Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 90
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
J Biol Chem ; 299(6): 104702, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37059182

RESUMO

Mitochondria are organelles known primarily for generating ATP via the oxidative phosphorylation process. Environmental signals are sensed by whole organisms or cells and markedly affect this process, leading to alterations in gene transcription and, consequently, changes in mitochondrial function and biogenesis. The expression of mitochondrial genes is finely regulated by nuclear transcription factors, including nuclear receptors and their coregulators. Among the best-known coregulators is the nuclear receptor corepressor 1 (NCoR1). Muscle-specific knockout of NCoR1 in mice induces an oxidative phenotype, improving glucose and fatty acid metabolism. However, the mechanism by which NCoR1 is regulated remains elusive. In this work, we identified the poly(A)-binding protein 4 (PABPC4) as a new NCoR1 interactor. Unexpectedly, we found that silencing of PABPC4 induced an oxidative phenotype in both C2C12 and MEF cells, as indicated by increased oxygen consumption, mitochondria content, and reduced lactate production. Mechanistically, we demonstrated that PABPC4 silencing increased the ubiquitination and consequent degradation of NCoR1, leading to the derepression of PPAR-regulated genes. As a consequence, cells with PABPC4 silencing had a greater capacity to metabolize lipids, reduced intracellular lipid droplets, and reduced cell death. Interestingly, in conditions known to induce mitochondrial function and biogenesis, both mRNA expression and PABPC4 protein content were markedly reduced. Our study, therefore, suggests that the lowering of PABPC4 expression may represent an adaptive event required to induce mitochondrial activity in response to metabolic stress in skeletal muscle cells. As such, the NCoR1-PABPC4 interface might be a new road to the treatment of metabolic diseases.


Assuntos
Receptores Citoplasmáticos e Nucleares , Fatores de Transcrição , Animais , Camundongos , Proteínas Correpressoras/metabolismo , Correpressor 1 de Receptor Nuclear/genética , Correpressor 1 de Receptor Nuclear/metabolismo , Fosforilação Oxidativa , Receptores Citoplasmáticos e Nucleares/metabolismo , Estresse Fisiológico , Fatores de Transcrição/metabolismo
2.
Pharmazie ; 73(3): 128-132, 2018 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-29544558

RESUMO

A reversed-phase liquid chromatography (RP-LC) method was successfully developed and validated for the determination of methotrexate in nanostructured liquid crystalline systems composed by polyether functional siloxane and silicone polyether copolymer. The LC method was performed on RP C18-ODS column, Agilent Zorbax® (4.6 x 250 mm, 5 µm), maintained at room temperature, with a mobile phase constituted by a mixture of 50 mM ammonium acetate buffer (pH 6.0) and methanol (77:23,v/v) with a flow rate of 1.0 mL/min, using ultraviolet detection at 313 nm. The parameters used in the validation process were linearity, specificity, intra and inter-day precision, accuracy, robustness. The quantitation and detection limits yielded good results. The calibration plot assumed linear behavior from 5.0-150.0 µg. mL-1 (r2 = 0.9999). The methotrexate was subjected to oxidation, acid, base and neutral degradation, photolysis and heat as stress conditions. There were no interfering peaks at or near the retention time of methotrexate. The nanostructured liquid crystalline systems did not interfere with the analysis and the recovery was quantitative. The intra and inter-day assay relative standard deviation were less than 0.20 %. The method developed proved to be simple, sensitive, accurate, precise, reproducible and therefore adequate for routine analysis of methotrexate in nanostructured liquid crystalline systems.


