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Biomedical subjects

K Atsumi

Publications and source records attributed to K Atsumi.

At least 73 records · Page 4Linked to original sources
PubMed1984

Quantitative approach to determine the application time of the left ventricular assist device.

This study was designed to establish a method for determining the optimal time of the application of the left ventricular assist device from the viewpoint of the metabolism of the vital organs. Quantitative systemic low flow states were made utilizing goats with total artificial hearts. During these experiments, arterial lactate and pyruvate values were sequentially measured. The behavior of anaerobic metabolism during low cardiac output states and in the recovery process following normalization of the cardiac output was quantitatively described and evaluated. The experimental results are summarized as follows: If a time when the decay of arterial lactate ceases at a level above the normal level by greater than 30 mg/dl is observed despite the use of intraaortic balloon pumping, that time is the exact optimal time for application of the left ventricular assist device. There is a great possibility that circulatory failure will be irreversible if left ventricular assist pumping is not initiated before the arterial lactate value increases to greater than or equal to 140 mg/dl. The method of evaluating the alteration of anaerobic metabolism described in this study is useful for determining the application time of the left ventricular assist device.

Animals↗
PubMed1984

How can the total artificial heart (TAH) patient be mobile and enjoy his life with an air driven system?

Two air driven VAD and TAH driving and control units were developed for clinical use, one to be installed at the bedside and the other to be installed in an electric wheelchair. The reliability and safety of the bedside unit were shown by long-term TAH experiments using animal models and by clinical application in conjunction with VAD. A TAH goat was safety taken on a 12 hr trip to a destination 550 km away while attached to a bedside unit. The driving and control functions of the wheelchair unit were found to be practically identical to those of the bedside unit.

Animals↗
PubMed1983

Inhibitory effect of laser irradiation on dermal syngeneic tumor growth in mice.

Mice (C57BL/6) with established intradermal tumors (melanoma B-16 or glioma 203G1) and inbred Swiss mice (SWM/Ms) with established intradermal tumors (3-methylcholanthrene-induced sarcoma) were treated by either surgical excision or laser irradiation. Laser irradiation is effective in preventing the growth of dermal melanoma, and laser therapy may be more efficacious than surgical therapy for induction of a reaction against melanoma in mice. The results also suggest that determination of a suitable laser wavelength may be required to obtain a good therapeutic effect on each tumor.

Animals↗
PubMed1983

Cytogenetic effects of argon laser irradiation on Chinese hamster cells.

The cytogenetic effects of argon laser light on V79 Chinese hamster cells were studied. Irradiation with a defocused continuous beam from an argon laser at doses of 100 to 400 J/cm2 had dose-related cytostatic and cytocidal effects. Cell cycle analysis by flow cytofluorometric measurement indicated that argon laser irradiation induced a temporary block at the G2 + M phase. The survival curve after laser irradiation was exponential without an initial shoulder and the D0 value (34% lethal dose) was calculated as 170 J/cm2. A significant increase in sister chromatid exchange was observed after laser irradiation. Laser irradiation also induced chromatid and chromosome aberrations, most of which were breaks and gaps. These chromosomal changes are probably not an artifact of the experimental procedures such as the use of phenol red and antibiotics or spontaneously emitted uv light. No mutation at the Na+/K+-dependent ATPase locus was induced by argon laser irradiation. Although the mechanism by which an argon laser beam induces cytogenetic damage remains to be investigated, the possible involvement of hyperthermia seemed to be excluded.

Animals↗