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1.
Artigo em Inglês | MEDLINE | ID: mdl-34279191

RESUMO

An emerging threat to membrane application is the seasonal proliferation of algae in water sources such as rivers, reservoirs and lakes. This study investigated the link between feed parameters and the membrane performance of a pilot-scale microfiltration (MF) plant for 7 months. The seasonal succession of algae in relation to temperature dynamics was monitored. Temperature-dependent seasonal patterns for algae species were observed. The water temperatures during the dominance of cyanobacteria, especially Microcystis, were relatively higher (over 25 °C) than those during the dominance of diatoms. Diatoms did not much affect membrane performance (less than 0.2 kgf/cm2), however, under the cyanobacterial dominance condition, especially Microcystis sp., transmembrane pressure (TMP) reached up to the limited level (0.4 kgf/cm2) within one month. Concurrently UV absorbance at 254 nm wavelength and dissolved organic carbon values increased significantly during the Microcystis bloom and the build-up rate of TMP increased up to 0.005 kgf/cm2/day. Membrane autopsy also showed that during the dominance of diatom, application of cleaning agents can fully remove foulants on the membrane surface. However, during the dominance of cyanobacteria, there is a lot of Al, Si and organic complex on the fouled membrane, indicating the formation of Al-organic complexes that contributed to the residual membrane fouling. It is suggested that the irrecoverable fouling layer still contained some Al, mostly in complex with organics. Thus, organic matter originated from cyanobacteria may cause a serious impact on membrane fouling by forming the complex with metal ions originated from coagulant.


Assuntos
Cianobactérias , Microcystis , Purificação da Água , Membranas Artificiais , Estações do Ano
3.
J Phys Ther Sci ; 30(3): 373-380, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29581654

RESUMO

[Purpose] The purpose of this study was to analyze the effects of pectoralis minor stretching and shoulder strengthening with an elastic band on balance and maximal shoulder muscle strength in young adults with rounded shoulder posture. [Subjects and Methods] Nineteen subjects with rounded shoulder posture were randomly divided into 2 groups: a shoulder stabilization exercise group and a stretching exercise group. The groups performed each exercise for 40 minutes, 3 times a week, for 4 weeks. Static balance (eyes open and closed), dynamic balance (the limits of stability in 4 directions) and shoulder muscle strength in 5 directions were measure before and after the exercises. [Results] The stretching exercise demonstrated a significant difference between the pre- and post-exercise in the static balance with eyes closed and extension and horizontal abduction strength while the stabilization exercise demonstrated significant difference in the left and right directions between the pre- and post-exercise of the dynamic balance and flexion strength. The stabilization exercise demonstrated significant differences shown in the flexion between the pre- and post-test. [Conclusion] The shoulder stabilization and stretching exercises improved the static balance, dynamic balance, and muscle strength.

4.
J Physiol Anthropol ; 36(1): 11, 2017 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-28126038

RESUMO

BACKGROUND: Several studies have used functional magnetic resonance imaging (fMRI) to show that neural activity is associated with driving. fMRI studies have also elucidated the brain responses associated with driving while performing sub-tasks. It is important to note that these studies used computer mouses, trackballs, or joysticks to simulate driving and, thus, were not comparable to real driving situations. In order to overcome these limitations, we used a driving wheel and pedal equipped with an MR-compatible driving simulator (80 km/h). The subjects drove while performing sub-tasks, and we attempted to observe differences in neuronal activation. METHODS: The experiments consisted of three blocks and each block consisted of both a control phase (1 min) and a driving phase (2 min). During the control phase, the drivers were instructed to look at the stop screen and to not perform driving tasks. During the driving phase, the drivers either drove (driving only condition) or drove while performing an additional sub-task (driving with sub-task condition) at 80 km/h. RESULTS: Compared to when the drivers were focused only on driving, when the drivers drove while performing a sub-task, the number of activation voxels greatly decreased in the parietal area, which is responsible for spatial perception. Task-performing areas, such as the inferior frontal gyrus and the superior temporal gyrus, showed increased activation. Performing a sub-task simultaneously while driving had affected the driver's driving. The cingulate gyrus and the sub-lobar region (lentiform nucleus, caudate, insula, and thalamus), which are responsible for error monitoring and control of unnecessary movements (e.g., wheel and pedal movements), showed increased activation during driving with sub-task condition compared to driving only condition. CONCLUSIONS: Unlike simple driving simulators (joysticks, computer mouses, or trackballs) used in previous research, the addition of a driving wheel and pedals (accelerator and brake) to the driving simulator used in this study closely represents real driving. Thus, the number of processed movements was increased, which led to an increased number of unnecessary movements that needed to be controlled. This in turn increased activation in the corresponding brain regions.


Assuntos
Condução de Veículo , Encéfalo/fisiologia , Imageamento por Ressonância Magnética/métodos , Adulto , Humanos , Masculino , Modelos Teóricos , Análise e Desempenho de Tarefas
5.
J Phys Ther Sci ; 28(11): 3099-3104, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27942128

RESUMO

[Purpose] The purpose of this study was to assess the effects of complex rehabilitation training on chronic low back pain. [Subjects and Methods] Complex rehabilitation training for lumbar isometric muscle strength was conducted for 12 weeks for males (n=10) and females (n=10) with chronic low back pain, who were aged in their 30s. [Results] Isometric strength of lumbar extension was increased post-test, and significant differences were found between males and females, at MedX angle of 0, 48, and 60. [Conclusion] This study showed that complex rehabilitation training had a beneficial effect on the muscle strength of lumbar extension in patients with chronic low back pain.

6.
Clin Anat ; 29(4): 473-80, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26710236

RESUMO

The purpose of this study is to investigate differences in and correlations between cognitive abilities and brain volumes in healthy control (HC), mild cognitive impairment (MCI), and Alzheimer's disease (AD) groups. The Korean Version of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD-K), which is used to diagnose AD, was used to measure the cognitive abilities of the study subjects, and the volumes of typical brain components related to AD diagnosis-cerebrospinal fluid (CSF), gray matter (GM), and white matter (WM)-were acquired. Of the CERAD-K subtests, the Boston Naming Test distinguished significantly among the HC, MCI, and AD groups. GM and WM volumes differed significantly among the three groups. There was a significant positive correlation between Boston Naming Test scores and GM and WM volumes. In conclusion, the Boston Naming Test and GM and WM brain volumes differentiated the three tested groups accurately, and there were strong correlations between Boston Naming Test scores and GM and WM volumes. These results will help to establish a test method that differentiates the three groups accurately and is economically feasible.


Assuntos
Doença de Alzheimer/patologia , Encéfalo/patologia , Disfunção Cognitiva/patologia , Testes Neuropsicológicos , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico , Atrofia , Encéfalo/anatomia & histologia , Estudos de Casos e Controles , Cognição , Disfunção Cognitiva/diagnóstico , Feminino , Humanos , Masculino , Tamanho do Órgão
7.
J Behav Health Serv Res ; 43(1): 116-26, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25047103

RESUMO

The purpose of this study is to provide information for the protection of Korean homecare patients with senile dementia by investigating accident cases using a survey. With the survey of accident cases, the caregivers of 55 Korean homecare patients with senile dementia (75.9 ± 7.0 years) were administered the short form of the Samsung Dementia Questionnaire (S-SDQ) and an activities of daily living (ADL) test. Twelve risk elements were extracted. The order of frequency of occurrence from highest to lowest was "egress," "fall," "violence," "collision," "gas accident," "slip," "faucet misuse," "overeating," "drop," "discharge," "weird eating," and "self-injury." The percentage of risk elements resulting in physical harm was 40.1% across all risk elements. The risk elements resulting in the most physical harm were "fall," "collision," "slip," and "drop," respectively. Regarding the location of occurrence of risk elements, risk elements resulting in physical harm showed no significant differences between indoors and outdoors. Some risk elements, such as "egress," "fall," and "gas accident" happened concurrently with more than four other elements, while "collision," "drop," and "violence" happened together with more than two other elements. "Slip" happened significantly more often in the low ADL score group, while "gas accident" happened significantly more often in the high ADL score group. This study provides basic information about monitoring factors to protect senior homecare patients with senile dementia.


