Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
1.
Int J Mol Sci ; 24(11)2023 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-37298502

RESUMEN

Iron accumulation in the brain accelerates Alzheimer's disease progression. To cure iron toxicity, we assessed the therapeutic effects of noncontact transcranial electric field stimulation to the brain on toxic iron deposits in either the Aß fibril structure or the Aß plaque in a mouse model of Alzheimer's disease (AD) as a pilot study. A capacitive electrode-based alternating electric field (AEF) was applied to a suspension of magnetite (Fe3O4) to measure field-sensitized reactive oxygen species (ROS) generation. The increase in ROS generation compared to the untreated control was both exposure-time and AEF-frequency dependent. The frequency-specific exposure of AEF to 0.7-1.4 V/cm on a magnetite-bound Aß-fibril or a transgenic Alzheimer's disease (AD) mouse model revealed the degradation of the Aß fibril or the removal of the Aß-plaque burden and ferrous magnetite compared to the untreated control. The results of the behavioral tests show an improvement in impaired cognitive function following AEF treatment on the AD mouse model. Tissue clearing and 3D-imaging analysis revealed no induced damage to the neuronal structures of normal brain tissue following AEF treatment. In conclusion, our results suggest that the effective degradation of magnetite-bound amyloid fibrils or plaques in the AD brain by the electro-Fenton effect from electric field-sensitized magnetite offers a potential electroceutical treatment option for AD.


Asunto(s)
Enfermedad de Alzheimer , Ratones , Animales , Enfermedad de Alzheimer/metabolismo , Ratones Transgénicos , Hierro/metabolismo , Péptidos beta-Amiloides/metabolismo , Especies Reactivas de Oxígeno , Estudios de Factibilidad , Óxido Ferrosoférrico , Proyectos Piloto , Oxidación-Reducción , Modelos Animales de Enfermedad , Placa Amiloide/terapia , Placa Amiloide/metabolismo
2.
J Alzheimers Dis ; 84(1): 377-392, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34569962

RESUMEN

BACKGROUND: The coexistence of magnetite within protein aggregates in the brain is a typical pathologic feature of Alzheimer's disease (AD), and the formation of amyloid-ß (Aß) plaques induces critical impairment of cognitive function. OBJECTIVE: This study aimed to investigate the therapeutic effect of proton stimulation (PS) targeting plaque magnetite in the transgenic AD mouse brain. METHODS: A proton transmission beam was applied to the whole mouse brain at a single entrance dose of 2 or 4 Gy to test the effect of disruption of magnetite-containing Aß plaques by electron emission from magnetite. The reduction in Aß plaque burden and the cognitive function of the PS-treated mouse group were assayed by histochemical analysis and memory tests, respectively. Aß-magnetite and Aß fibrils were treated with PS to investigate the breakdown of the amyloid protein matrix. RESULTS: Single PS induced a 48-87%reduction in both the amyloid plaque burden and ferrous-containing magnetite level in the early-onset AD mouse brain while saving normal tissue. The overall Aß plaque burden (68-82%) and (94-97%) hippocampal magnetite levels were reduced in late onset AD mice that showed improvements in cognitive function after PS compared with untreated AD mice (p < 0.001). Analysis of amyloid fibrils after exposure to a single 2 or 4 Gy proton transmission beam demonstrated that the protein matrix was broken down only in magnetite-associated Aß fibrils. CONCLUSION: Single PS targeting plaque magnetite effectively decreases the amyloid plaque burden and the ferrous-containing magnetite level, and this effect is useful for memory recovery.


