Sample records for hamster cricetulus griseus

  1. Comparative ecotoxicity of potential biofuels to water flea (Daphnia magna), zebrafish (Danio rerio) and Chinese hamster (Cricetulus griseus) V79 cells.

    PubMed

    Heger, Sebastian; Du, Miaomiao; Bauer, Kevin; Schäffer, Andreas; Hollert, Henner

    2018-08-01

    The ecotoxicity of two biofuel candidates (1‑octanol and 2‑butanone) was investigated by an integrative test strategy using three bioassays: the acute immobilisation test with water flea (D. magna), the fish embryo acute toxicity test with zebrafish (Danio rerio) and the in vitro micronucleus assay with Chinese hamster (Cricetulus griseus) V79 cells. The median effective concentration (EC 50 ) values were 14.9±0.66mgL -1 for 1‑octanol, and 2152.1±44.6mgL -1 for 2‑butanone in the D. magna test. Both 1‑octanol and 2‑butanone caused teratogenic and lethal effects on zebrafish embryos, while exposure to 1‑octanol significantly induced these effects at concentrations ≥2.0mgL -1 . These results indicate that 1‑octanol exert much higher ecotoxicity than 2‑butanone to D. magna and zebrafish embryos. Moreover, both 1‑octanol and 2‑butanone did not cause significant genotoxic effects, while their metabolites significantly induced micronuclei in V79 cells. The present study proposed an integrative test approach to evaluate the potential ecotoxicity of biofuels using simple, quick and inexpensive bioassays. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Molecular phylogenetics and taxonomy of dwarf hamsters Cricetulus Milne-Edwards, 1867 (Cricetidae, Rodentia): description of a new genus and reinstatement of another.

    PubMed

    Lebedev, V S; Bannikova, A A; Neumann, K; Ushakova, M V; Ivanova, N V; Surov, A V

    2018-02-26

    The taxonomy of the genus Cricetulus has been controversial. The phylogenetic relationships both within the genus and among Cricetulus lineages and other genera were examined using a set of five nuclear and two mitochondrial genes. The results demonstrate that Cricetulus in its current treatment is a polyphyletic assemblage because the subgenus Urocricetus is phylogenetically unrelated to all other Cricetulus and is a distant sister group to Phodopus. The grey hamster (C. migratorius) proved to be closer to Cricetus and Allocricetulus than to Cricetulus proper, which includes C. barabensis C. sokolovi and C. longicaudatus. Based on these results Urocricetus is elevated to the rank of a full genus and a new genus Nothocricetulus gen.nov. is described for the grey hamster.

  3. Variation of food availability affects male striped hamsters (Cricetulus barabensis) with different levels of metabolic rate.

    PubMed

    Wen, Jing; Tan, Song; Wang, Dhua; Zhao, Zhijun

    2018-05-31

    In the present study, we examined metabolic, morphological, and neurochemical changes in male striped hamsters (Cricetulus barabensis) in response to variations in food availability. Males with low and high levels of metabolic rate, MR (L-MR and H-MR), defined by their activity metabolic rates, were compared. In Experiment 1, 36-hrs food deprivation was found to significantly decrease MR levels, body fat content, mass of small and large intestines, and leptin gene expression in the white adipose tissues in male hamsters. Interestingly, L-MR males displayed decreased MR during both the day and night phases of circadian cycles, whereas H-MR males only showed a decrease in MR during the day (resting phase). These data indicate that individual differences in physical activity were associated with animal's different metabolic responses to food deprivation. In Experiment 2, both groups of males went through a 4-weeks fasting and re-feeding (re) paradigm. H-re males showed a persistent high level of MR, with a decreased body fat content and a trending decrease in leptin mRNA expression, compared to L-re males. Together, our data indicate that male striped hamsters with different levels of physical activity display altered, adaptive changes in response to variations in food availability. The neurochemical involvement of such adaptive changes needs to be further studied. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  4. The complete mitochondrial genome of lesser long-tailed Hamster Cricetulus longicaudatus (Milne-Edwards, 1867) and phylogenetic implications.

    PubMed

    Zhang, Ziqi; Sun, Tong; Kang, Chunlan; Liu, Yang; Liu, Shaoying; Yue, Bisong; Zeng, Tao

    2016-01-01

    The complete mitochondrial genome sequence of Cricetulus longicaudatus (Rodentia Cricetidae: Cricetinae) was determined and was deposited in GenBank (GenBank accession no. KM067270). The mitochondrial genome of C. longicaudatus was 16,302 bp in length and contained 13 protein-coding genes, 2 ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes and one control region, with an identical order to that of other rodents' mitochondrial genomes. The phylogenetic analysis was performed with Bayesian inference based on the concatenated nucleotide sequence of 12 protein-coding genes on the heavy strand. The result showed that these species from Cricetidae and its two subfamilies (Cricetinae and Arvicolines) formed solid monophyletic group, respectively. The Cricetulus had close phylogenetic relationship with Tscherskia among three genera (Cricetulus, Cricetulus and Mesocricetus). Neodon irene and Myodes regulus were embedded in Microtus and Eothenomys, respectively. The unusual phylogenetic positions of Neodon irene and Myodes regulus remain further study in the future.

  5. Karyotype evolution and phylogenetic relationships of hamsters (Cricetidae, Muroidea, Rodentia) inferred from chromosomal painting and banding comparison.

    PubMed

    Romanenko, Svetlana A; Volobouev, Vitaly T; Perelman, Polina L; Lebedev, Vladimir S; Serdukova, Natalya A; Trifonov, Vladimir A; Biltueva, Larisa S; Nie, Wenhui; O'Brien, Patricia C M; Bulatova, Nina Sh; Ferguson-Smith, Malcolm A; Yang, Fengtang; Graphodatsky, Alexander S

    2007-01-01

    The evolutionary success of rodents of the superfamily Muroidea makes this taxon the most interesting for evolution studies, including study at the chromosomal level. Chromosome-specific painting probes from the Chinese hamster and the Syrian (golden) hamster were used to delimit homologous chromosomal segments among 15 hamster species from eight genera: Allocricetulus, Calomyscus, Cricetulus, Cricetus, Mesocricetus, Peromyscus, Phodopus and Tscherskia (Cricetidae, Muroidea, Rodentia). Based on results of chromosome painting and G-banding, comparative maps between 20 rodent species have been established. The integrated maps demonstrate a high level of karyotype conservation among species in the Cricetus group (Cricetus, Cricetulus, Allocricetulus) with Tscherskia as its sister group. Species within the genera Mesocricetus and Phodopus also show a high degree of chromosomal conservation. Our results substantiate many of the conclusions suggested by other data and strengthen the topology of the Muroidea phylogenetic tree through the inclusion of genome-wide chromosome rearrangements. The derivation of the muroids karyotypes from the putative ancestral state involved centric fusions, fissions, addition of heterochromatic arms and a great number of inversions. Our results provide further insights into the karyotype relationships of all species investigated.

  6. Food restriction attenuates oxidative stress in brown adipose tissue of striped hamsters acclimated to a warm temperature.

    PubMed

    Zhang, Ji-Ying; Zhao, Xiao-Ya; Wang, Gui-Ying; Wang, Chun-Ming; Zhao, Zhi-Jun

    2016-05-01

    It has been suggested that the up-regulation of uncoupling proteins (UCPs) decreases reactive oxygen species (ROS) production, in which case there should be a negative relationship between UCPs expression and ROS levels. In this study, the effects of temperature and food restriction on ROS levels and metabolic rate, UCP1 mRNA expression and antioxidant levels were examined in the brown adipose tissue (BAT) of the striped hamsters (Cricetulus barabensis). The metabolic rate and food intake of hamsters which had been restricted to 80% of ad libitum food intake, and acclimated to a warm temperature (30°C), decreased significantly compared to a control group. Hydrogen peroxide (H2O2) levels were 42.9% lower in food restricted hamsters than in the control. Malonadialdehyde (MDA) levels of hamsters acclimated to 30°C that were fed ad libitum were significantly higher than those of the control group, but 60.1% lower than hamsters that had been acclimated to the same temperature but subject to food restriction. There were significantly positive correlations between H2O2 and, MDA levels, catalase activity, and total antioxidant capacity. Cytochrome c oxidase activity and UCP1 mRNA expression significantly decreased in food restricted hamsters compared to the control. These results suggest that warmer temperatures increase oxidative stress in BAT by causing the down-regulation of UCP1 expression and decreased antioxidant activity, but food restriction may attenuate the effects. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. L-Asparaginase Production by Streptomyces griseus

    PubMed Central

    DeJong, Peter J.

    1972-01-01

    Streptomyces griseus ATCC 10137 synthesizes about 1 IU of L-asparaginase/100 ml of a 4% peptone medium. The enzyme has a pH optimum of 8.5 which is comparable to that of the L-asparaginase derived from Escherichia coli which has antitumor properties. PMID:4626231

  8. The complete mitochondrial genome of Cricetulus kamensis (Rodentia: Cricetidae).

    PubMed

    Kang, Chunlan; Yue, Hao; Liu, Mengyao; Huang, Ting; Liu, Yang; Zhang, Xiuyue; Yue, Bisong; Zeng, Tao; Liu, Shaoying

    2016-01-01

    The Cricetulus kamensis is endemic to China and is popular as pet. In the present study, the complete mitogenome of C. kamensis was first determined. It was 16,270 bp in length and the composition and arrangement of its genes are analogous to most other mammals. The overall base composition of heavy strand is 33.2% A, 26.8% T, 27.2% C and 12.7% G. The sequence is highly G-C poor (∼40%) and A is the most numerous nucleotide followed by T >C >G, which is similar to other mammalian mitochondrial genomes. It is notable that three extra bases "CAT" were inserted in cytb at the 3' end position and no stop codon was found for this coding region. The mitogenome sequence of C. kamensis could contribute to a better solution of its phylogenetic position and phylogenetic relationship within Cricetinae in the future.

  9. Distribution and habitat of the western gray squirrel (Sciurus griseus) on Fort Lewis, Washington.

    Treesearch

    L.A. Ryan; A.B. Carey

    1995-01-01

    Sciurus griseus has been accorded a "threatened" status by the Washington Department of Wildlife. Our objectives were to determine the distribution, abundance, and factors limiting the abundance of Sciurus griseus on Fort Lewis. Between June 1992 and August 1993 we conducted walking surveys for squirrels in 169 oak-...

  10. Molecular phylogeny of the Cricetinae subfamily based on the mitochondrial cytochrome b and 12S rRNA genes and the nuclear vWF gene.

    PubMed

    Neumann, Karsten; Michaux, Johan; Lebedev, Vladimir; Yigit, Nuri; Colak, Ercument; Ivanova, Natalia; Poltoraus, Andrey; Surov, Alexei; Markov, Georgi; Maak, Steffen; Neumann, Sabine; Gattermann, Rolf

    2006-04-01

    Despite some popularity of hamsters as pets and laboratory animals there is no reliable phylogeny of the subfamily Cricetinae available so far. Contradicting views exist not only about the actual number of species but also concerning the validity of several genera. We used partial DNA sequences of two mitochondrial (cytochrome b, 12S rRNA) and one partial nuclear gene (von Willebrand Factor exon 28) to provide a first gene tree of the Cricetinae based on 15 taxa comprising six genera. According to our data, Palaearctic hamsters fall into three distinct phylogenetic groups: Phodopus, Mesocricetus, and Cricetus-related species which evolved during the late Miocene about 7-12MY ago. Surprisingly, the genus Phodopus, which was previously thought to have appeared during the Pleistocene, forms the oldest clade. The largest number of extant hamster genera is found in a group of Cricetus-related hamsters. The genus Cricetulus itself proved to be not truly monophyletic with Cricetulus migratorius appearing more closely related to Tscherskia, Cricetus, and Allocricetulus. We propose to place the species within a new monotypic genus. Molecular clock calculations are not always in line with the dating of fossil records. DNA based divergence time estimates as well as taxonomic relationships demand a reevaluation of morphological characters previously used to identify fossils and extant hamsters.

  11. Diet, dietary selectivity and density of South American grey fox, Lycalopex griseus, in Central Chile.

    PubMed

    Muñoz-Pedreros, Andrés; Yáñez, José; Norambuena, Heraldo V; Zúñiga, Alfredo

    2018-01-01

    The South American grey fox Lycalopex griseus is a canid widely distributed in southern South America; however, some aspects of its biology are still poorly known. We studied the diet and density of L. griseus in the Lago Peñuelas Biosphere Reserve, in Central Chile. The trophic niche breadth was B = 6.16 (B sta = 0.47) and prey diversity was H' = 2.46 (H max ' = 3.17, J' = 0.78). The highest proportions of prey consumed in the diet were Oryctolagus cuniculus (52.21%) and other mammals (32.78%). We compared these results with a latitudinal gradient of diet results for this species in Chile. L. griseus eats mostly mammals (>90% of total prey), consuming the rodent Phyllotis darwini and reptiles in the northern zone; Oryctolagus cuniculus, Octodon degus and Abrocoma bennetti in the central zone; Abrothrix spp. and lagomorphs in the southern zone; and Lepus capensis and Ovis aries in the austral zone. The estimated density of L. griseus in Lago Peñuelas NR was 1.3 foxes/km 2 . © 2017 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

  12. Transmission beam characteristics of a Risso's dolphin (Grampus griseus).

    PubMed

    Smith, Adam B; Kloepper, Laura N; Yang, Wei-Cheng; Huang, Wan-Hsiu; Jen, I-Fan; Rideout, Brendan P; Nachtigall, Paul E

    2016-01-01

    The echolocation system of the Risso's dolphin (Grampus griseus) remains poorly studied compared to other odontocete species. In this study, echolocation signals were recorded from a stationary Risso's dolphin with an array of 16 hydrophones and the two-dimensional beam shape was explored using frequency-dependent amplitude plots. Click source parameters were similar to those already described for this species. Centroid frequency of click signals increased with increasing sound pressure level, while the beamwidth decreased with increasing center frequency. Analysis revealed primarily single-lobed, and occasionally vertically dual-lobed, beam shapes. Overall beam directivity was found to be greater than that of the harbor porpoise, bottlenose dolphin, and a false killer whale. The relationship between frequency content, beam directivity, and head size for this Risso's dolphin deviated from the trend described for other species. These are the first reported measurements of echolocation beam shape and directivity in G. griseus.

  13. Characterization of heat-induced interaction of neutral liposome with lipid membrane of Streptomyces griseus cell.

    PubMed

    Ngo, Kien Xuan; Umakoshi, Hiroshi; Shimanouchi, Toshinori; Kuboi, Ryoichi

    2009-10-15

    The interaction between the neutral 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC) liposomes and cell membrane of Streptomyces griseus induced by the heat treatment at specific temperature was investigated, focusing on the internalization of the neutral POPC liposomes with S. griseus cells. In an attempt to clarify the modes of liposome internalization, various kinds of inhibitors of endocytotic pathways were used to treat S. griseus cells. The efficiency of the heat treatment on liposome-cell membrane interactions was finally characterized based on the hydrophobic, electrostatic interactions and hydration effect. In fact, the internalization of the neutral liposomes into these cells was found to show higher rate and greater amount at higher temperatures. The kinetic study showed that the maximum amount of the internalized liposomes was, respectively, 469 x 10(5) and 643 x 10(5) liposomes/cell at 37 and 41 degrees C. The internalization of the neutral liposomes induced by the heat treatment was characterized, implying that the endocytosis occurred. The interactions involving the internalization, adsorption, and fusion of these liposomes with S. griseus cells were mainly contributed by the hydrophobic interaction and the unstable hydrogen bonds caused by the loss of water of surface hydration of cell membrane rather than the electrostatic interaction under the specific heat condition.

  14. Species delimitation in the Stenocereus griseus (Cactaceae) species complex reveals a new species, S. huastecorum

    PubMed Central

    Alvarado-Sizzo, Hernán; Parra, Fabiola; Arreola-Nava, Hilda Julieta; Terrazas, Teresa; Sánchez, Cristian

    2018-01-01

    The Stenocereus griseus species complex (SGSC) has long been considered taxonomically challenging because the number of taxa belonging to the complex and their geographical boundaries remain poorly understood. Bayesian clustering and genetic distance-based methods were used based on nine microsatellite loci in 377 individuals of three main putative species of the complex. The resulting genetic clusters were assessed for ecological niche divergence and areolar morphology, particularly spination patterns. We based our species boundaries on concordance between genetic, ecological, and morphological data, and were able to resolve four species, three of them corresponding to S. pruinosus from central Mexico, S. laevigatus from southern Mexico, and S. griseus from northern South America. A fourth species, previously considered to be S. griseus and commonly misidentified as S. pruinosus in northern Mexico showed significant genetic, ecological, and morphological differentiation suggesting that it should be considered a new species, S. huastecorum, which we describe here. We show that population genetic analyses, ecological niche modeling, and morphological studies are complementary approaches for delimiting species in taxonomically challenging plant groups such as the SGSC. PMID:29342184

  15. Species delimitation in the Stenocereus griseus (Cactaceae) species complex reveals a new species, S. huastecorum.

    PubMed

    Alvarado-Sizzo, Hernán; Casas, Alejandro; Parra, Fabiola; Arreola-Nava, Hilda Julieta; Terrazas, Teresa; Sánchez, Cristian

    2018-01-01

    The Stenocereus griseus species complex (SGSC) has long been considered taxonomically challenging because the number of taxa belonging to the complex and their geographical boundaries remain poorly understood. Bayesian clustering and genetic distance-based methods were used based on nine microsatellite loci in 377 individuals of three main putative species of the complex. The resulting genetic clusters were assessed for ecological niche divergence and areolar morphology, particularly spination patterns. We based our species boundaries on concordance between genetic, ecological, and morphological data, and were able to resolve four species, three of them corresponding to S. pruinosus from central Mexico, S. laevigatus from southern Mexico, and S. griseus from northern South America. A fourth species, previously considered to be S. griseus and commonly misidentified as S. pruinosus in northern Mexico showed significant genetic, ecological, and morphological differentiation suggesting that it should be considered a new species, S. huastecorum, which we describe here. We show that population genetic analyses, ecological niche modeling, and morphological studies are complementary approaches for delimiting species in taxonomically challenging plant groups such as the SGSC.

  16. Effects of protein kinase inhibitors on in vitro protein phosphorylation and cellular differentiation of Streptomyces griseus.

    PubMed

    Hong, S K; Matsumoto, A; Horinouchi, S; Beppu, T

    1993-01-01

    In vitro phosphorylation reactions using extracts of Streptomyces griseus cells and gamma-[32P]ATP revealed the presence of multiple phosphorylated proteins. Most of the phosphorylations were distinctly inhibited by staurosporine and K-252a which are known to be eukaryotic protein kinase inhibitors. The in vitro experiments also showed that phosphorylation was greatly enhanced by manganese and inhibition of phosphorylation by staurosporine and K-252a was partially circumvented by 10 mM manganese. A calcium-activated protein kinase(s) was little affected by these inhibitors. Herbimycin and radicicol, known to be tyrosine kinase inhibitors, completely inhibited the phosphorylation of one protein. Consistent with their in vitro effects the protein kinase inhibitors inhibited aerial mycelium formation and pigment production by S. griseus. All these data suggest that S. griseus possesses several protein kinases of eukaryotic type which are essential for morphogenesis and secondary metabolism. In vitro phosphorylation of some proteins in a staurosporine-producing Streptomyces sp. was also inhibited by staurosporine, K-252a and herbimycin, which suggests the presence of a mechanism for self-protection in this microorganism.

  17. A ribonuclease from the wild mushroom Boletus griseus.

    PubMed

    Wang, Hexiang; Ng, T B

    2006-10-01

    A ribonuclease (RNase) with a molecular mass of 29 kDa and cospecific for poly A and poly U was isolated from fruiting bodies of the mushroom Boletus griseus. Its N-terminal sequence exhibited some similarity to those of RNases from the mushrooms Irpex lacteus and Lentinus edodes. The RNase was adsorbed on diethylaminoethyl-cellulose, Q-Sepharose, and Affi-gel blue gel and was unadsorbed on CM-cellulose. The enzyme exhibited a temperature optimum between 60 and 70 degrees C and a pH optimum at 3.5.

  18. Depression of streptomycin production by Streptomyces griseus at elevated growth temperature: studies using gene fusions.

    PubMed

    Deeble, V J; Lindley, H K; Fazeli, M R; Cove, J H; Baumberg, S

    1995-10-01

    Streptomyces griseus ATCC 12475 fails to produce streptomycin when grown at 34 degrees C or above, although growth is appreciable up to at least 37 degrees C. This depression of streptomycin production at elevated growth temperature is manifest equally in liquid and on solid, and with complex and minimal, media. We report studies with gene fusions of the reporter genes aph or xyIE to restriction fragments containing the streptomycin biosynthesis promoter PstrB1. aph constructs were in high, and xyIE constructs in low, copy number vectors. Two strB1 promoter fragments were used, one requiring activation by the pathway-specific activator StrR of S. griseus, the other reportedly activator independent. PstrB1 expression in the aph constructs in S. griseus and in S. lividans was significantly reduced at 37 degrees C compared to 30 degrees C. Some of this reduction could be explained by lower plasmid copy number at the higher temperature, but strR-dependent expression was clearly temperature controlled. Using the xyIE reporter system, the temperature dependence of PstrB1 expression was confirmed but, surprisingly, the strR dependence of the two promoter fragments differed from that observed in the multicopy aph constructs. These data identify a temperature-dependent promoter which may contribute to the depressive effect of elevated growth temperature on streptomycin production.

  19. Sarcoptic Mange in a South American Gray Fox (Chilla Fox; Lycalopex griseus ), Chile.

    PubMed

    Verdugo, Claudio; Espinoza, Angelo; Moroni, Manuel; Valderrama, Rocio; Hernandez, Carlos

    2016-07-01

    Mange, a prevalent disease of dogs in Chile, is also a serious threat to wildlife. We report a case of sarcoptic mange in a South American gray fox or chilla fox ( Lycalopex griseus ). Further research is needed to understand the impact of mange in wildlife populations.

  20. Genetic segregation in a high-yielding streptomycin-producing strain of Streptomyces griseus.

    PubMed

    Roth, M; Schwalenberg, B; Reiche, R; Noack, D; Geuther, R; Eritt, I

    1982-01-01

    The streptomycin-producing Streptomyces griseus HP spontaneously segregated non-reverting derivatives with altered phenotypes. Clones characterized by increased spore formation and decreased streptomycin production were found. Two other types of derivatives were defective in aerial mycelium and streptomycin formation as well, but differed in the capacity to synthesize a yellow pigment. These derivatives were examined with respect to further properties. The stability of S. griseus HP was investigated in relation to conditions of continuous culture. Both at 26 and 30 degrees C, under glycerol and NH4Cl limitation a rapid segregation and enrichment of streptomycin-non-producing derivatives occurred. At 34 degrees C and glycerol limitation segregation began only after about 35 generations of continuous culture. In NH4Cl-limited chemostats the original strain was stable during 80 generations. In the course of the continuous culture experiments it was shown that the onset of genetic segregation within mycelia can be detected before it becomes obvious in colonies grown from the mycelia. This was achieved by fractionation of the mycelia by protoplast formation and subsequent plating on regeneration medium allowing colony growth and differentiation.

  1. New families of site-specific repetitive DNA sequences that comprise constitutive heterochromatin of the Syrian hamster (Mesocricetus auratus, Cricetinae, Rodentia).

    PubMed

    Yamada, Kazuhiko; Kamimura, Eikichi; Kondo, Mariko; Tsuchiya, Kimiyuki; Nishida-Umehara, Chizuko; Matsuda, Yoichi

    2006-02-01

    We molecularly cloned new families of site-specific repetitive DNA sequences from BglII- and EcoRI-digested genomic DNA of the Syrian hamster (Mesocricetus auratus, Cricetrinae, Rodentia) and characterized them by chromosome in situ hybridization and filter hybridization. They were classified into six different types of repetitive DNA sequence families according to chromosomal distribution and genome organization. The hybridization patterns of the sequences were consistent with the distribution of C-positive bands and/or Hoechst-stained heterochromatin. The centromeric major satellite DNA and sex chromosome-specific and telomeric region-specific repetitive sequences were conserved in the same genus (Mesocricetus) but divergent in different genera. The chromosome-2-specific sequence was conserved in two genera, Mesocricetus and Cricetulus, and a low copy number of repetitive sequences on the heterochromatic chromosome arms were conserved in the subfamily Cricetinae but not in the subfamily Calomyscinae. By contrast, the other type of repetitive sequences on the heterochromatic chromosome arms, which had sequence similarities to a LINE sequence of rodents, was conserved through the three subfamilies, Cricetinae, Calomyscinae and Murinae. The nucleotide divergence of the repetitive sequences of heterochromatin was well correlated with the phylogenetic relationships of the Cricetinae species, and each sequence has been independently amplified and diverged in the same genome.

  2. Cloning, sequencing, and analysis of the griseusin polyketide synthase gene cluster from Streptomyces griseus.

    PubMed Central

    Yu, T W; Bibb, M J; Revill, W P; Hopwood, D A

    1994-01-01

    A fragment of DNA was cloned from the Streptomyces griseus K-63 genome by using genes (act) for the actinorhodin polyketide synthase (PKS) of Streptomyces coelicolor as a probe. Sequencing of a 5.4-kb segment of the cloned DNA revealed a set of five gris open reading frames (ORFs), corresponding to the act PKS genes, in the following order: ORF1 for a ketosynthase, ORF2 for a chain length-determining factor, ORF3 for an acyl carrier protein, ORF5 for a ketoreductase, and ORF4 for a cyclase-dehydrase. Replacement of the gris genes with a marker gene in the S. griseus genome by using a single-stranded suicide vector propagated in Escherichia coli resulted in loss of the ability to produce griseusins A and B, showing that the five gris genes do indeed encode the type II griseusin PKS. These genes, encoding a PKS that is programmed differently from those for other aromatic PKSs so far available, will provide further valuable material for analysis of the programming mechanism by the construction and analysis of strains carrying hybrid PKS. Images PMID:8169211

  3. Bioaccumulation of heavy metals in maricultured fish, Lates calcarifer (Barramudi), Lutjanus campechanus (red snapper) and Lutjanus griseus (grey snapper).

    PubMed

    Nasyitah Sobihah, Nasri; Ahmad Zaharin, Aris; Khairul Nizam, Mohammad; Ley Juen, Looi; Kyoung-Woong, Kim

    2018-04-01

    Mariculture fish contains a rich source of protein, but some species may bioaccumulate high levels of heavy metals, making them unsafe for consumption. This study aims to identify heavy metal concentration in Lates calcarifer (Barramudi), Lutjanus campechanus (Red snapper) and Lutjanus griseus (Grey snapper). Three species of mariculture fish, namely, L. calcarifer, L. campechanus and L. griseus were collected for analyses of heavy metals. The concentration of heavy metal (As, Cd, Cu, Cr, Fe, Pb, Mn, Ni, Se, and Zn) was determined using inductive coupled plasma mass spectrometry (ICP-MS). The distribution of heavy metals mean concentration in muscle is Zn > Fe > As > Se > Cr > Cu > Mn > Pb > Ni > Cd for L. calcarifer, Fe > Zn > Cr > As > Ni > Mn > Se > Cu > Pb > Cd for L. campechanus and Fe > Zn > Cr > Ni > Se > Cu > As > Mn > Pb > Cd for L. griseus. Among all of the species under investigation, the highest concentration of Fe was found in the muscle tissue of L. campechanus (19.985 ± 1.773 mg kg -1 ) and liver tissue of L. griseus (58.248 ± 8.736 mg kg -1 ). Meanwhile, L. calcarifer has the lowest concentration of Cd in both muscle (0.007 ± 0.004 mg kg -1 ) and liver tissue (0.027 ± 0.016 mg kg -1 ). The heavy metal concentration in muscle tissue is below the permissible limit guidelines stipulated by the Food & Agriculture Organization, 1983 and Malaysia Food Act, 1983. The concentration of heavy metals varies significantly among fish species and tissues. L. campechanus was found to have a higher ability to accumulate heavy metals as compared to the other two species (p < .00). Among all the studied fish, liver tissue has a higher concentration of heavy metals compared to muscle tissue (p < .05). The findings from this study can serve as baseline information for future monitoring and risk assessment studies

  4. Biofiltration technology for the removal of toluene from polluted air using Streptomyces griseus.

    PubMed

    Mohamed, Elham F; Awad, Gamal; Andriantsiferana, Caroline; El-Diwany, Ahmed I

    2016-01-01

    Biofiltration technology has been recognized as a promising biotechnology for treating the volatile organic compounds (VOCs) present in polluted air. This study aims to investigate the performance of a biofiltration system of Streptomyces griseus sp. DSM-40759 immobilized on activated carbon (PICA S23) towards the adsorption and degradation of toluene vapour as well as to regenerate the activated carbon in situ. The batch studies were performed using nutrient agar medium and basal salt medium (BSM) for microbial growth. Initially the pre-cultures were incubated at a temperature of 28°C on a rotary shaker at 150 rpm. After two days, the strain S. griseus DSM-40759 was immobilized on a known weight of activated carbon (12 g). The results of biofilter performance showed three different stages with a quick adsorption phase with approximately 95% of toluene removal after 70 min, a slow biotransformation phase by immobilized cells. In the later, the removal efficiency decreased significantly with the extension of time and reached 60% during this stage. Moreover, a final quick removal phase by the immobilized cells had an average removal efficiency of toluene around 95% after 500 min. The toluene degradation was found to be more than 84% after the second cycle and the biofilter was still capable of removing additional toluene. Thus, the results demonstrated the feasibility and reusability of a new biofilter system for toluene removal as well as extending the activated carbon's capacity and this could be a potential solution to reuse the activated carbon in industrial application.

  5. A large inversion in the linear chromosome of Streptomyces griseus caused by replicative transposition of a new Tn3 family transposon.

    PubMed

    Murata, M; Uchida, T; Yang, Y; Lezhava, A; Kinashi, H

    2011-04-01

    We have comprehensively analyzed the linear chromosomes of Streptomyces griseus mutants constructed and kept in our laboratory. During this study, macrorestriction analysis of AseI and DraI fragments of mutant 402-2 suggested a large chromosomal inversion. The junctions of chromosomal inversion were cloned and sequenced and compared with the corresponding target sequences in the parent strain 2247. Consequently, a transposon-involved mechanism was revealed. Namely, a transposon originally located at the left target site was replicatively transposed to the right target site in an inverted direction, which generated a second copy and at the same time caused a 2.5-Mb chromosomal inversion. The involved transposon named TnSGR was grouped into a new subfamily of the resolvase-encoding Tn3 family transposons based on its gene organization. At the end, terminal diversity of S. griseus chromosomes is discussed by comparing the sequences of strains 2247 and IFO13350.

  6. Male hamster preference for odors of female hamster vaginal discharges: studies of experiential and hormonal determinants.

    PubMed

    Gregory, E; Engel, K; Pfaff, D

    1975-07-01

    Male hamsters approach sources of odors from female hamster vaginal discharges and spend significantly more time around these odor sources than around control locations in the test box. This preference for female hamster vaginal odors appears in sexually inexperienced as well as experienced males, even in individuals isolated from females since the time of weaning. Castration significantly reduces the sex odor preference, and treatment with testosterone propionate partially restores it.

  7. Immune response in the hamster: definition of a novel IgG not expressed in all hamster strains.

    PubMed Central

    Coe, J E; Schell, R F; Ross, M J

    1995-01-01

    A new IgG isotype is described in serum from Syrian hamsters. This 7S-IgG is called IgG3 and was isolated from IgG1 and IgG2 because of its great affinity for protein A. The unique antigenic determinants of IgG3 were identified with a specific rabbit antisera. IgG3 is the least expressed IgG subclass in Syrian hamsters, but serum levels increase more than 10-fold after immunization or infection. Although found in all tested outbred strains, IgG3 is expressed in only some of the commercially available inbred strains of Syrian hamsters. Five inbred hamster strains were examined, and in three strains (CB, LHC and MHA) IgG3 was not detected in normal serum or in immune serum, indicating serum levels at least 100-fold less than other normal inbred/outbred hamsters. The results of breeding experiments suggests a single gene defect is responsible for this non-expression of IgG3. Immunodeficiency was not associated with this IgG3 deficiency. Selective deficiencies of immunoglobulin classes/subclasses in experimental animals are rare. The evolution of a similar IgG3 deficiency in these three hamster strains during inbreeding suggests a novel and efficient mechanism for regulation of IgG3 synthesis in the Syrian hamster. Images Figure 2 Figure 3 Figure 5 PMID:7590875

  8. Circularized Chromosome with a Large Palindromic Structure in Streptomyces griseus Mutants

    PubMed Central

    Uchida, Tetsuya; Ishihara, Naoto; Zenitani, Hiroyuki; Hiratsu, Keiichiro; Kinashi, Haruyasu

    2004-01-01

    Streptomyces linear chromosomes display various types of rearrangements after telomere deletion, including circularization, arm replacement, and amplification. We analyzed the new chromosomal deletion mutants Streptomyces griseus 301-22-L and 301-22-M. In these mutants, chromosomal arm replacement resulted in long terminal inverted repeats (TIRs) at both ends; different sizes were deleted again and recombined inside the TIRs, resulting in a circular chromosome with an extremely large palindrome. Short palindromic sequences were found in parent strain 2247, and these sequences might have played a role in the formation of this unique structure. Dynamic structural changes of Streptomyces linear chromosomes shown by this and previous studies revealed extraordinary strategies of members of this genus to keep a functional chromosome, even if it is linear or circular. PMID:15150216

  9. Evaluation of eight cephalosporins in hamster colitis model.

    PubMed Central

    Ebright, J R; Fekety, R; Silva, J; Wilson, K H

    1981-01-01

    Eight commonly used cephalosporins were evaluated in the hamster colitis mode. They were all found to cause hemorrhagic cecitis and death within 10 days of being given as subcutaneous or oral challenges. Necropsy findings were indistinguishable from clindamycin-induced cecitis. Bacteria-free cecal filtrate obtained from hamsters dying of cephalosporin-induced cecitis contained toxin similar or identical to hat produced by Clostridium difficile isolated from the cecum of a hamster. Daily oral administration of poorly absorbed cephalosporins protected hamsters from clindamycin-induced cecitis and death as long as the cephalosporins were continued. The absorbable cephalosporins were ineffective in protecting hamsters from clindamycin-induced cecitis. This difference probably relates to the lower concentrations of absorbable cephalosporins maintained in the ceca of the hamsters. The possible correlation of these findings to human cases of cephalosporin-induced pseudomembranous colitis is discussed. PMID:6973951

  10. L-Asparaginase from Streptomyces griseus NIOT-VKMA29: optimization of process variables using factorial designs and molecular characterization of L-asparaginase gene

    NASA Astrophysics Data System (ADS)

    Meena, Balakrishnan; Anburajan, Lawrance; Sathish, Thadikamala; Vijaya Raghavan, Rangamaran; Dharani, Gopal; Valsalan Vinithkumar, Nambali; Kirubagaran, Ramalingam

    2015-07-01

    Marine actinobacteria are known to be a rich source for novel metabolites with diverse biological activities. In this study, a potential extracellular L-asparaginase was characterised from the Streptomyces griseus NIOT-VKMA29. Box-Behnken based optimization was used to determine the culture medium components to enhance the L-asparaginase production. pH, starch, yeast extract and L-asparagine has a direct correlation for enzyme production with a maximum yield of 56.78 IU mL-1. A verification experiment was performed to validate the experiment and more than 99% validity was established. L-Asparaginase biosynthesis gene (ansA) from Streptomyces griseus NIOT-VKMA29 was heterologously expressed in Escherichia coli M15 and the enzyme production was increased threefold (123 IU mL-1) over the native strain. The ansA gene sequences reported in this study encloses several base substitutions with that of reported sequences in GenBank, resulting in altered amino acid sequences of the translated protein.

  11. Echolocation in the Risso's dolphin, Grampus griseus

    NASA Astrophysics Data System (ADS)

    Philips, Jennifer D.; Nachtigall, Paul E.; Au, Whitlow W. L.; Pawloski, Jeffrey L.; Roitblat, Herbert L.

    2003-01-01

    The Risso's dolphin (Grampus griseus) is an exclusively cephalopod-consuming delphinid with a distinctive vertical indentation along its forehead. To investigate whether or not the species echolocates, a female Risso's dolphin was trained to discriminate an aluminum cylinder from a nylon sphere (experiment 1) or an aluminum sphere (experiment 2) while wearing eyecups and free swimming in an open-water pen in Kaneohe Bay, Hawaii. The dolphin completed the task with little difficulty despite being blindfolded. Clicks emitted by the dolphin were acquired at average amplitudes of 192.6 dB re 1 μPa, with estimated sources levels up to 216 dB re 1 μPa-1 m. Clicks were acquired with peak frequencies as high as 104.7 kHz (Mfp=47.9 kHz), center frequencies as high as 85.7 kHz (Mf0=56.5 kHz), 3-dB bandwidths up to 94.1 kHz (MBW=39.7 kHz), and root-mean-square bandwidths up to 32.8 kHz (MRMS=23.3 kHz). Click durations were between 40 and 70 μs. The data establish that the Risso's dolphin echolocates, and that, aside from slightly lower amplitudes and frequencies, the clicks emitted by the dolphin were similar to those emitted by other echolocating odontocetes. The particular acoustic and behavioral findings in the study are discussed with respect to the possible direction of the sonar transmission beam of the species.

  12. Echolocation in the Risso's dolphin, Grampus griseus.

    PubMed

    Philips, Jennifer D; Nachtigall, Paul E; Au, Whitlow W L; Pawloski, Jeffrey L; Roitblat, Herbert L

    2003-01-01

    The Risso's dolphin (Grampus griseus) is an exclusively cephalopod-consuming delphinid with a distinctive vertical indentation along its forehead. To investigate whether or not the species echolocates, a female Risso's dolphin was trained to discriminate an aluminum cylinder from a nylon sphere (experiment 1) or an aluminum sphere (experiment 2) while wearing eyecups and free swimming in an open-water pen in Kaneohe Bay, Hawaii. The dolphin completed the task with little difficulty despite being blindfolded. Clicks emitted by the dolphin were acquired at average amplitudes of 192.6 dB re 1 microPa, with estimated sources levels up to 216 dB re 1 microPa-1 m. Clicks were acquired with peak frequencies as high as 104.7 kHz (Mf(p) = 47.9 kHz), center frequencies as high as 85.7 kHz (Mf(0) = 56.5 kHz), 3-dB bandwidths up to 94.1 kHz (M(BW) = 39.7 kHz), and root-mean-square bandwidths up to 32.8 kHz (M(RMS) = 23.3 kHz). Click durations were between 40 and 70 micros. The data establish that the Risso's dolphin echolocates, and that, aside from slightly lower amplitudes and frequencies, the clicks emitted by the dolphin were similar to those emitted by other echolocating odontocetes. The particular acoustic and behavioral findings in the study are discussed with respect to the possible direction of the sonar transmission beam of the species.

  13. Circadian rhythms accelerate wound healing in female Siberian hamsters

    PubMed Central

    Cable, Erin J.; Onishi, Kenneth G.; Prendergast, Brian J.

    2017-01-01

    Circadian rhythms (CRs) provide temporal regulation and coordination of numerous physiological traits, including immune function. CRs in multiple aspects of immune function are absent in rodents that have been rendered circadian-arrhythmic through various methods. In Siberian hamsters, circadian arrhythmia can be induced by disruptive light treatments (DPS). Here we examined CRs in wound healing, and the effects of circadian disruption on wound healing in DPS-arrhythmic hamsters. Circadian entrained/rhythmic (RHYTH) and behaviorally-arrhythmic (ARR) female hamsters were administered a cutaneous wound either 3 h after light onset (ZT03) or 2 h after dark onset (ZT18); wound size was quantified daily using image analyses. Among RHYTH hamsters, ZT03 wounds healed faster than ZT18 wounds, whereas in ARR hamsters, circadian phase did not affect wound healing. In addition, wounds healed slower in ARR hamsters. The results document a clear CR in wound healing, and indicate that the mere presence of organismal circadian organization enhances this aspect of immune function. Faster wound healing in CR-competent hamsters may be mediated by CR-driven coordination of the temporal order of mechanisms (inflammation, leukocyte trafficking, tissue remodeling) underlying cutaneous wound healing. PMID:27998755

  14. Mitochondrial function in diaphragm of emphysematous hamsters after treatment with nandrolone.

    PubMed

    Wijnhoven, Hanneke J H; Ennen, Leo; Rodenburg, Richard J T; Dekhuijzen, P N Richard

    2006-01-01

    Respiratory failure in patients with COPD may be caused by insufficient force production or insufficient endurance capacity of the respiratory muscles. Anabolic steroids may improve respiratory muscle function in COPD. The effect of anabolic steroids on mitochondrial function in the diaphragm in emphysema is unknown. In an emphysematous male hamster model, we investigated whether administration of the anabolic steroid nandrolone decanoate (ND) altered the activity of mitochondrial respiratory chain complexes in the diaphragm. The bodyweight of hamsters treated with ND was decreased after treatment compared with initial values, and serum testosterone levels were significantly lower in hamsters treated with ND than in control hamsters. No difference in the activity of mitochondrial respiratory chain complexes in the diaphragm between normal and emphysematous hamsters was observed. Treatment with ND did not change the activity of mitochondrial respiratory chain complexes in the diaphragm of both normal and emphysematous hamsters. In emphysematous hamsters, administration of ND decreased the activity of succinate:cytochrome c oxidoreductase compared with ND treatment in normal hamsters. We conclude that anabolic steroids have negative effects on the activity of succinate:cytochrome c oxidoreductase and anabolic status in this emphysematous hamster model.

  15. Mitochondrial function in diaphragm of emphysematous hamsters after treatment with nandrolone

    PubMed Central

    Wijnhoven, Hanneke JH; Ennen, Leo; Rodenburg, Richard JT; Dekhuijzen, PN Richard

    2006-01-01

    Respiratory failure in patients with COPD may be caused by insufficient force production or insufficient endurance capacity of the respiratory muscles. Anabolic steroids may improve respiratory muscle function in COPD. The effect of anabolic steroids on mitochondrial function in the diaphragm in emphysema is unknown. In an emphysematous male hamster model, we investigated whether administration of the anabolic steroid nandrolone decanoate (ND) altered the activity of mitochondrial respiratory chain complexes in the diaphragm. The bodyweight of hamsters treated with ND was decreased after treatment compared with initial values, and serum testosterone levels were significantly lower in hamsters treated with ND than in control hamsters. No difference in the activity of mitochondrial respiratory chain complexes in the diaphragm between normal and emphysematous hamsters was observed. Treatment with ND did not change the activity of mitochondrial respiratory chain complexes in the diaphragm of both normal and emphysematous hamsters. In emphysematous hamsters, administration of ND decreased the activity of succinate:cytochrome c oxidoreductase compared with ND treatment in normal hamsters. We conclude that anabolic steroids have negative effects on the activity of succinate:cytochrome c oxidoreductase and anabolic status in this emphysematous hamster model. PMID:18046906

  16. Etiology of Tetracycline-Associated Pseudomembranous Colitis in Hamsters

    PubMed Central

    Toshniwal, Renu; Fekety, Robert; Silva, Joseph

    1979-01-01

    Tetracyclines were implicated in the 1950s in induction of protracted diarrhea and pseudomembranous colitis. Because the pathogenetic mechanism of these illnesses has been questioned recently, we studied tetracycline in hamster models of antibiotic-associated colitis. Orogastric administration of tetracycline caused diarrhea and death, with evidence of hemorrhagic typhlitis. Filtrates of cecal contents were toxic when inoculated into normal hamsters and cell culture monolayers, and toxicity was neutralized with Clostridium sordellii antitoxin. Tetracycline-resistant C. difficile was cultured from stools of these hamsters, but Staphylococcus aureus was not isolated. The value of tetracycline for treatment or prevention of clindamycin-induced colitis in hamsters was also studied, and it was found that daily orogastric administration of tetracycline was poorly protective against clindamycin-induced colitis. PMID:485127

  17. Heat and cold acclimation in helium-cold hypothermia in the hamster.

    NASA Technical Reports Server (NTRS)

    Musacchia, X. J.

    1972-01-01

    A study was made of the effects of acclimation of hamsters to high (34-35 C) and low (4-5 C) temperatures for periods up to 6 weeks on the induction of hypothermia in hamsters. Hypothermia was achieved by exposing hamsters to a helox mixture of 80% helium and 20% oxygen at 0 C. Hypothermic induction was most rapid (2-3 hr) in heat-acclimated hamsters and slowest (6-12 hr) in cold-acclimated hamsters. The induction period was intermediate (5-8 hr) in room temperature nonacclimated animals (controls). Survival time in hypothermia was relatable to previous temperature acclimations. The hypothesis that thermogenesis in cold-acclimated hamsters would accentuate resistance to induction of hypothermia was substantiated.

  18. Induction of lyme arthritis in LSH hamsters

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Schmitz, J.L.; Schell, R.F.; Hejka, A.

    1988-09-01

    In studies of experimental Lyme disease, a major obstacle has been the unavailability of a suitable animal model. We found that irradiated LSH/Ss Lak hamsters developed arthritis after injection of Borrelia burgdorferi in the hind paws. When nonirradiated hamsters were injected in the hind paws with B. burgdorferi, acute transient synovitis was present. A diffuse neutrophilic infiltrate involved the synovia and periarticular structures. The inflammation was associated with edema, hyperemia, and granulation tissue. Numerous spirochetes were seen in the synovial and subsynovial tissues. The histopathologic changes were enhanced in irradiated hamsters. The onset and duration of the induced swelling weremore » dependent on the dose of radiation and the inoculum of spirochetes. Inoculation of irradiated hamsters with Formalin-killed spirochetes or medium in which B. burgdorferi had grown for 7 days failed to induce swelling. This animal model should prove useful for studies of the immune response to B. burgdorferi and the pathogenesis of Lyme arthritis.« less

  19. Sequencing, Annotation and Analysis of the Syrian Hamster (Mesocricetus auratus) Transcriptome

    PubMed Central

    Tchitchek, Nicolas; Safronetz, David; Rasmussen, Angela L.; Martens, Craig; Virtaneva, Kimmo; Porcella, Stephen F.; Feldmann, Heinz

    2014-01-01

    Background The Syrian hamster (golden hamster, Mesocricetus auratus) is gaining importance as a new experimental animal model for multiple pathogens, including emerging zoonotic diseases such as Ebola. Nevertheless there are currently no publicly available transcriptome reference sequences or genome for this species. Results A cDNA library derived from mRNA and snRNA isolated and pooled from the brains, lungs, spleens, kidneys, livers, and hearts of three adult female Syrian hamsters was sequenced. Sequence reads were assembled into 62,482 contigs and 111,796 reads remained unassembled (singletons). This combined contig/singleton dataset, designated as the Syrian hamster transcriptome, represents a total of 60,117,204 nucleotides. Our Mesocricetus auratus Syrian hamster transcriptome mapped to 11,648 mouse transcripts representing 9,562 distinct genes, and mapped to a similar number of transcripts and genes in the rat. We identified 214 quasi-complete transcripts based on mouse annotations. Canonical pathways involved in a broad spectrum of fundamental biological processes were significantly represented in the library. The Syrian hamster transcriptome was aligned to the current release of the Chinese hamster ovary (CHO) cell transcriptome and genome to improve the genomic annotation of this species. Finally, our Syrian hamster transcriptome was aligned against 14 other rodents, primate and laurasiatheria species to gain insights about the genetic relatedness and placement of this species. Conclusions This Syrian hamster transcriptome dataset significantly improves our knowledge of the Syrian hamster's transcriptome, especially towards its future use in infectious disease research. Moreover, this library is an important resource for the wider scientific community to help improve genome annotation of the Syrian hamster and other closely related species. Furthermore, these data provide the basis for development of expression microarrays that can be used in functional

  20. Directed Student Inquiry: Modeling in Roborovsky Hamsters

    ERIC Educational Resources Information Center

    Elwess, Nancy L.; Bouchard, Adam

    2007-01-01

    In this inquiry-based activity, Roborovsky hamsters are used to provide students with an opportunity to develop their skills of analysis, inquiry, and design. These hamsters are easy to maintain, yet offer students a means to use conventional techniques and those of their own design to make further observations through measuring, assessing, and…

  1. Pineal melatonin synthesis in Syrian hamsters: A summary

    NASA Astrophysics Data System (ADS)

    Rollag, M. D.

    1982-12-01

    During the past decade there has been ample documentation of the proposition that the pineal gland mediates photoperiodic influences upon reproductive behavior of hamsters. It is commonly hypothesized that the pineal gland expresses its activity by transformation of photoperiodic information into an hormonal output, that hormone being melatonin. If this hypothesis is correct, there must be some essential diffrence in melatonin's output when hamsters are exposed to different photoperiodic environments. The experiments summarized in this communication analyze pineal melatonin contents in Syrian hamsters maintained in a variety of photoperiodic conditions during different physiological states. The results demonstrate that adult hamsters have a daily surge in pineal melatonin content throughout their lifetime when exposed to simulated annual photoperiodic cycles. There is some fluctuation in the amount of pineal melatonin produced during different physiological states and photoperiodic environments, but these fluctuations seem small when compared to those normally found for other regulatory hormones. When hamsters are exposed to different photoperiodic regimens, the daily melatonin surge maintains a relatively constant phase relationship with respect to the onset of daily activity. There is a concomitant change in its phase relationship with respect to light-dark transitions.

  2. Fasting-induced daily torpor in desert hamsters (Phodopus roborovskii).

    PubMed

    Chi, Qing-Sheng; Wan, Xin-Rong; Geiser, Fritz; Wang, De-Hua

    2016-09-01

    Daily torpor is frequently expressed in small rodents when facing energetically unfavorable ambient conditions. Desert hamsters (Phodopus roborovskii, ~20g) appear to be an exception as they have been described as homeothermic. However, we hypothesized that they can use torpor because we observed reversible decreases of body temperature (Tb) in fasted hamsters. To test this hypothesis we (i) randomly exposed fasted summer-acclimated hamsters to ambient temperatures (Tas) ranging from 5 to 30°C or (ii) supplied them with different rations of food at Ta 23°C. All desert hamsters showed heterothermy with the lowest mean Tb of 31.4±1.9°C (minimum, 29.0°C) and 31.8±2.0°C (minimum, 29.0°C) when fasted at Ta of 23°C and 19°C, respectively. Below Ta 19°C, the lowest Tb and metabolic rate increased and the proportion of hamsters using heterothermy declined. At Ta 5°C, nearly all hamsters remained normothermic by increasing heat production, suggesting that the heterothermy only occurs in moderately cold conditions, perhaps to avoid freezing at extremely low Tas. During heterothermy, Tbs below 31°C with metabolic rates below 25% of those during normothermia were detected in four individuals at Ta of 19°C and 23°C. Consequently, by definition, our observations confirm that fasted desert hamsters are capable of shallow daily torpor. The negative correlation between the lowest Tbs and amount of food supply shows that heterothermy was mainly triggered by food shortage. Our data indicate that summer-acclimated desert hamsters can express fasting-induced shallow daily torpor, which may be of significance for energy conservation and survival in the wild. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Characteristics of 263K Scrapie Agent in Multiple Hamster Species

    PubMed Central

    Barbian, Kent D.; Race, Brent; Favara, Cynthia; Gardner, Don; Taubner, Lara; Porcella, Stephen; Race, Richard

    2009-01-01

    Transmissible spongiform encephalopathy (TSE) diseases are known to cross species barriers, but the pathologic and biochemical changes that occur during transmission are not well understood. To better understand these changes, we infected 6 hamster species with 263K hamster scrapie strain and, after each of 3 successive passages in the new species, analyzed abnormal proteinase K (PK)–resistant prion protein (PrPres) glycoform ratios, PrPres PK sensitivity, incubation periods, and lesion profiles. Unique 263K molecular and biochemical profiles evolved in each of the infected hamster species. Characteristics of 263K in the new hamster species seemed to correlate best with host factors rather than agent strain. Furthermore, 2 polymorphic regions of the prion protein amino acid sequence correlated with profile differences in these TSE-infected hamster species. PMID:19193264

  4. Xenogeneic spermatogenesis following transplantation of hamster germ cells to mouse testes.

    PubMed

    Ogawa, T; Dobrinski, I; Avarbock, M R; Brinster, R L

    1999-02-01

    It was recently demonstrated that rat spermatogenesis can occur in the seminiferous tubules of an immunodeficient recipient mouse after transplantation of testis cells from a donor rat. In the present study, hamster donor testis cells were transplanted to mice to determine whether xenogeneic spermatogenesis would result. The hamster diverged at least 16 million years ago from the mouse and produces spermatozoa that are larger than, and have a shape distinctly different from, those of the mouse. In four separate experiments with a total of 13 recipient mice, hamster spermatogenesis was identified in the testes of each mouse. Approximately 6% of the tubules examined demonstrated xenogeneic spermatogenesis. In addition, cryopreserved hamster testis cells generated spermatogenesis in recipients. However, abnormalities were noted in hamster spermatids and acrosomes in seminiferous tubules of recipient mice. Hamster spermatozoa were also found in the epididymis of recipient animals, but these spermatozoa generally lacked acrosomes, and heads and tails were separated. Thus, defects in spermiogenesis occur in hamster spermatogenesis in the mouse, which may reflect a limited ability of endogenous mouse Sertoli cells to support fully the larger and evolutionarily distant hamster germ cell. The generation of spermatogenesis from frozen hamster cells now adds this species to the mouse and rat, in which spermatogonial stem cells also can be cryopreserved. This finding has immediate application to valuable animals of many species, because the cells could be stored until suitable recipients are identified or culture techniques devised to expand the stem cell population.

  5. Molecular analysis of peroxisome proliferation in the hamster.

    PubMed

    Choudhury, Agharul I; Sims, Helen M; Horley, Neill J; Roberts, Ruth A; Tomlinson, Simon R; Salter, Andrew M; Bruce, Mary; Shaw, P Nicholas; Kendall, David; Barrett, David A; Bell, David R

    2004-05-15

    Three novel P450 members of the cytochrome P450 4A family were cloned as partial cDNAs from hamster liver, characterised as novel members of the CYP4A subfamily, and designated CYP4A17, 18, and 19. Hamsters were treated with the peroxisome proliferator-activated receptor alpha (PPARalpha) agonists, methylclofenapate (MCP) or Wy-14,643, and shown to develop hepatomegaly and induction of CYP4A17 RNA, and concomitant induction of lauric acid 12- hydroxylase. This treatment also resulted in hypolipidaemia, which was most pronounced in the VLDL fraction, with up to 50% reduction in VLDL-triglycerides; by contrast, blood cholesterol concentration was unaffected by this treatment. These data show that hamster is highly responsive to induction of CYP4A by peroxisome proliferators. To characterise the molecular basis of peroxisome proliferation, the hamster PPARalpha was cloned and shown to encode a 468-amino-acid protein, which is highly similar to rat and mouse PPARalpha proteins. The level of expression of hamster PPARalpha in liver is intermediate between mouse and guinea pig. These results fail to support the hypothesis that the level of PPARalpha in liver is directly responsible for species differences in peroxisome proliferation.

  6. Hamster and Murine Models of Severe Destructive Lyme Arthritis

    PubMed Central

    Munson, Erik; Nardelli, Dean T.; Du Chateau, Brian K.; Callister, Steven M.; Schell, Ronald F.

    2012-01-01

    Arthritis is a frequent complication of infection in humans with Borrelia burgdorferi. Weeks to months following the onset of Lyme borreliosis, a histopathological reaction characteristic of synovitis including bone, joint, muscle, or tendon pain may occur. A subpopulation of patients may progress to a chronic, debilitating arthritis months to years after infection which has been classified as severe destructive Lyme arthritis. This arthritis involves focal bone erosion and destruction of articular cartilage. Hamsters and mice are animal models that have been utilized to study articular manifestations of Lyme borreliosis. Infection of immunocompetent LSH hamsters or C3H mice results in a transient synovitis. However, severe destructive Lyme arthritis can be induced by infecting irradiated hamsters or mice and immunocompetent Borrelia-vaccinated hamsters, mice, and interferon-gamma- (IFN-γ-) deficient mice with viable B. burgdorferi. The hamster model of severe destructive Lyme arthritis facilitates easy assessment of Lyme borreliosis vaccine preparations for deleterious effects while murine models of severe destructive Lyme arthritis allow for investigation of mechanisms of immunopathology. PMID:22461836

  7. Isolation, antimicrobial activities, and primary structures of hamster neutrophil defensins.

    PubMed Central

    Mak, P; Wójcik, K; Thogersen, I B; Dubin, A

    1996-01-01

    Hamster (Mesocricetus auratus) neutrophil granules contain at least four microbicidal peptides belonging to the defensin family. These compounds were purified from granule acid extracts by reverse-phase chromatography and termed HaNP-1 to -4 (hamster neutrophil peptide). HaNP-1 and HaNP-3 revealed the most bactericidal activity, with a 50% inhibitory concentration of 0.3 to 0.8 microg/ml for Staphylococcus aureus and Streptococcus pyogenes strains. The HaNP-4 was always isolated in concentrations exceeding about 10 times the concentrations of other hamster peptides, but its antibacterial activity as well as that of HaNP-2 was relatively lower, probably as a result of conserved Arg residue substitutions. Other microorganisms were also tested, and generally, hamster defensins exhibited less potency against gram-negative bacteria. The amino acid sequence of hamster defensins showed a high percentage of identity to the sequence of mouse enteric defensins, reaching about 60% identical residues in the case of HaNP-3 and cryptdin 3. PMID:8890190

  8. [Rabies in the common hamster (Cricetus cricetus) in Slovakia].

    PubMed

    Svrcek, S; Ondrejka, R; Mlynarcíková, K; Svec, J

    1984-11-01

    The trials were conducted within the full-scale research on the ecology of lyssa virus. In a period of the mass outbreak of common hamster population in the East Slovakian region, 283 hamsters were examined for rabies. Using the direct immunofluorescence method (DIFM), the rabies antigen was detected in the brain of five hamsters. Three virus strains (denoted as 3 O, 7 E, 9 E) were isolated by means of the inoculation test on sucking mice. On the basis of the detection of the nucleo-protein antigen by DIFM, or its inhibition, detection of the Babes-Negri bodies, determination of the neutralization index, titration on mice and determination of incubation time, the isolated strains were identified as the street strains of rabies virus. As determined by further detailed studies on biological characteristics (determination of the invasiveness index on animals with different susceptibility to rabies virus, determination of pathogenicity for different species of laboratory animals, different weight categories, with different methods of administration, invasiveness index), the "hamster" strains are included among those of intermediate virulence or reduced virulence. At intramuscular administration, the most virulent of the three "hamster" strains studied (3 O) induces a fatal course of rabies in common fox and cat; for wolves, dogs and rabbits it is apathogenic. This strain is also contained in the salivary glands of foxes and cats. In immunofluorescent detection of the rabies nucleoprotein antigen, the "hamster" strains formed a mixed picture of fluorescing particles, characteristic of street strains.

  9. Absence of C-type natriuretic peptide receptors in hamster glomeruli.

    PubMed

    Luk, J K; Wong, E F; Wong, N L

    1994-01-01

    The distribution of atrial natriuretic peptide receptor B (ANPR-B) varies between tissues and species. The aim of this study is to determine whether ANPR-B is present in the hamster glomeruli. In vitro C-type natriuretic peptide (CNP)- and atrial natriuretic factor (ANF)-stimulated cGMP accumulation studies were performed in hamster glomeruli. Elevated cGMP accumulations were observed upon ANF addition. No cGMP response was seen with CNP. Competitive receptor-binding experiments were performed with 125I-CNP and 125I-ANF against their respective cold peptides in hamster glomeruli. Although no CNP binding was detected, positive ANF binding was found and two types of ANF receptor were demonstrated. The affinity (Kdl) and maximum binding capacity (Bmaxl) of the high-affinity ANF receptor were 0.014 +/- 0.001 nM and 60.4 +/- 10.2 fmol/mg protein, respectively. Those of the low-affinity receptor (Kd2 and Bmax2) were 45.7 +/- 6.2 nM and 28.3 +/- 6.3 pmol/mg protein, respectively. Similarly, saturation binding experiments also failed to show any CNP receptor binding in hamster glomeruli. This finding suggests that ANPR-B is not present in hamster glomeruli and CNP is not a direct physiological regulator of hamster renal function.

  10. Cucullanus pargi sp. n. (Nematoda: Cucullanidae) from the grey snapper Lutjanus griseus off the southern coast of Quintana Roo, Mexico.

    PubMed

    González-Solís, David; Tuz-Paredes, Vielka M; Quintal-Loria, Miguel A

    2007-09-01

    A new nematode species, Cucullanus pargi sp. n., is described from the intestine and pyloric caeca of the grey snapper, Lutjanus griseus (Linnaeus), off the southern Quintana Roo coast, Mexico. This species shows similar morphological features as cucullanids occurring in marine and brackish-water fishes; however, it differs from all other species in the length of spicules, arrangement and number of caudal papillae, position of the excretory pore and deirids. Cucullanus pargi is the third species of this genus described from fishes in Mexico and the second one from Mexican marine fishes.

  11. Histopathology of Lyme arthritis in LSH hamsters

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hejka, A.; Schmitz, J.L.; England, D.M.

    1989-05-01

    The authors studied the histopathologic evolution of arthritis in nonirradiated and irradiated hamsters infected with Borrelia burgdorferi. Nonirradiated hamsters injected in the hind paws with B. burgdorferi developed an acute inflammatory reaction involving the synovium, periarticular soft tissues, and dermis. This acute inflammatory reaction was short-lived and was replaced by a mild chronic synovitis as the number of detectable spirochetes in the synovium, periarticular soft tissues, and perineurovascular areas diminished. Exposing hamsters to radiation before inoculation with B. burgdorferi exacerbated and prolonged the acute inflammatory phase. Spirochetes also persisted longer in the periarticular soft tissues. A major histopathologic finding wasmore » destructive and erosive bone changes of the hind paws, which resulted in deformation of the joints. These studies should be helpful in defining the immune mechanism participating in the onset, progression, and resolution of Lyme arthritis.« less

  12. The Syrian hamster model of hantavirus pulmonary syndrome.

    PubMed

    Safronetz, David; Ebihara, Hideki; Feldmann, Heinz; Hooper, Jay W

    2012-09-01

    Hantavirus pulmonary syndrome (HPS) is a relatively rare, but frequently fatal disease associated with New World hantaviruses, most commonly Sin Nombre and Andes viruses in North and South America, respectively. It is characterized by fever and the sudden, rapid onset of severe respiratory distress and cardiogenic shock, which can be fatal in up to 50% of cases. Currently there are no approved antiviral therapies or vaccines for the treatment or prevention of HPS. A major obstacle in the development of effective medical countermeasures against highly pathogenic agents like the hantaviruses is recapitulating the human disease as closely as possible in an appropriate and reliable animal model. To date, the only animal model that resembles HPS in humans is the Syrian hamster model. Following infection with Andes virus, hamsters develop HPS-like disease which faithfully mimics the human condition with respect to incubation period and pathophysiology of disease. Perhaps most importantly, the sudden and rapid onset of severe respiratory distress observed in humans also occurs in hamsters. The last several years has seen an increase in studies utilizing the Andes virus hamster model which have provided unique insight into HPS pathogenesis as well as potential therapeutic and vaccine strategies to treat and prevent HPS. The purpose of this article is to review the current understanding of HPS disease progression in Syrian hamsters and discuss the suitability of utilizing this model to evaluate potential medical countermeasures against HPS. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. The Syrian hamster model of hantavirus pulmonary syndrome

    PubMed Central

    Safronetz, David; Ebihara, Hideki; Feldmann, Heinz; Hooper, Jay W.

    2012-01-01

    Hantavirus pulmonary syndrome (HPS) is a relatively rare, but frequently fatal disease associated with New World hantaviruses, most commonly Sin Nombre and Andes viruses in North and South America, respectively. It is characterized by fever and the sudden, rapid onset of severe respiratory distress and cardiogenic shock, which can be fatal in up to 50% of cases. Currently there are no approved antiviral therapies or vaccines for the treatment or prevention of HPS. A major obstacle in the development of effective medical countermeasures against highly pathogenic agents like the hantaviruses is recapitulating the human disease as closely as possible in an appropriate and reliable animal model. To date, the only animal model that resembles HPS in humans is the Syrian hamster model. Following infection with Andes virus, hamsters develop HPS-like disease which faithfully mimics the human condition with respect to incubation period and pathophysiology of disease. Perhaps most importantly, the sudden and rapid onset of severe respiratory distress observed in humans also occurs in hamsters. The last several years has seen an increase in studies utilizing the Andes virus hamster model which have provided unique insight into HPS pathogenesis as well as potential therapeutic and vaccine strategies to treat and prevent HPS. The purpose of this article is to review the current understanding of HPS disease progression in Syrian hamsters and discuss the suitability of utilizing this model to evaluate potential medical countermeasures against HPS. PMID:22705798

  14. Metabolic influences on circadian rhythmicity in Siberian and Syrian hamsters exposed to long photoperiods.

    PubMed

    Challet, E; Kolker, D E; Turek, F W

    2000-01-01

    Calorie restriction and other situations of reduced glucose availability in rodents alter the entraining effects of light on the circadian pacemaker located in the suprachiasmatic nuclei. Siberian and Syrian hamsters are photoperiodic species that are sexually active when exposed to long summer-like photoperiods, while both species show opposite changes in body mass when transferred from long to short or short to long days. Because metabolic cues may fine tune the photoperiodic responses via the suprachiasmatic nuclei, we tested whether timed calorie restriction can alter the photic synchronization of the light-entrainable pacemaker in these two hamster species exposed to long photoperiods. Siberian and Syrian hamsters were exposed to 16 h:8 h light:dark cycles and received daily hypocaloric (75% of daily food intake) or normocaloric diet (100% of daily food intake) 4 h after light onset. Four weeks later, hamsters were transferred to constant darkness and fed ad libitum. The onset of the nocturnal pattern of locomotor activity was phase advanced by 1.5 h in calorie-restricted Siberian hamsters, but not in Syrian hamsters. The lack of phase change in calorie-restricted Syrian hamsters was also observed in individuals exposed to 14 h:10 h dim light:dark cycles and fed with lower hypocaloric food (i.e. 60% of daily food intake) 2 h after light onset. Moreover, in hamsters housed in constant darkness and fed ad lib., light-induced phase shifts of the locomotor activity in Siberian hamsters, but not in Syrian hamsters were significantly reduced when glucose utilization was blocked by pretreatment with 500 mg/kg i.p. 2-deoxy-D-glucose. Taken together, these results show that the photic synchronization of the light-entrainable pacemaker can be modulated by metabolic cues in Siberian hamsters, but not in Syrian hamsters maintained on long days.

  15. A lethal disease model for New World hantaviruses using immunosuppressed Syrian hamsters.

    PubMed

    Vergote, Valentijn; Laenen, Lies; Vanmechelen, Bert; Van Ranst, Marc; Verbeken, Erik; Hooper, Jay W; Maes, Piet

    2017-10-01

    Hantavirus, the hemorrhagic causative agent of two clinical diseases, is found worldwide with variation in severity, incidence and mortality. The most lethal hantaviruses are found on the American continent where the most prevalent viruses like Andes virus and Sin Nombre virus are known to cause hantavirus pulmonary syndrome. New World hantavirus infection of immunocompetent hamsters results in an asymptomatic infection except for Andes virus and Maporal virus; the only hantaviruses causing a lethal disease in immunocompetent Syrian hamsters mimicking hantavirus pulmonary syndrome in humans. Hamsters, immunosuppressed with dexamethasone and cyclophosphamide, were infected intramuscularly with different New World hantavirus strains (Bayou virus, Black Creek Canal virus, Caño Delgadito virus, Choclo virus, Laguna Negra virus, and Maporal virus). In the present study, we show that immunosuppression of hamsters followed by infection with a New World hantavirus results in an acute disease that precisely mimics both hantavirus disease in humans and Andes virus infection of hamsters. Infected hamsters showed specific clinical signs of disease and moreover, histological analysis of lung tissue showed signs of pulmonary edema and inflammation within alveolar septa. In this study, we were able to infect immunosuppressed hamsters with different New World hantaviruses reaching a lethal outcome with signs of disease mimicking human disease.

  16. Foodborne transmission of nipah virus in Syrian hamsters.

    PubMed

    de Wit, Emmie; Prescott, Joseph; Falzarano, Darryl; Bushmaker, Trenton; Scott, Dana; Feldmann, Heinz; Munster, Vincent J

    2014-03-01

    Since 2001, outbreaks of Nipah virus have occurred almost every year in Bangladesh with high case-fatality rates. Epidemiological data suggest that in Bangladesh, Nipah virus is transmitted from the natural reservoir, fruit bats, to humans via consumption of date palm sap contaminated by bats, with subsequent human-to-human transmission. To experimentally investigate this epidemiological association between drinking of date palm sap and human cases of Nipah virus infection, we determined the viability of Nipah virus (strain Bangladesh/200401066) in artificial palm sap. At 22°C virus titers remained stable for at least 7 days, thus potentially allowing food-borne transmission. Next, we modeled food-borne Nipah virus infection by supplying Syrian hamsters with artificial palm sap containing Nipah virus. Drinking of 5×10⁸ TCID₅₀ of Nipah virus resulted in neurological disease in 5 out of 8 hamsters, indicating that food-borne transmission of Nipah virus can indeed occur. In comparison, intranasal (i.n.) inoculation with the same dose of Nipah virus resulted in lethal respiratory disease in all animals. In animals infected with Nipah virus via drinking, virus was detected in respiratory tissues rather than in the intestinal tract. Using fluorescently labeled Nipah virus particles, we showed that during drinking, a substantial amount of virus is deposited in the lungs, explaining the replication of Nipah virus in the respiratory tract of these hamsters. Besides the ability of Nipah virus to infect hamsters via the drinking route, Syrian hamsters infected via that route transmitted the virus through direct contact with naïve hamsters in 2 out of 24 transmission pairs. Although these findings do not directly prove that date palm sap contaminated with Nipah virus by bats is the origin of Nipah virus outbreaks in Bangladesh, they provide the first experimental support for this hypothesis. Understanding the Nipah virus transmission cycle is essential for preventing

  17. Foodborne Transmission of Nipah Virus in Syrian Hamsters

    PubMed Central

    de Wit, Emmie; Prescott, Joseph; Falzarano, Darryl; Bushmaker, Trenton; Scott, Dana; Feldmann, Heinz; Munster, Vincent J.

    2014-01-01

    Since 2001, outbreaks of Nipah virus have occurred almost every year in Bangladesh with high case-fatality rates. Epidemiological data suggest that in Bangladesh, Nipah virus is transmitted from the natural reservoir, fruit bats, to humans via consumption of date palm sap contaminated by bats, with subsequent human-to-human transmission. To experimentally investigate this epidemiological association between drinking of date palm sap and human cases of Nipah virus infection, we determined the viability of Nipah virus (strain Bangladesh/200401066) in artificial palm sap. At 22°C virus titers remained stable for at least 7 days, thus potentially allowing food-borne transmission. Next, we modeled food-borne Nipah virus infection by supplying Syrian hamsters with artificial palm sap containing Nipah virus. Drinking of 5×108 TCID50 of Nipah virus resulted in neurological disease in 5 out of 8 hamsters, indicating that food-borne transmission of Nipah virus can indeed occur. In comparison, intranasal (i.n.) inoculation with the same dose of Nipah virus resulted in lethal respiratory disease in all animals. In animals infected with Nipah virus via drinking, virus was detected in respiratory tissues rather than in the intestinal tract. Using fluorescently labeled Nipah virus particles, we showed that during drinking, a substantial amount of virus is deposited in the lungs, explaining the replication of Nipah virus in the respiratory tract of these hamsters. Besides the ability of Nipah virus to infect hamsters via the drinking route, Syrian hamsters infected via that route transmitted the virus through direct contact with naïve hamsters in 2 out of 24 transmission pairs. Although these findings do not directly prove that date palm sap contaminated with Nipah virus by bats is the origin of Nipah virus outbreaks in Bangladesh, they provide the first experimental support for this hypothesis. Understanding the Nipah virus transmission cycle is essential for preventing and

  18. Morphometric and histological analysis of the lungs of Syrian golden hamsters.

    PubMed Central

    Kennedy, A R; Desrosiers, A; Terzaghi, M; Little, J B

    1978-01-01

    Hamster lung morphometry and histology have been studied in an attempt to determine differences between hamster and human lungs which may have relevance for lung carcinogenesis studies. Morphometric measurements were made on fresh lungs, lung casts, and histological sections. Cell type and frequency measurements were determined from frozen, paraffin, 1 micron plastic (glycol methacrylate) and electron microscopic sections. A standard terminology for hamster lung histology is established, and differences between hamster and human lung morphometry and histology are discussed. Images Fig. 2 Fig. 3 Fig. 4 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 Fig. 15 Fig. 16 Fig. 17 Fig. 18 Fig. 19 Fig. 20 Fig. 21 Fig. 22 PMID:640957

  19. Decreased adult neurogenesis in hibernating Syrian hamster.

    PubMed

    León-Espinosa, Gonzalo; García, Esther; Gómez-Pinedo, Ulises; Hernández, Félix; DeFelipe, Javier; Ávila, Jesús

    2016-10-01

    Generation of new neurons from adult neural stem cells occurs in the dentate gyrus (DG) of the hippocampus and the lateral walls of the lateral ventricles. In this article, we study the neurogenesis that takes place during the hibernation of the Syrian hamster (Mesocricetus auratus). Using a variety of standard neurogenesis markers and 5-bromo-2-deoxyuridine (BrdU) incorporation, we describe a preferential decrease in the proliferation of newborn neurons in the subventricular zone (SVZ) of the hibernating hamsters (torpor) rather than in the hippocampus. Furthermore, we demonstrate that the proliferative capacity is recovered after 3-4days of torpor when arousal is triggered under natural conditions (i.e., not artificially provoked). In addition, we show that tau3R, a tau isoform with three microtubule-binding domains, is a suitable marker to study neurogenesis both in the SVZ and subgranular zone (SGZ) of the Syrian hamster brain. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  20. Karyotype morphology suggests that the Nyctibius griseus (Gmelin, 1789) carries an ancestral ZW-chromosome pair to the order Caprimulgiformes (Aves)

    PubMed Central

    Nieto, Leonardo Martin; Kretschmer, Rafael; Ledesma, Mario Angel; Garnero, Analía Del Valle; Gunski, Ricardo José

    2012-01-01

    Abstract Studies of karyotypes have been revealing important information on the taxonomic relationships and evolutionary patterns in various groups of birds. However, the order Caprimulgiformes is one of the least known in terms of its cytotaxonomy. So far, there are no cytogenetic data in the literature on birds belonging to 3 of 5 families of this order -Nyctibiidae, Steatornithidae and Aegothelidae. For this reason, the aim of our study was to describe the karyotype of Nyctibius griseus (Gmelin, 1789) (Aves, Nyctibiidae, Caprimulgiformes) and contribute with new data that could help to clarify the evolutionary relationships in this group. Bone marrow was cultured directly to obtain material for the chromosome study. C-banding was used to visualize the constitutive heterochromatin and Ag-NOR-banding to reveal nucleolus organizer regions. The diploid number observed was 2n=86±. Using sequential Giemsa/C-banding staining, we determined that the W chromosome was entirely C-band positive with the two most prominent markers in the interstitial and distal regions of the long arm. The nucleolus organizer regions showed a typical location in a pair of microchromosomes that exhibited Ag-NOR.The results obtained for Nyctibius griseus suggest that, of all the species studied in the references cited, it has the most ancestral sex chromosome composition of the order Caprimulgiformes. PMID:24260678

  1. Nipah virus transmission in a hamster model.

    PubMed

    de Wit, Emmie; Bushmaker, Trenton; Scott, Dana; Feldmann, Heinz; Munster, Vincent J

    2011-12-01

    Based on epidemiological data, it is believed that human-to-human transmission plays an important role in Nipah virus outbreaks. No experimental data are currently available on the potential routes of human-to-human transmission of Nipah virus. In a first dose-finding experiment in Syrian hamsters, it was shown that Nipah virus was predominantly shed via the respiratory tract within nasal and oropharyngeal secretions. Although Nipah viral RNA was detected in urogenital and rectal swabs, no infectious virus was recovered from these samples, suggesting no viable virus was shed via these routes. In addition, hamsters inoculated with high doses shed significantly higher amounts of viable Nipah virus particles in comparison with hamsters infected with lower inoculum doses. Using the highest inoculum dose, three potential routes of Nipah virus transmission were investigated in the hamster model: transmission via fomites, transmission via direct contact and transmission via aerosols. It was demonstrated that Nipah virus is transmitted efficiently via direct contact and inefficiently via fomites, but not via aerosols. These findings are in line with epidemiological data which suggest that direct contact with nasal and oropharyngeal secretions of Nipah virus infected individuals resulted in greater risk of Nipah virus infection. The data provide new and much-needed insights into the modes and efficiency of Nipah virus transmission and have important public health implications with regards to the risk assessment and management of future Nipah virus outbreaks.

  2. Nipah Virus Transmission in a Hamster Model

    PubMed Central

    de Wit, Emmie; Bushmaker, Trenton; Scott, Dana; Feldmann, Heinz; Munster, Vincent J.

    2011-01-01

    Based on epidemiological data, it is believed that human-to-human transmission plays an important role in Nipah virus outbreaks. No experimental data are currently available on the potential routes of human-to-human transmission of Nipah virus. In a first dose-finding experiment in Syrian hamsters, it was shown that Nipah virus was predominantly shed via the respiratory tract within nasal and oropharyngeal secretions. Although Nipah viral RNA was detected in urogenital and rectal swabs, no infectious virus was recovered from these samples, suggesting no viable virus was shed via these routes. In addition, hamsters inoculated with high doses shed significantly higher amounts of viable Nipah virus particles in comparison with hamsters infected with lower inoculum doses. Using the highest inoculum dose, three potential routes of Nipah virus transmission were investigated in the hamster model: transmission via fomites, transmission via direct contact and transmission via aerosols. It was demonstrated that Nipah virus is transmitted efficiently via direct contact and inefficiently via fomites, but not via aerosols. These findings are in line with epidemiological data which suggest that direct contact with nasal and oropharyngeal secretions of Nipah virus infected individuals resulted in greater risk of Nipah virus infection. The data provide new and much-needed insights into the modes and efficiency of Nipah virus transmission and have important public health implications with regards to the risk assessment and management of future Nipah virus outbreaks. PMID:22180802

  3. Reproductive responses to photoperiod persist in olfactory bulbectomized Siberian hamsters (Phodopus sungorus).

    PubMed

    Prendergast, Brian J; Pyter, Leah M; Galang, Jerome; Kay, Leslie M

    2009-03-02

    In reproductively photoperiodic Syrian hamsters, removal of the olfactory bulbs (OBx) leads to a marked and sustained increase in gonadotrophin secretion which prevents normal testicular regression in short photoperiods. In contrast, among reproductively nonphotoperiodic laboratory strains of rats and mice, bulbectomy unmasks reproductive responses to photoperiod. The role of the olfactory bulbs has been proposed to have opposite effects on responsiveness to photoperiod, depending on the photoperiodicity of the reproductive system; however, Syrian hamsters are the only reproductively photoperiodic rodent species for which the role of the olfactory bulb in reproductive endocrinology has been assessed. This experiment evaluated the role of the olfactory bulbs in the photoperiodic control of reproduction in Siberian hamsters (Phodopus sungorus), an established model species for the study of neural substrates mediating seasonality. Relative to control hamsters housed in long days (15 h light/day), exposure of adult male hamsters to short days (9h light/day) for 8 weeks led to a temporal expansion of the pattern of nocturnal locomotor activity, testicular regression, decreases in testosterone (T) production, and undetectable levels of plasma follicle-stimulating hormone (FSH). Bilateral olfactory bulbectomy failed to affect any of these responses to short days. The patterns of entrainment to long and short days suggests that pre-pineal mechanisms involved in photoperiodic timekeeping are functioning normally in OBx hamsters. The absence of increases in FSH following bulbectomy in long days is incompatible with the hypothesis that the olfactory bulbs provide tonic inhibition of the HPG axis in this species. In marked contrast to Syrian hamsters, the olfactory bulbs of Siberian hamsters play essentially no role in the modulation of tonic gonadotrophin production or gonadotrophin responses to photoperiod.

  4. Thermostability of sperm nuclei assessed by microinjection into hamster oocytes

    EPA Science Inventory

    Nuclei isolated from spermatozoa of various species (golden hamster, mouse, human, rooster, and the fish tilapia) were heated at 60 degrees-125 degrees C for 20-120 min and then microinjected into hamster oocytes to determine whether they could decondense and develop into pronucl...

  5. Black tea extract and dental caries formation in hamsters.

    PubMed

    Linke, Harald A B; LeGeros, Racquel Z

    2003-01-01

    Several studies have suggested that green tea and Oolong tea extracts have antibacterial and anticariogenic properties in vitro and in vivo. The aim of the present study was to determine the effect of a standardized black tea extract (BTE) on caries formation in inbred hamsters on a regular and a cariogenic diet. Eighty hamsters were divided into four groups of 20 animals each. Two groups received a pelleted regular diet (LabChow) with water or BTE ad libitum. The other two groups received a powdered cariogenic diet (Diet 2000, containing 56% sucrose) with water or BTE ad libitum. The animals were kept for 3 months on their respective diets and then were sacrificed. The heads were retained, the jaws were prepared and stained using alizarin mordant red II, and were then scored for dental caries according to the Keyes method. This is the first study indicating that BTE, as compared with water, significantly decreased caries formation by 56.6% in hamsters on a regular diet and by 63.7% in hamsters on a cariogenic diet (P < 0.05). In the cariogenic diet group BTE, reduced the mandibular caries score of the hamsters slightly more than the maxillary caries score. The fluoride content of the standardized BTE solution was frequently monitored during the experiment; the mean fluoride concentration was found to be 4.22 ppm. A frequent intake of black tea can significantly decrease caries formation, even in the presence of sugars in the diet.

  6. The hamster flank organ model: Is it relevant to man

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Franz, T.J.; Lehman, P.A.; Pochi, P.

    1989-10-01

    The critical role that androgens play in the etiology of acne has led to a search for topically active antiandrogens and the frequent use of the flank organ of the golden Syrian hamster as an animal model. 17-alpha-propyltestosterone (17-PT) has been identified as having potent antiandrogenic activity in the hamster model, and this report describes its clinical evaluation. Two double-blind placebo controlled studies comparing 4% 17-PT in 80% alcohol versus vehicle alone were conducted. One study examined 17-PT sebosuppressive activity in 20 subjects. The second study examined its efficacy in 44 subjects having mild to moderate acne. A third studymore » measured in vitro percutaneous absorption of 17-PT through hamster flank and monkey skin, and human face skin in-vivo, using radioactive drug. 17-PT was found to be ineffective in reducing either the sebum excretion rate or the number of inflammatory acne lesions. Failure of 17-PT to show clinical activity was not a result of poor percutaneous absorption. Total absorption in man was 7.7% of the dose and only 1.0% in the hamster. The sebaceous gland of hamster flank organ is apparently more sensitive to antiandrogens than the human sebaceous gland.« less

  7. Identification, Expression, and Physiological Functions of Siberian Hamster Gonadotropin-Inhibitory Hormone

    PubMed Central

    Ubuka, Takayoshi; Inoue, Kazuhiko; Fukuda, Yujiro; Mizuno, Takanobu; Ukena, Kazuyoshi; Kriegsfeld, Lance J.

    2012-01-01

    Gonadotropin-inhibitory hormone (GnIH) is a hypothalamic neuropeptide that inhibits gonadotropin secretion in birds and mammals. To further understand its physiological roles in mammalian reproduction, we identified its precursor cDNA and endogenous mature peptides in the Siberian hamster brain. The Siberian hamster GnIH precursor cDNA encoded two RFamide-related peptide (RFRP) sequences. SPAPANKVPHSAANLPLRF-NH2 (Siberian hamster RFRP-1) and TLSRVPSLPQRF-NH2 (Siberian hamster RFRP-3) were confirmed as mature endogenous peptides by mass spectrometry from brain samples purified by immunoaffinity chromatography. GnIH mRNA expression was higher in long days (LD) compared with short days (SD). GnIH mRNA was also highly expressed in SD plus pinealectomized animals, whereas expression was suppressed by melatonin, a nocturnal pineal hormone, administration. GnIH-immunoreactive (-ir) neurons were localized to the dorsomedial region of the hypothalamus, and GnIH-ir fibers projected to hypothalamic and limbic structures. The density of GnIH-ir perikarya and fibers were higher in LD and SD plus pinealectomized hamsters than in LD plus melatonin or SD animals. The percentage of GnRH neurons receiving close appositions from GnIH-ir fiber terminals was also higher in LD than SD, and GnIH receptor was expressed in GnRH-ir neurons. Finally, central administration of hamster RFRP-1 or RFRP-3 inhibited LH release 5 and 30 min after administration in LD. In sharp contrast, both peptides stimulated LH release 30 min after administration in SD. These results suggest that GnIH peptides fine tune LH levels via its receptor expressed in GnRH-ir neurons in an opposing fashion across the seasons in Siberian hamsters. PMID:22045661

  8. Cloning and characterization of the hamster and guinea pig nicotinic acid receptors.

    PubMed

    Torhan, April Smith; Cheewatrakoolpong, Boonlert; Kwee, Lia; Greenfeder, Scott

    2007-09-01

    In this study, we present the identification and characterization of hamster and guinea pig nicotinic acid receptors. The hamster receptor shares approximately 80-90% identity with the nucleotide and amino acid sequences of human, mouse, and rat receptors. The guinea pig receptor shares 76-80% identity with the nucleotide and amino acid sequences of these other species. [(3)H]nicotinic acid binding affinity at guinea pig and hamster receptors is similar to that in human (dissociation constant = 121 nM for guinea pig, 72 nM for hamster, and 74 nM for human), as are potencies of nicotinic acid analogs in competition binding studies. Inhibition of forskolin-stimulated cAMP production by nicotinic acid and related analogs is also similar to the activity in the human receptor. Analysis of mRNA tissue distribution for the hamster and guinea pig nicotinic acid receptors shows expression across a number of tissues, with higher expression in adipose, lung, skeletal muscle, spleen, testis, and ovary.

  9. Hibernation, stress, intestinal functions, and catecholoamine turnover rate in hamsters and gerbils

    NASA Technical Reports Server (NTRS)

    Musacchia, X. J.

    1973-01-01

    Bioenergetic studies on hamsters during depressed metabolic states are reported. External support of blood glucose extended the survival times of hibernating animals. Radioresistance increased in hibernating as well as in hypothermic hamsters. Marked changes in hamster catecholamine turnover rates were observed during acclimatization to high temperature stress. High radioresistance levels of the gerbil gastrointestinal system were attributed in part to the ability of the gut to maintain functional integrity.

  10. Photoperiod history differentially impacts reproduction and immune function in adult Siberian hamsters.

    PubMed

    Prendergast, Brian J; Pyter, Leah M

    2009-12-01

    Seasonal changes in numerous aspects of mammalian immune function arise as a result of the annual variation in environmental day length (photoperiod), but it is not known if absolute photoperiod or relative change in photoperiod drives these changes. This experiment tested the hypothesis that an individual's history of exposure to day length determines immune responses to ambiguous, intermediate-duration day lengths. Immunological (blood leukocytes, delayed-type hypersensitivity reactions [DTH]), reproductive, and adrenocortical responses were assessed in adult Siberian hamsters (Phodopus sungorus) that had been raised initially in categorically long (15-h light/day; 15L) or short (9L) photoperiods and were subsequently transferred to 1 of 7 cardinal experimental photoperiods between 9L and 15L, inclusive. Initial photoperiod history interacted with contemporary experimental photoperiods to determine reproductive responses: 11L, 12L, and 13L caused gonadal regression in hamsters previously exposed to 15L, but elicited growth in hamsters previously in 9L. In hamsters with a 15L photoperiod history, photoperiods < or = 11L elicited sustained enhancement of DTH responses, whereas in hamsters with a 9L photoperiod history, DTH responses were largely unaffected by increases in day length. Enhancement and suppression of blood leukocyte concentrations occurred at 13L in hamsters with photoperiod histories of 15L and 9L, respectively; however, prior exposure to 9L imparted marked hysteresis effects, which suppressed baseline leukocyte concentrations. Cortisol concentrations were only enhanced in 15L hamsters transferred to 9L and, in common with DTH, were unaffected by photoperiod treatments in hamsters with a 9L photoperiod history. Photoperiod history acquired in adulthood impacts immune responses to photoperiod, but manifests in a markedly dissimilar fashion as compared to the reproductive system. Prior photoperiod exposure has an enduring impact on the ability of the

  11. Infestivity of Demodex canis to hamster skin engrafted onto SCID mice.

    PubMed

    Tani, Kenji; Une, Satoshi; Hasegawa, Atsuhiko; Adachi, Makoto; Kanda, Naoko; Watanabe, Shin-ichi; Nakaichi, Munekazu; Taura, Yasuho

    2005-04-01

    We demonstrated that Demodex canis was transferred to skin xenografts of a dog and a hamster onto severe combined immunodeficiency mice. After the transfer of mites, the number of eggs, larvae, nymphs and adult mites per gram of canine and hamster xenografts increased, whereas no live mites were detected on murine allograft. These results indicate that D. canis proliferates in hair follicles of dog and hamster skins but not in murine allograft. Therefore, D. canis may have host preference but not strict host-specificity.

