Science.gov

Sample records for gold hamster mesocricetus

  1. Structural and Functional Studies of the Protamine 2-Zinc Complex from Syrian Gold Hamster (Mesocricetus Auratus) Spermatids and Sperm

    SciTech Connect

    Dolan, C E

    2004-08-30

    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) 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 mammalian sperm

  2. Asymmetric learning to avoid heterospecific males in Mesocricetus hamsters

    PubMed Central

    delBarco-Trillo, Javier; Johnston, Robert E.

    2012-01-01

    If a female mates with a male of a closely related species, her fitness is likely to decline. Consequently, females may develop behavioral mechanisms to avoid mating with heterospecific males. In some species, one such mechanism is for adult females to learn to discriminate against heterospecific males after exposure to such males. We have previously shown that adult, female Syrian hamsters (Mesocricetus auratus) learn to discriminate against male Turkish hamsters (Mesocricetus brandti) after exposure to a single heterospecific male during 8 days across a wire-mesh barrier. Here we repeated that experiment but this time we exposed female Turkish hamsters to a male Syrian hamster for 8 days and then measured sexual and aggressive behaviors towards that heterospecific male and towards a conspecific male. In contrast to female Syrian hamsters, female Turkish hamsters did not differ in their latency to go into lordosis or in any measure of aggression towards either type of male. Female Turkish hamsters spent less time in lordosis with the heterospecific male, but the percentage of trials in which females copulated with conspecific and heterospecific males did not differ. When comparing females from both species that had been exposed to a heterospecific male for 8 days, female Syrian hamsters copulated less and were more aggressive towards the heterospecific male compared to the behavior of female Turkish hamsters. We discuss how this asymmetric response between females of the two species may be due to the much larger geographical range of Turkish hamsters compared to Syrian hamsters. PMID:22658324

  3. Asymmetric learning to avoid heterospecific males in Mesocricetus hamsters.

    PubMed

    delBarco-Trillo, Javier; Johnston, Robert E

    2012-08-01

    If a female mates with a male of a closely related species, her fitness is likely to decline. Consequently, females may develop behavioral mechanisms to avoid mating with heterospecific males. In some species, one such mechanism is for adult females to learn to discriminate against heterospecific males after exposure to such males. We have previously shown that adult, female Syrian hamsters (Mesocricetus auratus) learn to discriminate against male Turkish hamsters (Mesocricetus brandti) after exposure to a single heterospecific male during 8 days across a wire-mesh barrier. Here we repeated that experiment but this time we exposed female Turkish hamsters to a male Syrian hamster for 8 days and then measured sexual and aggressive behaviors towards that heterospecific male and towards a conspecific male. In contrast to female Syrian hamsters, female Turkish hamsters did not differ in their latency to go into lordosis or in any measure of aggression towards either type of male. Female Turkish hamsters spent less time in lordosis with the heterospecific male, but the percentage of trials in which females copulated with conspecific and heterospecific males did not differ. When comparing females from both species that had been exposed to a heterospecific male for 8days, female Syrian hamsters copulated less and were more aggressive towards the heterospecific male compared to the behavior of female Turkish hamsters. We discuss how this asymmetric response between females of the two species may be due to the much larger geographical range of Turkish hamsters compared to Syrian hamsters. PMID:22658324

  4. Thyroid function and cold acclimation in the hamster, Mesocricetus auratus

    SciTech Connect

    Tomasi, T.E.; Horwitz, B.A.

    1987-02-01

    Basal metabolic rate (BMR), thyroxine utilization rate (T4U), and triiodothyronine utilization rate (T3U) were measured in cold-acclimated (CA) and room temperature-acclimated (RA) male golden hamsters, Mesocricetus auratus. Hormone utilization rates were calculated via the plasma disappearance technique using SVI-labeled hormones and measuring serum hormone levels via radioimmunoassay. BMR showed a significant 28% increase with cold acclimation. The same cold exposure also produced a 32% increase in T4U, and a 204% increase in T3U. The much greater increase in T3U implies that previous assessments of the relationship between cold acclimation and thyroid function may have been underestimated and that cold exposure induces both quantitative and qualitative changes in thyroid function. It is concluded that in the cold-acclimated state, T3U more accurately reflects thyroid function than does T4U. A mechanism for the cold-induced change in BMR is proposed.

  5. 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. PMID:25469817

  6. The Hymenolepis diminuta-golden hamster (Mesocricetus auratus) model for the evaluation of gastrointestinal anticestode activity.

    PubMed

    Ostlind, D A; Mickle, W G; Smith, S K; Cifelli, S; Ewanciw, D V

    2004-08-01

    A novel laboratory anticestode assay was developed using Hymenolepis diminuta in the hamster. The commercial anticestode compounds, praziquantel, bunamidine, and niclosamide were active against patent infections of Hymenolepis diminuta in golden hamsters (Mesocricetus auratus) when given orally at 3.125, 100, and 200 mg/kg, respectively. The gastrointestinal nematode anthelmintics, cambendazole and mebendazole, were active at 50 mg/kg. Rafoxanide (fasciolicide) was active at 25 mg/kg, the lowest level tested. The coccidiostat, nicarbazin, was active at experimental levels (800 mg/kg and up). The anthelmintic-ectoparasiticide (endectocide), ivermectin, was inactive against the tapeworm at 0.5 mg/kg, as expected. PMID:15357098

  7. Surface morphology of hamster (Mesocricetus auratus) decidual cells in vitro.

    PubMed

    Shukla, R; Pande, S; Mehrotra, P K; Maitra, S C; Kamboj, V P

    1995-02-01

    Cell surface morphology of hamster decidual cells isolated from day 8 implantation swellings was studied, using both phase-contrast and scanning electron microscopy. Two kinds of cells, fibroblastic and epithelioid, were identified in cultures examined by phase-contrast microscopy. Fibroblastic cells were spindle-shaped, having pointed or blunt terminals on one end and bifid or webbed projections at the other end. Epithelioid cells, on the other hand, were flat and discoid, having a distinctively ruffled plasma membrane. Further, the plasma membrane of epithelioid cells formed rope-like or flange-like processes. The significance of such adaptations is discussed. PMID:7877182

  8. Validation of Assays to Monitor Immune Responses in the Syrian Golden Hamster (Mesocricetus auratus)

    PubMed Central

    Zivcec, Marko; Safronetz, David; Haddock, Elaine; Feldmann, Heinz; Ebihara, Hideki

    2011-01-01

    The Syrian Golden hamster (Mesocricetus auratus) is a valuable but under-utilized animal model for studies of human viral pathogens such as bunyaviruses, arenaviruses, flaviviruses, henipaviruses, and SARS-coronavirus. A lack of suitable reagents and specific assays for monitoring host responses has limited the use of this animal model to clinical observations, pathology and humoral immune responses. The objective of this study was to establish and validate assays to monitor host immune responses in the hamster including important pro-inflammatory, anti-inflammatory and innate immune responses, as well as markers of apoptosis, cell proliferation, cell junction integrity and coagulation. Commercially available mouse and rat ELISA and luminex panels were screened for potential cross-reactivity, but were found to be of limited value for studying host responses in hamsters. Subsequently, quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) assays for the detection of 51 immune-related and four internal reference genes were developed. To validate the immune-related assays, hamsters were infected with vesicular stomatitis virus (VSV), Indiana species, or treated with lipopolysaccharide (LPS) and host immune responses were monitored in selected organs. Ribosomal protein L18 was identified as the most stable internal reference gene. In conclusion, these new assays will greatly improve the use of the hamster as an important small animal model in infectious disease research. PMID:21334343

  9. BODY WEIGHT AS A DETERMINANT OF CLINICAL EVOLUTION IN HAMSTERS (Mesocricetus auratus) INFECTED WITH Leishmania (Viannia) panamensis

    PubMed Central

    Gómez-Galindo, Ángela María; Delgado-Murcia, Lucy Gabriela

    2013-01-01

    SUMMARY The clinical outcome of infection with Leishmania species of the subgenus Viannia in hamster model (Mesocricetus auratus) has shown to be different depending on experimental protocol. Body weight has been a relevant determinant of the clinical outcome of the infection in hamsters with visceral leishmaniasis but its importance as a clinical parameter in hamsters with cutaneous leishmaniasis is not known. In this study, the clinical evolution of infection with L. (V) panamensis was evaluated in juvenile and adult male hamsters during 11 weeks by comparing clinical parameters such as attitude, temperature, respiratory rate, appearance of the stool, and body weight between infected and non-infected groups. Results showed that body weight decreased in adult hamsters after infection by L. (V) panamensis; this observation supports the use of body weight as an additional parameter to define the management or treatment of cutaneous leishmaniasis in infected adult hamsters used as an animal experimental model for leishmaniasis. PMID:24037292

  10. 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. PMID:25518818

  11. Sensitivity and integration in a visual pathway for circadian entrainment in the hamster (Mesocricetus auratus).

    PubMed Central

    Nelson, D E; Takahashi, J S

    1991-01-01

    1. Light-induced phase shifts of the circadian rhythm of wheel-running activity were used to measure the photic sensitivity of a circadian pacemaker and the visual pathway that conveys light information to it in the golden hamster (Mesocricetus auratus). The sensitivity to stimulus irradiance and duration was assessed by measuring the magnitude of phase-shift responses to photic stimuli of different irradiance and duration. The visual sensitivity was also measured at three different phases of the circadian rhythm. 2. The stimulus-response curves measured at different circadian phases suggest that the maximum phase-shift is the only aspect of visual responsivity to change as a function of the circadian day. The half-saturation constants (sigma) for the stimulus-response curves are not significantly different over the three circadian phases tested. The photic sensitivity to irradiance (1/sigma) appears to remain constant over the circadian day. 3. The hamster circadian pacemaker and the photoreceptive system that subserves it are more sensitive to the irradiance of longer-duration stimuli than to irradiance of briefer stimuli. The system is maximally sensitive to the irradiance of stimuli of 300 s and longer in duration. A quantitative model is presented to explain the changes that occur in the stimulus-response curves as a function of photic stimulus duration. 4. The threshold for photic stimulation of the hamster circadian pacemaker is also quite high. The threshold irradiance (the minimum irradiance necessary to induce statistically significant responses) is approximately 10(11) photons cm-2 s-1 for optimal stimulus durations. This threshold is equivalent to a luminance at the cornea of 0.1 cd m-2. 5. We also measured the sensitivity of this visual pathway to the total number of photons in a stimulus. This system is maximally sensitive to photons in stimuli between 30 and 3600 s in duration. The maximum quantum efficiency of photic integration occurs in 300 s

  12. Seco-limonoid derived from Raputia heptaphylla promotes the control of cutaneous leishmaniasis in hamsters (Mesocricetus auratus).

    PubMed

    Granados-Falla, Diana; Gomez-Galindo, Angela; Daza, Alejandro; Robledo, Sara; Coy-Barrera, Carlos; Cuca, Luis; Delgado, Gabriela

    2016-03-01

    The rational search of novel bioactive molecules against pathogens with immunomodulatory activity is presently one of the most significant approaches to discover and design new therapeutic agents for effective control of infectious diseases, such as the infection caused by Leishmania parasites. In the present study, we evaluated the therapeutic efficacy of the recently characterized immunomodulatory compound 11α,19β-dihydroxy-7-acetoxy-7-deoxoichangin, a seco-limonoid derived from the bark of Raputia heptaphylla (Pittier) using: (1) peritoneal macrophages and (2) Mesocricetus auratus hamsters infected with Leishmania (V.) panamensis and Leishmania (L.) amazonensis. We observed the ability of this seco-limonoid to induce the effective control of the parasite either in vitro [determining an effective concentration 50 (EC50) of 59 µ m at the infection model] and in vivo (inducing clinical improvement or even cure in infected animals treated compared with the groups of animals treated with vehicle solution or meglumine antimoniate). PMID:26694129

  13. Schistosoma japonicum-infected hamsters (Mesocricetus auratus) used as a model in experimental chemotherapy with praziquantel, artemether, and OZ compounds.

    PubMed

    Xiao, Shu-hua; Mei, Jing-yan; Jiao, Pei-ying

    2011-02-01

    The purpose of the study is to better understand the antischistosomal properties of artemether, praziquantel, and ozonide (OZ) compounds (synthetic trioxolanes, secondary ozonides) in hamster (Mesocricetus auratus) model. A total of 230 male hamsters infected each with 100 Schistosoma japonicum cercariae were used in the study. Groups of five to ten hamsters were treated orally with artemether, praziquantel, and OZ78 or OZ277 7-35 days post-infection at single doses of 50, 100, 150, or 200 mg/kg. Untreated but infected hamsters in each batch of test served as the control. All treated hamsters were sacrificed 4 weeks post-treatment for collection of residual worms using perfusion technique. Nonparametric method (Mann-Whitney test) was used to analyze the data. In groups of five hamsters treated with artemether 7, 14, 21, 28, and 35 days post-infection at single doses of 150 and 200 mg/kg, the difference of mean worm burden between each treated group and control group was statistically significant (P<0.01). Apart from individual group, no difference in mean worm burden between each two groups of them was seen (P>0.05). Further test with various single doses of 50-200 mg/kg confirmed the similar susceptibility of 7-day-old juvenile and 35-day-old adult schistosomes to artemether. After administration of praziquantel 100 mg/kg to groups of five hamsters 7, 21, and 35 days post-infection, higher worm burden reduction of 95.5% was seen in the group with 35-day-old adult schistosomes while in the groups with 7- and 21-day-old juvenile schistosomes, poor efficacy was seen with mean worm burden reductions of 36.6% and 35.6%. In the same batch of hamster treated with praziquantel 200 mg/kg, the moderate effect of the drug against 7- and 21-day-old worms was seen, but their mean worm burden was significantly higher than that of the group with adult schistosomes. In comparison of artemether and praziquantel against various stages of schistosomes, the results further

  14. Evaluation of the Leishmanicidal Activity of Rutaceae and Lauraceae Ethanol Extracts on Golden Syrian Hamster (Mesocricetus auratus) Peritoneal Macrophages

    PubMed Central

    Chávez Enciso, N. A.; Coy-barrera, E. D.; Patiño, O. J.; Cuca, L. E.; Delgado, Gabriela

    2014-01-01

    Traditional medicine has provided a number of therapeutic solutions for the control of infectious agents, cancers, and other diseases. After screening a wide variety of Colombian plant extracts, we have identified promising antileishmanial activity in ethanol extracts from Ocotea macrophylla (Lauraceae) and Zanthoxyllum monophyllum (Rutaceae). In this study, we evaluated the in vitro activity of two ethanol extracts, one from Ocotea macrophylla and the other from Zanthoxyllum monophyllum and one alkaloid fraction of ethanol extract of Zanthoxyllum monophyllum, on peritoneal macrophages isolated from golden Syrian hamsters (Mesocricetus auratus) infected with Leishmania panamensis and Leishmania major promastigotes. All of the extracts studied displayed promising (≥2) selectivity indices (S/I), the most significant of which were for ethanol extract of Zanthoxyllum monophyllum against Leishmania panamensis (S/I=12) and alkaloid fraction of ethanol extract of Zanthoxyllum monophyllum against Leishmania major (S/I=11). These results support the use of ethanol extracts and alkaloid fractions isolated from Ocotea macrophylla and Zanthoxyllum monophyllum, respectively; as therapeutic options for cutaneous leishmaniasis. PMID:25035529

  15. Evaluation of the Leishmanicidal Activity of Rutaceae and Lauraceae Ethanol Extracts on Golden Syrian Hamster (Mesocricetus auratus) Peritoneal Macrophages.

    PubMed

    Chávez Enciso, N A; Coy-Barrera, E D; Patiño, O J; Cuca, L E; Delgado, Gabriela

    2014-05-01

    Traditional medicine has provided a number of therapeutic solutions for the control of infectious agents, cancers, and other diseases. After screening a wide variety of Colombian plant extracts, we have identified promising antileishmanial activity in ethanol extracts from Ocotea macrophylla (Lauraceae) and Zanthoxyllum monophyllum (Rutaceae). In this study, we evaluated the in vitro activity of two ethanol extracts, one from Ocotea macrophylla and the other from Zanthoxyllum monophyllum and one alkaloid fraction of ethanol extract of Zanthoxyllum monophyllum, on peritoneal macrophages isolated from golden Syrian hamsters (Mesocricetus auratus) infected with Leishmania panamensis and Leishmania major promastigotes. All of the extracts studied displayed promising (≥2) selectivity indices (S/I), the most significant of which were for ethanol extract of Zanthoxyllum monophyllum against Leishmania panamensis (S/I=12) and alkaloid fraction of ethanol extract of Zanthoxyllum monophyllum against Leishmania major (S/I=11). These results support the use of ethanol extracts and alkaloid fractions isolated from Ocotea macrophylla and Zanthoxyllum monophyllum, respectively; as therapeutic options for cutaneous leishmaniasis. PMID:25035529

  16. Examination of the negative alcohol-deprivation effect in the golden hamster (Mesocricetus auratus).

    PubMed

    DiBattista, D

    1991-01-01

    When ethanol-consuming animals are denied access to their ethanol solution for a period of days, there is typically a temporary but substantial increase in their ethanol consumption when the solution is returned. Golden hamsters are unusual in that they actually decrease their consumption of a 7% ethanol solution (v/v) under these circumstances. There experiments were therefore undertaken to further investigate this unusual negative alcohol-deprivation effect (ADE) in hamsters. In Experiment 1, the negative ADE was observed across a wide range of ethanol concentrations; adult male hamsters were given access to food, water, and either a 7.5, 15, or 30% (v/v) ethanol solution, and when the ethanol solution was withdrawn for seven days and then returned, ethanol consumption decreased significantly for several days and then recovered. Experiment 2 demonstrated that similar negative deprivation effects occur with glucose (15% w/v) and saccharin (0.1%) solutions, suggesting that the nutritional and pharmacological properties of ethanol do not play an important role in the negative ADE of hamsters. In Experiment 3, when hamsters with continuous access to either an ethanol, glucose, or saccharin solution were switched to an alternate-days access schedule, their intake of solutions decreased substantially, supporting the conclusion that a common mechanism accounts for the golden hamster's negative deprivation responses to ethanol solutions and to other solutions, both nutritive and nonnutritive. Hypotheses relating to the mechanism underlying negative deprivation effects are presented and discussed. PMID:1797030

  17. 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. PMID:25722219

  18. Longevity and age-related pathology of LVG outbred golden Syrian hamsters (Mesocricetus auratus).

    PubMed

    Deamond, S F; Portnoy, L G; Strandberg, J D; Bruce, S A

    1990-01-01

    A colony of male Lakeview Golden (LVG) Syrian hamsters has been maintained for the last nine years as a source of various tissues for cellular aging studies. Observations on this colony also yielded data on survival time and physical and pathological manifestations of aging in this strain. Based on 150 spontaneous deaths, the median life span was found to be 19.5 months. The maximum life span was 36 months and the minimum 6 months. A cross-sectional pathological survey of sacrificed and spontaneously dying members of the population revealed a low rate of neoplasia and a variety of degenerative lesions that increased with age. These observations of a varied pathology and a low frequency of neoplasia provide justification for the continued development of the male LVG Syrian hamster as an animal model system for use in studies on the mechanism of both in vivo and in vitro aging. PMID:2257890

  19. Adolescent Anabolic/Androgenic Steroids: Aggression and Anxiety During Exposure Predict Behavioral Responding During Withdrawal in Syrian Hamsters (Mesocricetus auratus)

    PubMed Central

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

    2014-01-01

    In the U.S. and worldwide anabolic/androgenic steroid use remains high in the adolescent population. This is concerning given that anabolic/androgenic steroid use is associated with a higher incidence of aggressive behavior during exposure and anxiety during withdrawal. This study uses pubertal Syrian hamsters (Mesocricetus auratus) to investigate the hypothesis that an inverse behavioral relationship exists between anabolic/androgenic steroid-induced aggression and anxiety across adolescent exposure and withdrawal. In the first experiment, we examined aggression and anxiety during adolescent anabolic/androgenic steroid exposure and withdrawal. Adolescent anabolic/androgenic steroid administration produced significant increases in aggression and decreases in anxiety during the exposure period followed by significant decreases in aggression and increases in anxiety during anabolic/androgenic steroid withdrawal. In a second experiment, anabolic/androgenic steroid exposed animals were separated into groups based on their aggressive response during the exposure period and then tested for anxiety during exposure and then for both aggression and anxiety during withdrawal. Data were analyzed using a within subjects repeated measures predictive analysis. Linear regression analysis revealed that the difference in aggressive responding between the anabolic/androgenic steroid exposure and withdrawal periods was a significant predictor of differences in anxiety for both days of testing. Moreover, the combined data suggest that the decrease in aggressive behavior from exposure to withdrawal predicts an increase in anxiety-like responding within these same animals during this time span. Together these findings indicate that early anabolic/androgenic steroid exposure has potent aggression- and anxiety- eliciting effects and that these behavioral changes occur alongside a predictive relationship that exists between these two behaviors over time. PMID:24126136

  20. Melatonin alleviates hyperthyroidism induced oxidative stress and neuronal cell death in hippocampus of aged female golden hamster, Mesocricetus auratus.

    PubMed

    Rao, Geeta; Verma, Rakesh; Mukherjee, Arun; Haldar, Chandana; Agrawal, Neeraj Kumar

    2016-09-01

    Oxidative stress is a well known phenomenon under hyperthyroid condition that induces various physiological and neural problems with a higher prevalence in females. We, therefore investigated the antioxidant potential of melatonin (Mel) on hyperthyroidism-induced oxidative stress and neuronal cell death in the hippocampus region of brain (cognition and memory centre) of aged female golden hamster, Mesocricetus auratus. Aged female hamsters were randomly divided into four experimental groups (n=7); group-I: control, group-II: Melatonin (5mgkg(-1)day(-1), i.p., for one week), group-III: Hyperthyroid (100μg kg(-1)day(-1), i.p., for two weeks) and group-IV- Hyper+Mel. Hormonal profiles (thyroid and melatonin), activity of antioxidant enzymes (SOD, CAT and GPX), lipid peroxidation level (TBARS) and the specific apoptotic markers (Bax/Bcl-2 ratio and Caspase-3) expression were evaluated. A significant increase in the profile of total thyroid hormone (tT3 and tT4) in hyperthyroidic group as compared to control while tT3 significantly decreased in melatonin treated hyperthyroidic group. However, Mel level significantly decreased in hyperthyroidic group but increased in melatonin treated hyperthyroidic group. Further, the number of immune-positive cells for thyroid hormone receptor-alpha (TR-α) decreased in the hippocampus of hyperthyroidic group and increased in melatonin treated hyperthyroidic group. Profiles of antioxidant enzymes showed a significant decrease in hyperthyroidic group with a simultaneous increase in lipid peroxidation (TBARS). Melatonin treatment to hyperthyroidic group lead to decreased TBARS level with a concomitant increase in antioxidant enzyme activity. Moreover, increased expression of Bax/Bcl-2 ratio and Caspase-3, in hyperthyroidic group had elevated neuronal cell death in hippocampal area and melatonin treatment reduced its expression in hyperthyroidic group. Our findings thus indicate that melatonin reduced the hyperthyroidism

  1. X-ray kinematics analysis of vaginal scent marking in female Syrian hamsters (Mesocricetus auratus)

    PubMed Central

    Been, Laura E.; Bauman, Jay M.; Petrulis, Aras; Chang, Young-Hui

    2012-01-01

    Vaginal marking is a stereotyped scent marking behavior in female Syrian hamsters used to attract male hamsters for mating. Although the modulation of vaginal marking by hormones and odors is well understood, the motor control of this proceptive reproductive behavior remains unknown. Therefore, we used x-ray videography to visualize individual bone movements during vaginal marking. Kinematic analyses revealed several consistent motor patterns of vaginal marking. Despite exhibiting a diversity of trial-to-trial non-marking behaviors (e.g. locomotor stepping), we found that lowering and raising the pelvis consistently corresponded with coordinated flexion and extension cycles of the hip, knee, and tail, suggesting that these movements are fundamental to vaginal marking behavior. Surprisingly, we observed only small changes in the angles of the pelvic and sacral regions, suggesting previous reports of pelvic rotation during vaginal marking may need to be reconsidered. From these kinematic data, we inferred that vaginal marking is primarily due to the actions of hip and knee extensor muscles of the trailing leg working against gravity to support the weight of the animal as it controls the descent of the pelvis to the ground. The cutaneous trunci muscle likely mediates the characteristic flexion of the tail. Interestingly, this tail movement occurred on the same time scale as the joint kinematics suggesting possible synergistic recruitment of these muscle groups. These data therefore provide new targets for future studies examining the peripheral control of female reproductive behaviors. PMID:22138441

  2. Mechanisms of radio-protection by catecholamines in the hamster /Mesocricetus auratus/

    NASA Technical Reports Server (NTRS)

    Prewitt, R. L.; Musacchia, X. J.

    1975-01-01

    Experiments were conducted on normal and splenectomized male and female hamsters between 2 and 3 months old subjected to a whole-body exposure of 1000 or 2000 rads in a Co-60 source with a view toward evaluating their radio-protection by norepinephrine, isoproterenol, and phenylephrine. Vasoconstriction hypoxia mechanism of radio-protection is examined along with the hypothesis that isoproterenol protects by hypercalcemia-induced cell proliferation. Radiation experiment results are found to be consistent with the hypothesis that stimulation of alpha receptors results in radio-protection through a tissue hypoxia mechanism. Beta agonists seem to protect by a hypotensive-hypoxia mechanism. The catecholamines protect against the hematopoietic syndrome, but show no evidence of protection against the gastrointestinal syndrome.

  3. Stimulus requirements for pregnancy initiation in the golden hamster (Mesocricetus auratus) change with age and parity.

    PubMed

    Huck, U W; Lisk, R D; Guyton, C L

    1988-11-01

    Hamsters were mated repeatedly at 60, 180, 300 and 420 days of age or once during their lifetime at one of these ages. Copulatory stimulation was varied both for number of ejaculations (2 versus 14) and amount of vaginocervical stimulation (5 versus 50-60 intromissions). Two ejaculations provided sufficient spermatozoa to maximize litter size for all age and parity classes tested. Differences in fecundity depended on the amount of vaginocervical stimulation received. Higher levels of vaginocervical stimulation increased littering success at 300 and 420 days for nulliparous females and at 180, 300 and 420 days for multiparous females. Females which did not deliver litters did not show a cessation of oestrous cycles which characteristically follows the induction of a luteal phase. The decreased fecundity observed with increasing age or parity therefore resulted from a change in sensitivity to the stimulus conditions necessary to activate the neuroendocrine arc for establishment of pregnancy. PMID:3199363

  4. Dopamine in the nucleus accumbens modulates the memory of social defeat in Syrian hamsters (Mesocricetus auratus).

    PubMed

    Gray, C L; Norvelle, A; Larkin, T; Huhman, K L

    2015-06-01

    Conditioned defeat (CD) is a behavioral response that occurs in Syrian hamsters after they experience social defeat. Subsequently, defeated hamsters no longer produce territorial aggression but instead exhibit heightened levels of avoidance and submission, even when confronted with a smaller, non-aggressive intruder. Dopamine in the nucleus accumbens is hypothesized to act as a signal of salience for both rewarding and aversive stimuli to promote memory formation and appropriate behavioral responses to significant events. The purpose of the present study was to test the hypothesis that dopamine in the nucleus accumbens modulates the acquisition and expression of behavioral responses to social defeat. In Experiment 1, bilateral infusion of the non-specific D1/D2 receptor antagonist cis(z)flupenthixol (3.75 μg/150 nl saline) into the nucleus accumbens 5 min prior to defeat training significantly reduced submissive and defensive behavior expressed 24h later in response to a non-aggressive intruder. In Experiment 2, infusion of 3.75 μg cis-(Z)-flupenthixol 5 min before conditioned defeat testing with a non-aggressive intruder significantly increased aggressive behavior in drug-infused subjects. In Experiment 3, we found that the effect of cis-(Z)-flupenthixol on aggression was specific to defeated animals as infusion of drug into the nucleus accumbens of non-defeated animals did not significantly alter their behavior in response to a non-aggressive intruder. These data demonstrate that dopamine in the nucleus accumbens modulates both acquisition and expression of social stress-induced behavioral changes and suggest that the nucleus accumbens plays an important role in the suppression of aggression that is observed after social defeat. PMID:25721736

  5. Dopamine in the nucleus accumbens modulates the memory of social defeat in Syrian hamsters (Mesocricetus auratus)

    PubMed Central

    Gray, C.L.; Norvelle, A.; Larkin, T.; Huhman, K.L..

    2015-01-01

    Conditioned defeat (CD) is a behavioral response that occurs in Syrian hamsters after they experience social defeat. Subsequently, defeated hamsters no longer produce territorial aggression but instead exhibit heightened levels of avoidance and submission, even when confronted with a smaller, non-aggressive intruder. Dopamine in the nucleus accumbens is hypothesized to act as a signal of salience for both rewarding and aversive stimuli to promote memory formation and appropriate behavioral responses to significant events. The purpose of the present study was to test the hypothesis that dopamine in the nucleus accumbens modulates the acquisition and expression of behavioral responses to social defeat. In Exp. 1, bilateral infusion of the non-specific D1/D2 receptor antagonist cis(z)flupenthixol (3.75 μg/150 nl saline) into the nucleus accumbens 5 min prior to defeat training significantly reduced submissive and defensive behavior expressed 24 hr later in response to a non-aggressive intruder. In Exp. 2, infusion of 3.75 μg cis(z)flupenthixol 5 min before conditioned defeat testing with a non-aggressive intruder significantly increased aggressive behavior in drug-infused subjects. In Exp. 3, we found that the effect of cis(z)flupenthixol on aggression was specific to defeated animals as infusion of drug into the nucleus accumbens of non-defeated animals did not significantly alter their behavior in response to a non-aggressive intruder. These data demonstrate that dopamine in the nucleus accumbens modulates both acquisition and expression of social stress-induced behavioral changes and suggest that the nucleus accumbens plays an important role in the suppression of aggression that is observed after social defeat. PMID:25721736

  6. Neural mechanisms of individual and sexual recognition in Syrian hamsters (Mesocricetus auratus)

    PubMed Central

    Petrulis, Aras

    2008-01-01

    Recognizing the individual and sexual identities of conspecifics is critical for adaptive social behavior and, in most mammals this information is communicated primarily by chemosensory cues. Due to its heavy reliance on odor cues, we have used the Syrian hamster as our model species for investigating the neural regulation of social recognition. Using lesion, electrophysiological and immunocytochemical techniques, separate neural pathways underlying recognition of individual odors and guidance of sex-typical responses to opposite-sex odors have been identified in both male and female hamsters. Specifically, we have found that recognition of individual odor identity requires olfactory bulb connections to entorhinal cortex (ENT) rather than other chemoreceptive brain regions. This kind of social memory does not appear to require the hippocampus and may, instead, depend on ENT connections with piriform cortex. In contrast, sexual recognition, through either differential investigation or scent marking toward opposite-sex odors, depends on both olfactory and vomeronasal system input to the corticomedial amygdala. Preference for investigating opposite-sex odors requires primarily olfactory input to the medial amygdala (ME) whereas appropriately targeted scent marking responses require vomeronasal input to ME as well as to other structures. Within the ME, the anterior section (MEa) appears important for evaluating or classifying social odors whereas the posterodorsal region (MEpd) may be more involved in generating approach to social odors. Evidence is presented that analysis of social odors may initially be done in MEa and then communicated to MEpd, perhaps through micro-circuits that separately process male and female odors. PMID:19014975

  7. The effects of endomorphin-1 on conditioned defeat in Syrian hamsters (Mesocricetus auratus).

    PubMed

    Whitten, R D; Jasnow, A M; Albers, H E; Martin-Schild, S; Zadina, J E; Huhman, K L

    2001-09-28

    The present study examined the effect of endomorphin-1 (EM1), an endogenous opioid with a high affinity for the mu opiate receptor, on conditioned defeat. Conditioned defeat is a phenomenon in which hamsters that have been defeated subsequently fail to exhibit normal territorial aggression and instead display submissive/defensive behaviors even when paired with a non-aggressive intruder. In experiment 1, animals were placed in the home cage of a larger resident for 15 min and were defeated. After 24 h, animals received a 3-microl injection of EM1 (0.0, 0.3, 3.0, or 10 nmol) into the left lateral cerebral ventricle 5 min before a smaller non-aggressive intruder was placed in the home cage of the experimental animal. In experiment 2, animals were infused with EM1 immediately after the initial defeat and were paired with a non-aggressive intruder 24 h later as in experiment 1. EM1 reduced the duration of submissive/defensive behavior in experiment 1 (P<0.05) but not in experiment 2 (P>0.05). These data support the hypothesis that the highly selective mu receptor agonist endomorphin-1 modulates the expression of conditioned defeat, but provides no support for the hypothesis that endomorphin-1 modulates the consolidation of conditioned defeat. PMID:11578599

  8. Melatonin membrane receptor (MT1R) expression and nitro-oxidative stress in testis of golden hamster, Mesocricetus auratus: An age-dependent study.

    PubMed

    Mukherjee, Arun; Haldar, Chandana

    2015-09-01

    Age-dependent decline in melatonin level induces nitro-oxidative stress that compromises physiological homeostasis including reproduction. However, less information exist regarding the age-dependent variation in local melatonin (lMel) concentration and MT1R expression in testis and its interaction with testicular steroidogenesis and nitro-oxidative stress in golden hamster, Mesocricetus auratus. Therefore, we evaluated lMel level along with MT1R expression and its possible interaction with steroidogenesis and nitro-oxidative stress in testes of young (6weeks), adult (15weeks) and old (2years) aged hamsters. Further, we injected the old hamsters with melatonin to address whether age-related decline in lMel and MT1R is responsible for the reduction in testicular steroidogenesis and antioxidant status. Increased expression of steroidogenic markers suggests increased testicular steroidogenesis in adult hamsters that declined in old hamsters. An age-dependent elevation in the level of NOX, TBARS, corticosterone and the expression of iNOS and GR with a concomitant decrease in enzyme activities for SOD, CAT, GSH-PX indicate increased nitro-oxidative stress in testes. Data suggest that reproductive senescence in male hamsters might be a consequence of declined lMel concentration with MT1R expression inducing nitro-oxidative stress resulting in diminished testicular steroidogenesis. However, administration of Mel in old-aged hamsters significantly increased steroidogenesis and antioxidant status without a significant variation in lMel concentration and MT1R expression in testes. Therefore, decreased lMel and MT1R might not be the causative factor underlying the age-associated decrease in antioxidant defence and steroidogenesis in testes. In conclusion, Mel induced amelioration of testicular oxidative insult and elevation of steroidogenic activity suggests a potential role of increased nitro-oxidative stress underlying the age-dependent decrease in steroidogenesis. PMID

  9. Mate preference for dominant vs. subordinate males in young female Syrian hamsters (Mesocricetus auratus) following chemically-accelerated ovarian follicle depletion.

    PubMed

    Roosa, Kristen A; Place, Ned J

    2015-12-01

    Life history theory predicts that selectivity for mates generally declines as females age. We previously demonstrated this phenomenon in Syrian hamsters (Mesocricetus auratus), in that older females showed reduced preference for dominant over subordinate males. To test the hypothesis that decreased reproductive quality due to aging reduces mate preference, we decoupled reproductive and chronological age by treating young female hamsters with 4-vinylcyclohexene diepoxide (VCD), which destroys ovarian follicles and functionally accelerates ovarian follicle depletion without compromising the general health of rodents. In this study, VCD effectively reduced follicle numbers in young Syrian hamsters. VCD-treated and control females were allowed to choose between a dominant and a subordinate male in a Y-maze on the day of proestrus. Both VCD-treated and control females demonstrated preference for the dominant male by leaving a greater proportion of vaginal scent marks near him, which is a behavior that females display when soliciting prospective mates. However, there was no effect of treatment on the proportion of vaginal scent marks left for the dominant male. Furthermore, ovarian follicle numbers were not significantly correlated with any behaviors in either group. We conclude that accelerated ovarian follicle depletion does not reduce mate preference in young female hamsters. PMID:26335038

  10. 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

  11. Histochemical study of brown-fat cells in the golden hamster (Mesocricetus auratus) in cultures

    SciTech Connect

    Sokolov, V.E.; Boyadzhieva-Mikhailova, A.; Koncheva, L.; Angelova, P.; Evgen'eva, T.P.

    1985-11-01

    The authors undertake the task of studying the synthesis of certain hormones by brown-fat cells. The authors used brown-fat cells from the golden hamster. The metabolism of brown-fat cells was studied on precultured cells, which made it possible to detect the synthesis of the studied substances rather than their accumulation in the organ. The authors conducted three experiments. First, fragments of brown fat were cultivated in diffusion chambers in vivo. Pieces of brown fat were cultivated in parallel in vitro on agar (organotypic cultures) and on plasma (histotypic cultures). During cultivation in diffusion chambers, the chambers were implanted in the abdominal cavity of young white rats. For in vitro cultivation, TCM 199 plus 15-20% calf serum was used. A total of 36 cultures with 12 cultures in each series of experiments were performed. The auto-radiographic studies of brown-fat cells were conducted on 24-hour cultures and on brown-fat fragments taken from the intact animal. The cultures were incubated with isotopes for 1 h. Either (/sup 3/H)lysine (87.3 Ci/mM specific activity), (/sup 3/H)arginine (16.7 Ci/mM), (/sup 3/H)glycerol (43 Ci/mM), or (/sup 3/H)cholesterol (43 Ci/mM) were added to the medium. After incubation, the cultures were washed three times in pure medium, fixed in Sierra fluid, and embedded in paraffin. The paraffin sections were covered with Ilford K/sub 2/ emulsion, and the preparations were exposed for 20 days at 4/sup 0/C temperature. Radio-immunological methods were used to study the accumulation of estradiol-17-beta in the culture medium by the Dobson method and that of testerone. The culture medium was taken on cultivation days 2,4,6,8, and 10. The medium was changed during cultivation every third day, which made it possible to judge the rates of accumulation of material with increase in the cultivation times.

  12. The death of sertoli cells and the capacity to phagocytize elongated spermatids during testicular regression due to short photoperiod in Syrian hamster (Mesocricetus auratus).

    PubMed

    Seco-Rovira, Vicente; Beltrán-Frutos, Esther; Ferrer, Concepción; Sáez, Francisco José; Madrid, Juan Francisco; Pastor, Luis Miguel

    2014-05-01

    In the Syrian hamster (Mesocricetus auratus), an animal that displays testicular regression due to short photoperiod, germ cells are removed by apoptosis during this process and the apoptotic remains are phagocytized by Sertoli cells. The aim of this work was to investigate morphologically whether the testicular regression process due to short photoperiod leads to the apoptosis of Sertoli cells, and whether, during testicular regression, the elongated spermatids are eliminated through phagocytosis by Sertoli cells. To this end, we studied testis sections during testicular regression in Syrian hamster subjected to short photoperiod by means of several morphological techniques using conventional light microscopy (hematoxylin and eosin [H&E], semi-thin section vimentin, immunohistochemistry, SBA lectin, and TUNEL staining), fluorescence microscopy, and transmission electron microscopy (TEM). H&E and semi-thin sections identified Sertoli cells with a degenerated morphology. Greater portion of Sertoli cells that were positive for TUNEL staining were observed especially during the mild regression (MR) and strong regression (SR) phases. In addition, TEM identified the characteristic apoptotic changes in the nucleus and cytoplasm of Sertoli cells. Moreover, during testicular regression and using light microscopy, some elongated spermatids were seen in basal position next to the Sertoli cell nucleus. This Sertoli phagocytic activity was higher in MR and SR phases. TEM confirmed this to be the result of the phagocytic activity of Sertoli cells. In conclusion, during testicular regression in Syrian hamster due to short photoperiod, when germ cells are known to be lost through apoptosis, there is morphological evidences that Sertoli cells are also lost through apoptosis, while some elongated spermatids are phagocytized and eliminated by the Sertoli cells. PMID:24719257

  13. Syrian hamsters (Mesocricetus auratus) oronasally inoculated with a Nipah virus isolate from Bangladesh or Malaysia develop similar respiratory tract lesions.

    PubMed

    Baseler, L; de Wit, E; Scott, D P; Munster, V J; Feldmann, H

    2015-01-01

    Nipah virus is a paramyxovirus in the genus Henipavirus, which has caused outbreaks in humans in Malaysia, India, Singapore, and Bangladesh. Whereas the human cases in Malaysia were characterized mainly by neurological symptoms and a case fatality rate of ∼40%, cases in Bangladesh also exhibited respiratory disease and had a case fatality rate of ∼70%. Here, we compared the histopathologic changes in the respiratory tract of Syrian hamsters, a well-established small animal disease model for Nipah virus, inoculated oronasally with Nipah virus isolates from human cases in Malaysia and Bangladesh. The Nipah virus isolate from Bangladesh caused slightly more severe rhinitis and bronchointerstitial pneumonia 2 days after inoculation in Syrian hamsters. By day 4, differences in lesion severity could no longer be detected. Immunohistochemistry demonstrated Nipah virus antigen in the nasal cavity and pulmonary lesions; the amount of Nipah virus antigen present correlated with lesion severity. Immunohistochemistry indicated that both Nipah virus isolates exhibited endotheliotropism in small- and medium-caliber arteries and arterioles, but not in veins, in the lung. This correlated with the location of ephrin B2, the main receptor for Nipah virus, in the vasculature. In conclusion, Nipah virus isolates from outbreaks in Malaysia and Bangladesh caused a similar type and severity of respiratory tract lesions in Syrian hamsters, suggesting that the differences in human disease reported in the outbreaks in Malaysia and Bangladesh are unlikely to have been caused by intrinsic differences in these 2 virus isolates. PMID:25352203

  14. Sensitivity of Syrian hamsters (Mesocricetus auratus) to amplitudes and rates of photoperiodic change typical of the tropics.

    PubMed

    Heideman, P D; Bronson, F H

    1993-01-01

    Empirical data suggest that reproductive photoresponsiveness occurs in some populations of mammals above 13 degrees of latitude, but may be absent in populations from 0 degrees to 10 degrees of latitude. The present experiments examined the degree to which the low amplitude of change in photoperiod in the tropics constrains mammals from using daylength as a seasonal cue. The Syrian hamster, a temperate-zone species, was studied because of its well-documented ability to respond to small changes in photoperiod, and because of the absence of an alternative robustly responding species from the tropics. We subjected adult male hamsters to photoperiods that mimicked the amplitude and rate of photoperiod change of 30 degrees, 20 degrees, 10 degrees, and 5 degrees of latitude, but centered around an estimate of their critical daylength. For comparison, a fifth group was subjected to an abrupt change in daylength of a magnitude equal to the total annual variation occurring at 30 degrees. The two groups experiencing the gradually changing daylengths of 30 degrees and 20 degrees showed less within-group synchrony during testicular regression; in other dimensions of the annual testis cycle, including the degree of synchrony exhibited during recrudescence, they reacted similarly to the hamsters given the abrupt change in daylength. Some of the hamsters exposed to the gradually changing daylengths of 10 degrees responded to this challenge, as did a few in the 5 degrees treatment--in both cases, with poor within-group synchrony and a submaximal decrease in testis size. In an abbreviated second experiment, hamsters given abrupt decreases in daylength of magnitudes equal to those of the 10 degrees and 5 degrees groups responded slightly more frequently, and with maximal decreases in testis size. This suggests that mammals may not be constrained absolutely by an inability to respond to changes in photoperiod at 5 degrees to 10 degrees latitude. Seasonally breeding populations of

  15. Ultrasonic Vocalizations in Golden Hamsters (Mesocricetus auratus) Reveal Modest Sex Differences and Nonlinear Signals of Sexual Motivation

    PubMed Central

    Fernández-Vargas, Marcela; Johnston, Robert E.

    2015-01-01

    Vocal signaling is one of many behaviors that animals perform during social interactions. Vocalizations produced by both sexes before mating can communicate sex, identity and condition of the caller. Adult golden hamsters produce ultrasonic vocalizations (USV) after intersexual contact. To determine whether these vocalizations are sexually dimorphic, we analyzed the vocal repertoire for sex differences in: 1) calling rates, 2) composition (structural complexity, call types and nonlinear phenomena) and 3) acoustic structure. In addition, we examined it for individual variation in the calls. The vocal repertoire was mainly composed of 1-note simple calls and at least half of them presented some degree of deterministic chaos. The prevalence of this nonlinear phenomenon was confirmed by low values of harmonic-to-noise ratio for most calls. We found modest sexual differences between repertoires. Males were more likely than females to produce tonal and less chaotic calls, as well as call types with frequency jumps. Multivariate analysis of the acoustic features of 1-note simple calls revealed significant sex differences in the second axis represented mostly by entropy and bandwidth parameters. Male calls showed lower entropy and inter-quartile bandwidth than female calls. Because the variation of acoustic structure within individuals was higher than among individuals, USV could not be reliably assigned to the correct individual. Interestingly, however, this high variability, augmented by the prevalence of chaos and frequency jumps, could be the result of increased vocal effort. Hamsters motivated to produce high calling rates also produced longer calls of broader bandwidth. Thus, the sex differences found could be the result of different sex preferences but also of a sex difference in calling motivation or condition. We suggest that variable and complex USV may have been selected to increase responsiveness of a potential mate by communicating sexual arousal and

  16. Gonadotropin-Inhibitory Hormone Reduces Sexual Motivation But Not Lordosis Behavior In Female Syrian Hamsters (Mesocricetus auratus)

    PubMed Central

    Piekarski, David J.; Zhao, Sheng; Jennings, Kimberly J.; Iwasa, Takeshi; Legan, Sandra J.; Mikkelsen, Jens D.; Tsutsui, Kazuyoshi; Kriegsfeld, Lance J.

    2014-01-01

    Reproductive success is maximized when female sexual motivation and behavior coincide with the time of optimal fertility. Both processes depend upon coordinated hormonal events, beginning with signaling by the gonadotropin-releasing hormone (GnRH) neuronal system. Two neuropeptidergic systems that lie upstream of GnRH, gonadotropin-inhibitory hormone (GnIH; also known as RFamide related peptide-3) and kisspeptin, are potent inhibitory and excitatory modulators of GnRH, respectively, participate in the timing of the preovulatory luteinizing hormone (LH) surge and ovulation. Whether these neuropeptides serve as neuromodulators to coordinate female sexual behavior with the limited window of fertility has not been thoroughly explored. In the present study, either intact or ovariectomized, hormonetreated female hamsters were implanted for fifteen days with chronic release osmotic pumps filled with GnIH or saline. The effect of GnIH on sexual motivation, vaginal scent marking, and lordosis was examined. Following mating, FOS activation was quantified in brain regions implicated in the regulation of female sexual behavior. Intracerebroventricular administration of GnIH reduced sexual motivation and vaginal scent marking, but not lordosis behavior. GnIH administration altered FOS expression in key neural loci implicated in female reproductive behavior, including the medial preoptic area, medial amygdala and bed nucleus of the stria terminalis, independent of changes in circulating gonadal steroids and kisspeptin cell activation. Together, these data point to GnIH as an important modulator of female proceptive sexual behavior and motivation, independent of downstream alterations in sex steroid production. PMID:23827890

  17. Inference in a social context: A comparative study of capuchin monkeys (Cebus apella), tree shrews (Tupaia belangeri), hamsters (Mesocricetus auratus), and rats (Rattus norvegicus).

    PubMed

    Takahashi, Makoto; Ueno, Yoshikazu; Fujita, Kazuo

    2015-11-01

    Four species (capuchin monkeys, tree shrews, rats, and hamsters) performed an inference task situated in a social context. In Experiment 1, capuchin monkeys first explored food sites under 1 of 2 conditions: In 1 condition, food was refilled after it was eaten (replenished condition), whereas it was not refilled (depleted condition) in the other condition. Two food sites were presented for each condition. In the test phase, a subject watched a conspecific demonstrator visit 1 of the food sites in either the replenished or depleted condition. A screen placed in front of the sites prevented the subject from seeing the demonstrator actually eat the food. When the demonstrator was removed, the subject explored the cage. Three of 4 monkeys tended to go to the unvisited sites in the depleted condition, but tended to go to the visited site in the replenished condition. This suggests that they inferred that there was no food because the demonstrator had eaten it. In Experiment 2, using the same procedure, 2 nongroup-living species (tree shrews and hamsters) were indifferent to demonstrator behavior and visited sites only randomly, and group-living rats showed a strong tendency to follow demonstrators, irrespective of the type of food site. These tendencies were unchanged when olfactory information was added in Experiment 3 and when motivation to compete increased in Experiment 4. These results suggest that only capuchin monkeys have the ability to solve an inference task when cued by social information. PMID:26460855

  18. Oxytocin (OT) and arginine-vasopressin (AVP) act on OT receptors and not AVP V1a receptors to enhance social recognition in adult Syrian hamsters (Mesocricetus auratus).

    PubMed

    Song, Zhimin; Larkin, Tony E; Malley, Maureen O'; Albers, H Elliott

    2016-05-01

    Social recognition is a fundamental requirement for all forms of social relationships. A majority of studies investigating the neural mechanisms underlying social recognition in rodents have investigated relatively neutral social stimuli such as juveniles or ovariectomized females over short time intervals (e.g., 2h). The present study developed a new testing model to study social recognition among adult males using a potent social stimulus. Flank gland odors are used extensively in social communication in Syrian hamsters and convey important information such as dominance status. We found that the recognition of flank gland odors after a 3min exposure lasted for at least 24h, substantially longer than the recognition of other social cues in rats and mice. Intracerebroventricular injections of OT and AVP prolonged the recognition of flank gland odor for up to 48h. Selective OTR but not V1aR agonists, mimicked these enhancing effects of OT and AVP. Similarly, selective OTR but not V1aR antagonists blocked recognition of the odors after 20min. In contrast, the recognition of non-social stimuli was not blocked by either the OTR or the V1aR antagonists. Our findings suggest both OT and AVP enhance social recognition via acting on OTRs and not V1aRs and that the recognition enhancing effects of OT and AVP are limited to social stimuli. PMID:26975586

  19. Acute hematologic, hepatologic, and nephrologic changes after intraperitoneal injections of 18 nm gold nanoparticles in hamsters

    PubMed Central

    Saleh, Hazem Mohamed; Soliman, Omar A; Elshazly, Mohamed Osama; Raafat, Alaa; Gohar, Adel K; Salaheldin, Taher A

    2016-01-01

    In vivo responses to gold nanoparticles (GNPs) vary not only according to the size, shape, surface charge, and capping agent of GNPs but also according to the animal model, the route of administration, and the exposure frequency and duration. We illustrate here the changes in some hematologic parameters, in the hepatic and renal functions, and in the histopathology of solid organs after multiple intraperitoneal injections of 18 nm GNPs in adult male Syrian golden hamsters. We scored the histopathological changes in the liver and kidneys to grade the deleterious effects. Multiple intraperitoneal injections of 18 nm GNPs in hamsters were nonlethal in the short term but resulted in macrocytosis and hypochromasia, leukocytosis, neutrophilia, lymphocytosis, and monocytosis. The hepatic and renal functions showed nonsignificant changes; however, histopathological examination showed hepatic and renal alterations ranging from mild to marked degeneration, with occasional necrosis of hepatocytes and tubular epithelium. PMID:27354788

  20. Acute hematologic, hepatologic, and nephrologic changes after intraperitoneal injections of 18 nm gold nanoparticles in hamsters.

    PubMed

    Saleh, Hazem Mohamed; Soliman, Omar A; Elshazly, Mohamed Osama; Raafat, Alaa; Gohar, Adel K; Salaheldin, Taher A

    2016-01-01

    In vivo responses to gold nanoparticles (GNPs) vary not only according to the size, shape, surface charge, and capping agent of GNPs but also according to the animal model, the route of administration, and the exposure frequency and duration. We illustrate here the changes in some hematologic parameters, in the hepatic and renal functions, and in the histopathology of solid organs after multiple intraperitoneal injections of 18 nm GNPs in adult male Syrian golden hamsters. We scored the histopathological changes in the liver and kidneys to grade the deleterious effects. Multiple intraperitoneal injections of 18 nm GNPs in hamsters were nonlethal in the short term but resulted in macrocytosis and hypochromasia, leukocytosis, neutrophilia, lymphocytosis, and monocytosis. The hepatic and renal functions showed nonsignificant changes; however, histopathological examination showed hepatic and renal alterations ranging from mild to marked degeneration, with occasional necrosis of hepatocytes and tubular epithelium. PMID:27354788

  1. Laboratory trials of five rodenticides for the control of Mesocricetus auratus Waterhouse.

    PubMed

    Bradfield, A A; Gill, J E

    1984-10-01

    The efficacy of five rodenticides for use in bait against the golden hamster (Mesocricetus auratus Waterhouse) was investigated in the laboratory. The species proved to be resistant to warfarin (up to 0.5%) and difenacoum (0.005%), but brodifacoum (0.005%) gave complete mortality after three days' feeding. Calciferol (0.1%), though toxic, was significantly unpalatable. Zinc phosphide (5.0%) presented in a choice test for two days against unpoisoned feed gave 100% mortality, and appears to be the most suitable of these compounds for the control of M. auratus in the field. PMID:6334113

  2. Laboratory trials of five rodenticides for the control of Mesocricetus auratus Waterhouse.

    PubMed Central

    Bradfield, A. A.; Gill, J. E.

    1984-01-01

    The efficacy of five rodenticides for use in bait against the golden hamster (Mesocricetus auratus Waterhouse) was investigated in the laboratory. The species proved to be resistant to warfarin (up to 0.5%) and difenacoum (0.005%), but brodifacoum (0.005%) gave complete mortality after three days' feeding. Calciferol (0.1%), though toxic, was significantly unpalatable. Zinc phosphide (5.0%) presented in a choice test for two days against unpoisoned feed gave 100% mortality, and appears to be the most suitable of these compounds for the control of M. auratus in the field. PMID:6334113

  3. Effects of flavonol-rich diet on select cardiovascular parameters in a Gold Syrian Hamster model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We investigated the effects of a flavonoid-rich diet supplemented with cranberry on blood pressure and cholesterol ester levels in hypercholesterolemic Golden Syrian hamsters. Animals were fed one of four diets: high fat high cholesterol (HFHC) diet, HFHC with 2% cranberry concentrate powder (HFHC+...

  4. PULMONARY CELL POPULATIONS IN HAMSTERS MAINTAINED UNDER EGYPTIAN LABORATORY CONDITIONS

    EPA Science Inventory

    The study was conducted to obtain baseline values for pulmonary cells in golden hamsters (Mesocricetus auratus) bred and maintained under the laboratory conditions of Al-Azhar University in Egypt. An improvised technique is presented for measuring pulmonary cells obtained by lung...

  5. Development of Chronic and Acute Golden Syrian Hamster Infection Models with Leptospira borgpetersenii serovar Hardjo

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  6. 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. PMID:27436535

  7. Preference for bedding material in Syrian hamsters.

    PubMed

    Lanteigne, M; Reebs, S G

    2006-10-01

    This study aimed to determine whether Syrian (golden) hamsters, Mesocricetus auratus, prefer certain bedding materials and whether bedding material can affect paw condition, body weight gain and wheel-running activity. In a first experiment, 26 male hamsters had access to two connected cages, each cage containing a different bedding material (either pine shavings, aspen shavings, corn cob or wood pellets). In a second experiment, 14 male hamsters had access to four connected cages that contained the different bedding materials and also a piece of paper towel to serve as nest material. In a third experiment, 30 male hamsters were each placed in a single cage, 10 of them with pine shavings, 10 with aspen shavings and 10 with corn cob, and they were monitored for 50 days. Significant preferences in the first experiment were: pine shavings over aspen shavings, corn cob over wood pellets, pine shavings over corn cob and aspen shavings over wood pellets (aspen shavings versus corn cob was not tested). However, there was no significant preference expressed in the second experiment, suggesting that the general preference for shavings in the first experiment was based on bedding material suitability as a nesting material. No significant effect of bedding material on paw condition, body weight gain and wheel-running activity was detected. None of the four bedding materials tested in this study can be judged to be inappropriate in the short term if nesting material is added to the cage and if the litter is changed regularly. PMID:17018212

  8. 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

  9. Variation Between Strains of Hamsters in the Lethality of Pichinde Virus Infections

    PubMed Central

    Buchmeier, Michael J.; Rawls, William E.

    1977-01-01

    Infection by Pichinde virus, a member of the arenavirus group, was studied in Golden Syrian hamsters (Mesocricetus auratus) with regard to possible mechanisms of resistance to virus infection in adult hamsters. Two hamster strains were found to differ in their susceptibility to lethal Pichinde virus infection. LVG/Lak randomly bred hamsters were found to be 100% susceptible to low doses of Pichinde virus during the first 6 days of life, but after 8 days of life, mortality was uncommon. Peak virus titers in the serum of animals infected at 3 days of life were 4 logs greater than in animals infected at 12 days. MHA/Lak inbred hamsters, in contrast, were found to be susceptible to lethal virus infection both as newborns and as adults. Peak virus titers of greater than 108 plaque-forming units/ml were observed in serum 8 days after infection of adult MHA hamsters as compared with less than 103 plaque-forming units/ml in the serum of adult LVG hamsters. Cultured primary kidney cells and peritoneal macrophages from either hamster strain supported Pichinde virus replication equally well in vitro. Antibodies to the complement-fixing antigens and to antigens at the surface of virus-infected cells were produced by both strains of hamsters. Cyclophosphamide immunosuppression rendered adult LVG animals susceptible to lethal infections, and virus grew to high titers in the treated animals. These findings suggest that immunological factors that appear early in life in LVG hamsters and are deficient in MHA hamsters limit Pichinde virus infection. Unlike previously reported arenavirus diseases, the observations suggest that death is produced by a direct viral effect and not through immunopathological mechanisms. PMID:193786

  10. In Hamsters Dopamine D2 Receptors affect Ventilation during and following Intermittent Hypoxia

    PubMed Central

    Schlenker, Evelyn H.

    2007-01-01

    We tested the hypothesis that in golden Syrian hamsters (Mesocricetus auratus) carotid body dopaminergic D2 receptors modulate ventilation in air, during exposure to intermittent hypoxia (IH) and reoxygenation. Ventilation was evaluated using the barometric method and CO2 production was determined using the flow through method. Hamsters (n=8) received either subcutaneous injections of vehicle, haloperidol (0.5 mg/kg) or domperidone (0.5 mg/kg). Ventilatory and metabolic variables were determined 30 minutes following injections, after each of 5 bouts of 5 minutes of 10% oxygen interspersed by normoxia (IH), and 15, 30, 45 and 60 minutes following IH when hamsters were exposed to air. Haloperidol, but not domperidone decreased body temperature in hamsters. Neither treatment affected CO2 production. Vehicle-treated hamsters exhibited ventilatory long term facilitation (VLTF) following IH. Haloperidol or domperidone decreased ventilation in air, during IH and eliminated VLTF due to changes in tidal volume and not frequency of breathing. Thus, in hamsters D2 receptors are involved in control of body temperature and ventilation during and following IH PMID:17884646

  11. Brain ECF antioxidant interactions in hamsters during arousal from hibernation.

    PubMed

    Osborne, Peter G; Hashimoto, Masaaki

    2007-03-12

    Warming from hibernation to cenothermia involves intense metabolic activity and large fluxes in regional blood flow and volume. During this transition, levels of the antioxidants, ascorbate (AA), urate and glutathione (GSH) in brain tissue, extracellular fluid (ECF) and plasma change substantially. Striatal ECF was sampled and manipulated using very slow perfusion microdialysis to examine the mechanisms that influence the changing profile of striatal ECF AA, urate and GSH levels during arousal from hibernation to cenothermia in Syrian hamsters (Mesocricetus auratus). Omission of glucose from the perfusate had no effect upon the respective decrease, increase and transient increase in striatal ECF levels of AA, GSH and urate observed during arousal from hibernation to cenothermia. In contrast, inhibition of xanthine dehydrogenase/oxidase (XOR) activity by reverse dialysis with oxypurinol, itself a free radical scavenger, decreased ECF urate and preserved ECF AA levels. This suggests that some ECF AA is oxidized by free radical products of XOR flux and/or by other free radical producing processes activated during the transition from hibernation to cenothermia. Local supplementation of ECF AA, GSH and cystiene had no effect upon the profile of transient increase of ECF urate observed during arousal from hibernation. The production of free radicals by XOR and the disappearance of AA from the ECF continues for at least 2h immediately after the hamster has attained cenothermia. The hamster, immediately after arousal from hibernation, can be utilized as a natural model to study free radical production and effective scavenging at cenothermia. PMID:17207864

  12. Cohabitation impaired physiology, fitness and sex-related chemosignals in golden hamsters.

    PubMed

    Zhang, Jian-Xu; Rao, Xiao-Ping; Sun, Lixing; Wang, Da-Wei; Liu, Dingzhen; Zhao, Chenghua

    2008-03-18

    This study investigated the impact of long-term paternal presence (cohabitation) on several physiological parameters such as body weight, adrenal weight, cortisol of parents, and the survival of pups compared with brief daily encounters (isolation) of male-female pairs in golden hamsters (Mesocricetus auratus). We showed that females were affected more by cohabitation as evidenced by increased body and adrenal weights, elevated cortisol concentrations, and heavier uteri and spleens as compared with cohabiting male and isolated females. Furthermore, we found that tetradecanoic and hexadecanoic acids of the flank glands were sexually dimorphic, for which they were putative female pheromones. These two compounds were suppressed in females and elevated in males by cohabitation, suggesting that cohabitation impaired sex chemosignals. Overall, we concluded that housing females and males together had deleterious effects on adults and the survival of their pups in the golden hamster. PMID:18313701

  13. Adult female hamsters avoid interspecific mating after exposure to heterospecific males

    PubMed Central

    delBarco-Trillo, Javier; McPhee, M. E.; Johnston, Robert E.

