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W P Heffernan

Publications and source records attributed to W P Heffernan.

5 recordsLinked to original sources
PubMed1970

Accumulation of Escherichia coli by the Northern quahaug.

The uptake of Escherichia coli by the quahaug, Mercenaria mercenaria, was studied to obtain an insight into the environmental parameters significant to the accumulation of bacterial pathogens by shellfish growing in polluted waters and into the kinetics of the uptake process. Experimental uptake was achieved by placing the animals in a flowing water system in which the contamination level of the water and its temperature and salinity could be controlled. Data from periodic assays of individual animals suggested that accumulation of the bacteria by the quahaug proceeds to an equilibrium level which is a function of E. coli content of the water and its overall particulate matter. Accumulation takes place in the digestive gland and, to a lesser extent, in the siphon of the animal.

Animals↗
PubMed1965

Isolation and characterization of filterable marine bacteria.

Anderson, J. I. W. (Northeast Shellfish Sanitation Research Center, Narragansett, R.I.), and W. P. Heffernan. Isolation and characterization of filterable marine bacteria. J. Bacteriol 90:1713-1718. 1965.-By a process of double filtration of seawater, first through a membrane filter with a pore diameter of 0.45 mu and then through a membrane filter with a pore diameter of 0.22 mu, it was possible to isolate on the surface of the latter membrane a group of marine organisms not usually encountered by conventional techniques of pour plates or one-stage filtration. Many of the isolates could not be identified, but the largest single group belonged to the genus Spirillum; other isolates were placed in the genera Leucothrix, Flavobacterium, Cytophaga, and Vibrio. A group of four organisms which was not identified was characterized by the formation of large, club-shaped cells, 20 to 30 mu long. Of the 25 strains studied in detail, 22 required seawater for growth and 8 retained their filterable property after cultivation. No filterable bacteria were isolated from terrestrial samples.

Bacteria↗
PubMedDate not supplied

Oxidative damage to the erythrocyte induced by sodium chlorite, in vivo.

Sodium chlorite in drinking water was found to produce a slight but compensated anemia in rats after exposure to up to 500 ppm for 90 days. Decreases in hemoglobin, red cell count, and packed cell volume seen after 30 days exposure had substantially recovered by 90 days of treatment. Signs of adaptation remained in that 2,3-diphosphoglyceric acid concentrations in the red cell remained elevated after 90 days exposure to 50 and 100 ppm CIO2-. However, dose-related decreases in erythrocyte glutathione levels, detected at chlorite levels as low as 50 ppm, remained decreased after 90 days exposure. While no other signs of overt toxicity were observed, the fact that hemolytic anemia was involved was confirmed by an increased turnover of red cells in cats exposed to CIO2-. Chlorite-induced decreases in glutathione in vivo were demonstrated to enhance formation of hydrogen peroxide when treated further with chlorite in vitro. Consequently, before a comprehensive determination of the hazards of chlorite in water can b: made, particular attention must be paid to individuals sensitive to hemolytic anemia.

Animals↗
PubMedDate not supplied

Oxidative damage to the erythrocyte induced by sodium chlorite, in vitro.

The ability of sodium chlorite to react with constituents of the erythrocyte, in vitro, was examined and compared to that of nitrite. The oxidative damage resulting from chlorite is fundamentally different from that of nitrite. Nitrite is slightly more potent as an oxidant of hemoglobin, while chlorite appears to be less specific in its oxidation of cellular constituents. Unlike nitrite, chlorite was found to deplete erythrocyte glutathione, which was accompanied by an increase in hydrogen peroxide generation. Chlorite also produced substantial changes in erythrocyte membrane morphology. These effects of chlorite are characteristic of compounds that produce oxidant-induced hemolytic anemia in vivo.

Anaerobiosis↗