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Sample records for syrian hamster ii

  1. 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

  2. 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

  3. 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

  4. Experimental pancreatic carcinogenesis. II. Lifetime carcinogenesis studies in the outbred Syrian golden hamster with N-nitroso-bis(2-hydroxypropyl)amine.

    PubMed

    Levitt, M; Harris, C; Squire, R; Wenk, M; Mollelo, C; Springer, S

    1978-03-01

    A high incidence of pancreatic duct neoplasms was induced in outbred male Syrian golden hamsters following weekly sc injection of N-nitroso-bis(2-hydroxypropyl)amine for life. The first such tumors appeared as early as 16 experimental weeks; the maximum incidence reached 100% by the termination of the study. Tumors in the respiratory tracts and angiosarcomas of the livers of the hamsters were also observed in high frequency. Latency of the induced neoplasms was significantly decreased by the substitution of distilled water for olive oil as the vehicle for the carcinogen. PMID:625072

  5. 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

  6. 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.

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. A Syrian Golden Hamster Model Recapitulating Ebola Hemorrhagic Fever

    PubMed Central

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

    2013-01-01

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

  18. 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

  19. 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

  20. 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

  1. Pineal melatonin synthesis in Syrian hamsters: A summary

    NASA Astrophysics Data System (ADS)

    Rollag, M. D.

    1982-12-01

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

  2. Studies on the inhalation toxicology of two fiberglasses and amosite asbestos in the Syrian golden hamster. Part II. Results of chronic exposure.

    PubMed

    McConnell, E E; Axten, C; Hesterberg, T W; Chevalier, J; Miiller, W C; Everitt, J; Oberdörster, G; Chase, G R; Thevenaz, P; Kotin, P

    1999-09-01

    Fiberglass (FG) is the largest category of man-made mineral fibers (MMVFs). Many types of FG are manufactured for specific uses building insulation, air handling, filtration, and sound absorption. In the United States, > 95% of FG produced is for building insulation. Several inhalation studies in rodents of FG building insulation have shown no indication of pulmonary fibrosis or carcinogenic activity. However, because of increasing use and potential for widespread human exposure, a chronic toxicity/carcinogenicity inhalation study of a typical building insulation FG (MMVF 10a) was conducted in hamsters, which were shown to be highly sensitive to the induction of mesotheliomas with another MMVF. A special-application FG (MMVF 33) and amosite asbestos were used for comparative purposes. Groups of 140 weanling male Syrian golden hamsters were exposed via nose-only inhalation for 6 h/day, 5 days/wk for 78 wk to either filtered air (chamber controls) or MMVF 10a, MMVF 33, or amosite asbestos at 250-300 WHO fibers/cm(3) with two additional amosite asbestos groups at 25 and 125 WHO fibers/cm(3). They were then held unexposed for 6 wk until approximately 10-20% survival. After 13, 26, 52, and 78 wk, various pulmonary parameters and lung fiber burdens were evaluated. Groups hamsters were removed from exposure at 13 and 52 wk and were held until 78 wk (recovery groups). Initial lung deposition of long fibers (>20 microm in length) after a single 6-h exposure was similar for all 3 fibers exposed to 250-300 fibers/cm(3). MMVF 10a lungs showed inflammation (which regressed in recovery hamsters) but no pulmonary or pleural fibrosis or neoplasms. MMVF 33 induced more severe inflammation and mild interstitial and pleural fibrosis by 26 wk that progressed in severity until 52 wk, after which it plateaued. While the inflammatory lesions regressed in the recovery animals, pulmonary or pleural fibrosis did not. A single multicentric mesothelioma was observed at 32 wk. No neoplasms

  3. 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.

  4. 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

  5. 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...

  6. 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

  7. 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

  8. 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+...

  9. 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...

  10. 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.

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  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. 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

  10. 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

  11. Effect of 6-azacytidine on the course of experimental adenoviral infection in newborn Syrian hamsters.

    PubMed

    Zarubalev, V V; Slita, A V; Sukhinin, V P; Nosach, L N; Dyachenko, N S; Povnitsa, O Y; Zhovnovataya, V L; Alexeeva, I V; Palchikovskaya, L I

    2007-02-01

    Adenoviral infection is a serious human pathology leading to respiratory, gastrointestinal and ocular disorders and epidemic outbreaks, especially in children's groups. Here we present the results from an investigation of anti- adenoviral effect of 6-azacytidine (6-AC) both in vitro and in vivo. The selectivity index of 6-AC for adenovirus type 5 in HEp-2 cells was 374, the 50% effective concentration was 0.5 mg/ml. For in vivo investigations we developed a model of disseminated adenoviral infection in newborn Syrian hamsters. The infectious virus was recovered from the liver, kidney, lungs and heart. Application of 6-AC led to a reduced period of the virus presence (7 days in the liver and 4 days in the kidney and heart) and lowered virus titers on day 3 post-inoculation (p.i.) (liver - 2.7 and 4.1, heart - 0 and 3.2, kidney - 0 and 2.4 log(10 )CPD(50)/mg tissue weight, in the presence and absence of 6-AC, respectively). Application of 6-AC to newborn Syrian hamsters led to partial destruction of their splenocytes. The results obtained suggest that 6-AC or 6-ACbased drugs with lower toxicity or applied topically may be suitable for therapy and prevention of adenoviral infection in humans. PMID:17309850

  12. 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

  13. In vitro transformation of Syrian hamster epidermal cells by N-methyl-N'-nitro-N-nitrosoguanidine

    SciTech Connect

    Sun, N.C.; Sun, C.R.Y.; Chao, L.; Fung, W.P.; Tennant, R.W.; Hsie, A.W.

    1981-05-01

    The selection of Syrian hamster epidermal cells which do not terminally differentiate has provided a quantitative focus assay for in vitro chemical transformation. One-day-old Syrian hamster epidermal cells plated at 5 x 10/sup 6//100-mm dish were treated for 5 hr with various concentrations of N-methyl-N-nitro-N'-nitrosoguanidine. After 4 weeks, the normal epidermal cells began to terminally differentiate to keratinized squamous cells and died, but transformed epidermal colonies grew to higher cell densities and appeared as darker areas against a lightly stained normal cell background. Transformed epidermal foci were isolated and subcultured for at least 15 passages, whereas normal epidermal cells could not be subcultured under the same conditions. The transformed cells assumed the typical cobblestone-like morphology of epithelial cells, retained desmosomes and tonofilaments, and were able to use citrulline in place of arginine. Argininosuccinate synthetase (EC 6.3.4.5) activity was significantly higher in the epidermal cells than in fibroblasts. The injection of 5 x 10/sup 6/ cells of two transformed epidermal cell lines into athymic nude mice resulted in the formation of tumors which were identified as keratinizing squamous carcinomas.

