Biomedical subjects

Mikio Yasumura

Publications and source records attributed to Mikio Yasumura.

4 recordsLinked to original sources

PubMed2004

Experimental studies to estimate the intestinal viability in a rat strangulated ileus model using a dielectric parameter.

This study aimed at establishment of adequate evaluation of intestinal viability before release of the strangulated intestine by measuring electrical properties. In rats a 20-cm segment of the distal ileum and mesentery was strangulated. The intestine was strangulated for 0, 2, 15, 45, 90, and 120 min. The conductance and capacitance obtained by impedance analyzer were used to calculate tan(delta)m in the strangulated intestine. ATP was measured as well. In another experiment, after various periods of strangulation, tan(delta)m was measured just before release of the strangulation. Rats were divided into Group A (survived for 7 days) and Group D (died within 7 days). There was a positive correlation between tan(delta)m and ATP levels (P < 0.01). And tan(delta)m was significantly greater in Group A than in Group D (P < 0.05). There were no deaths at a tan(delta)m value of 2.36 or more and no survivors at a tan(delta)m of less than 2.20 except for one rat. These results suggested that tan(delta)m may be a useful index of the viability of the strangulated intestine before reperfusion.

Adenosine Triphosphate↗

PubMed2003

Simultaneous operations for abdominal aortic aneurysm and liver cancer complicated by severe ischemic heart disease: report of a case.

We performed successful simultaneous operations for an abdominal aortic aneurysm (AAA) and liver cancer in a patient complicated by severe ischemic heart disease. A 59-year-old man with a history of liver dysfunction presented with acute epigastric pain. Abdominal computed tomography findings of ascites and a liver tumor indicated a diagnosis of ruptured hepatocellular carcinoma. He had a concomitant 65-mm AAA and a 48-mm right common iliac aneurysm. Elective surgery was scheduled because of his good general condition. Although triple-vessel disease was detected preoperatively, there were no graftable coronary arteries. The aneurysms were repaired first to utilize intra-aortic balloon pumping (IABP) during resection of the liver cancer, followed by left lateral segmentectomy. Perioperative hemodynamics were maintained by administering catecholamines and vasodilators, without the need for IABP. The patient was discharged on the 21st postoperative day without any complications, and no recurrence of liver cancer has been found in the 5 months since his operation.

Aortic Aneurysm, Abdominal↗

PubMed2003

[A case of multiple liver metastases from colon cancer successfully treated with pharmacokinetic modulating chemotherapy].

The present patient was a 54-year-old woman with anemia. After examination to identify the cause of anemia, she was diagnosed with sigmoid colon cancer and multiple liver metastasis. Sigmoid colectomy and insertion of an intra-hepatic arterial catheter were carried out. Histopathological examination of the resection specimen revealed well-differentiated adenocarcinoma, with a depth of tumor invasion of ss and positive lymph node metastasis. Pharmacokinetic modulating chemotherapy (PMC) was performed after the operation. The PMC consisted of oral UFT 300 to 400 mg/day every day and continuous arterial infusion of 5-FU 750 to 1,000 mg/24 h once a week. On a CT scan of the abdomen performed 6 months after the operation, the liver metastasis had disappeared and the patient was in complete remission (CR). PMC was continued, but the hepatic artery became occluded 1 year and 11 months after the operation, and so PMC was replaced by systemic chemotherapy of 5-FU plus levofolinate at 2 years after the operation. This chemotherapy was discontinued after 3 courses. At present, 2 years and 10 months after the operation, the patient remains in CR and is followed as an outpatient.

Adenocarcinoma↗

PubMed2002

Dielectric spectrogram for evaluating ischemic microstructural changes of the liver in simple cold preservation.

PURPOSE: Monitoring ischemic liver injury is important in liver transplantation. We previously reported that dielectric properties were correlated with tissue adenosine triphosphate during liver preservation; however, it is unknown what the changes in dielectric properties are based on. Using rats, we studied the relationship between dielectric parameters and microstructural changes in liver tissues during preservation. METHODS: We serially measured the percent decrease in conductivity and the percent increase in relative permittivity in rat livers, and determined the areas of cellular and extracellular components using a charge-coupled device microscope and an NIH image. Thereafter, we evaluated the relationship between dielectric parameters and microstructural changes in the liver tissues. RESULTS: A positive linear and exponential correlation was found between the percent decrease in conductivity and the percent decrease in extracellular components ( P < 0.01). A positive linear and exponential correlation was also found between the percent increase in relative permittivity and the percent increase in cellular components ( P < 0.01). CONCLUSIONS: Our results suggest that the serial changes in tissue conductivity and the relative permittivity reflect changes in liver tissue microstructures during cold preservation.

Animals↗