopa/uso terapêutico , Transtornos Parkinsonianos/diagnóstico por imagem , Transtornos Parkinsonianos/tratamento farmacológico , Pterinas , Tomografia Computadorizada de Emissão de Fóton Único
12.
Expert Opin Pharmacother ; 22(3): 363-371, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32867552

RESUMO

BACKGROUND: Cholinergic neurotransmission regulates neuroinflammation in Parkinson disease (PD). RESEARCH DESIGN AND METHODS: The authors conducted a delayed-start study of donepezil for cognitive decline in non-demented PD patients. The study consisted of a 96-week randomized placebo-controlled double-blind phase 1, followed by a 24-week donepezil extension phase 2. The primary outcome measure was a change in the Mini-Mental State Examination (MMSE) at week 120. RESULTS: A total of 98 patients were randomly allocated to the early-start (donepezil-to-donepezil) and delayed-start (placebo-to-donepezil) groups. Mean (SD) of the baseline MMSE was 27.6 (2.0) and 28.0 (2.1), respectively. MMSE change at week 120 was better in the early-start group than in the delayed-start group, but the difference was not significant. The MMSE declined in apolipoprotein ε4 carriers, but not in non-carriers, and the factor interaction (intervention × Îµ4 genotype) was highly significant (P < 0.001). Analyzed with the interaction, the difference was significant (group difference 1.95 [0.33 to 3.57], P = 0.018). The MMSE decline slope in phase 1 was significantly better in the early-start group than in the delayed-start group (P = 0.048). CONCLUSIONS: Cognitive function deteriorated in ε4 carriers, but not in non-carriers, and early-start donepezil may postpone cognitive decline in the former.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Doença de Parkinson , Inibidores da Colinesterase/uso terapêutico , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/etiologia , Donepezila , Método Duplo-Cego , Humanos , Indanos , Doença de Parkinson/tratamento farmacológico , Piperidinas/uso terapêutico , Resultado do Tratamento
13.
Biochem Biophys Res Commun ; 391(1): 129-34, 2010 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-19900407

RESUMO

Parkinson's disease is characterized by selective loss of dopaminergic neurons in the substantia nigra and by the appearance of Lewy bodies. Fibrillar alpha-synuclein is the main component of Lewy bodies. Previous studies have suggested that dopamine promotes alpha-synuclein oligomerization and that partially aggregated or oligomeric alpha-synuclein could be cytotoxic. To confirm this hypothesis using cell cultures, we performed size exclusion chromatography as a pretreatment method prior to Western blotting to more clearly detect a small amount of alpha-synuclein oligomers in wild-type alpha-synuclein-overexpressing SH-SY5Y cells. Using this method, we confirmed that stable overexpression of alpha-synuclein in SH-SY5Y cells indeed increased the amounts of alpha-synuclein oligomers in these cells and exposure of the cells to dopamine for 6h facilitated alpha-synuclein oligomerization. These dopamine-induced alpha-synuclein oligomers continued to exist for the following 24h. However, the dopamine-treated cells did not undergo cell death or apoptosis in spite of the presence of increased oligomeric alpha-synuclein. Our data may contribute to the understanding of the mechanisms underlying alpha-synuclein oligomer formation and its suspected cytotoxicity toward dopaminergic neurons.


Assuntos
Dopamina/metabolismo , Neurônios/metabolismo , Doença de Parkinson/metabolismo , alfa-Sinucleína/metabolismo , Apoptose , Western Blotting , Linhagem Celular Tumoral , Cromatografia em Gel , Dopamina/química , Humanos , Corpos de Lewy/química , Corpos de Lewy/metabolismo , Neurônios/química , Substância Negra/metabolismo , alfa-Sinucleína/química
14.
J Neurosci Res ; 88(9): 1934-42, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20155807