  14. S22153, a melatonin antagonist, dissociates different aspects of photoperiodic responses in Syrian hamsters.

    PubMed

    Pitrosky, B; Delagrange, P; Rettori, M C; Pévet, P

    2003-01-22

    In the Syrian hamster, short photoperiod (SP) induces changes in several physiological functions (body mass, reproduction, hibernation), and these responses involve the pineal hormone melatonin. The present study investigated the effects of a melatonin antagonist, S22153, on photoperiodic adaptation of male Syrian hamster. When constantly released from subcutaneous implants, S22153 had no effect on body or testes masses of animals kept in long photoperiod. S22153 decreased the total hibernation duration observed in animals exposed to SP and low temperature. The decrease in hibernation duration was due to a marked reduction in the number and duration of hypothermic bouts. Moreover, S22153 significantly inhibited the increase of interscapular brown adipose tissue (BAT) mass induced by SP. However, neither the gonadal atrophy nor the body mass increase induced by SP were affected by S22153. These results show that S22153 affects only part of the physiological changes controlled by SP and cold. Whether the decreases in BAT mass and hibernation duration are linked still remains an open question. PMID:12527445

  15. 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

  16. 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

  17. [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

  18. 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

  19. 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

  20. 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

  1. Morphological cell transformation of Syrian hamster embryo (SHE) cells by the cyanotoxin, cylindrospermopsin.

    PubMed

    Maire, M-A; Bazin, E; Fessard, V; Rast, C; Humpage, A R; Vasseur, P

    2010-06-15

    Cylindrospermopsin (CYN) is a cyanotoxin which has been implicated in human intoxication and animal mortality. Genotoxic activity of this hepatotoxin is known but its carcinogenic activity remains to be elucidated. In this work, CYN was assessed for its cell-transforming activity using the Syrian hamster embryo (SHE) cell transformation assay. This in vitro assay is used to evaluate the carcinogenic potential of chemical, physical and biological agents in SHE cells, which are primary, normal, diploid, genetically stable and capable of metabolic activation. We demonstrated that CYN induced a significant increase in morphological cell transformation in SHE cells following a 7-day continuous treatment in the range of non-cytotoxic concentrations 1 x 10(-7)-1 x 10(-2) ng/mL. PMID:20144639

  2. Morphological transformation of an established Syrian hamster dermal cell with the anti-tussive agent noscapine.

    PubMed

    Porter, R; Parry, E M; Parry, J M

    1992-05-01

    Following exposure to the alkaloid noscapine hydrochloride over a concentration range of 10-120 micrograms/ml immortal cultures of Syrian hamster dermal fibroblasts were shown to undergo morphological transformation. The resultant transformed foci produced cultures which were anchorage independent as confirmed by soft agar tests. Karyotype analysis of a noscapine transformed colony demonstrated an increase in chromosome number compared to the immortal culture and the non-random duplication of a translocated chromosome 9 previously identified in the immortal culture. These data indicate that noscapine, which has previously been shown to be a spindle inhibitor and inducer of polyploidy in cultured cells, is capable of inducing in vitro cell transformation. Such data indicate a carcinogenic potential for this widely used cough suppressant. PMID:1602976

  3. Lung tumors from PuO2-ZrO2 aerosol particles in Syrian hamsters.

    PubMed

    Thomas, R G; Smith, D M

    1979-11-15

    Syrian golden hamsters were given PuO2/ZrO2 particles via inhalation and/or Pu-laden ZrO2 ceramic 10-micron diameter microspheres lodged in the capillary bed of the lung. The mean initial lung burdens ranged from 8 nCi to 143 nCi for the six experimental groups of animals. Significant numbers of primary lung tumors (5-50% per group) were induced in those animals that received inhalation exposures. Additional alpha radiation administered via Pu-laden intravenous microspheres had little or no effect on tumorigenesis or the production of non-neoplastic, degenerative changes in the respiratory tract. PMID:528076

  4. Assessment of the teratogenicity of ammonium vanadate using Syrian golden hamsters

    SciTech Connect

    Carlton, B.D.; Beneke, M.B.; Fisher, G.L.

    1982-12-01

    Vanadium is a ubiquitous trace metal present in most plant and animal tissues. Its presence as a porphyrin in plant tissue results in accumulation of relatively high concentrations of vanadium in fossil fuels. The exposure of pregnant Syrian golden hamsters to ammonium vanadate from days 5 through 10 of gestation resulted in a statistically significant increase in skeletal anomalies and a decrease in the male:female fetal sex ratio. Skeletal anomalies included micrognathia, supernumerary ribs, and alterations in sternebral ossification. Although not statistically significant, external anomalies included meningocoele, one fetus with multiple anomalies, and the presence of a molar pregnancy. Soft tissue anomalies did not differ significantly among groups but included hydronephrosis/hydroureter and kidney dysplasia. The small numbers of malformed offspring and the lack of a clear-cut dose-response did not allow a definitive assessment of the teratogenicity of ammonium vanadate.

  5. 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

  6. 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

  7. 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

  8. 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

  9. Sex differences due to dehydroepiandrosterone (DHEA) feeding affecting dehydroepiandrosterone sulfate secretion in golden Syrian hamsters.

    PubMed

    Maeda, Y; Nagatomo, J; Sueta, H; Tanaka, S; Ota, Y; Shiotsuki, H; Eto, T; Kai, M; Kondo, K; Chijiiwa, K

    2004-02-01

    The metabolism of orally administered dehydroepiandrosterone (DHEA) by male and female golden Syrian hamsters was examined by quantification of DHEA and dehydroepiandrosterone sulfate (DHEAS) in gallbladder bile, urine and feces using high-performance liquid chromatography (HPLC). Plasma levels of DHEA and DHEAS were also determined by radioimmunoassay (RIA). After 5 days of oral DHEA administration (100 mg/kg body weight twice a day), RIA showed that plasma levels of DHEA and DHEAS were increased approximately 3-6 and 4-5 times, respectively, compared to controls. More than 95 % of circulating DHEA (S) in the peripheral blood was DHEAS. There was no significant sex difference in DHEAS plasma levels between male and female animals in the DHEA-supplemented group. However, 0.2 - 0.3 % of ingested DHEA was conjugated to DHEAS and excreted in urine by females, whereas less than 0.002 % was excreted in urine by males (p < 0.005). DHEAS was excreted in bile by males after DHEA supplementation, and the sex differences in DHEAS levels observed in bile were statistically significant (male, 18.7 +/- 7.5 vs. female, 5.6 +/- 3.1 micromol/l) (p < 0.005). Small amounts of ingested DHEA were excreted in an unchanged state in feces, and no sex difference was observed. These results suggest that there is a considerable sex difference in the conjugation and excretion of orally administered DHEA in the hamster. PMID:15002061

