Biomedical subjects

K Yamashiro

Publications and source records attributed to K Yamashiro.

165 records · Page 10Linked to original sources

PubMedDate not supplied

Regulation of L-DOPA production by genetically modified primary fibroblasts transfected with retrovirus vector system.

Although intracerebral grafting has become established as a new strategy for the treatment of Parkinson's disease, there are many problems regarding such grafts. We focused on the grafting of primary skin fibroblasts. Rat primary skin fibroblasts were transfected with a retrovirus vector containing cDNA of human tyrosine hydroxylase (TH) type 1 (LTHSNL) or of cytomegalovirus promoter (CTHSNL) as a foreign promoter. In these genetically modified fibroblasts, L-DOPA production and release were analyzed in vitro by immunocytochemistry and high-performance liquid chromatography with electrochemical detection (HPLC-ECD). Being supplemented with the biopterin (BH4:(6R)-L-erythro-tetrahydrobiopterin) cofactors required for TH activity, these cells produced and released L-DOPA into the culture medium. When CTHSNL and BH4 were combined, L-DOPA production increased with time, regardless of the number of cell passages, or the duration of liquid nitrogen freezing. This suggests that the foreign gene (THcDNA) containing retrovirus vector integrates into the chromosomal DNA of the target cells (fibroblasts). Primary fibroblasts can be easily obtained and cultured. Thus, genetically modified primary skin fibroblasts transfected with a retrovirus vector system containing the TH cDNA may be promising grafts for transplantation and gene therapy in Parkinson's disease.

Animals↗

PubMedDate not supplied

Reproducibility of scanning laser Doppler flowmetry in the rat retina and optic nervehead.

PURPOSE: The purpose of this study is to confirm the reliability of scanning laser Doppler flowmetry in the rat retina and optic nervehead, and the validity of measuring changes of retinal blood flow in rats while breathing 100% oxygen. METHODS: We used a commercially available scanning laser Doppler flowmeter. To ascertain reliability, five consecutive and separate perfusion measurements of 12 eyes of 12 anesthetized pigmented rats were performed. To evaluate the validity of the system, repeated measurements were taken in anesthetized rats breathing room air or 100% oxygen. This series of measurements was repeated three times. RESULTS: The reliability coefficients of volume, flow, and velocity in the optic nervehead and the retina ranged from 0.80 to 0.83 and 0. 77 to 0.82, respectively. After the first exposure to oxygen, the measured values of volume, flow, and velocity were reduced by an average of 20.9-24.0%, 21.2-28.2%, and 19.5-24.5%, respectively. After the values returned to the basal condition, the second and third exposures to oxygen yielded measured values that were reduced by the same amounts as at the first exposure. CONCLUSIONS: Scanning laser Doppler flowmetry provided relatively good reliability in measurements of blood flow in the rat retina and optic nervehead. This study has indicated the possibility of applying this system to the rat retina.

Animals↗

PubMedDate not supplied

A case of partial autotransplantation of the liver in advanced hepatocellular carcinoma.

Hepatocellular carcinoma in Japan is frequently complicated by chronic hepatic disease such as chronic hepatitis and liver cirrhosis, and it is often impossible to decide the range to be resected only based on clinical stage and other tumor factors. We experienced a case with advanced hepatocellular carcinoma complicated by liver cirrhosis that directly infiltrated into the right and middle hepatic vein. Right trisegmentectomy was performed, the tumor site was extracorporeally removed and the hepatic posterior segment was autotransplanted. An anastomosis of the right hepatic vein and the inferior vena cava was performed with a vascular prosthesis. The patencies of the anastomosed vessels in the vascular reconstructions were confirmed by Doppler sonography, which was very useful, providing an easy and exact evaluation of hepatic blood flow at the patient's bedside. Throughout the post-operative course before the patient's discharge, no abnormal hepatic function was found. Though cases for which partial hepatic autotransplantation is appropriate may be few, this operation procedure, which applies hepatic transplantation techniques, is significant in that it increases the resectability and achieves curative resection of hepatocellular carcinoma.

Aged↗