  12. Cross-species transcriptomic approach reveals genes in hamster implantation sites.

    PubMed

    Lei, Wei; Herington, Jennifer; Galindo, Cristi L; Ding, Tianbing; Brown, Naoko; Reese, Jeff; Paria, Bibhash C

    2014-12-01

    The mouse model has greatly contributed to understanding molecular mechanisms involved in the regulation of progesterone (P4) plus estrogen (E)-dependent blastocyst implantation process. However, little is known about contributory molecular mechanisms of the P4-only-dependent blastocyst implantation process that occurs in species such as hamsters, guineapigs, rabbits, pigs, rhesus monkeys, and perhaps humans. We used the hamster as a model of P4-only-dependent blastocyst implantation and carried out cross-species microarray (CSM) analyses to reveal differentially expressed genes at the blastocyst implantation site (BIS), in order to advance the understanding of molecular mechanisms of implantation. Upregulation of 112 genes and downregulation of 77 genes at the BIS were identified using a mouse microarray platform, while use of the human microarray revealed 62 up- and 38 down-regulated genes at the BIS. Excitingly, a sizable number of genes (30 up- and 11 down-regulated genes) were identified as a shared pool by both CSMs. Real-time RT-PCR and in situ hybridization validated the expression patterns of several up- and down-regulated genes identified by both CSMs at the hamster and mouse BIS to demonstrate the merit of CSM findings across species, in addition to revealing genes specific to hamsters. Functional annotation analysis found that genes involved in the spliceosome, proteasome, and ubiquination pathways are enriched at the hamster BIS, while genes associated with tight junction, SAPK/JNK signaling, and PPARα/RXRα signalings are repressed at the BIS. Overall, this study provides a pool of genes and evidence of their participation in up- and down-regulated cellular functions/pathways at the hamster BIS. © 2014 Society for Reproduction and Fertility.

  13. Genetic Localization and Molecular Characterization of the nonS Gene Required for Macrotetrolide Biosynthesis in Streptomyces griseus DSM40695

    PubMed Central

    Smith, Wyatt C.; Xiang, Longkuan; Shen, Ben

    2000-01-01

    The macrotetrolides are a family of cyclic polyethers derived from tetramerization, in a stereospecific fashion, of the enantiomeric nonactic acid (NA) and its homologs. Isotope labeling experiments established that NA is of polyketide origin, and biochemical investigations demonstrated that 2-methyl-6,8-dihydroxynon-2E-enoic acid can be converted into NA by a cell-free preparation from Streptomyces lividans that expresses nonS. These results lead to the hypothesis that macrotetrolide biosynthesis involves a pair of enantiospecific polyketide pathways. In this work, a 55-kb contiguous DNA region was cloned from Streptomyces griseus DSM40695, a 6.3-kb fragment of which was sequenced to reveal five open reading frames, including the previously reported nonR and nonS genes. Inactivation of nonS in vivo completely abolished macrotetrolide production. Complementation of the nonS mutant by the expression of nonS in trans fully restored its macrotetrolide production ability, with a distribution of individual macrotetrolides similar to that for the wild-type producer. In contrast, fermentation of the nonS mutant in the presence of exogenous (±)-NA resulted in the production of nonactin, monactin, and dinactin but not in the production of trinactin and tetranactin. These results prove the direct involvement of nonS in macrotetrolide biosynthesis. The difference in macrotetrolide production between in vivo complementation of the nonS mutant by the plasmid-borne nonS gene and fermentation of the nonS mutant in the presence of exogenously added (±)-NA suggests that NonS catalyzes the formation of (−)-NA and its homologs, supporting the existence of a pair of enantiospecific polyketide pathways for macrotetrolide biosynthesis in S. griseus. The latter should provide a model that can be used to study the mechanism by which polyketide synthase controls stereochemistry during polyketide biosynthesis. PMID:10858335

  14. Mass distribution and rotational inertia of "microtype" and "freely mobile" middle ear ossicles in rodents.

    PubMed

    Lavender, Danielle; Taraskin, Sergei N; Mason, Matthew J

    2011-12-01

    The middle ears of seven species of rodents, including four hamster species, were examined under light microscopy and through micro-CT imaging. Hamsters were found to possess a spectrum of ossicular morphologies ranging from something approaching "freely mobile" (Mesocricetus) to something nearer the "microtype" (Cricetulus), although no hamster has an orbicular apophysis of the malleus. Rats, mice and Calomyscus were found to have typically microtype ossicles. To explore the functional effects of these morphological differences, CT scan data were used to calculate the magnitudes of the moments of inertia and positions of the centres of mass and principal rotational axes for the malleus-incus complexes. Microtype species were found to have much greater ossicular inertias, relative to size, about the "anatomical axis" extending between anterior process of the malleus and short process of the incus; ossicular centres of mass were displaced further from this axis. Calculated inertial values were then put into an existing model of middle ear function (Hemilä et al., 1995), in order to see whether the more accurate data would improve predictions of upper hearing limits. For the rat and mouse they did, but this was not so for the hamster Mesocricetus. This might indicate that the inner rather than the middle ear limits hearing in this species, or might simply reflect other shortcomings of the model. Functional differences appear to exist even among rodent ears of the same general type, but the adaptive significance of these differences remains enigmatic. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Social organization of the Alaotran gentle lemur (Hapalemur griseus alaotrensis).

    PubMed

    Mutschler, T; Nievergelt, C M; Feistner, A T

    2000-01-01

    Knowledge of the social organization of lemurs is still limited for most species. Where there is sufficient information, it has been shown that lemur social organization differs in essential points from that of other primates. In the field study reported here, demographic structure and life-history processes were investigated in order to characterize the social organization of the Alaotran gentle lemur (Hapalemur griseus alaotrensis). Data were obtained through captures and observations. Alaotran gentle lemurs were found in small groups of up to nine individuals. Although most groups contained just one breeding female, a substantial proportion of groups (35%) had two breeding females. Therefore, Alaotran gentle lemurs cannot be classed as being organized in monogamous family groups. An extended birth season was found, and groups with two breeding females had significantly higher breeding output per adult than groups with a single adult female. Limited data suggest that females emigrate from their natal group while still subadult, whereas males can stay in the natal group until they are fully grown and disperse as adults. Variability in group composition, significantly higher reproductive output per adult in groups with two breeding females, and delayed dispersal of males suggest that Alaotran gentle lemurs pursue a resource-defense mating strategy, rather than a female-defense mating strategy. The suggestion that extant social lemurs may have evolved from a monogamous system, could explain the differences between lemur social systems and those of other primates.

  16. Photoperiodic Regulation of the Orexigenic Effects of Ghrelin in Siberian Hamsters

    PubMed Central

    Bradley, Sean P.; Pattullo, Lucia M.; Patel, Priyesh N.; Prendergast, Brian J.

    2010-01-01

    Animals living in temperate climates with predictable seasonal changes in food availability may use seasonal information to engage different metabolic strategies. Siberian hamsters decrease costs of thermoregulation during winter by reducing food intake and body mass in response to decreasing or short day lengths (SD). These experiments examined whether SD reductions in food intake in hamsters is driven, at least in part, by altered behavioral responses to ghrelin, a gut-derived orexigenic peptide which induces food intake via NPY-dependent mechanisms. Relative to hamsters housed in long day (LD) photoperiods, SD hamsters consumed less food in response to i.p. treatment with ghrelin across a range of doses from 0.03 to 3 mg/kg. To determine whether changes in photoperiod alter behavioral responses ghrelin-induced activation of NPY neurons, c-Fos and NPY expression were quantified in the arcuate nucleus (ARC) via double-label fluorescent immunocytochemistry following i.p. treatment with 0.3 mg/kg ghrelin or saline. Ghrelin induced c-Fos immunoreactivity (-ir) in a greater proportion of NPY-ir neurons of LD relative to SD hamsters. In addition, following ghrelin treatment, a greater proportion of ARC c-Fos-ir neurons were identifiable as NPY-ir in LD relative to SD hamsters. Changes in day length markedly alter the behavioral response to ghrelin. The data also identify photoperiod-induced changes in the ability of ghrelin to activate ARC NPY neurons as a possible mechanism by which changes in day length alter food intake. PMID:20600050

  17. Regulation of lipid metabolism by obeticholic acid in hyperlipidemic hamsters.

    PubMed

    Dong, Bin; Young, Mark; Liu, Xueqing; Singh, Amar Bahadur; Liu, Jingwen

    2017-02-01

    The farnesoid X receptor (FXR) plays critical roles in plasma cholesterol metabolism, in particular HDL-cholesterol (HDL-C) homeostasis. Obeticholic acid (OCA) is a FXR agonist being developed for treating various chronic liver diseases. Previous studies reported inconsistent effects of OCA on regulating plasma cholesterol levels in different animal models and in different patient populations. The mechanisms underlying its divergent effects have not yet been thoroughly investigated. The scavenger receptor class B type I (SR-BI) is a FXR-modulated gene and the major receptor for HDL-C. We investigated the effects of OCA on hepatic SR-BI expression and correlated such effects with plasma HDL-C levels and hepatic cholesterol efflux in hyperlipidemic hamsters. We demonstrated that OCA induced a time-dependent reduction in serum HDL-C levels after 14 days of treatment, which was accompanied by a significant reduction of liver cholesterol content and increases in fecal cholesterol in OCA-treated hamsters. Importantly, hepatic SR-BI mRNA and protein levels in hamsters were increased to 1.9- and 1.8-fold of control by OCA treatment. Further investigations in normolipidemic hamsters did not reveal OCA-induced changes in serum HDL-C levels or hepatic SR-BI expression. We conclude that OCA reduces plasma HDL-C levels and promotes transhepatic cholesterol efflux in hyperlipidemic hamsters via a mechanism involving upregulation of hepatic SR-BI.

  18. Arnica Tincture Cures Cutaneous Leishmaniasis in Golden Hamsters.

    PubMed

    Robledo, Sara M; Vélez, Ivan D; Schmidt, Thomas J

    2018-01-12

    In search for potential therapeutic alternatives to existing treatments for cutaneous Leishmaniasis, we have investigated the effect of Arnica tincture Ph. Eur. (a 70% hydroethanolic tincture prepared from flowerheads of Arnica montana L.) on the lesions caused by infection with Leishmania braziliensis in a model with golden hamsters. The animals were treated topically with a daily single dose of the preparation for 28 days. Subsequently, the healing process was monitored by recording the lesion size in intervals of 15 days up to day 90. As a result, Arnica tincture fully cured three out of five hamsters while one animal showed an improvement and another one suffered from a relapse. This result was slightly better than that obtained with the positive control, meglumine antimonate, which cured two of five hamsters while the other three showed a relapse after 90 days. This result encourages us to further investigate the potential of Arnica tincture in the treatment of cutaneous Leishmaniasis.

  19. 9 CFR 3.36 - Primary enclosures used to transport live guinea pigs and hamsters.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... live guinea pigs and hamsters. 3.36 Section 3.36 Animals and Animal Products ANIMAL AND PLANT HEALTH..., Care, Treatment, and Transportation of Guinea Pigs and Hamsters Transportation Standards § 3.36 Primary enclosures used to transport live guinea pigs and hamsters. No person subject to the Animal Welfare...

  20. 9 CFR 3.36 - Primary enclosures used to transport live guinea pigs and hamsters.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... live guinea pigs and hamsters. 3.36 Section 3.36 Animals and Animal Products ANIMAL AND PLANT HEALTH..., Care, Treatment, and Transportation of Guinea Pigs and Hamsters Transportation Standards § 3.36 Primary enclosures used to transport live guinea pigs and hamsters. No person subject to the Animal Welfare...

  1. 9 CFR 3.36 - Primary enclosures used to transport live guinea pigs and hamsters.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... live guinea pigs and hamsters. 3.36 Section 3.36 Animals and Animal Products ANIMAL AND PLANT HEALTH..., Care, Treatment, and Transportation of Guinea Pigs and Hamsters Transportation Standards § 3.36 Primary enclosures used to transport live guinea pigs and hamsters. No person subject to the Animal Welfare...

  2. 9 CFR 3.36 - Primary enclosures used to transport live guinea pigs and hamsters.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... live guinea pigs and hamsters. 3.36 Section 3.36 Animals and Animal Products ANIMAL AND PLANT HEALTH..., Care, Treatment, and Transportation of Guinea Pigs and Hamsters Transportation Standards § 3.36 Primary enclosures used to transport live guinea pigs and hamsters. No person subject to the Animal Welfare...

  3. 9 CFR 3.36 - Primary enclosures used to transport live guinea pigs and hamsters.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... live guinea pigs and hamsters. 3.36 Section 3.36 Animals and Animal Products ANIMAL AND PLANT HEALTH..., Care, Treatment, and Transportation of Guinea Pigs and Hamsters Transportation Standards § 3.36 Primary enclosures used to transport live guinea pigs and hamsters. No person subject to the Animal Welfare...

  4. Seasonal adaptation of dwarf hamsters (Genus Phodopus): differences between species and their geographic origin.

    PubMed

    Müller, D; Hauer, J; Schöttner, K; Fritzsche, P; Weinert, D

    2015-12-01

    The genus Phodopus consists of three species--P. campbelli (Pc), P. sungorus (Ps), and P. roborovskii (Pr). They inhabit steppes, semi-deserts, and deserts in continental Asia with a climate changing from a moderate to a hard Continental one with extreme daily and seasonal variations. These different environmental challenges are likely to have consequences for hamsters' morphology, physiology, and behavior. Hamsters of all three species were investigated during the course of the year in the laboratory though using natural lighting and temperature conditions. Motor activity and body temperature were measured continuously, and body mass, testes size, and fur coloration every 1-2 weeks. With regard to the pattern of activity, nearly twice as many Pc as Ps hamsters (25 vs. 14%) failed to respond to changes of photoperiod, whereas all Pr hamsters did. Body mass and testes size were high in summer and low in winter, with the biggest relative change in Ps and the lowest in Pr hamsters. Changes of fur coloration were found in Ps hamsters only. All responding animals (that is excluding Pr), exhibited regular torpor bouts during the short winter days. In autumn, seasonal changes started considerably earlier in Ps hamsters. To investigate the putative causes of these different time courses, a further experiment was performed, to identify the critical photoperiod. Hamsters were kept for 10 weeks under different photoperiods, changing from 16 to 8 h light per day. Motor activity was recorded continuously, to identify responding and non-responding animals. Body mass was measured at the beginning and the end of the experiment, testes mass only at the end. The critical photoperiod was found to be similar in all three species. Though in a further experiment, Pc and Pr hamsters showed a delayed response, whereas the changes in Ps hamsters started immediately following transfer to short-day conditions. The results show that interspecific differences in seasonal adaptation exist, even

  5. Yellow fever 17-D vaccine is neurotropic and produces encephalitis in immunosuppressed hamsters.

    PubMed

    Mateo, Rosa I; Xiao, Shu-Yuan; Travassos da Rosa, Amelia P A; Lei, Hao; Guzman, Hilda; Lu, Liang; Tesh, Robert B

    2007-11-01

    Immunosuppressed (cyclophosphamide) adult golden hamsters inoculated intraperitoneally (i.p.) with wild-type Asibi yellow fever virus (YFV) developed a rapidly fatal illness. Histopathologic and immunohistochemical studies of tissues from these animals showed typical hepatic changes of severe yellow fever (inflammation, hepatocyte necrosis, and steatosis) without brain involvement. In contrast, 50% of immunosuppressed hamsters receiving the YFV-17D-attenuated vaccine developed a slowly progressive encephalitic-type illness. Brain tissue from these latter animals revealed focal neuronal changes, inflammation, and YFV antigen-positive neurons; however, the liver and spleen appeared normal. YFV was isolated from brain cultures of many of these animals. Immunocompetent (non-immunosuppressed) hamsters inoculated with both viruses developed a subclinical infection. Results of this study indicate that wild-type YFV is hepatotropic in immunosuppressed hamsters, whereas the attenuated YFV-17 is primarily neurotropic. These findings support current recommendations against yellow fever vaccination of immunosuppressed/immunocompromised people and suggest that this hamster model might be useful for monitoring the safety of other live-attenuated YFV vaccines.

  6. Depopulation of the ventromedial hypothalamic nucleus in the diabetic Chinese hamster.

    PubMed

    Garris, D R; Diani, A R; Smith, C; Gerritsen, G C

    1982-01-01

    The relationship between diabetes and the size, density and area of the ventromedial hypothalamic nucleus (VMH) was studied in the genetically diabetic Chinese hamster. Matched diabetic and non-diabetic control chinese hamsters were perfused, the hypothalamus collected, sectioned and stained for light microscopy. The mid-point of each VMH nucleus was located, photographed and enlarged for morphometric analysis. Each neuron that possessed a nucleolus and was located within the confines of a VMH was counted, and subsequently the area of each nucleus and the density of neurons per area of VMH were calculated. The results indicated that both the area and absolute number of neurons within the VMH of diabetic hamsters were significantly reduced compared to control values (P less than 0.01) The density of neurons per unit area of VMH was similar in both groups. These data suggest that the VMH experiences a neuronal depopulation in diabetic hamsters which may have a functional influence on the hypothalamic-pancreatic axis in this species.

  7. Stimulation of islet cell proliferation enhances pancreatic ductal carcinogenesis in the hamster model.

    PubMed Central

    Pour, P. M.; Kazakoff, K.

    1996-01-01

    Previous studies have shown that some N-nitrosobis (2-oxopropyl)amine (BOP)-induced ductal/ductular pancreatic cancers in the hamster model develop within islets and that streptozotocin (SZ) pretreatment that caused islet degeneration and atrophy inhibits pancreatic cancer induction. Hence, it appears that in this model islets play a significant role in exocrine pancreatic carcinogenesis. To examine whether stimulation of islet cell proliferation (nesidioblastosis) enhances pancreatic exocrine cancer development, we tested the effect of the pancreatic carcinogen BOP in hamsters after induction of nesidioblastosis by cellophane wrapping. Before wrapping, hamsters were treated with SZ to inhibit pancreatic tumor induction in the unwrapped pancreatic tissues. Control groups with a wrapped pancreas did not receive SZ. Six weeks after SZ treatment, all hamsters were treated with BOP (10 mg/kg body weight) weekly for 10 weeks and the experiment was terminated 38 weeks after the last BOP treatment. Many animals recovered from their diabetes at the time when BOP was injected and many more after BOP treatment. Only nine hamsters remained diabetic until the end of the experiment. Both SZ-treated and control groups developed proliferative and malignant pancreatic ductal-type lesions primarily in the wrapped area (47%) but less frequently in the larger segments of the pancreas, including the splenic lobe (34%), gastric lobe (13%), and duodenal lobe (6%). Only a few lesions developed in the unwrapped pancreatic region of nine diabetic hamsters with atrophic islets, whereas seven of these hamsters had tumors in the wrapped area. Histologically, most tumors appeared to originate from islets, many invasive carcinomas had foci of islets, and some tumor cells showed reactivity with anti-insulin. The results show that, in the BOP hamster model, islets are the site of formation of the major fraction of exocrine pancreatic cancer and that induction of nesidioblastosis enhances

  8. Individual differences in circadian waveform of Siberian hamsters under multiple lighting conditions

    PubMed Central

    Evans, Jennifer A.; Elliott, Jeffrey A.; Gorman, Michael R.

    2013-01-01

    Because the circadian clock in the mammalian brain derives from a network of interacting cellular oscillators, characterizing the nature and bases of circadian coupling is fundamental to understanding how the pacemaker operates. Various phenomena involving plasticity in circadian waveform have been theorized to reflect changes in oscillator coupling; however, it remains unclear whether these different behavioral paradigms reference a unitary underlying process. To test if disparate coupling assays index a common mechanism, we examined whether there is co-variation among behavioral responses to various lighting conditions that produce changes in circadian waveform. Siberian hamsters, Phodopus sungorus, were transferred from long to short photoperiods to distinguish short photoperiod responders (SP-R) from non-responders (SP-NR). Short photoperiod chronotyped hamsters were subsequently transferred, along with unselected controls, to 24 h light:dark:light:dark cycles (LDLD) with dim nighttime illumination, a procedure that induces bifurcated entrainment. Under LDLD, SP-R hamsters were more likely to bifurcate their rhythms than SP-NR hamsters or unselected controls. After transfer from LDLD to constant dim light, SP-R hamsters were also more likely to become arrhythmic compared to SP-NR hamsters and unselected controls. In contrast, short photoperiod chronotype did not influence more transient changes in circadian waveform. The present data reveal a clear relationship in the plasticity of circadian waveform across three distinct lighting conditions, suggesting a common mechanism wherein individual differences reflect variation in circadian coupling. PMID:23010663

  9. Pineal-Induced Depression of Free Thyroxine in Syrian Hamsters

    DTIC Science & Technology

    1985-01-01

    activation by blind- ness in Syrian hamsters, can influence free 14 concentration. MATERIALS AND METHODS Male golden hamsters, Mesocricetus auratus...considered that the changes in T4 passively result from pineal- induced hypogonadism and the possible resultant effects on T4 serum bind- ing proteins...the presence of pineal-induced hypogonadism and that, like T4 and FT41, -• ’. 328 Vaughan and Pruitt TESrE S PROSTATE 0.6 80- 20 gn Mgm ,... =_ 9 Mg_

  10. A Syrian golden hamster model recapitulating ebola hemorrhagic fever.

    PubMed

    Ebihara, Hideki; Zivcec, Marko; Gardner, Donald; Falzarano, Darryl; LaCasse, Rachel; Rosenke, Rebecca; Long, Dan; Haddock, Elaine; Fischer, Elizabeth; Kawaoka, Yoshihiro; Feldmann, Heinz

    2013-01-15

    Ebola hemorrhagic fever (EHF) is a severe viral infection for which no effective treatment or vaccine is currently available. While the nonhuman primate (NHP) model is used for final evaluation of experimental vaccines and therapeutic efficacy, rodent models have been widely used in ebolavirus research because of their convenience. However, the validity of rodent models has been questioned given their low predictive value for efficacy testing of vaccines and therapeutics, a result of the inconsistent manifestation of coagulopathy seen in EHF. Here, we describe a lethal Syrian hamster model of EHF using mouse-adapted Ebola virus. Infected hamsters displayed most clinical hallmarks of EHF, including severe coagulopathy and uncontrolled host immune responses. Thus, the hamster seems to be superior to the existing rodent models, offering a better tool for understanding the critical processes in pathogenesis and providing a new model for evaluating prophylactic and postexposure interventions prior to testing in NHPs.

  11. Regulation of lipid metabolism by obeticholic acid in hyperlipidemic hamsters[S

    PubMed Central

    Dong, Bin; Young, Mark; Liu, Xueqing; Singh, Amar Bahadur; Liu, Jingwen

    2017-01-01

    The farnesoid X receptor (FXR) plays critical roles in plasma cholesterol metabolism, in particular HDL-cholesterol (HDL-C) homeostasis. Obeticholic acid (OCA) is a FXR agonist being developed for treating various chronic liver diseases. Previous studies reported inconsistent effects of OCA on regulating plasma cholesterol levels in different animal models and in different patient populations. The mechanisms underlying its divergent effects have not yet been thoroughly investigated. The scavenger receptor class B type I (SR-BI) is a FXR-modulated gene and the major receptor for HDL-C. We investigated the effects of OCA on hepatic SR-BI expression and correlated such effects with plasma HDL-C levels and hepatic cholesterol efflux in hyperlipidemic hamsters. We demonstrated that OCA induced a time-dependent reduction in serum HDL-C levels after 14 days of treatment, which was accompanied by a significant reduction of liver cholesterol content and increases in fecal cholesterol in OCA-treated hamsters. Importantly, hepatic SR-BI mRNA and protein levels in hamsters were increased to 1.9- and 1.8-fold of control by OCA treatment. Further investigations in normolipidemic hamsters did not reveal OCA-induced changes in serum HDL-C levels or hepatic SR-BI expression. We conclude that OCA reduces plasma HDL-C levels and promotes transhepatic cholesterol efflux in hyperlipidemic hamsters via a mechanism involving upregulation of hepatic SR-BI. PMID:27940481

  12. Prevention by cromakalim of spontaneously occurring cardiac necroses in polymyopathic hamsters.

    PubMed

    Jasmin, G; Proschek, L

    1996-11-01

    Previous studies on the heart necrotizing process at early stages of the hamster polymyopathy have led us to believe that this hereditary disease derives from a defective transmembrane ion flux resulting in myocardial Ca2+ over-load. On the other hand, certain K+ ATP channel openers were shown to prevent cytosolic Ca2+ accumulation in ischemic hearts. Therefore, we investigated the potential beneficial effect of chronic treatment with cromakalim (CR) on the development of necrotic changes in hamster myopathic hearts. Young cardiomyopathic (CM) hamsters were treated parenterally with CR over 4 consecutive weeks. The K+ ATP opener was dissolved in 5% DMSO and injected twice daily (s.c. and i.p. alternatively) at a dose level of 2.5 mg/kg per injection. Microscopic readings were carried out in staged serial paraffin sections of heart ventricles, the diaphragm, and tongue, will all tissues freshly taken at autopsy. In comparison with control untreated hearts, which exhibit numerous necrotic calcific foci, only minute myolytic lesions were found in 5 of 12 hamsters hearts receiving CR (p < 0.0001). Interestingly, the dystrophic process in the tongue was significantly less severe (p < 0.0004) in CR-treated animals. These observations provide evidence for the first time that in vivo sustained treatment with a K+ ATP opener exerts cardioprotection upon development of the hamster hereditary cardiomyopathy.

  13. Dopamine mediates testosterone-induced social reward in male Syrian hamsters.

    PubMed

    Bell, Margaret R; Sisk, Cheryl L

    2013-03-01

    Adolescent maturation of responses to social stimuli is essential for adult-typical sociosexual behavior. Naturally occurring developmental changes in male Syrian hamster responses to a salient social cue, female hamster vaginal secretions (VS), provide a good model system for investigating neuroendocrine mechanisms of adolescent change in social reward. Sexually naïve adult, but not juvenile, males show a conditioned place preference (CPP) to VS, indicating that VS is not rewarding before puberty. In this series of experiments, the authors examined the roles of testosterone and dopamine receptor activation in mediating the adolescent gain in positive valence of VS. Experiment 1 showed that testosterone replacement is necessary for gonadectomized adult hamsters to form a CPP to VS. Experiment 2 showed that testosterone treatment is sufficient for juvenile hamsters to form a CPP to VS, and that the dopamine receptor antagonist haloperidol blocks formation of a CPP to VS in these animals. Experiments 3 and 4 demonstrated that the disruption of VS CPP with low doses of haloperidol is the result of a reduction in the attractive properties of VS and not attributable to aversive properties of haloperidol. Together, these studies demonstrate that the unconditioned rewarding properties of a social cue necessary for successful adult sociosexual interactions come about as the result of the pubertal increase in circulating testosterone in male hamsters. Furthermore, this social reward can be prevented by dopamine receptor antagonism, indicating that hypothalamic and/or mesocorticolimbic dopaminergic circuits are targets for hormonal activation of social reward.

  14. Syrian Hamster as an Animal Model for the Study of Human Influenza Virus Infection.

    PubMed

    Iwatsuki-Horimoto, Kiyoko; Nakajima, Noriko; Ichiko, Yurie; Sakai-Tagawa, Yuko; Noda, Takeshi; Hasegawa, Hideki; Kawaoka, Yoshihiro

    2018-02-15

    Ferrets and mice are frequently used as animal models for influenza research. However, ferrets are demanding in terms of housing space and handling, whereas mice are not naturally susceptible to infection with human influenza A or B viruses. Therefore, prior adaptation of human viruses is required for their use in mice. In addition, there are no mouse-adapted variants of the recent H3N2 viruses, because these viruses do not replicate well in mice. In this study, we investigated the susceptibility of Syrian hamsters to influenza viruses with a view to using the hamster model as an alternative to the mouse model. We found that hamsters are sensitive to influenza viruses, including the recent H3N2 viruses, without adaptation. Although the hamsters did not show weight loss or clinical signs of H3N2 virus infection, we observed pathogenic effects in the respiratory tracts of the infected animals. All of the H3N2 viruses tested replicated in the respiratory organs of the hamsters, and some of them were detected in the nasal washes of infected animals. Moreover, a 2009 pandemic (pdm09) virus and a seasonal H1N1 virus, as well as one of the two H3N2 viruses, but not a type B virus, were transmissible by the airborne route in these hamsters. Hamsters thus have the potential to be a small-animal model for the study of influenza virus infection, including studies of the pathogenicity of H3N2 viruses and other strains, as well as for use in H1N1 virus transmission studies. IMPORTANCE We found that Syrian hamsters are susceptible to human influenza viruses, including the recent H3N2 viruses, without adaptation. We also found that a pdm09 virus and a seasonal H1N1 virus, as well as one of the H3N2 viruses, but not a type B virus tested, are transmitted by the airborne route in these hamsters. Syrian hamsters thus have the potential to be used as a small-animal model for the study of human influenza viruses. Copyright © 2018 American Society for Microbiology.

  15. Proteomics analysis identified peroxiredoxin 2 involved in early-phase left ventricular impairment in hamsters with cardiomyopathy.

    PubMed

    Kuzuya, Kentaro; Ichihara, Sahoko; Suzuki, Yuka; Inoue, Chisa; Ichihara, Gaku; Kurimoto, Syota; Oikawa, Shinji

    2018-01-01

    Given the hypothesis that inflammation plays a critical role in the progression of cardiovascular diseases, the aim of the present study was to identify new diagnostic and prognostic biomarkers of myocardial proteins involved in early-phase cardiac impairment, using proteomics analysis. Using the two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) combined with MALDI-TOF/TOF tandem mass spectrometry, we compared differences in the expression of proteins in the whole left ventricles between control hamsters, dilated cardiomyopathic hamsters (TO-2), and hypertrophy cardiomyopathic hamsters (Bio14.6) at 6 weeks of age (n = 6, each group). Proteomic analysis identified 10 protein spots with significant alterations, with 7 up-regulated and 3 down-regulated proteins in the left ventricles of both TO-2 and Bio 14.6 hamsters, compared with control hamsters. Of the total alterations, peroxiredoxin 2 (PRDX2) showed significant upregulation in the left ventricles of TO-2 and Bio 14.6 hamsters. Our data suggest that PRDX2, a redox regulating molecule, is involved in early-phase left ventricular impairment in hamsters with cardiomyopathy.

  16. Molecular Prerequisites for Diminished Cold Sensitivity in Ground Squirrels and Hamsters.

    PubMed

    Matos-Cruz, Vanessa; Schneider, Eve R; Mastrotto, Marco; Merriman, Dana K; Bagriantsev, Sviatoslav N; Gracheva, Elena O

    2017-12-19

    Thirteen-lined ground squirrels and Syrian hamsters are known for their ability to withstand cold during hibernation. We found that hibernators exhibit cold tolerance even in the active state. Imaging and electrophysiology of squirrel somatosensory neurons reveal a decrease in cold sensitivity of TRPM8-expressing cells. Characterization of squirrel and hamster TRPM8 showed that the channels are chemically activated but exhibit poor activation by cold. Cold sensitivity can be re-introduced into squirrel and hamster TRPM8 by transferring the transmembrane domain from the cold sensitive rat ortholog. The same can be achieved in squirrel TRPM8 by mutating only six amino acids. Reciprocal mutations suppress cold sensitivity of the rat ortholog, supporting functional significance of these residues. Our results suggest that ground squirrels and hamsters exhibit reduced cold sensitivity, partially due to modifications in the transmembrane domain of TRPM8. Our study reveals molecular adaptations that accompany cold tolerance in two species of mammalian hibernators. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  17. A Syrian Golden Hamster Model Recapitulating Ebola Hemorrhagic Fever

    PubMed Central

    Ebihara, Hideki; Zivcec, Marko; Gardner, Donald; Falzarano, Darryl; LaCasse, Rachel; Rosenke, Rebecca; Long, Dan; Haddock, Elaine; Fischer, Elizabeth; Kawaoka, Yoshihiro; Feldmann, Heinz

    2013-01-01

    Ebola hemorrhagic fever (EHF) is a severe viral infection for which no effective treatment or vaccine is currently available. While the nonhuman primate (NHP) model is used for final evaluation of experimental vaccines and therapeutic efficacy, rodent models have been widely used in ebolavirus research because of their convenience. However, the validity of rodent models has been questioned given their low predictive value for efficacy testing of vaccines and therapeutics, a result of the inconsistent manifestation of coagulopathy seen in EHF. Here, we describe a lethal Syrian hamster model of EHF using mouse-adapted Ebola virus. Infected hamsters displayed most clinical hallmarks of EHF, including severe coagulopathy and uncontrolled host immune responses. Thus, the hamster seems to be superior to the existing rodent models, offering a better tool for understanding the critical processes in pathogenesis and providing a new model for evaluating prophylactic and postexposure interventions prior to testing in NHPs. PMID:23045629

  18. [Purification of arsenic-binding proteins in hamster plasma after oral administration of arsenite].

    PubMed

    Wang, Wenwen; Zhang, Min; Li, Chunhui; Qin, Yingjie; Hua, Naranmandura

    2013-01-01

    To purify the arsenic-binding proteins (As-BP) in hamster plasma after a single oral administration of arsenite (iAs(III)). Arsenite was given to hamsters in a single dose. Three types of HPLC columns, size exclusion, gel filtration and anion exchange columns, combined with an inductively coupled argon plasma mass spectrometer (ICP MS) were used to purify the As-BP in hamster plasma. SDS-PAGE was used to confirm the arsenic-binding proteins at each purification step. The three-step purification process successfully separated As-BP from other proteins (ie, arsenic unbound proteins) in hamster plasma. The molecular mass of purified As-BP in plasma was approximately 40-50 kD on SDS-PAGE. The three-step purification method is a simple and fast approach to purify the As-BP in plasma samples.

  19. Role of photoperiod and melatonin in seasonal acclimatization of the djungarian hamster, Phodopus sungorus

    NASA Astrophysics Data System (ADS)

    Steinlechner, S.; Heldmaier, G.

    1982-12-01

    The Djungarian hamster, Phodopus sungorus, shows a clear annual cycle in some thermogenic parameters such as nonshivering thermogenesis (NST) and cold resistance. These seasonal changes were found to be basically controlled by natural changes in photoperiod. Further support for this view was obtained by exposing the hamsters to artificial long and short photoperiods. Implantation of melatonin during fall and winter results in an increased thermogenic capacity in both short and long day hamsters comparable to that shown by values of control hamsters exposed to short photoperiods during winter. This thermotropic action of melatonin and of short photoperiod could be found only in fall and winter whereas during spring and summer, melatonin, like photoperiod, had no influence on thermogenic capacities. These results show that the actions of melatonin and photoperiod vary with the season and that they depend upon the photoperiodic history of the hamsters. Our results further indicate that the pineal gland with its hormone melatonin is involved in mediation of photoperiodic control of seasonal acclimatization.

  20. Secondhand smoke induces hepatic apoptosis and fibrosis in hamster fetus.

    PubMed

    Huang, Chien-Wei; Horng, Chi-Ting; Huang, Chih-Yang; Cho, Ta-Hsiung; Tsai, Yi-Chang; Chen, Li-Jeng; Hsu, Tsai-Ching; Tzang, Bor-Show

    2016-09-01

    Secondhand smoke (SHS) is an important health issue worldwide. Inhaling SHS during pregnancy could cause abnormalities in the internal tissues of newborns, which may then impair fetal development and even cause severe intrauterine damage and perinatal death. However, the understanding of cytopathic mechanisms of SHS by maternal passive smoking on fetus liver during pregnancy is still limited. This study analyzed the effects of high-dose SHS (SHSH) on fetus liver using a maternal passive smoking animal model. Experiments showed that hepatic matrix metalloproteinase-9 activity and terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling-positive cells were significantly increased in livers from fetuses of hamsters treated with SHSH. Similarly, expressions of both extrinsic and intrinsic apoptotic molecules were significantly higher in livers from fetuses of hamsters exposed to SHSH. Additionally, significantly increased inflammatory proteins, including transforming growth factor β, inducible nitric oxide synthase, and interleukin 1β, and fibrotic signaling molecules, including phosphorylated Smad2/3, SP1, and α-smooth muscle actin, were observed in the fetus livers from hamsters treated with SHSH. This study revealed that SHSH not only increased apoptosis through intrinsic and extrinsic pathways in the livers of fetuses from hamsters exposed to SHSH but also augmented hepatic fibrosis via Smad2/3 signaling. © The Author(s) 2015.

  1. A new species of Giardia Künstler, 1882 (Sarcomastigophora: Hexamitidae) in hamsters.

    PubMed

    Lyu, Zhangxia; Shao, Jingru; Xue, Min; Ye, Qingqing; Chen, Bing; Qin, Yan; Wen, Jianfan

    2018-03-20

    Giardia spp. are flagellated protozoan parasites that infect humans and many other vertebrates worldwide. Currently seven species of Giardia are considered valid. Here, we report a new species, Giardia cricetidarum n. sp. in hamsters. Trophozoites of G. cricetidarum n. sp. are pear-shaped with four pairs of flagella and measure on average 14 μm (range 12-18 μm) in length and 10 μm (range 8-12 μm) in width. The trophozoites of the new species are generally larger and stouter than those of most of the other Giardia spp. and exhibit the lowest length/width ratio (c.1.40) of all recognized Giardia species. Cysts of G. cricetidarum n. sp. are ovoid and measure on average 11 μm (range 9-12 μm) in length and 10 μm (range 8-10 μm) in width and are indistinguishable from the cysts of other Giardia species. Molecular phylogenetic analyses based on beta-giardin, small subunit rRNA, and elongation factor-1 alpha loci all demonstrated that G. cricetidarum n. sp. is genetically distinct from all currently accepted Giardia spp. Investigation of the host range indicated that the new species was only found in hamsters (including Phodopus sungorus, P. campbelli and Mesocricetus auratus), while all the other described mammal-parasitizing species (G. muris, G. microti and G. intestinalis) each infect multiple hosts. Cross-transmission studies further demonstrated the apparent host specificity of G. cricetidarum n. sp. as it only infected hamsters. Trophozoites were found in high numbers in hamster intestines (5 × 10 5 - 5 × 10 6 ) and was rarely detected co-infecting with other Giardia spp. in the common hamster, suggesting it has some advantages in parasitizing hamsters. This study has identified a new species of Giardia, which appears to be specific to hamsters, and together with the three other mammal-parasitizing Giardia species with different host ranges, may be able to be used as a model system for the study of evolutionary divergence of host parasitism strategies in

  2. Purification and characterization of an antioxidant glycoprotein from the hydrolysate of Mustelus griseus.

    PubMed

    Li, Zhongrui; Wang, Bin; Chi, Changfeng; Gong, Yandan; Tang, Jiajia; Luo, Hongyu

    2013-01-01

    An antioxidant glycoprotein (Fraction AIV-2) with molecular weight of 27.2 kDa was purified from the ethanol-soluble protein hydrolysate of Mustelus griseus muscle. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of Fraction AIV-2 reached up to 96.73±2.33% and was higher than that of ascorbic acid at the concentration of 5.0mg/mL. Total protein and carbohydrate contents of Fraction AIV-2 were 62.65±0.63% and 33.49±1.60%, respectively. Seventeen amino acids were identified in Fraction AIV-2, most of which are serine. GC-MS analysis showed that Fraction AIV-2 was composed of fucose, arabinose, galactose, glucose and mannose with the ratio of 1.00:1.53:7.27:9.07:2.09. The FT-IR spectrum of Fraction AIV-2 showed typical characteristics of polysaccharide and protein. For Fraction AIV-2, the changes of ultraviolet absorption curve, amino acid composition after the β-elimination reaction and its deglycosylation with the treatment of N-glycosidase F suggested that both O-glycosidic and N-glycosidic bonds were involved in the polysaccharide and protein moieties. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. A Comparison of Hamster Anesthetics and Their Effect on Mosquito Blood Feeding

    USDA-ARS?s Scientific Manuscript database

    Hamsters or mice are often anesthetized when they are used as the hosts for insect feeding experiments. An experiment was done to determine if there was a difference in mosquito blood feeding success when fed on hamsters anesthetized using two commonly used protocols. The number of blood-fed females...

  4. The pathophysiology of human obstructive cholestasis is mimicked in cholestatic Gold Syrian hamsters.

    PubMed

    van Golen, Rowan F; Olthof, Pim B; de Haan, Lianne R; Coelen, Robert J; Pechlivanis, Alexandros; de Keijzer, Mark J; Weijer, Ruud; de Waart, Dirk R; van Kuilenburg, André B P; Roelofsen, Jeroen; Gilijamse, Pim W; Maas, Martinus A; Lewis, Matthew R; Nicholson, Jeremy K; Verheij, Joanne; Heger, Michal

    2018-03-01

    Obstructive cholestasis causes liver injury via accumulation of toxic bile acids (BAs). Therapeutic options for cholestatic liver disease are limited, partially because the available murine disease models lack translational value. Profiling of time-related changes following bile duct ligation (BDL) in Gold Syrian hamsters revealed a biochemical response similar to cholestatic patients in terms of BA pool composition, alterations in hepatocyte BA transport and signaling, suppression of BA production, and adapted BA metabolism. Hamsters tolerated cholestasis well for up to 28days and progressed relatively slowly to fibrotic liver injury. Hepatocellular necrosis was absent, which coincided with preserved intrahepatic energy levels and only mild oxidative stress. The histological response to cholestasis in hamsters was similar to the changes seen in 17 patients with prolonged obstructive cholestasis caused by cholangiocarcinoma. Hamsters moreover upregulated hepatic fibroblast growth factor 15 (Fgf15) expression in response to BDL, which is a cytoprotective adaptation to cholestasis that hitherto had only been documented in cholestatic human livers. Hamster models should therefore be added to the repertoire of animal models used to study the pathophysiology of cholestatic liver disease. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Impact of wheel running on chronic ethanol intake in aged Syrian hamsters.

    PubMed

    Brager, Allison J; Hammer, Steven B

    2012-10-10

    Alcohol dependence in aging populations is seen as a public health concern, most recently because of the significant proportion of heavy drinking among "Baby Boomers." Basic animal research on the effects of aging on physiological and behavioral regulation of ethanol (EtOH) intake is sparse, since most of this research is limited to younger models of alcoholism. Here, EtOH drinking and preference were measured in groups of aged Syrian hamsters. Further, because voluntary exercise (wheel-running) is a rewarding substitute for EtOH in young adult hamsters, the potential for such reward substitution was also assessed. Aged (24 month-old) male hamsters were subjected to a three-stage regimen of free-choice EtOH (20% v/v) or water and unlocked or locked running wheels to investigate the modulatory effects of voluntary wheel running on EtOH intake and preference. Levels of fluid intake and activity were recorded daily across 60 days of experimentation. Prior to wheel running, levels of EtOH intake were significantly less than levels of water intake, resulting in a low preference for EtOH (30%). Hamsters with access to an unlocked running wheel had decreased EtOH intake and preference compared with hamsters with access to a locked running wheel. These group differences in EtOH intake and preference were sustained for up to 10 days after running wheels were re-locked. These results extend upon those of our previous work in young adult hamsters, indicating that aging dampens EtOH intake and preference. Voluntary wheel running further limited EtOH intake, suggesting that exercise could offer a practical approach for managing late-life alcoholism. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Acute encephalitis, a poliomyelitis-like syndrome and neurological sequelae in a hamster model for flavivirus infections.

    PubMed

    Leyssen, Pieter; Croes, Romaric; Rau, Philipp; Heiland, Sabine; Verbeken, Erik; Sciot, Raphael; Paeshuyse, Jan; Charlier, Nathalie; De Clercq, Erik; Meyding-Lamadé, Uta; Neyts, Johan

    2003-07-01

    Infection of hamsters with the murine flavivirus Modoc results in (meningo)encephalitis, which is, during the acute phase, frequently associated with flaccid paralysis, as also observed in patients with West Nile virus encephalitis. Twenty percent of the hamsters that recover from the acute encephalitis develop life-long neurological sequelae, reminiscent of those observed, for example, in survivors of Japanese encephalitis. Magnetic resonance imaging and histology revealed severe lesions predominantly located in the olfactory-limbic system, both in hamsters with acute encephalitis as in survivors. Prominent pathology was also detected in the spinal cord of hamsters with paralysis. Modoc virus infections in hamsters provide a unique model for the study of encephalitis, a poliomyelitis-like syndrome and neurological sequelae following flavivirus infection.

  7. A Lethal Disease Model for Hantavirus Pulmonary Syndrome in Immunosuppressed Syrian Hamsters Infected with Sin Nombre Virus

    PubMed Central

    Brocato, Rebecca L.; Hammerbeck, Christopher D.; Bell, Todd M.; Wells, Jay B.; Queen, Laurie A.

    2014-01-01

    Sin Nombre virus (SNV) is a rodent-borne hantavirus that causes hantavirus pulmonary syndrome (HPS) predominantly in North America. SNV infection of immunocompetent hamsters results in an asymptomatic infection; the only lethal disease model for a pathogenic hantavirus is Andes virus (ANDV) infection of Syrian hamsters. Efforts to create a lethal SNV disease model in hamsters by repeatedly passaging virus through the hamster have demonstrated increased dissemination of the virus but no signs of disease. In this study, we demonstrate that immunosuppression of hamsters through the administration of a combination of dexamethasone and cyclophosphamide, followed by infection with SNV, results in a vascular leak syndrome that accurately mimics both HPS disease in humans and ANDV infection of hamsters. Immunosuppressed hamsters infected with SNV have a mean number of days to death of 13 and display clinical signs associated with HPS, including pulmonary edema. Viral antigen was widely detectable throughout the pulmonary endothelium. Histologic analysis of lung sections showed marked inflammation and edema within the alveolar septa of SNV-infected hamsters, results which are similar to what is exhibited by hamsters infected with ANDV. Importantly, SNV-specific neutralizing polyclonal antibody administered 5 days after SNV infection conferred significant protection against disease. This experiment not only demonstrated that the disease was caused by SNV, it also demonstrated the utility of this animal model for testing candidate medical countermeasures. This is the first report of lethal disease caused by SNV in an adult small-animal model. PMID:24198421

  8. A lethal disease model for hantavirus pulmonary syndrome in immunosuppressed Syrian hamsters infected with Sin Nombre virus.

    PubMed

    Brocato, Rebecca L; Hammerbeck, Christopher D; Bell, Todd M; Wells, Jay B; Queen, Laurie A; Hooper, Jay W

    2014-01-01

    Sin Nombre virus (SNV) is a rodent-borne hantavirus that causes hantavirus pulmonary syndrome (HPS) predominantly in North America. SNV infection of immunocompetent hamsters results in an asymptomatic infection; the only lethal disease model for a pathogenic hantavirus is Andes virus (ANDV) infection of Syrian hamsters. Efforts to create a lethal SNV disease model in hamsters by repeatedly passaging virus through the hamster have demonstrated increased dissemination of the virus but no signs of disease. In this study, we demonstrate that immunosuppression of hamsters through the administration of a combination of dexamethasone and cyclophosphamide, followed by infection with SNV, results in a vascular leak syndrome that accurately mimics both HPS disease in humans and ANDV infection of hamsters. Immunosuppressed hamsters infected with SNV have a mean number of days to death of 13 and display clinical signs associated with HPS, including pulmonary edema. Viral antigen was widely detectable throughout the pulmonary endothelium. Histologic analysis of lung sections showed marked inflammation and edema within the alveolar septa of SNV-infected hamsters, results which are similar to what is exhibited by hamsters infected with ANDV. Importantly, SNV-specific neutralizing polyclonal antibody administered 5 days after SNV infection conferred significant protection against disease. This experiment not only demonstrated that the disease was caused by SNV, it also demonstrated the utility of this animal model for testing candidate medical countermeasures. This is the first report of lethal disease caused by SNV in an adult small-animal model.

  9. Leptin mediates seasonal variation in some but not all symptoms of sickness in Siberian hamsters

    PubMed Central

    Carlton, Elizabeth D.; Demas, Gregory E.

    2014-01-01

    Many seasonally breeding species, including Siberian hamsters (Phodopus sungorus), exhibit seasonal variation in sickness responses. One hypothesis regarding the mechanism of this variation is that sickness intensity tracks an animal's energetic state, such that sickness is attenuated in the season that an animal has the lowest fat stores. Energetic state may be signaled via leptin, an adipose hormone that provides a signal of fat stores. Siberian hamsters respond to extended housing in short, winter-like days by reducing fat stores and leptin levels, relative to those housed in long, summer-like days. Sickness responses are also attenuated in short-day hamsters as compared to long-day hamsters. We hypothesized that leptin provides a physiological signal by which seasonally breeding animals modulate sickness responses, such that animals with higher leptin levels show increased sickness intensity. To test this, we provided short-day hamsters with a long-day-like leptin signal and assessed their responses to lipopolysaccharide (LPS), a sickness-inducing antigen. We compared these responses to short-day vehicle-, long-day vehicle-, and long-day leptin-treated hamsters. Unexpectedly, LPS induced a hypothermic response (rather than fever) in all groups. Short-day vehicle-treated hamsters exhibited the greatest LPS-induced hypothermia, and leptin treatment attenuated this response, making hypothermia more long-day-like. Contrary to our hypothesis, short-day leptin-treated hamsters showed the least pronounced LPS-induced anorexia among all groups. These results suggest that leptin may mediate some but not all aspects of seasonal sickness variation in this species. Future studies should be targeted at determining roles of other energetic hormones in regulating seasonal sickness response variation. PMID:25461974

  10. Vasopressin differentially modulates aggression and anxiety in adolescent hamsters administered anabolic steroids.

    PubMed

    Morrison, Thomas R; Ricci, Lesley A; Melloni, Richard H

    2016-11-01

    Adolescent Syrian hamsters (Mesocricetus auratus) treated with anabolic/androgenic steroids display increased offensive aggression and decreased anxiety correlated with an increase in vasopressin afferent development, synthesis, and neural signaling within the anterior hypothalamus. Upon withdrawal from anabolic/androgenic steroids, this neurobehavioral relationship shifts as hamsters display decreased offensive aggression and increased anxiety correlated with a decrease in anterior hypothalamic vasopressin. This study investigated the hypothesis that alterations in anterior hypothalamic vasopressin neural signaling modulate behavioral shifting between adolescent anabolic/androgenic steroid-induced offensive aggression and anxiety. To test this, adolescent male hamsters were administered anabolic/androgenic steroids and tested for offensive aggression or anxiety following direct pharmacological manipulation of vasopressin V1A receptor signaling within the anterior hypothalamus. Blockade of anterior hypothalamic vasopressin V1A receptor signaling suppressed offensive aggression and enhanced general and social anxiety in hamsters administered anabolic/androgenic steroids during adolescence, effectively reversing the pattern of behavioral response pattern normally observed during the adolescent exposure period. Conversely, activation of anterior hypothalamic vasopressin V1A receptor signaling enhanced offensive aggression in hamsters exposed to anabolic/androgenic steroids during adolescence. Together, these findings suggest that the state of vasopressin neural development and signaling in the anterior hypothalamus plays an important role in behavioral shifting between aggression and anxiety following adolescent exposure to anabolic/androgenic steroids. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Vasopressin Differentially Modulates Aggression and Anxiety in Adolescent Hamsters Administered Anabolic Steroids

    PubMed Central

    Morrison, Thomas R.; Ricci, Lesley A.; Melloni, Richard H.

    2016-01-01

    Adolescent Syrian hamsters (Mesocricetus auratus) treated with anabolic/androgenic steroids display increased offensive aggression and decreased anxiety correlated with an increase in vasopressin afferent development, synthesis, and neural signaling within the anterior hypothalamus. Upon withdrawal from anabolic/androgenic steroids, this neurobehavioral relationship shifts as hamsters display decreased offensive aggression and increased anxiety correlated with a decrease in anterior hypothalamic vasopressin. This study investigated the hypothesis that alterations in anterior hypothalamic vasopressin neural signaling modulate behavioral shifting between adolescent anabolic/androgenic steroid-induced offensive aggression and anxiety. To test this, adolescent male hamsters were administered anabolic/androgenic steroids and tested for offensive aggression or anxiety following direct pharmacological manipulation of vasopressin V1A receptor signaling within the anterior hypothalamus. Blockade of anterior hypothalamic vasopressin V1A receptor signaling suppressed offensive aggression and enhanced general and social anxiety in hamsters administered anabolic/androgenic steroids during adolescence, effectively reversing the pattern of behavioral response pattern normally observed during the adolescent exposure period. Conversely, activation of anterior hypothalamic vasopressin V1A receptor signaling enhanced offensive aggression in hamsters exposed to anabolic/androgenic steroids during adolescence. Together, these findings suggest that the state of vasopressin neural development and signaling in the anterior hypothalamus plays an important role in behavioral shifting between aggression and anxiety following adolescent exposure to anabolic/androgenic steroids. PMID:27149949

  12. Chronic inhalation exposure of hamsters to nickel-enriched fly ash

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wehner, A.P.; Dagle, G.E.; Milliman, E.M.

    1981-10-01

    Hamsters were chronically exposed to approx.70 ..mu..g/liter respirable nickel-enriched fly ash (NEFA) aerosol, approx.17 ..mu..g/liter NEFA, or approx.70 ..mu..g/liter fly ash (FA) for up to 20 months. A control group received sham exposures. The NEFA particles of respirable size contained approximately 6% nickel, compared to about 0.3% for FA. Five hamsters/group were sacrificed after 4, 8, 12, or 16 months of exposure. An additional five hamsters/group were withdrawn from exposure at the same intervals for lifelong observations. Exposures to NEFA had no significant effect on body weight and life span of the animals although heavy deposits of NEFA in themore » lungs were demonstrated. However, lung weights of the high NEFA- and of the FA-exposed animals were significantly higher than those of the low-NEFA group and the controls, and mean lung volumes were significantly larger for the high-NEFA grop and the FA group than for the low-NEFA group and the controls. Dust was deposited (anthracosis) in the lungs of all exposed hamsters. Incidence and severity of interstitial reaction and bronchiolization were significantly higher in the dust-exposed groups than in the sham-exposed controls. The severity of anthracosis, interstitial reaction, and bronchiolization was significantly lower in the low-NEFA group than in the high-NEFA and FA groups. While two malignant primary thorax tumors were found in two hamsters of the high-NEFA group, no statistically significant carcinogenesis was observed. Of the exposure-related changes, only anthracosis decreased after withdrawal from exposure. Pulmonary nickel burdens after 20 months of exposure suggest that the pulmonary clearance rate was slower in the high-NEFA group than in the low-NEFA group.« less

  13. Characterisation of monoclonal antibodies specific for hamster leukocyte differentiation molecules.

    PubMed

    Rees, Jennifer; Haig, David; Mack, Victoria; Davis, William C

    2017-01-01

    Flow cytometry was used to identify mAbs that recognize conserved epitopes on hamster leukocyte differentiation molecules (hLDM) and also to characterize mAbs developed against hLDM. Initial screening of mAbs developed against LDMs in other species yielded mAbs specific for the major histocompatibility (MHC) II molecule, CD4 and CD18. Screening of sets of mAbs developed against hLDM yielded 22 new mAbs, including additional mAbs to MHC II molecules and mAbs that recognize LDMs expressed on all leukocytes, granulocytes, all lymphocytes, all T cells, a subset of T cells, or on all B cells. Based on comparison of the pattern of expression of LDMs expressed on all hamster leukocytes with the patterns of expression of known LDMs in other species, as detected by flow cytometry (FC), four mAbs are predicted to recognize CD11a, CD44, and CD45. Cross comparison of mAbs specific for a subset of hamster T cells with a cross reactive mAb known to recognize CD4 in mice and one recognising CD8 revealed they recognize CD4. The characterization of these mAbs expands opportunities to use hamsters as an additional model species to investigate the mechanisms of immunopathogenesis of infectious diseases. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  14. [Decorative forms of hamsters Phodopus (Mammalia, Cricetinae): an analysis of genetic lines distribution and peculiarities of hair changes].

    PubMed

    Feoktistova, N Iu; Chernova, O F; Meshcherskiĭ, I G

    2012-01-01

    Three species of dwarf hamsters (genus Phodopus, family Cricetidae) inhabit some regions of Russia, Kazakhstan, Mongolia, and China, each having quite extensive range. In recent decades, the dwarf hamsters became widely spread all over the world, initially as laboratory animals and later as popular pets. By now, there is lot of decorative breed lines and colored forms of these animals. Comparison of mtDNA nucleotide sequences of dwarf hamsters acquired in pet shops of some countries in Europe, South-East Asia and North America with distribution of mtDNA haplotypes within natural ranges showed the limitation of decorative line founders' points of origin by one region for each of the species. All haplotypes found in decorative Dzungarian hamsters (Ph. sungorus) purchased ounside Russia coincide with or are significantly close to haplotypes spread in the southern part of West Siberia (Russia) and adjacent regions of Kazakhstan; haplotypes of decorative Campbell's hamster (Ph. campbelli) belong to haplogroup of this species natural populations inhabiting South Tyva (Russia); and all studied decorative Desert hamsters (Ph. roborovskii) had one hapotype specific for South-Eastern Kazakhstan. The review of the history of researches on dwarf hamsters biology allows to determine delivery of hamsters from mentioned regions to scientific laboratories and zoos by certain expeditions and/or researchers. Unlike hamsters with natural hair color, the colored hamsters have no normal hair. Their hair is dull and straggly. The hair differentiation (presence of different hair types and their size characteristics) gets broken and results in deformation, bending, and splitting of the shaft, cracks in cuticle, change of configuration and location of medulla, uneven development of cortex. It is assumed that these destructive changes are associated with genetic characteristics of these hamsters' colored forms.

  15. Circadian body temperature variability is an indicator of poor prognosis in cardiomyopathic hamsters.

    PubMed

    Ahmed, Amany; Gondi, Sreedevi; Cox, Casey; Wang, Suwei; Stupin, Igor V; Shankar, K J; Munir, Shahzeb M; Sobash, Ed; Brewer, Alan; Ferguson, James J; Elayda, Macarthur A; Casscells, S Ward; Wilson, James M

    2010-03-01

    Low body temperature is an independent predictor of poor prognosis in patients with congestive heart failure. The cardiomyopathic hamster develops progressive biventricular dysfunction, resulting in heart failure death at 9 months to 1 year of life. Our goal was to use cardiomyopathic hamsters to examine the relationship between body temperature and heart failure decompensation and death. To this end, we implanted temperature and activity transducers with telemetry into the peritoneal space of 46 male Bio-TO-2 Syrian cardiomyopathic hamsters. Multiple techniques, including computing mean temperature, frequency domain analysis, and nonlinear analysis, were used to determine the most useful method for predicting poor prognosis. Data from 44 hamsters were included in our final analysis. We detected a decline in core body temperature in 98% of the hamsters 8+/-4 days before death (P < .001). We examined the dominant frequency of temperature variation (ie, the circadian rhythm) by using cosinor analysis, which revealed a significant decrease in the amplitude of the body temperature circadian rhythm 8 weeks before death (0.28 degrees C; 95% CI, 0.26-0.31) compared to baseline (0.36 degrees C; 95% CI, 0.34-0.39; P=.005). The decline in the circadian temperature variation preceded all other evidence of decompensation. We conclude that a decrease in the amplitude of the body temperature circadian rhythm precedes fatal decompensation in cardiomyopathic hamsters. Continuous temperature monitoring may be useful in predicting preclinical decompensation in patients with heart failure and in identifying opportunities for therapeutic intervention. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  16. Mesothelial cell proliferation induced by intrapleural instillation of man-made fibers in rats and hamsters.

    PubMed

    Rutten, A A; Bermudez, E; Mangum, J B; Wong, B A; Moss, O R; Everitt, J I

    1994-07-01

    Long-term inhalation exposure to a biopersistent man-made ceramic fiber (RCF 1) results in a high incidence of pleural mesotheliomas in Syrian golden hamsters but not in identically exposed rats. To understand better the mechanisms involved in the intraspecies pathobiology of fiber-exposed mesothelium, the ability of the two different man-made fibers to induce cell proliferation in hamster and rat pleural mesothelial cells was investigated. Three dose levels of either glass fibers (MMVF 10) or ceramic fibers (RCF 1) were instilled intrapleurally into male Fischer 344 rats and male Syrian Golden hamsters. Rats and hamsters were exposed to approximately equal numbers of long thin fibers per kilogram of body weight using a single intrapleural instillation. Bromodeoxyuridine (BrdU) was administered via an implanted osmotic pump, and mesothelial cell proliferation was assessed at 7 and 28 days postinstillation (PI) using immunocytochemical visualization of labeled S-phase cells. Both rats and hamsters exhibited dose-dependent increases in proliferation of pleural mesothelial cells following exposure to both fiber types. Interspecies differences in mesothelial cell proliferation were noted for fiber type and pleural site. At 28 days PI, RCF-induced mesothelial cell proliferation was found to be more pronounced in hamsters than in rats in the caudal visceral pleural. Comparing both fibers either by equal mass or by equal fiber numbers, mesothelial cell proliferation in RCF 1-treated animals was higher than in animals exposed to MMVF 10, especially in hamsters, and may be a factor in the difference in mesothelioma induced by the two fibers. The higher sustained (28 day) mesothelial cell proliferation in the visceral pleural of hamsters exposed to RCF may contribute to the species-specific differences in mesothelioma incidence found in long-term rodent inhalation studies.

  17. Alterations of male sexual behavior by learned aversions to hamster vaginal secretion.

    PubMed

    Johnston, R E; Zahorik, D M; Immler, K; Zakon, H

    1978-02-01

    Male hamsters poisoned after their first adult exposure to the vaginal secretion of female hamsters became hesitant to approach and ingest the secretion. The same aversion-training procedure also altered the responses of males to estrous females, changing the latency, frequency, and duration of a variety of behaviors that are commonly taken as indexes of sexual attraction or arousal and of copulatory performance. The effects suggest that the aversions to vaginal secretion alter the perceived meaning of the secretion for male hamsters, and analysis of the correlations between various measures of sexual arousal and performance support the hypothesis that separate mechanisms underlie the effects of the secretion on appetitive and consummatory sexual behavior.

  18. Delay of behavioral estrus in hamsters and phenobarbital.

    PubMed

    Alleva, J J

    1989-01-01

    The onset of behavioral estrus was used as a phase marker of the hamster timing system in SLD 16:8 (dark 20:00-04:00). TZ was injected between 11:00 of cycle day 3 and noon of cycle day 4 when onset of estrus was determined. At no time did injection of TZ cause a phase advance in SLD 16:8. Small delays of estrus resulted from 11:00-16:00 injections but marked delays began with the 17:00 injection. Phenobarbital was injected between noon and 19:30 on cycle day 3. Injections between noon and 16:00 had no effect but all later injections beginning at 17:00 delayed estrus, the 17:30 injection causing the greatest delay. Diazepam also markedly delayed estrus when tested at 17:30. These results with three drugs support results with light pulses that 18:00 in SLD 16:8 marks the same phase of the 24-h hamster timing system as the onset of wheel running does in DD, LL, and WLD. These findings with three GABA potentiators extend to SLD previous evidence based on the onset of wheel running in DD, LL and WLD that GABA may be involved in hamster timekeeping and its responses to light and drugs.

  19. Renal atrial natriuretic factor receptors in hamster cardiomyopathy.

    PubMed

    Mukaddam-Daher, S; Jankowski, M; Dam, T V; Quillen, E W; Gutkowska, J

    1995-12-01

    Hamsters with cardiomyopathy (CMO), an experimental model of congestive heart failure, display stimulated renin-angiotensin-aldosterone and enhanced sympathetic nervous activity, all factors that lead to sodium retention, volume expansion and subsequent elevation of plasma atrial natriuretic factor (ANF) by the cardiac atria. However, sodium and water retention persist in CMO, indicating hyporesponsiveness to endogenous ANF. These studies were undertaken to fully characterize renal ANF receptor subtypes in normal hamsters and to evaluate whether alterations in renal ANF receptors may contribute to renal resistance to ANF in cardiomyopathy. Transcripts of the guanylyl cyclase-A (GC-A) and guanylyl cyclase B (GC-B) receptors were detected by quantitative polymerase chain reaction (PCR) in renal cortex, and outer and inner medullas. Compared to normal controls, the cardiomyopathic hamster's GC-A mRNA was similar in cortex but significantly increased in outer and inner medulla. Levels of GC-B mRNA were not altered by the disease. On the other hand, competitive binding studies, autoradiography, and affinity cross-linking demonstrated the absence of functional GC-B receptors in the kidney glomeruli and inner medulla. Also, C-type natriuretic peptide (CNP), the natural ligand for the GC-B receptors, failed to stimulate glomerular production of its second messenger cGMP. In CMO, sodium and water excretion were significantly reduced despite elevated plasma ANF (50.5 +/- 11.1 vs. 309.4 +/- 32.6 pg/ml, P < 0.001). Competitive binding studies of renal glomerular ANF receptors revealed no change in total receptor density, Bmax (369.6 +/- 27.4 vs. 282.8 +/- 26.2 fmol/mg protein), nor in dissociation constant, Kd (647.4 +/- 79.4 vs. 648.5 +/- 22.9 pM). Also, ANF-C receptor density (254.3 +/- 24.8 vs. 233.8 +/- 23.5 fmol/mg protein), nor affinity were affected by heart failure. Inner medullary receptors were exclusively of the GC-A subtype with Bmax (153.2 +/- 26.4 vs. 134

  20. Heterogeneity of NK-2 tachykinin receptors in hamster and rabbit smooth muscles.

    PubMed

    Maggi, C A; Eglezos, A; Quartara, L; Patacchini, R; Giachetti, A

    1992-01-23

    The possible existence of NK-2 receptor subtypes in peripheral smooth muscle preparations from rabbit and hamster was investigated by studying the effect of neurokinin A, the selective NK-2 receptor agonist [beta Ala8] neurokinin A (4-10), the selective NK-2 tachykinin receptor antagonists, MEN 10,376, L 659,877 and R 396, and the pseudopeptide derivative of neurokinin A (4-10), MDL 28,564. All experiments were performed in the presence of peptidase inhibitors (captopril, bestatin and thiorphan, 1 microM each). Both neurokinin A and [beta Ala8] neurokinin A (4-10) produced concentration-dependent contractions of the rabbit isolated bronchus and hamster isolated stomach and colon, as well as enhancement of the nerve-mediated twitches of rabbit isolated vas deferens (pars prostatica). MEN 10,376, L 659,877 and R 396 antagonized the effect of the NK-2 receptor selective agonist in all four tissues under study, although marked differences in antagonist potency were evident for the three antagonists. Thus MEN 10,376 was distinctly more potent (about 100 times) in rabbit than in hamster preparations while L 659,877 and R 396 were more potent in hamster than rabbit preparations. MDL 28,564 showed a distinct agonist character in rabbit preparations while it was virtually inactive in hamster preparations, where it antagonized the effect of the NK-2 receptor selective agonist.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. After infection with Leishmania infantum, Golden Hamsters (Mesocricetus auratus) become more attractive to female sand flies (Lutzomyia longipalpis).

    PubMed

    Nevatte, T M; Ward, R D; Sedda, L; Hamilton, J G C

    2017-07-21

    In Brazil, human and canine visceral leishmaniasis is caused by infection with Leishmania infantum, a Protist parasite transmitted by blood-feeding female Lutzomyia longipalpis sand flies. The objective of this study was to determine if the odour of hamsters, infected with Le. infantum, was more attractive than the odour of the same hamsters, before they were infected. The attractiveness of odour collected from individual hamsters (n = 13), before they were infected, was compared in a longitudinal study, with the attractiveness of the odour of the same hamster in a Y-tube olfactometer bioassay, at a late stage of infection. The odour of six of the golden hamsters was significantly more attractive to 50% of the female sand flies at the end of infection compared to before infection and the odour of four of the golden hamsters was significantly more attractive to 75% of the female sand flies at the end of infection. These results strongly indicate that hamsters infected with Le. infantum become significantly more attractive to a greater proportion of female sand flies as the infection progresses.

  2. Behavioral and autonomic thermoregulation in hamsters during microwave-induced heat exposure

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gordon, C.J.; Long, M.D.; Fehlner, K.S.

    1984-01-01

    Preferred ambient temperature (Ta) and ventilatory frequency were measured in free-moving hamsters exposed to 2450-MHz microwaves. A waveguide exposure system that permits continuous monitoring of the absorbed heat load accrued from microwave exposure was imposed with a longitudinal temperature gradient which allowed hamsters to select their preferred Ta. Ventilatory frequency was monitored remotely by analysing the rhythmic shifts in unabsorbed microwave energy passing down the waveguide. Without microwave exposure hamsters selected an average T2 of 30.2 C. This preferred Ta did not change until the rate of heat absorption (SAR) from microwave exposure exceeded approx. 2 W kg-1. In amore » separate experiment, a SAR of 2.0 W kg-1 at a Ta of 30C was shown to promote an average 0.5 C increase in colonic temperature. Hamsters maintained their ventilatory frequency at baseline levels by selecting a cooler Ta during microwave exposure. These data support previous studies suggesting that during thermal stress behavioral thermo-regulation (i.e. preferred Ta) takes prescedence over autonomic thermoregulation (i.e. ventilatory frequency). It is apparent that selecting a cooler Ta is a more efficient and/or effective than autonomic thermoregulation for dissipating a heat load accrued from microwave exposure.« less

  3. Long-term carcinogenicity study in Syrian golden hamster of particulate emissions from coal- and oil-fired power plants

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Persson, S.A.; Ahlberg, M.; Berghem, L.

    1988-04-01

    Male Syrian golden hamsters were given 15 weekly intratracheal instillations with suspensions of coal fly ash or oil fly ash. Controls were instilled with saline containing gelatine (0.5 g/100 mL) or to check particle effects with suspensions of hematite (Fe/sub 2/O/sub 3/). The common weekly dose was 4.5 mg/hamster. In addition, one subgroup of hamsters was treated with oil fly ash at a weekly dose of 3.0 mg/hamster and another with coal fly ash at a weekly dose of 6.0 mg/hamster. Other groups of hamsters were treated with suspensions of benzo(a)pyrene (BaP) or with suspensions on coal fly ash, oilmore » fly ash, or Fe/sub 2/O/sub 3/ coated with BaP. The mass median aerodynamic diameters of the coal and oil fly ashes were 4.4 microns and 28 microns, respectively. Hamsters treated with oil fly ash showed a higher frequency of bronchiolar-alveolar hyperplasia than hamsters in the other treatment groups. Squamous dysplasia and squamous metaplasia were most frequent in animals treated with suspensions of BaP or BaP-coated particles. The earliest appearance of a tumor, the highest incidence of tumors, and the highest incidence of malignant tumors were observed in hamsters treated with oil fly ash coated with BaP. Squamous cell carcinoma and adenosquamous carcinoma were the most frequent malignant tumors. No malignant tumors and only few benign tumors were observed in hamsters instilled with suspensions of fly ash not coated with BaP. The present study gives no indication that coal fly ash could create more serious health problems than oil fly ash.« less

  4. Identification of hamster inducible nitric oxide synthase (iNOS) promoter sequences that influence basal and inducible iNOS expression

    PubMed Central

    Saldarriaga, Omar A.; Travi, Bruno L.; Choudhury, Goutam Ghosh; Melby, Peter C.

    2012-01-01

    IFN-γ/LPS-activated hamster (Mesocricetus auratus) macrophages express significantly less iNOS (NOS2) than activated mouse macrophages, which contributes to the hamster's susceptibility to intracellular pathogens. We determined a mechanism responsible for differences in iNOS promoter activity in hamsters and mice. The HtPP (1.2 kb) showed low basal and inducible promoter activity when compared with the mouse, and sequences within a 100-bp region (−233 to −133) of the mouse and hamster promoters influenced this activity. Moreover, within this 100 bp, we identified a smaller region (44 bp) in the mouse promoter, which recovered basal promoter activity when swapped into the hamster promoter. The mouse homolog (100-bp region) contained a cis-element for NF-IL-6 (−153/−142), which was absent in the hamster counterpart. EMSA and supershift assays revealed that the hamster sequence did not support the binding of NF-IL-6. Introduction of a functional NF-IL-6 binding sequence into the hamster promoter or its alteration in the mouse promoter revealed the critical importance of this transcription factor for full iNOS promoter activity. Furthermore, the binding of NF-IL-6 to the iNOS promoter (−153/−142) in vivo was increased in mouse cells but was reduced in hamster cells after IFN-γ/LPS stimulation. Differences in the activity of the iNOS promoters were evident in mouse and hamster cells, so they were not merely a result of species-specific differences in transcription factors. Thus, we have identified unique DNA sequences and a critical transcription factor, NF-IL-6, which contribute to the overall basal and inducible expression of hamster iNOS. PMID:22517919

  5. In hamsters the D1 receptor antagonist SCH23390 depresses ventilation during hypoxia.

    PubMed

    Schlenker, Evelyn H

    2008-01-02

    During exposure of animals to hypoxia, brain and blood dopamine levels increase stimulating dopaminergic receptors which influence the integrated ventilatory response to low oxygen. The purpose of the present study is to test the hypothesis that in conscious hamsters, systemic antagonism of D(1) receptors would depress their breathing in air and in response to hypoxic and hypercapnic challenges. Nine male hamsters were treated with saline or 0.25 mg/kg SCH-23390 (SCH), a D(1) receptor antagonist that crosses the blood-brain barrier. Ventilation was determined using the barometric method, and oxygen consumption and CO(2) production were evaluated utilizing the flow-through method. During exposure to air, SCH decreased frequency of breathing. During exposure to hypoxia (10% oxygen in nitrogen), relative to saline, SCH-treated hamsters decreased minute ventilation by decreasing tidal volume and oxygen consumption but not CO(2) production. During exposure to hypercapnia (5% CO(2) in 95% O(2)), frequency of breathing was decreased with SCH, but there was no significant effect on minute ventilation. Relative to saline treatment body temperature was lower in SCH-treated hamsters by 0.6 degrees C. These results demonstrate that in hamsters D(1) receptors can modulate control of ventilation in air and during hypoxia and hypercapnic exposures. Whether D(1) receptors located centrally or on carotid bodies modulate these effects is not clear from this study.

  6. Monosodium glutamate-induced arcuate nucleus damage affects both natural torpor and 2DG-induced torpor-like hypothermia in Siberian hamsters.

    PubMed

    Pelz, Kimberly M; Routman, David; Driscoll, Joseph R; Kriegsfeld, Lance J; Dark, John

    2008-01-01

    Siberian hamsters (Phodopus sungorus) have the ability to express daily torpor and decrease their body temperature to approximately 15 degrees C, providing a significant savings in energy expenditure. Daily torpor in hamsters is cued by winterlike photoperiods and occurs coincident with the annual nadirs in body fat reserves and chronic leptin concentrations. To better understand the neural mechanisms underlying torpor, Siberian hamster pups were postnatally treated with saline or MSG to ablate arcuate nucleus neurons that likely possess leptin receptors. Body temperature was studied telemetrically in cold-acclimated (10 degrees C) male and female hamsters moved to a winterlike photoperiod (10:14-h light-dark cycle) (experiments 1 and 2) or that remained in a summerlike photoperiod (14:10-h light-dark cycle) (experiment 3). In experiment 1, even though other photoperiodic responses persisted, MSG-induced arcuate nucleus ablations prevented the photoperiod-dependent torpor observed in saline-treated Siberian hamsters. MSG-treated hamsters tended to possess greater fat reserves. To determine whether reductions in body fat would increase frequency of photoperiod-induced torpor after MSG treatment, hamsters underwent 2 wk of food restriction (70% of ad libitum) in experiment 2. Although food restriction did increase the frequency of torpor in both MSG- and saline-treated hamsters, it failed to normalize the proportion of MSG-treated hamsters undergoing photoperiod-dependent torpor. In experiment 3, postnatal MSG treatments reduced the proportion of hamsters entering 2DG-induced torpor-like hypothermia by approximately 50% compared with saline-treated hamsters (38 vs. 72%). In those MSG-treated hamsters that did become hypothermic, their minimum temperature during hypothermia was significantly greater than comparable saline-treated hamsters. We conclude that 1) arcuate nucleus mechanisms mediate photoperiod-induced torpor, 2) food-restriction-induced torpor may also be

  7. Photoperiodic adjustments in immune function protect Siberian hamsters from lethal endotoxemia.

    PubMed

    Prendergast, Brian J; Hotchkiss, Andrew K; Bilbo, Staci D; Kinsey, Steven G; Nelson, Randy J

    2003-02-01

    Seasonal changes in day length enhance or suppress components of immune function in individuals of several mammalian species. Siberian hamsters (Phodopus sungorus) exhibit multiple changes in neuroendocrine, reproductive, and immune function after exposure to short days. The manner in which these changes are integrated into the host response to pathogens is not well understood. The present experiments tested the hypothesis that short-day changes in immune function alter the pathogenesis of septic shock and survival after challenge with endotoxin. Male and female Siberian hamsters raised in long-day photoperiods were transferred as adults to short days or remained in their natal photoperiod. Six to 8 weeks later, hamsters were injected i.p. with 0, 1, 2.5, 10, 25, or 50 mg/kg bacterial lipopolysaccharide (LPS) (the biologically active constituent of endotoxin), and survival was monitored for 96 h. Short days significantly improved survival of male hamsters treated with 10 or 25 mg/kg LPS and improved survival in females treated with 50 mg/kg LPS. Transfer from long to short days shifted the LD50 in males by approximately 90%, from 5.3 to 9.9 mg/kg, and in females from 11.1 to 15.0 mg/kg (+35%). Long-day females were more resistant than were males to lethal endotoxemia. In vitro production of the proinflammatory cytokine TNFalpha in response to LPS stimulation was significantly lower in macrophages extracted from short-day relative to long-day hamsters, as were circulating concentrations of TNFalpha in vivo after i.p. administration of LPS, suggesting that diminished cytokine responses to LPS in short days may mitigate the lethality of endotoxemia. Adaptation to short days induces changes in immune parameters that affect survival in the face of immune challenges.

  8. Photoperiod-dependent modulation of anti-Müllerian hormone in female Siberian hamsters, Phodopus sungorus.

    PubMed

    Kabithe, Esther W; Place, Ned J

    2008-03-01

    Fertility and fecundity decline with advancing age in female mammals, but reproductive aging was decelerated in Siberian hamsters (Phodopus sungorus) raised in a short-day (SD) photoperiod. Litter success was significantly improved in older hamsters when reared in SD and the number of primordial follicles was twice that of females held in long days (LD). Because anti-Müllerian hormone (AMH) appears to inhibit the recruitment of primordial follicles in mice, we sought to determine whether the expression patterns of AMH differ in the ovaries and serum of hamsters raised in SD versus LD. Ovaries of SD female hamsters are characterized by a paucity of follicular development beyond the secondary stage and are endowed with an abundance of large eosinophilic cells, which may derive from granulosa cells of oocyte-depleted follicles. In ovaries from 10-week-old SD hamsters, we found that the so-called 'hypertrophied granulosa cells' were immunoreactive for AMH, as were granulosa cells within healthy-appearing primary and secondary follicles. Conversely, ovaries from age-matched LD animals lack the highly eosinophilic cells present in SD ovaries. Therefore, AMH staining in LD was limited to primary and secondary follicles that are comparable in number to those found in SD ovaries. The substantially greater AMH expression in SD ovaries probably reflects the abundance of hypertrophied granulosa cells in SD ovaries and their relative absence in LD ovaries. The modulation of ovarian AMH by day length is a strong mechanistic candidate for the preservation of primordial follicles in female hamsters raised in a SD photoperiod.

  9. CELLULAR TOXICITY IN CHINESE HAMSTER OVARY CELL CULTURES. 2. A STATISTICAL APPRAISAL OF SENSITIVITY WITH THE RABBIT ALVEOLAR MACROPHAGE, SYRIAN HAMSTER EMBRYO, BALB 3T3 MOUSE, AND HUMAN NEONATAL FIBROBLAST CELL SYSTEMS

    EPA Science Inventory

    Chinese hamster ovary, rabbit alveolar macrophage, Syrian Hamster embryo, mouse, and human neonatal fibroblast cells were employed in a statistical evaluation of the relative sensitivity of the cells to toxic substances. The cells were exposed to 1,2,4-trichlorobenzene, 2,4-dimet...

  10. Histiocytic Sarcoma and Bilateral Facial Vein Thrombosis in a Siberian Hamster (Phodopus sungorus).

    PubMed

    Coble, Dondrae J; Shoemaker, Margaret; Harrington, Bonnie; Dardenne, Adrienne D; Bolon, Brad

    2015-04-01

    A 21-mo-old, male Siberian hamster (Phodopus sungorus) presented with left-sided facial swelling, proptosis of the left eye, and blepharospasm of the right eye. The hamster had been used only for breeding. Because of the poor prognosis, the hamster was euthanized without additional diagnostic assays or treatments. Routine gross pathologic evaluation demonstrated exophthalmos and presumptive hyphema of the left eye, bilateral facial edema, freely movable nodules within the mesentery, white foci within the liver, and a large mass effacing the cranial pole of the right kidney. On histologic evaluation, the mesenteric nodules and liver foci expressed histiocytic marker CD163 and thus were diagnosed as sites of histiocytic sarcoma, whereas the kidney mass was a well-differentiated renal cell carcinoma. The facial swelling resulted from bilateral, chronic, severe, branching thrombi in many facial veins. Additional age-related histopathologic findings were observed in other organs, including diffuse glomerulopathy, nesidioblastosis (pancreatic islet neoformation), and multiple foci of severe cartilage degeneration in the axial skeleton. To our knowledge, this report provides the first description of histiocytic sarcoma in a Siberian hamster.

  11. Laguna Negra Virus Infection Causes Hantavirus Pulmonary Syndrome in Turkish Hamsters (Mesocricetus brandti).

    PubMed

    Hardcastle, K; Scott, D; Safronetz, D; Brining, D L; Ebihara, H; Feldmann, H; LaCasse, R A

    2016-01-01

    Laguna Negra virus (LNV) is a New World hantavirus associated with severe and often fatal cardiopulmonary disease in humans, known as hantavirus pulmonary syndrome (HPS). Five hamster species were evaluated for clinical and serologic responses following inoculation with 4 hantaviruses. Of the 5 hamster species, only Turkish hamsters infected with LNV demonstrated signs consistent with HPS and a fatality rate of 43%. Clinical manifestations in infected animals that succumbed to disease included severe and rapid onset of dyspnea, weight loss, leukopenia, and reduced thrombocyte numbers as compared to uninfected controls. Histopathologic examination revealed lung lesions that resemble the hallmarks of HPS in humans, including interstitial pneumonia and pulmonary edema, as well as generalized infection of endothelial cells and macrophages in major organ tissues. Histologic lesions corresponded to the presence of viral antigen in affected tissues. To date, there have been no small animal models available to study LNV infection and pathogenesis. The Turkish hamster model of LNV infection may be important in the study of LNV-induced HPS pathogenesis and development of disease treatment and prevention strategies. © The Author(s) 2015.

  12. CHARACTERIZATION OF VIRULENCE OF Leptospira ISOLATES IN A HAMSTER MODEL

    PubMed Central

    Silva, Éverton F.; Santos, Cleiton S.; Athanazio, Daniel A.; Seyffert, Núbia; Seixas, Fabiana K.; Cerqueira, Gustavo M.; Fagundes, Michel Q.; Brod, Claudiomar S.; Reis, Mitermayer G.; Dellagostin, Odir A.; Ko, Albert I.

    2008-01-01

    Effort has been made to identify protective antigens in order to develop a recombinant vaccine against leptospirosis. Several attempts failed to conclusively demonstrate efficacy of vaccine candidates due to the lack of an appropriate model of lethal leptospirosis. The purposes of our study were: (i) to test the virulence of leptospiral isolates from Brazil, which are representative of important serogroups that cause disease in humans and animals; and (ii) to standardize the lethal dose 50% (LD50) for each of the virulent strains using a hamster (Mesocricetus auratus) model. Five of seven Brazilian isolates induced lethality in a hamster model, with inocula lower than 200 leptospires. Histopathological examination of infected animals showed typical lesions found in both natural and experimental leptospirosis. Results described here demonstrated the potential use of Brazilian isolates as highly virulent strains in challenge experiments using hamster as an appropriate animal model for leptospirosis. Furthermore these strains may be useful in heterologous challenge studies which aim to evaluate cross-protective responses induced by subunit vaccine candidates. PMID:18547690

  13. IN VITRO CULTURE OF POSTIMPLANTATION HAMSTER EMBRYOS

    EPA Science Inventory

    In vitro culture of intact rat and mouse embryos has been described extensively, but information on the culture of other species is sparse. The present study examined some culture requirements of early somite stage hamster embryos and assessed the embryotoxic effects of sodium sa...

  14. Transmission of chronic wasting disease identifies a prion strain causing cachexia and heart infection in hamsters.

    PubMed

    Bessen, Richard A; Robinson, Cameron J; Seelig, Davis M; Watschke, Christopher P; Lowe, Diana; Shearin, Harold; Martinka, Scott; Babcock, Alex M

    2011-01-01

    Chronic wasting disease (CWD) is an emerging prion disease of free-ranging and captive cervids in North America. In this study we established a rodent model for CWD in Syrian golden hamsters that resemble key features of the disease in cervids including cachexia and infection of cardiac muscle. Following one to three serial passages of CWD from white-tailed deer into transgenic mice expressing the hamster prion protein gene, CWD was subsequently passaged into Syrian golden hamsters. In one passage line there were preclinical changes in locomotor activity and a loss of body mass prior to onset of subtle neurological symptoms around 340 days. The clinical symptoms included a prominent wasting disease, similar to cachexia, with a prolonged duration. Other features of CWD in hamsters that were similar to cervid CWD included the brain distribution of the disease-specific isoform of the prion protein, PrP(Sc), prion infection of the central and peripheral neuroendocrine system, and PrP(Sc) deposition in cardiac muscle. There was also prominent PrP(Sc) deposition in the nasal mucosa on the edge of the olfactory sensory epithelium with the lumen of the nasal airway that could have implications for CWD shedding into nasal secretions and disease transmission. Since the mechanism of wasting disease in prion diseases is unknown this hamster CWD model could provide a means to investigate the physiological basis of cachexia, which we propose is due to a prion-induced endocrinopathy. This prion disease phenotype has not been described in hamsters and we designate it as the 'wasting' or WST strain of hamster CWD.

  15. Effect of Antiviral Agents in Equine Abortion Virus-Infected Hamsters1

    PubMed Central

    Lieberman, Melvin; Pascale, Andrea; Schafer, Thomas W.; Came, Paul E.

    1972-01-01

    Equine abortion virus, a member of the herpesvirus group, produces a lethal infection in hamsters. With this system, the protective effect of certain inhibitors of deoxyribonucleic acid viruses, inducers of interferon and exogenous interferon, was evaluated. Of the various agents studied, 9-β-d-arabinofuranosyladenine markedly suppressed mortality, and 5-iodo-2′-deoxyuridine, distamycin A, and N-ethylisatin β-thiosemicarbazone were inactive. Of the inducers tested, statolon, ultraviolet-irradiated Newcastle disease virus, and polyriboinosinic:polyribocytidylic acid (poly I:C) were protective, and endotoxin, polyacrylic acid, and polymethacrylic acid did not protect. Administration of exogenous interferon did not afford protection. Statolon and ultraviolet-irradiated Newcastle disease virus induced circulating interferon in hamsters, whereas poly I:C, endotoxin, and polyacrylic acid did not produce interferon. Because of the severity of the disease produced in hamsters by equine abortion virus, lack of protective activity by an agent in this system should not preclude possible efficacy against other members of the herpesvirus group. PMID:4376907

  16. [Genetic Structure of Urban Population of the Common Hamster (Cricetus cricetus)].

    PubMed

    Feoktistova, N Yu; Meschersky, I G; Surov, A V; Bogomolov, P L; Tovpinetz, N N; Poplavskaya, N S

    2016-02-01

    Over the past half-century, the common hamster (Cricetus cricetus), along with range-wide decline of natural populations, has actively populated the cities. The study of the genetic structure of urban populations of common hamster may shed light on features of the habitation of this species in urban landscapes. This article is focused on the genetic structure of common hamster populations in Simferopol (Crimea), one of the largest known urban populations of this species. On the basis of the analysis of nucleotide sequences of the cytochrome b gene and mtDNA control region, and the allelic composition of ten microsatellite loci of nDNA, we revealed that, despite the fact that some individuals can move throughout the city at considerable distances, the entire population of the city is represented by separate demes confined to different areas. These demes are characterized by a high degree of the genetic isolation and reduced genetic diversity compared to that found for the city as a whole.

  17. Topical Olive Leaf Extract Improves Healing of Oral Mucositis in Golden Hamsters.

    PubMed

    Showraki, Najmeh; Mardani, Maryam; Emamghoreishi, Masoumeh; Andishe-Tadbir, Azadeh; Aram, Alireza; Mehriar, Peiman; Omidi, Mahmoud; Sepehrimanesh, Masood; Koohi-Hosseinabadi, Omid; Tanideh, Nader

    2016-12-01

    Oral mucositis (OM) is a common side effect of anti-cancer drugs and needs significant attention for its prevention. This study aimed to evaluate the healing effects of olive leaf extract on 5-fluorouracil-induced OM in golden hamster. OM was induced in 63 male golden hamsters by the combination of 5-fluorouracil injections (days 0, 5 and 10) and the abrasion of the cheek pouch (days 3 and 4). On day 12, hamsters were received topical olive leaf extract ointment, base of ointment, or no treatment (control) for 5 days. Histopathology evaluations, blood examinations, and tissue malondialdehyde level measurement were performed 1, 3 and 5 days after treatments. Histopathology score and tissue malondialdehyde level were significantly lower in olive leaf extract treated group in comparison with control and base groups ( p = 0.000). Significant decreases in white blood cell, hemoglobin, hematocrit , and mean corpuscular volume and an increase in mean corpuscular hemoglobin concentration were observed in olive leaf extract treated group in comparison with control and base groups ( p < 0.05). Our findings demonstrated that daily application of olive leaf extract ointment had healing effect on 5-fluorouracil induced OM in hamsters. Moreover, the beneficial effect of olive leaf extract on OM might be due to its antioxidant and anti-inflammatory properties.