RESUMO

Postmortem studies have shown that heme oxygenase-1 (HO-1) immunoreactivity is increased in patients with Parkinson disease. HO-1 expression is highly upregulated by a variety of stress. Since the proteasome activity is decreased in patients with Parkinson disease, we investigated whether proteasome activity regulates HO-1 content. MG-132, a proteasome inhibitor, increased the amount of HO-1 protein mainly in astrocytes of primary mesencephalic cultures. Quantitative RT-PCR analysis revealed that lactacystin upregulated HO-1 mRNA expression. Proteasome inhibition with MG132 also increased the cytomegalovirus promoter-driven expression of Flag-HO-1 protein and resulted in an accumulation of ubiquitinated Flag-HO-1 in Flag-HO-1-overexpressing PC12 cells. In addition, a cycloheximide chase assay demonstrated that the degradation of Flag-HO-1 protein was slowed by MG-132. Next, the function of HO-1 which was upregulated by proteasome inhibitors was examined. Proteasome inhibitors protected dopaminergic neurons from 6-hydroxydopamine (6-OHDA)-induced toxicity and this neuroprotection was abrogated by co-treatment with zinc protoporphyrin IX, a HO-1 inhibitor. Furthermore, 6-OHDA-induced toxicity was blocked by bilirubin and carbon monoxide, products of the HO-1-catalyzed degradation of heme. These results suggest that mesencephalic HO-1 protein level is regulated by proteasome activity and the elevation by proteasome inhibition affords neuroprotection.


Assuntos
Dopamina/metabolismo , Heme Oxigenase (Desciclizante)/metabolismo , Heme Oxigenase-1/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Inibidores de Proteassoma , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/fisiologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Células Cultivadas , Estabilidade Enzimática/efeitos dos fármacos , Heme Oxigenase (Desciclizante)/antagonistas & inibidores , Humanos , Mesencéfalo/efeitos dos fármacos , Mesencéfalo/fisiologia , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Células PC12 , RNA Mensageiro/metabolismo , Ratos , Ubiquitinação
15.
Lancet Neurol ; 19(4): 298-306, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32199095

RESUMO

BACKGROUND: Pharmacological prevention against relapses in patients with neuromyelitis optica spectrum disorder (NMOSD) is developing rapidly. We aimed to investigate the safety and efficacy of rituximab, an anti-CD20 monoclonal antibody, against relapses in patients with NMOSD. METHODS: We did a multicentre, randomised, double-blind, placebo-controlled clinical trial at eight hospitals in Japan. Patients aged 16-80 years with NMOSD who were seropositive for aquaporin 4 (AQP4) antibody, were taking 5-30 mg/day oral steroids, and had an Expanded Disability Status Scale (EDSS) score of 7·0 or less were eligible for the study. Individuals taking any other immunosuppressants were excluded. Participants were randomly allocated (1:1) either rituximab or placebo by a computer-aided dynamic random allocation system. The doses of concomitant steroid (converted to equivalent doses of prednisolone) and relapses in previous 2 years were set as stratification factors. Participants and those assessing outcomes were unaware of group assignments. Rituximab (375 mg/m2) was administered intravenously every week for 4 weeks, then 6-month interval dosing was done (1000 mg every 2 weeks, at 24 weeks and 48 weeks after randomisation). A matching placebo was administered intravenously. Concomitant oral prednisolone was gradually reduced to 2-5 mg/day, according to the protocol. The primary outcome was time to first relapse within 72 weeks. Relapses were defined as patient-reported symptoms or any new signs consistent with CNS lesions and attributable objective changes in MRI or visual evoked potential. The primary analysis was done in the full analysis set (all randomly assigned patients) and safety analyses were done in the safety analysis set (all patients who received at least one infusion of assigned treatment). The primary analysis was by intention-to-treat principles. This trial is registered with the UMIN clinical trial registry, UMIN000013453. FINDINGS: Between May 10, 2014, and Aug 15, 2017, 38 participants were recruited and randomly allocated either rituximab (n=19) or placebo (n=19). Three (16%) patients assigned rituximab discontinued the study and were analysed as censored cases. Seven (37%) relapses occurred in patients allocated placebo and none were recorded in patients assigned rituximab (group difference 36·8%, 95% CI 12·3-65·5; log-rank p=0·0058). Eight serious adverse events were recorded, four events in three (16%) patients assigned rituximab (lumbar compression fracture and infection around nail of right foot [n=1], diplopia [n=1], and uterine cancer [n=1]) and four events in two (11%) people allocated to placebo (exacerbation of glaucoma and bleeding in the right eye chamber after surgery [n=1], and visual impairment and asymptomatic white matter brain lesion on MRI [n=1]); all patients recovered. No deaths were reported. INTERPRETATION: Rituximab prevented relapses for 72 weeks in patients with NMOSD who were AQP4 antibody-positive. This study is limited by its small sample size and inclusion of participants with mild disease activity. However, our results suggest that rituximab could be useful maintenance therapy for individuals with NMOSD who are AQP4 antibody-positive. FUNDING: Japanese Ministry of Health, Labour and Welfare, Japan Agency for Medical Research and Development, and Zenyaku Kogyo.


