ObjectiveTo discuss the 3D high resolution Magnetic resonance imaging (MRI) features of focal cortical dysplasia (FCD) in children.MethodsMRI data of 42 children with FCD confirmed by pathology, from April 2015 to June 2018, which were admitted to Qilu Children’s Hospital of Shandong University, were retrospectively analyzed. The following MRI signs were observed, blurring of junction of the gray matter-white matter, abnormality of structure with focal cortex (thick or thin), gray matter and white matter signal, white matter signal increased with T2WI/FLAIR, with or without transmantle sign (abnormal signal of white matter extending in the direction of ventricle), gray matter signal increased with T2WI/FLAIR, the abnormal sulci or gyri morphology and segmental and/or hypoplasia/atrophy of the lobes.ResultsAmong the 42 cases, 37 cases (88.1%) showed MRI positive signs, FCD typeⅠ accounted for 13 cases (35.1%), the main MRI features are focal blurring of junction in the gray matter-white matter, abnormality of structure with focal cortex in the corresponding part,and white matter signal increased with T2WI/FLAIR. FCD TypeⅡ accounted for 17 cases (45.9%), the MRI features are focal blurring of junction in the gray matter-white matter, abnormality of structure with focal cortex, white matter signal increased with T2WI/FLAIR, and transmantle sign. FCD TypeⅢ accounted for 7 cases (18.9%), among which hippocampal atrophy 2 cases (28.6%), dysembryoplastic neuroepithelial tumor (DNET) 2 cases (28.6%), section cell tumor 1 case (14.3%), softening lesion with gliosis 2 cases (28.6%).ConclusionThe 3D high-resolution MRI features of FCD in children are specific and could improve the detection rate of FCD lesions.
ObjectiveTo investigate the molecular mechanism by which metastasis-associated protein 3 (MTA3) participates in glioma resistance through reactive oxygen species. Methods Protein expression in glioma stem cells (GSCs) and non-GSCs was detected using Western blotting. GSCs included U87 and SHG44 cells, while non-GSCs included U87s and SU-2 cells. After overexpressing MTA3, U87 and SHG44 cells were divided into Lv-scr and Lv-MTA3 groups. The self-renewal capacity of glioma cells was assessed through a neurosphere formation assay. Cell survival fractions were examined following exposure to 0, 2, 4, 6, 8, and 10 Gy X-ray irradiation under normoxic or hypoxic conditions. Apoptosis and reactive oxygen species expression were analyzed using flow cytometry. Immunofluorescence staining was performed to detect the stem cell markers CD133 and nestin, as well as the differentiation markers glial fibrillary acidic protein (GFAP, for astrocytes) and neuronal class Ⅲ β-tubulin. Results In GSCs, MTA3 expression was lower in the U87s and SU-2 groups. After MTA3 overexpression, Lv-MTA3 expression was higher in U87s and SU-2 compared to the Lv-scr group. Under normoxic or hypoxic conditions, U87 and SU-2 showed greater radioresistance compared to glioma cell lines U87 and SHG44. Compared to non-GSCs, basal reactive oxygen species formation was reduced in GSCs, while reactive oxygen species generation was increased in non-GSCs. Following exposure to different doses of X-rays under normoxic or hypoxic conditions, GSCs with MTA3 overexpression exhibited greater radiosensitivity than those with stable integration. Additionally, MTA3 overexpression slightly increased the oxygen enhancement ratio (OER) in GSCs. MTA3 overexpression reduced the immunoreactivity of CD133 and nestin in both stem cell lines, and increased immunofluorescence staining of GFAP and neuronal class Ⅲ β-tubulin, with statistically significant differences (P<0.05). Conclusions MTA3 is downregulated in GSCs. Overexpression of MTA3 reduces the radioresistance and stemness of GSCs both in vitro and in vivo. MTA3 plays a crucial role in regulating the radiosensitivity and stemness of GSCs through reactive oxygen species.
In order to understand how the biomechanical properties of rabbit cornea change over time after corneal ablation, 21 healthy adult rabbits were used in this study, with the left eye as experimental side and the right eye as the control side. Firstly, a lamellar knife was used to remove a portion of the anterior corneal surface tissue (30%~50% of the original corneal thickness) from the left eye of each rabbit, as an animal model simulating corneal refractive surgery. Secondly, postoperative experimental rabbits were kept for one, three, or six months until being euthanized. Strip specimens were produced using their corneas in vitro to perform a uniaxial tensile test with an average loading-unloading rate of approximately 0.16 mm/s. Finally, the visco-hyperelastic material constitutive model was used to fit the data. The results showed that there was a significant difference in the viscoelastic parameters of the corneas between the experimental and the control eyes at the first and third postoperative months. There was a difference in tangential modulus between the experimental and the control eyes at strain levels of 0.02 and 0.05 at the third postoperative month. There was no significant difference in biomechanical parameters between the experimental and the control eyes at the sixth postoperative month. These results indicate that compared with the control eyes, the biomechanical properties of the experimental eyes vary over postoperative time. At the third postoperative month, the ratio of corneal tangential modulus between the experimental and the control eyes significantly increased, and then decreased. This work lays a preliminary foundation for understanding the biomechanical properties of the cornea after corneal refractive surgery based on rapid testing data obtained clinically.