  18. Female-biased anorexia and anxiety in the Syrian hamster.

    PubMed

    Shannonhouse, John L; Fong, Li An; Clossen, Bryan L; Hairgrove, Ross E; York, Daniel C; Walker, Benjamin B; Hercules, Gregory W; Mertesdorf, Lauren M; Patel, Margi; Morgan, Caurnel

    2014-06-22

    Anorexia and anxiety cause significant mortality and disability with female biases and frequent comorbidity after puberty, but the scarcity of suitable animal models impedes understanding of their biological underpinnings. It is reported here that in adult or weanling Syrian hamsters, relative to social housing (SH), social separation (SS) induced anorexia characterized as hypophagia, weight loss, reduced adiposity, and hypermetabolism. Following anorexia, SS increased reluctance to feed, and thigmotaxis, in anxiogenic environments. Importantly, anorexia and anxiety were induced post-puberty with female biases. SS also reduced hypothalamic corticotrophin-releasing factor mRNA and serum corticosteroid levels assessed by RT-PCR and RIA, respectively. Consistent with the view that sex differences in adrenal suppression contributed to female biases in anorexia and anxiety by disinhibiting neuroimmune activity, SS elevated hypothalamic interleukin-6 and toll-like receptor 4 mRNA levels. Although corticosteroids were highest during SH, they were within the physiological range and associated with juvenile-like growth of white adipose, bone, and skeletal muscle. These results suggest that hamsters exhibit plasticity in bioenergetic and emotional phenotypes across puberty without an increase in stress responsiveness. Thus, social separation of hamsters provides a model of sex differences in anorexia and anxiety during adulthood and their pathogeneses during adolescence. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Efficacy of a New Recrystallized Enrofloxacin Hydrochloride-Dihydrate against Leptospirosis in a Hamster Model.

    PubMed

    Carrascosa, Alma; Gutierrez, Lilia; De la Peña, Alejandro; Candanosa, Irma E; Tapia, Graciela; Sumano, Hector

    2017-11-01

    A trial on Syrian hamsters ( Mesocricetus auratus ) infected with Leptospira interrogans serovar Canicola was established to compare treatment efficacies of daily intramuscular (i.m.) injections of either 10 mg/kg of 5% enrofloxacin (Baytril [BE]; Bayer Animal Health, Mexico) or the same dose of enrofloxacin hydrochloride-dihydrate (enro-C). Hamsters were experimentally infected via the oral submucosa with 400 microorganisms/animal, in a sequential time schedule aligned to the initial treatment day, and were treated in groups as follows: a group treated with 5% enrofloxacin daily for 7 days after 24 h of infection (group BE 24 ); a group treated as described for group BE 24 but with enro-C (enro-C 24 ); a group also treated with 5% enrofloxacin but starting at 72 h after infection (BE 74 ); a group treated as described for group BE 74 but with injection of enro-C (enro-C 74 ). An untreated-uninfected control group (group CG - ) and an infected-untreated control group (group CG + ) were assembled ( n = 18 in all groups). Weights and temperatures of the hamsters were monitored daily for 28 days. After hamsters were euthanatized or following death, necropsy, histopathology, macroscopic agglutination tests (MAT), bacterial culture, and PCR were performed. The mortality rates were 38.8% in group BE 24 and 100% in group BE 74 No mortality was observed in group enro-C 24 , and 11.1% mortality was recorded in group enro-C 74 The mortality rates in groups CG + and CG - were 100% and zero, respectively. Combined necropsy and histopathologic findings revealed signs of septicemia and organ damage in groups BE 24 , BE 72 , and CG + Groups enro-C 24 and CG - showed no lesions. Moderated lesions were registered in 3 hamsters in group enro-C 72 MAT results were positive in 83.3% of BE 24 hamsters (83.3%) and 100% of BE 72 and CG + hamsters; MAT results were positive in 16.7% in group Enro-C 24 and 38.9% in group enro-C 72 Only 4/18 were PCR positive in group enro-C 72 and only 1

  20. Adrenal hormones mediate melatonin-induced increases in aggression in male Siberian hamsters (Phodopus sungorus).

    PubMed

    Demas, Gregory E; Polacek, Kelly M; Durazzo, Alfredo; Jasnow, Aaron M

    2004-12-01

    Among the suite of seasonal adaptations displayed by nontropical rodents, some species demonstrate increased territorial aggression in short compared with long day lengths despite basal levels of testosterone. The precise physiological mechanisms mediating seasonal changes in aggression, however, remain largely unknown. The goal of the present study was to examine the role of melatonin, as well as adrenal hormones, in the regulation of seasonal aggression in male Siberian hamsters (Phodopus sungorus). In Experiment 1, male Siberian hamsters received either daily (s.c.) injections of melatonin (15 microg/day) or saline 2 h before lights out for 10 consecutive days. In Experiment 2, hamsters received adrenal demedullations (ADMEDx), whereas in Experiment 3 animals received adrenalectomies (ADx); control animals in both experiments received sham surgeries. Animals in both experiments subsequently received daily injections of melatonin or vehicle as in Experiment 1. Animals in all experiments were tested using a resident-intruder model of aggression. In Experiment 1, exogenous melatonin treatment increased aggression compared with control hamsters. In Experiment 2, ADMEDx had no effect on melatonin-induced aggression. In Experiment 3, the melatonin-induced increase in aggression was significantly attenuated by ADx. Collectively, the results of the present study demonstrate that short day-like patterns of melatonin increase aggression in male Siberian hamsters and suggest that increased aggression is due, in part, to changes in adrenocortical steroids.

  1. Augmenting Chinese hamster genome assembly by identifying regions of high confidence.

    PubMed

    Vishwanathan, Nandita; Bandyopadhyay, Arpan A; Fu, Hsu-Yuan; Sharma, Mohit; Johnson, Kathryn C; Mudge, Joann; Ramaraj, Thiruvarangan; Onsongo, Getiria; Silverstein, Kevin A T; Jacob, Nitya M; Le, Huong; Karypis, George; Hu, Wei-Shou

    2016-09-01

    Chinese hamster Ovary (CHO) cell lines are the dominant industrial workhorses for therapeutic recombinant protein production. The availability of genome sequence of Chinese hamster and CHO cells will spur further genome and RNA sequencing of producing cell lines. However, the mammalian genomes assembled using shot-gun sequencing data still contain regions of uncertain quality due to assembly errors. Identifying high confidence regions in the assembled genome will facilitate its use for cell engineering and genome engineering. We assembled two independent drafts of Chinese hamster genome by de novo assembly from shotgun sequencing reads and by re-scaffolding and gap-filling the draft genome from NCBI for improved scaffold lengths and gap fractions. We then used the two independent assemblies to identify high confidence regions using two different approaches. First, the two independent assemblies were compared at the sequence level to identify their consensus regions as "high confidence regions" which accounts for at least 78 % of the assembled genome. Further, a genome wide comparison of the Chinese hamster scaffolds with mouse chromosomes revealed scaffolds with large blocks of collinearity, which were also compiled as high-quality scaffolds. Genome scale collinearity was complemented with EST based synteny which also revealed conserved gene order compared to mouse. As cell line sequencing becomes more commonly practiced, the approaches reported here are useful for assessing the quality of assembly and potentially facilitate the engineering of cell lines. Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Serotonergic modulation of hippocampal pyramidal cells in euthermic, cold-acclimated, and hibernating hamsters

    NASA Technical Reports Server (NTRS)

    Horrigan, D. J.; Horwitz, B. A.; Horowitz, J. M.

    1997-01-01

    Serotonergic fibers project to the hippocampus, a brain area previously shown to have distinctive changes in electroencephalograph (EEG) activity during entrance into and arousal from hibernation. The EEG activity is generated by pyramidal cells in both hibernating and nonhibernating species. Using the brain slice preparation, we characterized serotonergic responses of these CA1 pyramidal cells in euthermic, cold-acclimated, and hibernating Syrian hamsters. Stimulation of Shaffer-collateral/commissural fibers evoked fast synaptic excitation of CA1 pyramidal cells, a response monitored by recording population spikes (the synchronous generation of action potentials). Neuromodulation by serotonin (5-HT) decreased population spike amplitude by 54% in cold-acclimated animals, 80% in hibernating hamsters, and 63% in euthermic animals. The depression was significantly greater in slices from hibernators than from cold-acclimated animals. In slices from euthermic animals, changes in extracellular K+ concentration between 2.5 and 5.0 mM did not significantly alter serotonergic responses. The 5-HT1A agonist 8-hydroxy-2(di-n-propylamino)tetralin mimicked serotonergic inhibition in euthermic hamsters. Results show that 5-HT is a robust neuromodulator not only in euthermic animals but also in cold-acclimated and hibernating hamsters.

  3. Co-infection of the Siberian hamster (Phodopus sungorus) with a novel Helicobacter sp. and Campylobacter sp.

    PubMed

    Nagamine, Claude M; Shen, Zeli; Luong, Richard H; McKeon, Gabriel P; Ruby, Norman F; Fox, James G

    2015-05-01

    We report the isolation of a novel helicobacter isolated from the caecum of the Siberian hamster (Phodopus sungorus). Sequence analysis showed 97% sequence similarity to Helicobacter ganmani. In addition, we report the co-infection of these Siberian hamsters with a Campylobacter sp. and a second Helicobacter sp. with 99% sequence similarity to Helicobacter sp. flexispira taxon 8 (Helicobacter bilis), a species isolated previously from patients with bacteraemia. Gross necropsy and histopathology did not reveal any overt pathological lesions of the liver and gastrointestinal tract that could be attributed to the Helicobacter or Campylobacter spp. infections. This is the first helicobacter to be identified in the Siberian hamster and the first report of co-infection of Helicobacter spp. and Campylobacter sp. in asymptomatic Siberian hamsters. © 2015 The Authors.

  4. Co-infection of the Siberian hamster (Phodopus sungorus) with a novel Helicobacter sp. and Campylobacter sp.

    PubMed Central

    Shen, Zeli; Luong, Richard H.; McKeon, Gabriel P.; Ruby, Norman F.; Fox, James G.

    2015-01-01

    We report the isolation of a novel helicobacter isolated from the caecum of the Siberian hamster (Phodopus sungorus). Sequence analysis showed 97 % sequence similarity to Helicobacter ganmani. In addition, we report the co-infection of these Siberian hamsters with a Campylobacter sp. and a second Helicobacter sp. with 99 % sequence similarity to Helicobacter sp. flexispira taxon 8 (Helicobacter bilis), a species isolated previously from patients with bacteraemia. Gross necropsy and histopathology did not reveal any overt pathological lesions of the liver and gastrointestinal tract that could be attributed to the Helicobacter or Campylobacter spp. infections. This is the first helicobacter to be identified in the Siberian hamster and the first report of co-infection of Helicobacter spp. and Campylobacter sp. in asymptomatic Siberian hamsters. PMID:25752854

  5. Short photoperiod-induced ovarian regression is mediated by apoptosis in Siberian hamsters (Phodopus sungorus)

    PubMed Central

    Moffatt-Blue, C S; Sury, J J; Young, Kelly A

    2009-01-01

    Siberian hamster reproduction is mediated by photoperiod-induced changes in gonadal activity. However, little is known about how photoperiod induces cellular changes in ovarian function. We hypothesized that exposing female hamsters to short (inhibitory) as opposed to long (control) photoperiods would induce an apoptosis-mediated disruption of ovarian function. Ovaries and plasma from hamsters exposed to either long (LD, 16 h light:8 h darkness) or short (SD, 8 h light:16 h darkness) days were collected during diestrus II after 3, 6, 9 and 12 weeks and processed for histology or RIA respectively. Apoptosis was assessed by in situ TUNEL and active caspase-3 protein immunolabeling. No significant differences were observed among LD hamsters for any parameter; therefore, these control data were pooled. SD exposure induced a decline in preantral follicles (P < 0.05), early antral/antral follicles (P < 0.01) and corpora lutea (P < 0.01) by week 12 as compared with LD. Terminal atretic follicles appeared by SD week 9; by week 12, these had become the predominant ovarian structures. Estradiol concentrations decreased by weeks 9 and 12 SD when compared with both LD and week-3 SD hamsters (P < 0.05); however, no changes were observed for progesterone. TUNEL-positive follicles in SD ovaries increased at week 3 and subsequently declined by week 12 as compared with LD ovaries (P < 0.01). Active capsase-3 protein immunostaining peaked at SD week 3 as compared with all other groups (P < 0.01). TUNEL and capsase-3 immunolabeling were localized to granulosa cells of late-preantral and early-antral/antral follicles. These data indicate that SD exposure rapidly induces follicular apoptosis in Siberian hamsters, which ultimately disrupts both estradiol secretion and folliculogenesis, resulting in the seasonal loss of ovarian function. PMID:16595728

  6. The influence of sex and diet on the characteristics of hibernation in Syrian hamsters.

    PubMed

    Trefna, Marie; Goris, Maaike; Thissen, Cynthia M C; Reitsema, Vera A; Bruintjes, Jojanneke J; de Vrij, Edwin L; Bouma, Hjalmar R; Boerema, Ate S; Henning, Robert H

    2017-07-01

    Research on deep hibernators almost exclusively uses species captured from the wild or from local breeding. An exception is Syrian hamster (Mesocricetus auratus), the only standard laboratory animal showing deep hibernation. In deep hibernators, several factors influence hibernation quality, including body mass, sex and diet. We examined hibernation quality in commercially obtained Syrian hamsters in relation to body mass, sex and a diet enriched in polyunsaturated fatty acids. Animals (M/F:30/30, 12 weeks of age) were obtained from Harlan (IN, USA) and individually housed at 21 °C and L:D 14:10 until 20 weeks of age, followed by L:D 8:16 until 27 weeks. Then conditions were changed to 5 °C and L:D 0:24 for 9 weeks to induce hibernation. Movement was continuously monitored with passive infrared detectors. Hamsters were randomized to control diet or a diet 3× enriched in linoleic acid from 16 weeks of age. Hamsters showed a high rate of premature death (n = 24, 40%), both in animals that did and did not initiate torpor, which was unrelated to body weight, sex and diet. Time to death (31.7 ± 3.1 days, n = 12) or time to first torpor bout (36.6 ± 1.6 days, n = 12) was similar in prematurely deceased hamsters. Timing of induction of hibernation and duration of torpor and arousal was unaffected by body weight, sex or diet. Thus, commercially obtained Syrian hamsters subjected to winter conditions showed poor survival, irrespective of body weight, sex and diet. These factors also did not affect hibernation parameters. Possibly, long-term commercial breeding from a confined genetic background has selected against the hibernation trait.

  7. Transmission and adaptation of chronic wasting disease to hamsters and transgenic mice: evidence for strains.

    PubMed

    Raymond, Gregory J; Raymond, Lynne D; Meade-White, Kimberly D; Hughson, Andrew G; Favara, Cynthia; Gardner, Donald; Williams, Elizabeth S; Miller, Michael W; Race, Richard E; Caughey, Byron

    2007-04-01

    In vitro screening using the cell-free prion protein conversion system indicated that certain rodents may be susceptible to chronic wasting disease (CWD). Therefore, CWD isolates from mule deer, white-tailed deer, and elk were inoculated intracerebrally into various rodent species to assess the rodents' susceptibility and to develop new rodent models of CWD. The species inoculated were Syrian golden, Djungarian, Chinese, Siberian, and Armenian hamsters, transgenic mice expressing the Syrian golden hamster prion protein, and RML Swiss and C57BL10 wild-type mice. The transgenic mice and the Syrian golden, Chinese, Siberian, and Armenian hamsters had limited susceptibility to certain of the CWD inocula, as evidenced by incomplete attack rates and long incubation periods. For serial passages of CWD isolates in Syrian golden hamsters, incubation periods rapidly stabilized, with isolates having either short (85 to 89 days) or long (408 to 544 days) mean incubation periods and distinct neuropathological patterns. In contrast, wild-type mouse strains and Djungarian hamsters were not susceptible to CWD. These results show that CWD can be transmitted and adapted to some species of rodents and suggest that the cervid-derived CWD inocula may have contained or diverged into at least two distinct transmissible spongiform encephalopathy strains.

  8. A hamster model for Marburg virus infection accurately recapitulates Marburg hemorrhagic fever

    PubMed Central

    Marzi, Andrea; Banadyga, Logan; Haddock, Elaine; Thomas, Tina; Shen, Kui; Horne, Eva J.; Scott, Dana P.; Feldmann, Heinz; Ebihara, Hideki

    2016-01-01

    Marburg virus (MARV), a close relative of Ebola virus, is the causative agent of a severe human disease known as Marburg hemorrhagic fever (MHF). No licensed vaccine or therapeutic exists to treat MHF, and MARV is therefore classified as a Tier 1 select agent and a category A bioterrorism agent. In order to develop countermeasures against this severe disease, animal models that accurately recapitulate human disease are required. Here we describe the development of a novel, uniformly lethal Syrian golden hamster model of MHF using a hamster-adapted MARV variant Angola. Remarkably, this model displayed almost all of the clinical features of MHF seen in humans and non-human primates, including coagulation abnormalities, hemorrhagic manifestations, petechial rash, and a severely dysregulated immune response. This MHF hamster model represents a powerful tool for further dissecting MARV pathogenesis and accelerating the development of effective medical countermeasures against human MHF. PMID:27976688

  9. A hamster model for Marburg virus infection accurately recapitulates Marburg hemorrhagic fever.

    PubMed

    Marzi, Andrea; Banadyga, Logan; Haddock, Elaine; Thomas, Tina; Shen, Kui; Horne, Eva J; Scott, Dana P; Feldmann, Heinz; Ebihara, Hideki

    2016-12-15

    Marburg virus (MARV), a close relative of Ebola virus, is the causative agent of a severe human disease known as Marburg hemorrhagic fever (MHF). No licensed vaccine or therapeutic exists to treat MHF, and MARV is therefore classified as a Tier 1 select agent and a category A bioterrorism agent. In order to develop countermeasures against this severe disease, animal models that accurately recapitulate human disease are required. Here we describe the development of a novel, uniformly lethal Syrian golden hamster model of MHF using a hamster-adapted MARV variant Angola. Remarkably, this model displayed almost all of the clinical features of MHF seen in humans and non-human primates, including coagulation abnormalities, hemorrhagic manifestations, petechial rash, and a severely dysregulated immune response. This MHF hamster model represents a powerful tool for further dissecting MARV pathogenesis and accelerating the development of effective medical countermeasures against human MHF.

  10. EMODIN DOWNREGULATES CELL PROLIFERATION MARKERS DURING DMBA INDUCED ORAL CARCINOGENESIS IN GOLDEN SYRIAN HAMSTERS.

    PubMed

    Manimaran, Asokan; Buddhan, Rajamanickam; Manoharan, Shanmugam

    2017-01-01

    Cell-cycle disruption is the major characteristic features of neoplastic transformation and the status of cell-cycle regulators can thus be utilized to assess the prognostic significance in patients with cancer. The PCNA, cyclin D1, CDK4, CDK6 and survivin expression in the buccal mucosa was utilized to evaluate the Emodin efficacy on abnormal cell proliferation during 7,12-dimethylbenz(a)anthracene (DMBA) induced oral carcinogenesis in golden Syrian hamsters. Topical application of DMBA, three times a week for 14 weeks, on the hamsters' buccal pouches developed well differentiated squamous cell carcinoma. Cyclin D1 and PCNA over-expression and up-regulation of CDK4, CDK6 and survivin were noticed in the buccal mucosa of hamsters treated with DMBA alone. Emodin administration (50mg/kg b.w) orally to hamsters treated with DMBA down-regulated the expression of cell proliferation markers in the buccal mucosa. The anti-cell proliferative role of Emodin is owing to its modulating efficacy on cell-cycle markers towards the tumor suppression during DMBA induced oral carcinogenesis.

  11. Development of novel DNA markers for genetic analysis of grey hamsters by cross-species amplification of microsatellites.

    PubMed

    Wang, C; Zhang, S J; Du, X Y; Xu, Y M; Huo, X Y; Liao, L F; Chen, Z W

    2015-11-13

    The grey hamster has been used in biomedical research for decades. However, effective molecular methods for evaluating the genetic structure of this species are lacking, which hinders its wider usage. In this study, we employed cross-amplification of microsatellite loci of species within the same genus by polymerase chain reaction. Loci screened included 107 from the Mongolian gerbil (MG) and 60 from the Chinese hamster (CH); of these, 15 polymorphic loci were identified for the grey hamster. Of the 167 loci screened, 95 (56.9%) with clear bands on agarose gel were initially identified. After sequencing, 74 (77.9%) of these matched the criteria for microsatellite characteristics, including 41 from MG and 33 from CH. Lastly, 15 (20.3%) loci with more than two alleles for each locus were identified through capillary electrophoresis scanning. To justify the applicability of the 15 grey hamster loci, genetic indexes of grey hamsters were evaluated using 46 generations of outbred stock, established 20 years ago, from Xinjiang, China. Mean effective allele numbers and expected heterozygosity of stock were as low as, respectively, 1.2 and 0.14; these were 2.8 and 4.0 times inferior, respectively, to wild grey hamsters. This finding suggests that the genetic structure of the stock-bred population is too weak to resist artificial and natural selection, mutation and genetic drifting. In conclusion, we have developed de novo microsatellite markers for genetic analysis of the grey hamster, providing data and methodology for the enrichment of a genetic library for this species.

  12. Induction of carcinomas and sarcomas by 9,10-dimethyl-1,2-benzanthracene administration into the hamster maxillary sinus.

    PubMed

    Yura, Y; Tsujimoto, H; Kusaka, J; Harada, K; Yoshida, H; Sato, M

    1995-03-01

    To determine whether the local administration of 9,10-dimethyl-1,2-benzanthracene (DMBA) into the hamster maxillary sinus induced carcinoma at the injected site, hamsters were injected with 30 microliters of 0.5% solution of DMBA in dimethyl sulfoxide (DMSO) through the infraorbital foramen into the maxillary sinus once weekly for 10 weeks (Group 2). Another group of hamsters (Group 1) received similar injections of 30 microliters of DMSO only. In a third group of animals (Group 3), a roll of oxycellulose was inserted into the maxillary sinus and 40 microliters of a 2% solution of DMBA in DMSO was injected once. Sinonasal carcinomas were demonstrated in 73% (8/11) of the hamsters in Group 2 and sarcomas were shown in 73% (8/11) of the hamsters in Group 3, as well as some carcinomas. No tumors were seen in the Group 1 hamsters. Histologic examination revealed squamous cell carcinomas arising from the surface epithelium and submucous glands of the nasal cavity and maxillary sinus. These findings indicate that the intrasinal administration of a 0.5% solution of DMBA in DMSO is a reliable method for inducing maxillary sinus cancer.

  13. Serotonin modulates anxiety-like behaviors during withdrawal from adolescent anabolic–androgenic steroid exposure in Syrian hamsters

    PubMed Central

    Ricci, Lesley A.; Morrison, Thomas R.; Melloni, Richard H.

    2013-01-01

    From the U.S. to Europe and Australia anabolic steroid abuse remains high in the adolescent population. This is concerning given that anabolic steroid use is associated with a higher incidence of pathological anxiety that often appears during withdrawal from use. This study uses pubertal Syrian hamsters (Mesocricetus auratus) to investigate the hypothesis that adolescent anabolic/androgenic steroid (AAS) exposure predisposes hamsters to heightened levels of anxiety during AAS withdrawal that is modulated by serotonin (5HT) neural signaling. In the first two sets of experiments, adolescent AAS-treated hamsters were tested for anxiety 21 days after the cessation of AAS administration (i.e., during AAS withdrawal) using the elevated plus maze (EPM), dark/light (DL), and seed finding (SF) tests and then examined for differences in 5HT afferent innervation to select areas of the brain important for anxiety. In the EPM and DL tests, adolescent AAS exposure leads to significant increases in anxiety-like response during AAS withdrawal. AAS-treated hamsters showed long-term reductions in 5HT innervation within several areas of the hamster brain implicated in anxiety, most notably the anterior hypothalamus and the central and medial amygdala. However, no differences in 5HT were found in other anxiety areas, e.g., frontal cortex and lateral septum. In the last experiment, adolescent AAS-treated hamsters were scored for anxiety on the 21st day of AAS withdrawal following the systemic administration of saline or one of three doses of fluoxetine, a selective serotonin reuptake inhibitor. Saline-treated hamsters showed high levels of AAS withdrawal-induced anxiety, while treatment with fluoxetine reduced AAS withdrawal-induced anxiety. These findings indicate that early AAS exposure has potent anxiogenic effects during AAS withdrawal that are modulated, in part, by 5HT signaling. PMID:23026540

  14. Loss of LCAT activity in the golden Syrian hamster elicits pro-atherogenic dyslipidemia and enhanced atherosclerosis.

    PubMed

    Dong, Zhao; Shi, Haozhe; Zhao, Mingming; Zhang, Xin; Huang, Wei; Wang, Yuhui; Zheng, Lemin; Xian, Xunde; Liu, George

    2018-06-01

    Lecithin cholesterol acyltransferase (LCAT) plays a pivotal role in HDL metabolism but its influence on atherosclerosis remains controversial for decades both in animal and clinical studies. Because lack of cholesteryl ester transfer protein (CETP) is a major difference between murine and humans in lipoprotein metabolism, we aimed to create a novel Syrian Golden hamster model deficient in LCAT activity, which expresses endogenous CETP, to explore its metabolic features and particularly the influence of LCAT on the development of atherosclerosis. CRISPR/CAS9 gene editing system was employed to generate mutant LCAT hamsters. The characteristics of lipid metabolism and the development of atherosclerosis in the mutant hamsters were investigated using various conventional methods in comparison with wild type control animals. Hamsters lacking LCAT activity exhibited pro-atherogenic dyslipidemia as diminished high density lipoprotein (HDL) and ApoAI, hypertriglyceridemia, Chylomicron/VLDL accumulation and significantly increased ApoB100/48. Mechanistic study for hypertriglyceridemia revealed impaired LPL-mediated lipolysis and increased very low density lipoprotein (VLDL) secretion, with upregulation of hepatic genes involved in lipid synthesis and transport. The pro-atherogenic dyslipidemia in mutant hamsters was exacerbated after high fat diet feeding, ultimately leading to near a 3- and 5-fold increase in atherosclerotic lesions by aortic en face and sinus lesion quantitation, respectively. Our findings demonstrate that LCAT deficiency in hamsters develops pro-atherogenic dyslipidemia and promotes atherosclerotic lesion formation. Published by Elsevier Inc.

  15. Human sperm chromosome analysis after subzonal sperm insemination of hamster oocytes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cozzi, J.

    1994-09-01

    Sperm microinjection techniques, subzonal sperm insemination (SUZI) and intracytoplasmic sperm injection (ICSI), have achieved a wide spread clinical application for the treatment of male infertility. To date, only one study has focused on sperm karyotypes after microinjection. Martin et al. reported a very high incidence of abnormal human sperm complements after ICSI into hamster oocytes. In the present study, are reported the first human sperm karyotypes after SUZI of hamster oocytes. Spermatozoa from two control donors were treated by calcium ionophore A23187 and injected under the zona of hamster eggs. The microinjected eggs were then cultured for cytogenetic analysis ofmore » the pronuclei. Out of 47 analyzed sperm chromosome metaphases, 5 (10.6%) were abnormal, 4 (8.5%) were hypohaploid and 1 (2.1%) had a structural abnormality. The sex ratio was not significantly different from the expected 1:1 ratio. Rates of chromosomal abnormalities in microinjected spermatozoa were similar to those observed in spermatozoa inseminated with zona free eggs, suggesting that SUZI procedure per se does not increase sperm chromosomal abnormalities.« less

  16. Evaluation of selected antiprotozoal drugs in the Babesia microti-hamster model.

    PubMed Central

    Marley, S E; Eberhard, M L; Steurer, F J; Ellis, W L; McGreevy, P B; Ruebush, T K

    1997-01-01

    The presently used therapy for Babesia microti infections, a combination of quinine and clindamycin, does not always result in parasitologic cures. To identify possible alternative chemotherapeutic agents for such infections, we screened, in the hamster-B. microti system, 12 antiprotozoal drugs that have either recently been released for human use or were in experimental stages of development at the Walter Reed Army Institute of Research for the treatment of malaria and leishmaniasis. Several well-recognized antimalarial drugs, such as mefloquine, halofantrine, artesunate, and artelenic acid, exhibited little or no effect on parasitemia. Two 8-aminoquinolines, WR006026 [8-(6-diethylaminohexylamino)-6-methoxy-4-methylquinoline dihydrochloride] and WR238605 [8-[(4-amino-1-methylbutyl)amino]-2,6-dimethoxy-4-methyl-5 -(3-trifluoromethylphenoxy-7) quinoline succinate], produced clearance of patent parasitemia. Furthermore, blood from infected hamsters treated with WR238605 via an intramuscular injection failed to infect naive hamsters on subpassage, thus producing a parasitologic cure. These two compounds merit further screening in other systems and may prove useful in treating human babesiosis. PMID:8980761

  17. Kisspeptin mediates the photoperiodic control of reproduction in hamsters.

    PubMed

    Revel, Florent G; Saboureau, Michel; Masson-Pévet, Mireille; Pévet, Paul; Mikkelsen, Jens D; Simonneaux, Valérie

    2006-09-05

    The KiSS-1 gene encodes kisspeptin, the endogenous ligand of the G-protein-coupled receptor GPR54. Recent data indicate that the KiSS-1/GPR54 system is critical for the regulation of reproduction and is required for puberty onset. In seasonal breeders, reproduction is tightly controlled by photoperiod (i.e., day length). The Syrian hamster is a seasonal model in which reproductive activity is promoted by long summer days (LD) and inhibited by short winter days (SD). Using in situ hybridization and immunohistochemistry, we show that KiSS-1 is expressed in the arcuate nucleus of LD hamsters. Importantly, the KiSS-1 mRNA level was lower in SD animals but not in SD-refractory animals, which spontaneously reactivated their sexual activity after several months in SD. These changes of expression are not secondary to the photoperiodic variations of gonadal steroids. In contrast, melatonin appears to be necessary for these seasonal changes because pineal-gland ablation prevented the SD-induced downregulation of KiSS-1 expression. Remarkably, a chronic administration of kisspeptin-10 restored the testicular activity of SD hamsters despite persisting photoinhibitory conditions. Overall, these findings are consistent with a role of KiSS-1/GPR54 in the seasonal control of reproduction. We propose that photoperiod, via melatonin, modulates KiSS-1 signaling to drive the reproductive axis.

  18. Experimental Infection of Syrian Hamsters with Aerosolized Nipah virus.

    PubMed

    Escaffre, Olivier; Hill, Terence; Ikegami, Tetsuro; Juelich, Terry L; Smith, Jennifer K; Zhang, Lihong; Perez, David E; Atkins, Colm; Park, Arnold; Lawrence, William S; Sivasubramani, Satheesh K; Peel, Jennifer E; Peterson, Johnny W; Lee, Benhur; Freiberg, Alexander N

    2018-06-15

    Nipah virus (NiV) is a paramyxovirus (genus henipavirus) that can cause severe respiratory illness and encephalitis in humans. Transmission occurs through consumption of NiV-contaminated foods, and contact with NiV-infected animals or human body fluids. However, it is unclear whether aerosols derived from aforesaid sources or others also contribute to transmission, and current knowledge on NiV-induced pathogenicity after small particle aerosol exposure is still limited. infectivity, pathogenicity and real-time dissemination of aerosolized NiV in Syrian hamsters was evaluated using NiV-Malaysia (NiV-M) and/or its recombinant expressing firefly luciferase (rNiV-Fluc NP). both viruses had an equivalent pathogenicity in hamsters that developed respiratory and neurological symptoms of disease, similar to using intranasal route, with no direct correlations to the dose. Finally, we show that virus replication was predominantly initiated in the lower respiratory tract, and although delayed, also intensely in the oronasal cavity and possibly the brain, with gradual increase of signal in these regions until at least day 5-6 post-infection. hamsters infected with small-particle aerosolized NiV undergo similar clinical manifestations of the disease as previously described using liquid inoculum, and exhibit histopathological lesions consistent with NiV patient reports. NiV droplets could therefore play a role in transmission by close contact.

  19. EMODIN EFFICACY ON THE AKT, MAPK, ERK AND DNMT EXPRESSION PATTERN DURING DMBA-INDUCED ORAL CARCINOMA IN GOLDEN SYRIAN HAMSTERS.

    PubMed

    Manimaran, Asokan; Manoharan, Shanmugam; Neelakandan, Mani

    2016-01-01

    The present study has evaluated the Emodin efficacy on the Akt, MAPK, ERK and DNMT expression pattern during 7,12-dimethylbenz[a]anthracene (DMBA)-induced oral carcinoma in golden Syrian hamsters, in order to explore its antitumor potential. Oral tumors were developed in the buccal pouches of golden Syrian hamsters using the carcinogen, DMBA. While the incidence of tumor formation was 100% in hamsters treated with DMBA alone, the tumor formation was not noticed in DMBA+ Emodin treated hamsters. Also, Emodin reduced the severity of precancerous pathological lesions such as dysplasia, in the hamsters treated with DMBA. Emodin administration corrected the abnormalities in the expression pattern of Akt, MAPK, ERK and DNMT in the buccal mucosa of hamsters treated with DMBA. The present study thus suggests that the tumor preventive potential of Emodin is partly related to its modulating effect on the Akt, MAPK, ERK and DNMT expression pattern, as these molecular markers have a pivotal role in the process of cell proliferation, inflammation, invasion, and apoptosis.

  20. Effects of diurnal variation and anesthetic agents on intraocular pressure in Syrian hamsters (Mesocricetus auratus).

    PubMed

    Rajaei, Seyed Mehdi; Mood, Maneli Ansari; Paryani, Mohammad Reza; Williams, David L

    2017-01-01

    OBJECTIVE To determine effects of diurnal variation and anesthetic agents on intraocular pressure (IOP) in Syrian hamsters (Mesocricetus auratus). ANIMALS 90 healthy adult Syrian hamsters (45 males and 45 females). PROCEDURES IOP was measured with a rebound tonometer. In phase 1, IOP was measured in all hamsters 3 times during a 24-hour period (7 am, 3 pm, and 11 pm). In phase 2, hamsters were assigned to 5 groups (18 animals [9 males and 9 females]/group). Each group received an anesthetic agent or combination of anesthetic agents (ketamine hydrochloride, xylazine hydrochloride, diazepam, ketamine-diazepam [KD], or ketamine-xylazine [KX] groups) administered via the IP route. The IOP was measured before (time 0 [baseline]) and 10, 30, 60, 90, 120, and 150 minutes after administration of drugs. RESULTS Mean ± SD IOP values were 2.58 ± 0.87 mm Hg, 4.46 ± 1.58 mm Hg, and 5.96 ± 1.23 mm Hg at 7 am, 3 pm, and 11 pm, respectively. Mean baseline IOP was 6.25 ± 0.28 mm Hg, 6.12 ± 0.23 mm Hg, 5.75 ± 0.64 mm Hg, 5.12 ± 1.40 mm Hg, and 4.50 ± 1.30 mm Hg for the ketamine, xylazine, diazepam, KD, and KX groups, respectively. A significant decrease in IOP, compared with baseline IOP, was detected in only the KX group at 30, 60, and 90 minutes after drug administration. CONCLUSIONS AND CLINICAL RELEVANCE Maximum IOP in Syrian hamsters was detected at night. The ketamine-xylazine anesthetic combination significantly decreased IOP in Syrian hamsters.

  1. The Hamster Model for Identification of Specific Antigens of Taenia solium Tapeworms

    PubMed Central

    Ochoa-Sánchez, Alicia; Jiménez, Lucía; Landa, Abraham

    2011-01-01

    Humans acquire taeniasis by ingesting pork meat infected with Taenia solium cysticerci, which are the only definitive hosts of the adult stage (tapeworm) and responsible for transmitting the human and porcine cysticercosis. Hence, detection of human tapeworm carriers is a key element in the development of viable strategies to control the disease. This paper presents the identification of specific antigens using sera from hamsters infected with T. solium tapeworms analyzed by western blot assay with crude extracts (CEs) and excretion-secretion antigens (E/S Ag) obtained from T. solium cysticerci and tapeworms and extracts from other helminthes as controls. The hamster sera infected with T. solium tapeworms recognized specific bands of 72, 48, 36, and 24 kDa, in percentages of 81, 81, 90, and 88%, respectively, using the T. solium tapeworms E/S Ag. The antigens recognized by these hamster sera could be candidates to improve diagnosis of human T. solium taeniasis. PMID:22253530

  2. Zika virus infection of adult and fetal STAT2 knock-out hamsters.

    PubMed

    Siddharthan, Venkatraman; Van Wettere, Arnaud J; Li, Rong; Miao, Jinxin; Wang, Zhongde; Morrey, John D; Julander, Justin G

    2017-07-01

    Zika virus (ZIKV) infection was investigated in adult and fetal STAT2 knock-out (KO) hamsters. Subcutaneous injection of ZIKV of adults resulted in morbidity, mortality, and infection of the uterus, placenta, brain, spinal cord, and testicles, thus providing an opportunity to evaluate congenital ZIKV infection in a second rodent species besides mice. ZIKV-infected cells with morphologies of Sertoli cells and spermatogonia were observed in the testes, which may have implications for sexual transmission and male sterility. Neonates exposed as fetuses to ZIKV at 8 days post-coitus were not smaller than controls. Nevertheless, infectious virus and ZIKV RNA was detected in some, but not all, placentas and fetal brains of KO hamsters. STAT2 KO hamsters may be useful for addressing sexual transmission, pathogenesis, routes of fetal infection, and neurological disease outcomes, and may also be used in antiviral or vaccine studies to identify intervention strategies. Copyright © 2017. Published by Elsevier Inc.

  3. Dorsal shaving affects concentrations of faecal cortisol metabolites in lactating golden hamsters.

    PubMed

    Ohrnberger, Sarah A; Brinkmann, Katharina; Palme, Rupert; Valencak, Teresa G

    2018-01-15

    Breeding of golden hamsters is classically performed at thermal conditions ranging from 20 to 24 °C. However, growing evidence suggests that lactating females suffer from heat stress. We hypothesised that shaving females dorsally to maximise heat dissipation may reduce stress during reproduction. We thus compared faecal cortisol metabolites (FCM) from shaved golden hamster mothers with those from unshaved controls. We observed significantly lower FCM levels in the shaved mothers (F 1,22  = 8.69, p = 0.0075) pointing to lower stress due to ameliorated heat dissipation over the body surface. In addition, we observed 0.4 °C lower mean subcutaneous body temperatures in the shaved females, although this effect did not reach significance (F 1,22  = 1.86, p = 0.18). Our results suggest that golden hamsters having body masses being more than four times that of laboratory mice provide a very interesting model to study aspects of lactation and heat production at the same time.

  4. Dorsal shaving affects concentrations of faecal cortisol metabolites in lactating golden hamsters

    NASA Astrophysics Data System (ADS)

    Ohrnberger, Sarah A.; Brinkmann, Katharina; Palme, Rupert; Valencak, Teresa G.

    2018-02-01

    Breeding of golden hamsters is classically performed at thermal conditions ranging from 20 to 24 °C. However, growing evidence suggests that lactating females suffer from heat stress. We hypothesised that shaving females dorsally to maximise heat dissipation may reduce stress during reproduction. We thus compared faecal cortisol metabolites (FCM) from shaved golden hamster mothers with those from unshaved controls. We observed significantly lower FCM levels in the shaved mothers ( F 1,22 = 8.69, p = 0.0075) pointing to lower stress due to ameliorated heat dissipation over the body surface. In addition, we observed 0.4 °C lower mean subcutaneous body temperatures in the shaved females, although this effect did not reach significance ( F 1,22 = 1.86, p = 0.18). Our results suggest that golden hamsters having body masses being more than four times that of laboratory mice provide a very interesting model to study aspects of lactation and heat production at the same time.

  5. Amino Acid Concentrations in the Hamster Central Auditory System and Long-Term Effects of Intense Tone Exposure

    PubMed Central

    Godfrey, Donald A.; Kaltenbach, James A.; Chen, Kejian; Ilyas, Omer; Liu, Xiaochen; Licari, Frank; Sacks, Justin; McKnight, Darwin

    2015-01-01

    Exposure to intense sounds often leads to loss of hearing of environmental sounds and hearing of a monotonous tonal sound not actually present, a condition known as tinnitus. Chronic physiological effects of exposure to intense tones have been reported for animals and should be accompanied by chemical changes present at long times after the intense sound exposure. By using a microdissection mapping procedure combined with high-performance liquid chromatography (HPLC), we have measured concentrations of nine amino acids, including those used as neurotransmitters, in the cochlear nucleus, inferior colliculus, medial geniculate, and auditory cortex of hamsters 5 months after exposure to an intense tone, compared with control hamsters of the same age. No very large differences in amino acid concentrations were found between exposed and control hamsters. However, increases of glutamate and γ-aminobutyrate (GABA) in some parts of the inferior colliculus of exposed hamsters were statistically significant. The most consistent differences between exposed and control hamsters were higher aspartate and lower taurine concentrations in virtually all regions of exposed hamsters, which reached statistical significance in many cases. Although these amino acids are not considered likely neurotransmitters, they indirectly have roles in excitatory and inhibitory neurotransmission, respectively. Thus, there is evidence for small, widespread, long-term increases in excitatory transmission and decreases in inhibitory transmission after a level of acoustic trauma previously shown to produce hearing loss and tinnitus. PMID:22715056

  6. Lack of A-factor production induces the expression of nutrient scavenging and stress-related proteins in Streptomyces griseus.

    PubMed

    Birkó, Zsuzsanna; Swiatek, Magdalena; Szájli, Emília; Medzihradszky, Katalin F; Vijgenboom, Erik; Penyige, András; Keseru, Judit; van Wezel, Gilles P; Biró, Sándor

    2009-10-01

    The small gamma-butyrolactone A-factor is an important autoregulatory signaling molecule for the soil-inhabiting streptomycetes. Starvation is a major trigger for development, and nutrients are provided by degradation of the vegetative mycelium via a process of programmed cell death, reusing proteins, nucleic acids, and cell wall material. The A-factor regulon includes many extracellular hydrolases. Here we show via proteomics analysis that many nutrient-scavenging and stress-related proteins were overexpressed in an A-factor non-producing mutant of Streptomyces griseus B-2682. Transcript analysis showed that this is primarily due to differential transcription of the target genes during early development. The targets include proteins relating to nutrient stress and environmental stress and an orthologue of the Bacillus sporulation control protein Spo0M. The enhanced expression of these proteins underlines the stress that is generated by the absence of A-factor. Wild-type developmental gene expression was restored to the A-factor non-producing mutant by the signaling protein Factor C in line with our earlier observation that Factor C triggers A-factor production.

  7. Cardiovascular protection of deep-seawater drinking water in high-fat/cholesterol fed hamsters.

    PubMed

    Hsu, Chin-Lin; Chang, Yuan-Yen; Chiu, Chih-Hsien; Yang, Kuo-Tai; Wang, Yu; Fu, Shih-Guei; Chen, Yi-Chen

    2011-08-01

    Cardiovascular protection of deep-seawater (DSW) drinking water was assessed using high-fat/cholesterol-fed hamsters in this study. All hamsters were fed a high-fat/cholesterol diet (12% fat/0.2% cholesterol), and drinking solutions were normal distiled water (NDW, hardness: 2.48ppm), DSW300 (hardness: 324.5ppm), DSW900 (hardness: 858.5ppm), and DSW1500 (hardness: 1569.0ppm), respectively. After a 6-week feeding period, body weight, heart rates, and blood pressures of hamsters were not influenced by DSW drinking waters. Serum total cholesterol (TC), triacylglycerol (TAG), atherogenic index, and malondialdehyde (MDA) levels were decreased (p<0.05) in the DSW-drinking-water groups, as compared to those in the NDW group. Additionally, increased (p<0.05) serum Trolox equivalent antioxidant capacity (TEAC), and faecal TC, TAG, and bile acid outputs were measured in the DSW-drinking-water groups. Hepatic low-density-lipoprotein receptor (LDL receptor) and cholesterol-7α-hydroxylase (CYP7A1) gene expressions were upregulated (p<0.05) by DSW drinking waters. These results demonstrate that DSW drinking water benefits the attenuation of high-fat/cholesterol-diet-induced cardiovascular disorders in hamsters. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Adapting to alcohol: Dwarf hamster (Phodopus campbelli) ethanol consumption, sensitivity, and hoard fermentation.

    PubMed

    Lupfer, Gwen; Murphy, Eric S; Merculieff, Zoe; Radcliffe, Kori; Duddleston, Khrystyne N

    2015-06-01

    Ethanol consumption and sensitivity in many species are influenced by the frequency with which ethanol is encountered in their niches. In Experiment 1, dwarf hamsters (Phodopus campbelli) with ad libitum access to food and water consumed high amounts of unsweetened alcohol solutions. Their consumption of 15%, but not 30%, ethanol was reduced when they were fed a high-fat diet; a high carbohydrate diet did not affect ethanol consumption. In Experiment 2, intraperitoneal injections of ethanol caused significant dose-related motor impairment. Much larger doses administered orally, however, had no effect. In Experiment 3, ryegrass seeds, a common food source for wild dwarf hamsters, supported ethanol fermentation. Results of these experiments suggest that dwarf hamsters may have adapted to consume foods in which ethanol production naturally occurs. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Body temperature circadian rhythm variability corresponds to left ventricular systolic dysfunction in decompensated cardiomyopathic hamsters.

    PubMed

    Ahmed, Amany; Gondi, Sreedevi; Cox, Casey; Zheng, Minjuan; Mohammed, Anwarullah; Stupin, Igor V; Wang, Suwei; Vela, Deborah; Brewer, Alan; Elayda, Macarthur A; Buja, L Maximilian; Ward Casscells, S; Wilson, James M

    2011-11-01

    A declining amplitude of body temperature circadian rhythm (BTCR) predicts decompensation or death in cardiomyopathic hamsters. We tested the hypothesis that changes in BTCR amplitude accompany significant changes in left ventricular (LV) size and function. Using intraperitoneal transmitters, we continuously monitored the temperature of 30 male BIO TO-2 Syrian dilated cardiomyopathic hamsters. Cosinor analysis was used to detect significant changes--defined as changes >1 standard deviation from the baseline amplitude for 3 consecutive days--in BTCR amplitude over each hamster's lifespan. The Student t-test was used to compare BTCR variability and LV size and function (as assessed by 2D echocardiography) between baseline and the time that BTCR amplitude declined. All hamsters received 10 mg/kg furosemide daily. At the time of BTCR amplitude decline, functional parameters had changed significantly (P < .0001) from baseline: ejection fraction (0.31 ± 0.09% vs. 0.52 ± 0.08%), LV end-systolic volume (0.11 ± 0.03 vs. 0.05 ± 0.02 cm(3)), and LV end-diastolic volume (0.16 ± 0.04 vs. 0.10 ± 0.03 cm(3)). In decompensated cardiomyopathic hamsters, a decline in BTCR amplitude was associated with progression of heart failure and cardiac decompensation. Variation in BTCR warrants further investigation because of its potential implications for the diagnosis and treatment of cardiovascular disorders. Published by Elsevier Inc.

  10. Progesterone's 5 alpha-reduced metabolite, 3 alpha,5 alpha-THP, mediates lateral displacement of hamsters.

    PubMed

    Frye, Cheryl A; Rhodes, Madeline E

    2005-03-15

    5 alpha-Pregnan-3 alpha-ol-20-one (3 alpha,5 alpha-THP), progesterone (P4)'s 5 alpha-reduced, 3 alpha-hydroxysteroid oxidoreduced product, facilitates lordosis of rodents in part via agonist-like actions at GABA(A)/benzodiazepine receptor complexes in the ventral tegmental area (VTA). Whether 3 alpha,5 alpha-THP influences another reproductively-relevant behavior, lateral displacement, of hamsters was investigated. Lateral displacement is the movement that female hamsters make with their perineum towards male-like tactile stimulation. This behavior facilitates, and is essential for, successful mating. Hamsters in behavioral estrus had greater lateral displacement responses when endogenous progestin levels were elevated compared to when progestin levels were lower. Administration of P4, a prohormone for 3 alpha,5 alpha-THP, dose-dependently (500 > 200 > 100, 50, or 0 microg) enhanced lateral displacement of ovariectomized hamsters that had been primed with SC estradiol benzoate (5 or 10 microg). Inhibiting P4's metabolism to 3 alpha,5 alpha-THP by co-administering finasteride, a 5 alpha-reductase inhibitor, or indomethacin, a 3 alpha-hydroxysteroid oxidoreductase inhibitor, either systemically or to the VTA, significantly decreased lateral displacement and midbrain progestin levels of naturally receptive or hormone-primed hamsters compared to controls. These data suggest that lateral displacement is progestin-sensitive and requires the formation of 3 alpha,5 alpha-THP in the midbrain VTA.

  11. Effect of SO/sub 2/ on the clearance of Listeria monocytogenes from the lungs of emphysematous hamsters

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Trimpe, K.L.; Weiss, H.; Zwilling, B.S.

    1986-10-01

    The effect of sulfur dioxide on the clearance of Listeria monocytogenes from normal and emphysematous hamsters was assessed by measuring the number of colony forming units recovered from whole lung homogenates. Continuous exposure to SO/sub 2/ after intratracheal instillation of Listeria significantly altered the clearance of viable bacteria from the lungs of emphysematous but not normal hamsters. Pre-exposure of hamsters to SO/sub 2/ for 2 weeks prior to respiratory infection had similar effects. The emphysematous hamsters exposed to SO/sub 2/ had a lower average number of Listeria in the lungs after the first week of infection than control groups. Thismore » effect appears to result from the combined influence of the SO/sub 2/, the Listeria infection, and the emphysematous condition within the lungs.« less

  12. Pharmacokinetics and pharmacodynamics of tetra(m-hydroxyphenyl)chlorin in the hamster cheek pouch tumor model: comparison with clinical measurements.

    PubMed

    Glanzmann, T; Forrer, M; Blant, S A; Woodtli, A; Grosjean, P; Braichotte, D; van den Bergh, H; Monnier, P; Wagnières, G

    2000-08-01

    The pharmacokinetics (PK) of the photosensitizer tetra(m-hydroxyphenyl)chlorin (mTHPC) was measured by optical fiber-based light-induced fluorescence spectroscopy (LIFS) in the normal and tumoral cheek pouch mucosa of 29 Golden Syrian hamsters with chemically induced squamous cell carcinoma. Similar measurements were carried out on the normal oral cavity mucosa of five patients up to 30 days after injection. The drug doses were between 0.15 and 0.3 mg per kg of body weight (mg/kg), and the mTHPC fluorescence in the tissue was excited at 420 nm. The PK in both human and hamster exhibited similar behavior although the PK in the hamster mucosa was slightly delayed in comparison with that of its human counterpart. The mTHPC fluorescence signal of the hamster mucosa was smaller than that of the human mucosa by a factor of about 3 for the same injected drug dose. A linear correlation was found between the fluorescence signal and the mTHPC dose in the range from 0.075 to 0.5 mg/kg at times between 8 and 96 h after injection. No significant selectivity in mTHPC fluorescence between the tumoral and normal mucosa of the hamsters was found at any of the applied conditions. The sensitivity of the normal and tumoral hamster cheek pouch mucosa to mTHPC photodynamic therapy as a function of the light dose was determined by light irradiation at 650 nm and 150 mW/cm2, 4 days after the injection of a drug dose of 0.15 mg/kg. These results were compared with irradiations of the normal oral and normal and tumoral bronchial mucosa of 37 patients under the same conditions. The reaction to PDT of both types of human mucosae was considerably stronger than that of the hamster cheek pouch mucosa. The sensitivity to PDT became comparable between hamster and human mucosa when the drug dose for the hamster was increased to 0.5 mg/kg. A significant therapeutic selectivity between the normal and neoplastic hamster cheek pouch was observed. Less selectivity was found following irradiations of

  13. Characterization of an N-Terminal Non-Core Domain of RAG1 Gene Disrupted Syrian Hamster Model Generated by CRISPR Cas9.

    PubMed

    Miao, Jinxin; Ying, Baoling; Li, Rong; Tollefson, Ann E; Spencer, Jacqueline F; Wold, William S M; Song, Seok-Hwan; Kong, Il-Keun; Toth, Karoly; Wang, Yaohe; Wang, Zhongde

    2018-05-06

    The accumulating evidence demonstrates that Syrian hamsters have advantages as models for various diseases. To develop a Syrian hamster ( Mesocricetus auratus ) model of human immunodeficiency caused by RAG1 gene mutations, we employed the CRISPR/Cas9 system and introduced an 86-nucleotide frameshift deletion in the hamster RAG1 gene encoding part of the N-terminal non-core domain of RAG1. Histological and immunohistochemical analyses demonstrated that these hamsters (referred herein as RAG1-86nt hamsters) had atrophic spleen and thymus, and developed significantly less white pulp and were almost completely devoid of splenic lymphoid follicles. The RAG1-nt86 hamsters had barely detectable CD3⁺ and CD4⁺ T cells. The expression of B and T lymphocyte-specific genes (CD3γ and CD4 for T cell-specific) and (CD22 and FCMR for B cell-specific) was dramatically reduced, whereas the expression of macrophage-specific (CD68) and natural killer (NK) cell-specific (CD94 and KLRG1) marker genes was increased in the spleen of RAG1-nt86 hamsters compared to wildtype hamsters. Interestingly, despite the impaired development of B and T lymphocytes, the RAG1-86nt hamsters still developed neutralizing antibodies against human adenovirus type C6 (HAdV-C6) upon intranasal infection and were capable of clearing the infectious viruses, albeit with slower kinetics. Therefore, the RAG1-86nt hamster reported herein (similar to the hypomorphic RAG1 mutations in humans that cause Omenn syndrome), may provide a useful model for studying the pathogenesis of the specific RAG1-mutation-induced human immunodeficiency, the host immune response to adenovirus infection and other pathogens as well as for evaluation of cell and gene therapies for treatment of this subset of RAG1 mutation patients.

  14. A quantitative description of flagellar movement in golden hamster spermatozoa.

    PubMed

    Ishijima, S; Mohri, H

    1985-01-01

    Flagellar movement of golden hamster spermatozoa obtained from the testis and the caput and cauda epididymides was observed by a light microscope while holding them at their heads with a micropipette. Flagellar movement of capacitated spermatozoa and of reactivated spermatozoa demembranated with Triton X-100 was also observed. Testicular and caput epididymal spermatozoa showed weak movement in Tyrode's solution, whereas cauda epididymal spermatozoa showed vigorous movement. The flagellar bends of the cauda epididymal spermatozoa were almost planar. Capacitated spermatozoa moved with waves of a large amplitude. Demembranated spermatozoa reactivated with ATP only had a latent period before the initiation of flagellar movement, and beat at low frequency, whereas demembranated spermatozoa reactivated with both ATP and cAMP began to move immediately at high frequency. Thrust and hydrodynamic power output were calculated using the parameters for the typical waveforms of cauda epididymal spermatozoa before and after capacitation. The possible role of the large amplitude beat in capacitated spermatozoa is discussed. A comparison of the 'principal' and 'reverse' bends in golden hamster sperm flagella as defined by Woolley (1977) with those in sea urchin sperm flagella suggests that the so-called 'principal' bend in golden hamster sperm flagella corresponds to the reverse bend in sea urchin sperm flagella and vice versa.

  15. 2-Deoxy-D-glucose, not mercaptoacetate, induces a reversible reduction of body temperature in male desert hamsters (Phodopus roborovskii).

    PubMed

    Chi, Qing-Sheng; Li, Xiu-Juan; Wang, De-Hua

    2018-01-01

    The initiation of torpor is supposed to be related to the availability of metabolic fuels. Studies on metabolic fuel inhibition of glucose by using 2-deoxy-D-glucose (2DG) or fatty acid by mercaptoacetate (MA) in heterothermic mammals produced mixed outcomes. To examine the roles of availability of glucose and fatty acid in the initiation of torpor in desert hamsters (Phodopus roborovskii), we intraperitoneally administrated 2DG and MA to summer-acclimated male hamsters while body temperature (T b ), metabolic rate (MR) and respiratory quotient (RQ) were simultaneously recorded to monitor their thermoregulatory response. 2DG induced a reversible reduction of T b in desert hamsters both at ambient temperature (T a ) of 23°C and 5°C. At T a of 23°C, T b , MR and RQ decreased in a dose-dependent manner with a large T b -T a differential (> 6.5°C) and a lowest T b of 28.0°C which were comparable to those in fasted hamsters. At T a of 5°C, 2DG-treated hamsters also decreased T b to the same level as at T a 23°C, but MR was significantly higher than that at T a of 23°C at each dose, suggesting doses of 2DG directly affected the hypothalamic T b set-point. Different from fasted hamsters which maintain normothermic at T a of 5°C, 2DG-treated hamsters showed a substantial reduction of T b at T a 5°C, indic a ting an overwhelming effect on the thermoregulatory system regardless of T a . Furthermore, the rapid decrease of T b and outstretched body posture in 2DG-treated hamsters suggest that the effects of 2DG were not simply mimicking the torpor pathways but that other mechanisms are involved. Interestingly, MA failed to induce a torpor-like state in male desert hamsters. Our results suggest that availability of glucose rather than fatty acid plays an important role for initiation of torpor in desert hamsters. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Characterization of the Host Response to Pichinde Virus Infection in the Syrian Golden Hamster by Species-Specific Kinome Analysis*

    PubMed Central

    Falcinelli, Shane; Gowen, Brian B.; Trost, Brett; Napper, Scott; Kusalik, Anthony; Johnson, Reed F.; Safronetz, David; Prescott, Joseph; Wahl-Jensen, Victoria; Jahrling, Peter B.; Kindrachuk, Jason

    2015-01-01

    The Syrian golden hamster has been increasingly used to study viral hemorrhagic fever (VHF) pathogenesis and countermeasure efficacy. As VHFs are a global health concern, well-characterized animal models are essential for both the development of therapeutics and vaccines as well as for increasing our understanding of the molecular events that underlie viral pathogenesis. However, the paucity of reagents or platforms that are available for studying hamsters at a molecular level limits the ability to extract biological information from this important animal model. As such, there is a need to develop platforms/technologies for characterizing host responses of hamsters at a molecular level. To this end, we developed hamster-specific kinome peptide arrays to characterize the molecular host response of the Syrian golden hamster. After validating the functionality of the arrays using immune agonists of defined signaling mechanisms (lipopolysaccharide (LPS) and tumor necrosis factor (TNF)-α), we characterized the host response in a hamster model of VHF based on Pichinde virus (PICV1) infection by performing temporal kinome analysis of lung tissue. Our analysis revealed key roles for vascular endothelial growth factor (VEGF), interleukin (IL) responses, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling, and Toll-like receptor (TLR) signaling in the response to PICV infection. These findings were validated through phosphorylation-specific Western blot analysis. Overall, we have demonstrated that hamster-specific kinome arrays are a robust tool for characterizing the species-specific molecular host response in a VHF model. Further, our results provide key insights into the hamster host response to PICV infection and will inform future studies with high-consequence VHF pathogens. PMID:25573744

  17. Infection of hamsters with historical and epidemic BI types of Clostridium difficile.

    PubMed

    Razaq, Nadia; Sambol, Susan; Nagaro, Kristin; Zukowski, Walter; Cheknis, Adam; Johnson, Stuart; Gerding, Dale N

    2007-12-15

    North American and European hospitals have reported outbreaks of Clostridium difficile-associated disease with unexpectedly high mortality caused by a newly recognized group of C. difficile strains, group BI. Our objective was to compare, in hamsters, the virulence of a historical nonepidemic BI type, BI1, with that of 2 recent epidemic BI types, BI6 and BI17, and with that of 2 standard toxigenic strains, K14 and 630. For each strain, 10 hamsters were given 1 dose of clindamycin, followed 5 days later with 100 C. difficile spores administered by gastric inoculation. Outcomes were recorded. The hamster model demonstrated variations in mean times from inoculation to death (for BI6, 40 h; for BI1, 48 h; for K14, 49 h; for BI17, 69 h; for 630, 102 h; for BI6, BI1, and K14 vs. 630, P< .01; for BI17 vs. 630, P< .05) and from colonization to death (for BI1, 7 h; for BI17, 13 h; for BI6, 16 h; for K14, 17 h; for 630, 52 h; for BI1, BI17, BI6, and K14 vs. 630, P< .01). Group BI strains were not more rapidly fatal than the standard toxinotype 0 strain K14 but were more rapidly fatal than the standard toxinotype 0 strain 630. BI6, the most common BI type in our collection, was particularly virulent in hamsters, consistently causing death within 48 h of inoculation.

  18. Unexpected Positive Buoyancy in Deep Sea Sharks, Hexanchus griseus, and a Echinorhinus cookei.

    PubMed

    Nakamura, Itsumi; Meyer, Carl G; Sato, Katsufumi

    2015-01-01

    We do not expect non air-breathing aquatic animals to exhibit positive buoyancy. Sharks, for example, rely on oil-filled livers instead of gas-filled swim bladders to increase their buoyancy, but are nonetheless ubiquitously regarded as either negatively or neutrally buoyant. Deep-sea sharks have particularly large, oil-filled livers, and are believed to be neutrally buoyant in their natural habitat, but this has never been confirmed. To empirically determine the buoyancy status of two species of deep-sea sharks (bluntnose sixgill sharks, Hexanchus griseus, and a prickly shark, Echinorhinus cookei) in their natural habitat, we used accelerometer-magnetometer data loggers to measure their swimming performance. Both species of deep-sea sharks showed similar diel vertical migrations: they swam at depths of 200-300 m at night and deeper than 500 m during the day. Ambient water temperature was around 15°C at 200-300 m but below 7°C at depths greater than 500 m. During vertical movements, all deep-sea sharks showed higher swimming efforts during descent than ascent to maintain a given swimming speed, and were able to glide uphill for extended periods (several minutes), indicating that these deep-sea sharks are in fact positively buoyant in their natural habitats. This positive buoyancy may adaptive for stealthy hunting (i.e. upward gliding to surprise prey from underneath) or may facilitate evening upward migrations when muscle temperatures are coolest, and swimming most sluggish, after spending the day in deep, cold water. Positive buoyancy could potentially be widespread in fish conducting daily vertical migration in deep-sea habitats.

  19. Intestinal transfer of choline in rat and hamster

    PubMed Central

    Sanford, P. A.; Smyth, D. H.

    1971-01-01

    1. The transfer of choline was studied with sacs of everted intestine of rat and hamster. 2. The choline transfer can be divided into two components, a diffusion process and a saturable process. The latter plays a relatively greater part at low concentrations of choline, which include the physiological concentration in the plasma. The saturable process is better seen in the hamster than in the rat. 3. Intestinal transfer of choline is influenced by substances altering the availability of energy in the cell, and by some substances chemically or pharmacologically related to choline. These findings are consistent with some kind of specific mechanism for choline transfer. 4. Part of the choline taken up by the cell appears as a metabolite not yet identified. The formation of the metabolite is a saturable process and is abolished by anaerobic conditions and by homogenization. 5. The results are also discussed in relation to parameters of transfer. PMID:5090994

  20. [Cardiac neuronal depopulation in hamsters (Mesocricetus auratus) chronically infected with Trypanosoma cruzi].

    PubMed

    Chapadeiro, E; Silva, E L; Silva, A C; Fernandes, P; Ramirez, L E

    1999-01-01

    The aim of this study was to obtain an experimental animal model of destruction of cardiac neurons in order to investigate the behavior of the cardiac nervous system of hamsters chronically infected with Trypanosoma cruzi. We counted the neuronal cells of the cardiac autonomic nervous plexus in hamsters inoculated with 35,000 blood forms of three different T. cruzi strains and killed 5, 8 and 10 months after infection. We showed for the first time severe neuronal destruction in an experimental animal model with characteristics similar to those observed in human Chagas'disease.

  1. X-ray induced dominant lethal mutations in mature and immature oocytes of guinea-pigs and golden hamsters.

    PubMed

    Cox, B D; Lyon, M F

    1975-06-01

    The induction of dominant lethal mutations by doses of 100-400 rad X-rays in oocytes of the guinea-pig and golden hamster was studied using criteria of embryonic mortality. For both species higher yields were obtained from mature than from immature oocytes, in contrast to results for the mouse. Data on fertility indicated that in the golden hamster, as in the mouse, immature oocytes were more sensitive to killing by X-rays than mature oocytes but that the converse was true in the guinea-pig. The dose-response relationship for mutation to dominant lethals in pre-ovulatory oocytes of guinea-pig and golden hamsters was linear, both when based on pre- and post-implantation loss and when on post-implantation loss only. The rate per unit dose was higher for the golden hamster, and the old golden hamsters were possibly slightly more sensitive than young ones. The mutation rate data for mature oocytes of the mouse, using post-implantation loss alone, also fitted a linear dose-response relationship, except that the rate per unit dose was lower than for the other two species.

  2. Effects of bedding material and running wheel surface on paw wounds in male and female Syrian hamsters.

    PubMed

    Beaulieu, A; Reebs, S G

    2009-01-01

    The present study investigated the effects of bedding material (pine shavings versus beta chip) and running wheel surfaces (standard metal bars versus metal bars covered with a plastic mesh) on the occurrence of wounds on the paws of male and female Syrian (golden) hamsters, Mesocricetus auratus. Four groups of 10 males and 10 females were each assigned to one of the following treatments: pine/no mesh, pine/mesh, chips/no mesh and chips/mesh. Each hamster paw was observed at 1-3-day intervals for 60 days. A total of 1-3 wounds, separate in time, developed on the paws (mostly the hind ones) of almost all animals. Wounds appeared as small pinpricks, cuts or scabs, mostly on the palms. Females ran 15% less than males, yet their front paws were more commonly affected and their wounds tended to last longer. Hamsters with plastic mesh inside their wheels took longer to develop wounds but once they appeared, the wounds were larger and lasted longer. Hamsters on pine shavings developed fewer wounds and had more wound-free days. Hamsters kept running at high levels and many wounds did not heal during the study, suggesting a need for veterinary intervention.

  3. T cells are not required for pathogenesis in the Syrian hamster model of hantavirus pulmonary syndrome.

    PubMed

    Hammerbeck, Christopher D; Hooper, Jay W

    2011-10-01

    Andes virus (ANDV) is associated with a lethal vascular leak syndrome in humans termed hantavirus pulmonary syndrome (HPS). In hamsters, ANDV causes a respiratory distress syndrome closely resembling human HPS. The mechanism for the massive vascular leakage associated with HPS is poorly understood; however, T cell immunopathology has been implicated on the basis of circumstantial and corollary evidence. Here, we show that following ANDV challenge, hamster T cell activation corresponds with the onset of disease. However, treatment with cyclophosphamide or specific T cell depletion does not impact the course of disease or alter the number of surviving animals, despite significant reductions in T cell number. These data demonstrate, for the first time, that T cells are not required for hantavirus pathogenesis in the hamster model of human HPS. Depletion of T cells from Syrian hamsters did not significantly influence early events in disease progression. Moreover, these data argue for a mechanism of hantavirus-induced vascular permeability that does not involve T cell immunopathology.

  4. Golden hamster: quantitative anatomy with age

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Thomas, R.G.; London, J.E.; Drake, G.A.

    1979-10-01

    The Syrian (golden) hamster, Mesocricetus auratus, is used widely in biomedical research, particularly in experimental carcinogenesis. The data presented here, a relatively complete addition to data already in print, give standard values for tissues and blood components for the conditions at the Los Alamos Scientific Laboratory (LASL) in Los Alamos, New Mexico. This study delineates median values for the tissues and blood parameters versus the time from weaning through 18 months of age.

  5. [Prokaryotic expression of Leptospira interrogans groEL gene and immunoprotection of its products in hamsters].

    PubMed

    Li, Xiaoyu; Wang, Yinhuan; Yan, Jie; Cheng, Dongqing

    2013-03-01

    To construct a prokaryotic expression system of groEL gene of Leptospira interrogans serogroup Icterohaemorrhagia serovar Lai strain Lai, and to determine the immunoprotective effect of recombinant GroEL protein (rGroEL) in LVG hamsters. The groEL gene was amplified by high fidelity PCR and the amplification products were then sequenced. A prokaryotic expression system of groEL gene was constructed using routine genetic engineering technique. SDS-PAGE plus Bio-Rad Gel Image Analyzer was applied to examine the expression and dissolubility of rGroEL protein while Ni-NTA affinity chromatography was used to extract the expressed rGroEL. The immunoprotective rate in rGroEL-immunized LVG hamsters was determined after challenge with L.interrogans strain Lai. The cross agglutination titers of sera from immunized hamsters with different L.interrogans serogroups were detected using MAT. The nucleotide and amino acid sequences of the cloned groEL gene were the same as those reported in GenBank. The constructed prokaryotic expression system of groEL gene expressed soluble rGroEL. The immunoprotective rates of 100 and 200 μg rGroEL in LVG hamsters were 50.0 % and 75.0%, respectively. The sera from the rGroEL-immunized LVG hamsters agglutinated all the L.interrogans serogroups tested with different levels. The GroEL protein is a genus-specific immunoprotective antigen of L.interrogans and can be used to develop an universal genetically engineering vaccine of Leptospira.

  6. Effects of short photoperiod on energy intake, thermogenesis, and reproduction in desert hamsters (Phodopus roborovskii).

    PubMed

    Zhang, Xueying; Zhao, Zhijun; Vasilieva, Nina; Khrushchova, Anastasia; Wang, Dehua

    2015-03-01

    Desert hamsters (Phodopus roborovskii) are the least known species in the genus Phodopus with respect to ecology and physiology, and deserve scientific attention, particularly because of their small body size. Here, the responses of energy metabolism and reproductive function to short photoperiods in desert hamsters were investigated. Male and female desert hamsters were acclimated to either long day (LD) (L:D 16:8 h) or short day (SD) photoperiods (L:D 8:16 h) for three months, and then the females were transferred back to an LD photoperiod for a further five months, while at the end of the SD acclimation the males were killed and measurements were taken for serum leptin as well as molecular markers for thermogenesis. We found that like the other two species from the genus Phodopus, the desert hamsters under SD decreased body mass, increased adaptive thermogenesis as indicated by elevated mitochondrial protein content and uncoupling protein-1 content in brown adipose tissue, and suppressed reproduction compared to those under LD. However, different from the other two species, desert hamsters did not show any differences in energy intake or serum leptin concentration between LD and SD. These data suggest that different species from the same genus respond in different ways to the environmental signals, and the desert adapted species are not as sensitive to change in photoperiod as the other two species. © 2014 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

  7. Survival of Chinese Hamster Ovary Cells Following Ultrahigh Dose Rate Electron and Bremsstrahlung Radiation

    DTIC Science & Technology

    1990-04-01

    and a stepped lead flattening filter. The electron energy used for these studies was 13 MeV. Dosimetry was performed by the Health Physics Division...VolI LJSAFSAPA-TR-90-4 AD-A222 722 SURVIVAL OF CHINESE HAMSTER OVARY CELLS FOLLOWING ULTRAHIGH DOSE RATE ELECTRON AND BREMISSTRAHLUNG RADIATION...Include Security ;a!. iatcn) Survival of Chinese Hamster Ovary Cells Following Ultrahigh Dose Rate Electron and Bremsstrahlung Radiation 12 PERSONAL

  8. Novel function of lipids as a pheromone from the Harderian gland of golden hamster

    PubMed Central

    Seyama, Yousuke; Uchijima, Yasunobu

    2007-01-01

    Sexual diversity of ADG in Harderian gland of golden hamster was demonstrated on TLC. Female ADG contained iso- and anteiso-branched acyl and alkyl components, but male ADG contained only straight chain ones, which suggested the hormonal control of the expression of acyl-CoA dehydrogenases in the catabolism of BCAA. Acyl-CoA dehydrogenases were not expressed in the absence of testosterone, and then isovaleryl-CoA, 2-methylbutyryl-CoA, and isobutyryl-CoA accumulated, and acted as primers for the synthesis of iso- and anteiso-branched fatty acids. The incorporation of [U-14C] leucine into lipids was monitored by TLC. The cholesterol fraction was labeled in males but not in female, which means that cholesterol was not produced from BCAA in female gland due to the lack of expression of acyl-CoA dehydrogenases. We monitored the behavior of male hamsters toward female gland lipids, and found slightly greater attractiveness in female ones than that in male ones although the difference was not significant. Considering the lifestyle of golden hamster in nature, we propose a hypothesis that the lipids from the Harderian gland of golden hamster serve as a pheromone to declare their territory and to seek the mate with good congeniality. PMID:24019586

  9. Effects of red mold dioscorea on oral carcinogenesis in DMBA-induced hamster animal model.

    PubMed

    Hsu, Wei-Hsuan; Lee, Bao-Hong; Pan, Tzu-Ming

    2011-06-01

    Monascus-fermented products offer valuable therapeutic benefits and have been extensively used for centuries in East Asia. Dioscorea has been proved to have anti-cancer effect. The aim of this study is to investigate the anti-tumor ability of the ethanol extract of red mold dioscorea (RMDE) on 7,12-dimethyl-1,2-benz[a]anthracene (DMBA)-induced hamster buccal pouch carcinogenesis. We induced oral squamous cell carcinoma (OSCC) in the buccal pouch of male Syrian golden hamsters by painting with 0.5% DMBA three times a week for 14 weeks. From 9 to 14 weeks, a dose of 50, 100, and 200 mg RMDE per kg body weight were painting with the hamsters for 6 weeks on days alternate to the DMBA application. The results demonstrated that RMDE decreased nitric oxide (NO), reactive oxygen species (ROS), and prostaglandin E(2) (PGE(2)) overexpression in hamster buccal pouches in the DMBA treatment group and increased p53, serum tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) to significantly stimulate caspase-8 and -3 activities, indicating that RMDE reduced oxidative damage causing by DMBA and induced apoptosis in oral cancer cells. Therefore, RMDE may have therapeutic potentials against OSCC. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Behavioral and hormonal changes associated with the infective dose in experimental taeniasis in golden hamsters (Mesocricetus auratus).

    PubMed

    Domínguez-Roldan, Rosa; Hallal-Calleros, Claudia; Sciutto, Edda; Hernández, Marisela; Aguirre-Flores, Virginio; García-Jiménez, Sara; Báez-Saldaña, Armida; Flores-Pérez, Fernando Iván

    2016-07-01

    It has been reported that behavioral changes relate to infection in different parasitoses. However, the relation between the extent of the behavioral changes and the magnitude of the infection has been scarcely studied. The aim of this study was to evaluate the relationship between different doses of infection and the behavioral changes induced in the experimental Taenia pisiformis taeniasis in golden hamsters. Groups of nine hamsters were infected with three or six T. pisiformis metacestodes. The locomotor activity was quantified daily in an open field test during the 21 days after infection; anxiety test was performed in an elevated plus-maze with a dark/light area at 7, 14 and 21 days post-infection, and serum cortisol levels were determined by radioimmunoassay before infection and at day 22 after infection. The challenge itself induced modifications on behavior and cortisol levels in hamsters, with or without successful infection (taenia development). Animals challenged with three metacestodes induced a decrease in locomotor activity and an increase in anxiety in infected animals. A higher and earlier decrease in locomotor activity and increased anxiety levels were observed in hamsters challenged with six cysticerci, which were accompanied by higher levels of sera cortisol at the end of the experiment. At necropsy, 44-55% of hamster became infected with an efficiency of implantation of 22-26%, challenged with three or six cysticerci respectively. The challenge of hamsters with metacestodes, promote behavioral changes in an extent dependent on the magnitude of the challenge, disregarding the effectiveness of the infection. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Thermal acclimation and nutritional history affect the oxidation of different classes of exogenous nutrients in Siberian hamsters, Phodopus sungorus.

    PubMed

    McCue, Marshall D; Voigt, Christian C; Jefimow, Małgorzata; Wojciechowski, Michał S

    2014-11-01

    During acclimatization to winter, changes in morphology and physiology combined with changes in diet may affect how animals use the nutrients they ingest. To study (a) how thermal acclimation and (b) nutritional history affect the rates at which Siberian hamsters (Phodopus sungorus) oxidize different classes of dietary nutrients, we conducted two trials in which we fed hamsters one of three (13) C-labeled compounds, that is, glucose, leucine, or palmitic acid. We predicted that under acute cold stress (3 hr at 2°C) hamsters previously acclimated to cold temperatures (10°C) for 3 weeks would have higher resting metabolic rate (RMR) and would oxidize a greater proportion of dietary fatty acids than animals acclimated to 21°C. We also investigated how chronic nutritional stress affects how hamsters use dietary nutrients. To examine this, hamsters were fed four different diets (control, low protein, low lipid, and low-glycemic index) for 2 weeks. During cold challenges, hamsters previously acclimated to cold exhibited higher thermal conductance and RMR, and also oxidized more exogenous palmitic acid during the postprandial phase than animals acclimated to 21°C. In the nutritional stress trial, hamsters fed the low protein diet oxidized more exogenous glucose, but not more exogenous palmitic acid than the control group. The use of (13) C-labeled metabolic tracers combined with breath testing demonstrated that both thermal and nutritional history results in significant changes in the extent to which animals oxidize dietary nutrients during the postprandial period. © 2014 Wiley Periodicals, Inc.

  12. Progressive proliferative and dysplastic typhlocolitis in aging syrian hamsters naturally infected with Helicobacter spp.: a spontaneous model of inflammatory bowel disease.

    PubMed

    Nambiar, P R; Kirchain, S M; Courmier, K; Xu, S; Taylor, N S; Theve, E J; Patterson, M M; Fox, J G

    2006-01-01

    Helicobacter spp. have been implicated in a variety of gastrointestinal tract diseases, including peptic ulcer disease, gastric cancer, and inflammatory bowel disease (IBD), in humans and animals. Although most models of IBD are experimentally induced, spontaneous or natural models of IBD are rare. Herein, we describe a long-term study of chronic, progressive lesions that develop in the distal portion of the large bowel of unmanipulated Syrian hamsters naturally infected with Helicobacter spp. Twenty-four Syrian hamsters of three age groups (group A, 1 month [n = 4], group B, 7-12 months [n = 12], group C, 18-24 months [n = 12]), underwent complete postmortem examination. Results of microbial isolation and polymerase chain reaction and restriction fragment length polymorphism analyses confirmed the presence of Helicobacter spp. infection in the distal portion of the large bowel of all animals. Additionally, confounding pathogens, such as Clostridium difficile, Lawsonia intracellularis, and Giardia spp. that can cause proliferative enteritis, were absent in the hamsters of this study. Histopathologic scores for inflammation (P < 0.01), hyperplasia (P < 0.01), and dysplasia (P < 0.05) were significantly higher in the ileocecocolic (ICC) junction of animals in group C, relative to group A. Dysplastic lesions of various grades were detected in 5 of 11 hamsters in group C. Interestingly, the segment of the bowel that is usually colonized by Helicobacter spp. in hamsters had the most severe lesions. One hamster of group C developed a malignant fibrous histiocytoma, whereas another hamster developed a round cell sarcoma originating from the ICC junction. Thus, lesions in the distal portion of the large bowel of aging hamsters naturally colonized with Helicobacter spp. warrants developing the hamster as an animal model of IBD and potentially IBD-related cancer.

  13. Voluntary exercise increases resilience to social defeat stress in Syrian hamsters.

    PubMed

    Kingston, Rody C; Smith, Michael; Lacey, Tiara; Edwards, Malcolm; Best, Janae N; Markham, Chris M

    2018-05-01

    Exposure to social stressors can cause profound changes in an individual's well-being and can be an underlying factor in the etiology of a variety of psychopathologies, such as post-traumatic stress disorder (PTSD). In Syrian hamsters, a single social defeat experience results in behavioral changes collectively known as conditioned defeat (CD), and includes an abolishment of territorial aggression and the emergence of high levels of defensive behaviors. In contrast, voluntary exercise has been shown to promote stress resilience and can also have anxiolytic-like effects. Although several studies have investigated the resilience-inducing effects of voluntary exercise after exposure to physical stressors, such as restraint and electric shock, few studies have examined whether exercise can impart resilience in response to ethologically-based stressors, such as social defeat. In Experiment 1, we tested the hypothesis that voluntary exercise can have anxiolytic-like effects in socially defeated hamsters. In the elevated plus maze, the exercise group exhibited a significant reduction in risk assessment, a commonly used index of anxiety, compared to the no-exercise group. In the open-field test, animals in the exercise group exhibited a significant reduction in locomotor behavior and rearing, also an indication of an anxiolytic-like effect of exercise. In Experiment 2, we examined whether exercise can reverse the defeat-induced potentiation of defensive behaviors using the CD model. Socially defeated hamsters in the exercise group exhibited significantly lower levels of defensive/submissive behaviors compared to the no-exercise group upon exposure to the resident aggressor. Taken together, these results are among the first to suggest that voluntary exercise may promote resilience to social defeat stress in Syrian hamsters. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. Different effects of acute and chronic immobilization stress on plasma testosterone levels in male Syrian hamsters.

    PubMed

    Tsuchiya, T; Horii, I

    1995-01-01

    Time-course variations in plasma testosterone levels after various periods of immobilization stress (10 min, 30 min, 2 h, 6 h) were examined in male Syrian hamsters. The immobilization stress consisted of placing the animals in a prone position and wrapping them with flexible steel wire gauze. This was done at room temperature. Testosterone levels were determined in blood samples taken after the hamsters were decapitated. Chronic (2 h, 6 h) immobilization stress produced a drastic and enduring fall in plasma testosterone levels. Reduction of plasma testosterone following the 6-h immobilization stress was observed even 18 h after the stress had been relieved. However, acute (10 min, 30 min) immobilization stress did not influence plasma testosterone. These findings indicated that the effect of immobilization stress on plasma testosterone in hamsters was not biphasic, which it is in rats. Further, these results suggest that immobilization stress in hamsters would be a valuable technique with which to investigate the effects of physiological ranges of testosterone on physiological and psychological functions.

  15. Detection of pathogenic Yersinia enterocolitica in pet Djungarian hamsters in Japan

    PubMed Central

    KAMEYAMA, Mitsuhiro; YABATA, Junko; OBANE, Noriko; OTSUKA, Hitoshi; NOMURA, Yasuharu

    2016-01-01

    The prevalence of Yersinia enterocolitica (Y. enterocolitica) and Yersinia pseudotuberculosis was examined in 151 pet animals including 108 rodents, 39 rabbits and four sugar gliders from 13 pet stores in the Yamaguchi Prefecture, Japan. Y. enterocolitica serogroup O:3 biotype 3 negative for the Voges-Proskauer reaction (O:3/3 variant VP-) was isolated from five Djungarian hamsters (Phodopus sungorus) raised at the same pet store. These pathogenic Y. enterocolitica isolates carried the virulence genes, yadA, ail and virF, and were shown to be clonal by pulsed-field gel electrophoresis with NotI digestion. This is a first report of pathogenic Y. enterocolitica O:3/3 variant VP- in pet Djungarian hamsters in Japan. PMID:27396397

  16. A new species of Dentiphilometra (Nematoda: Philometridae) from the musculature of the gray snapper Lutjanus griseus (osteichthyes) off the Caribbean coast of Mexico.

    PubMed

    González-Solís, David; Moravec, Frantisek; Paredes, Vielka M Tuz

    2007-10-01

    A new nematode, Dentiphilometra lutjani n. sp. (Philometridae), is described from gravid females (the male is unknown) collected from the body musculature of the marine perciform fish gray snapper, Lutjanus griseus (Lutjanidae), from the Bay of Chetumal and southern coast of Quintana Roo, off the Caribbean coast of Mexico. The new species differs from the only other congener, Dentiphilometra monopteri, from the swamp eel Monopterus albus in China, mainly in the body length of gravid female (15.40-53.21 mm), the shape of the posterior body end (not markedly narrowed, with low caudal projections), the esophageal gland (maximum width near its posterior end), and the length (344-483 microm) of larvae from the uterus; both species also differ in their host types (marine perciform fish vs. freshwater swamp eel) and geographical distribution (Mexico vs. China).

  17. T Cells Are Not Required for Pathogenesis in the Syrian Hamster Model of Hantavirus Pulmonary Syndrome ▿

    PubMed Central

    Hammerbeck, Christopher D.; Hooper, Jay W.

    2011-01-01

    Andes virus (ANDV) is associated with a lethal vascular leak syndrome in humans termed hantavirus pulmonary syndrome (HPS). In hamsters, ANDV causes a respiratory distress syndrome closely resembling human HPS. The mechanism for the massive vascular leakage associated with HPS is poorly understood; however, T cell immunopathology has been implicated on the basis of circumstantial and corollary evidence. Here, we show that following ANDV challenge, hamster T cell activation corresponds with the onset of disease. However, treatment with cyclophosphamide or specific T cell depletion does not impact the course of disease or alter the number of surviving animals, despite significant reductions in T cell number. These data demonstrate, for the first time, that T cells are not required for hantavirus pathogenesis in the hamster model of human HPS. Depletion of T cells from Syrian hamsters did not significantly influence early events in disease progression. Moreover, these data argue for a mechanism of hantavirus-induced vascular permeability that does not involve T cell immunopathology. PMID:21775442

  18. Inhibitory effect of vitamin D-binding protein-derived macrophage activating factor on DMBA-induced hamster cheek pouch carcinogenesis and its derived carcinoma cell line.

    PubMed

    Toyohara, Yukiyo; Hashitani, Susumu; Kishimoto, Hiromitsu; Noguchi, Kazuma; Yamamoto, Nobuto; Urade, Masahiro

    2011-07-01

    This study investigated the inhibitory effect of vitamin D-binding protein-derived macrophage-activating factor (GcMAF) on carcinogenesis and tumor growth, using a 9,10-dimethyl-1,2-benzanthracene (DMBA)-induced hamster cheek pouch carcinogenesis model, as well as the cytocidal effect of activated macrophages against HCPC-1, a cell line established from DMBA-induced cheek pouch carcinoma. DMBA application induced squamous cell carcinoma in all 15 hamsters of the control group at approximately 10 weeks, and all 15 hamsters died of tumor burden within 20 weeks. By contrast, 2 out of the 14 hamsters with GcMAF administration did not develop tumors and the remaining 12 hamsters showed a significant delay of tumor development for approximately 3.5 weeks. The growth of tumors formed was significantly suppressed and none of the hamsters died within the 20 weeks during which they were observed. When GcMAF administration was stopped at the 13th week of the experiment in 4 out of the 14 hamsters in the GcMAF-treated group, tumor growth was promoted, but none of the mice died within the 20-week period. On the other hand, when GcMAF administration was commenced after the 13th week in 5 out of the 15 hamsters in the control group, tumor growth was slightly suppressed and all 15 hamsters died of tumor burden. However, the mean survival time was significantly extended. GcMAF treatment activated peritoneal macrophages in vitro and in vivo, and these activated macrophages exhibited a marked cytocidal effect on HCPC-1 cells. Furthermore, the cytocidal effect of activated macrophages was enhanced by the addition of tumor-bearing hamster serum. These findings indicated that GcMAF possesses an inhibitory effect on tumor development and growth in a DMBA-induced hamster cheek pouch carcinogenesis model.

  19. Inhibitory effect of vitamin D-binding protein-derived macrophage activating factor on DMBA-induced hamster cheek pouch carcinogenesis and its derived carcinoma cell line

    PubMed Central

    TOYOHARA, YUKIYO; HASHITANI, SUSUMU; KISHIMOTO, HIROMITSU; NOGUCHI, KAZUMA; YAMAMOTO, NOBUTO; URADE, MASAHIRO

    2011-01-01

    This study investigated the inhibitory effect of vitamin D-binding protein-derived macrophage-activating factor (GcMAF) on carcinogenesis and tumor growth, using a 9,10-dimethyl-1,2-benzanthracene (DMBA)-induced hamster cheek pouch carcinogenesis model, as well as the cytocidal effect of activated macrophages against HCPC-1, a cell line established from DMBA-induced cheek pouch carcinoma. DMBA application induced squamous cell carcinoma in all 15 hamsters of the control group at approximately 10 weeks, and all 15 hamsters died of tumor burden within 20 weeks. By contrast, 2 out of the 14 hamsters with GcMAF administration did not develop tumors and the remaining 12 hamsters showed a significant delay of tumor development for approximately 3.5 weeks. The growth of tumors formed was significantly suppressed and none of the hamsters died within the 20 weeks during which they were observed. When GcMAF administration was stopped at the 13th week of the experiment in 4 out of the 14 hamsters in the GcMAF-treated group, tumor growth was promoted, but none of the mice died within the 20-week period. On the other hand, when GcMAF administration was commenced after the 13th week in 5 out of the 15 hamsters in the control group, tumor growth was slightly suppressed and all 15 hamsters died of tumor burden. However, the mean survival time was significantly extended. GcMAF treatment activated peritoneal macrophages in vitro and in vivo, and these activated macrophages exhibited a marked cytocidal effect on HCPC-1 cells. Furthermore, the cytocidal effect of activated macrophages was enhanced by the addition of tumor-bearing hamster serum. These findings indicated that GcMAF possesses an inhibitory effect on tumor development and growth in a DMBA-induced hamster cheek pouch carcinogenesis model. PMID:22848250

  20. Cycloheximide: No Ordinary Bitter Stimulus

    PubMed Central

    Hettinger, Thomas P.; Formaker, Bradley K.; Frank, Marion E.

