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Biomedical subjects

J H Swinehart

Publications and source records attributed to J H Swinehart.

9 recordsLinked to original sources
PubMed2003

The effect of humic acid on the uptake of mercury(II), cadmium(II), and zinc(II) by Chinook salmon (Oncorhynchus tshawytscha) eggs.

The Chinook salmon (Oncorhynchus tshawytscha) is endangered or threatened in several of its ranges. The uptake of metals by Chinook salmon eggs and how humic acid (HA) affects the uptake is a subject of interest. Humic acid (0, 0.001, 0.01, and 0.05g/l) reduces the uptake of the metal ions Hg(II), Cd(II), and Zn(II), (1.0 microM) by eggs. HA is more effective in reducing the uptake of Hg than that of Cd or Zn. At [HA] = 0.001 g/L Hg uptake is reduced by 44% compared to no HA, while Cd and Zn uptakes are slightly or not reduced. Once the metals are taken up by the eggs, Hg migrates more slowly from the chorion to the yolk than either Zn or Cd. In experiments in which the metal contents of the chorion and yolk were measured at up to 24 h and five days after uptake, the order of migration was Cd > Zn > Hg. This observation is important when discussing the effects of metals on biological processes in the yolk because when Hg is taken up by eggs, a smaller percentage reaches the yolk than does Cd and Zn.

Animals↗
PubMed1994

Vanadium in ascidians: changes in vanadium coordination and oxidation state upon cell lysis.

Changes in vanadium coordination during cell lysis have been followed by EPR spectroscopy of the blood cells of the phleborbranch ascidians Ascidia ceratodes and PHallusia julinea. The spectra obtained for A. ceratodes whole blood samples can be mainly ascribed to aquated oxovanadium(IV) in which the signals are broadened in freshly frozen blood relative to when the cells are lysed by thawing. The sources of this broadening are discussed and it is shown that the oxovanadium(IV) signal has its origin in a small percentage of damaged or lysed cells which release vanadium into a low sulfate, low acid environment in fresh samples. When thawed, the cells lyse releasing acid and sulfate into the environment of the oxovanadium(IV), with consequent narrowing of the EPR spectral linewidth. Freshly frozen P. julinea blood cell samples have EPR spectra with parameters intermediate between aquated oxovanadium(IV) and the "type I" parameters observed in a previous investigation of tissue samples of this species (S. G. Brand, C. J. Hawkins, A. T. Marshall, G. W. Nette, and D. L. Parry, Comp. Biochem. Physiol. 93B, 425 (1989)). A. ceratodes tissue samples also have EPR spectra that differ from that of the blood. It is suggested that EPR studies on tissue samples are more indicative of the resting state of vanadium in the cells as there is more physiological material to provide a pH buffering effect to stabilize the cells. Schemes are presented which incorporate all of the EPR observations in ascidian literature, where cellular lysis is proposed to be accompanied by vanadium undergoing oxidation and a series of chelate exchanges from a "type I" complex to aquated oxovanadium(IV). Protons released during these exchanges are suggested to provide the acidity characteristic of blood cell lysates. The biological implications of the concomitant release of vanadium and tunichrome (S. W. Taylor, D. L. Parry, C. J. Hawkins, and J. H. Swinehart, Comp. Biochem. Physiol. 106A, 531 (1993)) from the blood cells, to the process of wound repair are discussed.

Animals↗
PubMed1987

Interactions of organic pollutants with gills of the bivalve molluscs Anodonta californiensis and Mytilus californianus: uptake and effect on membrane fluxes. II.

1. The uptakes of 2,4,5-T, glyphosate, parathion, paranitrophenol, naphthalene, glycine, and inulin by gills of the bivalve molluscs Anodonta californiensis (freshwater) and Mytilus californianus (marine) show non-polar compounds are taken up to a greater extent than polar compounds except where active transport occurs. 2. The uptake of glycine by M. californianus is reduced by pollutants containing complexing functional groups but not by non-polar compounds. 3. The uptake of parathion alters the polyphosphate-inorganic phosphate balance in M. californianus. 4. The uptakes of pollutants parallel their toxicities toward rats.

Animals↗
PubMed1984

The effect of acid water on the loss of divalent cations and primary amines from natural membranes.

Losses of Ca2+, Mg2+ and primary amines into waters between pH = 5 and 3 from eyed Chinook salmon eggs, Oncorhynchus tshawytscha , and gills excised from the freshwater, bivalve mollusc Anodonta californiensis were measured and compared to effluxes into distilled water. Sulfuric, nitric and hydrochloric acids were used. Even at pH = 5 losses of Ca2+ and Mg2+ from both biological systems occur at short times, minutes, and can exceed those found in water of higher pH (non-acid waters). Increasing acidity increases short term primary amine loss from both systems. For both divalent cation and amino acid losses gills of A. californiensis are more sensitive to acidity than eggs of O. tshawytscha .

Acids↗
PubMed1980

Effects of divalent cations on amino acid and divalent cation fluxes in gills of the bivalve mollusc, Mytilus californianus.

Effects of the deletion of Ca++, Mg++, or Ca++ and Mg++ on the leakage of primary amines, Ca++, and Mg++ from gills of Mytilus californianus were studied. In the absence of Ca++ the gills leak primary amines and Ca++ for about 30 minutes, after which the primary amines are reabsorbed. In the absence of Mg++ the gills leak primary amines, with no net reabsorption for at least 90 minutes, and show rapid leakage of Mg++. In the absence of both Ca++ and Mg++ amino acid leakage is initially less than in the absence of only one of the cations. Measurements of the kinetics of leakages of Ca++ and Mg++ are consistent with the hypothesis that both ions are associated with the cell surface, but the affinity of Ca++ for the cell surface is greater than that of Mg++. In the absence of Mg++, the influx of 14C-glycine was depressed to about 1/3 that seen in controls, while deletion of Ca++ had no effect on the rate of influx. Increasing the [Mg++] stepwise between 5 x 10(-6) and 1 x 10(-1) M results in a sigmoidal increase in the rate of influx of 14C-glycine and a hyperbolic increase in the y-intercept of influx curves.

Amino Acids↗
PubMed1979

Studies of the blood of Ascidia ceratodes. Total blood cell counts, differential blood cell counts, hematocrit values, seasonal variations, and fluorescent characteristics of blood cells.

Seasonal, and animal size and weight variations of the blood cells of the vanadium-containing ascidian. Ascidia ceratodes, were determined. The fluorescent properties of various cell types were ascertained, and discussed in terms of cell development, phylogenic position of the species, and chemicals in the cells.

Acclimatization↗