    2010-01-01

    When females mate with a heterospecific male, they do not usually produce viable offspring. Thus, there is a selective pressure for females to avoid interspecific mating. In many species, females innately avoid heterospecific males; females can also imprint on their parents to avoid later sexual interactions with heterospecific males. However, it was previously unknown whether adult females can learn to discriminate against heterospecific males. We tested the hypothesis that adult females previously unable to avoid interspecific mating learn to avoid such mating after being exposed to heterospecific males. Syrian hamster (Mesocricetus auratus) females not previously exposed to Turkish hamster (Mesocricetus brandti) males can discriminate between odors of conspecific and heterospecific males, but they mate with either type of male. However, when we exposed adult females to both a conspecific male and a heterospecific male through wire-mesh barriers for 8 days, and then paired them sequentially with the two males, females were more receptive to conspecific males and more aggressive to heterospecific males. When females were paired with the heterospecific male first and the conspecific male second, no female was receptive and all were aggressive to heterospecific males. When females were paired with the conspecific male first, only 43% of females were then aggressive toward the heterospecific male. That is, interactions with conspecific males may decrease a female’s ability to properly avoid heterospecific males. Our study clearly shows for the first time that females can learn during adulthood to avoid interspecific mating just by being exposed to stimuli from heterospecific males. PMID:20676390

  14. Effect of dietary fatty acids on metabolic rate and nonshivering thermogenesis in golden hamsters.

    PubMed

    Jefimow, Małgorzata; Wojciechowski, Michał S

    2014-02-01

    Hibernating rodents prior to winter tend to select food rich in polyunsaturated fatty acids (PUFA). Several studies found that such diet may positively affect their winter energy budget by enhancing torpor episodes. However, the effect of composition of dietary fatty acids (FA) on metabolism of normothermic heterotherms is poorly understood. Thus we tested whether diets different in FA composition affect metabolic rate (MR) and the capacity for nonshivering thermogenesis (NST) in normothermic golden hamsters (Mesocricetus auratus). Animals were housed in outdoor enclosures from May 2010 to April 2011 and fed a diet enriched with PUFA (i.e., standard food supplemented weekly with sunflower and flax seeds) or with saturated and monounsaturated fatty acids (SFA/MUFA, standard food supplemented with mealworms). Since diet rich in PUFA results in lower MR in hibernating animals, we predicted that PUFA-rich diet would have similar effect on MR of normothermic hamsters, that is, normothermic hamsters on the PUFA diet would have lower metabolic rate in cold and higher NST capacity than hamsters supplemented with SFA/MUFA. Indeed, in winter resting metabolic rate (RMR) below the lower critical temperature was higher and NST capacity was lower in SFA/MUFA-supplemented animals than in PUFA-supplemented ones. These results suggest that the increased capacity for NST in PUFA-supplemented hamsters enables them lower RMR below the lower critical temperature of the thermoneural zone. PMID:24151228

  15. Vomeronasal organ lesion disrupts social odor recognition, behaviors and fitness in golden hamsters.

    PubMed

    Liu, Yingjuan; Zhang, Jinhua; Liu, Dingzhen; Zhang, Jianxu

    2014-06-01

    Most studies support the viewpoint that the vomeronasal organ has a profound effect on conspecific odor recognition, scent marking and mating behavior in the golden hamster (Mesocricetus auratus). However, the role of the vomeronasal organ in social odor recognition, social interaction and fitness is not well understood. Therefore, we conducted a series of behavioral and physiological tests to examine the referred points in golden hamster. We found that male hamsters with vomeronasal organ lesion showed no preference between a predator odor (the anal gland secretion of the Siberian weasels (Mustela sibirica) and putative female pheromone components (myristic acid and palmitic acid), but were still able to discriminate between these 2 kinds of odors. In behavioral tests of anxiety, we found that vomeronasal organ removal causes female hamsters to spend much less time in center grids and to cross fewer center grids and males to make fewer crossings between light and dark boxes than sham-operated controls. This indicates that a chronic vomeronasal organ lesion induced anxious responses in females. In aggressive behavioral tests, we found that a chronic vomeronasal organ lesion decreased agonistic behavior in female hamsters but not in males. The pup growth and litter size show no differences between the 2 groups. All together, our data suggested that vomeronasal organ ablation disrupted the olfactory recognition of social chemosignals in males, and induced anxiety-like and aggressive behavior changes in females. However, a vomeronasal organ lesion did not affect the reproductive capacity and fitness of hamsters. Our studies may have important implications concerning the role of the vomeronasal organ in golden hamsters and also in rodents. PMID:24952966

  16. Development of a Hamster Model for Chikungunya Virus Infection and Pathogenesis

    PubMed Central

    Bosco-Lauth, Angela M.; Han, Sushan; Hartwig, Airn; Bowen, Richard A.

    2015-01-01

    Chikungunya virus is transmitted by mosquitoes and causes severe, debilitating infectious arthritis in humans. The need for an animal model to study the disease process and evaluate potential treatments is imminent as the virus continues its spread into novel geographic locations. Golden hamsters (Mesocricetus auratus) are often used as outbred laboratory animal models for arboviral diseases. Here we demonstrate that hamsters inoculated with chikungunya virus developed viremia and histopathologic lesions in their limbs and joints similar to those seen in human patients. The virus disseminated rapidly and was found in every major organ, including brain, within a few days of infection. Hamsters did not manifest overt clinical signs, and the virus was generally cleared within 4 days, followed by a strong neutralizing antibody response. These results indicate that hamsters are highly susceptible to chikungunya virus infection and develop myositis and tenosynovitis similar to human patients followed by a complete recovery. This animal model may be useful for testing antiviral drugs and vaccines. PMID:26070211

  17. Central amygdalar nucleus treated with orexin neuropeptides evoke differing feeding and grooming responses in the hamster.

    PubMed

    Alò, Raffaella; Avolio, Ennio; Mele, Maria; Di Vito, Anna; Canonaco, Marcello

    2015-04-15

    Interaction of the orexinergic (ORXergic) neuronal system with the excitatory (glutamate, l-Glu) or the inhibitory (GABA) neurosignaling complexes evokes major homeostatic physiological events. In this study, effects of the two ORXergic neuropeptides (ORX-A/B) on their receptor (ORX-2R) expression changes were correlated to feeding and grooming actions of the hibernating hamster (Mesocricetus auratus). Infusion of the central amygdala nucleus (CeA) with ORX-A caused hamsters to consume notable quantities of food, while ORX-B accounted for a moderate increase. Interestingly the latter neuropeptide was responsible for greater frequencies of grooming with respect to both controls and the hamsters treated with ORX-A. These distinct behavioral changes turned out to be even greater in the presence of l-Glu agonist (NMDA) while the α1 GABAA receptor agonist (zolpidem, Zol) greatly reduced ORX-A-dependent feeding bouts. Moreover, ORX-A+NMDA mainly promoted greater ORX-2R expression levels with respect to ORX-A-treated hamsters while ORX-B+Zol was instead largely responsible for a down-regulatory trend. Overall, these features point to CeA ORX-2R sites as key sensory limbic elements capable of regulating eating and grooming responses, which may provide useful insights regarding the type of molecular mechanism(s) operating during feeding bouts. PMID:25732800

  18. Anterior hypothalamic vasopressin modulates the aggression-stimulating effects of adolescent cocaine exposure in Syrian hamsters.

    PubMed

    Jackson, D; Burns, R; Trksak, G; Simeone, B; DeLeon, K R; Connor, D F; Harrison, R J; Melloni, R H

    2005-01-01

    Repeated low-dose cocaine treatment (0.5 mg/kg/day) during adolescence induces offensive aggression in male Syrian hamsters (Mesocricetus auratus). This study examines the hypothesis that adolescent cocaine exposure predisposes hamsters to heightened levels of aggressive behavior by increasing the activity of the anterior hypothalamic-vasopressinergic neural system. In a first experiment, adolescent male hamsters were treated with low-dose cocaine and then scored for offensive aggression in the absence or presence of vasopressin receptor antagonists applied directly to the anterior hypothalamus. Adolescent cocaine-treated hamsters displayed highly escalated offensive aggression that could be reversed by blocking the activity of vasopressin receptors within the anterior hypothalamus. In a second set of experiments, adolescent hamsters were administered low-dose cocaine or vehicle, tested for offensive aggression, and then examined for differences in vasopressin innervation patterns and expression levels in the anterior hypothalamus, as well as the basal- and stimulated-release of vasopressin in this same brain region. Aggressive, adolescent cocaine-treated hamsters showed no differences in vasopressin afferent innervation and/or peptide levels in the anterior hypothalamus compared with non-aggressive, saline-treated littermates. Conversely, significant increases in stimulated, but not basal, vasopressin release were detected from the anterior hypothalamus of aggressive, cocaine-treated animals compared with non-aggressive, saline-treated controls. Together, these data suggest that adolescent cocaine exposure increases aggression by increasing stimulated release of vasopressin in the anterior hypothalamus, providing direct evidence for a causal role of anterior hypothalamic-vasopressin activity in adolescent cocaine-induced offensive aggression. A model for how alterations in anterior hypothalamic-vasopressin neural functioning may facilitate the development of the

  19. Recovery of Syrian hamster hippocampal signaling following its depression during oxygen-glucose deprivation is enhanced by cold temperatures and by hibernation.

    PubMed

    Mikhailova, Alexandra; Mack, Jacob; Vitagliano, Nicholas; Hamilton, Jock S; Horowitz, John M; Horwitz, Barbara A

    2016-05-16

    Signal transmission over a hippocampal network of CA3 and CA1 neurons in Syrian hamsters (Mesocricetus auratus), facultative hibernators, has not been fully characterized in response to oxygen-glucose deprivation (OGD). We hypothesized that during OGD, hippocampal signal transmission fails first at the synapse between CA3 and CA1 pyramidal neurons and that recovery of signal processing following OGD is more robust in hippocampal slices at cold temperature, from hamsters vs. rats, and from hibernating vs. non-hibernating hamsters. To test these hypotheses, we recorded fEPSPs and population spikes of CA1 neurons at 25°C, 30°C, and 35°C in 400μm slices over a 15min control period with the slice in oxygenated aCSF containing glucose (control solution), a 10min treatment period (OGD insult) where oxygen was replaced by nitrogen in aCSF lacking glucose, and a 30min recovery period with the slice in the control solution. The initial site of transmission failure during OGD occurred at the CA3-CA1 synapse, and recovery of signal transmission was at least, if not more (depending on temperature), complete in slices from hibernating vs. non-hibernating hamsters, and from non-hibernating hamsters vs. rats. Thus, hamster neuroprotective mechanisms supporting functional recovery were enhanced by cold temperatures and by hibernation. PMID:27068759

  20. Different palm oil preparations reduce plasma cholesterol concentrations and aortic cholesterol accumulation compared to coconut oil in hypercholesterolemic hamsters.

    PubMed

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

    2005-10-01

    Several studies have reported on the effect of refined, bleached and deodorized palm oil (RBD-PO) incorporation into the diet on blood cholesterol concentrations and on the development of atherosclerosis. However, very little work has been reported on the influence of red palm oil (RPO), which is higher in carotenoid and tocopherol content than RBD-PO. Thus, we studied the influence of RPO, RBD-PO and a RBD-PO plus red palm oil extract (reconstituted RBD-PO) on plasma cholesterol concentrations and aortic accumulation vs. hamsters fed coconut oil. Forty-eight F1B Golden Syrian hamsters (Mesocricetus auratus) (BioBreeders, Watertown, MA) were group housed (three/cage) in hanging polystyrene cages with bedding in an air-conditioned facility maintained on a 12-h light/dark cycle. The hamsters were fed a chow-based hypercholesterolemic diet (HCD) containing 10% coconut oil and 0.1% cholesterol for 2 weeks at which time they were bled after an overnight fast and segregated into four groups of 12 with similar plasma cholesterol concentrations. Group 1 continued on the HCD, Group 2 was fed the HCD containing 10% RPO in place of coconut oil, Group 3 was fed the HCD containing 10% RBD-PO in place of coconut oil and Group 4 was fed the HCD with 10% reconstituted RBD-PO for an additional 10 weeks. Plasma total cholesterol (TC) and non-high-density lipoprotein-cholesterol (HDL-C) (very low- and low-density lipoprotein) concentrations were significantly lower in the hamsters fed the RPO (-42% and -48%), RBD-PO (-32% and -36%) and the reconstituted RBD-PO (-37% and -41%) compared to the coconut oil-fed hamsters. Plasma HDL-C concentrations were significantly higher by 14% and 31% in hamsters fed the RBD-PO and RPO compared to the coconut oil-fed hamsters. Plasma triglyceride (TG) concentrations were significantly lower in hamsters fed RBD-PO (-32%) and the reconstituted RBD-PO (-31%) compared to the coconut oil-fed hamsters. The plasma gamma-tocopherol concentrations were higher

  1. Acute Hendra virus infection: Analysis of the pathogenesis and passive antibody protection in the hamster model

    SciTech Connect

    Guillaume, Vanessa; Wong, K. Thong; Looi, R.Y.; Georges-Courbot, Marie-Claude; Barrot, Laura; Buckland, Robin; Wild, T. Fabian; Horvat, Branka

    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 HeV 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.

  2. Effect of cage enrichment on the daily use of running wheels by Syrian hamsters.

    PubMed

    Reebs, Stéphan G; Maillet, Dominique

    2003-01-01

    Institutional animal care committees may one day require for the welfare of captive hamsters more floor space and the introduction of tunnels and toys. As hamsters are popular animal subjects in chronobiological research, and as clock phase is usually measured through running wheel activity, it is important to determine what effect cage enrichment might have on daily wheel use. Here the daily number of wheel revolutions, the daily duration of the running activity phase, the phase relationship between lights-off and onset of running activity, and the free-running period of circadian activity rhythms were measured in Syrian hamsters, Mesocricetus auratus, housed in single cages or in multiple cages linked by tunnels and supplied with commercial wooden toys. Free-running periodicity was not affected by cage enrichment. In multiple-cage systems, there were fewer daily revolutions, shorter wheel-running activity phases, and delayed running activity onsets. These effects, however, were small as compared to interindividual and week-to-week variation. They were statistically significant only under a light:dark cycle, not in constant darkness, and only when interindividual variation was eliminated through a paired design or when the number of cages was increased to five (the maximum tested). Daily wheel use is thus affected by cage enrichment, but only slightly. PMID:12638687

  3. Lethal disease in infant and juvenile Syrian hamsters experimentally infected with Imjin virus, a newfound crocidurine shrew-borne hantavirus.

    PubMed

    Gu, Se Hun; Kim, Young-Sik; Baek, Luck Ju; Kurata, Takeshi; Yanagihara, Richard; Song, Jin-Won

    2015-12-01

    To gain insights into the pathogenicity of Imjin virus (MJNV), a newfound hantavirus isolated from the Ussuri white-toothed shrew (Crocidura lasiura), groups of Syrian hamsters (Mesocricetus auratus) of varying ages (<1, 5, 10, 14, 21, 35 and 56 days) were inoculated by the intraperitoneal route with 1000 pfu of MJNV strains 04-55 and 05-11. MJNV-infected Syrian hamsters, aged 21 days or less, exhibited reduced activity, weight loss, respiratory distress, hind-limb paralysis and seizures. Death ensued 1 to 6 days after onset of clinical disease. MJNV RNA was detected in brain and other major organs by RT-PCR and real time-PCR. Histopathological examination showed alveolar hemorrhage, interstitial pneumonia and severe pulmonary congestion; focal hepatic necrosis and portal inflammation; and acute meningoencephalitis. By immunohistochemistry, MJNV antigen was detected in pulmonary microvascular endothelial cells and glial cells. Older hamsters (35 and 56 days of age) developed subclinical infection without histopathological changes. Future studies are warranted to determine the pathophysiologic bases for the differential age susceptibility of Syrian hamsters to lethal MJNV disease. PMID:26371066

  4. Brain antioxidant levels in hamsters during hibernation, arousal and cenothermia.

    PubMed

    Osborne, Peter G; Hashimoto, Masaaki

    2006-04-01

    Warming from hibernation to cenothermia involves intense metabolic activity coincident with large fluxes in blood flow and is considered to be a period of oxidative stress during which utilization of endogenous antioxidants prevents pathology. Very slow flow brain microdialysis enabled temperature independent sampling of the brain striatal extracellular fluid (ECF) during hibernation, arousal and cenothermia in Syrian hamsters (Mesocricetus auratus). Brain tissue and dialysates were analyzed to provide the first profile of changes in ECF levels of ascorbate (AA), glutathione (GSH) and urate during hibernation and the transition to cenothermia. Brain tissue content of AA and GSH was unchanged between hibernation and cenothermia; however, arousal was associated with substantial oxidation of AA from the brain ECF and plasma compartments. ECF GSH increased during arousal. Brain tissue urate content was decreased 50% during hibernation. ECF urate levels were unchanged in hibernation and cenothermia but transiently increased 100% during arousal. These experiments demonstrate that arousal from hibernation is a suitable experimental model for examination of the mechanisms by which non-pathological tissue integrity is maintained in the face of the generation of free radicals during increasing metabolism, temperature and cerebral reperfusion. PMID:16343656

  5. The influence of negative ionization of the air on motor activity in Syrian hamsters ( Masocricetus auratus Waterhouse) in light conditions

    NASA Astrophysics Data System (ADS)

    Lenkiewicz, Zofia; Dabrowska, Barbara; Schiffer, Zofia

    1989-12-01

    The motor activity of Syrian hamsters ( Mesocricetus auratus Waterhouse) under the influence of negative ionization of the atmosphere applied for 10, 20 or 30 min per day was investigated. An ionizer with output of 14000 light negative ions per 1 cm3 of air was used. Studies carried out in the light phase of a 12∶12 h light/dark regime revealed a relation between the reaction of the animal and the time of day at which ionization was applied. Ionization for 20 or 30 min in the light phase decreased motor activity, while 10 min of ionization increased it compared to control animals. Ionization in the dark phase gave a more distinct rise in activity than that applied in the light phase for all three durations of ionization.

  6. Cross-species fertilization: the hamster egg receptor, Juno, binds the human sperm ligand, Izumo1.

    PubMed

    Bianchi, Enrica; Wright, Gavin J

    2015-02-01

    Fertilization is the culminating event in sexual reproduction and requires the recognition and fusion of the haploid sperm and egg to form a new diploid organism. Specificity in these recognition events is one reason why sperm and eggs from different species are not normally compatible. One notable exception is the unusual ability of zona-free eggs from the Syrian golden hamster (Mesocricetus auratus) to recognize and fuse with human sperm, a phenomenon that has been exploited to assess sperm quality in assisted fertility treatments. Following our recent finding that the interaction between the sperm and egg recognition receptors Izumo1 and Juno is essential for fertilization, we now demonstrate concordance between the ability of Izumo1 and Juno from different species to interact, and the ability of their isolated gametes to cross-fertilize each other in vitro. In particular, we show that Juno from the golden hamster can directly interact with human Izumo1. These data suggest that the interaction between Izumo1 and Juno plays an important role in cross-species gamete recognition, and may inform the development of improved prognostic tests that do not require the use of animals to guide the most appropriate fertility treatment for infertile couples. PMID:25533103

  7. Cross-species fertilization: the hamster egg receptor, Juno, binds the human sperm ligand, Izumo1

    PubMed Central

    Bianchi, Enrica; Wright, Gavin J.

    2015-01-01

    Fertilization is the culminating event in sexual reproduction and requires the recognition and fusion of the haploid sperm and egg to form a new diploid organism. Specificity in these recognition events is one reason why sperm and eggs from different species are not normally compatible. One notable exception is the unusual ability of zona-free eggs from the Syrian golden hamster (Mesocricetus auratus) to recognize and fuse with human sperm, a phenomenon that has been exploited to assess sperm quality in assisted fertility treatments. Following our recent finding that the interaction between the sperm and egg recognition receptors Izumo1 and Juno is essential for fertilization, we now demonstrate concordance between the ability of Izumo1 and Juno from different species to interact, and the ability of their isolated gametes to cross-fertilize each other in vitro. In particular, we show that Juno from the golden hamster can directly interact with human Izumo1. These data suggest that the interaction between Izumo1 and Juno plays an important role in cross-species gamete recognition, and may inform the development of improved prognostic tests that do not require the use of animals to guide the most appropriate fertility treatment for infertile couples. PMID:25533103

  8. Tspy is nonfunctional in the Mongolian gerbil but functional in the Syrian hamster.

    PubMed

    Karwacki, Violetta; Kovac, Judit; Mauceri, Grazia; Backhaus, Arne; Föhse, Lisa; Schmidtke, Jörg; Schubert, Stephanie

    2006-07-01

    The TSPY gene is conserved in placental mammals and encodes the testis-specific protein, Y encoded. Within the testis, TSPY expression is restricted to germ cells, and it is assumed that TSPY plays a role in the proliferation of germ cells. Since it was first discovered in humans, TSPY orthologous gene families have been subsequently characterized in many mammalian lineages. In contrast to the situation in cattle and primates, in which TSPY is organized in a moderately repetitive cluster, including functional members and pseudogenes, a peculiar situation is observed in rodents, in which Tspy has been become low or single copy and degenerated to a pseudogene in some species of the subgenus Mus. We have extended this approach and investigated Tspy gene evolution in the Syrian hamster (Mesocricetus auratus) and the Mongolian gerbil (Meriones unguiculatus). Whereas the Syrian hamster Tspy is functionally conserved, organized in multiple copies, and expressed only in testis, the closely related Mongolian gerbil possesses a single-copy pseudogene that is unable to generate a functional transcript. Thus, the Tspy locus has degenerated at least twice at different points of rodent evolution, strongly supporting the hypothesis that the decay of Y-chromosomal genes is an intrinsic evolutionary process. TSPY is the first example of a Y-chromosomal tandem repetitive gene whose decay could be studied in two independent mammalian lineages. PMID:16626932

  9. A method for electrophysiological characterization of hamster retinal ganglion cells using a high-density CMOS microelectrode array

    PubMed Central

    Jones, Ian L.; Russell, Thomas L.; Farrow, Karl; Fiscella, Michele; Franke, Felix; Müller, Jan; Jäckel, David; Hierlemann, Andreas

    2015-01-01

    Knowledge of neuronal cell types in the mammalian retina is important for the understanding of human retinal disease and the advancement of sight-restoring technology, such as retinal prosthetic devices. A somewhat less utilized animal model for retinal research is the hamster, which has a visual system that is characterized by an area centralis and a wide visual field with a broad binocular component. The hamster retina is optimally suited for recording on the microelectrode array (MEA), because it intrinsically lies flat on the MEA surface and yields robust, large-amplitude signals. However, information in the literature about hamster retinal ganglion cell functional types is scarce. The goal of our work is to develop a method featuring a high-density (HD) complementary metal-oxide-semiconductor (CMOS) MEA technology along with a sequence of standardized visual stimuli in order to categorize ganglion cells in isolated Syrian Hamster (Mesocricetus auratus) retina. Since the HD-MEA is capable of recording at a higher spatial resolution than most MEA systems (17.5 μm electrode pitch), we were able to record from a large proportion of RGCs within a selected region. Secondly, we chose our stimuli so that they could be run during the experiment without intervention or computation steps. The visual stimulus set was designed to activate the receptive fields of most ganglion cells in parallel and to incorporate various visual features to which different cell types respond uniquely. Based on the ganglion cell responses, basic cell properties were determined: direction selectivity, speed tuning, width tuning, transience, and latency. These properties were clustered to identify ganglion cell types in the hamster retina. Ultimately, we recorded up to a cell density of 2780 cells/mm2 at 2 mm (42°) from the optic nerve head. Using five parameters extracted from the responses to visual stimuli, we obtained seven ganglion cell types. PMID:26528115

  10. Seasonal changes in the thermoregulation of laboratory golden hamsters during acclimation to seminatural outdoor conditions.

    PubMed

    Jefimow, Małgorzata; Wojciechowski, Michał; Tegowska, Eugenia

    2004-11-01

    Proper adjustments of the thermoregulatory mechanisms ensure survival in the natural environment. In the present study, we tested the hypothesis that laboratory golden hamsters (Mesocricetus auratus) housed under seminatural outdoor conditions are able to acclimatize to daily and seasonal changes in the environment despite their long history of breeding in captivity. The animals experienced natural changes in the photoperiod and ambient temperature characteristic for central Poland. During experiments in the thermal gradient system, the daily rhythms of body temperature (measured as the temperature of brown adipose tissue, TBAT), preferred ambient temperature (PTa) and activity were measured in summer, autumn and spring. We found that mean TBAT was highest in autumn and least in summer, reflecting seasonal changes in the capacity for nonshivering thermogenesis (NST). In summer, TBAT followed the robust daily rhythm with the amplitude of 1.1+/-0.1 degrees C. This amplitude was depressed in autumn (0.2+/-0.1 degrees C) and partially restored in spring (0.4+/-0.1 degrees C). Seasonal changes in the daily amplitude of TBAT recorded during both transitional periods, i.e., in autumn and spring, seem to be associated with hamsters' hibernation. In autumn, mean daily PTa was lower than in summer and spring, indicating the lowering of a set point for core body temperature (Tb) regulation. Locomotor activity was much higher in spring than in summer and autumn, and it always predominated at night. We conclude that laboratory golden hamsters housed under seminatural conditions express daily and seasonal changes in the thermoregulatory mechanisms that, despite long history of breeding in captivity, enable proper acclimatization to seasonally changing environment and ensure successful hibernation and winter survival. PMID:15556395

  11. 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

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

    PubMed

    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

  13. Exposure to sub-chronic unpredictable stress accounts for antidepressant-like effects in hamsters treated with BDNF and CNQX.

    PubMed

    Alò, Raffaella; Mele, Maria; Fazzari, Gilda; Avolio, Ennio; Canonaco, Marcello

    2015-09-01

    Recent evidences indicate that cerebral neurotrophic factors like vascular endothelial growth factor plus signaling pathways of the glutamatergic neuroreceptor system (L-Glu) are determinant modulators of depression-like states. In the present study, the type of interaction(s) exerted by the AMPAergic antagonist, 6-cyano-7-nitroquinoxalin-2,3-dione (CNQX) and the brain derived neurotrophic factor (BDNF) on depression-like behaviors in hamsters (Mesocricetus auratus) were investigated. Sub-chronic administration of BDNF in the hippocampal dentate gyrus (DG) of stressed hamsters was responsible for very evident (p<0.001) sucrose consumption along with notably elevated swimming bouts and reduced immobility states in the forced swim test (FST). Meanwhile, CNQX displayed evident anxiolytic actions in the elevated plus maze (EPM) as shown by marked (p<0.01) increases of movements to and from both arms. Interestingly cerebral neurodegeneration events, which are viewed during depression states, were reduced following treatment with both compounds. Contextually, marked mRNA expression levels of the BDNF receptor (tropomyosin-related kinase B; TrkB) were detected in DG and the oriens-pyramidalis of HIP (Or-Py) while a moderate (p<0.05) up-regulation was registered in the amygdalar central nucleus (CeA) and the hypothalamic ventromedial nucleus (VMH) of hamsters treated with BDNF. Similarly, this treatment caused moderate increases of the major stress protein (Hsp70) in DG and Or-Py. Conversely, while CNQX induced similar TrkB expression levels, it instead accounted for a moderate reduction of Hsp70 mRNAs in the same brain areas. Overall these results support crucial roles played by BDNF and AMPAergic neurosignaling mechanisms during distinct adaptive responses of depression- and anxiety-like states in hamsters. PMID:26409118

  14. Pathological effects of in utero methylmercury exposure on the cerebellum of the golden hamster: early effects upon the neonatal cerebellar cortex-Part I

    SciTech Connect

    Reuhl, K.R.; Chang, L.W.; Townsend, J.W.

    1981-12-01

    Pregnant golden hamsters (Mesocricetus auratus) were given either a single dose of 10 mg methylmercury/kg on gestational day 10 or daily doses of 2 mg/kg on gestational days 10-15. Cerebella of experimental and control offspring were examined by light and electron microscopy during the first month of postnatal life. Degenerative changes, characterized by accumulations of lysosomes and areas of floccular cytoplasmic degradation, were frequently observed in neuroblasts of the external granular layer (EGL) as well as in more differentiated neural elements in the molecular and internal granular layers. Pyknotic nuclei were seen singly and in groups throughout the EGL of treated animals. Developing dendrites appeared particularly sensitive to methylmercury. Affected dendrites were swollen and packed with degenerating cytoplasmic material. Astrocytes and perivascular macrophages also contained large aggregates of irregular electron-opague debris, lysosomes, and large lipid droplets. Pathological alterations in the cerebellum were most pronounced during the first 15 days of postpartum life.

  15. Tau phosphorylation-associated spine regression does not impair hippocampal-dependent memory in hibernating golden hamsters.

    PubMed

    Bullmann, Torsten; Seeger, Gudrun; Stieler, Jens; Hanics, János; Reimann, Katja; Kretzschmann, Tanja Petra; Hilbrich, Isabel; Holzer, Max; Alpár, Alán; Arendt, Thomas

    2016-03-01

    The microtubule-associated protein tau, in its hyperphosphorylated form, is the major component of paired helical filaments and other aggregates in neurodegenerative disorders commonly referred to as "tauopathies". Recent evidence, however, indicates that mislocalization of hyperphosphorylated tau to subsynaptic sites leads to synaptic impairment and cognitive decline even long before formation of tau aggregates and neurodegeneration occur. A similar, but reversible hyperphosphorylation of tau occurs under physiologically controlled conditions during hibernation. Here, we study the hibernating Golden hamster (Syrian hamster, Mesocricetus auratus). A transient spine reduction was observed in the hippocampus, especially on apical dendrites of hippocampal CA3 pyramidal cells, but not on their basal dendrites. This distribution of structural synaptic regression was correlated to the distribution of phosphorylated tau, which was highly abundant in apical dendrites but hardly detectable in basal dendrites. Surprisingly, hippocampal memory assessed by a labyrinth maze was not affected by hibernation. The present study suggests a role for soluble hyperphosphorylated tau in the process of reversible synaptic regression, which does not lead to memory impairment during hibernation. We hypothesize that tau phosphorylation associated spine regression might mainly affect unstable/dynamic spines while sparing established/stable spines. PMID:26332578

  16. REPEATED ANABOLIC/ANDROGENIC STEROID EXPOSURE DURING ADOLESCENCE ALTERS PHOSPHATE-ACTIVATED GLUTAMINASE AND GLUTAMATE RECEPTOR 1 SUBUNIT IMMUNOREACTIVITY IN HAMSTER BRAIN: CORRELATION WITH OFFENSIVE AGGRESSION

    PubMed Central

    Fischer, Shannon G.; Ricci, Lesley A.; Melloni, Richard H.

    2007-01-01

    Male Syrian hamsters (Mesocricetus auratus) treated with moderately high doses (5.0mg/kg/day) of anabolic/androgenic steroids (AAS) during adolescence (P27–P56) display highly escalated offensive aggression. The current study examined whether adolescent AAS-exposure influenced the immunohistochemical localization of phosphate-activated glutaminase (PAG), the rate-limiting enzyme in the synthesis of glutamate, a fast-acting neurotransmitter implicated in the modulation of aggression in various species and models of aggression, as well as glutamate receptor 1 subunit (GluR1). Hamsters were administered AAS during adolescence, scored for offensive aggression using the resident-intruder paradigm, and then examined for changes in PAG and GluR1 immunoreactivity in areas of the brain implicated in aggression control. When compared with sesame oil-treated control animals, aggressive AAS-treated hamsters displayed a significant increase in the number of PAG- and area density of GluR1- containing neurons in several notable aggression regions, although the differential pattern of expression did not appear to overlap across brain regions. Together, these results suggest that altered glutamate synthesis and GluR1 receptor expression in specific aggression areas may be involved in adolescent AAS-induced offensive aggression. PMID:17418431

  17. Cellular changes in the hamster testicular interstitium with ageing and after exposure to short photoperiod.

    PubMed

    Beltrán-Frutos, E; Seco-Rovira, V; Ferrer, C; Madrid, J F; Sáez, F J; Canteras, M; Pastor, L M

    2016-04-01

    The aim of this study was to evaluate the cellular changes that occur in the hamster testicular interstitium in two very different physiological situations involving testicular involution: ageing and exposure to a short photoperiod. The animals were divided into an 'age group' with three subgroups - young, adult and old animals - and a 'regressed group' with animals subjected to a short photoperiod. The testicular interstitium was characterised by light and electron microscopy. Interstitial cells were studied histochemically with regard to their proliferation, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP in situ nick end labelling (TUNEL+) and testosterone synthetic activity. We identified two types of Leydig cell: Type A cells showed a normal morphology, while Type B cells appeared necrotic. With ageing, pericyte proliferation decreased but there was no variation in the index of TUNEL-positive Leydig cells. In the regressed group, pericyte proliferation was greater and TUNEL-positive cells were not observed in the interstitium. The testicular interstitium suffered few ultrastructural changes during ageing and necrotic Leydig cells were observed. In contrast, an ultrastructural involution of Leydig cells with no necrosis was observed in the regressed group. In conclusion, the testicular interstitium of Mesocricetus auratus showed different cellular changes in the two groups (age and regressed), probably due to the irreversible nature of ageing and the reversible character of changes induced by short photoperiod. PMID:25437143

  18. Maintenance of dominance status is necessary for resistance to social defeat stress in Syrian hamsters

    PubMed Central

    Morrison, Kathleen E.; Bader, Lauren R.; Clinard, Catherine T.; Gerhard, Danielle M.; Gross, Sonya E.; Cooper, Matthew A.

    2014-01-01

    Resilience is an active process that involves a discrete set of neural substrates and cellular mechanisms and enables individuals to avoid some of the negative consequences of extreme stress. We have previously shown that dominant individuals show less stress-induced changes in behavior compared to subordinates using a conditioned defeat model in male Syrian hamsters (Mesocricetus auratus). To rule out pre-existing differences between dominants and subordinates, we examined whether 14 days of dominance experience is required to reduce the conditioned defeat response and whether the development of conditioned defeat resistance correlates with defeat-induced neural activation in select brain regions. We paired hamsters in daily 5-min aggressive encounters for 1, 7, or 14 days and then exposed animals to 3, 5-min social defeat episodes. The next day animals received conditioned defeat testing which involved a 5-min social interaction test with a non-aggressive intruder. In separate animals brains were collected after social defeat for c-Fos immunohistochemistry. We found that 14-day dominants showed a decreased conditioned defeat response compared to 14-day subordinates and controls, while 1-day and 7-day dominants did not differ from their subordinate counterparts. Also, the duration of dominance relationship was associated with distinct patterns of defeat-induced neural activation such that only 14-day dominants showed elevated c-Fos immunoreactivity in the ventral medial prefrontal cortex, medial amygdala, and lateral portions of the ventral medial hypothalamus. Our data suggest that resistance to social stress develops during the maintenance of dominance relationships and is associated with experience-dependent neural plasticity in select brain regions. PMID:24875769

  19. Cytokine, Antibody and Proliferative Cellular Responses Elicited by Taenia solium Calreticulin upon Experimental Infection in Hamsters

    PubMed Central

    Mendlovic, Fela; Cruz-Rivera, Mayra; Ávila, Guillermina; Vaughan, Gilberto; Flisser, Ana

    2015-01-01

    Taenia solium causes two diseases in humans, cysticercosis and taeniosis. Tapeworm carriers are the main risk factor for neurocysticercosis. Limited information is available about the immune response elicited by the adult parasite, particularly the induction of Th2 responses, frequently associated to helminth infections. Calreticulin is a ubiquitous, multifunctional protein involved in cellular calcium homeostasis, which has been suggested to play a role in the regulation of immune responses. In this work, we assessed the effect of recombinant T. solium calreticulin (rTsCRT) on the cytokine, humoral and cellular responses upon experimental infection in Syrian Golden hamsters (Mesocricetus auratus). Animals were infected with T. solium cysticerci and euthanized at different times after infection. Specific serum antibodies, proliferative responses in mesenteric lymph nodes and spleen cells, as well as cytokines messenger RNA (mRNA) were analyzed. The results showed that one third of the infected animals elicited anti-rTsCRT IgG antibodies. Interestingly, mesenteric lymph node (MLN) cells from either infected or non-infected animals did not proliferate upon in vitro stimulation with rTsCRT. Additionally, stimulation with a tapeworm crude extract resulted in increased expression of IL-4 and IL-5 mRNA. Upon stimulation, rTsCRT increased the expression levels of IL-10 in spleen and MLN cells from uninfected and infected hamsters. The results showed that rTsCRT favors a Th2-biased immune response characterized by the induction of IL-10 in mucosal and systemic lymphoid organs. Here we provide the first data on the cytokine, antibody and cellular responses to rTsCRT upon in vitro stimulation during taeniasis. PMID:25811778

  20. Beta-endorphin-like and adrenocorticotropin-like materials in heart tissues of the rat, gerbil, hamster and guinea pig.

    PubMed

    Ng, T B; Ng, S L

    1990-01-01

    1. Heart tissues of several rodent species including the rat, gerbil (Meriones unguiculatus), hamster (Mesocricetus auratus) and guinea pig (Cavia porcellus) were extracted with an acetone-water-HCl mixture. An acid acetone powder was obtained by adding a copious volume of acetone to the extract. 2. Rat heart acid acetone powder was subjected to ion exchange chromatography on CM-cellulose. Gerbil heart acid acetone powder was subjected to salt fractionation, gel filtration on Sephadex G-10 and then ion exchange chromatography on CM-cellulose. Hamster and guinea pig heart acid acetone powders were subjected to gel filtration on Sephadex G-25. 3. The fractions were assayed for the ability to stimulate corticosterone production in isolated rat adrenal decapsular (zona fasciculata, zona reticularis and medulla) cells, to displace D-ala2-D-leu5-(tyrosyl-3,5-3H) enkephalin from binding to rat brain membranes, and to inhibit 125I-human beta-endorphin from binding to its antibodies. 4. The widespread occurrence of beta-endorphin-like immunoreactivity among the rat heart CM-cellulose fractions may reflect different species of beta-endorphin. The fraction with the highest beta-endorphin-like immunoreactivity and opiate receptor binding activity was strongly adsorbed on CM-cellulose. 5. In hamster and guinea pig hearts, beta-endorphin-like immunoreactivity and opiate receptor binding activity were distributed among high molecular weight and low molecular weight fractions. 6. In gerbil hearts, opiate receptor binding activity was present in fractions unretarded on Sephadex G-10 (i.e. with a molecular weight greater than 700) as well as in the retarded fractions (i.e. with a molecular weight smaller than 700).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1971555

  1. Decreases in body temperature and body mass constitute pre-hibernation remodelling in the Syrian golden hamster, a facultative mammalian hibernator

    PubMed Central

    Chayama, Yuichi; Ando, Lisa; Tamura, Yutaka; Miura, Masayuki

    2016-01-01

    Hibernation is an adaptive strategy for surviving during periods with little or no food availability, by profoundly reducing the metabolic rate and the core body temperature (Tb). Obligate hibernators (e.g. bears, ground squirrels, etc.) hibernate every winter under the strict regulation of endogenous circannual rhythms, and they are assumed to undergo adaptive remodelling in autumn, the pre-hibernation period, prior to hibernation. However, little is known about the nature of pre-hibernation remodelling. Syrian hamsters (Mesocricetus auratus) are facultative hibernators that can hibernate irrespective of seasons when exposed to prolonged short photoperiod and cold ambient temperature (SD-Cold) conditions. Their Tb set point reduced by the first deep torpor (DT) and then increased gradually after repeated cycles of DT and periodic arousal (PA), and finally recovered to the level observed before the prolonged SD-Cold in the post-hibernation period. We also found that, before the initiation of hibernation, the body mass of animals decreased below a threshold, indicating that hibernation in this species depends on body condition. These observations suggest that Syrian hamsters undergo pre-hibernation remodelling and that Tb and body mass can be useful physiological markers to monitor the remodelling process during the pre-hibernation period. PMID:27152216

  2. Decreases in body temperature and body mass constitute pre-hibernation remodelling in the Syrian golden hamster, a facultative mammalian hibernator.

    PubMed

    Chayama, Yuichi; Ando, Lisa; Tamura, Yutaka; Miura, Masayuki; Yamaguchi, Yoshifumi

    2016-04-01

    Hibernation is an adaptive strategy for surviving during periods with little or no food availability, by profoundly reducing the metabolic rate and the core body temperature (T b). Obligate hibernators (e.g. bears, ground squirrels, etc.) hibernate every winter under the strict regulation of endogenous circannual rhythms, and they are assumed to undergo adaptive remodelling in autumn, the pre-hibernation period, prior to hibernation. However, little is known about the nature of pre-hibernation remodelling. Syrian hamsters (Mesocricetus auratus) are facultative hibernators that can hibernate irrespective of seasons when exposed to prolonged short photoperiod and cold ambient temperature (SD-Cold) conditions. Their T b set point reduced by the first deep torpor (DT) and then increased gradually after repeated cycles of DT and periodic arousal (PA), and finally recovered to the level observed before the prolonged SD-Cold in the post-hibernation period. We also found that, before the initiation of hibernation, the body mass of animals decreased below a threshold, indicating that hibernation in this species depends on body condition. These observations suggest that Syrian hamsters undergo pre-hibernation remodelling and that T b and body mass can be useful physiological markers to monitor the remodelling process during the pre-hibernation period. PMID:27152216

  3. Effect of Hibiscus sabdariffa extract on high fat diet–induced obesity and liver damage in hamsters

    PubMed Central

    Huang, To-Wei; Chang, Chia-Ling; Kao, Erl-Shyh; Lin, Jenq-Horng

    2015-01-01

    Background Obesity is a chronic metabolic disorder associated with an increase in adipogenesis and often accompanied with fatty liver disease. Objective In this study, we investigated the anti-obesity effects of Hibiscus sabdariffa water extract (HSE) in vivo. Method Eight-weeks-old male mice were divided into six groups (n=8 per group) and were fed either normal feed, a high fat diet (HFD), HFD supplemented with different concentrations of HSE, or HFD supplemented with anthocyanin. After 10 weeks of feeding, all the blood and livers were collected for further analysis. Results Mesocricetus auratus hamster fed with a high-fat diet developed symptoms of obesity, as determined from their body weight change and from their plasma lipid levels. Meanwhile, HSE treatment reduced fat accumulation in the livers of hamsters fed with HFD in a concentration-dependent manner. Administration of HSE reduced the levels of liver cholesterol and triglycerides, which were elevated by HFD. Analysis of the effect of HSE on paraoxonase 1, an antioxidant liver enzyme, revealed that HSE potentially regulates lipid peroxides and protects organs from oxidation-associated damage. The markers of liver damage such as serum alanine aminotransferase and aspartate aminotransferase levels that were elevated by HFD were also reduced on HSE treatment. The effects of HSE were as effective as treatment with anthocyanin; therefore the anthocyanins present in the HSE may play a crucial role in the protection established against HFD-induced obesity. Conclusions In conclusion HSE administration constitutes an effective and viable treatment strategy against the development and consequences of obesity. PMID:26475512

  4. 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…

  5. FATE OF INHALED FLY ASH IN HAMSTERS

    EPA Science Inventory

    To determine pulmonary deposition, translocation, and clearance of inhaled fly ash, hamsters received a single 95-min nose-only exposure to neutron-activated fly ash. Over a period of 99 days postexposure, the hamsters were sacrificed in groups of six animals. Lungs, liver, kidne...

  6. Follicular growth and intraovarian and extraovarian oocyte release after daily injections of melatonin and 6-chloro-melatonin in the Syrian hamster.

    PubMed

    Spanel-Borowski, K; Richardson, B A; King, T S; Petterborg, L J; Reiter, R J

    1983-07-01

    Groups of adult female Syrian hamsters (Mesocricetus auratus) were injected daily at 17:00 hr with 2.5, 15, or 25 micrograms of melatonin (Mel) or 6-chloro-melatonin (Cl-Mel) for 12 weeks. An ovary from each animal was completely serially sectioned for light microscopic investigation. Judging from the presence of corpora lutea, there were some animals in each group that continued to cycle, although the postestrous, white mucous discharge had disappeared. Noncycling animals were most often found in the 25-micrograms group of Cl-Mel. Only uterine weights of noncycling animals treated with either 25 or 15 micrograms of Mel or Cl-Mel were statistically significantly depressed versus controls. Cl-Mel (25 micrograms) significantly suppressed the total number and size of antral follicles (P less than 0.05). Follicular ruptures with incomplete or complete release of the oocyte out of the follicular compartment were observed. The oocyte release occurred either into the ovary ("intraovarian oocyte release: IOR") or outside of the ovary ("extraovarian oocyte release: EOR"). Compared with controls, the total number of IOR was increased in all experimental groups with the exception of the 2.5-micrograms group of Cl-Mel. IOR appeared in both preantral and antral follicles, and often IOR was complete. In controls, only preantral follicles were involved in IOR; these were primarily incomplete ones. IOR was seen in cycling and noncycling animals. By contrast, EOR was exclusively observed in noncycling hamsters. It is concluded that the cessation of postestrous, white mucous discharge is not necessarily an index for a halt in cyclic ovarian function. Injections of 25 micrograms of Cl-Mel are more effective than 25 micrograms of Mel in suppressing ovarian function. Both Mel and Cl-Mel increase the frequency of IOR. Finally, noncycling hamsters show EOR that is regarded as an abnormal ovulation. PMID:6683925

  7. Induction of lyme arthritis in LSH hamsters

    SciTech Connect

    Schmitz, J.L.; Schell, R.F.; Hejka, A.; England, D.M.; Konick, L.

    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 were 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.

  8. Spontaneous endomyometrial neoplasms in aging Chinese hamsters

    SciTech Connect

    Brownstein, D.G.; Brooks, A.L.

    1980-05-01

    Twenty-one endomyometrial neoplasms among 93 nulliparous noninbred Chinese hamsters were evaluated. The median survival time of the 93 females was 1040 days. The median age of hamsters with endomyometrial neoplasms was 1200 days. Neoplasms were classified as carcinomas or malignant mixed muellerian tumors of the endometrium and benign or malignant myometrial neoplasms. There were 13 endometrial adenocarcinomas. Three tumors were mixed adenosquamous carcinomas, which occurred in significantly older Chinese hamsters than did adenocarcinomas. Three malignant mixed muellerian tumors consisted of 2 carcinosarcomas and 1 mixed mesodermal tumor. The 2 myometrial neoplasms were a lelomyoma and a lelomyosarcoma. The classification and relative frequency of these neoplasms were similar to endomyometrial neoplasms of women, which makes Chinese hamsters useful subjects for studies of spontaneous endomyometrial cancers.

  9. Excitatory/inhibitory equilibrium of the central amygdala nucleus gates anti-depressive and anxiolytic states in the hamster.

    PubMed

    Alò, Raffaella; Avolio, Ennio; Mele, Maria; Storino, Francesca; Canonaco, Alessia; Carelli, Antonio; Canonaco, Marcello

    2014-03-01

    Several studies have pointed to the amygdala as a main limbic station capable of regulating different stressful states such as anxiety and depression. In this work it was our intention to determine the role of the central amygdala nucleus (CeA) on the execution of either anxiolytic and/or anti-depressant behaviors in the hibernating hamster (Mesocricetus auratus) via infusion of CeA with the antagonist, 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) specific for α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR) plus the specific agonist for α4 GABAAR i.e. 4,5,6,7-tetrahydroisoxazolo(5,4-c)pyridin-3-ol (THIP). Treatment with CNQX appeared to mainly prompt anti-depressant effects as shown by the achievements of swimming feats during forced swim test while THIP prevalently accounted for evident bouts of climbing when exposed to the same test. Moreover, even in the presence of the concomitant administration of both of these compounds, hamsters continued to spend more time in swimming despite this significant behavioral effect resulted to be numerically reduced for hamsters treated with only the α4 GABAAR agonist. Conversely, when these animals were tested in elevated plus maze (EPM), THIP tended to mostly favor anxiolytic activities as exhibited by stressed animals spending more time entering and remaining in EPM open arms. It was interesting to note that behavioral changes induced by both drugs appeared to be also responsible for glutamate receptor (GluR) expression differences as indicated by CNQX favoring an evident up-regulation of GluR2-containing neurons whereas THIP induced an up-regulation, this time of GluR1-containing neurons. Overall, the anti-depressant role of CNQX seems to be mostly attributed to elevated GluR2 levels while an anxiolytic-like effect of THIP was correlated to high GluR1values thereby proposing distinct GluRs as useful therapeutic sites against degenerative diseases such as depression-like behaviors. PMID:24468014

  10. SV40 lymphomagenesis in Syrian golden hamsters

    PubMed Central

    McNees, Adrienne L.; Vilchez, Regis A.; Heard, Tiffany C.; Sroller, Vojtech; Wong, Connie; Herron, Alan J.; Hamilton, Mary J.; Davis, William C.; Butel, Janet S.

    2013-01-01

    Simian virus 40 (SV40) isolates differ in oncogenic potential in Syrian golden hamsters following intraperitoneal inoculation. Here we describe the effect of intravenous exposure on tumor induction by SV40. Strains SVCPC (simple regulatory region) and VA45-54(2E) (complex regulatory region) were highly oncogenic following intravenous inoculation, producing a spectrum of tumor types. Three lymphoma cell lines were established; all expressed SV40 T-antigen, were immortalized for growth in culture, and were tumorigenic following transplantation in vivo. New monoclonal antibodies directed against hamster lymphocyte surface antigens are described. The cell lines expressed MHC class II and macrophage markers and were highly phagocytic, indicating a histiocytic origin. Many hamsters that remained tumor-free developed SV40 T-antigen antibodies, suggesting that viral replication occurred. This study shows that route of exposure influences the pathogenesis of SV40-mediated carcinogenesis, that SV40 strain VA45-54(2E) is lymphomagenic in hamsters, that hamster lymphoid cells of histiocytic origin can be transformed in vivo and established in culture, and that reagents to hamster leukocyte differentiation molecules are now available. PMID:19038412

  11. Up-regulation of an extracellular superoxide dismutase-like activity in hibernating hamsters subjected to oxidative stress in mid- to late arousal from torpor.

    PubMed

    Okamoto, Iwao; Kayano, Tohru; Hanaya, Toshiharu; Arai, Shigeyuki; Ikeda, Masao; Kurimoto, Masashi

    2006-09-01

    Torpor-arousal cycles, one of the inherent features in hibernators, are associated with a rapid increase in body temperature and respiration, and it would lead to elevation of reactive oxygen species (ROS) generation. However, hibernators apparently tolerate this oxidative stress. We have observed in Syrian hamsters (Mesocricetus auratus) a maximal temperature shift and respiratory rate in mid- to late arousal (16-33 degrees C rectal temperature) from torpor. To examine plasma antioxidant status during arousal, we studied total superoxide radical-scavenging activity in plasma by electron spin resonance. The superoxide radical-scavenging activity reached a maximum at 32 degrees C, coincident with a peak in plasma uric acid levels, a ROS generation indicator. The up-regulated activity at 32 degrees C was attributable to the peak of the activity eluted at 260-kDa on gel-filtration chromatography, but was not to small antioxidant molecules such as ascorbate and alpha-tocopherol. The activity eluted at 260-kDa increased 3-fold at 32 degrees C compared with that of the torpid state, and was not detected either at 6 h after the onset of arousal or in the euthermic state. Moreover, the activity exhibited extracellular SOD-like properties: its induction in plasma by heparin injection and its affinity for heparin. Our results suggest that the 260-kDa extracellular SOD-like activity plays a role in the tolerance for the oxidative stress during arousal from torpor. PMID:16807121

  12. Histopathology of Lyme arthritis in LSH hamsters

    SciTech Connect

    Hejka, A.; Schmitz, J.L.; England, D.M.; Callister, S.M.; Schell, R.F.

    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 was 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.

  13. Human follicular fluid adverses hamster spermatozoa motility.

    PubMed

    Wetzels, A; Goverde, H J; Bastiaans, L A; Rolland, R

    1989-01-01

    To determine the optimal conditions for in vitro spermatozoa vitality, human and hamster spermatozoa were incubated at 37 degrees C in T6 medium supplemented with different biologic fluids (10% v/v). The fluids tested were human serum (HUS), hamster serum (HAS), and human follicular fluid (HUF). After incubation the spermatozoa were investigated for their qualitative and quantitative motility. Human spermatozoa maintained a good vitality in all fluids tested (approximately 25% motility after 18-h incubation). The hamster spermatozoa had after an incubation of 4 h a motility of 28.4% in HUS, 14.2% in HAS, and 2.2% in HUF. The quality of the motility was also extremely low in HUF, whereas it was adequate in HUS and in HAS. The presence of species-specific substances in mammalian follicular fluid is discussed. PMID:2589906

  14. Cell killing and mutation induction on Chinese hamster cells by photoradiations

    SciTech Connect

    Lam, C.K.C.

    1982-11-01

    Applying radiation directly on cells, far-uv is more effective than black light, and black light is more effective than white light in inducing proliferative death and in inducing resistance to 6-thioguanine (6-TG), ouabain and diptheria toxin (DT). Gold light has no killing and mutagenic effects on CHO (Chinese hamster ovary) cells. Use of filters showed that a small percentage of shorter wavelengths in the far-uv region is responsible for most of the killing and mutagenic effects in the unfiltered broad spectra of black and white light.

  15. Identification of the Syrian hamster cardiomyopathy gene.

    PubMed

    Nigro, V; Okazaki, Y; Belsito, A; Piluso, G; Matsuda, Y; Politano, L; Nigro, G; Ventura, C; Abbondanza, C; Molinari, A M; Acampora, D; Nishimura, M; Hayashizaki, Y; Puca, G A

    1997-04-01

    The BIO14.6 hamster is a widely used model for autosomal recessive cardiomyopathy. These animals die prematurely from progressive myocardial necrosis and heart failure. The primary genetic defect leading to the cardiomyopathy is still unknown. Recently, a genetic linkage map localized the cardiomyopathy locus on hamster chromosome 9qa2.1-b1, excluding several candidate genes. We now demonstrate that the cardiomyopathy results from a mutation in the delta-sarcoglycan gene that maps to the disease locus. This mutation was completely coincident with the disease in backcross and F2 pedigrees. This constitutes the first animal model identified for human sarcoglycan disorders. PMID:9097966

  16. Congenital Transmission of Experimental Leishmaniasis in a Hamster Model

    PubMed Central

    Osorio, Yaneth; Rodriguez, Luz D.; Bonilla, Diana L.; Peniche, Alex G.; Henao, Hector; Saldarriaga, Omar; Travi, Bruno L.

    2012-01-01

    Little information is available on transplacental transmission of Leishmania spp. We determined the frequency and impact of congenital infection caused by Leishmania panamensis or L. donovani in experimentally infected hamsters. A polymerase chain reaction showed that congenital transmission occurred in 25.8% (24 of 93) of offspring born to L. panamensis-infected hamsters and 14.6% (11 of 75) offspring born to L. donovani-infected hamsters. Mortality during lactation was higher in offspring born to L. panamensis-infected hamsters and offspring born to L. donovani-infected hamsters than controls, and lymphoproliferation to Leishmania was more frequent in offspring born to L. panamensis-infected hamsters (17.4%, 11 of 63) than in offspring born to L. donovani-infected hamsters (8.5%, 3 of 35). After weaning, only offspring born to L. donovani-infected hamsters had lower weight gain (P < 0.001) and hematocrit levels (P = 0.0045) than controls. Challenge of offspring born to L. panamensis-infected hamsters with L. panamensis showed no differences in lesion evolution, and offspring born to L. donovani-infected hamsters were more susceptible to L. donovani challenge than controls. Consequently, prenatal exposure of hamsters to L. donovani significantly increased the mortality risk and susceptibility to secondary homologous infection. PMID:22556079

  17. 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...

  18. Molecular and immunological characterization of the first allergenic lipocalin in hamster: the major allergen from Siberian hamster (Phodopus sungorus).

    PubMed

    Torres, José Alberto; de Las Heras, Manuel; Maroto, Aroa Sanz; Vivanco, Fernando; Sastre, Joaquín; Pastor-Vargas, Carlos

    2014-08-22

    The most frequent pet allergy is to cat and dog, but in recent years, it has become increasingly popular to have other pets, and the risk of exposure to new allergens is more prevalent. The list of new pets includes hamsters, and one of the most popular hamsters is the Siberian hamster (Phodopus sungorus). The aim of this study was the characterization and cloning of the major allergen from this hamster. The study of its allergenicity and cross-reactivity could improve the specific diagnosis and treatment for hamster-allergic patients. Thirteen Siberian hamster-allergic patients were recruited at the outpatient clinic. Protein extracts were prepared from the hair, urine, and salivary glands of four hamster species (European, golden, Siberian, and Roborovski). IgE-binding proteins were detected by immunoblotting and identified by mass spectrometry. The recombinant protein was produced in Escherichia coli and then purified by metal chelate affinity chromatography. The allergenic properties of the recombinant protein were tested by ELISA and immunoblotting, and biological activity was tested according to capacity for basophil activation. Three IgE-binding proteins were identified in extracts obtained from Siberian hamster hair, urine, and salivary glands. All proteins corresponded to the same protein, which was identified as a lipocalin. This lipocalin had no cross-reactivity with common and golden hamsters. The recombinant allergen was cloned and purified, showing similar IgE reactivity in vitro to Siberian hamster protein extracts. Also, the recombinant allergen was capable of producing biological activation in vivo. The major Siberian hamster allergen was cloned, and allergenic properties were characterized, providing a new tool for specific diagnosis of allergy to Siberian hamster. PMID:24993820

  19. Gold Coating

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Epner Technology Inc. responded to a need from Goddard Space Flight Center for the ultimate in electroplated reflectivity needed for the Mars Global Surveyor Mars Orbiter Laser Altimeter (MOLA). Made of beryllium, the MOLA mirror was coated by Epner Technology Laser Gold process, specially improved for the project. Improved Laser Gold- coated reflectors have found use in an epitaxial reactor built for a large semiconductor manufacturer as well as the waveguide in Braun-Thermoscan tympanic thermometer and lasing cavities in various surgical instruments.

  20. Transformation of Hamster Embryo Cells and Tumor Induction in Newborn Hamsters by Simian Adenovirus SV11

    PubMed Central

    Casto, Bruce C.

    1969-01-01

    Simian adenovirus, SV11, readily transformed hamster embryo cell cultures in vitro and produced tumors in vivo when inoculated into newborn hamsters. Foci consisting of small, loosely attached, rounded cells could be seen as early as 7 days postinoculation. Many of these cells contained several nuclei or the nucleus was multilobed. The cells grew without extensive cell to cell contact or formed small chains or clusters when passaged in vitro. This pattern of cell morphology and growth has not been reported with other simian or human adenovirus-transformed cells. Linearity of foci formation with virus dilution was observed when the virus multiplicity was less than 3 plaque-forming units (PFU)/cell. The PFU to focus-forming units ratio for SV11 was found to be 2 × 104 to 4 × 104, which is approximately 5- to 10-fold and 50- to 100-fold lower than those reported for simian adenovirus, SA7, and human adenovirus type 12, respectively. Cells transformed by SV11: (i) produced tumors when inoculated into young hamsters, (ii) contained tumor antigen which reacts with serum obtained from hamsters bearing SV11 passaged tumors, and (iii) could be propagated in vitro through an indefinite number of generations. Images PMID:5786181

  1. 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 for 20-120 min and then microinjected into hamster oocytes to determine whether they could decondense and develop into pronucl...

  2. 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...

  3. Activation of 5-HT2a receptors in the basolateral amygdala promotes defeat-induced anxiety and the acquisition of conditioned defeat in Syrian hamsters.

    PubMed

    Clinard, Catherine T; Bader, Lauren R; Sullivan, Molly A; Cooper, Matthew A

    2015-03-01

    Conditioned defeat is a model in Syrian hamsters (Mesocricetus auratus) in which normal territorial aggression is replaced by increased submissive and defensive behavior following acute social defeat. The conditioned defeat response involves both a fear-related memory for a specific opponent as well as anxiety-like behavior indicated by avoidance of novel conspecifics. We have previously shown that systemic injection of a 5-HT2a receptor antagonist reduces the acquisition of conditioned defeat. Because neural activity in the basolateral amygdala (BLA) is critical for the acquisition of conditioned defeat and BLA 5-HT2a receptors can modulate anxiety but have a limited effect on emotional memories, we investigated whether 5-HT2a receptor modulation alters defeat-induced anxiety but not defeat-related memories. We injected the 5-HT2a receptor antagonist MDL 11,939 (0 mM, 1.7 mM or 17 mM) or the 5-HT2a receptor agonist TCB-2 (0 mM, 8 mM or 80 mM) into the BLA prior to social defeat. We found that injection of MDL 11,939 into the BLA impaired acquisition of the conditioned defeat response and blocked defeat-induced anxiety in the open field, but did not significantly impair avoidance of former opponents in the Y-maze. Furthermore, we found that injection of TCB-2 into the BLA increased the acquisition of conditioned defeat and increased anxiety-like behavior in the open field, but did not alter avoidance of former opponents. Our data suggest that 5-HT2a receptor signaling in the BLA is both necessary and sufficient for the development of conditioned defeat, likely via modulation of defeat-induced anxiety. PMID:25458113

  4. Activation of 5-HT2a Receptors in the Basolateral Amygdala Promotes Defeat-Induced Anxiety and the Acquisition of Conditioned Defeat in Syrian Hamsters

    PubMed Central

    Clinard, Catherine T.; Bader, Lauren R.; Sullivan, Molly A.; Cooper, Matthew A.