Asunto(s)
Enfermedad de Alzheimer , Óxido Ferrosoférrico/metabolismo , Hierro/toxicidad , Memoria/fisiología , Oxidación-Reducción , Placa Amiloide/patología , Enfermedad de Alzheimer/patología , Enfermedad de Alzheimer/radioterapia , Animales , Encéfalo/patología , Modelos Animales de Enfermedad , Femenino , Humanos , Ratones , Ratones Transgénicos , Terapia de Protones
3.
J Biomed Opt ; 24(9): 1-9, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31512440

RESUMEN

Inexpensive near-infrared microscopy (NIRM) was developed as a convenient technique to detect the medulla loss of scalp hair while reducing analytical time with easy sample preparation, leading to a field screening tool for breast cancer. NIRM has been evaluated as an alternative to synchrotron-based nanoscopy and to the relatively expensive method of conventional infrared microscopy to determine the degree and pattern of medulla loss of scalp hairs of patients with breast cancer and benign diseases, as well as normal healthy individuals. NIR imaging showed a strong, scattering-based hyperintense contrast of the medulla compared to the fully attenuated cortex in medullated healthy hair. Complete medulla loss (CML) per hair strand was more extensively (60.9 ± 10.2 %) (p < 0.001) detected in the hair of all cancer patients than in the hair of either healthy individuals (less than 3.7 ± 7.5%) or those with benign disease (30.6 ± 5.9 % ), suggesting a potential biomarker for breast cancer diagnosis. The medulla structure was retained mostly in the hair of age-matched healthy individuals, but discontinuous medulla loss was observed concomitantly with less CML in fibroadenoma patients. Potentially, compact NIRM modules can be integrated into a mobile platform as point-of-care technology for breast cancer screening.


Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Cabello/diagnóstico por imagen , Microscopía/métodos , Espectroscopía Infrarroja Corta/métodos , Adulto , Anciano , Neoplasias de la Mama/patología , Diseño de Equipo , Femenino , Cabello/patología , Humanos , Persona de Mediana Edad , Cuero Cabelludo/fisiología , Espectroscopía Infrarroja Corta/instrumentación
4.
Oncol Rep ; 40(1): 339-345, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29749554

RESUMEN

Concurrent low­dose carboplatin/Photofrin® photodynamic therapy (ccPDT) has been shown to promote relapse­free complete tumor regression in cervical or endometrial cancer patients as a fertility­preservation therapy. This study aimed to investigate the molecular mechanism of the enhanced therapeutic efficacy of ccPDT by determining intracellular reactive oxygen species (ROS) and necrotic or apoptotic cell damage in HeLa cells loaded with fluorescent oxidant agents and Photofrin or/and carboplatin under light irradiation. The cytotoxic effects of ccPDT were compared when monitored with a light dose under carboplatin or Photofrin alone. Photofrin­PDT alone did not enhance either hydroxyl radicals (OH•) or superoxide anions (O2•-), but a slight enhancement of hydrogen peroxide (H2O2) production was observed. A larger enhancement of ROS production was obtained in a dose­dependent manner following ccPDT, especially OH• and H2O2, in conjunction with both necrotic and apoptotic cell death, compared with necrotic­prone PDT alone. The carboplatin­mediated Fenton reaction: 2[PtII]2 + H2O2 → [Pt2.25]4 + OH¯+ OH• was proposed to explain the dose­dependent enhancement of OH•. In conclusion, the therapeutic enhancement of ccPDT in vitro was attributable to the carboplatin­mediated synergetic production of OH▪ and apoptotic cellular damage, compared with Photofrin­PDT alone.


Asunto(s)
Carboplatino/farmacología , Recurrencia Local de Neoplasia/tratamiento farmacológico , Fotoquimioterapia , Neoplasias del Cuello Uterino/tratamiento farmacológico , Apoptosis/efectos de los fármacos , Éter de Dihematoporfirina/farmacología , Femenino , Preservación de la Fertilidad/métodos , Células HeLa , Humanos , Peróxido de Hidrógeno/metabolismo , Recurrencia Local de Neoplasia/metabolismo , Recurrencia Local de Neoplasia/fisiopatología , Fármacos Fotosensibilizantes/farmacología , Especies Reactivas de Oxígeno/metabolismo , Superóxidos/metabolismo , Neoplasias del Cuello Uterino/metabolismo , Neoplasias del Cuello Uterino/fisiopatología
SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda