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M Iwasaka

Publications and source records attributed to M Iwasaka.

4 recordsLinked to original sources
PubMed2003

Detection of intracellular macromolecule behavior under strong magnetic fields by linearly polarized light.

Strong static magnetic fields on the order of 10 T have a diamagnetic force on cell components and generate a clear alignment of a smooth muscle cell assembly, parallel to the direction of the magnetic fields within an exposure period of 3 days. This work shows the effects of diamagnetic torque forces on cell component motion. Linearly polarized light was utilized to detect the displacement of intracellular macromolecules. The polarized light passed through a mass of cells in a magnetic field, and transmission of the light increased and reached a plateau 2 h after the beginning of magnetic field exposure at 14 T. However, no distinct change was observed in transmission of the light under zero magnetic field exposure. The change in polarized light intensity through the lamellar cell assembly under magnetic fields corresponds to behavioral changes in cell components. It was speculated that intracellular macromolecules rotated and showed a displacement due to diamagnetic torque forces during 2-3 h of magnetic field exposure at 14 T.

Animals↗
PubMed2000

High-intensity static magnetic fields modulate skin microcirculation and temperature in vivo.

We investigated the acute effect of static magnetic fields of up to 8 T on skin blood flow and body temperature in anesthetized rats. These variables were measured prior to, during, and following exposure to a magnetic field in a superconducting magnet with a horizontal bore. The dorsal skin was transversely incised for 1 cm to make a subcutaneous pocket. Probes of a laser Doppler flowmeter and a thermistor were inserted into the pocket and positioned at mid-dorsum to measure skin blood flow and temperature. Another thermistor probe was put into the rectum to monitor rectal temperature. After baseline measurement outside the magnet, the rat was inserted into the bore for 20 min so that mid-dorsum was exactly positioned at the center, where the magnetic field was nearly homogeneous. Post-exposure changes were then recorded for 20 min outside the bore. Sham-exposed animals were submitted to exactly the same conditions, except that the superconducting magnet was not energized. Skin blood flow and temperature decreased significantly during magnetic field exposure and recovered after removal of the animal from the magnet. The rectal temperature showed a tendency to decrease while the animal was in the magnet. The microcirculatory and thermal reactions in the present study were consistent and agreed with some of the predictions based on mathematical simulations and model experiments.

Animals↗
PubMed1998

Biological effects of static magnetic fields on the microcirculatory blood flow in vivo: a preliminary report.

There have been few studies of the effect of static magnetic fields on microcirculatory haemodynamics in vivo. The rat skinfold transparent chamber technique was used, which provides an excellent means of observing and quantifying direct in vivo microvascular haemodynamic responses to static magnetic fields up to 8 T. An intravital videomicroscope was used to measure the changes in blood flow before and after exposure to a magnetic field for 20 min in a horizontal type superconducting magnet with a bore 100 mm in diameter and 700 mm long. After exposure, microcirculatory blood flow showed an initial increase for about 5 min followed by a gradual decrease and a return to the control value. It is hypothesised that these changes represent rebound hyperaemia following reduced blood flow during exposure.

Animals↗