    2014-01-01

    Conditioned defeat is a model in Syrian hamsters (Mesocricetus auratus) in which normal territorial aggression is replaced by increased submissive and defensive behavior following acute social defeat. The conditioned defeat response involves both a fear-related memory for a specific opponent as well as anxiety-like behavior indicated by avoidance of novel conspecifics. We have previously shown that systemic injection of a 5-HT2a receptor antagonist reduces the acquisition of conditioned defeat. Because neural activity in the basolateral amygdala (BLA) is critical for the acquisition of conditioned defeat and BLA 5-HT2a receptors can modulate anxiety but have a limited effect on emotional memories, we investigated whether 5-HT2a receptor modulation alters defeat-induced anxiety but not defeat-related memories. We injected the 5-HT2a receptor antagonist MDL 11,939 (0 mM, 1.7 mM or 17 mM) or the 5-HT2a receptor agonist TCB-2 (0 mM, 8 mM or 80 mM) into the BLA prior to social defeat. We found that injection of MDL 11,939 into the BLA impaired acquisition of the conditioned defeat response and blocked defeat-induced anxiety in the open field, but did not significantly impair avoidance of former opponents in the Y-maze. Furthermore, we found that injection of TCB-2 into the BLA increased the acquisition of conditioned defeat and increased anxiety-like behavior in the open field, but did not alter avoidance of former opponents. Our data suggest that 5-HT2a receptor signaling in the BLA is both necessary and sufficient for the development of conditioned defeat, likely via modulation of defeat-induced anxiety. PMID:25458113

  5. Peroral Echinococcus multilocularis egg inoculation in Myodes glareolus, Mesocricetus auratus and Mus musculus (CD-1 IGS and C57BL/6j).

    PubMed

    Woolsey, Ian David; Jensen, Per Moestrup; Deplazes, Peter; Kapel, Christian Moliin Outzen

    2016-08-01

    Echinococcus multilocularis transmission predominantly occurs in Europe between the red fox (Vulpes vulpes) and various species of rodent intermediate hosts. We infected 3 species of rodent, Myodes glareolus (n = 47), Mesocricetus auratus (n = 11) and outbred Mus musculus (CD-1 IGS) (n = 9) with an E. multilocularis egg suspension that contained 100 eggs with viable oncospheres and performed post mortem examination 6, 8 (M. glareolus) and 10 weeks post inoculation (wpi). C57BL/6j mice (n = 4) were used as positive controls as they have been shown to exhibit macroscopic liver lesions 4 wpi. To the best of our knowledge, this is the first study to experimentally assess susceptibility in the ostensibly competent host M. glareolus. Lesions were only detected in 2 of 47 M. glareolus (4.3%) at 8 and 10 wpi and although both contained protoscolices (1675 at 8 wpi and 88 at 12 wpi) the low percentage of infected animals brings into question their role as transmitters of the parasite. Significant differences were observed between inbred and outbred mice with E. multilocularis infection in the former demonstrating increased establishment (p ≤ 0.0001) and growth (p ≤ 0.0001). No lesions were found in all 11 M. auratus. PMID:27330986

  6. Gold liposomes

    SciTech Connect

    Hainfeld, J.F.

    1996-12-31

    Lipids are an important class of molecules, being found in membranes, HDL, LDL, and other natural structures, serving essential roles in structure and with varied functions such as compartmentalization and transport. Synthetic liposomes are also widely used as delivery and release vehicles for drugs, cosmetics, and other chemicals; soap is made from lipids. Lipids may form bilayer or multilammellar vesicles, micelles, sheets, tubes, and other structures. Lipid molecules may be linked to proteins, carbohydrates, or other moieties. EM study of this essential ingredient of life has lagged, due to lack of direct methods to visualize lipids without extensive alteration. OsO4 reacts with double bonds in membrane phospholipids, forming crossbridges. This has been the method of choice to both fix and stain membranes, thus far. An earlier work described the use of tungstate clusters (W{sub 11}) attached to lipid moieties to form lipid structures and lipid probes. With the development of gold clusters, it is now possible to covalently and specifically link a dense gold sphere to a lipid molecule; for example, reacting a mono-N-hydroxysuccinimide Nanogold cluster with the amino group on phosphatidyl ethanolaminine. Examples of a gold-fatty acid and a gold-phospholipid are shown.

  7. 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

  8. Is It Real Gold?

    ERIC Educational Resources Information Center

    Harris, Harold H.

    1999-01-01

    Features acid tests for determining whether jewelry is "real" gold or simply gold-plated. Describes the carat system of denoting gold content and explains how alloys are used to create various shades of gold jewelry. Addresses the question of whether gold jewelry can turn a wearer's skin green by considering various oxidation reactions. (WRM)

  9. 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.

  10. Rice bran oil and oryzanol reduce plasma lipid and lipoprotein cholesterol concentrations and aortic cholesterol ester accumulation to a greater extent than ferulic acid in hypercholesterolemic hamsters.

    PubMed

    Wilson, Thomas A; Nicolosi, Robert J; Woolfrey, Benjamin; Kritchevsky, David

    2007-02-01

    Our laboratory has reported that the hypolipidemic effect of rice bran oil (RBO) is not entirely explained by its fatty acid composition. Because RBO has a greater content of the unsaponifiables, which also lower cholesterol compared to most vegetable oils, we wanted to know whether oryzanol or ferulic acid, two major unsaponifiables in RBO, has a greater cholesterol-lowering activity. Forty-eight F(1)B Golden Syrian hamsters (Mesocricetus auratus) (BioBreeders, Watertown, MA) were group housed (three per cage) in cages with bedding in an air-conditioned facility maintained on a 12-h light/dark cycle. The hamsters were fed a chow-based hypercholesterolemic diet (HCD) containing 10% coconut oil and 0.1% cholesterol for 2 weeks, at which time they were bled after an overnight fast (16 h) and segregated into 4 groups of 12 with similar plasma cholesterol concentrations. Group 1 (control) continued on the HCD, group 2 was fed the HCD containing 10% RBO in place of coconut oil, group 3 was fed the HCD plus 0.5% ferulic acid and group 4 was fed the HCD plus 0.5% oryzanol for an additional 10 weeks. After 10 weeks on the diets, plasma total cholesterol (TC) and non-high-density lipoprotein cholesterol (HDL-C) (very low- and low-density lipoprotein) concentrations were significantly lower in the RBO (-64% and -70%, respectively), the ferulic acid (-22% and -24%, respectively) and the oryzanol (-70% and -77%, respectively) diets compared to control. Plasma TC and non-HDL-C concentrations were also significantly lower in the RBO (-53% and -61%, respectively) and oryzanol (-61% and -70%, respectively) diets compared to the ferulic acid. Compared to control and ferulic acid, plasma HDL-C concentrations were significantly higher in the RBO (10% and 20%, respectively) and oryzanol (13% and 24%, respectively) diets. The ferulic acid diet had significantly lower plasma HDL-C concentrations compared to the control (-9%). The RBO and oryzanol diets were significantly lower for

  11. NEONATAL CHIORDECONE EXPOSURE ALTERS BEHAVIORAL SEX DIFFERENTIATION IN FEMALE HAMSTERS

    EPA Science Inventory

    The present study was designed in order to determine if exposure to the weakly estrogenic pesticide Chlordecone during a critical period of behavioral sex differentiation of the brain could masculinize and defeminize the behavior of female hamsters.

  12. 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. PMID:27215346

  13. Evidence for a metabolic limitation of survival in hypothermic hamsters.

    NASA Technical Reports Server (NTRS)

    Prewitt, R. L.; Anderson, G. L.; Musacchia, X. J.

    1972-01-01

    The underlying factors limiting survival in the hypothermic state are studied. Hamsters of both sexes, clipped and unclipped, were inducted into profound hypothermia by the helium cold method until they reached a temperature between 7 and 10 C. It appears that the primary cause of death is failure of respiration due to the depletion of carbohydrate energy supplies and may explain why survival time in hypothermia is shorter than the normal hibernation time of the hamster.

  14. Regulation of tonic gonadotropin release in prepubertal female hamsters

    SciTech Connect

    Smith, S.G.; Matt, K.S.; Prestowitz, W.F.; Stetson, M.H.

    1982-04-01

    Basal serum gonadotropin levels were monitored weekly in female hamsters from birth to 10 weeks of age. Hamsters raised on three different photoperiods presented uniform pre- and postpubertal patterns of serum LH and FSH, suggesting that gonadotropin release in the young hamster occurs independently of ambient photoperiod. In all groups, serum LH levels increased gradually in animals up to 4 weeks of age, after which levels plateaued at 50--100 ng/ml. Serum FSH was markedly elevated in 2- and 3-week-old hamsters (800--1200 ng/ml), but remained at 200--400 ng/ml in all other groups. We next examined the change in the responsiveness of the pituitary to exogenous gonadotropin-releasing hormone (GnRH) challenge. Female hamsters 2 days of age failed to respond to any dose (0.025--1000 ng) of GnRH, while 10-day old females responded in typical dose-dependent fashion. GnRH-stimulated LH release first occurred in 6-day-old hamsters and was maximal by day 9, whereas FSH release first occurred on day 8 and was maximal by day 9. The prepubertal pattern of gonadotropin release can, in part, be explained on the basis of the development of pituitary GnRH sensitivity, which occurs independently of photoperiod.

  15. Regulation of hamster splenocyte reactivity to concanavalin A during pregnancy

    SciTech Connect

    Weppner, W.A.; Coggin, J.H. Jr.

    1980-08-15

    The survival to term of mammalian fetuses regardless of their expression of paternal or embryonic developmental antigens suggests that some alteration in the immune capabilities of a female occur during pregnancy. The immunocompetence of female Syrian golden hamsters during pregnancy was investigated with respect to the blastogenic response of spleen cells to the T-cell mitogen concanavalin A (Con A). The blastogenic response of spleen cells from pregnant hamsters during mid- or late gestation is 10% of that observed for spleen cells from age-matched, virgin female animals. The spleen cells from pregnant hamsters are not capable of suppressing the proliferative response of spleen cells from virgin females to Con A. However, the serum from pregnant hamsters, in comparison with serum from virgin female animals, is capable of reducing this mitogenic response. Extensive washing of the splenocytes from pregnant hamsters does reduce the degree of suppression. These results suggest that the hamster is an excellent animal model for the investigation of the mechanism(s) of immune regulation that operate during pregnancy.

  16. Differential effects of glucocorticoids on energy homeostasis in Syrian hamsters.

    PubMed

    Solomon, Matia B; Sakai, Randall R; Woods, Stephen C; Foster, Michelle T

    2011-08-01

    Syrian hamsters, like many humans, increase food intake and body adiposity in response to stress. We hypothesized that glucocorticoids (cortisol and corticosterone) mediate these stress-induced effects on energy homeostasis. Because Syrian hamsters are dual secretors of cortisol and corticosterone, differential effects of each glucocorticoid on energy homeostasis were investigated. First, adrenal intact hamsters were injected with varying physiological concentrations of cortisol, corticosterone, or vehicle to emulate our previously published defeat regimens (i.e., 1 injection/day for 5 days). Neither food intake nor body weight was altered following glucocorticoid injections. Therefore, we investigated the effect of sustained glucocorticoid exposure on energy homeostasis. This was accomplished by implanting hamsters with supraphysiological steady-state pellets of cortisol, corticosterone, or cholesterol as a control. Cortisol, but not corticosterone, significantly decreased food intake, body mass, and lean and fat tissue compared with controls. Despite decreases in body mass and adiposity, cortisol significantly increased circulating free fatty acids, triglyceride, cholesterol, and hepatic triglyceride concentrations. Although corticosterone did not induce alterations in any of the aforementioned metabolic end points, Syrian hamsters were responsive to the effects of corticosterone since glucocorticoids both induced thymic involution and decreased adrenal mass. These findings indicate that cortisol is the more potent glucocorticoid in energy homeostasis in Syrian hamsters. However, the data suggest that cortisol alone does not mediate stress-induced increases in food intake or body mass in this species. PMID:21540447

  17. Weather entrainment and multispectral diel activity rhythm of desert hamsters.

    PubMed

    Wan, Xinrong; Zhang, Xinjie; Huo, Yingjun; Wang, Guiming

    2013-10-01

    The circadian rhythm of animals is an adaptation to predictable variation in environmental conditions. Multiple internal oscillators may allow animals to cope with environmental oscillations in different frequencies. Heat stress and dramatic differences between night and day temperatures are the main selective pressures of the diel activity of desert mammals, particularly small-sized rodents. We tested the hypotheses that the diel activities of desert hamsters (Phodopus roborovskii) would be entrained by ambient humidity and temperature. We predicted that increases in night temperature and humidity would improve the propensity to perform activities of the hamster. We observed hourly activities of desert hamsters under semi natural conditions for 24 consecutive hours, with seven replicates in 7 different days. We fit generalized linear mixed models to observed proportions of active hamsters, temperatures, and relative humidity. Observed diel activities of desert hamsters consisted of three harmonic oscillations in the periodicities of 24 h, 12 h, and 6 h, respectively. Furthermore, probabilities to perform activities were positively related to night temperature and humidity. Therefore, the diel activities of desert hamsters are synchronized by atmospheric humidity, temperatures, and environmental cues of ultradian fluctuations. PMID:23810901

  18. Suppression of hamster lymphocyte reactivity to simian virus 40 tumor surface antigens by spleen cells from pregnant hamsters

    SciTech Connect

    Weppner, W.A.; Adkinson, L.R.; Coggin, J.H.Jr

    1980-09-01

    SV40-transformed tumor cells in hamsters have been found to have cell surface antigens cross-reactive with antigens temporally expressed on fetal tissues. Using a lymphocyte transformation assay, spleen cells from pregnant hamsters were found to be incapable of responding to preparations of either hamster fetal tissue or SV40-transformed cells. However, a suppressor component can be demonstrated in spleen cell populations of both primi-and multiparous hamsters during pregnancy that is capable of reducing the response of lymphocytes sensitized against SV40 tumor-associated antigens. The degree of suppression is proportional to the ratio of responder cells to spleen cells from pregnant animals. These results suggest there is a subpopulation of spleen cells involved in immunoregulation during pregnancy that has the ability to suppress the reactivity of lymphocytes sensitized against SV40-associated oncofetal antigens.

  19. Copulatory and agonistic behavior in Syrian hamsters following social defeat.

    PubMed

    Jeffress, Elizabeth C; Huhman, Kim L

    2013-01-01

    Syrian hamsters are highly aggressive animals that reliably defend their home territory. After social defeat, however, hamsters no longer defend their home cage but instead display submissive and defensive behavior toward an intruder, a response that we have termed conditioned defeat. Plasma testosterone is significantly reduced in Syrian hamsters following repeated defeat suggesting that social defeat might also impair copulatory behavior. The present study aimed to determine whether copulatory behavior in male Syrian hamsters is suppressed following repeated social defeats and additionally whether exposure to a hormone-primed stimulus female after social defeat reduces the behavioral response to defeat. Hamsters were paired with an aggressive opponent for one or nine defeats using a resident-intruder model, while controls were placed into the empty cage of a resident aggressor. On the day after the last treatment, half of the hamsters were paired with a receptive female for 10 min. There were no significant differences in the copulatory behavior of defeated versus non-defeated hamsters, and the opportunity to copulate had no effect on subsequent conditioned defeat testing, as defeated animals displayed significantly more submissive behavior than did non-defeated animals. The current data suggest that conditioned defeat is not necessarily a maladaptive response to social stress, at least in terms of reproductive behavior, but may instead represent a viable behavioral strategy adopted by losing animals following social defeat. Further, these data indicate that conditioned defeat is relatively persistent and stable, as the opportunity to copulate does not reduce the subsequent display of submissive behavior. PMID:23382023

  20. Proteomic Analysis of Chinese Hamster Ovary Cells

    PubMed Central

    Baycin-Hizal, Deniz; Tabb, David L.; Chaerkady, Raghothama; Chen, Lily; Lewis, Nathan E.; Nagarajan, Harish; Sarkaria, Vishaldeep; Kumar, Amit; Wolozny, Daniel; Colao, Joe; Jacobson, Elena; Tian, Yuan; O'Meally, Robert N.; Krag, Sharon S.; Cole, Robert N.; Palsson, Bernhard O.; Zhang, Hui; Betenbaugh, Michael

    2013-01-01

    In order to complement the recent genomic sequencing of Chinese hamster ovary (CHO) cells, proteomic analysis was performed on CHO including the cellular proteome, secretome, and glycoproteome using tandem mass spectrometry (MS/MS) of multiple fractions obtained from gel electrophoresis, multi-dimensional liquid chromatography, and solid phase extraction of glycopeptides (SPEG). From the 120 different mass spectrometry analyses generating 682,097 MS/MS spectra, 93,548 unique peptide sequences were identified with at most a 0.02 false discovery rate (FDR). A total of 6164 grouped proteins were identified from both glycoproteome and proteome analysis, representing an 8-fold increase in the number of proteins currently identified in the CHO proteome. Furthermore, this is the first proteomic study done using CHO genome exclusively which provides for more accurate identification of proteins. From this analysis, the CHO codon frequency was determined and found to be distinct from humans, which will facilitate expression of human proteins in CHO cells. Analysis of the combined proteomic and mRNA data sets indicated the enrichment of a number of pathways including protein processing and apoptosis but depletion of proteins involved in steroid hormone and glycosphingolipid metabolism. 504 of the detected proteins included N-acetylation modifications and 1292 different proteins were observed to be N-glycosylated. This first large-scale proteomic analysis will enhance the knowledge base about CHO capabilities for recombinant expression and provide information useful in cell engineering efforts aimed at modifying CHO cellular functions. PMID:22971049

  1. Proteomic analysis of Chinese hamster ovary cells.

    PubMed

    Baycin-Hizal, Deniz; Tabb, David L; Chaerkady, Raghothama; Chen, Lily; Lewis, Nathan E; Nagarajan, Harish; Sarkaria, Vishaldeep; Kumar, Amit; Wolozny, Daniel; Colao, Joe; Jacobson, Elena; Tian, Yuan; O'Meally, Robert N; Krag, Sharon S; Cole, Robert N; Palsson, Bernhard O; Zhang, Hui; Betenbaugh, Michael

    2012-11-01

    To complement the recent genomic sequencing of Chinese hamster ovary (CHO) cells, proteomic analysis was performed on CHO cells including the cellular proteome, secretome, and glycoproteome using tandem mass spectrometry (MS/MS) of multiple fractions obtained from gel electrophoresis, multidimensional liquid chromatography, and solid phase extraction of glycopeptides (SPEG). From the 120 different mass spectrometry analyses generating 682,097 MS/MS spectra, 93,548 unique peptide sequences were identified with at most 0.02 false discovery rate (FDR). A total of 6164 grouped proteins were identified from both glycoproteome and proteome analysis, representing an 8-fold increase in the number of proteins currently identified in the CHO proteome. Furthermore, this is the first proteomic study done using the CHO genome exclusively, which provides for more accurate identification of proteins. From this analysis, the CHO codon frequency was determined and found to be distinct from humans, which will facilitate expression of human proteins in CHO cells. Analysis of the combined proteomic and mRNA data sets indicated the enrichment of a number of pathways including protein processing and apoptosis but depletion of proteins involved in steroid hormone and glycosphingolipid metabolism. Five-hundred four of the detected proteins included N-acetylation modifications, and 1292 different proteins were observed to be N-glycosylated. This first large-scale proteomic analysis will enhance the knowledge base about CHO capabilities for recombinant expression and provide information useful in cell engineering efforts aimed at modifying CHO cellular functions. PMID:22971049

  2. Influence of social dominance on self-stimulation behavior in male golden hamsters.

    PubMed

    Kureta, Y; Watanabe, S

    1996-01-01

    The effect of a socially dominant hamster on the self-stimulation behavior of the subordinate hamster was examined. After determining social ranking, six hamsters were trained to press a lever in an operant chamber in which a dominant hamster was presented over a grid wall. The threshold of rewarding effect was evaluated by using a descending series of current intensity as electrical reward. When a dominant hamster was present, the subordinate hamster showed a shift of intensity-response function to the right (higher intensity). The presence of a subordinate hamster did not influence the response in dominant hamsters. Furthermore, beta-carboline (FG-7142) (5, 10, and 20 mg/kg, IP) caused a decrease in rewarding effect in dose-dependant manner. These results suggest that the presence of a dominant animal may have caused "a state of anxiety" somewhat similar to the anxiety caused by the benzodiazepine inverse agonist. PMID:8778844

  3. Protective effect of glucan against visceral leishmaniasis in hamsters.

    PubMed Central

    Cook, J A; Holbrook, T W; Dougherty, W J

    1982-01-01

    The effect of pre- or posttreatment with glucan, a reticuloendothelial stimulant, on the course of Leishmania donovani infection was assessed in highly susceptible hamsters. Intravenous administration of glucan before or after L. donovani infection significantly suppressed proliferation of amastigote-stage parasites in liver and spleen. Glucan-activated peritoneal macrophages in vitro also significantly reduced multiplication of the intracellular parasite. Ultrastructural studies revealed a well-defined hepatic granulomatous response to glucan, with hypertrophic Kupffer cells and reduced numbers of intracellular parasites compared to the control group. In additional studies, groups of hamsters were immunized by intravenous injections of glucan with Formalin-killed promastigote-stage L. donovani cells and challenged 60 days after the last immunizing injection. This treatment regimen significantly prolonged the mean survival time of those hamsters which died after infection, relative to untreated control groups. Hamsters stimulated with the glucan-killed promastigote preparation also exhibited significant reductions in splenic amastigotes on days 10 and 21 postinfection compared with all other control groups, but on day 35, splenic amastigotes did not differ significantly from those of control animals. Our composite observations provide evidence for glucan-enhanced nonspecific resistance of hamsters to visceral leishmaniasis. Images PMID:7129637

  4. 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.

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

    SciTech Connect

    Franz, T.J.; Lehman, P.A.; Pochi, P.; Odland, G.F.; Olerud, J. )

    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 study 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.

  6. Altered behaviour in hamsters conceived and born in hypergravity.

    PubMed

    Sondag, H N; de Jong, H A; Oosterveld, W J

    1997-01-01

    We studied vestibular function in 37 hamsters (1 month old) conceived and born in either hypergravity (n = 21) or normal gravity (n = 16). Four groups were made: (1) HL group: 20 weeks in 2.5 G and 14 weeks in 1 G; (2) HS group: 4 weeks in 2.5 G and 30 weeks in 1 G; (3) CON group: 34 weeks in 1 G; and (4) ROT group: 4 weeks in 1 G, 16 weeks in rotation in 1 G, at the centre of the centrifuge and 14 weeks 1 G. When the hamsters were 4 weeks old, their locomotor activity, swimming ability, and air-righting was assessed. We found that HL and HS hamsters had no disturbances during locomotion in 1 G but their swimming ability was disturbed (swimming underwater, circling, and decreased speed of swimming). The HL hamsters showed less activity during 2.5 G and showed fewer correct air-rightings than the other groups. Differences between groups in swimming ability and the number of correct air-righting responses remained even after 3 months of normal gravity. Based on these findings, we suggest that the persistent behavioural disturbances are caused by the embryonal development of the hamsters in a hypergravity environment. Furthermore, hypergravity and rotation each have a different effect on behaviour. PMID:9227839

  7. 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...

  8. 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... pigs or hamsters contained therein; (3) the inner surfaces of corrugated fiberboard, cardboard,...

  9. 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...

  10. 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...

  11. 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

  12. Pathology of experimental Babesia microti infection in the Syrian hamster.

    PubMed

    Cullen, J M; Levine, J F

    1987-10-01

    Pathologic changes produced after 4 weeks of infection by Babesia microti in Syrian hamsters are described and compared to babesiosis of humans. Following intraperitoneal inoculation, both intravascular and extravascular hemolysis developed. Up to 70% of red blood cells were parasitized. The principal morphologic abnormalities were an increase in extramedullary hematopoiesis and hyperplasia of the mononuclear phagocytic cells of the red pulp manifested grossly as splenomegaly, marked renal tubular hemosiderosis and hypertrophy of Kupffer cells. The disease was not fatal to any hamsters during the 4 week study. The clinical signs and lesions were less severe than fatal babesiosis of asplenic humans and similar to severe, but nonfatal disease in spleen intact humans. The hamster may serve as an animal model for the studying the pathophysiology of human babesiosis and for studying potential chemotherapeutic agents. PMID:3695401

  13. Auditory deprivation modifies biological rhythms in the golden hamster.

    PubMed

    Cutrera, R; Pedemonte, M; Vanini, G; Goldstein, N; Savorini, D; Cardinali, D P; Velluti, R A

    2000-11-01

    To assess to what extent auditory sensory deprivation affects biological rhythmicity, sleep/wakefulness cycle and 24 h rhythm in locomotor activity were examined in golden hamsters after bilateral cochlear lesion. An increase in total sleep time as well as a decrease in wakefulness (W) were associated to an augmented number of W episodes, as well as of slow wave sleep (SWS) and paradoxical sleep (PS) episodes in deaf hamsters. The number of episodes of the three behavioural states and the percent duration of W and SWS increased significantly during the light phase of daily photoperiod only. Lower amplitudes of locomotor activity rhythm and a different phase angle as far as light off were found in deaf hamsters kept either under light-dark photoperiod or in constant darkness. Period of locomotor activity remained unchanged after cochlear lesions. The results indicate that auditory deprivation disturbs photic synchronization of rhythms with little effect on the clock timing mechanism itself. PMID:11116570

  14. Antibody response to rabies virus in Syrian hamsters.

    PubMed

    Coe, J E; Bell, J F

    1977-06-01

    Syrian hamsters were injected with inactivated, attenuated, and virulent rabies virus (RV), and the antibody response was quantified by a neutralization test and the immunoglobulin class of the virus antibody was characterized by indirect fluorescent microscopy. Serum antibodies to RV were found to be predominantly of the immunoglobulin G2 (IgG2) class, although IgG1 anti-RV also were detected in high-titered sera obtained after secondary challenge. Brain extracts of hamsters inoculated intracerebrally with RV contained only IgG2 anti-RV. IgA and IgM anti-RV were not detected. The preferential IgG2 response to RV is in marked contrast to the isolated IgG1 response detected after inoculation of hamsters with soluble purified protein antigens. PMID:330398

  15. Deposition of salicylic acid into hamster sebaceous.

    PubMed

    Motwani, M R; Rhein, L D; Zatz, J L

    2004-01-01

    In an earlier paper, we identified vehicles that are miscible with sebum, using differential scanning calorimetry (DSC). In this paper, the potential of these vehicles to deliver salicylic acid (SA) into the sebum-filled follicles of hamster ears is examined. The main objective of this study is to correlate the melting transitions of a model sebum with the follicular delivery of SA, using two different types of vehicles (fatty and polar). Generally, the fatty vehicles show higher deposition than the polar vehicles. Follicular delivery of salicylic acid correlates well with its solubility in the respective vehicles. This extent of deposition also shows a relationship with the effect of the vehicle on thermal behavior of the model sebum. The nature of the relationship depends on the vehicle (polar or fatty) tested. We conclude that DSC could be used to identify appropriate vehicles for drugs whose follicular delivery depends on solubility. The results also suggest that delivery into the sebaceous glands occurs by two different mechanisms, depending upon the polarity of the vehicle and the physicochemical properties of the drug. The results of these experiments are further extended to investigate follicular delivery of SA from two different types of oil-in-water emulsion formulations. From these studies we conclude that either increasing the volume of the oil phase or changing the emulsion to a water-in-oil emulsion would increase follicular deposition. Our research highlights the role of sebum, its compatibility with drug molecules, and vehicle selection in the transport of drugs into the follicles. The overall results of these experiments provide a reasonable understanding of the mechanisms underlying the transport of drugs to, and subsequently through, the sebaceous follicle. PMID:15645108

  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. Autonomic Nervous Dysfunction in Hamsters Infected with West Nile Virus

    PubMed Central

    Wang, Hong; Siddharthan, Venkatraman; Hall, Jeffery O.; Morrey, John D.

    2011-01-01

    Clinical studies and case reports clearly document that West Nile virus (WNV) can cause respiratory and gastrointestinal (GI) complications. Other functions controlled by the autonomic nervous system may also be directly affected by WNV, such as bladder and cardiac functions. To investigate how WNV can cause autonomic dysfunctions, we focused on the cardiac and GI dysfunctions of rodents infected with WNV. Infected hamsters had distension of the stomach and intestines at day 9 after viral challenge. GI motility was detected by a dye retention assay; phenol red dye was retained more in the stomachs of infected hamsters as compared to sham-infected hamsters. The amplitudes of electromygraphs (EMGs) of intestinal muscles were significantly reduced. Myenteric neurons that innervate the intestines, in addition to neurons in the brain stem, were identified to be infected with WNV. These data suggest that infected neurons controlling autonomic function were the cause of GI dysfunction in WNV-infected hamsters. Using radiotelemetry to record electrocardiograms and to measure heart rate variability (HRV), a well-accepted readout for autonomic function, we determined that HRV and autonomic function were suppressed in WNV-infected hamsters. Cardiac histopathology was observed at day 9 only in the right atrium, which was coincident with WNV staining. A subset of WNV infected cells was identified among cells with hyperplarization-activated cyclic nucleotide-gated potassium channel 4 (HCN4) as a marker for cells in the sinoatrial (SA) and atrioventricular (AV) nodes. The unique contribution of this study is the discovery that WNV infection of hamsters can lead to autonomic dysfunction as determined by reduced HRV and reduced EMG amplitudes of the GI tract. These data may model autonomic dysfunction of the human West Nile neurological disease. PMID:21573009

  19. Susceptibility of Hamsters to Clostridium difficile Isolates of Differing Toxinotype

    PubMed Central

    Buckley, Anthony M.; Spencer, Janice; Maclellan, Lindsay M.; Candlish, Denise; Irvine, June J.; Douce, Gillian R.

    2013-01-01

    Clostridium difficile is the most commonly associated cause of antibiotic associated disease (AAD), which caused ∼21,000 cases of AAD in 2011 in the U.K. alone. The golden Syrian hamster model of CDI is an acute model displaying many of the clinical features of C. difficile disease. Using this model we characterised three clinical strains of C. difficile, all differing in toxinotype; CD1342 (PaLoc negative), M68 (toxinotype VIII) & BI-7 (toxinotype III). The naturally occurring non-toxic strain colonised all hamsters within 1-day post challenge (d.p.c.) with high-levels of spores being shed in the faeces of animals that appeared well throughout the entire experiment. However, some changes including increased neutrophil influx and unclotted red blood cells were observed at early time points despite the fact that the known C. difficile toxins (TcdA, TcdB and CDT) are absent from the genome. In contrast, hamsters challenged with strain M68 resulted in a 45% mortality rate, with those that survived challenge remaining highly colonised. It is currently unclear why some hamsters survive infection, as bacterial & toxin levels and histology scores were similar to those culled at a similar time-point. Hamsters challenged with strain BI-7 resulted in a rapid fatal infection in 100% of the hamsters approximately 26 hr post challenge. Severe caecal pathology, including transmural neutrophil infiltrates and extensive submucosal damage correlated with high levels of toxin measured in gut filtrates ex vivo. These data describes the infection kinetics and disease outcomes of 3 clinical C. difficile isolates differing in toxin carriage and provides additional insights to the role of each toxin in disease progression. PMID:23704976

  20. Maternal Photoperiodic History Affects Offspring Development in Syrian Hamsters

    PubMed Central

    Beery, Annaliese K.; Paul, Matthew J.; Routman, David M.; Zucker, Irving

    2009-01-01

    During the first 7 weeks of postnatal life, short day lengths inhibit the onset of puberty in many photoperiodic rodents, but not in Syrian hamsters. In this species, timing of puberty and fecundity are independent of the early postnatal photoperiod. Gestational day length affects postnatal reproductive development in several rodents; its role in Syrian hamsters has not been assessed. We tested the hypothesis that cumulative effects of pre- and postnatal short day lengths would restrain gonadal development in male Syrian hamsters. Males with prenatal short day exposure were generated by dams transferred to short day lengths 6 weeks, 3 weeks, and 0 weeks prior to mating. Additional groups were gestated in long day lengths and transferred to short days at birth, at 4 weeks of age, or not transferred (control hamsters). In pups of dams exposed to short day treatment throughout gestation, decreased testis growth was apparent by 3 weeks and persisted through 9 weeks of age, at which time maximum testis size was attained. A subset of males (14%), whose dams had been in short days for 3 to 6 weeks prior to mating displayed pronounced delays in testicular development, similar to those of other photoperiodic rodents. This treatment also increased the percentage of male offspring that underwent little or no gonadal regression postnatally (39%). By 19 weeks of age, males housed in short days completed spontaneous gonadal development. After prolonged long day treatment to break refractoriness, hamsters that initially were classified as nonregressors underwent testicular regression in response to a 2nd sequence of short day lengths. The combined action of prenatal and early postnatal short day lengths diminishes testicular growth of prepubertal Syrian hamsters no later than the 3rd week of postnatal life, albeit to a lesser extent than in other photoperiodic rodents. PMID:18838610

  1. Isolation and identification of normal killer cells from Syrian hamsters

    SciTech Connect

    Matveeva, V.A.; Klyuchareva, T.E.

    1986-09-01

    This paper gives data on isolation of normal killer cells from the blood and various tissues of Syrian hamsters in a Percoll density gradient and their identification on the basis of morphologic criteria and cytotoxic activity (CTA). CTA of the isolated cells was studied in the cytotoxic test with target cells of a human MOLT-4 thymoma cell labeled with /sup 51/Cr. Isolation of large granular lymphocytes from blood, spleen, and bone marrow of Syrian hamsters in Percoll density gradient is shown in the results of five experiments used for cells of each type.

  2. Use of CB hamsters in the study of Treponema pertenue.

    PubMed

    Schell, R F; Le Frock, J L; Babu, J P; Chan, J K

    1979-10-01

    The CB/Ss LAK strain of inbred hamster was used as a model for studies of infection with Treponema pertenue and of acquired resistance to it. When infected, this strain developed cutaneous lesions which lasted for six to seven months, even in the presence of peak titres of antitreponemal antibody. The rate of appearance and resolution of these lesions varied with the size of the inoculum. The infected hamsters' inguinal lymph nodes increased significantly in weight and teemed with treponemes for several weeks. Animals infected for eight or 10 weeks obtained quick resolution of their lesions by treatment with penicillin and were thereafter resistant to reinfection. PMID:509189

  3. The Hamster Buccal Pouch Model of Oral Carcinogenesis.

    PubMed

    Nagini, Siddavaram; Kowshik, Jaganathan

    2016-01-01

    The hamster buccal pouch (HBP) carcinogenesis model is one of the most well-characterized animal tumor models used as a prelude to investigate multistage oral carcinogenesis and to assess the efficacy of chemointervention. Hamster buccal pouch carcinomas induced by 7,12-dimethylbenz[a]anthracene (DMBA) show extensive similarities to human oral squamous cell carcinomas. The HBP model offers a number of advantages including a simple and predictable tumor induction procedure, easy accessibility for examination and follow-up of lesions, and reproducibility. This model can be used to test both chemopreventive and chemotherapeutic agents. PMID:27246045

  4. Molecular cloning of hamster brain and atrial natriuretic peptide cDNAs. Cardiomyopathic hamsters are useful models for brain and atrial natriuretic peptides.

    PubMed Central

    Tamura, N; Ogawa, Y; Itoh, H; Arai, H; Suga, S; Nakagawa, O; Komatsu, Y; Kishimoto, I; Takaya, K; Yoshimasa, T

    1994-01-01

    Brain and atrial natriuretic peptides (BNP and ANP) are cardiac hormones with diuretic, natriuretic, and vasodilatory activities. Cardiomyopathic hamsters are widely used animal models of heart failure. Due to the structural divergence of BNP among species, examination on pathophysiological roles of BNP using cardiomyopathic hamsters is so far impossible. We therefore isolated hamster BNP and ANP cDNAs, and investigated synthesis and secretion of these peptides in normal and cardiomyopathic hamsters. The COOH-terminal 32-residue peptide of cloned hamster preproBNP with 122 amino acids, preceded by a single arginine residue, supposedly represents hamster BNP showing < 50% homology to rat BNP. Alpha-hamster ANP, 28-residue peptide, is identical to alpha-rat ANP. In hamsters, BNP and ANP occur mainly in the ventricle and the atrium, respectively. The 32-wk-old hypertrophic cardiomyopathic BIO14.6 strain exhibited ventricular hypertrophy. The 32-wk-old dilated cardiomyopathic BIO53.58 strain remained at the stage without apparent heart failure. In BIO14.6 and BIO53.58 strains at this age, ventricular BNP and ANP gene expressions are augmented, and the plasma BNP concentration is elevated to 136 and 108 fmol/ml, respectively, three times greater than the elevated plasma ANP concentration, which well mimics changes of the plasma BNP and ANP concentrations in human heart failure. Cardiomyopathic hamsters, therefore, are useful models to investigate the implication of BNP in human cardiovascular diseases. Images PMID:8083346

  5. Gold bead implants.

    PubMed

    Durkes, T E

    1992-03-01

    Gold bead implantation is an experimental area of study in the acupuncture field dealing with chronic diseases. Special acupuncture techniques are required to implant the gold beads successfully in the proper location. Gold beads are used to treat degenerative joint disease, osteochondritis, osteochondritis dessicans, ventral spondylosis, and seizures. PMID:1581658

  6. DOSE RESPONSE OF ELASTASE-INDUCED EMPHYSEMA IN HAMSTERS

    EPA Science Inventory

    Elastase-induced emhysema in hamsters was studied using pulmonary function tests in an effort to develop techniques for determining the effects of air pollutants on the progression of this disease. It appears that as little as 6 units of elastase produces mild emphysema in hamste...

  7. Hamster bite peritonitis: Pasteurella pneumotropica peritonitis in a dialysis patient.

    PubMed

    Campos, A; Taylor, J H; Campbell, M

    2000-11-01

    We report the first case of Pasteurella pneumotropica peritonitis in a peritoneal dialysis patient. This rare infection was the result of contamination of the dialysis tubing by a pet hamster. We stress the importance of household pets as a source of infection in the peritoneal dialysis population. PMID:11095007

  8. Melatonin production accompanies arousal from daily torpor in Siberian hamsters.

    PubMed

    Larkin, Jennie E; Yellon, Steven M; Zucker, Irving

    2003-01-01

    Arousal from deep hibernation is accompanied by a transient rise of melatonin (Mel) in circulation; there are no comparable analyses of Mel concentrations in species that undergo much shallower, shorter duration episodes of daily torpor. Serum Mel concentrations were determined during arousal from both natural daily torpor and torpor induced by 2-deoxy-D-glucose (2-DG) treatment (2,500 mg/kg, intraperitoneal [IP]); blood samples were drawn from the retro-orbital sinus of anesthetized Siberian hamsters. For animals kept in darkness during torpor, Mel concentrations were highest during early arousal when thermogenesis is maximal, and they decreased as body temperature increased during arousal and returned to baseline once euthermia was reestablished. In hamsters kept in the light during the torpor bout, Mel concentrations were elevated above basal values during arousal, but the response was significantly blunted in comparison with values recorded in darkness. Increased Mel concentrations were detected in hamsters only during arousal from torpor (either natural or 2-DG induced) and were not simply a result of the drug treatment; hamsters that remained euthermic or manifested mild hypothermia after drug treatment maintained basal Mel concentrations. We propose that increased Mel production may reflect enhanced sympathetic activation associated with intense thermogenesis during arousal from torpor rather than an adjustment of the circadian rhythm of Mel secretion. PMID:13130436

  9. CARCINOGENIC POTENTIAL OF ROTENONE. PHASE I: DIETARY ADMINISTRATION TO HAMSTERS

    EPA Science Inventory

    Studies were performed to evaluate the potential carcinogenicity rotenone in the Syrian Golden hamster. Several ancillary range-finding studies were carried out including 14-day feeding trials and a reproduction experiment. The latter experiment indicated that rotenone at a level...

  10. 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. PMID:26612555

  11. Genetics of Sex-linked yellow in the Syrian hamster.

    PubMed

    Alizadeh, Azita; Hong, Lewis Z; Kaelin, Christopher B; Raudsepp, Terje; Manuel, Hermogenes; Barsh, Gregory S

    2009-04-01

    Alternating patches of black and yellow pigment are a ubiquitous feature of mammalian color variation that contributes to camouflage, species recognition, and morphologic diversity. X-linked determinants of this pattern--recognized by variegation in females but not in males--have been described in the domestic cat as Orange, and in the Syrian hamster as Sex-linked yellow (Sly), but are curiously absent from other vertebrate species. Using a comparative genomic approach, we develop molecular markers and a linkage map for the euchromatic region of the Syrian hamster X chromosome that places Sly in a region homologous to the centromere-proximal region of human Xp. Comparison to analogous work carried out for Orange in domestic cats indicates, surprisingly, that the cat and hamster mutations lie in nonhomologous regions of the X chromosome. We also identify the molecular cause of recessively inherited black coat color in hamsters (historically referred to as nonagouti) as a Cys115Tyr mutation in the Agouti gene. Animals doubly mutant for Sly and nonagouti exhibit a Sly phenotype. Our results indicate that Sly represents a melanocortin pathway component that acts similarly to, but is genetically distinct from, Mc1r and that has implications for understanding both the evolutionary history and the mutational mechanisms of pigment-type switching. PMID:19189957

  12. RELATIONSHIP BETWEEN AUTONOMIC AND BEHAVIORAL THERMOREGULATION IN THE GOLDEN HAMSTER

    EPA Science Inventory

    Preferred ambient temperature (Ta) of male golden hamsters (Mesocricitus auratus) was measured repeatedly by placing the animals in a temperature gradient for 80 min. A total of 180 observations were made during the last 20 min of treatment in the gradient. The mean preferred Ta ...

  13. Genetics of Sex-linked yellow in the Syrian Hamster

    PubMed Central

    Alizadeh, Azita; Hong, Lewis Z.; Kaelin, Christopher B.; Raudsepp, Terje; Manuel, Hermogenes; Barsh, Gregory S.

    2009-01-01

    Alternating patches of black and yellow pigment are a ubiquitous feature of mammalian color variation that contributes to camouflage, species recognition, and morphologic diversity. X-linked determinants of this pattern—recognized by variegation in females but not in males—have been described in the domestic cat as Orange, and in the Syrian hamster as Sex-linked yellow (Sly), but are curiously absent from other vertebrate species. Using a comparative genomic approach, we develop molecular markers and a linkage map for the euchromatic region of the Syrian hamster X chromosome that places Sly in a region homologous to the centromere-proximal region of human Xp. Comparison to analogous work carried out for Orange in domestic cats indicates, surprisingly, that the cat and hamster mutations lie in nonhomologous regions of the X chromosome. We also identify the molecular cause of recessively inherited black coat color in hamsters (historically referred to as nonagouti) as a Cys115Tyr mutation in the Agouti gene. Animals doubly mutant for Sly and nonagouti exhibit a Sly phenotype. Our results indicate that Sly represents a melanocortin pathway component that acts similarly to, but is genetically distinct from, Mc1r and that has implications for understanding both the evolutionary history and the mutational mechanisms of pigment-type switching. PMID:19189957

  14. Seasonal aspects of sleep in the Djungarian hamster

    PubMed Central

    Palchykova, Svitlana; Deboer, Tom; Tobler, Irene

    2003-01-01

    Background Changes in photoperiod and ambient temperature trigger seasonal adaptations in the physiology and behaviour of many species, including the Djungarian hamster. Exposure of the hamsters to a short photoperiod and low ambient temperature leads to a reduction of the polyphasic distribution of sleep and waking over the light and dark period. In contrast, a long photoperiod enhances the daily sleep-wake amplitude leading to a decline of slow-wave activity in NREM sleep within the light period. It is unknown whether these changes can be attributed specifically to photoperiod and/or ambient temperature, or whether endogenous components are contributing factors. The influence of endogenous factors was investigated by recording sleep in Djungarian hamsters invariably maintained at a low ambient temperature and fully adapted to a short photoperiod. The second recording was performed when they had returned to summer physiology, despite the maintenance of the 'winter' conditions. Results Clear winter-summer differences were seen in sleep distribution, while total sleep time was unchanged. A significantly higher light-dark cycle modulation in NREM sleep, REM sleep and waking was observed in hamsters in the summer physiological state compared to those in the winter state. Moreover, only in summer, REM sleep episodes were longer and waking bouts were shorter during the light period compared to the dark period. EEG power in the slow-wave range (0.75–4.0 Hz) in both NREM sleep and REM sleep was higher in animals in the summer physiological state than in those in the 'winter' state. In winter SWA in NREM sleep was evenly distributed over the 24 h, while in summer it decreased during the light period and increased during the dark period. Conclusion Endogenous changes in the organism underlie the differences in sleep-wake redistribution we have observed previously in hamsters recorded in a short and long photoperiod. PMID:12756056

  15. Effects of pegylated hamster red blood cells on microcirculation.

    PubMed

    Chen, Peter C Y; Huang, Wei; Stassinopoulos, Adonis; Cheung, Anthony T W

    2008-01-01

    The objective of this study was to examine the effects of polyethylene glycol (PEG) treated red blood cells (RBCs) on the microcirculation in a hamster back skin window chamber model. Donor hamster RBCs were PEGylated through an incubation with an activated PEG solution, washed, resuspended, and infused through a 10% volume top loading procedure into the carotid artery in an awake Syrian Golden hamster. Eight hamster groups were treated with activated PEG different sizes and concentrations: 0.05 mM-5 kDa PEG, 0.5 mM-5 kDa PEG, 1.1 mM-5 kDa PEG, 2.2 mM-5 kDa PEG, 22 mM-5 kDa PEG, 0.05 mM-20 kDa PEG, 0.5 mM-20 kDa PEG, and 5 mM-20 kDa PEG. Non-treated RBCs were used as control. The microvascular bed under observation was videotaped 30 min before the infusion and followed for 30 min post infusion. The diameter of individual blood vessels and blood flow velocities in selected vessels was measured. Hematocrit and hemoglobin concentration were recorded before infusion and at the end of experiment. Tissue pO(2) was also monitored. Results showed the hamsters tolerated the PEGylated RBCs without apparent ill effects. No significant changes were recorded for the hematocrit, the hemoglobin concentration, the blood vessel diameters, blood flow velocities, and the interstitial partial oxygen pressure (pO(2)) before, during, and after the injections of PEG-RBCs (P > 0.05). Unlike most hemoglobin-based oxygen carrying compounds, which can cause vasoconstriction, the PEGylated RBCs did not produce any measurable vasoactivity. Together with the absence of rouleaux formation and the fact that PEG molecules can mask the surface antigens on RBCs, PEGylation appeared promising as a circulation enhancement treatment. PMID:18649167

  16. A low-cost automated apparatus for investigating the effects of social defeat in Syrian hamsters.

    PubMed

    Askew, Alicia; González, Fernando

    2014-12-01

    We describe an automated apparatus that can be used to investigate the effects of defeat in hamsters. It consists of a covered alleyway that leads to a box, or arena, where hamsters can be kept separate or allowed to fight. The alleyway is divided into seven equal-sized chambers. Low-power lasers and laser detectors are used to keep track of a hamster's position in the alleyway. A CFL flood lamp placed over the chamber farthest from the arena generates a light gradient in the alleyway that engenders in the subjects a preference for the darker chambers near the arena. A computer automatically records the interruption of the laser beams and yields three measures: average position, the frequency of visits to each chamber, and the frequency of changes in direction of travel in each chamber. The results of a pilot study indicated that when a dominant hamster was placed behind a screened gate in the arena and a subordinate hamster was placed in the alleyway, the subordinate maintained a significantly greater distance from the dominant than did a nondefeated hamster. The subordinate hamster also changed its direction of travel more frequently than did the nondefeated hamster. The results suggest that conditioned fear was elicited in the defeated hamster by proximity to the dominant hamster, an effect that is consistent with published results in which the data were recorded manually or by using commercially available event-tracking software. PMID:24519494

  17. Modification of aortic contractility in the cardiomyopathic hamster.

    PubMed Central

    Dumont, E. C.; Lambert, C.; Lamontagne, D.

    1996-01-01

    1. The functional arterial response in the cardiomyopathic hamster compared with inbred control, was investigated in thoracic aortae. For this purpose, vessels were cut into 6-mm rings and mounted in 20-ml organ baths. 2. In a first experimental series, the function of the endothelium was evaluated. Dose-response curves to acetylcholine (0.1 nM-10 microM) on phenylephrine (0.3 microM)-preconstricted rings of cardiomyopathic hamsters and inbred age-matched controls were comparable (log[EC50] of -7.08 +/- 0.12 and -7.18 +/- 0.12, respectively; n = 4). 3. Changes in contractility of cardiomyopathic hamster endothelium-denuded aortae were investigated. Dose-response curves to phenylephrine (1 nM-0.1 mM), angiotensin II (10 pM-0.3 microM), 5-hydroxytryptamine (5-HT) (1 nM-0.1 mM) and KCl (1 mM-0.1 M) were performed. Increased sensitivity in cardiomyopathic hamster aortae, compared to controls, was observed with phenylephrine (log[EC50] of -7.25 +/- 0.05 and -6.83 +/- 0.05, respectively, n = 6, P < 0.001) and angiotensin II (log[EC50] of -8.67 +/- 0.07 and -8.26 +/- 0.06, respectively, n = 6, P = 0.001) but not with 5-HT or KCl. A decreased maximum response in cardiomyopathic, compared to control, was observed with 5-HT (1.28 +/- 0.06 g vs 1.56 +/- 0.07 g, respectively, n = 6, P = 0.03). Comparable results were found in aortae with an intact endothelium. 4. No difference in the maximum contractile response to the G-protein activator, NaF (3, 10 and 30 mM) was observed in either group of animals. 5. Phorbol 12-myristate 13-acetate (PMA, 1-10 microM) was used to assess changes in the activity of protein kinase C (PKC). Contractility to PMA was increased in cardiomyopathic hamster aortae compared to controls (0.22 +/- 0.02 g vs 0.07 +/- 0.03 g at 3 microM, respectively, n = 6, P = 0.003). 6. Finally, cardiomyopathic hamsters aortae were found to be less sensitive when exposed to increasing concentrations of Ca2+ (10 microM-1 mM) in KCl-depolarized rings (0.58 +/- 0.04 g in

  18. 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.

  19. GOLD PLATING PROCESS

    DOEpatents

    Seegmiller, R.

    1957-08-01

    An improved bath is reported for plating gold on other metals. The composition of the plating bath is as follows: Gold cyanide from about 15 to about 50 grams, potassium cyanide from about 70 to about 125 grams, and sulfonated castor oil from about 0.1 to about 10 cc. The gold plate produced from this bath is smooth, semi-hard, and nonporous.

  20. Cystolithiasis in a Syrian hamster: a different outcome.

    PubMed

    Petrini, D; Di Giuseppe, M; Deli, G; De Caro Carella, C

    2016-01-01

    A 14-month-old intact male Syrian hamster was admitted for lethargy and hematuria. A total body radiographic image and abdominal ultrasonography showed the presence of a vesical calculus. During cystotomy, a sterile urine sample was obtained and sent to the diagnostic laboratory along with the urolith for analysis. Urine culture was found negative for bacterial growth, and the urolith was identified as a calcium-oxalate stone. Diet supplementation with palmitoylethanolamide, glucosamine and hesperidin was adopted the day after discharge. One year follow up revealed no presence of vesical calculi. Although this is the report of a single clinical case, this outcome differs from the results reported in the literature characterized by recurrences after few months. Considering the positive outcome and the beneficial properties of palmitoylethanolamide, glucosamine, and hesperidin, these nutritional elements in Syrian hamsters, are recommended to reduce recurrence after surgical treatment of urolithiasis. PMID:27540515

  1. Sarcolemmal phospholipid N-methylation in genetically determined hamster cardiomyopathy

    SciTech Connect

    Okumura, K.; Panagia, V.; Jasmin, G.; Dhalla, N.S.

    1987-02-27

    The heart sarcolemmal phosphatidylethanolamine N-methylation in UM-X7.1 strain of cardiomyopathic hamsters was examined by using 0.055, 10 and 150 microM S-adenosyl-L-(methyl-/sup 3/H) methionine as methyl donor for sites I, II and III, respectively. In comparison with control values, methylation activities at site I was increased in 40, 120 and 250 days old cardiomyopathic hamsters. On the other hand, methylation activities at sites II and III in 120 and 250 days old cardiomyopathic animals were depressed without any change in the 40 days old group. The alterations in N-methylation activities were associated with kinetic changes in apparent Vmax values without any changes in the apparent Km. These results indicate a defect in the phospholipid N-methylation process in heart sarcolemma during the development of genetically determined cardiomyopathy.

  2. Lymphoreticular and myeloid pathogenesis of Venezuelan equine encephalitis in hamsters.

    PubMed

    Walker, D H; Harrison, A; Murphy, K; Flemister, M; Murphy, F A

    1976-08-01

    Ultrastructural, histopathologic, and virologic studies of adult hamsters infected with virulent Venezuelan equine encelphalomyelitis (VEE) virus (Subtype I-B) demonstrated precise chronologic and topographic progression of lesions and viral replication in extraneural sites. Thymus contained the earliest lesions and the highest initial and subsequent viral titers. No particular cytotropism was observed as highly efficient viral replication and severe cytonecrosis proceded. Early cortical necrosis of splenic periarteriolar lymphocytic sheath was followed by lymphoblastoid repopulation of the peripheral zone. Massive bone marrow necrosis was accompained by ultrastructural evidence of VEE viral particle production in reticulum cells, rubricytes, myeloid cells, lymphoblastoid cells, and megakaryocytes. Speed, efficiency, destructiveness, and relative sensitivity of virtually all lymphoreticular and hematopoetic cells were hallmarks of virulent VEE infection in the hamster. PMID:941983

  3. Spontaneous Fibrosarcoma in a Djungarian Hamster (Phodopus sungorus)

    PubMed Central

    Kondo, Hirotaka; Onuma, Mamoru; Ito, Hidetoshi; Shibuya, Hisashi; Sato, Tsuneo

    2008-01-01

    A 1.5-y-old female Djungarian hamster (Phodopus sungorus) presented with a large subcutaneous mass surrounding the right shoulder. Radiography revealed dislocation of the right humeral articulation and osteolytic lesions of the right scapula. Histologically, the mass was composed of spindle to stellate cells arranged in fascicles interwoven with delicate collagen fibers, and neoplastic cells infiltrated the bone, skeletal muscle, and subcutaneous tissues. Neoplastic cells stained intensely positive for vimentin and negative for S100 protein, neurofilament, and desmin. A minority of neoplastic cells (10% to 20%) stained moderately for smooth muscle actin. The mass was diagnosed as a fibrosarcoma. Although fibrosarcomas are relatively common in dogs and cats, this is the first report of fibrosarcoma in a domestic Djungarian hamster. PMID:18589873

  4. Effect of DMSO and DMBA hamster pouch carcinogenesis

    SciTech Connect

    Rivera-Hidalgo, F.; Miller, E.G.; Binnie, W.H.

    1987-01-01

    The penetration of mucosal surfaces by chemical carcinogens is required for tumor induction. The effectiveness of dimethyl sulfoxide (DMSO) as a carrier for carcinogen is controversial. The purpose of this study was to determine what effect DMSO would have on the 9,10-dimethyl- 1,2-benzanthracene (DMBA)-induced carcinogenesis in the hamster cheek pouch. Thirty Syrian golden hamsters were divided into two groups: the control group received a topical application of 0.5% DMBA in mineral oil three times per week for 16 weeks, while the experimental group received a topical application of DMSO previous to each DMBA application. At autopsy, both groups had developed tumors, the tumor ratio of control to experimental was 3.5:1.9 and the average size of tumors was 2.2 to 1.9 mm sq. The results suggest that DMSO interfered with the usual DMBA induction mechanism.

  5. Cystolithiasis in a Syrian hamster: a different outcome

    PubMed Central

    Petrini, D.; Di Giuseppe, M.; Deli, G.; De Caro Carella, C.

    2016-01-01

    A 14-month-old intact male Syrian hamster was admitted for lethargy and hematuria. A total body radiographic image and abdominal ultrasonography showed the presence of a vesical calculus. During cystotomy, a sterile urine sample was obtained and sent to the diagnostic laboratory along with the urolith for analysis. Urine culture was found negative for bacterial growth, and the urolith was identified as a calcium-oxalate stone. Diet supplementation with palmitoylethanolamide, glucosamine and hesperidin was adopted the day after discharge. One year follow up revealed no presence of vesical calculi. Although this is the report of a single clinical case, this outcome differs from the results reported in the literature characterized by recurrences after few months. Considering the positive outcome and the beneficial properties of palmitoylethanolamide, glucosamine, and hesperidin, these nutritional elements in Syrian hamsters, are recommended to reduce recurrence after surgical treatment of urolithiasis. PMID:27540515

  6. 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.

  7. Photoperiodic Influences on Ultradian Rhythms of Male Siberian Hamsters

    PubMed Central

    Prendergast, Brian J.; Zucker, Irving

    2012-01-01

    Seasonal changes in mammalian physiology and behavior are proximately controlled by the annual variation in day length. Long summer and short winter day lengths markedly alter the amplitude of endogenous circadian rhythms and may affect ultradian oscillations, but the threshold photoperiods for inducing these changes are not known. We assessed the effects of short and intermediate day lengths and changes in reproductive physiology on circadian and ultradian rhythms of locomotor activity in Siberian hamsters. Males were maintained in a long photoperiod from birth (15 h light/day; 15 L) and transferred in adulthood to 1 of 7 experimental photoperiods ranging from 14 L to 9 L. Decreases in circadian rhythm (CR) robustness, mesor and amplitude were evident in photoperiods ≤14 L, as were delays in the timing of CR acrophase and expansion of nocturnal activity duration. Nocturnal ultradian rhythms (URs) were comparably prevalent in all day lengths, but 15 L markedly inhibited the expression of light-phase URs. The period (τ’), amplitude and complexity of URs increased in day lengths ≤13 L. Among hamsters that failed to undergo gonadal regression in short day lengths (nonresponders), τ’ of the dark-phase UR was longer than in photoresponsive hamsters; in 13 L the incidence and amplitude of light-phase URs were greater in hamsters that did not undergo testicular regression. Day lengths as long as 14 L were sufficient to trigger changes in the waveform of CRs without affecting UR waveform. The transition from a long- to a short-day ultradian phenotype occurred for most UR components at day lengths of 12 L–13 L, thereby establishing different thresholds for CR and UR responses to day length. At the UR-threshold photoperiod of 13 L, differences in gonadal status were largely without effect on most UR parameters. PMID:22848579

  8. Regulation of hamster sperm hyperactivation by extracellular Na.

    PubMed

    Takei, Gen L; Fujinoki, Masakatsu

    2016-06-01

    Mammalian sperm motility has to be hyperactivated to be fertilization-competent. Hyperactivation is regulated by extracellular environment. Osmolality of mammalian semen is higher than that in female reproductive tract; however, the effect of them on hyperactivation has not been investigated. So we investigated the effect of osmotic environment on hyperactivation using hamster spermatozoa at first. Increase in the osmolality of the media (∼370 mOsm) by increasing the concentration of NaCl (∼150 mmol/L) caused the delay of the expression of hyperactivation. When NaCl concentration varied in the same range (75-150 mmol/L) whereas the osmolality was fixed at 370 mOsm by adding mannitol, the delay of hyperactivation occurred dependent on NaCl concentration. Increase in NaCl concentration also caused suppression of curvilinear velocity, bend angle, and sliding velocity of the flagellum at the onset of incubation, suggesting that NaCl concentration affect both activation and hyperactivation in hamster spermatozoa. Hamster sperm intracellular Ca(2+) concentration decreased as extracellular NaCl concentration increased, whereas membrane potential and intracellular pH were unaffected by extracellular NaCl concentration. SN-6 and SEA0400, inhibitors of Na(+)-Ca(2+) exchanger (NCX), increased intracellular Ca(2+) and accelerated hyperactivation in the presence of 150 mmol/L NaCl. Tyrosine phosphorylation on fibrous sheath proteins was unaffected by extracellular NaCl concentration. These results suggest that extracellular Na(+) suppresses hamster sperm hyperactivation by reducing intracellular Ca(2+) via an action of NCX in a tyrosine phosphorylation-independent manner. It seems that the removal of suppression by extracellular Na(+) leads to the expression of hyperactivated motility. PMID:26952096

  9. Expression of human angiogenin in cultured baby hamster kidney cells

    SciTech Connect

    Kurachi, K.; Rybak, S.M.; Fett, J.W.; Shapiro, R.; Strydom, D.J.; Olson, K.A.; Riordan, J.F.; Davie, E.W.; Vallee, B.L.

    1988-08-23

    Baby hamster kidney cells were transformed with DNA sequences derived from the gene for human angiogenin. Expression was under the transcriptional control of the inducible mouse metallothionein 1 promoter. Recombinant angiogenin was purified and shown to be chemically, biologically, and enzymatically indistinguishable from the natural product. The large-scale production of recombinant angiogenin achieved should facilitate detailed studies into the structure-function relationships of this potent angiogenic molecule.

  10. Learned magnetic compass orientation by the Siberian hamster, Phodopus sungorus

    SciTech Connect

    Deutschlander, Mark E.; Freake, Michael J.; Borland, Christopher; Phillips, John B.; Madden, R C.; Anderson, Larry E.; Wilson, B W.

    2003-04-01

    Magnetic orientation has been demonstrated in Siberian hamsters, Phodopus sungorus. The behavior, using a nest building assay, shows a directional preference in nest position and appears in this animal to be a learned behavior. Hamsters were housed prior to testing in rectangular cages aligned along perpendicular axes. When subsequently tested in a radially-symmetrical arena, the hamsters positioned their nests in a bimodal distribution that coincided with the magnetic direction of the long-axis of the holding cages. In addition, results are presented that illustrate some of the factors that can influence behavioral responses to the magnetic field. In particular for P. sungorus, holding conditions prior to testing and the presence of non-magnetic cues may influence the strength and expression of magnetic orientation. Failure to consider these and other factors may help to explain why previous attempts to demonstrate magnetic orientation in a number of rodent species have failed or, when positive results have been obtained, have been difficult to replicate in other laboratories.

