RESUMEN
Deficient visual organization ability not only indicates possible brain dysfunctions but further affects an individual's daily activities. This study aimed to use functional magnetic resonance imaging (fMRI) to investigate the neural network contributing to visual organization abilities in children and adolescents. A two-choice version of the Hooper Visual Organization Test (T-HVOT) was adapted as the fMRI task for the present study. The effects of age and gender on overall visual perceptual functions and related neural foundations were also analyzed. Seventy children and adolescents were administered with the Test of Visual Perceptual Skill-Third Edition and 41 completed the fMRI scans. The whole-brain fMRI mapping results showed the cortical activation of multiple brain areas relating to visual organization. The greatest cortical activities were seen in the middle occipital gyrus, middle temporal gyrus, middle frontal gyrus and inferior frontal gyrus, and two age groups showed significant differences in cortical activation patterns as well. Gender had no significant effects on visual perceptual functions nor related cortical activation patterns. The overall visual perception functions improve with age, and the different cortical activation patterns indicated that the two groups adopt different strategies while performing visual organization tasks. The sensitivity and spatial resolution of fMRI allowed us to make specific conclusions about cortical regions involved in visual organization function and to provide a reference for objectively judging rehabilitative outcomes.
Asunto(s)
Mapeo Encefálico , Imagen por Resonancia Magnética , Adolescente , Encéfalo/fisiología , Niño , Humanos , Imagen por Resonancia Magnética/métodos , Lóbulo Temporal , Percepción Visual/fisiologíaRESUMEN
This study investigated the effectiveness of the Computerized Visual Perception Training (CVPT) program on individuals with Down syndrome (DS, mean age=13.17±4.35years, age range: 6.54-20.75 years). All participants have mild intellectual disability classified by the standard IQ measures (mean=61.2, ranges from 55 to 68). Both the Test of Visual Perceptual Skill- Third Edition (TVPS-3) and functional magnetic resonance imaging (fMRI) were used to evaluate the training outcomes. Results of TVPS-3 and fMRI showed that DS group had visual perceptual deficits and abnormal neural networks related to visual organization. The results showed that DS intervention group had significant improvements on TVPS-3 after intervention. The fMRI results indicated more activation in superior and inferior parietal lobes (spatial manipulation), as well as precentral gyrus and dorsal premotor cortex (motor imagery) in DS intervention group. The CVPT program was effective in improving visual perceptual functions and enhancing associated cortical activations in DS.
Asunto(s)
Instrucción por Computador/métodos , Síndrome de Down , Educación de las Personas con Discapacidad Intelectual/métodos , Educación de Personas con Discapacidad Visual/métodos , Percepción Visual/fisiología , Adolescente , Encéfalo/diagnóstico por imagen , Mapeo Encefálico , Niño , Síndrome de Down/diagnóstico , Síndrome de Down/fisiopatología , Síndrome de Down/psicología , Educación , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Evaluación de Programas y Proyectos de Salud , Percepción Espacial/fisiología , TaiwánRESUMEN
Hypoxia in tumors is closely related to drug resistance. It has not been verified whether hypoxia-inducible factor-1α (HIF-1α) or ABCG2 is related to hypoxia-induced resistance. Ursolic acid (UA), when used in combination with cisplatin can significantly increase the sensitivity of ovarian cancer stem cells (CSCs) to cisplatin, but the exact mechanism is unknown. The cell growth inhibitory rate of cisplatin under different conditions was evaluated using Cell Counting Kit-8 (CCK-8) in adherence and sphere cells (SKOV3, A2780, and HEY). The expression of HIF-1α and ABCG2 was tested using quantitative PCR, western blotting, and immuno-fluorescence under different culture conditions and treated with UA. Knockdown of HIF-1α by shRNA and LY294002 was used to inhibit the activity of PI3K/Akt pathway. Ovarian CSCs express stemness-related genes and drug resistance significantly higher than normal adherent cells. Under hypoxic conditions, the ovarian CSCs grew faster and were more drug resistant than under normoxia. UA could inhibit proliferation and reverse the drug resistance of ovarian CSC by suppressing ABCG2 and HIF-1α under different culture conditions. HIF-1α inhibitor YC-1 combined with UA suppressed the stemness genes and ABCG2 under hypoxic condition. The PI3K/Akt signaling pathway activation plays an important functional role in UA-induced downregulation of HIF-1α and reduction of ABCG2. UA inhibits the proliferation and reversal of drug resistance in ovarian CSCs by suppressing the expression of downregulation of HIF-1α and ABCG2.
Asunto(s)
Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Proliferación Celular/efectos de los fármacos , Regulación hacia Abajo/efectos de los fármacos , Resistencia a Antineoplásicos/efectos de los fármacos , Proteínas de Neoplasias/genética , Células Madre Neoplásicas/efectos de los fármacos , Neoplasias Ováricas/tratamiento farmacológico , Triterpenos/farmacología , Hipoxia de la Célula/efectos de los fármacos , Hipoxia de la Célula/genética , Línea Celular Tumoral , Cisplatino/farmacología , Regulación hacia Abajo/genética , Resistencia a Antineoplásicos/genética , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Neoplasias Ováricas/genética , Fosfatidilinositol 3-Quinasas/genética , Proteínas Proto-Oncogénicas c-akt/genética , ARN Interferente Pequeño/genética , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética , Ácido UrsólicoRESUMEN
The primary purpose of this study was to investigate the visual perceptual functions measured by the Test of Visual Perceptual Skill-Third Edition (TVPS-3) in Down syndrome (DS). Seventy individuals with DS, seventy with typical development (TD), and forty mental-age-matched participants with intellectual disabilities (ID) were recruited for the assessment session. Significant between-group differences in TVPS-3 were observed between either DS or ID and TD groups. There was no significant difference on TVPS-3 between DS and ID groups. Implications for clinical professionals and recommendations for further research are discussed.
