The Experts below are selected from a list of 222 Experts worldwide ranked by ideXlab platform

Pierre E Rollin - One of the best experts on this subject based on the ideXlab platform.

  • black creek canal virus infection in Sigmodon hispidus in southern florida
    American Journal of Tropical Medicine and Hygiene, 1998
    Co-Authors: Gregory E Glass, Walter Livingstone, James N Mills, W G Hlady, Joshua B Fine, W Biggler, T Coke, D Frazier, S Atherley, Pierre E Rollin
    Abstract:

    A total of 1,500 small mammals were collected and tested for antibodies cross-reactive to Sin Nombre virus (Hantavirus: Bunyaviridae) at 89 sites in a 1,600 km2 study area of southern Florida. More than 95% of the 123 seropositive animals were cotton rats (Sigmodon hispidus), suggesting infection by Black Creek Canal Virus, although seroreactive Rattus rattus (5 of 294) and Peromyscus gossypinus (1 of 39) also were captured. Crude seroprevalence in S. hispidus was 11%. Seroprevalence increased with body size and was more common in male (18%; n=451) than in female (6%; n=593) cotton rats. Infection within S. hispidus populations was widespread throughout the study area. Prevalence ranged from 0% to 60% at sites where more than five cotton rats were sampled but was not only a function of sample size. Sites with seropositive cotton rats were geographically clustered compared with sites with no seropositive cotton rats. Clustering was not due to the spatial distribution of sites with few animals, season of collection, or sex bias of animals captured at these sites. However, sites with no seropositive animals had an excess of animals in the intermediate size class (60-99 g) and a deficit of the largest and smallest animals. These data suggest that population structure within the habitat mosaic may play a significant role in the spatial distribution of hantavirus infection in local populations of reservoir species.

  • isolation of black creek canal virus a new hantavirus from Sigmodon hispidus in florida
    Journal of Medical Virology, 1995
    Co-Authors: Pierre E Rollin, Thomas G Ksiazek, Luanne H Elliott, Eugene V Ravkov, Mary Lane Martin, Sergey P Morzunov, Walter Livingstone, Marty Monroe, Gregory E Glass, Ali S Khan
    Abstract:

    Numerous rodents were trapped for serologic and virologic studies following the identification of a hantavirus pulmonary syndrome (HPS) case in Dade County, Florida. Cotton rats (Sigmodon hispidus) were the most frequently captured rodent and displayed the highest seroprevalence to a variety of hantavirus antigens. Hantavirus genome RNA was detected in all the seropositive cotton rats tested, using a reverse transcriptase-polymerase chain reaction (RT-PCR) assay. A virus was isolated from tissues of two seropositive cotton rats by cultivation of lung and spleen homogenates on Vero E6 cells. Nucleotide sequence information obtained by direct RT-PCR and the serologic relationships of this virus with the other hantaviruses indicate that this virus, Black Creek Canal virus, represents a new hantavirus distinct from the previously known serotypes. © 1995 Wiley-Liss, Inc.

Robert L Lochmiller - One of the best experts on this subject based on the ideXlab platform.

  • Population Dynamics of Cotton Rats (Sigmodon hispidus) Inhabiting Abandoned Petroleum Landfarms in Oklahoma, USA
    Ecotoxicology, 2006
    Co-Authors: James A. Wilson, Robert L Lochmiller, David M. Janz
    Abstract:

    Previous work by our group has shown bioaccumulation of contaminants and alterations in the immune system of hispid cotton rats ( Sigmodon hispidus ) inhabiting petrochemical waste sites (landfarms). We studied populations of cotton rats inhabiting petrochemical landfarms or uncontaminated reference sites. Cotton rat populations inhabiting abandoned landfarms experienced reduced summer population densities and lower mean monthly survival, with maximum densities 65% that of populations inhabiting non-contaminated grassland (reference) sites. Survival was lower in populations from landfarms (0.62±0.04) compared to reference sites (0.75±0.04), with differences most notable during summer months. Cotton rat populations sampled from landfarms had even sex ratios and a lower proportion of juveniles compared to populations from reference sites. No differences were observed in the weight of epididymides, testes, uteri, or ovaries, and no differences in fecundity were detected among sites.