    2007-01-01

    Cycloheximide (CyX), a toxic antibiotic with a unique chemical structure generated by the actinomycete, Streptomyces griseus, has emerged as a primary focus of studies on mammalian bitter taste. Rats and mice avoid it at concentrations well below the thresholds for most bitter stimuli and T2R G-protein-coupled receptors specific for CyX with appropriate sensitivity are identified for those species. Like mouse and rat, golden hamsters, Mesocricetus auratus, also detected and rejected micromolar levels of CyX, although 1 mM CyX failed to activate the hamster chorda tympani nerve. Hamsters showed an initial tolerance for 500 μM CyX, but after that, avoidance of CyX dramatically increased, plasticity not reported for rat or mouse. As the hamster lineage branches well before division of the mouse-rat lineage in evolutionary time, differences between hamster and mouse-rat reactions to CyX are not surprising. Furthermore, unlike hamster LiCl-induced learned aversions, the induced CyX aversion neither specifically nor robustly generalized to other non-ionic bitter stimuli; and unlike adverse reactions to other chemosensory stimuli, aversions to CyX were not mollified by adding a sweetener. Thus, CyX is unlike other bitter stimuli. The gene for the high-affinity CyX receptor is a member of a cluster of 5 orthologous T2R genes that are likely rodent specific; this “CyX clade” is found in the mouse, rat and probably hamster, but not in the human or rabbit genome. The rodent CyX-T2R interaction may be one of multiple lineage-specific stimulus-receptor interactions reflecting a response to a particular environmental toxin. The combination of T2R multiplicity, species divergence and gene duplication results in diverse ligands for multiple species-specific T2R receptors, which confounds definition of ‘bitter’ stimuli across species. PMID:17400304

  1. Smokeless tobacco impacts oral microbiota in a Syrian Golden hamster cheek pouch carcinogenesis model.

    PubMed

    Jin, Jinshan; Guo, Lei; VonTungeln, Linda; Vanlandingham, Michelle; Cerniglia, Carl E; Chen, Huizhong

    2018-05-28

    The use of smokeless tobacco products (STPs) can cause many serious health problems. The oral microbiota plays important roles in oral and systemic health, and the disruption in the oral microbial population is linked to periodontal disease and other health problems. To assess the impact of smokeless tobacco on oral microbiota in vivo, high-throughput sequencing was used to examine the oral microbiota present in Syrian Golden hamster cheek pouches. Sixteen hamsters were divided into four groups and treated with the STP Grizzly snuff (0, 2.5, 25, or 250 mg) twice daily for 4 weeks. After 0, 1, 2, 3, and 4 weeks of treatment, bacterial genomic DNA was extracted from oral swabs sampled from the cheek pouches of the hamsters. The oral bacterial communities present in different hamster groups were characterized by sequencing the hypervariable regions V1-V2 and V4 of 16S rRNA using the Illumina MiSeq platform. Fifteen phyla, 27 classes, 59 orders, 123 families, and 250 genera were identified from 4,962,673 sequence reads from the cheek pouch samples. The bacterial diversity and taxonomic abundances for the different treatment groups were compared to the non-treated hamsters. Bacterial diversity was significantly decreased after 4 weeks of exposure to 2.5 mg, and significantly increased by exposure to 250 mg STP. Treatment with 250 mg STP significantly increased Firmicutes, transiently increased Cyanobacteria and TM7, and decreased Bacteroidetes and Fusobacteria compared to the control group. At the genus level, 4 weeks of administration of 250 mg STP significantly increased Granulicatella, Streptococcus, Oribacterium, Anaerococcus, Acidaminococcus, Actinomyces, Eubacterium, Negativicoccus, and Staphylococcus, and decreased Bacteroides, Buleidia, Dialister, and Leptotrichia, and transiently decreased Arcanobacterium compared to the control group. For the first time, an animal model was used for evaluating the effects of STP on oral microbiota by metagenomic

  2. Depletion of Alveolar Macrophages Does Not Prevent Hantavirus Disease Pathogenesis in Golden Syrian Hamsters.

    PubMed

    Hammerbeck, Christopher D; Brocato, Rebecca L; Bell, Todd M; Schellhase, Christopher W; Mraz, Steven R; Queen, Laurie A; Hooper, Jay W

    2016-07-15

    Andes virus (ANDV) is associated with a lethal vascular leak syndrome in humans termed hantavirus pulmonary syndrome (HPS). The mechanism for the massive vascular leakage associated with HPS is poorly understood; however, dysregulation of components of the immune response is often suggested as a possible cause. Alveolar macrophages are found in the alveoli of the lung and represent the first line of defense to many airborne pathogens. To determine whether alveolar macrophages play a role in HPS pathogenesis, alveolar macrophages were depleted in an adult rodent model of HPS that closely resembles human HPS. Syrian hamsters were treated, intratracheally, with clodronate-encapsulated liposomes or control liposomes and were then challenged with ANDV. Treatment with clodronate-encapsulated liposomes resulted in significant reduction in alveolar macrophages, but depletion did not prevent pathogenesis or prolong disease. Depletion also did not significantly reduce the amount of virus in the lung of ANDV-infected hamsters but altered neutrophil recruitment, MIP-1α and MIP-2 chemokine expression, and vascular endothelial growth factor (VEGF) levels in hamster bronchoalveolar lavage (BAL) fluid early after intranasal challenge. These data demonstrate that alveolar macrophages may play a limited protective role early after exposure to aerosolized ANDV but do not directly contribute to hantavirus disease pathogenesis in the hamster model of HPS. Hantaviruses continue to cause disease worldwide for which there are no FDA-licensed vaccines, effective postexposure prophylactics, or therapeutics. Much of this can be attributed to a poor understanding of the mechanism of hantavirus disease pathogenesis. Hantavirus disease has long been considered an immune-mediated disease; however, by directly manipulating the Syrian hamster model, we continue to eliminate individual immune cell types. As the most numerous immune cells present in the respiratory tract, alveolar macrophages are

  3. Depletion of Alveolar Macrophages Does Not Prevent Hantavirus Disease Pathogenesis in Golden Syrian Hamsters

    PubMed Central

    Hammerbeck, Christopher D.; Brocato, Rebecca L.; Bell, Todd M.; Schellhase, Christopher W.; Mraz, Steven R.; Queen, Laurie A.

    2016-01-01

    ABSTRACT Andes virus (ANDV) is associated with a lethal vascular leak syndrome in humans termed hantavirus pulmonary syndrome (HPS). The mechanism for the massive vascular leakage associated with HPS is poorly understood; however, dysregulation of components of the immune response is often suggested as a possible cause. Alveolar macrophages are found in the alveoli of the lung and represent the first line of defense to many airborne pathogens. To determine whether alveolar macrophages play a role in HPS pathogenesis, alveolar macrophages were depleted in an adult rodent model of HPS that closely resembles human HPS. Syrian hamsters were treated, intratracheally, with clodronate-encapsulated liposomes or control liposomes and were then challenged with ANDV. Treatment with clodronate-encapsulated liposomes resulted in significant reduction in alveolar macrophages, but depletion did not prevent pathogenesis or prolong disease. Depletion also did not significantly reduce the amount of virus in the lung of ANDV-infected hamsters but altered neutrophil recruitment, MIP-1α and MIP-2 chemokine expression, and vascular endothelial growth factor (VEGF) levels in hamster bronchoalveolar lavage (BAL) fluid early after intranasal challenge. These data demonstrate that alveolar macrophages may play a limited protective role early after exposure to aerosolized ANDV but do not directly contribute to hantavirus disease pathogenesis in the hamster model of HPS. IMPORTANCE Hantaviruses continue to cause disease worldwide for which there are no FDA-licensed vaccines, effective postexposure prophylactics, or therapeutics. Much of this can be attributed to a poor understanding of the mechanism of hantavirus disease pathogenesis. Hantavirus disease has long been considered an immune-mediated disease; however, by directly manipulating the Syrian hamster model, we continue to eliminate individual immune cell types. As the most numerous immune cells present in the respiratory tract

  4. Pregnancy outcome in heat-exposed hamsters; the involvement of the pineal.

    PubMed

    Kaplanski, J; Zohar, R; Sod-Moriah, U A; Magal, E; Hirschmann, N; Nir, I

    1988-01-01

    The effect of high ambient temperature (34 degrees C) on the function of the female reproductive system, on embryonic development and on outcome of pregnancy, was investigated in heat-exposed sham-operated (Sh) and pinealectomized (Px) golden hamsters maintained under short photoperiod. Plasma prolactin levels were reduced in both heat-exposed groups (ShH and PxH) but pituitary prolactin was increased in the pinealectomized groups irrespective of ambient temperature (21 or 34 degrees C). Pituitary weights and LH contents were not affected in any test group. Heat exposure brought about a reduction in the number of corpora lutea and of pups born, the latter being more drastically reduced in absence of the pineal; the depressant effect of heat on ovarian weight was evident only in the pinealectomized animals. Progesterone levels were not affected in any test group and pregnancy was not prolonged, thus, it would seem that pregnant hamsters adapt themselves well to heat. Moreover, high ambient temperature promoted a rise in pineal. HIOMT activity and boosted cortisol levels in presence of the pineal gland only, which, together with the above findings, shows that the pineal can provide protection for pregnant hamsters against adverse effects of high ambient temperature.

  5. Unexpected Positive Buoyancy in Deep Sea Sharks, Hexanchus griseus, and a Echinorhinus cookei

    PubMed Central

    Nakamura, Itsumi; Meyer, Carl G.; Sato, Katsufumi

    2015-01-01

    We do not expect non air-breathing aquatic animals to exhibit positive buoyancy. Sharks, for example, rely on oil-filled livers instead of gas-filled swim bladders to increase their buoyancy, but are nonetheless ubiquitously regarded as either negatively or neutrally buoyant. Deep-sea sharks have particularly large, oil-filled livers, and are believed to be neutrally buoyant in their natural habitat, but this has never been confirmed. To empirically determine the buoyancy status of two species of deep-sea sharks (bluntnose sixgill sharks, Hexanchus griseus, and a prickly shark, Echinorhinus cookei) in their natural habitat, we used accelerometer-magnetometer data loggers to measure their swimming performance. Both species of deep-sea sharks showed similar diel vertical migrations: they swam at depths of 200–300 m at night and deeper than 500 m during the day. Ambient water temperature was around 15°C at 200–300 m but below 7°C at depths greater than 500 m. During vertical movements, all deep-sea sharks showed higher swimming efforts during descent than ascent to maintain a given swimming speed, and were able to glide uphill for extended periods (several minutes), indicating that these deep-sea sharks are in fact positively buoyant in their natural habitats. This positive buoyancy may adaptive for stealthy hunting (i.e. upward gliding to surprise prey from underneath) or may facilitate evening upward migrations when muscle temperatures are coolest, and swimming most sluggish, after spending the day in deep, cold water. Positive buoyancy could potentially be widespread in fish conducting daily vertical migration in deep-sea habitats. PMID:26061525

  6. Observations on abundance of bluntnose sixgill sharks, Hexanchus griseus, in an urban waterway in Puget Sound, 2003-2005.

    PubMed

    Griffing, Denise; Larson, Shawn; Hollander, Joel; Carpenter, Tim; Christiansen, Jeff; Doss, Charles

    2014-01-01

    The bluntnose sixgill shark, Hexanchus griseus, is a widely distributed but poorly understood large, apex predator. Anecdotal reports of diver-shark encounters in the late 1990's and early 2000's in the Pacific Northwest stimulated interest in the normally deep-dwelling shark and its presence in the shallow waters of Puget Sound. Analysis of underwater video documenting sharks at the Seattle Aquarium's sixgill research site in Elliott Bay and mark-resight techniques were used to answer research questions about abundance and seasonality. Seasonal changes in relative abundance in Puget Sound from 2003-2005 are reported here. At the Seattle Aquarium study site, 45 sixgills were tagged with modified Floy visual marker tags, along with an estimated 197 observations of untagged sharks plus 31 returning tagged sharks, for a total of 273 sixgill observations recorded. A mark-resight statistical model based on analysis of underwater video estimated a range of abundance from a high of 98 sharks seen in July of 2004 to a low of 32 sharks seen in March of 2004. Both analyses found sixgills significantly more abundant in the summer months at the Seattle Aquarium's research station.

  7. Observations on Abundance of Bluntnose Sixgill Sharks, Hexanchus griseus, in an Urban Waterway in Puget Sound, 2003-2005

    PubMed Central

    Griffing, Denise; Larson, Shawn; Hollander, Joel; Carpenter, Tim; Christiansen, Jeff; Doss, Charles

    2014-01-01

    The bluntnose sixgill shark, Hexanchus griseus, is a widely distributed but poorly understood large, apex predator. Anecdotal reports of diver-shark encounters in the late 1990’s and early 2000’s in the Pacific Northwest stimulated interest in the normally deep-dwelling shark and its presence in the shallow waters of Puget Sound. Analysis of underwater video documenting sharks at the Seattle Aquarium’s sixgill research site in Elliott Bay and mark-resight techniques were used to answer research questions about abundance and seasonality. Seasonal changes in relative abundance in Puget Sound from 2003–2005 are reported here. At the Seattle Aquarium study site, 45 sixgills were tagged with modified Floy visual marker tags, along with an estimated 197 observations of untagged sharks plus 31 returning tagged sharks, for a total of 273 sixgill observations recorded. A mark-resight statistical model based on analysis of underwater video estimated a range of abundance from a high of 98 sharks seen in July of 2004 to a low of 32 sharks seen in March of 2004. Both analyses found sixgills significantly more abundant in the summer months at the Seattle Aquarium’s research station. PMID:24475229

  8. Obeticholic acid raises LDL-cholesterol and reduces HDL-cholesterol in the Diet-Induced NASH (DIN) hamster model.

    PubMed

    Briand, François; Brousseau, Emmanuel; Quinsat, Marjolaine; Burcelin, Rémy; Sulpice, Thierry

    2018-01-05

    The use of rat and mouse models limits the translation to humans for developing novel drugs targeting nonalcoholic steatohepatitis (NASH). Obeticholic acid (OCA) illustrates this limitation since its dyslipidemic effect in humans cannot be observed in these rodents. Conversely, Golden Syrian hamsters have a lipoprotein metabolism mimicking human dyslipidemia since it does express the cholesteryl ester transfer protein (CETP). We therefore developed a Diet-Induced NASH (DIN) hamster model and evaluated the impact of OCA. Compared with chow fed controls, hamsters fed for 20 weeks with a free-choice (FC) diet, developed obesity, insulin resistance, dyslipidemia and NASH (microvesicular steatosis, inflammation, hepatocyte ballooning and perisinusoidal to bridging fibrosis). After 20 weeks of diet, FC fed hamsters were treated without or with obeticholic acid (15mg/kg/day) for 5 weeks. Although a non-significant trend towards higher dietary caloric intake was observed, OCA significantly lowered body weight after 5 weeks of treatment. OCA significantly increased CETP activity and LDL-C levels by 20% and 27%, and reduced HDL-C levels by 20%. OCA blunted hepatic gene expression of Cyp7a1 and Cyp8b1 and reduced fecal bile acids mass excretion by 64% (P < 0.05). Hamsters treated with OCA showed a trend towards higher scavenger receptor Class B type I (SR-BI) and lower LDL-receptor hepatic protein expression. OCA reduced NAS score for inflammation (P < 0.01) and total NAS score, although not significantly. Compared to mouse and rat models, the DIN hamster replicates benefits and side effects of OCA as observed in humans, and should be useful for evaluating novel drugs targeting NASH. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Topical photosan-mediated photodynamic therapy for DMBA-induced hamster buccal pouch premaligant lesions: an in vivo study

    NASA Astrophysics Data System (ADS)

    Hsu, Yih-Chih; Chiang, Chun-Pin; Chen, Jian Wen; Chen, Ying-Ru; Lee, Jeng-Woei

    2010-02-01

    One of the best strategies to prevent the occurrence of oral cancer is to eliminate oral precancers and block their further malignant transformation. Previous studies showed that photosan-mediated photodynamic therapy (photosan-PDT) is very effective for human head and neck cancers. To avoid the systemic photodynamic toxicity of photosan, this study was designed to use a topical photosan-PDT for treatment of DMBA-induced hamster buccal pouch precancerous lesions. Twelve 10-week-old male Syrian golden hamsters were used in this study. DMBA was applied to the left buccal pouches thrice a week for 8 to 10 weeks and mineral oil was painted on the right buccal pouches thrice a week for 8 to 10 weeks as the normal controls. Six hamsters were euthanized for tissue harvest. Precancerous lesions of moderate to severe dysplasia were consistently induced and proven by histological examination. These induced precancerous lesions in the remaining 6 hamsters were used for testing the efficacy of topical photosan-PDT. Before PDT, fluorescence spectroscopy was used to determine when protoporphyrine IX (PpIX) reached its peak level in the lesional epithelial cells after topical application of photosan-gel. We found that PpIX reached its peak level in precancerous lesions about 13.5 min after topical application of photosan-gel. The precancerous lesions in 4 hamsters were treated with topical photosan-PDT using the 635-nm LED light once or twice a week. Complete regression of the precancerous lesions was found after 2-4 PDT treatments by visual and histological examination. Our findings indicate that topical photosan-PDT is a very effective treatment modality for DMBA-induced hamster buccal pouch precancerous lesions.

  10. Coptisine attenuates obesity-related inflammation through LPS/TLR-4-mediated signaling pathway in Syrian golden hamsters.

    PubMed

    Zou, Zong-Yao; Hu, Yin-Ran; Ma, Hang; Wang, Yan-Zhi; He, Kai; Xia, Shuang; Wu, Hao; Xue, Dong-Fang; Li, Xue-Gang; Ye, Xiao-Li

    2015-09-01

    It is known that obesity resulted from consumption of diets high in fat and calories and associated with a chronic low-grade inflammation. Because the fat, sterol and bile acid metabolism of male Syrian golden hamster are more similar to that of human, in the present study, high fat and high cholesterol (HFHC) induced obese hamsters were used to evaluate the anti-inflammation and hypolipidemic role of coptisine. The results showed that body weight, plasma lipid levels of total cholesterol (TC), triglyceride (TG), low density lipoprotein-cholesterol (LDL-c), very low density lipoprotein-cholesterol (VLDL-c), ApoB and pro-inflammatory cytokines including TNF-α, IL-6 and lipopolysaccharide (LPS) were significantly altered in hamsters fed with HFHC diet. A strong correlation was observed between the LPS level in serum and the level of LBP and pro-inflammatory cytokines. Coptisine from the concentrations of 60 to 700 mg/L dose-dependently inhibited Enterobacter cloacae growth, which can easily induce obesity and insulin resistance. The results of endotoxin neutralization assay suggest that coptisine is capable of reducing the LPS content under inflammation status. Real time RT-PCR analyses revealed that coptisine suppressed TLR-4 in visceral fat of hamsters and decreased CD14 expression in livers of hamsters. These encouraging findings make the development of coptisine a good candidate for preventing obesity-related diseases through the LPS/TLR-4-mediated signaling pathway. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Hypothalamic Ventricular Ependymal Thyroid Hormone Deiodinases Are an Important Element of Circannual Timing in the Siberian Hamster (Phodopus sungorus)

    PubMed Central

    Bolborea, Matei; Wilson, Dana; Mercer, Julian G.; Ebling, Francis J. P.; Morgan, Peter J.; Barrett, Perry

    2013-01-01

    Exposure to short days (SD) induces profound changes in the physiology and behaviour of Siberian hamsters, including gonadal regression and up to 30% loss in body weight. In a continuous SD environment after approximately 20 weeks, Siberian hamsters spontaneously revert to a long day (LD) phenotype, a phenomenon referred to as the photorefractory response. Previously we have identified a number of genes that are regulated by short photoperiod in the neuropil and ventricular ependymal (VE) cells of the hypothalamus, although their importance and contribution to photoperiod induced physiology is unclear. In this refractory model we hypothesised that the return to LD physiology involves reversal of SD expression levels of key hypothalamic genes to their LD values and thereby implicate genes required for LD physiology. Male Siberian hamsters were kept in either LD or SD for up to 39 weeks during which time SD hamster body weight decreased before increasing, after more than 20 weeks, back to LD values. Brain tissue was collected between 14 and 39 weeks for in situ hybridization to determine hypothalamic gene expression. In VE cells lining the third ventricle, expression of nestin, vimentin, Crbp1 and Gpr50 were down-regulated at 18 weeks in SD photoperiod, but expression was not restored to the LD level in photorefractory hamsters. Dio2, Mct8 and Tsh-r expression were altered by SD photoperiod and were fully restored, or even exceeded values found in LD hamsters in the refractory state. In hypothalamic nuclei, expression of Srif and Mc3r mRNAs was altered at 18 weeks in SD, but were similar to LD expression values in photorefractory hamsters. We conclude that in refractory hamsters not all VE cell functions are required to establish LD physiology. However, thyroid hormone signalling from ependymal cells and reversal of neuronal gene expression appear to be essential for the SD refractory response. PMID:23637944

  12. Structured triglycerides containing caprylic (8:0) and oleic (18:1) fatty acids reduce blood cholesterol concentrations and aortic cholesterol accumulation in hamsters.

    PubMed

    Wilson, Thomas A; Kritchevsky, David; Kotyla, Timothy; Nicolosi, Robert J

    2006-03-01

    The effects of structured triglycerides containing one long chain fatty acid (oleic acid, C18:1) and one short chain saturated fatty acid (caprylic acid, 8:0) on lipidemia, liver and aortic cholesterol, and fecal neutral sterol excretion were investigated in male Golden Syrian hamsters fed a hypercholesterolemic regimen consisting of 89.9% commercial ration to which was added 10% coconut oil and 0.1% cholesterol (w/w). After 2 weeks on the HCD diet, the hamsters were bled, following an overnight fast (16 h) and placed into one of three dietary treatments of eight animals each based on similar plasma cholesterol levels. The hamsters either continued on the HCD diet or were placed on diets in which the coconut oil was replaced by one of two structured triglycerides, namely, 1(3),2-dicaproyl-3(1)-oleoylglycerol (OCC) or 1,3-dicaproyl-2-oleoylglycerol (COC) at 10% by weight. Plasma total cholesterol (TC) in hamsters fed the OCC and COC compared to the HCD were reduced 40% and 49%, respectively (P<0.05). Similarly, hamsters fed the OCC and COC diets reduced their plasma nonHDL cholesterol levels by 47% and 57%, respectively (P<0.05), compared to hamsters fed the HCD after 2 weeks of dietary treatment. Although hamsters fed the OCC (-26%) and COC (-32%) had significantly lower plasma HDL levels compared to HCD, (P<0.05), the plasma nonHDL/HDL cholesterol ratio was significantly lower (P<0.05) compared to the HCD for the OCC-fed (-27%) and the COC-fed (-38%) hamsters, respectively. Compared to the HCD group, aortic esterified cholesterol was 20% and 53% lower for the OCC and COC groups, respectively, with the latter reaching statistical significance, P<0.05. In conclusion, the hamsters fed the structured triglyceride oils had lower blood cholesterol levels and lower aortic accumulation of cholesterol compared to the control fed hamsters.

  13. Adaptation to short photoperiods augments circadian food anticipatory activity in Siberian hamsters.

    PubMed

    Bradley, Sean P; Prendergast, Brian J

    2014-06-01

    This article is part of a Special Issue "Energy Balance". Both the light-dark cycle and the timing of food intake can entrain circadian rhythms. Entrainment to food is mediated by a food entrainable circadian oscillator (FEO) that is formally and mechanistically separable from the hypothalamic light-entrainable oscillator. This experiment examined whether seasonal changes in day length affect the function of the FEO in male Siberian hamsters (Phodopus sungorus). Hamsters housed in long (LD; 15 h light/day) or short (SD; 9h light/day) photoperiods were subjected to a timed-feeding schedule for 10 days, during which food was available only during a 5h interval of the light phase. Running wheel activity occurring within a 3h window immediately prior to actual or anticipated food delivery was operationally-defined as food anticipatory activity (FAA). After the timed-feeding interval, hamsters were fed ad libitum, and FAA was assessed 2 and 7 days later via probe trials of total food deprivation. During timed-feeding, all hamsters exhibited increases FAA, but FAA emerged more rapidly in SD; in probe trials, FAA was greater in magnitude and persistence in SD. Gonadectomy in LD did not induce the SD-like FAA phenotype, indicating that withdrawal of gonadal hormones is not sufficient to mediate the effects of photoperiod on FAA. Entrainment of the circadian system to light markedly affects the functional output of the FEO via gonadal hormone-independent mechanisms. Rapid emergence and persistent expression of FAA in SD may reflect a seasonal adaptation that directs behavior toward sources of nutrition with high temporal precision at times of year when food is scarce. © 2013.

  14. Isradipine prevents the development of spontaneously occurring cardiac necrosis in cardiomyopathic hamster.

    PubMed

    Jacques, Danielle; Bkaily, Ghassan; Jasmin, Gaétan; D'Orléans-Juste, Pedro; Chahine, Mirna

    2003-02-01

    Recent studies on the heart necrotizing process at the early stages of hamster polymyopathy have led us to believe that this hereditary disease derives from an anomalous transmembrane ion flux due to the presence of slow Na+ channels that contribute to intracellular Na+ accumulation which promote intracellular Ca2+ overload via the Ca2+ influx through the Na+-Ca2+ exchanger. In the present study, we investigated the potential beneficial effect of chronic treatment with a dual L-type Ca2+ and slow Na+ channel blockers isradipine, on the development of necrosis in myopathic hamster hearts. Young cardiomyopathic (CM) hamsters (CMH) were treated with isradipine (0.1 mg x kg(-1) x day(-1)) and nifedipine (1 mg x kg(-1) x day(-1)) for 4 consecutive weeks. Microscopic assessments were carried out in staged serial paraffin sections of heart ventricles from tissues freshly dissected at autopsy. In comparison with control nontreated hearts, which exhibited numerous necrotic calcific foci, myolytic lesions, and dilated right ventricle, isradipine treatment prevented, in a significant manner, all the above spontaneous pathological changes, while nifedipine had no effect. Our present observations provide evidence for the first time that in vivo treatment with a DHP Ca2+ channel blocker, isradipine, is cardioprotective against the development of necrosis in hereditary cardiomyopathy in the hamster. It is possible that the protective effect of isradipine in CMH could be largely due to the indirect blockade of Ca2+ influx through the Na+-Ca2+ exchanger as well as to possible direct blockade of Ca2+ influx through the T-type Ca2+ channel.

  15. Red algae (Gelidium amansii) hot-water extract ameliorates lipid metabolism in hamsters fed a high-fat diet.

    PubMed

    Yang, Tsung-Han; Yao, Hsien-Tsung; Chiang, Meng-Tsan

    2017-10-01

    The purpose of this study was to investigate the effects of Gelidium amansii (GA) hot-water extracts (GHE) on lipid metabolism in hamsters. Six-week-old male Syrian hamsters were used as the experimental animals. Hamsters were divided into four groups: (1) control diet group (CON); (2) high-fat diet group (HF); (3) HF with GHE diet group (HF + GHE); (4) HF with probucol diet group (HF + PO). All groups were fed the experimental diets and drinking water ad libitum for 6 weeks. The results showed that GHE significantly decreased body weight, liver weight, and adipose tissue (perirenal and paraepididymal) weight. The HF diet induced an increase in plasma triacylglycerol (TG), total cholesterol (TC), low-density lipoprotein cholesterol and very-low-density lipoprotein cholesterol levels. However, GHE supplementation reversed the increase of plasma lipids caused by the HF diet. In addition, GHE increased fecal cholesterol, TG and bile acid excretion. Lower hepatic TC and TG levels were found with GHE treatment. GHE reduced hepatic sterol regulatory element-binding proteins (SREBP) including SREBP 1 and SREBP 2 protein expressions. The phosphorylation of adenosine monophosphate (AMP)-activated protein kinase (AMPK) protein expression in hamsters was decreased by the HF diet; however, GHE supplementation increased the phosphorylation of AMPK protein expression. Our results suggest that GHE may ameliorate lipid metabolism in hamsters fed a HF diet. Copyright © 2017. Published by Elsevier B.V.

  16. Cutaneous leishmaniasis in the dorsal skin of hamsters: a useful model for the screening of antileishmanial drugs.

    PubMed

    Robledo, Sara M; Carrillo, Lina M; Daza, Alejandro; Restrepo, Adriana M; Muñoz, Diana L; Tobón, Jairo; Murillo, Javier D; López, Anderson; Ríos, Carolina; Mesa, Carol V; Upegui, Yulieth A; Valencia-Tobón, Alejandro; Mondragón-Shem, Karina; Rodríguez, Berardo; Vélez, Iván D

    2012-04-21

    Traditionally, hamsters are experimentally inoculated in the snout or the footpad. However in these sites an ulcer not always occurs, measurement of lesion size is a hard procedure and animals show difficulty to eat, breathe and move because of the lesion. In order to optimize the hamster model for cutaneous leishmaniasis, young adult male and female golden hamsters (Mesocricetus auratus) were injected intradermally at the dorsal skin with 1 to 1.5 x l0(7) promastigotes of Leishmania species and progression of subsequent lesions were evaluated for up to 16 weeks post infection. The golden hamster was selected because it is considered the adequate bio-model to evaluate drugs against Leishmania as they are susceptible to infection by different species. Cutaneous infection of hamsters results in chronic but controlled lesions, and a clinical evolution with signs similar to those observed in humans. Therefore, the establishment of the extent of infection by measuring the size of the lesion according to the area of indurations and ulcers is feasible. This approach has proven its versatility and easy management during inoculation, follow up and characterization of typical lesions (ulcers), application of treatments through different ways and obtaining of clinical samples after different treatments. By using this method the quality of animal life regarding locomotion, search for food and water, play and social activities is also preserved.

  17. In vivo but not in vitro leptin enhances lymphocyte proliferation in Siberian hamsters (Phodopus sungorus).

    PubMed

    Demas, Gregory E

    2010-04-01

    Mounting an immune response requires a relatively substantial investment of energy and marked reductions in energy availability can suppress immune function and presumably increase disease susceptibility. We have previously demonstrated that a moderate reduction in energy stores by partial surgical lipectomy impairs humoral immunity of Siberian hamsters (Phodopus sungorus) and is mediated, in part, by changes in the adipose tissue hormone leptin. The goals of the present study were to assess the role of leptin in cell-mediated immunity and to determine if the potential effects of leptin on immunity are via the direct actions of this hormone on lymphocytes, or indirect, via the sympathetic nervous system (SNS). In Experiment 1, hamsters received osmotic minipumps containing either murine leptin (0.5 microl/h) or vehicle alone for 10 days and splenocyte proliferation in response to the T-cell mitogen Concanavalin A (Con A) was determined. In Experiment 2, Con A-induced splenocyte proliferation was tested in the presence or absence of leptin in vitro. In Experiment 3, exogenous leptin was administered to intact or sympathetically denervated hamsters. Hamsters treated with in vivo leptin displayed increased splenocyte proliferation compared with control hamsters receiving vehicle. In contrast, in vitro leptin had no effect on splenocyte proliferation. Sympathetic denervation attenuated, but did not block, leptin-induced increases in immunity. Taken together, these results are consistent with the idea that leptin can enhance cell-mediated immunity; the SNS appears to contribute, least in part, to leptin-induced increases in immunity. Importantly, these findings confirm previous studies that leptin serves as an important endocrine link between energy balance and immunity. (c) 2009 Elsevier Inc. All rights reserved.

  18. Nocturnal illumination maintains reproductive function and simulates the period-lengthening effect of constant light in the mature male Djungarian hamster (Phodopus sungorus)

    NASA Technical Reports Server (NTRS)

    Ferraro, J. S.

    1990-01-01

    Mature male Djungarian hamsters (Phodopus sungorus) were placed in individual light-tight, sound attenuated chambers and exposed to one of four lighting conditions for a duration of approximately seven weeks. The four lighting conditions were: constant light (LL); constant dark (DD); feedback lighting (LDFB; a condition that illuminates the cage in response to locomotor activity); or a feedback lighting neighbor control (LDFB NC; the animal receives the same light pattern as a paired animal in feedback lighting, but has no control over it). Exposure of hamsters to LL or LDFB produced significantly and similarly longer free-running periods of the locomotor activity rhythm than exposure of animals to DD. Hamsters exposed to LDFB NC did not free-run or entrain, but rather displayed "relative coordination". The paired testes and sex accessory glands weights suggest that in the Djungarian hamster, LL and LDFB exposed animals maintained reproductive function, whereas DD exposed animals did not. Animals exposed to LDFB NC had intermediate paired testes weights. Since several previous studies have demonstrated that short pulses of light, which are coincident with the subjective night, are photostimulatory, it is not surprising that LDFB maintained reproductive function in the mature Djungarian hamster. Feedback lighting, however, has been shown to be an insufficient stimulus to maintain reproductive function of mature male and female Syrian hamsters, and to the reproductive maturation of immature Djungarian hamsters. The results suggest that there may be slight, but significant differences in the way these two species interpret photoperiod, as well as a developmental change in the photoperiodic response of Djungarian hamsters.

  19. Seasonality of fecal androgen and glucocorticoid metabolite excretion in male goral (Naemorhedus griseus) in Thailand.

    PubMed

    Khonmee, Jaruwan; Brown, Janine L; Rojanasthien, Suvichai; Thumasanukul, Dissakul; Kongphoemphun, Adisorn; Siriaroonrat, Boripat; Tipkantha, Wanlaya; Punyapornwithaya, Veerasak; Thitaram, Chatchote

    2014-04-01

    There is no information on the endocrinology of Chinese goral (Naemorhedus griseus), a high priority species for captive breeding and reintroduction in Thailand. This study characterized fecal androgen and glucocorticoid metabolites in male goral at Omkoi Wildlife Sanctuary to investigate seasonal relationships. Fecal samples were collected 3 days/week for 1 year from eight adult males. Mean androgen metabolite concentrations were greater (P<0.05) during the rainy season (289.82±9.18ng/g) and winter (224.09±11.97ng/g) compared to the summer (195.48±8.23ng/g), and were related to breeding activity. A similar pattern was observed for glucocorticoid concentrations (22.10±0.72ng/g compared to 21.98±0.98ng/g compared to 15.30±0.48ng/g), respectively, and this resulted in a positive correlation between the two hormones (P<0.05). There also were positive correlations between fecal androgen metabolite concentrations and temperature (P<0.05) and day length (P<0.05). In summary, this is the first study to assess endocrine function in male goral, and results showed seasonal variation in testicular and adrenal steroidogenic function, with greater activity in the rainy season and winter. Given that resources for captive male goral are consistent throughout the year, reproduction may be regulated primarily by photoperiod in this species. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. In-vivo monitoring of development of cholangiocarcinoma induced with C. sinensis and N-nitrosodimethylamine in Syrian golen hamsters using ultrasonography and magnetic resonance imaging: a preliminary study.

    PubMed

    Woo, Hyunsik; Han, Joon Koo; Kim, Jung Hoon; Hong, Sung-Tae; Uddin, Md Hafiz; Jang, Ja-June

    2017-04-01

    The purpose of this study is to evaluate high-resolution ultrasound and magnetic resonance imaging (MRI) in monitoring of cholangiocarcinoma in the hamsters with C. sinensis infection and N-nitrosodimethylamine (NDMA). Twenty-four male Syrian golden hamsters of were divided into four groups composed of five hamsters as control, five hamsters receiving 30 metacercariae of C. sinensis per each hamster, five hamsters receiving NDMA in drinking water, and nine hamsters receiving both metacercariae and NDMA. Ultrasound was performed every other week from baseline to the 12th week of infection. MRI and histopathologic examination was done from the 4th week to 12th week. Cholangiocarcinomas appeared as early as the 6th week of infection. There were 12 cholangiocarcinomas, nine and ten of which were demonstrated by ultrasound and MRI, respectively. Ultrasound and MRI findings of cholangiocarcinomas in the hamsters were similar to those of the mass-forming intrahepatic cholangiocarcinomas in humans. Ultrasound and MRI also showed other findings of disease progression such as periductal increased echogenicity or signal intensity, ductal dilatation, complicated cysts, and sludges in the gallbladder. High-resolution ultrasound and MRI can monitor and detect the occurrence of cholangiocarcinoma in the hamsters non-invasively. • High-resolution ultrasound and MRI can monitor occurrence of cholangiocarcinoma in the hamsters. • Cholangiocarcinomas were detected as early as the 6th week after C. sinensis infection. • Axial T2-weighted MRI demonstrated cholangiocarcinomas and various inflammatory findings in the hamsters.

  1. Blood Vessel Normalization in the Hamster Oral Cancer Model for Experimental Cancer Therapy Studies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ana J. Molinari; Romina F. Aromando; Maria E. Itoiz

    Normalization of tumor blood vessels improves drug and oxygen delivery to cancer cells. The aim of this study was to develop a technique to normalize blood vessels in the hamster cheek pouch model of oral cancer. Materials and Methods: Tumor-bearing hamsters were treated with thalidomide and were compared with controls. Results: Twenty eight hours after treatment with thalidomide, the blood vessels of premalignant tissue observable in vivo became narrower and less tortuous than those of controls; Evans Blue Dye extravasation in tumor was significantly reduced (indicating a reduction in aberrant tumor vascular hyperpermeability that compromises blood flow), and tumor bloodmore » vessel morphology in histological sections, labeled for Factor VIII, revealed a significant reduction in compressive forces. These findings indicated blood vessel normalization with a window of 48 h. Conclusion: The technique developed herein has rendered the hamster oral cancer model amenable to research, with the potential benefit of vascular normalization in head and neck cancer therapy.« less

  2. Caffeine induces metformin anticancer effect on fibrosarcoma in hamsters.

    PubMed

    Popović, D J; Lalošević, D; Miljković, D; Popović, K J; Čapo, I; Popović, J K

    2018-04-01

    We investigated the effect of metformin and caffeine on fibrosarcoma in hamsters. 32 Syrian golden hamsters of both sexes, weighing approximately 100 g, were randomly allocated to 3 experimental and 2 control groups, with a minimum of 6 animals per group. 2 x 106 BHK-21/C13 cells in 1 ml were injected subcutaneously into the animals' back in 4 groups. The first experimental group started peroral treatment with metformin 500 mg/kg daily, the second with caffeine 100 mg/kg daily and the third with a combination of metformin 500 mg/kg and caffeine 100 mg/kg daily, via a gastric probe 3 days before tumor inoculation. After 2 weeks, when the tumors were approximately 2 cm in the control group, all animals were sacrificed. The blood was collected for glucose and other analyses. The tumors were excised and weighed and their diameters were measured. The tumor samples were pathohistologically (HE) and immunohistochemically (Ki-67, CD 31, COX IV, GLUT-1, iNOS) assessed and the main organs toxicologically analyzed, including the control animals that had received metformin and caffeine. Tumor volume was determined using the formula LxS2/2, where L was the longest and S the shortest diameter. Ki-67-positive cells in the tumor samples were quantified. Images were taken and processed by software UTHSCSA Image Tools for Windows Version 3.00. Statistical significances were determined by the Student's t-test. The combination of metformin and caffeine inhibited fibrosarcoma growth in hamsters without toxicity. Administration of metformin with caffeine might be an effective and safe approach in novel nontoxic adjuvant anticancer treatment.

  3. In Adult Female Hamsters Hypothyroidism Stimulates D1 Receptor-mediated Breathing without altering D1 Receptor Expression

    PubMed Central

    Schlenker, Evelyn H.; Rio, Rodrigo Del; Schultz, Harold D.

    2015-01-01

    Hypothyroidism affects cardiopulmonary regulation and function of dopaminergic receptors. Here we evaluated effects of 5 months of hypothyroidism on dopamine D1 receptor modulation of breathing in female hamsters using a D1 receptor antagonist SCH23390. Euthyroid hamsters (EH) served as controls. Results indicated that hypothyroid female hamsters (HH) exhibited decreased body weights and minute ventilation (VE) following hypoxia due to decreased frequency of breathing (F). Moreover, SCH 23390 administration in HH increased VE by increasing tidal volume during exposure to air, hypoxia and following hypoxia. Relative to vehicle, SCH 23390 treatment decreased body temperature and hypoxic VE responsiveness in both groups. In EH, SCH 23390 decreased F in air, hypoxia and post hypoxia, and VE during hypoxia trended to decrease (P=0.053). Finally, expression of D1 receptor protein was not different between the two groups in any region evaluated. Thus, hypothyroidism in older female hamsters affected D1 receptor modulation of ventilation differently relative to euthyroid animals, but not expression of D1 receptors. PMID:26232642

  4. In adult female hamsters hypothyroidism stimulates D1 receptor-mediated breathing without altering D1 receptor expression.

    PubMed

    Schlenker, Evelyn H; Del Rio, Rodrigo; Schultz, Harold D

    2015-11-01

    Hypothyroidism affects cardiopulmonary regulation and function of dopaminergic receptors. Here we evaluated effects of 5 months of hypothyroidism on dopamine D1 receptor modulation of breathing in female hamsters using a D1 receptor antagonist SCH 23390. Euthyroid hamsters (EH) served as controls. Results indicated that hypothyroid female hamsters (HH) exhibited decreased body weights and minute ventilation (VE) following hypoxia due to decreased frequency of breathing (F). Moreover, SCH 23390 administration in HH increased VE by increasing tidal volume during exposure to air, hypoxia and following hypoxia. Relative to vehicle, SCH 23390 treatment decreased body temperature and hypoxic VE responsiveness in both groups. In EH, SCH 23390 decreased F in air, hypoxia and post hypoxia, and VE during hypoxia trended to decrease (P=0.053). Finally, expression of D1 receptor protein was not different between the two groups in any region evaluated. Thus, hypothyroidism in older female hamsters affected D1 receptor modulation of ventilation differently relative to euthyroid animals, but not expression of D1 receptors. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Ezetimibe ameliorates intestinal chylomicron overproduction and improves glucose tolerance in a diet-induced hamster model of insulin resistance

    PubMed Central

    Naples, Mark; Baker, Chris; Lino, Marsel; Iqbal, Jahangir; Hussain, M. Mahmood

    2012-01-01

    Ezetimibe is a cholesterol uptake inhibitor that targets the Niemann-Pick C1-like 1 cholesterol transporter. Ezetimibe treatment has been shown to cause significant decreases in plasma cholesterol levels in patients with hypercholesterolemia and familial hypercholesterolemia. A recent study in humans has shown that ezetimibe can decrease the release of atherogenic postprandial intestinal lipoproteins. In the present study, we evaluated the mechanisms by which ezetimibe treatment can lower postprandial apoB48-containing chylomicron particles, using a hyperlipidemic and insulin-resistant hamster model fed a diet rich in fructose and fat (the FF diet) and fructose, fat, and cholesterol (the FFC diet). Male Syrian Golden hamsters were fed either chow or the FF or FFC diet ± ezetimibe for 2 wk. After 2 wk, chylomicron production was assessed following intravenous triton infusion. Tissues were then collected and analyzed for protein and mRNA content. FFC-fed hamsters treated with ezetimibe showed improved glucose tolerance, decreased fasting insulin levels, and markedly reduced circulating levels of TG and cholesterol in both the LDL and VLDL fractions. Examination of triglyceride (TG)-rich lipoprotein (TRL) fractions showed that ezetimibe treatment reduced postprandial cholesterol content in TRL lipoproteins as well as reducing apoB48 content. Although ezetimibe did not decrease TRL-TG levels in FFC hamsters, ezetimibe treatment in FF hamsters resulted in decreases in TRL-TG. Jejunal apoB48 protein expression was lower in ezetimibe-treated hamsters. Reductions in jejunal protein levels of scavenger receptor type B-1 (SRB-1) and fatty acid transport protein 4 were also observed. In addition, ezetimibe-treated hamsters showed significantly lower jejunal mRNA expression of a number of genes involved in lipid synthesis and transport, including srebp-1c, sr-b1, ppar-γ, and abcg1. These data suggest that treatment with ezetimibe not only inhibits cholesterol uptake, but may

  6. Pleural lesions in Syrian golden hamsters and Fischer-344 rats following intrapleural instillation of man-made ceramic or glass fibers.

    PubMed

    Everitt, J I; Bermudez, E; Mangum, J B; Wong, B; Moss, O R; Janszen, D; Rutten, A A

    1994-01-01

    The mesothelium is a target of the toxic and carcinogenic effects of certain natural mineral and man-made fibers. Long-term inhalation of a ceramic fiber (RCF-1) results in a high incidence of pleural mesotheliomas in Syrian golden hamsters but not in identically exposed Fischer-344 rats. The present study compared the histopathology of the early pleural response in rats and hamsters instilled with artificial fibers. Groups of Syrian golden hamsters and Fischer-344 rats were instilled with ceramic (RCF-1) or glass (MMVF-10) fibers directly into the pleural space. Each species received approximately equal numbers of long, thin fibers per g body weight. Fiber-induced lesions were compared 7 and 28 days postinstillation. Both hamsters and rats developed qualitatively similar dose-dependent inflammatory lesions that were not fiber-type specific. Both species developed fibrosis in conjunction with inflammation in the visceral pleura, but a striking interspecies difference was noted in the pattern of mesothelial cell response. Hamsters developed greater surface mesothelial cell proliferation and had focal aggregates of mesothelial cells embedded deep within regions of visceral pleural fibrosis. It is hypothesized from the present study that the marked fiber-induced proliferative mesothelial cell response of the hamster visceral pleura may explain the high number of pleural mesotheliomas found in long-term fiber studies in this species.

  7. Use of vital dyes to assess embryonic viability in the hamster, Mesocricetus auratus

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hutz, R.J.; DeMayo, F.J.; Dukelow, W.R.

    1985-05-01

    Experiments were designed to assess the use of the vital dyes trypan blue and fluorescein diacetate as indicators of the viability of hamster ova and embryos. Exclusion of trypan blue and fluorescence with fluorescein diacetate showed high correlations with uptake of (/sup 3/H)uridine by ova and further development of embryos in vitro. Ova killed by freezing and thawing incorporated (/sup 3/H)uridine at background levels. Trypan blue exclusion and fluorescein diacetate uptake were highly correlated with each other (r = 0.99). Trypan blue and fluorescein diacetate serve as excellent indices of viability in ova and early embryos of hamsters.

  8. Effects of pelleted or powdered diets containing soy protein or sodium caseinate on lipid concentrations and bile acid excretion in golden Syrian hamsters.

    PubMed

    Butteiger, Dustie N; Krul, Elaine S

    2015-08-01

    Custom diets are a convenient vector for oral administration of test articles, but the processing and physical form of a diet can affect its nutritional properties and how it is consumed. Here, the authors evaluated the feeding behavior and physiology of golden Syrian hamsters fed diets of either soy or caseinate protein in pelleted or powdered forms for 28 d to determine whether dietary processing and form mediates the physiological effects of dietary proteins. The authors compared body weight, food consumption, serum cholesterol concentration, serum triglyceride concentration, fecal weight and fecal excretion of bile acids between treatment groups. Hamsters fed powdered diets showed higher food consumption than hamsters fed pelleted diets, regardless of protein source. Hamsters fed soy pelleted diets showed lower serum cholesterol concentration and higher fecal excretion of bile acid than hamsters fed caseinate pelleted diets, and serum cholesterol concentration correlated strongly with fecal excretion of bile acid. This correlation suggests that the physiological effects of soy protein on cholesterol and excretion of bile acid might be related or similarly mediated through diet. The differences observed between hamsters on different diets indicate that dietary form can influence both feeding behavior and the physiological effects of a diet in hamsters.

  9. Tumorigenicity of fine man-made fibers after intratracheal administrations to hamsters.

    PubMed

    Adachi, S; Takemoto, K; Kimura, K

    1991-02-01

    Six types of man-made fibers were administered intratracheally (2.0 mg/animal each a week, for 5 weeks; total 10 mg/animal) to female Syrian hamsters that were observed histologically for 2 years after administration. The fibers were rock wool [average diameter (D) = 6.1 microns, average length (L) = 296 microns], fiberglass (D = 0.65 microns, L = 16.8 microns), potassium titanate fiber (D = 0.36 microns, L = 7.17 microns), calcium sulfate fiber (D = 1.0 microns, L = 17.8 microns), basic magnesium sulfate fiber (D = 0.45 microns, L = 22.4 microns), and metaphosphate fiber (D = 2.38 microns, L = 64.1 microns). Tumors were observed in hamsters that had received basic magnesium sulfate fiber (9/20), metaphosphate fiber (6/20), calcium sulfate fiber (3/20), and fiberglass (2/20) but not in the control, rock wool, or potassium titanate fiber groups. The primary sites of the tumors were not only in the pleural cavity but also in the intracelial organs, kidney, adrenal gland, bladder, and uterus. Only a few of the tumors were identified as mesotheliomas by histological examination. In addition to neoplastic lesions, fibrosis, pleural thickening, and chronic inflammatory changes in the lungs were observed in the hamsters, but these changes appeared too mild to foster a pneumoconiosis such as asbestosis.

  10. Pleural dosimetry and pathobiological responses in rats and hamsters exposed subchronically to MMVF 10a fiberglass.

    PubMed

    Bermudez, Edilberto; Mangum, James B; Moss, Owen R; Wong, Brian A; Everitt, Jeffrey I

    2003-07-01

    Interspecies differences in pulmonary and pleural responses to the inhalation of natural mineral and synthetic vitreous fibers have been observed in chronic and subchronic studies. However, the reasons for these differences are not clearly understood. There are also fiber-specific differences in the outcome of chronic inhalation exposure to natural mineral and synthetic vitreous fibers. Whether these differences are dependent upon the ability of these fibers to translocate to the pleural space is unknown. The present study was conducted to compare retained fiber burdens and selected pathological responses in the pleural compartments of rats and hamsters following subchronic inhalation of MMVF 10a fiberglass, a fiber negative for tumorigenesis or fibrosis in chronic studies. Fischer 344 rats and Syrian golden hamsters were exposed for 4 or 12 weeks by nose-only inhalation at nominal aerosol mass concentrations of 45 mg/m3 (610 WHO fibers/cc). Pulmonary fiber burdens and pulmonary inflammatory responses were greater in rats than in hamsters. The total number of fibers in the lung was approximately three orders of magnitude greater than in the pleural compartment. Pleural burdens in the hamster (160 fibers/cm2 surface area) were significantly greater than burdens in similarly exposed rats (60 fibers/cm2 surface area) following 12 weeks of exposure. With time postexposure, pleural burdens decreased in hamsters but were essentially unchanged in rats. Pleural inflammatory responses in both species were minimal. In rats, pleural inflammation was characterized by increased numbers of macrophages and increases in mesothelial cell replication during the period of fiber exposure. In contrast, hamsters had increased numbers of macrophages and lymphocytes, and mesothelial-cell replication indices were elevated on the parietal pleura of the costal wall and diaphragm, with some of these responses persisting through 12 weeks of postexposure recovery. Taken together, the results

  11. Effect of food restriction on energy budget in warm-acclimated striped hamsters.

    PubMed

    Zhao, Zhi-Jun; Chi, Qing-Sheng; Zhao, Liang; Zhu, Qiao-Xia; Cao, Jing; Wang, De-Hua

    2015-08-01

    The capacity of small mammals to sustain periods of food shortage largely depends on the adaptive regulation of energy budget in response to the decrease in food supply. In addition to food availability, ambient temperature (Ta) is an important factor affecting the rates of both energy intake and expenditure. To examine the effect of Ta on energy strategy and the capacity to sustain food shortage, striped hamsters were exposed to a warm condition (30°C) and were then restricted to 70% of ad libitum food intake. Body mass, energy intake and expenditure and physiological markers indicative of thermogenesis were measured. Warm exposure had no effect on body mass and digestibility, but decreased energy intake, basal metabolic rate and maximum nonshivering thermogenesis. The mitochondria protein content, cytochrome c oxidase activity and uncoupling protein 1 level of brown adipose tissue were significantly lower in hamsters at 30°C than at 21°C. Food restriction induced a significant decrease in body mass, but the decreased body mass was attenuated at 30°C relative to 21°C. This suggests that striped hamsters could not compensate for the limited food supply by decreasing daily energy expenditure at 21°C, whereas they could at 30°C. The significant reductions in the rates of metabolism and thermogenesis in warm-acclimated hamsters increase the capacity to cope with food shortage. Although, it remains uncertain whether this response represents some generalized evolutionary adaptation, the Ta-dependent adjustment in the capacity to survive food restriction may reflect that warm acclimation plays an important role in adaptive regulation of both physiology and behavior in response to the variations of food availability. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Inhibition of fatty acid synthesis decreases very low density lipoprotein secretion in the hamster.

    PubMed

    Arbeeny, C M; Meyers, D S; Bergquist, K E; Gregg, R E

    1992-06-01

    The hamster was developed as a model to study very low density lipoprotein (VLDL) metabolism, since, as is the case in humans, the hamster liver was found to synthesize apoB-100 and not apoB-48. The effect of inhibiting fatty acid synthesis on the hepatic secretion of VLDL triglyceride (TG) and apolipoprotein (apo) B-100 in this model was then investigated. In an in vivo study, hamsters were fed a chow diet containing 0.15% TOFA (5-tetradecyloxy-2-furancarboxylic acid), an inhibitor of acetyl-CoA carboxylase. After 6 days of treatment, plasma triglyceride and cholesterol levels were decreased by 30.2% and 11.6%, respectively. When the secretion of VLDL-TG by the liver was measured in vivo after injection of Triton WR 1339, TOFA treatment was found to decrease VLDL-TG secretion by 40%. In subsequent in vitro studies utilizing cultured primary hamster hepatocytes, incubation with 20 microM TOFA for 4 h resulted in 98% and 76% inhibition in fatty acid and triglyceride synthesis, respectively; VLDL-TG secretion was decreased by 90%. When hepatocytes were pulsed with [3H]leucine, incubation with TOFA resulted in a 50% decrease in the incorporation of radiolabel into secreted VLDL apoB-100. The results of this study indicate that inhibition of intracellular triglyceride synthesis decreases the secretion of VLDL-TG and apoB-100, and does not result in the secretion of a dense, triglyceride-depleted lipoprotein.

  13. Pulmonary toxicity in hamsters of smoke particles from Kuwaiti oil fires.

    PubMed Central

    Brain, J D; Long, N C; Wolfthal, S F; Dumyahn, T; Dockery, D W

    1998-01-01

    The Kuwaiti oil wells set on fire by retreating Iraqi troops at the end of the Persian Gulf War released complex particles, inorganic and organic gases, and hydrocarbons into the atmosphere, damaging the environment where many people live and work. In this study, we assessed the health effects of particles from the Kuwaiti oil fires by instilling hamsters intratracheally with particles (<3.5 microM in size) collected in Ahmadi, a residential area in Kuwait located downwind of hundreds of oil fires. Twenty-four hours after instillation, we performed bronchoalveolar lavage (BAL) to assess various indicators of pulmonary inflammation, including neutrophil and macrophage numbers; albumin, an index of air-blood barrier permeability; and activities of three enzymes: lactate dehydrogenase (LDH; an indicator of cell injury), myeloperoxidase (MPO; which indicates activation of neutrophils), and ss-N-acetylglucosaminidase (GLN; which is indicative of damage to macrophages or neutrophils). We compared the response of hamsters instilled with particles from Ahmadi to animals instilled with urban particles collected in St. Louis, Missouri. We also compared the Ahmadi particles against a highly fibrogenic positive control ([alpha]-quartz) and a relatively nontoxic negative control (iron oxide). When compared to hamsters instilled with particles from St. Louis, the animals treated with the Ahmadi particles had between 1.4- and 2.2-fold more neutrophils in their BAL fluids. The Ahmadi hamsters had more macrophages and lower MPO and LDH activities, but comparable albumin levels and GLN activities. Thus, the acute toxicity of the Ahmadi particles was roughly similar to that of urban particles collected in the United States, when identical masses were compared. However, the relatively higher concentrations of particles measured in Kuwait and Saudi Arabia during the oil fires (at times more than 16 times higher than the EPA standard) is of particular concern. In addition, since the

  14. Curcuma oil ameliorates insulin resistance & associated thrombotic complications in hamster & rat

    PubMed Central

    Singh, Vishal; Jain, Manish; Misra, Ankita; Khanna, Vivek; Prakash, Prem; Malasoni, Richa; Dwivedi, Anil Kumar; Dikshit, Madhu; Barthwal, Manoj Kumar

    2015-01-01

    Background & objectives: Curcuma oil (C. oil) isolated from turmeric (Curcuma longa L.) has been shown to have neuro-protective, anti-cancer, antioxidant and anti-hyperlipidaemic effects in experimental animal models. However, its effect in insulin resistant animals remains unclear. The present study was carried out to investigate the disease modifying potential and underlying mechanisms of the C. oil in animal models of diet induced insulin resistance and associated thrombotic complications. Methods: Male Golden Syrian hamsters on high fructose diet (HFr) for 12 wk were treated orally with vehicle, fenofibrate (30 mg/kg) or C. oil (300 mg/kg) in the last four weeks. Wistar rats fed HFr for 12 wk were treated orally with C. oil (300 mg/kg) in the last two weeks. To examine the protective effect of C. oil, blood glucose, serum insulin, platelet aggregation, thrombosis and inflammatory markers were assessed in these animals. Results: Animals fed with HFr diet for 12 wk demonstrated hyperlipidaemia, hyperglycaemia, hyperinsulinaemia, alteration in insulin sensitivity indices, increased lipid peroxidation, inflammation, endothelial dysfunction, platelet free radical generation, tyrosine phosphorylation, aggregation, adhesion and intravascular thrombosis. Curcuma oil treatment for the last four weeks in hamsters ameliorated HFr-induced hyperlipidaemia, hyperglycaemia, insulin resistance, oxidative stress, inflammation, endothelial dysfunction, platelet activation, and thrombosis. In HFr fed hamsters, the effect of C. oil at 300 mg/kg was comparable with the standard drug fenofibrate. Curcuma oil treatment in the last two weeks in rats ameliorated HFr-induced hyperglycaemia and hyperinsulinaemia by modulating hepatic expression of sterol regulatory element binding protein 1c (SREBP-1c), peroxisome proliferator-activated receptor-gamma co-activator 1 (PGC-1)α and PGC-1β genes known to be involved in lipid and glucose metabolism. Interpretation & conclusions: High

  15. Curcuma oil ameliorates insulin resistance & associated thrombotic complications in hamster & rat.

    PubMed

    Singh, Vishal; Jain, Manish; Misra, Ankita; Khanna, Vivek; Prakash, Prem; Malasoni, Richa; Dwivedi, Anil Kumar; Dikshit, Madhu; Barthwal, Manoj Kumar

    2015-06-01

    Curcuma oil (C. oil) isolated from turmeric (Curcuma longa L.) has been shown to have neuro-protective, anti-cancer, antioxidant and anti-hyperlipidaemic effects in experimental animal models. However, its effect in insulin resistant animals remains unclear. The present study was carried out to investigate the disease modifying potential and underlying mechanisms of the C. oil in animal models of diet induced insulin resistance and associated thrombotic complications. Male Golden Syrian hamsters on high fructose diet (HFr) for 12 wk were treated orally with vehicle, fenofibrate (30 mg/kg) or C. oil (300 mg/kg) in the last four weeks. Wistar rats fed HFr for 12 wk were treated orally with C. oil (300 mg/kg) in the last two weeks. To examine the protective effect of C. oil, blood glucose, serum insulin, platelet aggregation, thrombosis and inflammatory markers were assessed in these animals. Animals fed with HFr diet for 12 wk demonstrated hyperlipidaemia, hyperglycaemia, hyperinsulinaemia, alteration in insulin sensitivity indices, increased lipid peroxidation, inflammation, endothelial dysfunction, platelet free radical generation, tyrosine phosphorylation, aggregation, adhesion and intravascular thrombosis. Curcuma oil treatment for the last four weeks in hamsters ameliorated HFr-induced hyperlipidaemia, hyperglycaemia, insulin resistance, oxidative stress, inflammation, endothelial dysfunction, platelet activation, and thrombosis. In HFr fed hamsters, the effect of C. oil at 300 mg/kg [ ] was comparable with the standard drug fenofibrate. Curcuma oil treatment in the last two weeks in rats ameliorated HFr-induced hyperglycaemia and hyperinsulinaemia by modulating hepatic expression of sterol regulatory element binding protein 1c (SREBP-1c), peroxisome proliferator-activated receptor-gamma co-activator 1 (PGC-1)α and PGC-1β genes known to be involved in lipid and glucose metabolism. High fructose feeding to rats and hamsters led to the development of insulin

  16. The evolution of chromosomal instability in Chinese hamster cells: a changing picture?

    NASA Technical Reports Server (NTRS)

    Ponnaiya, B.; Limoli, C. L.; Corcoran, J.; Kaplan, M. I.; Hartmann, A.; Morgan, W. F.

    1998-01-01

    PURPOSE: To investigate the kinetics of chromosomal instability induced in clones of Chinese hamster cells following X-irradiation. MATERIALS AND METHODS: X-irradiated clones of GM10115, human-hamster hybrid cells containing a single human chromosome 4 (HC4), have been previously established. These clones were defined as unstable if they contained > or = three subpopulations of cells with unique rearrangements of HC4 as detected by FISH. Stable and unstable clones were analysed by FISH and Giemsa staining at various times post-irradiation. RESULTS: While most of the stable clones continued to show chromosomal stability of HC4 over time, one became marginally unstable at approximately 45 population doublings post-irradiation. Clones exhibiting chromosomal instability had one of several fates. Many of the unstable clones were showed similar levels of instability over time. However, one unstable clone became stable with time in culture, while another became even more unstable over time. Cytogenetic analyses of all clones after Giemsa staining indicated that in some clones the hamster chromosomes were rearranged independent of HC4, demonstrating increased frequencies of chromatid breaks and dicentric chromosomes. The majority of the unstable clones also had higher yields of chromatid gaps. CONCLUSIONS: These data demonstrate the dynamic nature of chromosomal instability as measured by two different cytogenetic assays.

  17. Ribavirin protects Syrian hamsters against lethal hantavirus pulmonary syndrome--after intranasal exposure to Andes virus.

    PubMed

    Ogg, Monica; Jonsson, Colleen B; Camp, Jeremy V; Hooper, Jay W

    2013-11-08

    Andes virus, ANDV, harbored by wild rodents, causes the highly lethal hantavirus pulmonary syndrome (HPS) upon transmission to humans resulting in death in 30% to 50% of the cases. As there is no treatment for this disease, we systematically tested the efficacy of ribavirin in vitro and in an animal model. In vitro assays confirmed antiviral activity and determined that the most effective doses were 40 µg/mL and above. We tested three different concentrations of ribavirin for their capability to prevent HPS in the ANDV hamster model following an intranasal challenge. While the highest level of ribavirin (200 mg/kg) was toxic to the hamster, both the middle (100 mg/kg) and the lowest concentration (50 mg/kg) prevented HPS in hamsters without toxicity. Specifically, 8 of 8 hamsters survived intranasal challenge for both of those groups whereas 7 of 8 PBS control-treated animals developed lethal HPS. Further, we report that administration of ribavirin at 50 mg/kg/day starting on days 6, 8, 10, or 12 post-infection resulted in significant protection against HPS in all groups. Administration of ribavirin at 14 days post-infection also provided a significant level of protection against lethal HPS. These data provide in vivo evidence supporting the potential use of ribavirin as a post-exposure treatment to prevent HPS after exposure by the respiratory route.

  18. Effect of pigeon pea (Cajanus cajan L.) on high-fat diet-induced hypercholesterolemia in hamsters.

    PubMed

    Dai, Fan-Jhen; Hsu, Wei-Hsuan; Huang, Jan-Jeng; Wu, She-Ching

    2013-03-01

    Obesity is associated with increased systemic and airway oxidative stress, which may result from a combination of adipokine imbalance and antioxidant defenses reduction. Obesity-mediated oxidative stress plays an important role in the pathogenesis of dyslipidemia, vascular disease, and nonalcoholic hepatic steatosis. The antidyslipidemic activity of pigeon pea were evaluated by high-fat diet (HFD) hamsters model, in which the level of high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), total cholesterol (TC), and total triglyceride (TG) were examined. We found that pigeon pea administration promoted cholesterol converting to bile acid in HFD-induced hamsters, thereby exerting hypolipidemic activity. In the statistical results, pigeon pea significantly increased hepatic carnitine palmitoyltransferase-1 (CPT-1), LDL receptor, and cholesterol 7α-hydroxylase (also known as cytochrome P450 7A1, CYP7A1) expression to attenuate dyslipidemia in HFD-fed hamsters; and markedly elevated antioxidant enzymes in the liver of HFD-induced hamsters, further alleviating lipid peroxidation. These effects may attribute to pigeon pea contained large of unsaturated fatty acids (UFA; C18:2) and phytosterol (β-sitosterol, campesterol, and stigmasterol). Moreover, the effects of pigeon pea on dyslipidemia were greater than β-sitosterol administration (4%), suggesting that phytosterone in pigeon pea could prevent metabolic syndrome. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Effects of dietary carbohydrates on glucose and lipid metabolism in golden Syrian hamsters.

    PubMed

    Kasim-Karakas, S E; Vriend, H; Almario, R; Chow, L C; Goodman, M N

    1996-08-01

    Frequent coexistence of insulin resistance, central obesity, and hypertriglyceridemia in the same individual suggests an underlying common pathogenesis. Insulin resistance and hypertriglyceridemia can be induced by carbohydrate feeding in rats. Golden Syrian hamsters are believed to be resistant to the metabolic effects of dietary carbohydrates. We investigated the effects of diets containing 60% fructose or sucrose on glucose and lipid metabolism in hamsters, both in the fasting state and during an intravenous glucose tolerance test. Fructose caused obesity (weight after treatment: 131 +/- 7 gm in the control group, 155 +/- 5 gm in the fructose group, 136 +/- 7 gm in sucrose group, p < 0.04). Fructose also reduced glucose disappearance rate (KG: 2.69% +/- 0.39% in the control group, 1.45% +/- 0.18% in the fructose group, p < 0.02). Sucrose caused a marginal decrease in glucose disappearance (KG: 1.93% +/- 0.21%, p = 0.08 vs the control group). Only fructose feeding increased fasting plasma nonesterified fatty acids (0.645 +/- 0.087 mEq/L in the control group, 1.035 +/- 0.083 mEq/L in the fructose group, 0.606 +/- 0.061 mEq/L in the sucrose group, p < 0.002), plasma triglycerides (84 +/- 6 mg/dl in the control group, 270 +/- 65 mg/dl in the fructose group, 94 +/- 16 mg/dl in the sucrose group, p < 0.0002), and liver triglycerides (1.88 +/- 0.38 mg/gm liver weight in the control group, 2.35 =/- 0.24 mg/gm in the fructose group, 1.41 +/- 0.13 mg/gm in the sucrose group, p < 0.04). Previous studies in the rat have suggested that dietary carbohydrates induce insulin resistance by increasing plasma nonesterified fatty acids and triglycerides, which are preferentially used by the muscles. The present report shows that sucrose also can cause some decrease in glucose disappearance in the hamster without causing hypertriglyceridemia or increasing plasma nonesterified fatty acids. Thus other mechanisms may also contribute to the insulin resistance in the hamster. These

  20. neu mutation in schwannomas induced transplacentally in Syrian golden hamsters by N-nitrosoethylurea: high incidence but low allelic representation.

    PubMed

    Buzard, G S; Enomoto, T; Hongyo, T; Perantoni, A O; Diwan, B A; Devor, D E; Reed, C D; Dove, L F; Rice, J M

    1999-10-01

    Peripheral nerve tumors (PNT) and melanomas induced transplacentally on day 14 of gestation in Syrian golden hamsters by N-nitrosoethylurea were analyzed for activated oncogenes by the NIH 3T3 transfection assay, and for mutations in the neu oncogene by direct sequencing, allele-specific oligonucleotide hybridization, MnlI restriction-fragment-length polymorphism, single-strand conformation polymorphism, and mismatch amplification mutation assays. All (67/67) of the PNT, but none of the melanomas, contained a somatic missense T --> A transversion within the neu oncogene transmembrane domain at a site corresponding to that which also occurs in rat schwannomas transplacentally induced by N-nitrosoethylurea. In only 2 of the 67 individual hamster PNT did the majority of tumor cells appear to carry the mutant neu allele, in contrast to comparable rat schwannomas in which it overwhelmingly predominates. The low fraction of hamster tumor cells carrying the mutation was stable through multiple transplantation passages. In the hamster, as in the rat, specific point-mutational activation of the neu oncogene thus constitutes the major pathway for induction of PNT by transplacental exposure to an alkylating agent, but the low allelic representation of mutant neu in hamster PNT suggests a significant difference in mechanism by which the mutant oncogene acts in this species.

  1. High frequency stimulation of the entopeduncular nucleus sets the cortico-basal ganglia network to a new functional state in the dystonic hamster.

    PubMed

    Reese, René; Charron, Giselle; Nadjar, Agnès; Aubert, Incarnation; Thiolat, Marie-Laure; Hamann, Melanie; Richter, Angelika; Bezard, Erwan; Meissner, Wassilios G

    2009-09-01

    High frequency stimulation (HFS) of the internal pallidum is effective for the treatment of dystonia. Only few studies have investigated the effects of stimulation on the activity of the cortex-basal ganglia network. We here assess within this network the effect of entopeduncular nucleus (EP) HFS on the expression of c-Fos and cytochrome oxidase subunit I (COI) in the dt(sz)-hamster, a well-characterized model of paroxysmal dystonia. In dt(sz)-hamsters, we identified abnormal activity in motor cortex, basal ganglia and thalamus. These structures have already been linked to the pathophysiology of human dystonia. EP-HFS (i) increased striatal c-Fos expression in controls and dystonic hamsters and (ii) reduced thalamic c-Fos expression in dt(sz)-hamsters. EP-HFS had no effect on COI expression. The present results suggest that EP-HFS induces a new network activity state which may improve information processing and finally reduces the severity of dystonic attacks in dt(sz)-hamsters.

  2. Identification of Reference Genes for Quantitative Real Time PCR Assays in Aortic Tissue of Syrian Hamsters with Bicuspid Aortic Valve.

    PubMed

    Rueda-Martínez, Carmen; Fernández, M Carmen; Soto-Navarrete, María Teresa; Jiménez-Navarro, Manuel; Durán, Ana Carmen; Fernández, Borja

    2016-01-01

    Bicuspid aortic valve (BAV) is the most frequent congenital cardiac malformation in humans, and appears frequently associated with dilatation of the ascending aorta. This association is likely the result of a common aetiology. Currently, a Syrian hamster strain with a relatively high (∼40%) incidence of BAV constitutes the only spontaneous animal model of BAV disease. The characterization of molecular alterations in the aorta of hamsters with BAV may serve to identify pathophysiological mechanisms and molecular markers of disease in humans. In this report, we evaluate the expression of ten candidate reference genes in aortic tissue of hamsters in order to identify housekeeping genes for normalization using quantitative real time PCR (RT-qPCR) assays. A total of 51 adult (180-240 days old) and 56 old (300-440 days old) animals were used. They belonged to a control strain of hamsters with normal, tricuspid aortic valve (TAV; n = 30), or to the affected strain of hamsters with TAV (n = 45) or BAV (n = 32). The expression stability of the candidate reference genes was determined by RT-qPCR using three statistical algorithms, GeNorm, NormFinder and Bestkeeper. The expression analyses showed that the most stable reference genes for the three algorithms employed were Cdkn1β, G3pdh and Polr2a. We propose the use of Cdkn1β, or both Cdkn1β and G3pdh as reference genes for mRNA expression analyses in Syrian hamster aorta.

  3. Antigenic specificity and morphologic characteristics of Chlamydia trachomatis, strain SFPD, isolated from hamsters with proliferative ileitis.

    PubMed

    Fox, J G; Stills, H F; Paster, B J; Dewhirst, F E; Yan, L; Palley, L; Prostak, K

    1993-10-01

    Profound diarrhea associated with proliferating intestinal cells containing intraepithelial campylobacter-like organisms (ICLO) occurs in a variety of mammalian hosts, particularly swine and hamsters. Recently, intracellular bacteria were isolated from proliferative intestinal tissue of hamsters and propagated in intestine cell line 407. Oral inoculation of hamsters with cell culture lysates containing these organisms reproduced the disease in susceptible hamsters. In the present study, an intracellular bacterium from the INT 407 cell line was shown by a variety of techniques to be a member of the genus Chlamydia and has been designated Chlamydia sp. strain SFPD. McCoy cells infected with Chlamydia sp. strain SFPD demonstrated bright fluorescent-stained intracytoplasmic inclusions when examined with fluorescein-labeled species-specific C. trachomatis monoclonal antibodies. The organism also reacted to fluorescein-labeled polyclonal but not monoclonal ICLO "omega" antisera. Ultrastructural examination of the Chlamydia sp. strain SFPD from McCoy cells revealed electrondense elementary bodies and a less electron-dense reticulate-like body that was circular; both features are consistent in morphology to developmental forms of Chlamydia and do not conform to ICLO morphology. Molecular studies, 16S ribosomal sequence analysis, and sequencing of the outer membrane protein confirmed that the isolate is a C. trachomatis closely related to the mouse pneumonitis strain of C. trachomatis.

  4. Delineation of molecular pathways that regulate hepatic PCSK9 and LDL receptor expression during fasting in normolipidemic hamsters

    PubMed Central

    Wu, Minhao; Dong, Bin; Cao, Aiqin; Li, Hai; Liu, Jingwen

    2015-01-01

    Background PCSK9 has emerged as a key regulator of serum LDL-C metabolism by promoting the degradation of hepatic LDL receptor (LDLR). In this study, we investigated the effect of fasting on serum PCSK9, LDL-C, and hepatic LDLR expression in hamsters and further delineated the molecular pathways involved in fasting-induced repression of PCSK9 transcription. Results Fasting had insignificant effects on serum total cholesterol and HDL-C levels, but reduced LDL-C, triglyceride and insulin levels. The decrease in serum LDL-C was accompanied by marked reductions of hepatic PCSK9 mRNA and serum PCSK9 protein levels with concomitant increases of hepatic LDLR protein amounts. Fasting produced a profound impact on SREBP1 expression and its transactivating activity, while having modest effects on mRNA expressions of SREBP2 target genes in hamster liver. Although PPARα mRNA levels in hamster liver were elevated by fasting, ligand-induced activation of PPARα with WY14643 compound in hamster primary hepatocytes did not affect PCSK9 mRNA or protein expressions. Further investigation on HNF1α, a critical transactivator of PCSK9, revealed that fasting did not alter its mRNA expression, however, the protein abundance of HNF1α in nuclear extracts of hamster liver was markedly reduced by prolonged fasting. Conclusion Fasting lowered serum LDL-C in hamsters by increasing hepatic LDLR protein amounts via reductions of serum PCSK9 levels. Importantly, our results suggest that attenuation of SREBP1 transactivating activity owing to decreased insulin levels during fasting is primarily responsible for compromised PCSK9 gene transcription, which was further suppressed after prolonged fasting by a reduction of nuclear HNF1α protein abundance. PMID:22954675

  5. Male-specific pulmonary hemorrhage and cytokine gene expression in golden hamster in early-phase Leptospira interrogans serovar Hebdomadis infection.

    PubMed

    Tomizawa, Rina; Sugiyama, Hiromu; Sato, Ryoichi; Ohnishi, Makoto; Koizumi, Nobuo

    2017-10-01

    Leptospirosis causes severe clinical signs more frequently in men than in women, but the mechanism underlying the gender differences in leptospirosis remains unclear. In this study, petechial hemorrhage was observed in male but not in female hamster lung tissues infected with Leptospira interrogans serovar Hebdomadis at 120 h pi, demonstrating that male hamsters were more susceptible to the development of a severe disease upon Leptospira infection. No leptospiral DNA was detected in the lung tissues at 120 h pi when pulmonary hemorrhage was observed, indicating that pulmonary hemorrhage is attributable to the immune reactions of the host rather than from the direct effect of leptospires. The upregulation of nitric oxide synthase genes in the hamsters without pulmonary hemorrhage, inos and enos in female hamsters at 96 h pi and enos in male animals without hemorrhage at 120 h pi, may suggest that nitric oxide has a suppressive effect on leptospirosis-associated pulmonary hemorrhage. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Healing acceleration in hamsters of oral mucositis induced by 5-fluorouracil with topical Calendula officinalis.

    PubMed

    Tanideh, Nader; Tavakoli, Parisa; Saghiri, Mohammad Ali; Garcia-Godoy, Franklin; Amanat, Dariush; Tadbir, Azadeh Andisheh; Samani, Soleiman Mohammadi; Tamadon, Amin

    2013-03-01

    This study assessed the potential of topical Calendula officinalis extract on the healing of oral mucositis induced by 5-fluorouracil (5-FU) in hamsters. Oral mucositis was induced in 60 male hamsters by 5-FU (60 mg/kg) on days 0, 5, and 10 of the study. The cheek pouch was scratched with a sterile needle on days 1 and 2. On days 12-17, 5% and 10% C. officinalis gel and gel base groups were treated and then compared with a control group. Macroscopic and microscopic scores and weights were evaluated. Microscopic and macroscopic scores of mucositis were lower in the 5% and 10% C. officinalis gel groups than in the gel base and control groups (P < .05). Weight gain was noted in the treatment groups compared with the gel base and control groups (P < .05). Calendula officinalis extract accelerated the healing of oral mucositis in hamsters. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. The effect of pinealectomy, melatonin and leptin hormones on ovarian follicular development in female Syrian hamsters (Mesocricetus auratus).

    PubMed

    Karakaş, A; Kaya, Aliye; Gündüz, B

    2010-12-01

    We studied the effects of melatonin and leptin hormones on ovarian follicular development in intact and pinealectomized female Syrian hamsters. We first monitored the oestrous cycle of the hamsters by the vaginal smear samples throughout a ten day period to start the injections simultaneously in all groups and performed saline, melatonin and leptin hormone injection groups for both control and pinealectomized hamsters. Then the injections were applied for four days starting the oestrus phase of the cycle and the ovaries were removed for preparation of histological analysis. We measured the diameters and the numbers of the follicles and we classified the follicles according to the number of the granulosa cell layer. Leptin hormone injection increased melatonin hormone injection decreased the number and the diameter of the follicles. The stimulating effect of the leptin hormone was more pronounced in the pinealectomized group. The results of the present study indicate that the removal of the pineal gland and leptin hormone administration are playing a stimulatory while melatonin hormone administration is playing an inhibitory role on the follicular development in female Syrian hamsters.

  8. INGN 007, an oncolytic adenovirus vector, replicates in Syrian hamsters but not mice: comparison of biodistribution studies

    PubMed Central

    Ying, B; Toth, K; Spencer, JF; Meyer, J; Tollefson, AE; Patra, D; Dhar, D; Shashkova, EV; Kuppuswamy, M; Doronin, K; Thomas, MA; Zumstein, LA; Wold, WSM; Lichtenstein, DL

    2012-01-01

    Preclinical biodistribution studies with INGN 007, an oncolytic adenovirus (Ad) vector, supporting an early stage clinical trial were conducted in Syrian hamsters, which are permissive for Ad replication, and mice, which are a standard model for assessing toxicity and biodistribution of replication-defective (RD) Ad vectors. Vector dissemination and pharmacokinetics following intravenous administration were examined by real-time PCR in nine tissues and blood at five time points spanning 1 year. Select organs were also examined for the presence of infectious vector/virus. INGN 007 (VRX-007), wild-type Ad5 and AdCMVpA (an RD vector) were compared in the hamster model, whereas only INGN 007 was examined in mice. DNA of all vectors was widely disseminated early after injection, but decayed rapidly in most organs. In the hamster model, DNA of INGN 007 and Ad5 was more abundant than that of the RD vector AdCMVpA at early times after injection, but similar levels were seen later. An increased level of INGN 007 and Ad5 DNA but not AdCMVpA DNA in certain organs early after injection, and the presence of infectious INGN 007 and Ad5 in lung and liver samples at early times after injection, strongly suggests that replication of INGN 007 and Ad5 occurred in several Syrian hamster organs. There was no evidence of INGN 007 replication in mice. In addition to providing important information about INGN 007, the results underscore the utility of the Syrian hamster as a permissive immunocompetent model for Ad5 pathogenesis and oncolytic Ad vectors. PMID:19197322

  9. INGN 007, an oncolytic adenovirus vector, replicates in Syrian hamsters but not mice: comparison of biodistribution studies.

    PubMed

    Ying, B; Toth, K; Spencer, J F; Meyer, J; Tollefson, A E; Patra, D; Dhar, D; Shashkova, E V; Kuppuswamy, M; Doronin, K; Thomas, M A; Zumstein, L A; Wold, W S M; Lichtenstein, D L

    2009-08-01

    Preclinical biodistribution studies with INGN 007, an oncolytic adenovirus (Ad) vector, supporting an early stage clinical trial were conducted in Syrian hamsters, which are permissive for Ad replication, and mice, which are a standard model for assessing toxicity and biodistribution of replication-defective (RD) Ad vectors. Vector dissemination and pharmacokinetics following intravenous administration were examined by real-time PCR in nine tissues and blood at five time points spanning 1 year. Select organs were also examined for the presence of infectious vector/virus. INGN 007 (VRX-007), wild-type Ad5 and AdCMVpA (an RD vector) were compared in the hamster model, whereas only INGN 007 was examined in mice. DNA of all vectors was widely disseminated early after injection, but decayed rapidly in most organs. In the hamster model, DNA of INGN 007 and Ad5 was more abundant than that of the RD vector AdCMVpA at early times after injection, but similar levels were seen later. An increased level of INGN 007 and Ad5 DNA but not AdCMVpA DNA in certain organs early after injection, and the presence of infectious INGN 007 and Ad5 in lung and liver samples at early times after injection, strongly suggests that replication of INGN 007 and Ad5 occurred in several Syrian hamster organs. There was no evidence of INGN 007 replication in mice. In addition to providing important information about INGN 007, the results underscore the utility of the Syrian hamster as a permissive immunocompetent model for Ad5 pathogenesis and oncolytic Ad vectors.

  10. Highly Virulent Leptospira borgpetersenii Strain Characterized in the Hamster Model

    PubMed Central

    Diniz, Juliana Alcoforado; Félix, Samuel Rodrigues; Bonel-Raposo, Josiane; Seixas Neto, Amilton Clair Pinto; Vasconcellos, Flávia Aleixo; Grassmann, André Alex; Dellagostin, Odir Antônio; Aleixo, José Antonio Guimarães; da Silva, Éverton Fagonde

    2011-01-01

    A recent study by our group reported the isolation and partial serological and molecular characterization of four Leptospira borgpetersenii serogroup Ballum strains. Here, we reproduced experimental leptospirosis in golden Syrian hamsters (Mesocricetus auratus) and carried out standardization of lethal dose 50% (LD50) of one of these strains (4E). Clinical disease features and histopathologic analyses of tissue lesions were also observed. As results, strain 4E induced lethality in the hamster model with inocula lower than 10 leptospires, and histopathological examination of animals showed typical lesions found in severe leptospirosis. Gross pathological findings were peculiar; animals that died early had more chance of presenting severe jaundice and less chance of presenting pulmonary hemorrhages (P < 0.01). L. borgpetersenii serogroup Ballum has had a considerable growth in human leptospirosis cases in recent years. This strain has now been thoroughly characterized and can be used in more studies, especially evaluations of vaccine candidates. PMID:21813846

  11. Effects of porcine pancreatic enzymes on the pancreas of hamsters. Part 2: carcinogenesis studies.

    PubMed

    Nozawa, Fumiaki; Yalniz, Mehmet; Saruc, Murat; Standop, Jens; Egami, Hiroshi; Pour, Parviz M

    2012-09-10

    Our previous study suggested that porcine pancreatic extract in hamsters with peripheral insulin resistance, normalizes insulin output, islet size and pancreatic DNA synthetic rate. It also inhibited the growth of human pancreatic cancer cells in nude mice. To examine the potential value of the porcine pancreatic extract in controlling pancreatic carcinogenesis in this model, the present experiment was performed. Hamsters were fed a high fat diet and four weeks later when insulin resistance emerges, they were divided into two groups. One group received 1 g/kg BW of porcine pancreatic extract in drinking water and the other group received tap water. One week later, when insulin output normalizes in porcine pancreatic extract-treated hamsters, a single subcutaneous injection of N-nitrosobis-(2-oxopropyl) amine (BOP) at a dose of 40 mg/kg BW was given to all hamsters. The experiment was terminated at 43 weeks after the porcine pancreatic extract treatment. The number and size of pancreatic tumors, blood glucose, insulin, amylase and lipase levels, the average size of islets and the number of insulin cells/islets were determined. The incidence of pancreatic cancer was significantly lower in the porcine pancreatic extract group (P=0.043), as well as the plasma insulin level and the size of the islets in the porcine pancreatic extract group were significantly lower (P<0.001) than in the control group. No significantly differences were found in the glucose level between the groups. These results show that porcine pancreatic extract has a potential to inhibit pancreatic cancer growth.

  12. Acute brown adipose tissue temperature response to cold in monosodium glutamate-treated Siberian hamsters

    PubMed Central

    Leitner, Claudia; Bartness, Timothy J.

    2014-01-01

    Neonatal monosodium glutamate (MSG) administration increases adiposity, decreases energy expenditure and is associated with arcuate nucleus (Arc) destruction. Disrupted brown adipose tissue (BAT) thermogenesis underlies some of these effects, although, interscapular BAT temperature (TIBAT) has not been measured. Therefore, we tested the effects of neonatal MSG or vehicle administration in Siberian hamsters and, when they were adults, measured TIBAT during acute cold exposure. The Arc and its projection to the hypothalamic paraventricular nucleus (PVH) are both components of the CNS outflow circuits to IBAT, with the latter implicated in BAT thermogenesis that could be compromised by MSG treatment. Using a viral transneuronal tract tracer, pseudorabies virus (PRV), we also tested whether the components of these circuits were intact. As adults, MSG-treated hamsters had significantly increased body mass and some white fat pad masses, markedly reduced Arc Nissl and neuropeptide staining, and PVH neuropeptide fiber staining. Cold-exposed (18 h at 5 °C) MSG- and vehicle-treated hamsters initially maintained TIBAT, but the ability of the former waned after 2 h being significantly decreased by 18 h. PRV immunoreactive fibers/cells were not altered by neonatal MSG treatment despite substantial Arc and PVH destruction. MSG- and vehicle-treated hamsters given an exogenous norepinephrine challenge showed identical increases in the duration and peak of TIBAT. Thus, the inability of MSG-treated animals to sustain TIBAT in the cold is not due to any obvious MSG-induced deletions of central sympathetic outflow circuits to IBAT, but appears to be extrinsic to the tissue nevertheless. PMID:19643091

  13. Vaccination with leptospiral outer membrane lipoprotein LipL32 reduces kidney invasion of Leptospira interrogans serovar canicola in hamsters.

    PubMed

    Humphryes, P C; Weeks, M E; AbuOun, M; Thomson, G; Núñez, A; Coldham, N G

    2014-04-01

    The Leptospira interrogans vaccines currently available are serovar specific and require regular booster immunizations to maintain protection of the host. In addition, a hamster challenge batch potency test is necessary to evaluate these vaccines prior to market release, requiring the use of a large number of animals, which is ethically and financially undesirable. Our previous work showed that the N terminus of the outer membrane protein LipL32 was altered in Leptospira interrogans serovar Canicola vaccines that fail the hamster challenge test, suggesting that it may be involved in the protective immune response. The aim of this study was to determine if vaccination with LipL32 protein alone could provide a protective response against challenge with L. interrogans serovar Canicola to hamsters. Recombinant LipL32, purified from an Escherichia coli expression system, was assessed for protective immunity in five groups of hamsters (n = 5) following a challenge with the virulent L. interrogans serovar Canicola strain Kito as a challenge strain. However, no significant survival against the L. interrogans serovar Canicola challenge was observed compared to that of unvaccinated negative controls. Subsequent histological analysis revealed reduced amounts of L. interrogans in the kidneys from the hamsters vaccinated with recombinant LipL32 protein prior to challenge; however, no significant survival against the L. interrogans serovar Canicola challenge was observed compared to that of unvaccinated negative controls. This finding corresponded to a noticeably reduced severity of renal lesions. This study provides evidence that LipL32 is involved in the protective response against L. interrogans serovar Canicola in hamsters and is the first reported link to LipL32-induced protection against kidney invasion.