Assuntos
Prevenção de Acidentes , Acidentes , Atividades Cotidianas , Doença de Alzheimer/enfermagem , Serviços de Assistência Domiciliar , Idoso , Idoso de 80 Anos ou mais , Cuidadores , Feminino , Humanos , Masculino , República da Coreia , Risco , Medição de Risco
8.
Medicine (Baltimore) ; 94(38): e1657, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26402840

RESUMO

In this study, a constant pressure stimulus was applied on the 3 joints (first [p1], second [p2], and third [p3] joints) of 4 fingers (index, middle, ring, and little fingers), and the activation areas within Brodmann area 2 (BA 2) were compared for these different fingers and joints by using functional magnetic resonance imaging. Eight healthy male college students (25.4 ±â€Š1.32 years) participated in the study. Each session was composed of 3 blocks, and each block was composed of a Control phase (30 seconds) and a Pressure phase (30 seconds). No pressure stimulus was applied in the Control phase, during which the subjects would simply lay comfortably with their eyes closed. In the Pressure phase, a pressure stimulus was applied onto one of the joints of the selected finger. For each finger and joint, BA 2 areas activated by the pressure stimulus were extracted by the region of interest method. There was a significant difference in the activation areas for the different fingers (P = .042) as well as for the different joints (P = .050). The activation area decreased in the order of the little, index, and middle fingers, as well as in the order of p1, p3, and p2.


Assuntos
Articulações dos Dedos/fisiologia , Mecanorreceptores/fisiologia , Córtex Somatossensorial/fisiologia , Percepção do Tato/fisiologia , Adulto , Feminino , Voluntários Saudáveis , Humanos , Imageamento por Ressonância Magnética , Masculino , Pressão , Adulto Jovem
9.
Biomed Mater Eng ; 26 Suppl 1: S833-40, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26406081

RESUMO

The change of neuronal activation due to the passive perception of various driving speeds in comparison to a reference driving speed was assessed using functional Magnetic Resonance Imaging. Videos recorded in real driving conditions on the road at driving speeds of 50, 70, 90, and 110 km/h were shown as visual stimuli. An experiment consisted of three blocks, each having a control phase (50km/h) and a stimulation phase (70, 90, or 110 km/h). In the passive perception of various driving speed differences, the areas related to visual cognition and spatial attention such as temporal, occipital, parietal, frontal areas, and cerebellum were activated. As the driving speed difference increased, the number of activated voxels also increased in the areas related to visual cognition. However, the visual cognition related areas showed a different pattern from the spatial attention related area with an increase of the driving speed difference. This implies that each brain area has a different level of involvement in the passive perception of the driving speed difference, although both visual cognitions related areas and spatial attention related area are related to it.


Assuntos
Atenção/fisiologia , Condução de Veículo , Encéfalo/fisiologia , Cognição/fisiologia , Desempenho Psicomotor/fisiologia , Percepção Visual/fisiologia , Adulto , Mapeamento Encefálico , Feminino , Humanos , Masculino , Rede Nervosa/fisiologia
10.
J Physiol Anthropol ; 34: 3, 2015 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-25857667

RESUMO

BACKGROUND: The present study addressed how 92% oxygen administration affects cognitive performance, blood oxygen saturation (SpO2), and heart rate (HR) of intellectually and developmentally disabled people. METHODS: Seven males (28.9 ± 1.8 years) and seven females (34.4 ± 8.3 years) with intellectual and developmental disabilities (disabled level 2.1 ± 0.5) completed an experiment consisting a 0-back task with normal air (21% oxygen) administered in one run and hyperoxic air (92% oxygen) administered in the other run. The experimental sequence in each run consisted of a 1-min adaptation phase, 2-min control phase, and 2-min 0-back task phase, where SpO2 and HR were gauged for each phase. RESULTS: The administration of 92% oxygen increased 0-back task performance of intellectually and developmentally disabled people, in association with increased SpO2 and decreased HR. Our results demonstrate that sufficient oxygen supply subserving cognitive functions, even as a short-term effect, could increase cognitive ability for the intellectually and developmentally disabled people. CONCLUSIONS: It is concluded that enriched oxygen can positively affect, at least in the short-term, the working memory of those with intellectual and developmental disability.


