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Biomedical subjects

M T Marron

Publications and source records attributed to M T Marron.

8 recordsLinked to original sources
PubMed1988

Low frequency electric and magnetic fields have different effects on the cell surface.

There is a considerable controversy over the nature of weak electromagnetic-field effects in living organisms. Part of the controversy can be traced to a lack of understanding of whether electric or magnetic fields are involved in producing bioeffects. We find that both 60 Hz electric and magnetic fields alter the cell surface of Physarum polycephalum. Exposure to electric fields increases the negative charge on the cell surface while magnetic-field exposure decreases the hydrophobic character of the surface. These effects appear to be additive and independent of the waveform of the applied fields.

Cell Membrane↗
PubMed1986

Pulsed magnetic fields alter the cell surface.

Pulsed magnetic fields (PMFS) are routinely used in the medical community to facilitate bone repair in clinical cases of non-union or pseudarthoses [(1984) Orth. Clin. No. Am. 15, 61-87]. Although this therapeutic regimen appears to be reasonably effective, the mechanism of action between specific PMFs and the target tissue remains unknown. Adding urgency to the need to understand the mechanism are a wide number of reports that have appeared which demonstrate that PMFs similar to those in clinical use can alter many basic physiological functions. We report that a 24 h exposure to PMFs alters the cell surface of Physarum polycephalum amoebae. Further, using the technique of aqueous two-phase partitioning, we present evidence for individual magnetic and electric field, cell surface effects.

Cell Membrane↗
PubMed1986

Effects of sinusoidal 60-Hz electric and magnetic fields on ATP and oxygen levels in the slime mold, Physarum polycephalum.

We have previously reported that exposing the vegetative plasmodia stage of Physarum polycephalum to either individual or simultaneously applied electric and magnetic fields (45-75 Hz, 0.14-2.0 G, and 0.035-0.7 V/m) lengthens their mitotic cycle, depresses their rate of reversible shuttle streaming, and lowers their respiration rate. In this article we report the effects of simultaneously applied electromagnetic fields (60 Hz, 1.0 G, 1.0 V/m), electric fields only (60 Hz, 1.0 V/m), magnetic fields only (60 Hz, 1.0 G) on the haploid amoeba of Physarum exposed for 120-180 days. Statistically significant depressions (about 8-11%) in ATP levels were observed with all field conditions; however, respiration was significantly decreased only when amoebae were subjected to either combined fields or electric fields alone. Magnetic fields alone failed to induce a significant decrease in respiration.

Adenosine Triphosphate↗
PubMed1982

Magnetic field effects on mitotic cycle length in Physarum.

Large plasmodia of Physarum polycephalum were formed from mixtures of micro-plasmodia grown in shaker cultures exposed to 2.0 G (rms), 75 Hz magnetic fields and non-exposed, control cultures. The exposed cultures had been grown continuously in the field and displayed a longer mitotic cycle than the controls. Mixed cultures display synchronous mitosis and a cycle length intermediate to the cycle lengths of exposed and control cultures. The cycle length of mixed cultures varied with the proportions of the mixture in a non-linear manner. The results are discussed in terms of several models.

Kinetics↗