  14. A Hamster Model of Diet-Induced Obesity for Preclinical Evaluation of Anti-Obesity, Anti-Diabetic and Lipid Modulating Agents

    PubMed Central

    Hansen, Gitte; Fabricius, Katrine; Hansen, Henrik B.; Jelsing, Jacob; Vrang, Niels

    2015-01-01

    Aim Unlike rats and mice, hamsters develop hypercholesterolemia, and hypertriglyceridemia when fed a cholesterol-rich diet. Because hyperlipidemia is a hallmark of human obesity, we aimed to develop and characterize a novel diet-induced obesity (DIO) and hypercholesterolemia Golden Syrian hamster model. Methods and Results Hamsters fed a highly palatable fat- and sugar-rich diet (HPFS) for 12 weeks showed significant body weight gain, body fat accumulation and impaired glucose tolerance. Cholesterol supplementation to the diet evoked additional hypercholesterolemia. Chronic treatment with the GLP-1 analogue, liraglutide (0.2 mg/kg, SC, BID, 27 days), normalized body weight and glucose tolerance, and lowered blood lipids in the DIO-hamster. The dipeptidyl peptidase-4 (DPP-4) inhibitor, linagliptin (3.0 mg/kg, PO, QD) also improved glucose tolerance. Treatment with peptide YY3-36 (PYY3-36, 1.0 mg/kg/day) or neuromedin U (NMU, 1.5 mg/kg/day), continuously infused via a subcutaneous osmotic minipump for 14 days, reduced body weight and energy intake and changed food preference from HPFS diet towards chow. Co-treatment with liraglutide and PYY3-36 evoked a pronounced synergistic decrease in body weight and food intake with no lower plateau established. Treatment with the cholesterol uptake inhibitor ezetimibe (10 mg/kg, PO, QD) for 14 days lowered plasma total cholesterol with a more marked reduction of LDL levels, as compared to HDL, indicating additional sensitivity to cholesterol modulating drugs in the hyperlipidemic DIO-hamster. In conclusion, the features of combined obesity, impaired glucose tolerance and hypercholesterolemia in the DIO-hamster make this animal model useful for preclinical evaluation of novel anti-obesity, anti-diabetic and lipid modulating agents. PMID:26266945

  15. Lymphocyte function in experimental endemic syphilis of Syrian hamsters.

    PubMed Central

    Bagasra, O; Kushner, H; Hashemi, S

    1985-01-01

    We have studied the changes in the lymph nodes, spleen and thymus that occur in inbred LSH Syrian hamsters infected with Treponema pallidum Bosnia A, the causative agent of endemic syphilis, as well as the B-cell responses of these infected animals to helper T-cell independent and dependent antigens. The lymph nodes increased significantly in weight up to 6 weeks after infection, and contained viable treponemes. No significant changes in the spleen weight were observed, and no viable treponemes could be recovered from the spleen. However, the size of the thymus decreased steadily during the course of the disease. The relative number of Ig+ cells (B cells) increased in the spleen and regional lymph nodes, whereas the relative number of T cells decreased during the course of infection. In both the spleen and lymph nodes, the relative number of macrophages increased initially and decreased thereafter in the form of a bell-shaped curve showing a peak at 4-6 weeks of infection. The ability of splenic lymphocytes from infected hamsters to mount a primary PFC response to pneumococcal polysaccharide type III (SIII), a helper T-cell independent antigen, was elevated throughout the course of infection. However, the splenic PFC response to sheep erythrocytes (SRBC), a helper T-cell dependent antigen, was increased only during the first 4 weeks of infection and progressively decreased thereafter. The PFC responses of infected lymph node lymphocytes to both SIII and SRBC were increased during the first 4 weeks and decreased thereafter. These data suggested that atrophy of the thymus seen in syphilitic infection is accompanied by the complex losses of subsets of T cells and altered B-cell functions. An early loss of suppressor T cells in both the lymph nodes and spleen occurs concomitantly with a loss of T helper cells and heterologous (treponema-unrelated) B-cell functions in the lymph nodes. Helper T cells are lost from the spleen only in the later stages of infection, whereas

  16. Identification of Reference Genes for Quantitative Real Time PCR Assays in Aortic Tissue of Syrian Hamsters with Bicuspid Aortic Valve

    PubMed Central

    Rueda-Martínez, Carmen; Fernández, M. Carmen; Soto-Navarrete, María Teresa; Jiménez-Navarro, Manuel; Durán, Ana Carmen; Fernández, Borja

    2016-01-01

    Bicuspid aortic valve (BAV) is the most frequent congenital cardiac malformation in humans, and appears frequently associated with dilatation of the ascending aorta. This association is likely the result of a common aetiology. Currently, a Syrian hamster strain with a relatively high (∼40%) incidence of BAV constitutes the only spontaneous animal model of BAV disease. The characterization of molecular alterations in the aorta of hamsters with BAV may serve to identify pathophysiological mechanisms and molecular markers of disease in humans. In this report, we evaluate the expression of ten candidate reference genes in aortic tissue of hamsters in order to identify housekeeping genes for normalization using quantitative real time PCR (RT-qPCR) assays. A total of 51 adult (180–240 days old) and 56 old (300–440 days old) animals were used. They belonged to a control strain of hamsters with normal, tricuspid aortic valve (TAV; n = 30), or to the affected strain of hamsters with TAV (n = 45) or BAV (n = 32). The expression stability of the candidate reference genes was determined by RT-qPCR using three statistical algorithms, GeNorm, NormFinder and Bestkeeper. The expression analyses showed that the most stable reference genes for the three algorithms employed were Cdkn1β, G3pdh and Polr2a. We propose the use of Cdkn1β, or both Cdkn1β and G3pdh as reference genes for mRNA expression analyses in Syrian hamster aorta. PMID:27711171

  17. Hematologic Assessment in Pet Rats, Mice, Hamsters, and Gerbils: Blood Sample Collection and Blood Cell Identification.

    PubMed

    Lindstrom, Nicole M; Moore, David M; Zimmerman, Kurt; Smith, Stephen A

    2015-09-01

    Hamsters, gerbils, rats, and mice are presented to veterinary clinics and hospitals for prophylactic care and treatment of clinical signs of disease. Physical examination, history, and husbandry practice information can be supplemented greatly by assessment of hematologic parameters. As a resource for veterinarians and their technicians, this article describes the methods for collection of blood, identification of blood cells, and interpretation of the hemogram in mice, rats, gerbils, and hamsters. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Graded response to short photoperiod during development and early adulthood in Siberian hamsters and the effects on reproduction as females age

    PubMed Central

    Place, Ned J.; Cruickshank, Jenifer

    2009-01-01

    Short day (SD) lengths delay puberty, suppress ovulation, inhibit sexual behavior, and decelerate reproductive aging in female Siberian hamsters (Phodopus sungorus). To date, the modulation of the age-associated decline in reproductive outcomes has only been demonstrated in female hamsters experiencing different day lengths during development. To determine if developmental delay is necessary for photo-inhibition to decelerate reproductive aging, hamsters raised in LD were transferred to SD as young adults and remained there for 6 months. Females that demonstrated the most immediate and sustained photo-inhibition were found to have greater numbers of ovarian primordial follicles at advanced ages (9 and 12 months) than did females held in LD, nonresponders to SD, and females with a marginal SD-response. Similarly, for females raised in SD from conception to 6 months of age, prolonged developmental delay was associated with greater numbers of primordial follicles at later ages as compared to hamsters that became refractory to SD. A robust response to SD in juvenile and adult hamsters is associated with decelerated reproductive aging, which may result in greater reproductive success in older females as compared to age-matched individuals demonstrating a more modest response to SD. PMID:19470367

  19. Impaired nitric oxide modulation of myocardial oxygen consumption in genetically cardiomyopathic hamsters.

    PubMed

    Loke, K E; Messina, E J; Mital, S; Hintze, T H

    2000-12-01

    We investigated the role of kinin and nitric oxide (NO) in the modulation of cardiac O(2)consumption in Syrian hamsters with overt heart failure (HF) and age-matched normal hamsters. Using echocardiography, the hamsters with heart failure had reduced ejection fraction [31(+/-8) v 76(+/-5)%] and LV dilation [4.9(+/-0. 2) v 5.7(+/-0.3) mm, both P<0.05 from normal]. O(2)consumption in the left ventricular free wall was measured using a Clark-type O(2)electrode in an air-tight chamber, containing Krebs solution buffered with Hepes (37 degrees C, pH 7.4). Concentration response curves to bradykinin (BK), ramiprilat (RAM), amlodipine (AMLO) and the NO donor, S -nitroso- N -acetyl-penicillamine (SNAP) were performed. Basal myocardial O(2)consumption was lower in the HF group compared to normal [316(+/-21) v 404(+/-36) nmol O(2)/min/g, respectively, P<0.05]. In the hearts from normal hamsters BK (10(-4)mol/l), RAM (10(-4)mol/l), and AMLO (10(-5)mol/l) all significantly reduced myocardial O(2)consumption by 42(+/-6)%, 29(+/-7)% and 27(+/-5)% respectively. This reduction was attenuated in the presence of N -nitro- l -arginine methyl ester (l -NAME) [BK: 3.3(+/-1.5)%, RAM: 3.3(+/-1.2)%, AMLO: 2.3(+/-1.2)%, P<0.05]. Interestingly in the hearts from HF group, BK, RAM and AMLO caused a significantly smaller reduction in myocardial O(2)consumption [10(+/-2)%, 2.5(+/-1.3)%, 6.3(+/-2.3)%, P<0.05]. In contrast, the NO donor SNAP reduced myocardial O(2)consumption in both groups and all those responses were not affected by l -NAME. These data indicate that endogenous NO production through the kinin-dependent mechanism is impaired at end-stage heart failure. The loss of kinin and NO control of mitochondrial respiration may contribute to the pathogenesis of heart failure. Copyright 2000 Academic Press.

  20. Results of selected ophthalmic diagnostic tests for clinically normal Syrian hamsters (Mesocricetus auratus).

    PubMed

    Rajaei, Seyed Mehdi; Mood, Maneli Ansari; Sadjadi, Reza; Williams, David L

    2016-01-01

    To determine values for tear production, horizontal palpebral fissure length (HPFL), eye blink frequency, and intraocular pressure (IOP) in healthy Syrian hamsters (Mesocricetus auratus). 40 healthy adult Syrian hamsters (80 eyes). Tear production was measured with the phenol red thread test (PRTT), modified Schirmer tear test (mSTT), and endodontic absorbent paper points tear test (EAPPTT). The IOP was measured by use of rebound tonometry. Correlations between test results and body weight were evaluated. Mean ± SD values for the IOP, PRTT, EAPPTT, mSTT, HPFL, and blink frequency for all 80 eyes were 4.55 ± 1.33 mm Hg, 5.57 ± 1.51 mm/15 s, 4.52 ± 1.55 mm/min, 2.07 ± 0.97 mm/min, 5.84 ± 0.45 mm, and 1.68 ± 0.43 blinks/min, respectively. For all variables, values did not differ significantly between the right and left eyes or between males and females. There was no correlation between measured variables and body weight. Results for this study provided information on values for the IOP, PRTT, mSTT, EAPPTT, HPFL, and eye blink frequency in healthy Syrian hamsters. It was important to determine reference intervals for this species because they commonly are kept as pets or used as research animals.

  1. Immunogenicity and Protective Efficacy in Mice and Hamsters of a β-Propiolactone Inactivated Whole Virus SARS-CoV Vaccine

    PubMed Central

    Roberts, Anjeanette; Lamirande, Elaine W.; Vogel, Leatrice; Baras, Benoît; Goossens, Geneviève; Knott, Isabelle; Chen, Jun; Ward, Jerrold M.; Vassilev, Ventzislav

    2010-01-01

    Abstract The immunogenicity and efficacy of β-propiolactone (BPL) inactivated whole virion SARS-CoV (WI-SARS) vaccine was evaluated in BALB/c mice and golden Syrian hamsters. The vaccine preparation was tested with or without adjuvants. Adjuvant Systems AS01B and AS03A were selected and tested for their capacity to elicit high humoral and cellular immune responses to WI-SARS vaccine. We evaluated the effect of vaccine dose and each adjuvant on immunogenicity and efficacy in mice, and the effect of vaccine dose with or without the AS01B adjuvant on the immunogenicity and efficacy in hamsters. Efficacy was evaluated by challenge with wild-type virus at early and late time points (4 and 18 wk post-vaccination). A single dose of vaccine with or without adjuvant was poorly immunogenic in mice; a second dose resulted in a significant boost in antibody levels, even in the absence of adjuvant. The use of adjuvants resulted in higher antibody titers, with the AS01B-adjuvanted vaccine being slightly more immunogenic than the AS03A-adjuvanted vaccine. Two doses of WI-SARS with and without Adjuvant Systems were highly efficacious in mice. In hamsters, two doses of WI-SARS with and without AS01B were immunogenic, and two doses of 2 μg of WI-SARS with and without the adjuvant provided complete protection from early challenge. Although antibody titers had declined in all groups of vaccinated hamsters 18 wk after the second dose, the vaccinated hamsters were still partially protected from wild-type virus challenge. Vaccine with adjuvant provided better protection than non-adjuvanted WI-SARS vaccine at this later time point. Enhanced disease was not observed in the lungs or liver of hamsters following SARS-CoV challenge, regardless of the level of serum neutralizing antibodies. PMID:20883165

  2. Crocidolite asbestos and SV40 are cocarcinogens in human mesothelial cells and in causing mesothelioma in hamsters

    PubMed Central

    Kroczynska, Barbara; Cutrone, Rochelle; Bocchetta, Maurizio; Yang, Haining; Elmishad, Amira G.; Vacek, Pamela; Ramos-Nino, Maria; Mossman, Brooke T.; Pass, Harvey I.; Carbone, Michele

    2006-01-01

    Only a fraction of subjects exposed to asbestos develop malignant mesothelioma (MM), suggesting that additional factors may render some individuals more susceptible. We tested the hypothesis that asbestos and Simian virus (SV40) are cocarcinogens. Asbestos and SV40 in combination had a costimulatory effect in inducing ERK1/2 phosphorylation and activator protein-1 (AP-1) activity in both primary Syrian hamster mesothelial cells (SHM) and primary human mesothelial cells (HM). Ap-1 activity caused the expression and activation of matrix metalloprotease (MMP)-1 and MMP-9, which in turn led to cell invasion. Experiments using siRNA and chemical inhibitors confirmed the specificity of these results. The same effects were observed in HM and SHM. Experiments in hamsters showed strong cocarcinogenesis between asbestos and SV40: SV40 did not cause MM, asbestos caused MM in 20% of hamsters, and asbestos and SV40 together caused MM in 90% of hamsters. Significantly lower amounts of asbestos were sufficient to cause MM in animals infected with SV40. Our results indicate that mineral fibers and viruses can be cocarcinogens and suggest that lower amounts of asbestos may be sufficient to cause MM in individuals infected with SV40. PMID:16966607

  3. Specific strychnine binding sites on acrosome-associated membranes of golden hamster spermatozoa.

    PubMed

    Llanos, Miguel N; Ronco, Ana M; Aguirre, María C

    2003-06-27

    This study demonstrates for the first time, that membrane vesicles originated from the hamster sperm head after the occurrence of the acrosome reaction, possess specific strychnine binding sites. [3H]Strychnine binding was saturable and reversible, being displaced by unlabeled strychnine (IC(50)=26.7+/-2.3 microM). Kinetic analysis revealed one binding site with K(d)=120nM and B(max)=142fmol/10(6) spermatozoa. Glycine receptor agonists beta-alanine and taurine inhibited strychnine binding by 20-30%. Surprisingly, glycine stimulated binding by about 40-50%. Results obtained in this study strongly suggest the presence of glycine receptors-with distinctive kinetic properties on the periacrosomal plasma membrane of hamster spermatozoa. Localization of this receptor fits well with its previously proposed role in acrosomal exocytosis during mammalian fertilization.

  4. Pneumonitis in Syrian golden hamsters (Mesocricetus auratus) infected with Rio Mamoré virus (family Bunyaviridae, genus Hantavirus).

    PubMed

    Milazzo, Mary Louise; Eyzaguirre, Eduardo J; Fulhorst, Charles F

    2014-10-13

    Rio Mamoré virus is an etiological agent of hantavirus pulmonary syndrome in South America. The purpose of this study was to determine whether Rio Mamoré virus strain HTN-007 in Syrian golden hamsters is pathogenic. None of 37 adult hamsters infected by intramuscular injection of HTN-007, including 10 animals killed on Day 42 or 43 post-inoculation, exhibited any symptom of disease. Histological abnormalities included severe or moderately severe pneumonitis in 6 (46.2%) of the 13 animals killed on Day 7 or 10 post-inoculation. The primary target of infection in lung was the endothelium of the microvasculature. Collectively, these results indicate that Rio Mamoré virus strain HTN-007 in adult Syrian golden hamsters can cause a nonlethal disease that is pathologically similar to hantavirus pulmonary syndrome. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. The effects of radiation on antitumor efficacy of an oncolytic adenovirus vector in the Syrian hamster model

    PubMed Central

    Young, Brittany A.; Spencer, Jacqueline F.; Ying, Baoling; Toth, Karoly; Wold, William S. M.

    2013-01-01

    We report that radiation enhances the antitumor efficacy of the oncolytic adenovirus vector VRX-007 in Syrian hamster tumors. We used tumor-specific irradiation of subcutaneous tumors and compared treatment options of radiation alone or combined with VRX-007 and cyclophosphamide (CP). Radiation therapy further augmented the VRX-007-mediated inhibition of tumor growth, in both CP-treated and non-CP-treated hamsters, even though radiation did not lead to increased viral replication in tumors when compared to those treated with VRX-007 alone. Moreover, tumor growth inhibition was similar in tumors irradiated either one week before or after injection with VRX-007, which suggests that radiation exerts its antitumor effect independently from vector therapy. Thus, our results demonstrate that these two therapies do not have to be provided simultaneously to enhance their combined effectiveness against subcutaneous hamster tumors. PMID:23928730

  6. The effects of radiation on antitumor efficacy of an oncolytic adenovirus vector in the Syrian hamster model.

    PubMed

    Young, B A; Spencer, J F; Ying, B; Toth, K; Wold, W S M

    2013-09-01

    We report that radiation enhances the antitumor efficacy of the oncolytic adenovirus vector VRX-007 in Syrian hamster tumors. We used tumor-specific irradiation of subcutaneous tumors and compared treatment options of radiation alone or combined with VRX-007 and cyclophosphamide (CP). Radiation therapy further augmented the VRX-007-mediated inhibition of tumor growth, in both CP-treated and non-CP-treated hamsters, even though radiation did not lead to increased viral replication in tumors when compared with those treated with VRX-007 alone. Moreover, tumor growth inhibition was similar in tumors irradiated either 1 week before or after injection with VRX-007, which suggests that radiation exerts its antitumor effect independently from vector therapy. Thus, our results demonstrate that these two therapies do not have to be provided simultaneously to enhance their combined effectiveness against subcutaneous hamster tumors.

  7. Neurochemistry of olivocochlear neurons in the hamster.

    PubMed

    Reuss, Stefan; Disque-Kaiser, Ursula; Antoniou-Lipfert, Patricia; Gholi, Maryam Najaf; Riemann, Elke; Riemann, Randolf

    2009-04-01

    The present study was conducted to characterize the superior olivary complex (SOC) of the lower brain stem in the pigmented Djungarian hamster Phodopus sungorus. Using Nissl-stained serial cryostat sections from fresh-frozen brains, we determined the borders of the SOC nuclei. We also identified olivocochlear (OC) neurons by retrograde neuronal tracing upon injection of Fluoro-Gold into the scala tympani. To evaluate the SOC as a putative source of neuronal nitric oxide synthase (nNOS), arginine-vasopressin (AVP), oxytocin (OT), vasoactive intestinal polypeptide (VIP), or pituitary adenylate cyclase-activating polypeptide (PACAP) that were all found in the cochlea, we conducted immunohistochemistry on sections exhibiting retrogradely labeled neurons. We did not observe AVP-, OT-, or VIP-immunoreactivity, neither in OC neurons nor in the SOC at all, revealing that cochlear AVP, OT, and VIP are of nonolivary origin. However, we found nNOS, the enzyme responsible for nitric oxide synthesis in neurons, and PACAP in neuronal perikarya of the SOC. Retrogradely labeled neurons of the lateral olivocochlear (LOC) system in the lateral superior olive did not contain PACAP and were only infrequently nNOS-immunoreactive. In contrast, some shell neurons and some of the medial OC (MOC) system exhibited immunofluorescence for either substance. Our data obtained from the dwarf hamster Phodopus sungorus confirm previous observations that a part of the LOC system is nitrergic. They further demonstrate that the medial olivocochlear system is partly nitrergic and use PACAP as neurotransmitter or modulator.

  8. Propranolol blocks the stimulatory effects of naloxone on ventilation and oxygen consumption in hamsters.

    PubMed

    Schlenker, E H; Eikanger, J

    1997-06-01

    The purposes of these studies were: 1) to determine the effects of various doses of propranolol, a nonspecific beta-adrenergic antagonist, on ventilation, oxygen consumption, and body temperature in hamsters, and 2) to test the hypothesis that in hamsters the stimulatory effects of naloxone, an opioid receptor antagonist, on ventilation and oxygen consumption occur, at least in part, through the release of catecholamines that act via beta-adrenergic receptors. Propranolol, a non-specific beta adrenergic receptor antagonist, at a 20 mg/kg depressed body temperature, oxygen consumption, tidal volume, and ventilation relative to saline. The lower dose of 10 mg/kg had only transitory effects on tidal volume at 60 min and ventilation at 30 min post-injection-Naloxone (1 mg/kg) relative to saline stimulated ventilation and oxygen consumption. These effects were blocked by propranolol pretreatment. The results of these experiments demonstrate that in the hamster, 1) body temperature, oxygen consumption, and ventilation appear to be modulated by beta-adrenergic receptors, and 2) the stimulatory effects of naloxone on oxygen consumption and ventilation may occur through the interaction of endogenous opioids and beta-adrenergic receptor systems.

  9. Effects of intense tone exposure on choline acetyltransferase activity in the hamster cochlear nucleus.

    PubMed

    Jin, Yong-Ming; Godfrey, Donald A; Wang, Jie; Kaltenbach, James A

    2006-01-01

    Choline acetyltransferase (ChAT) activity has been mapped in the cochlear nucleus (CN) of control hamsters and hamsters that had been exposed to an intense tone. ChAT activity in most CN regions of hamsters was only a third or less of the activity in rat CN, but in granular regions ChAT activity was similar in both species. Eight days after intense tone exposure, average ChAT activity increased on the tone-exposed side as compared to the opposite side, by 74% in the anteroventral CN (AVCN), by 55% in the granular region dorsolateral to it, and by 74% in the deep layer of the dorsal CN (DCN). In addition, average ChAT activity in the exposed-side AVCN and fusiform soma layer of DCN was higher than in controls, by 152% and 67%, respectively. Two months after exposure, average ChAT activity was still 53% higher in the exposed-side deep layer of DCN as compared to the opposite side. Increased ChAT activity after intense tone exposure may indicate that this exposure leads to plasticity of descending cholinergic innervation to the CN, which might affect spontaneous activity in the DCN that has been associated with tinnitus.

  10. Characterization of Disease Course after Intramuscular or Intranasal Exposure to Sin Nombre Virus in Immunosuppressed Syrian Hamsters

    DTIC Science & Technology

    2017-04-03

    145 the 7 surviving hamsters on day 28 (end of study), results of a nucleocapsid (N)- ELISA assay 146 indicate that 6 of the hamsters immunosuppressed...magnitude of the antibody response as measured by N- ELISA . 155 However, the results of this experiment do support the hypothesis that longer 156...supports the requirement for including Dex in a 177 combination treatment (Fig. 6D). Furthermore, results of an N- ELISA conducted with sera from 178

  11. Anti-hypercholesterolemic effect of Saccharomyces boulardii in the hamster.

    PubMed

    Girard, Philippe; Pansart, Yannick; Verleye, Marc

    2014-01-01

    Hypercholesterolemia is a major risk factor for coronary artery disease and probiotics have been suggested as tools to manage elevated cholesterol levels. The present study investigated the ability of the biotherapeutic agent Saccharomyces boulardii (Sb-Biocodex) to reduce the hypercholesterolemia induced by a 0.1% cholesterol-enriched diet in the hamster. In a first experiment, chronic oral treatment with S. boulardii at 12 × 10(10) CFU/kg (3 g/kg) twice a day was started from the beginning of the cholesterol diet and continued for 14 days ('preventive protocol'). In the second experiment, S. boulardii was given 14 days after the beginning of the cholesterol diet when hypercholesterolemia had developed and continued for an additional 14 days ('curative protocol'). In the preventive protocol, administration of the yeast significantly reduced hypercholesterolemia (14%) induced by the cholesterol-enriched diet compared to the group receiving only the cholesterol diet. In the curative protocol, S. boulardii significantly reduced hypercholesterolemia (12%) induced by the cholesterol-enriched diet, too. Moreover, the yeast significantly decreased the serum triglyceride increase by 39%. S. boulardii possesses anti-hypercholesterolemic properties in the hamster worthy of further evaluation in clinical studies. © 2014 S. Karger AG, Basel.

  12. Pneumonitis in Syrian golden hamsters (Mesocricetus auratus) infected with Río Mamoré virus (family Bunyaviridae, genus Hantavirus)

    PubMed Central

    Milazzo, Mary Louise; Eyzaguirre, Eduardo J.; Fulhorst, Charles F.

    2014-01-01

    Rio Mamoré virus is an etiological agent of hantavirus pulmonary syndrome in South America. The purpose of this study was to determine whether Rio Mamoré virus strain HTN-007 in Syrian golden hamsters is pathogenic. None of 37 adult hamsters infected by intramuscular injection of HTN-007, including 10 animals killed on Day 42 or 43 post-inoculation, exhibited any symptom of disease. Histological abnormalities included severe or moderately severe pneumonitis in 6 (46.2%) of the 13 animals killed on Day 7 or 10 post-inoculation. The primary target of infection in lung was the endothelium of the microvasculature. Collectively, these results indicate that Rio Mamoré virus strain HTN-007 in adult Syrian golden hamsters can cause a nonlethal disease that is pathologically similar to hantavirus pulmonary syndrome. PMID:25064267

  13. The adaptive immune response does not influence hantavirus disease or persistence in the Syrian hamster

    PubMed Central

    Prescott, Joseph; Safronetz, David; Haddock, Elaine; Robertson, Shelly; Scott, Dana; Feldmann, Heinz

    2013-01-01

    Pathogenic New World hantaviruses cause severe disease in humans characterized by a vascular leak syndrome, leading to pulmonary oedema and respiratory distress with case fatality rates approaching 40%. Hantaviruses infect microvascular endothelial cells without conspicuous cytopathic effects, indicating that destruction of the endothelium is not a mechanism of disease. In humans, high levels of inflammatory cytokines are present in the lungs of patients that succumb to infection. This, along with other observations, suggests that disease has an immunopathogenic component. Currently the only animal model available to study hantavirus disease is the Syrian hamster, where infection with Andes virus (ANDV), the primary agent of disease in South America, results in disease that closely mimics that seen in humans. Conversely, inoculation of hamsters with a passaged Sin Nombre virus (SNV), the virus responsible for most cases of disease in North America, results in persistent infection with high levels of viral replication. We found that ANDV elicited a stronger innate immune response, whereas SNV elicited a more robust adaptive response in the lung. Additionally, ANDV infection resulted in significant changes in the blood lymphocyte populations. To determine whether the adaptive immune response influences infection outcome, we depleted hamsters of CD4+ and CD8+ T cells before infection with hantaviruses. Depletion resulted in inhibition of virus-specific antibody responses, although the pathogenesis and replication of these viruses were unaltered. These data show that neither hantavirus replication, nor pathogenesis caused by these viruses, is influenced by the adaptive immune response in the Syrian hamster. PMID:23600567

  14. Role of chymase in cigarette smoke-induced pulmonary artery remodeling and pulmonary hypertension in hamsters.

    PubMed

    Wang, Tao; Han, Su-Xia; Zhang, Shang-Fu; Ning, Yun-Ye; Chen, Lei; Chen, Ya-Juan; He, Guang-Ming; Xu, Dan; An, Jin; Yang, Ting; Zhang, Xiao-Hong; Wen, Fu-Qiang

    2010-03-31

    Cigarette smoking is an important risk factor for pulmonary arterial hypertension (PAH) in chronic obstructive pulmonary disease (COPD). Chymase has been shown to function in the enzymatic production of angiotensin II (AngII) and the activation of transforming growth factor (TGF)-beta1 in the cardiovascular system. The aim of this study was to determine the potential role of chymase in cigarette smoke-induced pulmonary artery remodeling and PAH. Hamsters were exposed to cigarette smoke; after 4 months, lung morphology and tissue biochemical changes were examined using immunohistochemistry, Western blotting, radioimmunoassay and reverse-transcription polymerase chain reaction. Our results show that chronic cigarette smoke exposure significantly induced elevation of right ventricular systolic pressures (RVSP) and medial hypertrophy of pulmonary arterioles in hamsters, concurrent with an increase of chymase activity and synthesis in the lung. Elevated Ang II levels and enhanced TGF-beta1/Smad signaling activation were also observed in smoke-exposed lungs. Chymase inhibition with chymostatin reduced the cigarette smoke-induced increase in chymase activity and Ang II concentration in the lung, and attenuated the RVSP elevation and the remodeling of pulmonary arterioles. Chymostatin did not affect angiotensin converting enzyme (ACE) activity in hamster lungs. These results suggest that chronic cigarette smoke exposure can increase chymase activity and expression in hamster lungs. The capability of activated chymase to induce Ang II formation and TGF-beta1 signaling may be part of the mechanism for smoking-induced pulmonary vascular remodeling. Thus, our study implies that blockade of chymase might provide benefits to PAH smokers.

  15. Prevention of Simian Virus 40 Tumors by Hamster Fetal Tissue: Influence of Parity Status of Donor Females on Immunogenicity of Fetal Tissue and on Immune Cell Cytotoxicity

    PubMed Central

    Girardi, Anthony J.; Reppucci, Phyllis; Dierlam, Peggy; Rutala, William; Coggin, Joseph H.

    1973-01-01

    Fetal tissue from primiparous hamsters prevented simian virus 40 (SV40) tumorigenesis in male hamsters, whereas fetal tissue from multiparous hamsters did not. The parity status of normal (uninoculated) hamsters also influenced the cytotoxicity of their lymphoid cells against tumor cells. Lymph node cells from nonpregnant primiparous and multiparous animals were cytotoxic in microcytotoxicity tests against SV40, polyoma, and adenovirus 7 tumor cells, but were not active against control BHK cells. Lymph node cells from virgin female donors were inactive. Peritoneal exudate cells from these donors reacted in similar fashion against SV40 tumor cells in vitro and in adoptive transfer tests in vivo. However, the cytotoxicity of peritoneal exudate cells from multiparous hamsters was greatly reduced during pregnancy, a time when noncytotoxic humoral antibody reactive with surface antigen of SV40 tumor cells is present. This humoral antibody is not detected during first pregnancy, and peritoneal exudate cells obtained from pregnant primiparous hamsters demonstrated a high degree of cytotoxicity. PMID:4346032

  16. Ambient temperature affects postnatal litter size reduction in golden hamsters.

    PubMed

    Ohrnberger, Sarah A; Monclús, Raquel; Rödel, Heiko G; Valencak, Teresa G

    2016-01-01

    To better understand how different ambient temperatures during lactation affect survival of young, we studied patterns of losses of pups in golden hamsters ( Mesocricetus auratus ) at different ambient temperatures in the laboratory, mimicking temperature conditions in natural habitats. Golden hamsters produce large litters of more than 10 young but are also known to wean fewer pups at the end of lactation than they give birth to. We wanted to know whether temperature affects litter size reductions and whether the underlying causes of pup loss were related to maternal food (gross energy) intake and reproductive performance, such as litter growth. For that, we exposed lactating females to three different ambient temperatures and investigated associations with losses of offspring between birth and weaning. Overall, around one third of pups per litter disappeared, obviously consumed by the mother. Such litter size reductions were greatest at 30 °C, in particular during the intermediate postnatal period around peak lactation. Furthermore, litter size reductions were generally higher in larger litters. Maternal gross energy intake was highest at 5 °C suggesting that mothers were not limited by milk production and might have been able to raise a higher number of pups until weaning. This was further supported by the fact that the daily increases in litter mass as well as in the individual pup body masses, a proxy of mother's lactational performance, were lower at higher ambient temperatures. We suggest that ambient temperatures around the thermoneutral zone and beyond are preventing golden hamster females from producing milk at sufficient rates. Around two thirds of the pups per litter disappeared at high temperature conditions, and their early growth rates were significantly lower than at lower ambient temperatures. It is possible that these losses are due to an intrinsic physiological limitation (imposed by heat dissipation) compromising maternal energy intake and

  17. Neonatal monosodium glutamate treatment counteracts circadian arrhythmicity induced by phase shifts of the light-dark cycle in female and male Siberian hamsters

    PubMed Central

    Prendergast, Brian J.; Onishi, Kenneth G.; Zucker, Irving

    2013-01-01

    Studies of rats and voles suggest that distinct pathways emanating from the anterior hypothalamic-retrochiasmatic area and the mediobasal hypothalamic arcuate nucleus independently generate ultradian rhythms (URs) in hormone secretion and behavior. We evaluated the hypothesis that destruction of arcuate nucleus (ARC) neurons, in concert with dampening of suprachiasmatic nucleus (SCN) circadian rhythmicity, would compromise the generation of ultradian rhythms (URs) of locomotor activity. Siberian hamsters of both sexes treated neonatally with monosodium glutamate (MSG) that destroys ARC neurons were subjected in adulthood to a circadian disrupting phase-shift protocol (DPS) that produces SCN arrhythmia. MSG treatments induced hypogonadism and obesity, and markedly reduced the size of the optic chiasm and primary optic tracts. MSG-treated hamsters exhibited normal entrainment to the light-dark cycle, but MSG treatment counteracted the circadian arrhythmicity induced by the DPS protocol: only 6% of MSG-treated hamsters exhibited circadian arrhythmia, whereas 50% of control hamsters were circadian disrupted. In MSG-treated hamsters that retained circadian rhythmicity after DPS treatment, quantitative parameters of URs appeared normal, but in the 2 MSG-treated hamsters that became circadian arrhythmic after DPS, both dark-phase and light-phase URs were abolished. Although preliminary, these data are consistent with reports in voles suggesting that the combined disruption of SCN and ARC function impairs the expression of behavioral URs. The data also suggest that light thresholds for entrainment of circadian rhythms may be lower than those required to disrupt circadian organization. PMID:23701725

  18. Female Hamster Preference for Odors is Not Regulated by Circulating Gonadal Hormones

    PubMed Central

    Eidson, Lori N.; Maras, Pamela M.; Epperson, Erin; Petrulis, Aras

    2009-01-01

    Proceptive and receptive behaviors of female rodents, such as golden hamsters, are often regulated by changes in circulating levels of ovarian hormones. However, less is known about how ovarian hormones might regulate female hamster’s attraction and preference for volatile odor from males. To evaluate this, we assessed female preference by recording investigation and proximity to male and female volatile odorants in a Y-maze across all days of the estrous cycle (Experiment 1 & 2) or following ovariectomy (Experiment 3). In Experiment 1, female subjects were tested four times, once on each day of their estrous cycle. Females showed a preference for male odors on diestrus day 1 and to a lesser degree on proestrus, but showed no preference on the day of behavioral estrus. Irrespective of cycle day, preference was apparent in the first few days of testing and disappeared by the fourth day, suggesting that repeated testing attenuated female preference. To avoid this problem, in Experiment 2 each animal was tested only on one day of the 4-day estrous cycle. Female preference for male volatile odors over those from females was observed on each day of their estrous cycle, including estrus. Moreover, following gonadectomy (Experiment 3) female hamsters still preferred male volatile odors to those of females. Taken together, this suggests that circulating levels of gonadal hormones do not influence preference for male volatile odors in female hamsters. PMID:17374544

  19. Comparison of Bacterial Burden and Cytokine Gene Expression in Golden Hamsters in Early Phase of Infection with Two Different Strains of Leptospira interrogans.

    PubMed

    Fujita, Rie; Koizumi, Nobuo; Sugiyama, Hiromu; Tomizawa, Rina; Sato, Ryoichi; Ohnishi, Makoto

    2015-01-01

    Leptospirosis, a zoonotic infection with worldwide prevalence, is caused by pathogenic spirochaetes of Leptospira spp., and exhibits an extremely broad clinical spectrum in human patients. Although previous studies indicated that specific serovars or genotypes of Leptospira spp. were associated with severe leptospirosis or its outbreak, the mechanism underlying the difference in virulence of the various Leptospira serotypes or genotypes remains unclear. The present study addresses this question by measuring and comparing bacterial burden and cytokine gene expression in hamsters infected with strains of two L. interrogans serovars Manilae (highly virulent) and Hebdomadis (less virulent). The histopathology of kidney, liver, and lung tissues was also investigated in infected hamsters. A significantly higher bacterial burden was observed in liver tissues of hamsters infected with serovar Manilae than those infected with serovar Hebdomadis (p < 0.01). The average copy number of the leptospiral genome was 1,302 and 20,559 in blood and liver, respectively, of hamsters infected with serovar Manilae and 1,340 and 4,896, respectively, in hamsters infected with serovar Hebdomadis. The expression levels of mip1alpha in blood; tgfbeta, il1beta, mip1alpha, il10, tnfalpha and cox2 in liver; and tgfbeta, il6, tnfalpha and cox2 in lung tissue were significantly higher in hamsters infected with serovar Manilae than those infected with serovar Hebdomadis (p < 0.05). In addition, infection with serovar Manilae resulted in a significantly larger number of hamsters with tnfalpha upregulation (p = 0.04). Severe distortion of tubular cell arrangement and disruption of renal tubules in kidney tissues and hemorrhage in lung tissues were observed in Manilae-infected hamsters. These results demonstrate that serovar Manilae multiplied more efficiently in liver tissues and induced significantly higher expression of genes encoding pro- and anti-inflammatory cytokines than serovar Hebdomadis

  20. Comparison of Bacterial Burden and Cytokine Gene Expression in Golden Hamsters in Early Phase of Infection with Two Different Strains of Leptospira interrogans

    PubMed Central

    Fujita, Rie; Koizumi, Nobuo; Sugiyama, Hiromu; Tomizawa, Rina; Sato, Ryoichi; Ohnishi, Makoto

    2015-01-01

    Leptospirosis, a zoonotic infection with worldwide prevalence, is caused by pathogenic spirochaetes of Leptospira spp., and exhibits an extremely broad clinical spectrum in human patients. Although previous studies indicated that specific serovars or genotypes of Leptospira spp. were associated with severe leptospirosis or its outbreak, the mechanism underlying the difference in virulence of the various Leptospira serotypes or genotypes remains unclear. The present study addresses this question by measuring and comparing bacterial burden and cytokine gene expression in hamsters infected with strains of two L. interrogans serovars Manilae (highly virulent) and Hebdomadis (less virulent). The histopathology of kidney, liver, and lung tissues was also investigated in infected hamsters. A significantly higher bacterial burden was observed in liver tissues of hamsters infected with serovar Manilae than those infected with serovar Hebdomadis (p < 0.01). The average copy number of the leptospiral genome was 1,302 and 20,559 in blood and liver, respectively, of hamsters infected with serovar Manilae and 1,340 and 4,896, respectively, in hamsters infected with serovar Hebdomadis. The expression levels of mip1alpha in blood; tgfbeta, il1beta, mip1alpha, il10, tnfalpha and cox2 in liver; and tgfbeta, il6, tnfalpha and cox2 in lung tissue were significantly higher in hamsters infected with serovar Manilae than those infected with serovar Hebdomadis (p < 0.05). In addition, infection with serovar Manilae resulted in a significantly larger number of hamsters with tnfalpha upregulation (p = 0.04). Severe distortion of tubular cell arrangement and disruption of renal tubules in kidney tissues and hemorrhage in lung tissues were observed in Manilae-infected hamsters. These results demonstrate that serovar Manilae multiplied more efficiently in liver tissues and induced significantly higher expression of genes encoding pro- and anti-inflammatory cytokines than serovar Hebdomadis

  1. Transformation of Primary Hamster Brain Cells with JC Virus and Its DNA

    PubMed Central

    Frisque, R. J.; Rifkin, D. B.; Walker, D. L.

    1980-01-01

    We transformed primary hamster brain cells with four isolates of JC virus and JC virus DNA. Several properties of these transformants were characterized and compared to those of simian virus 40 transformants isolated under identical conditions. Images PMID:6251275

  2. The effects of feedback lighting on the circadian rhythm of locomotor activity and the reproductive maturation of the male Djungarian hamster (Phodopus sungorus)

    NASA Technical Reports Server (NTRS)

    Ferraro, J. S.

    1988-01-01

    The non-parametric model of entrainment suggests that brief pulses of light, delivered between dusk and dawn can simulate the phasing effects of full photoperiods or even constant light (LL). Feedback lighting (LDFB) is a lighting condition where individual animals, otherwise in constant darkness (DD), are exposed to light in response to a monitored behavior. The specific purpose of this type of illumination is to expose the circadian cycle to light only during the subjective night. LDFB has been used to support this hypothesis in several species of nocturnal rodents and one species of diurnal primate by producing similar free-running periods in LDFB as in LL. This lighting condition has also been used to test the hypothesis that exposing the subjective night to even short duration light pulses will maintain reproductive function in long day breeders. In the Syrian hamster (Mesocricetus auratus), however, LDFB is not as photostimulatory as LL despite extensive light exposure during the subjective night. In the experiments presented here, a group of immature male Djungarian hamsters (Phodopus sungorus) were placed in individual light-tight sound attenuated chambers where they had free access to food, water and an activity wheel. The animals were exposed to one of four lighting conditions [DD, LL, LDFB or a neighbor control of feedback lighting (LDFB NC)] for approximately 30 days shortly after weaning. LDFB NC is a lighting condition where a neighbor control hamster receives the identical lighting regime as a paired animal exposing itself to LDFB, yet the neighbor has no control over it. A fifth group was exposed to a light-dark cycle of 16 hours of light and 8 hours of dark (LD16:8). This group was housed in cages in a colony room and did not have access to a running wheel. The free-running periods of the locomotor activity rhythms for hamsters exposed to LDFB and LL were not similar, unlike the results for rats, Syrian hamsters, mice, monkeys and even mature

  3. Reduced and high molecular weight barley beta-glucans decrease plasma total and non-HDL-cholesterol in hypercholesterolemic Syrian golden hamsters.

    PubMed

    Wilson, Thomas A; Nicolosi, Robert J; Delaney, Bryan; Chadwell, Kim; Moolchandani, Vikas; Kotyla, Timothy; Ponduru, Sridevi; Zheng, Guo-Hua; Hess, Richard; Knutson, Nathan; Curry, Leslie; Kolberg, Lore; Goulson, Melanie; Ostergren, Karen

    2004-10-01

    Consumption of concentrated barley beta-glucan lowers plasma cholesterol because of its soluble dietary fiber nature. The role of molecular weight (MW) in lowering serum cholesterol is not well established. Prior studies showed that enzymatic degradation of beta-glucan eliminates the cholesterol-lowering activity; however, these studies did not evaluate the MW of the beta-glucan. The current study was conducted to evaluate whether barley beta-glucan concentrates, partially hydrolyzed to reduce MW, possess cholesterol-lowering and antiatherogenic activities. The reduced MW fraction was compared with a high MW beta-glucan concentrate from the same barley flour. Concentrated beta-glucan preparations were evaluated in Syrian Golden F(1)B hamsters fed a hypercholesterolemic diet (HCD) with cholesterol, hydrogenated coconut oil, and cellulose. After 2 wk, hamsters were fed HCD or diets that contained high or reduced MW beta-glucan at a concentration of 8 g/100 g at the expense of cellulose. Decreases in plasma total cholesterol (TC) and non-HDL-cholesterol (non-HDL-C) concentrations occurred in the hamsters fed reduced MW and high MW beta-glucan diets. Plasma HDL-C concentrations did not differ. HCD-fed hamsters had higher plasma triglyceride concentrations. Liver TC, free cholesterol, and cholesterol ester concentrations did not differ. Aortic cholesterol ester concentrations were lower in the reduced MW beta-glucan-fed hamsters. Consumption of either high or reduced MW beta-glucan increased concentrations of fecal total neutral sterols and coprostanol, a cholesterol derivative. Fecal excretion of cholesterol was greater than in HCD-fed hamsters only in those fed the reduced MW beta-glucan. Study results demonstrate that the cholesterol-lowering activity of barley beta-glucan may occur at both lower and higher MW.

  4. Synergetic cholesterol-lowering effects of main alkaloids from Rhizoma Coptidis in HepG2 cells and hypercholesterolemia hamsters.

    PubMed

    Kou, Shuming; Han, Bing; Wang, Yue; Huang, Tao; He, Kai; Han, Yulong; Zhou, Xia; Ye, Xiaoli; Li, Xuegang

    2016-04-15

    Hyperlipidemia contributes to the progression of cardiovascular diseases. Main alkaloids from Rhizoma Coptidis including berberine (BBR), coptisine (COP), palmatine (PAL), epiberberine (EPI) and jatrorrhizine (JAT), improved dyslipidemia in hypercholesterolemic hamsters to a different degree. In this study, HepG2 cells and hypercholesterolemic hamsters were used to investigate the synergetic cholesterol-lowering efficacy of these five main alkaloids. The cellular lipid and cholesterol accumulation and in HepG2 cells were evaluated by Oil Red O staining and HPLC analysis. LDL receptor, 3-Hydroxy-3-methylglutaryl CoA reductase (HMGCR) and cholesterol 7-alpha-hydroxylase (CYP7A1) that involving cholesterol metabolism in HepG2 cells were measured by qRT-PCR, western blot and immunofluorescence analysis. The serum profiles including total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-c) and high-density lipoprotein cholesterol (HDL-c), as well as TC and total bile acids (TBA) of feces in hypercholesterolemic hamsters were also measured. As compared to single alkaloids, the combination of five main alkaloids (COM) reduced the lipid and cholesterol accumulation in HepG2 cells more effectively and performed an advantageous effect on controlling TC, TG, LDL-c and HDL-c in hypercholesterolemic hamsters. More effective reduction of TBA and TC levels in feces of hamsters were achieved after the administration of COM. These effects were derived from the up-regulation of LDL receptor and CYP7A1, as well as HMGCR downregulation. Our results demonstrated that COM showed a synergetic cholesterol-lowering efficacy, which was better than single alkaloids and it might be considered as a potential therapy for hypercholesterolemia. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Dim light at night provokes depression-like behaviors and reduces CA1 dendritic spine density in female hamsters.

    PubMed

    Bedrosian, Tracy A; Fonken, Laura K; Walton, James C; Haim, Abraham; Nelson, Randy J

    2011-08-01

    The prevalence of major depression has increased in recent decades; however, the underlying causes of this phenomenon remain unspecified. One environmental change that has coincided with elevated rates of depression is increased exposure to artificial light at night. Shift workers and others chronically exposed to light at night are at increased risk of mood disorders, suggesting that nighttime illumination may influence brain mechanisms mediating affect. We tested the hypothesis that exposure to dim light at night may impact affective responses and alter morphology of hippocampal neurons. Ovariectomized adult female Siberian hamsters (Phodopus sungorus) were housed for 8 weeks in either a light/dark cycle (LD) or a light/dim light cycle (DM), and then behavior was assayed. DM-hamsters displayed more depression-like responses in the forced swim and the sucrose anhedonia tests compared with LD-hamsters. Conversely, in the elevated plus maze DM-hamsters reduced anxiety-like behaviors. Brains from the same animals were processed using the Golgi-Cox method and hippocampal neurons within CA1, CA3, and the dentate gyrus were analyzed for morphological characteristics. In CA1, DM-hamsters significantly reduced dendritic spine density on both apical and basilar dendrites, an effect which was not mediated by baseline cortisol, as concentrations were equivalent between groups. These results demonstrate dim light at night is sufficient to reduce synaptic spine connections to CA1. Importantly, the present results suggest that night-time low level illumination, comparable to levels that are pervasive in North America and Europe, may contribute to the increasing prevalence of mood disorders. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Expression and regulation of Icer mRNA in the Syrian hamster pineal gland.

    PubMed

    Diaz, Elena; Garidou, Marie-Laure; Dardente, Hugues; Salingre, Anthony; Pévet, Paul; Simonneaux, Valérie

    2003-04-10

    Inducible-cAMP early repressor (ICER) is a potent inhibitor of CRE (cAMP-related element)-driven gene transcription. In the rat pineal gland, it has been proposed to be part of the mechanisms involved in the shutting down of the transcription of the gene coding for arylalkylamine N-acetyltransferase (AA-NAT, the melatonin rhythm-generating enzyme). In this study, we report that ICER is expressed in the pineal gland of the photoperiodic rodent Syrian hamster although with some difference compared to the rat. In the Syrian hamster pineal, Icer mRNA levels, low at daytime, displayed a 20-fold increase during the night. Nighttime administration of a beta-adrenergic antagonist, propranolol, significantly reduced Icer mRNA levels although daytime administration of a beta-adrenergic agonist, isoproterenol, was unable to raise the low amount of Icer mRNA. These observations indicate that Icer mRNA expression is induced by the clock-driven norepinephrine release and further suggest that this stimulation is restricted to nighttime, as already observed for Aa-nat gene transcription. Furthermore, we found that the daily profile of Icer mRNA displayed photoperiodic variation with a lengthening of the nocturnal peak in short versus long photoperiod. These data indicate that ICER may be involved in both daily and seasonal regulation of melatonin synthesis in the Syrian hamster.

  7. Dominance relationships in Syrian hamsters modulate neuroendocrine and behavioral responses to social stress.

    PubMed

    Dulka, Brooke N; Koul-Tiwari, Richa; Grizzell, J Alex; Harvey, Marquinta L; Datta, Subimal; Cooper, Matthew A

    2018-06-22

    Stress is a well-known risk factor for psychopathology and rodent models of social defeat have strong face, etiological, construct and predictive validity for these conditions. Syrian hamsters are highly aggressive and territorial, but after an acute social defeat experience they become submissive and no longer defend their home territory, even from a smaller, non-aggressive intruder. This defeat-induced change in social behavior is called conditioned defeat (CD). We have shown that dominant hamsters show increased neural activity in the ventromedial prefrontal cortex (vmPFC) following social defeat stress and exhibit a reduced CD response at social interaction testing compared to subordinates. Although the vmPFC can inhibit the neuroendocrine stress response, it is unknown whether dominants and subordinates differ in stress-induced activity of the extended hypothalamic-pituitary-adrenal (HPA) axis. Here, we show that, following acute social defeat, dominants exhibit decreased submissive and defensive behavior compared to subordinates but do not differ from subordinates or social status controls (SSCs) in defeat-induced cortisol concentrations. Furthermore, both dominants and SSCs show greater corticotropin-releasing hormone (CRH) mRNA expression in the basolateral/central amygdala compared to subordinates, while there was no effect of social status on CRH mRNA expression in the paraventricular nucleus of the hypothalamus or bed nucleus of the stria terminalis. Overall, status-dependent differences in the CD response do not appear linked to changes in stress-induced cortisol concentrations or CRH gene expression, which is consistent with the view that stress resilience is not a lack of a physiological stress response but the addition of stress coping mechanisms. Lay summary Dominant hamsters show resistance to the behavioral effects of acute social defeat compared to subordinates, but it is unclear whether social status modulates the neuroendocrine stress response

  8. Correlations between phytohemagglutinin response and leukocyte profile, and bactericidal capacity in a wild rodent.

    PubMed

    Zhang, Zhiqiang; Zhao, Zhijun

    2015-05-01

    Phytohemagglutinin (PHA)-induced swelling is widely used to investigate cell-mediated and innate immunity across different vertebrate taxa. However, its physiological mechanism is still an open question due to the complexity of the involved immune components. In the present study, we measured the synchronous variations of PHA response, the proportion of different subtypes of leukocytes, as well as serum bactericidal capacity in circulation blood at 6, 12 and 24 h after PHA versus PBS injection in striped hamster, Cricetulus barabensis. First, the results showed that PHA responses reached a peak at 6 h postinjection, then sharply declined at 12 h and 24 h postinjection. Serum bactericidal capacity was higher at 6 h and 12 h than at 24 h. The proportion of different subtypes of leukocytes, as well as the ratio of neutrophils to lymphocytes did not display significant changes across different time points. Second, PHA response was positively correlated with the proportion of neutrophils and serum bactericidal capacity. The proportion of monocytes was negatively correlated with that of eosinophils and neutrophils. The proportion of basophils was negatively correlated with that of lymphocytes. Our results indicate that earlier enhanced PHA response is important for the striped hamster to cope with changing environmental conditions due to its small body mass, and the increased components of innate immunity in circulation blood may contribute to the enhancement of PHA swelling response. © 2015 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

  9. The adaptive immune response does not influence hantavirus disease or persistence in the Syrian hamster.

    PubMed

    Prescott, Joseph; Safronetz, David; Haddock, Elaine; Robertson, Shelly; Scott, Dana; Feldmann, Heinz

    2013-10-01

    Pathogenic New World hantaviruses cause severe disease in humans characterized by a vascular leak syndrome, leading to pulmonary oedema and respiratory distress with case fatality rates approaching 40%. Hantaviruses infect microvascular endothelial cells without conspicuous cytopathic effects, indicating that destruction of the endothelium is not a mechanism of disease. In humans, high levels of inflammatory cytokines are present in the lungs of patients that succumb to infection. This, along with other observations, suggests that disease has an immunopathogenic component. Currently the only animal model available to study hantavirus disease is the Syrian hamster, where infection with Andes virus (ANDV), the primary agent of disease in South America, results in disease that closely mimics that seen in humans. Conversely, inoculation of hamsters with a passaged Sin Nombre virus (SNV), the virus responsible for most cases of disease in North America, results in persistent infection with high levels of viral replication. We found that ANDV elicited a stronger innate immune response, whereas SNV elicited a more robust adaptive response in the lung. Additionally, ANDV infection resulted in significant changes in the blood lymphocyte populations. To determine whether the adaptive immune response influences infection outcome, we depleted hamsters of CD4(+) and CD8(+) T cells before infection with hantaviruses. Depletion resulted in inhibition of virus-specific antibody responses, although the pathogenesis and replication of these viruses were unaltered. These data show that neither hantavirus replication, nor pathogenesis caused by these viruses, is influenced by the adaptive immune response in the Syrian hamster. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  10. Blood Lipid Distribution, Aortic Cholesterol Concentrations, and Selected Inflammatory and Bile Metabolism Markers in Syrian Hamsters Fed a Standard Breeding Diet

    USDA-ARS?s Scientific Manuscript database

    Hamsters are often used to determine the effects of various dietary ingredients on the development of cardiovascular disease (CVD). The study was conducted to obtain baseline data on CVD risk factors and mRNA expression of selected genes in hamsters fed a standard maintenance diet (STD) for 24 wk, b...

  11. Identification of leptospiral 3-hydroxyacyl-CoA dehydrogenase released in the urine of infected hamsters

    PubMed Central

    2014-01-01

    Background Leptospirosis is a global zoonosis caused by pathogenic Leptospira. The non-specific clinical signs and symptoms of leptospirosis lead to its misdiagnosis. To date, there is still no reliable rapid test kit that can accurately diagnose leptospirosis at bedside or in field. In this research, with the ultimate goal of formulating a rapid and accurate diagnostic tool for leptospirosis, we aimed to identify leptospiral proteins excreted in urine of infected hamsters, which are thought to mimic Weil’s disease. Results Hamsters were subcutaneously infected with leptospires, and the general attributes of urine as well as the proteins excreted in it were examined. Some leptospiral proteins were found to be excreted in the urine from the early phase of infection. The most important finding of this study was the detection of the lipid-metabolizing enzyme, 3-hydroxyacyl-CoA dehydrogenase (HADH), before the onset of illness, when leptospires were not yet detected in the urine of infected hamsters. Conclusions This is the first report on the detection of leptospiral HADH in the host urine, which may be a possible candidate leptospiral antigen that can be used in the early diagnosis of human and animal leptospirosis. PMID:24884439

  12. Comparative pattern of growth and development of Echinostoma paraensei (Digenea: Echinostomatidae) in hamster and Wistar rat using light and confocal laser scanning microscopy.

    PubMed

    Souza, Joyce G R; Garcia, Juberlan S; Gomes, Ana Paula N; Machado-Silva, José Roberto; Maldonado, Arnaldo

    2017-12-01

    Echinostoma paraensei (Digenea: Echinostomatidae) lives in the duodenum and bile duct of rodents and is reported as a useful model for studies on the biology of flatworms. Here, we compared the growth and development of pre and post ovigerous worms collected 3, 7, 14 and 21 days post infection from experimentally infected hamster (permissive host) and Wistar rat (less permissive hosts). Linear measurements and ratios were examined by light (morphology and morphometry) and confocal laser scanning microscopy. At day 3, either worm from hamsters or rats were small with poorly developed gonads. At seven day, worms increased in size and morphometric differences between hosts are statistically significant after this time. In addition, adult worms (14 and 21 days of age) harvested from hamster showed developed gonads and vitelline glands laterally distributed on the body, whereas worms from rat showed atrophied reproductive system characterized by underdeveloped vitelline glands and stunted ovary. The worm rate recovery in rat decreased from 29.3% (day 7) to 20.6% (day 14) and 8% (day 21), whilst it remained around 37% in hamster. In conclusion, this is the first appointment demonstrating that low permissiveness influences the reproductive system of echinostome since the immature stages of development. The phenotypic analysis evidenced that hamster provides a more favorable microenvironment for gonads development than rat, confirming golden hamster as a permissive host, whereas Wistar rat is less permissive host. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Chronic anabolic-androgenic steroid treatment during adolescence increases anterior hypothalamic vasopressin and aggression in intact hamsters.

    PubMed

    Harrison, R J; Connor, D F; Nowak, C; Nash, K; Melloni, R H

    2000-05-01

    The present study examines the hypothesis that exposure to anabolic-androgenic steroids (AAS) during adolescent development predisposes hamsters to heightened levels of aggressive behavior by influencing the anterior hypothalamic-arginine vasopressin (AH-AVP) neural system. To test this, adolescent male hamsters (Mesocricetus auratus) were treated with high doses of AAS, tested for offensive aggression in the absence or presence of AH-AVP receptor antagonists, and then examined for changes in AH-AVP expression and neural organization. AAS exposure during adolescence significantly increased aggression intensity (number of attacks and bites) and initiation (latency to the first bite). Yet, only increases in aggression intensity were inhibited by AH-AVP receptor antagonism. Adolescent AAS-treated hamsters showed significant increases in AH-AVP fiber density and peptide content. However, no alterations in AH-AVP neuronal organization or mRNA expression were found. Together, these data suggest that adolescent AAS exposure increase aggression intensity by altering AH-AVP expression and activity, providing direct evidence for a causal role of AH-AVP expression and function in early onset AAS-stimulated aggression.

  14. Acute Hendra virus infection: Analysis of the pathogenesis and passive antibody protection in the hamster model

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Guillaume, Vanessa; Ecole Normale Superieure de Lyon, Lyon, F-69007; IFR128 BioSciences Lyon-Gerland Lyon-Sud, University of Lyon 1, 21 Avenue Tony Garnier, 69365 Lyon Cedex 07

    2009-05-10

    Hendra virus (HeV) and Nipah virus (NiV) are recently-emerged, closely related and highly pathogenic paramyxoviruses. We have analysed here the pathogenesis of the acute HeV infection using the new animal model, golden hamster (Mesocricetus auratus), which is highly susceptible to HeV infection. HeV-specific RNA and viral antigens were found in multiple organs and virus was isolated from different tissues. Dual pathogenic mechanism was observed: parenchymal infection in various organs, including the brain, with vasculitis and multinucleated syncytia in many blood vessels. Furthermore, monoclonal antibodies specific for the NiV fusion protein neutralized HeV in vitro and efficiently protected hamsters from HeVmore » if given before infection. These results reveal the similarities between HeV and NiV pathogenesis, particularly in affecting both respiratory and neuronal system. They demonstrate that hamster presents a convenient novel animal model to study HeV infection, opening new perspectives to evaluate vaccine and therapeutic approaches against this emergent infectious disease.« less

  15. The hypocholesterolemic and antiatherogenic effects of Cholazol H, a chemically functionalized insoluble fiber with bile acid sequestrant properties in hamsters.

    PubMed

    Wilson, T A; Romano, C; Liang, J; Nicolosi, R J

    1998-08-01

    Cholazol H (Alpha-Beta Technology, Worcester, MA), a chemically functionalized, insoluble dietary fiber with bile acid sequestrant properties, was studied in 30 male F1 B Golden Syrian hamsters for its effect on plasma lipid concentrations and early atherogenesis in experiment 1. In experiment 2, 30 male Golden Syrian hamsters were studied for the effects on plasma lipids and fecal excretion of bile acids. In experiment 1, three groups of 10 hamsters each were fed a chow-based hypercholesterolemic diet supplemented with 5% coconut oil and 0.1% cholesterol for 6 weeks. After 6 weeks, hamsters were continued on the diet with either 0% drug (hypercholesterolemic diet [HCD]), 0.5% cholestyramine (CSTY), or 0.5% Cholazol H for 8 weeks. Fasting plasma lipids were measured at weeks 6, 10, and 14, and early atherosclerosis (fatty streak formation) was measured at week 14. Relative to HCD, CSTY and Cholazol H significantly lowered plasma total cholesterol (TC) (-37%, P < .03, and -30%, P < .04, respectively) and plasma very-low and low-density lipoprotein-cholesterol (nonHDL-C) (-45%, P < .02, and -36%, P < .03, respectively) with no significant effects on plasma HDL-C or triglycerides (TG). Despite similar reductions in nonHDL-C, only Cholazol H significantly prevented early atherosclerosis (-38%, P < .02) relative to HCD. In experiment 2, three groups of 10 hamsters each were fed a chow-based hypercholesterolemic diet supplemented with 10% coconut oil and 0.05% cholesterol and either 0% drug HCD, 0.5% CSTY, or 0.5% Cholazol H for 4 weeks. Fasting plasma lipids were measured at weeks 2 and 4, and fecal bile acids were measured at week 4. Both Cholazol H and CSTY were equally effective in significantly lowering plasma TC (-16%, P < .003, and -13%, P < .01, respectively) and nonHDL-C (-22%, P < .004, and -18%, P < .02, respectively), with no significant effect on HDL-C and TG relative to HCD. Cholazol H and CSTY produced a significantly greater concentration of fecal total

  16. Ionotropic glutamate receptor GluR2/3-immunoreactive neurons in the cat, rabbit, and hamster superficial superior colliculus.

    PubMed

    Park, Won-Mee; Kim, Min-Jeong; Jeon, Chang-Jin

    2004-06-01

    Ionotropic glutamate receptor (GluR) subtypes occur in various types of cells in the central nervous system. We studied the distribution of AMPA glutamate receptor subtype GluR2/3 in the superficial layers of cat, rabbit, and hamster superior colliculus (SC) with antibody immunocytochemistry and the effect of enucleation on this distribution. Furthermore, we compared this labeling to that of calbindin D28K and parvalbumin. Anti-GluR2/3-immunoreactive (IR) cells formed a dense band of labeled cells within the lower superficial gray layer (SGL) and upper optic layer (OL) in the cat SC. By contrast, GluR2/3-IR cells formed a dense band within the upper OL in the rabbit and within the OL in the hamster SC. Calbindin D28K-IR cells are located in three layers in the SC: one within the zonal layer (ZL) and the upper SGL in all three animals, a second within the lower OL and upper IGL in the cat, within the IGL in the rabbit and within the OL in the hamster, and a third within the deep gray layer (DGL) in all three animals. Many parvalbumin-IR neurons were found within the lower SGL and upper OL. Thus, the GluR2/3-IR band was sandwiched between the first and second layers of calbindin D28K-IR cells in the cat and rabbit SC while the distribution of GluR2/3-IR cells in the hamster matches the second layer of calbindin D28K-IR cells. The patterned distribution of GluR2/3-IR cells overlapped the tier of parvalbumin-IR neurons in cat, but only partially overlapped in hamster and rabbit. Two-color immunofluorescence revealed that more than half (55.1%) of the GluR2/3-IR cells in the hamster SC expressed calbindin D28K. By contrast, only 9.9% of GluR2/3-IR cells expressed calbindin D28K in the cat. Double-labeled cells were not found in the rabbit SC. Some (4.8%) GluR2/3-IR cells in the cat SC also expressed parvalbumin, while no GluR2/3-IR cells in rabbit and hamster SC expressed parvalbumin. In this dense band of GluR2/3, the majority of labeled cells were small to medium

  17. Effect of testosterone replacement on the alteration of steroid metabolism in the hypothalamic-preoptic area of male hamsters treated with melatonin.

    PubMed

    Petterborg, L J; West, D A; Rudeen, P K; Ganjam, V K

    1991-11-01

    Adult male hamsters were maintained under 14 hours of light per day and randomly assigned to groups that received daily afternoon melatonin (25 micrograms) or vehicle injections. Animals from both groups were killed following 4, 8, and 12 weeks of treatment. By 12 weeks, the melatonin-treated hamsters had significant reductions in the weights of the testes and seminal vesicles, serum testosterone levels, and activities did not differ between groups. In a second experiment, hamsters were hypothalamic-preoptic area (HPOA) aromatase activities. Hypothalamic-preoptic area 5 alpha-reductase activities did not differ between groups. In a second experiment, hamsters were again treated with melatonin or vehicle for 12 weeks prior to being killed. After 10 weeks of treatment, groups of melatonin-treated animals received subcutaneous silastic capsules (5, 10, or 20 mm) filled with testosterone. Animals in two other groups were given blank implants or no implants at all. Two weeks later, at autopsy, reproductive organ weights, serum testosterone levels, and HPOA aromatase activities were significantly suppressed by melatonin administration. 5 alpha-Reductase activity in the HPOA was not affected. Hamsters that had been given the 10- and 20-mm testosterone implants exhibited normal seminal vesicle weights and HPOA aromatase activities. These results suggest that melatonin-induced reduction of HPOA aromatase activity is mediated by decreased circulating levels of testosterone.

  18. Acute and subchronic inhalation exposures of hamsters to nickel-enriched fly ash

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wehner, A.P.; Moss, O.R.; Milliman, E.M.

    1979-08-01

    One 6-h inhalation exposure of hamsters to Ni-enriched fly ash (NEFA) aerosol (respirable aerosol concentration approx. 200 ..mu..g/liter) deposited about 80 ..mu..g in the deep lung, of which 75 ..mu..g was still present 30 days postexposure. The animals tolerated the exposure well during the 30-day postexposure observation period. Two-month exposures of hamsters to NEFA or fly ash (FA) aerosols (approx. 185 ..mu..g/liter) resuled in a deep lung burden of about 5.7 mg, dark discoloration of lungs, heavily dust-laden macrophages, and significantly higher lung weights than in controls, but only minimal inflammatory reaction and no deaths. There was no difference betweenmore » NEFA and FA effects. The NEFA contained 9% Ni; FA contained 0.03% Ni. The results of this study indicate low acute and subchronic toxicity and slow lung clearance of NEFA and FA.« less

  19. Investigation of Blue Bedding in Cages Housing Treatment-Naïve Hamsters

    PubMed Central

    Shah, Vishal D; Walton, Betsy J; Culp, Amanda G; Castellino, Stephen

    2015-01-01

    During the acclimation phase of a preclinical safety study involving Syrian golden hamsters, some of the cages of treatment-naïve animals were noted to contain blue-tinged bedding; the urine of these hamsters was not discolored. We sought to understand the underlying cause of this unusual finding to ensure that the study animals were healthy and free from factors that might confound the interpretation of the study. Analysis of extracts from the blue bedding by using HPLC with inline UV detection and high-resolution mass spectrometry indicated that the color was due to the presence of indigo blue. Furthermore, the indigo blue likely was formed through a series of biochemical events initiated by the intestinal metabolism of tryptophan to an indoxyl metabolite. We offer 2 hypotheses regarding the fate of the indoxyl metabolite: indigo blue formation through oxidative coupling in the liver or through urinary bacterial metabolism. PMID:26632791

  20. Investigation of Blue Bedding in Cages Housing Treatment-Naïve Hamsters.

    PubMed

    Shah, Vishal D; Walton, Betsy J; Culp, Amanda G; Castellino, Stephen

    2015-11-01

    During the acclimation phase of a preclinical safety study involving Syrian golden hamsters, some of the cages of treatment-naïve animals were noted to contain blue-tinged bedding; the urine of these hamsters was not discolored. We sought to understand the underlying cause of this unusual finding to ensure that the study animals were healthy and free from factors that might confound the interpretation of the study. Analysis of extracts from the blue bedding by using HPLC with inline UV detection and high-resolution mass spectrometry indicated that the color was due to the presence of indigo blue. Furthermore, the indigo blue likely was formed through a series of biochemical events initiated by the intestinal metabolism of tryptophan to an indoxyl metabolite. We offer 2 hypotheses regarding the fate of the indoxyl metabolite: indigo blue formation through oxidative coupling in the liver or through urinary bacterial metabolism.

  1. The hamster (Mesocricetus auratus) as an experimental model of toxocariasis: histopathological, immunohistochemical, and immunoelectron microscopic findings.

    PubMed

    da Silva, Ana Maria Gonçalves; Chieffi, Pedro Paulo; da Silva, Wellington Luiz Ferreira; Kanashiro, Edite Hatsumi Yamashiro; Rubinsky-Elefant, Guita; Cunha-Neto, Edécio; Mairena, Eliane Conti; De Brito, Thales

    2015-03-01

    Toxocariasis is a globally distributed parasitic infection caused by the larval stage of Toxocara spp. The typical natural hosts of the parasite are dogs and cats, but humans can be infected by the larval stage of the parasite after ingesting embryonated eggs in soil or from contaminated hands or fomites. The migrating larvae are not adapted to complete their life cycle within accidental or paratenic hosts like humans and laboratory animals, respectively, but they are capable of invading viscera or other tissues where they may survive and induce disease. In order to characterize hamsters (Mesocricetus auratus) as a model for Toxocara canis infection, histopathological and immunohistochemistry procedures were used to detect pathological lesions and the distribution of toxocaral antigens in the liver, lungs, and kidneys of experimentally infected animals. We also attempted to characterize the immunological parameters of the inflammatory response and correlate them with the histopathological findings. In the kidney, a correlation between glomerular changes and antigen deposits was evaluated using immunoelectron microscopy. The hamster is an adequate model of experimental toxocariasis for short-term investigations and has a good immunological and pathological response to the infection. Lung and liver manifestations of toxocariasis in hamsters approximated those in humans and other experimental animal models. A mixed Th2 immunological response to T. canis infection was predominant. The hamster model displayed a progressive rise of anti-toxocaral antibodies with the formation of immune complexes. Circulating antigens, immunoglobulin, and complement deposits were detected in the kidney without the development of a definite immune complex nephropathy.

  2. [6]-Shogaol, a Novel Chemopreventor in 7,12-Dimethylbenz[a]anthracene-induced Hamster Buccal Pouch Carcinogenesis.

    PubMed

    Kathiresan, Suresh; Govindhan, Annamalai

    2016-04-01

    Oral cancer is a major cause of morbidity and mortality in developing countries. Despite advances in chemotherapy for the cancer management, the survival rate has not yet been improved. Dietary nutrient has been receiving a lot of attention and interest in the chemotherapeutic development. [6]-Shogaol is a major bioactive compound identified in ginger that possesses many pharmacological properties. The aim of the present study is to investigate the effect of [6]-shogaol on 7,12-dimethylbenz[a]anthracene-induced hamster buccal pouch (HBP) carcinogenesis. Oral squamous cell carcinoma induced in HBP by painting with 0.5% 7,12-dimethylbenz(a)anthracene (DMBA), thrice in a week for 16 weeks. We observed 100% tumour incidence, decreased levels of lipid peroxidation, antioxidant, and phase II detoxification enzymes (GST, GR and GSH) in DMBA-induced hamsters. Further, enhanced activity of phase I enzymes (cytochrome p450 and b5) and over-expression of mutant p53, Bcl-2 and decreased expression of wild type p53 and Bax were noticed in DMBA-induced hamsters. Our results indicated that [6]-shogaol (10, 20 and 40 mg/kg body weight) treated with DMBA-painted hamsters, considerably reversed tumour incidence, improved antioxidant status, phase II detoxification enzymes, and also inhibit lipid peroxidation and phase I enzymes. Moreover, [6]-shogaol inhibits mutant p53 and Bcl-2 expression and significantly restored normal p53, Bax levels. Thus, we concluded that [6]-shogaol prevents DMBA-induced HBP carcinogenesis through its antioxidant as well as modulating apoptotic signals. Copyright © 2016 John Wiley & Sons, Ltd.

  3. The Shift of Thermoneutral Zone in Striped Hamster Acclimated to Different Temperatures

    PubMed Central

    Zhao, Zhi-Jun; Chi, Qing-Sheng; Liu, Quan-Sheng; Zheng, Wei-Hong; Liu, Jin-Song; Wang, De-Hua

    2014-01-01

    Temperature affects all biological functions and will therefore modulate ecologically significant interactions between animals and their environment. Here, we examined the effect of ambient temperature (Ta) on the thermal biology and energy budget in striped hamsters acclimated to cold (5°C), warm (21°C) and hot temperatures (31°C). Thermoneutral zone (TNZ) was 22.5–32.5°C, 25–32.5°C and 30–32.5°C in the cold-, warm- and hot-acclimated hamsters, respectively. The cold acclimation decreased the lower critical temperature and made the TNZ wider, and hot exposure elevated the lower critical temperature, resulting in a narrow TNZ. Within the TNZ, cold-acclimated hamsters showed a significantly higher rate of metabolism and thermogenesis than those acclimated to hot temperature. Digestive enzymes activities, including intestinal sucrase, maltase, L-alanine aminopeptidase-N and leucine aminopeptidase were higher in the cold than in the hot. The changes in metabolic rate and thermogenesis at different temperatures were in parallel with cytochrome c oxidase activity and uncoupling protein 1 gene expression of brown adipose tissue. This suggests that the shift of the lower critical temperature of TNZ is possibly associated with the rate of metabolism and thermogenesis, as well as with the digestive capacity of the gastrointestinal tract at different Ta. The upper critical temperature of TNZ may be independent of the changes in Ta. The changes of lower critical temperature of TNZ are an important strategy in adaption to variations of Ta. PMID:24400087

  4. Appropriateness of the hamster as a model to study diet-induced atherosclerosis

    USDA-ARS?s Scientific Manuscript database

    Golden-Syrian hamsters have been used as an animal model to assess diet-induced atherosclerosis since the early 1980s. Advantages appeared to include a low rate of endogenous cholesterol synthesis, receptor-mediated uptake of LDL cholesterol, cholesteryl ester transfer protein activity, hepatic apo...

  5. Independent regulation of periarteriolar and perivenular nitric oxide mechanisms in the in vivo hamster cheek pouch microvasculature

    PubMed Central

    Kim, David D.; Kanetaka, Takehito; Durán, Ricardo G.; Sánchez, Fabiola A.; Bohlen, H Glenn; Durán, Walter N.

    2011-01-01

    Objective We tested the hypothesis that differential stimulation of nitric oxide (NO) production can be induced in pre- and postcapillary segments of the microcirculation in the hamster cheek pouch. Methods We applied acetylcholine (ACh) or platelet-activating factor (PAF) topically and measured perivascular NO concentration ([NO]) with NO-sensitive microelectrodes in arterioles and venules of the hamster cheek pouch. We also measured NO in cultured coronary endothelial cells (CVEC) after ACh or PAF. Results ACh increased periarteriolar [NO] significantly in a dose-dependent manner. ACh at 1 μM increased [NO] from 438.1±43.4 nM at baseline to 647.9±66.3 nM, while 10 μM ACh increased [NO] from baseline to 1035.0±59.2 nM (P < 0.05). Neither 1 μM nor 10 μM ACh changed perivenular [NO] in the hamster cheek pouch. PAF, at 100 nM, increased perivenular [NO] from 326.6±50.8 nM to 622.8±41.5 nM. Importantly, 100 nM PAF did not increase periarteriolar [NO]. PAF increased [NO] from 3.6 ± 2.1 to 455.5 ± 19.9 in CVEC, while ACh had no effect. Conclusions We conclude that NO production can be stimulated in a differential manner in preand postcapillary segments in the hamster cheek pouch. ACh selectively stimulates the production of NO only in arterioles, while PAF stimulates the production of NO only in venules. PMID:19235626

  6. AUTONOMIC AND BEHAVIORAL THERMOREGULATION IN THE GOLDEN HAMSTER DURING SUBCHRONIC ADMINISTRATION OF CLORGYLINE

    EPA Science Inventory

    Chronic administration of clorgyline, a type-A monoamine oxidase inhibitor, leads to a decrease in peritoneal (i.e., core) temperature of golden hamsters. o better understand the mechanisms of clorgyline's thermoregulatory effects, autonomic and behavioral thermoregulatory effect...

  7. Effect of ambient temperature on the proliferation of brown adipocyte progenitors and endothelial cells during postnatal BAT development in Syrian hamsters.

    PubMed

    Nagaya, Kazuki; Okamatsu-Ogura, Yuko; Nio-Kobayashi, Junko; Nakagiri, Shohei; Tsubota, Ayumi; Kimura, Kazuhiro

    2018-04-02

    In Syrian hamsters, brown adipose tissue (BAT) develops postnatally through the proliferation and differentiation of brown adipocyte progenitors. In the study reported here, we investigated how ambient temperature influenced BAT formation in neonatal hamsters. In both hamsters raised at 23 or 30 °C, the interscapular fat changed from white to brown coloration in an age-dependent manner and acquired the typical morphological features of BAT by day 16. However, the expression of uncoupling protein 1, a brown adipocyte marker, and of vascular endothelial growth factor α were lower in the group raised at 30 °C than in that raised at 23 °C. Immunofluorescent staining revealed that the proportion of Ki67-expressing progenitors and endothelial cells was lower in the 30 °C group than in the 23 °C group. These results indicate that warm ambient temperature suppresses the proliferation of brown adipocyte progenitors and endothelial cells and negatively affects the postnatal development of BAT in Syrian hamsters.

  8. Plasma and hepatic cholesterol-lowering in hamsters by tomato pomace, tomato seed oil and defatted tomato seed supplemented in high fat diets

    USDA-ARS?s Scientific Manuscript database

    We determined the cholesterol-lowering effects of tomato pomace (TP), a byproduct of tomato processing, and its components such as tomato seed oil (TSO) and defatted tomato seed (DTS) in hamsters, a widely used animal model for cholesterol metabolism. Male Syrian Golden hamsters were fed high-fat di...

  9. Combination therapies in adjuvant with topical ALA-mediated photodynamic therapy for DMBA-induced hamster buccal pouch premalignant lesions

    NASA Astrophysics Data System (ADS)

    Yang, Deng-Fu; Hsu, Yih-Chih

    2012-03-01

    In Taiwan, oral cancer has becomes the fastest growth male cancer disease due to the betel nut chewing habit combing with smoking and alcohol-drinking lifestyle of people. In order to eliminate the systemic phototoxic effect of 5-aminolevulinic acid (ALA), this study was designed to use a topical ALA-mediated PDT for treatment of DMBA-induced hamster buccal pouch precancerous lesions. DMBA was applied to one of the buccal pouches of hamsters thrice a week for 10 to 12 weeks. Cancerous lesions were induced and proven by histological examination. These DMBA-induced cancerous lesions were used for testing the efficacy of topical ALA-mediated PDT. Before PDT, fluorescence spectroscopy was used to determine when ALA reached its peak level in the lesional epithelial cells after topical application of ALA gel. We found that ALA reached its peak level in precancerous lesions about 2.5 hrs after topical application of ALA gel. The cancerous lesions in hamsters were then treated with topical ALA -mediated PDT with light exposure dose of 150 J/cm2 using LED 635 nm fiber-guided light device. Visual examination demonstrated that adjuvant topical ALA -mediated PDT group has shown better therapeutic results in compared to those of non-adjuvant topical ALA-mediated PDT group for DMBA-induced hamster buccal pouch precancerous lesions.

  10. Effect of curcumin on pathogenesis of hamster-opisthorchiasis through apoptosis-related gene expression.

    PubMed

    Sriraj, Pranee; Boonmars, Thidarut; Boonjaraspinyo, Sirintip; Kaewsamut, Butsara; Srisawangwong, Tuanchai; Sithithaworn, Paiboon; Wu, Zhiliang

    2009-11-01

    The present study investigated the effect of curcumin, a phenolic compound with yellow color from Curcuma longa L., on the expression of the apoptosis-related genes [BAX (Bcl-2 associated protein X), PKB, p53, MDM2 (mouse double minute 2), caspase 9, c-Ski, smad1 and smad4] in hamster opisthorchiasis. On Opisthorchis viverrini infection treated with dietary curcumin apoptosis-related gene expression profiles were similar to O. viverrini-infected group, but the expression levels seemed lower. Light microscopic observation revealed that aggregation of inflammatory cells surrounding the hepatic bile ducts in the groups infected with O. viverrini and treated with dietary curcumin was lower than in infected group. The intensity of the response is correlated with expression of the genes studied. The results suggest that curcumin reduces pathogenesis in hamster-opisthorchiasis by controlling apoptosis-related gene expression.

  11. Male hamster investigatory and copulatory responses to vaginal discharge: an attempt to impart sexual significance to an arbitrary chemosensory stimulus.

    PubMed

    Macrides, F; Clancy, A N; Singer, A G; Agosta, W C

    1984-10-01

    Hamster vaginal discharge elicits intense genital investigation and facilitates overt copulatory behavior toward anesthetized males (female surrogates) whose hindquarters have been scented with this material. The ability of an arbitrary chemosensory stimulus to acquire behavioral activity like that of vaginal discharge through association with maternal stimuli and/or adult sexual experience was examined in male hamsters. Vanillin was used as the arbitrary stimulus because it is attractive to hamsters, is not likely to be a natural constituent of hamster scents, is not known to exert any adverse physiological effects, and is a subliming solid with an extremely long persistence when used as an artificial scent. The males were reared by vanillin-scented or control solvent (water)-scented foster mothers, and in adulthood were paired repeatedly with vanillin- or solvent-scented receptive females. Behavioral testing with scented surrogates was performed one week preceding, and again following, the sexual pairings. Rearing by vanillin-scented mothers modestly but significantly increased the amount of time sexually naive males spent investigating the hindquarters as compared to other body regions of vanillin-scented surrogates. However, neither neonatal nor adult interactions with vanillin-scented females imparted to this stimulus the capacity to facilitate overt copulatory behavior. Also, regardless of the males' exposure history, only vaginal discharge caused the males to direct their investigatory behavior predominantly toward the hindquarters. The characteristic investigatory and copulatory responses exhibited by male hamsters toward vaginal discharge thus do not appear to be readily developed toward arbitrary chemosensory stimuli associated with particular females to which the males have been exposed.

  12. Senile amyloidosis and neuron binding antibody in the aging Syrian hamster

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Blumenthal, H.T.; Musacchia, X.J.

    1985-05-01

    The effects of age, sex, and irradiation on the genesis of amyloidosis, neuron-binding antibody (NBA), and the concomitant appearance of these two phenomena were studied in a colony of Syrian hamsters. In nonirradiated controls amyloidosis increased in prevalence with age after 12 months, and prevalence was higher in females than in males. Irradiation had the effect of advancing the appearance of amyloidosis to the 7-12 months group but did not intensify the amyloidotic process. IgG binding to the nucleus or cytoplasm of neurons was rare, and, despite the fact that IgM and IgA binding to these structures was present inmore » about one-third of the animals, there was neither an aging nor an irradiation effect. The only statistically significant findings with respect to the concomitant occurrence of amyloid and NBA were negative correlations between nuclear IgM and IgA binding and amyloidosis. Of the various species thus far studied, the hamster is the first in which there has been no aging effect in respect to NBA.« less

  13. Omega 3 Fatty Acids Promote Macrophage Reverse Cholesterol Transport in Hamster Fed High Fat Diet

    PubMed Central

    Kasbi Chadli, Fatima; Nazih, Hassane; Krempf, Michel; Nguyen, Patrick; Ouguerram, Khadija

    2013-01-01

    The aim of this study was to investigate macrophage reverse cholesterol transport (RCT) in hamster, a CETP-expressing species, fed omega 3 fatty acids (ω3PUFA) supplemented high fat diet (HFD). Three groups of hamsters (n = 6/group) were studied for 20 weeks: 1) control diet: Control, 2) HFD group: HF and 3) HFD group supplemented with ω3PUFA (EPA and DHA): HFω3. In vivo macrophage-to-feces RCT was assessed after an intraperitoneal injection of 3H-cholesterol-labelled hamster primary macrophages. Compared to Control, HF presented significant (p<0.05) increase in body weight, plasma TG (p<0.01) and cholesterol (p<0.001) with an increase in VLDL TG and in VLDL and LDL cholesterol (p<0.001). Compared to HF, HFω3 presented significant decrease in body weight. HFω3 showed less plasma TG (p<0.001) and cholesterol (p<0.001) related to a decrease in VLDL TG and HDL cholesterol respectively and higher LCAT activity (p<0.05) compared to HF. HFω3 showed a higher fecal bile acid excretion (p<0.05) compared to Control and HF groups and higher fecal cholesterol excretion (p<0.05) compared to HF. This increase was related to higher gene expression of ABCG5, ABCA1 and SR-B1 in HFω3 compared to Control and HF groups (<0.05) and in ABCG1 and CYP7A1 compared to HF group (p<0.05). A higher plasma efflux capacity was also measured in HFω3 using 3H- cholesterol labeled Fu5AH cells. In conclusion, EPA and DHA supplementation improved macrophage to feces reverse cholesterol transport in hamster fed HFD. This change was related to the higher cholesterol and fecal bile acids excretion and to the activation of major genes involved in RCT. PMID:23613796

  14. Discrimination of fast click-series produced by tagged Risso's dolphins (Grampus griseus) for echolocation or communication.

    PubMed

    Arranz, P; DeRuiter, S L; Stimpert, A K; Neves, S; Friedlaender, A S; Goldbogen, J A; Visser, F; Calambokidis, J; Southall, B L; Tyack, P L

    2016-09-15

    Early studies that categorized odontocete pulsed sounds had few means of discriminating signals used for biosonar-based foraging from those used for communication. This capability to identify the function of sounds is important for understanding and interpreting behavior; it is also essential for monitoring and mitigating potential disturbance from human activities. Archival tags were placed on free-ranging Grampus griseus to quantify and discriminate between pulsed sounds used for echolocation-based foraging and those used for communication. Two types of rapid click-series pulsed sounds, buzzes and burst pulses, were identified as produced by the tagged dolphins and classified using a Gaussian mixture model based on their duration, association with jerk (i.e. rapid change of acceleration) and temporal association with click trains. Buzzes followed regular echolocation clicks and coincided with a strong jerk signal from accelerometers on the tag. They consisted of series averaging 359±210 clicks (mean±s.d.) with an increasing repetition rate and relatively low amplitude. Burst pulses consisted of relatively short click series averaging 45±54 clicks with decreasing repetition rate and longer inter-click interval that were less likely to be associated with regular echolocation and the jerk signal. These results suggest that the longer, relatively lower amplitude, jerk-associated buzzes are used in this species to capture prey, mostly during the bottom phase of foraging dives, as seen in other odontocetes. In contrast, the shorter, isolated burst pulses that are generally emitted by the dolphins while at or near the surface are used outside of a direct, known foraging context. © 2016. Published by The Company of Biologists Ltd.

  15. Sleep deprivation attenuates endotoxin-induced cytokine gene expression independent of day length and circulating cortisol in male Siberian hamsters (Phodopus sungorus).

    PubMed

    Ashley, Noah T; Walton, James C; Haim, Achikam; Zhang, Ning; Prince, Laura A; Fruchey, Allison M; Lieberman, Rebecca A; Weil, Zachary M; Magalang, Ulysses J; Nelson, Randy J

    2013-07-15

    Sleep is restorative, whereas reduced sleep leads to negative health outcomes, such as increased susceptibility to disease. Sleep deprivation tends to attenuate inflammatory responses triggered by infection or exposure to endotoxin, such as bacterial lipopolysaccharide (LPS). Previous studies have demonstrated that Siberian hamsters (Phodopus sungorus), photoperiodic rodents, attenuate LPS-induced fever, sickness behavior and upstream pro-inflammatory gene expression when adapted to short day lengths. Here, we tested whether manipulation of photoperiod alters the suppressive effects of sleep deprivation upon cytokine gene expression after LPS challenge. Male Siberian hamsters were adapted to long (16 h:8 h light:dark) or short (8 h:16 h light:dark) photoperiods for >10 weeks, and were deprived of sleep for 24 h using the multiple platform method or remained in their home cage. Hamsters received an intraperitoneal injection of LPS or saline (control) 18 h after starting the protocol, and were killed 6 h later. LPS increased liver and hypothalamic interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF) gene expression compared with vehicle. Among LPS-challenged hamsters, sleep deprivation reduced IL-1 mRNA levels in liver and hypothalamus, but not TNF. IL-1 attenuation was independent of circulating baseline cortisol, which did not increase after sleep deprivation. Conversely, photoperiod altered baseline cortisol, but not pro-inflammatory gene expression in sleep-deprived hamsters. These results suggest that neither photoperiod nor glucocorticoids influence the suppressive effect of sleep deprivation upon LPS-induced inflammation.

