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Biomedical subjects

K Tsuchiya

Publications and source records attributed to K Tsuchiya.

At least 505 records · Page 28Linked to original sources
PubMed1988

A portable pneumatic driving unit for a left ventricular assist device.

The authors developed a portable air driving unit for an artificial heart. As the portable energy source of the driver, a commercially available Ni-Cd battery was used. A linear compressor was selected as a portable size compressor. To reduce the number of parts to be assembled, a new type of pneumatic system was employed. In this system, the pressure level was regulated by varying the output flow rate of the compressor instead of using a pressure regulator and large air reservoirs. A one-board microcomputer and pressure sensors were used to control the pressure level. The total weight of the unit is 9.5 Kg. After assembling the components into the portable unit, a blood pump was connected to examine the output characteristics of the system. It was confirmed that the unit could drive the blood pump continuously for more than 2 hours under the following conditions: output flow rate of the blood pump = 5 L/min and output pressure = 100 mmHg.

Assisted Circulation↗
PubMed1987

[Subcutaneous injection of spleen cells from mice bearing large methylcholanthrene-induced sarcoma enhances subcutaneous tumors and artificial pulmonary metastases].

To examine the effect of spleen cell on host antitumor immunity, spleen cells from mice bearing large Methylcholanthrene-induced sarcoma (MCA-F) (F4w spc) were injected subcutaneously into mice which had been inoculated subcutaneously with MCA-F cells or intravenously with the subline from MCA-F cells which had high potential of metastasis (FLn2). F4w spc enhanced significantly the growth of subcutaneous MCA-F tumor in a dose-dependent fashion (p less than 0.05) and increased the number of metastatic lesions induced by intravenous FLn2, but not spleen cells from normal mice or spleen cells from mice bearing MCA-D tumor which is antigenically different from MCA-F. These results suggest that spleen cells of mice bearing a large tumor have a component suppressing specifically antitumor immunity. In this study, effects of spleen cells were assessed by the subcutaneous injection into tumor bearing mice instead of Winn's assay, and this method was thought to be useful for analysis of effector cells in tumor immunity.

Animals↗
PubMed1987

Aberrant expression of ganglioside and asialoglycosphingolipid antigens in adult T-cell leukemia cells.

Gangliosides (GM3, GD3, GM2, gangliotetraose-series gangliosides) and their asialo derivatives of several adult T-cell leukemia (ATL) cell lines (ATL-1K, ATL-3I, ATL-5S, and MT-2 cells) and the lymphocytes from a patient with ATL were quantified by highly sensitive enzyme-immunostaining on silica gel thin layer chromatograms using specific antiglycolipid antibodies. GM2 and GD3 gangliosides and asialo GM1 (GA1) newly appeared in all cultured ATL cells and the lymphocytes from patients with ATL but not in normal human T-lymphocyte-rich fraction. Gangliotetraose-series gangliosides, GM1a, GD1a and GD1b, were also found in cultured ATL cells, but were not detected in normal human lymphocytes or the lymphocytes of a patient with ATL. Quantitative immunostaining analysis of GM2, GD3 gangliosides and GA1 in T-cell lines from non ATL leukemia (Molt-3, CEM and Jurkat) revealed GM2 gangliosides in all the T-cells from non ATL tested and GA1 in Jurkat cells, but no GD3 ganglioside was found in the non ATL leukemia cells tested. The above results indicate that ganglioside GD3 may be a T-cell glycosphingolipid antigen associated with ATL, and ganglioside GM2 and GA1 may be useful as surface markers related with ATL, as well as T-cell lymphoma. The contents of GA1, GM3, GD3, GM2 and gangliotetraose-series gangliosides in ATL cells were all different, even though all the cells used have a common antigen reactive with monoclonal OKT-4 antibody, indicating that there are several subsets of human inducer/helper T-cells, which possess different metabolism and expression of gangliosides.

Antigens, Neoplasm↗
PubMed1987

Renal effects of synthetic rat-atrial natriuretic peptide in nephron-reduced rats with nephrotoxic nephritis.

Following nephron reduction by means of five--sixths nephrectomy (Nx), nephritis was induced in rats by injection of nephrotoxic serum (NTS). A continuous intravenous infusion of synthetic rat--atrial natriuretic peptide (r-ANP) at 2.5 micrograms/min for produced remarkable diuresis and natriuresis in these rats. Furthermore, inulin clearance, para-amino-hippuric acid clearance and filtration fraction increased in spite of the reduction of mean arterial pressure during the infusion of r-ANP. It was therefore evident that diuresis and natriuresis were mediated by a direct action of r-ANP in the kidney. We observed that r-ANP was a diuretic, natriuretic and hypotensive agent but at a higher dosage in Nx rats with NTN.

Animals↗
PubMed1987

[Mitral regurgitation in the acute phase of Kawasaki disease: scrutiny using real-time two-dimensional Doppler flow imaging].

To study valvular lesions in the acute phase of Kawasaki disease, 17 patients who were admitted to our institution before the 12th day of their illness were examined using real-time two-dimensional Doppler flow imaging (2DD: Toshiba SSH 65A) from January to September 1986. Pulsed Doppler, continuous wave Doppler, and M-mode echocardiography were also performed. Patients were examined daily from their admission to 12th day of illness, and after that, more than twice a week until the 28th day of illness. Fourteen of the 17 patients underwent Ga-67 scintigraphy. Cardiac catheterization, including selective coronary arteriography, was performed in 15 patients in the convalescent phase. Mitral regurgitation (MR) was detected in eight of the 17 cases (47%). MR appeared on 2DD 7.5 +/- 1.6th day of illness (mean +/- SD), lasting until 11.9 +/- 5.7th day of illness. MR was transient and mild in degree in all cases, and the regurgitant jet was directed towards the left atrial posterior wall. Neither prolapse nor deformity of the mitral valve was detected. The left ventricular volume indices (determined by the Pombo method) measured by M-mode echocardiography in the acute and convalescent phases were compared. In the group with MR in the acute phase, the end-diastolic volume index was 66.9 +/- 19.9 ml/m2 and the end-systolic volume index was 21.0 +/- 11.7 ml/m2. These were significantly greater than those in the convalescent phase (51.3 +/- 13.1 ml/m2, 14.1 +/- 4.0 ml/m2, respectively). However, no significant differences were observed in the group without MR. Positive uptake of Ga-67 was observed in six patients with MR, but in none of the seven without MR. The incidence of positive uptake was significantly higher in the patients with MR. Cardiac catheterization performed in the convalescent phase revealed that no patient had the findings of MR, other valvular lesions, coronary arterial lesions, or abnormal ventricular performance.

Acute Disease↗