  10. Desipramine enhances the ability of risperidone to decrease alcohol intake in the Syrian golden hamster.

    PubMed

    Gulick, Danielle; Chau, David T; Khokhar, Jibran Y; Dawson, Ree; Green, Alan I

    2014-08-30

    The atypical antipsychotic clozapine reduces alcohol drinking in patients with schizophrenia. We have proposed that clozapine׳s ability to decrease alcohol drinking relates to its weak blockade of the dopamine D2 receptor and potent blockade of the norepinephrine α-2 receptor, as well as its ability to elevate plasma and brain norepinephrine. Another atypical antipsychotic, risperidone, which is a potent blocker of both the dopamine D2 receptor and norepinephrine α-2 receptor, does not decrease alcohol drinking. In this study, we used the Syrian golden hamster to test whether the ability of risperidone to reduce alcohol drinking would be enhanced if it was used in combination with the norepinephrine reuptake inhibitor desipramine. Hamsters were given free access to water and alcohol (15% v/v) until they reached a steady drinking baseline. They were then treated daily with each drug or drug combination for 20 days. Risperidone (0.2mg/kg) only transiently decreased alcohol drinking. However, 5.0mg/kg, and possibly 1.0mg/kg, desipramine added to 0.2mg/kg risperidone appeared to produce a more substantial and relatively sustained effect than risperidone alone. Data from this study provide leads toward the development of new treatments for patients with schizophrenia and alcoholism, and also for those with alcoholism alone. PMID:24836200

  11. Nasal Associated Lymphoid Tissue of the Syrian Golden Hamster Expresses High Levels of PrPC

    PubMed Central

    Clouse, Melissa D.; Shikiya, Ronald A.; Bartz, Jason C.; Kincaid, Anthony E.

    2015-01-01

    The key event in the pathogenesis of the transmissible spongiform encephalopathies is a template-dependent misfolding event where an infectious isoform of the prion protein (PrPSc) comes into contact with native prion protein (PrPC) and changes its conformation to PrPSc. In many extraneurally inoculated models of prion disease this PrPC misfolding event occurs in lymphoid tissues prior to neuroinvasion. The primary objective of this study was to compare levels of total PrPC in hamster lymphoid tissues involved in the early pathogenesis of prion disease. Lymphoid tissues were collected from golden Syrian hamsters and Western blot analysis was performed to quantify PrPC levels. PrPC immunohistochemistry (IHC) of paraffin embedded tissue sections was performed to identify PrPC distribution in tissues of the lymphoreticular system. Nasal associated lymphoid tissue contained the highest amount of total PrPC followed by Peyer’s patches, mesenteric and submandibular lymph nodes, and spleen. The relative levels of PrPC expression in IHC processed tissue correlated strongly with the Western blot data, with high levels of PrPC corresponding with a higher percentage of PrPC positive B cell follicles. High levels of PrPC in lymphoid tissues closely associated with the nasal cavity could contribute to the relative increased efficiency of the nasal route of entry of prions, compared to other routes of infection. PMID:25642714

  12. 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

  13. 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.

  14. 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

  15. 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

  16. 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

  17. 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

  18. Twice Daily Melatonin Peaks in Siberian but not Syrian Hamsters under 24 h Light:Dark:Light:Dark Cycles

    PubMed Central

    Raiewski, Evan E.; Elliott, Jeffrey A.; Evans, Jennifer A.; Glickman, Gena L.; Gorman, Michael R.

    2016-01-01

    The daily pattern of blood borne melatonin varies seasonally under the control of a multi-oscillator circadian pacemaker. Here we examine patterns of melatonin secretion and locomotor activity in Siberian and Syrian hamsters entrained to bimodal LDLD8:4:8:4 and LD20:4 lighting schedules that facilitate novel temporal arrangements of component circadian oscillators. Under LDLD, both species robustly bifurcated wheel-running activity in distinct day scotophase (DS) and night scotophase (NS) bouts. Siberian hamsters displayed significant melatonin increases during each scotophase in LDLD, and in the single daily scotophase of LD20:4. The bimodal melatonin secretion pattern persisted in acutely extended 16 h scotophases. Syrian hamsters, in contrast, showed no significant increases in plasma melatonin during either scotophase of LDLD8:4:8:4 or in LD20:4. In this species, detectable levels were observed only when the day scotophase of LDLD was acutely extended to yield 16 h of darkness. Established species differences in the phase lag of nocturnal melatonin secretion relative to activity onset may underlie the above contrast: In non-bifurcated entrainment to 24 h LD cycles, Siberian hamsters show increased melatonin secretion within ~ 2 h after activity onset, whereas in Syrian hamsters, detectable melatonin secretion phase lags activity onset and the L/D transition by at least 4 h. The present results provide new evidence indicating multi-oscillator regulation of the waveform of melatonin secretion, specifically, the circadian control of the onset, offset, and duration of nocturnal secretion. PMID:23003567

  19. 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.

  20. 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

  1. 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

  2. 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

  3. Effects of iloperidone, combined with desipramine, on alcohol drinking in the Syrian golden hamster.

    PubMed

    Khokhar, Jibran Y; Green, Alan I

    2016-06-01

    Alcohol use disorder in patients with schizophrenia dramatically worsens their clinical course, and few treatment options are available. Clozapine appears to reduce alcohol use in these patients, but its toxicity limits its use. To create a safer clozapine-like drug, we tested whether the antipsychotic iloperidone, a drug that combines a weak dopamine D2 receptor blockade and a potent norepinephrine alpha-2 receptor blockade would reduce alcohol drinking, and whether its effect on alcohol drinking could be increased if combined with an agent to facilitate norepinephrine activity. Syrian golden hamsters (useful animal model for screening drugs that reduce alcohol drinking in patients with schizophrenia) were given free access to water and alcohol (15% v/v) until stable drinking was established. Animals (n = 6-7/group), matched according to alcohol intake, were treated daily with each drug (iloperidone; clozapine; haloperidol; desipramine [norepinephrine reuptake inhibitor]; with idazoxan [norepinephrine alpha-2 receptor antagonist]) or with a two-drug (iloperidone + desipramine; iloperidone + idazoxan) combination for 14 days. Moderate doses of iloperidone (1-5 mg/kg) significantly reduced alcohol drinking (p < 0.05) in the hamster, whereas higher doses (10-20 mg/kg) did not. In addition, 5 mg/kg of iloperidone reduced alcohol drinking to the same extent as clozapine (8 mg/kg), whereas haloperidol (0.2 mg/kg) did not. Moreover, iloperidone's effects were enhanced via the addition of desipramine (3 mg/kg), but not idazoxan (1.5/3 mg/kg). In this animal model, iloperidone decreases alcohol drinking as effectively as clozapine, and desipramine appears to amplify this effect. The data suggest that iloperidone, alone or in combination with desipramine, should be tested in patients with schizophrenia and alcohol use disorder. PMID:26796639

  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. 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

  6. Recommended protocol for the Syrian hamster embryo (SHE) cell transformation assay.

    PubMed

    Maire, Marie-Aline; Pant, Kamala; Phrakonkham, Pascal; Poth, Albrecht; Schwind, Karl-Rainer; Rast, Claudine; Bruce, Shannon Wilson; Sly, Jamie E; Bohnenberger, Susanne; Kunkelmann, Thorsten; Schulz, Markus; Vasseur, Paule