Assuntos
Metotrexato/análise , Cromatografia Líquida de Alta Pressão , Limite de Detecção , Cristais Líquidos , Metotrexato/administração & dosagem , Nanoestruturas , Padrões de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrofotometria Ultravioleta
3.
Nanotechnology ; 28(44): 445703, 2017 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-28820739

RESUMO

An individual tin oxide (SnO2) nanobelt was connected in a back-gate field-effect transistor configuration and the conductivity of the nanobelt was measured at different temperatures from 400 K to 4 K, in darkness and under UV illumination. In darkness, the SnO2 nanobelts showed semiconductor behavior for the whole temperature range measured. However, when subjected to UV illumination the photoinduced carriers were high enough to lead to a metal-to-insulator transition (MIT), near room temperature, at T MIT = 240 K. By measuring the current versus gate voltage curves, and considering the electrostatic properties of a non-ideal conductor, for the SnO2 nanobelt on top of a gate-oxide substrate, we estimated the capacitance per unit length, the mobility and the density of carriers. In darkness, the density was estimated to be 5-10 × 1018 cm-3, in agreement with our previously reported result (Phys. Status Solid. RRL 6, 262-4 (2012)). However, under UV illumination the density of carriers was estimated to be 0.2-3.8 × 1019 cm-3 near T MIT, which exceeded the critical Mott density estimated to be 2.8 × 1019 cm-3 above 240 K. These results showed that the electrical properties of the SnO2 nanobelts can be drastically modified and easily tuned from semiconducting to metallic states as a function of temperature and light.

4.
Acta Neurol Scand ; 134(3): 197-204, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26553747

RESUMO

BACKGROUND: Evidence of attack-related cognitive dysfunction in migraine is growing. Controversy exists on whether cognitive dysfunction, mainly executive, may persist between attacks. Measuring the impact of cognitive function is gaining importance in clinical and research settings in migraine. OBJECTIVE: To compare the performance of interictal migraine patients to controls in an assembled neuropsychological battery focused on executive functions and to study the practice effect of its repeated applications. METHOD: Assembly of the battery that was then applied twice within 6 weeks to interictal migraineurs and matched healthy controls. RESULTS: Migraine patients (n = 24) and controls (n = 24) had similar performance in both applications of the battery. There was a slight practice effect between the first and second evaluation, significant in Stroop Interference test (P = 0.002, multiplicity corrected); a meaningful score change was determined for each raw test scores. CONCLUSIONS: Interictal migraineurs and controls performance is identical in a brief cognitive battery focused on executive functions. Repeated applications produced a practice effect that was quantified.


Assuntos
Disfunção Cognitiva/fisiopatologia , Função Executiva/fisiologia , Transtornos de Enxaqueca/fisiopatologia , Adulto , Disfunção Cognitiva/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos de Enxaqueca/complicações , Testes Neuropsicológicos , Adulto Jovem
5.
J Med Entomol ; 52(5): 925-31, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26336242

RESUMO

The understanding of the transmission dynamics of Leishmania spp. Ross as well as the epidemiology and spread of leishmaniasis is related to parasite-vector-host interactions. These interactions can be studied using specimens of a sand fly population reared in the laboratory, exposing individuals to experimental infection for the investigation of vector competence and parameters of the vectorial capacity of the species. The present study sought to describe an alternative method for the implantation of a Lutzomyia (Lutzomyia) cruzi colony with wild specimens captured in the municipality of Corumbá, Brazil. With Method 1, engorged females were individualized for oviposition. The eggs were transferred to an acrylic petri dish with a layer of plaster on the bottom, on which food was placed after hatching of the first larvae. With Method 2, females were kept in groups for oviposition in containers, in which soil and food were placed on their bottom for the larvae. In addition, the exposure time of the larvae to light was reduced in comparison with Method 1. With Method 2, a significantly greater number of specimens of Lu. cruzi was obtained. The ratio between the number of emerged adults and the females followed for oviposition was 0.42 with Method 1 and 2.75 with Method 2. The optimization of the rearing conditions for Lu. cruzi will enable the establishment of a colony providing a sufficient number of specimens to develop experimental infection by Leishmania as well as vectorial competence and some parameters of the vectorial capacity of this sand fly.