Assuntos
Cognição/efeitos dos fármacos , Deficiências do Desenvolvimento/fisiopatologia , Deficiência Intelectual/fisiopatologia , Oxigênio/administração & dosagem , Oxigênio/farmacologia , Adulto , Atenção/efeitos dos fármacos , Feminino , Frequência Cardíaca , Humanos , Masculino , Oxigênio/sangue
11.
Neurosci Lett ; 594: 70-5, 2015 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-25823997

RESUMO

The present study compared event-related potential (ERP) patterns for two stimuli types, puff and suction, by applying these stimuli to the fingers; ERP patterns for the two stimuli were compared at C3, an area related to somatosensory perception, and at FC5, an area related to motor function. Participants were 12 healthy males in their 20s (mean age=23.1±2.0 years). One session consisted of a Control Phase (3s), a Stimulation Phase (3s), and a Rest Phase (9s). During the Stimulation Phase, a 4-psi suction or puff stimulus was applied to the first joint of the right index finger. After completion of the session, a subjective magnitude test was presented. In all phases, electroencephalography signals were recorded. We extracted maximum positive amplitude and minimum negative amplitude as well as relevant latency values for C3 and FC5 signals. Suction and puff stimuli had similar subjective magnitude scores. For both C3 and FC5, the maximum and minimum amplitude latency was reached earlier for the suction stimulus than for the puff stimulus. In conclusion, when suction and puff stimuli of the same intensity were applied to the fingers, the suction stimulus caused a more sensitive response in the somatosensory area (C3) and motor area (FC5) than did the puff stimulus.


Assuntos
Potenciais Evocados , Córtex Somatossensorial/fisiologia , Adulto , Eletroencefalografia , Humanos , Masculino , Estimulação Física , Pressão , Adulto Jovem
12.
J Phys Ther Sci ; 27(12): 3895-9, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26834376

RESUMO

[Purpose] This study aimed to provide a predictable evaluation method for the progression of scoliosis in adolescents based on quick and reliable measurements using the naked eye, such as the calcaneal valgus angle of the foot, which can be performed at public facilities such as schools. [Subjects and Methods] Idiopathic scoliosis patients with a Cobb's angle of 10° or more (96 females, 22 males) were included in this study. To identify relationships between factors, Pearson's product-moment correlation coefficient was computed. The degree of scoliosis was set as a dependent variable to predict thoracic and lumbar scoliosis using ankle angle and physique factors. Height, weight, and left and right calcaneal valgus angles were set as independent variables; thereafter, multiple regression analysis was performed. This study extracted variables at a significance level (α) of 0.05 by applying a stepwise method, and calculated a regression equation. [Results] Negative correlation (R=-0.266) was shown between lumbar lordosis and asymmetrical lumbar rotation angles. A correlation (R=0.281) was also demonstrated between left calcaneal valgus angles and asymmetrical thoracic rotation angles. [Conclusion] Prediction of scoliosis progress was revealed to be possible through ocular inspection of the calcaneus and Adams forward bending test and the use of a scoliometer.

13.
Biomed Mater Eng ; 24(6): 2971-7, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25227004

RESUMO

This study investigated neuronal activation differences under two conditions: driving only and distracted driving. Driving and distraction tasks were performed using a Magnetic Resonance (MR)-compatible driving simulator with a driving wheel and pedal. The experiment consisted of three blocks, and each block had both a Rest phase (1 min) and a Driving phase (2 min). During the Rest phase, drivers were instructed to simply look at the stop screen without performing any driving tasks. During the Driving phase, each driver was required to drive at 110 km/h under two conditions: driving only and driving while performing additional distraction tasks. The results show that the precuneus, inferior parietal lobule, supramarginal gyrus, middle frontal gyrus, cuneus, and declive are less activated in distracted driving than in driving only. These regions are responsible for spatial perception, spatial attention, visual processing and motor control. However, the cingulate gyrus and sub-lobar regions (lentiform nucleus and caudate), which are responsible for error monitoring and control of unnecessary movement, show increased activation during distracted driving compared with driving only.