  11. Histogenesis of pancreatic carcinogenesis in the hamster: ultrastructural evidence.

    PubMed Central

    Flaks, B

    1984-01-01

    Pancreatic carcinogenesis in the Syrian hamster, induced by beta-oxidized derivatives of N-nitroso-di-n-propylamine, constitutes a valuable model of human cancer of the exocrine pancreas. In both species the majority of tumors are adenocarcinomas: superficially, on the basis of their histological appearance, these appear to be ductal in origin. However, sequential analysis, by electron microscopy, of the development of pancreatic neoplasia in the hamster model indicates that acinar cells may participate in the histogenesis of "ductal" adenomas and carcinomas. Acinar cells appear to undergo changes in differentiation, including pseudoductular transformation, giving rise to a new population of cells that resemble ductular or centroacinar types. This new population may then proliferate to form, first, cystic foci and subsequently cystadenomas and adenocarcinomas. Mucous metaplasia appears to develop at late stages of tumor development. Although the participation of ductular and centroacinar cells in pancreatic carcinogenesis cannot be excluded, very few tumors arise from the ductal epithelium. It is possible that some human pancreatic adenocarcinomas may also have their origin from dysplastic acinar cells, by analogy with the hamster model: focal acinar dysplasia being common in human pancreatic cancer patients. Images FIGURE 1. FIGURE 2. FIGURE 3. FIGURE 4. FIGURE 5. FIGURE 6. FIGURE 7. FIGURE 8. FIGURE 9. FIGURE 10. FIGURE 11. FIGURE 12. FIGURE 13. FIGURE 14. FIGURE 15. FIGURE 16. FIGURE 17. FIGURE 18. PMID:6383797

  12. Experimental Models in Syrian Golden Hamster Replicate Human Acute Pancreatitis.

    PubMed

    Wang, Yunan; Kayoumu, Abudurexiti; Lu, Guotao; Xu, Pengfei; Qiu, Xu; Chen, Liye; Qi, Rong; Huang, Shouxiong; Li, Weiqin; Wang, Yuhui; Liu, George

    2016-01-01

    The hamster has been shown to share a variety of metabolic similarities with humans. To replicate human acute pancreatitis with hamsters, we comparatively studied the efficacy of common methods, such as the peritoneal injections of caerulein, L-arginine, the retrograde infusion of sodium taurocholate, and another novel model with concomitant administration of ethanol and fatty acid. The severity of pancreatitis was evaluated by serum amylase activity, pathological scores, myeloperoxidase activity, and the expression of inflammation factors in pancreas. The results support that the severity of pathological injury is consistent with the pancreatitis induced in mice and rat using the same methods. Specifically, caerulein induced mild edematous pancreatitis accompanied by minimal lung injury, while L-arginine induced extremely severe pancreatic injury including necrosis and neutrophil infiltration. Infusion of Na-taurocholate into the pancreatic duct induced necrotizing pancreatitis in the head of pancreas and lighter inflammation in the distal region. The severity of acute pancreatitis induced by combination of ethanol and fatty acids was between the extent of caerulein and L-arginine induction, with obvious inflammatory cells infiltration. In view of the advantages in lipid metabolism features, hamster models are ideally suited for the studies of pancreatitis associated with altered metabolism in humans. PMID:27302647

  13. Lack of carcinogenicity of cadmium chloride in female Syrian hamsters.

    PubMed

    Waalkes, M P; Rehm, S

    1998-04-01

    Cadmium is very effective at inducing necrosis within the ovaries of rodents, and the Syrian hamster appears particularly sensitive. The extent of cadmium-induced necrosis depends on the stage of the estrous cycle and is most pronounced when injected on the day prior to ovulation (proestrous). In male rodents cadmium induces a similar necrosis within the testes, which given sufficient time can lead to the development of testicular tumors. In this study we tested the hypothesis that cadmium-induced ovarian necrosis could eventually lead to tumor formation. In sexually mature groups of female Syrian hamsters (> 8 weeks old; n = 50-59), the estrous cycle was determined by visual inspection of vaginal discharge for four consecutive cycles. The animals were then given cadmium (0, 30, 40 and 50 micromol/kg) subcutaneously as a single injection in the dorsal thoracic midline on cycle day 4 (proestrous). Based on prior work, these doses are sufficient to induce extensive acute ovarian damage. Animals were then observed over the next 78 weeks. Although survival and body weight were reduced by cadmium, treatment with the metal did not result in an enhanced incidence of tumors at any site including the ovaries. Non-neoplastic lesions such as amyloidosis and pancreatic hepatocytes were linked to cadmium exposure. These results indicate that the association of cadmium-induced testicular necrosis with tumor development seen in males does not occur in the Syrian hamster ovaries. PMID:9674965

  14. Melanin content of hamster tissues, human tissues, and various melanomas

    SciTech Connect

    Watts, K.P.; Fairchild, R.G.; Slatkin, D.N.; Greenberg, D.; Packer, S.; Atkins, H.L.; Hannon, S.J.

    1981-02-01

    Melanin content (percentage by weight) was determined in both pigmented and nonpigmented tissues of Syrian golden hamsters bearing Greene melanoma. Melanin content was also measured in various other melanoma models (B-16 in C57 mice, Harding-Passey in BALB/c mice, and KHDD in C3H mice) and in nine human melanomas, as well as in selected normal tissues. The purpose was to evaluate the possible efficacy of chlorpromazine, which is known to bind to melanin, as a vehicle for boron transport in neutron capture therapy. Successful therapy would depend upon selective uptake and absolute concentration of borated compounds in tumors; these parameters will in turn depend upon melanin concentration in melanomas and nonpigmented ''background'' tissues. Hamster whole eyes, hamster melanomas, and other well-pigmented animal melanomas were found to contain 0.3 to 0.8% melanin by weight, whereas human melanomas varied from 0.1 to 0.9% (average, 0.35%). Other tissues, with the exception of skin, were lower in content by a factor of greater than or equal to30. Melanin pigment was extracted from tissues, and the melanin content was determined spectrophotometrically. Measurements were found to be sensitive to the presence of other proteins. Previous procedures for isolating and quantifying melanin often neglected the importance of removing proteins and other interfering nonmelanic substances.

  15. Experimental Models in Syrian Golden Hamster Replicate Human Acute Pancreatitis

    PubMed Central

    Wang, Yunan; Kayoumu, Abudurexiti; Lu, Guotao; Xu, Pengfei; Qiu, Xu; Chen, Liye; Qi, Rong; Huang, Shouxiong; Li, Weiqin; Wang, Yuhui; Liu, George

    2016-01-01

    The hamster has been shown to share a variety of metabolic similarities with humans. To replicate human acute pancreatitis with hamsters, we comparatively studied the efficacy of common methods, such as the peritoneal injections of caerulein, L-arginine, the retrograde infusion of sodium taurocholate, and another novel model with concomitant administration of ethanol and fatty acid. The severity of pancreatitis was evaluated by serum amylase activity, pathological scores, myeloperoxidase activity, and the expression of inflammation factors in pancreas. The results support that the severity of pathological injury is consistent with the pancreatitis induced in mice and rat using the same methods. Specifically, caerulein induced mild edematous pancreatitis accompanied by minimal lung injury, while L-arginine induced extremely severe pancreatic injury including necrosis and neutrophil infiltration. Infusion of Na-taurocholate into the pancreatic duct induced necrotizing pancreatitis in the head of pancreas and lighter inflammation in the distal region. The severity of acute pancreatitis induced by combination of ethanol and fatty acids was between the extent of caerulein and L-arginine induction, with obvious inflammatory cells infiltration. In view of the advantages in lipid metabolism features, hamster models are ideally suited for the studies of pancreatitis associated with altered metabolism in humans. PMID:27302647

  16. Teratogenicity and embryotoxicity of nickel carbonyl in Syrian hamsters

    SciTech Connect

    Sunderman, F.W. Jr.; Shen, S.K.; Reid, M.C.; Allpass, P.R.

    1980-01-01

    Nickel carbonyl was administered to groups of pregnant hamsters by inhalation on days 4, 5, 6, 7, or 8 of gestation. The dams were killed on day 15 of gestation, and the fetuses were examined for malformations. Exposure to Ni(CO)/sub 4/ on days 4 or 5 of gestation resulted in malformation in 5.5% and 5.8% of the progeny, respectively. Progeny included 9 fetuses with cystic lungs, 7 fetuses with exencephaly, 1 fetus with exencephaly plus fused rib and 1 fetus with anophthalmia plus cleft palate. Hemorrhages into serious cavities were found. In progeny of dams exposed to Ni(CO)/sub 4/ on days 6 or 7 of gestation, there was 1 fetus with fused ribs and there were 2 fetuses with hydronephrosis. In another experiment, pregnant hamsters were exposed to inhalation of Ni(CO)/sub 4/ on day 5 of gestation; these dams were permitted to deliver their litters and to nurse their pups. There was no significant difference in the average number of live pups in the Ni(CO)/sub 4/-exposed litters compared to control litters. Neonatal mortality was increased in Ni(CO)/sub 4/-exposed litters. This study demonstrates that Ni(CO)/sub 4/ is teratogenic and embryotoxic in Syrian hamsters.

  17. 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

  18. Regulation of cholesteryl ester transfer activity in adipose tissue: comparison between hamster and rat species.

    PubMed

    Shen, G X; Angel, A

    1995-07-01

    The present study demonstrates cholesteryl ester transfer activity (CETA) in cultured hamster and rat adipose tissue. Cultured hamster and rat adipose tissue fragments released CETA into the conditioned medium, and this was associated with a reciprocal decrease in adipose tissue CETA. Regional variations in adipose CETA were observed. The levels of CETA released from cultured hamster and rat adipocytes were higher than those from adipose tissue fragments. In hamsters but not in rats, the secretion of CETA from cultured adipose tissue was increased by insulin and inhibited by EDTA in a dose-dependent fashion. Monoclonal antibodies against human cholesteryl ester transfer protein inhibited the CETA secreted from hamster adipose tissue but not that from rat adipose tissue. Fasting for 24 h and a high-cholesterol saturated fat-rich diet increased adipose CETA in hamsters and rats, and this was associated with an elevation of plasma CETA only in hamsters. This supports the view that, in hamsters, adipose CETA has in situ and intravascular functions, whereas in rats the role of adipose CETA is restricted to tissue-specific functions. Hamster cholesteryl ester transfer protein may differ from rat adipose-associated CETA in the structure of the active site and the regulatory mechanism for its secretion. PMID:7631784

  19. DNA (deoxyribonucleic acid) synthesis following microinjection of heterologous sperm and somatic cell nuclei into hamster oocytes

    SciTech Connect

    Naish, S.J.; Perreault, S.D.; Zirkin, B.R.

    1987-01-01

    The authors 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 /sup 3/H-thymidine after being parthenogenetically activated by sham microinjection, or microinjected with hamster, mouse, rabbit, or fish sperm nuclei, or hamster hepatocyte nuclei. Within 6 hr of sham or nucleus microinjection, nuclei of each type underwent transformation into pronuclei and synthesized DNA. These results demonstrated that the hamster egg can access and utilize its own and each type of template provided, whether homologous or heterologous. However, pronuclei derived from hamster sperm nuclei were more likely to be synthesizing DNA at 6 hr than pronuclei derived from sperm nuclei of other species. The authors conclude that the mechanisms employed by the hamster oocyte to transform hamster sperm nuclei into pronuclei and to effect DNA synthesis in these nuclei are not specific for the hamster sperm nucleus. Nevertheless, these mechanisms apparently operate more efficiently when the hamster sperm nucleus, rather than a heterologous sperm nucleus, is present.

  20. Androgen dependence in hamsters: overdose, tolerance, and potential opioidergic mechanisms.

    PubMed

    Peters, K D; Wood, R I

    2005-01-01

    Anabolic steroids are drugs of abuse. However, the potential for steroid reward and addiction remains largely unexplored. This study used i.c.v. testosterone self-administration and controlled infusions of testosterone or vehicle in hamsters to explore central mechanisms of androgen overdose. Forty-two hamsters used nose-pokes to self-administer 1 microg/microl testosterone i.c.v. 4 h/day in an operant chamber. During 1-56 days of androgen self-administration, 10 (24%) hamsters died. Deaths correlated with peak daily intake of testosterone. Of the hamsters that self-administered a peak intake of <20 microg/day, there was 100% survival (10/10). Survival decreased to 86% (19/22) when daily testosterone intake peaked at 20-60 microg/day. Only 30% (three of 10) survived when daily testosterone intake exceeded 60 microg/day. Deaths are not due to volume or vehicle because i.c.v. infusions of 80 mul vehicle had no effect. Testosterone overdose resembles opiate intoxication. When male hamsters received infusions of 40 microg testosterone, locomotion (25.1+/-18.8 grid-crossings/10 min), respiration (72.7+/-5.4 breaths/min) and body temperature (33.5+/-0.4 degrees C) were significantly reduced, compared with males receiving vehicle infusions (186.1+/-8.1 crossings/10 min, 117.6+/-1.0 breaths/min, 35.9+/-0.1 degrees C, P<0.05). However, males developed tolerance to continued daily testosterone infusion. After 15 days, locomotion (170.2+/-6.3 crossings), respiration (118.4+/-1.3 breaths/min), and body temperature (35.3+/-0.3 degrees C) in testosterone-infused males were equivalent to that in vehicle controls (P>0.05). The depressive effects of testosterone infusion are blocked by the opioid antagonist, naltrexone. With naltrexone pre-treatment (10 mg/kg s.c.), locomotion (183.7+/-1.8 crossings/10 min), respiration (116.9+/-0.3 breaths/min), and body temperature (36.1+/-0.4 degrees C) during testosterone infusion were equivalent to vehicle controls. Likewise, naltrexone

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

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Primary enclosures used to transport... enclosures used to transport live guinea pigs and hamsters. No person subject to the Animal Welfare regulations shall offer for transportation, or transport, in commerce any live guinea pig or hamster in...

  2. CARBENDAZIM (MBC) DISRUPTS OOCYTE SPINDLE FUNCTION AND INDUCES ANEUPLOIDY IN HAMSTERS EXPOSED DURING FERTILIZATION (MEIOSIS II)

    EPA Science Inventory

    Peri-fertilization exposure to Carbendazim (MBC; a microtubule poison) induces infertility and early pregnancy loss (EPL) in hamsters. resently, both in vivo and in vitro techniques were employed to characterize the effects of MBC on cellular aspects of fertilization in hamsters....

  3. On the analysis of neonatal hamster tooth germs with the photon microprobe at Daresbury, UK

    NASA Astrophysics Data System (ADS)

    Tros, G. H. J.; Van Langevelde, F.; Vis, R. D.

    1990-04-01

    Complementary to the micro-PIXE experiments performed on hamster tooth germs to elucidate the role of fluoride during the growth, the photon microprobe at Daresbury was used to obtain information on the distribution of Zn. The germs of fluoride-administered hamsters, together with a control group, were analyzed with the micro-synchrotron radiation fluorescence method (micro-SXRF).

  4. Effect of exercise on redistribution and clearance of inhaled particles from hamster lungs

    SciTech Connect

    Sweeney, T.D.; Tryka, A.F.; Brain, J.D. )

    1990-03-01

    Does exercise alter the redistribution and clearance of particles from the lungs Sedentary hamsters and hamsters that were exercise trained by voluntary wheel running for the previous 5 wk were exposed to a 198Au-labeled aerosol for 25 min. Six trained and 6 sedentary animals were killed within 5 min after the exposure (day 0); the same number were killed 5 days later. The trained hamsters ran ad libitum during those 5 days. The lungs of all animals were excised, dried at total lung capacity, sliced into 1-mm-thick sections, and dissected into pieces that were counted for radioactivity and weighed. On day 0, trained hamsters had 80% more particles per milligram of lung than sedentary hamsters, although both were exposed under identical conditions of restraint. After five days, exercising hamsters cleared 38% of the particles present at day 0, whereas sedentary animals removed only 15%. Significant clearance was observed from the middle lung regions of sedentary hamsters and from all lung regions in exercising hamsters. We conclude that exercise can enhance the redistribution and clearance of particles from the lungs; the mechanisms responsible are as yet unclear.

  5. Lack of negative effects on Syrian hamsters and Mongolian gerbils housed in the same secondary enclosure.

    PubMed

    Pritchett-Corning, Kathleen R; Gaskill, Brianna N

    2015-05-01

    In cases where different species might be housed in the same room or secondary enclosure, the Guide for the Care and Use of Laboratory Animals recommends that the animals should be behaviorally compatible and have the same health status. Syrian hamsters and Mongolian gerbils, both desert-dwelling rodents, appear to be reasonable candidates for such a combination. This study was undertaken to evaluate whether housing hamsters and gerbils in the same secondary enclosure is an acceptable practice. Weanling and breeding-age hamsters and gerbils were housed in open-topped cages in an isolator for 5 mo; the isolator also contained with nude and haired mice, which acted as sentinels. Cages housing hamsters and gerbils were rotated between species, and dirty bedding was exchanged between species in an effort to transmit microorganisms. In addition, sentinel mice housed in the isolator were supplied with dirty bedding from both hamsters and gerbils. Neither species showed clinical signs of illness, the health status of neither the hamsters nor the gerbils changed significantly, and the sentinel mice acquired only 2 infectious organisms, a Helicobacter species and Staphylococcus aureus. Both hamsters and gerbils bred successfully when housed together in the same isolator, and no infanticide or mortality was seen. Breeding performance did not differ between isolator breeding and barrier breeding. This study supports the housing of hamsters and gerbils in the same secondary enclosure. PMID:26045450

  6. Anti-HER-2 DNA vaccine protects Syrian hamsters against squamous cell carcinomas

    PubMed Central

    Berta, G N; Mognetti, B; Spadaro, M; Trione, E; Amici, A; Forni, G; Di Carlo, F; Cavallo, F

    2005-01-01

    This paper illustrates the efficacy of DNA vaccination through electroporation in the prevention of oral transplantable carcinoma in Syrian hamsters. At 21 and 7 days before tumour challenge, 19 hamsters were vaccinated with plasmids coding for the extracellular and transmembrane domains of rat HER-2 receptor (EC-TM plasmids), whereas 19 control hamsters were injected intramuscularly with the empty plasmid. Immediately following plasmid injection, hamsters of both groups received two square-wave 25 ms, 375 V cm−1 electric pulses via two electrodes placed on the skin of the injection area. At day 0, all hamsters were challenged in the submucosa of the right cheek pouch with HER-2-positive HCPC I cells established in vitro from an 7,12-dimethylbenz[a]anthracene-induced oral carcinoma. This challenge gave rise to HER-2-positive buccal neoplastic lesions in 14 controls (73.37%), compared with only seven (36.8%, P<0.0027) vaccinated hamsters. In addition, the vaccinated hamsters displayed both a stronger proliferative and cytotoxic response than the controls and a significant anti-HER-2 antibody response. Most of the hamsters that rejected the challenge displayed the highest antibody titres. These findings suggest that DNA vaccination may have a future in the prevention of HER-2-positive human oral cancer. PMID:16265350

  7. Abnormalities of ADP/ATP carrier protein in J-2-N cardiomyopathic hamsters.

    PubMed

    Kato, M; Yang, J; Iwai, T; Tanamura, A; Arino, T; Kawashima, O; Takeda, N

    1993-02-17

    ADP/ATP carrier protein (AAC) is located in the mitochondrial inner membrane and has an important function in mitochondrial energy supply. This protein transports ATP to the cytoplasm and counter transports ADP into the mitochondria. J-2-N cardiomyopathic hamsters were investigated to determine the AAC content in cardiac mitochondria. After recording an electrocardiogram and collecting blood, the cardiac mitochondria were isolated. The mitochondrial membranes were labelled with eosin-5-maleimide (EMA) and separated on SDS polyacrylamide gels. The position of the AAC component was identified by exposing the gel under UV light, and the AAC content was determined by densitometry after staining with Coomassie blue. The AAC content ratio was significantly decreased in both 10-week-old and 1-year survived J-2-N hamsters when compared to control Golden hamster. Among 10-week-old J-2-N hamsters, the decrease in the AAC content ratio was more marked for the animals with more severe myocardial damage. The H(+)-ATPase activities of mitochondrial membrane were higher in 10-week-old J-2-N hamsters than in control hamsters. These results suggest that the decrease of AAC in J-2-N hamster plays an important role in the pathogenesis of cardiomyopathy in J-2-N hamsters. PMID:8455591

  8. DNA SYNTHESIS IN THE FERTILIZING HAMSTER SPERM NUCLEUS: SPERM TEMPLATE AVAILABILITY AND EGG CYTOPLASMIC CONTROL

    EPA Science Inventory

    To assess the role of sperm template availability in the regulation of DNA synthesis, the morphological status of the fertilizing hamster sperm nucleus was correlated with its ability to synthesize DNA after in vivo and in vitro fertilization. Fertilized hamster eggs were incubat...

  9. OBSERVATIONS OF SYRIAN HAMSTER FETUSES AFTER EXPOSURE TO 2450-MHZ MICROWAVES

    EPA Science Inventory

    The teratogenic potential of microwaves was examined in a rodent species, the Syrian hamster. Exposure of hamsters to 2450-MHz CW microwaves at a power denisty of 20 mW/sq. cm. for 100 minutes daily on days 6-14 of gestation caused no significant change in fetal survival, body we...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. BODY TEMPERATURE IN THE MOUSE, HAMSTER, AND RAT EXPOSED TO RADIOFREQUENCY RADIATION: AN INTERSPECIES COMPARISON

    EPA Science Inventory

    Colonic temperatures of BALB/c and CBA/J mice, golden hamsters, and Sprague-Dawley rats were taken immediately after exposure for 90 min to radiofrequency (RF) radiation. Exposures were made in 2450 MHz (mouse and hamster) or 600 MHz (rat) waveguide exposure systems while the dos...

  12. Lack of Negative Effects on Syrian Hamsters and Mongolian Gerbils Housed in the Same Secondary Enclosure

    PubMed Central

    Pritchett-Corning, Kathleen R; Gaskill, Brianna N

    2015-01-01

    In cases where different species might be housed in the same room or secondary enclosure, the Guide for the Care and Use of Laboratory Animals recommends that the animals should be behaviorally compatible and have the same health status. Syrian hamsters and Mongolian gerbils, both desert-dwelling rodents, appear to be reasonable candidates for such a combination. This study was undertaken to evaluate whether housing hamsters and gerbils in the same secondary enclosure is an acceptable practice. Weanling and breeding-age hamsters and gerbils were housed in open-topped cages in an isolator for 5 mo; the isolator also contained with nude and haired mice, which acted as sentinels. Cages housing hamsters and gerbils were rotated between species, and dirty bedding was exchanged between species in an effort to transmit microorganisms. In addition, sentinel mice housed in the isolator were supplied with dirty bedding from both hamsters and gerbils. Neither species showed clinical signs of illness, the health status of neither the hamsters nor the gerbils changed significantly, and the sentinel mice acquired only 2 infectious organisms, a Helicobacter species and Staphylococcus aureus. Both hamsters and gerbils bred successfully when housed together in the same isolator, and no infanticide or mortality was seen. Breeding performance did not differ between isolator breeding and barrier breeding. This study supports the housing of hamsters and gerbils in the same secondary enclosure. PMID:26045450

  13. Corn fiber oil and sitostanol decrease cholesterol absorption independently of intestinal sterol transporters in hamsters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aim of this study was to investigate the cholesterol-lowering mechanism of corn fiber oil (CFO), ferulate phytostanyl esters (FPE) and parent compounds including sitostanol and ferulic acid in hamsters. Method: Seventy male golden syrian hamsters were randomly assigned to six experimental diets ...

  14. The hamster cheek pouch model for field cancerization studies.

    PubMed

    Monti-Hughes, Andrea; Aromando, Romina F; Pérez, Miguel A; Schwint, Amanda E; Itoiz, Maria E

    2015-02-01

    External carcinogens, such as tobacco and alcohol, induce molecular changes in large areas of oral mucosa, which increase the risk of malignant transformation. This condition, known as 'field cancerization', can be detected in biopsy specimens using histochemical techniques, even before histological alterations are identified. The efficacy of these histochemical techniques as biomarkers of early cancerization must be demonstrated in appropriate models. The hamster cheek pouch oral cancer model, universally employed in biological studies and in studies for the prevention and treatment of oral cancer, is also an excellent model of field cancerization. The carcinogen is applied in solution to the surface of the mucosa and induces alterations that recapitulate the stages of cancerization in human oral mucosa. We have demonstrated that the following can be used for the early detection of cancerized tissue: silver staining of nucleolar organizer regions; the Feulgen reaction to stain DNA followed by ploidy analysis; immunohistochemical analysis of fibroblast growth factor-2, immunohistochemical labeling of proliferating cells to demonstrate an increase of epithelial cell proliferation in the absence of inflammation; and changes in markers of angiogenesis (i.e. those indicating vascular endothelial growth factor activity, endothelial cell proliferation and vascular density). The hamster cheek pouch model of oral cancer was also proposed and validated by our group for boron neutron capture therapy studies for the treatment of oral cancer. Clinical trials of this novel treatment modality have been performed and are underway for certain tumor types and localizations. Having demonstrated the efficacy of boron neutron capture therapy to control tumors in the hamster cheek pouch oral cancer model, we adapted the model for the long-term study of field cancerized tissue. We demonstrated the inhibitory effect of boron neutron capture therapy on tumor development in field

  15. Distribution and metabolism of four different dimethylated arsenicals in hamsters

    SciTech Connect

    Naranmandura, Hua; Iwata, Katsuya; Suzuki, Kazuo T.; Ogra, Yasumitsu

    2010-05-15

    Arsenic toxicity and distribution are highly dependent on animal species and its chemical species. Recently, thioarsenical has been recognized in highly toxic arsenic metabolites, which was commonly found in human and animal urine. In the present study, we revealed the mechanism underlying the distribution and metabolism of non-thiolated and thiolated dimethylarsenic compounds such as dimethylarsinic acid (DMA{sup V}), dimethylarsinous acid (DMA{sup III}), dimethylmonothioarsinic acid (DMMTA{sup V}), and dimethyldithioarsinic acid (DMDTA{sup V}) after the administration of them into femoral vein of hamsters. DMA{sup V} and DMDTA{sup V} distributed in organs and body fluids were in their unmodified form, while DMA{sup III} and DMMTA{sup V} were bound to proteins and transformed to DMA{sup V} in organs. On the other hand, DMA{sup V} and DMDTA{sup V} were mostly excreted into urine as their intact form 1 h after post-injection, and more than 70% of the doses were recovered in urine as their intact form. By contrast, less than 8-14% of doses were recovered in urine as DMA{sup V}, while more than 60% of doses were distributed in muscles and target organs (liver, kidney, and lung) of hamsters after the injection of DMMTA{sup V} and DMA{sup III}. However, in red blood cells (RBCs), only a small amount of the arsenicals was distributed (less than 4% of the doses) after the injection of DMA{sup III} and DMMTA{sup V}, suggesting that the DMA{sup III} and DMMTA{sup V} were hardly accumulated in hamster RBCs. Based on these observations, we suggest that although DMMTA{sup V} and DMDTA{sup V} are thioarsenicals, DMMTA{sup V} is taken up efficiently by organs, in a manner different from that of DMDTA{sup V}. In addition, the distribution and metabolism of DMMTA{sup V} are like in manner similar to DMA{sup III} in hamsters, while DMDTA{sup V} is in a manner similar to DMA{sup V}.

  16. Quantitative mutagenesis and mutagen screening with Chinese hamster ovary cells

    SciTech Connect

    Hsie, A.W.; San Sebastian, J.R.; Tan, E.L.

    1980-01-01

    A summary is presented on the development of a specific gene mutation assay, the Chinese hamster ovary cells/hypoxanthine-guanine phosphoribosyl transferase (CHO/HGPRT) system, and the utilization of this system to study structure-activity relationship affecting cytotoxicity and gene mutation by various carcinogens. Then, preliminary development and validation of a Multiplex CHO System for the simultaneous determination of chromosome aberration, sister chromatid exchange in addition to cytotoxicity and gene mutation is presented. The potential use of a CHO/human cell hybrid system for measuring chromosomal deletion and loss is discussed.

  17. Economic geology: Hidden gold

    NASA Astrophysics Data System (ADS)

    Richards, Jeremy P.

    2011-02-01

    How the giant sediment-hosted gold deposits of Nevada were formed is disputed. A model linking regional tectonics with magma emplacement and fluid generation at depth suggests that these deposits result from an optimal coincidence of processes.

  18. Gold-bearing skarns

    USGS Publications Warehouse

    Theodore, Ted G.; Orris, Greta J.; Hammerstrom, Jane M.; Bliss, James D.

    1991-01-01

    In recent years, a significant proportion of the mining industry's interest has been centered on discovery of gold deposits; this includes discovery of additional deposits where gold occurs in skarn, such as at Fortitude, Nevada, and at Red Dome, Australia. Under the classification of Au-bearing skarns, we have modeled these and similar gold-rich deposits that have a gold grade of at least 1 g/t and exhibit distinctive skarn mineralogy. Two subtypes, Au-skarns and byproduct Au-skarns, can be recognized on the basis of gold, silver, and base-metal grades, although many other geological factors apparently are still undistinguishable largely because of a lack of detailed studies of the Au-skarns. Median grades and tonnage for 40 Au-skarn deposits are 8.6 g/t Au, 5.0 g/t Ag, and 213,000 t. Median grades and tonnage for 50 byproduct and Au-skarn deposits are 3.7 g/t Au, 37 g/t Ag, and 330,000 t. Gold-bearing skarns are generally calcic exoskarns associated with intense retrograde hydrosilicate alteration. These skarns may contain economic amounts of numerous other commodities (Cu, Fe, Pb, Zn, As, Bi, W, Sb, Co, Cd, and S) as well as gold and silver. Most Au-bearing skarns are found in Paleozoic and Cenozoic orogenic-belt and island-arc settings and are associated with felsic to intermediate intrusive rocks of Paleozoic to Tertiary age. Native gold, electru, pyrite, pyrrhotite, chalcopyrite, arsenopyrite, sphalerite, galena, bismuth minerals, and magnetite or hematite are the most common opaque minerals. Gangue minerals typically include garnet (andradite-grossular), pyroxene (diopside-hedenbergite), wollastonite, chlorite, epidote, quartz, actinolite-tremolite, and (or) calcite.

  19. Gold nanoprobes for theranostics

    PubMed Central

    Panchapakesan, Balaji; Book-Newell, Brittany; Sethu, Palaniappan; Rao, Madhusudhana; Irudayaraj, Joseph

    2011-01-01

    Gold nanoprobes have become attractive diagnostic and therapeutic agents in medicine and life sciences research owing to their reproducible synthesis with atomic level precision, unique physical and chemical properties, versatility of their morphologies, flexibility in functionalization, ease of targeting, efficiency in drug delivery and opportunities for multimodal therapy. This review highlights some of the recent advances and the potential for gold nanoprobes in theranostics. PMID:22122586

  20. Getting the Gold Treatment

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Epner Technology, Inc., worked with Goddard Space Center to apply gold coating to the Vegetation Canopy Lidar (VCL) mirror. This partnership resulted in new commercial applications for Epner's LaserGold(R) process in the automotive industry. Previously, the company did not have equipment large enough to handle the plating of the stainless steel panels cost effectively. Seeing a chance to renew this effort, Epner Technology and Goddard entered into an agreement by which NASA would fund the facility needed to do the gold-plating, and Epner Technology would cover all other costs as part of their internal research and development. The VCL mirror project proceeded successfully, fulfilling Goddard's needs and leaving Epner Technology with a new facility to provide LaserGold for the automotive industry. The new capability means increased power savings and improvements in both quality and production time for BMW Manufacturing Corporation of Spartanburg, South Carolina, and Cadillac of Detroit, Michigan, as well as other manufacturers who have implemented Epner Technology's LaserGold process. LaserGold(R) is a registered trademark of Epner Technology, Inc.

  1. Acid-induced secretory cell metaplasia in hamster bronchi

    SciTech Connect

    Christensen, T.G.; Lucey, E.C.; Breuer, R.; Snider, G.L.

    1988-02-01

    Hamsters were exposed to an intratracheal instillation of 0.5 ml of 0.08 N nitric, hydrochloric, or sulfuric acid to determine their airway epithelial response. Three weeks after exposure, the left intrapulmonary bronchi in Alcian blue/PAS-strained paraffin sections were evaluated for the amount of secretory product in the airway epithelium as a measure of secretory cell metaplasia (SCM). Compared to saline-treated control animals, all three acids caused statistically significant SCM. In addition to the bronchial lesion, all three acids caused similar interstitial fibrosis, bronchiolectasis, and bronchiolization of alveoli that varied in individual animals from mild to severe. In a separate experiment to study the persistence of the SCM, hamsters treated with a single instillation of 0.1 N nitric acid showed significant SCM 3, 7, and 17 weeks after exposure. There was a high correlation (r = 0.96) between a subjective assessment of SCM and objective assessment using a digital image-analysis system. We conclude that protons induce SCM independently of the associated anion; the SCM persists at least 17 weeks. Sulfuric acid is an atmospheric pollutant and nitric acid may form locally on the mucosa of lungs exposed to nitrogen dioxide. These acids may contribute to the development of maintenance of the SCM seen in the conducting airways of humans with chronic obstructive pulmonary disease.

  2. Role of luteinizing hormone in luteotropic complex of pregnant hamster

    SciTech Connect

    Tamura, H.; Greenwald, G.S.

    1987-04-01

    Hamsters were hypophysectomized on day 4 of pregnancy and injected subcutaneously on days 4-7 with various combinations of 200 ..mu..g prolactin (Prl), 10 ..mu..g follicle-stimulating hormone (FSH), and 20 ..mu..g luteinizing hormone (LH) in polyvinylpyrrolidone (PVP) to decrease its rate of absorption or in saline. End points for luteal function on day 8 were maintenance of pregnancy, serum progesterone (P/sub 4/), luteal weight, and luteal binding for human chorionic gonadotropin, FSH, and Prl. After hypophysectomy, a drastic decline occurred in all parameters including an 89% decrease in luteal weight. Injection of Prl did not maintain pregnancy nor serum P/sub 4/ but partially maintained luteal weight and human chorionic gonadotropin binding sites per corpus luteum. The minimal luteotropic complex of Prl and FSH was effective in maintaining pregnancy and significantly increased serum P/sub 4/ and Prl and FSH receptors but not to control levels. Thus, the luteotropic activity of LH was only demonstrable when it was injected in a long-acting form; when delivered as a bolus, LH (saline) was luteolytic. P/sub 4/ and estradiol were measured by radioimmunoassay. Radioiodinated gonadotropins were prepared. The percentage of tracer reacting with an excess of receptor were 51% of /sup 125/I-FSH and 45.9% of /sup 125/I-hCG using whole homogenates of hamster ovaries.

  3. Rift Valley Fever Virus Infection in Golden Syrian Hamsters

    PubMed Central

    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. PMID:25607955

  4. Lymphoreticular and myeloid pathogenesis of Venezuelan equine encephalitis in hamsters.

    PubMed Central

    Walker, D. H.; Harrison, A.; Murphy, K.; Flemister, M.; Murphy, F. A.

    1976-01-01

    Ultrastructural, histopathologic, and virologic studies of adult hamsters infected with virulent Venezuelan equine encelphalomyelitis (VEE) virus (Subtype I-B) demonstrated precise chronologic and topographic progression of lesions and viral replication in extraneural sites. Thymus contained the earliest lesions and the highest initial and subsequent viral titers. No particular cytotropism was observed as highly efficient viral replication and severe cytonecrosis proceded. Early cortical necrosis of splenic periarteriolar lymphocytic sheath was followed by lymphoblastoid repopulation of the peripheral zone. Massive bone marrow necrosis was accompained by ultrastructural evidence of VEE viral particle production in reticulum cells, rubricytes, myeloid cells, lymphoblastoid cells, and megakaryocytes. Speed, efficiency, destructiveness, and relative sensitivity of virtually all lymphoreticular and hematopoetic cells were hallmarks of virulent VEE infection in the hamster. Images Figure 8 Figure 9 Figure 1 Figure 2 Figure 3 Figure 10 Figure 11 Figure 4 Figure 5 Figure 6 Figure 12A and B Figure 13 Figure 7 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 PMID:941983

  5. Sex differences in Siberian hamster ultradian locomotor rhythms.

    PubMed

    Prendergast, Brian J; Stevenson, Tyler J; Zucker, Irving

    2013-02-17

    Sex differences in ultradian activity rhythms (URs) and circadian rhythms (CRs) were assessed in Siberian hamsters kept in long day (LD) or short day (SD) photoperiods for 40 weeks. For both sexes URs of locomotor activity were more prevalent, greater in amplitude and more robust in SDs. The UR period was longer in females than males in both day lengths. The reproductive system underwent regression and body mass declined during the initial 10 weeks of SD treatment, and in both sexes these traits spontaneously reverted to the LD phenotype at or before 40 weeks in SD, reflecting the development of neuroendocrine refractoriness to SD patterns of melatonin secretion. Hamsters of both sexes, however, continued to display SD-like URs at the 40 weeks time point. CRs were less prevalent and the waveform less robust and lower in amplitude in SDs than LDs; the SD circadian waveform also did not revert to the long-day phenotype after 40 weeks of SD treatment. Short day lengths enhanced ultradian and diminished circadian rhythms in both sexes. Day length controls several UR characteristics via gonadal steroid and melatonin-independent mechanisms. Sex differences in ultradian timing may contribute to sex diphenisms in rhythms of sleep, food intake and exercise. PMID:23333554

  6. LUMINOSITY INCREASES IN GOLD-GOLD OPERATION IN RHIC.

    SciTech Connect

    FISCHER,W.AHERNS,L.BAI,M.ET AL.

    2004-07-05

    After an exploratory phase, during which a number of beam parameters were varied, the RHIC experiments now demand higher luminosity to study heavy ion collisions in detail. In gold-gold, operation, RHIC delivers now twice the design luminosity. During the last gold-gold operating period (Run-4) the machine delivered 15 times more luminosity than during the previous gold-gold operating period (Run-2), two years ago. We give an overview of the changes that increased the instantaneous luminosity and luminosity lifetime, raised the reliability, and improved the operational efficiency.

  7. Comparative pathogenesis of human WA1 and Babesia microti isolates in a Syrian hamster model.

    PubMed

    Wozniak, E J; Lowenstine, L J; Hemmer, R; Robinson, T; Conrad, P A

    1996-10-01

    The pathogenesis of a newly recognized, molecularly and antigenically distinct human babesial isolate (WA1) and Babesia microti, the common cause of human babesiosis in the United States, were compared in a Syrian hamster model. A group of 33 adult female hamsters were inoculated intraperitoneally with either WA1-infected, B. microti-infected, or uninfected hamster erythrocytes. All WA1-infected animals became parasitemic by postinoculation (PI) day 3 or 4 and were severely lethargic and dyspneic by PI days 6 to 10. Death often occurred spontaneously by PI day 10, with parasitemia of 12 to 90%. Hamsters inoculated with B. microti became parasitemic by PI day 7 and developed peak parasitemia (42 to 60%) by PI day 14 that subsequently decreased to low or undetectable values. Although the B. microti-infected hamsters developed severe anemia, they generally remained asymptomatic. Postmortem examination of WA1-infected hamsters revealed intravascular aggregates of large mononuclear inflammatory cells that occasionally occluded small to medium veins, pulmonary leukoclastic phlebitis, thrombosis, and multifocal coagulative necrosis in the heart, spleen, lung, and liver. No vascular lesions or areas of coagulative necrosis were detected in any B. microti-infected or control hamsters. The results of this study suggest that marked leukocytosis followed by acute necrotizing phlebitis resulting in disseminated intravascular coagulation, thromboembolism, and infarction may be central to the pathogenesis of WA1 infections. PMID:8905583

  8. A putative interferon induced in hamsters by poly(I) . poly(C).

    PubMed

    Round, E M; Stebbing, N

    1981-01-01

    Encephalomyocarditis (EMC) virus causes lethal infection of hamsters against which poly(I) . poly(C) causes dose-dependent protection. In contrast, no antiviral effects occur with poly(I) . poly(C) against influenza virus infection of hamsters. Serum from poly(I) . poly(C) treated hamsters protects other hamsters against EMC virus infection with maximum protection with serum removed 3h after poly(I) . poly(C) treatment of the donor hamsters. In such assays the factor was found to be inactivated by trypsin and pH 2 and 56 degrees C for 1 hr. The serum factor did not confer protection against EMC virus infection of L-929, BHK, Hak or primary hamster embryo cells. The amount of poly(I) . poly(C) carried over into serum samples of poly(I) . poly(C) treated hamsters was insufficient to account for the antiviral effects. The antiviral serum factor is presumed to be a form of interferon despite the fact that it does not titrate in cell cultures and has a novel set of properties from those which describe known interferons. PMID:6180078

  9. Daidzin suppresses ethanol consumption by Syrian golden hamsters without blocking acetaldehyde metabolism.

    PubMed Central

    Keung, W M; Lazo, O; Kunze, L; Vallee, B L

    1995-01-01

    Daidzin is a potent, selective, and reversible inhibitor of human mitochondrial aldehyde dehydrogenase (ALDH) that suppresses free-choice ethanol intake by Syrian golden hamsters. Other ALDH inhibitors, such as disulfiram (Antabuse) and calcium citrate carbimide (Temposil), have also been shown to suppress ethanol intake of laboratory animals and are thought to act by inhibiting the metabolism of acetaldehyde produced from ingested ethanol. To determine whether or not daidzin inhibits acetaldehyde metabolism in vivo, plasma acetaldehyde in daidzin-treated hamsters was measured after the administration of a test dose of ethanol. Daidzin treatment (150 mg/kg per day i.p. for 6 days) significantly suppresses (> 70%) hamster ethanol intake but does not affect overall acetaldehyde metabolism. In contrast, after administration of the same ethanol dose, plasma acetaldehyde concentration in disulfiram-treated hamsters reaches 0.9 mM, 70 times higher than that of the control. In vitro, daidzin suppresses hamster liver mitochondria-catalyzed acetaldehyde oxidation very potently with an IC50 value of 0.4 microM, which is substantially lower than the daidzin concentration (70 microM) found in the liver mitochondria of daidzin-treated hamsters. These results indicate that (i) the action of daidzin differs from that proposed for the classic, broad-acting ALDH inhibitors (e.g., disulfiram), and (ii) the daidzin-sensitive mitochondrial ALDH is not the one and only enzyme that is essential for acetaldehyde metabolism in golden hamsters. PMID:7568058

  10. Of humans and hamsters: the hamster buccal pouch carcinogenesis model as a paradigm for oral oncogenesis and chemoprevention.

    PubMed

    Nagini, S

    2009-10-01

    Oral squamous cell carcinoma (OSCC), a common malignancy worldwide, is an important contributor to the overall international cancer burden. Squamous cell carcinomas (SCCs) induced by 7,12-dimethylbenz[a]anthracene (DMBA) in the HBP reiterate many of the features observed in human OSCCs. The major risk factors associated with human oral cancer such as tobacco, betel quid and alcohol promote HBP carcinogenesis. SCCs induced by DMBA in the cheek pouch of Syrian hamsters are morphologically and histologically similar to human OSCC. Like human oral carcinogenesis, HBP carcinogenesis is a multistep process that involves sequential progression from hyperplasia to invasive carcinoma through varying degrees of dysplasia. In addition, HBP tumours express several biochemical and molecular markers that are also expressed in human OSCC. Multiple signaling pathways are dysfunctional in both human and hamster OSCCs. In particular, cell proliferation, apoptosis and angiogenesis are intricately interlinked in malignant transformation of the HBP mucosa by DMBA. The HBP carcinogenesis model is the best-known animal system for intervention by chemopreventive agents because of easy accessibility for examination, and follow-up of lesions. A number of synthetic and natural products have been documented to exhibit chemopreventive efficacy in the HBP model. Chemoprevention studies in the HBP model can serve as a crucial link in the potential efficacy assessment of candidate agents for oral cancer prevention and therapy. PMID:19538166

  11. Application study of intracytoplasmic sperm injection for golden hamster and cattle production.

    PubMed

    Horiuchi, Toshitaka

    2006-02-01

    This paper describes several technical improvements and our results in hamster intracytoplasmic sperm injection (ICSI), hamster round spermatid injection (ROSI) and bovine ICSI. The hamster is the mammalian species in which ICSI was first tried to produce fertilized oocytes. However, until recently, no live offspring following ICSI have ever been obtained. We reported the birth of live offspring following hamster ICSI. Improved points to success were 1) performing hamster ICSI in a dark room with a small incandescent lamp and manipulating both oocytes and fertilized eggs under microscope with a red light source and 2) injecting sperm heads without acrosomes. Under controlled illumination, the majority of the oocytes injected with acrosomeless sperm heads were fertilized normally, cleaved, and developed into morulae. Nine live offspring (19%) were born by transfer of hamster ICSI-derived embryos. Furthermore, we reported the birth of live offspring following hamster ROSI. About 70% of oocytes injected with round spermatids broken before injection were fertilized normally and about half of them developed to morulae and blastocysts. Three (5%) live young were born by transfer of hamster ROSI-derived embryos. On the other hand, in cattle, the main improvements were 1) injection of spermatozoa immobilized by scoring their tail just before injection into oocytes, and 2) additional ethanol activation 4 h after ICSI. About 70% of oocytes injected were activated 4 h after ICSI, and about 30% of them developed to blastocysts. Twenty-four live calves (39%) were born by non-surgical transfer of ICSI-derived embryos. Those results shows that, at present, live offspring are able to be obtained following hamster ICSI, ROSI and bovine ICSI, but further improvement is required due to higher production efficiency of offspring. PMID:16538031

  12. Malignant transformation of hamster cells following infection with bovine herpesvirus (infectious bovine rhinotracheitis virus.

    PubMed

    Michalski, F; Hsiung, G D

    1975-03-01

    Hamster embryo cells, following infection with IBR virus, showed malignant transformation. Hamsters of all ages, inbred or random bred, inoculated with two of the transformed cell lines developed solid tumors. Preliminary characterization of the tumors induced by one of the cell lines has indicated undifferentiated sarcomas. Viral specific antigen was detected in about 5% of the transformed cells and 10% of primary tumor cells in culture. Viral specific antibody was detected in the serum of tumor-bearing hamsters by the indirect immunofluorescent method, but no neutralizing antibodies were found. Infectious virus has not been recovered from either the transformed or tumor cells by cocultivation with bovine embryonic kidney cells. PMID:165538

  13. Gold carbenes, gold-stabilized carbocations, and cationic intermediates relevant to gold-catalysed enyne cycloaddition.

    PubMed

    Harris, R J; Widenhoefer, R A

    2016-08-21

    Cationic gold complexes in which gold is bound to a formally divalent carbon atom, typically formulated as gold carbenes or α-metallocarbenium ions, have been widely invoked in a range of gold-catalyzed transformations, most notably in the gold-catalyzed cycloisomerization of 1,n-enynes. Although the existence of gold carbene complexes as intermediates in gold-catalyzed transformations is supported by a wealth of indirect experimental data and by computation, until recently no examples of cationic gold carbenes/α-metallocarbenium ions had been synthesized nor had any cationic intermediates generated via gold-catalyzed enyne cycloaddition been directly observed. Largely for this reason, there has been considerable debate regarding the electronic structure of these cationic complexes, in particular the relative contributions of the carbene (LAu(+)[double bond, length as m-dash]CR2) and α-metallocarbenium (LAu-CR2(+)) forms, which is intimately related to the extent of d → p backbonding from gold to the C1 carbon atom. However, over the past ∼ seven years, a number of cationic gold carbene complexes have been synthesized in solution and generated in the gas phase and cationic intermediates have been directly observed in the gold-catalyzed cycloaddition of enynes. Together, these advances provide insight into the nature and electronic structure of gold carbene/α-metallocarbenium complexes and the cationic intermediates generated via gold-catalyzed enyne cycloaddition. Herein we review recent advances in this area. PMID:27146712

  14. Silver and Gold NMR

    PubMed Central

    Zangger, Klaus

    1999-01-01

    Silver and gold, together with copper, form the transition metal group IB elements in the periodic table and possess very different nuclear magnetic resonance (NMR) spectroscopic properties. While there is only one gold isotope (197Au), which has a spin of 3/2 and therefore a quadrupole moment, silver occurs in two isotopic forms (109Ag and 109Au), both of which have a spin 1/2 and similar NMR spectroscopic properties. The unfavorable properties of gold have prevented its NMR spectroscopic investigation thus far. On the other hand, there are several reports of silver NMR. However, the low sensitivity of silver, combined with its long relaxation times have rendered the direct detection of silver possible only with concentrations greater than a few tenth molar. Reviewed here are the general limitations of silver NMR and some techniques to partially overcome these limitations, as well as a summary of currently available chemical shift and scalar coupling data on 109Ag. PMID:18475898

  15. Biorecovery of gold

    USGS Publications Warehouse

    Eisler, R.

    2003-01-01

    Recovery of ionic and metallic gold (Au) from a wide variety of solutions by selected species of bacteria, yeasts, fungi, algae, and higher plants is documented. Gold accumulations were up to 7.0 g/kg dry weight (DW) in various species of bacteria, 25.0 g/kg DW in freshwater algae, 84.0 g/kg DW in peat, and 100.0 g/kg DW in dried fungus mixed with keratinous material. Mechanisms of accumulation include oxidation, dissolution, reduction, leaching, and sorption. Uptake patterns are significantly modified by the physicochemical milieu. Crab exoskeletons accumulate up to 4.9 g Au/kg DW; however, gold accumulations in various tissues of living teleosts, decapod crustaceans, and bivalve molluscs are negligible.

  16. Of humans and hamsters: a comparative evaluation of carcinogen activation, DNA damage, cell proliferation, apoptosis, invasion, and angiogenesis in oral cancer patients and hamster buccal pouch carcinomas.

    PubMed

    Nagini, Siddavaram; Letchoumy, Paramasivame Vidjaya; A, Thangavelu; Cr, Ramachandran

    2009-06-01

    The hamster buccal pouch (HBP) carcinogenesis model is one of the most well characterized animal systems for analyzing the development of oral squamous cell carcinoma (OSCC), a common malignancy worldwide. HBP carcinomas that closely mimic human OSCC are useful in understanding the molecular mechanisms of neoplastic transformation. The present study is a comparative evaluation of markers of carcinogen activation, oxidative stress, cell proliferation, apoptosis, invasion, and angiogenesis in human and hamster OSCCs. Enhanced expression of CYP1A1 and CYP1B1 isoforms in both human and hamster oral tumours was associated with significantly increased expression of 8-hydroxy 2-deoxyguanosine (8-OHdG) indicating oxidative DNA damage. Analysis of markers of cell survival and proliferation revealed increased expression of PCNA, GST-P, and NF-kappaB with downregulation of p21, p53 and IkappaB in both human and hamster OSCCs. In addition, both human and hamster oral carcinomas displayed invasive, and angiogenic properties as revealed by dysregulated cytokeratin expression, downregulation of RECK, and increased expression of uPA, MMP-2 and-9, HIF-1alpha, and VEGF. The results reveal aberrant expression of multiple molecules in key signaling pathways in both human OSCCs and HBP carcinomas rendering the HBP model as an important tool for monitoring oral oncogenesis. PMID:19250857

  17. An NSF rotator's perspective: view from inside the hamster wheel

    NASA Astrophysics Data System (ADS)

    White, Gary

    2015-03-01

    Duncan McBride served as my unofficial mentor during my time at NSF as a ``rotator'' (or, in NSF-speak, an IPA, short for an Intergovernmental Personnel Act assignee), from fall 2012 through summer of 2013. A rotator's main job is to help keep the wheels of the grant submission process turning, shepherding individual proposal jackets through the submission cycle. While most proposals are eventually ``Declined'' it is the few that are funded that evoke the most vivid memories of my time there. I hope to relay a little bit about what that was like on a daily basis, to give one hamster's take on the machinations of the NSF machine, and testify to Duncan McBride's critical role in establishing physics as the leader in disciplinary based educational research (DBER). It was a heady experience in many ways, despite the sheer girth of proposal jackets to be processed and the uncertain footing upon which federal employees tread these days.

  18. 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.

  19. X-ray microanalysis of hamster tracheal epithelium

    SciTech Connect

    Spencer, A.J.; Roomans, G.M. )

    1989-06-01

    Studies of ion transport across respiratory epithelia are of great interest if we are to understand the pathophysiology of diseases such as cystic fibrosis in which ion transport is abnormal. Concentrations of elements were determined in various subcellular regions of normal or isoproterenol-treated hamster tracheal epithelium, using X-ray microanalysis of freeze-dried cryosections. Samples of trachea were taken from animals under anesthesia and either frozen in situ or dissected and plunge frozen. Concentrations of Mg, P, S, Cl, K and Ca were higher in cytoplasm and nuclei of control epithelial cells in dissected samples than in cryoneedle samples. Following treatment with isoproterenol, a large decrease in the concentration of Cl was observed. The results confirm that cyclic AMP-regulated chloride secretion is unaffected by anesthesia.

  20. A magnetic field effect on learning in male golden hamsters.

    PubMed

    Łopuch, Sylwia

    2009-05-01

    The aim of this experiment was to investigate the influence of repeated exposure to 10, 20, 30 or 40 Hz magnetic fields at 0.1T on the learning of male golden hamsters in a Skinner box, in which the animals learned to press a lever to receive a food reward. The latency of the first response was not affected by exposure to the magnetic fields used in this experiment. No significant field-dependent effects on the performance of the task were observed in males exposed to 10 and 20 Hz magnetic fields at 0.1T. However, exposure significantly improved the learning of the task in animals exposed to 30 and 40 Hz magnetic fields at 0.1T. PMID:19150395

  1. Chinese hamster pleiotropic multidrug-resistant cells are not radioresistant

    SciTech Connect

    Mitchell, J.B.; Gamson, J.; Russo, A.; Friedman, N.; DeGraff, W.; Carmichael, J.; Glatstein, E.

    1988-01-01

    The inherent cellular radiosensitivity of a Chinese hamster ovary pleiotropic cell line that is multidrug resistant (CHRC5) was compared to that of its parental cell line (AuxB1). Radiation survival curve parameters n and D0 were 4.5 and 1.1 Gy, respectively, for the CHRC5 line and 5.0 and 1.2 Gy, respectively, for the parental line. Thus, the inherent radiosensitivity of the two lines was similar even though key intracellular free radical scavenging and detoxifying systems employing glutathione, glutathione transferase, and catalase produced enzyme levels that were 2.0-, 1.9-, and 1.9-fold higher, respectively, in the drug-resistant cell line. Glutathione depletion by buthionine sulfoximine resulted in the same extent of aerobic radiosensitization in both lines (approximately 10%). Incorporation of iododeoxyuridine into cellular DNA sensitized both cell lines to radiation. These studies indicate that pleiotropic drug resistance does not necessarily confer radiation resistance.

  2. Ultrastructural features of left ventricular myocytes in active and torpid hamsters compared with rats: a morphometric study.

    PubMed Central

    Skepper, J N; Navaratnam, V

    1995-01-01

    Myocytes from the midmyocardium of the left ventricle of rats and hamsters were examined by transmission electron microscopy. The volume fraction of lipid droplets in such myocytes was about 6 times greater in the active hamster than in the rat, but it became progressively reduced during cold exposure and entry into hibernation to values similar to those of the rat. The volume fraction of the T-system as well as the surface density of its membranes were each found to be twice as large in hamster myocytes as in the rat but there was no difference in these parameters between control, cold-exposed and torpid hamsters. The surface density of the junctional sarcoplasmic reticulum coupled with elements of the T-system was greater in active hamsters when compared with those of the rat, and greater still in torpid hamsters. There was no significant difference in the surface density of free sarcoplasmic reticulum between control hamsters, cold-exposed hamsters and rats but it was almost doubled in torpid hamsters. It is proposed that these features represent inherent differences in the ultrastructure of the left ventricle between the rat and hamster that may facilitate entry into hibernation. Additionally, further structural modifications during entry into hibernation may be related to alterations in lipid metabolism and modifications of calcium handling. Images Fig. 1 Fig. 2 PMID:7559131

  3. Photoperiod Regulates vgf-Derived Peptide Processing in Siberian Hamsters

    PubMed Central

    Noli, Barbara; Brancia, Carla; Pilleri, Roberta; D’Amato, Filomena; Messana, Irene; Manconi, Barbara; Ebling, Francis J. P.; Ferri, Gian-Luca; Cocco, Cristina

    2015-01-01

    VGF mRNA is induced in specific hypothalamic areas of the Siberian hamster upon exposure to short photoperiods, which is associated with a seasonal decrease in appetite and weight loss. Processing of VGF generates multiple bioactive peptides, so the objective of this study was to determine the profile of the VGF-derived peptides in the brain, pituitary and plasma from Siberian hamsters, and to establish whether differential processing might occur in the short day lean state versus long day fat. Antisera against short sequences at the C- or N- termini of proVGF, as well as against NERP-1, TPGH and TLQP peptides, were used for analyses of tissues, and both immunohistochemistry and enzyme linked immunosorbent assay (ELISA) coupled with high-performance liquid (HPLC) or gel chromatography were carried out. VGF peptide immunoreactivity was found within cortex cholinergic perikarya, in multiple hypothalamic nuclei, including those containing vasopressin, and in pituitary gonadotrophs. ELISA revealed that exposure to short day photoperiod led to a down-regulation of VGF immunoreactivity in the cortex, and a less pronounced decrease in the hypothalamus and pituitary, while the plasma VGF levels were not affected by the photoperiod. HPLC and gel chromatography both confirmed the presence of multiple VGF-derived peptides in these tissues, while gel chromatography showed the presence of the VGF precursor in all tissues tested except for the cortex. These observations are consistent with the view that VGF-derived peptides have pleiotropic actions related to changing photoperiod, possibly by regulating cholinergic systems in the cortex, vasopressin hypothalamic pathways, and the reproductive axis. PMID:26555143

  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. PMID:27068049

  5. Ductuli efferentes of the male Golden Syrian hamster reproductive tract.

    PubMed

    Ford, J; Carnes, K; Hess, R A

    2014-07-01

    Efferent ductules are responsible for the transportation of spermatozoa from the testis to the epididymis and their epithelium is responsible for the reabsorption of over 90% of the luminal fluid. The purpose of this research was to characterize the gross morphology and histology of efferent ductules in the male Golden Syrian hamster. The efferent ductules emerge from rete testis with a unique polarity at the apex or cephalic pole of the testis. The number of efferent ductules varied from 3 to 10 with an average of 6.0 and blind ending ducts were observed in approximately 56% of the males. The ductules merged into a single common duct prior to entering the caput epididymidis. The proximal efferent ductule lumen was wider than the distal (conus and common ducts), consistent with reabsorption of most of the luminal fluid, as was morphology of the ductal epithelium. Non-ciliated cells in the proximal region had prominent endocytic apparatuses, showing both coated pits and apical tubules in the apical cytoplasm. Large basolateral, intercellular spaces were also present in the epithelium of the proximal region. Distal non-ciliated cells had an abundance of large endosomes and lysosomal granules. Localisation of sodium/hydrogen exchanger-3 (NHE3; SLC9A3) and aquaporins 1 and 9 (AQP1, AQP9) along the microvillus border was also consistent with ion transport and fluid reabsorption by this epithelium. In comparison, the caput epididymidis epithelium expressed only AQP9 immunostaining. Another unusual feature of the hamster efferent ductules was the presence of glycogen aggregates in the basal cytoplasm of small groups of epithelial cells, but only in the proximal ducts near the rete testis. Androgen (AR), estrogen (ESR1 and ESR2) and vitamin D receptors (VDR) were also abundant in epithelial nuclei of proximal and distal efferent ductules. In comparison, caput epididymidis showed very little immunostaining for ESR1. PMID:24677666

  6. Langerhans cell function dictates induction of contact hypersensitivity or unresponsiveness to DNFB in Syrian hamsters

    SciTech Connect

    Streilein, J.W.; Bergstresser, P.R.

    1981-09-01

    The relationship between distribution and function of Langerhans cells within the epidermis and the capacity of cutaneous surfaces to promote the induction of contact hypersensitivity to DNFB have been examined in inbred Syrian hamsters. In a manner very similar to previous findings in mice, the results indicate that hamster cutaneous surfaces deficient in normally functioning Langerhans cells, naturally (cheek pouch epithelium) or artificially (after perturbation with ultraviolet light), are inefficient at promoting DNFB sensitization. Instead, DNFB applied to these regions of skin results in the induction of a state of specific unresponsiveness. Viable lymphoid cells from unresponsive hamsters can transfer the unresponsiveness to naive hamsters suggesting that active suppression is at least partly responsible, probably mediated by T lymphocytes.

  7. 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...

  8. INVESTIGATION OF POSSIBLE AGE EFFECTS ON MEIOTIC CHROMOSOMAL RECOMBINATION AND SEGREGATION IN ARMENIAN HAMSTER SPERMATOCYTES

    EPA Science Inventory

    Male Armenian hamsters (Cricetulus migratorius; 2N:22) were evaluated for age effects upon meiotic recombination and aneuploidy incidence. Primary spermatocytes from young and old animals revealed similar chiasma frequencies. The incidence of terminal-type chiasmata in sex bivale...

  9. Embryotoxic response produced by inorganic mercury in different strains of hamsters

    SciTech Connect

    Gale, T.F.

    1981-02-01

    This report compares the mercury-induced embryotoxicity among one noninbred and five inbred strains of hamsters. A single dose of mercuric acetate was injected into pregnant hamsters on the morning of the 8th gestation day. Treated and control animals were killed on either the 12th or 15th gestation day and studied for the types and frequency of external and internal abnormalities as well as the incidence of resorption sites. The hamster strains exhibited significant resorption rates as well as a variety of abnormalities including edema, retardation, ventral wall defects, pericardial cavity distention, cleft palate, hydrocephalus, and heart defects. Significant but varied interstrain differences were observed for most of these indicators of mercury-induced embryotoxicity. The results of this study were compared with prior work in which the same hamster strains were exposed to cadmium or lead.

  10. Processing Gold Quarry refractory ores

    NASA Astrophysics Data System (ADS)

    Hausen, D. M.