Assuntos
Criação de Animais Domésticos/métodos , Entomologia/métodos , Psychodidae/crescimento & desenvolvimento , Animais , Feminino , Larva/crescimento & desenvolvimento , Masculino , Pupa/crescimento & desenvolvimento
6.
Nanotechnology ; 25(9): 094008, 2014 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-24522012

RESUMO

Cotton-based nanocrystalline cellulose (NCC), also known as nanopaper, one of the major sources of renewable materials, is a promising substrate and component for producing low cost fully recyclable flexible paper electronic devices and systems due to its properties (lightweight, stiffness, non-toxicity, transparency, low thermal expansion, gas impermeability and improved mechanical properties).Here, we have demonstrated for the first time a thin transparent nanopaper-based field effect transistor (FET) where NCC is simultaneously used as the substrate and as the gate dielectric layer in an 'interstrate' structure, since the device is built on both sides of the NCC films; while the active channel layer is based on oxide amorphous semiconductors, the gate electrode is based on a transparent conductive oxide.Such hybrid FETs present excellent operating characteristics such as high channel saturation mobility (>7 cm(2) V (-1) s(-1)), drain-source current on/off modulation ratio higher than 10(5), enhancement n-type operation and subthreshold gate voltage swing of 2.11 V/decade. The NCC film FET characteristics have been measured in air ambient conditions and present good stability, after two weeks of being processed, without any type of encapsulation or passivation layer. The results obtained are comparable to ones produced for conventional cellulose paper, marking this out as a promising approach for attaining high-performance disposable electronics such as paper displays, smart labels, smart packaging, RFID (radio-frequency identification) and point-of-care systems for self-analysis in bioscience applications, among others.

7.
J Med Entomol ; 50(2): 277-84, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23540114

RESUMO

The study of some of the behavioral aspects of the main vector of Leishmania infantum chagasi Cunha & Chagas in the Americas, Lutzomyia longipalpis (Lutz & Neiva), such as dispersion, population size, and vector survival rates, is important for the elucidation of the mechanisms of visceral leishmaniasis transmission. These parameters were studied by means of capture-mark-release-recapture experiments in an urban area of Campo Grande municipality, an endemic area of visceral leishmaniasis, situated in Mato Grosso do Sul state, Brazil. Six capture-mark-release-recapture experiments were undertaken between November 2009 and November 2010 and once in January 2012 with a view to assessing the population size and survival rate of Lu. longipalpis. The insects were released in a peridomicile surrounded by 13 residences. The recaptures were undertaken with automatic light traps for four consecutive weeks after release in the surrounding area. In total, 3,354 sand flies were captured, marked, and released. The overall recapture rate during the capture-mark-release-recapture experiments was 4.23%, of which 92.45% were recaptured at the release site, indicating limited dispersal. The greatest distance recorded from the release site was 165 m for males and 241 m for females. The male daily survival rate, calculated on the basis of regressions from the numbers of marked recaptured insects during the 15 successive days after release was 0.897. The estimated male population size measured by the Lincoln Index was 10,947.127. Though Lu. longipalpis presented a limited dispersion the physical barriers typical of urban environments did not prevent the sand flies from flying long distances.


Assuntos
Distribuição Animal , Insetos Vetores/fisiologia , Psychodidae/fisiologia , Animais , Brasil , Cidades , Feminino , Insetos Vetores/parasitologia , Leishmania/fisiologia , Leishmaniose Visceral/transmissão , Masculino , Densidade Demográfica , Psychodidae/parasitologia , Estações do Ano , Fatores de Tempo
8.
Surg Radiol Anat ; 35(6): 535-8, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23262557

RESUMO

This article describes the clinical case of an 86-year-old female patient with an asymptomatic clinical condition, without presenting a history of previous traumatisms. When routine radiographic exam-panoramic radiograph-was performed, the following extensions of the paranasal sinuses were found: maxillary sinus (palate), sphenoid sinus (pterygoid process, major wing, and anterior clinoid process), and supraorbital portion of the frontal sinus. Thus computerized tomography was performed to confirm the diagnosis.