Assuntos
Aquaporina 4/genética , Fatores Imunológicos/uso terapêutico , Neuromielite Óptica/tratamento farmacológico , Rituximab/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Avaliação da Deficiência , Método Duplo-Cego , Quimioterapia Combinada , Potenciais Evocados Visuais , Feminino , Humanos , Fatores Imunológicos/efeitos adversos , Infusões Intravenosas , Japão , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Neuromielite Óptica/diagnóstico por imagem , Neuromielite Óptica/genética , Prednisolona/uso terapêutico , Recidiva , Rituximab/efeitos adversos , Esteroides/uso terapêutico , Resultado do Tratamento , Substância Branca/diagnóstico por imagem , Adulto Jovem
16.
J Neurochem ; 110(2): 745-55, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19457068

RESUMO

Dopaminergic neurons are more vulnerable than other types of neurons in cases of Parkinson disease and ischemic brain disease. An increasing amount of evidence suggests that endogenous dopamine plays a role in the vulnerability of dopaminergic neurons. Although glutamate toxicity contributes to the pathogenesis of these disorders, the sensitivity of dopaminergic neurons to glutamate toxicity has not been clarified. In this study, we demonstrated that dopaminergic neurons were preferentially affected by glutamate toxicity in rat mesencephalic cultures. Glutamate toxicity in dopaminergic neurons was blocked by inhibiting extracellular signal-regulated kinase (ERK), c-jun N-terminal kinase, and p38 MAPK. Furthermore, depletion of dopamine by alpha-methyl-dl-p-tyrosine methyl ester (alpha-MT), an inhibitor of tyrosine hydroxylase (TH), protected dopaminergic neurons from the neurotoxicity. Exposure to glutamate facilitated phosphoryration of TH at Ser31 by ERK, which contributes to the increased TH activity. Inhibition of ERK had no additive effect on the protection offered by alpha-MT, whereas alpha-MT and c-jun N-terminal kinase or p38 MAPK inhibitors had additive effects and yielded full protection. These data suggest that endogenous dopamine is responsible for the vulnerability to glutamate toxicity of dopaminergic neurons and one of the mechanisms may be an enhancement of dopamine synthesis mediated by ERK.


Assuntos
Dopamina/fisiologia , Ácido Glutâmico/toxicidade , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Neurônios/fisiologia , Animais , Células Cultivadas , Dopamina/toxicidade , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/fisiologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/fisiologia , Neurônios/enzimologia , Neurônios/metabolismo , Ratos , Tirosina 3-Mono-Oxigenase/metabolismo
17.
J Neurosci Res ; 87(2): 576-85, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18803299

RESUMO

Parkinson's disease (PD) is the second most common neurodegenerative disease and is characterized by dopaminergic (DA) neuronal cell loss in the substantia nigra. Although the entire pathogenesis of PD is still unclear, both environmental and genetic factors contribute to neurodegeneration. Epidemiologic studies show that prevalence of PD is lower in smokers than in nonsmokers. Nicotine, a releaser of dopamine from DA neurons, is one of the candidates of antiparkinson agents in tobacco. To assess the protective effect of nicotine against rotenone-induced DA neuronal cell toxicity, we examined the neuroprotective effects of nicotine in rotenone-induced PD models in vivo and in vitro. We observed that simultaneous subcutaneous administration of nicotine inhibited both motor deficits and DA neuronal cell loss in the substantia nigra of rotenone-treated mice. Next, we analyzed the molecular mechanisms of DA neuroprotective effect of nicotine against rotenone-induced toxicity with primary DA neuronal culture. We found that DA neuroprotective effects of nicotine were inhibited by dihydro-beta-erythroidine (DHbetaE), alpha-bungarotoxin (alphaBuTx), and/or PI3K-Akt/PKB (protein serine/threonine kinase B) inhibitors, demonstrating that rotenone-toxicity on DA neurons are inhibited via activation of alpha4beta2 or alpha7 nAChRs-PI3K-Akt/PKB pathway or pathways. These results suggest that the rotenone mouse model may be useful for assessing candidate antiparkinson agents, and that nAChR (nicotinic acetylcholine receptor) stimulation can protect DA neurons against degeneration.