Assuntos
Atenção/fisiologia , Condução de Veículo/psicologia , Córtex Cerebral/fisiologia , Movimento/fisiologia , Mascaramento Perceptivo/fisiologia , Desempenho Psicomotor/fisiologia , Percepção Espacial/fisiologia , Adulto , Mapeamento Encefálico/métodos , Sinais (Psicologia) , Humanos , Imageamento por Ressonância Magnética , Masculino
14.
Biomed Mater Eng ; 24(6): 3619-27, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25227076

RESUMO

In this study, a tactile stimulator that could separately or simultaneously display the vibrotactile and pressure sense was developed. The developed system consisted of a control unit, a drive unit, and an actuator, and can be operated with PC or manually. This system quantitatively controls the stimulation parameters such as the stimulation intensity, duration, frequency, and stimulation type. A preliminary electroencephalogram (EEG) experiment for three types of stimulation (vibrotactile, pressure sense, vibrotactile + pressure sense) highlights that the system could be used in complex tactile cognitive studies. An event-related desynchronization (ERD) and synchronization (ERS) were measured at the area of C3 and C4 for all three types of stimulation, and a clear response was identified in the contralateral somatosensory area from the brain topology. Therefore, it is expected that this system could be widely used in single and complex human tactile cognition and perception studies for vibrotactile and pressure sensation.


Assuntos
Cognição/fisiologia , Sistemas Microeletromecânicos/instrumentação , Estimulação Física/instrumentação , Pressão , Córtex Somatossensorial/fisiologia , Tato/fisiologia , Vibração , Adulto , Desenho de Equipamento , Análise de Falha de Equipamento , Potenciais Somatossensoriais Evocados/fisiologia , Feminino , Humanos , Imãs , Masculino , Estresse Mecânico
15.
J Nanosci Nanotechnol ; 12(2): 1444-7, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22629975

RESUMO

In order to understand and control the properties of Si quantum dot (QD) superlattice structures (SLS), it is necessary to investigate the bonding between the dots and their matrix and also the structures' crystallinities. In this study, a SiOx matrix system was investigated and analyzed for potential use as an all-silicon multi-junction solar cell. Si QD SLS were prepared by alternating deposition of Si rich SiOx (x = 0.8) and SiO2 layers using RF magnetron co-sputtering and subsequent annealing at temperatures between 800 and 1,100 degrees C under nitrogen ambient. Annealing temperatures and times affected the formation of Si QDs in the SRO film. Raman and FTIR spectra revealed that nanocrystalline Si QDs started to precipitate after annealing at 1,100 degrees C for 1 hour. TEM images clearly showed SRO/SiO2 SLS and Si QDs formation in SRO layers after annealing at 1,100 degrees C for 2 hours. XPS analysis showed that Si-Si and Si-O bonding changes occurred above 1,100 degrees C. XPS analysis also revealed that Si QD SLSs started stabilizing after 2 hours' annealing and approached completion after 3 hours'. The systematic investigation of Si QDs in SiO2 matrices and their properties for solar cell application are presented.

16.
J Nanosci Nanotechnol ; 12(2): 1448-52, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22629976

RESUMO

Silicon quantum dot superlattice was fabricated by alternating deposition of silicon rich nitride (SRN) and Si3N4 layers using RF magnetron co-sputtering. Samples were then annealed at temperatures between 800 and 1,100 degrees C and characterized by grazing incident X-ray diffraction (GIXRD), transmission electron microscopy (TEM), Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR). GIXRD and Raman analyses show that the formation of silicon quantum dots occurs with annealing above 1,100 degrees C for at least 60 minutes. As the annealing time increased the crystallization of silicon quantum dots was also increased. TEM images clearly showed SRN/Si3N4 superlattice structure and silicon quantum dots formation in SRN layers after annealing at 1,100 degrees C for more than 60 minutes. The changes in FTIR transmission spectra observed with annealing condition corresponded to the configuration of Si-N bonds. Crystallization of silicon quantum dots in a silicon nitride matrix started stabilizing after 60 minutes' annealing and approached completion after 120 minutes'. The systematic investigation of silicon quantum dots in a silicon nitride matrix and their properties for solar cell application are presented.