Assuntos
Seio Frontal/diagnóstico por imagem , Seio Maxilar/diagnóstico por imagem , Radiografia Panorâmica , Seio Esfenoidal/diagnóstico por imagem , Idoso de 80 Anos ou mais , Prótese Total , Feminino , Seio Frontal/anatomia & histologia , Humanos , Achados Incidentais , Seio Maxilar/anormalidades , Seios Paranasais/anatomia & histologia , Seios Paranasais/diagnóstico por imagem , Medição de Risco , Seio Esfenoidal/anatomia & histologia , Tomografia Computadorizada por Raios X/métodos
9.
Braz J Med Biol Res ; 55: e12076, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36000612

RESUMO

Glioblastoma is the most prevalent and malignant brain tumor identified in adults. Surgical resection followed by radiotherapy and chemotherapy, mainly with temozolomide (TMZ), is the chosen treatment for this type of tumor. However, the average survival of patients is around 15 months. Novel approaches to glioblastoma treatment are greatly needed. Here, we aimed to investigate the anti-glioblastoma effect of the combination of matteucinol (Mat) (dihydroxyflavanone derived from Miconia chamissois Naudin) with the chemotherapeutic TMZ in vitro using tumor (U-251MG) and normal astrocyte (NHA) cell lines and in vivo using the chick embryo chorioallantoic membrane (CAM) assay. The combination was cytotoxic and selective for tumor cells (28 µg/mL Mat and 9.71 µg/mL TMZ). Additionally, the combination did not alter cell adhesion but caused morphological changes characteristic of apoptosis in vitro. Notably, the combination was also able to reduce tumor growth in the chick embryo model (CAM assay). The docking results showed that Mat was the best ligand to the cell death membrane receptor TNFR1 and to TNFR1/TMZ complex, suggesting that these two molecules may be working together increasing their potential. In conclusion, Mat-TMZ can be a good candidate for pharmacokinetic studies in view of clinical use for the treatment of glioblastoma.


Assuntos
Glioblastoma , Receptores Tipo I de Fatores de Necrose Tumoral , Animais , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Embrião de Galinha , Cromonas , Biologia Computacional , Glioblastoma/tratamento farmacológico , Humanos , Temozolomida/farmacologia , Temozolomida/uso terapêutico
10.
Braz J Biol ; 83: e237813, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34161451

RESUMO

Bamboo (Bambusa sp.) is a grass species with high potential for exploitation, however, this raw material is easily attacked by xylophagous agents such as Coleoptera. The objective of this study is thus to analyse the presence of wood-boring beetles associated with Bambusa sp. in Alta Floresta, Mato Grosso, Brazil. The study was carried out in a bamboo plantation, from August 2016 to July 2017. Two models of ethanolic traps were used, PET Santa Maria and ESALQ-84. Three families of wood-boring beetles were observed in this study: Bostrichidae, Cerambycidae and Curculionidae. 2,144 individuals were identified, belonging to 19 species, in four subfamilies and 11 tribes, and the species Xyleborus affinis was the most frequently collected. Thus, this study constitutes an important contribution to the knowledge of coleoborers associated with bamboo plantations, with the registration of the occurrence of species, as well as contributing to the knowledge of the entomofauna associated with species cultivated in the Southern Amazon.


Assuntos
Bambusa , Besouros , Gorgulhos , Animais , Brasil , Madeira
11.
Drug Deliv Transl Res ; 11(5): 2108-2133, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33164165

RESUMO

Poorly soluble active pharmaceutical ingredients (APIs) create major problems in drug dosage form formulation resulting in significant delays in drug pharmaceutical screening, impairing the drug dosage form production. Aiming to minimize the use of excipients for increasing drug apparent solubility and, as a result, its bioavailability, exploration of innovative approaches is an earnest need. Microemulsion is an alternative drug delivery system that emerged as a valuable tool to achieve safe formulations for insoluble compounds and to improve their biopharmaceutical properties and pharmacokinetics. This review aims to present the state of the art of microemulsion systems, bringing an overview about their origin and how they can be properly produced and thoroughly characterized by different approaches. Furthermore, comments on regulatory issues regarding stability assessment and toxicity evaluation are discussed. The review concludes with a current opinion on microemulsion systems. The overall objective of this work was to describe all the potentialities of microemulsion systems as a drug carrier for therapeutic purposes, highlighting the unique features of this nanotechnological platform. Display Image.