    1989-04-01

    The Gold Quarry deposit is the largest sediment-hosted gold deposit yet discovered on the Carlin trend in northern Nevada. However, despite the locale's vast reserves, the gold is difficult to extract from portions of the deposit. Detailed, ongoing mineralogical analyses assure proper treatment of the ore.

  11. 16 CFR Appendix to Part 23 - Exemptions Recognized in the Assay for Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled Gold Plate, Silver, and Platinum Industry...—Exemptions Recognized in the Assay for Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled Gold Plate... in any assay for quality of a karat gold industry product include springs, posts, and separable...

  12. 16 CFR Appendix to Part 23 - Exemptions Recognized in the Assay for Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled Gold Plate, Silver, and Platinum Industry...—Exemptions Recognized in the Assay for Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled Gold Plate... in any assay for quality of a karat gold industry product include springs, posts, and separable...

  13. Derivatized gold clusters and antibody-gold cluster conjugates

    DOEpatents

    Hainfeld, James F.; Furuya, Frederic R.

    1994-11-01

    Antibody- or antibody fragment-gold cluster conjugates are shown wherein the conjugate size can be as small as 5.0 nm. Methods and reagents are disclosed in which antibodies, Fab' or F(ab').sub.2 fragments thereof are covalently bound to a stable cluster of gold atoms. The gold clusters may contain 6, 8, 9, 11, 13, 55 or 67 gold atoms in their inner core. The clusters may also contain radioactive gold. The antibody-cluster conjugates are useful in electron microscopy applications as well as in clinical applications that include imaging, diagnosis and therapy.

  14. Derivatized gold clusters and antibody-gold cluster conjugates

    DOEpatents

    Hainfeld, J.F.; Furuya, F.R.

    1994-11-01

    Antibody- or antibody fragment-gold cluster conjugates are shown wherein the conjugate size can be as small as 5.0 nm. Methods and reagents are disclosed in which antibodies, Fab' or F(ab')[sub 2] fragments are covalently bound to a stable cluster of gold atoms. The gold clusters may contain 6, 8, 9, 11, 13, 55 or 67 gold atoms in their inner core. The clusters may also contain radioactive gold. The antibody-cluster conjugates are useful in electron microscopy applications as well as in clinical applications that include imaging, diagnosis and therapy. 7 figs.

  15. 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

  16. Earth's continental crustal gold endowment

    NASA Astrophysics Data System (ADS)

    Frimmel, H. E.

    2008-03-01

    The analysis of the temporal distribution of gold deposits, combined with gold production data as well as reserve and resource estimates for different genetic types of gold deposit, revealed that the bulk of the gold known to be concentrated in ore bodies was added to the continental crust during a giant Mesoarchaean gold event at a time (3 Ga) when the mantle temperature reached a maximum and the dominant style of tectonic movement changed from vertical, plume-related to subhorizontal plate tectonic. A magmatic derivation of the first generation of crustal gold from a relatively hot mantle that was characterized by a high degree of partial melting is inferred from the gold chemistry, specifically high Os contents. While a large proportion of that gold is still present in only marginally modified palaeoplacer deposits of the Mesoarchaean Witwatersrand Basin in South Africa, accounting for about 40% of all known gold, the remainder has been recycled repeatedly on a lithospheric scale, predominantly by plate-tectonically induced magmatic and hydrothermal fluid circulation, to produce the current variety of gold deposit types. Post-Archaean juvenile gold addition to the continental crust has been limited, but a mantle contribution to some of the largest orogenic or intrusion-related gold deposits is indicated, notably for the Late Palaeozoic Tien Shan gold province. Magmatic fluids in active plate margins seem to be the most effective transport medium for gold mobilization, giving rise to a large proportion of volcanic-arc related gold deposits. Due to their generally shallow crustal level of formation, they have a low preservation potential. In contrast, those gold deposits that form at greater depth are more widespread also in older rocks. This explains the high proportion of orogenic (including intrusion-related) gold (32%) amongst all known gold deposits. The overall proportion of gold concentrated in known ore bodies is only 7 × 10- 7 of the estimated total

  17. Use of hamster as a model to study diet-induced atherosclerosis

    PubMed Central

    2010-01-01

    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 apoB-100 and intestinal apoB-48 secretion, and uptake of the majority of LDL cholesterol via the LDL receptor pathway. Early work suggested hamsters fed high cholesterol and saturated fat diets responded similarly to humans in terms of lipoprotein metabolism and aortic lesion morphology. Recent work has not consistently replicated these findings. Reviewed was the literature related to controlled hamster feeding studies that assessed the effect of strain, background diet (non-purified, semi-purified) and dietary perturbation (cholesterol and/or fat) on plasma lipoprotein profiles and atherosclerotic lesion formation. F1B hamsters fed a non-purified cholesterol/fat-supplemented diet had more atherogenic lipoprotein profiles (nHDL-C > HDL-C) than other hamster strains or hamsters fed cholesterol/fat-supplemented semi-purified diets. However, fat type; saturated (SFA), monounsaturated or n-6 polyunsaturated (PUFA) had less of an effect on plasma lipoprotein concentrations. Cholesterol- and fish oil-supplemented semi-purified diets yielded highly variable results when compared to SFA or n-6 PUFA, which were antithetical to responses observed in humans. Dietary cholesterol and fat resulted in inconsistent effects on aortic lipid accumulation. No hamster strain was reported to consistently develop lesions regardless of background diet, dietary cholesterol or dietary fat type amount. In conclusion, at this time the Golden-Syrian hamster does not appear to be a useful model to determine the mechanism(s) of diet-induced development of atherosclerotic lesions. PMID:21143982

  18. 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. PMID:26297409

  19. Role of caloric homeostasis and reward in alcohol intake in Syrian golden hamsters.

    PubMed

    Gulick, Danielle; Green, Alan I

    2010-11-01

    The Syrian golden hamster drinks alcohol readily, but only achieves moderate blood alcohol levels, and does not go through withdrawal from alcohol. Because the hamster is a model of caloric homeostasis, both caloric content and reward value may contribute to the hamster's alcohol consumption. The current study examines alcohol consumption in the hamster when a caloric or non-caloric sweet solution is concurrently available and caloric intake in the hamster before, during, and after exposure to either: alcohol, sucrose or saccharin. In Experiments 1 and 2, hamsters were given access to alcohol (15% v/v) and water; once alcohol consumption steadied, a bottle containing an ascending concentration of sucrose (99-614 mM) or saccharin (2-10 mM), or water was added. In Experiment 3, hamsters were given access to alcohol (15% v/v), sucrose (614 mM), saccharin (4 mM), or a second water bottle for 14 days. After the second bottle was removed, measurements continued for 14days. Sucrose exposure suppressed alcohol consumption at concentrations lower in calories than the alcohol solution. Saccharin exposure failed to suppress alcohol consumption. Exposure to sucrose and alcohol but not saccharin decreased food intake. Decreased alcohol consumption in response to a caloric sweetener and decreased food intake during alcohol exposure support that alcohol consumption by the hamster is mediated by caloric content. However, suppression of alcohol intake by a sucrose solution of lower caloric content and the equivalent intake of individual alcohol, sucrose and saccharin solutions support a role for reward value in alcohol consumption. PMID:20688091

  20. Experimental infection of hamsters with avian paramyxovirus serotypes 1 to 9

    PubMed Central

    2011-01-01

    Avian paramyxoviruses (APMVs) are frequently isolated from domestic and wild birds throughout the world and are separated into nine serotypes (APMV-1 to -9). Only in the case of APMV-1, the infection of non-avian species has been investigated. The APMVs presently are being considered as human vaccine vectors. In this study, we evaluated the replication and pathogenicity of all nine APMV serotypes in hamsters. The hamsters were inoculated intranasally with each virus and monitored for clinical disease, pathology, histopathology, virus replication, and seroconversion. On the basis of one or more of these criteria, each of the APMV serotypes was found to replicate in hamsters. The APMVs produced mild or inapparent clinical signs in hamsters except for APMV-9, which produced moderate disease. Gross lesions were observed over the pulmonary surface of hamsters infected with APMV-2 & -3, which showed petechial and ecchymotic hemorrhages, respectively. Replication of all of the APMVs except APMV-5 was confirmed in the nasal turbinates and lungs, indicating a tropism for the respiratory tract. Histologically, the infection resulted in lung lesions consistent with bronchointerstitial pneumonia of varying severity and nasal turbinates with blunting or loss of cilia of the epithelium lining the nasal septa. The majority of APMV-infected hamsters exhibited transient histological lesions that self resolved by 14 days post infection (dpi). All of the hamsters infected with the APMVs produced serotype-specific HI or neutralizing antibodies, confirming virus replication. Taken together, these results demonstrate that all nine known APMV serotypes are capable of replicating in hamsters with minimal disease and pathology. PMID:21345199

  1. 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

    2015-01-01

    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. PMID:25421023

  2. Gold and gold working in Late Bronze Age Northern Greece.

    PubMed

    Vavelidis, M; Andreou, S

    2008-04-01

    Numerous objects of gold displaying an impressive variety of types and manufacturing techniques are known from the Late Bronze Age (LBA) contexts of Mycenaean Greece, but very little is known about the origin and processing of gold during the second millennium B.C: . Ancient literature and recent research indicate that northern Greece is probably the richest gold-bearing region in Greece, and yet, very little evidence exists regarding the exploitation of its deposits and the production as well as use of gold in the area during prehistory. The unusual find of a group of small stone crucibles at the prehistoric settlement of Thessaloniki Toumba, one with visible traces of gold melting, proves local production and offers a rare opportunity to examine the process of on-site gold working. Furthermore, the comparison of the chemical composition of prehistoric artefacts from two settlements with those of gold deposits in their immediate areas supports the local extraction of gold and opens up the prospect for some of the Mycenaean gold to have originated in northern Greece. The scarcity of gold items in northern Greek LBA contexts may not represent the actual amount of gold produced and consumed, but could be a result of the local social attitudes towards the circulation and deposition of artefacts from precious metals. PMID:18087685

  3. 'Cascade Gold' raspberry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘Cascade Gold’ is a new gold fruited, floricane fruiting raspberry cultivar (Rubus idaeus L.) jointly released by Washington State University (WSU), Oregon State University (OSU) and the U.S. Department of Agriculture (USDA). It has been evaluated at Puyallup, Wash. in plantings from 1988 to 2008. ...

  4. Digging for Gold

    ERIC Educational Resources Information Center

    Waters, John K.

    2012-01-01

    In the case of higher education, the hills are more like mountains of data that "we're accumulating at a ferocious rate," according to Gerry McCartney, CIO of Purdue University (Indiana). "Every higher education institution has this data, but it just sits there like gold in the ground," complains McCartney. Big Data and the new tools people are…

  5. Gold trifluoromethyl complexes.

    PubMed

    Gil-Rubio, Juan; Vicente, José

    2015-12-01

    This article reviews the synthesis, reactivity and applications of gold trifluoromethyl complexes, which are the only isolated perfluoroalkyl complexes of gold. The most reported examples are neutral Au(i) complexes of the type [Au(CF3)L], whereas only two Au(ii) trifluoromethyl complexes have been reported, both being diamagnetic and containing a strong Au-Au bond. A number of Au(iii) trifluoromethyl complexes have been prepared by oxidative addition of halogens or iodotrifluoromethane to Au(i) complexes or, in a few cases, by transmetallation reactions. Owing to the limitations of the available synthetic methods, a lower number of examples is known, particularly for the oxidation states (ii) and (iii). Gold trifluoromethyl complexes present singular characteristics, such as thermal stability, strong Au-C bonds and, in some cases, reactive α-C-F bonds. Some of the Au(iii) complexes reported, show unusually easy reductive elimination reactions of trifluoromethylated products which could be applied in the development of gold-catalyzed processes for the trifluoromethylation of organic compounds. PMID:26169553

  6. GOLD PRESSURE VESSEL SEAL

    DOEpatents

    Smith, A.E.

    1963-11-26

    An improved seal between the piston and die member of a piston-cylinder type pressure vessel is presented. A layer of gold, of sufficient thickness to provide an interference fit between the piston and die member, is plated on the contacting surface of at least one of the members. (AEC)

  7. Preventing dyslipidemia by Chlorella pyrenoidosa in rats and hamsters after chronic high fat diet treatment.

    PubMed

    Cherng, Jong-Yuh; Shih, Mei-Fen

    2005-05-13

    The effects of Chlorella pyrenoidosa on serum lipid profiles, after concomitant long-term treatment of high-fat diet (HFD) in rats and hamsters was studied. Wistar rats and Syrian hamsters were fed with or without various concentrations of Chlorella pyrenoidosa contained high-fat diet (CHFD) for 2, 4 and 8 weeks prior to assay of serum lipids. Fasting triglycerides, total cholesterol, and LDL cholesterol as well as HDL cholesterol levels in high-fat diet treated rats and hamster were determined. Results showed that triglycerides, total cholesterol and LDL cholesterol levels in HFD treated rats and hamsters were increased from the normal rodent diet (NRD) treated controls after 2, 4, and 8-week treatments. However, the presence of Chlorella pyrenoidosa in high-fat diets significantly decreased the levels of triglycerides, total cholesterol and LDL cholesterol with comparison to HFD group in rats and hamsters. The total cholesterol/HDL ratios, an indication of occurrence of coronary heart disease, were decreased in all CHFD treated grouped rats and hamsters which suggests administration of Chlorella pyrenoidosa could lower the occurring risk of heart diseases. In conclusion, Chlorella pyrenoidosa has the ability to prevent dyslipidemia in chronic high-fat fed animals and could be potential in use to prevent intestinal absorption of redundant lipid from our daily intake and subsequently to prevent hyperlipidemia as well as atherosclerosis. PMID:15850594

  8. Dual tracer autoradiographic study with thallium-201 and radioiodinated fatty acid in cardiomyopathic hamsters

    SciTech Connect

    Kurata, C.; Kobayashi, A.; Yamazaki, N.

    1989-01-01

    To investigate the usefulness of myocardial scintigraphy with radioiodinated 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) in cardiomyopathy, quantitative dual tracer autoradiographic study with /sup 201/Tl and (/sup 125/I)BMIPP was performed in 27 cardiomyopathic Bio 14.6 Syrian hamsters and eight normal hamsters. Furthermore, 16 Bio 14.6 Syrian hamsters aged 21 days were divided into verapamil-treated (during 70 days) and control groups (respectively, n = 8), and autoradiography with /sup 201/Tl and (/sup 125/I)BMIPP was performed. Quantitative autoradiography demonstrated an uncoupling of /sup 201/Tl and (/sup 125/I)BMIPP distributions and a regional heterogeneity of (/sup 125/I)BMIPP distribution in cardiomyopathic hamsters aged more than 2 mo, while normal hamsters showed only mild heterogeneity of (/sup 125/I)BMIPP distribution without an uncoupling of tracers. Age-matched comparison between normal and cardiomyopathic hamsters (5-8 mo old) demonstrated that a difference between their (/sup 125/I)BMIPP distributions are more marked than that between their /sup 201/Tl distributions. Furthermore, (/sup 125/I)BMIPP visualized effects of verapamil on cardiomyopathy more distinctly than did /sup 201/Tl. In conclusion, myocardial imaging with (/sup 123/I)BMIPP could be useful for investigating cardiomyopathy and evaluating the efficacy of therapeutic intervention in patients with cardiomyopathy.

  9. Aneuploidy in spermatozoa detected by FISH. Comparison with sperm chromosome data obtained via hamster system

    SciTech Connect

    Estop, A.M.; Van Kirk, V.; Cieply, K.

    1994-09-01

    Fluorescence in-situ hybridization (FISH) with two-color and cocktail DNA probes was used to assess the rates of aneuploidy for the X,Y and 18 chromosomes in 3 male donors. (Experiment 1). These individuals had previously been studied with the hamster system and published. Experiment 2 was designed in order to compare aneuploidy rates for chromosome 18 in donor 2 in conjunction with chromosome 6 and 12 as an internal control. (1) Aneuploidy for the sex chromosomes in the hamster system was 0.5 for Donor 1 and 0.7 (3) which was very similar to 0.49 (1) and 0.41 (3) found in this experiment. However, Donor 2 showed a lower rate of sex non-disjunction with this system: 0.18 vs. 0.7 with the hamster system. (2) Diploidy rates are in the same ranges in experiments 1 and 2. (3) If autosome aneuploidy rates are extrapolated to 22 chromosomes, the following values are found: Donor 1:2.42 (vs. 2.0 in the hamster system); donor 3:2.2 (vs. 1.34 with the hamster system) and donor 2:1.32 which is lower than 4.32 found with the hamster system. More data needs to be collected on the use of FISH for this study of aneuploides in sperm cells and attention needs to be paid to the different types of probes used for validation of results.

  10. Autoradiographic localization of tritiated dihydrotestosterone in the flank organ of the albino hamster

    SciTech Connect

    Lucky, A.W.; Eisenfeld, A.J.; Visintin, I.

    1985-02-01

    In the hamster flank organ, the growth of hair and growth of sebaceous glands are androgen-dependent functions. Although dihydrotestosterone (DHT) is known to be a potent stimulator of flank organ growth, there is no information about localization of DHT receptor sites in this organ. The purpose of this study was to use steroid autoradiography to localize DHT receptors in the hamster flank organ. Because steroid hormones are functional when translocated to nuclear receptors, nuclear localization by autoradiography defines receptor sites. In order to be able to visualize autoradiographic grains from radiolabeled androgens around hair follicles, albino hamsters were studied to avoid confusion between the grains and pigment granules which are abundant in the more common Golden Syrian hamster. Mature male hamsters castrated 24 hours earlier were given tritium-labeled dihydrotestosterone ( (/sup 3/H)DHT). Using the technique of thaw-mount steroid autoradiography, 4-micron unfixed frozen sections were mounted in the dark onto emulsion-coated glass slides and allowed to develop for 4-6 months. (/sup 3/H)DHT was found to be concentrated over sebocyte nuclei. The label was present peripherally as well as in differentiating sebocytes. There was no nuclear localization of (/sup 3/H)DHT in animals pretreated with excessive quantities of unlabeled DHT. Steroid metabolites of (/sup 3/H) DHT were assessed by thin-layer chromatography in paired tissue samples. Most of the label remained with DHT. Uptake was inhibited in the flank organ of hamsters pretreated with unlabeled DHT.

  11. Beneficial effects of noni (Morinda citrifolia L.) juice on livers of high-fat dietary hamsters.

    PubMed

    Lin, Yi-Ling; Chang, Yuan-Yen; Yang, Deng-Jye; Tzang, Bor-Show; Chen, Yi-Chen

    2013-09-01

    Polyphenols in noni juice (NJ) are mainly composed of phenolic acids, mainly gentisic, p-hydroxybenoic, and chlorogenic acids. To investigate the beneficial effects of NJ on the liver, hamsters were fed with two diets, normal-fat and high-fat diets. Furthermore, high-fat dietary hamsters were received distilled water, and 3, 6, and 9 mL NJ/kg BW, respectively. After a 6-week feeding period, the increased (p<0.05) sizes of liver and visceral fat in high-fat dietary hamsters compared to the control hamsters were ameliorated (p<0.05) by NJ supplementation. NJ also decreased (p<0.05) serum/liver lipids but enhanced (p<0.05) daily faecal lipid/bile acid outputs in the high-fat dietary hamsters. High-fat dietary hamsters supplemented with NJ had higher (p<0.05) liver antioxidant capacities but lowered (p<0.05) liver iNOS, COX-2, TNF-α, and IL-1β expressions, gelatinolytic levels of MMP9, and serum ALT values compared to those without NJ. Hence, NJ protects liver against a high-fat dietary habit via regulations of antioxidative and anti-inflammatory responses. PMID:23578611

  12. Gold Nanoparticles Cytotoxicity

    NASA Astrophysics Data System (ADS)

    Mironava, Tatsiana

    Over the last two decades gold nanoparticles (AuNPs) have been used for many scientific applications and have attracted attention due to the specific chemical, electronic and optical size dependent properties that make them very promising agents in many fields such as medicine, imagine techniques and electronics. More specifically, biocompatible gold nanoparticles have a huge potential for use as the contrast augmentation agent in X-ray Computed Tomography and Photo Acoustic Tomography for early tumor diagnostic as well these nanoparticles are extensively researched for enhancing the targeted cancer treatment effectiveness such as photo-thermal and radiotherapy. In most biomedical applications biocompatible gold nanoparticles are labeled with specific tumor or other pathology targeting antibodies and used for site specific drug delivery. However, even though gold nanoparticles poses very high level of anti cancer properties, the question of their cytotoxicity ones they are released in normal tissue has to be researched. Moreover, the huge amount of industrially produced gold nanoparticles raises the question of these particles being a health hazard, since the penetration is fairly easy for the "nano" size substances. This study focuses on the effect of AuNPs on a human skin tissue, since it is fall in both categories -- the side effects for biomedical applications and industrial workers and users' exposure during production and handling. Therefore, in the present project, gold nanoparticles stabilized with the biocompatible agent citric acid were generated and characterized by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). The cytotoxic effect of AuNPs release to healthy skin tissue was modeled on 3 different cell types: human keratinocytes, human dermal fibroblasts, and human adipose derived stromal (ADS) cells. The AuNPs localization inside the cell was found to be cell type dependent. Overall cytotoxicity was found to be dependent

  13. 'Pot of Gold'

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This false-color image taken by the panoramic camera on the Mars Exploration Rover Spirit shows the rock dubbed 'Pot of Gold' (upper left), located near the base of the 'Columbia Hills' in Gusev Crater. The rock's nodules and layered appearance have inspired rover team members to investigate the rock's detailed chemistry in coming sols. This picture was taken on sol 158 (June 13, 2004).

  14. Radioactive gold ring dermatitis

    SciTech Connect

    Miller, R.A.; Aldrich, J.E. )

    1990-08-01

    A superficial squamous cell carcinoma developed in a woman who wore a radioactive gold ring for more than 30 years. Only part of the ring was radioactive. Radiation dose measurements indicated that the dose to basal skin layer was 2.4 Gy (240 rad) per week. If it is assumed that the woman continually wore her wedding ring for 37 years since purchase, she would have received a maximum dose of approximately 4600 Gy.

  15. Cranioschisis aperta with encephaloschisis in cephalothoracopagus hamster twins.

    PubMed Central

    Willhite, C C; Rossi, N L; Frakes, R A; Sharma, R P

    1985-01-01

    The results of gross and histopathological study of a near-term male hamster exencephalic lateral cephalothoracopagus are presented. There was minimal duplication of the internal organs to the point of division at the abdomen. The appendicular skeleton was relatively unaffected by the severe malformations of the axial skeleton. The studies suggested that the lateral relationship of the skull to the spinal columns was a consequence of the presence of two embryonic neural tubes; the chordomesodermal systems of the right and left twins apparently contributed the tissues for the right and left cephalic neural folds, respectively. Anomalies of the vertebral bodies and neural arches were not related to failure of closure of the neural tube as there was no evidence for rachischisis in either body half. Rather, the anomalous axial skeletal elements were apparently the result of competing fields of development by two chordomesodermal systems. The twins were recovered from a dam maintained on a diet consisting of 80% cassava, a cyanide-containing staple consumed by humans in tropical countries. Because the numbers of resorbed implantation sites and malformed litermates were low and the failure to produce conjoined twins in other litters recovered from dams given cassava diets, it appears unlikely that the malformation was related to the composition of the diet. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. PMID:4016585

  16. Neoplastic transformation of hamster embyro cells by heavy ions.

    PubMed

    Han, Z; Suzuki, H; Suzuki, F; Suzuki, M; Furusawa, Y; Kato, T; Ikenaga, M

    1998-01-01

    We have studied the induction of morphological transformation of Syrian hamster embryo cells by low doses of heavy ions with different linear energy transfer (LET), ranging from 13 to 400 keV/micrometer. Exponentially growing cells were irradiated with 12C or 28Si ion beams generated by the Heavy Ion Medical Accelerator in Chiba (HIMAC), inoculated to culture dishes, and transformed colonies were identified when the cells were densely stacked and showed a crisscross pattern. Over the LET range examined, the frequency of transformation induced by the heavy ions increased sharply at very low doses no greater than 5 cGy. The relative biological effectiveness (RBE) of the heavy ions relative to 250 kVp X-rays showed an initial increase with LET, reaching a maximum value of about 7 at 100 keV/micrometer, and then decreased with the further increase in LET. Thus, we confirmed that high LET heavy ions are significantly more effective than X-rays for the induction of in vitro cell transformation. PMID:11542417

  17. Gastrointestinal absorption of protactinium, uranium, and neptunium in the hamster

    SciTech Connect

    Harrison, J.D.; Stather, J.W.

    1981-10-01

    The gastrointestinal absorption of protactinium, uranium, and neptunium in adult hamsters was measured. The actinide preparations were administered intragastrically and animals were kept 2 to 4 weeks prior to the radiochemical analysis of selected tissue samples. Total absorption was estimated using data for the distribution of the actinides after intravenous injection in soluble form. The values obtained were 3.9 and 0.22% for /sup 231/Pa citrate and /sup 231/Pa fluoride, respectively; 0.77 and 0.11% for /sup 233/U (uranyl) nitrate and /sup 233/U dioxide, respectively; and 0.06 and 0.05% for /sup 237/Np citrate and /sup 237/Np nitrate, respectively. The absorption factors recommended by the International Commission on Radiological Protection for use in calculating annual limits on intake for occupationally exposed workers are: 0.1% for all compounds of Pa; 5 and 0.2% for soluble hexavalent and relatively insoluble tetravalent forms of U, respectively; and 1.0% for all chemical forms of Np. The experimental basis for these values is discussed.

  18. Aromatase activity in ovarian follicles of the golden hamster.

    PubMed

    Matson, P L; Collins, W P

    1984-09-01

    The aromatizing ability of recombined granulosa and thecal cells in culture, isolated from hamsters 72-78 h and 96-102 h after PMSG-stimulation, was assessed by the addition to the culture medium of androstenedione, testosterone, dehydroepiandrosterone (DHEA) or 5 alpha-dihydrotestosterone (DHT), and measuring the output of oestradiol 4 h later. The cells from all follicles taken after 96-102 h had a reduced oestradiol output compared to those isolated after 72-78 h (P less than 0.02). Recombined cells from the unluteinized follicles at 96-102 h (Group I) showed similar oestradiol output in the presence of androstenedione, testosterone and DHEA to the cells from follicles taken at 72-78 h. However, the recombined cells from the luteinized follicles (Group II) showed a reduced output of oestradiol in the presence of androstenedione, testosterone and DHEA when compared to the recombined cells from the previous period cultured with the corresponding C19 steroid. The results show that a reduced oestradiol output can be caused by (1) the reduced availability of aromatizable substrate and (2) a reduced potential aromatase activity. PMID:6471042

  19. Adherence of Bordetella bronchiseptica to hamster lung fibroblasts.

    PubMed Central

    Plotkin, B J; Bemis, D A

    1984-01-01

    The adherence of Bordetella bronchiseptica smooth-, intermediate-, and rough-phase isolates to hamster lung fibroblasts (HLF) (Don line) was characterized by competitive inhibition studies and enzyme and chemical treatments of both the bacteria and the HLF. The adherence of the rough- and intermediate-phase isolates (n = 13) was altered by coincubation of the bacteria and HLF with cationic chelators, including EGTA and citrate. EGTA inhibition of the adherence of the rough- and intermediate-phase isolates could be overcome by the addition of Ca2+, Mn2+, Cd2+, or Sr2+ to the reaction mixture. In addition, citrate released bound bacteria from the HLF. Although the adherence of the smooth-phase isolates (n = 4) was unaltered by cationic chelators, binding was inhibited by N-acetylated amino sugars, with N-acetylglucosamine inhibiting 98% of the adherence of the smooth-phase isolates. Homogenization, protease K, and heat treatment (60 min, 60 degrees C) of the bacteria also resulted in a loss of adherence. It was concluded that B. bronchiseptica can adhere to HLF by at least two mechanisms and that the ligand responsible appears to be a proteinacious, heat labile cell surface component. PMID:6437989

  20. Chlorpromazine distribution in hamsters and mice bearing transplantable melanoma

    SciTech Connect

    Fairchild, R.G.; Greenberg, D.; Watts, K.P.; Packer, S.; Atkins, H.L.; Som, P.; Hannon, S.J.; Brill, A.B.; Fand, I.; McNally, W.P.

    1982-02-01

    Chlorpromazine (CPZ) distribution was measured in tissues of Syrian golden hamsters bearing Greene melanoma and in BALB/c mice bearing Harding-Passey melanoma. Distribution was evaluated as a function of time (0.5 to 14 days) and as a function of single and multiple doses (up to five) of from 5 to 50 mg CPZ per kg body weight. Routes of administration (i.p., i.v., p.o.) were compared. The physiological behavior of CPZ is of interest as it is used extensively as a tranquilizing drug (Thorazine). Further, since CPZ binds to the pigment melanin, the possibility exists of using CPZ to transport diagnostic or therapeutic agents to melanoma. It was found that, at 2 days postinjection, tumor/tissue concentration ratios exceeded 10 for metabolizing organs, such as liver, and 100 for background tissues, such as blood and muscle. Absolute concentrations of CPZ in tumor exceeding 100 ..mu..g CPZ per g tumor were obtained with both single and multiple doses. This selective high concentration in tumor would make CPZ an ideal vehicle for the transport of boron to tumor for use in neutron capture therapy via the /sup 10/B(n,..cap alpha..)/sup 7/Li reaction.

  1. The dystrophic hamster: an animal model of alveolar hypoventilation.

    PubMed

    Schlenker, E H; Burbach, J A

    1991-11-01

    The BIO 14.6 dystrophic hamster (DH) is a genetically determined animal model of alveolar hypoventilation (AH) that exhibits a ventilatory control pattern of compensation and then decompensation similar to that in progressive forms of muscular dystrophy and nonprogressive congenital myopathies in humans. Possible causes of AH in the DH include respiratory muscle weakness, ventilation-to-perfusion inequalities, and an inadequate drive to breathe. Histochemical and contractile abnormalities of the diaphragm, reduced lung surface area available for gas exchange, abnormal pulmonary microvascular reactivity to hypoxia, altered levels of neurochemicals, and abnormal cellular regulation of calcium are among the specific factors that may contribute to the development of AH. The potential role of hypothyroidism in the development of AH is reviewed because many hypothyroid patients exhibit AH and other ventilatory dysfunctions, hypothyroidism is present in human patients and animals with muscular dystrophy, and thyroid status is known to influence lung architecture, myocyte function, and neural activity. Additional studies linking neurohormonal signals, transcellular signal processing, and control of ventilation in the DH may help us understand the etiology of AH in human disease. PMID:1684789

  2. Magnesium sulfate-induced water secretion in hamster small intestine

    SciTech Connect

    Reichelderfer, M.; Pero, B.; Lorenzsonn, V.; Olsen, W.A.

    1984-05-01

    Possible mechanisms of magnesium sulfate (MgSO/sup 4/)-induced diarrhea were studied. In vivo perfusion of hamster small intestine with an isotonic electrolyte solution containing 50 mM MgSO/sub 4/ produced nearly three times as much fluid secretion as did a solution containing an equiosmotic amount of mannitol. It was found that magnesium was absorbed at a faster rate than mannitol under these conditions, suggesting that differences in solute permeability do not explain the differences in secretory rates. Magnesium ion rather than sulfate appeared largely responsible for the effect as replacement of sulfate with chloride did not diminish the response. MgSO/sub 4/ perfusion of a proximal intestinal segment did not affect water transport in an isolated distal segment suggesting that release of cholecystokinin or alterations in serum levels of other hormones were not responsible. Intestinal permeability, morphology, and cyclic nucleotide levels were normal after MgSO/sub 4/ perfusion. Thus, MgSO/sub 4/-induced diarrhea cannot be explained by the usual mechanisms, and additional processes responsible for intestinal secretion must exist.

  3. ULTRASTRUCTURE OF THE NUCLEOLUS DURING THE CHINESE HAMSTER CELL CYCLE

    PubMed Central

    Noel, J. S.; Dewey, W. C.; Abel, J. H.; Thompson, R. P.

    1971-01-01

    Changes in the structure of the nucleolus during the cell cycle of the Chinese hamster cell in vitro were studied. Quantitative electron microscopic techniques were used to establish the size and volume changes in nucleolar structures. In mitosis, nucleolar remnants, "persistent nucleoli," consisting predominantly of ribosome-like granular material, and a granular coating on the chromosomes were observed. Persistent nucleoli were also observed in some daughter nuclei as they were leaving telophase and entering G1. During very early G1, a dense, fibrous material characteristic of interphase nucleoli was noted in the nucleoplasm of the cells. As the cells progressed through G1, a granular component appeared which was intimately associated with the fibrous material. By the middle of G1, complete, mature nucleoli were present. The nucleolar volume enlarged by a factor of two from the beginning of G1 to the middle of S primarily due to the accumulation of the granular component. During the G2 period, there was a dissolution or breakdown of the nucleolus prior to the entry of the cells into mitosis. Correlations between the quantitative aspects of this study and biochemical and cytochemical data available in the literature suggest the following: nucleolar reformation following division results from the activation of the nucleolar organizer regions which transcribe for RNA first appearing in association with protein as a fibrous component (45S RNA) and then later as a granular component (28S and 32S RNA). PMID:4933472

  4. Watching single gold nanorods grow.

    PubMed

    Wei, Zhongqing; Qi, Hua; Li, Min; Tang, Bochong; Zhang, Zhengzheng; Han, Ruiling; Wang, Jiaojiao; Zhao, Yuliang

    2012-05-01

    The consecutive evolution process of single gold nanorods is monitored using atomic force microscopy (AFM). The single-crystal gold nanorods investigated are grown directly on surfaces to which gold seed particles are covalently linked. The growth kinetics for single nanorods is derived from the 3D information recorded by AFM. A better understanding of the seed-mediated growth mechanism may ultimately lead to the direct growth of aligned nanorods on surfaces. PMID:22378704

  5. In Hamsters the D1 Receptor Antagonist SCH 23390 Depresses Ventilation during Hypoxia

    PubMed Central

    Schlenker, Evelyn H.

    2008-01-01

    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 D1 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 D1 receptor antagonist that crosses the blood-brain barrier. Ventilation was determined using the barometric method and oxygen consumption and CO2 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 CO2 production. During exposure to hypercapnia (5% CO2 in 95% O2) 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 Celsius. These results demonstrate that in hamsters D1 receptors can modulate control of ventilation in air and during hypoxia and hypercapnic exposures. Whether D1 receptors located centrally or on carotid bodies modulate these effects is not clear from this study. PMID:18036574

  6. Hematologic, Serologic, and Histologic Profile of Aged Siberian Hamsters (Phodopus sungorus)

    PubMed Central

    McKeon, Gabriel P; Nagamine, Claude M; Ruby, Norman F; Luong, Richard H

    2011-01-01

    Biologic samples from 18 (12 female, 6 male) Siberian hamsters (Phodopus sungorus) representing an aged colony (17 to 27 mo) were examined. Values for CBC and serum biochemical parameters were determined, and macroscopic and microscopic pathologic evaluations were performed. Blood urea nitrogen levels were significantly higher in male (54.2 ± 14 mg/dL) compared with female (35.3 ± 22 mg/dL) hamsters and correlated histologically with a higher incidence of chronic glomerulonephropathy in males (5 of 6 males; 0 of 12 females). All 18 hamsters had histologic evidence of follicular mite infestation. Half (6 of 12) of the female hamsters showed cystic rete ovarii. Other histologic findings included thymic or thyroid branchial cysts (3 of 18), focal enteritis (2 of 18), and single cases of hepatic hemangiosarcoma, renal adenoma, subcutaneous mast cell tumor, cutaneous sebaceous adenoma, cutaneous trichofolliculoma, squamous papilloma of the nonglandular stomach, epididymal cholesteatoma, pyometra, and pituitary craniopharyngeal cyst. This study is the first published report of hematologic and serum chemical values for any population of Siberian hamsters and the first published report showing a potential male predisposition for chronic progressive glomerulonephropathy and a potential female predisposition for cystic rete ovarii. PMID:21640024

  7. Thermogenin amount and activity in hamster brown fat mitochondria: effect of cold acclimation

    SciTech Connect

    Sundin, U.; Moore, G.; Nedergaard, J.; Cannon, B.

    1987-05-01

    To investigate the acclimation process in a hibernator, four different parameters of thermogenin amount and activity were investigated in brown adipose tissue mitochondria from cold-exposed and cold-acclimated Syrian hamsters. Hamsters, which are hibernators, have been considered to be primed for thermogenesis and thus not to show cold-acclimation effects, but here a significant increase in (/sup 3/H)GDP-binding capacity was observed, and this increase was paralleled by an increase in thermogenin antigen amount, as measured in an enzyme-linked immunosorbent assay. The transient nature of the effect of cold exposure on (/sup 3/H)GDP binding, characteristically observed with rat mitochondria, was not observed with hamster mitochondria, and the increase in (/sup 3/H)GDP binding occurred without a change in the dissociation constant. The increase in thermogenin amount was paralleled by an increase both in GDP-sensitive Cl/sup -/ permeability of the mitochondria and in GDP-sensitive respiration. It was established that it is the maximal activity of thermogenin that is rate limiting for thermogenesis in isolated mitochondria, provided that an optimal substrate is used (such as palmitoyl carnitine). Cold acclimation also increased the total amount of mitochondria in the tissue, leading totally to a sixfold increase in thermogenin content of the hamster. It is concluded that hamsters show the expected physiological, pharmacological, and biochemical signs of cold acclimation.

  8. Evaluation of amitrole (aminotriazole) for potential carcinogenicity in orally dosed rats, mice, and golden hamsters

    SciTech Connect

    Steinhoff, D.; Weber, H.; Mohr, U.; Boehme, K.

    1983-06-30

    Amitrole was evaluated for carcinogenic potential in lifespan studies on Wistar rats, NMRI mice, and golden hamsters. At the start of the studies the animals were 6 weeks old. Amitrole was administered, mixed with pulverized chow, at dietary concentrations of 0, 1, 10, and 100 micrograms/g (ppm). Each treated group and control group consisted of 75 male and 75 female rats and mice and of 76 male and 76 female golden hamsters. Additional animals were used to evaluate the functional state of the thyroid. Somewhat lower body weights, slightly reduced survival times, and transient effects on thyroid function were observed in golden hamsters at 100 ppm. In mice, a slight increase in pituitary gland hyperemias was seen at 100 ppm; also an effect on thyroid function usually occurred at the same concentration. In rats, a very large number of cystic dilatations of follicles in the thyroid at 100 ppm and a dose-unrelated increase in hemorrhages and hyperemias in the pituitary gland were indicative of an effect of amitrole on these organs. The strongest effect of amitrole on thyroid function, as compared to golden hamsters and mice, was seen in rats at 100 ppm. At this concentration a highly increased number of thyroid and pituitary gland tumors was observed in rats. In golden hamsters and mice, no tumor induction was seen.

  9. Effect of age on respiratory carcinogenesis with diethyl-nitrosamine (DEN) in hamsters

    SciTech Connect

    Stinson, S.F.; Saffiotti, U.

    1986-03-01

    Groups of male and female Syrian golden hamsters were given 12 weekly s.c. injections of 10 mg/kg DEN beginning at 1 day (85 animals) or 8 weeks (70 animals) of age, and were held for lifetime observation. In hamsters receiving DEN from birth, the first respiratory tumors were observed at 15 experimental weeks; all animals were dead by 66 weeks with a 99% respiratory tumor incidence. Of these hamster, 87% developed carcinomas or adenomas in the nasal cavities, 75% papillomas of the trachea, larynx or extrapulmonary bronchi and 7% adenomas or adenocarcinomas of the peripheral lung. Hamsters given DEN from 8 weeks of age first showed respiratory tumors after 25 weeks with a 96% incidence by 62 weeks when all had died. Of these hamsters, 24% developed carcinomas or adenomas in the nasal cavities, 91% papillomas of the trachea, larynx or bronchi, and 9% adenomas or adenocarcinomas of the peripheral lung. In comparison, the nasal tumors in the first group were more anaplastic and invaded the brain more frequently than in the second. These results indicate that the nasal mucosa of newborns is more sensitive to carcinogenesis with DEN than is that of adults, while there appears to be little age-related susceptibility of the epithelium of the airways or lung. A serial sacrifice experiment is currently under way to study the cells of origin of the various tumors using immuno-histochemical and electron microscopic techniques.

  10. 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.

  11. 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. PMID:25311843

  12. Temperature regulation in the mouse and hamster exposed to microwaves in hot environments

    SciTech Connect

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

    1986-01-01

    Colonic temperature was measured in naive BALB/c mice and golden hamsters immediately following 90-min exposures to 2450-MHz radiofrequency (RF) radiation at an ambient temperature (Ta) of 32.2 or 35 C (dry air). Exposures were performed in a temperature-controlled waveguide that permitted continuous monitoring of the specific absorption rate (SAR) of RF energy. At a Ta of 32.2 C, the threshold SAR for elevating colonic temperature and the SAR resulting in a 1.0 C elevation in colonic temperature were, respectively, 4.3 and 10.0 W/kg for the mouse and 0.69 and 1.9 W/kg for the hamster. At a Ta of 35 C, these values were 0.12 and 5.3 W/kg for the mouse and 0.46 and 1.4 W/kg for the hamster. The SARs required to induce hyperthermia in the mouse and hamster at these relatively warm Ta's are considerably lower than those required at cooler Ta's of 20 to 3 C. Overall, the hamster became hyperthermic at lower SARs than in the mouse. Ta's of 35 C and greater are frequently encountered during heat waves in the summer months.

  13. 31 CFR 100.4 - Gold coin and gold certificates in general.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance: Treasury 1 2012-07-01 2012-07-01 false Gold coin and gold certificates in... MONETARY OFFICES, DEPARTMENT OF THE TREASURY EXCHANGE OF PAPER CURRENCY AND COIN In General § 100.4 Gold coin and gold certificates in general. Gold coins, and gold certificates of the type issued...

  14. 31 CFR 100.4 - Gold coin and gold certificates in general.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance: Treasury 1 2013-07-01 2013-07-01 false Gold coin and gold certificates in... MONETARY OFFICES, DEPARTMENT OF THE TREASURY EXCHANGE OF PAPER CURRENCY AND COIN In General § 100.4 Gold coin and gold certificates in general. Gold coins, and gold certificates of the type issued...

  15. 31 CFR 100.4 - Gold coin and gold certificates in general.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance: Treasury 1 2014-07-01 2014-07-01 false Gold coin and gold certificates in... MONETARY OFFICES, DEPARTMENT OF THE TREASURY EXCHANGE OF PAPER CURRENCY AND COIN In General § 100.4 Gold coin and gold certificates in general. Gold coins, and gold certificates of the type issued...

  16. 31 CFR 100.4 - Gold coin and gold certificates in general.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance: Treasury 1 2011-07-01 2011-07-01 false Gold coin and gold certificates in... MONETARY OFFICES, DEPARTMENT OF THE TREASURY EXCHANGE OF PAPER CURRENCY AND COIN In General § 100.4 Gold coin and gold certificates in general. Gold coins, and gold certificates of the type issued...

  17. Surface-stabilized gold nanocatalysts

    DOEpatents

    Dai, Sheng [Knoxville, TN; Yan, Wenfu [Oak Ridge, TN

    2009-12-08

    A surface-stabilized gold nanocatalyst includes a solid support having stabilizing surfaces for supporting gold nanoparticles, and a plurality of gold nanoparticles having an average particle size of less than 8 nm disposed on the stabilizing surfaces. The surface-stabilized gold nanocatalyst provides enhanced stability, such as at high temperature under oxygen containing environments. In one embodiment, the solid support is a multi-layer support comprising at least a first layer having a second layer providing the stabilizing surfaces disposed thereon, the first and second layer being chemically distinct.

  18. The extractive metallurgy of gold

    NASA Astrophysics Data System (ADS)

    Kongolo, K.; Mwema, M. D.

    1998-12-01

    Mössbauer spectroscopy has been successfully used in investigation of the gold compounds present in ores and the gold species which occur during the process metallurgy of this metal. This paper is a survey of the basic recovery methods and techniques used in extractive metallurgy of gold. Process fundamentals on mineral processing, ore leaching, zinc dust cementation, adsorption on activated carbon, electrowinning and refining are examined. The recovery of gold as a by-product of the copper industry is also described. Alternative processing methods are indicated in order to shed light on new interesting research topics where Mössbauer spectroscopy could be applied.

  19. Effects of single and repeated inhalation exposure of Syrian hamsters to aerosols of /sup 144/CeO/sub 2/

    SciTech Connect

    Lundgren, D.L.; Hahn, F.F.; McClellan, R.O.

    1982-05-01

    Male Syrian hamsters (84 days old at the time of the initial exposure) were repeatedly exposed by inhalation at approximately 60-day intervals for 1 year (seven exposures) to aerosols of /sup 144/CeO/sub 2/ to reestablish lung burdens of 0.4, 2.0, or 10 ..mu..Ci of /sup 144/Ce. Other hamsters were exposed once when either 84, 220, or 360 days old to achieve similar initial lung burdens. Primary lung tumors were observed in 7 of 197 hamsters repeatedly exposed to /sup 144/CeO/sub 2/ that died between 177 and 685 days after the initial inhalation exposure. The cumulative adsorbed ..beta..-radiation doses to the lungs of these hamsters were 14,000 to 50,000 rad. Primary lung tumors also were observed in 6 of 153 hamsters exposed once to /sup 144/CeO/sub 2/ when 84 or 220 days old that died between 270 and 695 days after exposure. The cumulative ..beta..-radiation doses to the lungs of these hamsters were 6000 to 21,000 rad. Lung tumors were not observed in hamsters exposed when 360 days old or in control hamsters. The incidences of primary lung tumors were more dependent on the cumulative dose to the lung than the radiation dose pattern that resulted in the cumulative dose.

  20. Radioresistance secondary to low pH in human glial cells and Chinese hamster ovary cells

    SciTech Connect

    Rottinger, E.M.; Mendonca, M.

    1982-08-01

    The influence of the extracellular pH on the radiosensitivity of human glial cells and Chinese hamster ovary cells was examined. The period of low pH varied from 0 to 96 hours in glial cells and from 0 to 48 hours in Chinese hamster cells. Maintenance of low pH after a dose of 10 Gy for at least 24 hours for glial cells and at least 6 hours for Chinese hamster cells improved survival by more than one order of magnitude at pH 6.4. Cellular inactivation by irradiation may be impaired by an extracellular pH at or below pH 6.7.

  1. Blood leukocyte and spleen lymphocyte immune response of spleen lymphocytes and whole blood leukocytes of hamsters

    SciTech Connect

    Peters, B.A.; Sothmann, M.; Wehrenberg, W.B. )

    1989-01-01

    This study was designed to evaluate the effects of chronic physical activity on the immune response of spleen lymphocytes and whole blood leukocytes of hamsters. Animals were kept sedentary or allowed to exercise spontaneously on running wheels for eight weeks. Physically active animals averaged 12 kilometers per day. The immune response of spleen lymphocytes whole blood leukocytes was evaluated by {sup 3}H-thymidine incorporation in response to Concanavalin A or lipopolysaccharide. There was no treatment effect between physically active and sedentary hamster in response of spleen lymphocytes. The immune response of whole blood leukocytes to these mitogens was significantly greater in physically active vs. sedentary hamsters. These results demonstrate that chronic physical activity has the capacity to modulate immunoresponses.

  2. A brief view of known landmarks reorientates path integration in hamsters

    NASA Astrophysics Data System (ADS)

    Etienne, A. S.; Boulens, V.; Maurer, R.; Rowe, T.; Siegrist, C.

    In darkness, hamsters commute between their nest and a feeding site through path integration only, and therefore show cumulative errors in the return direction to the nest. We examined whether a brief presentation of familiar room cues could reset the path integrator. The hamsters could see the room cues either during, or at the end of, the outward journey to the food place, in a conflict situation where motion cues and visual information were set at variance. In both conditions, the animals used mainly visual information to return home. Thus, hamsters can determine their azimuth, and possibly their location, through a visual fix, and can reset their path integrator through the fix. This allows them to update their position during further locomotion in the dark and thus to compute a correct homing vector with respect to a visually induced reference frame. Taking episodic positional fixes may greatly enhance the functional value of path integration.

  3. 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. PMID:25712038

  4. Deficient induction of sulfobromophthalein conjugating activity by phenobarbital in hamster liver.

    PubMed

    Foliot, A; Touchard, D; Myara, A; Trivin, F; Chauffert, M

    1987-08-15

    Administration of phenobarbital, a known inducer of glutathione S-transferase activity in rat liver, failed to stimulate sulfobromophthalein (BSP) conjugation by liver cytosol in hamsters. The latter displayed poor ability to conjugate this substrate, despite very high glutathione-conjugating activity with the broad-spectrum substrate 1-chloro-2,4-dinitrobenzene (CDNB). Of the six substrates tested, in this species, 1,2-epoxy-3-(4-nitrophenoxy)propane (ENPP) was the only one whose conjugation was greatly enhanced by phenobarbital (+172%). Nevertheless, hamsters proved as responsive to phenobarbital induction as rats, since it increased their relative liver weight and microsomal enzyme activity. The deficient induction of liver BSP-conjugating activity observed with phenobarbital is consistent with the finding that it did not affect the hepatic transport of this substrate in hamsters. PMID:3606660

  5. Temperature effects on evoked potentials of hippocampal slices from euthermic chipmunks, hamsters and rats

    NASA Technical Reports Server (NTRS)

    Hooper, D. C.; Martin, S. M.; Horowitz, J. M.

    1985-01-01

    1. Neural activity was recorded in hippocampal slices from euthermic chipmunks, hamsters and rats. 2. While recording the evoked potentials, the temperature of the Ringer's solution bathing the slice was varied by controlling the temperature of an outer chamber jacketing the recording chamber. 3. The temperature just below that at which a population spike could be evoked, Tt, was 10.4 +/- 0.3 degrees C (mean +/- SEM) for chipmunk slices, 14.1 +/- 0.4 degrees C for rat slices and 14.8 +/- 0.4 degrees C for hamster slices. Tt was significantly lower in the chipmunk slices (P<0.01) than in the rat and hamster slices. 4. Data were interpreted as consistent with the hypothesis that chipmunk hippocampal neurons are intrinsically cold resistant.

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

    SciTech Connect

    Ana J. Molinari; Romina F. Aromando; Maria E. Itoiz; Marcela A. Garabalino; Andrea Monti Hughes; Elisa M. Heber; Emiliano C. C. Pozzi; David W. Nigg; Veronica A. Trivillin; Amanda E. Schwint

    2012-07-01

    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 blood 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.

  7. Stressors, including social conflict, decrease plasma prolactin in male golden hamsters.

    PubMed

    Huhman, K L; Mougey, E H; Moore, T O; Meyerhoff, J L

    1995-12-01

    Following exposure to a stressor, plasma prolactin (PRL) rises in most species. The purpose of the present study was to examine the effect of social conflict or of footshock stress on PRL responsiveness in male Syrian hamsters. Contrary to expectations, PRL was significantly lower in subordinate hamsters than in their dominant opponents or in controls following one, five, or nine exposures to social conflict. Similarly, PRL was reduced in hamsters subjected to a mild footshock stressor. By contrast, adrenocorticotropin, another stress-responsive hormone, was elevated following exposure to each of these stressors. We also demonstrate that PRL release is inhibited by dopamine as it is in other species by showing that there is a dose-dependent increase in PRL release following treatment with the dopamine receptor blocker, domperidone. PMID:8748515

  8. The embryotoxic response to maternal chromium trioxide exposure in different strains of hamsters

    SciTech Connect

    Gale, T.F.

    1982-10-01

    This paper compares the chromium trioxide-induced embryotoxic effects among one noninbred (LVG) and five inbred (CB, LHC, LSH, MHA, PD4) strains of hamsters. A single dose of chromium trioxide (8 mg/kg, iv) was injected into pregnant hamsters on the morning of gestation Day 8. Treated and control animals were killed on gestation Day 15 and studied for the types and incidence of external and internal abnormalities, as well as the frequency of resorption sites per uterus. The embryotoxic effects described in this study include significant rates of resorptions, external abnormalities, cleft palate, and hydrocephalus. The results indicate that the MHA, LSH, and LVG strains are susceptible, while the CB, LHC, and PD4 strains are resistant to chromium trioxide-induced embryotoxicity. This study was compared with prior work in which the same hamster strains were treated with either cadmium, lead, or mercury.

  9. Irradiation- and cyclophosphamide-induced alterations in Syrian hamster T-cell population activity

    SciTech Connect

    Bagasra, O.; Tabor, D.

    1986-02-01

    The treatment of hamsters with either irradiation (IR) or cyclophosphamide (CYP) markedly alters select aspects of their cellular immune functions in a dose-related manner. One mechanism that may be responsible for this activity appears to be the dimunition of a T-lymphocyte subpopulation that exerts suppressive influence upon the B-lymphocyte reactivity toward antigens. This study shows that in the hamster, immune susceptibility is affected by the magnitude and orientation of these agents (ie, IR, CYP) as they temporally relate to immunization and/or challenge with the antigen. Moreover, there is evidence that T-independent as well as T-dependent responses are affected by these treatments. Therefore, cyclophosphamide and irradiation modalities can be employed to modify the cellular immune responses in the hamster.

  10. Conduction of hyperpolarization along hamster feed arteries: augmentation by acetylcholine.

    PubMed

    Emerson, Geoffrey G; Neild, Timothy O; Segal, Steven S

    2002-07-01

    The conduction of vasodilation along resistance vessels has been presumed to reflect the electrotonic spread of hyperpolarization from cell to cell along the vessel wall through gap junction channels. However, the vasomotor response to acetylcholine (ACh) encompasses greater distances than can be explained by passive decay. To investigate the underlying mechanism for this behavior, we tested the hypothesis that ACh augments the conduction of hyperpolarization. Feed arteries (n = 23; diameter, 58 +/- 4 microm; segment length, 2-8 mm) were isolated from the hamster retractor muscle, cannulated at each end, and pressurized to 75 mmHg (at 37 degrees C). Vessels were impaled with one or two dye-containing microelectrodes simultaneously (separation distance, 50 microm to 3.5 mm). Membrane potential (E(m)) (rest, approximately -30 mV) and electrical responses were similar between endothelium and smooth muscle, as predicted for robust myoendothelial coupling. Current injection (-0.8 nA, 1.5 s) evoked hyperpolarization (-10 +/- 1 mV; membrane time constant, 240 ms) that conducted along the vessel with a length constant (lambda) = 1.2 +/- 0.1 mm; spontaneous E(m) oscillations (approximately 1 Hz) decayed with lambda = 1.2 + 0.1 mm. In contrast, ACh microiontophoresis (500 nA, 500 ms, 1 microm tip) evoked hyperpolarization (-14 +/- 2 mV) that conducted with lambda = 1.9 +/- 0.1 mm, 60% further (P < 0.05) than responses evoked by purely electrical stimuli. These findings indicate that ACh augments the conduction of hyperpolarization along the vessel wall. PMID:12063280

  11. Transcriptome dynamics of transgene amplification in Chinese hamster ovary cells.

    PubMed

    Vishwanathan, Nandita; Le, Huong; Jacob, Nitya M; Tsao, Yung-Shyeng; Ng, Sze-Wai; Loo, Bernard; Liu, Zhong; Kantardjieff, Anne; Hu, Wei-Shou

    2014-03-01

    Dihydrofolate reductase (DHFR) system is used to amplify the product gene to multiple copies in Chinese Hamster Ovary (CHO) cells for generating cell lines which produce the recombinant protein at high levels. The physiological changes accompanying the transformation of the non-protein secreting host cells to a high producing cell line is not well characterized. We performed transcriptome analysis on CHO cells undergoing the selection and amplification processes. A host CHO cell line was transfected with a vector containing genes encoding the mouse DHFR (mDHFR) and a recombinant human IgG (hIgG). Clones were isolated following selection and subcloned following amplification. Control cells were transfected with a control plasmid which did not have the hIgG genes. Although methotrexate (MTX) amplification increased the transcript level of the mDHFR gene significantly, its effect on both hIgG heavy and light chain genes was more modest. The subclones appeared to retain the transcriptome signatures of their parental clones, however, their productivity varied among those derived from the same clone. The transcript levels of hIgG transgenes of all subclones fall in a narrower range than the product titer, alluding to the role of many functional attributes, other than transgene transcript, on productivity. We cross examined functional class enrichment during selection and amplification as well as between high and low producers and discerned common features among them. We hypothesize that the role of amplification is not merely increasing transcript levels, but also enriching survivors which have developed the cellular machinery for secreting proteins, leading to an increased frequency of isolating high-producing clones. We put forward the possibility of assembling a hyper-productivity gene set through comparative transcriptome analysis of a wide range of samples. PMID:24108600

  12. Metal mutagenesis in transgenic Chinese hamster cell lines.

    PubMed Central

    Klein, C B; Kargacin, B; Su, L; Cosentino, S; Snow, E T; Costa, M

    1994-01-01

    Metals are toxic agents for which genotoxic effects are often difficult to demonstrate. To study metal mutagenesis, we have used two stable hprt/gpt+ transgenic cell lines that were derived from Chinese hamster V79 cells. Both the G12 and G10 cell lines are known to be very sensitive to clastogens such as X-rays and bleomycin, with the mutagenic response of the integrated xanthine guanine phosphoribosyl transferase (gpt) gene in G10 usually exceeding that of the same gene in the transgenic G12 cells. In studies with carcinogenic insoluble nickel compounds, a high level of mutagenesis was found at the gpt locus of G12 cells but not at the endogenous hypoxanthine phosphoribosyl transferase (hprt) locus of V79 cells. We have since demonstrated the similar recovery of a high frequency of viable G12 mutants with other insoluble nickel salts including nickel oxides (black and green). The relative mutant yield for the insoluble nickel compounds (G12 > G10) is the opposite of that obtained with nonmetal clastogens (G10 > G12). In the G12 cells, nickel mutagenesis may be related to the integration of the gpt sequence into a heterochromatic region of the genome. For some of the insoluble nickel compounds, significant inhibition of both cytotoxicity and mutant yield resulted when the G12 cells were pretreated with vitamin E. In comparison with the nickel studies, the mutagenic responses to chromium compounds in these cell lines were not as dramatic. Mutagenesis of the gpt target could not be demonstrated with other metals such as mercury or vanadium. PMID:7843139

  13. 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. PMID:25252651

  14. Effect of dietary vitamin E supplements on cholesteryl ester transfer activity in hamster adipose tissue.

    PubMed

    Shen, G X; Novak, C; Angel, A

    1996-08-01

    Increased concentration of cholesteryl ester transfer protein (CETP) in plasma favours a lipoprotein profile characterized by a reduced high density lipoprotein (HDL) cholesterol. Previous studies have demonstrated that a diet high in cholesterol and saturated fat (HCSF) is associated with elevated plasma CETP and increased release of cholesterol ester transfer activity (CETA) from hamster adipose tissue incubated in vitro. The present study investigated the effects of vitamin E (Vit.E) ingestion on plasma CETP activity and adipose tissue CETA in Syrian Golden hamsters. A regular diet supplemented by the addition of 1% cholesterol and 10% coconut oil (w/w) was associated with a time-dependent increase in plasma CETP activity and increased release of adipose CETA following incubation of fragments of perirenal adipose tissue. Vit.E ingestion (100 mg/kg body weight per day for 8 weeks) suppressed 85% of the increase of CETA released from cultured hamster adipose tissue and 70% of the increase of plasma CETP activity induced by the HCSF diet. Significant decreases in plasma total and LDL cholesterol and an increase in HDL cholesterol were found in hamsters receiving the HCSF diet plus Vit.E compared to the animals on the HCSF diet alone. In the hamsters on regular chow, Vit.E ingestion alone did not significantly alter adipose tissue CETA, plasma CETP activity or plasma lipoproteins. The results indicate that Vit.E prevents the HCSF diet-induced increase in plasma CETP activity, probably via a reduction of CETA secretion from hamster adipose tissue. This suggests that Vit.E supplementation may help to ameliorate the dyslipidemia caused by a HCSF diet through its inhibitory influence on CETP production in adipose tissue. PMID:8830934

  15. Effects of microwave exposure on the hamster immune system. II. Peritoneal macrophage function

    SciTech Connect

    Rama Rao, G.; Cain, C.A.; Lockwood, J.; Tompkins, W.A.

    1983-01-01

    Acute exposure to hamsters to microwave energy (2.45 GHz; 25 mW/cm2 for 60 min) resulted in activation of peritoneal macrophages that were significantly more viricidal to vaccinia virus as compared to sham-exposed or normal (minimum-handling) controls. Macrophages from microwave-exposed hamsters became activated as early as 6 h after exposure and remained activated for up to 12 days. The activation of macrophages by microwave exposure paralleled the macrophage activation after vaccinia virus immunization. Activated macrophages from vaccinia-immunized hamsters did not differ in their viricidal activity when the hamsters were microwave- or sham-exposed. Exposure for 60 min at 15 mW/cm2 did not activate the macrophages while 40 mW/cm2 exposure was harmful to some hamsters. Average maximum core temperatures in the exposed (25 mW/cm2) and sham groups were 40.5 degrees C (+/- 0.35 SD) and 38.4 degrees C (+/- 0.5 SD), respectively. In vitro heating of macrophages to 40.5 degrees C was not as effective as in vivo microwave exposure in activating macrophages to the viricidal state. Macrophages from normal, sham-exposed, and microwave-exposed hamsters were not morphologically different, and they all phagocytosed India ink particles. Moreover, immune macrophage cytotoxicity for virus-infected or noninfected target cells was not suppressed in the microwave-irradiated group (25 mW/cm2, 1 h) as compared to sham-exposed controls, indicating that peritoneal macrophages were not functionally suppressed or injured by microwave hyperthermia.

