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Biomedical subjects

T L Yates

Publications and source records attributed to T L Yates.

25 records · Page 2Linked to original sources

Eimerians from different karyotypes of the Japanese wood mouse (Apodemus spp.), with descriptions of two new species and a redescription of Eimeria montgomeryae Lewis and Ball, 1983.

Examination of 131 wood mice (Apodemus spp.) representing 2 species and 6 subspecies collected from the Japanese islands of Hokkaido, Honshu, Kyushu, and Tsushima showed that 70 mice (53%) had coccidian oocysts in their feces. These included 21 of 42 (50%) Apodemus argenteus argenteus; 7 of 14 (50%) Apodemus argenteus hokkaidi; 2 of 3 (67%) Apodemus argenteus sagax; 3 of 9 (33%) Apodemus speciosus ainu; 36 of 61 (59%) Apodemus speciosus speciosus; and 1 of 2 (50%) Apodemus speciosus tusimaensis. Four distinct coccidians were identified: Eimeria argenteus n. sp. from A. a. argenteus, A. a. hokkaidi, A. a. sagax, and A. s. speciosus; Eimeria inuyamensis n. sp. from A. a. argenteus, A. s. speciosus, and A. s. tusimaensis; Eimeria montgomeryae Lewis and Ball, 1983, from A. a. argenteus, A. a. hokkaidi, A. a. sagax, A. s. ainu, and A. s. speciosus; and Eimeria uptoni Lewis and Ball, 1983, from A. a. argenteus, A. a. hokkaidi, and A. s. speciosus. Standard karyotypes were prepared from selected specimens of each host subspecies. All 3 subspecies of A. argenteus and A. s. tusimaensis have a 2n = 46; A. s. ainu, from Hokkaido, has a 2n = 48; and A. s. speciosus has at least 2 chromosomal races, 1 on northern (2n = 48) and 1 on southern (2n = 46) Honshu. Both chromosomal races of A. s. speciosus, as well as the other subspecies of Apodemus examined, shared their coccidian parasites freely.

Animals↗

Chromosome banding patterns and the nucleolar organizer region of the eastern mole (Scalopus aquaticus).

The C and G chromosome banding patterns and the AgAS positive sites (NOR regions) of cultured lung cells of the Eastern mole (Scalopus aquaticus) are presented. A distinctive secondary constriction is found on a pair of autosomes instead of on the X-chromosome as previously believed. The presence of a heterochromatic heteromorphism is noted and a large amount of constitutive heterochromatin is present in the karyotype.

Animals↗

Enzyme variation of Eimeria arizonensis from Peromyscus truei and P. boylii.

Cricetid rodents, Peromyscus truei and P. boylii, were inoculated with sporulated oocysts of Eimeria arizonensis collected from wild P. truei maintained in the lab. In P. truei the prepatent period was 4-5 days, the patent period was 9-11 days, and sporulated oocysts were 21.5 x 25.0 (20-23 x 24-26) microns with sporocysts 7.7 x 12.0 (6-8 x 10-13) microns. In P. boylii the prepatent period was 6-7 days, the patent period was 8-9 days, and sporulated oocysts were 20.1 x 23.2 (18-22 x 21-24) microns with sporocysts 6.8 x 10.0 (5-8 x 9-12) microns. Sporulated oocysts from both host species were used in direct side-by-side comparison of isozyme banding patterns using protein electrophoresis. The parasite has polytypic loci for leucine aminopeptidase (LAP), lactate dehydrogenase (LDH), and 6-phosphogluconate dehydrogenase (6-PGD). In oocysts from P. truei, LAP showed one band with fast migration and LDH and 6-PGD each showed two bands, one with fast and one with slow migration. In oocysts from P. boylii, LAP and LDH each had one band with slow migration and 6-PGD had one band with moderate migration. Oocysts of E. arizonensis collected from P. boylii were used to inoculate P. truei. The prepatent and patent periods, structural measurements, and isozyme banding patterns of the resultant oocysts were the same as those from P. truei when inoculated with oocysts from P. truei.

Adaptation, Physiological↗

Long-term studies of hantavirus reservoir populations in the southwestern United States: rationale, potential, and methods.

Hantaviruses are rodent-borne zoonotic agents that cause hemorrhagic fever with renal syndrome in Asia and Europe and hantavirus pulmonary syndrome (HPS) in North and South America. The epidemiology of human diseases caused by these viruses is tied to the ecology of the rodent hosts, and effective control and prevention relies on a through understanding of host ecology. After the 1993 HPS outbreak in the southwestern United States, the Centers for Disease Control and Prevention initiated long-term studies of the temporal dynamics of hantavirus infection in host populations. These studies, which used mark-recapture techniques on 24 trapping webs at nine sites in the southwestern United States, were designed to monitor changes in reservoir population densities and in the prevalence and incidence of infection; quantify environmental factors associated with these changes; and when linked to surveillance databases for HPS, lead to predictive models of human risk to be used in the design and implementation of control and prevention measures for human hantavirus disease.

Animals↗

Statistical sensitivity for detection of spatial and temporal patterns in rodent population densities.

A long-term monitoring program begun 1 year after the epidemic of hantavirus pulmonary syndrome in the U.S. Southwest tracked rodent density changes through time and among sites and related these changes to hantavirus infection rates in various small-mammal reservoir species and human disease outbreaks. We assessed the statistical sensitivity of the program's field design and tested for potential biases in population estimates due to unintended deaths of rodents. Analyzing data from two sites in New Mexico from 1994 to 1998, we found that for many species of Peromyscus, Reithrodontomys, Neotoma, Dipodomys, and Perognathus, the monitoring program detected species-specific spatial and temporal differences in rodent densities; trap-related deaths did not significantly affect long-term population estimates. The program also detected a short-term increase in rodent densities in the winter of 1997-98, demonstrating its usefulness in identifying conditions conducive to increased risk for human disease.

Analysis of Variance↗