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Biomedical subjects

L K Duffy

Publications and source records attributed to L K Duffy.

63 records · Page 4Linked to original sources
PubMed1978

Amino acid differences between major and minor hemoglobins from lemmings (Lemmus and Dicrostonyx).

1. Dual hemoglobins were isolated from both Lemmus and Discrostonyx, two genera of microtine rodents of the tribe Lemmini. 2. The dual hemoglobins result from dual alpha-chains and the charge difference Asp----Ala at position alpha 5. 3. The beta-chains of Dicrostonyx and Lemmus hemoglobins differ in charge by Ala----Asp at beta 125. 4. Cladograms are presented for the hemoglobin chains of microtine rodents.

Amino Acid Sequence↗
PubMed1977

Comparative solubilities and electrophoresis of microtine hemoglobins.

1. The electrophoretic mobilities of the hemoglobins of 7 taxa of microtines were compared. Microtus oeconomus, M. pennsylvanicus pullatus and M. xanthognatus showed identical 2-band patterns on electrophoresis of their hemoglobins while M. pennsylvanicus tananaensis showed only a single hemoglobin corresponding to the major band of the others. Dicrostonyx rubricatus and D. stevensoni exhibited identical patterns different from the Microtus species. Lemmus sibiricus had a slow hemoglobin component with mobility slightly different from the slow ones of the Microtus species while the fast component appeared the same. 2. Electrophoresis of individual globin chains from hemolysates, purified hemoglobins, and isolated chains indicated a large degree of similarity between the species studied, although there were significant differences in hemoglobin patterns. 3. The minor hemoglobin band in Microtus seems to be the result of a second alpha chain locus as determined from the hemoglobins from hybrids of two subspecies. 4. Salting-out studies indicated differences between hemoglobins that were not detectable by electrophoresis of either whole hemoglobins or isolated chains. 5. M. xanthognathus hemolysate was considerably less soluble than those of M. oeconomus and M. pennsylvanicus pullatus which had essentially the same solubility. 6. The major hemoglobin components of M. pennsylvanicus pullatus and M. xanthognathus were considerably less soluble than either the corresponding unfractionated hemolysates or purified minor components.

Animals↗
PubMed1976

Amino acid differences between the alpha-chains from two hemoglobins of the yellow-cheeked vole (Family Cricetidae).

The yellow-cheeked vole (Microtus xanthognathus) shows two electrophoretic hemoglobin components. Electrophoresis of the polypeptide chains from the separated hemoglobin components shows identical beta-chains but two alpha-chains of different mobility, alphaf and alphas. The composition of soluble tryptic peptides was determined for each alpha-chain. Amino acid differences were found in peptides alpha T1 and alpha T9; the compositions of the remainder of the homologous peptides were identical. Differences in alpha T1, found at alpha4 (alpha2-Gly-alphaf-Val) and alpha 5 (alphas-Thr-alphaf-Asp), were confirmed after a run to residue 20 of the fast component in an automatic sequencer. The differences in charge between alphaT1 peptides can account for the electrophoretic pattern of two hemoglobins. This is the first time that it has been possible to identity the residues which can account for the charge difference between the two hemoglobins observed in a Microtus species.

Amino Acids↗
PubMedDate not supplied

Ethanol elimination among different racial groups.

This study examined the relationship between ethanol elimination and race, specifically exploring differences among Alaskan Natives, American Indians, and whites. Native Americans, believed to be of recent Asian origin, were expected to eliminate alcohol faster than whites. The data suggested that both Native American men and women eliminated alcohol faster than whites. A relationship was also found between age, gender, and rate of alcohol elimination. The implications of these findings were reviewed and specific needs for future research were noted.

Adult↗
PubMedDate not supplied

Regional health assessment relating to mercury content of fish caught in the Yukon-Kuskokwim Delta rivers system.

Seven species of fish were surveyed for muscle tissue mercury content across a broad area of western Alaska. Total mercury levels were determined by cold vapor atomic fluorescence spectroscopy in 66 fish sampled during 1997. Methylmercury in sampled fish amounted to 97 to 100% of total mercury values. Using mercury consumption risk levels derived from U.S. Environmental Protection Agency hazard assessment models, mean total mercury was determined to be above the human critical value of 0.2 g/g (ppm) in 29% of the fish species, and 62% of the fish species contained mercury exceeding the wildlife critical value for piscivorous mammals. Overall, 24% of the fish exceed the critical value for human consumption and 58% the wildlife critical value. Similarly 31% of sites sampled exceeded the human consumption critical value. Based on the mean of all fish sampled and a small number of river otters, a biomagnification factor of 12 was calculated for the Yukon-Kuskokwim Delta Region of Alaska.

Alaska↗