Assuntos
Sistemas de Liberação de Medicamentos , Excipientes , Disponibilidade Biológica , Sistemas de Liberação de Medicamentos/métodos , Emulsões , Solubilidade , Tensoativos
12.
Clin Immunol ; 131(1): 129-38, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19186111

RESUMO

The usefulness of a synthetic peptide in the serodiagnosis of Taenia solium human neurocysticercosis (NC) has been evaluated. Phage-displayed peptides were screened with human antibodies to scolex protein antigen from cysticercus cellulosae (SPACc). One clone was found to interact specifically with anti-SPACc IgGs. The corresponding synthetic peptide was found to be recognized in ELISA by NC patient's sera. The study was carried out with sera from 28 confirmed NC patients, 13 control sera and 73 sera from patients suffering from other infectious diseases. A 93% sensibility and a 94.3% specificity was achieved. Figures of 89% and 31.4% of sensibility and specificity were obtained in a SPACc-based ELISA. Immunoblotting of SPACc with anti-peptide antibodies revealed a single band of approximately 45 kDa in 1D and four 45 kDa isoforms in 2D-gel electrophoresis. A strong and specific immunostaining in the fibers beneath the suckers, at the base of the rostellum, and in the tissue surrounding the scolex of cysticerci was observed by immunomicroscopy. Our results show that a peptide-based immunodiagnostic of neurocisticercosis can be envisioned.


Assuntos
Anticorpos Anti-Helmínticos/sangue , Antígenos de Helmintos/imunologia , Testes Imunológicos/métodos , Neurocisticercose/imunologia , Peptídeos/imunologia , Taenia solium/imunologia , Animais , Anticorpos Anti-Helmínticos/imunologia , Especificidade de Anticorpos , DNA de Helmintos/química , DNA de Helmintos/genética , Eletroforese em Gel Bidimensional , Ensaio de Imunoadsorção Enzimática , Humanos , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos BALB C , Neurocisticercose/sangue , Neurocisticercose/diagnóstico , Neurocisticercose/parasitologia , Biblioteca de Peptídeos , Reação em Cadeia da Polimerase , Taenia solium/isolamento & purificação
13.
J Med Entomol ; 46(3): 428-34, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19496409

RESUMO

Improving vector control remains a key goal in reducing the world's burden of infectious diseases. More cost-effective approaches to vector control are urgently needed, particularly because vaccines are unavailable and treatment is prohibitively expensive. The causative agent of American visceral leishmaniasis (AVL), Leishmania chagasi, Cunha and Chagas (Kinetoplastida: Trypanosomatidae), is transmitted between animal and human hosts by blood-feeding female sand flies attracted to mating aggregations formed on or above host animals by male-produced sex pheromones. Our results show the potential of using synthetic pheromones to control populations of Lutzomyia longipalpis Lutz and Neiva (Diptera: Psychodidae), the sand fly vector of one of the world's most important neglected diseases, AVL. We showed that a synthetic pheromone, (+/-)-9-methylgermacrene-B, produced from a low-cost plant intermediate, attracted females in the laboratory. By formulating dispensers that released this pheromone at a rate similar to that released by aggregating males, we were able to attract flies of both sexes to traps in the field. These dispensers worked equally well when deployed with mechanical light traps and inexpensive sticky traps. If deployed effectively, pheromone-based traps could be used to decrease AVL transmission rates through specific targeting and reduction of L. longipalpis populations. This is the first study to show attraction of a human disease-transmitting insect to a synthetic pheromone in the field, showing the general applicability of this novel approach for developing new tools for use in vector control.