  16. Effects of binary taste stimuli on the neural activity of the hamster chorda tympani

    PubMed Central

    1980-01-01

    Binary mixtures of taste stimuli were applied to the tongue of the hamster and the reaction of the whole corda tympani was recorded. Some of the chemicals that were paired in mixtures (HCl, NH4Cl, NaCl, CaCl2, sucrose, and D-phenylalanine) have similar tastes to human and/or hamster, and/or common stimulatory effects on individual fibers of the hamster chorda tympani; other pairs of these chemicals have dissimilar tastes and/or distinct neural stimulatory effects. The molarity of each chemical with approximately the same effect on the activity of the nerve as 0.01 M NaCl was selected, and an established relation between stimulus concentration and response allowed estimation of the effect of a "mixture" of two concentrations of one chemical. Each mixture elicited a response that was smaller than the sum of the responses to its components. However, responses to some mixtures approached this sum, and responses to other mixtures closely approached the response to a "mixture" of two concentrations of one chemical. Responses of the former variety were generated by mixtures of an electrolyte and a nonelectrolyte and the latter by mixtures of two electrolytes or two nonelectrolytes. But, beyond the distinction between electrolytes and nonelectrolytes, the whole-nerve response to a mixture could not be predicted from the known neural or psychophysical effects of its components. PMID:7411114

  17. Parent-of-origin growth effects and the evolution of hybrid inviability in dwarf hamsters.

    PubMed

    Brekke, Thomas D; Good, Jeffrey M

    2014-11-01

    Mammalian hybrids often show abnormal growth, indicating that developmental inviability may play an important role in mammalian speciation. Yet, it is unclear if this recurrent phenotype reflects a common genetic basis. Here, we describe extreme parent-of-origin-dependent growth in hybrids from crosses between two species of dwarf hamsters, Phodopus campbelli and Phodopus sungorus. One cross type resulted in massive placental and embryonic overgrowth, severe developmental defects, and maternal death. Embryos from the reciprocal cross were viable and normal sized, but adult hybrid males were relatively small. These effects are strikingly similar to patterns from several other mammalian hybrids. Using comparative sequence data from dwarf hamsters and several other hybridizing mammals, we argue that extreme hybrid growth can contribute to reproductive isolation during the early stages of species divergence. Next, we tested if abnormal growth in hybrid hamsters was associated with disrupted genomic imprinting. We found no association between imprinting status at several candidate genes and hybrid growth, though two interacting genes involved in embryonic growth did show reduced expression in overgrown hybrids. Collectively, our study indicates that growth-related hybrid inviability may play an important role in mammalian speciation but that the genetic underpinnings of these phenotypes remain unresolved. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  18. Comparison of functional biochemical, and morphometric alterations in the lungs of four rat strains and hamsters following repeated intratracheal instillation of crocidolite asbestos

    EPA Science Inventory

    Four rat strains and hamsters were exposed to 0.7mg crocidolite asbestos/g lung once/wk for 3weeks by intratracheal instillation (IT). Pulmonary function, biochemistry, and morphometry were evaluated at 3 and 6-months after IT. Each rat strain, but not the hamster, exhibited ele...

  19. Experimental mixed infection of Leishmania (Leishmania) amazonensis and Leishmania (L.) infantum in hamsters (Mesocricetus auratus).

    PubMed

    DE Lima Celeste, Jordanna Luíza; Venuto Moura, Ana Paula; França-Silva, João Carlos; Matos DE Sousa, Gabriela; Oliveira Silva, Soraia; Norma Melo, Maria; Luiz Tafuri, Wagner; Carvalho Souza, Carolina; Monteiro DE Andrade, Hélida

    2017-08-01

    In South America, visceral leishmaniasis is frequently caused by Leishmania infantum and, at an unknown frequency, by Leishmania amazonensis. Therefore, mixed infections with these organisms are possible. Mixed infections might affect the clinical course, immune response, diagnosis, treatment and epidemiology of the disease. Here we describe the clinical course of mixed infections with L. amazonensis and L. infantum in a hamster model. We show that mixed infections are associated with more severe clinical disease than infection with L. amazonensis or L. infantum alone. In spleens with mixed infections, L. infantum outcompeted L. amazonensis in the tissue, but not in culture from tissue. We found increased levels of IgG in animals infected with L. infantum. Although more than 30 bands were revealed in a Western blot, the highest immunogenicity was observed with proteins having molecular masses of 95 and 90 kDa, whereas proteins with molecular masses of lower than 50 kDa were reactive frequently with serum from hamsters infected with L. amazonensis, and proteins with molecular masses of 80 and 70 kDa were reactive only with serum from hamsters infected with L. infantum. This finding has important implications regarding the biology of Leishmania and humoral immune responses to infections with these organisms.

  20. The hamster clock phase-response curve from summerlike light:dark cycles and its role in daily and seasonal timekeeping.

    PubMed

    Alleva, John J; Alleva, Frederic R

    2002-11-01

    We address the subject of entrainment of the hamster clock by the day:night cycle in summer when the sun sets after 6 PM and rises before 6 AM (nights < 12 h). Summer day:night cycles were simulated by 6 light:dark (LD) cycles with D < 12 h (summerlike, SLD) ranging from SLD 12.5 h:11.5 h (D, 6:15 PM-5:45 AM) to 18 h:6 h (D, 9 PM-3 AM). These are the near limiting SLDs for constant PM timing (entrainment) of behavioral estrus and wheel running in hamsters. The onset of estrus was observed every 4 d in the same hamsters as a phase marker of their 24 h clock. On the day before an experimental estrus, preceded and followed by control onsets, a dark period was imposed to cover a putative 6 PM-6 AM light-sensitive period (LSP). This was scanned with a light pulse (and periodic 5 sec bell alarms) lasting 5-240 min. Shifts in onset of estrus on the next day were plotted vs. the end of the light pulse for PM times ("dusk") and its onset for AM times ("dawn"). The resulting phase shifts from the six SLDs were similar, permitting their combination into a single phase-response curve (PRC) of 1605 shifts. This SLD composite PRC rose at 10:15 PM, peaked at 2 AM (81 min advanced shift), fell linearly to 5:55 AM, and then abruptly to normal at 6 AM (no shift). Peak shift was unaffected by light pulse duration or intensity, or hamster age. The SLD composite PRC lacked the 6 PM-9 PM curve of delayed shifts present in reported PRCs from LD 12 h:12 h and DD. However, a two-pulse experiment showed that all light from 6 PM to L-off was needed to block (balance) the advancing action of a 5 min morning light pulse, thereby maintaining entrainment. A working hypothesis to explain daily entrainment and seasonal fertility in the golden hamster is illustrated. A nomenclature for labeling the phases of the hamster clock (circadian time) is proposed.

  1. Kinetics of Leptospira interrogans Infection in Hamsters after Intradermal and Subcutaneous Challenge

    PubMed Central

    Coutinho, Mariana L.; Matsunaga, James; Wang, Long-Chieh; de la Peña Moctezuma, Alejandro; Lewis, Michael S.; Babbitt, Jane T.; Aleixo, Jose Antonio G.; Haake, David A.

    2014-01-01

    Background Leptospirosis is a zoonosis caused by highly motile, helically shaped bacteria that penetrate the skin and mucous membranes through lesions or abrasions, and rapidly disseminate throughout the body. Although the intraperitoneal route of infection is widely used to experimentally inoculate hamsters, this challenge route does not represent a natural route of infection. Methodology/Principal Findings Here we describe the kinetics of disease and infection in hamster model of leptospirosis after subcutaneous and intradermal inoculation of Leptospira interrogans serovar Copenhageni, strain Fiocruz L1-130. Histopathologic changes in and around the kidney, including glomerular and tubular damage and interstitial inflammatory changes, began on day 5, and preceded deterioration in renal function as measured by serum creatinine. Weight loss, hemoconcentration, increased absolute neutrophil counts (ANC) in the blood and hepatic dysfunction were first noted on day 6. Vascular endothelial growth factor, a serum marker of sepsis severity, became elevated during the later stages of infection. The burden of infection, as measured by quantitative PCR, was highest in the kidney and peaked on day 5 after intradermal challenge and on day 6 after subcutaneous challenge. Compared to subcutaneous challenge, intradermal challenge resulted in a lower burden of infection in both the kidney and liver on day 6, lower ANC and less weight loss on day 7. Conclusions/Significance The intradermal and subcutaneous challenge routes result in significant differences in the kinetics of dissemination and disease after challenge with L. interrogans serovar Copenhageni strain Fiocruz L1-130 at an experimental dose of 2×106 leptospires. These results provide new information regarding infection kinetics in the hamster model of leptospirosis. PMID:25411782

  2. Winning agonistic encounters increases testosterone and androgen receptor expression in Syrian Hamsters

    PubMed Central

    Clinard, Catherine T.; Barnes, Abigail K.; Adler, Samuel G.; Cooper, Matthew A.

    2016-01-01

    Winning aggressive disputes is one of several experiences that can alter responses to future stressful events. We have previously tested dominant and subordinate male Syrian hamsters in a conditioned defeat model and found that dominant individuals show less change in behavior following social defeat stress compared to subordinates and controls, indicating a reduced conditioned defeat response. Resistance to the effects of social defeat in dominants is experience-dependent and requires the maintenance of dominance relationships for 14 days. For this study we investigated whether winning aggressive interactions increases plasma testosterone and whether repeatedly winning increases androgen receptor expression. First, male hamsters were paired in daily 10-min aggressive encounters and blood samples were collected immediately before and 15-min and 30-min after the formation of dominance relationships. Dominants showed an increase in plasma testosterone at 15-min post-interaction compared to their pre-interaction baseline, whereas subordinates and controls showed no change in plasma testosterone. Secondly, we investigated whether 14 days of dominant social status increased androgen or estrogen alpha-receptor immunoreactivity in brain regions that regulate the conditioned defeat response. Dominants showed more androgen, but not estrogen alpha, receptor immuno-positive cells in the dorsal medial amygdala (dMeA) and ventral lateral septum (vLS) compared to subordinates and controls. Finally, we showed that one day of dominant social status was insufficient to increase androgen receptor immunoreactivity compared to subordinates. These results suggest that elevated testosterone signaling at androgen receptors in the dMeA and vLS might contribute to the reduced conditioned defeat response exhibited by dominant hamsters. PMID:27619945

  3. Effect of probiotic-fermented, genetically modified soy milk on hypercholesterolemia in hamsters.

    PubMed

    Tsai, Tsung-Yu; Chen, Li-Ying; Pan, Tzu-Ming

    2014-02-01

    The rapid progress of biotechnology and molecular biology has led to genetically modified (GM) crops becoming a part of agricultural production. There are concerns that the issues of the functional ingredients in GM products have not been addressed, such as the bioactivities of soy proteins and isoflavones. This study aimed to investigate the effects of probiotic-fermented GM soy milk on hypercholesterolemia, and atherosclerotic risks in hamsters. One hundred and twelve male Golden Syrian hamsters (Mesocricetus auratus) were randomly assigned into 14 groups of 8 animals each. Normal- and high-cholesterol experimental diets were supplemented with GM or non-GM soy milk with or without probiotic-fermentation for 8 weeks. Serum and fecal lipid levels were measured. Moreover, aortic plaque in artery were stained, and thiobarbituric acid reactive substance content, super oxide dismutase activity and caralase activity were determined. GM or non-GM soy milk with or without probiotic-fermentation significantly decreased (p < 0.05) serum TC levels, compared with a high-cholesterol diet group. TC levels in hamsters fed GM soy milk were not significantly different from TC levels in the non-GM soy milk group (p > 0.05). GM soy milk groups can reduce risk of developing atherosclerosis through lowered oxidative stress and reduced atherosclerotic plaque formation in the aorta, and are thus at least equivalent to non-GM soy milk. GM soy milk with or without probiotic-fermentation can improve hypercholesterolemia and reduce the risk of atherosclerosis, and is considered substantially equivalent to non-GM soy milk in terms of these bioactive functions. Copyright © 2012. Published by Elsevier B.V.

  4. Assessment of ovarian activity in captive goral (Naemorhedus griseus) using noninvasive fecal steroid monitoring.

    PubMed

    Khonmee, Jaruwan; Brown, Janine L; Taya, Kazuyoshi; Rojanasthien, Suvichai; Punyapornwithaya, Veerasak; Thumasanukul, Dissakul; Kongphoemphun, Adisorn; Siriaroonrat, Boripat; Tipkantha, Wanlaya; Pongpiachan, Petai; Thitaram, Chatchote

    2014-10-15

    To date, there is no information on gonadal steroidogenic activity of female goral (Naemorhedus griseus), a threatened species of Thailand. Captive goral populations have been established to produce animals for ex situ conservation and reintroduction, but as yet none are self-sustaining. The objectives of the present study were to (1) determine the influence of season on ovarian steriodogenic function; and (2) examine the relationship between gonadal hormone excretion and sexual behaviors throughout the year. Fecal samples were collected 5 to 7 days/wk for 15 months from 8 adult females housed at Omkoi Wildlife Breeding Center in Thailand and analyzed for ovarian steroid metabolites using validated enzyme immunoassays. Observations of sexual behaviors and mating were conducted each morning for 30 min/session. Based on fecal estrogen and progestagen metabolite concentrations, the overall estrous cycle length was about 21 days, with a 2- to 3-day follicular phase and an 18- to 20-day luteal phase. Sexual behaviors, most notably tail-up, increased for 2 to 3 days during the time estrogens were elevated during mating. Fecal progestagens were elevated during luteal phases and increased further during gestation, which lasted approximately 7 months. The lactation period was 5 months, and females were anestrus for 2 to 5 of those months, with the exception of one that cycled continuously throughout. Two females conceived around 2 months postpartum and so were pregnant during lactation. Birth records over the past 21 years indicated young are born throughout the year. This combined with the hormonal data suggests that female gorals are not strongly seasonal, at least in captivity, although there was considerable variation among females in estrogen and progestagen patterns. In conclusion, fecal steroid metabolite monitoring is an effective means of assessing ovarian function in this species and will be a useful tool for breeding management and planned development of

  5. Main extracts and hypolipidemic effects of the Bauhinia racemosa Lam. leaf extract in HFD-fed hamsters.

    PubMed

    Sashidhara, Koneni V; Singh, Suriya P; Srivastava, Anuj; Puri, Anju

    2013-01-01

    The lipid lowering effects of ethanolic extract (BR) obtained from leaves of Bauhinia racemosa on hyperlipidemic hamsters were examined. BR showed significant lowering of lipid profile at a dose of 250 mg kg(-1) body-wt of hamster. Chloroform fraction (F2) obtained from BR showed pronounced activity at lower dose of 100 mg kg(-1). F2 gave two most active fractions (L and T) whose chromatographic separations led to the isolation of constituents 1-5, which are being reported for the first time from this natural source. The results of activity profile of the plant were found to be better than the standard drug lovastatin.

  6. p-Aminophenol-induced hepatotoxicity in hamsters: role of glutathione.

    PubMed

    Fu, Xin; Chen, Theresa S; Ray, Mukunda B; Nagasawa, Herbert T; Williams, Walter M

    2004-01-01

    p-Aminophenol (PAP) is a widely used industrial chemical and a known nephrotoxin. Recently, it was found to also cause hepatotoxicity and glutathione (GSH) depletion in mice. The exact mechanism of liver toxicity is not known. The aims of this study were to determine whether PAP can cause acute hepatotoxicity in hamsters and to further investigate the role of GSH in PAP-induced toxicity. PAP was administered ip to hamsters in doses of 200-800 mg/kg. Liver damage at 24 h after PAP administration was assessed by elevations in plasma enzyme activities and histopathologic examination. GSH and cysteine (Cys) levels in liver at 4 h were determined by HPLC. PAP decreased hepatic GSH concentration to 8% and Cys to 30% of vehicle control values. It increased plasma glutamic pyruvic transaminase (GPT) activity by 47-fold and sorbitol dehydrogenase (SDH) activity by 113-fold. PAP also caused severe centrilobular hepatocellular necrosis. 2(RS)-n-Propylthiazolidine-4(R)-carboxylic acid (PTCA), a Cys precursor, attenuated the PAP-induced decreases in hepatic sulfhydryl levels; GSH and Cys were 39% and 78% of vehicle controls, respectively. PTCA also attenuated the PAP-induced elevations in plasma enzyme activities and hepatic necrosis. It was concluded that PAP hepatotoxicity is associated with depletion of hepatic GSH and can be prevented by PTCA. Copyright 2004 Wiley Periodicals, Inc.

  7. Evaluation of formalin-inactivated Clostridium difficile vaccines administered by parenteral and mucosal routes of immunization in hamsters.

    PubMed Central

    Torres, J F; Lyerly, D M; Hill, J E; Monath, T P

    1995-01-01

    Clostridium difficile produces toxins that cause inflammation, necrosis, and fluid in the intestine and is the most important cause of nosocomial antibiotic-associated diarrhea and colitis. We evaluated C. difficile antigens as vaccines to protect against systemic and intestinal disease in a hamster model of clindamycin colitis. Formalin-inactivated culture filtrates from a highly toxigenic strain were administered by mucosal routes (intranasal, intragastric, and rectal) with cholera toxin as a mucosal adjuvant. A preparation of culture filtrate and killed whole cells was also tested rectally. The toxoid was also tested parenterally (subcutaneously and intraperitoneally) and by a combination of three intranasal immunizations followed by a combined intranasal-intraperitoneal boost. Serum antibodies against toxins A and B and whole-cell antigen were measured by enzyme-linked immunosorbent assay, neutralization of cytotoxic activity, and bacterial agglutination. The two rectal immunization regimens induced low antibody responses and protected only 20% of hamsters against death and 0% against diarrhea. The intragastric regimen induced high antibody responses but low protection, 40% against death and 0% against diarrhea. Hamsters immunized by the intranasal, intraperitoneal, and subcutaneous routes were 100% protected against death and partially protected (40, 40, and 20%, respectively) against diarrhea. Among the latter groups, intraperitoneally immunized animals had the highest serum anticytotoxic activity and the highest agglutinating antibody responses. Hamsters immunized intranasally and revaccinated intraperitoneally were 100% protected against both death and diarrhea. Protection against death and diarrhea correlated with antibody responses to all antigens tested. The results indicate that optimal protection against C. difficile disease can be achieved with combined parenteral and mucosal immunization. PMID:7591115

  8. Decreasing temperature shifts hippocampal function from memory formation to modulation of hibernation bout duration in Syrian hamsters.

    PubMed

    Arant, Ryan J; Goo, Marisa S; Gill, Phoebe D; Nguyen, Yen; Watson, Katherine D; Hamilton, Jock S; Horowitz, John M; Horwitz, Barbara A

    2011-08-01

    Previous studies in hibernating species have characterized two forms of neural plasticity in the hippocampus, long-term potentiation (LTP) and its reversal, depotentiation, but not de novo long-term depression (LTD), which is also associated with memory formation. Studies have also shown that histamine injected into the hippocampus prolonged hibernation bout duration. However, spillover into the ventricles may have affected brain stem regions, not the hippocampus. Here, we tested the hypothesis that decreased brain temperature shifts the major function of the hippocampus in the Syrian hamster (Mesocricetus auratus) from one of memory formation (via LTP, depotentiation, and de novo LTD) to increasing hibernation bout duration. We found reduced evoked responses in hippocampal CA1 pyramidal neurons following low-frequency stimulation in young (<30 days old) and adult (>60 days old) hamsters, indicating that de novo LTD was generated in hippocampal slices from both pups and adults at temperatures >20°C. However, at temperatures below 20°C, synchronization of neural assemblies (a requirement for LTD generation) was markedly degraded, implying that de novo LTD cannot be generated in hibernating hamsters. Nonetheless, even at temperatures below 16°C, pyramidal neurons could still generate action potentials that may traverse a neural pathway, suppressing the ascending arousal system (ARS). In addition, histamine increased the excitability of these pyramidal cells. Taken together, these findings are consistent with the hypothesis that hippocampal circuits remain operational at low brain temperatures in Syrian hamsters and suppress the ARS to prolong bout duration, even though memory formation is muted at these low temperatures.

  9. Anovulatory hamster: a comparison of the effects of short photoperiod and daily melatonin injections on the induction and termination of ovarian acyclicity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Stetson, M.H.; Hamilton, B.

    1981-02-01

    Cyclic female hamsters were rendered anovulatory by daily subcutaneous melatonin injections (25 microgram/0.1 ml oil) in 29 days or by transfer to a short light cycle, LD 6:18 (lights 1000-1600 hrs) in 33 days. Estrous cyclicity was reinitiated in these animals in 44 or 45 days following cessation of melatonin injections or transfer to long light cycles (LD 14:10, lights 0600-2000 hrs), respectively. Exposure of both groups to LD 6:18 after reinitiation of estrous cyclicity caused a second cessation of ovulation in 75 (melatonin group) or 61 (short light cycle group) days. Thus, although both treatments disrupted estrous cyclicity formore » nearly 6 weeks, this was not sufficient to induce photorefractoriness (failure to respond to short light cycles with continued estrous cyclicity). Rather, every animal responded to LD 6:18 and ceased ovulating. Melatonin-induced anovulatory hamsters showed daily gonadotropin release patterns identical to those reported in hamsters in other anovulatory states (lactating, prepubertal, and photoinduced anovulatory hamsters); that is, peak LH and FSH release at 1700 hrs daily.« less

  10. Lack of protection against ebola virus from chloroquine in mice and hamsters.

    PubMed

    Falzarano, Darryl; Safronetz, David; Prescott, Joseph; Marzi, Andrea; Feldmann, Friederike; Feldmann, Heinz

    2015-06-01

    The antimalarial drug chloroquine has been suggested as a treatment for Ebola virus infection. Chloroquine inhibited virus replication in vitro, but only at cytotoxic concentrations. In mouse and hamster models, treatment did not improve survival. Chloroquine is not a promising treatment for Ebola. Efforts should be directed toward other drug classes.

  11. Topical photosan-mediated photodynamic therapy for DMBA-induced hamster buccal pouch early cancer lesions: an in vivo study

    NASA Astrophysics Data System (ADS)

    Hsu, Yih-Chih; Chang, Walter Hong-Shong; Chang, Junn-Liang; Liu, Kuang-Ting; Chiang, Chun-Pin; Liu, Chung-Ji; Chen, Chih-Ping

    2011-03-01

    Oral cancer has becomes the most prominent cancer disease in recent years in Taiwan. The reason is the betel nut chewing habit combing with smoking and alcohol-drinking lifestyle of people results in oral cancer becomes the fastest growth incident cancer amongst other major cancer diseases. In previous studies showed that photosan, haematoporphyrin derivative (HPD), has demonstrated effective PDT results on human head and neck disease studies. To avoid the systemic phototoxic effect of photosan, this study was designed to use a topical photosan-mediated PDT for treatment of DMBA-induced hamster buccal pouch cancerous lesions. DMBA was applied to one of the buccal pouches of hamsters thrice a week for 10 to 12 weeks. Cancerous lesions were induced and proven by histological examination. These DMBA-induced cancerous lesions were used for testing the efficacy of topical photosan-mediated PDT. Before PDT, fluorescence spectroscopy was used to determine when photosan reached its peak level in the lesional epithelial cells after topical application of photosan gel. We found that photosan reached its peak level in cancerous lesions about 13.5 min after topical application of photosan gel. The cancerous lesions in hamsters were then treated with topical photosan-mediated PDT (fluence rate: 600 mW/cm2; light exposure dose 200 J/cm2) using the portable Lumacare 635 nm fiber-guided light device. Visual examination demonstrated that topical photosan-mediated PDT was an applicable treatment modality for DMBA-induced hamster buccal pouch cancerous lesions.

  12. Hypolipidemic Effect of Tomato Juice in Hamsters in High Cholesterol Diet-Induced Hyperlipidemia

    PubMed Central

    Lee, Li-Chen; Wei, Li; Huang, Wen-Ching; Hsu, Yi-Ju; Chen, Yi-Ming; Huang, Chi-Chang

    2015-01-01

    Tomato is a globally famous food and contains several phytonutrients including lycopene, β-carotene, anthocyanin, and flavonoids. The increased temperature used to produce tomato juice, ketchup, tomato paste and canned tomato enhances the bioactive composition. We aimed to verify the beneficial effects of processed tomato juice from Kagome Ltd. (KOT) on hypolipidemic action in hamsters with hyperlipidemia induced by a 0.2% cholesterol and 10% lard diet (i.e., high-cholesterol diet (HCD)). Male Golden Syrian hamsters were randomly divided into two groups for treatment: normal (n = 8), standard diet (control); and experimental (n = 32), HCD. The 32 hamsters were further divided into four groups (n = 8 per group) to receive vehicle or KOT by oral gavage at 2787, 5573, or 13,934 mg/kg/day for six weeks, designated the HCD-1X, -2X and -5X groups, respectively. The efficacy and safety of KOT supplementation was evaluated by lipid profiles of serum, liver and feces and by clinical biochemistry and histopathology. HCD significantly increased serum levels of total cholesterol (TC), triacylglycerol (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), LDL-C/HDL-C ratio, hepatic and fetal TC and TG levels, and degree of fatty liver as compared with controls. KOT supplementation dose-dependently decreased serum TC, TG, LDL-C levels, LDL-C/HDL-C ratio, hepatic TC and TG levels, and fecal TG level. Our study provides experiment-based evidence to support that KOT may be useful in treating or preventing the onset of hyperlipidemia. PMID:26694461

  13. Hypolipidemic Effect of Tomato Juice in Hamsters in High Cholesterol Diet-Induced Hyperlipidemia.

    PubMed

    Lee, Li-Chen; Wei, Li; Huang, Wen-Ching; Hsu, Yi-Ju; Chen, Yi-Ming; Huang, Chi-Chang

    2015-12-17

    Tomato is a globally famous food and contains several phytonutrients including lycopene, β-carotene, anthocyanin, and flavonoids. The increased temperature used to produce tomato juice, ketchup, tomato paste and canned tomato enhances the bioactive composition. We aimed to verify the beneficial effects of processed tomato juice from Kagome Ltd. (KOT) on hypolipidemic action in hamsters with hyperlipidemia induced by a 0.2% cholesterol and 10% lard diet (i.e., high-cholesterol diet (HCD)). Male Golden Syrian hamsters were randomly divided into two groups for treatment: normal (n = 8), standard diet (control); and experimental (n = 32), HCD. The 32 hamsters were further divided into four groups (n = 8 per group) to receive vehicle or KOT by oral gavage at 2787, 5573, or 13,934 mg/kg/day for six weeks, designated the HCD-1X, -2X and -5X groups, respectively. The efficacy and safety of KOT supplementation was evaluated by lipid profiles of serum, liver and feces and by clinical biochemistry and histopathology. HCD significantly increased serum levels of total cholesterol (TC), triacylglycerol (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), LDL-C/HDL-C ratio, hepatic and fetal TC and TG levels, and degree of fatty liver as compared with controls. KOT supplementation dose-dependently decreased serum TC, TG, LDL-C levels, LDL-C/HDL-C ratio, hepatic TC and TG levels, and fecal TG level. Our study provides experiment-based evidence to support that KOT may be useful in treating or preventing the onset of hyperlipidemia.

  14. Social forces can impact the circadian clocks of cohabiting hamsters.

    PubMed

    Paul, Matthew J; Indic, Premananda; Schwartz, William J

    2014-03-22

    A number of field and laboratory studies have shown that the social environment influences daily rhythms in numerous species. However, underlying mechanisms, including the circadian system's role, are not known. Obstacles to this research have been the inability to track and objectively analyse rhythms of individual animals housed together. Here, we employed temperature dataloggers to track individual body temperature rhythms of pairs of cohabiting male Syrian hamsters (Mesocricetus auratus) in constant darkness and applied a continuous wavelet transform to determine the phase of rhythm onset before, during, and after cohabitation. Cohabitation altered the predicted trajectory of rhythm onsets in 34% of individuals, representing 58% of pairs, compared to 12% of hamsters single-housed as 'virtual pair' controls. Deviation from the predicted trajectory was by a change in circadian period (τ), which tended to be asymmetric-affecting one individual of the pair in nine of 11 affected pairs-with hints that dominance might play a role. These data implicate a change in the speed of the circadian clock as one mechanism whereby social factors can alter daily rhythms. Miniature dataloggers coupled with wavelet analyses should provide powerful tools for future studies investigating the principles and mechanisms mediating social influences on daily timing.

  15. Auto-inhibitory regulation of angiotensin II functionality in hamster aorta during the early phases of dyslipidemia.

    PubMed

    Pereira, Priscila Cristina; Pernomian, Larissa; Côco, Hariane; Gomes, Mayara Santos; Franco, João José; Marchi, Kátia Colombo; Hipólito, Ulisses Vilela; Uyemura, Sergio Akira; Tirapelli, Carlos Renato; de Oliveira, Ana Maria

    2016-06-15

    Emerging data point the crosstalk between dyslipidemia and renin-angiotensin system (RAS). Advanced dyslipidemia is described to induce RAS activation in the vasculature. However, the interplay between early dyslipidemia and the RAS remains unexplored. Knowing that hamsters and humans have a similar lipid profile, we investigated the effects of early and advanced dyslipidemia on angiotensin II-induced contraction. Cumulative concentration-response curves for angiotensin II (1.0pmol/l to 1.0µmol/l) were obtained in the hamster thoracic aorta. We also investigated the modulatory action of NAD(P)H oxidase on angiotensin II-induced contraction using ML171 (Nox-1 inhibitor, 0.5µmol/l) and VAS2870 (Nox-4 inhibitor, 5µmol/l). Early dyslipidemia was detected in hamsters treated with a cholesterol-rich diet for 15 days. Early dyslipidemia decreased the contraction induced by angiotensin II and the concentration of Nox-4-derived hydrogen peroxide. Advanced dyslipidemia, observed in hamsters treated with cholesterol-rich diet for 30 days, restored the contractile response induced by angiotensin II by compensatory mechanism that involves Nox-4-mediated oxidative stress. The hyporresponsiveness to angiotensin II may be an auto-inhibitory regulation of the angiotensinergic function during early dyslipidemia in an attempt to reduce the effects of the upregulation of the vascular RAS during the advanced stages of atherogenesis. The recovery of vascular angiotensin II functionality during the advanced phases of dyslipidemia is the result of the upregulation of redox-pro-inflammatory pathway that might be most likely involved in atherogenesis progression rather than in the recovery of vascular function. Taken together, our findings show the early phase of dyslipidemia may be the most favorable moment for effective atheroprotective therapeutic interventions. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Comparison of the pathogenicity of Nipah virus isolates from Bangladesh and Malaysia in the Syrian hamster.

    PubMed

    DeBuysscher, Blair L; de Wit, Emmie; Munster, Vincent J; Scott, Dana; Feldmann, Heinz; Prescott, Joseph

    2013-01-01

    Nipah virus is a zoonotic pathogen that causes severe disease in humans. The mechanisms of pathogenesis are not well described. The first Nipah virus outbreak occurred in Malaysia, where human disease had a strong neurological component. Subsequent outbreaks have occurred in Bangladesh and India and transmission and disease processes in these outbreaks appear to be different from those of the Malaysian outbreak. Until this point, virtually all Nipah virus studies in vitro and in vivo, including vaccine and pathogenesis studies, have utilized a virus isolate from the original Malaysian outbreak (NiV-M). To investigate potential differences between NiV-M and a Nipah virus isolate from Bangladesh (NiV-B), we compared NiV-M and NiV-B infection in vitro and in vivo. In hamster kidney cells, NiV-M-infection resulted in extensive syncytia formation and cytopathic effects, whereas NiV-B-infection resulted in little to no morphological changes. In vivo, NiV-M-infected Syrian hamsters had accelerated virus replication, pathology and death when compared to NiV-B-infected animals. NiV-M infection also resulted in the activation of host immune response genes at an earlier time point. Pathogenicity was not only a result of direct effects of virus replication, but likely also had an immunopathogenic component. The differences observed between NiV-M and NiV-B pathogeneis in hamsters may relate to differences observed in human cases. Characterization of the hamster model for NiV-B infection allows for further research of the strain of Nipah virus responsible for the more recent outbreaks in humans. This model can be used to study NiV-B pathogenesis, transmission, and countermeasures that could be used to control outbreaks.

  17. 2-(/sup 125/I)iodomelatonin binding sites in hamster brain membranes: pharmacological characteristics and regional distribution

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Duncan, M.J.; Takahashi, J.S.; Dubocovich, M.L.

    1988-05-01

    Studies in a variety of seasonally breeding mammals have shown that melatonin mediates photoperiodic effects on reproduction. Relatively little is known, however, about the site(s) or mechanisms of action of this hormone for inducing reproductive effects. Although binding sites for (3H)melatonin have been reported previously in bovine, rat, and hamster brain, the pharmacological selectivity of these sites was never demonstrated. In the present study, we have characterized binding sites for a new radioligand, 2-(125I)iodomelatonin, in brains from a photoperiodic species, the Syrian hamster. 2-(125I)Iodomelatonin labels a high affinity binding site in hamster brain membranes. Specific binding of 2-(125I)iodomelatonin is rapid,more » stable, saturable, and reversible. Saturation studies demonstrated that 2-(125I)iodomelatonin binds to a single class of sites with an affinity constant (Kd) of 3.3 +/- 0.5 nM and a total binding capacity (Bmax) of 110.2 +/- 13.4 fmol/mg protein (n = 4). The Kd value determined from kinetic analysis (3.1 +/- 0.9 nM; n = 5) was very similar to that obtained from saturation experiments. Competition experiments showed that the relative order of potency of a variety of indoles for inhibition of 2-(125I)iodomelatonin binding site to hamster brain membranes was as follows: 6-chloromelatonin greater than or equal to 2-iodomelatonin greater than N-acetylserotonin greater than or equal to 6-methoxymelatonin greater than or equal to melatonin greater than 6-hydroxymelatonin greater than or equal to 6,7-dichloro-2-methylmelatonin greater than 5-methoxytryptophol greater than 5-methoxytryptamine greater than or equal to 5-methoxy-N,N-dimethyltryptamine greater than N-acetyltryptamine greater than serotonin greater than 5-methoxyindole (inactive).« less

  18. Comparison of the Pathogenicity of Nipah Virus Isolates from Bangladesh and Malaysia in the Syrian Hamster

    PubMed Central

    DeBuysscher, Blair L.; de Wit, Emmie; Munster, Vincent J.; Scott, Dana; Feldmann, Heinz; Prescott, Joseph

    2013-01-01

    Nipah virus is a zoonotic pathogen that causes severe disease in humans. The mechanisms of pathogenesis are not well described. The first Nipah virus outbreak occurred in Malaysia, where human disease had a strong neurological component. Subsequent outbreaks have occurred in Bangladesh and India and transmission and disease processes in these outbreaks appear to be different from those of the Malaysian outbreak. Until this point, virtually all Nipah virus studies in vitro and in vivo, including vaccine and pathogenesis studies, have utilized a virus isolate from the original Malaysian outbreak (NiV-M). To investigate potential differences between NiV-M and a Nipah virus isolate from Bangladesh (NiV-B), we compared NiV-M and NiV-B infection in vitro and in vivo. In hamster kidney cells, NiV-M-infection resulted in extensive syncytia formation and cytopathic effects, whereas NiV-B-infection resulted in little to no morphological changes. In vivo, NiV-M-infected Syrian hamsters had accelerated virus replication, pathology and death when compared to NiV-B-infected animals. NiV-M infection also resulted in the activation of host immune response genes at an earlier time point. Pathogenicity was not only a result of direct effects of virus replication, but likely also had an immunopathogenic component. The differences observed between NiV-M and NiV-B pathogeneis in hamsters may relate to differences observed in human cases. Characterization of the hamster model for NiV-B infection allows for further research of the strain of Nipah virus responsible for the more recent outbreaks in humans. This model can be used to study NiV-B pathogenesis, transmission, and countermeasures that could be used to control outbreaks. PMID:23342177

  19. Norepinephrine turnover in heart and spleen of 7-, 22-, and 34 C-acclimated hamsters

    NASA Technical Reports Server (NTRS)

    Jones, S. B.; Musacchia, X. J.

    1976-01-01

    The relationship of norepinephrine (NE) concentration and endogenous turnover rates in both myocardial and spleen tissues in the golden hamster is examined as a function of chronic exposure to either high or low ambient temperatures. Changes in myocardial and spleen NE turnover values are discussed in terms of functional alterations in sympathetic nerve activity and the importance of such changes in temperature acclimation. It is found that acclimation of hamsters to 7 C for 7-10 weeks results in decreased myocardial NE concentration and an apparent increase in myocardial NE turnover. In contrast, exposure to 34 C for 6-8 weeks results in increased myocardial NE concentration and an apparent decrease in NE turnover in both myocardial and spleen tissues. The implication of altered NE synthesis is that sympathetic nerve activity is reduced with heat acclimation and is enhanced with cold acclimation.

  20. Atypical fibrosarcomas derived from cutaneous ganglion cell-like cells in 2 domestic Djungarian hamsters (Phodopus sungorus).

    PubMed

    Kondo, Hirotaka; Onuma, Mamoru; Shibuya, Hisashi; Sato, Tsuneo; Abbott, Jeffrey R

    2011-07-01

    Androgen-dependent atypical fibromas are benign tumors derived from ganglion-cell-like cells that are particular to Djungarian hamsters (Phodopus sungorus). Masses excised from 2 hamsters were composed of pleomorphic ganglion cell-like cells supported by small to moderate amounts of collagenous matrix. Intracytoplasmic fibrils were present in silver-stained sections, and immunohistochemistry showed that the cells expressed vimentin, androgen receptor, and, in one case, estrogen receptor α. In contrast to previously reported atypical fibromas, these tumors had features of anaplasia and were locally invasive. We diagnosed the tumors as atypical fibrosarcomas and consider them an unusual malignant counterpart of atypical fibroma. Copyright 2011 by the American Association for Laboratory Animal Science

  1. Gender, Season and Management Affect Fecal Glucocorticoid Metabolite Concentrations in Captive Goral (Naemorhedus griseus) in Thailand

    PubMed Central

    Khonmee, Jaruwan; Brown, Janine L.; Rojanasthien, Suvichai; Aunsusin, Anurut; Thumasanukul, Dissakul; Kongphoemphun, Adisorn; Siriaroonrat, Boripat; Tipkantha, Wanlaya; Punyapornwithaya, Veerasak; Thitaram, Chatchote

    2014-01-01

    Chinese goral (Naemorhedus griseus) are a threatened species in Thailand and the focus of captive breeding for possible reintroduction. However, little is known of their biology or what factors in the captive environment affect welfare. Our objective was to determine the impact of gender, season, and management on goral adrenal activity. We hypothesized that differences in fecal glucocorticoid concentrations would be related to animal density. Fecal samples were collected 3 days/week for 1 year from 63 individuals (n = 32 males, 31 females) at two facilities that house the majority of goral in Thailand: Omkoi Wildlife Sanctuary (Omkoi), an off-exhibit breeding center that houses goral in individual pens (16 pens; n = 8 males, 8 females) and in small family groups (8 pens; n = 8 males, 8 females); and the Chiang Mai Night Safari (NS), a zoo that maintains 31 goral (n = 17 males, 14 females) in one large pen. Glucocorticoid metabolite concentrations were higher in male than female goral at Omkoi throughout the year, and there was a seasonal effect on adrenal activity (p<0.05). Goral at Omkoi and NS were used to test the effect of animal density on fecal glucocorticoid excretion of goral housed in similar-sized enclosures. Overall, the highest levels were found at NS (n = 31 adults/pen; 27 m2 per animal) compared to Omkoi (n = 2 adults/pen; 400 m2 per animal) (p<0.05). Overall findings support our hypothesis that animal density and aspects of the captive environment impact adrenal steroid activity in captive goral. In addition, gender and season also had significant effects on glucocorticoid metabolite production. Potential stressors pertaining to the welfare of this species were identified, which will guide future efforts to improve management and create self-sustaining and healthy populations of this threatened species. PMID:24637886

  2. Gender, season and management affect fecal glucocorticoid metabolite concentrations in captive goral (Naemorhedus griseus) in Thailand.

    PubMed

    Khonmee, Jaruwan; Brown, Janine L; Rojanasthien, Suvichai; Aunsusin, Anurut; Thumasanukul, Dissakul; Kongphoemphun, Adisorn; Siriaroonrat, Boripat; Tipkantha, Wanlaya; Punyapornwithaya, Veerasak; Thitaram, Chatchote

    2014-01-01

    Chinese goral (Naemorhedus griseus) are a threatened species in Thailand and the focus of captive breeding for possible reintroduction. However, little is known of their biology or what factors in the captive environment affect welfare. Our objective was to determine the impact of gender, season, and management on goral adrenal activity. We hypothesized that differences in fecal glucocorticoid concentrations would be related to animal density. Fecal samples were collected 3 days/week for 1 year from 63 individuals (n = 32 males, 31 females) at two facilities that house the majority of goral in Thailand: Omkoi Wildlife Sanctuary (Omkoi), an off-exhibit breeding center that houses goral in individual pens (16 pens; n = 8 males, 8 females) and in small family groups (8 pens; n = 8 males, 8 females); and the Chiang Mai Night Safari (NS), a zoo that maintains 31 goral (n = 17 males, 14 females) in one large pen. Glucocorticoid metabolite concentrations were higher in male than female goral at Omkoi throughout the year, and there was a seasonal effect on adrenal activity (p<0.05). Goral at Omkoi and NS were used to test the effect of animal density on fecal glucocorticoid excretion of goral housed in similar-sized enclosures. Overall, the highest levels were found at NS (n = 31 adults/pen; 27 m2 per animal) compared to Omkoi (n = 2 adults/pen; 400 m2 per animal) (p<0.05). Overall findings support our hypothesis that animal density and aspects of the captive environment impact adrenal steroid activity in captive goral. In addition, gender and season also had significant effects on glucocorticoid metabolite production. Potential stressors pertaining to the welfare of this species were identified, which will guide future efforts to improve management and create self-sustaining and healthy populations of this threatened species.

  3. Comparsion of light dose on topical ALA-mediated photodynamic therapy for DMBA-induced hamster buccal pouch premalignant lesions

    NASA Astrophysics Data System (ADS)

    Yang, Deng-Fu; Tseng, Meng-Ke; Liu, Chung-Ji; Hsu, Yih-Chih

    2012-03-01

    Oral cancer has becomes the most prominent male cancer disease due to the local betel nut chewing habit combing with smoking and alcohol-drinking lifestyle. In order to minimize the systemic phototoxic effect of 5-aminolevulinic acid (ALA), this study was designed to use a topical ALA-mediated PDT for treatment of DMBA-induced hamster buccal pouch cancerous lesions. DMBA was applied to one of the buccal pouches of hamsters thrice a week for 8 to 10 weeks. Precancerous lesions were induced and proven by histological examination. These DMBA-induced cancerous lesions were used for testing the efficacy of topical ALA -mediated PDT. We found that ALA reached its peak level in cancerous lesions about 2.5 hrs after topical application of ALA gel. The precancerous lesions in hamsters were then treated with topical ALA -mediated PDT with light exposure dose of 75 and 100 J/cm2 using LED 635 nm Wonderlight device. It is suggesting that optimization of the given light dose is critical to the success of PDT results.

  4. Sunitinib Improves Some Clinical Aspects and Reverts DMBA-Induced Hyperplasic Lesions in Hamster Buccal Pouch

    PubMed Central

    de Souza, Fernanda Lopes; Oliveira, Mariana; Nunes, Marianne Brochado; Serafim, Lucas Horstmann; Azambuja, Alan Arrieira; Braga, Luisa Maria G. de M.; Saur, Lisiani; de Souza, Maria Antonieta Lopes; Xavier, Léder Leal

    2014-01-01

    Oral squamous cell carcinoma (OSCC) is a public health problem. The hamster buccal pouch model is ideal for analyzing the development of OSCC. This research analysed the effects of sunitinib (tyrosine kinase inhibitor) in precancerous lesions induced by 7,12-dimethylbenz(a)anthracene (DMBA) in this model. Thirty-four male hamsters, divided into six groups: control—C (n = 7), acetone—A (n = 12), carbamide peroxide—CP (n = 5 ), acetone and CP—A+CP (n = 8), 1% DMBA in acetone and CP—DA+CP (n = 6), and 1% DMBA in acetone and CP and 4-week treatment with sunitinib—DA+CP+S (n = 7). The aspects evaluated were anatomopathological features (peribuccal area, paws, nose, and fur), histological sections of the hamster buccal pouches (qualitatively analyzed), epithelium thickness, and the rete ridge density (estimated). Sunitinib was unable to attenuate the decrease in weight gain induced by DMBA; no increase in volume was detected in the pouch and/or ulceration, observed in 43% of the animals in the DA+CP group. DA+CP groups presented a significant increase in rete ridge density compared to the control groups (P < 0.01) which was reverted by sunitinib in the DA+CP+S group. Sunitinib seems to have important benefits in early stage carcinogenesis and may be useful in chemoprevention. PMID:24693453

  5. Lesions of the area postrema and underlying solitary nucleus fail to attenuate the inhibition of feeding produced by systemic injections of cholecystokinin in Syrian hamsters.

    PubMed

    Miceli, M O; Post, C A; van der Kooy, D

    1986-01-01

    A large body of evidence indicates that the intestinal hormone cholecystokinin (CCK) may serve as a signal for satiety. The abdominal vagus has been shown to be important for the satiety response to exogenous, and by inference, endogenous, CCK in rats and hamsters. Thus, it appears that stimulation of CCK receptors on afferent fibers of the abdominal vagus activates a gut-brain pathway to signal satiety. The present study was undertaken to further trace this viscerosensory pathway by examining food intake after administration of one of two doses (2.0 and 8.0 micrograms/kg) of CCK-octapeptide to intact hamsters and to hamsters sustaining lesions of the area postrema (AP) and underlying nucleus of the solitary tract (NST), regions containing neurons postsynaptic to vagal afferent fibers. As lesions of the AP/NST result in many alterations in ingestive behaviour and body weight regulation in rats, various aspects of feeding and drinking behaviour (spontaneous food intake, body weight maintenance, and responsiveness to a palatable drinking solution and osmotic stimulation) were also examined in lesioned hamsters. Aside from producing transient hypophagia and weight loss immediately after surgery, AP/NST lesions had no effects on these various parameters of ingestive behaviour. The lack of lesion effects on these particular parameters may be explained on the basis that hamsters are generally unresponsive to many of the stimuli for feeding and drinking which purportedly act on the vagus and/or AP/NST. Hamsters with AP/NST lesions were as responsive to the two tested doses of CCK as intact animals.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Perception of scent over-marks by golden hamsters (Mesocricetus auratus): novel mechanisms for determining which individual's mark is on top.

    PubMed

    Johnston, R E; Bhorade, A

    1998-09-01

    Hamsters preferentially remember or value the top scent of a scent over-mark. What cues do they use to do this? Using habituation-discrimination techniques, we exposed male golden hamsters (Mesocricetus auratus) on 3 to 4 trials to genital over-marks from 2 females and then tested subjects for their familiarity with these 2 scents compared with that of a novel female's secretion. Preferential memory for 1 of the 2 individuals' scents did not occur if the 2 marks did not overlap or did not overlap but differed in age, but it did occur if a region of overlap existed or 1 mark apparently occluded another (but did not overlap it). Thus, hamsters use regions of overlap and the spatial configuration of scents to evaluate over-marks. These phenomena constitute evidence for previously unsuspected perceptual abilities, including olfactory scene analysis, which is analogous to visual and auditory scene analysis.

  7. Parasite burden in hamsters infected with two different strains of leishmania (Leishmania) infantum: "Leishman Donovan units" versus real-time PCR.

    PubMed

    Moreira, Nádia das Dores; Vitoriano-Souza, Juliana; Roatt, Bruno Mendes; Vieira, Paula Melo de Abreu; Ker, Henrique Gama; de Oliveira Cardoso, Jamille Mirelle; Giunchetti, Rodolfo Cordeiro; Carneiro, Cláudia Martins; de Lana, Marta; Reis, Alexandre Barbosa

    2012-01-01

    To develop and test new therapeutics and immune prophylaxis strategies for visceral leishmaniasis (VL), understanding tissue parasitism evolution after experimental infection with Leishmania infantum is important. Experimental infection in a hamster model (Mesocricetus auratus) reproduces several typical aspects of canine and human VL that are closely related to the inoculum's route. We quantified the parasitism in the liver and spleen of hamsters experimentally infected by various routes (intradermal, intraperitoneal, and intracardiac [IC]) and different strains of L. infantum (MHOM/BR/74/PP75 and Wild) and compared two different methodologies to evaluate tissue parasitism (Leishman Donovan units [LDU] and real-time qPCR). In addition, the quantification of specific total-IgG in the serum of uninfected and infected hamsters was determined by ELISA. The animals were followed for 1, 3, 6 and 9 months post-infection for survival analysis. We found that infection with the Wild strain by the IC route resulted in higher mortality. Positive antibody (IgG) responses were detected with higher peaks at 6 and 9 months in the IC group inoculated with PP75 strain. However, in animals infected with the Wild strain the IgG levels were elevated in all infected groups during all the time evaluated. We also observed by LDU analysis that the IC route lead to higher parasitism in the liver and spleen with both strains. Furthermore, qPCR showed higher sensitivity for identifying animals with low parasitic burden. In conclusion, qPCR can be useful for assessing parasitism in the spleen and liver of a hamster model infected with L. infantum independent of the route of infection, and this technique may become an essential tool for assessing parasite density in the hamster model after experimental treatment or immunization with potential vaccine candidates.

  8. Pterocarpanquinone LQB-118 induces apoptosis in Leishmania (Viannia) braziliensis and controls lesions in infected hamsters.

    PubMed

    Costa, Luciana; Pinheiro, Roberta O; Dutra, Patrícia M L; Santos, Rosiane F; Cunha-Júnior, Edézio F; Torres-Santos, Eduardo C; da Silva, Alcides J M; Costa, Paulo R R; Da-Silva, Silvia A G

    2014-01-01

    Previous results demonstrate that the hybrid synthetic pterocarpanquinone LQB-118 presents antileishmanial activity against Leishmania amazonensis in a mouse model. The aim of the present study was to use a hamster model to investigate whether LQB-118 presents antileishmanial activity against Leishmania (Viannia) braziliensis, which is the major Leishmania species related to American tegumentary leishmaniasis. The in vitro antileishmanial activity of LQB-118 on L. braziliensis was tested on the promastigote and intracellular amastigote forms. The cell death induced by LQB-118 in the L. braziliensis promastigotes was analyzed using an annexin V-FITC/PI kit, the oxidative stress was evaluated by 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA) and the ATP content by luminescence. In situ labeling of DNA fragments by terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) was used to investigate apoptosis in the intracellular amastigotes. L. braziliensis-infected hamsters were treated from the seventh day of infection with LQB-118 administered intralesionally (26 µg/kg/day, three times a week) or orally (4,3 mg/kg/day, five times a week) for eight weeks. LQB-118 was active against the L. braziliensis promastigotes and intracellular amastigotes, producing IC50 (50% inhibitory concentration) values of 3,4±0,1 and 7,5±0,8 µM, respectively. LQB-118 induced promastigote phosphatidylserine externalization accompanied by increased reactive oxygen species production and ATP depletion. Intracellular amastigote DNA fragmentation was also observed, without affecting the viability of macrophages. The treatment of L. braziliensis-infected hamsters with LQB-118, either orally or intralesionally, was effective in the control of lesion size, parasite load and increase intradermal reaction to parasite antigen. Taken together, these results show that the antileishmanial effect of LQB-118 extends to L. braziliensis in the hamster model, involves the

  9. Pterocarpanquinone LQB-118 Induces Apoptosis in Leishmania (Viannia) braziliensis and Controls Lesions in Infected Hamsters

    PubMed Central

    Costa, Luciana; Pinheiro, Roberta O.; Dutra, Patrícia M. L.; Santos, Rosiane F.; Cunha-Júnior, Edézio F.; Torres-Santos, Eduardo C.; da Silva, Alcides J. M.; Costa, Paulo R. R.; Da-Silva, Silvia A. G.

    2014-01-01

    Previous results demonstrate that the hybrid synthetic pterocarpanquinone LQB-118 presents antileishmanial activity against Leishmania amazonensis in a mouse model. The aim of the present study was to use a hamster model to investigate whether LQB-118 presents antileishmanial activity against Leishmania (Viannia) braziliensis, which is the major Leishmania species related to American tegumentary leishmaniasis. The in vitro antileishmanial activity of LQB-118 on L. braziliensis was tested on the promastigote and intracellular amastigote forms. The cell death induced by LQB-118 in the L. braziliensis promastigotes was analyzed using an annexin V-FITC/PI kit, the oxidative stress was evaluated by 2′,7′-dichlorodihydrofluorescein diacetate (H2DCFDA) and the ATP content by luminescence. In situ labeling of DNA fragments by terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) was used to investigate apoptosis in the intracellular amastigotes. L. braziliensis-infected hamsters were treated from the seventh day of infection with LQB-118 administered intralesionally (26 µg/kg/day, three times a week) or orally (4,3 mg/kg/day, five times a week) for eight weeks. LQB-118 was active against the L. braziliensis promastigotes and intracellular amastigotes, producing IC50 (50% inhibitory concentration) values of 3,4±0,1 and 7,5±0,8 µM, respectively. LQB-118 induced promastigote phosphatidylserine externalization accompanied by increased reactive oxygen species production and ATP depletion. Intracellular amastigote DNA fragmentation was also observed, without affecting the viability of macrophages. The treatment of L. braziliensis-infected hamsters with LQB-118, either orally or intralesionally, was effective in the control of lesion size, parasite load and increase intradermal reaction to parasite antigen. Taken together, these results show that the antileishmanial effect of LQB-118 extends to L. braziliensis in the hamster model, involves the

  10. The medial preoptic area is necessary for sexual odor preference, but not sexual solicitation, in female Syrian hamsters

    PubMed Central

    Martinez, Luis A.; Petrulis, Aras

    2013-01-01

    Precopulatory behaviors that are preferentially directed towards opposite-sex conspecifics are critical for successful reproduction, particularly in species wherein the sexes live in isolation, such as Syrian hamsters (Mesocricetus auratus). In females, these behaviors include sexual odor preference and vaginal scent marking. The neural regulation of precopulatory behaviors is thought to involve a network of forebrain areas that includes the medial amygdala (MA), the bed nucleus of the stria terminalis (BNST), and the medial preoptic area (MPOA). Although MA and BNST are necessary for sexual odor preference and preferential vaginal marking to male odors, respectively, the role of MPOA in odor-guided female precopulatory behaviors is not well understood. To address this issue, female Syrian hamsters with bilateral, excitotoxic lesions of MPOA (MPOA-X) or sham lesions (SHAM) were tested for sexual odor investigation, scent marking, and lordosis. MPOA-X females did not investigate male odors more than female odors in an odor preference test, indicating that MPOA may be necessary for normal sexual odor preference in female hamsters. This loss of preference cannot be attributed to a sensory deficit, since MPOA-X females successfully discriminated male odors from female odors during an odor discrimination test. Surprisingly, no deficits in vaginal scent marking were observed in MPOA-X females, although these females did exhibit decreased overall levels of flank marking compared to SHAM females. Finally, all MPOA-X females exhibited lordosis appropriately. These results suggest that MPOA plays a critical role in the neural regulation of certain aspects of odor-guided precopulatory behaviors in female Syrian hamsters. PMID:23415835

  11. Effect of heavy-ion beam irradiation on the level of serum soluble interleukin-2 receptors in hamster cheek pouch carcinoma model

    PubMed Central

    AN, XIAOLI; LI, MINGXIN; LI, NA; LIU, BIN; ZHANG, HONG; WANG, JIZENG

    2014-01-01

    Soluble interleukin-2 receptor (sIL-2R) is a glycoprotein derived from α chain of interleukin 2 receptors of mononuclear as well as T-cell membranes. The aims of this study were to detect the changes of serum soluble interleukin-2 receptor (sIL-2R) levels following heavy-ion beam irradiation in the hamster model with cheek pouch carcinoma, as well as to examine the impact of immune status of the hamster cheek pouch carcinoma model using heavy-ion beam irradiation. sIL-2R serum levels were detected by radioimmunoassay (RIA) in 40 hamsters bearing cheek pouch carcinoma prior to and following exposure to heavy-ion beam irradiation, and 8 normal animals served as the control. The sIL-2R serum level in hamster cheek pouch carcinoma model was significantly increased as compared to the normal control group (P<0.05). Results showed that an increase in the irradiation dose led to a gradual decrease in the sIL-2R serum level. Additionally, a statistical significance was observed compared to the tumor group (P<0.05). In conclusion, alterations in serum sIL-2R expression have an effect on the hamsters cheek pouch carcinoma model subsequent to heavy-ion beam irradiation. An increase in the irradiation dose indicated a decreased tendency in serum sIL-2R content. Detection of serum level changes may lead to an improved understanding of heavy-ion irradiation in vivo immune status, which is crucial for clinical diagnosis and prognosis. It can also provide a sensitive indicator to help estimate the effects of heavy-ion cancer targets. PMID:24748984

  12. Rift Valley fever virus infection in golden Syrian hamsters.

    PubMed

    Scharton, Dionna; Van Wettere, Arnaud J; Bailey, Kevin W; Vest, Zachary; Westover, Jonna B; Siddharthan, Venkatraman; Gowen, Brian B

    2015-01-01

    Rift Valley fever virus (RVFV) is a formidable pathogen that causes severe disease and abortion in a variety of livestock species and a range of disease in humans that includes hemorrhagic fever, fulminant hepatitis, encephalitis and blindness. The natural transmission cycle involves mosquito vectors, but exposure can also occur through contact with infected fluids and tissues. The lack of approved antiviral therapies and vaccines for human use underlies the importance of small animal models for proof-of-concept efficacy studies. Several mouse and rat models of RVFV infection have been well characterized and provide useful systems for the study of certain aspects of pathogenesis, as well as antiviral drug and vaccine development. However, certain host-directed therapeutics may not act on mouse or rat pathways. Here, we describe the natural history of disease in golden Syrian hamsters challenged subcutaneously with the pathogenic ZH501 strain of RVFV. Peracute disease resulted in rapid lethality within 2 to 3 days of RVFV challenge. High titer viremia and substantial viral loads were observed in most tissues examined; however, histopathology and immunostaining for RVFV antigen were largely restricted to the liver. Acute hepatocellular necrosis associated with a strong presence of viral antigen in the hepatocytes indicates that fulminant hepatitis is the likely cause of mortality. Further studies to assess the susceptibility and disease progression following respiratory route exposure are warranted. The use of the hamsters to model RVFV infection is suitable for early stage antiviral drug and vaccine development studies.

  13. Happy hamsters? Enrichment induces positive judgement bias for mildly (but not truly) ambiguous cues to reward and punishment in Mesocricetus auratus

    PubMed Central

    Bethell, Emily J.; Koyama, Nicola F.

    2015-01-01

    Recent developments in the study of animal cognition and emotion have resulted in the ‘judgement bias’ model of animal welfare. Judgement biases describe the way in which changes in affective state are characterized by changes in information processing. In humans, anxiety and depression are characterized by increased expectation of negative events and negative interpretation of ambiguous information. Positive wellbeing is associated with enhanced expectation of positive outcomes and more positive interpretation of ambiguous information. Mood-congruent judgement biases for ambiguous information have been demonstrated in a range of animal species, with large variation in the way tests are administered and in the robustness of analyses. We highlight and address some issues using a laboratory species not previously tested: the Syrian hamster (Mesocricetus auratus). Hamsters were tested using a spatial judgement go/no-go task in enriched and unenriched housing. We included a number of controls and additional behavioural tests and applied a robust analytical approach using linear mixed effects models. Hamsters approached the ambiguous cues significantly more often when enriched than unenriched. There was no effect of enrichment on responses to the middle cue. We discuss these findings in light of mechanisms underlying processing cues to reward, punishment and true ambiguity, and the implications for the welfare of laboratory hamsters. PMID:26587255

  14. Gene expression profiles of immune mediators and histopathological findings in animal models of leptospirosis: comparison between susceptible hamsters and resistant mice.

    PubMed

    Matsui, Mariko; Rouleau, Vincent; Bruyère-Ostells, Lilian; Goarant, Cyrille

    2011-11-01

    Leptospirosis is a widespread zoonosis characterized by multiple organ failure and variable host susceptibility toward pathogenic Leptospira strains. In this study, we put the role of inflammatory mediators in parallel with bacterial burdens and organ lesions by comparing a susceptible animal model, the hamster, and a resistant one, the Oncins France 1 (OF1) mouse, both infected with virulent Leptospira interrogans serovar Icterohaemorrhagiae strain Verdun. Histological observations evidenced edema, congestion, hemorrhage, and inflammatory infiltration in the organs of hamsters, in contrast to limited changes in mice. Using reverse transcription-quantitative PCR techniques, we showed that the relative Leptospira burden progressively increased in hamster tissues, while a rapid clearance was observed in mouse tissues. The early regulation of the proinflammatory mediators interleukin-1β (IL-1β), IL-6, tumor necrosis factor alpha, and cyclo-oxygenase-2 and the chemokines gamma interferon-inducible protein 10 kDa/CXCL10 and macrophage inflammatory protein-1α/CCL3 in mouse tissues contrasted with their delayed and massive overexpression in hamster tissues. Conversely, the induction of the anti-inflammatory cytokine IL-10 was faster in the resistant than in the susceptible animal model. The role of these cytokines in the pathophysiology of leptospirosis and the implications of their differential regulation in the development of this disease are discussed.

  15. Circadian Disruption Alters the Effects of Lipopolysaccharide Treatment on Circadian and Ultradian Locomotor Activity and Body Temperature Rhythms of Female Siberian Hamsters

    PubMed Central

    Prendergast, Brian J.; Cable, Erin J.; Stevenson, Tyler J.; Onishi, Kenneth G.; Zucker, Irving; Kay, Leslie M.

    2016-01-01

    The effect of circadian rhythm (CR) disruption on immune function depends on the method by which CRs are disrupted. Behavioral and thermoregulatory responses induced by lipopolysaccharide (LPS) treatment were assessed in female Siberian hamsters in which circadian locomotor activity (LMA) rhythms were eliminated by exposure to a disruptive phase-shifting protocol (DPS) that sustains arrhythmicity even when hamsters are housed in a light-dark cycle. This noninvasive treatment avoids genome manipulations and neurological damage associated with other models of CR disruption. Circadian rhythmic (RHYTH) and arrhythmic (ARR) hamsters housed in a 16L:8D photocycle were injected with bacterial LPS near the onset of the light (zeitgeber time 1; ZT1) or dark (ZT16) phase. LPS injections at ZT16 and ZT1 elicited febrile responses in both RHYTH and ARR hamsters, but the effect was attenuated in the arrhythmic females. In ZT16, LPS inhibited LMA in the dark phase immediately after injection but not on subsequent nights in both chronotypes; in contrast, LPS at ZT1 elicited more enduring (~4 day) locomotor hypoactivity in ARR than in RHYTH hamsters. Power and period of dark-phase ultradian rhythms (URs) in LMA and Tb were markedly altered by LPS treatment, as was the power in the circadian waveform. Disrupted circadian rhythms in this model system attenuated responses to LPS in a trait- and ZT-specific manner; changes in UR period and power are novel components of the acute-phase response to infection that may affect energy conservation. PMID:26566981

  16. Altered cytokeratin expression during chemoprevention of experimental hamster buccal pouch carcinogenesis by garlic.

    PubMed

    Balasenthil, S; Rao, K S; Nagini, S

    2002-03-01

    Cytokeratins (also known as keratins (K)) are members of the family of intermediate filaments and form major components of the mammalian epithelial cell cytoskeleton. Cytokeratins have emerged as reliable cellular markers of oral cancer development and chemoprevention because of their abundance, stability and high antigenicity. We investigated the effect of aqueous garlic extract on cytokeratin expression during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis. Hamsters were divided into four groups of six animals. Animals in group 1 were painted with a 0.5% solution of DMBA in liquid paraffin, on the right buccal pouches, three times a week for 14 weeks. Group 2 animals were painted with DMBA as in group 1 and also received 250 mg/kg body weight aqueous garlic extract orally on alternate days to the DMBA application. Group 3 animals received garlic extract only, as in group 2. Group 4 animals received neither DMBA nor garlic extract and served as the control. The hamsters were killed after an experimental period of 14 weeks. Cytokeratin expression was studied using human monoclonal antibodies AE1 and AE3, which react with type I and II keratins. In DMBA-induced squamous cell carcinomas, decreased expression of high molecular weight keratins was observed. Administration of garlic extract to animals painted with DMBA suppressed HBP carcinomas and restored normal cytokeratin expression. The results of the present study suggest that inhibition of HBP carcinogenesis by garlic may be due to its regulatory effects on differentiation, tumour invasiveness, migratory and metastatic potential. We suggest that one of the mechanisms of tumour inhibition by garlic is an influence on cellular differentiation.

  17. Single Unit Recordings of Cells Responsive to Visual, Somatic, Acoustic, and Noxious Stimuli in the Superior Colliculus of the Golden Hamster.

    DTIC Science & Technology

    1978-08-01

    Acoustic, and Noxious Stimuli Thesis in the Superior Colliculus of the Golden 6. PERFORMING OG. REPORT NUMBER Hamster -. _ // 7. AUTHOR( a ) S. CONTRACT...OR GRANT NUMBER(s) James P. Dixon I - "JV 9. PERF 7 MING ORGANIZATION NAME A D10. PROGRAM ELEMENT, PROJECT, TASK AFIT Student at: Virginia...studied in the superior colliculus of the golden hamster. A laminar organiza- tion was observed with cells in the superficial layers responding exclusively

  18. Microcirculatory effects of zinc on fructose-fed hamsters.

    PubMed

    Castiglione, R C; Barros, C M M R; Boa, B C S; Bouskela, E

    2016-04-01

    Fructose is a major dietary component directly related to vascular dysfunction and diseases such as obesity, diabetes, and hypertension. Zinc is considered a non-pharmacological alternative for treating diabetes due to its antioxidant and hyperglycemia-lowering effects in diabetic animals. Therefore, the aim of this study was to evaluate the effects of dietary zinc supplementation on the microcirculatory parameters of fructose-fed hamsters. Male hamsters (Mesocricetus auratus) were fed drinking water substituted by 10% fructose solution for 60 days, whereas control animals were fed drinking water alone. Their microcirculatory function was evaluated using cheek pouch preparation, as well as their blood glucose and serum insulin levels. Their microcirculatory responses to acetylcholine (ACh, an endothelium-dependent vasodilator) and to sodium nitroprusside (SNP, an endothelium-independent vasodilator) as well as the increase in macromolecular permeability induced by 30 min of ischemia/reperfusion (I/R) were noted. Endothelium-dependent vasodilation was significantly increased in control animals with high zinc supplementation compared to the groups without zinc supplementation. Zinc was able to protect against plasma leakage induced by I/R in all control and fructose-fed groups, although the microvascular permeability was higher in animals fed drinking water substituted by 10% fructose solution compared to those fed filtered drinking water alone. Our results indicate that dietary zinc supplementation can improve microvascular dysfunction by increasing endothelial-dependent dilatation and reducing the increase in macromolecular permeability induced by I/R in fructose-fed animals. Copyright © 2015 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

  19. Time course of VMN lesion effects on lordosis and proceptive behavior in female hamsters.

    PubMed

    Floody, Owen R

    2002-06-01

    Previous studies suggest that ultrasound production by female hamsters is better able than other reproductive behaviors to recover from an initial drop caused by damage to the ventromedial hypothalamus (VMN). At the same time, few studies have examined the time course of such lesion effects. To remedy this, female hamsters were observed before and after control operations or VMN lesions. The behaviors considered were ultrasound production, lordosis, approach, and vaginal marking. Ultrasound production, lordosis, and approach were affected by lesions, permitting the description of the time course of each of these effects. Only ultrasound rates showed evidence of recovery, which culminated in rates significantly above those observed preoperatively in the same animals. This suggests that ultrasound production is unusual in its response to VMN damage and that the underlying mechanism could be of interest in studies of the processes that determine recovery from brain damage. (c) 2002 Elsevier Science (USA).

  20. Decreased risk of cholangiocarcinogenesis following repeated cycles of Opisthorchis viverrini infection-praziquantel treatment: Magnetic Resonance Imaging (MRI) and histopathological study in a hamster model.

    PubMed

    Hanpanich, Petcharakorn; Laha, Thewarach; Sripa, Banchob; Mairiang, Eimorn; Sereerak, Piya; Upontain, Songkaid; Tangkawattana, Prasarn; Brindley, Paul J; Tangkawattana, Sirikachorn

    2017-08-01

    It has been suggested that repeated infection of Opisthorchis viverrini followed by repeated treatment with praziquantel (PZQ) increases risk of development of cholangiocarcinoma (CCA). Evidence for the prediction has accumulated based on findings of indirect approaches involving molecular changes and epidemiological trends. By contrast, here we directly monitored the impact of repeated liver fluke infection and treatment with PZQ on cholangiocarcinogenesis in a rodent model of human opisthorchiasis, using magnetic resonance imaging (MRI) and histopathology. Twenty five Syrian golden hamsters were assigned to five treatment groups: 1) infection with O. viverrini (OV group), 2) treatment with the carcinogen N-nitrosodimethylamine (NDMA) at 12.5ppm (DMN), 3) O. viverrini infection in tandem with NDMA (OD), 4) O. viverrini infection, NDMA, and treatment with PZQ (ODP), and 5) uninfected, untreated control. The repeated infections were established by intragastric inoculation of 50 metacercariae of O. viverrini to the OV, OD and ODP hamsters at weeks 0, 5 and 10. PZQ at 300mg/kg body weight was given to each hamster of the ODP group on weeks 4, 9 and 13 (four weeks after each infection). Imaging by MRI was undertaken on weeks 5, 10 and 14 (i.e. one week after each PZQ treatment). MRI revealed that the ODP hamsters did not develop CCA, whereas necropsy at week 40 revealed CCA in hamsters of the OD and DMN groups. Findings for histopathology and for proliferating cell nuclear antigen index conformed to the MRI findings. In overview, and notwithstanding that the immune response of individual hosts may play roles in cholangiocarcinogenesis, three cycles of the infection with O. viverrini followed treatment of the infection with PZQ did not increase the risk of bile duct cancer in this hamster model of liver fluke infection-induced CCA. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  1. Pentoxifylline increases sperm penetration into zona-free hamster oocytes without increasing the acrosome reaction.

    PubMed

    Morales, P; Llanos, M; Yovich, J L; Cummins, J M; Vigil, P

    1993-01-01

    Several drugs have been used to stimulate human sperm motility, including 3-deoxy-adenosine, caffeine, and pentoxifylline. Pentoxifylline is an inhibitor of the phosphodiesterase and may stimulate sperm motility by increasing the intracellular levels of cAMP. In this study we have evaluated the effect of pentoxifylline in the outcome of the sperm penetration assay into zona-free hamster oocytes. Twenty-seven semen samples, obtained for diagnostic purposes, were used. After the motile sperm were selected by the swim-up technique, the samples were divided into two aliquots. One aliquot was incubated with 1 mg ml-1 of pentoxifylline at 37 degrees C, 5% CO2 for 30 min. The control aliquot was incubated with culture medium. The samples were then washed and resuspended in fresh, pentoxifylline-free medium, at a sperm concentration of 10 x 10(6) cells ml-1. One hundred microlitres of each sperm suspension was then deposited under oil and 30-40 zona-free hamster oocytes were added. After 6 h of gamete coincubation, the percentage of penetrated oocytes and the number of decondensed sperm heads were evaluated. The percentage of acrosome-reacted sperm was evaluated using the Pisum sativum lectin. The percentage of zona-free hamster oocytes penetrated was increased after pentoxifylline-treatment. The percentage of acrosome reacted sperm and the number of decondensed sperm heads per egg were not different between the control and the pentoxifylline-treated groups. The results suggest that the beneficial effect of pentoxifylline upon the sperm cells is not mediated by stimulation of the acrosome reaction.

  2. Effects of thalidomide on DMBA-induced oral carcinogenesis in hamster with respect to angiogenesis.

    PubMed

    Yang, Y; Ge, J-P; Zhou, Z-T

    2009-05-01

    Thalidomide has been shown to have anti-angiogenic effects in pre-clinical models as well as a significant antitumor effect in hematologic tumors. However, the effects of thalidomide on oral pre-malignant lesions and oral carcinogenesis remain unexplored. The authors aimed to investigate the chemopreventive effect of thalidomide on 7,12-dimethylbenz[a]anthracene (DMBA)-induced oral carcinogenesis in hamsters with respect to angiogenesis. Seventy male Syrian golden hamsters were randomly divided into five groups, with two of 20 and three of 10. DMBA solution (0.5% in acetone) was applied topically to the left cheek pouch of male Syrian golden hamsters in group A and B, while animals in group C were painted with acetone, three times a week for 6 weeks. For the next 18 weeks, animals in group B and D received thalidomide daily (40 mg/kg body weight/day) by gavage, animals in group A and C received same volume of saline. Animals in group E received no treatment and served as blank control. At the end of the experiment, animals were killed and tissue samples were collected for examinations. Thalidomide significantly decreased the squamous cell carcinoma (SCC) incidence from 57.9 to 11.8%; angiogenesis was inhibited in dysplasia and SCC. The gene expression of vascular endothelium growth factor and tumor necrosis factor (TNF)-alpha was downregulated. Thalidomide has inhibitory effect against the malignant transformation of oral pre-cancerous lesion and angiogenesis during oral carcinogenesis. Such inhibition is related to its modulation of TNF-alpha.

  3. Effects of porcine pancreatic enzymes on the pancreas of hamsters. Part 1: basic studies.

    PubMed

    Saruc, Murat; Nozawa, Fumiaki; Yalniz, Mehmet; Itami, Atsushi; Pour, Parviz M

    2012-09-10

    Porcine pancreatic enzymes (PPE) extracted from glandular stomach has been used for the treatment of pancreatic cancer patients. Unfortunately, no information is available on the in vitro and in vivo effect on the pancreas and other tissues. We used Syrian Golden hamsters, a unique pancreatic cancer model, to obtain basic information on PPE for its eventual use for the treatment of pancreatic cancer. PPE was used in different concentrations in vitro and in vivo. The stability of the enzyme in the water solution was investigated. It was given to the hamsters by gavage in concentrations of 1g/kg and 400 mg/kg for short periods and in aqueous solution for 65 days. Plasma enzyme and insulin, the size of islets and the number of the insulin cells per islet were examined. The enzyme activity of PPE was maintained in water solution for at least 24 hours. Due to its content of calcium chloride it showed a high toxicity to normal and malignant hamster pancreatic cancer cells and human pancreatic cancer cell lines in vitro. PPE did not alter the plasma pancreatic enzyme levels regardless of the dose, duration and application route. On the contrary, PPE reduced their levels significantly. Remarkably, it also reduced the level of insulin, the size of the islets and the number of insulin cells in the islets significantly. The results imply that PPE does not enter the blood circulation but it appears to slow down the function of both the exocrine and endocrine pancreas.

  4. Androgenic regulation of chemoinvestigatory behaviors in male and female hamsters.

    PubMed

    Powers, J B; Bergondy, M L

    1983-03-01

    In male hamsters, chemosensory responsiveness to sexually relevant female odors is facilitated by testosterone (T). Some evidence suggests that this is not a sexually dimorphic response in that adult females can respond similarly to males following administration of T. This was evaluated and additionally, the hypothesis that facilitation of chemosensory responsiveness by T might be mediated by the conversion of T to aromatized or 5 alpha-reduced metabolites was tested. In 2-min tests, we measured the time adult males or females investigated female hamster vaginal secretion (FHVS). These animals were gonadectomized and administered T, 5 alpha-dihydrotestosterone (DHT), estradiol (E2), or a combination of DHT and E2, by subcutaneous implantation of Silastic capsules. FHVS tests were conducted either 2 and 4 weeks, or 4 and 6 weeks subsequent to gonadectomy and hormone treatment. Comparisons among groups receiving different hormone doses indicated that (1) males and females are not equally responsive to the attractant properties of FHVS, and that (2) neither DHT, E2, nor their combination, can duplicate the effects of T in facilitating responsiveness to FHVS in either sex. The copulatory behavior of males under the hormone conditions described was also tested and it was found that variations in the rate at which the test males sniffed or licked the receptive female's anogenital region correlated with variations in measures of the males' sexual performance.

  5. Hypothalamic over-expression of VGF in the Siberian hamster increases energy expenditure and reduces body weight gain

    PubMed Central

    Brameld, John M.; Hill, Phil; Cocco, Cristina; Noli, Barbara; Ferri, Gian-Luca; Barrett, Perry; Ebling, Francis J. P.; Jethwa, Preeti H.

    2017-01-01

    VGF (non-acronymic) was first highlighted to have a role in energy homeostasis through experiments involving dietary manipulation in mice. Fasting increased VGF mRNA in the Arc and levels were subsequently reduced upon refeeding. This anabolic role for VGF was supported by observations in a VGF null (VGF-/-) mouse and in the diet-induced and gold-thioglucose obese mice. However, this anabolic role for VGF has not been supported by a number of subsequent studies investigating the physiological effects of VGF-derived peptides. Intracerebroventricular (ICV) infusion of TLQP-21 increased resting energy expenditure and rectal temperature in mice and protected against diet-induced obesity. Similarly, ICV infusion of TLQP-21 into Siberian hamsters significantly reduced body weight, but this was due to a decrease in food intake, with no effect on energy expenditure. Subsequently NERP-2 was shown to increase food intake in rats via the orexin system, suggesting opposing roles for these VGF-derived peptides. Thus to further elucidate the role of hypothalamic VGF in the regulation of energy homeostasis we utilised a recombinant adeno-associated viral vector to over-express VGF in adult male Siberian hamsters, thus avoiding any developmental effects or associated functional compensation. Initially, hypothalamic over-expression of VGF in adult Siberian hamsters produced no effect on metabolic parameters, but by 12 weeks post-infusion hamsters had increased oxygen consumption and a tendency to increased carbon dioxide production; this attenuated body weight gain, reduced interscapular white adipose tissue and resulted in a compensatory increase in food intake. These observed changes in energy expenditure and food intake were associated with an increase in the hypothalamic contents of the VGF-derived peptides AQEE, TLQP and NERP-2. The complex phenotype of the VGF-/- mice is a likely consequence of global ablation of the gene and its derived peptides during development, as well

  6. Hypothalamic over-expression of VGF in the Siberian hamster increases energy expenditure and reduces body weight gain.

    PubMed

    Lewis, Jo E; Brameld, John M; Hill, Phil; Cocco, Cristina; Noli, Barbara; Ferri, Gian-Luca; Barrett, Perry; Ebling, Francis J P; Jethwa, Preeti H

    2017-01-01

    VGF (non-acronymic) was first highlighted to have a role in energy homeostasis through experiments involving dietary manipulation in mice. Fasting increased VGF mRNA in the Arc and levels were subsequently reduced upon refeeding. This anabolic role for VGF was supported by observations in a VGF null (VGF-/-) mouse and in the diet-induced and gold-thioglucose obese mice. However, this anabolic role for VGF has not been supported by a number of subsequent studies investigating the physiological effects of VGF-derived peptides. Intracerebroventricular (ICV) infusion of TLQP-21 increased resting energy expenditure and rectal temperature in mice and protected against diet-induced obesity. Similarly, ICV infusion of TLQP-21 into Siberian hamsters significantly reduced body weight, but this was due to a decrease in food intake, with no effect on energy expenditure. Subsequently NERP-2 was shown to increase food intake in rats via the orexin system, suggesting opposing roles for these VGF-derived peptides. Thus to further elucidate the role of hypothalamic VGF in the regulation of energy homeostasis we utilised a recombinant adeno-associated viral vector to over-express VGF in adult male Siberian hamsters, thus avoiding any developmental effects or associated functional compensation. Initially, hypothalamic over-expression of VGF in adult Siberian hamsters produced no effect on metabolic parameters, but by 12 weeks post-infusion hamsters had increased oxygen consumption and a tendency to increased carbon dioxide production; this attenuated body weight gain, reduced interscapular white adipose tissue and resulted in a compensatory increase in food intake. These observed changes in energy expenditure and food intake were associated with an increase in the hypothalamic contents of the VGF-derived peptides AQEE, TLQP and NERP-2. The complex phenotype of the VGF-/- mice is a likely consequence of global ablation of the gene and its derived peptides during development, as well

  7. Cathinone increases body temperature, enhances locomotor activity, and induces striatal c-fos expression in the Siberian hamster.

    PubMed

    Jones, S; Fileccia, E L; Murphy, M; Fowler, M J; King, M V; Shortall, S E; Wigmore, P M; Green, A R; Fone, K C F; Ebling, F J P

    2014-01-24

    Cathinone is a β-keto alkaloid that is the major active constituent of khat, the leaf of the Catha edulis plant that is chewed recreationally in East Africa and the Middle East. Related compounds, such as methcathinone and mephedrone have been increasing in popularity as recreational drugs, resulting in the recent proposal to classify khat as a Class C drug in the UK. There is still limited knowledge of the pharmacological effects of cathinone. This study examined the acute effects of cathinone on core body temperature, locomotor and other behaviors, and neuronal activity in Siberian hamsters. Adult male hamsters, previously implanted with radio telemetry devices, were treated with cathinone (2 or 5mg/kg i.p.), the behavioral profile scored and core body temperature and locomotor activity recorded by radio telemetry. At the end of the study, hamsters received vehicle or cathinone (5mg/kg) and neuronal activation in the brain was determined using immunohistochemical evaluation of c-fos expression. Cathinone dose-dependently induced significant (p<0.0001) increases in both temperature and locomotor activity lasting 60-90min. Cathinone (2mg/kg) increased rearing (p<0.02), and 5mg/kg increased both rearing (p<0.001) and lateral head twitches (p<0.02). Both cathinone doses decreased the time spent at rest (p<0.001). The number of c-fos immunopositive cells were significantly increased in the striatum (p<0.0001) and suprachiasmatic nucleus (p<0.05) following cathinone, indicating increased neuronal activity. There was no effect of cathinone on food intake or body weight. It is concluded that systemic administration of cathinone induces significant behavioral changes and CNS activation in the hamster. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  8. [PCR as a tool in confirming the experimental transmission of Leishmania chagasi to hamsters by Lutzomyia longipalpis (Diptera:Psychodidae)].

    PubMed

    Cabrera, Olga L; Munstermann, Leonard E; Cárdenas, Rocío; Ferro, Cristina

    2003-06-01

    The use of PCR (polymerase chain reaction) was evaluated for its effectiveness as a tool in the detection of transmission of Leishmania chagasi to a hamster host, Mesocricetus auratus, by insect vector bite. Two pairs of uninfected and anesthetized hamsters were introduced into cages containing infected females of the typical phlebotomine sand fly vector, Lutzomyia longipalpis. The flies were experimentally infected with Leishmania chagasi and the infection was verified by dissection of subsamples. At 37 and 51 days after exposure to the infected flies, biopsies of each hamster's liver and spleen were subjected to direct histopathological and PCR examination. DNA was extracted with Chelex 100; for PCR amplification, primers specific to Leishmania minicircle DNA were used. PCR product was separated on agarose gels and visualized with UV. A band of approximately 120 base pairs was observed in 3 of the 4 biopsies, corresponding to the expected minicircle size. PCR was the only method that detected presence of the parasite. The results demonstrated that the sensitivity of PCR greatly expedites the confirmation process of a particular phlebotomine species as a vector of leishmaniasis.

  9. Melatonin and 6-methoxy-2-benzoxazolinone (6-MBOA) alter the response of the male Syrian hamster to natural photoperiod

    NASA Astrophysics Data System (ADS)

    Vaughan, M. K.; Little, J. C.; Powell, D. C.; Puig-Domingo, M.; Reiter, R. J.

    1988-06-01

    Adult male hamsters bearing either a blank beeswax, 6-methoxy-2-benzoxazolinone (6-MBOA), or melatonin pellet were exposed to 8 weeks (Oct. 6 Dec. 6) of natural autumn decreasing photoperiod (<11 h light) and temperature conditions (mean 10°C for last 4 weeks) or to a 14 h light/10 h dark (14L∶10D) photoperiod and controlled temperature (20°C). Melatonin but not 6-MBOA pellets partially prevented the combined effects of short photoperiod and cold temperatures on the testes and accessory organs. However, both 6-MBOA-and melatonin-treated hamsters maintained outdoors had significantly higher pituitary follicle stimulating hormone (FSH) values compared to their respective indoor-treated controls or to the animals kept outdoors and treated with a blank beeswax pellet. When one compares the various effects of 6-MBOA and melatonin (2 mg/month) on the reproductive system of the male hamster, 6-MBOA is not as effective as melatonin in altering reproductive responses to short photoperiod and cool temperatures at the dose administered.

  10. Background diet and fat type alters plasma lipoprotein response but not aortic cholesterol accumulation in F1B Golden Syrian hamsters.

    PubMed

    Dillard, Alice; Matthan, Nirupa R; Spartano, Nicole L; Butkowski, Ann E; Lichtenstein, Alice H

    2013-12-01

    Dietary modification alters plasma lipoprotein profiles and atherosclerotic lesion progression in humans and some animal models. Variability in response to diet induced atherosclerosis has been reported in hamsters. Assessed was the interaction between background diet composition and dietary fat type on aortic cholesterol accumulation, lipoprotein profiles, hepatic lipids and selected genes. F1B Golden Syrian hamsters (20/group) were fed (12 weeks) semi-purified or non-purified diets containing either 10 % (w/w) coconut oil or safflower oil and 0.15 % (w/w) cholesterol. The non-purified diets relative to semi-purified diets resulted in significantly higher TC (72 % [percent difference] and 38 %, coconut oil and safflower oil, respectively) and nHDL-C (84 and 61 %, coconut oil and safflower oil, respectively), and lower HDL-C (-47 and -45 %, coconut oil and safflower oil, respectively) concentrations. Plasma triacylglycerol concentrations in the hamsters fed the non-purified coconut oil-supplemented diets were three- to fourfold higher than non-purified safflower oil-supplemented, and both semi-purified diets. With the exception of HDL-C, a significant effect of fat type was observed in TC, nHDL-C and triacylglycerol (all P < 0.05) concentrations. Regardless of diet induced differences in lipoprotein profiles, there was no significant effect on aortic cholesterol accumulation. There was an inverse relationship between plasma nHDL-C and triacylglycerol, and hepatic cholesteryl ester content (P < 0.001). Diet induced differences in hepatic gene transcription (LDL receptor, apoB-100, microsomal transfer protein) were not reflected in protein concentrations. Although hamsters fed non-purified and/or saturated fatty acid-supplemented diets had more atherogenic lipoprotein profiles compared to hamsters fed semi-purified and/or polyunsaturated fatty acid-supplemented diets these differences were not reflected in aortic cholesterol accumulation.

  11. PLACENTAL TRANSFER AND FETAL DEPOSITION OF HEXACHLOROBENZENE IN THE HAMSTER AND GUINEA PIG

    EPA Science Inventory

    Hexachlorobenzene (HCB) was administered at dose levels of 0, 1.0, 10.0, or 50.0 mg HCB/kg body wt by gavage to pregnant hamsters and guinea pigs for 6 days up to the time of liver development in the fetus. Samples of maternal fat, thymus, skin, liver, lung, brain, spleen, urinar...

  12. The medial preoptic area is necessary for sexual odor preference, but not sexual solicitation, in female Syrian hamsters.

    PubMed

    Martinez, Luis A; Petrulis, Aras

    2013-04-01

    Precopulatory behaviors that are preferentially directed towards opposite-sex conspecifics are critical for successful reproduction, particularly in species wherein the sexes live in isolation, such as Syrian hamsters (Mesocricetus auratus). In females, these behaviors include sexual odor preference and vaginal scent marking. The neural regulation of precopulatory behaviors is thought to involve a network of forebrain areas that includes the medial amygdala (MA), the bed nucleus of the stria terminalis (BNST), and the medial preoptic area (MPOA). Although MA and BNST are necessary for sexual odor preference and preferential vaginal marking to male odors, respectively, the role of MPOA in odor-guided female precopulatory behaviors is not well understood. To address this issue, female Syrian hamsters with bilateral, excitotoxic lesions of MPOA (MPOA-X) or sham lesions (SHAM) were tested for sexual odor investigation, scent marking, and lordosis. MPOA-X females did not investigate male odors more than female odors in an odor preference test, indicating that MPOA may be necessary for normal sexual odor preference in female hamsters. This loss of preference cannot be attributed to a sensory deficit, since MPOA-X females successfully discriminated male odors from female odors during an odor discrimination test. Surprisingly, no deficits in vaginal scent marking were observed in MPOA-X females, although these females did exhibit decreased overall levels of flank marking compared to SHAM females. Finally, all MPOA-X females exhibited lordosis appropriately. These results suggest that MPOA plays a critical role in the neural regulation of certain aspects of odor-guided precopulatory behaviors in female Syrian hamsters. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Effects of 13 T Static Magnetic Fields (SMF) in the Cell Cycle Distribution and Cell Viability in Immortalized Hamster Cells and Human Primary Fibroblasts Cells

    NASA Astrophysics Data System (ADS)

    Zhao, Guoping; Chen, Shaopeng; Zhao, Ye; Zhu, Lingyan; Huang, Pei; Bao, Lingzhi; Wang, Jun; Wang, Lei; Wu, Lijun; Wu, Yuejin; Xu, An

    2010-02-01

    Magnetic resonance image (MRI) systems with a much higher magnetic flux density were developed and applied for potential use in medical diagnostic. Recently, much attention has been paid to the biological effects of static, strong magnetic fields (SMF). With the 13 T SMF facility in the Institute of Plasma Physics, Chinese Academy of Sciences, the present study focused on the cellular effects of the SMF with 13 T on the cell viability and the cell cycle distribution in immortalized hamster cells, such as human-hamster hybrid (AL) cells, Chinese hamster ovary (CHO) cells, DNA double-strand break repair deficient mutant (XRS-5) cells, and human primary skin fibroblasts (AG1522) cells. It was found that the exposure of 13 T SMF had less effect on the colony formation in either nonsynchronized or synchronized AL cells. Moreover, as compared to non-exposed groups, there were slight differences in the cell cycle distribution no matter in either synchronized or nonsynchronized immortalized hamster cells after exposure to 13 T SMF. However, it should be noted that the percentage of exposed AG1522 cells at G0/G1 phase was decreased by 10% as compared to the controls. Our data indicated that although 13 T SMF had minimal effects in immortalized hamster cells, the cell cycle distribution was slightly modified by SMF in human primary fibroblasts.