Assuntos
Neurônios/metabolismo , Transtornos Parkinsonianos/metabolismo , Transtornos Parkinsonianos/patologia , Receptores Nicotínicos/metabolismo , Substância Negra/metabolismo , Animais , Comportamento Animal/efeitos dos fármacos , Western Blotting , Colinérgicos/farmacologia , Dopamina/metabolismo , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/efeitos dos fármacos , Neurônios/patologia , Nicotina/farmacologia , Transtornos Parkinsonianos/induzido quimicamente , Receptores Nicotínicos/efeitos dos fármacos , Rotenona/toxicidade , Substância Negra/efeitos dos fármacos , Substância Negra/patologia , Desacopladores/toxicidade
18.
RSC Adv ; 9(69): 40523-40530, 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-35542662

RESUMO

This paper introduces a novel directional control method of self-propelled oil droplets. Oil droplets locomote spontaneously with surfactant action. This self-propulsion is caused by Marangoni convection within the oil droplet due to differences in the surfactant concentration at the droplet surface. Recent studies have reported that self-propelled oil droplets change their locomotion style depending on their shapes. We confirm that spherical oil droplets move randomly, including straight motion, bending motion, and rotation. In particular, we discover that boomerang-shaped oil droplets exhibit only straight motion. In this study, we introduce an exoskeleton for the directional and velocity control of oil droplets. A droplet shaped as a boomerang by an exoskeleton locomotes in the direction from a concave region to a convex region. Through experimental studies, we found that the stability of the velocity and locomotion direction depended on the boomerang shape. Self-propelled oil droplets with exoskeletons were then applied to a transporting robot driven only by the energy obtained from chemical reactions. We demonstrate the robot pushes and transports an object floating on water.

19.
Front Robot AI ; 6: 152, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-33501167

RESUMO

Self-folding technologies have been studied by many researchers for applications to various engineering fields. Most of the self-folding methods that use the physical properties of materials require complex preparation, and usually take time to complete. In order to solve these problems, we focus on the elasticity of a material, and propose a model for forming a 3D structure using its characteristics. Our proposed model achieves high-speed and high-precision self-folding with a simple structure, by attaching rigid frames to a stretchable elastomer. The self-folded structure is applied to introduce a self-assembled actuator by exploiting a dielectric elastomer actuator (DEA). We develop the self-assembled actuator driven with the voltage application by attaching stretchable electrodes on the both side of the elastomer. We attempt several experiments to investigate the basic characteristics of the actuator. We also propose an application of the self-assembled actuator as a gripper based on the experimental results. The gripper has three joints with the angle of 120°, and successfully grabs objects by switching the voltage.

20.
Sci Rep ; 9(1): 15977, 2019 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-31685859

RESUMO

Emerging evidence implicates α-synuclein oligomers as potential culprits in the pathogenesis of Lewy body disease (LBD). Soluble oligomeric α-synuclein accumulation in cytoplasm is believed to modify neuronal activities and intraneural Ca2+ dynamics, which augment the metabolic burden in central neurons vulnerable to LBD, although this hypothesis remains to be fully tested. We evaluated how intracellular α-synuclein oligomers affect the neuronal excitabilities and Ca2+ dynamics of pyramidal neurons in neocortical slices from mice. Intracellular application of α-synuclein containing stable higher-order oligomers (αSNo) significantly reduced spike frequency during current injection, elongated the duration of spike afterhyperpolarization (AHP), and enlarged AHP current charge in comparison with that of α-synuclein without higher-order oligomers. This αSNo-mediated alteration was triggered by spike-induced Ca2+ release from inositol trisphosphate receptors (IP3R) functionally coupled with L-type Ca2+ channels and SK-type K+ channels. Further electrophysiological and immunochemical observations revealed that α-synuclein oligomers greater than 100 kDa were directly associated with calcium-binding protein 1, which is responsible for regulating IP3R gating. They also block Ca2+-dependent inactivation of IP3R, and trigger Ca2+-induced Ca2+ release from IP3R during multiple spikes. This aberrant machinery may result in intraneural Ca2+ dyshomeostasis and may be the molecular basis for the vulnerability of neurons in LBD brains.


Assuntos
Cálcio/metabolismo , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Multimerização Proteica , alfa-Sinucleína/metabolismo , Animais , Canais de Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Espaço Intracelular , Corpos de Lewy/metabolismo , Corpos de Lewy/patologia , Doença por Corpos de Lewy/etiologia , Doença por Corpos de Lewy/metabolismo , Doença por Corpos de Lewy/patologia , Camundongos , Modelos Biológicos , Neurônios/metabolismo , Canais de Potássio Ativados por Cálcio de Condutância Baixa/metabolismo , alfa-Sinucleína/química
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