Assuntos
Comportamento Animal/efeitos dos fármacos , Controle de Insetos/métodos , Insetos Vetores/efeitos dos fármacos , Leishmaniose/prevenção & controle , Psychodidae/efeitos dos fármacos , Sesquiterpenos de Germacrano/farmacologia , Atrativos Sexuais/farmacologia , Animais , Insetos Vetores/parasitologia , Psychodidae/parasitologia
14.
J Nanosci Nanotechnol ; 9(8): 4673-8, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19928133

RESUMO

Direct evidences of enhanced Ga interdiffusion in InAs free-standing nanowires grown at moderate temperatures by molecular beam epitaxy on GaAs (111)B are presented in this work. Scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction measurements in coplanar and grazing incidence geometries show that nominally grown InAs NWs are actually made of an In0.86Ga0.14As alloy. Unlike typical vapor-liquid-solid growth, these nanowires are formed by diffusion-induced growth combined with strong interdiffusion from substrate material. Based on the experimental results, a simple nanowire growth model accounting for the Ga interdiffusion is also presented. This growth model could be generally applicable to the molecular beam heteroepitaxy of III-V nanowires.

15.
Int Endod J ; 42(7): 609-13, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19467051

RESUMO

AIM: To evaluate several protocols for the application of ultrasound during removal of cast posts with varying core configurations cemented with zinc phosphate. METHODOLOGY: Sixty maxillary canines were distributed into three groups (n = 20): group 1 - core with 5 mm diameter/height and post diameter of 1.3 mm; groups 2 and 3 - core with the same diameter as the post (1.3 mm) and heights of 5 mm and 3 mm, respectively. Posts/cores were cemented using a standard technique with zinc phosphate cement. Each group was divided into two subgroups according to the ultrasonic vibration mode: point vibration - ultrasonic vibration applied to the core surface for 5 s, on each face totalling 25 s; alternate vibration - intermittent application of ultrasonic vibration for 10 s to the labial and lingual surfaces, 10 s to the mesial and distal surfaces and 5 s to the incisal surface, totalling 25 s. The specimens were submitted to the tensile test using an Instron machine (1 mm min(-1)) and results were analysed by anova and t-test. The failure type was also analysed. RESULTS: Statistical analysis showed significant differences between groups relating to the core preparations (P < 0.05). The lowest mean values of traction force were obtained for group 3 (46.1 +/- 7.7 N), followed by group 2 (89.0 +/- 2.7 N) and group 1 (160.4 +/- 7.5 N). Regarding ultrasonic vibration, the lowest mean was observed with alternate vibration (81.1 +/- 10.1 N), which was significantly lower than the point vibration (115.9 +/- 9.5 N) (P < 0.05). Cohesive failure occurred in all cases. CONCLUSION: A reduction in core diameter/height and intermittent ultrasonic application improved the removal of cast posts cemented with zinc phosphate.


Assuntos
Cimentação , Descolagem Dentária/métodos , Técnica para Retentor Intrarradicular/instrumentação , Ultrassom , Cimento de Fosfato de Zinco/química , Óxido de Alumínio/química , Ligas de Cromo/química , Dente Canino/patologia , Planejamento de Prótese Dentária , Análise do Estresse Dentário/instrumentação , Humanos , Teste de Materiais , Preparo de Canal Radicular/instrumentação , Preparo de Canal Radicular/métodos , Estresse Mecânico , Propriedades de Superfície , Vibração
16.
Folia Phoniatr Logop ; 61(2): 76-82, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19287176

RESUMO

The present study was carried out to evaluate the effectiveness of a specific program regarding the occurrence of vocal attrition symptoms in telemarketers. A total of 71 subjects participated in this study: 28 completed the Vocal Symptoms questionnaire to test its reliability, and 43 were randomly assigned to two groups: an 8-week vocal training group (n = 14) and a no-training control group (n = 29), to evaluate the effectiveness of the training program with this tool. The voice training group also filled in the posttraining questionnaire 'Benefits Obtained with Voice Training' (BVT). The vocal training program was not considered effective with regard to the occurrence of vocal symptoms. However, due to a probable increase in symptoms in untrained telemarketers, it can work as a protective factor. According to BVT answers, the vocal training contributed to an improvement in vocal use as a communication tool for telemarketers.