  16. Comparative Metabolism of Carbon Tetrachloride in Rats, Mice and Hamsters Using Gas Uptake and PBPK Modeling

    SciTech Connect

    Thrall, Karla D. ); Vucelick, Mark E.; Gies, Richard A. ); Zangar, Richard C. ); Weitz, Karl K. ); Poet, Torka S. ); Springer, David L. ); Grant, Donna M. ); Benson, Janet M.

    2000-08-25

    No study has comprehensively compared the rate of metabolism of carbon tetrachloride (CCl4) across species. Therefore, the in vivo metabolism of CCl4 was evaluated using groups of male animals (F344 rats, B6C3F1 mice, and Syrian hamsters) exposed to 40-1800 ppm CCl4 in a closed, recirculating gas-uptake system. For each species, an optimal fit of the family of uptake curves was obtained by adjusting Michaelis-Menten metabolic constants Km (affinity) and Vmax (capacity) using a physiologically based pharmacokinetic (PBPK) model. The results show that the mouse has a slightly higher capacity and lower affinity for metabolizing CCl4 compared to the rat, while the hamster has a higher capacity and lower affinity than either rat or mouse. A comparison of the Vmax to Km ratio, normalized for mg of liver protein (L/hr/mg) across species indicates that hamsters metabolize more CCl4 than either rats or mice, and should be more susceptible to CCl4-induced hepatotoxicity. These species comparisons were evaluated against toxicokinetic studies conducted in animals exposed by nose-only inhalation to 20 ppm 14C-labeled CCl4 for 4 hours. The toxicokinetic study results are consistent with the in vivo rates of metabolism, with rats eliminating less radioactivity associated with metabolism (14CO2 and urine/feces) and more radioactivity associated with the parent compound (radioactivity trapped on charcoal) compared to either hamsters or mice. The in vivo metabolic constants determined here, together with in vitro constants determined using rat, mouse, hamster and human liver microsomes, were used to estimate human in vivo metabolic rates of 1.49 mg/hr/kg body weight and 0.25 mg/L for Vmax and Km, respectively. Normalizing the rate of metabolism (Vmax/Km) by mg liver protein, the rate of metabolism of CCl4 differs across species, with hamster > mouse& > rat > human.

  17. Autonomic and behavioral thermoregulation in the golden hamster during subchronic administration of clorgyline.

    PubMed

    Gordon, C J; Duncan, W C

    1994-05-01

    Chronic administration of clorgyline, a type-A monoamine oxidase inhibitor, leads to a decrease in peritoneal (i.e., core) temperature of golden hamsters. To better understand the mechanisms of clorgyline's thermoregulatory effects, autonomic and behavioral thermoregulatory effectors were measured in Syrian hamsters following chronic infusion of clorgyline via a minipump (2 mg/kg/day). Metabolic rate, evaporative water loss, motor activity, and core temperature were measured after 60 min of exposure to ambient temperatures (Ta) of 5, 20, 30, and 35 degrees C. Behavioral thermoregulatory responses were assessed by measuring selected Ta and motor activity of the same animals in a temperature gradient over the course of 23 h. Metabolic rate and motor activity were significantly elevated in clorgyline-treated hamsters exposed to a Ta of 5 degrees C. There were no effects of clorgyline on evaporative water loss. In the temperature gradient the mean selected Ta of clorgyline-treated hamsters was nearly equal to that of the saline-treated hamsters, 30.7 and 31.2 degrees C, respectively. On the other hand, the mode of selected Ta in the clorgyline group was 2.8 degrees C higher than that of the saline group. Motor activity in the gradient was significantly elevated and food consumption was depressed by clorgyline treatment. Overall, these findings indicate that chronic clorgyline treatment in the golden hamster results in novel autonomic and behavioral modification; it stimulates metabolic thermogenesis during cold exposure, but appears to increase the behavioral zone of thermoneutrality. This latter effect may mean an improvement in heat tolerance, suggesting that this drug might assist in the adaptation to warm temperatures. PMID:8029282

  18. Autonomic and behavioral thermoregulation in golden hamsters exposed perinatally to dioxin.

    PubMed

    Gordon, C J; Yang, Y; Gray, L E

    1996-03-01

    Perinatal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) cause s a permanent change in thermoregulatory control of male offspring of the rat, characterized by a reduced core temperature (Tc over a wide range of ambient temperatures (Ta). To examine the similarities in this effect across species, the thermoregulatory effects of perinatal TCDD were evaluated in the golden hamster, a species which is very resistant to the lethal effects of TCDD. Adult male hamsters exposed on Gestational Day 11.5-11.75 to 2.0 microgram TCDD/kg by gavage were subjected to a variety of behavioral and autonomic thermoregulatory measurements. Nocturnal Tc of TCDD-treated animals was 0.4 to 1.0 degrees C below that of controls over a Ta range of 14 to 34 degrees C. Hypothermia persisted in spite of normal metabolic responses to cold exposure. The hypothermic effect of perinatal TCDD exposure was found to persist over a 24-hr period in unrestrained hamsters monitored by radiotelemetry. The TCDD-treated hamster offspring placed in a temperature gradient exhibited a preference for warm Ta's for 2 to 3 hr; however, when maintained over a 22-hr period in the gradient there was no effect of TCDD on behavioral thermoregulation. TCDD had no effect on motor activity measured over a 24-hr period. TCDD resulted in an approximately 30% reduction in body weight compared to controls; however, this weight loss appeared to have no bearing on the thermoregulatory deficiencies of the TCDD-treated animals. TCDD-treated hamsters displayed a normal metabolic response to cold exposure; thus, it would appear that perinatal exposure to TCDD leads to a dysfunction in the central control of body temperature. The perinatal effects of TCDD on thermoregulation in the rat and hamster appear to be similar. PMID:8607137

  19. Modification of visual response properties in the superior colliculus of the golden hamster following stroboscopic rearing

    PubMed Central

    Chalupa, Leo M.; Rhoades, Robert W.

    1978-01-01

    1. Visual response properties of superior collicular neurones were investigated in golden hamsters reared from birth to adulthood in a stroboscopic environment. 2. In comparison to normally reared animals, there was a marked decrease in the incidence of directionally selective cells in the colliculus of the strobe-reared hamsters. This effect was apparent when directional selectivity was determined by either the null criterion or a statistical measure. The reduction in directionally selective cells was found in both superficial and the deep layers of the colliculus. 3. Neurones in strobe-reared hamsters also exhibited a different speed preference distribution from that obtained for normal animals, in that more cells in the restricted hamsters responded only to slow velocities, and less were broadly tuned with regard to the speed of moving stimuli. 4. In addition to the effects obtained in dynamic response properties, there were also changes in the static response properties of superior collicular neurones. These were an increase in the proportion of cells whose responses were not affected by changing the size of a stationary flashed stimulus, and a concomitant decrease in the number of cells demonstrating either partial or complete suppression when the size of a flashed stimulus exceeded the boundaries of the receptive field activating region. Furthermore, while all cells which responded to stationary stimuli in normal animals yielded only phasic responses to stimulus onset and/or offset, in the strobe-reared hamsters eight cells were encountered which responded in a sustained fashion to stationary spots. 5. There was no indication of an increased responsivity in the restricted animals to strobe stimulation, even when a strobe rate identical to that employed in the rearing environment was employed. 6. The results were interpreted as indicating a disruption of normal visual functional organization in the hamster's superior colliculus by an aberrant visual input

  20. Antibody-gold cluster conjugates

    DOEpatents

    Hainfeld, J.F.

    1988-06-28

    Antibody- or antibody fragment-gold cluster conjugates are shown wherein the conjugate size can be about 5.0 nm. Methods and reagents are disclosed in which antibodies or Fab' fragments thereof are covalently bound to a stable cluster of gold atoms. 2 figs.

  1. The Gold at Fort Knox.

    ERIC Educational Resources Information Center

    Wood, William C.

    1994-01-01

    Maintains that, although U.S. currency today is pure fiat money and not backed by gold or any other precious metal, students frequently ask, "But what about the gold at Fort Knox?" Describes what is really located at Fort Knox, why it is there, its implications for public policy. (CFR)

  2. When cyclopropenes meet gold catalysts

    PubMed Central

    Miege, Frédéric

    2011-01-01

    Summary Cyclopropenes as substrates entered the field of gold catalysis in 2008 and have proven to be valuable partners in a variety of gold-catalyzed reactions. The different contributions in this growing research area are summarized in this review. PMID:21804867

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

    SciTech Connect

    Persson, S.A.; Ahlberg, M.; Berghem, L.; Koenberg, E.N.; Nordberg, G.F.; Bergman, F.

    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, oil 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.

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

    PubMed Central

    Persson, S A; Ahlberg, M; Berghem, L; Könberg, E; Nordberg, G F; Bergman, F

    1988-01-01

    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 (Fe2O3). 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, oil fly ash, or Fe2O3 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. Images FIGURE 3. FIGURE 4. PMID:3383816

  5. The Effects of Vaccinium myrtillus Extract on Hamster Pial Microcirculation during Hypoperfusion-Reperfusion Injury

    PubMed Central

    Mastantuono, Teresa; Starita, Noemy; Sapio, Daniela; D’Avanzo, Sabato Andrea; Di Maro, Martina; Muscariello, Espedita; Paterni, Marco; Colantuoni, Antonio; Lapi, Dominga

    2016-01-01

    Introduction The present study was aimed to assess the in vivo hamster pial microvessel alterations due to 30 min transient bilateral common carotid artery occlusion (BCCAO) and reperfusion (60 min); moreover, the neuroprotective effects of Vaccinium myrtillus extract, containing 34.7% of anthocyanins, were investigated. Materials and Methods Two groups of male hamsters were used: the first fed with control diet and the other with Vaccinium myrtillus supplemented diet. Hamster pial microcirculation was visualized by fluorescence microscopy through an open cranial window. Pial arterioles were classified according to Strahler’s method. Results In age-matched control diet-fed hamsters, BCCAO caused a decrease in diameter of all arterioles. At the end of reperfusion, the reduction of diameter in order 3 arterioles was by 8.4 ± 3.1%, 10.8 ± 2.3% and 12.1 ± 1.1% of baseline in the 2, 4 and 6 month control diet-fed hamsters, respectively. Microvascular permeability and leukocyte adhesion were markedly enhanced, while perfused capillary length (PCL) decreased. The response to acetylcholine and papaverine topical application was impaired; 2’-7’-dichlorofluoresceine-diacetate assay demonstrated a significant ROS production. At the end of BCCAO, in age-matched Vaccinium myrtillussupplemented diet-fed hamsters, the arteriolar diameter did not significantly change compared to baseline. After 60 min reperfusion, order 3 arterioles dilated by 9.3 ± 2.4%, 10.6 ± 3.1% and 11.8 ± 2.7% of baseline in the 2, 4 and 6 month Vaccinium myrtillus supplemented diet-fed hamsters, respectively. Microvascular leakage and leukocyte adhesion were significantly reduced in all groups according to the time-dependent treatment, when compared with the age-matched control diet-fed hamsters. Similarly, the reduction in PCL was progressively prevented. Finally, the response to acetylcholine and papaverine topical application was preserved and there was no significant increase in ROS

  6. The adjuvanticity of gold nanoparticles

    NASA Astrophysics Data System (ADS)

    Dykman, Lev A.; Bogatyrev, Vladimir A.; Staroverov, Sergey A.; Pristensky, Dmitry V.; Shchyogolev, Sergey Yu.; Khlebtsov, Nikolai G.

    2006-06-01

    A new variant of a technique for in vivo production of antibodies to various antigens with colloidal-gold nanoparticles as carrier is discussed. With this technique we obtained highly specific and relatively high-titre antibodies to different antigens. The antibodies were tested by an immunodot assay with gold nanoparticle markers. Our results provide the first demonstration that immunization of animals with colloidal gold complexed with either haptens or complete antigens gives rise to highly specific antibodies even without the use of complete Freund's adjuvant. These findings may attest to the adjuvanticity of gold nanoparticles itself. We provide also experimental results and discussion aimed at elucidation of possible mechanisms of the discovered colloidal-gold-adjuvanticity effect.

  7. Optical properties of gold-silica-gold multilayer nanoshells.

    PubMed

    Hu, Ying; Fleming, Ryan C; Drezek, Rebekah A

    2008-11-24

    The spectral and angular radiation properties of gold-silica-gold multilayer nanoshells are investigated using Mie theory for concentric multilayer spheres. The spectral tunability of multilayer nanoshells is explained and characterized by a plasmon hybridization model and a universal scaling principle. A thinner intermediate silica layer, scaled by particle size, red shifts the plasmon resonance. This shift is relatively insensitive to the overall particle size and follows the universal scaling principle with respect to the resonant wavelength of a conventional silica-gold core-shell nanoshell. The extra tunability provided by the inner core further shifts the extinction peak to longer wavelengths, which is difficult to achieve on conventional sub-100 nm nanoshells due to limitations in synthesizing ultrathin gold coatings. We found multilayer nanoshells to be more absorbing with a larger gold core, a thinner silica layer, and a thinner outer gold shell. Both scattering intensity and angular radiation pattern were found to differ from conventional nanoshells due to spectral modulation from the inner core. Multilayer nanoshells may provide more backscattering at wavelengths where silica-gold core-shell nanoshells predominantly forward scatter. PMID:19030045

  8. Non-parametric photic entrainment of Djungarian hamsters with different rhythmic phenotypes.

    PubMed

    Schöttner, Konrad; Hauer, Jane; Weinert, Dietmar

    2016-01-01

    To investigate the role of non-parametric light effects in entrainment, Djungarian hamsters of two different circadian phenotypes were exposed to skeleton photoperiods, or to light pulses at different circadian times, to compile phase response curves (PRCs). Wild-type (WT) hamsters show daily rhythms of locomotor activity in accord with the ambient light/dark conditions, with activity onset and offset strongly coupled to light-off and light-on, respectively. Hamsters of the delayed activity onset (DAO) phenotype, in contrast, progressively delay their activity onset, whereas activity offset remains coupled to light-on. The present study was performed to better understand the underlying mechanisms of this phenomenon. Hamsters of DAO and WT phenotypes were kept first under standard housing conditions with a 14:10 h light-dark cycle, and then exposed to skeleton photoperiods (one or two 15-min light pulses of 100 lx at the times of the former light-dark and/or dark-light transitions). In a second experiment, hamsters of both phenotypes were transferred to constant darkness and allowed to free-run until the lengths of the active (α) and resting (ρ) periods were equal (α:ρ = 1). At this point, animals were then exposed to light pulses (100 lx, 15 min) at different circadian times (CTs). Phase and period changes were estimated separately for activity onset and offset. When exposed to skeleton-photoperiods with one or two light pulses, the daily activity patterns of DAO and WT hamsters were similar to those obtained under conditions of a complete 14:10 h light-dark cycle. However, in the case of giving only one light pulse at the time of the former light-dark transition, animals temporarily free-ran until activity offset coincided with the light pulse. These results show that photic entrainment of the circadian activity rhythm is attained primarily via non-parametric mechanisms, with the "morning" light pulse being the essential cue. In the second experiment, typical

  9. Gold-catalyzed homogeneous oxidative cross-coupling reactions.

    PubMed

    Zhang, Guozhu; Peng, Yu; Cui, Li; Zhang, Liming

    2009-01-01

    Oxidizing gold? A gold(I)/gold(III) catalytic cycle is essential for the first oxidative cross-coupling reaction in gold catalysis. By using Selectfluor for gold(I) oxidation, this chemistry reveals the synthetic potential of incorporating gold(I)/gold(III) catalytic cycles into contemporary gold chemistry and promises a new area of gold research by merging powerful gold catalysis and oxidative metal-catalyzed cross-coupling reactions. PMID:19322869

  10. α-Tocopherol Improves Microcirculatory Dysfunction on Fructose Fed Hamsters

    PubMed Central

    Boa, Beatriz C. S.; Barros, Carlos M. M. R.; Souza, Maria das Graças C.; Castiglione, Raquel C.; Cyrino, Fátima Z. G. A.; Bouskela, Eliete

    2015-01-01

    Fructose, an everyday component of western diet associated to chronic hyperglycemia and enhanced free radical production, impairs endothelial function and supplementation with antioxidants might improve it. In this study we investigated if vitamin E could reverse the microvascular damage elicited by fructose. Male Syrian golden hamsters drank either 10% fructose solution (F) or filtered water (C), combined with three concentrations of vitamin E in their chows [zero, normal (VE) or 5X (5XVE)] during 60 days. Microvascular reactivity in response to topical application of acetylcholine (Ach; endothelium-dependent vasodilator) or sodium nitroprusside (SNP; endothelium-independent vasodilator) and macromolecular permeability increase induced by either 30 min ischemia followed by reperfusion (I/R) or topical application of histamine (5 μM) were assessed using the cheek pouch preparation. Compared to controls (drinking filtered water), fructose-drinking animals showed decreased vasodilatation to acetylcholine in all concentrations tested (-56.2% for 10-9M, -53.9% for 10-7M and -43.7% for 10-5M). On the other hand, vitamin E supplementation resulted in increased responses for both water and fructose drinking groups (177.4% for F vs. F/5XVE and 241.6% for C vs. C/5XVE for 10-5M Ach). Endothelial-independent vasodilatation explored by topical application of SNP was restored and even enhanced with the supplementation of 5X vitamin E in both groups (80.1% for F vs. F/5XVE; 144.2% for C vs. C/5XVE; 3.4% of difference for C/5XVE vs. F/5XVE on 10-5M SNP). The number of leaky sites after I/R and histamine stimuli in vitamin E supplemented animals decreased (-25.1% and -15.3% for F vs. F/5XVE; and -21.7% and -16% of leaky sites comparing C vs. C/5XVE, respectively for I/R and histamine stimuli) pointing to tightening of the endothelial barrier for macromolecular permeability. Our results strongly suggest that vitamin E could improve the endothelial function and permeability

  11. Synthesis of gold structures by gold-binding peptide governed by concentration of gold ion and peptide.

    PubMed

    Kim, Jungok; Kim, Dong-Hun; Lee, Sylvia J; Rheem, Youngwoo; Myung, Nosang V; Hur, Hor-Gil

    2016-08-01

    Although biological synthesis methods for the production of gold structures by microorganisms, plant extracts, proteins, and peptide have recently been introduced, there have been few reports pertaining to controlling their size and morphology. The gold ion and peptide concentrations affected on the size and uniformity of gold plates by a gold-binding peptide Midas-11. The higher concentration of gold ions produced a larger size of gold structures reached 125.5 μm, but an increased amount of Midas-11 produced a smaller size of gold platelets and increased the yield percentage of polygonal gold particles rather than platelets. The mechanisms governing factors controlling the production of gold structures were primarily related to nucleation and growth. These results indicate that the synthesis of gold architectures can be controlled by newly isolated and substituted peptides under different reaction conditions. PMID:27108675

  12. Increases in plasma pool size of lipoprotein components in copper-deficient hamsters

    SciTech Connect

    Al-Othman, A.A.; Rosenstein, F.; Lei, K.Y. )

    1991-03-15

    Twenty-four male Golden Syrian hamsters, were randomly assigned to 2 dietary copper (Cu) treatments; deficient and adequate. Reductions in weight gain, hematocrit and liver Cu as well as increases in heart weight and plasma volume were observed in CD hamsters after 7 weeks of treatment. Plasma very low (VLDL), low (LDL) and high (HDL) density lipoproteins were isolated by ultracentrifugation and Sepharose column chromatography. The percentage of total plasma cholesterol carried by LDL was increased from 20 to 24% but was reduced from 71 to 68% for HDL as a result of Cu deficiency. In LDL the % composition of triglycerides (TG) and phospholipids (PL) was increased by 25% but that of cholesterol was reduced by 13%. The % composition of protein was reduced 24% but that of TG was increased 18% in VLDL by Cu deficiency. Since plasma volume was increased 50% in CD hamsters, the data were expressed as the amount present in the plasma pool corrected for body weight. With the exceptions of smaller increased in VLDL protein and PL as well as the more than threefold increases in LDL TG and PL plasma pool size, the pool size for the rest of the lipoprotein components were increased about twofold in CD hamsters. The lipoprotein data further indicate that Cu deficiency increased the particle number of VLDL, LDL and HDL but enlarged the size of only VLDL and LDL.

  13. Ribavirin Protects Syrian Hamsters against Lethal Hantavirus Pulmonary Syndrome — After Intranasal Exposure to Andes Virus

    PubMed Central

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

    2013-01-01

    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. PMID:24217424

  14. 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. PMID:23600567

  15. Quadricuspid aortic valves in Syrian hamsters and their formation according to current knowledge on valvulogenesis.

    PubMed

    López-García, Alejandro; Carmen Fernández, M; Durán, Ana Carmen; Sans-Coma, Valentín; Fernández, Borja

    2015-02-01

    Occurrence of quadricuspid aortic valves has been reported in humans, in nine dogs and in a greater white-toothed shrew. Moreover, two cases of developing aortic valves with four anticipated leaflets have been described in Syrian hamster embryos. Currently, however, no case of quadricuspid aortic valve in adult hamsters has been recorded. The aim here is to present four adults of this rodent species, two of them with unequivocally quadricuspid aortic valves and the other two with quadricuspid-like aortic valves. The four anomalous aortic valves were detected among 4,190 Syrian hamsters examined in our laboratory, representing an incidence of 0.09%. None of the affected hamsters showed apparent signs of disease. The present findings are considered on the light of current empirical knowledge about the morphogenesis of quadricuspid and bicuspid aortic and pulmonary valves. Quadricuspid aortic valves result from the partition of one of the normal mesenchymal cushions which normally give rise to normal (tricuspid) valves, while quadricuspid-like valves might be the product of a combined mechanism of fusion and partition of the cushions at the onset of the valvulogenesis. The presence of aortic valves with four leaflets in ancient mammalian lineages such as insectivors and rodents suggest that quadricuspid aortic valves, although showing almost certainly a low incidence, may be widespread among the different groups of mammals, including domestic animals. PMID:25854086

  16. GENOTOXIC EFFECTS OF COMPLEX MARINE SEDIMENT EXTRACTS ON V79 CHINESE HAMSTER LUNG FIBROBLASTS

    EPA Science Inventory

    A mammalian in vitro system was used to evaluate the genotoxic potential of two complex environmental samples. ister chromatid exchanges (SCEs) were measured in Chinese hamster V79 lung fibroblast cells, following exposure to whole extracts of sediments collected from a highly co...

  17. Irreversible bronchial goblet cell metaplasia in hamsters with elastase-induced panacinar emphysema.

    PubMed Central

    Christensen, T G; Korthy, A L; Snider, G L; Hayes, J A

    1977-01-01

    A single intratracheal instillation of pancreatic elastase in hamsters induces a lesion resembling human panacinar emphysema. This paper reports the occurrence of irreversible goblet cell metaplasia in the bronchial epithelium of hamsters similarly exposed to elastase. The goblet cell change was dose related; a dose of 0.1 mg/100 g body wt or less at 16 days, produced slight or moderate goblet cell metaplasia in fewer than half the animals, whereas 84% of animals treated with a dose between 0.2 and 0.5 mg/100 g body wt developed goblet cell metaplastic lesions, more than half of which were considered to be severe. The percentage of goblet cells in the epithelium of elastase-treated hamsters (32.5) was significantly higher (P less than 0.005) than that of unexposed (12.2) and saline-exposed controls (18.7). All hamsters examined 6 and 12 mo after elastase treatment showed the lesion. The pathogenesis of the changes is unclear but the possibility is raised that the bronchial changes may be due to disturbance of an endogenous protease-antiprotease system. The findings suggest the hypothesis that, under appropriate circumstances, a single pulmonary insult in man could lead to a permanent lung injury demonstrating the anatomic lesions of both chronic bronchitis and panacinar emphysema. Images PMID:838856

  18. SYNAPTONEMAL COMPLEX ABERRATIONS IN THE PSEUDOAUTOSOMAL REGION OF X,Y CHROMOSOMES IN IRRADIATED HAMSTERS

    EPA Science Inventory

    Armenian hamsters were treated with X-radiation, bleomycin or amsacrine (m-AMSA) and the effects on meiotic chromosomes determined by electron microscopic analysis of synaptonemal complex (SC) formation. achytene cells were analyzed five or six days following their treatment at p...

  19. Cholesteryl ester transfer activity in hamster plasma: increase by fat and cholesterol rich diets.

    PubMed

    Stein, Y; Dabach, Y; Hollander, G; Stein, O

    1990-01-16

    We investigated the presence of cholesteryl ester transfer activity (CETA) in plasma of hamsters kept on various dietary regimens. In hamsters kept on a regular diet, CETA activity was about 5 units/4 mg protein of d greater than 1.21 g/ml fraction of plasma, as compared to about 35 units present in human d greater than 1.21 g/ml fraction. Addition of 15% margarine or butter alone or together with 2% cholesterol resulted in a 2-3-fold increase in plasma CETA. The increase in plasma CETA was correlated with plasma cholesterol levels (r = 0.78; P less than 0.001) and plasma triacylglycerol levels (r = 0.56, P less than 0.001). Hamsters consuming the cholesterol + butter-supplemented diets had the highest plasma CETA, cholesterol and triacylglycerol levels, while CETA in plasma of rats and mice remained nondetectable even after 4 weeks on the diet. The causal relation between hypercholesterolemia, hypertriglyceridemia and evaluation in CETA in hamsters remains to be elucidated. PMID:2297517

  20. ANALYSIS IN BLOOD OF GOLDEN HAMSTER BY NAA FOR CLINICAL PRACTICE

    SciTech Connect

    Aguiar, R.; Zamboni, C. B.; Genezini, F. A.

    2009-06-03

    In the present study Neutron Activation Analysis (NAA) technique has been used to determine, simultaneously, some element concentrations of clinical relevance in whole blood samples of Golden Hamster. The normal range for Br, Cl, K and Na concentrations were determined. The knowledge of these values permits clinical investigation of animal model using whole blood as well as to check the similarities with human blood.

  1. Conditioned flavor aversion and location avoidance in hamsters from toxic extract of tall larkspur (Delphinium barbeyi)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  2. Appropriateness of the hamster as a model to study diet-induced atherosclerosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    SciTech Connect

    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 a 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.

  4. Cholesterol 26-hydroxylase activity of hamster liver mitochondria: Isotope ratio analysis using deuterated 26-hydroxycholesterol

    SciTech Connect

    Kok, E.; Javitt, N.B. )

    1990-04-01

    Deuterated 26-hydroxycholesterol prepared from diosgenin by modifications of existing methods permitted the determination of mitochondrial cholesterol 26-hydroxylase using endogenous cholesterol as the substrate. Enzyme activity in a group of Syrian hamsters was found to be 10.3 +/- 3.7 pmol.min-1.mg protein-1.

  5. CHARACTERIZATION OF SULFHYDRYL PROTEINS INVOLVED IN THE MAINTENANCE OF FLAGELLAR STRAIGHTNESS IN HAMSTER SPERMATOZOA

    EPA Science Inventory

    Hamster caput epididymal spermatozoa exhibit a marked 90-180 degree bend when induced to acquire progressive motility in vitro (Cornwall et al, 1988). lagellar bending is prevented by oxidizing sperm sulfhydryl (SH) groups with diamide. n the present study, the authors examined t...

  6. Altered cytokeratin expression during chemoprevention of hamster buccal pouch carcinogenesis by S-allylcysteine.

    PubMed

    Balasenthil, Seetharaman; Rao, Kunchala S; Nagini, Siddavaram

    2003-01-01

    We examined the effect of S-allylcysteine (SAC), a water-soluble garlic constituent, on cytokeratin expression, a sensitive and specific marker for differentiation status during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis in male Syrian hamsters. Hamsters were divided into four groups of six animals each. 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 I, and in addition they received orally 200 mg/kg of SAC on days alternate to DMBA application. Group 3 animals received SAC as in group 2. Group 4 animals received neither DMBA nor SAC and served as the control. The hamsters were killed after an experimental period of 14 weeks. Cytokeratin expression was detected by Western blot analysis using monoclonal antibodies AE1 and AE3. In DMBA-induced HBP tumors, the decreased expression of high molecular weight cytokeratins of molecular mass between 55-70 kDa was observed. Administration of SAC (200 mg/kg) to animals painted with DMBA suppressed the incidence of DMBA-induced carcinomas and was associated with restoration of normal cytokeratin expression. The results of the present study suggest that inhibition of HBP tumorigenesis by SAC may be due to its regulatory effects on differentiation, tumor invasiveness, and its ability to migrate and form metastases. PMID:14704476

  7. TWENTY-FOUR HOUR RHYTHMS OF SELECTED AMBIENT TEMPERATURE IN RAT AND HAMSTER

    EPA Science Inventory

    The purpose of this study was to assess the effect of time of day on the behavioral thermoregulatory patterns of nocturnal rodents, the Long-Evans (LE) rat, Fischer 344 (F344) rat, and the golden hamster. Individual animals were placed in a temperature gradient for four days whil...

  8. Pineal melatonin is a circadian time-giver for leptin rhythm in Syrian hamsters.

    PubMed

    Chakir, Ibtissam; Dumont, Stéphanie; Pévet, Paul; Ouarour, Ali; Challet, Etienne; Vuillez, Patrick

    2015-01-01

    Nocturnal secretion of melatonin from the pineal gland may affect central and peripheral timing, in addition to its well-known involvement in the control of seasonal physiology. The Syrian hamster is a photoperiodic species, which displays gonadal atrophy and increased adiposity when adapted to short (winter-like) photoperiods. Here we investigated whether pineal melatonin secreted at night can impact daily rhythmicity of metabolic hormones and glucose in that seasonal species. For that purpose, daily variations of plasma leptin, cortisol, insulin and glucose were analyzed in pinealectomized hamsters, as compared to sham-operated controls kept under very long (16 h light/08 h dark) or short photoperiods (08 h light/16 h dark). Daily rhythms of leptin under both long and short photoperiods were blunted by pinealectomy. Furthermore, the phase of cortisol rhythm under a short photoperiod was advanced by 5.6 h after pinealectomy. Neither plasma insulin, nor blood glucose displays robust daily rhythmicity, even in sham-operated hamsters. Pinealectomy, however, totally reversed the decreased levels of insulin under short days and the photoperiodic variations in mean levels of blood glucose (i.e., reduction and increase in long and short days, respectively). Together, these findings in Syrian hamsters show that circulating melatonin at night drives the daily rhythmicity of plasma leptin, participates in the phase control of cortisol rhythm and modulates glucose homeostasis according to photoperiod-dependent metabolic state. PMID:26074760

  9. 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…

  10. 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...

  11. Characterization of diethylnitrosamine-induced liver carcinogenesis in Syrian golden hamsters.

    PubMed

    Chen, Guo; Dai, Zhi-Kai; Liang, Rong-Gan; Xiao, Sheng-Jun; He, Song-Qing; Zhao, Hai-Lu; Xu, Qing

    2012-02-01

    The aim of this study was to characterize hepatocarcinogenesis in diethylnitrosamine (DEN)-treated hamsters. Syrian golden hamsters (n=36) were administered DEN by hypodermic injection and addition to drinking water. Morphological analyses, including light microscopy and immunohistochemistry of α-fetal protein (AFP), were performed on liver and lung tissues. Primary cell culture and tumor transplantation were carried out to evaluate the potential application in hepatocellular carcinoma (HCC) research. From 25 to 50 weeks of treatment, liver tumors, including macronodular HCC and ascites, were found in one-third (4/12) of the animals treated with DEN. HCC was characterized by poor differentiation, frequent mitosis, AFP reaction, vessel invasion and potential application in primary cell culture and xenotransplantation. Pre-neoplastic lesions were hyperplastic nodules comprised of clear cells, bile duct proliferation, fatty metamorphosis and multilocular cysts. The DEN-treated hamsters also showed lung tumors consisting of AFP-negative, well-differentiated neoplastic cells. Characterization of DEN-induced HCC in hamsters provides insights into human hepatocarcinogenesis. This animal model has potential applications in HCC research. PMID:22969883

  12. Pineal melatonin is a circadian time-giver for leptin rhythm in Syrian hamsters

    PubMed Central

    Chakir, Ibtissam; Dumont, Stéphanie; Pévet, Paul; Ouarour, Ali; Challet, Etienne; Vuillez, Patrick

    2015-01-01

    Nocturnal secretion of melatonin from the pineal gland may affect central and peripheral timing, in addition to its well-known involvement in the control of seasonal physiology. The Syrian hamster is a photoperiodic species, which displays gonadal atrophy and increased adiposity when adapted to short (winter-like) photoperiods. Here we investigated whether pineal melatonin secreted at night can impact daily rhythmicity of metabolic hormones and glucose in that seasonal species. For that purpose, daily variations of plasma leptin, cortisol, insulin and glucose were analyzed in pinealectomized hamsters, as compared to sham-operated controls kept under very long (16 h light/08 h dark) or short photoperiods (08 h light/16 h dark). Daily rhythms of leptin under both long and short photoperiods were blunted by pinealectomy. Furthermore, the phase of cortisol rhythm under a short photoperiod was advanced by 5.6 h after pinealectomy. Neither plasma insulin, nor blood glucose displays robust daily rhythmicity, even in sham-operated hamsters. Pinealectomy, however, totally reversed the decreased levels of insulin under short days and the photoperiodic variations in mean levels of blood glucose (i.e., reduction and increase in long and short days, respectively). Together, these findings in Syrian hamsters show that circulating melatonin at night drives the daily rhythmicity of plasma leptin, participates in the phase control of cortisol rhythm and modulates glucose homeostasis according to photoperiod-dependent metabolic state. PMID:26074760

  13. Differential effect of lithium on the circadian oscillator in young and old hamsters

    SciTech Connect

    Iwahana, Eiko; Hamada, Toshiyuki; Uchida, Ayumi; Shibata, Shigenobu . E-mail: shibatas@waseda.jp

    2007-03-16

    Lithium is one of the most commonly used drugs in the prophylaxis and treatment of bipolar disorder. It is also known to lengthen circadian period in several organisms. Previously, we reported that there was the association between lengthening circadian period by lithium and GSK-3 protein and its enzyme activity in the mouse suprachiasmatic nucleus (SCN). In this study, we show that lithium affects the circadian oscillator in young and old hamster SCN, in an age-dependent manner. We found that basal levels of phosphorylated GSK-3 (pGSK-3) protein expression in old hamsters are much lower than that in young hamsters. Furthermore, in the old hamsters, lithium did not affect the period of the locomotor activity rhythm or pGSK-3 expression, while changing period and pGSK-3 in the younger animals. These results indicate that the content of pGSK-3 in the SCN has an important role in age-dependent effects of lithium on the circadian oscillator.

  14. Development of Hamster Models for Acute and Chronic Infections with Leptospira borgpetersenii serovar Hardjo

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Golden Syrian hamster is frequently used as a small animal model to study acute leptospirosis. However, use of this small animal model to study Leptospira borgpetersenii serovar Hardjo infections has not been well documented. Cattle are the normal maintenance hosts of L. borgpetersenii serovar...

  15. 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.

  16. 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. PMID:27374913

  17. Nuciferine Prevents Hepatic Steatosis and Injury Induced by a High-Fat Diet in Hamsters

    PubMed Central

    Li, Xiaoxia; Feng, Rennan; Guan, Chunmei; Wang, Yanwen; Li, Ying; Sun, Changhao

    2013-01-01

    Background Nuciferine is a major active aporphine alkaloid from the leaves of N. nucifera Gaertn that possesses anti-hyperlipidemia, anti-hypotensive, anti-arrhythmic, and insulin secretagogue activities. However, it is currently unknown whether nuciferine can benefit hepatic lipid metabolism. Methodology/Principal Findings In the current study, male golden hamsters were randomly divided into four groups fed a normal diet, a high-fat diet (HFD), or a HFD supplemented with nuciferine (10 and 15 mg/kg·BW/day). After 8 weeks of intervention, HFD-induced increases in liver and visceral adipose tissue weight, dyslipidemia, liver steatosis, and mild necroinflammation in hamsters were analyzed. Nuciferine supplementation protected against HFD-induced changes, alleviated necroinflammation, and reversed serum markers of metabolic syndrome in hamsters fed a HFD. RT-PCR and western blot analyses revealed that hamsters fed a HFD had up-regulated levels of genes related to lipogenesis, increased free fatty acid infiltration, and down-regulated genes involved in lipolysis and very low density lipoprotein secretion. In addition, gene expression of cytochrome P4502E1 and tumor necrosis factor-α were also increased in the HFD group. Nuciferine supplementation clearly suppressed HFD-induced alterations in the expression of genes involved in lipid metabolism. Conclusions/Significance Nuciferine supplementation ameliorated HFD-induced dyslipidemia as well as liver steatosis and injury. The beneficial effects of nuciferine were associated with altered expression of hepatic genes involved in lipid metabolism. PMID:23691094

  18. 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...

  19. TEMPERATURE REGULATION IN THE MOUSE AND HAMSTER EXPOSED TO MICROWAVES IN HOT ENVIRONMENTS

    EPA Science Inventory

    Colonic temperature was measured in naive BALB/c mice and golden hamsters immediately following 90 min exposures to 2450 MHz radiofrequency (RF) radiation at an ambient temperature (Ta) of 32.2 or 35 C (dry air). Exposures were performed in a temperature-controlled waveguide whic...

  20. BEHAVIOURAL AND AUTONOMIC THERMOREGULATION IN HAMSTERS DURING MICROWAVE-INDUCED HEAT EXPOSURE

    EPA Science Inventory

    Preferred ambient temperature (Ta) and ventilatory frequency were measured in free-moving hamsters exposed to 2450 MHz microwaves. A waveguide exposure system which permits continuous monitoring of the absorbed heat load accrued from microwave exposure was imposed with a longitud...

  1. METABOLISM OF ALPHA-NAPHTHOFLAVONE BY RAT, MOUSE, RABBIT, AND HAMSTER LIVER MICROSOMES

    EPA Science Inventory

    The metabolism of alpha-naphthoflavone (ANF) was studied in hepatic microsomes from rats, mice, rabbits, and hamsters, species in which ANF exerts its biological activities. The major metabolites produced by all species were ANF-5,6-oxide, ANF-6-phenol, and ANF-7,8-dihydrodiol. M...

  2. VENTILATORY FREQUENCY OF MOUSE AND HAMSTER DURING MICROWAVE-INDUCED HEAT EXPOSURE

    EPA Science Inventory

    Ventilatory frequency was recorded in unrestrained mice and hamsters using microwave radiation. The microwave exposure system was also used to impart varying heat loads to the rodents at ambient temperatures of 10, 20 and 30 C. The absorbed heat load accrued from microwave exposu...

  3. PATHOLOGIC CHANGES INDUCED BY COAL-FIRED FLY ASH IN HAMSTER TRACHEAL GRAFTS

    EPA Science Inventory

    The toxicity of fly ash from a coal-fired power plant for respiratory tract epithelium was studied in heterotropic tracheal grafts. Hamster tracheal grafts were continuously exposed to beeswax-cholesterol pellets containing 100, 1000 and 5000 micrograms fly ash and evaluated at 1...

  4. Paradoxical effect of omega-3 fatty acids on plasma lipoprotein profile in the Golden Syrian hamster

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective was to determine the effect of dietary omega-3 and omega-6 fatty acids, and cholesterol (C) loading or C depletion on plasma lipids and mRNA levels of genes associated with C metabolism. Hamsters were fed high safflower (SO) or fish (FO) oil diets (10% w/w) for 12 weeks, with 0.01% (-C...

  5. Characterization of diethylnitrosamine-induced liver carcinogenesis in Syrian golden hamsters

    PubMed Central

    CHEN, GUO; DAI, ZHI-KAI; LIANG, RONG-GAN; XIAO, SHENG-JUN; HE, SONG-QING; ZHAO, HAI-LU; XU, QING

    2012-01-01

    The aim of this study was to characterize hepatocarcinogenesis in diethylnitrosamine (DEN)-treated hamsters. Syrian golden hamsters (n=36) were administered DEN by hypodermic injection and addition to drinking water. Morphological analyses, including light microscopy and immunohistochemistry of α-fetal protein (AFP), were performed on liver and lung tissues. Primary cell culture and tumor transplantation were carried out to evaluate the potential application in hepatocellular carcinoma (HCC) research. From 25 to 50 weeks of treatment, liver tumors, including macronodular HCC and ascites, were found in one-third (4/12) of the animals treated with DEN. HCC was characterized by poor differentiation, frequent mitosis, AFP reaction, vessel invasion and potential application in primary cell culture and xenotransplantation. Pre-neoplastic lesions were hyperplastic nodules comprised of clear cells, bile duct proliferation, fatty metamorphosis and multilocular cysts. The DEN-treated hamsters also showed lung tumors consisting of AFP-negative, well-differentiated neoplastic cells. Characterization of DEN-induced HCC in hamsters provides insights into human hepatocarcinogenesis. This animal model has potential applications in HCC research. PMID:22969883

  6. Analysis in Blood of Golden Hamster by Naa for Clinical Practice

    NASA Astrophysics Data System (ADS)

    Aguiar, R.; Zamboni, C. B.; Genezini, F. A.

    2009-06-01

    In the present study Neutron Activation Analysis (NAA) technique has been used to determine, simultaneously, some element concentrations of clinical relevance in whole blood samples of Golden Hamster. The normal range for Br, Cl, K and Na concentrations were determined. The knowledge of these values permits clinical investigation of animal model using whole blood as well as to check the similarities with human blood.

  7. 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. PMID:25926398

  8. EFFECT OF PHORBOL ESTERS ON CLONAL CULTURES OF HUMAN, HAMSTER, AND RAT RESPIRATORY EPITHELIAL CELLS

    EPA Science Inventory

    The effect of the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) on the growth of epithelial cells from rat, hamster, and human respiratory tract has been measured by monitoring colony formation in culture. TPA and its active derivatives stimulated colony formation of ...

  9. Dietary Soluble Celluloses Prevent Obesity-Related Metabolic Diseases in Fat Fed Hamsters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soluble, and to some extent, natural, unmodified cellulose demonstrate physiological activities, including plasma cholesterol-lowering. Male Syrian hamsters, ten per dietary treatment, were fed diets containing 5% total dietary fiber, 8% butterfat, 10% corn oil, 2% menhaden oil, and 0.1% cholestero...

  10. INFLUENCE OF OZONE ON PENTOBARBITAL-INDUCED SLEEPING TIME IN MICE, RATS, AND HAMSTERS

    EPA Science Inventory

    Prior studies have shown that ozone (O3) increases pentobarbital (PEN)-induced sleeping time (S.T.) in female mice, rats, and hamsters. To investigate some potential mechanisms producing these effects, the authors measured zoxazolamine-induced paralysis time and thiopental- and h...

  11. 41 CFR 101-45.002 - Gold.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 41 Public Contracts and Property Management 2 2012-07-01 2012-07-01 false Gold. 101-45.002 Section... PERSONAL PROPERTY § 101-45.002 Gold. (a) Gold will be sold in accordance with this section and part 102-38 of the Federal Management Regulation. (b) Sales of gold shall be processed to— (1) Use the sealed...

  12. 41 CFR 101-45.002 - Gold.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 41 Public Contracts and Property Management 2 2014-07-01 2012-07-01 true Gold. 101-45.002 Section... PERSONAL PROPERTY § 101-45.002 Gold. (a) Gold will be sold in accordance with this section and part 102-38 of the Federal Management Regulation. (b) Sales of gold shall be processed to— (1) Use the sealed...

  13. 41 CFR 101-45.002 - Gold.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 2 2013-07-01 2012-07-01 true Gold. 101-45.002 Section... PERSONAL PROPERTY § 101-45.002 Gold. (a) Gold will be sold in accordance with this section and part 102-38 of the Federal Management Regulation. (b) Sales of gold shall be processed to— (1) Use the sealed...

  14. 41 CFR 101-45.002 - Gold.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 41 Public Contracts and Property Management 2 2011-07-01 2007-07-01 true Gold. 101-45.002 Section... PERSONAL PROPERTY § 101-45.002 Gold. (a) Gold will be sold in accordance with this section and part 102-38 of the Federal Management Regulation. (b) Sales of gold shall be processed to— (1) Use the sealed...

  15. 41 CFR 101-45.002 - Gold.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Gold. 101-45.002 Section... PERSONAL PROPERTY § 101-45.002 Gold. (a) Gold will be sold in accordance with this section and part 102-38 of the Federal Management Regulation. (b) Sales of gold shall be processed to— (1) Use the sealed...

  16. 20th-Century Gold Rush.

    ERIC Educational Resources Information Center

    Wargo, Joseph G.

    1992-01-01

    Presents Nevada's gold rush activities spurred by technological advancements in search methods. Describes the events that led to the twentieth-century gold rush, the techniques for finding deposits and the geological formation process of disseminated gold deposits. Vignettes present the gold extraction process, cross-section, and profile of a…

  17. Enhancement of gold recovery using bioleaching from gold concentrate

    NASA Astrophysics Data System (ADS)

    Choi, S. H.; Cho, K. H.; Kim, B. J.; Choi, N. C.; Park, C. Y.

    2012-04-01

    The gold in refractory ores is encapsulated as fine particles (sometimes at a molecular level) in the crystal structure of the sulfide (typically pyrite with or without arsenopyrite) matrix. This makes it impossible to extract a significant amount of refractory gold by cyanidation since the cyanide solution cannot penetrate the pyrite/arsenopyrite crystals and dissolve gold particles, even after fine grinding. To effectively extract gold from these ores, an oxidative pretreatment is necessary to break down the sulfide matrix. The most popular methods of pretreatment include nitric acid oxidation, roasting, pressure oxidation and biological oxidation by microorganisms. This study investigated the bioleaching efficiency of Au concentrate under batch experimental conditions (adaptation cycles and chemical composition adaptation) using the indigenous acidophilic bacteria collected from gold mine leachate in Sunsin gold mine, Korea. We conducted the batch experiments at two different chemical composition (CuSO4 and ZnSO4), two different adaptation cycles 1'st (3 weeks) and 2'nd (6 weeks). The results showed that the pH in the bacteria inoculating sample decreased than initial condition and Eh increased. In the chemical composition adaptation case, the leached accumulation content of Fe and Pb was exhibited in CuSO4 adaptation bacteria sample more than in ZnSO4 adaptation bacteria samples, possibly due to pre-adaptation effect on chalcopyrite (CuFeS2) in gold concentrate. And after 21 days on the CuSO4 adaptation cycles case, content of Fe and Pb was appeared at 1'st adaptation bacteria sample(Fe - 1.82 and Pb - 25.81 times per control sample) lower than at 2'nd adaptation bacteria sample(Fe - 2.87 and Pb - 62.05 times per control sample). This study indicates that adaptation chemical composition and adaptation cycles can play an important role in bioleaching of gold concentrate in eco-/economic metallurgy process.

  18. Alterations in erythrocyte plasma membrane ATPase activity and adenine nucleotide content in a spontaneously diabetic subline of the Chinese hamster.

    PubMed

    Bettin, D; Klöting, I; Kohnert, K D

    1996-01-01

    The CHIG/Han subline of the Chinese hamster develops noninsulin-dependent diabetes mellitus characterized by hyperinsulinemia and different degrees of glucose intolerance. To study whether these abnormalities could affect transmembrane cation transport activity, we determined membrane ATPase activity and ATP concentrations in red blood cells of diabetes-resistant CHIA and diabetes-susceptible CHIG sublines of the Chinese hamster. Mg(2+)-ATPase activity was increased in red blood cell membranes of diabetic hamsters compared with that of nondiabetic CHIG and the diabetes-resistant CHIA animals and correlated with plasma triglyceride and cholesterol levels. Ca(2+)-ATPase and Na+/K+ATPase activity were not significantly different between diabetic and nondiabetic hamsters, but for the Na+/K(+)-ATPase, Km was decreased and the Vmax value increased in membrane preparations from severely diabetic hamsters. Both ATP and ADP content were lower in erythrocytes from diabetic than nondiabetic hamsters. Independently of the levels of glycemia, AMP concentrations were higher in CHIG than in CHIA hamsters. While ATP/AMP ratios were found to be decreased in erythrocytes from diabetes-susceptible CHIG hamsters compared to the diabetes-resistant CHIA animals, they were significantly correlated with the levels of glycemia. Furthermore, the relationship between blood glucose levels and kidney weight in hamsters of the diabetes-susceptible CHIG subline was such, that severely hyperglycemic animals displayed the greatest increase in kidney wet weight. These results indicate that the progressive metabolic deterioration in the development of noninsulin-dependent diabetes is associated with significant changes in the activity and kinetic parameters of cellular ATPases which could probably indicate early membrane alterations which may eventually result in the late microangiopathic complications of diabetes. PMID:8820985

  19. Gold-Catalyzed Synthesis of Heterocycles

    NASA Astrophysics Data System (ADS)

    Arcadi, Antonio

    2014-04-01

    The following sections are included: * Introduction * Synthesis of Heterocycles via Gold-Catalyzed Heteroatom Addition to Unsaturated C-C Bonds * Synthesis of Heterocyclic Derivatives through Gold-Catalyzed Cyclization of Polyunsaturated Compounds * Synthesis of Heterocyclic Compounds via α-Oxo Gold Carbenoid * Synthesis of Heterocyclic Derivatives through Gold-Catalyzed Cycloaddition Reactions * Synthesis of Heterocyclic Derivatives through Gold-Catalyzed Activation of Carbonyl Groups and Alcohols * Synthesis of Heterocyclic Compounds through Gold-Mediated C-H Bond Functionalization * Gold-Catalyzed Domino Cyclization/Oxidative Coupling Reactions * Conclusions * References

  20. Hamster-adapted Sin Nombre virus causes disseminated infection and efficiently replicates in pulmonary endothelial cells without signs of disease.

    PubMed

    Safronetz, David; Prescott, Joseph; Haddock, Elaine; Scott, Dana P; Feldmann, Heinz; Ebihara, Hideki

    2013-04-01

    To date, a laboratory animal model for the study of Sin Nombre virus (SNV) infection or associated disease has not been described. Unlike infection with Andes virus, which causes lethal hantavirus pulmonary syndrome (HPS)-like disease in hamsters, SNV infection is short-lived, with no viremia and little dissemination. Here we investigated the effect of passaging SNV in hamsters. We found that a host-adapted SNV achieves prolonged and disseminated infection in hamsters, including efficient replication in pulmonary endothelial cells, albeit without signs of disease. PMID:23388711

  1. Clinical laboratory, virologic, and pathologic changes in hamsters experimentally infected with Pirital virus (Arenaviridae): a rodent model of Lassa fever.

    PubMed

    Sbrana, Elena; Mateo, Rosa I; Xiao, Shu-Yuan; Popov, Vsevolod L; Newman, Patrick C; Tesh, Robert B

    2006-06-01

    The clinical laboratory, virologic, and pathologic changes occurring in hamsters after infection with Pirital virus (Arenaviridae) are described. Pirital virus infection in the hamsters was characterized by high titered viremia, leukocytosis, coagulopathy, pulmonary hemorrhage and edema, hepatocellular and splenic necrosis, and marked elevation of serum transaminase levels. All of the animals died within 9 days. The clinical and histopathological findings in the Pirital virus-infected hamsters were very similar to those reported in severe human cases of Lassa fever, suggesting that this new animal model could serve as a low-cost and relatively safe alternative for studying the pathogenesis and therapy of Lassa fever. PMID:16760527

  2. Three hamster species with different scrapie incubation times and neuropathological features encode distinct prion proteins.

    PubMed Central

    Lowenstein, D H; Butler, D A; Westaway, D; McKinley, M P; DeArmond, S J; Prusiner, S B

    1990-01-01

    Given the critical role of the prion protein (PrP) in the transmission and pathogenesis of experimental scrapie, we investigated the PrP gene and its protein products in three hamster species, Chinese (CHa), Armenian (AHa), and Syrian (SHa), each of which were found to have distinctive scrapie incubation times. Passaging studies demonstrated that the host species, and not the source of scrapie prions, determined the incubation time for each species, and histochemical studies of hamsters with clinical signs of scrapie revealed characteristic patterns of neuropathology. Northern (RNA) analysis showed the size of PrP mRNA from CHa, AHa, and SHa hamsters to be 2.5, 2.4, and 2.1 kilobases, respectively. Immunoblotting demonstrated that the PrP isoforms were of similar size (33 to 35 kilodaltons); however, the monoclonal antibody 13A5 raised against SHa PrP did not react with the CHa or AHa PrP molecules. Comparison of the three predicted amino acid sequences revealed that each is distinct. Furthermore, differences within the PrP open reading frame that uniquely distinguish the three hamster species are within a hydrophilic segment of 11 amino acids that includes polymorphisms linked to scrapie incubation times in inbred mice and an inherited prion disease of humans. Single polymorphisms in this region correlate with the presence or absence of amyloid plaques for a given hamster species or mouse inbred strain. Our findings demonstrate distinctive molecular, pathological, and clinical characteristics of scrapie in three related species and are consistent with the hypothesis that molecular properties of the host PrP play a pivotal role in determining the incubation time and neuropathological features of scrapie. Images PMID:2406562

  3. Intracellular potassium as a possible inducer of amino acid transport across hamster jejunal enterocytes.

    PubMed Central

    Cremaschi, D; James, P S; Meyer, G; Rossetti, C; Smith, M W

    1986-01-01

    Brush border membrane potentials (Vm), intracellular K+ activity (aiK) and alanine uptake were measured in different parts of villi in mid-jejunal tissue taken from hamsters fed different amounts of food at high and low environmental temperatures. Basal villus enterocytes (Y cells) were found to have lower values for Vm and aiK than upper villus enterocytes (O cells). Alanine uptake was confined to O cells. The position on the villus where values for Vm and aiK changed, and where alanine uptake could first be seen to take place, depended on the energy intake and environmental temperature at which hamsters were kept. Na+-dependent alanine uptake and Vm were both higher in O cells of hamsters fed 10 kcal day-1 at 30 degrees C (10 k/30 degrees C) compared with animals fed 30 kcal day-1 at an environmental temperature of 12 degrees C (30 k/12 degrees C hamsters). The rates at which enterocytes migrated along the crypt-villus axis, measured separately in thymidine-labelling experiments, were 6.9 and 16.1 micron h-1 for 10 k/30 degrees C and 30 k/12 degrees C hamsters respectively. Both Vm and aiK were estimated, from these measurements, to have increased significantly by the time enterocytes became 30 h old. Alanine uptake began 15 h later. Neither of these parameters were influenced by previous adaptation conditions. The close temporal and variable positional relationship found between changes in aiK and onset of transport suggests that early changes in electrolyte composition might initiate a second phase of development enabling the enterocyte to absorb nutrients. The possibility that other ions besides K+ might also be involved in this aspect of regulation is also discussed. PMID:3795055

  4. Effect of temperature on oxidative stress, antioxidant levels and uncoupling protein expression in striped hamsters.

    PubMed

    Zhou, Si-Si; Cao, Li-Li; Xu, Wei-Dong; Cao, Jing; Zhao, Zhi-Jun

    2015-11-01

    According to the rate of living-free radical hypothesis, higher metabolic rates should increase reactive oxygen species (ROS) production. However, the "uncoupling to survive" hypothesis postulates that uncoupling proteins (UCPs) can decrease ROS production by lowering the potential of the inner mitochondrial membrane, in which case the correlation between metabolic rate and ROS levels would be a negative rather than positive. In this study, we examined energy intake, oxidative stress levels, antioxidant activity and the expression of UCPs in brown adipose tissue (BAT), and in the liver, heart, skeletal muscle and brain, of striped hamsters (Cricetulus barabensis) acclimated to either 5 °C or 32.5 °C. The energy intake of hamsters acclimated to 5 °C increased by 70.7%, whereas the energy intake of hamsters acclimated to 32.5 °C decreased by 31.3%, relative to hamsters kept at room temperature (21 °C) (P<0.05). Malonadialdehyde (MDA) levels, total antioxidant capacity (T-AOC) and glutathione peroxidase (GSH-PX) activity in BAT significantly decreased in 5 °C group, but increased in 32.5 °C group, relative to the 21 °C group. Neither ROS levels (i.e. H2O2 levels), nor antioxidants in skeletal muscle, liver, heart or brain tissue, were affected by temperature. UCP1 expression in BAT was significantly up-regulated in 5 °C group, but down-regulated in 32.5 °C group, relative to the 21 °C group. UCP3 expression of skeletal muscle was also up-regulated significantly in hamsters acclimated to 5 °C. These results suggest that the relationship between ROS levels and metabolic rate was negative, rather than positive. UCP1 expression in BAT may have played a role in lowering ROS levels. PMID:26244518

  5. Basking hamsters reduce resting metabolism, body temperature and energy costs during rewarming from torpor.

    PubMed

    Geiser, Fritz; Gasch, Kristina; Bieber, Claudia; Stalder, Gabrielle L; Gerritsmann, Hanno; Ruf, Thomas

    2016-07-15

    Basking can substantially reduce thermoregulatory energy expenditure of mammals. We tested the hypothesis that the largely white winter fur of hamsters (Phodopus sungorus), originating from Asian steppes, may be related to camouflage to permit sun basking on or near snow. Winter-acclimated hamsters in our study were largely white and had a high proclivity to bask when resting and torpid. Resting hamsters reduced metabolic rate (MR) significantly (>30%) when basking at ambient temperatures (Ta) of ∼15 and 0°C. Interestingly, body temperature (Tb) also was significantly reduced from 34.7±0.6°C (Ta 15°C, not basking) to 30.4±2.0°C (Ta 0°C, basking), which resulted in an extremely low (<50% of predicted) apparent thermal conductance. Induced torpor (food withheld) during respirometry at Ta 15°C occurred on 83.3±36.0% of days and the minimum torpor MR was 36% of basal MR at an average Tb of 22.0±2.6°C; movement to the basking lamp occurred at Tb<20.0°C. Energy expenditure for rewarming was significantly reduced (by >50%) during radiant heat-assisted rewarming; however, radiant heat per se without an endogenous contribution by animals did not strongly affect metabolism and Tb during torpor. Our data show that basking substantially modifies thermal energetics in hamsters, with a drop of resting Tb and MR not previously observed and a reduction of rewarming costs. The energy savings afforded by basking in hamsters suggest that this behaviour is of energetic significance not only for mammals living in deserts, where basking is common, but also for P. sungorus and probably other cold-climate mammals. PMID:27207637

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

    SciTech Connect

    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 the 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.

  7. Colloidal Synthesis of Gold Semishells

    PubMed Central

    Rodríguez-Fernández, Denis; Pérez-Juste, Jorge; Pastoriza-Santos, Isabel; Liz-Marzán, Luis M

    2012-01-01

    This work describes a novel and scalable colloid chemistry strategy to fabricate gold semishells based on the selective growth of gold on Janus silica particles (500 nm in diameter) partly functionalized with amino groups. The modulation of the geometry of the Janus silica particles allows us to tune the final morphology of the gold semishells. This method also provides a route to fabricating hollow gold semishells through etching of the silica cores with hydrofluoric acid. The optical properties were characterized by visible near-infrared (vis-NIR) spectroscopy and compared with simulations performed using the boundary element method (BEM). These revealed that the main optical features are located beyond the NIR region because of the large core size. PMID:24551496

  8. Gold based bulk metallic glass

    SciTech Connect

    Schroers, Jan; Lohwongwatana, Boonrat; Johnson, William L.; Peker, Atakan

    2005-08-08

    Gold-based bulk metallic glass alloys based on Au-Cu-Si are introduced. The alloys exhibit a gold content comparable to 18-karat gold. They show very low liquidus temperature, large supercooled liquid region, and good processibility. The maximum casting thickness exceeds 5 mm in the best glassformer. Au{sub 49}Ag{sub 5.5}Pd{sub 2.3}Cu{sub 26.9}Si{sub 16.3} has a liquidus temperature of 644 K, a glass transition temperature of 401 K, and a supercooled liquid region of 58 K. The Vickers hardness of the alloys in this system is {approx}350 Hv, twice that of conventional 18-karat crystalline gold alloys. This combination of properties makes the alloys attractive for many applications including electronic, medical, dental, surface coating, and jewelry.

  9. Nanoporous gold for enzyme immobilization.

    PubMed

    Stine, Keith J; Jefferson, Kenise; Shulga, Olga V

    2011-01-01

    Nanoporous gold (NPG) is a material of emerging interest for immobilization of biomolecules and -especially enzymes. NPG materials provide a high gold surface area onto which biomolecules can either be directly physisorbed or covalently linked after first modifying the NPG with a self-assembled monolayer. The material can be used as a high surface area electrode and with immobilized enzymes can be used for amperometric detection schemes. NPG can be prepared in a variety of formats from alloys containing less than 50 atomic% gold by dealloying procedures. Related high surface area gold structures have been prepared using templating approaches. Covalent enzyme immobilization can be achieved by first forming a self-assembled monolayer on NPG bearing a terminal reactive functional group followed by conjugation to the enzyme through amide linkages to lysine residues. PMID:20865389

  10. Gold based bulk metallic glass

    NASA Astrophysics Data System (ADS)

    Schroers, Jan; Lohwongwatana, Boonrat; Johnson, William L.; Peker, Atakan

    2005-08-01

    Gold-based bulk metallic glass alloys based on Au-Cu-Si are introduced. The alloys exhibit a gold content comparable to 18-karat gold. They show very low liquidus temperature, large supercooled liquid region, and good processibility. The maximum casting thickness exceeds 5mm in the best glassformer. Au49Ag5.5Pd2.3Cu26.9Si16.3 has a liquidus temperature of 644K, a glass transition temperature of 401K, and a supercooled liquid region of 58K. The Vickers hardness of the alloys in this system is ˜350Hv, twice that of conventional 18-karat crystalline gold alloys. This combination of properties makes the alloys attractive for many applications including electronic, medical, dental, surface coating, and jewelry.

