Biomedical subjects

Norihiko Tateishi

Publications and source records attributed to Norihiko Tateishi.

5 recordsLinked to original sources

PubMed2006

Triglyceride in plasma: prospective effects on microcirculatory functions.

The effect of triglyceride in plasma on RBC aggregation was examined, and the prospective influence on the flow of RBCs in microcirculation and the O2 release was discussed. To minimize the individual differences, blood samples were collected from one subject 2 hrs after high-fat and low fat meals. Triglyceride content in plasma was measured by an enzymatic method, and the rate of rouleaux formation was measured with a low shear rheoscope. The rate of rouleaux formation was increased with the increase of triglyceride concentration. Our previous findings suggested some functional impairment in microcirculation. (1) The enhanced RBC aggregation tends to reduce flow resistance in arterioles, but results in inhomogeneous flow of RBCs in capillaries. (2) The sclerotic change of microvessels alters flow behavior of RBCs, and thereby flow resistance is increased. (3) The enhanced RBC aggregation reduces O2 release from RBCs flowing in microvessels. In conclusion, high triglyceride level in plasma not only changes flow behavior of RBCs in microcirculation and thus increases flow resistance, but also prevents homogeneous tissue oxygenation.

Blood Viscosity↗

PubMed2004

Prognostic significance of Bcl-xL in human hepatocellular carcinoma.

BACKGROUND: Proliferation and apoptosis of liver cancer cells are closely related phenomena. We investigated the correlation between overexpression of Bcl-xL, an anti-apoptosis-related protein of the Bcl-2 family, and the clinical course of hepatocellular carcinoma (HCC). METHODS: Specimens from 7 HCC patients were used for Western blotting and immunoelectron microscopy tests. Samples from 33 HCC patients who had undergone hepatectomies were used for immunohistochemical staining. The degrees of expression of Bcl-xL and Ki-67, as an index of HCC mitosis severity, were each classified into 2 groups. RESULTS: With the use of Western blot analysis, enhanced immunoreactivity of Bcl-xL was found in cancerous specimens. Bcl-xL overexpression was found in cancer specimens in 21 of 33 patients (63.6%). The overall survival (P=.019) and disease-free survival (P=.030) rates of the group overexpressing Bcl-xL were definitely poorer. The Ki-67 higher labeling index LI > 10) group had a poorer survival rate (P=.016). There were significant correlations between Bcl-xL and overall survival and disease-free survival. Multivariate analyses revealed that Bcl-xL, tumor size, histologic portal invasion, and histologic metastatic foci were independent prognostic factors for overall survival and disease-free survival. CONCLUSIONS: These results showed Bcl-xL in HCC specimens, suggesting that Bcl-xL was a significant prognostic factor for disease progression in human HCC.

Adult↗

PubMed2003

Changes of RBC aggregation in oxygenation-deoxygenation: pH dependency and cell morphology.

The effects of the oxygenation-deoxygenation process on red blood cell (RBC) aggregation were examined in relation to morphological changes in RBCs and the contribution of CO(2). A low-shear rheoscope was used to measure the rate of rouleaux (one-dimensional aggregate) formation in diluted autologous plasma exposed to gas mixtures with different Po(2) and Pco(2). RBC indexes and RBC suspension pH were measured for the oxygenated or the deoxygenated condition, and the cell shape was observed with a scanning electron microscope. In the oxygenation-deoxygenation process, the rate of rouleaux formation increased with rising pH of the RBC suspension, which was lowered in the presence of CO(2). The rate increased with increasing mean corpuscular hemoglobin concentration (thus the cells shrank), which increased with rising pH and decreased in the presence of CO(2). With rising pH, cell diameter increased and cell thickness decreased (thus the cell flattened). In addition, slight echinocytosis was induced in the presence of CO(2), and the aggregation was reduced by the morphological change. In conclusion, RBC aggregation in the oxygenation-deoxygenation process is mainly influenced by the pH-dependent change in the surface area-to-volume ratio of the cells, and the aggregation is modified by CO(2)-induced acidification and the accompanying changes in mean corpuscular hemoglobin concentration and cell shape.

Adult↗

PubMed2003

Development of a tele-echography system by using an echographic diagnosis robot.

We have developed a tele-diagnosis system of echography (tele-echography system) using an Echographic Diagnosis Robot. The examiner moves the robot by using a control device at a distance from the patient and obtaining the echogram and the situation around the patient. The examiner and the patient locations are connected by a wireless local area network. Remote control is realized by the Object Request Broker (ORB) technique. We experimentally verified possibility of our system for clinical use. The robot was safe and stable even when there was slight movement of the patient and an adult patient never felt any discomfort due to the robot weight. Remote diagnosis of echograms was proved to be possible with sufficient image quality after a skilled examiner got used to controlling the robot. Since the required bandwidth of this system was at most 1Mbps, we confirmed the ability of this system for mobile robotic telemedicine.

Humans↗

PubMed2002

Reduced oxygen release from erythrocytes by the acceleration-induced flow shift, observed in an oxygen-permeable narrow tube.

The oxygen release from flowing erythrocytes under accelerational force (0-4 g) was examined using an oxygen-permeable, fluorinated ethylenepropylene copolymer tube (25 microm in inner diameter). The narrow tube was fixed vertically on the rotating disk of a new centrifuge apparatus, and erythrocyte suspension was perfused in the direction of Earth gravity. The accelerational force was applied perpendicularly to the flow direction of cells by centrifugation. The microscopic images of the flowing cells obtained at five different wavelengths were analyzed, and marginal cell-free layer and oxygen saturation of the cells were measured. By lowering oxygen tension around the narrow tube, erythrocytes were deoxygenated in proportion to their traveling distance, and the deoxygenation was enhanced with decreasing flow velocity and hematocrit. With increase of the g-value, the shift of flowing erythrocyte column to the centrifugal side was increased, the column was compressed, and the oxygen release from the cells was suppressed. Qualitatively, similar results were obtained by inducing erythrocyte aggregation with Dextran T-70 (MW = 70,400), without accelerational force. These results conclude that both the accumulation of erythrocytes under accelerational force and the enhancement of erythrocyte aggregation by macromolecules lead to the reduction of oxygen release from the flowing cells.

Acceleration↗