  14. Evaluation of the mutagenic and cytotoxic effects of mercurous chloride by the micronuclei technique in golden Syrian hamsters.

    PubMed

    Cortés-Gutiérrez, Elva I; Cerda-Flores, Ricardo M; González-Ramírez, Diego; Zúñiga-Charles, Miguel A; Lazcano-Martínez, Sigifredo; Sampayo-Reyes, Adriana; Leal-Garza, Carlos H

    2004-05-01

    The aims of this study were to evaluate the mutagenic and cytotoxic activity of mercurous chloride by the micronucleus technique in vivo on the bone marrow of golden Syrian hamsters after a single i.p. drug administration. Forty male golden Syrian hamsters were classified into eight groups: negative control, positive control and six groups treated with different doses of mercurous chloride (1.25, 2.5, 5, 10, 20 and 40 mg/kg). The negative control was injected with physiological saline i.p. and the positive control with cyclophosphamide at a dose of 80 mg/kg i.p. With respect to mutagenic effect, the average number of micronucleated polychromatic erythrocytes (MPE) in hamsters treated with different doses of mercurous chloride was not significant compared with the negative control. With respect to cytotoxic effect, the average polychromatic erythrocyte/red blood cell ratio showed a significant decrease when the doses were higher than the 2.5 mg/kg dose compared with the negative control. In conclusion, this preliminary study shows a cytotoxic effect but not a mutagenic effect of calomel in vivo at one time point (24 h).

  15. Genotoxicity induced by Taenia solium and its reduction by immunization with calreticulin in a hamster model of taeniosis.

    PubMed

    Salazar, Ana María; Mendlovic, Fela; Cruz-Rivera, Mayra; Chávez-Talavera, Oscar; Sordo, Monserrat; Avila, Guillermina; Flisser, Ana; Ostrosky-Wegman, Patricia

    2013-06-01

    Genotoxicity induced by neurocysticercosis has been demonstrated in vitro and in vivo in humans. The adult stage of Taenia solium lodges in the small intestine and is the main risk factor to acquire neurocysticercosis, nevertheless its carcinogenic potential has not been evaluated. In this study, we determined the genotoxic effect of T. solium infection in the hamster model of taeniosis. In addition, we assessed the effect of oral immunization with recombinant T. solium calreticulin (rTsCRT) plus cholera toxin as adjuvant on micronuclei induction, as this protein has been shown to induce 33-44% protection in the hamster model of taeniosis. Blood samples were collected from the orbital venous plexus of noninfected and infected hamsters at different days postinfection, as well as from orally immunized animals, to evaluate the frequency of micronucleated reticulocytes as a measure of genotoxicity induced by parasite exposure and rTsCRT vaccination. Our results indicate that infection with T. solium caused time-dependent DNA damage in vivo and that rTsCRT immunization reduced the genotoxic damage induced by the presence of the tapeworms. Copyright © 2013 Wiley Periodicals, Inc.

  16. Dissimilatory arsenate reductase activity and arsenate-respiring bacteria in bovine rumen fluid, hamster feces, and the termite hindgut

    USGS Publications Warehouse

    Herbel, M.J.; Switzer, Blum J.; Hoeft, S.E.; Cohen, S.M.; Arnold, L.L.; Lisak, J.; Stolz, J.F.; Oremland, R.S.

    2002-01-01

    Bovine rumen fluid and slurried hamster feces completely reduced millimolar levels of arsenate to arsenite upon incubation under anoxic conditions. This activity was strongly inhibited by autoclaving or aerobic conditions, and partially inhibited by tungstate or chloramphenicol. The rate of arsenate reduction was faster in feces from a population of arsenate-watered (100 ppm) hamsters compared to a control group watered without arsenate. Using radioisotope methods, arsenate reductase activity in hamster feces was also detected at very low concentrations of added arsenate (???10 ??M). Bacterial cultures were isolated from these materials, as well as from the termite hindgut, that grew using H2 as their electron donor, acetate as their carbon source, and arsenate as their respiratory electron acceptor. The three cultures aligned phylogenetically either with well-established enteric bacteria, or with an organism associated with feedlot fecal wastes. Because arsenite is transported across the gut epithelium more readily than arsenate, microbial dissimilatory reduction of arsenate in the gut may promote the body's absorption of arsenic and hence potentiate its toxicity. ?? 2002 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.

  17. How maize monoculture and increasing winter rainfall have brought the hibernating European hamster to the verge of extinction.

    PubMed

    Tissier, Mathilde L; Handrich, Yves; Robin, Jean-Patrice; Weitten, Mathieu; Pevet, Paul; Kourkgy, Charlotte; Habold, Caroline

    2016-05-06

    Over the last decades, climate change and agricultural intensification have been identified as two major phenomena negatively affecting biodiversity. However, little is known about their effects on the life-history traits of hibernating species living in agro-ecosystems. The European hamster (Cricetus cricetus), once a common rodent on agricultural land, is now on the verge of extinction in France. Despite the implemented measures for its protection, populations are still in sharp decline but the reasons for it remain unclear. To investigate how environmental change has affected this hibernating rodent, we used a data set based on 1468 recordings of hamster body mass at emergence from hibernation from 1937 to 2014. We reveal the adverse effects of increasing winter rainfall and maize monoculture intensification on the body mass of wild hamsters. Given the links that exist between body mass, reproductive success and population dynamics in mammals, these results are of particular importance to understand the decline of this species. In view of the rates of maize monoculture intensification and the predicted increase in winter rainfall, it is of the utmost importance to improve land management in Western Europe to avoid the extinction of this species.

  18. Anti-inflammatory and anti-periductal fibrosis effects of an anthocyanin complex in Opisthorchis viverrini-infected hamsters.

    PubMed

    Intuyod, Kitti; Priprem, Aroonsri; Limphirat, Wanwisa; Charoensuk, Lakhanawan; Pinlaor, Porntip; Pairojkul, Chawalit; Lertrat, Kamol; Pinlaor, Somchai

    2014-12-01

    The pharmacological activities of herbal extracts can be enhanced by complex formation. In this study, we manipulated cyanidin and delphinidin-rich extracts to form an anthocyanin complex (AC) with turmeric and evaluated activity against inflammation and periductal fibrosis in Opisthorchis viverrini-infected hamsters. The AC was prepared from anthocyanins extracted from cobs of purple waxy corn (70%), petals of blue butterfly pea (20%) and turmeric extract (10%), resulting in an enhanced free-radical scavenging capacity. Oral administration of AC (175 and 700 mg/kg body weight) every day for 1 month to O. viverrini-infected hamsters resulted in reduced inflammatory cells and periductal fibrosis. Fourier transform infrared spectroscopy and partial least square discriminant analysis suggested nucleic acid changes in the O. viverrini-infected liver samples, which were partially prevented by the AC treatment. AC reduced 8-oxodG formation, an oxidative DNA damage marker, significantly decreased levels of nitrite in the plasma and alanine aminotransferase activity and increased the ferric reducing ability of plasma. AC also decreased the expression of oxidant-related genes (NF-κB and iNOS) and increased the expression of antioxidant-related genes (CAT, SOD, and GPx). Thus, AC increases free-radical scavenging capacity, decreases inflammation, suppresses oxidative/nitrative stress, and reduces liver injury and periductal fibrosis in O. viverrini-infected hamsters.

  19. Visual pigment coexpression in all cones of two rodents, the Siberian hamster, and the pouched mouse.

    PubMed

    Lukáts, Akos; Dkhissi-Benyahya, Ouria; Szepessy, Zsuzsanna; Röhlich, Pál; Vígh, Béla; Bennett, Nigel C; Cooper, Howard M; Szél, Agoston

    2002-07-01

    To decide whether the identical topography of short- and middle-wavelength cone photoreceptors in two species of rodents reflects the presence of both opsins in all cone cells. Double-label immunocytochemistry using antibodies directed against short-wavelength (S)-and middle- to long-wavelength (M/L)-sensitive opsin were used to determine the presence of visual pigments in cones of two species of rodents, the Siberian hamster (Phodopus sungorus) and the pouched mouse (Saccostomus campestris) from South Africa. Topographical distribution was determined from retinal whole-mounts, and the colocalization of visual pigments was examined using confocal laser scanning microscopy. Opsin colocalization was also confirmed in consecutive semithin tangential sections. The immunocytochemical results demonstrate that in both the Siberian hamster and the pouched mouse all retinal cones contain two visual pigments. No dorsoventral gradient in the differential expression of the two opsins is observed. The retina of the Siberian hamster and the pouched mouse is the first example to show a uniform coexpression of M and S cone opsins in all cones, without any topographical gradient in opsin expression. This finding makes these two species good models for the study of molecular control mechanisms in opsin coexpression in rodents, and renders them suitable as sources of dual cones for future investigations on the role and neural connections of this cone type.

  20. Expression of FSH receptor in the hamster ovary during perinatal development

    PubMed Central

    Chakraborty, Prabuddha; Roy, Shyamal K.

    2014-01-01

    FSH plays an important role in ovarian follicular development, and it functions via the G-protein coupled FSH receptor. The objectives of the present study were to determine if full-length FSHR mRNA and corresponding protein were expressed in fetal through postnatal hamster ovaries to explain the FSH-induced primordial follicle formation, and if FSH or estrogen (E) would affect the expression. A full-length and two alternately spliced FSHR transcripts were expressed from E14 through P20. The level of the full-length FSHR mRNA increased markedly through P7 before stabilizing at a lower level with the formation and activation of primordial follicles. A predicted 87kDa FSHR protein band was detected in fetal through P4 ovaries, but additional bands appeared as ovary developed. FSHR immunosignal was present in undifferentiated somatic cells and oocytes in early postnatal ovaries, but was granulosa cells specific after follicles formed. Both eCG and E significantly up-regulated full-length FSHR mRNA levels. Therefore, FSHR is expressed in the hamster ovary from the fetal life to account for FSH-induced primordial follicle formation and cAMP production. Further, FSH or E regulates the receptor expression. PMID:25462586

  1. Milrinone attenuates arteriolar vasoconstriction and capillary perfusion deficits on endotoxemic hamsters.

    PubMed

    de Miranda, Marcos Lopes; Pereira, Sandra J; Santos, Ana O M T; Villela, Nivaldo R; Kraemer-Aguiar, Luiz Guilherme; Bouskela, Eliete

    2015-01-01

    Apart from its inotropic property, milrinone has vasodilator, anti-inflammatory and antithrombotic effects that could assist in the reversal of septic microcirculatory changes. This paper investigates the effects of milrinone on endotoxemia-related microcirculatory changes and compares them to those observed with the use of norepinephrine. After skinfold chamber implantation procedures and endotoxemia induction by intravenous Escherichia coli lipopolysaccharide administration (2 mg.kg-1), male golden Syrian hamsters were treated with two regimens of intravenous milrinone (0.25 or 0.5 μg.kg-1.min-1). Intravital microscopy of skinfold chamber preparations allowed quantitative analysis of microvascular variables. Macro-hemodynamic, biochemical, and hematological parameters and survival rate were also analyzed. Endotoxemic non-treated animals, endotoxemic animals treated with norepinephrine (0.2 μg.kg-1.min-1), and non-endotoxemic hamsters served as controls. Milrinone (0.5 μg.kg-1.min-1) was effective in reducing lipopolysaccharide-induced arteriolar vasoconstriction, capillary perfusion deficits, and inflammatory response, and in increasing survival. Norepinephrine treated animals showed the best mean arterial pressure levels but the worst functional capillary density values among all endotoxemic groups. Our data suggests that milrinone yielded protective effects on endotoxemic animals' microcirculation, showed anti-inflammatory properties, and improved survival. Norepinephrine did not recruit the microcirculation nor demonstrated anti-inflammatory effects.

  2. Study of the combined effects of smoking and inhalation of uranium ore dust, radon daughters and diesel oil exhaust fumes in hamsters and dogs. Final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cross, F.T.; Palmer, R.F.; Filipy, R.E.

    1978-09-01

    Exposure to particulates from uranium ore dust and diesel exhaust soot provoked inflammatory and proliferative responses in lungs. Also exposure to radon and radon daughters yielded increased occurrences of bronchiolar epithelial hyperplasia and metaplastic changes of alveolar epithelium. The data suggest that this cellular change is also a precursor of premalignant change in hamsters. The authors suggest an animal model other than the hamster based on two observations: (1) the Syrian golden hamster has been shown to be highly refractory to carcinoma induction; and (2) that when exposed to realistic levels of agents in life-span exposure regimens, the hamster doesmore » not develop lesions. Dog studies with cigarette smoke exposure showed mitigating effects on radon daughter induced respiratory tract cancer. Two reasons are suggested although no empirical evidence was gathered. A strict comparison of human and animal exposures and interpolative models are not possible at this time. (PCS)« less

  3. Cycles of Transient High-Dose Cyclophosphamide Administration and Oncolytic Adenovirus Vector Intratumoral Injection for Long Term Tumor Suppression in Syrian Hamsters

    PubMed Central

    Dhar, Debanjan; Toth, Karoly; Wold, William S.M.

    2014-01-01

    Immune responses against oncolytic adenovirus (Ad) vectors are thought to limit vector anti-tumor efficacy. In Syrian hamsters, which are immunocompetent and whose tumors and normal tissues are permissive for replication of Ad5-based oncolytic Ad vectors, treating with high-dose cyclophosphamide to suppress the immune system and exert chemotherapeutic effects enhances Ad vector anti-tumor efficacy. However, long term cyclophosphamide treatment and immunosuppression can lead to anemia and vector spread to normal tissues. Here we employed three cycles of transient high-dose cyclophosphamide administration plus intratumoral injection of the oncolytic Ad vector VRX-007 followed by withdrawal from cyclophosphamide. Each cycle lasted 4-6 weeks. This protocol allowed the hamsters to remain healthy so the study could be continued for ~100 days. The tumors were very well suppressed throughout the study. With immunocompetent hamsters, the vector retarded tumor growth initially, but after 3-4 weeks the tumors resumed rapid growth and further injections of vector were ineffective. Preimmunization of the hamsters with Ad5 prevented vector spillover from the tumor to the liver yet still allowed for effective long term anti-tumor efficacy. Our results suggest that a clinical protocol might be developed with cycles of transient chemotherapy plus intratumoral vector injection to achieve significant anti-tumor efficacy while minimizing the side effects of cytostatic treatment. PMID:24722357

  4. Cycles of transient high-dose cyclophosphamide administration and intratumoral oncolytic adenovirus vector injection for long-term tumor suppression in Syrian hamsters.

    PubMed

    Dhar, D; Toth, K; Wold, W S M

    2014-04-01

    Immune responses against oncolytic adenovirus (Ad) vectors are thought to limit vector anti-tumor efficacy. With Syrian hamsters, which are immunocompetent and whose tumors and normal tissues are permissive for replication of Ad5-based oncolytic Ad vectors, treating with high-dose cyclophosphamide (CP) to suppress the immune system and exert chemotherapeutic effects enhances Ad vector anti-tumor efficacy. However, long-term CP treatment and immunosuppression can lead to anemia and vector spread to normal tissues. Here, we employed three cycles of transient high-dose CP administration plus intratumoral injection of the oncolytic Ad vector VRX-007 followed by withdrawal of CP. Each cycle lasted 4-6 weeks. This protocol allowed the hamsters to remain healthy so the study could be continued for ~100 days. The tumors were very well suppressed throughout the study. With immunocompetent hamsters, the vector retarded tumor growth initially, but after 3-4 weeks the tumors resumed rapid growth and further injections of vector were ineffective. Preimmunization of the hamsters with Ad5 prevented vector spillover from the tumor to the liver yet still allowed for effective long-term anti-tumor efficacy. Our results suggest that a clinical protocol might be developed with cycles of transient chemotherapy plus intratumoral vector injection to achieve significant anti-tumor efficacy while minimizing the side effects of cytostatic treatment.

  5. Immunoprotective properties of recombinant LigA and LigB in a hamster model of acute leptospirosis

    PubMed Central

    Lourdault, Kristel; Matsunaga, James; Haake, David A.

    2017-01-01

    Leptospirosis is the most widespread zoonosis and is considered a major public health problem worldwide. Currently, there is no widely available vaccine against leptospirosis for use in humans. A purified, recombinant subunit vaccine that includes the last six immunoglobulin-like (Ig-like) domains of the leptospiral protein LigA (LigA7’-13) protects against lethal infection but not renal colonization after challenge by Leptospira interrogans. In this study, we examined whether the addition of the first seven Ig-like domains of LigB (LigB0-7) to LigA7’-13, can enhance immune protection and confer sterilizing immunity in the Golden Syrian hamster model of acute leptospirosis. Hamsters were subcutaneously immunized with soluble, recombinant LigA7’-13, LigB0-7, or a combination of LigA7’-13 and LigB0-7 in Freund’s adjuvant. Immunization with Lig proteins generated a strong humoral immune response with high titers of IgG that recognized homologous protein, and cross-reacted with the heterologous protein as assessed by ELISA. LigA7’-13 alone, or in combination with LigB0-7, protected all hamsters from intraperitoneal challenge with a lethal dose of L. interrogans serovar Copenhageni strain Fiocruz L1-130. However, bacteria were recovered from the kidneys of all animals. Of eight animals immunized with LigB0-7, only three survived Leptospira challenge, one of which lacked renal colonization and had antibodies to native LigB by immunoblot. In addition, sera from two of the three LigB0-7 immunized survivors cross-reacted with LigA11-13, a region of LigA that is sufficient for protection. In summary, we confirmed that LigA7’-13 protects hamsters from death but not infection, and immunization with LigB0-7, either alone or in combination with LigA7’-13, did not confer sterilizing immunity. PMID:28704385

  6. Natural Immunity to Ebola Virus in the Syrian Hamster Requires Antibody Responses.

    PubMed

    Prescott, Joseph; Falzarano, Darryl; Feldmann, Heinz

    2015-10-01

    Most ebolaviruses can cause severe disease in humans and other primates, with high case fatality rates during human outbreaks. Although these viruses have been studied for almost 4 decades, little is know regarding the mechanisms by which they cause disease and what is important for protection or treatment after infection. Because of the sporadic nature of the outbreaks and difficulties accessing the populations affected by ebolaviruses, little is also known about what constitutes an appropriate immune response to infection in humans that survive infection. Such knowledge would allow a targeted approach to therapies. In contrast to humans, rodents are protected from disease on infection with ebolaviruses, although adapted versions of some of the viruses are lethal in mice, hamsters and guinea pigs. Using the recently described hamster model, along with T-cell depletion strategies, we show that CD4(+) T cells are required for natural immunity to Ebola virus infection and that CD4-dependent antibody responses are required for immunity in this model. Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  7. Nonphotic phase shifting in female Syrian hamsters: interactions with the estrous cycle.

    PubMed

    Young Janik, L; Janik, Daniel

    2003-08-01

    Nonphotic phase shifting of circadian rhythms was examined in female Syrian hamsters. Animals were stimulated at zeitgeber time 4.5 by either placing them in a novel running wheel or by transferring them to a clean home cage. Placement in a clean home cage was more effective than novel wheel treatment in stimulating large (> 1.5 h) phase shifts. Peak phase shifts (ca. 3.5 h) and the percentage of females showing large phase shifts were comparable to those found in male hamsters stimulated with novel wheels. The amount of activity induced by nonphotic stimulation and the amount of phase shifting varied slightly with respect to the 4-day estrous cycle. Animals tended to run less and shift less on the day of estrus. Nonphotic stimulation on proestrus often resulted in a 1-day delay of the estrous cycle reflected in animals' postovulatory vaginal discharge and the expression of sexual receptivity (lordosis). This delay of the estrous cycle was associated with large phase advances and high activity. These results extend the generality of nonphotic phase shifting to females for the first time and raise the possibility that resetting of circadian rhythms can induce changes in the estrous cycle.

  8. The circadian clock stops ticking during deep hibernation in the European hamster

    PubMed Central

    Revel, Florent G.; Herwig, Annika; Garidou, Marie-Laure; Dardente, Hugues; Menet, Jérôme S.; Masson-Pévet, Mireille; Simonneaux, Valérie; Saboureau, Michel; Pévet, Paul

    2007-01-01

    Hibernation is a fascinating, yet enigmatic, physiological phenomenon during which body temperature and metabolism are reduced to save energy. During the harsh season, this strategy allows substantial energy saving by reducing body temperature and metabolism. Accordingly, biological processes are considerably slowed down and reduced to a minimum. However, the persistence of a temperature-compensated, functional biological clock in hibernating mammals has long been debated. Here, we show that the master circadian clock no longer displays 24-h molecular oscillations in hibernating European hamsters. The clock genes Per1, Per2, and Bmal1 and the clock-controlled gene arginine vasopressin were constantly expressed in the suprachiasmatic nucleus during deep torpor, as assessed by radioactive in situ hybridization. Finally, the melatonin rhythm-generating enzyme, arylalkylamine N-acetyltransferase, whose rhythmic expression in the pineal gland is controlled by the master circadian clock, no longer exhibits day/night changes of expression but constantly elevated mRNA levels over 24 h. Overall, these data provide strong evidence that in the European hamster the molecular circadian clock is arrested during hibernation and stops delivering rhythmic output signals. PMID:17715068

  9. Changes in cholesterol homeostasis modify the response of F1B hamsters to dietary very long chain n-3 and n-6 polyunsaturated fatty acids

    PubMed Central

    2011-01-01

    Background The plasma lipoprotein response of F1B Golden-Syrian hamsters fed diets high in very long chain (VLC) n-3 polyunsaturated fatty acids (PUFA) is paradoxical to that observed in humans. This anomaly is attributed, in part, to low lipoprotein lipase activity and is dependent on cholesterol status. To further elucidate the mechanism(s) for these responses, hamsters were fed diets containing supplemental fish oil (VLC n-3 PUFA) or safflower oil (n-6 PUFA) (both 10% [w/w]) and either cholesterol-supplemented (0.1% cholesterol [w/w]) or cholesterol-depleted (0.01% cholesterol [w/w] and 10 days prior to killing fed 0.15% lovastatin+2% cholestyramine [w/w]). Results Cholesterol-supplemented hamsters fed fish oil, relative to safflower oil, had higher non-high density lipoprotein (HDL) cholesterol and triglyceride concentrations (P < 0.001) which were associated with lower hepatic low density lipoprotein (LDL) receptor, sterol regulatory element binding protein (SREBP)-1c and acyl-CoA: cholesterol acyl transferase-2 (ACAT) mRNA and protein (p < 0.05), and higher hepatic apolipoprotein (apo) B-100 and apo E protein levels. In contrast, cholesterol-depleted hamsters fed fish oil, relative to safflower oil, had lower non-HDL cholesterol and triglyceride concentrations (P < 0.001) which were associated with lower hepatic SREBP-1c (p < 0.05) but not apo B-100, apo E or ACAT-2 mRNA or protein levels. Independent of cholesterol status, fish oil fed hamsters had lower HDL cholesterol concentrations (p < 0.001), which were associated with lower hepatic apoA-I protein levels (p < 0.05). Conclusion These data suggest disturbing cholesterol homeostasis in F1B hamsters alters their response to dietary fatty acids, which is reflected in altered plasma lipoprotein patterns and regulation of genes associated with their metabolism. PMID:22018327

  10. Changes in cholesterol homeostasis modify the response of F1B hamsters to dietary very long chain n-3 and n-6 polyunsaturated fatty acids.

    PubMed

    Lecker, Jaime L; Matthan, Nirupa R; Billheimer, Jeffrey T; Rader, Daniel J; Lichtenstein, Alice H

    2011-10-21

    The plasma lipoprotein response of F1B Golden-Syrian hamsters fed diets high in very long chain (VLC) n-3 polyunsaturated fatty acids (PUFA) is paradoxical to that observed in humans. This anomaly is attributed, in part, to low lipoprotein lipase activity and is dependent on cholesterol status. To further elucidate the mechanism(s) for these responses, hamsters were fed diets containing supplemental fish oil (VLC n-3 PUFA) or safflower oil (n-6 PUFA) (both 10% [w/w]) and either cholesterol-supplemented (0.1% cholesterol [w/w]) or cholesterol-depleted (0.01% cholesterol [w/w] and 10 days prior to killing fed 0.15% lovastatin+2% cholestyramine [w/w]). Cholesterol-supplemented hamsters fed fish oil, relative to safflower oil, had higher non-high density lipoprotein (HDL) cholesterol and triglyceride concentrations (P < 0.001) which were associated with lower hepatic low density lipoprotein (LDL) receptor, sterol regulatory element binding protein (SREBP)-1c and acyl-CoA: cholesterol acyl transferase-2 (ACAT) mRNA and protein (p < 0.05), and higher hepatic apolipoprotein (apo) B-100 and apo E protein levels. In contrast, cholesterol-depleted hamsters fed fish oil, relative to safflower oil, had lower non-HDL cholesterol and triglyceride concentrations (P < 0.001) which were associated with lower hepatic SREBP-1c (p < 0.05) but not apo B-100, apo E or ACAT-2 mRNA or protein levels. Independent of cholesterol status, fish oil fed hamsters had lower HDL cholesterol concentrations (p < 0.001), which were associated with lower hepatic apoA-I protein levels (p < 0.05). These data suggest disturbing cholesterol homeostasis in F1B hamsters alters their response to dietary fatty acids, which is reflected in altered plasma lipoprotein patterns and regulation of genes associated with their metabolism.

  11. Altered gene expression patterns during the initiation and promotion stages of neonatally diethylstilbestrol-induced hyperplasia/dysplasia/neoplasia in the hamster uterus.

    PubMed

    Hendry, William J; Hariri, Hussam Y; Alwis, Imala D; Gunewardena, Sumedha S; Hendry, Isabel R

    2014-12-01

    Neonatal treatment of hamsters with diethylstilbestrol (DES) induces uterine hyperplasia/dysplasia/neoplasia (endometrial adenocarcinoma) in adult animals. We subsequently determined that the neonatal DES exposure event directly and permanently disrupts the developing hamster uterus (initiation stage) so that it responds abnormally when it is stimulated with estrogen in adulthood (promotion stage). To identify candidate molecular elements involved in progression of the disruption/neoplastic process, we performed: (1) immunoblot analyses and (2) microarray profiling (Affymetrix Gene Chip System) on sets of uterine protein and RNA extracts, respectively, and (3) immunohistochemical analysis on uterine sections; all from both initiation stage and promotion stage groups of animals. Here we report that: (1) progression of the neonatal DES-induced hyperplasia/dysplasia/neoplasia phenomenon in the hamster uterus involves a wide spectrum of specific gene expression alterations and (2) the gene products involved and their manner of altered expression differ dramatically during the initiation vs. promotion stages of the phenomenon. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Sex-specific modulation of the gut microbiome and behavior in Siberian hamsters.

    PubMed

    Sylvia, Kristyn E; Jewell, Cathleen P; Rendon, Nikki M; St John, Emma A; Demas, Gregory E

    2017-02-01

    The gut microbiome is a diverse, host-specific, and symbiotic bacterial environment that is critical for mammalian survival and exerts a surprising yet powerful influence on brain and behavior. Gut dysbiosis has been linked to a wide range of physical and psychological disorders, including autism spectrum disorders and anxiety, as well as autoimmune and inflammatory disorders. A wealth of information on the effects of dysbiosis on anxiety and depression has been reported in laboratory model systems (e.g., germ-free mice); however, the effects of microbiome disruption on social behaviors (e.g., aggression) of non-model species that may be particularly important in understanding many aspects of physiology and behavior have yet to be fully explored. Here we assessed the sex-specific effects of a broad-spectrum antibiotic on the gut microbiome and its effects on social behaviors in male and female Siberian hamsters (Phodopus sungorus). In Experiment 1, we administered a broad-spectrum antibiotic on a short-term basis and found that antibiotic treatment altered the microbial communities in the gut in male and female hamsters. In Experiment 2, we tested the effects of single versus repeated antibiotic treatment (including a recovery phase) on behavior, and found that two, but not one, treatments caused marked decreases in aggressive behavior, but not other social behaviors, in males; aggression returned to normal levels following recovery. Antibiotic-treated females, in contrast, showed decreased aggression after a single treatment, with all other social behaviors unaffected. Unlike males, female aggression did not return to normal during either recovery period. The present findings demonstrate that modest antibiotic treatment results in marked disruption of the gut microbiome in hamsters, akin to research done in other rodent species and humans. Further, we show that treatment with a broad-spectrum antibiotic, which has dysbiotic effects, also has robust, sex

  13. Characteristics of the uridine uptake system in normal and polyoma transformed hamster embryo cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lemkin, J.A.

    1973-01-01

    The lability of the uridine uptake system in the normal and polyoma transformed hamster embryo fibroblast was studied. The major areas investigated were: the kinetic parameters of uridine transport, a comparison of changes in cellular ATP content by factors which modulate uridine uptake, and a comparison of the qualitative and quantitative effects of the same modulating agent on uridine transport, cell growth, and cellular ATP content. Uridine uptake into cells in vitro was examined using tritiated uridine as a tracer to measure the amount of uridine incorporated into the acid soluble and acid-insoluble fractions of the cells studied. The ATPmore » content of the cells was determined by the firefly bioluminescence method. It was found that the K/sub t/ for uridine uptake into the normal hamster embryo cell and two polyoma transformed hamster embryo cell lines was identical. However, the V/sub max/ for uridine transport was higher in both polyoma transformed cell lines. Furthermore, the K/sub t/ in both the normal and transformed cell cultured in serum-less or serum-containing media was identical, although the V/sub max/ was higher in the serum-stimulated cell in both the normal and transformed cell. Stimulation of the normal cell with adenosine produced a different K/sub t/ for uridine transport. Preliminary investigations have demonstrated that treatment of the polyoma transformed with adenosine also induces a different K/sub t/ (not shown). The K/sub i/ for phloretin inhibition in serum-less and serum-stimulated normal and polyoma transformed cells was found to be identical in each case.« less

  14. Development of Chronic and Acute Golden Syrian Hamster Infection Models with Leptospira borgpetersenii serovar Hardjo

    USDA-ARS?s Scientific Manuscript database

    The golden Syrian hamster (Mesocricetus auratus) is frequently used as a model to study virulence for several species of Leptospira. Onset of an acute, lethal infection following infection with several pathogenic Leptospira species has been widely adopted for vaccine testing. An important exceptio...

  15. Estrogen suppresses melatonin-enhanced hyperactivation of hamster spermatozoa

    PubMed Central

    FUJINOKI, Masakatsu; TAKEI, Gen L.

    2015-01-01

    Hamster sperm hyperactivation is enhanced by progesterone, and this progesterone-enhanced hyperactivation is suppressed by 17β-estradiol (17βE2) and γ-aminobutyric acid (GABA). Although it has been indicated that melatonin also enhances hyperactivation, it is unknown whether melatonin-enhanced hyperactivation is also suppressed by 17βE2 and GABA. In the present study, melatonin-enhanced hyperactivation was significantly suppressed by 17βE2 but not by GABA. Moreover, suppression of melatonin-enhanced hyperactivation by 17βE2 occurred through non-genomic regulation via the estrogen receptor (ER). These results suggest that enhancement of hyperactivation is regulated by melatonin and 17βE2 through non-genomic regulation. PMID:25959801

  16. Effects of female odors on the sexual behavior of male hamsters.

    PubMed

    Johnston, R E

    1986-09-01

    A series of experiments was undertaken to investigate the effects of removal of several scent glands and scent-producing organs of female hamsters on the copulatory performance of male hamsters. In the first experiment it was shown that males engage in less copulatory activity toward females lacking vaginal secretions than toward females with these odors. Eliminating visual cues by observing pairs under infrared illumination did not change the performance of males toward these two kinds of females. The results of Experiment 2 indicated the importance of flank, ear, and Harderian glands as well as vaginal secretions--males showed the highest levels of copulatory behavior toward females with a full complement of odors and the lowest levels toward those lacking three of four sources of scent. Similar results were obtained in the third experiment in which anesthetized females were used as stimulus animals to increase the importance of chemical cues and to reduce variability due to the behavior of females. The sexual behavior of males was greatest toward females with all sources of scent present, lower toward those lacking vaginal secretions, and still lower toward those lacking vaginal secretions and other sources of odors. In the fourth experiment we asked whether any one of the nonvaginal scent glands was particularly important in stimulating male sexual behavior, but we found no differences in male performance toward females that lacked vaginal secretions or that in addition lacked one of the other scent glands. In the fifth experiment males displayed higher levels of sexual behavior toward vaginectomized females than toward vaginectomized females that had been deodorized by a cleaning procedure, again indicating the importance of nonvaginal odors in stimulating copulatory performance. Thus these experiments demonstrate the importance of vaginal secretions in the sexual arousal of male hamsters, a role for nonvaginal odors in sexual arousal of males, and the lack of

  17. Suppression by Saccharomyces boulardii of toxigenic Clostridium difficile overgrowth after vancomycin treatment in hamsters.

    PubMed Central

    Elmer, G W; McFarland, L V

    1987-01-01

    Saccharomyces boulardii prevented the development of high counts of Clostridium difficile, high titers of toxin B, and positive latex agglutination tests after cessation of vancomycin treatment for hamsters. The protocol used was designed to stimulate relapse of human C. difficile-associated colitis. S. boulardii was protective in this model. PMID:3566236

  18. Topical chlorophyll-pheophytin derivative-mediated photodynamic therapy for DMBA-induced hamster buccal pouch premaligant lesions: an in vivo study

    NASA Astrophysics Data System (ADS)

    Hsu, Yih-Chih; Chiang, Chung-Pin; Chen, Jian Wen; Lee, Jeng-Woei; How, Mon-Hsin

    2010-02-01

    In Taiwan, oral cancer has become a prominent cancer because of its highest annual increase rate among all cancer diseases. Betel quid chewing habit is a major risk factor for oral precancerous and cancerous lesions and there are more than two million people who have this habit in Taiwan. Our previous studies showed that chlorophyll-pheophytin derivative (CPD)-mediated PDT is very effective for killing of SCC-4 cell lines in vitro. In order to decrease the systemic phototoxic effect of CPD, this study was designed to use a topical CPD-mediated PDT for treatment of DMBA-induced hamster buccal pouch precancerous lesions. DMBA was applied to one of the buccal pouches of hamsters thrice a week for 8 to 10 weeks. Precancerous lesions of moderate to severe dysplasia were induced and proven by histological examination. These induced precancerous lesions were used for testing the efficacy of topical CPD-mediated PDT. Before PDT, fluorescence spectroscopy was used to determine when CPD reached its peak level in the lesional epithelial cells after topical application of CPD gel. We found that CPD reached its peak level in precancerous lesions about 1 hour (range, 0 to 30 hours) after topical application of CPD gel. The precancerous lesions in hamsters were then treated with topical CPD-mediated PDT (fluence rate: 200 mW/cm2; light exposure dose 100 J/cm2) using the portable WonderLight LED 635 nm fiber-guided light device once or twice a week. Visual and histological examination demonstrated that topical CPD-mediated PDT was partially effective treatment modality for DMBA-induced hamster buccal pouch precancerous lesions.

  19. Inhaled ozone as a mutagen. II - Effect on the frequency of chromosome aberrations observed in irradiated Chinese hamsters.

    NASA Technical Reports Server (NTRS)

    Zelac, R. E.; Cromroy, H. L.; Bolch, W. E., Jr.; Dunavant, B. G.; Bevis, H. A.

    1971-01-01

    Exposure-adjusted break frequencies for chromosome aberrations produced in Chinese hamster circulating blood lymphocytes were the quantitative indicator of damage from 5 hrs of exposure to X-radiation and/or to ozone. Radiation produced 5.51 x 0.0001 breaks/cell rad for cells withdrawn 2 weeks after exposure, a reasonable value when compared with data from in vivo exposure of human lymphocytes and Chinese hamster bone marrow cells. Animals exposed to the two agents simultaneously exhibited more than 70% of the total breaks anticipated assuming the expected equal contributions to be additive. Extending to humans, at presently permitted levels, exposure to ozone would be much more detrimental than exposure to radiati*n.

  20. Hypothyroidism Attenuates SCH 23390-mediated Depression of Breathing and Decreases D1 Receptor Expression in Carotid Bodies, PVN and Striatum of Hamsters

    PubMed Central

    Schlenker, Evelyn H.; Schultz, Harold D.

    2011-01-01

    Hypothyroidism can lead to depressed breathing. We determined if propylthiouracil (PTU)–induced hypothyroidism in hamsters (HH) altered dopamine D1 receptor expression, D1 receptor-modulated ventilation, and ventilatory chemoreflex activation by hypoxia or hypercapnia. Hypothyroidism was induced by administering 0.04% PTU in drinking water for three months. Ventilation was evaluated following saline or 0.25 mg/kg SCH 23390, a D1 receptor antagonist, while awake hamsters breathed normoxic (21% O2 in N2), hypoxic (10% O2 in N2) and hypercapnic (5% CO2 in O2) air. Relative to euthyroid hamsters (EH), HH exhibited decreased D1 receptor protein levels in carotid bodies, striatum, and hypothalamic paraventricular nucleus, but not in the nucleus tractus solitarius. Relative to EH, HH exhibited lower ventilation during exposure to normoxia, hypoxia, or hypercapnia, but comparable ventilatory responsiveness to chemoreflex activation. SCH 23390 decreased ventilation of EH hamsters exposed to normoxia, hypoxia, and hypercapnia. In HH SCH 23390 increased ventilation during baseline normoxia and did not affect ventilation during exposure to hypoxia and hypercapnia, resulting in reduced ventilatory responsivess to chemoreflex activation by hypoxia and hypercapnia. Furthermore, in HH D1 receptor protein levels are decreased in several brain regions and within the carotid bodies. Moreover, D1 receptor-modulation of breathing at rest and during gas exposures were depressed in EH but not HH. PMID:21669406

  1. Modeling Severe Fever with Thrombocytopenia Syndrome Virus Infection in Golden Syrian Hamsters: Importance of STAT2 in Preventing Disease and Effective Treatment with Favipiravir

    PubMed Central

    Westover, Jonna B.; Miao, Jinxin; Van Wettere, Arnaud J.; Rigas, Johanna D.; Hickerson, Brady T.; Jung, Kie-Hoon; Li, Rong; Conrad, Bettina L.; Nielson, Skot; Furuta, Yousuke; Wang, Zhongde

    2016-01-01

    ABSTRACT Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne disease endemic in parts of Asia. The etiologic agent, SFTS virus (SFTSV; family Bunyaviridae, genus Phlebovirus) has caused significant morbidity and mortality in China, South Korea, and Japan, with key features of disease being intense fever, thrombocytopenia, and leukopenia. Case fatality rates are estimated to be in the 30% range, and no antivirals or vaccines are approved for use for treatment and prevention of SFTS. There is evidence that in human cells, SFTSV sequesters STAT proteins in replication complexes, thereby inhibiting type I interferon signaling. Here, we demonstrate that hamsters devoid of functional STAT2 are highly susceptible to as few as 10 PFU of SFTSV, with animals generally succumbing within 5 to 6 days after subcutaneous challenge. The disease included marked thrombocytopenia and inflammatory disease characteristic of the condition in humans. Infectious virus titers were present in the blood and most tissues 3 days after virus challenge, and severe inflammatory lesions were found in the spleen and liver samples of SFTSV-infected hamsters. We also show that SFTSV infection in STAT2 knockout (KO) hamsters is responsive to favipiravir treatment, which protected all animals from lethal disease and reduced serum and tissue viral loads by 3 to 6 orders of magnitude. Taken together, our results provide additional insights into the pathogenesis of SFTSV infection and support the use of the newly described STAT2 KO hamster model for evaluation of promising antiviral therapies. IMPORTANCE Severe fever with thrombocytopenia syndrome (SFTS) is an emerging viral disease for which there are currently no therapeutic options or available vaccines. The causative agent, SFTS virus (SFTSV), is present in China, South Korea, and Japan, and infections requiring medical attention result in death in as many as 30% of the cases. Here, we describe a novel model of SFTS in

  2. Modeling Severe Fever with Thrombocytopenia Syndrome Virus Infection in Golden Syrian Hamsters: Importance of STAT2 in Preventing Disease and Effective Treatment with Favipiravir.

    PubMed

    Gowen, Brian B; Westover, Jonna B; Miao, Jinxin; Van Wettere, Arnaud J; Rigas, Johanna D; Hickerson, Brady T; Jung, Kie-Hoon; Li, Rong; Conrad, Bettina L; Nielson, Skot; Furuta, Yousuke; Wang, Zhongde

    2017-02-01

    Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne disease endemic in parts of Asia. The etiologic agent, SFTS virus (SFTSV; family Bunyaviridae, genus Phlebovirus) has caused significant morbidity and mortality in China, South Korea, and Japan, with key features of disease being intense fever, thrombocytopenia, and leukopenia. Case fatality rates are estimated to be in the 30% range, and no antivirals or vaccines are approved for use for treatment and prevention of SFTS. There is evidence that in human cells, SFTSV sequesters STAT proteins in replication complexes, thereby inhibiting type I interferon signaling. Here, we demonstrate that hamsters devoid of functional STAT2 are highly susceptible to as few as 10 PFU of SFTSV, with animals generally succumbing within 5 to 6 days after subcutaneous challenge. The disease included marked thrombocytopenia and inflammatory disease characteristic of the condition in humans. Infectious virus titers were present in the blood and most tissues 3 days after virus challenge, and severe inflammatory lesions were found in the spleen and liver samples of SFTSV-infected hamsters. We also show that SFTSV infection in STAT2 knockout (KO) hamsters is responsive to favipiravir treatment, which protected all animals from lethal disease and reduced serum and tissue viral loads by 3 to 6 orders of magnitude. Taken together, our results provide additional insights into the pathogenesis of SFTSV infection and support the use of the newly described STAT2 KO hamster model for evaluation of promising antiviral therapies. Severe fever with thrombocytopenia syndrome (SFTS) is an emerging viral disease for which there are currently no therapeutic options or available vaccines. The causative agent, SFTS virus (SFTSV), is present in China, South Korea, and Japan, and infections requiring medical attention result in death in as many as 30% of the cases. Here, we describe a novel model of SFTS in hamsters genetically

  3. Histological study of cell migration in the dermis of hamsters after immunisation with two different vaccines against visceral leishmaniasis.

    PubMed

    Moreira, Nádia das Dores; Giunchetti, Rodolfo Cordeiro; Carneiro, Cláudia Martins; Vitoriano-Souza, Juliana; Roatt, Bruno Mendes; Malaquias, Luiz Cosme Cotta; Corrêa-Oliveira, Rodrigo; Reis, Alexandre Barbosa

    2009-04-15

    Vaccine candidates, including live and/or killed parasites, Leishmania-purified fractions, defined recombinant antigens and antigen-encoding DNA-plasmids have been proposed to use as vaccine anti-Leishmania. More recently, the hamsters have been used to pre-selection of antigens candidate to apply in further experiments using canine model. In this report we evaluated the kinetics of cell migration in dermal inflammatory infiltrate, circulating leukocytes and the presence of nitric oxide (NO)/induced nitric oxide synthase during the early (1-24h) and late (48-168h) periods following inoculation of hamsters with antigenic components of anti-canine visceral leishmaniasis vaccines Leishmune and Leishmania braziliensis antigen (LB) with and without saponin (Sap) adjuvant. Our results show that LB caused an early reduction of lymphocytes in the dermis while Sap and LBSap triggered a late recruitment, suggesting the role of the adjuvant in the traffic of antigen-presenting cells and the induction of lymphocyte migration. In that manner our results suggest that the kinetics of cell migration on hamster model may be of value in the selection of vaccine antigens prior the tests in dogs particularly in respect of the toxicity of the preparations.

  4. Influence of photoperiod on pineal melatonin synthesis, fur color, body weight, and reproductive function in the female Djungarian hamster, Phodopus sungorus.

    PubMed

    Lerchl, A; Schlatt, S

    1993-01-01

    In order to investigate female Djungarian hamsters' reactions to changes of the photoperiod, the following two experiments were performed. Experiment I: Age-matched female hamsters were exposed to either short (8L:16D) or long days (16L:8D) for 38 weeks. Initially, the short-day group showed a decline in body weight, associated with changes in gonadal function and fur color. This was not maintained by the short-day group which returned, on the most part, to long-day levels, thus becoming insensitive to this regressive lighting regimen. The time courses of these events compare well with those observed in males, which suggests a common mechanism. Experiment II: Two groups of female hamsters were exposed for 8 weeks to either long days or short days. At the end of the test period, the diurnal variations in pineal content of melatonin, serotonin, hydroxyindole acetic acid, and serum melatonin were estimated, revealing marked differences between the two groups. Not only was there a prolongation of melatonin synthesis observed in the short-day animals, but there was also a significant elevation of the melatonin levels when compared to the long-day animals. Together with recent findings in males, these findings lend support to the hypothesis that, in the Djungarian hamster, the elevation of nocturnal melatonin levels may be of additional significance, with respect to the physiological changes induced by short-day photoperiods.

  5. Phylogenetic relationships between Hapalemur species and subspecies based on mitochondrial DNA sequences

    PubMed Central

    Fausser, Jean-Luc; Prosper, Prosper; Donati, Giuseppe; Ramanamanjato, Jean-Baptiste; Rumpler, Yves

    2002-01-01

    Background Phylogenetic relationships of the genus Hapalemur remains controversial, particularly within the Hapalemur griseus species group. In order to obtain more information on the taxonomic status within this genus, and particularly in the cytogenetic distinct subspecies group of Hapalemur griseus, 357 bp sequence of cytochrome b and 438 bp of 12S mitochondrial DNAs were analyzed on a sample of animals captured in areas extending from the north to the south-east of Madagascar. This sample covers all cytogenetically defined types recognized of the genus Hapalemur. Results Phylogenetic trees and distances analyses demonstrate a first emergence of Hapalemur simus followed by H. aureus which is the sister clade of the H. griseus subspecies. Hapalemur griseus is composed of 4 subspecies separated into two clades. The first contains H. g. griseus, H. g. alaotrensis and H. g. occidentalis. The second consists of H. g. meridionalis. A new chromosomal polymorphic variant from the region of Ranomafana, H. griseus ssp, has been analysed and was found in both clades. Conclusions Our results support the raising of H. g. meridionalis to the specific rank H. meridionalis, while neither cytogenetic nor molecular evidences support the raising of H. g. alaotrensis to a species rank despite its morphological characteristics. The new cytotype H. g. ssp which has been previously characterized by cytogenetic studies contains animals clustering either with the group of Hapalemur griseus griseus or with that of Hapalemur meridionalis. This suggests the existence of an ancestral polymorphism or an introgression of mitochondrial DNA between subspecies. PMID:11914128

  6. Phylogeographic structure of the Common hamster (Cricetus cricetus L.): Late Pleistocene connections between Caucasus and Western European populations

    PubMed Central

    Meschersky, Ilya G.; Bogomolov, Pavel L.; Sayan, Alexandra S.; Poplavskaya, Natalia S.; Surov, Alexey V.

    2017-01-01

    The Common hamster (Cricetus cricetus) is one of the most endangered mammals in Western and Central Europe. Its genetic diversity in Russia and Kazakhstan was investigated for the first time. The analysis of sequences of an mtDNA control region and cytochrome b gene revealed at least three phylogenetic lineages. Most of the species range (approximately 3 million km2), including central Russia, Crimea, the Ural region, and northern Kazakhstan), is inhabited by a single, well-supported phylogroup, E0. Phylogroup E1, previously reported from southeastern Poland and western Ukraine, was first described from Russia (Bryansk Province). E0 and E1 are sister lineages but both are monophyletic and separated by considerable genetic distance. Hamsters inhabiting Ciscaucasia represent a separate, distant phylogenetic lineage, named “Caucasus”. It is sister to the North phylogroup from Western Europe and the contemporary phylogeography for this species is discussed considering new data. These data enabled us to develop a new hypothesis to propose that in the Late Pleistocene, the continuous range of the Common hamster in the northern Mediterranean extended from the central and southern parts of modern France to the Caucasus; however, its distribution was subsequently interrupted, likely because of climate change. PMID:29095950

  7. Effects of geolocation archival tags on reproduction and adult body mass of sooty shearwaters (Puffinus griseus)

    USGS Publications Warehouse

    Adams, J.; Scott, D.; McKechnie, S.; Blackwell, G.; Shaffer, S.A.; Moller, H.

    2009-01-01

    We attached 11 g (1.4% body-mass equivalent) global location sensing (GLS) archival tag packages to tarsi of 25 breeding sooty shearwaters (Puffinus griseus, titi) on Whenua Hou (Codfish Island), New Zealand during the chick-rearing period in 2005. Compared with chicks reared by non-handled adults that did not carry tags, deployment of tags on one or both adult parents ultimately resulted in 35% reduction in chick body mass and significantly reduced chick skeletal size preceding fledging (19 April). However, body mass between chick groups was not significantly different after controlling for skeletal size. Effects on chicks were more pronounced in six pairs where both parents carried tags. Chick mass was negatively related to the duration that adults carried tags. In this study, none of the chicks reared by pairs where both parents were tagged, 54% of chicks reared by pairs where one parent was tagged, and 83% of chicks reared by non-handled and non-tagged parents achieved a previously determined pre-fledging mass threshold (564 g; Sagar & Horning 1998). Body mass of adults carrying tags and returning from transequatorial migration the following year were 4% lighter on average than non-tagged birds, but this difference was not statistically significant. Reduced mass among chicks reared by adults carrying tags during the chick-provisioning period indicated that adults altered "normal" provisioning behaviours to maintain their own body condition at the expense of their chicks. Population-level information derived from telemetry studies can reveal important habitat-linked behaviours, unique aspects of seabird foraging behaviours, and migration ecology. Information for some species (e.g., overlap with fisheries) can aid conservation and marine ecosystem management. We advise caution, however, when interpreting certain data related to adult provisioning behaviours (e.g., time spent foraging, provisioning rates, etc.). If effects on individuals are of concern, we suggest

  8. Milrinone Attenuates Arteriolar Vasoconstriction and Capillary Perfusion Deficits on Endotoxemic Hamsters

    PubMed Central

    de Miranda, Marcos Lopes; Pereira, Sandra J.; Santos, Ana O. M. T.; Villela, Nivaldo R.; Kraemer-Aguiar, Luiz Guilherme; Bouskela, Eliete

    2015-01-01

    Background and Objective Apart from its inotropic property, milrinone has vasodilator, anti-inflammatory and antithrombotic effects that could assist in the reversal of septic microcirculatory changes. This paper investigates the effects of milrinone on endotoxemia-related microcirculatory changes and compares them to those observed with the use of norepinephrine. Materials and Methods After skinfold chamber implantation procedures and endotoxemia induction by intravenous Escherichia coli lipopolysaccharide administration (2 mg.kg-1), male golden Syrian hamsters were treated with two regimens of intravenous milrinone (0.25 or 0.5 μg.kg-1.min-1). Intravital microscopy of skinfold chamber preparations allowed quantitative analysis of microvascular variables. Macro-hemodynamic, biochemical, and hematological parameters and survival rate were also analyzed. Endotoxemic non-treated animals, endotoxemic animals treated with norepinephrine (0.2 μg.kg-1.min-1), and non-endotoxemic hamsters served as controls. Results Milrinone (0.5 μg.kg-1.min-1) was effective in reducing lipopolysaccharide-induced arteriolar vasoconstriction, capillary perfusion deficits, and inflammatory response, and in increasing survival. Norepinephrine treated animals showed the best mean arterial pressure levels but the worst functional capillary density values among all endotoxemic groups. Conclusion Our data suggests that milrinone yielded protective effects on endotoxemic animals’ microcirculation, showed anti-inflammatory properties, and improved survival. Norepinephrine did not recruit the microcirculation nor demonstrated anti-inflammatory effects. PMID:25646813

  9. Inhibiting Sperm Pyruvate Dehydrogenase Complex and Its E3 Subunit, Dihydrolipoamide Dehydrogenase Affects Fertilization in Syrian Hamsters

    PubMed Central

    Sailasree, Purnima; Singh, Durgesh K.; Kameshwari, Duvurri B.; Shivaji, Sisinthy

    2014-01-01

    Background/Aims The importance of sperm capacitation for mammalian fertilization has been confirmed in the present study via sperm metabolism. Involvement of the metabolic enzymes pyruvate dehydrogenase complex (PDHc) and its E3 subunit, dihydrolipoamide dehydrogenase (DLD) in hamster in vitro fertilization (IVF) via in vitro sperm capacitation is being proposed through regulation of sperm intracellular lactate, pH and calcium. Methodology and Principal Findings Capacitated hamster spermatozoa were allowed to fertilize hamster oocytes in vitro which were then assessed for fertilization, microscopically. PDHc/DLD was inhibited by the use of the specific DLD-inhibitor, MICA (5-methoxyindole-2-carboxylic acid). Oocytes fertilized with MICA-treated (MT) [and thus PDHc/DLD-inhibited] spermatozoa showed defective fertilization where 2nd polar body release and pronuclei formation were not observed. Defective fertilization was attributable to capacitation failure owing to high lactate and low intracellular pH and calcium in MT-spermatozoa during capacitation. Moreover, this defect could be overcome by alkalinizing spermatozoa, before fertilization. Increasing intracellular calcium in spermatozoa pre-IVF and in defectively-fertilized oocytes, post-fertilization rescued the arrest seen, suggesting the role of intracellular calcium from either of the gametes in fertilization. Parallel experiments carried out with control spermatozoa capacitated in medium with low extracellular pH or high lactate substantiated the necessity of optimal sperm intracellular lactate levels, intracellular pH and calcium during sperm capacitation, for proper fertilization. Conclusions This study confirms the importance of pyruvate/lactate metabolism in capacitating spermatozoa for successful fertilization, besides revealing for the first time the importance of sperm PDHc/ DLD in fertilization, via the modulation of sperm intracellular lactate, pH and calcium during capacitation. In addition, the

  10. The induction by X-rays of chromosome aberrations in male guinea-pigs, golden hamsters and rabbits. II. Properties of translocations induced in post-meiotic stages.

    PubMed

    Cox, B D; Lyon, M F

    1975-07-01

    Translocations induced by X-rays in post-meiotic germ cells of male guinea-pigs, golden hamsters and rabbits were studied cytologically in the F1 sons of the irradiated males. The percentage of spermatocytes displaying multivalent configurations varied with the translocation, but the average percentage appeared to depend on the species: fewer quadrivalents were observed in hamster than in guinea-pig heterozygotes and most were recorded for rabbit heterozygotes. Chain quadrivalents were more abundant than ring quadrivalents at meiosis for the guinea-pig and hamster, in contrast to the mouse. Too few translocation heterozygotes were examined to determine which meiotic configuration was the more prevalent in the rabbit. In all three species, as in the mouse, translocations were found which caused male sterility, due to partial or complete failure of spermatogenesis, although most translocations caused semi-sterility. For these semi-sterile males both the frequency and time of embryonic death in the progeny appeared to be the same as in the mouse. It is concluded that similar types of chromosome aberrations are induced by X-rays in post-meiotic germ cells of male guinea-pigs, rabbits, golden hamsters and mice.

  11. Effect of mangrove black tea extract from Ceriops decandra (Griff.) on hematology and biochemical changes in dimethyl benz[a]anthracene-induced hamster buccal pouch carcinogenesis.

    PubMed

    Sithranga Boopathy, N; Kathiresan, K; Jeon, Y J

    2011-09-01

    Effect of the black tea extracted from a mangrove plant species, Ceriops decandra (Griff.) was studied on dimethyl benz[a]anthracene (DMBA)-induced changes in blood hematology and plasma non-enzymatic antioxidants in male hamsters. Hamsters were painted with 0.5% solution of DMBA in liquid paraffin on the right buccal pouch three times in a week up to 14 weeks. Each application treated with 0.4mg of DMBA. The mangrove black tea extract (MBTE) was administrated orally with 5mgkg(-1) twice a day and then with DMBA on alternate days. Results showed that the DMBA caused a significant (P<0.05) decline in the levels of reduced glutathione (GSH), vitamin-C, -E, red blood cells, hemoglobin, mean corpuscular volume and hematocrit; and increase in the levels of WBC, platelets, lymphocytes and neutrophils. The MBTE prevented the DMBA-induced adverse changes significantly in blood and biochemical parameters of the male hamsters. This work concluded that the black tea extracted from the coastal mangrove species C. decandra prevented the DMBA-induced buccal pouch carcinogenesis in hamsters. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Conditioned flavor aversion and location avoidance in hamsters from toxic extract of tall larkspur (Delphinium barbeyi)

    USDA-ARS?s Scientific Manuscript database

    Studies were conducted to address conditioned flavour aversion (CFA) and place avoidance learning in hamsters given injections of alkaloid extracts from tall larkspur (Delphinium barbeyi), to determine if larkspur had reinforcing or negative properties sufficient to cause place avoidance or preferen...

  13. Ammonium Sulfate Fractionation of Sera: Mouse, Hamster, Guinea Pig, Monkey, Chimpanzee, Swine, Chicken, and Cattle

    PubMed Central

    Hebert, G. Ann

    1974-01-01

    Optimal (NH4)2SO4 concentrations were sought for serum fractionation in order to obtain the gamma globulin as free as possible from other serum components while maintaining a reasonable recovery. Various ammonium sulfate concentrations were used to fractionate sera from mice, hamsters, guinea pigs, monkeys, chimpanzees, swine, chicken, and cattle. All precipitates and supernatants were analyzed by electrophoresis to study the effects of various treatments on the composition of these materials. Approximately 75% of all the gamma globulins were recovered when each serum was fractionated with its optimal sulfate concentration. These optimals were determined to be as follows: three precipitations in 35% saturated ammonium sulfate (SAS) for hamster, chimpanzee, swine, and chicken serum; one precipitation in 35% SAS followed by two in 40% SAS for mouse and guinea pig serum; one precipitation in 30% SAS and then two in 40% SAS for monkey serum; and one precipitation in 30% SAS followed by two in 35% SAS for cattle serum. Images PMID:4132689

  14. A role for glucose in hypothermic hamsters

    NASA Technical Reports Server (NTRS)

    Resch, G. E.; Musacchia, X. J.

    1976-01-01

    Hypothermic hamsters at a rectal temperature of 7 C showed a fivefold increase in survival times from 20 to 100.5 hr when infused with glucose which maintained a blood level at about 45 mg/100 ml. A potential role for osmotic effects of the infusion was tested and eliminated. There was no improvement in survival of 3-O-methylglucose or dextran 40-infused animals. The fact that death eventually occurs even in the glucose-infused animal after about 4 days and that oxygen consumption undergoes a slow decrement in that period suggests that hypothermic survival is not wholly substrate limited. Radioactive tracer showed that localization of the C-14 was greatest in brain tissue and diaphragm, intermediate in heart and kidney, and lowest in skeletal muscle and liver. The significance of the label at sites important to respiration and circulation was presented.

  15. BCX4430, a novel nucleoside analog, effectively treats yellow fever in a Hamster model.

    PubMed

    Julander, Justin G; Bantia, Shanta; Taubenheim, Brian R; Minning, Dena M; Kotian, Pravin; Morrey, John D; Smee, Donald F; Sheridan, William P; Babu, Yarlagadda S

    2014-11-01

    No effective antiviral therapies are currently available to treat disease after infection with yellow fever virus (YFV). A Syrian golden hamster model of yellow fever (YF) was used to characterize the effect of treatment with BCX4430, a novel adenosine nucleoside analog. Significant improvement in survival was observed after treatment with BCX4430 at 4 mg/kg of body weight per day dosed intraperitoneally (i.p.) twice daily (BID). Treatment with BCX4430 at 12.5 mg/kg/day administered i.p. BID for 7 days offered complete protection from mortality and also resulted in significant improvement of other YF disease parameters, including weight loss, serum alanine aminotransferase levels (6 days postinfection [dpi]), and viremia (4 dpi). In uninfected hamsters, BCX4430 at 200 mg/kg/day administered i.p. BID for 7 days was well tolerated and did not result in mortality or weight loss, suggesting a potentially wide therapeutic index. Treatment with BCX4430 at 12 mg/kg/day i.p. remained effective when administered once daily and for only 4 days. Moreover, BCX4430 dosed at 200 mg/kg/day i.p. BID for 7 days effectively treated YF, even when treatment was delayed up to 4 days after virus challenge, corresponding with peak viral titers in the liver and serum. BCX4430 treatment did not preclude a protective antibody response, as higher neutralizing antibody (nAb) concentrations corresponded with increasing delays of treatment initiation, and greater nAb responses resulted in the protection of animals from a secondary challenge with YFV. In summary, BCX4430 is highly active in a hamster model of YF, even when treatment is initiated at the peak of viral replication. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  16. Deep brain stimulation changes basal ganglia output nuclei firing pattern in the dystonic hamster.

    PubMed

    Leblois, Arthur; Reese, René; Labarre, David; Hamann, Melanie; Richter, Angelika; Boraud, Thomas; Meissner, Wassilios G

    2010-05-01

    Dystonia is a heterogeneous syndrome of movement disorders characterized by involuntary muscle contractions leading to abnormal movements and postures. While medical treatment is often ineffective, deep brain stimulation (DBS) of the internal pallidum improves dystonia. Here, we studied the impact of DBS in the entopeduncular nucleus (EP), the rodent equivalent of the human globus pallidus internus, on basal ganglia output in the dt(sz)-hamster, a well-characterized model of dystonia by extracellular recordings. Previous work has shown that EP-DBS improves dystonic symptoms in dt(sz)-hamsters. We report that EP-DBS changes firing pattern in the EP, most neurons switching to a less regular firing pattern during DBS. In contrast, EP-DBS did not change the average firing rate of EP neurons. EP neurons display multiphasic responses to each stimulation impulse, likely underlying the disruption of their firing rhythm. Finally, neurons in the substantia nigra pars reticulata display similar responses to EP-DBS, supporting the idea that EP-DBS affects basal ganglia output activity through the activation of common afferent fibers. Copyright 2010 Elsevier Inc. All rights reserved.

  17. Immunosuppression Enhances Oncolytic Adenovirus Replication and Antitumor Efficacy in the Syrian Hamster Model

    PubMed Central

    Thomas, Maria A; Spencer, Jacqueline F; Toth, Karoly; Sagartz, John E; Phillips, Nancy J; Wold, William SM

    2012-01-01

    We recently described an immunocompetent Syrian hamster model for oncolytic adenoviruses (Ads) that permits virus replication in tumor cells as well as some normal tissues. This model allows exploration of interactions between the virus, tumor, normal organs, and host immune system that could not be examined in the immunodeficient or nonpermissive animal models previously used in the oncolytic Ad field. Here we asked whether the immune response to oncolytic Ad enhances or limits antitumor efficacy. We first determined that cyclophosphamide (CP) is a potent immunosuppressive agent in the Syrian hamster and that CP alone had no effect on tumor growth. Importantly, we found that the antitumor efficacy of oncolytic Ads was significantly enhanced in immunosuppressed animals. In animals that received virus therapy plus immunosuppression, significant differences were observed in tumor histology, and in many cases little viable tumor remained. Notably, we also determined that immunosuppression allowed intratumoral virus levels to remain elevated for prolonged periods. Although favorable tumor responses can be achieved in immunocompetent animals, the rate of virus clearance from the tumor may lead to varied antitumor efficacy. Immunosuppression, therefore, allows sustained Ad replication and oncolysis, which leads to substantially improved suppression of tumor growth. PMID:18665155

  18. Male hamsters discriminate estrous state from vaginal secretions and individuals from flank marks

    PubMed Central

    delBarco-Trillo, Javier; LaVenture, Alex B.; Johnston, Robert E.

    2009-01-01

    It is clear that male hamsters discriminate between the odors of individual, conspecific females, as shown by using habituation-dishabituation methods. However, it is not clear from past research whether male hamsters are able to discriminate between the odors of estrous and non-estrous females. A series of habituation-dishabituation experiments were conducted to determine whether males discriminated between different estrous cycle states using two female secretions, those from flank glands and vaginal secretions. We found that, when habituated to a female flank-gland secretion, males discriminated between this female and a second female on the test trial, whether both were in estrus, both were in diestrus, or one was in estrus and the other in diestrus. There was no difference, however, in the magnitude of their dishabituation response toward flank-gland odors of females in estrus and diestrus. These results suggest that males use flank-gland odors to gain information primarily about individuals. When tested with vaginal secretions in habituation-dishabituation tests, males only showed differences in investigation when the second female was in estrus, indicating that males use vaginal secretions to gain information primarily about reproductive state. PMID:19615611

  19. Male hamsters discriminate estrous state from vaginal secretions and individuals from flank marks.

    PubMed

    delBarco-Trillo, Javier; LaVenture, Alex B; Johnston, Robert E

    2009-09-01

    It is clear that male hamsters discriminate between the odors of individual, conspecific females, as shown by using habituation-dishabituation methods. However, it is not clear from past research whether male hamsters are able to discriminate between the odors of estrous and non-estrous females. A series of habituation-dishabituation experiments was conducted to determine whether males discriminated between different estrous cycle states using two female secretions, those from flank-glands and vaginal secretions. We found that, when habituated to a female flank-gland secretion, males discriminated between this female and a second female on the test trial, whether both were in estrus, both were in diestrus, or one was in estrus and the other in diestrus. There was no difference, however, in the magnitude of their dishabituation response toward flank-gland odors of females in estrus and diestrus. These results suggest that males use flank-gland odors to gain information primarily about individuals. When tested with vaginal secretions in habituation-dishabituation tests, males only showed differences in investigation when the second female was in estrus, indicating that males use vaginal secretions to gain information primarily about reproductive state.

  20. Comparative Analysis of Cellular Immune Responses in Treated Leishmania Patients and Hamsters against Recombinant Th1 Stimulatory Proteins of Leishmania donovani

    PubMed Central

    Joshi, Sumit; Yadav, Narendra K.; Rawat, Keerti; Tripathi, Chandra Dev P.; Jaiswal, Anil K.; Khare, Prashant; Tandon, Rati; Baharia, Rajendra K.; Das, Sanchita; Gupta, Reema; Kushawaha, Pramod K.; Sundar, Shyam; Sahasrabuddhe, Amogh A.; Dube, Anuradha

    2016-01-01

    Our prior studies demonstrated that cellular response of T helper 1 (Th1) type was generated by a soluble antigenic fraction (ranging from 89.9 to 97.1 kDa) of Leishmania donovani promastigote, in treated Leishmania patients as well as hamsters and showed significant prophylactic potential against experimental visceral leishmaniasis (VL). Eighteen Th1 stimulatory proteins were identified through proteomic analysis of this subfraction, out of which 15 were developed as recombinant proteins. In the present work, we have evaluated these 15 recombinant proteins simultaneously for their comparative cellular responses in treated Leishmania patients and hamsters. Six proteins viz. elongation factor-2, enolase, aldolase, triose phosphate isomerase, protein disulfide isomerase, and p45 emerged as most immunogenic as they produced a significant lymphoproliferative response, nitric oxide generation and Th1 cytokine response in PBMCs and lymphocytes of treated Leishmania patients and hamsters respectively. The results suggested that these proteins may be exploited for developing a successful poly-protein and/or poly-epitope vaccine against VL. PMID:27047452

  1. DNA (DEOXYRIBONUCLEIC ACID) SYNTHESIS FOLLOWING MICROINJECTION OF HETEROLOGOUS SPERM AND SOMATIC CELL NUCLEI INTO HAMSTER OOCYTES

    EPA Science Inventory

    The authors have investigated the ability of the hamster oocyte to initiate DNA synthesis in nuclei differing in basic protein content. DNA synthesis was studied by autoradiography in oocytes that had been incubated in 3H-thymidine after being parthenogenetically activated by sha...

  2. Alkaline phosphatases contribute to uterine receptivity, implantation, decidualization and defense against bacterial endotoxin in hamsters

    PubMed Central

    Lei, Wei; Nguyen, Heidi; Brown, Naoko; Ni, Hua; Kiffer-Moreira, Tina; Reese, Jeff; Millán, José Luis; Paria, Bibhash C.

    2013-01-01

    Alkaline phosphatase (AP) activity has been demonstrated in the uterus of several species, but its importance in the uterus, in general and during pregnancy, is yet to be revealed. In this study, we focused on identifying AP isozyme types, and their hormonal regulation, cell-type and event-specific expression and possible functions in the hamster uterus during the cycle and early pregnancy. Our RT-PCR and in situ hybridization studies demonstrated that among the known Akp2, Akp3, Akp5 and Akp6 murine AP isozyme genes, hamster uteri express only Akp2 and Akp6; and both genes are co-expressed in luminal epithelial cells. Studies in cyclic and ovariectomized hamsters established that while progesterone is the major uterine Akp2 inducer, both progesterone and estrogen are strong Akp6 regulators. Studies in preimplantation uteri showed induction of both genes and the activity of their encoded isozymes in luminal epithelial cells during uterine receptivity. However, at the beginning of implantation, Akp2 showed reduced expression in luminal epithelial cells surrounding the implanted embryo. In contrast, expression of Akp6 and its isozyme was maintained in luminal epithelial cells adjacent to, but not away from, the implanted embryo. Following implantation, stromal transformation to decidua was associated with induced expressions of only Akp2 and its isozyme. We next demonstrated that uterine APs dephosphorylate and detoxify endotoxin lipopolysaccharide at their sites of production and activity. Taken together, our findings suggest that uterine APs contribute to uterine receptivity, implantation, and decidualization in addition to their role in protection of the uterus and pregnancy against bacterial infection. PMID:23929901

  3. Tumor incidence was not related to the thickness of visceral pleural in female Syrian hamsters intratracheally administered amphibole asbestos or manmade fibers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Adachi, Shuichi; Kawamura, K.; Takemoto, Kazuo

    1992-06-01

    Histological observations were performed on female Syrian hamsters 2 years after the intratracheal administration of amphibole asbestos, amosite, and crocidolite to evaluate the tumorigenicity of six types of fine manmade fibers (reported previously). A mesothelioma and a lung tumor were induced in 20 animals administered amosite, but no tumors were found in the crocidolite group. Because this incidence is not higher than that of manmade fibers, such as basic magnesium sulfate fiber (9 tumor-bearing hamsters in 20 hamsters (9/20)), metaphosphate fiber (5/20), calcium sulfate fiber (3.20), and fiberglass (2/20), it is suggested that some types of manmade fibers have amore » greater ability than asbestos to induce tumors. Moreover, as a specific observation in manmade fiber groups, tumors were induced at intracelial organs rather than at the pleural cavity. On the other hand, the average thickness of visceral pleura was higher in all asbestos and manmade fiber groups than in the control (2.9 {mu}m), for instance, 36.95 {mu}m in potassium titanate fiber group, 15.90 {mu}m crocidolite group, 13.00 {mu}m basic magnesium sulfate fiber group, and 10.45 {mu} in the rockwool group. Although both pleural thickening and mesotherlioma were known as peculiar lesions in asbestos-exposed people, it might also be suggested that these lesions could be induced by different mechanisms from the result that there was no relation between the pleural thickening and mesothelioma incidence in hamsters.« less

  4. Fluoxetine disrupts motivation and GABAergic signaling in adolescent female hamsters.

    PubMed

    Shannonhouse, John L; DuBois, Dustin W; Fincher, Annette S; Vela, Alejandra M; Henry, Morgan M; Wellman, Paul J; Frye, Gerald D; Morgan, Caurnel

    2016-08-01

    Initial antidepressant treatment can paradoxically worsen symptoms in depressed adolescents by undetermined mechanisms. Interestingly, antidepressants modulate GABAA receptors, which mediate paradoxical effects of other therapeutic drugs, particularly in females. Although the neuroanatomic site of action for this paradox is unknown, elevated GABAA receptor signaling in the nucleus accumbens can disrupt motivation. We assessed fluoxetine's effects on motivated behaviors in pubescent female hamsters - anhedonia in the reward investigational preference (RIP) test as well as anxiety in the anxiety-related feeding/exploration conflict (AFEC) test. We also assessed accumbal signaling by RT-PCR and electrophysiology. Fluoxetine initially worsened motivated behaviors at puberty, relative to adulthood. It also failed to improve these behaviors as pubescent hamsters transitioned into adulthood. Low accumbal mRNA levels of multiple GABAA receptor subunits and GABA-synthesizing enzyme, GAD67, assessed by RT-PCR, suggested low GABAergic tone at puberty. Nonetheless, rapid fluoxetine-induced reductions of α5GABAA receptor and BDNF mRNA levels at puberty were consistent with age-related differences in GABAergic responses to fluoxetine and disruption of the motivational state. Whole-cell patch clamping of accumbal slices also suggested low GABAergic tone by the low amplitude of miniature inhibitory postsynaptic currents (mIPSCs) at puberty. It also confirmed age-related differences in GABAergic responses to fluoxetine. Specifically, fluoxetine potentiated mIPSC amplitude and frequency at puberty, but attenuated the amplitude during adulthood. These results implicate GABAergic tone and GABAA receptor plasticity in adverse motivational responses and resistance to fluoxetine during adolescence. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Inhibitory effect of esculin on oxidative DNA damage and carcinogenesis induced by N-nitrosobis(2-oxopropyl)amine in hamster pancreas.

    PubMed

    Kaneko, Takao; Tahara, Shoichi; Takabayashi, Fumiyo; Harada, Noboru

    2004-01-01

    The effects of esculin, a natural coumarin compound, on the formation of 8-oxo-2'-deoxyguanosine (8-oxodG) and carcinogenesis induced by a chemical carcinogen, N-nitrosobis(2-oxopropyl)amine (BOP), were examined in the pancreas of female Syrian golden hamsters. Animals were given a diet containing esculin for 7 days, and killed 4~h after BOP treatment, and the contents of 8-oxodG were measured in the nuclear DNA of the pancreas. Esculin suppressed significantly the increase in the 8-oxodG content of hamster pancreas induced by BOP. Furthermore, the effect of esculin on the rapid production model experiment for pancreatic carcinogenesis using BOP was investigated. Esculin was given ad libitum as a 0.05% aqueous solution during either the initiation or promotion phases. The incidence of invasive tumors in animals given esculin during the initiation phase was significantly lower than in the control group, while the incidence in animals given esculin during the promotion phase showed no significant change. These results suggest that the intake of esculin has an inhibitory effect on BOP-induced oxidative DNA damage and carcinogenesis in hamster pancreas.

  6. [Observation on alpha-SMA during Erigeron Breviscapus (Vant) Hand-Mazz obstructs the evolution of carcinogenesis of golden hamster cheek pouch].

    PubMed

    Zhou, C T; Zhang, S L; Ding, R Y; Hua, L; Zhong, W J

    2000-06-01

    To observe dynamically that Erigeron Breviscapus (Vant) Hand-Mazz (HEr) affects the expression of alpha-smooth muscle actin (alpha-SMA). To discuss the probable mechanism of obstructing leukoplakia carcinogenesis of this medicine. 120 golden hamsters were randomly divided into model group (48), HEr group (48) and control group (6). HEr was applied to obstruct the evolution of carcinogenesis of golden hamster cheek pouch. Immunohistochemistry was used to detect the expression level of alpha-SMA with cheek pouch specimen that besmears DMBA in 4-9 weeks. Results were compared with model group. Vessel density dyed with alpha-SMA continuously of HEr group was 65.76 significantly higher than that of model group 42.12 (P<0.001). High classification cases in HEr group were much more than model group when cases were divided into five groups as follow: 100%, 50%, 20%, 10%, 3% (P<0.01). HEr can raise the expression level of alpha-SMA exactly during the evolution of leukoplakia carcinogenesis of golden hamster, which shows that this medicine obstructs carcinogenesis by keeping the normal physiological function of vascular myoepithelial cell and integrity of vascular basement membrane.

  7. Substitution of drinking water by fructose solution induces hyperinsulinemia and hyperglycemia in hamsters.

    PubMed

    Barros, Carlos Magno M R; Lessa, Rosane Q; Grechi, Mauricio P; Mouço, Tanial L M; Souza, Maria das Graças C; Wiernsperger, Nicolas; Bouskela, Eliete

    2007-06-01

    To test the possibility of obtaining a practical and stable model of hyperinsulinemia and hyperglycemia in hamsters, substituting the drinking water by 10% or 20% fructose solutions for a period of 2, 4, or 6 months. Male hamsters were divided into 3 main groups, further divided in 3 subgroups: Two months: Group Ia control (n = 51) received filtered water, Group Ib (n = 49) received 10% fructose solution instead of water, Group Ic (n=8) received 20% fructose solution instead of water. Four months: Group IIa control (n=8), Group IIb 10% fructose (n = 7), Group IIc 20% fructose (FIIc, n = 7). Six months: Group IIIa control (n = 6), Group IIIb 10% Fructose (n = 6), Group IIIc 20% Fructose (n = 5). All groups were fed with the same laboratory diet. The animals were weighed every 2 weeks during the study period. On the final day of each experiment (61st, 121st, and 181st day after the beginning of the study, respectively), the animals were weighed and anesthetized for blood collection to determine plasma glucose and insulin after at least a 12-h fast. Ten animals of group Ia and 10 of group Ib were evaluated to determine changes in macromolecular permeability induced by ischemia/reperfusion as measured in the cheek pouch microcirculation. Compared to controls, the animals that drank the 10% or 20% fructose solution had significantly greater weight gain (P < .001), fasting plasma glucose (P < .001) Reperfusion, after 30 min ischemia, resulted in an immediate but reversible increase in postcapillary leakage (L) of 89.0 +/- 2.0 L/cm(2) (group Ia - controls), and 116.5 +/- 4.8 L/cm(2) (group Ib 10% fructose), P < .001. These results suggest that chronic administration of either 10% or 20% fructose solutions could be used to experimentally induce a stable hamster model of hyperinsulinemia and hyperglycemia. The model might facilitate the study of basic mechanisms of hyperglycemia and hyperinsulinemia affecting the microvasculature as demonstrated by the findings regarding

  8. Inhibitory effects of Zengshengping fractions on DMBA-induced buccal pouch carcinogenesis in hamsters.

    PubMed

    Guan, Xiao-Bing; Sun, Zheng; Chen, Xiao-Xin; Wu, Hong-Ru; Zhang, Xin-Yan

    2012-01-01

    Zengshengping (ZSP) tablets had inhibitory effects on oral precancerous lesions by reducing the incidence of oral cancer. However, the severe liver toxicity caused by systemic administration of ZSP limits the long-term use of this anti-cancer drug. The purpose of this study was to evaluate the tumor inhibitory effects due to the topical application of extracts from ZSP, a Chinese herbal drug, on 7, 12-dimethlbenz(a)anthracene (DMBA) induced oral tumors in hamsters. The study also investigated the anti-cancer mechanisms of the ZSP extracts on oral carcinogenesis. DMBA (0.5%) was applied topically to the buccal pouches of Syrian golden hamsters (6 - 8 weeks old) three times per week for six weeks in order to induce the development of oral tumors. Different fractions of ZSP were either applied topically to the oral tumor lesions or fed orally at varying dosages to animals with oral tumors for 18 weeks. Tumor volume was measured by histopathological examination. Tumor cell proliferation was evaluated by counting BrdU labeled cells and by Western blotting for mitogen-activated protein kinase (MAPK) protein levels. The protein levels of apoptosis marker Caspase-3 and regulator Bcl-2 protein were also measured by Western blotting. Topical application of DMBA to the left pouch of hamsters induced oral tumor formation. Animals treated with DMBA showed a loss in body weight while animals treated with ZSP maintained normal body weights. Both the ZSP n-butanol fraction and water fraction significantly reduced tumor volume by 32.6% (P < 0.01) and 22.9% (P < 0.01) respectively. Topical application of ZSP also markedly decreased the BrdU-positive cell numbers in oral tumor lesions and reduced the expression level of MAPK. In addition, ZSP promoted tumor cell apoptosis by increasing Caspase-3 expression but decreasing Bcl-2 protein production. The n-butanol and water fractions of ZSP are effective at inhibiting tumor cell proliferation and stimulating apoptosis in oral cancer

  9. An Intact Dorsomedial Posterior Arcuate Nucleus is Not Necessary for Photoperiodic Responses in Siberian Hamsters1

    PubMed Central

    Teubner, Brett J.W.; Leitner, Claudia; Thomas, Michael A.; Ryu, Vitaly; Bartness, Timothy J.

    2015-01-01

    Seasonal responses of many animal species are triggered by changes in daylength and its transduction into a neuroendocrine signal by the pineal gland through the nocturnal duration of melatonin (MEL) release. The precise central sites necessary to receive, transduce, and relay the short day (SD) fall-winter MEL signals into seasonal responses and changes in physiology and behavior are unclear. In Siberian hamsters, SDs trigger decreases in body and lipid mass, testicular regression and pelage color changes. Several candidate genes and their central sites of expression have been proposed as components of the MEL transduction system with considerable recent focus on the arcuate nucleus (ARC) and its component, the dorsomedial posterior arcuate nucleus (dmpARC). This site has been postulated as a critical relay of SD information through the modulation of a variety of neurochemicals/receptors important for the control of energy balance. Here the necessity of an intact dmpARC for SD responses was tested by making electrolytic lesions of the Siberian hamster dmpARC and then exposing them to either long days (LD) or SDs for 12 weeks. The SD typical decreases in body and fat mass, food intake, testicular volume, serum testosterone concentrations, pelage color change and increased UCP-1 protein expression (a proxy for brown adipose tissue thermogenesis) all occurred despite the lack of an intact dmpARC. Although the Siberian hamster dmpARC contains photoperiod-modulated constituents, these data demonstrate that an intact dmpARC is not necessary for SD responses and not integral to the seasonal energy- and reproductive-related responses measured here. PMID:25647158

  10. An increase in estradiol facilitates the onset of paternal behavior in the dwarf hamster (Phodopus campbelli).

    PubMed

    Romero-Morales, Luis; Martínez-Torres, Martín; Cárdenas, Mario; Álvarez, Carmen; Carmona, Agustín; Cedillo, Benita; Loya-Zurita, Eduardo; Luis, Juana

    2018-03-01

    In the dwarf hamster (Phodopus campbelli), activational effects of testosterone (T) and estradiol (E 2 ) in the regulation of paternal behavior have been repeatedly rejected because peripheral concentrations of E 2 do not change across the reproductive cycle of males. Further, castration no affected paternal behavior despite that both T and E 2 concentrations decreased significantly. However, the role of these hormones has not been evaluated in models of castration and hormonal replacement in virgin males. Here, we analysed the effects of E 2 and T in paternal behavior in virgin male dwarf hamster (Phodopus campbelli). Thirty paternal (PAT) males were bilaterally castrated; of them, 10 were implanted with T, 10 with E 2 and 10 males received no treatment. Other 10 PAT males underwent sham-castration. Seventeen aggressive (AGG) males were also bilaterally castrated; of these, 10 AGG received E 2 replacement, 7 were not treated. Other 7 AGG males were submitted to sham-castration. Following treatments, paternal behavior tests were conducted again. T and E 2 levels in plasma were quantified by radioimmunoassay (RIA). The results showed that the treatments did not affect the paternal behavior of males that were initially paternal. Neither castration nor sham-castration surgery affected the behavior of AGG males. However, when these males were treated with E 2 and the concentrations of this hormone increase significantly they became paternal. Our data suggest that an increase in E 2 levels shifted infanticidal behavior to paternal behavior in dwarf hamster. Copyright © 2018 Elsevier Inc. All rights reserved.

  11. Thyrotrophin-releasing hormone decreases feeding and increases body temperature, activity and oxygen consumption in Siberian hamsters.

    PubMed

    Schuhler, S; Warner, A; Finney, N; Bennett, G W; Ebling, F J P; Brameld, J M

    2007-04-01

    Thyrotrophin-releasing hormone (TRH) is known to play an important role in the control of food intake and energy metabolism in addition to its actions on the pituitary-thyroid axis. We have previously shown that central administration of TRH decreases food intake in Siberian hamsters. This species is being increasingly used as a physiological rodent model in which to understand hypothalamic control of long-term changes in energy balance because it accumulates fat reserves in long summer photoperiods, and decreases food intake and body weight when exposed to short winter photoperiods. The objectives of our study in Siberian hamsters were: (i) to investigate whether peripheral administration of TRH would mimic the effects of central administration of TRH on food intake and whether these effects would differ dependent upon the ambient photoperiod; (ii) to determine whether TRH would have an effect on energy expenditure; and (iii) to investigate the potential sites of action of TRH. Both peripheral (5-50 mg/kg body weight; i.p.) and central (0.5 microg/ml; i.c.v.) administration of TRH decreased food intake, and increased locomotor activity, body temperature and oxygen consumption in the Siberian hamster, with a rapid onset and short duration of action. Systemic treatment with TRH was equally effective in suppressing feeding regardless of ambient photoperiod. The acute effects of TRH are likely to be centrally mediated and independent of its role in the control of the production of thyroid hormones. We conclude that TRH functions to promote a catabolic energetic state by co-ordinating acute central and chronic peripheral (thyroid-mediated) function.

  12. Is the Medial Amygdala Part of the Neural Circuit Modulating Conditioned Defeat in Syrian Hamsters?

    ERIC Educational Resources Information Center

    Markham, Chris M.; Huhman, Kim L.

    2008-01-01

    Conditioned defeat is a model wherein hamsters that have previously experienced a single social defeat subsequently exhibit heightened levels of avoidance and submission in response to a smaller, non-aggressive intruder. While we have previously demonstrated the critical involvement of the basolateral and central nuclei of the amygdala in the…

  13. Development of Automated Whistle and Click Classifiers for Odontocete Species in the Northwest Atlantic Ocean and the Waters Surrounding the Hawaiian Islands

    DTIC Science & Technology

    2014-09-30

    confirmation of species identity. Species Number of encounters Delphinus delphis 9 Grampus griseus 8 Globicephala macrorhynchus 17 Steno ...Globicephala macrorhynchus 30 Steno bredanensis 30 Stenella coeruleoalba 31 Stenella longirostris 9 Peponocephala electra 17 Grampus griseus 9...2 (287) 15 (25410) 17 25697 Grampus griseus 2 (15) 6 (143) - 8 158 Steno bredanensis 1 (9) 1 (416) 1 (85) 3 510 Delphinus delphis 4 (301) 5 (1651

  14. Immune correlates of protection against yellow fever determined by passive immunization and challenge in the hamster model.

    PubMed

    Julander, Justin G; Trent, Dennis W; Monath, Thomas P

    2011-08-11

    Live, attenuated yellow fever (YF) 17D vaccine is highly efficacious but causes rare, serious adverse events resulting from active replication in the host and direct viral injury to vital organs. We recently reported development of a potentially safer β-propiolactone-inactivated whole virion YF vaccine (XRX-001), which was highly immunogenic in mice, hamsters, monkeys, and humans [10,11]. To characterize the protective efficacy of neutralizing antibodies stimulated by the inactivated vaccine, graded doses of serum from hamsters immunized with inactivated XRX-001 or live 17D vaccine were transferred to hamsters by the intraperitoneal (IP) route 24h prior to virulent, viscerotropic YF virus challenge. Neutralizing antibody (PRNT(50)) titers were determined in the sera of treated animals 4h before challenge and 4 and 21 days after challenge. Neutralizing antibodies were shown to mediate protection. Animals having 50% plaque reduction neutralization test (PRNT(50)) titers of ≥40 4h before challenge were completely protected from disease as evidenced by viremia, liver enzyme elevation, and protection against illness (weight change) and death. Passive titers of 10-20 were partially protective. Immunization with the XRX-001 vaccine stimulated YF neutralizing antibodies that were equally effective (based on dose response) as antibodies stimulated by live 17D vaccine. The results will be useful in defining the level of seroprotection in clinical studies of new yellow fever vaccines. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. The role of cyclophosphamide in enhancing antitumor efficacy of an adenovirus oncolytic vector in subcutaneous Syrian hamster tumors

    PubMed Central

    Young, Brittany A.; Spencer, Jacqueline F.; Ying, Baoling; Tollefson, Ann E.; Toth, Karoly; Wold, William S. M.

    2013-01-01

    We have previously reported that intratumoral injection of VRX-007—an Ad5-based vector overexpressing ADP (Adenovirus Death Protein)—can suppress the growth of subcutaneous HaK (hamster renal cancer) tumors. VRX-007 replication and tumor growth inhibition are enhanced when the hamsters are immunosuppressed by a high dose of cyclophosphamide (CP), an immunosuppressive and chemotherapeutic agent. Here we report that continuous immunosuppression with CP was not required for increased oncolytic activity of VRX-007 because short-term dosing or continuous dosing with the drug yielded similar antitumor results. Prolonged viral replication was found only in animals on continuous CP treatment. We used 007-Luc, a replication-competent, luciferase-expressing vector similar to VRX-007 to investigate the replication of the vector over time. Tumor growth inhibition was similar in hamsters given CP treatment either one week before or one week after 007-Luc injection, which suggests that CP exerts its antitumor efficacy independently of vector therapy. 007-Luc did not spread far from the inoculation site, even in immunosuppressed, CP-treated animals. Our results indicate that the enhanced effectiveness that is produced by the combination of VRX-007 and CP therapies is due to their two independent mechanisms and that they do not have to be given simultaneously for the improved outcome shown. PMID:23928731

  16. The role of cyclophosphamide in enhancing antitumor efficacy of an adenovirus oncolytic vector in subcutaneous Syrian hamster tumors.