  11. Gold, currencies and market efficiency

    NASA Astrophysics Data System (ADS)

    Kristoufek, Ladislav; Vosvrda, Miloslav

    2016-05-01

    Gold and currency markets form a unique pair with specific interactions and dynamics. We focus on the efficiency ranking of gold markets with respect to the currency of purchase. By utilizing the Efficiency Index (EI) based on fractal dimension, approximate entropy and long-term memory on a wide portfolio of 142 gold price series for different currencies, we construct the efficiency ranking based on the extended EI methodology we provide. Rather unexpected results are uncovered as the gold prices in major currencies lay among the least efficient ones whereas very minor currencies are among the most efficient ones. We argue that such counterintuitive results can be partly attributed to a unique period of examination (2011-2014) characteristic by quantitative easing and rather unorthodox monetary policies together with the investigated illegal collusion of major foreign exchange market participants, as well as some other factors discussed in some detail.

  12. A eutectic gold vapour laser

    NASA Astrophysics Data System (ADS)

    Tou, T. Y.; Cheak, K. E.; Low, K. S.

    This paper presents a eutectic gold vapour laser (EGVL) which uses the eutectic alloy of gold and silicon, Au/3.15Si, as the lasant. It was observed that, at low input power operation, the presence of the silicon vapour could increase the output of the 627.8 nm laser line by (50-60)% when compared with a gold vapour laser (GVL) which uses pure gold as the lasant. The improved laser output for the EGVL may be explained by an increased electron density, as a result of Penning ionization of silicon atoms. However, for higher input power operation, the EGVL showed a slower rate of increase in its laser output power and was overtaken by GVLs at a tube operating temperature of around 1650°C. This may be explained by a lowering of the electron temperature owing to increasing inelastic collisions between the electrons and silicon atoms which, although excited, may not produce additional electrons.

  13. GOLD: The Genomes Online Database

    DOE Data Explorer

    Kyrpides, Nikos; Liolios, Dinos; Chen, Amy; Tavernarakis, Nektarios; Hugenholtz, Philip; Markowitz, Victor; Bernal, Alex

    Since its inception in 1997, GOLD has continuously monitored genome sequencing projects worldwide and has provided the community with a unique centralized resource that integrates diverse information related to Archaea, Bacteria, Eukaryotic and more recently Metagenomic sequencing projects. As of September 2007, GOLD recorded 639 completed genome projects. These projects have their complete sequence deposited into the public archival sequence databases such as GenBank EMBL,and DDBJ. From the total of 639 complete and published genome projects as of 9/2007, 527 were bacterial, 47 were archaeal and 65 were eukaryotic. In addition to the complete projects, there were 2158 ongoing sequencing projects. 1328 of those were bacterial, 59 archaeal and 771 eukaryotic projects. Two types of metadata are provided by GOLD: (i) project metadata and (ii) organism/environment metadata. GOLD CARD pages for every project are available from the link of every GOLD_STAMP ID. The information in every one of these pages is organized into three tables: (a) Organism information, (b) Genome project information and (c) External links. [The Genomes On Line Database (GOLD) in 2007: Status of genomic and metagenomic projects and their associated metadata, Konstantinos Liolios, Konstantinos Mavromatis, Nektarios Tavernarakis and Nikos C. Kyrpides, Nucleic Acids Research Advance Access published online on November 2, 2007, Nucleic Acids Research, doi:10.1093/nar/gkm884]

    The basic tables in the GOLD database that can be browsed or searched include the following information:

    • Gold Stamp ID
    • Organism name
    • Domain
    • Links to information sources
    • Size and link to a map, when available
    • Chromosome number, Plas number, and GC content
    • A link for downloading the actual genome data
    • Institution that did the sequencing
    • Funding source
    • Database where information resides
    • Publication status and information

    • Titanium/gold process characterization

      SciTech Connect

      Fajardo, L.S.

      1991-11-01

      Characterization of the titanium/gold (Ti/Au) deposition process used at the Allied-Signal Inc., Albuquerque Microelectronics Operation (AMO) was performed. Tests were conducted to set up evaporation parameters, correlate titanium and gold thicknesses to sheet resistance, improve thickness uniformity, and reduce frontside contamination of deposit material on product wafers. The Ti/Au process is the final step in the production of integrated circuits (ICs) at the AMO wafer fabrication facility. 3 figs.

    • Photochemical synthesis of gold nanorods.

      PubMed

      Kim, Franklin; Song, Jae Hee; Yang, Peidong

      2002-12-01

      Gold nanorods have been synthesized by photochemically reducing gold ions within a micellar solution. The aspect ratio of the rods can be controlled with the addition of silver ions. This process reported here is highly promising for producing uniform nanorods, and more importantly it will be useful in resolving the growth mechanism of anisotropic metal nanoparticles due to its simplicity and the relatively slow growth rate of the nanorods. PMID:12452700

    • Precipitation of gold into metastable gold silicide in silicon

      SciTech Connect

      Baumann, F.H.; Schroeter, W. )

      1991-03-15

      We report a detailed investigation of the precipitation behavior of gold in float-zone silicon from a highly supersaturated solution. Nucleation, morphology, and crystallography as well as the decomposition of the solution were examined using high-resolution electron microscopy, selected area diffraction combined with tilting experiments, Hall-effect measurements, and energy dispersive x-ray spectroscopy. After in-diffusion of gold at 1275 {degree}C annealing experiments were performed at 850 {degree}C for durations ranging from 5 min up to 35 d. It is shown that gold precipitates in small spherical particles (diameter: 10--20 nm) consisting of a metastable gold silicide. By means of selected area diffraction combined with a special tilting procedure, the unit cell is proved to be orthorhombic with lattice parameters {ital a}=0.971 nm, {ital b}=0.768 nm, and {ital c}=0.703 nm. Systematic absence of reflections in several precipitate zone-axis patterns reveals the space group of the silicide to be {ital Pnma} or {ital Pn}2{sub 1}{ital a}. According to Hall-effect measurements the concentration of substitutional gold decreases to a few percent within 5 min annealing at 850 {degree}C. Only a part of it has precipitated in gold silicide particles, which are found at small extrinsic stacking faults. The stacking faults represent a density of self-interstitials Si{sub {ital i}} of about 10{sup 18} cm{sup {minus}3}, which according to control experiments is about a factor of 50 above the equilibrium concentration of Si{sub {ital i}} at 1274 {degree}C. As annealing proceeds the stacking faults disappear, and gold is finally found in spherical particles embedded stress-free into the silicon matrix.

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

      SciTech Connect

      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. This effect appears to result from the combined influence of the SO/sub 2/, the Listeria infection, and the emphysematous condition within the lungs.

    • 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. PMID:25752854

    • 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

    • Biocompatibility and degradation of gold-covered magneto-elastic biosensors exposed to cell culture.

      PubMed

      Menti, C; Beltrami, M; Possan, A L; Martins, S T; Henriques, J A P; Santos, A D; Missell, F P; Roesch-Ely, M

      2016-07-01

      Magneto-elastic materials (ME) have important advantages when applied as biosensors due to the possibility of wireless monitoring. Commercial Metglas 2826MB3™ (FeNiMoB) is widely used, however sensor stabilization is an important factor for biosensor performance. This study compared the effects of biocompatibility and degradation of the Metglas 2826MB3™ alloy, covered or not with a gold layer, when in contact with cell culture medium. Strips of amorphous Metglas 2826MB3™ were cut and coated with thin layers of Cr and Au, as verified by Rutherford Backscattering Spectroscopy (RBS). Using Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES), the presence of metals in the culture medium was quantitatively determined for up to seven days after alloy exposure. Biocompatibility of fibroblast Chinese Hamster Ovary (CHO) cultures was tested and cytotoxicity parameters were investigated by indirect means of reduction of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) at 1, 2 and 7 days. Cell death was further evaluated through in situ analysis using Acridine Orange/Ethidium Bromide (AO/EB) staining and images were processed with ImageJ software. Ions from Metglas(®) 2826MB3™ induced a degradation process in living organisms. The cytotoxicity assay showed a decrease in the percentage of live cells compared to control for the ME strip not coated with gold. AO/EB in situ staining revealed that most of the cells grown on top of the gold-covered sensor presented a normal morphology (85.46%). Covering ME sensors with a gold coating improved their effectiveness by generating protection of the transducer by reducing the release of ions and promoting a significant cell survival. PMID:26998872

  1. Modeling of gold production in Malaysia

    NASA Astrophysics Data System (ADS)

    Muda, Nora; Ainuddeen, Nasihah Rasyiqah; Ismail, Hamizun; Umor, Mohd Rozi

    2013-04-01

    This study was conducted to identify the main factors that contribute to the gold production and hence determine the factors that affect to the development of the mining industry in Malaysia. An econometric approach was used by performing the cointegration analysis among the factors to determine the existence of long term relationship between the gold prices, the number of gold mines, the number of workers in gold mines and the gold production. The study continued with the Granger analysis to determine the relationship between factors and gold production. Results have found that there are long term relationship between price, gold production and number of employees. Granger causality analysis shows that there is only one way relationship between the number of employees with gold production in Malaysia and the number of gold mines in Malaysia.

  2. 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

  3. Characterization of the host response to pichinde virus infection in the Syrian golden hamster by species-specific kinome analysis.

    PubMed

    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

    2015-03-01

    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 (PICV(1)) 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

  4. A comparison of liver protein changes in mice and hamsters treated with the peroxisome proliferator Wy-14,643.

    SciTech Connect

    Giometti, C. S.; Tollaksen, S. L.; Cunningham, M. L.; Center for Mechanistic Biology and Biotechnology; National Inst. of Environmental Health Sciences

    1998-01-01

    Interspecies differences in the liver response to Wy-14,643, a potent peroxisome proliferator in rats and mice, have been demonstrated. While both rats and mice show dramatic increases in the number of peroxisomes, the activity of peroxisomal enzymes involved in the {beta}-oxidation of fatty acids, and heptocyte replication, Syrian hamsters have a more moderate peroxisome proliferation response and no sustained increase in cell replication. Rats and mice, but not hamsters, develop hepatocellular carcinoma after prolonged exposure to Wy-14,643. To further characterize this species difference, two-dimensional gel electrophoresis (2-DE) has been used to compare the effect of 14-day exposure to various dietary concentrations of Wy-14,643 on liver protein expression in male mice and hamsters. Digitized images of the 2-DE protein maps were searched for significant changes. The peroxisome bifunctional enzyme (PBE) enoyl CoA hydratase/3-hydroxyacyl dehydrogenase, which migrates to the same position in mouse and hamster liver protein 2-DE patterns, increased in abundance by more than three times the control level in both mice and hamsters. In addition to the quantitative change in PBE, significant quantitative changes (P < 0.001) were found in 49 mouse liver proteins (47 decreasing and 2 increasing) and in 35 hamster liver proteins (27 decreasing and 8 increasing). There was little overlap in the mouse and hamster proteins showing quantitative changes in response to Wy-14,643, with the exception of PBE and one unidentified liver protein with an approximate molecular weight of 50 000. These results show that although peroxisome proliferation occurs in the livers of both mice and hamsters exposed to Wy-14,643, other species-specific changes in proteins occur that are independent of the peroxisome proliferation response and that could be related to species-specific susceptibility or resistance to liver tumor induction.

  5. Involvement of cells of hematopoietic origin in genetically determined resistance of Syrian hamsters to vesicular stomatitis virus.

    PubMed Central

    Fultz, P N; Shadduck, J A; Kang, C Y; Streilein, J W

    1981-01-01

    Susceptibility of Syrian hamsters of the inbred LSH and MHA strains to injection of as few as 10 plaque-forming units of vesicular stomatitis virus (VSV) was shown to occur only after intraperitoneal and intrapleural injection and not after injection of VSV intravenously, intranasally, or in the footpads. Despite the fact that fewer LSH hamsters died when VSV was injected via the latter routes, the histopathology of the VSV-induced disease at early times after infection was identical irrespective of the route of virus administration. Histological examination of tissues at various times after administration of VSV by the various routes revealed that VSV exhibited tropism for lymphoreticular tissue, with the greatest amount of necrosis in the splenic periarteriolar lymphoid sheath. A similar pattern also was observed in VSV-infected tissues from genetically resistant UT1 hamsters. Infectivity titrations of various tissues at different times after intraperitoneal injection of VSV revealed that resistant UT1 hamsters began to clear virus from tissues between 40 and 48 h postinfection, whereas virus titers remained high in susceptible animals. Resistance of UT1 hamsters appeared to require an intact spleen since survival of splenectomized animals was less than that of sham-splenectomized UT1 controls. Sublethal whole-body irradiation was also able to reduce resistance of UT1 hamsters (survival was reduced from 100 to 50%). Bone marrow cells from resistant (UT1 X LSH) F1 females were transferred into lethally irradiated susceptible LSH hamsters, and hematopoietic chimeras were produced. After intraperitoneal injection of 100 plaque-forming units of VSV, all of the female chimeras survived, but only 33% of male chimeras survived. These data indicate that resistance to VSV in Syrian hamsters is mediated, at least partially, by cells of hematopoietic origin. Images PMID:6273320

  6. Genetically alike Syrian hamsters display both bifoliate and trifoliate aortic valves.

    PubMed

    Sans-Coma, Valentín; Carmen Fernández, M; Fernández, Borja; Durán, Ana C; Anderson, Robert H; Arqué, Josep M

    2012-01-01

    The bifoliate, or bicuspid, aortic valve (BAV) is the most frequent congenital cardiac anomaly in man. It is a heritable defect, but its mode of inheritance remains unclear. Previous studies in Syrian hamsters showed that BAVs with fusion of the right and left coronary leaflets are expressions of a trait, the variation of which takes the form of a phenotypic continuum. It ranges from a trifoliate valve with no fusion of the coronary leaflets to a bifoliate root devoid of any raphe. The intermediate stages are represented by trifoliate valves with fusion of the coronary aortic leaflets, and bifoliate valves with raphes. The aim of this study was to elucidate whether the distinct morphological variants rely on a common genotype, or on different genotypes. We examined the aortic valves from 1 849 Syrian hamsters belonging to a family subjected to systematic inbreeding by full-sib mating. The incidence of the different trifoliate aortic valve (TAV) and bifoliate aortic valve (BAV) morphological variants widely varied in the successive inbred generations. TAVs with extensive fusion of the leaflets, and BAVs, accounted for five-sixths of the patterns found in Syrian hamsters considered to be genetically alike or virtually isogenic, with the probability of homozygosity being 0.999 or higher. The remaining one-sixth hamsters had aortic valves with a tricuspid design, but in most cases the right and left coronary leaflets were slightly fused. Results of crosses between genetically alike hamsters, with the probability of homozygosity being 0.989 or higher, revealed no significant association between the valvar phenotypes in the parents and their offspring. Our findings are consistent with the notion that the BAVs of the Syrian hamster are expressions of a quantitative trait subject to polygenic inheritance. They suggest that the genotype of the virtually isogenic animals produced by systematic inbreeding greatly predisposes to the development of anomalous valves, be they

  7. The structure of adenovirus type 12 DNA integration sites in the hamster cell genome.

    PubMed Central

    Knoblauch, M; Schröer, J; Schmitz, B; Doerfler, W

    1996-01-01

    Foreign DNA can integrate into the genomes of mammalian cells, and this process plays major roles in viral oncogenesis and in the generation of transgenic organisms and will be important in evolving regimens for human somatic gene therapy. In the present study, the insertion sites of adenovirus type 12 (Ad12) DNA genomes have been analyzed in detail in the Ad12-transformed hamster cell line T637, its revertants, which have lost most of the >20 Ad12 genome equivalents integrated chromosomally in cell line T637, and in the Ad12-induced tumor T191. Some of these junction sites have been molecularly cloned, and the nucleotide sequences at the sites of transition between viral and cellular DNAs have been determined. The sites of linkage between the hamster cellular and the foreign (viral) DNA are characterized by the frequent occurrence of patch homologies between the recombination partners. The cellular junction sites investigated here are not transcriptionally active. One of the cellular DNA sequences abutting the right Ad12 DNA terminus in cell line T637 (os2) is represented only once in the hamster genome and has a strikingly low abundance of 5'-CG-3' dinucleotide sequences. One 5'-GCGC-3' sequence close to the Ad12 DNA integration site is heavily methylated in normal cells, Ad12-transformed cells, and Ad12-induced tumor cells. The second such sequence is more remote from the junction site, is partly methylated in BHK21 hamster cells, and shows differences in methylation in different Ad12-transformed cell lines. This site is unmethylated in liver DNA. The cellular DNA sequence at the site of Ad12 linkage in the tumor T191 exhibits homologies to highly repetitive sequences of the Alu family and to an origin of hamster DNA replication containing an Alu element. A number of junction sites between Ad12 DNA and hamster or mouse DNA in Ad12-transformed cell lines or Ad12-induced tumor cell lines, investigated here and previously, are characterized by stem-loop structures

  8. 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

  9. Monoclonal antibody "gold rush".

    PubMed

    Maggon, Krishan

    2007-01-01

    The market, sales and regulatory approval of new human medicines, during the past few years, indicates increasing number and share of new biologics and emergence of new multibillion dollar molecules. The global sale of monoclonal antibodies in 2006 were $20.6 billion. Remicade had annual sales gain of $1 billion during the past 3 years and five brands had similar increase in 2006. Rituxan with 2006 sales of $4.7 billion was the best selling monoclonal antibody and biological product and the 6th among the top selling medicinal brand. It may be the first biologic and monoclonal antibody to reach $10 billion annual sales in the near future. The strong demand from cancer and arthritis patients has surpassed almost all commercial market research reports and sales forecast. Seven monoclonal antibody brands in 2006 had sales exceeding $1 billion. Humanized or fully human monoclonal antibodies with low immunogenicity, enhanced antigen binding and reduced cellular toxicity provide better clinical efficacy. The higher technical and clinical success rate, overcoming of technical hurdles in large scale manufacturing, low cost of market entry and IND filing, use of fully human and humanized monoclonal antibodies has attracted funds and resources towards R&D. Review of industry research pipeline and sales data during the past 3 years indicate a real paradigm shift in industrial R&D from pharmaceutical to biologics and monoclonal antibodies. The antibody bandwagon has been joined by 200 companies with hundreds of new projects and targets and has attracted billions of dollars in R&D investment, acquisitions and licensing deals leading to the current Monoclonal Antibody Gold Rush. PMID:17691940

  10. Investigation of venereal, transplacental, and contact transmission of the Lyme disease spirochete, Borrelia burgdorferi, in Syrian hamsters.

    PubMed

    Woodrum, J E; Oliver, J H

    1999-06-01

    A hamster was inoculated with the SI-1 strain of Borrelia burgdorferi and subsequently served as a host to larval Ixodes scapularis Say. Approximately 68% of the nymphs resulting from the fed larvae were infected. Nymphs from this group were fed on uninfected hamsters, and 3 of 4 males and 6 of 6 females became infected. The infected hamsters were allowed to mate with uninfected partners to test for venereal transmission. Six infected females were mated with 6 uninfected males, whereas 3 infected males were mated with 6 uninfected females. None of the uninfected hamsters became infected after mating. Two protocols were used to determine if transplacental transmission of B. burgdorferi occurred. One group included 6 nonpregnant infected females that were subsequently mated and became pregnant. Three of the females were allowed to carry to full term, whereas the other 3 were killed prior to parturition. All fetuses and offspring were negative for B. burgdorferi based on cultures and monoclonal antibody assays. Another group of 6 females was infected via tick bite after becoming pregnant; those females were allowed to carry fetuses to birth and all were negative. Attempts at contact transmission of B. burgdorferi from 2 infected females to 2 uninfected male and 2 uninfected female hamsters and from 2 infected males to 2 uninfected male and uninfected female hamsters via urine or feces failed. PMID:10386432

  11. 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. PMID:27157336

  12. Species differences in the handling of lysosomotropic metals and Triton WR 1339 by rat and Chinese hamster liver.

    PubMed

    Seidel, A; Heumann, H G; Sütterlin, U; Wiener, M; Haffner, H

    1985-05-01

    The study was undertaken in order to understand the reasons for the distinct differences in the elimination rate of lanthanides and transuranium elements from the liver of different mammalian species. The binding of monomeric 239Pu in livers of rats and Chinese hamsters was analyzed by density gradient centrifugation and electrophoresis. It was concluded that this nuclide is initially bound to lysosomes in liver of rats and Chinese hamsters. The influence of Triton WR 1339 (TWR) on the density of lysosomal marker enzymes from rat and Chinese hamster liver at day 4 was very similar for both animal species but the TWR induced shift persisted in Chinese hamsters up to day 60 whereas in rat liver the lysosomal density increased again with time. Electron microscopic inspection confirmed the similarity of the initial reaction of hepatocyte lysosomes. However, after 60 to 70 days typical TWR induced "tritosomes" were absent from rat hepatocytes but could be found regularly in hepatocytes from Chinese hamsters. The elimination rate of 3H-activity from liver injection of 3H-TWR was lower in Chinese hamsters than in rats. It was concluded that the differences in elimination rate of lanthanides and transuranium elements from liver of various mammalian species and the differences observed after TWR injection might reflect differences in the composition or function of the lysosomal system in the livers of different mammalian species. With respect to the transport of certain heavy metals the rat liver is not a reliable model for human liver. PMID:4029172

  13. Induction of Spermatogenesis by Bone Marrow-derived Mesenchymal Stem Cells in Busulfan-induced Azoospermia in Hamster

    PubMed Central

    Tamadon, Amin; Mehrabani, Davood; Rahmanifar, Farhad; Jahromi, Alireza Raayat; Panahi, Mohadeseh; Zare, Shahrokh; Khodabandeh, Zahra; Jahromi, Iman Razeghian; Tanideh, Nader; Dianatpour, Mehdi; Ramzi, Mani; Koohi-Hoseinabadi, Omid

    2015-01-01

    Background Bone marrow-derived mesenchymal stem cells (BM-MSCs) have potential of differentiation and they secrete anti-inflammatory cytokines and growth factors which make them appropriate for cell therapy. Aim of the Work Were to evaluate the healing effect of BM-MSCs transplantation on germinal cells of busulfan-induced azoospermic hamsters. Material and Methods In the present experimental case control study, BM-MSCs were isolated from bone marrow of donor albino hamsters. Five mature male recipient hamsters received two doses of 10 mg/kg of busulfan with 21 days interval to stop endogenous spermatogenesis. After induction of azoospermia, right testis of hamsters was injected with 106 BM-MSCs via efferent duct and the left one remained as azoospermia control testis. Five normal mature hamsters were selected as normal intact control. After 35 days, testes and epididymis of three groups were removed for histological evaluation. Results Histomorphological analyses of BM-MSCs treated testes and epididymis showed the epithelial tissue of seminiferous tubules had normal morphology and spermatozoa were present in epididymis tubes. Spermatogenesis was observed in most cell-treated seminiferous tubules. The untreated seminiferous tubules were empty. Conclusion Transplanted BM-MSCs could successfully induce spermatogenesis in seminiferous tubules of azoospermic hamster. Therefore, BM-MSCs can be an attractive candidate in cell transplantation of azoospermia. PMID:26634062

  14. Deformation mechanisms in gold nanowires and nanoporous gold

    NASA Astrophysics Data System (ADS)

    Dou, R.; Derby, B.

    2011-03-01

    We present a study of the deformation of gold nanowires of diameter 30-70 nm and nanoporous gold specimens with ligament diameter 5-10 nm, both produced by electrodeposition into anodised aluminium oxide templates. The nanowires show extensive surface slip steps and low dislocation densities with a few perfect dislocation loops, Shockley partial dislocations and microtwins observed after deformation. Nanoporous specimens show deformation localised to the nodes between the ligaments of the foamed structure, with high densities of microtwins and Shockley partial dislocations in these regions. Similar dislocation structures are seen in larger nanowires deformed in bending. This is shown to be consistent with a strain gradient plasticity model for the deformation of nanoporous gold, with the strain gradient accommodated by geometrically necessary twins and partial dislocations.

  15. Annealing relaxation of ultrasmall gold nanostructures

    NASA Astrophysics Data System (ADS)

    Chaban, Vitaly

    2015-01-01

    Except serving as an excellent gift on proper occasions, gold finds applications in life sciences, particularly in diagnostics and therapeutics. These applications were made possible by gold nanoparticles, which differ drastically from macroscopic gold. Versatile surface chemistry of gold nanoparticles allows coating with small molecules, polymers, biological recognition molecules. Theoretical investigation of nanoscale gold is not trivial, because of numerous metastable states in these systems. Unlike elsewhere, this work obtains equilibrium structures using annealing simulations within the recently introduced PM7-MD method. Geometries of the ultrasmall gold nanostructures with chalcogen coverage are described at finite temperature, for the first time.

  16. Phage based green chemistry for gold ion reduction and gold retrieval.

    PubMed

    Setyawati, Magdiel I; Xie, Jianping; Leong, David T

    2014-01-22

    The gold mining industry has taken its toll on the environment, triggering the development of more environmentally benign processes to alleviate the waste load release. Here, we demonstrate the use of bacteriophages (phages) for biosorption and bioreduction of gold ions from aqueous solution, which potentially can be applied to remediate gold ions from gold mining waste effluent. Phage has shown a remarkably efficient sorption of gold ions with a maximum gold adsorption capacity of 571 mg gold/g dry weight phage. The product of this phage mediated process is gold nanocrystals with the size of 30-630 nm. Biosorption and bioreduction processes are mediated by the ionic and covalent interaction between gold ions and the reducing groups on the phage protein coat. The strategy offers a simple, ecofriendly and feasible option to recover of gold ions to form readily recoverable products of gold nanoparticles within 24 h. PMID:24359519

  17. Biomedical applications of gold nanoparticles.

    PubMed

    Cabuzu, Daniela; Cirja, Andreea; Puiu, Rebecca; Grumezescu, Alexandru Mihai

    2015-01-01

    Gold nanoparticles may be used in different domains, one of most important being the biomedical field. They have suitable properties for controlled drug delivery, cancer treatment, biomedical imaging, diagnosis and many others, due to their excellent compatibility with the human organism, low toxicity and tunable stability, small dimensions, and possibility to interact with a variety of substances. They also have optical properties, being able to absorb infrared light. Moreover, due to their large surface and the ability of being coated with a variety of therapeutic agents, gold nanoparticles have been showed a great potential to be used as drug delivery systems. Gold nanoparticles are intensively studied in biomedicine, and recent studies revealed the fact that they can cross the blood-brain barrier, may interact with the DNA and produce genotoxic effects. Because of their ability of producing heat, they can target and kill the tumors, being used very often in photodynamic therapy. Gold nanoparticles can be synthesized in many ways, but the most common are the biological and chemical methods, however the chemical method offers the advantage of better controlling the size and shape of the nanoparticles. In this review, we present the principal applications of gold nanoparticles in the biomedical field, like cancer treatment, amyloid-like fibrillogenesis inhibitors, transplacental treatment, the development of specific scaffolds and drug delivery systems. PMID:25877087

  18. Characterization of proteins in membrane vesicles from scrapie-infected hamster brain.

    PubMed

    Dees, C; German, T L; Wade, W F; Marsh, R F

    1985-04-01

    Previous studies have shown that the scrapie agent is highly membrane-associated. We examined the protein composition of gradient fractions enriched for large membrane vesicles prepared from scrapie-infected and uninfected hamster brain using various methods to extract membrane proteins. We also examined proteins in detergent-extracted membrane vesicles fractionated on CsCl gradients. No qualitative differences in protein composition were seen comparing scrapie-infected and uninfected samples by one-dimensional gel electrophoresis. Extraction of proteins from membrane vesicles by phenol, pyridine, perchloric acid or lithium diiodosalicylate also failed to reveal any unique proteins in scrapie-infected hamster brain. Attempts to solubilize hydrophobic proteins (proteolipids) from CsCl gradient fractions into organic solvents were unsuccessful. These findings indicate that any hydrophobic protein associated with the scrapie agent is not a proteolipid, and that the ability of solvents to reduce scrapie infectivity is not a result of extraction of a proteolipid. PMID:3920349

  19. The Middle East respiratory syndrome coronavirus (MERS-CoV) does not replicate in Syrian hamsters.

    PubMed

    de Wit, Emmie; Prescott, Joseph; Baseler, Laura; Bushmaker, Trenton; Thomas, Tina; Lackemeyer, Matthew G; Martellaro, Cynthia; Milne-Price, Shauna; Haddock, Elaine; Haagmans, Bart L; Feldmann, Heinz; Munster, Vincent J

    2013-01-01

    In 2012 a novel coronavirus, MERS-CoV, associated with severe respiratory disease emerged in the Arabian Peninsula. To date, 55 human cases have been reported, including 31 fatal cases. Several of the cases were likely a result of human-to-human transmission. The emergence of this novel coronavirus prompts the need for a small animal model to study the pathogenesis of this virus and to test the efficacy of potential intervention strategies. In this study we explored the use of Syrian hamsters as a small animal disease model, using intratracheal inoculation and inoculation via aerosol. Clinical signs of disease, virus replication, histological lesions, cytokine upregulation nor seroconversion were observed in any of the inoculated animals, indicating that MERS-CoV does not replicate in Syrian hamsters. PMID:23844250

  20. 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.

  1. 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. PMID:25582913

  2. Behavioral adaptation to fixed-interval and fixed-time food delivery in golden hamsters1

    PubMed Central

    Anderson, Merrill C.; Shettleworth, Sara J.

    1977-01-01

    Food-deprived golden hamsters in a large enclosure received food every 30 sec contingent on lever pressing, or free while their behavior was continuously recorded in terms of an exhaustive classification of motor patterns. As with other species in other situations, behavior became organized into two main classes. One (terminal behaviors) increased in probability throughout interfood intervals; the other (interim behaviors) peaked earlier in interfood intervals. Which class an activity belonged to was independent of whether food was contingent on lever pressing. When food was omitted on some of the intervals (thwarting), the terminal activities began sooner in the next interval, and different interim activities changed in different ways. The interim activities did not appear to be schedule-induced in the usual sense. Rather, the hamsters left the area of the feeder when food was not due and engaged in activities they would normally perform in the experimental environment. PMID:16811980

  3. EEG characterization of audiogenic seizures in the hamster strain GASH:Sal.

    PubMed

    Carballosa-Gonzalez, Melissa M; Muñoz, Luis J; López-Alburquerque, Tomás; Pardal-Fernández, José Manuel; Nava, Eduardo; de Cabo, Carlos; Sancho, Consuelo; López, Dolores E

    2013-10-01

    The study was performed to characterize GASH:SAL audiogenic seizures as true epileptic activity based on electroencephalographic markers acquired with a wireless implanted radiotelemetry system. We analyzed cortical EEG patterns synchronized with video recordings of convulsive behavior of the GASH:Sal hamster following an acoustic stimulus. All GASH:Sal presented archetypal motor symptoms comparable to current animal models of generalized tonic-clonic epilepsy. Seizures consisted of an initial bout of wild running, followed by opisthotonus, tonic-clonic convulsions, tonic limb extension, and terminated in postictal depression. EEG patterns correlated with behavior and displayed phase appropriate spike-wave complexes, low-amplitude desynchronized activity, and high frequency large-amplitude peaks. Our results confirm that electroencephalographic profiles of the audiogenic seizures of the hamster GASH:Sal are parallel to EEG patterns of other animal models of generalized tonic-clonic seizures. Therefore, this animal may serve as an appropriate model for epilepsy research. PMID:23916142

  4. 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. PMID:12804573

  5. Chinese hamster ovary cells contain transcriptionally active full-length type C proviruses.

    PubMed Central

    Lie, Y S; Penuel, E M; Low, M A; Nguyen, T P; Mangahas, J O; Anderson, K P; Petropoulos, C J

    1994-01-01

    We have isolated a genomic locus from Chinese hamster ovary (CHO) cells that contains a full-length provirus. Nucleotide sequence analysis indicates that it is a defective member of the rodent type C retrovirus family with an env region that is similar to those of mouse amphotropic retrovirus and subgroup B feline leukemia virus. We were able to demonstrate that this provirus is a member of a closely related family of full-length proviruses in CHO cells and Chinese hamster liver. Hybridization probes generated from this genomic clone were used to characterize type C retrovirus RNA expression in CHO cells. Full-length genomic RNA and subgenomic envelope mRNA were detected in CHO cell lines but not in the human-derived 293 cell line. Interestingly, we discovered that the site of retrovirus integration lies within a G repeat sequence belonging to the short interspersed element family of retroposons. Images PMID:7966574

  6. Chinese hamster ovary cells contain transcriptionally active full-length type C proviruses.

    PubMed

    Lie, Y S; Penuel, E M; Low, M A; Nguyen, T P; Mangahas, J O; Anderson, K P; Petropoulos, C J

    1994-12-01

    We have isolated a genomic locus from Chinese hamster ovary (CHO) cells that contains a full-length provirus. Nucleotide sequence analysis indicates that it is a defective member of the rodent type C retrovirus family with an env region that is similar to those of mouse amphotropic retrovirus and subgroup B feline leukemia virus. We were able to demonstrate that this provirus is a member of a closely related family of full-length proviruses in CHO cells and Chinese hamster liver. Hybridization probes generated from this genomic clone were used to characterize type C retrovirus RNA expression in CHO cells. Full-length genomic RNA and subgenomic envelope mRNA were detected in CHO cell lines but not in the human-derived 293 cell line. Interestingly, we discovered that the site of retrovirus integration lies within a G repeat sequence belonging to the short interspersed element family of retroposons. PMID:7966574

  7. Effects of tachykinins on inositol phospholipid hydrolysis in slices of hamster urinary bladder.

    PubMed Central

    Bristow, D. R.; Curtis, N. R.; Suman-Chauhan, N.; Watling, K. J.; Williams, B. J.

    1987-01-01

    Tachykinin-stimulated inositol phospholipid hydrolysis was examined in slices of hamster urinary bladder. In the presence of lithium, to inhibit inositol monophosphatase activity, substance P, eledoisin and related tachykinins induced large, dose-dependent increases in [3H]-inositol monophosphate accumulation. The responses to substance P and eledoisin were not antagonized by the cholinoceptor antagonist, atropine. The rank order of potency for various tachykinins was kassinin greater than neurokinin A greater than neurokinin B greater than eledoisin greater than physaelamin greater than substance P greater than substance P methyl ester. The synthetic analogue [p-Glu6, D-Pro9]SP (6-11) was considerably more potent than its L-prolyl stereoisomer at stimulating inositol phospholipid hydrolysis. These results suggest that in the hamster urinary bladder, tachykinin-induced inositol phospholipid breakdown is mediated via tachykinin receptors of the SP-E type, as opposed to the SP-P type. PMID:3028559

  8. The Middle East Respiratory Syndrome Coronavirus (MERS-CoV) Does Not Replicate in Syrian Hamsters

    PubMed Central

    de Wit, Emmie; Prescott, Joseph; Baseler, Laura; Bushmaker, Trenton; Thomas, Tina; Lackemeyer, Matthew G.; Martellaro, Cynthia; Milne-Price, Shauna; Haddock, Elaine; Haagmans, Bart L.; Feldmann, Heinz; Munster, Vincent J.

    2013-01-01

    In 2012 a novel coronavirus, MERS-CoV, associated with severe respiratory disease emerged in the Arabian Peninsula. To date, 55 human cases have been reported, including 31 fatal cases. Several of the cases were likely a result of human-to-human transmission. The emergence of this novel coronavirus prompts the need for a small animal model to study the pathogenesis of this virus and to test the efficacy of potential intervention strategies. In this study we explored the use of Syrian hamsters as a small animal disease model, using intratracheal inoculation and inoculation via aerosol. Clinical signs of disease, virus replication, histological lesions, cytokine upregulation nor seroconversion were observed in any of the inoculated animals, indicating that MERS-CoV does not replicate in Syrian hamsters. PMID:23844250

  9. Blood epididymal barrier to (/sup 3/H)-inulin in intact and vasectomized hamsters

    SciTech Connect

    Turner, T.T.; D'Addario, D.A.; Howards, S.S.

    1981-09-01

    The net transport of (/sup 3/H)-inulin into the fluids of the hamster seminiferous and caput, corpus, and cauda epididymal tubules was examined in both intact animals and those vasectomized 10 months previously. Mean isotope concentrations in reproductive tract tubule fluids did not exceeded 10 per cent of blood plasma isotope concentrations during the experiment. There were no significant differences in net transport of (/sup 3/H)-inulin into any of the tubule fluids sampled. Ten months after vasectomy, the seminiferous tubule, and all regions of the epididymal tubule retain the capacity to exclude (/sup 3/H)-insulin. Thus in the hamster 10 months after vasectomy, the blood testis and blood epididymal barriers to inulin are intact.

  10. Characterization of nucleic acids in membrane vesicles from scrapie-infected hamster brain.

    PubMed Central

    Dees, C; McMillan, B C; Wade, W F; German, T L; Marsh, R F

    1985-01-01

    This study reports the partial characterization of nucleic acids present in gradient fractions enriched for large membrane vesicles from scrapie-infected and uninfected hamster brains. Labeling of phenol-extracted nucleic acids at the 3' or 5' ends revealed abundant amounts of low-molecular-weight RNA and little or no DNA. These nucleic acids survived nuclease treatment of membrane vesicles but were sensitive to RNase after phenol extraction. Analysis of 5'-end-labeled nucleic acids by one- and two-dimensional gel electrophoresis revealed an RNA of ca. 100 bases in preparations from scrapie-infected hamster brain that could not be detected in uninfected brain. The possibility that this apparently unique small RNA may result from tissue damage or abnormal RNA processing or may be a component of the infectious complex is discussed. Images PMID:2409296

  11. 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

  12. 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. PMID:26632791

  13. Gold nanoparticles for photoacoustic imaging.

    PubMed

    Li, Wanwan; Chen, Xiaoyuan

    2015-01-01

    Photoacoustic (PA) imaging is a biomedical imaging modality that provides functional information regarding the cellular and molecular signatures of tissue by using endogenous and exogenous contrast agents. There has been tremendous effort devoted to the development of PA imaging agents, and gold nanoparticles as exogenous contrast agents have great potential for PA imaging due to their inherent and geometrically induced optical properties. The gold-based nanoparticles that are most commonly employed for PA imaging include spheres, rods, shells, prisms, cages, stars and vesicles. This article provides an overview of the current state of research in utilizing these gold nanomaterials for PA imaging of cancer, atherosclerotic plaques, brain function and image-guided therapy. PMID:25600972

  14. Gold nanoparticles for photoacoustic imaging

    PubMed Central

    Li, Wanwan; Chen, Xiaoyuan

    2015-01-01

    Photoacoustic (PA) imaging is a biomedical imaging modality that provides functional information regarding the cellular and molecular signatures of tissue by using endogenous and exogenous contrast agents. There has been tremendous effort devoted to the development of PA imaging agents, and gold nanoparticles as exogenous contrast agents have great potential for PA imaging due to their inherent and geometrically induced optical properties. The gold-based nanoparticles that are most commonly employed for PA imaging include spheres, rods, shells, prisms, cages, stars and vesicles. This article provides an overview of the current state of research in utilizing these gold nanomaterials for PA imaging of cancer, atherosclerotic plaques, brain function and image-guided therapy. PMID:25600972

  15. Hypolipidemic Effects of Alkaloids from Rhizoma Coptidis in Diet-Induced Hyperlipidemic Hamsters.

    PubMed

    He, Kai; Kou, Shuming; Zou, Zongyao; Hu, Yinran; Feng, Min; Han, Bing; Li, Xuegang; Ye, Xiaoli

    2016-05-01

    This study was conducted to evaluate the antihyperlipidemic activity of five major alkaloids in Rhizoma Coptidis using high-fat- and high-cholesterol-induced hyperlipidemic hamsters. Hyperlipidemic hamsters were treated with coptisine, berberine, jatrorrhizine, palmatine, epiberberine, and total Rhizoma Coptidis alkaloids with a dose of 46.7 mg/kg × day for 140 days. Serum total cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and total bile acids were examined after alkaloid treatment. The results showed that all therapy agents prevented body weight gain, reduced the serum total cholesterol, and increased the high-density lipoprotein cholesterol of hamsters. Berberine, jatrorrhizine, and total Rhizoma Coptidis alkaloids decreased the triglyceride level in hyperlipidemic hamsters, while coptisine, jatrorrhizine, palmatine, and total Rhizoma Coptidis alkaloids significantly suppressed the elevation of the low-density lipoprotein cholesterol level. The fecal excretion of bile acids was significantly elevated by berberine, coptisine, jatrorrhizine, palmatine, total Rhizoma Coptidis alkaloids, and orlistat. Notably, total Rhizoma Coptidis alkaloids possess a much stronger lipid-lowering effect than the pure Rhizoma Coptidis alkaloids. Quantitative reverse transcription-polymerase chain reaction analyses revealed that Rhizoma Coptidis alkaloids could retard the synthesis of cholesterol by downregulating the mRNA expression of 3-hydroxy-3-methyl glutaryl coenzyme A reductase and accelerate the clearance of lipids by upregulating the low-density lipoprotein receptor, cholesterol 7α-hydroxylase, and uncoupling protein-2 expression. These findings highlight the critical role of Rhizoma Coptidis alkaloids in hyperlipidemia treatment. Thus, they need to be considered in future therapeutic approaches. PMID:26848702

  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. PMID:23342177

  17. Inhibition of cholesterol ester transfer protein CGS 25159 and changes in lipoproteins in hamsters.

    PubMed

    Kothari, H V; Poirier, K J; Lee, W H; Satoh, Y

    1997-01-01

    As a result of screening, several isoflavans were identified to be antagonists of cholesterol ester transfer protein (CETP) activity. The present study evaluates CGS 25159, a synthetic isoflavan, as a putative inhibitor of CETP activity of human and hamster plasma. Determined by [3]CE transfer from HDL to VLDL + LDL fraction or by fluorescent-CE transfer assay, CGS 25159 inhibited CETP in both human plasma bottom fraction (d = 1.21 g/ml) and in plasma from Golden Syrian Hamsters with an IC50 < 10 microM. The compound also inhibited (IC 50 approximately equal to 15 microM) the reciprocal transfer of triglycerides in the incubated whole plasma from normal and hyperlipidemic hamsters. When orally administered to normolipidemic hamsters, CGS 25159 (10 mg/kg, 4 days) reduced plasma transfer activity by 35-60%. Treatment with CGS 25159 (10 and 30 mg/kg, p.o.) resulted in dose dependent and time dependent changes in CETP activity. After two weeks of treatment at 10 mg/kg, the changes in VLDL + LDL cholesterol, total triglycerides and HDL cholesterol were -22 +/- 4.6*, -23 +/- 7.5 and +10 +/- 2.8%, respectively. The corresponding changes at 30 mg/kg were -28 +/- 5.5*, -38 +/- 6.8* and +29 +/-4.4.*%, (*, P, 0.05; mean +/- S.E.M., n = 6). A single spin gradient density ultracentrifugation of plasma lipoproteins and treated animals showed an increase in HDL cholesterol and a redistribution to larger HDL particles. These data support the contention that pharmacological down regulation of CETP activity could result in favorable changes in lipoprotein profile. PMID:9051198

  18. 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. PMID:24666779

  19. Concentration and chemical status of arsenic in the early placentas of arsenate-dosed hamsters

    SciTech Connect

    Hanlon, D.P.; Ferm, V.H.

    1987-04-01

    The authors determined the concentration and chemical status of arsenic in the placentas of hamsters following continuous exposure via the osmotic minipump to minimally and frankly teratogenic doses of arsenate. Close to 70% of the placental arsenic is bound to macromolecules, two-thirds of which is dialyzable. The remaining 30% of arsenic consists of low molecular weight species, predominantly inorganic arsenic. This mix is the same for minimally teratogenic and frankly teratogenic doses of arsenate.

  20. In vivo metabolic activity of hamster suprachiasmatic nuclei: use of anesthesia

    SciTech Connect

    Schwartz, W.J.

    1987-02-01

    In vivo glucose utilization was measured in the suprachiasmatic nuclei (SCN) of Golden hamsters using the /sup 14/C-labeled deoxyglucose technique. A circadian rhythm of SCN metabolic activity could be measured in this species, but only during pentobarbital sodium anesthesia when the surrounding background activity of adjacent hypothalamus was suppressed. Both the SCN's metabolic oscillation and its time-keeping ability are resistant to general anesthesia.

  1. The safety and anti-hypercholesterolemic effect of coptisine in Syrian golden hamsters.

    PubMed

    He, Kai; Ye, Xiaoli; Wu, Hao; Wang, YanZhi; Zou, Zongyao; Ning, Na; Hu, Yinran; Chen, Biao; Fang, Xuedong; Li, Xuegang

    2015-02-01

    Current work was conducted to evaluate the cholesterol-lowering effect of coptisine extracted from Rhizoma coptidis in Syrian golden hamsters. The safety results indicated that coptisine was a safe and low-toxic compound. Coptisine showed a beneficial effect in the abnormal serum lipid levels induced by a high-fat and high-cholesterol diet (HFHC): at a concentration of 70.05 mg/kg, coptisine significantly led to a decrease in total cholesterol, triglycerides, and low-density lipoprotein cholesterol (LDL-c) levels by 26.70, 15.38, and 22.22 %, respectively, and high-density lipoprotein cholesterol (HDL-c) was increased by 41.74 % in serum of hamsters (p < 0.01). In addition, total bile acid (TBA) levels in feces of hamsters were elevated after coptisine administration. Further investigation has suggested that the mRNA and protein expression of 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGCR) in the liver of hamsters was down-regulated by high-dosage coptisine treatment (p < 0.05); mRNA and protein expression of low-density lipoprotein receptor (LDLR) and cholesterol 7α-hydroxylase (CYP7A1) were dramatically up-regulated by coptisine administration. The apical sodium-dependent bile salt transporter expression was down-regulated in the coptisine-treated animals, but showed no significant differences from the HFHC groups. Taken together, our results demonstrate that a high dosage of coptisine could inhibit cholesterol synthesis via suppressing the HMGCR expression and promoting the use and excretion of cholesterol via up-regulating LDLR and CYP7A1 expression. These findings suggest a critical role for coptisine in anti- hypercholesterolemia, and thus it needs to be considered as a potential natural cholesterol lowering agent. PMID:25547428

  2. Identification of liver CYP51 as a gene responsive to circulating cholesterol in a hamster model.

    PubMed

    Huang, Haiqiu; Xie, Zhuohong; Yokoyama, Wallace; Yu, Liangli; Wang, Thomas T Y

    2016-01-01

    Hypercholesterolaemia is a risk factor for CVD, which is a leading cause of death in industrialised societies. The biosynthetic pathways for cholesterol metabolism are well understood; however, the regulation of circulating cholesterol by diet is still not fully elucidated. The present study aimed to gain more comprehensive understanding of the relationship between circulating cholesterol levels and molecular effects in target tissues using the hamster model. Male golden Syrian hamsters were fed with chow or diets containing 36 % energy from fat with or without 1 % cholesteyramine (CA) as a modulator of circulating cholesterol levels for 35 d. It was revealed that the expression of lanosterol 14α-demethylase (CYP51) instead of 3-hydroxy-3-methyl-glutaryl (HMG)-CoA reductase mRNA expression was responsive to circulating cholesterol in hamsters fed hypercholesterolaemic diets. The high-fat diet increased circulating cholesterol and down-regulated CYP51, but not HMG-CoA reductase. The CA diet decreased cholesterol and increased CYP51 expression, but HMG-CoA reductase expression was not affected. The high-fat diet and CA diet altered the expression level of cholesterol, bile acids and lipid metabolism-associated genes (LDL receptor, cholesterol 7α-hydroxylase (CYP7A1), liver X receptor (LXR) α, and ATP-binding cassette subfamily G member 5/8 (ABCG5/8)) in the liver, which were significantly correlated with circulating cholesterol levels. Correlation analysis also showed that circulating cholesterol levels were regulated by LXR/retinoid X receptor and PPAR pathways in the liver. Using the hamster model, the present study provided additional molecular insights into the influence of circulating cholesterol on hepatic cholesterol metabolism pathways during hypercholesterolaemia. PMID:27110359

  3. The effects of argon in the bioenergetics of the hamster and the rat

    NASA Technical Reports Server (NTRS)

    Tempel, G. E.; Musacchia, X. J.

    1974-01-01

    Oxygen consumption was examined in hamsters and rats exposed to normoxic mixtures of argon at 1 atm. In fasted and nonfasted animals, no marked change in O2 utilization was detectable at 22 C. However, at 7 C a significant decrease in oxygen consumption was observed where the animals were exposed in argon. The data are interpreted in terms of the greater thermal conductivity of nitrogen. The study was prompted by conflicting reports on the metabolic effects of argon and helium.

  4. Human sperm chromosomes obtained from hamster eggs after sperm capacitation in TEST-yolk buffer

    SciTech Connect

    Brandriff, B.; Gordon, L.; Watchmaker, G.

    1985-01-01

    Human sperm chromosomes were obtained after capacitation with TES-Tris (TEST) yolk buffer and fusion with Syrian hamster eggs. Semen samples could be stored at 4/sup 0/C for 3 days and remain functional in the assay system. The efficiency of TEST yolk buffer for obtaining karyotypes was as good as, or greater than, the efficiency of standard BWW medium containing human serum albumin. 16 references, 3 tables.

  5. 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. PMID:25936822

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

    PubMed Central

    Bradley, Sean P.; Prendergast, Brian J.

    2014-01-01

    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; 9 h light/day) photoperiods were subjected to a timed-feeding schedule for 10 days, during which food was available only during a 5 h interval of the light phase. Running wheel activity occurring within a 3 h 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. PMID:24666779

  7. 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.

  8. Cardiac and non-cardiac malformations produced by Mercury in hamsters. [None

    SciTech Connect

    Gale, T.F.

    1980-11-01

    The susceptibility of the developing mammalian embryo to the adverse effects of mercury is well documented. A variety of organic mercury compounds have been demonstrated to produce embryotoxic effects in experimental animals. HARADA recently summarized the reports of human intrauterine methylmercury poisoning, i.e., congenital Minamata disease, resulting from the ingestion of contaminated food. Ongoing studies in this laboratory have involved several different aspects of the embryotoxicity produced by inorganic mercury in hamsters including a dose response study, the interaction of mercuric acetate with cadmium and zinc, the effect of different routes of administration, the placental permeability of /sup 203/Hg and the embryotoxic response in several different hamster strains. Little is known regarding a human syndrome of congenital malformations characterized by ectopia cordis, internal cardiac defects and abnormalities of the diaphragm and ventral body wall. Most papers regarding this human syndrome are clinical reports describing the characteristics and management of specific cases; only speculative information is provided regarding etiology and possible embryopathic mechanisms. The observation that a similar syndrome, which will be designated CNC for cardiac and non-cardiac malformations, can be produced by mercury in hamsters prompted the present study. The specific goals of this study were 1) to study the effect of treating pregnant hamsters at different times during embryonic organogenesis to determine the time which produces the highest incidence of the CNC syndrome and whether different treatment times modify the morphological characteristics of the inclusive malformations and 2) to study the structural features of all mercury-induced external and internal abnormalities of the CNC syndrome in late gestation fetuses.

  9. Affective responses to changes in day length in Siberian hamsters (Phodopus sungorus).

    PubMed

    Prendergast, Brian J; Nelson, Randy J

    2005-06-01

    The goal of these experiments was to test the hypothesis that day length influences anxious- and depressive-like behaviors in reproductively photoperiodic rodents. Male and female Siberian hamsters (Phodopus sungorus) were exposed to long (16 h light/day; LD) or short (8 h light/day; SD) photoperiods beginning at the time of weaning (day 18). Two weeks later hamsters were subjected to a series of behavioral tests to quantify anxiety-and depressive-like behaviors. In an elevated plus maze, SD males exhibited longer latencies to enter an open arm, entered fewer open arms, and spent less time exploring open arms relative to LD hamsters. SD males were likewise slower to enter either of the distal arms of a completely enclosed T-maze, and in a hunger-motivated exploratory paradigm SD males were slower to enter an open arena for food as compared to LD males. In a forced-swimming model of behavioral despair, SD males exhibited immobility sooner, more often, and for a greater total amount of time relative to LD males. Total activity levels, aversiveness to light, olfactory function, and limb strength were unaffected by SD, suggesting that the behavioral changes consequent to SD are not attributable to sensory or motor deficits, but rather may arise from changes in general affective state. The anxiogenic and depressive effects of SD were largely absent in female hamsters. Together the results indicate that adaptation to short photoperiods is associated with increased expression of anxiety- and depressive-like behaviors relative to those observed under LD photoperiod conditions. PMID:15721056

  10. 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

  11. Effect of fenofibrate and LF 2151 on hepatic peroxisomes in hamsters.

    PubMed

    Pourbaix, S; Heller, F; Harvengt, C

    1984-11-15

    Hamsters were given a diet containing fenofibrate (0.5% or 0.05%) or its metabolite, LF 2151 (0.15% or 0.015%) or a standard diet for a 3-week period. At the end of this period, the analysis of plasma lipids showed that the mean plasma triglyceride concentrations were not significantly different in the five groups of animals. The mean plasma cholesterol concentrations were significantly reduced in animals treated with both drugs but only when given at the high dosage. No consistent changes were noted in the liver weight/body weight ratio and the DNA content of the liver; the number of peroxisomes was increased in the hepatocytes of animals given fenofibrate at the high dosage. Liver homogenates were fractionated and the fractions rich in peroxisomes were used for assays of several enzymes involved in lipid metabolism. Compared with the control animals, activity of cyanide-insensitive fatty acyl-CoA (FA-CoA) oxidizing system was significantly increased by fenofibrate at the high dosage, carnitine acetyltransferase activity was markedly increased by both drugs at the high dosage and catalase activity remained unmodified. As there was a significant inverse correlation between the peroxisomal activity of FA-CoA oxidizing system and the plasma cholesterol concentrations, it is suggested that the increase of peroxisomal beta-oxidation activity can be involved in the hypocholesterolemic action of fenofibrate and LF 2151. This is further substantiated by the finding that fenofibrate and LF 2151 were present in the peroxisomal fraction only in hamsters displaying hypocholesterolemia and high activity of FA-CoA oxidizing system. The presence of fenofibric acid in the plasma of hamsters given LF 2151 suggested that hepatocytes are able to generate the parent drug from this metabolite, underlining that the pharmacokinetics of fenofibrate are rather complex in hamsters. PMID:6508822

  12. Antilithiasic effect of beta-cyclodextrin in LPN hamster: comparison with cholestyramine.

    PubMed

    Boehler, N; Riottot, M; Férézou, J; Souidi, M; Milliat, F; Sérougne, C; Smith, J L; Lutton, C

    1999-04-01

    Beta-Cyclodextrin (BCD), a cyclic oligosaccharide that binds cholesterol and bile acids in vitro, has been previously shown to be an effective plasma cholesterol lowering agent in hamsters and domestic pigs. This study examined the effects of BCD as compared with cholestyramine on cholesterol and bile acid metabolism in the LPN hamster model model for cholesterol gallstones. The incidence of cholesterol gallstones was 65% in LPN hamsters fed the lithogenic diet, but decreased linearly with increasing amounts of BCD in the diet to be nil at a dose of 10% BCD. In gallbladder bile, cholesterol, phospholipid and chenodeoxycholate concentrations, hydrophobic and lithogenic indices were all significantly decreased by 10% BCD. Increases in bile acid synthesis (+110%), sterol 27-hydroxylase activity (+106%), and biliary cholate secretion (+140%) were also observed, whereas the biliary secretion of chenodeoxycholate decreased (-43%). The fecal output of chenodeoxycholate and cholate (plus derivatives) was increased by +147 and +64%, respectively, suggesting that BCD reduced the chenodeoxycholate intestinal absorption preferentially. Dietary cholestyramine decreased biliary bile acid concentration and secretion, but dramatically increased the fecal excretion of chenodeoxycholate and cholate plus their derivatives (+328 and +1940%, respectively). In contrast to BCD, the resin increased the lithogenic index in bile, induced black gallstones in 34% of hamsters, and stimulated markedly the activities of HMG-CoA reductase (+670%), sterol 27-hydroxylase (+310%), and cholesterol 7alpha-hydroxylase (+390%). Thus, beta-cyclodextrin (BCD) prevented cholesterol gallstone formation by decreasing specifically the reabsorption of chenodeoxycholate, stimulating its biosynthesis and favoring its fecal elimination. BCD had a milder effect on lipid metabolism than cholestyramine and does not predispose animals to black gallstones as cholestyramine does in this animal model. PMID:10191297

  13. A high-cholesterol, n-3 polyunsaturated fatty acid diet causes different responses in rats and hamsters.

    PubMed

    Lin, Mei-Huei; Lu, Shao-Chun; Huang, Po-Chao; Liu, Young-Chau; Liu, Shyun-Yeu

    2005-01-01

    This study was designed to investigate the response to a high-cholesterol, n-3 polyunsaturated fatty acid (PUFA) or n-6 PUFA diet in rats and hamsters. Animals were fed n-3 or n-6 PUFA with a cholesterol-free diet, or with a diet enriched with cholesterol (0.5%, w/w) for 2 weeks. In rats and hamsters fed a cholesterol-free diet, plasma cholesterol, triglycerides and very-low-density lipoprotein (VLDL)-triglyceride levels in n-3 PUFA group were significantly lower than those in n-6 PUFA group. In contrast, when diets were supplemented with 0.5% cholesterol, the plasma cholesterol- and triglyceride-lowering effect of dietary n-3 PUFA disappeared. In hamsters fed with the atherogenic diet (0.5% dietary cholesterol) for 2 weeks, n-3 PUFA induced hypercholesterolemia more than n-6 PUFA, the increase being in the VLDL and low-density lipoprotein (LDL) fractions. Our data thus indicate that elevation of VLDL- and LDL-cholesterol in hamsters by n-3 PUFA, compared with n-6 PUFA, is dependent on 0.5% dietary cholesterol supplementation. In rats, on the other hand, dietary n-3 PUFA did not induce hypercholesterolemia more than n-6 PUFA when 0.5% cholesterol was supplemented. Although the effects of n-3 PUFA on plasma cholesterol, triglycerides and VLDL-triglycerides were similar in hamsters and rats, the interactive effects of n-3 PUFA and cholesterol on plasma and lipoprotein cholesterol levels differed in the two species. It was also found that plasma triglycerides, cholesterol and lipoprotein cholesterol levels in hamsters are higher than in rats in the presence and absence of dietary cholesterol. In addition, cholesterol feeding induces hypertriglyceridemia and hypercholesterolemia only in hamsters. Moreover, liver triglyceride concentrations increased in rats fed a cholesterol-rich diet and hepatic triglyceride levels of the n-3 PUFA-fed rats were significantly lower than those in the n-6 PUFA-fed rats in the presence and absence of dietary cholesterol. However

  14. Leptin inhibits the reproductive axis in adult male Syrian hamsters exposed to long and short photoperiod.

    PubMed

    Boggio, Veronica; Cutrera, Rodolfo; Carbone, Silvia; Scacchi, Pablo; Ponzo, Osvaldo J

    2013-09-01

    The aim of the study was to investigate the effects of acute leptin treatment of adult Syrian hamsters exposed to a long (LP, eugonadal males) and short photoperiod (SP, hypogonadal males). Animals were exposed to LP (L:D 14:10) or SP (L:D 10:14) for 10 weeks. Afterwards, both LP and SP hamsters were allocated to a control (SP-C, LP-C) or leptin-treated group (SP 3, SP 10, SP 30 or LP3, LP 10, LP 30). One hour before sacrifice, a single dose of leptin (3, 10 or 30 μg/kg) or vehicle was administered (i.p.) to the males. Testis weight, serum and pituitary luteinizing hormone (LH) concentrations, as well as the hypothalamic concentration of gonadotropin-releasing hormone (GnRH) were recorded. Histological analysis of the testis was performed and GnRH concentration in the culture medium of hypothalamic explants was examined. A dramatic regression of testicular weight and histological atrophy of seminiferous tubules, as well as a decrease in serum and pituitary LH concentrations were found in SP males. All doses of leptin significantly reduced serum LH levels and medium GnRH concentrations in both photoperiod groups. Pituitary LH and hypothalamic GnRH concentrations were not affected by leptin. In conclusion, we demonstrated that leptin inhibited the reproductive axis of Syrian male hamsters exposed to LP and SP and fed ad libitum. PMID:24011191

  15. Enhanced antioxidant defense due to extracellular catalase activity in Syrian hamster during arousal from hibernation.

    PubMed

    Ohta, Hitomi; Okamoto, Iwao; Hanaya, Toshiharu; Arai, Shigeyuki; Ohta, Tsunetaka; Fukuda, Shigeharu

    2006-08-01

    Mammalian hibernators are considered a natural model for resistance to ischemia-reperfusion injuries, and protective mechanisms against oxidative stress evoked by repeated hibernation-arousal cycles in these animals are increasingly the focus of experimental investigation. Here we show that extracellular catalase activity provides protection against oxidative stress during arousal from hibernation in Syrian hamster. To examine the serum antioxidant defense system, we first assessed the hibernation-arousal state-dependent change in serum attenuation of cytotoxicity induced by hydrogen peroxide. Serum obtained from hamsters during arousal from hibernation at a rectal temperature of 32 degrees C, concomitant with the period of increased oxidative stress, attenuated the cytotoxicity four-fold more effectively than serum from cenothermic control hamsters. Serum catalase activity significantly increased during arousal, whereas glutathione peroxidase activity decreased by 50%, compared with cenothermic controls. The cytoprotective effect of purified catalase at the concentration found in serum was also confirmed in a hydrogen peroxide-induced cytotoxicity model. Moreover, inhibition of catalase by aminotriazole led to an 80% loss of serum hydrogen peroxide scavenging activity. These results suggest that extracellular catalase is effective for protecting hibernators from oxidative stress evoked by arousal from hibernation. PMID:16807122

  16. The role of leptin in striped hamsters subjected to food restriction and refeeding.

    PubMed

    Zhao, Zhi-Jun; Liu, Yong-An; Xing, Jing-Ya; Zhang, Mao-Lun; Ni, Xiao-Ying; Cao, Jing

    2014-07-01

    Food restriction (FR) and refeeding (Re) have been suggested to impair body mass regulation and thereby making it easier to regain the lost weight and develop over-weight when FR ends. However, it is unclear if this is the case in small mammals showing seasonal forging behaviors. In the present study, energy budget, body fat and serum leptin level were measured in striped hamsters that were exposed to FR-Re. The effects of leptin on food intake, body fat and genes expressions of several hypothalamus neuropeptides were determined. Body mass, fat content and serum leptin level decreased during FR and then increased during Re. Leptin supplement significantly attenuated the increase in food intake during Re, decreased genes expressions of neuropepetide Y (NPY) and agouti-related protein (AgRP) of hypothalamus and leptin of white adipose tissue (WAT). Hormone-sensitive lipase (HSL) gene expression of WAT increased in leptin-treated hamsters that were fed ad libitum, but decreased in FR-Re hamsters. This indicates that the adaptive regulation of WAT HSL gene expression may be involved in the mobilization of fat storage during Re, which partly contributes to the resistance to FR-Re-induced overweight. Leptin may be involved in the down regulations of hypothalamus orexigenic peptides gene expression and consequently plays a crucial role in controlling food intake when FR ends. PMID:25017744

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

    SciTech Connect

    Adachi, Shuichi; Takemoto, Kazuo ); Kimura, Kikuzi )

    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, fiberglass, potassium titanate fiber, calcium sulfate fiber, basic magnesium sulfate fiber, and metaphosphate fiber. 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.