    2012-04-11

    The Syrian hamster embryo (SHE) cell transformation assay (CTA) is a short-term in vitro assay recommended as an alternative method for testing the carcinogenic potential of chemicals. SHE cells are "normal" cells since they are diploid, genetically stable, non-tumourigenic, and have metabolic capabilities for the activation of some classes of carcinogens. The CTA, first developed in the 1960s by Berwald and Sachs (1963,1964) [3,4], is based on the change of the phenotypic feature of cell colonies expressing the first steps of the conversion of normal to neoplastic-like cells with oncogenic properties. Pienta et al. (1977) [22] developed a protocol using cryopreserved cells to enhance practicality of the assay and limit sources of variability. Several variants of the assay are currently in use, which mainly differ by the pH at which the assay is performed. We present here the common version of the SHE pH 6.7 CTA and SHE pH 7.0 CTA protocols used in the ECVAM (European Centre for the Validation of Alternative Methods) prevalidation study on CTA reported in this issue. It is recommended that this protocol, in combination with the photo catalogues presented in this issue, should be used in the future and serve as a basis for the development of the OECD test guideline. PMID:22198328

  7. Picomolar-affinity binding and inhibition of adenylate cyclase activity by melatonin in Syrian hamster hypothalamus

    SciTech Connect

    Niles, L.P.; Hashemi, F. )

    1990-12-01

    1. The effect of melatonin on forskolin-stimulated adenylate cyclase activity was measured in homogenates of Syrian hamster hypothalamus. In addition, the saturation binding characteristics of the melatonin receptor ligand, ({sup 125}I)iodomelatonin, was examined using an incubation temperature (30{degree}C) similar to that used in enzyme assays. 2. At concentrations ranging from 10 pM to 1 nM, melatonin caused a significant decrease in stimulated adenylate cyclase activity with a maximum inhibition of approximately 22%. 3. Binding experiments utilizing ({sup 125}I)iodomelatonin in a range of approximately 5-80 pM indicated a single class of high-affinity sites: Kd = 55 +/- 9 pM, Bmax = 1.1 +/- 0.3 fmol/mg protein. 4. The ability of picomolar concentrations of melatonin to inhibit forskolin-stimulated adenylate cyclase activity suggests that this affect is mediated by picomolar-affinity receptor binding sites for this hormone in the hypothalamus.

  8. A minute fraction of Syrian golden hamster retinal ganglion cells project bilaterally.

    PubMed

    Hsiao, K; Sachs, G M; Schneider, G E

    1984-02-01

    Bilaterally projecting retinal ganglion cells (BPRGCs) in the adult Syrian golden hamster were identified through the use of two retrogradely transported neuronal labels, horseradish peroxidase and Nuclear Yellow, placed separately in each optic tract. The distribution and size of doubly labeled retinal ganglion cells were characterized and their numbers were determined. Strict criteria were used to exclude artifactual doubly labeled cells. This work revealed that: (a) BPRGCs comprise less than 0.01% of the entire retinal ganglion cell population, averaging 7.4 (SD = 3) cells per retina; (b) BPRGCs are found primarily in the upper, peripheral retina and not along the vertical meridian or in the temporal crescent; and (c) BPRGCs correspond in size to ordinary retinal ganglion cells in their immediate vicinity, thus providing no evidence that they comprise a separate population of cells. Electrophysiological collision experiments were also performed, with stimulating electrodes in the two brachia of the superior colliculi and a recording electrode in one optic nerve. A collision effect was not detected, thus supporting the anatomical findings of rare bilateral branching of optic nerve axons. The occurrence of BPRGCs may reflect occasional ambiguities in the cues that guide axons through the chiasm. PMID:6199482

  9. [Antioxidative status changes in golden syrian hamsters with experimental metabolic syndrome].

    PubMed

    Zahaĭko, A L; Voronina, L M; Kaliman, P A; Strel'chenko, K V

    2008-01-01

    Some indices of the antioxidant status (content of the alpha-tocopherol, reduced glutathione and ascorbic acid, activity of the glutathione reductase and aryl-esterase) and lipid peroxidation processes in the liver, blood serum, and some blood serum lipoprotein fractions of the Golden Syrian hamsters of different sex and age status under high-caloric diet were investigated. It has been shown that the hypercaloric diet leads to a decreaseng of reduced glutathione content and increase of the level of lipid peroxidation products in the liver of experimental animals. The ascorbic acids content in male liver is decreased and in female liver is increased. In the blood serum under hypercaloric nutrition the accumulation of lipid peroxidation products and alpha-tocopherol content a decrease in ApoB-lipoproteins and HDL is observed. Simultaneously the ascorbic acid content is increased in the blood serum of all experimental animals. Activation of free-radical oxidation both in the liver, and blood serum is more significant in males compared with females. The data obtained allow to suppose that atherosclerotic complications of metabolic syndrome development may be connected to the lipoprotein oxidant status infringement. PMID:18959034

  10. STAT2 Knockout Syrian Hamsters Support Enhanced Replication and Pathogenicity of Human Adenovirus, Revealing an Important Role of Type I Interferon Response in Viral Control.

    PubMed

    Toth, Karoly; Lee, Sang R; Ying, Baoling; Spencer, Jacqueline F; Tollefson, Ann E; Sagartz, John E; Kong, Il-Keun; Wang, Zhongde; Wold, William S M

    2015-08-01

    Human adenoviruses have been studied extensively in cell culture and have been a model for studies in molecular, cellular, and medical biology. However, much less is known about adenovirus replication and pathogenesis in vivo in a permissive host because of the lack of an adequate animal model. Presently, the most frequently used permissive immunocompetent animal model for human adenovirus infection is the Syrian hamster. Species C human adenoviruses replicate in these animals and cause pathology that is similar to that seen with humans. Here, we report findings with a new Syrian hamster strain in which the STAT2 gene was functionally knocked out by site-specific gene targeting. Adenovirus-infected STAT2 knockout hamsters demonstrated an accentuated pathology compared to the wild-type control animals, and the virus load in the organs of STAT2 knockout animals was 100- to 1000-fold higher than that in wild-type hamsters. Notably, the adaptive immune response to adenovirus is not adversely affected in STAT2 knockout hamsters, and surviving hamsters cleared the infection by 7 to 10 days post challenge. We show that the Type I interferon pathway is disrupted in these hamsters, revealing the critical role of interferon-stimulated genes in controlling adenovirus infection. This is the first study to report findings with a genetically modified Syrian hamster infected with a virus. Further, this is the first study to show that the Type I interferon pathway plays a role in inhibiting human adenovirus replication in a permissive animal model. Besides providing an insight into adenovirus infection in humans, our results are also interesting from the perspective of the animal model: STAT2 knockout Syrian hamster may also be an important animal model for studying other viral infections, including Ebola-, hanta-, and dengue viruses, where Type I interferon-mediated innate immunity prevents wild type hamsters from being effectively infected to be used as animal models. PMID

  11. STAT2 Knockout Syrian Hamsters Support Enhanced Replication and Pathogenicity of Human Adenovirus, Revealing an Important Role of Type I Interferon Response in Viral Control

    PubMed Central

    Spencer, Jacqueline F.; Tollefson, Ann E.; Sagartz, John E.; Kong, Il-Keun; Wang, Zhongde; Wold, William S. M.