    PubMed

    Young, B A; Spencer, J F; Ying, B; Tollefson, A E; Toth, K; Wold, W S M

    2013-09-01

    We have previously reported that intratumoral injection of VRX-007--an Ad5 (a species C adenovirus)-based vector overexpressing adenovirus death protein--can suppress the growth of subcutaneous HaK (hamster renal cancer) tumors. VRX-007 replication and tumor growth inhibition are enhanced when the hamsters are immunosuppressed by a high dose of cyclophosphamide (CP), an immunosuppressive and chemotherapeutic agent. Here, we report that continuous immunosuppression with CP was not required for increased oncolytic activity of VRX-007 because short-term dosing or continuous dosing with the drug yielded similar antitumor results. Prolonged viral replication was found only in animals on continuous CP treatment. We used 007-Luc, a replication-competent, luciferase-expressing vector similar to VRX-007, to investigate the replication of the vector over time. Tumor growth inhibition was similar in hamsters given CP treatment either 1 week before or 1 week after 007-Luc injection, which suggests that CP exerts its antitumor efficacy independently of vector therapy. 007-Luc did not spread far from the inoculation site, even in immunosuppressed, CP-treated animals. Our results indicate that the enhanced effectiveness that is produced by the combination of VRX-007 and CP therapies is due to their two independent mechanisms and that they do not have to be given simultaneously for the improved outcome.

  17. A 15-minute light pulse during darkness prevents the antigonadotrophic action of afternoon melatonin injections in male hamsters

    NASA Astrophysics Data System (ADS)

    Reiter, R. J.; Hurlbut, E. C.; King, T. S.; Richardson, B. A.; Vaughan, M. K.; Kosub, K. Y.

    1982-12-01

    When adult male Syrian hamsters were maintained under 14 h light and 10 h darkness daily (lights on from 0600-2000 h), peak pineal melatonin levels (705 pg/gland) were attained at 0500 h. When the dark phase of the light:dark cycle was interrupted with a 15 min pulse of light from 2300 2315 h (3 h after lights out), the highest melatonin levels achieved was roughly 400 pg/gland. Finally, if the 15 min pulse of light was given at 0200 0215 h (6 h after lights out) the nocturnal rise in pineal melatonin was completely abolished. Having made these observations, a second experiment was designed to determine the ability of afternoon melatonin injections to inhibit reproduction in hamsters kept under an uninterrupted 14∶10 cycle or under the same lighting regimen where the dark phase was interrupted with a 15 min pulse of light (0200 0215 h). In the uninterrupted light:dark schedule the daily afternoon injection of 25 μg melatonin caused the testes and the accessory sex organs to atrophy within 11 weeks. Conversely, if the dark phase was interrupted with light between 0200 0215 h, afternoon melatonin injections were incapable of inhibiting the growth of the reproductive organs. The findings suggest that exogenously administered melatonin normally synergizes with endogenously produced melatonin to cause gonadal involution in hamsters.

  18. Peripheral gustatory processing of sweet stimuli by golden hamsters.

    PubMed

    Frank, Marion E; Formaker, Bradley K; Hettinger, Thomas P

    2005-07-15

    Behaviors and taste-nerve responses to bitter stimuli are linked to compounds that bind T2 receptors expressed in one subset of taste-bud receptor cells (TRCs); and behavioral and neural responses to sweet stimuli are linked to chemical compounds that bind a T1 receptor expressed in a different TRC subset. Neural and behavioral responses to bitter-sweet mixtures, however, complicate the ostensible bitter and sweet labeled lines. In the golden hamster, Mesocricetus auratus, quinine hydrochloride, the bitter prototype, suppresses chorda tympani (CT) nerve responses to the sweet prototype: sucrose. This bitter-sweet inhibition was tested with concentration series of sucrose and dulcin, a hydrophobic synthetic sweetener that hamsters behaviorally cross-generalize with sucrose. Dulcin, sucrose and other sweeteners activate one subset of CT fibers: S neurons; whereas, quinine activates a separate subset of CT fibers: E neurons. Whole-nerve and S-neuron CT responses to a sweetener concentration series, mixed with 0, 1, 3 and 10 mM quinine, were measured for 0-2.5 s transient and/or 2.6-10 s steady-state response periods. Ten-sec total single-fiber records, aligned at response onset, were averaged for 100 ms bins to identify response oscillations. Quinine inhibition of dulcin and sucrose responses was identical. Each log molar increment in quinine resulted in equivalent declines in response to either sweetener. Furthermore, sucrose response decrements paralleled response increments in quinine-sensitive CT neurons to the same quinine increases. A 1.43 Hz bursting rhythm to the sweeteners was unchanged by quinine inhibition or decreases in sweetener concentration. Taste-bud processing, possibly between-cell inhibition and within-cell negative feedback, must modify signals initiated by T1 receptors before they are transmitted to the brain.

  19. Daytime Unresponsiveness of the Human and Syrian Hamster Pineal to Adrenergic Stimulation

    DTIC Science & Technology

    1989-01-01

    exposure) raises pineal melatonin content; injection outside this sensitive period does not. (CajP-" This dramatic change in response of the pineal gland ...1988, 264 (abstract976). Binkley, S. (1976): Comprative biochemistry of the pineal glands of birds and mammals. Am. Zool. 16, 57-65. Bowers, C.V., an...R.J. (1982): In vivo responses of the pineal gland of the Syrian hamster to isoproterenol or -or-epinephrine. In The Pineal and Its Hormones, pp 107

  20. Temporal Analysis of Andes Virus and Sin Nombre Virus Infections of Syrian Hamsters

    DTIC Science & Technology

    2007-05-01

    from PBMCs, and real-time PCR was per- formed following cDNA synthesis . Samples were analyzed for the presence of S-segment viral RNA (vRNA). Levels...disease course from exposure to fulminant disease. This model was recently used to investigate the possibility that cardiogenic shock is involved in...dysfunction allowing dissemination of virus and subsequent fulminant disease. As hamster-specific reagents become available, it will become pos- sible to

  1. Inoculation of Scrapie with the Self-Assembling RADA-Peptide Disrupts Prion Accumulation and Extends Hamster Survival

    USDA-ARS?s Scientific Manuscript database

    Intercerebral inoculation of 263K Scrapie brain homogenate (PrPsc) with a self-assembling RADA-peptide (RADA) significantly delayed disease onset and increased hamster survival. Time of survival was dependent on the dose of RADA and pre-incubation with PrPsc prior to inoculation. RADA treatment resu...

  2. Neural mechanisms controlling seasonal reproduction: principles derived from the sheep model and its comparison with hamsters.

    PubMed

    Weems, Peyton W; Goodman, Robert L; Lehman, Michael N

    2015-04-01

    Seasonal reproduction is a common adaptive strategy among mammals that allows for breeding to occur at times of the year when it is most advantageous for the subsequent survival and growth of offspring. A major mechanism responsible for seasonal reproduction is a striking increase in the responsiveness of gonadotropin-releasing hormone (GnRH) neurons to the negative feedback effects of estradiol. The neural and neuroendocrine circuitry responsible for mammalian seasonal reproduction has been primarily studied in three animal models: the sheep, and two species of hamsters. In this review, we first describe the afferent signals, neural circuitry and transmitters/peptides responsible for seasonal reproductive transitions in sheep, and then compare these mechanisms with those derived from studies in hamsters. The results suggest common principles as well as differences in the role of specific brain nuclei and neuropeptides, including that of kisspeptin cells of the hypothalamic arcuate nucleus, in regulating seasonal reproduction among mammals. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Effect of different anesthetic agents on left ventricular systolic function assessed by echocardiography in hamsters.

    PubMed

    Tanaka, D M; Romano, M M D; Carvalho, E E V; Oliveira, L F L; Souza, H C D; Maciel, B C; Salgado, H C; Fazan-Júnior, R; Simões, M V

    2016-08-25

    Determination of left ventricular ejection fraction (LVEF) using in vivo imaging is the cardiac functional parameter most frequently employed in preclinical research. However, there is considerable conflict regarding the effects of anesthetic agents on LVEF. This study aimed at assessing the effects of various anesthetic agents on LVEF in hamsters using transthoracic echocardiography. Twelve female hamsters were submitted to echocardiography imaging separated by 1-week intervals under the following conditions: 1) conscious animals, 2) animals anesthetized with isoflurane (inhaled ISO, 3 L/min), 3) animals anesthetized with thiopental (TP, 50 mg/kg, intraperitoneal), and 4) animals anesthetized with 100 mg/kg ketamine plus 10 mg/kg xylazine injected intramuscularly (K/X). LVEF obtained under the effect of anesthetics (ISO=62.2±3.1%, TP=66.2±2.7% and K/X=75.8±1.6%) was significantly lower than that obtained in conscious animals (87.5±1.7%, P<0.0001). The K/X combination elicited significantly higher LVEF values compared to ISO (P<0.001) and TP (P<0.05). K/X was associated with a lower dispersion of individual LVEF values compared to the other anesthetics. Under K/X, the left ventricular end diastolic diameter (LVdD) was increased (0.60±0.01 cm) compared to conscious animals (0.41±0.02 cm), ISO (0.51±0.02 cm), and TP (0.55±0.01 cm), P<0.0001. The heart rate observed with K/X was significantly lower than in the remaining conditions. These results indicate that the K/X combination may be the best anesthetic option for the in vivo assessment of cardiac systolic function in hamsters, being associated with a lower LVEF reduction compared to the other agents and showing values closer to those of conscious animals with a lower dispersion of results.

  4. Effect of different anesthetic agents on left ventricular systolic function assessed by echocardiography in hamsters

    PubMed Central

    Tanaka, D.M.; Romano, M.M.D.; Carvalho, E.E.V.; Oliveira, L.F.L.; Souza, H.C.D.; Maciel, B.C.; Salgado, H.C.; Fazan-Júnior, R.; Simões, M.V.

    2016-01-01

    Determination of left ventricular ejection fraction (LVEF) using in vivo imaging is the cardiac functional parameter most frequently employed in preclinical research. However, there is considerable conflict regarding the effects of anesthetic agents on LVEF. This study aimed at assessing the effects of various anesthetic agents on LVEF in hamsters using transthoracic echocardiography. Twelve female hamsters were submitted to echocardiography imaging separated by 1-week intervals under the following conditions: 1) conscious animals, 2) animals anesthetized with isoflurane (inhaled ISO, 3 L/min), 3) animals anesthetized with thiopental (TP, 50 mg/kg, intraperitoneal), and 4) animals anesthetized with 100 mg/kg ketamine plus 10 mg/kg xylazine injected intramuscularly (K/X). LVEF obtained under the effect of anesthetics (ISO=62.2±3.1%, TP=66.2±2.7% and K/X=75.8±1.6%) was significantly lower than that obtained in conscious animals (87.5±1.7%, P<0.0001). The K/X combination elicited significantly higher LVEF values compared to ISO (P<0.001) and TP (P<0.05). K/X was associated with a lower dispersion of individual LVEF values compared to the other anesthetics. Under K/X, the left ventricular end diastolic diameter (LVdD) was increased (0.60±0.01 cm) compared to conscious animals (0.41±0.02 cm), ISO (0.51±0.02 cm), and TP (0.55±0.01 cm), P<0.0001. The heart rate observed with K/X was significantly lower than in the remaining conditions. These results indicate that the K/X combination may be the best anesthetic option for the in vivo assessment of cardiac systolic function in hamsters, being associated with a lower LVEF reduction compared to the other agents and showing values closer to those of conscious animals with a lower dispersion of results. PMID:27580004

  5. Effects of different ratios of monounsaturated and polyunsaturated fatty acids to saturated fatty acids on regulating body fat deposition in hamsters.

    PubMed

    Liao, Fang-Hsuean; Liou, Tsan-Hon; Shieh, Ming-Jer; Chien, Yi-Wen

    2010-01-01

    Effects of monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid consumption on regulating body fat accumulation and body weight gain are controversial between animal and human studies. We designed a 2 x 2 factorial study, with two levels of MUFAs (60% and 30%) and two levels of polyunsaturated-to-saturated fatty acid (P/S) ratio (5 and 3) to prepare four kinds of experimental oils consisting of 60% MUFAs with a high or low P/S ratio (HMHR or HMLR, respectively) or 30% MUFAs with a high or low P/S ratio (LMHR or LMLR, respectively). Thirty-two male golden Syrian hamsters were randomly divided into four groups and fed the experimental diets containing 15% (w/w) fat for 12 wk. No difference was observed in the mean daily food intake. Hamsters fed the LMLR diet had increased weight gain, epididymal and retroperitoneal white adipose tissues, plasma non-esterified fatty acids, insulin, hepatic acetyl coenzyme A carboxylase and malic enzyme activities, and mRNA expressions of peroxisome proliferator-activated receptor-alpha and sterol regulatory element-binding protein-1c among all groups (P < 0.05). Hamsters fed the HMHR diet had lower plasma insulin levels and hepatic acetyl coenzyme A carboxylase activities among groups (P < 0.05) and elevated hepatic acyl coenzyme A oxidase and carnitine palmitoyltransferase-I activities compared with those fed the LMLR diet (P < 0.05). Hamsters fed the LMLR diet had increased weight gain and body fat accumulation, whereas the HMHR diet appeared to be beneficial in preventing white adipose tissue accumulation by decreasing plasma insulin levels and increasing hepatic lipolytic enzyme activities involved in beta-oxidation. 2010 Elsevier Inc. All rights reserved.

  6. Hair follicle response of the golden Syrian hamster flank organ to continuous testosterone stimulation using silastic capsules.

    PubMed

    Lucky, A W; McGuire, J; Nydorf, E; Halpert, G; Nuck, B A

    1986-01-01

    The hamster flank organ has served as a model to study androgen-dependent responses of the skin, but the quantitative response of hair follicles to androgenic stimulation has been neglected. We assayed the hair follicle response to testosterone (T) and compared it to the response of the sebaceous glands and of the dermal pigment in the Golden Syrian hamster flank organ. Because of biologic variation in male animals and uneven absorption of hormone from parenteral injections, we implanted silastic capsules 0.25, 0.5, 1, and 2 cm in length filled with crystalline T subcutaneously into female hamsters for 6 weeks. Hair follicle response to T was more sensitive than sebaceous gland or pigment. Diameters of hairs under the sebaceous gland increased significantly from control values of 27.7 +/- 1.0 micron to 38.0 +/- 1.6 micron at the lowest dose of T tested, the 0.25-cm capsule (p less than 0.001). There was an increase in the absolute number of hairs under the sebaceous gland as the flank organ enlarged, from 27.9 +/- 9.9 control to 55.3 +/- 5.8 with the 2-cm T capsule. There was no concomitant increase in hair density, 14.4 +/- 3.5 hairs/mm control vs 12.5 +/- 1.1 hairs/mm with the 2-cm capsule. Hair follicles lateral to the sebaceous gland did not show the same response to androgen stimulation. Sebaceous gland and pigmentation responded in a dose-dependent fashion, the maximum effect being achieved with a 1-cm T capsule. We conclude that T affects hair by specifically stimulating growth of individual hairs physically under the sebaceous gland. As the whole flank organ enlarges more hairs are recruited to become larger but no new follicles appear. These studies also confirm that there are different sensitivities to androgen within the various androgen-dependent components of the hamster flank organ, with increase in hair diameter being highly sensitive. This model should be useful for the specific and quantitative assessment of androgenic and antiandrogenic substances

  7. Voluntary exercise at the expense of reproductive success in Djungarian hamsters ( Phodopus sungorus)

    NASA Astrophysics Data System (ADS)

    Petri, Ines; Scherbarth, Frank; Steinlechner, Stephan

    2010-09-01

    Energy demands of gestation and lactation represent a severe challenge for small mammals. Therefore, additional energetic burdens may compromise successful breeding. In small rodents, food restriction, cold exposure (also in combination) and wheel running to obtain food have been shown to diminish reproductive outcome. Although exhibited responses such as lower incidence of pregnancy, extended lactation periods and maternal infanticide were species dependent, their common function is to adjust energetic costs to the metabolic state reflecting the trade-off between maternal investment and self-maintenance. In the present study, we sought to examine whether voluntary exercise affects reproduction in Djungarian hamsters ( Phodopus sungorus), which are known for their high motivation to run in a wheel. Voluntary exercise resulted in two different effects on reproduction; in addition to increased infanticide and cannibalism, which was evident across all experiments, the results of one experiment provided evidence that free access to a running wheel may prevent successful pregnancy. It seems likely that the impact of voluntary wheel running on reproduction was associated with a reduction of internal energy resources evoked by extensive exercise. Since the hamsters were neither food-restricted nor forced to run in the present study, an energetic deficit as reason for infanticide in exercising dams would emphasise the particularly high motivation to run in a wheel.

  8. Effects of Persian leek (Allium ampeloprasum) on hepatic lipids and the expression of proinflammatory gene in hamsters fed a high-fat/ high-cholesterol diet.

    PubMed

    Fatoorechi, Vahideh; Rismanchi, Marjan; Nasrollahzadeh, Javad

    2016-01-01

    Persian leek is one of the most widely used herbal foods among Iranians. In this study, effects of oral administration of Persian leek on plasma and liver lipids were examined in hamster. Male Syrian hamsters were randomly divided into three groups: control (standard diet), high fat control (high-fat/high-cholesterol diet), Persian leek (high-fat/high-cholesterol diet + 1% per weight of diet from dried powdered Persian leek) for 14 weeks. High fat diet increased plasma and liver lipids as compared to standard diet. Adding Persian leek to the high-fat/high-cholesterol diet resulted in no significant changes in the concentration of the plasma lipids or liver cholesterol. However, liver triglycerides (TG), plasma Alanine aminotransferase and gene expression of tumor necrosis factor- α were decreased in hamsters fed high-fat diet containing Persian leek as compared to high-fat diet only. Persian leek might be considered as a herbal food that can reduce liver TG accumulation induced by high fat diets.

  9. Piper species protect cardiac, hepatic and renal antioxidant status of atherogenic diet fed hamsters.

    PubMed

    Agbor, Gabriel A; Akinfiresoye, Luli; Sortino, Julianne; Johnson, Robert; Vinson, Joe A

    2012-10-01

    Pre-clinical and clinical studies points to the use of antioxidants as an effective measure to reduce the progression of oxidative stress related disorders. The present study evaluate the effect of three Piper species (Piper guineense, Piper nigrum and Piper umbellatum) for the protection of cardiac, hepatic and renal antioxidant status of atherogenic diet fed hamsters. Hamsters were classified into eight groups: a normal control, atherogenic control and six other experimental groups (fed atherogenic diet supplemented with different doses of P. nigrum, P. guineense and P. umbellatum (1 and 0.25 g/kg) for 12 weeks. At the end of the feeding period the heart, liver and kidney from each group were analyzed for lipid profile and antioxidant enzymes activities. Atherogenic diet induced a significant (P<0.001) increase in the lipid profile across the board and equally significantly altered the antioxidant enzyme activities. Supplementation with Piper species significantly inhibited the alteration effect of atherogenic diet on the lipid profile and antioxidant enzymes activities. The Piper extracts may possess an antioxidant protective role against atherogenic diet induced oxidative stress in cardiac, hepatic and renal tissues. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Protection of hamsters against Clostridium difficile ileocaecitis by prior colonisation with non-pathogenic strains.

    PubMed

    Borriello, S P; Barclay, F E

    1985-06-01

    Prior colonisation of clindamycin-treated hamsters with non-toxigenic strains of C. difficile protected them from subsequent colonisation with a toxigenic pathogenic strain. In total, 13 of 18 'protected' hamsters survived for up to 27 days whereas all 27 animals challenged with the toxigenic strain alone died within 48 h. Protection was not evident if a heat-killed suspension was used or if the colonising non-toxigenic strain was first removed with vancomycin. No antitoxic activity could be detected in the faeces of animals colonised with the non-toxigenic strains. Other species of clostridia did not protect against the lethal effects of subsequent exposure to the toxigenic strain. Conversely, non-toxigenic strains would not protect the animals from the lethal effects of a different clostridial pathogen, C. spiroforme. In most cases, even in the protected animals, the toxigenic strain eventually became dominant and caused disease, with translocation across the gut wall occurring early in the disease process. It was also shown that a non-toxigenic strain of C. difficile can adhere to gut mucosa. It is proposed that the protection afforded by the non-toxigenic strains may be due to competition for ecological niches.

  11. [Histologic study on impeding leukoplakia carcinogenesis of golden hamster cheek pouch about Erigeron breviscapus (Vant) Hand-Mazz].

    PubMed

    Zhou, C T; Zhong, W J; Hua, L; Hu, H F; Jin, Z G

    2000-06-01

    To observe the effect of Erigeron breviscapus (Vant) Hand Mazz (HEr) in impeding oral leukoplakia carcinogenesis, and to seek effective Chinese herb medicine that can impede precarcinoma of oral mucosas. 132 golden hamsters were randomly divided into model group (60 animals), HEr group (60 animals), and control group 12 animals. Salley's leukoplakia carcinogenesis model of golden hamster cheek pouch was used in this study. HEr was injected into the stomach to impede evolution of carcinogenesis. Pathological specimens were observed via naked eye and light microscope between model group and HEr group. Results were compared. Observation via naked-eye showed that leukoplakia rate of HEr group (18.2%) was lower than that of model group (27.3%). Observation via light microscope showed that carcinogenesis rate descended one fold and displasia rate descended 0.4 fold in HEr group. HEr has exact effect in impeding leukoplakia carcinogenesis.

  12. Treatment of yellow fever virus with an adenovirus-vectored interferon, DEF201, in a hamster model.

    PubMed

    Julander, Justin G; Ennis, Jane; Turner, Jeffrey; Morrey, John D

    2011-05-01

    Interferon (IFN) is an innate immune response protein that is involved in the antiviral response during viral infection. Treatment of acute viral infections with exogenous interferon may be effective but is generally not feasible for clinical use due to many factors, including cost, stability, and availability. To overcome these limitations, an adenovirus type 5-vectored consensus alpha IFN, termed DEF201, was constructed as a potential way to deliver sustained therapeutic levels of systemic IFN. To demonstrate the efficacy of DEF201 against acute flaviviral disease, various concentrations of the construct were administered as a single intranasal dose prior to virus infection, which resulted in a dose-responsive, protective effect in a hamster model of yellow fever virus (YFV) disease. A DEF201 dose of 5×10(7) PFU/animal administered intranasally just prior to YFV challenge protected 100% of the animals, while a 10-fold lower DEF201 dose exhibited lower, although significant, levels of protection. Virus titers in the liver and serum and levels of serum alanine aminotransferase were all significantly reduced as a result of DEF201 administration at all doses tested. No toxicity, as indicated by weight loss or gross morbidity, was observed in non-YFV-infected animals treated with DEF201. Protection of YFV-infected animals was observed when DEF201 was delivered as early as 7 days prior to virus challenge and as late as 2 days after virus challenge, demonstrating effective prophylaxis and therapy in a hamster model of disease. Overall, it appears that DEF201 is effective in the treatment of YFV in a hamster model.

  13. Complete mitochondrial genome sequence of the heart failure model of cardiomyopathic Syrian hamster (Mesocricetus auratus).

    PubMed

    Hu, Bo; Liu, Dong-Xing; Zhang, Yu-Qing; Song, Jian-Tao; Ji, Xian-Fei; Hou, Zhi-Qiang; Zhang, Zhen-Hai

    2016-05-01

    In this study we sequenced the complete mitochondrial genome sequencing of a heart failure model of cardiomyopathic Syrian hamster (Mesocricetus auratus) for the first time. The total length of the mitogenome was 16,267 bp. It harbored 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and 1 non-coding control region.

  14. Time-dependent effects of dim light at night on re-entrainment and masking of hamster activity rhythms.

    PubMed

    Frank, David W; Evans, Jennifer A; Gorman, Michael R

    2010-04-01

    Bright light has been established as the most ubiquitous environmental cue that entrains circadian timing systems under natural conditions. Light equivalent in intensity to moonlight (<1 lux), however, also strongly modulates circadian function in a number of entrainment paradigms. For example, compared to completely dark nights, dim nighttime illumination accelerated re-entrainment of hamster activity rhythms to 4-hour phase advances and delays of an otherwise standard laboratory photocycle. The purpose of this study was to determine if a sensitive period existed in the night during which dim illumination had a robust influence on speed of re-entrainment. Male Siberian hamsters were either exposed to dim light throughout the night, for half of the night, or not at all. Compared to dark nights, dim illumination throughout the entire night decreased by 29% the time for the midpoint of the active phase to re-entrain to a 4-hour phase advance and by 26% for a 4-hour delay. Acceleration of advances and delays were also achieved with 5 hours of dim light per night, but effects depended on whether dim light was present in the first half, second half, or first and last quarters of the night. Both during phase shifting and steady-state entrainment, partially lit nights also produced strong positive and negative masking effects, as well as entrainment aftereffects in constant darkness. Thus, even in the presence of a strong zeitgeber, light that might be encountered under a natural nighttime sky potently modulates the circadian timing system of hamsters.

  15. The influence of natural short photoperiodic and temperature conditions on plasma thyroid hormones and cholesterol in male Syrian hamsters

    NASA Astrophysics Data System (ADS)

    Vaughan, M. K.; Brainard, G. C.; Reiter, R. J.

    1984-09-01

    Adult male Syrian hamsters were subjected to 1, 3, 5, 7 or 11 weeks of either natural winter conditions or rigorously controlled laboratory conditions (LD 10∶14; 22 ± 2‡C). Although both groups of hamsters gained weight over the course of the experiment, hamsters housed indoors were significantly heavier after 5 weeks of treatment compared to their outdoors counterparts. Animals housed under natural conditions exhibited a significant decrease in circulating levels of thyroxine (T4) and a rapid rise in triiodothyronine (T3) levels; the free T4 and free T3 index (FT4I and FT3I) mirrored the changes in circulating levels of the respective hormones. Laboratory-housed animals had a slight rise in T4 and FT4I at 3 weeks followed by a slow steady decline in these values; T3 and FT3I values did not change remarkably in these animals. Plasma cholesterol declined steadily over the course of the experiment in laboratory-maintained animals but increased slightly during the first 5 weeks in animals under natural conditions. Since the photoperiodic conditions were approximately of the same duration in these 2 groups, it is concluded that the major differences in body weight, thyroid hormone values and plasma cholesterol are due to some component (possibly temperature) in the natural environment.

  16. Quantitative analysis of fluoride-induced hypermineralization of developing enamel in neonatal hamster tooth germs

    NASA Astrophysics Data System (ADS)

    Tros, G. H. J.; Lyaruu, D. M.; Vis, R. D.

    1993-10-01

    A procedure was developed for analysing the effect of fluoride on mineralization in the enamel of neonatal hamster molars during amelogenesis by means of the quantitative determination of the mineral content. In this procedure the distribution of calcium and mineral concentration was determined in sections containing developing tooth enamel mineral embedded in an organic epoxy resin matrix by means of the micro-PIXE technique. This allowed the determination of the calcium content along preselected tracks with a spatial resolution of 2 μm using a microprobe PIXE setup with a 3 MeV proton beam of 10 to 50 pA with a spot size of 2 μm in the track direction. In this procedure the X-ray yield is used as a measure for the calcium content. The thickness of each sample section is determined independently by measuring the energy loss of α-particles from a calibration source upon passing through the sample. The sample is considered as consisting of two bulk materials, allowing the correction for X-ray self-absorption and the calculation of the calcium concentration. The procedure was applied for measuring the distribution of mineral concentration in 2 μm thick sections taken from tooth germs of hamsters administered with NaF. The measurements indicated that a single intraperitoneal administration of 20 mg NaF/kg body weight to 4-to-5-day-old hamsters leads within 24 h to hypermineralization of certain focal enamel surface areas containing cystic lesions under transitional and early secretory ameloblasts. The mineral concentration there is substantially increased due to the fluoride treatment (35%, instead of 5 to 10% as in the controls), indicating that the normal mineralization process has been seriously disturbed. Furthermore it is found that using this technique the mineral concentration peaks at about 70% at the dentine-enamel junction, which is comparable to that reported for human dentine using other techniques.

  17. Local anti-fertility effect of inhibin-enriched preparation (IEP) in female hamsters.

    PubMed

    Bapat, B V; Nandedkar, T D; Sheth, A R

    1984-04-01

    An inhibin-enriched preparation (IEP) involved in the regulation of follicle stimulating hormone (FSH) is known to play an important role in the normal ovarian cycle. In utero administration of 10 micrograms of IEP on day 3 of pregnancy completely prevented implantation in hamsters. No toxic effect of IEP was observed on the blastocysts as indicated by the dye exclusion test performed with Trypan blue. Thus, the results of the present study indicate an extra-pituitary site of action for the anti-implantation effect of IEP.

  18. Silibinin Capsules improves high fat diet-induced nonalcoholic fatty liver disease in hamsters through modifying hepatic de novo lipogenesis and fatty acid oxidation.

    PubMed

    Cui, Chun-Xue; Deng, Jing-Na; Yan, Li; Liu, Yu-Ying; Fan, Jing-Yu; Mu, Hong-Na; Sun, Hao-Yu; Wang, Ying-Hong; Han, Jing-Yan

    2017-08-17

    Silibinin Capsules (SC) is a silybin-phospholipid complex with silybin as the bioactive component. Silybin accounts for 50-70% of the seed extract of Silybum marianum (L.) Gaertn.. As a traditional medicine, silybin has been used for treatment of liver diseases and is known to provide a wide range of hepatoprotective effects. High fat diet (HFD)-induced nonalcoholic fatty liver disease (NAFLD) is a worldwide health problem. This study was to investigate the role of SC in NAFLD with focusing on its underlying mechanism and likely target. Male hamsters (Cricetidae) received HFD for 10 weeks to establish NAFLD model. NAFLD was assessed by biochemical assays, histology and immunohistochemistry. Proton nuclear magnetic resonance spectroscopy and western blot were conducted to gain insight into the mechanism. Hamsters fed HFD for 10 weeks developed fatty liver accompanying with increased triglyceride (TG) accumulation, enhancing de novo lipogenesis, increase in fatty acid (FA) uptake and reducing FA oxidation and TG lipolysis, as well as a decrease in the expression of phospho-adenosine monophosphate activated protein kinase α (p-AMPKα) and Sirt 1. SC treatment at 50mg/kg silybin and 100mg/kg silybin for 8 weeks protected hamsters from development of fatty liver, reducing de novo lipogenesis and increasing FA oxidation and p-AMPKα expression, while having no effect on FA uptake and TG lipolysis. SC protected against NAFLD in hamsters by inhibition of de novo lipogenesis and promotion of FA oxidation, which was likely mediated by activation of AMPKα. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  19. CELLULAR TOXICITY IN CHINESE HAMSTER OVARY CELL CULTURES. 1. ANALYSIS OF CYTOTOXICITY ENDPOINTS FOR TWENTY-NINE PRIORITY POLLUTANTS

    EPA Science Inventory

    Chinese hamster ovary cells were exposed to 29 toxic chemical substances which were representative of several classes of compounds listed by the Natural Resources Defense Council Consent Decree as priority toxic pollutants. After cell cultures were exposed to the test substance, ...

  20. Chemoprevention by Quercetin of Oral Squamous Cell Carcinoma by Suppression of the NF-κB Signaling Pathway in DMBA-treated Hamsters.

    PubMed

    Zhang, Wen; Yin, Gang; Dai, Jianguo; Sun, Y U; Hoffman, Robert M; Yang, Zhijian; Fan, Yuan

    2017-08-01

    The aim of this study was to investigate the effects of the flavonoid quercetin on chemoprevention of oral squamous cell carcinoma (OSCC). The study involved molecular signaling pathways in 7,12-dimethylbenz(a) anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis. DMBA (0.5%) was painted at the right buccal pouches of hamsters for 14 weeks to induce carcinoma. DMBA-treated hamsters received simultaneous doses of quercetin. Animals without DMBA induction were used as normal controls. The incidence of OSCC and the severity of pre-malignant lesions were determined histologically. Apoptosis in the pouch tissue was determined by TUNEL staining. The mRNA and protein expression of NF-κB p50 and p65, as well as Bcl-2 and Bax genes were analyzed using RT-PCR and Western blotting, respectively. Quercetin, at various doses, significantly reduced OSCC incidence and severity of hyperplasia and dysplasia compared to the DMBA-induction-only group (p<0.01). Apoptosis was induced by quercetin treatment compared to the DMBA-induction-only group (p<0.01). mRNA and protein expression of NF-κB p50, p65 as well as Bcl-2 genes were significantly suppressed by quercetin at high doses compared to DMBA induction only (p<0.05). However, mRNA and protein expression of the Bax gene was increased by quercetin treatment at medium and high doses, compared to the DMBA-induction-only group (p<0.05). Quercetin significantly reduced body-weight loss compared to the DMBA-induction-only group (p<0.05). Quercetin reduced tumor incidence and induced apoptosis through modulation of NF-κB signaling and its target genes Bcl-2 and Bax in the DMBA-induced carcigenesis hamster model, suggesting the potential of quercetin as a candidate for OSCC chemoprevention. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  1. Vaginal secretions increase the likelihood of intermale aggression in Syrian hamsters.

    PubMed

    Fischer, R B; Brown, P S

    1993-08-01

    Although sexually receptive female hamsters prefer dominant males as mating partners, it is not clear what role the female might play facilitating aggressive interactions among males that would lead to the establishment of a status relationship. The ability of vaginal odors to stimulate male aggression was examined by paring randomly chosen males in a neutral arena with vaginal odors either present or absent. Males exhibited significantly more aggression when tested in the scented arena. Vaginal odors are efficient broadcast signals serving to space females, attract males, and to stimulate aggressive interactions among the males while inhibiting aggression towards the female.

  2. Vomeronasal organ removal before sexual experience impairs male hamster mating behavior.

    PubMed

    Meredith, M

    1986-01-01

    Removal of vomeronasal chemoreceptors before sexual experience in male hamsters resulted in complete failure to mate in some animals but removal of these receptors after sexual experience had no effect. Animals were tested for mating behavior with intact behaviorally receptive females and also with anesthetized males scented with vaginal fluid. The two tests produced essentially the same result. Histological analysis of the lesions and radioimmunoassay of androgen levels showed no group differences, other than vomeronasal organ removal, that could account for the results. The behavioral data suggest that the vomeronasal system may be concerned with the production of preprogrammed behavior.

  3. Large-Scale Transient Transfection of Chinese Hamster Ovary Cells in Suspension.

    PubMed

    Rajendra, Yashas; Balasubramanian, Sowmya; Hacker, David L

    2017-01-01

    We describe a one-liter transfection of suspension-adapted Chinese hamster ovary (CHO-DG44) cells using polyethyleneimine (PEI) for DNA delivery. The method involves transfection at a high cell density (5 × 10 6 cells/mL) by direct addition of plasmid DNA (pDNA) and PEI to the culture and subsequent incubation at 31 °C with agitation by orbital shaking. We also describe an alternative method in which 90% of the pDNA is replaced by nonspecific (filler) DNA, and the production phase is performed at 31 °C in the presence of 0.25% N, N-dimethylacetamide (DMA).

  4. Congenital malformations induced by mescaline, lysergic acid diethylamide, and bromolysergic acid in the hamster.

    PubMed

    Geber, W F

    1967-10-13

    Malformations of the brain, spinal cord, liver, and other viscera; body edema; and localized hemorrhages were found in fetal hamsters from mothers injected subcutaneously with a single dose of mescaline, lysergic acid diethylamide, or 2-bromo-D lysergic acid diethylamide on the 8th day of pregnancy. In addition, all three drugs produced an increase in the percentages of small fetuses per litter, of resorptions, and of fetal mortality.

  5. Photoperiod-Induced Increases in Bone Mineral Apposition Rate in Siberian Hamsters and the Involvement of Seasonal Leptin Changes

    PubMed Central

    Kokolski, Marie; Ebling, Francis J.; Henstock, James R.; Anderson, Susan I.

    2017-01-01

    The adipokine leptin regulates energy balance, appetite, and reproductive maturation. Leptin also acts on bone growth and remodeling, but both osteogenic and anti-osteogenic effects have been reported depending on experimental conditions. Siberian hamsters (Phodopus sungorus) have natural variation in circulating leptin concentrations, where serum leptin is significantly decreased during the short day (SD)-induced winter state. In summer long day (LD) photoperiods, appetite and body adiposity increase with associated central leptin insensitivity. This natural change in leptin secretion was exploited to investigate leptin’s effect on bone growth. Hamsters were injected with calcium-chelating fluorescent dyes to measure bone mineral apposition rate (MAR). Measurements were initially obtained from 5-week and 6-month-old animals maintained in low leptin (SD) or high leptin (LD) states. A further study investigated effects of chronic administration of recombinant mouse leptin to hamsters housed in SD and LD conditions; growth plate thickness and bone density were also assessed. As expected, a reduction in body mass was seen in hamsters exposed to SD, confirming the phenotype change in all studies. Serum leptin concentrations were significantly reduced in SD animals in all studies. MAR was reproducibly and significantly increased in the femurs of SD animals in all studies. Vitamin D and growth plate thickness were significantly increased in SD animals at 6 months. No effect on bone density was observed in any study. Taken together these data suggest that bone growth is associated with the low leptin, winter, lean state. In leptin-treated animals, there was a significant interaction effect of leptin and photoperiod. In comparison to their vehicle counterparts, SD animals had decreased and LD animals had increased MAR, which was not apparent prior to leptin administration. In conclusion, increased MAR was associated with low serum leptin levels in early life and

  6. Photoperiod-Induced Increases in Bone Mineral Apposition Rate in Siberian Hamsters and the Involvement of Seasonal Leptin Changes.

    PubMed

    Kokolski, Marie; Ebling, Francis J; Henstock, James R; Anderson, Susan I

    2017-01-01

    The adipokine leptin regulates energy balance, appetite, and reproductive maturation. Leptin also acts on bone growth and remodeling, but both osteogenic and anti-osteogenic effects have been reported depending on experimental conditions. Siberian hamsters ( Phodopus sungorus ) have natural variation in circulating leptin concentrations, where serum leptin is significantly decreased during the short day (SD)-induced winter state. In summer long day (LD) photoperiods, appetite and body adiposity increase with associated central leptin insensitivity. This natural change in leptin secretion was exploited to investigate leptin's effect on bone growth. Hamsters were injected with calcium-chelating fluorescent dyes to measure bone mineral apposition rate (MAR). Measurements were initially obtained from 5-week and 6-month-old animals maintained in low leptin (SD) or high leptin (LD) states. A further study investigated effects of chronic administration of recombinant mouse leptin to hamsters housed in SD and LD conditions; growth plate thickness and bone density were also assessed. As expected, a reduction in body mass was seen in hamsters exposed to SD, confirming the phenotype change in all studies. Serum leptin concentrations were significantly reduced in SD animals in all studies. MAR was reproducibly and significantly increased in the femurs of SD animals in all studies. Vitamin D and growth plate thickness were significantly increased in SD animals at 6 months. No effect on bone density was observed in any study. Taken together these data suggest that bone growth is associated with the low leptin, winter, lean state. In leptin-treated animals, there was a significant interaction effect of leptin and photoperiod. In comparison to their vehicle counterparts, SD animals had decreased and LD animals had increased MAR, which was not apparent prior to leptin administration. In conclusion, increased MAR was associated with low serum leptin levels in early life and

  7. Altered Gene Expression Patterns During the Initiation and Promotion Stages of Neonatally Diethylstilbestrol-Induced Hyperplasia/Dysplasia/Neoplasia in the Hamster Uterus

    PubMed Central

    Hendry, William J.; Hariri, Hussam Y.; Alwis, Imala D.; Gunewardena, Sumedha S.; Hendry, Isabel R.

    2014-01-01

    Neonatal treatment of hamsters with diethylstilbestrol (DES) induces uterine hyperplasia/dysplasia/neoplasia (endometrial adenocarcinoma) in adult animals. We subsequently determined that the neonatal DES exposure event directly and permanently disrupts the developing hamster uterus (initiation stage) so that it responds abnormally when it is stimulated with estrogen in adulthood (promotion stage). To identify candidate molecular elements involved in progression of the disruption/neoplastic process, we performed: 1) immunoblot analyses and 2) microarray profiling (Affymetrix Gene Chip System) on sets of uterine protein and RNA extracts, respectively, and 3) immunohistochemical analysis on uterine sections; all from both initiation stage and promotion stage groups of animals. Here we report that: 1) progression of the neonatal DES-induced hyperplasia/dysplasia/neoplasia phenomenon in the hamster uterus involves a wide spectrum of specific gene expression alterations and 2) the gene products involved and their manner of altered expression differ dramatically during the initiation vs. promotion stages of the phenomenon. Particularly interesting changes included members in the functional categories of nuclear receptors (progesterone receptor), cell-cell interactions (E-cadherin, connexins), cytokine action (IRF-1, Stat5A), growth factor action (IRS-1), extracellular matrix component (tenascin-C), transcription factors (Nrf2, Sp1), and multi-functional nuclear protein (SAFB1). PMID:25242112

  8. Reinforcement and the Organization of Behavior in Golden Hamsters: Pavlovian Conditioning with Food and Shock Unconditioned Stimuli

    ERIC Educational Resources Information Center

    Shettleworth, Sara J.

    1978-01-01

    There has been considerable interest lately in cases where instrumental conditionability appears to depend on the reinforcer used. Here the effects of Pavlovian conditioned stimuli (CSs)on golden hamster behaviors was observed. The intent was to see whether previously reported differences among the behaviors produced by food reinforcement and…

  9. A 13-week toxicity study of acrylamide administered in drinking water to hamsters.

    PubMed

    Imai, Toshio; Kitahashi, Tsukasa

    2014-01-01

    Acrylamide (AA) is known to induce tumors in various organs/tissues in rats and mice. Epidemiological studies of oral exposure have generated controversial results but mortality studies of people who work with AA have indicated increased rates of pancreatic cancer. In the present study, for dose selection for chronic toxicity/carcinogenicity studies, 13-week toxicity of AA was evaluated in Syrian hamsters, which are sensitive to induction of pancreatic ductal carcinogenesis, at concentrations required to provide doses of 0 (control), 20, 30 and 50 mg kg(-1) body weight in drinking water. Treatment with AA caused abnormal gait advancing to hind limb paralysis in all males and females at 50 mg kg(-1). Body weights in 30 and 50 mg kg(-1) males and 50 mg kg(-1) females were lower than in the controls. At termination of the study, red blood cells (RBC) and hemoglobin (Hb) were decreased or showed a tendency for a decrease at 20 and 30 mg kg(-1) in females. Microscopically, axonal/myelin degeneration of sciatic nerves was observed in all AA-treated groups with dose dependence. No obvious changes were found in pancreatic ducts/ductules in any groups of animal. These results indicated the maximum tolerated dose for long-term studies of AA to be 20 mg kg(-1) or less in both male and female Syrian hamsters. Copyright © 2012 John Wiley & Sons, Ltd.

  10. Maintenance of a fully functional digestive system during hibernation in the European hamster, a food-storing hibernator.

    PubMed

    Weitten, Mathieu; Oudart, Hugues; Habold, Caroline

    2016-03-01

    Some small mammals limit energy expenditure during winter conditions through torpor bouts, which are characterized by a decrease in body temperature and metabolic rate. Individuals arise periodically from torpor to restore critical functions requiring euthermia. Although most of the species involved do not feed during hibernation and rely on body reserves to fulfil energy requirements (fat-storing species), others hoard food in a burrow (food-storing species) and can feed during interbout euthermy. Whereas fat-storing species undergo a marked atrophy of the digestive tract, food-storing species have to maintain a functional digestive system during hibernation. Our study aimed to evaluate the absorption capacities of a food-storing species, the European hamster, throughout the annual cycle. In vivo intestinal perfusions were conducted in different groups of hamsters (n=5) during the different life periods, namely before hibernation, in torpor, during interbout euthermy, and during summer rest. The triglyceride, non-esterified free fatty acid, starch, glucose and protein composition of the perfusate was evaluated before and after the 1h perfusion of a closed intestinal loop. Triglyceride, starch and protein hydrolysis rates were similar in hibernating (torpid and euthermic) and non-hibernating hamsters. Intestinal absorption of free fatty acid was also similar in all groups. However, glucose uptake rate was higher during hibernation than during the summer. In contrast with fat-storing species, the intestinal absorption capacities of food-storing species are fully maintained during hibernation to optimize nutrient assimilation during short interbout euthermy. In particular, glucose uptake rate is increased during hibernation to restore glycaemia and ensure glucose-dependent pathways. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. A time course study on prothrombotic parameters and their modulation by anti-platelet drugs in hyperlipidemic hamsters.

    PubMed

    Singh, Vishal; Jain, Manish; Prakash, Prem; Misra, Ankita; Khanna, Vivek; Tiwari, Rajiv Lochan; Keshari, Ravi Shankar; Singh, Shivendra; Dikshit, Madhu; Barthwal, Manoj Kumar

    2011-06-01

    The present study was undertaken to assess the chronology of major pathological events associated with high cholesterol (HC) diet and their modulation by anti-platelet drugs. Male Golden Syrian hamsters were fed HC diet up to 90 days. Plasma lipid, glucose and coagulation parameters (commercial kits), platelet activation (whole blood aggregation and static adhesion), endothelial dysfunction (aortic ring vasoreactivity), splenocyte TNF-α, IFN-γ and iNOS mRNA transcripts (RT-PCR), and ferric chloride (time to occlusion) induced thrombosis were monitored at 15, 30, 60, and 90 days after HC feeding and compared with normolipidemic hamsters. A significant increase in plasma lipid levels was observed at 15 days of HC feeding, but other parameters remain unaltered. Enhanced ADP, collagen, and thrombin-induced platelet aggregation, splenocyte TNF-α expression along with endothelial dysfunction were observed from 30 to 90 days of HC feeding. Platelet adhesion on collagen-/fibrinogen-coated surface and IFN-γ expression were augmented only after 60 days, while enhanced iNOS expression, reduction in thrombin time, and potentiation of ferric chloride-induced thrombosis was observed only at 90 days of HC feeding. Thus, pathological changes induced by HC diet depend on the duration and extent of hyperlipidemia. Moreover, hamsters treated with anti-platelet drugs aspirin (5 mg/kg) or clopidogrel (10 mg/kg) along with HC feeding exhibited reduction in platelet activation as well as subsequent changes observed in the abovementioned parameters following HC feeding. Since reduction in TNF-α was associated with reversion in endothelial dysfunction and prothrombotic state, the role of platelets is implicated in the pathological changes associated with HC feeding.

  12. Destruction of the hepatocyte junction by intercellular invasion of Leptospira causes jaundice in a hamster model of Weil's disease.

    PubMed

    Miyahara, Satoshi; Saito, Mitsumasa; Kanemaru, Takaaki; Villanueva, Sharon Y A M; Gloriani, Nina G; Yoshida, Shin-ichi

    2014-08-01

    Weil's disease, the most severe form of leptospirosis, is characterized by jaundice, haemorrhage and renal failure. The mechanisms of jaundice caused by pathogenic Leptospira remain unclear. We therefore aimed to elucidate the mechanisms by integrating histopathological changes with serum biochemical abnormalities during the development of jaundice in a hamster model of Weil's disease. In this work, we obtained three-dimensional images of infected hamster livers using scanning electron microscope together with freeze-cracking and cross-cutting methods for sample preparation. The images displayed the corkscrew-shaped bacteria, which infiltrated the Disse's space, migrated between hepatocytes, detached the intercellular junctions and disrupted the bile canaliculi. Destruction of bile canaliculi coincided with the elevation of conjugated bilirubin, aspartate transaminase and alkaline phosphatase levels in serum, whereas serum alanine transaminase and γ-glutamyl transpeptidase levels increased slightly, but not significantly. We also found in ex vivo experiments that pathogenic, but not non-pathogenic leptospires, tend to adhere to the perijunctional region of hepatocyte couplets isolated from hamsters and initiate invasion of the intercellular junction within 1 h after co-incubation. Our results suggest that pathogenic leptospires invade the intercellular junctions of host hepatocytes, and this invasion contributes in the disruption of the junction. Subsequently, bile leaks from bile canaliculi and jaundice occurs immediately. Our findings revealed not only a novel pathogenicity of leptospires, but also a novel mechanism of jaundice induced by bacterial infection. © 2014 The Authors. International Journal of Experimental Pathology © 2014 International Journal of Experimental Pathology.

  13. Destruction of the hepatocyte junction by intercellular invasion of Leptospira causes jaundice in a hamster model of Weil's disease

    PubMed Central

    Miyahara, Satoshi; Saito, Mitsumasa; Kanemaru, Takaaki; Villanueva, Sharon Y A M; Gloriani, Nina G; Yoshida, Shin-ichi

    2014-01-01

    Weil's disease, the most severe form of leptospirosis, is characterized by jaundice, haemorrhage and renal failure. The mechanisms of jaundice caused by pathogenic Leptospira remain unclear. We therefore aimed to elucidate the mechanisms by integrating histopathological changes with serum biochemical abnormalities during the development of jaundice in a hamster model of Weil's disease. In this work, we obtained three-dimensional images of infected hamster livers using scanning electron microscope together with freeze-cracking and cross-cutting methods for sample preparation. The images displayed the corkscrew-shaped bacteria, which infiltrated the Disse's space, migrated between hepatocytes, detached the intercellular junctions and disrupted the bile canaliculi. Destruction of bile canaliculi coincided with the elevation of conjugated bilirubin, aspartate transaminase and alkaline phosphatase levels in serum, whereas serum alanine transaminase and γ-glutamyl transpeptidase levels increased slightly, but not significantly. We also found in ex vivo experiments that pathogenic, but not non-pathogenic leptospires, tend to adhere to the perijunctional region of hepatocyte couplets isolated from hamsters and initiate invasion of the intercellular junction within 1 h after co-incubation. Our results suggest that pathogenic leptospires invade the intercellular junctions of host hepatocytes, and this invasion contributes in the disruption of the junction. Subsequently, bile leaks from bile canaliculi and jaundice occurs immediately. Our findings revealed not only a novel pathogenicity of leptospires, but also a novel mechanism of jaundice induced by bacterial infection. PMID:24945433

  14. Sex and age differences in hibernation patterns of common hamsters: adult females hibernate for shorter periods than males.

    PubMed

    Siutz, Carina; Franceschini, Claudia; Millesi, Eva

    2016-08-01

    In this study, we investigated the timing and duration of hibernation as well as body temperature patterns in free-ranging common hamsters (Cricetus cricetus) with regard to sex and age differences. Body temperature was recorded using subcutaneously implanted data loggers. The results demonstrate that although immergence and vernal emergence sequences of sex and age groups resembled those of most hibernators, particularly adult females delayed hibernation onset until up to early January. Thus, in contrast to other hibernators, female common hamsters hibernated for shorter periods than males and correspondingly spent less time in torpor. These sex differences were absent in juvenile hamsters. The period between the termination of hibernation and vernal emergence varied among individuals but did not differ between the sex and age groups. This period of preemergence euthermy was related to emergence body mass: individuals that terminated hibernation earlier in spring and had longer euthermic phases prior to emergence started the active season in a better condition. In addition, males with longer periods of preemergence euthermy had larger testes at emergence. In conclusion, females have to rely on sufficient food stores but may adjust the use of torpor in relation to the available external energy reserves, whereas males show a more pronounced energy-saving strategy by hibernating for longer periods. Nonetheless, food caches seem to be important for both males and females as indicated by the euthermic preemergence phase and the fact that some individuals, mainly yearlings, emerged with a higher body mass than shortly before immergence in autumn.

  15. Detection of rare species of volatile organic selenium metabolites in male golden hamster urine.

    PubMed

    Kwak, Jae; Ohrnberger, Sarah A; Valencak, Teresa G

    2016-07-01

    Selenium has been considered as an essential trace element in mammals and its intake comes mainly from food. Mammals can metabolize both inorganic and organic species, and urinary excretion is the primary elimination route of selenium. Selenosugars and trimethylselenonium ion have been identified as major urinary metabolites. Other metabolites have been reported, but they were detected in some studies and not in others. Still, a large portion of the ingested selenium eliminated from the body is unknown. Volatile selenium species may account for a certain portion of the unknown species since they can easily be lost during sample analyses. While we analyzed male golden hamster urine in search of potential volatile pheromone(s), four volatile selenium compounds were detected. They were dimethyl selenenylsulfide, dimethyl diselenide, dimethyl bis(thio)selenide, and dimethyl selenodisulfide. When the urine samples were aged and dried for 48 h, dimethyl selenodisulfide tended to increase, while others decreased. The increase might be due to the formation of dimethyl selenodisulfide via reaction of dimethyl diselenide and dimethyl trisulfide whose concentration increased as urine aged. To our knowledge, dimethyl bis(thio)selenide and dimethyl selenodisulfide have never been demonstrated in urine. It remains to be determined whether these species are common metabolites in other animals or hamster-specific.

  16. Taxonomy of the genus Lycalopex (Carnivora: Canidae) in Argentina

    USGS Publications Warehouse

    Zunino, G.E.; Vaccaro, O.B.; Canevari, M.; Gardner, A.L.

    1995-01-01

    Previously treated as species of Pseudalopex, Argentine members of the genus Lycalopex (L. griseus, L. gymnocercus, and L. culpaeus) are examined to clarify the taxonomic status of each named form. Principal components analyses of 26 cranial measurements of 151 adult specimens and 11 pelage characters of 111 specimens, clearly distinguish L. culpaeus from the other two taxa. Lycalopex griseus and L. gymnocercus show clinal variation in cranial measurements and pelage characters. Qualitative cranial characters, used as diagnostic for L. griseus and L. gymnocercus, revealed great nongeographic variation. We conclude that L. griseus and L. gymnocercus are conspecific, and should be known as L. gymnocercus. Therefore, we recognize only two species of the genus Lycalopex (L. culpaeus and L. gymnocercus) in Argentina. We also use this opportunity to review synonymies of the recognized species of Lycalopex.

  17. Asbestos-Induced Epithelial Changes in Organ Cultures of Hamster Trachea: Inhibition by Retinyl Methyl Ether

    NASA Astrophysics Data System (ADS)

    Mossman, B. T.; Craighead, J. E.; MacPherson, B. V.

    1980-01-01

    The epithelium of the hamster trachea in organ culture undergoes hyperplasia and squamous metaplasia after exposure to the amphibole types of asbestos, crocidolite and amosite. These changes are inhibited when the synthetic vitamin A analog, retinyl methyl ether, is incorporated into the culture medium. These findings suggest a possible use for retinoids in the prevention and treatment of respiratory tract disease associated with environmental exposure to asbestos.

  18. Detection and localization of specific antigens in the reproductive tracts of cycling, pregnant, and ovariectomized hamsters.

    PubMed

    Fox, L L; Shivers, C A

    1975-06-01

    A systematic search was made for components specific to the female reproductive tract in golden hamsters. Antisera produced in rabbits against saline homogenates of hamster uteri (collected on the night of estrus) cross-reacted extensively with extracts of 12 other tissues in agar gel double-diffusion assays. Absorption of the antisera with small intestine, lung, and liver rendered the immune sera specific for uterine and oviductal antigens (within the limits of the sensitivity of the precipitin assays). Immunoelectrophoretic analysis resolved 12 uterine antigens, many of which were similar to components in several other tissues. Absorbed antisera specific for reproductive tract antigens formed one postalbumin arc with uterine and oviductal extracts in immunoelectrophoretic studies. No reactions were detected between specific antisera and five other organ extracts or plasma. An indirect immunofluorescent antibody technique was used to detect changes in the distribution of specific antigens in reproductive tracts of cycling, pregnant, and ovariectomized hamsters. The gamma-globulin fraction of anti-uterus sera (absorbed with small intestine, lung, and liver), shown to be specific for reproductive tract tissues in precipitin tests, was used to localize antigens. Appropriate controls indicated that the fluorescence observed was due to antigen-antibody interactions. During the cycle, specific antigens were usually confined to the ampullary lamina propria, except during estrus, when they were prominent in the lamina propria and luminal epithelium of the ampula. Specific antigens were never abundant in the isthmus of nonpregnant hamsters. On day 1 postcoitum, the components were found throughout the ampullary and isthmic regions. By day 2 postcoitum, ampullary antigens were usually confined to the lamina propria. The specific components were not prominent in the oviduct on day 3 postcoitum, but were conspicuous in both ampulla and isthmus on day 4. Specific antigens in

  19. INHIBITION OF IN VITRO FERTILIZATION IN THE HAMSTER BY ANTIBODIES RAISED AGAINST THE RAT SPERM PROTEIN SP22

    EPA Science Inventory

    INHIBITION OF IN VITRO FERTILIZATION IN THE HAMSTER BY ANTIBODIES RAISED AGAINST THE RAT SPERM PROTEIN SP22. SC Jeffay*, SD Perreault, KL Bobseine*, JE Welch*, GR Klinefelter, US EPA, Research Triangle Park, NC.
    SP22, a rat sperm membrane protein that is highly-correlated w...

  20. METABOLISM AND DNA ADDUCT FORMATION OF 2-ACETYLAMINOFLUORENE BY BLADDER EXPLANTS FROM HUMAN, DOG, MONKEY, HAMSTER AND RAT

    EPA Science Inventory

    It is concluded that bladder explants of the human, dog, monkey, hamster, and rat metabolize AAF mainly to ring-hydroxylated products, but also form small amounts of the proximate carcinogenic metabolite N-hydroxy-AAF. Neither the overall binding of AAF to bladder DNA, nor the fo...

  1. Effects of vomeronasal organ removal on individual odor discrimination, sex-odor preference, and scent marking by female hamsters.

    PubMed

    Petrulis, A; Peng, M; Johnston, R E

    1999-03-01

    Removal of the vomeronasal organ (VNX) did not eliminate the ability of female hamsters to discriminate between individual male's flank gland or urine odors in a habituation/discrimination task nor did it impair preference for male odors over female odors from a distance. Vomeronasal organ removal did reduce overall levels of investigation of flank gland odor in the habituation/discrimination task. Although VNX females did not show severe impairments in the frequency of either flank or vaginal marking in response to odors, they did show an abnormal pattern of marking. VNX females, unlike shams, did not flank mark more to female odors than to male odors, nor did they vaginal mark more to male odors than to female odors. Thus, the vomeronasal organ in female hamsters appears to be important for differences in scent marking toward male and female odors, but is not essential for discrimination of individual odors or for preferences for male over female odors.

  2. Structural and Functional Studies of the Protamine 2-Zinc Complex from Syrian Gold Hamster (Mesocricetus Auratus) Spermatids and Sperm

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dolan, Cheryl E.

    The research described in this dissertation consists of four major areas: (1) sequence analysis of protamine 2 from Muroid rodents to identify potential zinc-binding domain(s) of protamine 2; (2) structural studies of the protamine 2-zinc complex from Syrian Gold hamster sperm and spermatids to elucidate the role of zinc during spermiogenesis; (3) structural studies of an unique protamine 2-zinc complex from chinchilla sperm; and (4) Nuclear Magnetic Resonance (NMR) studies of soluble complexes of hairpin oligonucleotides with synthetic arginine-rich peptides or protamine 1 isolated from bull sperm. First, zinc was quantitated in spermatids and sperm by Proton-Induced X-ray Emission (PIXE)more » to determine whether zinc is present in the early stages of spermiogenesis. The PIXE results revealed the zinc content varies proportionately with the amount of protamine 2 in both spermatid and sperm nuclei. An exception was chinchilla sperm containing twice the amount of protamine 2 than zinc. Further analyses by PIXE and X-ray Absorption Spectroscopy (XAS) of zinc bound to protamines isolated from hamster sperm confirmed the majority of the zinc is bound to protamine and identified the zinc ligands of protamine 2 in hamster spermatids and sperm in vivo. These studies established that zinc is bound to the protamine 2 precursor in hamster spermatids and the coordination of zinc by protamine 2 changes during spermiogenesis. Finally, the sequence analysis combined with the XAS results suggest that the zinc-binding domain in protamine 2 resides in the amino-terminus. Similar analyses of chinchilla sperm by XAS were performed to clarify the unusual PIXE results and revealed that chinchilla has an atypical protamine 2-zinc structure. Two protamine 2 molecules coordinate one zinc atom, forming homodimers that facilitate the binding of protamine 2 to DNA and provide an organizational scheme that would accommodate the observed species-specific protamine stoichiometry in

  3. Dim light at night disrupts the short-day response in Siberian hamsters.

    PubMed

    Ikeno, Tomoko; Weil, Zachary M; Nelson, Randy J

    2014-02-01

    Photoperiodic regulation of physiology, morphology, and behavior is crucial for many animals to survive seasonally variable conditions unfavorable for reproduction and survival. The photoperiodic response in mammals is mediated by nocturnal secretion of melatonin under the control of a circadian clock. However, artificial light at night caused by recent urbanization may disrupt the circadian clock, as well as the photoperiodic response by blunting melatonin secretion. Here we examined the effect of dim light at night (dLAN) (5lux of light during the dark phase) on locomotor activity rhythms and short-day regulation of reproduction, body mass, pelage properties, and immune responses of male Siberian hamsters. Short-day animals reduced gonadal and body mass, decreased spermatid nuclei and sperm numbers, molted to a whiter pelage, and increased pelage density compared to long-day animals. However, animals that experienced short days with dLAN did not show these short-day responses. Moreover, short-day specific immune responses were altered in dLAN conditions. The nocturnal activity pattern was blunted in dLAN hamsters, consistent with the observation that dLAN changed expression of the circadian clock gene, Period1. In addition, we demonstrated that expression levels of genes implicated in the photoperiodic response, Mel-1a melatonin receptor, Eyes absent 3, thyroid stimulating hormone receptor, gonadotropin-releasing hormone, and gonadotropin-inhibitory hormone, were higher in dLAN animals than those in short-day animals. These results suggest that dLAN disturbs the circadian clock function and affects the molecular mechanisms of the photoperiodic response. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Food restriction dissociates sexual motivation, sexual performance, and the rewarding consequences of copulation in female Syrian hamsters

    PubMed Central

    Klingerman, Candice M.; Patel, Anand; Hedges, Valerie L.; Meisel, Robert L.; Schneider, Jill E.

    2012-01-01

    Animals can switch their behavioral priorities from ingestive to sex behaviors to optimize reproductive success in environments where energy fluctuates. We hypothesized that energy availability differentially affects the appetitive (motivation), consummatory (performance), and learned (rewarding) components of behavior. In Experiment 1, appetitive and consummatory aspects of sex behavior were dissociated in the majority of female Syrian hamsters restricted to 75% of their ad libitum food intake for 11 days. Food restriction significantly inhibited vaginal scent marking, decreased the preference for spending time with male hamsters vs. spending time with food, and increased food hoarding with no significant effect on consummatory behaviors such as the incidence of lordosis or food intake. In Experiments 2 and 3, we attempted to use a similar level of food restriction to dissociate sexual appetite from sexual reward. In hamsters, formation of a conditioned place preference (CPP) for copulatory reward is reflected in increased nucleus accumbens (NAc) neural activation, measured as immunocytochemical staining for c-Fos, the protein product of the immediate-early gene, c-fos. In Experiment 2, neural activation increased 1 h after copulation in the NAc core and shell, and did not differ significantly between 10-day food-restricted and ad libitum-fed females in any brain area examined. In Experiment 3, females were either food-restricted or fed ad libitum over 8-30 days of conditioning with copulatory stimuli. Food-restricted females showed significantly fewer appetitive behaviors, but no difference in formation of a CPP compared to females fed ad libitum. Together these data are consistent with the idea that mild levels of food restriction that inhibit appetitive behaviors fail to attenuate consummatory behaviors and the rewarding consequences of copulation. Thus, appetitive sex behaviors are, at least partially, neuroanatomically and behaviorally distinct from both

  5. Enhancement of antioxidative activity and cardiovascular protection in hamsters by camellia oil and soybean-camellia blended oil.

    PubMed

    Chou, Ting-Yi; Lu, Yi-Fa; Inbaraj, Baskaran Stephen; Chen, Bing-Huei

    2018-02-07

    The aim of this study was to examine the effects of several vegetable oils and blended oil composed of soybean and camellia oils on blood lipid reduction and antioxidative activity. Forty male hamsters were fed an AIN-93 G diet for 1 wk, followed by dividing into five groups: control group-1 was fed a low-fat diet containing 5% oil for 6 wk, and the other four groups were fed high-fat diets with group-2 containing 14% palm oil, group-3 containing 14% camellia oil, group-4 containing 14% soybean oil, and group-5 containing 14% blended oil (8.4% soybean oil and 5.6% camellia oil) along with 0.2% cholesterol and 0.1% bile acid. High-fat diets raised serum triacylglycerol, total cholesterol, and aspartate aminotransferase in hamsters without affecting alanine aminotransferase. Compared with palm oil-containing diet, the other three high-fat diets reduced serum total cholesterol, low-density lipoprotein cholesterol, and the ratio of low-density lipoprotein to high-density lipoprotein cholesterol with an opposite trend for liver total cholesterol. However, compared with the control group, the serum high-density lipoprotein cholesterol level was raised for all four high-fat diets. The higher the degree of oil unsaturation, the higher the serum thiobarbituric acid reactive substances and the lower the liver triacylglycerol level and activities of fatty acid synthase, glucose 6-phosphate dehydrogenase, and malic enzymes. Both soybean and blended oils lowered the antioxidative activity of liver. Camellia and blended oils were more efficient than soybean oil in elevating serum high-density lipoprotein cholesterol and decreasing the ratio of low-density lipoprotein to high-density lipoprotein cholesterol in hamsters. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. Uptake of indocyanine green by hamster sebaceous glands

    NASA Astrophysics Data System (ADS)

    McMillan, Kathleen; Lo, Kai-Ming; Wang, Zhi

    2001-05-01

    Photothermal injury to the sebaceous glands is a potential curative treatment for the common skin disease acne vulgaris. Accumulation of the exogenous chromophore indocyanine green in the sebaceous glands may be accomplished using an emulsion or liposomal formulation applied to the skin surface. An emulsion containing 0.09% by weight indocyanine green (ICG) was applied to the epidermis of hamster ears ex vivo and the flank organ in vivo. Fluorescence microscopy demonstrated selective accumulation of ICG in the underlying sebaceous glands. The concentration of ICG that may be expected to accumulate in sebaceous glands of humans was then estimated on the basis of the gland size and orifice area, for the case of topical application of a more concentrated 1% ICG liposomal formulation. Monte Carlo modeling and heat transfer calculations showed that the sebaceous glands containing the exogenous chromophore may be selectively damaged by pulsed 810 nm laser radiation in conjunction with cryogen spray cooling.

  7. Complete Genome Sequence of the Streptomyces Phage Nanodon.

    PubMed

    Erill, Ivan; Caruso, Steven M

    2016-10-06

    Streptomyces phage Nanodon is a temperate double-stranded DNA Siphoviridae belonging to cluster BD1. It was isolated from soil collected in Kilauea, HI, using Streptomyces griseus subsp. griseus as a host. Copyright © 2016 Erill et al.

  8. Sex ratio adjustment by sex-specific maternal cannibalism in hamsters.

    PubMed

    Beery, Annaliese K; Zucker, Irving

    2012-10-10

    Mammalian offspring sex ratios can be biased via prenatal and postnatal mechanisms, including sperm selection, sex-specific embryo loss, and differential postnatal investment in males and females. Syrian hamsters routinely cannibalize some of their pups in the first days after birth. We present evidence that short day lengths, typically predictive of poor autumn and winter field conditions, are associated with male-biased sex ratios, achieved in part through selective perinatal maternal infanticide of female offspring. Higher peak litter sizes were associated with increased cannibalism rates, decreased final litter counts, and increased body mass of pups surviving to weaning. To our knowledge this is the first report of sex ratio adjustment by offspring cannibalism. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Demonstration of 3 alpha(17 beta)-hydroxysteroid dehydrogenase distinct from 3 alpha-hydroxysteroid dehydrogenase in hamster liver.

    PubMed Central

    Ohmura, M; Hara, A; Nakagawa, M; Sawada, H

    1990-01-01

    NAD(+)-linked and NADP(+)-linked 3 alpha-hydroxysteroid dehydrogenases were purified to homogeneity from hamster liver cytosol. The two monomeric enzymes, although having similar molecular masses of 38,000, differed from each other in pI values, activation energy and heat stability. The two proteins also gave different fragmentation patterns by gel electrophoresis after digestion with protease. The NADP(+)-linked enzyme catalysed the oxidoreduction of various 3 alpha-hydroxysteroids, whereas the NAD(+)-linked enzyme oxidized the 3 alpha-hydroxy group of pregnanes and some bile acids, and the 17 beta-hydroxy group of testosterone and androstanes. The thermal stabilities of the 3 alpha- and 17 beta-hydroxysteroid dehydrogenase activities of the NAD(+)-linked enzyme were identical, and the two enzyme activities were inhibited by mixing 17 beta- and 3 alpha-hydroxysteroid substrates, respectively. Medroxyprogesterone acetate, hexoestrol and 3 beta-hydroxysteroids competitively inhibited 3 alpha- and 17 beta-hydroxysteroid dehydrogenase activities of the enzyme. These results show that hamster liver contains a 3 alpha(17 beta)-hydroxysteroid dehydrogenase structurally and functionally distinct from 3 alpha-hydroxysteroid dehydrogenase. Images Fig. 1. Fig. 2. PMID:2317205

  10. Gene expression analysis and microdialysis suggest hypothalamic triiodothyronine (T3) gates daily torpor in Djungarian hamsters (Phodopus sungorus).

    PubMed

    Bank, Jonathan H H; Cubuk, Ceyda; Wilson, Dana; Rijntjes, Eddy; Kemmling, Julia; Markovsky, Hanna; Barrett, Perry; Herwig, Annika

    2017-07-01

    Thyroid hormones play an important role in regulating seasonal adaptations of mammals. Several studies suggested that reduced availability of 3,3',5-triiodothyronine (T3) in the hypothalamus is required for the physiological adaptation to winter in Djungarian hamsters. We have previously shown that T3 is involved in the regulation of daily torpor, but it remains unclear, whether T3 affects torpor by central or peripheral mechanisms. To determine the effect of T3 concentrations within the hypothalamus in regulating daily torpor, we tested the hypothesis that low hypothalamic T3 metabolism would favour torpor and high T3 concentrations would not. In experiment 1 gene expression in torpid hamsters was assessed for transporters carrying thyroid hormones between cerebrospinal fluid and hypothalamic cells and for deiodinases enzymes, activating or inactivating T3 within hypothalamic cells. Gene expression analysis suggests reduced T3 in hypothalamic cells during torpor. In experiment 2, hypothalamic T3 concentrations were altered via microdialysis and torpor behaviour was continuously monitored by implanted body temperature transmitters. Increased T3 concentrations in the hypothalamus reduced expression of torpor as well as torpor bout duration and depth. Subsequent analysis of gene expression in the ependymal layer of the third ventricle showed clear up-regulation of T3 inactivating deiodinase 3 but no changes in several other genes related to photoperiodic adaptations in hamsters. Finally, serum analysis revealed that increased total T3 serum concentrations were not necessary to inhibit torpor expression. Taken together, our results are consistent with the hypothesis that T3 availability within the hypothalamus significantly contributes to the regulation of daily torpor via a central pathway.

  11. Effects of conjugated linoleic acid on body fat accumulation and serum lipids in hamsters fed an atherogenic diet.

    PubMed

    Navarro, V; Zabala, A; Macarulla, M T; Fernández-Quintela, A; Rodríguez, V M; Simón, E; Portillo, M P

    2003-09-01

    Conjugated linoleic acid (CLA) refers to a mixture of naturally occurring positional and geometric isomers of linoleic acid that exist in dairy products and meat. The aim of the present work was to study the effects of c-9,t-11 and t-10,c-12 CLA isomers on body fat accumulation and serum lipids in hamsters fed an atherogenic diet. Hamsters were divided in four groups: one group was fed a chow diet (control) and the other three groups were given semi-purified atherogenic diets with 0.5% linoleic acid (LA), c-9,t-11 or t-10,c-12 CLA. Body weight and food intake were measured daily. After 6 weeks, adipose tissues from different anatomical locations and liver were dissected and weighed. Serum glucose, total cholesterol, HDL-c, LDL-c and triacylglycerol levels, as well as total and free cholesterol, triacylglycerol and phospholipid content in liver were determined by enzymatic methods. No differences in either energy intake or final body weight were found. The addition of t-10,c-12 CLA reduced fat accumulation and led to lower serum cholesterol, as compared with LA group. Nevertheless the level remained higher than in the control animals. The reduction in serum cholesterol was limited to LDL-c. This isomer also reduced triacylglycerol content in liver but did not modify serum triacylglycerol level. In summary, the present study demonstrates that t-10,c-12 CLA is the biologically active agent when anti-obesity and hypocholesterolaemic properties of CLA are considered. In contrast, the isomer c-9,t-11 has no effect on lipid metabolism in hamsters.

  12. [Two cases of Trichophyton mentagrophytes infection contracted from a hamster and a chinchilla].

    PubMed

    Hata, Y; Amagai, M; Naka, W; Harada, R; Nishikawa, T

    2000-01-01

    We report two cases of Trichophyton mentagrophytes infection. Case 1: A 10-year-old girl visited Tokyo Electric Power Hospital in June 1994 for evaluation of an erythematous lesion on her head. Three months of topical steroid therapy exacerbated the lesion with pustular formation. Histopathological and mycological examination revealed that the patient had tinea capitis caused by T. mentagrophytes. T. mentagrophytes was also isolated from her pet, a hamster. Case 2: A-14-year-old girl was referred to Shonan Clinic in January 1996 with scaly erythema on her face. She had been treated with neticonazole hydrochloride at another clinic, but the lesion became worse. Direct microscopic examination of the scale was negative at that time, so treatment with topical steroid was started. After 10 days, the lesion was almost cured, but one month later it recurred with an annular distribution. KOH preparation of the scale revealed mycelia and T. mentagrophytes was isolated on culture. T. mentagrophytes was also isolated from her pet, a chinchilla. In both cases, the oral administration of itraconazole at 50 mg/day was effective. The isolated pathogen was identified as Arthroderma vanbreuseghemii with species-specific primers of chitin synthase 1 gene. T. mentagrophytes is one of the most common dermatophytes isolated from man and animals. Rodents like the hamster and the chinchilla have recently become popular as pets in Japan. We should be aware that rodents may carry this kind of fungal pathogen as they become even more popular as pets.

  13. [The polyploidization characteristics of the hepatocytes of the mouse-like hamster Calomyscus mystax].

    PubMed

    Anatskaia, O V; Malikov, V G; Meĭer, M N; Kudriavtsev, B N

    1995-01-01

    A cytophotometric measurement of DNA content in hepatocytes of maturing mouse-like hamsters was made. Cells belonging to ordinary mammalian ploidy classes 2c, 2c x 2, 4c, and 4c x 2 made about 90% of the hepatocyte population. The share of binucleated cells wa high (about 80%), the majority of these cells being 2c X 2 hepatocytes. Binucleated cells with tetraploid and diploid nuclei occur in almost every animal. An average hepatocyte ploidy level in mouse-like hamster is 4.6c. The main peculiarity of parenchymal liver cell populations is that up 5% of hepatocytes contain 3--11 nuclei of different ploidy classes. Multinucleated cells increase in number from 1.5% to 4% within the period from one year (the age of maturation) to two years. Later on their percentage does not change. It is found that in binucleated and multinucleated hepatocytes DNA synthesis can proceed asynchronously. Asynchrony in DNA synthesis elevates as the number of nuclei increases. Among the 2c x 2 and 2c x 3 cells an uneven distribution of 3H-thymidine label can occur, respectively, in 5 and in 50% cases, whereas all the cells with more than 3 nuclei display an uneven an uneven 3H-thymidin label distribution. The formation of multinucleated cells is supposed to be associated with asynchrony in DNA-synthesis in binucleated cells and with the restitution of mitosis.

  14. Regulation of hepatic 7 alpha-hydroxylase expression by dietary psyllium in the hamster.

    PubMed Central

    Horton, J D; Cuthbert, J A; Spady, D K

    1994-01-01

    Soluble fiber consistently lowers plasma total and low density lipoprotein (LDL)-cholesterol concentrations in humans and various animal models including the hamster; however, the mechanism of this effect remains incompletely defined. We performed studies to determine the activity of dietary psyllium on hepatic 7 alpha-hydroxylase, 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase and LDL receptor expression in the hamster. In animals fed a cholesterol-free semisynthetic diet containing 7.5% cellulose (avicel) as a fiber source, substitution of psyllium for avicel increased hepatic 7 alpha-hydroxylase activity and mRNA levels by 3-4-fold. Comparable effects on 7 alpha-hydroxylase expression were observed with 1% cholestyramine. Psyllium also increased hepatic 7 alpha-hydroxylase activity and mRNA in animals fed a diet enriched with cholesterol and triglyceride. Activation of 7 alpha-hydroxylase was associated with an increase in hepatic cholesterol synthesis that was apparently not fully compensatory since the cholesterol content of the liver declined. Although dietary psyllium did not increase hepatic LDL receptor expression in animals fed the cholesterol-free, very-low-fat diet, it did increase (or at least restore) receptor expression that had been downregulated by dietary cholesterol and triglyceride. Thus, 7.5% dietary psyllium produced effects on hepatic 7 alpha-hydroxylase and LDL metabolism that were similar to those of 1% cholestyramine. Induction of hepatic 7 alpha-hydroxylase activity by dietary psyllium may account, in large part, for the hypocholesterolemic effect of this soluble fiber. Images PMID:8182140

  15. Dual control of seasonal time keeping in male and female juvenile European hamsters.

    PubMed

    Monecke, Stefanie; Amann, Birgit; Lemuth, Karin; Wollnik, Franziska

    2014-05-10

    In contrast to photoperiodic rodent species, adult circannual European hamsters (Cricetus cricetus) do not rely on melatonin as transducer of the photoperiodic message. Instead, seasonal entrainment involves a special circadian organisation which characterizes a photoperiod-sensitive phase. When days shorten a precise activity pattern ("summer pattern") switches to a weak or arrhythmic "winter pattern". At the very same day gonadal regression is initiated and the circannual clock is reset. In contrast to this difference in photoperiodic time measurement, the broad time span in which offspring are born and the birth-season dependent timing of puberty is similar to photoperiodic rodents. We investigated how juvenile European hamsters measure photoperiod to situate themselves at the proper position in the annual cycle. Activity and 6-sulphatoxymelatonin (aMT6s) excretion were recorded in pups of five litters born at different seasons. Pups of all litters showed an activity pattern identical with the adults' summer pattern until postnatal day 78, suggesting that the pathway known to reset the circannual clock in adults is functional. The synchronous start of reproduction in yearlings supports this. However, since puberty and gonadal regression occurred before the switch in the activity pattern, the timing of reproduction in the birth year must be controlled by other means. As in photoperiodic species melatonin might be involved, since the aMT6s excretion showed daily and seasonal rhythms from early life on. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Blocking oxytocin receptors inhibits vaginal marking to male odors in female Syrian hamsters.

    PubMed

    Martinez, Luis A; Albers, H Elliott; Petrulis, Aras

    2010-12-02

    In Syrian hamsters (Mesocricetus auratus), precopulatory behaviors such as vaginal scent marking are essential for attracting a suitable mate. Vaginal marking is dependent on forebrain areas implicated in the neural regulation of reproductive behaviors in rodents, including the medial preoptic/anterior hypothalamus (MPOA-AH). Within MPOA-AH, the neuropeptide oxytocin (OT) acts to facilitate copulation (lordosis), as well as ultrasonic vocalizations towards males. It is not known, however, if OT in this area also facilitates vaginal marking. In the present study, a specific oxytocin receptor antagonist (OTA) was injected into MPOA-AH of intact female Syrian hamsters to determine if oxytocin receptor-dependent signaling is critical for the normal expression of vaginal marking elicited by male, female, and clean odors. OTA injections significantly inhibited vaginal marking in response to male odors compared with vehicle injections. There was no effect of OTA on marking in response to either female or clean odors. When injected into the bed nucleus of the stria terminalis (BNST), a nearby region to MPOA-AH, OTA was equally effective in decreasing marking. Finally, the effects of OTA appear to be specific to vaginal marking, as OTA injections in MPOA-AH or BNST did not alter general locomotor activity, flank marking, or social odor investigation. Considered together, these results suggest that OT in MPOA-AH and/or BNST normally facilitates male odor-induced vaginal marking, providing further evidence that OT generally supports prosocial interactions among conspecifics. Copyright © 2010 Elsevier Inc. All rights reserved.

  17. USC-087 protects Syrian hamsters against lethal challenge with human species C adenoviruses.

    PubMed

    Toth, Karoly; Spencer, Jacqueline F; Ying, Baoling; Tollefson, Ann E; Hartline, Caroll B; Richard, Eric T; Fan, Jiajun; Lyu, Jinglei; Kashemirov, Boris A; Harteg, Cheryl; Reyna, Dawn; Lipka, Elke; Prichard, Mark N; McKenna, Charles E; Wold, William S M

    2018-05-01

    Human adenoviruses (AdV) cause generally mild infections of the respiratory and GI tracts as well as some other tissues. However, AdV can cause serious infection in severely immunosuppressed individuals, especially pediatric patients undergoing allogeneic hematopoietic stem cell transplantation, where mortality rates are up to 80% with disseminated disease. Despite the seriousness of AdV disease, there are no drugs approved specifically to treat AdV infections. We report here that USC-087, an N-alkyl tyrosinamide phosphonate ester prodrug of HPMPA, the adenine analog of cidofovir, is highly effective against multiple AdV types in cell culture. USC-087 is also effective against AdV-C6 in our immunosuppressed permissive Syrian hamster model. In this model, hamsters are immunosuppressed by treatment with high dose cyclophosphamide. Injection of AdV-C6 (or AdV-C5) intravenously leads to a disseminated infection that resembles the disease seen in humans, including death. We have tested the efficacy of orally-administered USC-087 against the median lethal dose of intravenously administered AdV-C6. USC-087 completely prevented or significantly decreased mortality when administered up to 4 days post challenge. USC-087 also prevented or significantly decreased liver damage caused by AdV-C6 infection, and suppressed virus replication even when administered 4 days post challenge. These results imply that USC-087 is a promising candidate for drug development against HAdV infections. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Cucumis melo ssp. Agrestis var. Agrestis Ameliorates High Fat Diet Induced Dyslipidemia in Syrian Golden Hamsters and Inhibits Adipogenesis in 3T3-L1 Adipocytes.

    PubMed

    Shankar, Kripa; Singh, Sumit K; Kumar, Durgesh; Varshney, Salil; Gupta, Abhishek; Rajan, Sujith; Srivastava, Ankita; Beg, Muheeb; Srivastava, Anurag Kumar; Kanojiya, Sanjeev; Mishra, Dipak K; Gaikwad, Anil N

    2015-10-01

    Cucumis melo ssp. agrestis var. agrestis (CMA) is a wild variety of C. melo. This study aimed to explore anti-dyslipidemic and anti-adipogenic potential of CMA. For initial anti-dyslipidemic and antihyperglycemic potential of CMA fruit extract (CMFE), male Syrian golden hamsters were fed a chow or high-fat diet with or without CMFE (100 mg/kg). Further, we did fractionation of this CMFE into two fractions namely; CMA water fraction (CMWF) and CMA hexane fraction (CMHF). Phytochemical screening was done with liquid chromatography-mass spectrometry LC- (MS)/MS and direct analysis in real time-MS to detect active compounds in the fractions. Further, high-fat diet fed dyslipidemic hamsters were treated with CMWF and CMHF at 50 mg/kg for 7 days. Oral administration of CMFE and both fractions (CMWF and CMHF) reduced the total cholesterol, triglycerides, low-density lipoprotein cholesterol, and very low-density lipoprotein-cholesterol levels in high fat diet-fed dyslipidemic hamsters. CMHF also modulated expression of genes involved in lipogenesis, lipid metabolism, and reverse cholesterol transport. Standard biochemical diagnostic tests suggested that neither of fractions causes any toxicity to hamster liver or kidneys. CMFE and CMHF also decreased oil-red-O accumulation in 3T3-L1 adipocytes. Based on these results, it is concluded that CMA possesses anti-dyslipidemic and anti-hyperglycemic activity along with the anti-adipogenic activity. The oral administration of Cucumis melo agrestis fruit extract (CMFE) and its fractions (CMWF and CMHF) improved serum lipid profile in HFD fed dyslipidemic hamsters.CMFE, CMWF and CMHF significantly attenuated body weight gain and eWAT hypertrophy.The CMHF decreased lipogenesis in both liver and adipose tissue.CMFE and CMHF also inhibited adipogenesis in 3T3-L1 adipocytes. Abbreviation used: CMA: Cucumis melo ssp. agrestis var. agrestis, CMFE: CMA fruit extract, CMWF: CMA water fraction, CMHF: CMA hexane fraction, FAS: Fatty acid

  19. Cucumis melo ssp. Agrestis var. Agrestis Ameliorates High Fat Diet Induced Dyslipidemia in Syrian Golden Hamsters and Inhibits Adipogenesis in 3T3-L1 Adipocytes

    PubMed Central

    Shankar, Kripa; Singh, Sumit K.; Kumar, Durgesh; Varshney, Salil; Gupta, Abhishek; Rajan, Sujith; Srivastava, Ankita; Beg, Muheeb; Srivastava, Anurag Kumar; Kanojiya, Sanjeev; Mishra, Dipak K.; Gaikwad, Anil N.

    2015-01-01

    Background: Cucumis melo ssp. agrestis var. agrestis (CMA) is a wild variety of C. melo. This study aimed to explore anti-dyslipidemic and anti-adipogenic potential of CMA. Materials and Methods: For initial anti-dyslipidemic and antihyperglycemic potential of CMA fruit extract (CMFE), male Syrian golden hamsters were fed a chow or high-fat diet with or without CMFE (100 mg/kg). Further, we did fractionation of this CMFE into two fractions namely; CMA water fraction (CMWF) and CMA hexane fraction (CMHF). Phytochemical screening was done with liquid chromatography-mass spectrometry LC- (MS)/MS and direct analysis in real time-MS to detect active compounds in the fractions. Further, high-fat diet fed dyslipidemic hamsters were treated with CMWF and CMHF at 50 mg/kg for 7 days. Results: Oral administration of CMFE and both fractions (CMWF and CMHF) reduced the total cholesterol, triglycerides, low‐density lipoprotein cholesterol, and very low‐density lipoprotein-cholesterol levels in high fat diet-fed dyslipidemic hamsters. CMHF also modulated expression of genes involved in lipogenesis, lipid metabolism, and reverse cholesterol transport. Standard biochemical diagnostic tests suggested that neither of fractions causes any toxicity to hamster liver or kidneys. CMFE and CMHF also decreased oil-red-O accumulation in 3T3-L1 adipocytes. Conclusion: Based on these results, it is concluded that CMA possesses anti-dyslipidemic and anti-hyperglycemic activity along with the anti-adipogenic activity. SUMMARY The oral administration of Cucumis melo agrestis fruit extract (CMFE) and its fractions (CMWF and CMHF) improved serum lipid profile in HFD fed dyslipidemic hamsters.CMFE, CMWF and CMHF significantly attenuated body weight gain and eWAT hypertrophy.The CMHF decreased lipogenesis in both liver and adipose tissue.CMFE and CMHF also inhibited adipogenesis in 3T3-L1 adipocytes. Abbreviation used: CMA: Cucumis melo ssp. agrestis var. agrestis, CMFE: CMA fruit extract, CMWF

  20. Dietary Fish Oil Blocks the Microcirculatory Manifestations of Ischemia- Reperfusion Injury in Striated Muscle in Hamsters

    NASA Astrophysics Data System (ADS)

    Lehr, Hans-Anton; Hubner, Christoph; Nolte, Dirk; Kohlschutter, Alfried; Messmer, Konrad

    1991-08-01

    Epidemiologic observations and experimental studies have demonstrated a protective effect of dietary fish oil on the clinical manifestations of ischemia-reperfusion injury. To investigate the underlying mechanisms, we used the dorsal skinfold chamber model for intravital fluorescence microscopy of the microcirculation in striated muscle of awake hamsters. In control hamsters (n = 7), reperfusion after a 4-hr pressure-induced ischemia to the muscle tissue elicited the adhesion of fluorescently stained leukocytes to the endothelium of postcapillary venules, capillary obstruction, and the breakdown of endothelial integrity. These microvascular manifestations of ischemia-reperfusion injury were significantly attenuated in animals (n = 7) when fed with a fish oil-enriched diet for 4 weeks prior to the experiments. In leukocyte total lipids, the fish oil diet resulted in a substantial displacement of arachidonic acid, the precursor of the potent adhesionpromoting leukotriene (LT) B_4, by fish oil-derived eicosapentaenoic acid, the precursor of biologically less potent LTB_5, emphasizing the mediator role of LTB_4 in ischemia-reperfusion injury. These results suggest that the preservation of microvascular perfusion by dietary fish oil contributes to its protective effects on the clinical manifestations of ischemia-reperfusion injury.