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Hideyuki Nakama

Publications and source records attributed to Hideyuki Nakama.

5 recordsLinked to original sources

Encapsulation cell therapy for mucopolysaccharidosis type VII using genetically engineered immortalized human amniotic epithelial cells.

Mucopolysaccharidosis type VII (MPSVII) is a lysosomal storage disease resulted from a deficiency of the enzyme beta-glucuronidase (GUSB), which is necessary for degradation of glycosaminoglycans (GAGs). The deficiency of GUSB causes progressive accumulation of GAGs and subsequent lysosomal distension in multiple tissues, including the central nervous system (CNS). In murine experiments, bone marrow transplant, enzyme replacement, viral vectors, and genetically modified cells were successfully used for correction of the visceral accumulation of GAGs, but little improvement was seen in the brain, because these therapeutic agents cannot cross the blood-brain barrier (BBB). Although direct intracerebral injection of GUSB-encoding viral vectors has been developed to bypass the BBB, the possibility of tumor formation and the toxicity of over-expressed GUSB have been reported. In this study, we generated immortalized human amniotic epithelial (IHAE) cells to maintain the effect of implantation, and encapsulated these cells to prevent harmful immunological response and tumor formation and to regulate the level of GUSB expression within the host. Moreover, we generated IHAE cells that over-express and secrete human GUSB following transduction with an adenoviral vector encoding human GUSB. Therapeutic efficacy for MPSVII was evaluated in and ex vivo experiments using these encapsulated genetically engineered GUSB-encoding IHAE cells. We confirmed that encapsulated genetically engineered IHAE cells could secrete significant amounts of GUSB outside the capsule in vitro and into the cerebral parenchyma of C3H mice seven days after the capsule implantation. Thus, encapsulation cell therapy using genetically engineered IHAE cells is an effective armamentarium for the treatment of MPSVII.

Amnion↗

Glutamate metabolism in epilepsy: 13C-magnetic resonance spectroscopy observation in the human brain.

To clarify changes in glutamate metabolism in the brain with chronic epileptic activities, 13C-magnetic resonance spectroscopy observation of glutamate and glutamine synthesis after oral administration of [1-13C] glucose (Glc C1) (0.75 g/kg) was performed in intractable occipital lobe epilepsy patients (n=5) and controls (n=10). 1H[13C]-spectra were obtained from two voxels of 64 ml placed on the bilateral parieto-occipital lobes of the study participants. Time courses for 13C-incorporation into 4-glutamate and 3-glutamate (Glu C4, C3) and 4-glutamine (Gln C4) were obtained and the concentrations of Glu C4, C3 and Gln C4 at the time between 120 and 150 min after Glc C1 administration was calculated. Concentration of Gln C4 was increased in the epilepsy patients [control: 0.39 mM (SD 0.14), epilepsy: 0.60 mM (SD 0.15), P<0.05], whereas those of Glu C4 and Glu C3 were not. The present study revealed increased glutamine synthesis compared with glutamate formation in a widespread cortical area with sustained epileptiform activities, possibly a result of chronic excessive glutamate release from neurons and subsequent uptake into astrocytes.

Adult↗

Complex behavioral automatism arising from insular cortex.

We describe two cases of complex partial seizures with ictal violent movements arising from the insular cortex. The first patient, a 14-year-old girl, presented with hyperkinetic behavior such as rolling, thrashing, and pedaling, and the second case, a 38-year-old woman, had been suffering from frequent daytime hyperkinetic seizures characterized by bizarre vocalization, jumping, and violent bimanual movements. Both patients showed a slight high signal change in the right posterior ventral insular cortex in fluid-attenuated inversion recovery (FLAIR) studies involving magnetic resonance imaging, and extensive subdural electroencephalographic monitoring revealed EEG seizure onset from the temporal lobe. The posterior ventral insular and lateral temporal cortices were resected, resulting in complete seizure freedom in both cases. The histological diagnoses were focal cortical dysplasia in the first case and gliosis in the second case. There may exist a group of patients with complex partial seizures with ictal violent automatism that can be ameliorated by the resection of epileptogenic lesions in the insular cortex. Careful inspection of the insular cortex is necessary to diagnose this type of epileptic seizure.

Adolescent↗

Visual activation positron emission tomography for presurgical evaluation of occipital lobe epilepsy--case report.

A 14-year-old boy suffered from daily epileptic seizures originating from the left polymicrogyric occipital cortex. Visual activation positron emission tomography (PET) was used to map the function of the occipital cortex presurgically. Loss of visual function in the left occipital cortex was suggested by both visual activation PET and electrical cortical stimulation. Left occipital lobectomy resulted in a completely seizure-free status without deterioration in the visual function. Preoperative evaluation of the visual function in the epileptogenic occipital cortex by activation studies using PET or functional magnetic resonance imaging is the key to the successful surgical treatment of occipital lobe epilepsy.

Adolescent↗