目的:探讨不同分级脑星形细胞瘤的M R I表现的规律性。方法:经手术病理证实的脑星形细胞瘤100例,全部行M R I平扫及增强。结果:低级别星形细胞瘤信号较均匀,囊变、出血少,占位轻,多无强化。高级别肿瘤信号不均匀,有出血,占位明显,增强...目的:探讨不同分级脑星形细胞瘤的M R I表现的规律性。方法:经手术病理证实的脑星形细胞瘤100例,全部行M R I平扫及增强。结果:低级别星形细胞瘤信号较均匀,囊变、出血少,占位轻,多无强化。高级别肿瘤信号不均匀,有出血,占位明显,增强后强化明显且多不均匀。结论:不同分级的脑星形细胞瘤的M R I表现有一定规律性,多种表现综合分析,术前对肿瘤的良恶性可做出诊断。展开更多
Gamma-aminobutyric acid(GABA) contributes substantially to neurocognitive function as an important inhibitory neurotransmitter in the human cerebral cortex. However, the pathophysiology of disorders such as epilepsy a...Gamma-aminobutyric acid(GABA) contributes substantially to neurocognitive function as an important inhibitory neurotransmitter in the human cerebral cortex. However, the pathophysiology of disorders such as epilepsy are not well understood, since GABA agonists are not quite effective in treating epilepsy. Knowledge of the mechanism of action of GABA would contribute to review previously proposed anti-epileptic processes by GABA agonists. In this study based on recent experiments on GABAergic astrocytes, we developed a modified GABAergic astrocyte model, and successfully simulated a long-lasting Ca^(2+) oscillation in astrocytes after 0.5-s stimulation of GABAergic transmission. We then incorporated this GABAergic astrocyte model into a classical Ullah-Schiff seizure model and surprisingly found that this GABAergic astrocyte model functions to hinder the anti-epileptic action of GABA agonists, thereby explaining their low efficiency in previous experiments. These results also update our knowledge of the mechanism of action of GABA and the effects of astrocytes on physiological and pathological functions of the brain.展开更多
文摘目的:探讨不同分级脑星形细胞瘤的M R I表现的规律性。方法:经手术病理证实的脑星形细胞瘤100例,全部行M R I平扫及增强。结果:低级别星形细胞瘤信号较均匀,囊变、出血少,占位轻,多无强化。高级别肿瘤信号不均匀,有出血,占位明显,增强后强化明显且多不均匀。结论:不同分级的脑星形细胞瘤的M R I表现有一定规律性,多种表现综合分析,术前对肿瘤的良恶性可做出诊断。
基金supported by the National Natural Science Foundation of China(Grant No.11472202)
文摘Gamma-aminobutyric acid(GABA) contributes substantially to neurocognitive function as an important inhibitory neurotransmitter in the human cerebral cortex. However, the pathophysiology of disorders such as epilepsy are not well understood, since GABA agonists are not quite effective in treating epilepsy. Knowledge of the mechanism of action of GABA would contribute to review previously proposed anti-epileptic processes by GABA agonists. In this study based on recent experiments on GABAergic astrocytes, we developed a modified GABAergic astrocyte model, and successfully simulated a long-lasting Ca^(2+) oscillation in astrocytes after 0.5-s stimulation of GABAergic transmission. We then incorporated this GABAergic astrocyte model into a classical Ullah-Schiff seizure model and surprisingly found that this GABAergic astrocyte model functions to hinder the anti-epileptic action of GABA agonists, thereby explaining their low efficiency in previous experiments. These results also update our knowledge of the mechanism of action of GABA and the effects of astrocytes on physiological and pathological functions of the brain.