    2015-01-01

    Human adenoviruses have been studied extensively in cell culture and have been a model for studies in molecular, cellular, and medical biology. However, much less is known about adenovirus replication and pathogenesis in vivo in a permissive host because of the lack of an adequate animal model. Presently, the most frequently used permissive immunocompetent animal model for human adenovirus infection is the Syrian hamster. Species C human adenoviruses replicate in these animals and cause pathology that is similar to that seen with humans. Here, we report findings with a new Syrian hamster strain in which the STAT2 gene was functionally knocked out by site-specific gene targeting. Adenovirus-infected STAT2 knockout hamsters demonstrated an accentuated pathology compared to the wild-type control animals, and the virus load in the organs of STAT2 knockout animals was 100- to 1000-fold higher than that in wild-type hamsters. Notably, the adaptive immune response to adenovirus is not adversely affected in STAT2 knockout hamsters, and surviving hamsters cleared the infection by 7 to 10 days post challenge. We show that the Type I interferon pathway is disrupted in these hamsters, revealing the critical role of interferon-stimulated genes in controlling adenovirus infection. This is the first study to report findings with a genetically modified Syrian hamster infected with a virus. Further, this is the first study to show that the Type I interferon pathway plays a role in inhibiting human adenovirus replication in a permissive animal model. Besides providing an insight into adenovirus infection in humans, our results are also interesting from the perspective of the animal model: STAT2 knockout Syrian hamster may also be an important animal model for studying other viral infections, including Ebola-, hanta-, and dengue viruses, where Type I interferon-mediated innate immunity prevents wild type hamsters from being effectively infected to be used as animal models. PMID

  12. Pharmacokinetics of meso-(tetrahydroxyphenyl)chlorin (m-THPC) studied by fluorescence spectroscopy on early cancer of the cheek pouch mucosa of Golden Syrian hamsters

    NASA Astrophysics Data System (ADS)

    Glanzmann, Thomas M.; Theumann, Jean-Francois; Braichotte, Daniel; Forrer, Martin; Wagnieres, Georges A.; van den Bergh, Hubert; Andrejevic-Blant, Snezana; Savary, Jean-Francois; Monnier, Philippe

    1995-01-01

    Golden Syrian hamsters are evaluated as an animal model for phototherapy of early squamous cell carcinomas of the mucosa of the upper aerodigestive tract, the esophagus and the tracheobronchial tree. Carcinomas of this type are induced on the hamster cheek pouch mucosa by the application of the carcinogen 7,12 DMBA. For phototherapeutic experiments on the animals we utilized meso- (tetrahydoxyphenyl)chlorin (mTHPC). The same drug is currently in phase I, II clinical trials for ENT patients with superficial squamous cell carcinomas. By means of light induced fluorescence (LIF) we measured in vivo the kinetics of the uptake and removal of mTHPC in the normal and tumoral cheek mucosa and in the skin. The photodynamic therapy (PDT) reaction of the tissue after excitation of the photosensitizer by laser light at 652 nm was studied. Both pharmacokinetics and PDT efficacy are compared between animal model and clinical results with special emphasis on selectivity between normal and tumoral mucosa. These first experiments show that this tumor model in the hamster cheek pouch seems to be suitable for tests of a number of PDT variables of new photosensitizers preceding their clinical application as well as for optimization of the multiple parameters of clinical phototherapy.

  13. Acute toxicity of polyethylene glycol p-isooctylphenol ether in Syrian hamsters exposed by inhalation or bronchopulmonary lavage

    SciTech Connect

    Damon, E.G.; Halliwell, W.H.; Henderson, T.R.; Mokler, B.V.; Jones, R.K.

    1982-01-01

    Dose-response studies were conducted with Syrian hamsters exposed to polyethylene glycol p-isooctylphenyl ether (Triton X-100) via inhalation or bronchopulmonary lavage. Syrian hamsters were exposed to an aerosol of Triton X-100 with a mass median aerodynamic diameter of 1.5 ..mu..m and a concentration of 3.0 mg/liter. Estimated initial lung burdens of Triton X-100 ranged from 800 to 3100 ..mu..g. Hamsters were lavaged with concentrations of Triton X-100 ranging from 0.01 to 0.10% in isotonic saline resulting in initial lung burdens of Triton X-100 that ranged from 300 to 3200 ..mu..g. The LD50/7 values were 1700 ..mu..g (1300 to 2100 ..mu..g, 95% confidence limits) for the inhalation study and 2100 (1900 to 2700) ..mu..g for the lavage study. The difference between the LD50/7 values for the two methods of exposure was not significant. However, histopathological examination revealed differences in the nature and distribution of pathologic changes observed in animals exposed by the two routes of administration. Animals exposed by inhalation died as a result of ulcerative laryngitis and laryngeal edema with only minimal pulmonary pathologic alterations. Animals exposed by lavage, where the larynx was not exposed to Triton X-100, died from pulmonary edema and acute exudative pneumonia. These results demonstrate the need for careful selection of exposure methods to meet the specific objectives of a toxicology study.

  14. Comprehensive Transcriptome Analyses of the Fructose-Fed Syrian Golden Hamster Liver Provides Novel Insights into Lipid Metabolism.

    PubMed

    Li, Ziyang; Xiong, Chaoliang; Mo, Suo; Tian, Haiying; Yu, Mengqian; Mao, Tingting; Chen, Qian; Luo, Haitao; Li, Quanzhen; Lu, Jianxin; Zhao, Yi; Li, Wei

    2016-01-01

    Dyslipidemia has been widely proven to contribute to cardiovascular diseases and other metabolic disorders, especially in insulin resistance and type 2 diabetes. The overproduction of VLDL is a significant characteristic of dyslipidemia, indicating the dysfunction of hepatic lipid metabolism, from triglyceride synthesis to transport. The fructose-fed Syrian golden hamster is an established animal model for the study of VLDL assembly with insulin resistance, however, it remains unknown how VLDL production is regulated at the transcriptional level due to the absence of a complete hamster genome. Here, we performed deep sequencing and constructed an mRNA-miRNA-lncRNA interaction network of Syrian golden hamster liver in order to reveal the global transcription profile and find potential RNA molecular regulation of VLDL production. We identified 4,450 novel multi-exon hamster lncRNAs and 755 miRNAs expressed in liver. Additionally, 146 differentially expressed coding genes, 27 differentially expressed lncRNA genes, as well as 16 differentially expressed miRNAs were identified. We then constructed an mRNA-miRNA-lncRNA interaction network that may potentially regulate VLDL production, and interestingly found several microRNA-centered regulatory networks. In order to verify our interpretation, miR-486 was selected for further experiments. Overexpression or down-regulation of miR-486 in fructose-fed hamsters resulted in altered hepatic expression of proteins involved in VLDL production, and in modulated levels of circulating VLDL. Our findings implicated that miR-486 is a potential regulator of circulating VLDL levels. These results provide new insights and a valuable resource for further study of the molecular mechanisms of VLDL secretion. PMID:27589064

  15. Classification of agents using Syrian hamster embryo (SHE) cell transformation assay (CTA) with ATR-FTIR spectroscopy and multivariate analysis.

