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Biomedical subjects

T Mitsui

Publications and source records attributed to T Mitsui.

491 records · Page 28Linked to original sources

Hepatic granuloma with progressive calcification: CT appearance.

Calcification in the liver is uncommon but not rare in clinical practice, and may be caused by many pathological conditions. We report a patient with hepatic mass on abdominal sonogram and CT scan. The mass was shown as a hypoechoic lesion on abdominal sonogram and as a well-marginated hypodense mass on pre- and postcontrast CT. Inflammatory granuloma was diagnosed by pathological examination following percutaneous needle biopsy. A follow-up precontrast CT scan was performed 22 months after the initial examination, and the hepatic granuloma could be the cause of hepatic parenchymal calcification.

Adult↗

Method of noninvasive and continuous hemolysis/thrombogenesis measurement by laser photometry during artificial heart development.

The purpose of this research is to propose and develop a method to measure hemolysis and thrombogenesis non invasively and continuously to aid in development of an artificial heart. Generally, the optical absorption rate of hemoglobin is influenced by oxygen saturation except at the isosbestic point, which is not influenced by oxygen saturation. The authors, therefore, used an 805 nm laser diode, an optical spectrum analyzer to obtain greater accuracy. An experimental blood circuit system was constructed using a Bio-Pump, Tygon tubing, a soft shell reservoir, and an optical measurement system. Experimental settings for monitoring hemolysis were as follows; blood volume 200 ml, blood flow 6 L/min, and afterload 200 mmHg. Blood was sampled six times (0, 30, 60, 120, 180, and 240 min), and hemolysis in each sampled was measured using a colorimetric method. Comparing continuous laser measurement data with the sample data, an adequate correlation is obtained, proving that the dynamic trend of hemolysis could be continuously measured. Furthermore, to analyze the process of thrombogenesis, simple experiments were performed using blood neutralized by protamine. As a result, the authors could see the process of thrombogenesis as it occurred and could confirm that this method is able to dynamically detect hemolysis and thrombogenesis.

Biomedical Engineering↗

Species differences in erythrocyte mechanical fragility: comparison of human, bovine, and ovine cells.

The erythrocyte destruction rate under constant shear stress was measured to clarify species differences in red blood cell (RBC) mechanical fragility between human, bovine, and ovine cells. Blood was collected from healthy donors by venipuncture. RBC age fractionation was performed by high speed centrifugation (20 min at 12,000 g). Relatively young, middle, and old age RBCs was suspended in Dulbecco's phosphate buffered saline to adjust the hematocrit to 35%. Uniform shear stress was applied to each sample contained in a concavo-convex Couette flow testing machine. Young and old aged samples were exposed to 300 dyne-sec-cm2 for 0 and 15 min. Middle aged samples were exposed to 300 dyne-sec-cm2 for 0, 5, 10 and 15 min. Liberated hemoglobin was estimated by tetramethylbenzidine colorimetric measurement and the erythrocyte destruction rate was calculated. Older samples had a higher hemolysis rate than younger samples in every species. The destruction under constant shear stress is approximately linear in time. Mechanical fragility of ovine and bovine RBCs was 1.8 and 0.5 times as large as human RBCs, respectively. These values could serve as universal standards when extrapolating animal hemolysis data for any blood pump to predict its safety and biocompatibility in human clinical trials.

Animals↗