17.
Obes Res Clin Pract ; 5(3): e169-266, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-24331103

RESUMO

OBJECTIVE: To establish reference values for fat-free mass index (FFMI), fat mass index (FMI), and percent body fat (%BF) in a large Korean adult group of apparently healthy subjects, and to analyze the characteristics of body composition indices among the subtypes of obesity in Korean adults. SUBJECTS AND METHODS: A multicenter, cross-sectional study was conducted on a sample of 1275 community-dwelling healthy Koreans, 504 men and 771 women, aged 18-89 years. Body composition parameters were measured by dual-energy X-ray absorptiometry. FFMI (FFM/height squared) and FMI (FM/height squared) were calculated, and then three subtypes of obesity were divided by FFMI; underlean (or sarcopenic), proportional, and heavy (or muscular) obesity. RESULTS: The reference values (5th-95th percentile) of the reference group (18-59 yr) for the FFMI was 16.3-22.3 kg/m(2) in men and 13.3-17.8 kg/m(2) in women. The %BF increased with age because of the reduction of FFM. Due to lower FFMI in the oldest men, they had the lowest BMI while FMI and BMI of Korean women increased with age like Caucasian women. The %BF among three subtypes of obesity was similar while FMI and BMI were increased as FFMI increased. The prevalence of underlean obesity in men was more than double in women. CONCLUSION: It is essential to analyze FFMI as well as %BF because %BF alone cannot explain the effects of ageing on FFM and the characteristics of subtypes of obesity. This is the first study to present DXA-determined age- and sex-specific percentiles for body composition indices in Korean adults. These reference values may be useful for clinical evaluation of body composition and nutritional status for Korean adults.

18.
Cancer Lett ; 273(1): 86-97, 2009 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-18848748

RESUMO

Plant polyphenols possess anti-oxidant and anti-inflammatory activities and are hence potential candidates for preventing cancer. The present study was aimed at evaluating the anti-inflammatory and anti-tumor promoting activity of oligonol, a formulation of catechin-type oligomers, in mouse skin stimulated with a proto-type tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). Pretreatment of mouse skin with oligonol significantly inhibited TPA-induced expression of cyclooxygenase-2 (COX-2). Oligonol diminished nuclear translocation and DNA binding of nuclear factor-kappaB (NF-kappaB) via blockade of phosphorylation and subsequent degradation of IkappaB alpha in TPA-treated mouse skin. Moreover, oligonol suppressed TPA-induced DNA binding of CCAAT/enhancer-binding protein (C/EBP) in mouse skin. Oligonol pretreatment also attenuated the phosphorylation and/or catalytic activities of extracellular signal-regulated protein kinase-1/2 (ERK1/2) and p38 mitogen-activated protein (MAP) kinase. Moreover, p38 MAP kinase inhibitor SB203580, but not the MEK inhibitor U0126, negated TPA-induced DNA binding of C/EBP. In addition, oligonol reduced the incidence and the multiplicity of papillomas and squamous cell carcinomas in 7,12-dimethylbenz[a]anthracene (DMBA)-initiated and TPA-promoted mouse skin, and prolonged the survival of tumor-bearing mice. Pretreatment with oligonol diminished the levels of proliferating cell nuclear antigen and expression of COX-2 in papillomas and carcinomas, respectively, as compared to DMBA plus TPA treatment alone. Taken together, the above findings suggest that oligonol inhibits TPA-induced COX-2 expression by blocking the activation of NF-kappaB and C/EBP via modulation of MAP kinases and suppresses chemically induced mouse skin tumorigenesis.


Assuntos
Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Catequina/análogos & derivados , Ciclo-Oxigenase 2/metabolismo , NF-kappa B/metabolismo , Fenóis/farmacologia , Ésteres de Forbol/farmacologia , Neoplasias Cutâneas/fisiopatologia , Pele/efeitos dos fármacos , Animais , Catequina/farmacologia , Células Cultivadas , Imuno-Histoquímica , Camundongos , Neoplasias Cutâneas/tratamento farmacológico
19.
Carcinogenesis ; 28(7): 1491-8, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17372274