    PubMed

    Ahmadzai, Abdullah A; Trevisan, Júlio; Pang, Weiyi; Riding, Matthew J; Strong, Rebecca J; Llabjani, Valon; Pant, Kamala; Carmichael, Paul L; Scott, Andrew D; Martin, Francis L

    2015-09-01

    The Syrian hamster embryo (SHE) cell transformation assay (pH 6.7) has a reported sensitivity of 87% and specificity of 83%, and an overall concordance of 85% with in vivo rodent bioassay data. To date, the SHE assay is the only in vitro assay that exhibits multistage carcinogenicity. The assay uses morphological transformation, the first stage towards neoplasm, as an endpoint to predict the carcinogenic potential of a test agent. However, scoring of morphologically transformed SHE cells is subjective. We treated SHE cells grown on low-E reflective slides with 2,6-diaminotoluene, N-nitroso-N-ethylnitroguanidine, N-nitroso-N-methylurea, N-nitroso-N-ethylurea, EDTA, dimethyl sulphoxide (DMSO; vehicle control), methyl methanesulfonate, benzo[e]pyrene, mitomycin C, ethyl methanesulfonate, ampicillin or five different concentrations of benzo[a]pyrene. Macroscopically visible SHE colonies were located on the slides and interrogated using attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy acquiring five spectra per colony. The acquired IR data were analysed using Fisher's linear discriminant analysis (LDA) followed by principal component analysis (PCA)-LDA cluster vectors to extract major and minor discriminating wavenumbers for each treatment class. Each test agent vs. DMSO and treatment-induced transformed cells vs. corresponding non-transformed were classified by a unique combination of major and minor discriminating wavenumbers. Alterations associated with Amide I, Amide II, lipids and nucleic acids appear to be important in segregation of classes. Our findings suggest that a biophysical approach of ATR-FTIR spectroscopy with multivariate analysis could facilitate a more objective interrogation of SHE cells towards scoring for transformation and ultimately employing the assay for risk assessment of test agents. PMID:25925069

  16. Carcinogenic potency of perfluorooctane sulfonate (PFOS) on Syrian hamster embryo (SHE) cells.

    PubMed

    Jacquet, N; Maire, M A; Landkocz, Y; Vasseur, P

    2012-02-01

    Perfluorooctane sulfonate (PFOS) is the degradation product of many fluoroderivatives and a widespread environmental contaminant. Its persistence, its long half-life in humans and its toxicity explain high concerns on human health side effects in future. PFOS is suspected to be a non-genotoxic carcinogen. In the present work, we assessed carcinogenic potential of PFOS by studying morphological transformation in Syrian hamster embryo (SHE) cells; cell transformation of SHE cells is an in vitro assay recommended by the Organization for Economic Cooperation and Development to detect carcinogens, genotoxic or not. Genotoxicity of PFOS and expression of PPARs genes in SHE cells were also measured. PFOS was shown to induce cell transformation (P < 0.05) at non-cytotoxic concentrations (0.2 and 2 μg/mL) (P ≤ 0.01). No genotoxic effect was recorded in the range of PFOS concentrations tested (2 × 10(-4) to 50 μg/mL) using the single-cell gel electrophoresis (comet) assay after 5 and 24 h of exposure. The expression of PPARs genes was measured by qPCR within the first 24 h and after 7 days of PFOS treatment. Results indicated an increased expression of ppar-β/δ isoform as early as 24 h. After 7 days, the increase of ppar-β/δ mRNA was significant at the concentrations inducing cell transformation (0.2 and 2 μg/mL), while overexpression of ppar-γ and ppar-α did not closely relate to effective concentrations. The results indicate that PFOS behave as a non-genotoxic carcinogen and impacted PPARs genes. Its cell transforming potential paralleled an increased expression of ppar-β/δ. PMID:22057587

  17. Modulation of Vascular ACE by Oxidative Stress in Young Syrian Cardiomyopathic Hamsters: Therapeutic Implications.

    PubMed

    Cruz, Nildris; Miranda, Jorge D; Crespo, Maria J

    2016-01-01

    Increased vascular angiotensin-converting enzyme (ACE) activity and oxidative stress are present in young Syrian cardiomyopathic hamsters (SCH) before the clinical manifestation of heart failure (HF). The developmental time-course of these alterations and their potential interactions, however, are still unknown. We evaluated mRNA and protein levels of ACE, endothelial nitric oxide synthase (eNOS), and inducible nitric oxide synthase (iNOS) in the vasculature of SCH from one to four months of age. Total RNA and proteins were quantified with real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot, respectively. The role of nitric oxide (NO) on vascular ACE activity was also assessed. ACE mRNA and protein levels were up-regulated in SCH at two months of age compared with controls (CT) (p < 0.05). At this two-month stage, eNOS protein levels were lower in SCH (87%) than in CT (100%) (p < 0.05), although iNOS protein levels increased significantly (482%) compared to CT (100%; p < 0.05). In addition, ACE mRNA expression and activity were modulated by NO at two months of age. Thus, the combination of low eNOS and high iNOS protein levels may underlie vascular renin-angiotensin system (RAS) over-activation. Altogether, these factors may contribute to the development of endothelial dysfunction and vascular hyper-reactivity in the early stages of heart failure, and eventually trigger cardiac deterioration in this animal model of HF. PMID:27420103