Assuntos
Doenças Profissionais/terapia , Telefone , Distúrbios da Voz/terapia , Treinamento da Voz , Adolescente , Adulto , Comunicação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Inquéritos e Questionários , Resultado do Tratamento , Adulto Jovem
17.
Int J Nanomedicine ; 14: 7975-7985, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31632012

RESUMO

BACKGROUND: Multidrug-resistant bacteria such as extended-spectrum beta-lactamase (ESBL), Enterobacteriaceae, and methicillin-resistant Staphylococcus aureus (MRSA) pose a challenge to the human health care system. MRSA is among the major causes of hospital-acquired and community infections. METHODS: Therefore, in the present study, we evaluated the antibacterial activity of silver nanoparticles synthesized by Fusarium oxysporum (AgNPbio) in combination with simvastatin against reference and multidrug-resistant bacterial strains. RESULTS: Simvastatin showed a minimal inhibitory concentration (MIC) ranging from 0.062 to 0.25 mg mL-1 against MRSA. AgNPbio with a size of 77.68± 33.95 nm and zeta potential -34.6 ± 12.7 mV showed an MIC of 0.212 mg mL-1 against S. aureus including MRSA strains. The checkerboard assay and time-kill curves exhibited a synergistic effect of the simvastatin-AgNPbio combination on antibacterial activity against MRSA strains. The combination of simvastatin and AgNPbio demonstrated antibacterial activity against Escherichia coli producing ESBL. Scanning electron microscopy showed the formation of cell surface protrusions after treatment with AgNPbio and the formation of a large amorphous mass after treatment with simvastatin, both in MRSA. CONCLUSION: Our results indicate that the combination of AgNPbio and simvastatin could be a great future alternative in the control of bacterial infections, where, when combined with simvastatin, smaller doses of AgNPbio are required, with the same antibacterial activity.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Fusarium/metabolismo , Nanopartículas Metálicas/química , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Prata/farmacologia , Sinvastatina/farmacologia , Morte Celular/efeitos dos fármacos , Sinergismo Farmacológico , Eritrócitos/efeitos dos fármacos , Fusarium/efeitos dos fármacos , Fusarium/ultraestrutura , Humanos , Nanopartículas Metálicas/ultraestrutura , Staphylococcus aureus Resistente à Meticilina/ultraestrutura , Testes de Sensibilidade Microbiana
18.
Vis Neurosci ; 25(3): 469-74, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18598420

RESUMO

We examined achromatic contrast discrimination in asymptomatic carriers of 11778 Leber's hereditary optic neuropathy (LHON 18 controls) and 18 age-match were also tested. To evaluate magnocellular (MC) and Parvocellular (PC) contrast discrimination, we used a version of Pokorny and Smith's (1997) pulsed/steady-pedestal paradigms (PPP/SPP) thought to be detected via PC and MC pathways, respectively. A luminance pedestal (four 1 degree x 1 degree squares) was presented on a 12 cd/m2 surround. The luminance of one of the squares (trial square, TS) was randomly incremented for either 17 or 133 ms. Observers had to detect the TS, in a forced-choice task, at each duration, for three pedestal levels: 7, 12, 19 cd/m2. In the SPP, the pedestal was fixed, and the TS was modulated. For the PPP, all four pedestal squares pulsed for 17 or 133 ms, and the TS was simultaneously incremented or decremented. We found that contrast discrimination thresholds of LHON carriers were significantly higher than controls' in the condition with the highest luminance of both paradigms, implying impaired contrast processing with no evidence of differential sensitivity losses between the two systems. Carriers' thresholds manifested significantly longer temporal integration than controls in the SPP, consistent with slowed MC responses. The SPP and PPP paradigms can identify contrast and temporal processing deficits in asymptomatic LHON carriers, and thus provide an additional tool for early detection and characterization of the disease.