RESUMO

Humulone, a bitter acid derived from hop (Humulus lupulus L.), possesses antioxidative, anti-inflammatory and other biologically active activities. Although humulone has been reported to inhibit chemically induced mouse skin tumor promotion, the underlying mechanisms are yet to be elucidated. Since an inappropriate over-expression of cyclooxygenase-2 (COX-2) is implicated in carcinogenesis, we investigated effects of humulone on COX-2 expression in mouse skin stimulated with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). Topical application of humulone (10 mumol) significantly inhibited TPA-induced epidermal COX-2 expression. Humulone also diminished TPA-induced DNA binding of nuclear factor-kappaB (NF-kappaB) and activator protein-1 (AP-1). Pre-treatment with humulone attenuated TPA-induced phosphorylation of p65 and nuclear translocation of NF-kappaB subunit proteins. Humulone blunted TPA-induced activation of inhibitory kappaB (IkappaB) kinase (IKK) in mouse skin, which accounts for its suppression of phosphorylation and subsequent degradation of IkappaBalpha. An in vitro kinase assay revealed that humulone could directly inhibit the catalytic activity of IKKbeta. Humulone suppressed the activation of mitogen-activated protein kinases (MAPKs) in TPA-treated mouse skin. The roles of extracellular signal-regulated protein kinase-1/2 and p38 MAPK in TPA-induced activation of NF-kappaB in mouse skin had been defined in our previous studies. The present study revealed that topical application of SP600125, a pharmacological inhibitor of c-Jun-N-terminal kinase (JNK), abrogated the activation of AP-1 and the expression of COX-2 in TPA-treated mouse skin. Taken together, humulone suppressed TPA-induced activation of NF-kappaB and AP-1 and subsequent expression of COX-2 by blocking upstream kinases IKK and JNK, respectively, which may account for its antitumor-promoting effects on mouse skin carcinogenesis.


Assuntos
Antineoplásicos/farmacologia , Cicloexenos/farmacologia , Ciclo-Oxigenase 2/biossíntese , Quinase I-kappa B/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , NF-kappa B/metabolismo , Pele/efeitos dos fármacos , Terpenos/farmacologia , Fator de Transcrição AP-1/metabolismo , Animais , Antracenos/farmacologia , Feminino , Humulus , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos ICR , Fosforilação , Transdução de Sinais/efeitos dos fármacos , Pele/enzimologia , Acetato de Tetradecanoilforbol/farmacologia
20.
Carcinogenesis ; 28(2): 363-71, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16950795

RESUMO

Conjugated linoleic acid (CLA) has been reported to inhibit mouse skin carcinogenesis, particularly in the promotion stage, but underlying molecular mechanisms remain poorly understood. Since persistent induction of cyclooxygenase-2 (COX-2) is frequently implicated in carcinogenesis, we investigated the effect of cis-9,trans-11-CLA (9Z,11E-CLA) on the tumor promoter-induced COX-2 expression in HR-1 hairless mouse skin in vivo. Topical application of 9Z,11E-CLA caused significant inhibition of COX-2 expression at 6 h induced by 10 nmol 12-O-tetradecanoylphorbol-13-acetate (TPA) in HR-1 mouse skin. Since NF-kappaB is known to regulate COX-2 gene expression, we determined the effect of 9Z,11E-CLA on TPA-induced activation of this transcription factor. Treatment of mouse skin with 9Z,11E-CLA reduced TPA-induced DNA binding as well as nuclear translocation of NF-kappaB by blocking phosphorylation and subsequent degradation of IkappaBalpha. In addition, 9Z,11E-CLA attenuated TPA-induced phosphorylation of extracellular signal-regulated protein kinase, p38 mitogen-activated protein kinase and Akt. To further elucidate the molecular mechanism underlying the inactivation of NF-kappaB by 9Z,11E-CLA, we investigated its effect on TPA-induced activation of IkappaB kinase (IKK), an upstream kinase that regulates NF-kappaB via phosphorylation and degradation of IkappaBalpha. 9Z,11E-CLA treatment down-regulated phosphorylation and catalytic activities of IKKalpha/beta in TPA-treated mouse skin. Co-treatment of mouse skin with the IKKbeta-specific inhibitor SC-514 (1 micromol) attenuated TPA-induced activation of Akt and NF-kappaB, and also the expression of COX-2 in hairless mouse skin. Taken together, 9Z,11E-CLA inhibits NF-kappaB driven-COX-2 expression by blocking the IKK and PI3K-Akt signaling in TPA-treated hairless mouse skin in vivo, which may account for its previously reported anti-tumor promoting effects.


Assuntos
Ciclo-Oxigenase 2/metabolismo , Quinase I-kappa B/metabolismo , Ácidos Linoleicos Conjugados/farmacologia , NF-kappa B/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Pele/efeitos dos fármacos , Acetato de Tetradecanoilforbol/farmacologia , Animais , Sequência de Bases , Primers do DNA , Ativação Enzimática , Masculino , Camundongos , Camundongos Pelados , Fosforilação , Pele/enzimologia , Pele/metabolismo
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