  • widespread risks of dental fluorosis in cotton rats Sigmodon hispidus residing on petrochemical waste sites
    Journal of Toxicology and Environmental Health, 2001
    Co-Authors: Eric L Stair, Robert L Lochmiller, D P Rafferty, James W Lish, Jackie L Schroder, Nicholas T Basta, Charles W. Qualls
    Abstract:

    Fluoride has been identified as a ubiquitous contaminant of soils where petrochemical wastes have been disposed. The purpose of this study was to assess how widespread toxicity risks are to resident vertebrates from chronic exposure to fluoride in the soil of petrochemical-contaminated waste sites. In total, 573 wild cotton rats (Sigmodon hispidus) were examined. The rats that were seasonally collected from 12 contaminated and 12 ecologically matched reference sites across Oklahoma over a 3-yr period. The risks of cotton rats exposed to fluoride were analyzed by means of gross examination, histopathology, and scanning electron microscopy of rat incisors. Cotton rats from reference sites showed no pathologic changes in incisors (98%). In comparison, 46% of cotton rats from contaminated sites had various degrees of dental lesions. The prevalence and severity of dental lesions in cotton rats from contaminated sites were significantly influenced by season. There was a 45% increase in prevalence and a 65% incr...

  • seasonal hepatic cytochrome p 450 induction in cotton rats Sigmodon hispidus inhabiting petrochemical waste sites
    Environmental Pollution, 1999
    Co-Authors: Robert L Lochmiller, Scott T Mcmurry, Karen Mcbee, D P Rafferty, James W Lish, C W Qualls
    Abstract:

    Abstract Wildlife species inhabiting contaminated sites are often exposed to complex mixtures of chemicals that have known effects on physiological and biochemical function. We evaluated the induction of major hepatic cytochrome P-450 isoenzymes through O -dealkylation of various resorufin ethers in wild cotton rats ( Sigmodon hispidus ) inhabiting three reference areas and three contaminated areas at an abandoned oil refinery Superfund waste site in Oklahoma. Isoenzyme activities were monitored in animals from these sites in summer and winter for 2 years. O -dealkylation of ethoxyresorufin and methoxyresorufin was significantly greater (170–180%) in cotton rats from contaminated areas compared to those from reference areas in summer, but not winter. These results indicate that the cotton rat may be a sensitive model species for biomonitoring petrochemical-contaminated ecosystems and demonstrate the importance of multi-season sampling in biomonitoring studies.

  • ENVIRONMENTAL INFLUENCES ON MASS DYNAMICS OF THE COTTON RAT (Sigmodon hispidus) THYMUS GLAND
    Biological Rhythm Research, 1998
    Co-Authors: Robert L Lochmiller, Stephen S. Ditchkoff
    Abstract:

    The influence of season on thymus gland mass was examined relative to captivity, gender, and age in 921 cotton rats (Sigmodon hispidus) from free-ranging and laboratory populations. Age-related involution of the thymus gland was evident in free-ranging males and females and captive females. A distinct seasonal cycle in thymus mass dynamics was apparent among adult cotton rats. Mass of the thymus gland was greatest from late fall to early winter before declining 2-4 fold during spring. Thymus gland mass remained low through spring and summer in adult cotton rats when reproductive activity was maximum. No seasonal cycle in thymus mass was apparent among juveniles. Possible involvement of sex hormones in regulating thymus size is discussed.

  • requirements for reproduction in the hispid cotton rat Sigmodon hispidus a re evaluation
    Journal of Mammalogy, 1997
    Co-Authors: Eric C Hellgren, Robert L Lochmiller
    Abstract:

    Randolph et al. (1995, Journal of Mammalogy , 76:1113–1126) estimated requirements for reproduction in the hispid cotton rat ( Sigmodon hispidus ) by using a mass-balance equation. We argue that their algorithm is incomplete, and provide a modified equation with illustrative examples.

Gregory E Glass - One of the best experts on this subject based on the ideXlab platform.

  • black creek canal virus infection in Sigmodon hispidus in southern florida
    American Journal of Tropical Medicine and Hygiene, 1998
    Co-Authors: Gregory E Glass, Walter Livingstone, James N Mills, W G Hlady, Joshua B Fine, W Biggler, T Coke, D Frazier, S Atherley, Pierre E Rollin
    Abstract:

    A total of 1,500 small mammals were collected and tested for antibodies cross-reactive to Sin Nombre virus (Hantavirus: Bunyaviridae) at 89 sites in a 1,600 km2 study area of southern Florida. More than 95% of the 123 seropositive animals were cotton rats (Sigmodon hispidus), suggesting infection by Black Creek Canal Virus, although seroreactive Rattus rattus (5 of 294) and Peromyscus gossypinus (1 of 39) also were captured. Crude seroprevalence in S. hispidus was 11%. Seroprevalence increased with body size and was more common in male (18%; n=451) than in female (6%; n=593) cotton rats. Infection within S. hispidus populations was widespread throughout the study area. Prevalence ranged from 0% to 60% at sites where more than five cotton rats were sampled but was not only a function of sample size. Sites with seropositive cotton rats were geographically clustered compared with sites with no seropositive cotton rats. Clustering was not due to the spatial distribution of sites with few animals, season of collection, or sex bias of animals captured at these sites. However, sites with no seropositive animals had an excess of animals in the intermediate size class (60-99 g) and a deficit of the largest and smallest animals. These data suggest that population structure within the habitat mosaic may play a significant role in the spatial distribution of hantavirus infection in local populations of reservoir species.

  • isolation of black creek canal virus a new hantavirus from Sigmodon hispidus in florida
    Journal of Medical Virology, 1995
    Co-Authors: Pierre E Rollin, Thomas G Ksiazek, Luanne H Elliott, Eugene V Ravkov, Mary Lane Martin, Sergey P Morzunov, Walter Livingstone, Marty Monroe, Gregory E Glass, Ali S Khan
    Abstract:

    Numerous rodents were trapped for serologic and virologic studies following the identification of a hantavirus pulmonary syndrome (HPS) case in Dade County, Florida. Cotton rats (Sigmodon hispidus) were the most frequently captured rodent and displayed the highest seroprevalence to a variety of hantavirus antigens. Hantavirus genome RNA was detected in all the seropositive cotton rats tested, using a reverse transcriptase-polymerase chain reaction (RT-PCR) assay. A virus was isolated from tissues of two seropositive cotton rats by cultivation of lung and spleen homogenates on Vero E6 cells. Nucleotide sequence information obtained by direct RT-PCR and the serologic relationships of this virus with the other hantaviruses indicate that this virus, Black Creek Canal virus, represents a new hantavirus distinct from the previously known serotypes. © 1995 Wiley-Liss, Inc.

Raymond W Nims - One of the best experts on this subject based on the ideXlab platform.

  • induction of cytochrome p 450 in Sigmodon hispidus cotton rats exposed to dietary aroclor 1254
    Journal of Toxicology and Environmental Health, 1994
    Co-Authors: John R Henneman, Ronald A Lubet, Jerrold M Ward, Raymond W Nims
    Abstract:

    The induction of immunoreactive cytochrome P‐450 protein and associated catalytic activities in 10‐wk‐old male and female Sigmodon hispidus (cotton rats) exposed for 2 wk to low dietary levels of Aroclor 1254 (0.33, 1.0, 3.3, 10, and 33 ppm), or the prototype P‐450 inducers phenobarbital, DDT, clotrimazole, and β‐naphthoflavone was examined. Ethoxy‐(ETR), methoxy‐ (MTR), pentoxy‐ (PTR), and benzyloxyresorufin (BZR) O‐dealkylation activities were significantly increased at 0.33 ppm Aroclor for males and 1.0 ppm for females.