  18. Effect of ursodeoxycholic acid administration on bile acid composition in hamster bile.

    PubMed

    Matejka, M; Vescina, C; Carducci, C N; Alayón, A; Dios, A; Scarlatto, E; Mamianetti, A

    1990-01-01

    The modification in the composition of bile acids in hamster by the administration of high dose of ursodeoxycholic acid (UDCA) was investigated. Male Golden Syrian hamsters were divided into five groups: a control group, two groups that received 0.5 g of UDCA per 100 g of standard diet during 30 and 60 days and another two groups that received 1 g of UDCA per 100 g of standard diet during 30 and 60 days. After ether anaesthesia the gallbladder was removed and bile was immediately aspirated. Bile acids were determined by high performance liquid chromatography (HPLC). Taurolithocholic (TLCA) and glycolithocholic acids (GLCA) increased significantly in all treated groups. The glyco/tauro ratio of 0.69 in controls became more than 1 in treated animals except in the case of lithocholic acid (LCA) conjugates which remained less than 1. UDCA derivatives increased proportionally to the administered dose and the cholic/cheno ratio diminished significantly. A moderate increase of 3- and 7-keto derivatives of chenodeoxycholic acid (CDCA) was observed in all treated groups but the above mentioned increment was especially evident in 3-keto derivatives. A high percentage of UDCA administered in the hamster was likely transformed to CDCA and the glyco conjugates of the bile acids were the predominant species except for the LCA derivatives. PMID:2367280

  19. Effects of topically applied spironolactone on androgen stimulated sebaceous glands in the hamster pinna.

    PubMed

    Seki, T; Toyomoto, T; Morohashi, M

    1995-04-01

    The effects of spironolactone (5% SYC-201G, a preparation developed for clinical use in acne vulgaris by Searle Yakuhin K.K.), which is known to have antiandrogenic effects by competitively inhibiting dihydrotestosterone at androgen receptor sites, was topically applied to the androgen stimulated sebaceous glands of adult female golden hamsters. Androgen stimulation, induced by intramuscular injection of testosterone propionate (TP) every other day over a two week period, resulted in a 2.5 to 2.7 time increase in the size of the sebaceous glands of the hamster pinna. Once-daily treatment with 5% SYC-201G or matching placebo was applied to androgen-stimulated hamsters on one pinna only during the same period as TP injection. Comparison between the treated and untreated sides revealed a significant suppression in the sebaceous gland size (p < 0.05) by 5% SYC-201G; no such effect was observed with placebo. The difference in the suppression rate of the sebaceous gland size between 5% SYC-201G (23%) and matching placebo (-4.7%) was significant (p < 0.01). PMID:7608379

  20. Seasonal pelage changes are synchronized by simulated natural photoperiods in Siberian hamsters (Phodopus sungorus).

    PubMed

    Butler, Matthew P; Zucker, Irving

    2009-08-01

    The extent to which changing day lengths (DLs) synchronize the seasonal molt was assessed in nine cohorts of male and female Siberian hamsters (Phodopus sungorus) born into a simulated natural photoperiod (SNP) beginning 4 weeks before and ending 12 weeks after the summer solstice. Hamsters in early cohorts displayed rapid somatic and gonadal growth and early puberty, whereas those in later cohorts delayed puberty until the next spring. Despite the varying birth dates and puberty strategies, the seasonal pattern of change in pelage is much better predicted by calendar date than by age in both sexes. Males born over the course of 16 weeks first made the transition to the winter pelage during a 5-week interval beginning on October 25; the autumn molt, however, was not significantly synchronized by either age or calendar date. The autumn molt of females on the other hand began 2 weeks later, and was significantly synchronized to calendar date with no detectable age effects. In both sexes, the autumn molt lagged gonadal and somatic seasonal changes by many weeks. Date of birth did not affect the timing of the spring molt, which was significantly synchronized by calendar date in both sexes. Incrementally changing photoperiods exert a strong organizing effect on the seasonal molt by providing hamsters with timing cues that are absent in laboratory analyses that employ static DLs and abrupt transitions from summer to winter DLs, thereby extending and validating conclusions derived from previous analyses. PMID:19425044

  1. Seasonal pelage changes are synchronized by simulated natural photoperiods in Siberian hamsters (Phodopus sungorus)

    PubMed Central

    Butler, Matthew P.; Zucker, Irving

    2013-01-01

    The extent to which changing day lengths synchronize the seasonal molt was assessed in nine cohorts of male and female Siberian hamsters (Phodopus sungorus) born into a simulated natural photoperiod (SNP) beginning 4 weeks before and ending 12 weeks after the summer solstice. Hamsters in early cohorts displayed rapid somatic and gonadal growth and early puberty, whereas those in later cohorts delayed puberty until the next spring. Despite the varying birth dates and puberty strategies, the seasonal pattern of change in pelage is much better predicted by calendar date than by age in both sexes. Males born over the course of 16 weeks first made the transition to the winter pelage during a 5 week interval beginning on October 25; the autumn molt, however, was not significantly synchronized by either age or calendar date. The autumn molt of females on the other hand began 2 weeks later, and was significantly synchronized to calendar date with no detectable age effects. In both sexes, the autumn molt lagged gonadal and somatic seasonal changes by many weeks. Date of birth did not affect the timing of the spring molt, which was significantly synchronized by calendar date in both sexes. Incrementally changing photoperiods exert a strong organizing effect on the seasonal molt by providing hamsters with timing cues that are absent in laboratory analyses that employ static day lengths and abrupt transitions from summer to winter day lengths, thereby extending and validating conclusions derived from previous analyses. PMID:19425044

  2. Hypolipidemic and Antioxidative Effects of Glossogyne tenuifolia in Hamsters Fed an Atherogenic Diet.

    PubMed

    Lee, Yi-Ning; Hsu, Guoo-Shyng Wang; Lin, Wan-Teng; Lu, Yi-Fa

    2016-05-01

    Glossogyne tenuifolia (GT) Cassini is a special herbal tea in the Penghu Islands, Taiwan, and has a long history of being used as an antipyretic, detoxifying, and anti-inflammatory remedy in folk medicine among local residents. The aim of this study was to investigate the effect of hot water extracts from GT on oxidative stress and lipid metabolism in animals. Five- to 6-week-old male Syrian hamsters were divided into four groups (n = 14) for different treatments, that is: control group (C), high-fat/cholesterol (HF) group, HF diet containing 0.5% (GT0.5) and 1.5% (GT1.5) GT extracts for 4 weeks. Hamsters fed with 0.5% GT powder as well as 1.5% GT powder exhibited reduced serum total cholesterol (TC), conjugated diene of low-density lipoprotein (LDL), and increased serum antioxidant capacity, but 1.5% GT powder was more potent at lowering serum LDL cholesterol and thiobarbituric acid reactive substance concentrations than 0.5% GT. GT extracts significantly lowered liver triacylglycerol (TG) concentration by diminishing activities of fatty acid synthase (FAS) and glucose-6-phosphate dehydrogenase (G-6-PDH). In addition, fecal excretion of cholesterol and bile acids were increased in GT extract groups. In conclusion, GT extracts increase the antioxidative capacity, decrease serum TC, inhibit the activities of FAS and G-6-PDH, and further reduce liver TG accumulation in hamster fed on atherogenic diets. PMID:27152981

  3. Inhibition and regression of tumors in hamster DMBA model following laser microvascular targeting

    NASA Astrophysics Data System (ADS)

    McMillan, Kathleen; Wang, Zhi; Shapshay, Stanley M.

    1998-07-01

    Vascular targeting is a recent approach to cancer therapy that aims at damaging tumor vasculature to induce tumor cell hypoxia and subsequent cell death. Squamous cell cancer arises in the superficial mucosal and cutaneous epithelial layers, and tumor microvasculature therefore may be particularly well suited for targeting by selective photothermolysis. An initial evaluation of the effect of selective eradication of microvasculature on tumor development was undertaken here using the chemically-induced hamster cheek pouch model and a 585 nm pulsed dye laser. In a first group of 6 hamsters, progression of premalignant mucosal lesions was compared between control and laser treatment groups, and laser-induced regression of established tumors was evaluated. In a second group of 12 hamsters, the number of laser treatments required to produce complete regression of tumors of the buccal mucosa was determined. The effect of the laser on tumors appearing on the skin in these animals was also investigated. These experiments showed that laser treatment inhibited tumor development and caused complete regression of established tumors 10 mm3 or smaller. Photothermal microvascular targeting may be useful in treating dyplasia and early tumors of the upper aerodigestive tract and skin, with fewer adverse sequelae than existing modalities.

  4. Vaccination with a cocktail of Ancylostoma ceylanicum recombinant antigens leads to worm burden reduction in hamsters.

    PubMed

    Wiśniewski, Marcin; Łapiński, Maciej; Daniłowicz-Luebert, Emilia; Jaros, Sławomir; Długosz, Ewa; Wędrychowicz, Halina

    2016-09-01

    Hookworms, a group to which Ancylostoma ceylanicum belongs, are gastrointestinal nematodes that infect more than 700 million people around the world. They are a leading cause of anemia in developing countries. In order to effectively prevent hookworm infections research is conducted to develop an effective vaccine using recombinant antigens of the parasite. The aim of this study was to examine the influence of the hosts' on protection against ancylostomiasis and the shaping of the humoral immune response among Syrian hamsters after immunization with a cocktail of five A. ceylanicum recombinant antigens. Ace-ASP-3, Ace-ASP-4, Ace-APR-1, Ace-MEP-6 and Ace-MEP-7 were obtained in the pET expression system. Immunization with a vaccine cocktail resulted in a 33.5% worm burden reduction. The immunogenicity of the recombinant proteins were determined using ELISA. Statistical analysis showed that vaccinated hamsters developed stronger humoral responses to four of five recombinant antigens (the exception being Ace-ASP-3) compared to hamsters from the control group. PMID:27447220

  5. [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. PMID:27215037

  6. 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.

  7. 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. PMID:12670714

  8. Expression of vasopressin receptors in hamster hypothalamus is sexually dimorphic and dependent upon photoperiod.

    PubMed Central

    Dubois-Dauphin, M; Theler, J M; Zaganidis, N; Dominik, W; Tribollet, E; Pévet, P; Charpak, G; Dreifuss, J J

    1991-01-01

    The distribution of vasopressin receptors was studied in the brain of a photoperiodic animal, the Siberian hamster. Attention was focused on [3H]vasopressin binding sites located in the hypothalamic ventromedial nucleus, medial tuberal nucleus, and ventral premammillary nucleus in males or females kept in long or short photoperiod conditions. Displacement experiments with structural analogs suggested that vasopressin receptors in the hamster hypothalamus are of the vasopressor (V1) type. Quantitative data obtained with a gaseous detector of beta-particles indicated that in the ventromedial nucleus and in the ventral premammillary nucleus of animals in long photoperiod, the number of beta-particles emitted per unit area was significantly greater in males than in females. In the ventromedial hypothalamic nucleus, in both males and females, the number of beta-particles emitted was significantly lower in short than in long photoperiod conditions. In the ventral premammillary nucleus, shortening of the photoperiod had a significant effect in reducing the amount of [3H]vasopressin bound in females, but not in males. These data suggest that, in the hamster, the control of the expression of vasopressin receptors differs among various hypothalamic nuclei and may depend on the sex and/or on the level of circulating gonadal steroids. Images PMID:1837144

  9. [Genetical analysis and characterization of a new mutant, black tremor appearing in the Syrian hamster].

    PubMed

    Mizutani, M; Katsuie, Y; Umezawa, H; Kuramasu, S

    1986-04-01

    A black coat-color mutant with tremor was discovered in babies of 61 generations of an inbred strain APG of Syrian hamster which had been maintained in the Nippon Institute for Biological Science, Laboratory Animal Research Station. The genetical analysis by matings between four inbred strains which had different genes in the E and B loci and four mutant strains which were introduced the mutant gene into the four inbred strains and characterization were carried out on the mutant. The results obtained are summarized as follows: 1) The mutation occurred in a different locus with E and B loci. 2) The mutant was controlled by an autosomal recessive gene designated as "bt", and it was thought that both tremor and black coat-color were the pleiotropic effect of bt gene. 3) At least one E gene in the E locus was necessary for the appearance of black coat color. Therefore, the coat-color remained cream in ee (cream) hamsters showing only trembling. 4) The degree of blackness of the coat-color of EE hamsters differed from Ee ones. The former was darker than the latter. 5) The mutant may be a useful animal model for studying abnormal myelogenesis and biosynthesis of melanin. PMID:3732409

  10. Worm development in hamsters infected with unisex and cross-mated Schistosoma mansoni and Schistosoma haematobium.

    PubMed

    Khalil, S B; Mansour, N S

    1995-02-01

    Schistosoma mansoni and Schistosoma haematobium coexist in Egypt and in other areas in Africa, and people frequently are infected with parasites of both species. The effects of the interactions between worms of both sexes of the 2 species on development and egg laying were evaluated in vivo by infecting hamsters with cercariae from Biomphalaria alexandrina and Bulinus truncatus snails infected with single miracidia. In hamsters with unisex infections, male worms of both species were small. Schistosoma mansoni females were stunted and partially mature but did not contain eggs. Schistosoma haematobium females, though stunted, sometimes contained and laid small eggs, which were deposited in the liver, but few of which contained motile embryos. This suggests that unisexual infection with S. haematobium female worms produces a risk for liver damage due to egg deposition in tissues. Both S. mansoni and S. haematobium females that mated with males of the heterologous species were significantly larger than females from unisexual infections; they were sexually mature and possessed eggs in the uterus. The eggs in the liver homogenates of cross-specific infected hamsters contained fully developed miracidia that hatched in filtered pond water. PMID:7876983

  11. Characterization and localization of in vivo phospholipid methylation in the hamster testis

    SciTech Connect

    Schlegel, P.N.; Wright, W.W.; Chang, T.S.

    1989-06-01

    Although previous studies have demonstrated that phospholipid methylation occurs in the testis and may be involved in Leydig cell function, phospholipid methylation in spermatogenic cells has not been characterized. In this study we describe the occurrence, time course, and localization of phospholipid methylation in the hamster testis following intratesticular injection of radioactive methyl precursor. Adult and pubertal (seven day old) hamsters were injected intratesticularly with (/sup 3/H-methyl)-methionine and sacrificed 10 min. to 31 hours thereafter. The testes were then removed and homogenized or dispersed into cell suspensions. Spermatogenic cell and Leydig cell enriched preparations were isolated from the dispersed cell preparations using elutriation and Percoll gradient centrifugation and assayed for methylated phospholipids and proteins. These experiments demonstrated that (1) phospholipid methylation occurs in the hamster testis at a level seven-fold greater than protein methylation, (2) the incorporation of radioactivity associated with phospholipid methylation is progressive over time, and (3) in vivo, spermatogenic cell preparations enriched with pachytene spermatocytes have an almost four-fold higher level of measurable phospholipid methylation when compared to whole testis preparations. Taken together, these results suggest that phospholipid methylation may play an important stage-specific role in spermatogenesis.

  12. Changes in responsiveness to newborn pups in pregnant, nulliparous golden hamsters.

    PubMed

    Buntin, J D; Jaffe, S; Lisk, R D

    1984-03-01

    Virgin female hamsters were mated and tested once daily for maternal retrieving behavior beginning on days 0, 5, 9, 13, 15, of the 16 day gestation period to determine if responsiveness toward newborn pups changes as pregnancy proceeds. Upon initial exposure to 3 newborn pups, only a small percentage of early-to-mid-pregnant females exhibited maternal retrieving behavior spontaneously. In contrast, over half of the 15 day pregnant females displayed retrieving during the first test. Despite the high frequency of initial pup-directed aggression and cannibalism, maternal retrieval was induced in the majority of the females in all groups by repeated daily exposure to 3 newborn pups. However, no significant differences were observed in the number of pup exposure periods required to induce maternal retrieving in 0, 5, and 9 day pregnant females. It is concluded that the high level of maternal responsiveness observed in the parturient hamster develops somewhat abruptly during late pregnancy. In this respect, the pattern observed in the hamster differs from the more gradual increase in maternal responsiveness reported in mid-to-late-pregnant mice and rats. PMID:6540458

  13. Resistance of the hamster to amiodarone-induced pulmonary toxicity following repeated intraperitoneal administration.

    PubMed

    Leeder, R G; Evans, C D; Brien, J F; Massey, T E

    1994-10-01

    Amiodarone is an effective antidysrhythmic agent, restricted in use by the development of pulmonary toxicity. Several in vivo animal models have been used to study amiodarone-induced pulmonary toxicity. Intratracheal administration of amiodarone to the hamster has been used as a model for the critical amiodarone-induced pulmonary fibrosis (AIPF). In order to investigate the cellular mechanism of human AIPF, which occurs following oral or intravenous administration, an animal model of AIPF resulting from systemic administration of the drug would appear to be preferable. We have evaluated pulmonary toxicity following repeated intraperitoneal amiodarone administration to the hamster. Intraperitoneal treatment of hamsters for 1, 4, or 7 weeks with amiodarone (100 mg/kg/day) did not lead to pulmonary toxicity based on wet lung weight, hydroxyproline content, or histological examination. Furthermore, when comparing 1- and 7-week treatment groups, there was no pulmonary accumulation of either amiodarone or desethylamiodarone beyond levels found at 1 week. Therefore, failure to develop pulmonary toxicity may be due to an inability to accumulate sufficient amiodarone and/or desethylamiodarone. Intratracheal administration of amiodarone to rodents remains the only in vivo animal model for studying the mechanism(s) of AIPF. PMID:8085270

  14. Fly ash-induced changes in hamster tracheal epithelium in vivo and in vitro

    SciTech Connect

    Schiff, L.J.; Byrne, M.M.; Graham, J.A.

    1981-09-01

    The effects of fly ash from a coal-fired power plant on tracheal epithelium of CrRGH (SYR) Syrian golden hamsters were studied in organ cultures and after in vivo exposures. The tracheal epithelium of animals receiving 5-9 daily (5 d/wk) 3-h exposures to 2 mg fly ash per cubic meter showed large areas of basal cell hyperplasia and stratification. Surface alterations characteristic of stratified metaplasia were observed. Exposure to 1 mg/m/sup 3/ produced diffuse basal cell hyperplasia. Hamster tracheal ring cultures exposed in vitro to 50 ..mu..g/ml fly ash for 1 h/d or to 10 ..mu..g/ml for 3 h/d showed epithelial changes similar to those observed in vivo. Whole suckling hamster tracheas in organ culture exposed to fly ash at concentrations of 10 and 50 ..mu..g/ml for 1 or 3 h/d exhibited cornifying epidermoid metaplasia after 7 exposures. The most characteristic findings in surface cells were broad metaplastic areas with keratin formation.

  15. In vivo characterization of two additional Leishmania donovani strains using the murine and hamster model.

    PubMed

    Kauffmann, F; Dumetz, F; Hendrickx, S; Muraille, E; Dujardin, J-C; Maes, L; Magez, S; De Trez, C

    2016-05-01

    Leishmania donovani is a protozoan parasite causing the neglected tropical disease visceral leishmaniasis. One difficulty to study the immunopathology upon L. donovani infection is the limited adaptability of the strains to experimental mammalian hosts. Our knowledge about L. donovani infections relies on a restricted number of East African strains (LV9, 1S). Isolated from patients in the 1960s, these strains were described extensively in mice and Syrian hamsters and have consequently become 'reference' laboratory strains. L. donovani strains from the Indian continent display distinct clinical features compared to East African strains. Some reports describing the in vivo immunopathology of strains from the Indian continent exist. This study comprises a comprehensive immunopathological characterization upon infection with two additional strains, the Ethiopian L. donovani L82 strain and the Nepalese L. donovani BPK282 strain in both Syrian hamsters and C57BL/6 mice. Parameters that include parasitaemia levels, weight loss, hepatosplenomegaly and alterations in cellular composition of the spleen and liver, showed that the L82 strain generated an overall more virulent infection compared to the BPK282 strain. Altogether, both L. donovani strains are suitable and interesting for subsequent in vivo investigation of visceral leishmaniasis in the Syrian hamster and the C57BL/6 mouse model. PMID:27012562

  16. Body temperature in the mouse, hamster, and rat exposed to radiofrequency radiation: an interspecies comparison

    SciTech Connect

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

    1986-01-01

    Colonic temperatures of BALB/c and CBA/J mice, golden hamsters, and Sprague-Dawley rats were taken immediately after exposure for 90 min to radiofrequency (RF) radiation. Exposures were made in 2450 MHz (mouse and hamster) or 600-MHz (rat) waveguide exposure systems while the dose rate, to specific adsorption rate (SAR), was continuously recorded. Experiments were performed on naive, unrestrained animals at ambient temperatures (Ta) of 20 and 30 C. Body mass and Ta were found to be significant factors in influencing the threshold SAR for the elevation of colonic temperature. The threshold SARs at Ta's of 20 and 30 C were, respectively: 27.5 and 12.1 W/kg for the BALB/c mouse; 40.7 and 8.5 W/kg for the CBA/J mouse; 8.7 and 0.61 W/kg for the golden hamster; and 1.58 and 0.4 W/kg for the Sprague-Dawley rat.

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

    SciTech Connect

    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 of 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.

  18. Chronic effects of dietary exposure to amosite and chrysotile asbestos in Syrian golden hamsters.

    PubMed Central

    McConnell, E E; Shefner, A M; Rust, J H; Moore, J A

    1983-01-01

    Bioassays of amosite, short-range (SR), intermediate-range (IR) or intermediate-range chrysotile asbestos in combination with the intestinal carcinogen 1,2-dimethylhydrazine dihydrochloride (DMH) were conducted with male and female Syrian golden hamsters. Amosite and both forms of chrysotile asbestos were administered at a concentration of 1% in pelleted diet for the entire lifetime of the hamsters starting with mothers of the test animals. Group sizes varied from 125-254. There was no adverse effect on body weight gain or survival by either type of asbestos or by IR chrysotile asbestos in combination with DMH. A significant increase (p less than 0.05) in adrenal cortical tumors was observed in male hamsters exposed to SR and IR chrysotile asbestos and in females treated with IR chrysotile asbestos when compared to the pooled control groups. However, statistical significance (p less than 0.05) was lost when these dosed groups were compared with temporal control groups. Neither of the male or female amosite asbestos groups showed increased neoplasia in any tissue or organ compared to the control groups. The cocarcinogen studies using IR chrysotile asbestos and 1,2-dimethylhydrazine dihydrochloride were considered inadequate because there was no increase in intestinal neoplasia in the DMH group. PMID:6319115

  19. Economic geology: Gold buried by oxygen

    NASA Astrophysics Data System (ADS)

    Gaillard, Fabrice; Copard, Yoann

    2015-03-01

    The Witwatersrand Basin in South Africa contains extraordinary amounts of gold. Thermodynamic calculations suggest that the gold may have accumulated there in response to a perfect storm of conditions available only during the Archaean.

  20. Recent Developments in Australian Gold Extraction.

    ERIC Educational Resources Information Center

    Thiele, Rodney B.

    1995-01-01

    Describes new technologies that have greatly improved the extraction efficiency of gold ore, including: altering plant layout to promote efficiency, engaging Filiblast forced oxidation and bioxidation systems, and updating the electrowinning procedure at the gold recovery stage. (JRH)

  1. Colloidal gold nanorods: from reduction to growth

    NASA Astrophysics Data System (ADS)

    Park, Kyoungweon; El-Sayed, Mostafa; Srinivasarao, Mohan

    2005-03-01

    Formation of gold nanorods(NRs) in controlled reduction condition was investigated. Gold NRs were synthesized by seed mediated method where pre-made gold nanospheres were added to a growth solution containing surfactants, reducing agent and compound of gold ion and surfactant. Reduction mechanism was manipulated by changing catalytic activity of seed. Seed of different size and capping agent coverage led to different dispersity of NRs since seed plays a role as catalyst as well as nucleation site. The difference between the redox potentials of gold species and reducing agent(δE) was controlled by the strength of reducing agent and the stability of the gold compound. As δE leading to changing the morphology of resulting gold NRs. The surface of gold NRs with a series of aspect ratio was functionalized by thiolated beta cyclodextrin which binds preferentially to the end of NRs and promotes the orientation of rod-rod pair even without host-guest interaction.

  2. Ultrastable and Biofunctionalizable Gold Nanoparticles.

    PubMed

    Gupta, Akash; Moyano, Daniel F; Parnsubsakul, Attasith; Papadopoulos, Alexander; Wang, Li-Sheng; Landis, Ryan F; Das, Riddha; Rotello, Vincent M

    2016-06-01

    Gold nanoparticles provide an excellent platform for biological and material applications due to their unique physical and chemical properties. However, decreased colloidal stability and formation of irreversible aggregates while freeze-drying nanomaterials limit their use in real world applications. Here, we report a new generation of surface ligands based on a combination of short oligo (ethylene glycol) chains and zwitterions capable of providing nonfouling characteristics while maintaining colloidal stability and functionalization capabilities. Additionally, conjugation of these gold nanoparticles with avidin can help the development of a universal toolkit for further functionalization of nanomaterials. PMID:27191946

  3. Immunization and challenge shown by hamsters infected with Opisthorchis viverrini following exposure to gamma-irradiated metacercariae of this carcinogenic liver fluke.

    PubMed

    Papatpremsiri, A; Junpue, P; Loukas, A; Brindley, P J; Bethony, J M; Sripa, B; Laha, T

    2016-01-01

    Here we report findings to optimize and standardize conditions to attenuate metacercariae of Opisthorchis viverrini by ionizing radiation to elicit protective immune responses to challenge infection. Metacercariae were gamma-irradiated and the ability of irradiated metacercariae to prevent patent infection of challenge metacercariae in hamsters was determined, as well as their ability to induce a host antibody response. Metacercariae irradiated in a dose-dependent manner, with 3, 5, 10, 12, 20, 25 and 50 Gray, were used to infect Syrian golden hamsters by stomach gavage to ascertain the effect of irradiation on ability of the worms to establish infection. In addition, other hamsters were infected with metacercariae irradiated with 20-50 Gray, followed by challenge with intact/wild-type (non-irradiated) metacercariae to determine the protective effect as established by the numbers of adult flukes, eggs of O. viverrini in hamster faeces and anti-O. viverrini antibody titres. Significantly fewer worms were recovered from hamsters immunized with metacercariae irradiated at 20, 25 and 50 Gray than from control hamsters infected with intact metacercariae or 0 Gray, and the worms showed damaged reproductive organs. Faecal egg numbers were decreased significantly in hamsters immunized with 25 and 50 Gray metacercariae of O. viverrini. Moreover, hamsters administered metacercariae that were protected elicited a robust, specific anti-fluke immunoglobulin G response compared to control hamsters, suggesting a role for antibody in protection elicited by radiation-attenuated metacercariae. PMID:25315797

  4. Characterizing the textural features of gold ores for optimizing gold extraction

    NASA Astrophysics Data System (ADS)

    Hausen, Donald M.

    2000-04-01

    The beneficiation of gold ores begins with an examination and classification of the types of gold occurrences and recovery methods. Measurements can provide the necessary grind size for liberation and determine the sizes and associations of gold with gangue materials. In this article, the textural features several gold occurrences are described and compared.

  5. 31 CFR 100.4 - Gold coin and gold certificates in general.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Gold coin and gold certificates in general. 100.4 Section 100.4 Money and Finance: Treasury Regulations Relating to Money and Finance EXCHANGE OF PAPER CURRENCY AND COIN In General § 100.4 Gold coin and gold certificates in general....

  6. Formation, structure, and orientation of gold silicide on gold surfaces

    NASA Technical Reports Server (NTRS)

    Green, A. K.; Bauer, E.

    1976-01-01

    The formation of gold silicide on Au films evaporated onto Si(111) surfaces is studied by Auger electron spectroscopy (AES) and low-energy electron diffraction (LEED). Surface condition, film thickness, deposition temperature, annealing temperature, and heating rate during annealing are varied. Several oriented crystalline silicide layers are observed.

  7. Substituting gold for silver improves electrical connections

    NASA Technical Reports Server (NTRS)

    Loyd, J. R.; Pickard, R. F.

    1967-01-01

    In attaching external leads to thin film sensors of platinum ribbon, liquid gold is applied to each end of the ribbon and the leads are soldered to the cured gold. The cured and soldered liquid gold shows no tendency to migrate and retains initial resistance characteristics when exposed to elevated temperatures.

  8. 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

    2015-01-01

    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. PMID:26600493

  9. Effects of neonatal enucleation on the functional organization of the superior colliculus in the golden hamster.

    PubMed Central

    Rhoades, R W

    1980-01-01

    1. The responses of visual, auditory and somatosensory superior collicular neurones were investigated using extracellular single unit recording techniques in hamsters which were subjected to the removal of one eye on the day of birth. 2. Neonatal enucleation resulted in a marked increase in the region of the colliculus from which visual neurones activated by stimulation of the ipsilateral eye could be recorded. In most cases the visuotopic representation in the colliculus ipsilateral to the remaining eye mirrored that observed in the contralateral tectum along both the rostrocaudal and mediolateral axes: in both colliculi temporal retina projected rostrally and inferior retina medially. In some animals, however, there appeared to be a dual mapping of the remaining eye onto the ipsilateral tectum. In these hamsters the central portion of the visual field was represented twice along the rostrocaudal axis of colliculus. 3. No changes in the topography of the somatosensory and auditory representations in the tectum were observed following neonatal enucleation. 4. The laminar distribution of visual neurones in the ipsilateral colliculus was markedly altered in the neonatally enucleated hamsters. Very few exclusively visual units were encountered in the layers ventral to the stratum opticum and almost all of the visual cells recorded in the ipsilateral colliculus were isolated within 150 microM of the tectal surface. 5. In the posterior half of the ipsilateral tectum a large number of extravisually responsive cells were encountered in the stratum griseum superficiale and stratum opticum. This was not the case in the colliculus contralateral to the remaining eye, nor has it ever been observed in normal hamsters. 6. Recordings from animals subjected to both neonatal enucleation and acute bilateral removal of somatosensory and auditory cortex indicated that the projections from these areas to the colliculus were not essential to the observed changes in laminar organization

  10. Gold, Silver and Bronze Citations.

    ERIC Educational Resources Information Center

    American School & University, 2003

    2003-01-01

    Presents the gold, silver, and bronze winners of a competition, which judged the most outstanding learning environments at educational institutions nationwide. Jurors spent two days reviewing projects, focusing on concepts and ideas that made them exceptional. For each citation, the article offers information on the firm, client, total area, total…

  11. Shape Stability of Gold Nanorods

    NASA Astrophysics Data System (ADS)

    Robertson, Steve; Bertone, Jane; Cizeron, Joel; Wahi, Raj; Colvin, Vicki

    2000-03-01

    Photoreduction of gold salts in inverse micelles can lead to the formation of colloidal gold. A wide variety of well-defined and facetted shapes are seen in the product; though these nanocrystals are highly crystalline, high resolution transmission electron microscopy reveal the presence of specific crystalline defects, primarily twin planes. These defects are correlated to the nanocrystals shape, and lead us to postulate a shape control mechanism dependent on the presence of crystalline defects. Among the observed shapes from this reaction are anisotropic nanocrystals with aspect ratios ranging from 5 to 10. The rod percentage can be maximized by controlling the water to surfactant ratio in the solution, and is only observed when the reduction process is photoinitiated. Rod growth can be activated, allowing for the formation of gold nanoneedles with aspect ratios exceeding 30. The smallest dimensions of these nanocrystals are 10 nm, which is large enough that melting point depressions because of finite size are expected to be minimal. Nevertheless, anisotropic particles anneal to more symmetric shapes at temperatures of only 600 to 700 C. Electron microscopy studies of these shape changing processes at high temperatures indicate that the nanocrystals anneal quite suddenly, with rapid movements of many gold atoms.

  12. Gold color in dental alloys.

    PubMed

    Cameron, T

    1997-01-01

    This article will help the dental laboratory with alloy selection by exploring how the relationship among color, ductility and strength applies to gold and how color can be quantified. Because higher quality materials translate into higher profits, upselling to the dentist and patient is also discussed. PMID:9524484

  13. [Biosynthesis of gold nanoparticles by Azospirillum brasilense].

    PubMed

    Kupriashina, M A; Vetchinkina, E P; Burov, A M; Ponomareva, E G; Nikitina, V E

    2014-01-01

    Plant-associated nitrogen-fixing soil bacteria Azospirillum brasilense were shown to reduce the gold of chloroauric acid to elemental gold, resulting in formation of gold nanoparicles. Extracellular phenoloxidizing enzymes (laccases and Mn peroxidases) were shown to participate in reduction of Au+3 (HAuCl4) to Au(0). Transmission electron microscopy revealed accumulation of colloidal gold nanoparticles of diverse shape in the culture liquid of A. brasilense strains Sp245 and Sp7. The size of the electron-dense nanospheres was 5 to 50 nm, and the size of nanoprisms varied from 5 to 300 nm. The tentative mechanism responsible for formation of gold nanoparticles is discussed. PMID:25423733

  14. Bimodal porous gold opals for molecular sensing

    NASA Astrophysics Data System (ADS)

    Chae, Weon-Sik; Yu, Hyunung; Ham, Sung-Kyoung; Lee, Myung-Jin; Jung, Jin-Seung; Robinson, David B.

    2013-11-01

    We have fabricated bimodal porous gold skeletons by double-templating routes using poly(styrene) colloidal opals as templates. The fabricated gold skeletons show a bimodal pore-size distribution, with small pores within spheres and large pores between spheres. The templated bimodal porous gold skeletons were applied in Raman scattering experiments to study sensing efficiency for probe molecules. We found that the bimodal porous gold skeletons showed obvious enhancement of Raman scattering signals versus that of the unimodal porous gold which only has interstitial pores of several hundred nanometers.

  15. Gold recycling; a materials flow study

    USGS Publications Warehouse

    Amey, Earle B.

    2000-01-01

    This materials flow study includes a description of trends in consumption, loss, and recycling of gold-containing materials in the United States in 1998 in order to illustrate the extent to which gold is presently being recycled and to identify recycling trends. The quantity of gold recycled, as a percent of the apparent supply of gold, was estimated to be about 30 percent. Of the approximately 446 metric tons of gold refined in the United States in 1998, the fabricating and industrial use losses were 3 percent.

  16. Heteroepitaxial gold (111) rings on mica substrates

    SciTech Connect

    Zhang, X.W.; Chen, N.F.; Yan, F.; Goedel, Werner A.

    2005-05-16

    Two-dimensionally arranged gold rings were prepared by depositing a polymeric membrane bearing a dense array of uniform pores onto a mica substrate, filling the pores with a solution of a gold precursor, evaporation of the solvent and calcinations. The epitaxy of gold rings is confirmed by x-ray diffraction measurements, and the epitaxial relationship between gold rings and the mica was found to be Au(111)[1-10] parallel mica(001)[010]. The polar and azimuthal angular spreads are 0.3 deg. and 1 deg., respectively, which is at least equal to or better than the quality of the corresponding epitaxial gold-film on mica.

  17. 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

  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. PMID:22848250

  19. Determination of Hepatotoxicity and Its Underlying Metabolic Basis of 1,2-Dichloropropane in Male Syrian Hamsters and B6C3F1 Mice

    PubMed Central

    Gi, Min; Fujioka, Masaki; Yamano, Shotaro; Shimomura, Eri; Ishii, Naomi; Kakehashi, Anna; Takeshita, Masanori; Wanibuchi, Hideki

    2015-01-01

    1,2-Dichloropropane (1,2-DCP) has recently been reclassified from not classifiable as to its carcinogenicity to humans (Group 3) to carcinogenic to humans (Group 1) by the International Agency for Research on Cancer. This was based on the findings of epidemiological studies in Japan that occupational exposure to paint stripers containing 1,2-DCP was associated with increased cholangiocarcinomas. It is known that 1,2-DCP is negative for cholangiocarcinogenicity in rats and mice. However, its toxicity and carcinogenicity has not been examined in hamsters and little is known about the regulation of its metabolism in hamsters. The purpose of this study was to determine the hepatobiliary toxicity of 1,2-DCP in hamsters and to characterize and compare the altered patterns of hepatic xenometabolic enzymes in hamsters and mice. Male Syrian hamsters and male B6C3F1 mice were treated with various doses of 1,2-DCP for 4 h or 3 days or 4 weeks. These experiments demonstrated that a high dose of 1,2-DCP induced centrilobular hepatocellular necrosis in hamsters. CYP2E1 is possibly the key enzyme responsible for bioactivation and the consequent hepatocytotoxicity of 1,2-DCP, and GSH conjugation catalyzed by GST-T1 may exert a cytoprotective role in hamsters and mice. Notably, the expression pattern of GST-T1 in bile duct epithelial cells differed between hamsters and mice: GST-T1 was expressed in bile duct epithelial cells of mice but not hamsters. This indicates that responses to 1,2-DCP in the bile duct of hamsters might differ from that of mice, and suggests that long-term studies are necessary to clarify the chalangiocarcinogenicity of 1,2-DCP in hamsters, though no biliary toxicity was observed in the present short-term experiments. PMID:25711234

  20. Determination of Hepatotoxicity and Its Underlying Metabolic Basis of 1,2-Dichloropropane in Male Syrian Hamsters and B6C3F1 Mice.

    PubMed

    Gi, Min; Fujioka, Masaki; Yamano, Shotaro; Shimomura, Eri; Ishii, Naomi; Kakehashi, Anna; Takeshita, Masanori; Wanibuchi, Hideki

    2015-05-01

    1,2-Dichloropropane (1,2-DCP) has recently been reclassified from not classifiable as to its carcinogenicity to humans (Group 3) to carcinogenic to humans (Group 1) by the International Agency for Research on Cancer. This was based on the findings of epidemiological studies in Japan that occupational exposure to paint stripers containing 1,2-DCP was associated with increased cholangiocarcinomas. It is known that 1,2-DCP is negative for cholangiocarcinogenicity in rats and mice. However, its toxicity and carcinogenicity has not been examined in hamsters and little is known about the regulation of its metabolism in hamsters. The purpose of this study was to determine the hepatobiliary toxicity of 1,2-DCP in hamsters and to characterize and compare the altered patterns of hepatic xenometabolic enzymes in hamsters and mice. Male Syrian hamsters and male B6C3F1 mice were treated with various doses of 1,2-DCP for 4 h or 3 days or 4 weeks. These experiments demonstrated that a high dose of 1,2-DCP induced centrilobular hepatocellular necrosis in hamsters. CYP2E1 is possibly the key enzyme responsible for bioactivation and the consequent hepatocytotoxicity of 1,2-DCP, and GSH conjugation catalyzed by GST-T1 may exert a cytoprotective role in hamsters and mice. Notably, the expression pattern of GST-T1 in bile duct epithelial cells differed between hamsters and mice: GST-T1 was expressed in bile duct epithelial cells of mice but not hamsters. This indicates that responses to 1,2-DCP in the bile duct of hamsters might differ from that of mice, and suggests that long-term studies are necessary to clarify the chalangiocarcinogenicity of 1,2-DCP in hamsters, though no biliary toxicity was observed in the present short-term experiments. PMID:25711234

  1. High-fructose feeding promotes accelerated degradation of hepatic LDL receptor and hypercholesterolemia in hamsters via elevated circulating PCSK9 levels

    PubMed Central

    Dong, Bin; Singh, Amar Bahadur; Azhar, Salman; Seidah, Nabil G.; Liu, Jingwen

    2015-01-01

    Background High fructose diet (HFD) induces dyslipidemia and insulin resistance in experimental animals and humans with incomplete mechanistic understanding. By utilizing mice and hamsters as in vivo models, we investigated whether high fructose consumption affects serum PCSK9 and liver LDL receptor (LDLR) protein levels. Results Feeding mice with a HFD increased serum cholesterol and reduced serum PCSK9 levels as compared with the mice fed a normal chow diet (NCD). In contrast to the inverse relationship in mice, serum PCSK9 and cholesterol levels were co-elevated in HFD-fed hamsters. Liver tissue analysis revealed that PCSK9 mRNA and protein levels were both reduced in mice and hamsters by HFD feeding, however, liver LDLR protein levels were markedly reduced by HFD in hamsters but not in mice. We further showed that circulating PCSK9 clearance rates were significantly lower in hamsters fed a HFD as compared with the hamsters fed NCD, providing additional evidence for the reduced hepatic LDLR function by HFD consumption. The majority of PCSK9 in hamster serum was detected as a 53 kDa N-terminus cleaved protein. By conducting in vitro studies, we demonstrate that this 53 kDa truncated hamster PCSK9 is functionally active in promoting hepatic LDLR degradation. Conclusion Our studies for the first time demonstrate that high fructose consumption increases serum PCSK9 concentrations and reduces liver LDLR protein levels in hyperlipidemic hamsters. The positive correlation between circulating cholesterol and PCSK9 and the reduction of liver LDLR protein in HFD-fed hamsters suggest that hamster is a better animal model than mouse to study the modulation of PCSK9/LDLR pathway by atherogenic diets. PMID:25682035

  2. Dating native gold by noble gas analyses

    NASA Technical Reports Server (NTRS)

    Niedermann, S.; Eugster, O.; Hofmann, B.; Thalmann, CH.; Reimold, W. U.

    1993-01-01

    Our recent work on He, Ne, and Ar in Alpine gold samples has demonstrated that gold is extremely retentive for He and could thus, in principle, be used for U/Th-He-4 dating. For vein-type gold from Brusson, Northern Italy, we derived a U/Th-He-4 age of 36 Ma, in agreement with the K-Ar formation age of associated muscovites and biotites. However, in placer gold from the Napf area, Central Switzerland, we observed large excesses of both He-4 and radiogenic Ar-40 (Ar-40 sub rad, defined as Ar-40-295.5-Ar-.36). The gas release systematics indicate two distinct noble gas components, one of which is released below about 800 C and the other one at the melting point of gold (1064 C). We now present results of He and Xe measurements in a 1 g placer gold sample from the river Kruempelgraben, as well as He and Ar data for Brusson vein-type gold and for gold from the Lily Gold Mine, South Africa. We calculate reasonable U/Th-He-4 as well as U-Xe ages based on those gases which are released at approximately 800 C. Probably the low-temperature components represent in-situ-produced radiogenic He and fission Xe, whereas the gases evolving when gold melts have been trapped during gold formation. Therefore, only the low-temperature components are relevant for dating purposes.

  3. Selective increase of antioxidant enzyme activity in the alveolar macrophages from cigarette smokers and smoke-exposed hamsters.

    PubMed

    McCusker, K; Hoidal, J

    1990-03-01

    Oxidants from cigarette smoke or those produced by phagocytes are implicated in the pathogenesis of emphysema. We reasoned that augmentation of antioxidant enzymes in cigarette smokers may be important in restricting direct and indirect oxidant damage to alveolar structures. Accordingly, we studied the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSHPx), in alveolar macrophages (AM) from cigarette smokers and from smoke-exposed hamsters. The activities of these antioxidant enzymes were compared with the activities found in AM from nonsmoking control subjects. The activities of SOD and CAT from AM of smokers and smoke-exposed hamsters were twice that found in control subjects (p less than 0.01), but there was no change in the activity of GSHPx. Using the hamster model, we found that filtration of smoke attenuated the increase in antioxidant activities, and that after smoking cessation, the increased activities had returned to those found with control subjects. An adaptive response was further suggested by prolonged survival of smoke-exposed hamsters in normobaric hyperoxia (O2 greater than 95%). Chronic smoke exposure in humans or hamsters causes increased SOD and CAT activities in AM. This augmented activity may serve as a mechanism to limit oxidant-mediated damage to alveolar structures. PMID:2310098

  4. Effects of microwave exposure on the hamster immune system. III. Macrophage resistance to vesicular stomatitis virus infection

    SciTech Connect

    Rao, G.R.; Cain, C.A.; Tompkins, W.A.

    1984-01-01

    Exposure of hamsters to microwave (MW) energy (2.45 GHz, 25 mW/cm2, 1 h) resulted in activation of peritoneal macrophages (PM) to a viricidal state restricting the replication of vesicular stomatitis virus (VSV). The PM from MW-exposed hamsters were viricidal as early as 1 day after exposure and remained active for 5 days. Immunization of hamsters with vaccinia virus induced viricidal PM by 3 to 4 days and they remained active for 7 days. To test the hypothesis that thermogenic MW exposure results in the release of endotoxin across the intestinal epithelium which subsequently activates PM, hamsters were injected with lipopolysaccharide (LPS) and their viricidal activity was studied. Lipopolysaccharide in vitro (0.2 microgram) and in vivo (0.5 microgram) activated macrophages to a viricidal state. When administered in vivo, LPS (0.5 microgram) activated macrophages as early as 1 day and the activity remained for 3 days. While MW exposure of PM in vitro failed to induce viricidal activity, exposure of PM to LPS in vitro induced strong viricidal activity. This suggests that the in vivo response of PM to MW is an indirect one, which is consistent with the hypothesis that MW-induced PM viricidal activity may be mediated via LPS. In preliminary experiments, MW exposure resulted in extended survival time for hamsters challenged with a lethal dose of vesicular stomatitis virus, supporting the concept that MW-activated PM may be a useful therapeutic modality.

  5. Male golden hamster in male reproductive toxicology testing: Assessment of protective activity of selenium in acute cadmium intoxication

    SciTech Connect

    Wiodarczyk, B.; Biernacki, B.; Minta, M.; Juszkiewicz, T.; Kozaczynski, W.

    1995-06-01

    The golden hamster has a short history as a laboratory animal. In spite of this, it has been extensively used as a subject for biomedical research. The hamster has also been utilized in toxicological evaluations, especially in teratology studies. Results of these investigations reveal that laboratory hamsters are very sensitive to many chemical compounds, including: drugs, food additives, industrial chemicals, heavy metals, and other environmental contaminants. The animals most frequently used in toxicological investigations are rats and mice. This is also true in male reproductive toxicology. Apparent differences in species sensitivity to chemical compounds suggest a need to examine a new species in this field of toxicology. A good example of chemical specific differences in species sensitivity is the testicular toxicity of 1,2-dibromo-3-chloropropane (DBCP), which was a testicular toxicant in humans and in rats, but it was not effective, even at relatively high dose levels, in the mouse. From our own vast experience in using hamsters in toxicological studies, we decided to use this laboratory animal in male reproductive toxicology screening tests. The purpose of this study was to determine the suitability of golden hamsters as an experimental animal species for male reproductive toxicology testing. To this effect we have chosen selenium and cadmium as test agents as they were well known for their spectacular effect on the male reproductive system. 13 refs., 1 tab.

  6. Pegylation increases platelet biocompatibility of gold nanoparticles.

    PubMed

    Santos-Martinez, Maria Jose; Rahme, Kamil; Corbalan, J Jose; Faulkner, Colm; Holmes, Justin D; Tajber, Lidia; Medina, Carlos; Radomski, Marek Witold

    2014-06-01

    The increasing use of gold nanoparticles in medical diagnosis and treatment has raised the concern over their blood compatibility. The interactions of nanoparticles with blood components may lead to platelet aggregation and endothelial dysfunction. Therefore, medical applications of gold nanoparticles call for increased nanoparticle stability and biocompatibility. Functionalisation of nanoparticles with polythelene glycol (PEGylation) is known to modulate cell-particle interactions. Therefore, the aim of the current study was to investigate the effects of PEGylated-gold nanoparticles on human platelet function and endothelial cells in vitro. Gold nanoparticles, 15 nm in diameter, were synthesised in water using sodium citrate as a reducing and stabilising agent. Functionalised polyethylene glycol-based thiol polymers were used to coat and stabilise pre-synthesised gold nanoparticles. The interaction of gold nanoparticles-citrate and PEGylated-gold nanoparticles with human platelets was measured by Quartz Crystal Microbalance with Dissipation. Platelet-nanoparticles interaction was imaged using phase-contrast, scanning and transmission electron microscopy. The inflammatory effects of gold nanoparticles-citrate and PEGylated-gold nanoparticles in endothelial cells were measured by quantitative real time polymerase chain reaction. PEGylated-gold nanoparticles were stable under physiological conditions and PEGylated-gold nanoparticles-5400 and PEGylated-gold nanoparticles-10800 did not affect platelet aggregation as measured by Quartz Crystal Microbalance with Dissipation. In addition, PEGylated-gold nanoparticles did not induce an inflammatory response when incubated with endothelial cells. Therefore, this study shows that PEGylated-gold nanoparticles with a higher molecular weight of the polymer chain are both platelet- and endothelium-compatible making them attractive candidates for biomedical applications. PMID:24749395

  7. The recombinant C-terminus of the human MUC2 mucin forms dimers in Chinese-hamster ovary cells and heterodimers with full-length MUC2 in LS 174T cells.

    PubMed Central

    Lidell, Martin E; Johansson, Malin E V; Mörgelin, Matthias; Asker, Noomi; Gum, James R; Kim, Young S; Hansson, Gunnar C

    2003-01-01

    The entire cDNA corresponding to the C-terminal cysteine-rich domain of the human MUC2 apomucin, after the serine- and threonine-rich tandem repeat, was expressed in Chinese-hamster ovary-K1 cells and in the human colon carcinoma cell line, LS 174T. The C-terminus was expressed as a fusion protein with the green fluorescent protein and mycTag sequences and the murine immunoglobulin kappa-chain signal sequence to direct the protein to the secretory pathway. Pulse-chase studies showed a rapid conversion of the C-terminal monomer into a dimer in both Chinese-hamster ovary-K1 and LS 174T cells. Disulphide-bond-stabilized dimers secreted into the media of both cell lines had a higher apparent molecular mass compared with the intracellular forms. The MUC2 C-terminus was purified from the spent culture medium and visualized by molecular electron microscopy. The dimer nature of the molecule was visible clearly and revealed that each monomer was attached to the other by a large globular domain. Gold-labelled antibodies against the mycTag or green fluorescent protein revealed that these were localized to the ends opposite to the parts responsible for the dimerization. The C-terminus expressed in LS 174T cells formed heterodimers with the full-length wild-type MUC2, but not with the MUC5AC mucin, normally expressed in LS 174T cells. The homodimers of the MUC2 C-termini were secreted continuously from the LS 174T cells, but no wild-type MUC2 secretion has been observed from these cells. This suggests that the information for sorting the MUC2 mucin into the regulated secretory pathway in cells having this ability is present in parts other than the C-terminus of MUC2. PMID:12597771

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  9. Plasma and hepatic cholesterol-lowering in hamsters by tomato pomace, tomato seed oil and defatted tomato seed supplemented in high fat diets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  10. 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...

  11. PULMONARY FUNCTION IN NORMAL AND ELASTASE-TREATED HAMSTERS EXPOSED TO A COMPLEX MIXTURE OF OLEFIN-OZONE-SULFUR DIOXIDE REACTION PRODUCTS

    EPA Science Inventory

    An elastase-induced emphysema model was utilized to determine if hamsters with preexisting lung disease were more susceptible to lung damage from air pollutant exposure. Male golden hamsters, divided into two treatment groups, were given a single intratracheal injection of either...

  12. ALTERATION OF BEHAVIORAL SEX DIFFERENTIATION BY EXPOSURE TO ESTROGENIC COMPOUNDS DURING A CRITICAL NEONATAL PERIOD: EFFECTS OF ZEARALENONE, METHOXYCHLOR, AND ESTRADIOL IN HAMSTERS

    EPA Science Inventory

    The present study was designed to determine if neonatal exposure to the estrogenic mycotoxin zearalenone or the weakly estrogenic pesticide methoxychlor could masculinize and/or defeminize the behavior of female hamsters. Neonatal hamsters were given a single s.c. injection of ei...

  13. Metal release from gold-containing jewelry materials: no gold release detected.

    PubMed

    Lidén, C; Nordenadler, M; Skare, L

    1998-12-01

    Metal release from 13 different gold-containing jewelry alloys stored for 1 and 3 weeks in artificial sweat was analysed. For chemical analysis, inductively-coupled plasma detection (ICP) and atomic absorption spectrophotometry (AA), with flame and with furnace, were used. No release of gold was detected. It is unlikely that skin contact with gold-containing metallic items such as jewelry is responsible for inducing contact allergy to gold or allergic contact dermatitis due to the gold. The patch-test reactivity to gold sodium thiosulfate needs to be explained by some other mechanism(s). PMID:9874018

  14. Gold nanoparticles and vaccine development.

    PubMed

    Salazar-González, Jorge Alberto; González-Ortega, Omar; Rosales-Mendoza, Sergio

    2015-01-01

    Mucosal vaccines constitute an advantageous immunization approach to achieve broad immunization against widespread diseases; however, improvements in this field are still required to expand their exploitation. As gold nanoparticles are biocompatible and can be easily functionalized with antigens, they have been proposed as carriers for the delivery of vaccines. The study of gold nanoparticles (AuNPs) in vaccinology has been of interest for a number of research groups in recent years and important advances have been made. This review provides a summary of the AuNPs synthesis methodologies and an updated overview of the current AuNPs-based vaccines under development. The implications of these advances for the development of new mucosal vaccines as well as future prospects for the field are discussed. PMID:26152550

  15. Behavioral responses of predator-naïve dwarf hamsters (Phodopus campbelli) to odor cues of the European ferret fed with different prey species.

    PubMed

    Apfelbach, Raimund; Soini, Helena A; Vasilieva, Nina Y; Novotny, Milos V

    2015-07-01

    Many mammalian predators are able to identify their prey by odors and, vice versa, numerous prey species recognize predator odors as well. The present paper reports on the behavioral responses of predator-naïve dwarf hamsters (Phodopus campbelli) towards the urine odors of carnivorous ferrets, which were raised on either a chicken, mouse or hamster diet. Chemical composition from ferret urines of the different diet groups was analyzed, while quantitative differences in urinary volatile constituents were observed through capillary gas chromatography–mass spectrometry. In a Y-maze arrangement, hamsters were offered several two-choice odor discrimination tasks and their behavior was quantified. Hamsters were easily able to discriminate the urine odor of ferrets fed with mice against ferrets fed with hamsters. This is probably the first report indicating that a prey species can distinguish urine odors of even an unknown predator species that has been fed different prey species. The analytical data complemented behavioral assays. PMID:26066723

  16. Biomolecular Assembly of Gold Nanocrystals

    SciTech Connect

    Micheel, Christine Marya

    2005-05-20

    Over the past ten years, methods have been developed to construct discrete nanostructures using nanocrystals and biomolecules. While these frequently consist of gold nanocrystals and DNA, semiconductor nanocrystals as well as antibodies and enzymes have also been used. One example of discrete nanostructures is dimers of gold nanocrystals linked together with complementary DNA. This type of nanostructure is also known as a nanocrystal molecule. Discrete nanostructures of this kind have a number of potential applications, from highly parallel self-assembly of electronics components and rapid read-out of DNA computations to biological imaging and a variety of bioassays. My research focused in three main areas. The first area, the refinement of electrophoresis as a purification and characterization method, included application of agarose gel electrophoresis to the purification of discrete gold nanocrystal/DNA conjugates and nanocrystal molecules, as well as development of a more detailed understanding of the hydrodynamic behavior of these materials in gels. The second area, the development of methods for quantitative analysis of transmission electron microscope data, used computer programs written to find pair correlations as well as higher order correlations. With these programs, it is possible to reliably locate and measure nanocrystal molecules in TEM images. The final area of research explored the use of DNA ligase in the formation of nanocrystal molecules. Synthesis of dimers of gold particles linked with a single strand of DNA possible through the use of DNA ligase opens the possibility for amplification of nanostructures in a manner similar to polymerase chain reaction. These three areas are discussed in the context of the work in the Alivisatos group, as well as the field as a whole.

  17. Bi-directional actions of dehydroepiandrosterone and aggression in female Siberian hamsters.

    PubMed

    Rendon, Nikki M; Demas, Gregory E

    2016-02-01

    There is a well-established positive relationship between gonadal steroids and aggression. In some seasonally breeding species, however, aggression often persists or is increased during short "winter-like" days when the gonads are regressed and circulating levels of gonadal steroids are relatively low. Although the mechanisms underlying short-day increases in aggression are not fully known, the adrenal androgen dehydroepiandrosterone (DHEA) has been suggested as an alternative neuroendocrine mechanism regulating seasonal aggression. We used two complementary experimental approaches to examine the bi-directional actions of DHEA and aggression in female Siberian hamsters, a seasonal rodent that displays increased aggression concomitant with elevated circulating DHEA in short days. In Experiment 1, we examined the effects of aggressive interactions on DHEA concentrations before and after an aggressive encounter in long- and short-day hamsters. Serum DHEA was altered in a photoperiod-dependent manner, with decreased DHEA levels in response to aggression in short- but not long-day hamsters. Next, we experimentally induced adrenal DHEA release via injections of exogenous ACTH and assessed changes in aggressive behavior across photoperiods. We show a robust increase in aggression in short compared with long days during baseline aggression trials; however, aggression was not significantly increased further in response to ACTH in either photoperiod during post-ACTH aggression trials. These findings suggest that DHEA plays a role in the regulation of short-day aggression, while also highlighting the need for additional studies addressing the causal relationship between DHEA and aggression in this and others species. PMID:26700024

  18. Characterization of integrin expression in islets isolated from hamster, canine, porcine, and human pancreas.

    PubMed

    Wang, R N; Paraskevas, S; Rosenberg, L

    1999-04-01

    The reasons for the failure of clinical islet transplantation remain obscure. Islet isolation, however, exposes the islet to variety of cellular stresses, including disruption of the cell-matrix relationship, an event associated with apoptosis. The cell-matrix relationship is characterized by an interaction between cell surface integrin receptors and matrix molecules of the surrounding basement membrane (BM). The purpose of this study was to characterize integrin expression and the distribution of the peri-insular BM in human, porcine, canine, and hamster pancreas, and after routine islet isolation. Whereas islets in the porcine pancreas do not have a demonstrable BM, islets in the human, canine, and hamster pancreas have an almost continuous BM with very little direct exocrine to endocrine cell-cell contact. After islet isolation, the BM was destroyed, only to be reestablished during the period of culture. In the pancreas of all four species, integrin alpha3 was expressed only on islet cells, and integrin alpha5 was present on islet cells as well as on acinar, centroacinar, and duct cells. Integrin alphaV was detected only in human and canine pancreas. Integrin beta1 was demonstrated only in the human pancreas. In isolated islets, integrin alpha3, alpha5, and alphaV expression decreased during the culture period and the intensity of the staining was observed to be coincident with the distribution of the BM. In summary, this is the first report of integrin expression in hamster, canine, porcine, and human islets. After islet isolation, the altered islet cell-matrix relationship is reflected both in the decrease in integrin expression and in the destruction of the peri-insular BM. These profound changes will need to be considered as the process of islet isolation for transplantation is refined. (J Histochem Cytochem 47:499-506, 1999) PMID:10082751

  19. Iron metabolism in hamsters experimentally infected with Leptospira interrogans serovar Pomona: influence on disease pathogenesis.

    PubMed

    Sobroza, Ânderson O; Tonin, Alexandre A; Da Silva, Alekandro S; Dornelles, Guilherme L; Wolkmer, Patrícia; Duarte, Marta M M F; Hausen, Bruna S; Sangoi, Manuela B; Moresco, Rafael N; Stefani, Lenita M; Mazzantti, Cinthia M; Lopes, Sonia T A; Leal, Marta L R

    2014-12-01

    The aim of this study was to analyze the classic iron markers associated to the storage process in hamsters experimentally infected by Leptospira interrogans serovar Pomona. Four groups with six hamsters each were used; two were negative controls (C7 and C14) and two were composed by infected animals (T7 and T14). Blood samples were collected on the seventh (C7 and T7) and fourteenth days (C14 and T14) post-inoculation. Iron availability was determined in sera samples through the assessment of iron, ferritin, transferrin, and iron binding capacity, whereas the bone marrow was also evaluated for the presence of iron by Pearl's reaction. Additionally, the total antioxidant capacity (TAC) and total oxidant status (TOS) were assessed, along with hepcidin and IL-6 levels. Based on the results, it was possible to observe the onset of an anemic profile, predominantly hemolytic and regenerative. Also, The other parameters showed an increase in seric iron (P<0.01) and ferritin (P<0.01), and a positive Pearl's reaction in T7 and T14, when compared with the control groups. Transferrin levels decreased (P<0.05) in animals of T14 with saturation index. TAC was increased in both periods (P<0.01), while TOS was increased only on T14 (P<0.05). Hepcidin and IL-6 were increased on T7 and T14 (P<0.01). Therefore, it was observed that the serum profile from infected animals showed a strong hemolytic pattern, with some demonstration of ferric tissue sequestration when the infection tended to become chronic. The results show that iron metabolism is activated in hamsters infected by L. interrogans serovar Pomona. PMID:25449998

  20. 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