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Biomedical subjects

W H Stickel

Publications and source records attributed to W H Stickel.

8 recordsLinked to original sources
PubMed1979

Mercury residues in tissues of dead and surviving birds fed methylmercury.

Concentrations of mercury in passerine birds fed diets containing 40 ppm methylmercury were similar in tissues of birds that died from mercury poisoning and in those that were sacrificed after half the group had died. Residues were higher in tissues of birds that died, but the differences were not statistically significant. Residue levels were highest in livers, followed by kidneys and brains. Levels of mercury were similar in breast muscle, carcass, and whole body. Mercury levels were highest in redwinged blackbirds, lowest in grackles, and intermediate in starlings and cowbirds. Mercury concentrations exceeded 20 ppm in all tissues of all species and were similar to levels reported in wild birds known to have died of mercury poisoning.

Animals↗
PubMed1977

Prolonged retention of methyl mercury by mallard drakes.

Mallard drakes accumulated mercury rapidly from dietary dosage of methylmercury dicyandiamide and eliminated it slowly, retaining approximately one half at the end of 84 days; no measurable loss occurred between the end of the 7th and 56th days, but loss resumed concurrently with new feather growth, and continued through the 112th day, the close of the study.

Animals↗
PubMed1966

Residues of DDT in brains and bodies of birds that died on dosage and in survivors.

Residues of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)-ethane (DDT) and 1,1-dichloro-2,2-bis(p-chlorophenyl)-ethane (DDD) in brains of cowbirds (Molothrus ater) killed by dietary dosage of DDT were similar in birds that died after various lengths of time on dosage and in birds that died of delayed effects after as much as 40 days on clean food. Residues of DDT and DDD, but not of 1,1-dichloro-2,2-bis-(p-chlorophenyl)-ethylene (DDE), were much lower in survivors 112 days after dosage. The relative importance of DDT and DDD in brains could not be determined, but DDE appeared not to be critical. Residues in brains of cowbirds were similar to those reported for robins, sparrows, eagles, and white rats. Residues in livers and carcass remainders (with the possible exception of DDD in the liver) appeared unsuitable for diagnosing the cause of death.

Animals↗
PubMedDate not supplied

Oxychlordane, HCS-3260, and nonachlor in birds: lethal residues and loss rates.

Oxychlordane reached lethal levels in birds given dietary dosages of HCS-3260 (70.75% cis-chlordane and 23.51% trans-chlordane) at 6 levels from 50 to 500 ppm. Oxychlordane ranged from 9.4 to 22.1 ppm in brains of cowbirds (Molothrus ater), grackles (Quiscalus quiscula), and red-winged blackbirds (Agelaius phoeniceus) that died on dosage and from 1.3 to 4.8 ppm in sacrificed birds, providing a clear diagnostic separation. Among starlings (Sturnus vulgaris), however, oxychlordane ranged from 5.0 to 19.1 ppm in brains of birds that died, significantly lower than in the other species, and from 1.4 to 10.5 ppm in sacrificed birds, overlapping the levels in those that died. Lethal levels, therefore, begin near 5.0 ppm, as in a previous study in which oxychlordane itself was fed, but the data from starlings emphasizes the need for confirmatory necropsy findings in diagnosis of poisoning. Nonachlor had a very low order of toxicity, killing only 1 of 12 birds dosed at 100 ppm for 35 d; 3 others died and 1 was incapacitated during a short period of food deprivation. Lethal levels of oxychlordane were present in the brains of birds that died. Oxychlordane accumulated in the bodies of birds on dietary dosage of HCS-3260 in proportion to dosage and time, but did not approach equilibrium at the levels (10, 50, and 100 ppm) that were fed. Loss rates of oxychlordane from HCS-3260, oxychlordane, or technical chlordane dosages (the last in a previous study) did not differ significantly from each other; respective half-lives were 57, 63, and 74 d. Residues of cis-chlordane in birds fed HCS-3260 were consistently lower than oxychlordane during the accumulation period and declined abruptly when dosage ceased; individual variation was high.

Animals↗