  • Induction of cytochrome P‐450 in Sigmodon hispidus (cotton rats) exposed to dietary aroclor 1254
    Journal of Toxicology and Environmental Health, 1994
    Co-Authors: John R Henneman, Ronald A Lubet, Jerrold M Ward, Raymond W Nims
    Abstract:

    The induction of immunoreactive cytochrome P‐450 protein and associated catalytic activities in 10‐wk‐old male and female Sigmodon hispidus (cotton rats) exposed for 2 wk to low dietary levels of Aroclor 1254 (0.33, 1.0, 3.3, 10, and 33 ppm), or the prototype P‐450 inducers phenobarbital, DDT, clotrimazole, and β‐naphthoflavone was examined. Ethoxy‐(ETR), methoxy‐ (MTR), pentoxy‐ (PTR), and benzyloxyresorufin (BZR) O‐dealkylation activities were significantly increased at 0.33 ppm Aroclor for males and 1.0 ppm for females.

Walter Livingstone - One of the best experts on this subject based on the ideXlab platform.

  • black creek canal virus infection in Sigmodon hispidus in southern florida
    American Journal of Tropical Medicine and Hygiene, 1998
    Co-Authors: Gregory E Glass, Walter Livingstone, James N Mills, W G Hlady, Joshua B Fine, W Biggler, T Coke, D Frazier, S Atherley, Pierre E Rollin
    Abstract:

    A total of 1,500 small mammals were collected and tested for antibodies cross-reactive to Sin Nombre virus (Hantavirus: Bunyaviridae) at 89 sites in a 1,600 km2 study area of southern Florida. More than 95% of the 123 seropositive animals were cotton rats (Sigmodon hispidus), suggesting infection by Black Creek Canal Virus, although seroreactive Rattus rattus (5 of 294) and Peromyscus gossypinus (1 of 39) also were captured. Crude seroprevalence in S. hispidus was 11%. Seroprevalence increased with body size and was more common in male (18%; n=451) than in female (6%; n=593) cotton rats. Infection within S. hispidus populations was widespread throughout the study area. Prevalence ranged from 0% to 60% at sites where more than five cotton rats were sampled but was not only a function of sample size. Sites with seropositive cotton rats were geographically clustered compared with sites with no seropositive cotton rats. Clustering was not due to the spatial distribution of sites with few animals, season of collection, or sex bias of animals captured at these sites. However, sites with no seropositive animals had an excess of animals in the intermediate size class (60-99 g) and a deficit of the largest and smallest animals. These data suggest that population structure within the habitat mosaic may play a significant role in the spatial distribution of hantavirus infection in local populations of reservoir species.

  • isolation of black creek canal virus a new hantavirus from Sigmodon hispidus in florida
    Journal of Medical Virology, 1995
    Co-Authors: Pierre E Rollin, Thomas G Ksiazek, Luanne H Elliott, Eugene V Ravkov, Mary Lane Martin, Sergey P Morzunov, Walter Livingstone, Marty Monroe, Gregory E Glass, Ali S Khan
    Abstract:

    Numerous rodents were trapped for serologic and virologic studies following the identification of a hantavirus pulmonary syndrome (HPS) case in Dade County, Florida. Cotton rats (Sigmodon hispidus) were the most frequently captured rodent and displayed the highest seroprevalence to a variety of hantavirus antigens. Hantavirus genome RNA was detected in all the seropositive cotton rats tested, using a reverse transcriptase-polymerase chain reaction (RT-PCR) assay. A virus was isolated from tissues of two seropositive cotton rats by cultivation of lung and spleen homogenates on Vero E6 cells. Nucleotide sequence information obtained by direct RT-PCR and the serologic relationships of this virus with the other hantaviruses indicate that this virus, Black Creek Canal virus, represents a new hantavirus distinct from the previously known serotypes. © 1995 Wiley-Liss, Inc.