Assuntos
Sensibilidades de Contraste , Triagem de Portadores Genéticos , Atrofia Óptica Hereditária de Leber/genética , Adolescente , Adulto , Discriminação Psicológica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Testes Visuais , Acuidade Visual , Vias Visuais
19.
Colloids Surf B Biointerfaces ; 66(2): 253-9, 2008 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-18676122

RESUMO

In this work the structural features of microemulsions (MEs) containing the pharmaceutical biocompatible Soya phosphatidylcholine/Tween 20 (1:1) as surfactant (S), Captex 200 as oil phase (O), and phosphate buffer 10mM, pH 7.2 as aqueous phase (W) were studied. Systems obtained with different proportions of the components were described by pseudo-ternary phase diagrams in order to characterize the microemulsions studied here. MEs were prepared with and without the polyene antifungal drug amphotericin B (AmB). The maximum AmB incorporation into the ME system was dependent on both the oil phase and surfactant proportions with 6.80 and 5.7 mg/mL in high contents, respectively. The incorporation of AmB into the ME systems significantly increased the profile of the droplet size of the ME for all ranges of surfactant proportions used in the formulations. The microstructures of the system were characterized by dynamic light scattering (DLS) and rheological behavior. The DLS results showed that the size of the oil droplets increases 4.6-fold when AmB is incorporated into the ME system. In all cases the increase in the proportion of the oil phase of the ME leads to a slight increase in the diameter of the oil droplets of the system. Furthermore, for both the AmB-loaded and AmB-unloaded MEs, the size of the oil droplets decrease significantly with the increase of the S proportion in the formulations, demonstrating the efficiency of the surfactant in stabilizing the ME. Depending on the ME composition, an anti-thixotropic behavior was found. The maximum increases of the consistency index caused by the increase of the oil phase of the ME were of 17- and 25-times for the drug-loaded and drug-unloaded MEs, respectively. However, the observed effect for the drug-loaded ME was about 4.6 times higher than that for the drug-unloaded one, demonstrating the strong effect of the drug on the rheological characteristics of the ME system. Therefore, it is possible to conclude that the investigated ME can be used as a very promising vehicle for AmB.


Assuntos
Anfotericina B/química , Caprilatos/química , Sistemas de Liberação de Medicamentos , Lecitinas/química , Óleos/química , Polietilenoglicóis/química , Emulsões , Luz , Conformação Molecular , Tamanho da Partícula , Fosfatos/química , Fosfatidilcolinas/química , Polissorbatos/química , Espalhamento de Radiação , Glycine max/química , Propriedades de Superfície , Tensoativos/química , Água/química
20.
Colloids Surf B Biointerfaces ; 63(2): 287-95, 2008 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-18313903

RESUMO

Depending on the composition, the mixture of surfactant, oil and water, may form supramolecular aggregates with different structures which can significantly influence the drug release. In this work several microemulsion (ME) systems containing soya phosphatidylcholine (SPC) and eumulgin HRE40 (EU) as surfactant, cholesterol (O) as oil phase, and ultra-pure water as an aqueous phase were studied. MEs with and without the antitumoral drug doxorubicin (DOX) were prepared. The microstructures of the systems were characterized by photon correlation spectroscopy, rheological behavior, polarized light microscopy, small-angle X-ray scattering (SAXS) and X-ray diffraction (XRD). The results reveal that the diameter of the oil droplets was dependent on the surfactant (S) amount added to formulations. The apparent viscosity was dependent on the O/S ratio. High O/S ratio leads to the crystallization of cholesterol polymorphs phases which restricts the mobility of the DOX molecules into the ME structure. Droplets with short-range spatial correlation were formed from the ME with the low O/S ratio. The increase of the cholesterol fraction in the O/S mixture leads to the formation of ordered structures with lamellar arrangements. These different structural organizations directly influenced the drug release profiles. The in vitro release assay showed that the increase of the O/S ratio in the formulations inhibited the constant rate of DOX release. Since the DOX release ratio was directly dependent on the ratio of O/S following an exponential decay profile, this feature can be used to control the DOX release from the ME formulations.


Assuntos
Materiais Biocompatíveis , Doxorrubicina/química , Emulsões , Glycine max/química , Fosfatidilcolinas/química , Viscosidade , Difração de Raios X
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA