Biomedical subjects
Publications and source records attributed to Tohru Hoshida.
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INTRODUCTION: Vascular endothelial growth factor (VEGF) plays an important role in tumor angiogenesis. The soluble form of flt-1 VEGF receptor inhibits VEGF activity in a dominant-negative manner. AIM: This study demonstrated the regional tumor suppression effect of adenovirus-mediated soluble flt-1 in human pancreatic cancer cells. METHODOLOGY: The VEGF expression level was examined in nine cell lines. Panc-1 and PK-8 were used as lower- and higher-VEGF-producing cell lines, respectively. The in vitro proliferation of cancer cells infected with adenovirus vectors encoding soluble flt-1 (Adsflt) and control vectors (AdLacZ) was not different. To assess the in vivo tumor growth suppression, cancer cells were inoculated subcutaneously in SCID mice. Adsflt, AdLacZ, or vehicle was injected directly into the tumors. The early process of tumor angiogenesis in a dorsal skinfold chamber was monitored by intravital microscopy. RESULTS: In both Panc-1 cells and PK-8 cells, the tumor growth of the Adsflt-treated group was significantly suppressed. The microvessel density, revealed by CD31 immunostaining, was also significantly lower in the Adsflt-treated group. Apoptosis index was higher in the Adsflt group. Immunofluorescence staining revealed the expression of VEGF not only in cancer cells but also in tumor stromal cells. Wild-type cells and AdLacZ-infected cells prompted strong tumor angiogenesis, whereas Adsflt-infected cells failed to exert such an effect. CONCLUSION: These results indicate that antiangiogenic gene therapy using soluble flt-1 might be an effective approach for pancreatic cancer treatment.
Laser-Doppler (LD) flowmetry was used to measure tissue perfusion non-invasively and continuously during neurosurgical operations using an LD scanner. Scanning was usually completed in 20 seconds. Measurements were processed in software to provide a color-coded image of the tissue perfusion. Moreover, the measurement data, expressed in LD-units, could be used for statistical data analysis. No physical contact was necessary between the scanning device and the exposed brain tissue. The imager provided two-dimensional microvascular flow maps non-invasively and quantitatively during brain operations, and could show the CO2 reactivity in the vessels. LD scanning flowmetry is a promising intraoperative monitoring method for cerebral blood flow changes.
We studied 4 cases of complex partial seizures due to temporal lesions presenting with benign partial epilepsy in infancy. None of them had neurologic abnormalities. All cases had complex partial seizures, and two had lateralizing signs. All cases had temporal lesions. One of them was detected only by fluid-attenuated inversion recovery (FLAIR) imaging. Histopathologically they were astrocytomas (grade 2 and 3), glio neuronal hamartoma and focal cortical dysplasia. The present cases suggest that patient with infantile complex partial seizures should be carefully followed up, even after the disappearance of seizures, by serial MRI examination including FLAIR imaging and by clinical observation.