  18. Phytosterols protect against diet-induced hypertriglyceridemia in Syrian golden hamsters

    PubMed Central

    2014-01-01

    Background In addition to lowering LDL-C, emerging data suggests that phytosterols (PS) may reduce blood triglycerides (TG), however, the underlying mechanisms are not known. Methods We examined the TG-lowering mechanisms of dietary PS in Syrian golden hamsters randomly assigned to a high fat (HF) diet or the HF diet supplemented with PS (2%) for 6 weeks (n = 12/group). An additional subset of animals (n = 12) was provided the HF diet supplemented with ezetimibe (EZ, 0.002%) as a positive control as it is a cholesterol-lowering agent with known TG-lowering properties. Results In confirmation of diet formulation and compound delivery, both the PS and EZ treatments lowered (p < 0.05) intestinal cholesterol absorption (24 and 31%, respectively), blood non-HDL cholesterol (61 and 66%, respectively), and hepatic cholesterol (45 and 55%, respectively) compared with the HF-fed animals. Blood TG concentrations were lower (p < 0.05) in the PS (49%) and EZ (68%)-treated animals compared with the HF group. The TG-lowering response in the PS-supplemented group was associated with reduced (p < 0.05) intestinal SREBP1c mRNA (0.45 fold of HF), hepatic PPARα mRNA (0.73 fold of HF), hepatic FAS protein abundance (0.68 fold of HD), and de novo lipogenesis (44%) compared with the HF group. Similarly, lipogenesis was lower in the EZ-treated animals, albeit through a reduction in the hepatic protein abundance of ACC (0.47 fold of HF). Conclusions Study results suggest that dietary PS are protective against diet-induced hypertriglyceridemia, likely through multiple mechanisms that involve modulation of intestinal fatty acid metabolism and a reduction in hepatic lipogenesis. PMID:24393244

  19. Social status alters defeat-induced neural activation in Syrian hamsters

    PubMed Central

    Morrison, Kathleen E.; Curry, Daniel W.; Cooper, Matthew A.

    2012-01-01

    While exposure to social stress leads to increased depression-like and anxiety-like behavior, some individuals are more vulnerable than others to these stress-induced changes in behavior. Prior social experience is one factor that can modulate how individuals respond to stressful events. In this study we investigated whether experience-dependent resistance to the behavioral consequences of social defeat was associated with a specific pattern of neural activation. We paired weight-matched male Syrian hamsters in daily aggressive encounters for two weeks, during which they formed a stable dominance relationship. We also included controls that were exposed to an empty cage each day for two weeks. Twenty-four hours after the final pairing or empty cage exposure, half of the subjects were socially defeated in 3, 5-min encounters, while the others were not socially defeated. Twenty-four hours after social defeat, animals were tested for conditioned defeat in a 5-min social interaction test with a non-aggressive intruder. We collected brains following social defeat and processed tissue for c-Fos immunoreactivity. We found that dominants were more likely to counter-attack the resident aggressor during social defeat than were subordinates, and they showed less submissive and defensive behavior at conditioned defeat testing compared to subordinates. Also, social status was associated with distinct patterns of defeat-induced neural activation in select brain regions including the amygdala, prefrontal cortex, hypothalamus, and lateral septum. Our results indicate that social status is an important form of prior experience that predicts both initial coping style and the degree of resistance to social defeat. Further, the differences in defeat-induced neural activation suggest possible brain regions that may control resistance to conditioned defeat in dominant individuals. PMID:22433296

  20. Perfluorooctanoic acid (PFOA) acts as a tumor promoter on Syrian hamster embryo (SHE) cells.

    PubMed

    Jacquet, N; Maire, M A; Rast, C; Bonnard, M; Vasseur, P

    2011-08-01

    Perfluorooctane sulfonate (PFOS) (C(8)F(17)SO(3)) and perfluorooctanoic acid (PFOA) (C(8)HF(15)O(2)) are synthetic chemicals widely used in industrial applications for their hydrophobic and oleophobic properties. They are persistent, bioaccumulative, and toxic to mammalian species. Their widespread distribution on earth and contamination of human serum raised concerns about long-term side effects. They are suspected to be carcinogenic through a nongenotoxic mode of action, a mechanism supported by recent findings that PFOS induced cell transformation but no genotoxicity in Syrian hamster embryo (SHE) cells. In the present study, we evaluated carcinogenic potential of PFOA using the cell transformation assay on SHE cells. The chemical was applied alone or in combination with a nontransformant concentration of benzo[a]pyrene (BaP, 0.4 μM) in order to detect PFOA ability to act as tumor initiator or tumor promoter. The results showed that PFOA tested alone in the range 3.7 × 10(-5) to 300 μM did not induce SHE cell transformation frequency in a 7-day treatment. On the other side, the combination BaP/PFOA induced cell transformation at all PFOA concentrations tested, which revealed synergistic effects. No genotoxicity of PFOA on SHE cells was detected using the comet assay after 5 and 24 h of exposure. No significant increase in DNA breakage was found in BaP-initiated cells exposed to PFOA in a 7-day treatment. The whole results showed that PFOA acts as a tumor promoter and a nongenotoxic carcinogen. Cell transformation in initiated cells was observed at concentrations equivalent to the ones found in human serum of nonoccupationally and occupationally exposed populations. An involvement of PFOA in increased incidence of cancer recorded in occupationally exposed population cannot be ruled out. PMID:22828883

  1. Modulation of Vascular ACE by Oxidative Stress in Young Syrian Cardiomyopathic Hamsters: Therapeutic Implications

    PubMed Central

    Cruz, Nildris; Miranda, Jorge D.; Crespo, Maria J.

    2016-01-01

    Increased vascular angiotensin-converting enzyme (ACE) activity and oxidative stress are present in young Syrian cardiomyopathic hamsters (SCH) before the clinical manifestation of heart failure (HF). The developmental time-course of these alterations and their potential interactions, however, are still unknown. We evaluated mRNA and protein levels of ACE, endothelial nitric oxide synthase (eNOS), and inducible nitric oxide synthase (iNOS) in the vasculature of SCH from one to four months of age. Total RNA and proteins were quantified with real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot, respectively. The role of nitric oxide (NO) on vascular ACE activity was also assessed. ACE mRNA and protein levels were up-regulated in SCH at two months of age compared with controls (CT) (p < 0.05). At this two-month stage, eNOS protein levels were lower in SCH (87%) than in CT (100%) (p < 0.05), although iNOS protein levels increased significantly (482%) compared to CT (100%; p < 0.05). In addition, ACE mRNA expression and activity were modulated by NO at two months of age. Thus, the combination of low eNOS and high iNOS protein levels may underlie vascular renin-angiotensin system (RAS) over-activation. Altogether, these factors may contribute to the development of endothelial dysfunction and vascular hyper-reactivity in the early stages of heart failure, and eventually trigger cardiac deterioration in this animal model of HF. PMID:27420103

  2. Lifetime carcinogenesis studies of amosite asbestos (Case No. 121-72-73-5) in Syrian golden hamsters (feed studies). Technical report series

    SciTech Connect

    Not Available

    1983-11-01

    Carcinogenesis studies of amosite asbestos were conducted by administering diets containing 1% of the asbestos in pellets from the conception of the mothers through the lifetime of male and female Syrian golden hamsters. Control groups consisted of 127 male and 126 female hamsters and the amosite asbestos group consisted of 252 male and 254 female hamsters. No adverse effect on body-weight gain or survival was observed from treatment with amosite asbestos. Neither of the amosite asbestos groups showed increased neoplasia in any organ or tissue compared to the control groups. Under the conditions of these studies, the ingestion of amosite asbestos at a level of 1% in the diet for their lifetime was not toxic and did not cause a carcinogenic response in male and female Syrian golden hamsters.

  3. Misoprostol-induced radioprotection of Syrian hamster embryo cells in utero from cell death and oncogenic transformation

    SciTech Connect

    Miller, R.C.; LaNasa, P.; Hanson, W.R.

    1994-07-01

    Misoprostol, a PGE analog, is an effective radioprotector of murine intestine and hematopoietic and hair cell renewal systems. The radioprotective nature of misoprostol was extended to examine its ability to influence clonogenic cell survival and induction of oncogenic transformation in Syrian hamster embryo cells exposed to X rays in utero and assayed in vitro. Hamsters in their 12th day of pregnancy were injected subcutaneously with misoprostal, and 2 h later the pregnant hamsters were exposed to graded doses of X rays. Immediately after irradiation, hamsters were euthanized and embryonic tissue was explanted into culture dishes containing complete growth medium. After a 2-week incubation period, clongenic cell survival and morphologically transformed foci were determined. Survival of misoprostol-treated SHE cells was increased and yielded a dose reduction factor of 1.5 compared to SHE cells treated with X rays alone. In contrast, radiation-induced oncogenic transformation of misoprostol-treated cells was reduced by a factor of 20 compared to cells treated with X rays alone. These studies suggest that misoprostol not only protects normal tissues in vivo from acute radiation injury, but also protects cells, to a large extent, from injury leading to transforming events. 26 refs., 6 figs., 2 tabs.

  4. 2-Arachidonoyl glycerol sensitizes the pars distalis and enhances forskolin-stimulated prolactin secretion in Syrian hamsters.

    PubMed

    Yasuo, Shinobu; Fischer, Claudia; Bojunga, Joerg; Iigo, Masayuki; Korf, Horst-Werner

    2014-04-01

    2-Arachidonoyl glycerol (2-AG) is a major endocannabinoid and an important regulator of neuroendocrine system. In Syrian hamster and human, we found that 2-AG is synthesized in the hypophysial pars tuberalis (PT), an interface between photoperiodic melatonin signals and neuroendocrine output pathways. The target of 2-AG produced in the PT is likely to be the pars distalis (PD). Here we demonstrate that 2-AG in combination with forskolin stimulated prolactin secretion from PD organ cultures of Syrian hamsters, whereas incubation with 2-AG alone had no effect. Forskolin-induced prolactin secretion was also significantly enhanced when cultured PD tissue was preincubated with 2-AG. The stimulatory effects of 2-AG on prolactin secretion were blocked by AM251, a selective CB1 antagonist, and were still observed in the presence of quinpirole, a D2-class dopamine receptor agonist. 2-AG also enhanced prolactin secretion in the presence of adenosine, while it had little effect when applied together with adenosine diphosphate (ADP) and adenosine triphosphate (ATP). Moreover, the effect of forskolin was mimicked by adenosine in a dose-dependent manner. In conclusion, our data suggest that 2-AG sensitizes the PD tissue to potentiate the stimulating effects of forskolin and adenosine on prolactin secretion and thus provide novel insight into the mode of action of 2-AG in the PD. PMID:24200164

  5. The effect of escapable versus inescapable social defeat on conditioned defeat and social recognition in Syrian hamsters.

    PubMed

    McCann, Katharine E; Huhman, Kim L

    2012-01-18

    Male Syrian hamsters are naturally aggressive animals that reliably defend their home territory against intruding conspecifics. Hamsters that lose agonistic encounters subsequently exhibit a striking change in their agonistic behavior, however, expressing no aggression and instead becoming highly submissive, a behavioral change that we have termed conditioned defeat. We have generally employed an inescapable defeat training protocol when studying conditioned defeat. The purpose of the present study was to determine if conditioned defeat is an epiphenomenon of the inescapable defeat experience by comparing the behavior of hamsters exposed to inescapable versus escapable defeat. In the conditioned defeat model, defeated hamsters subsequently generalize their submission and social avoidance to a novel, non-aggressive opponent, suggesting that hamsters subjected to inescapable defeat may not form a specific memory of their aggressive opponent. Thus, a secondary purpose of the present study was to determine whether hamsters subjected to our defeat protocol have the ability to recognize a familiar opponent following defeat. Our results provide evidence that conditioned defeat is not solely a by-product of inescapable defeat because all experimental animals, regardless of the type of defeat, expressed conditioned defeat during testing. We also found that animals experiencing an inescapable defeat avoided a familiar aggressor significantly more than they did an unfamiliar aggressor, demonstrating that these animals have the ability to recognize their previous attacker. Thus, we maintain that a variety of social defeat models, and conditioned defeat in particular, represent generalizable and ethologically valid models with which to study the effects of social stress on physiology and behavior. PMID:21945371

  6. Dorsomedial hypothalamic lesions counteract decreases in locomotor activity in male Syrian hamsters transferred from long to short day lengths.

    PubMed

    Jarjisian, Stephan G; Butler, Matthew P; Paul, Matthew J; Place, Ned J; Prendergast, Brian J; Kriegsfeld, Lance J; Zucker, Irving

    2015-02-01

    The dorsomedial nucleus (DMN) of the hypothalamus has been implicated in seasonal control of reproduction. Syrian hamsters with DMN lesions, unlike control hamsters, do not undergo testicular regression after transfer from a long day length (14 h of light per day; LD) to a short day length (8 h of light per day; SD). SDs also markedly reduce hamster locomotor activity (LMA). To assess whether the DMN is a component of the neural circuitry that mediates seasonal variation in LMA, neurologically intact males (controls) and hamsters that had sustained lesions of the DMN (DMNx) were housed in an LD or SD photoperiod for 26 weeks. DMNx that prevented testicular regression counteracted decreases in LMA during 8 to10 weeks of SD treatment; steroid-independent effects of SDs did not override high levels of LMA in DMNx males. As in previous studies, testosterone (T) restoration increased LMA in LD but not SD castrated control males. In the present study, T also failed to increase LMA in SD-DMNx hamsters. The DMN is not necessary to maintain decreased responsiveness of locomotor activity systems to T in SDs, which presumably is mediated by other central nervous system androgen target tissues. Finally, DMNx did not interfere with the spontaneous increase in LMA exhibited by photorefractory hamsters after 26 weeks of SD treatment. We propose that DMN is an essential part of the substrate that mediates seasonal decreases in LMA as day length decreases but is not required to sustain decreased SD responsiveness to T or for development of refractoriness to SDs. PMID:25512303

  7. Solution structure of Syrian hamster prion protein rPrP(90-231).

    PubMed

    Liu, H; Farr-Jones, S; Ulyanov, N B; Llinas, M; Marqusee, S; Groth, D; Cohen, F E; Prusiner, S B; James, T L

    1999-04-27

    NMR has been used to refine the structure of Syrian hamster (SHa) prion protein rPrP(90-231), which is commensurate with the infectious protease-resistant core of the scrapie prion protein PrPSc. The structure of rPrP(90-231), refolded to resemble the normal cellular isoform PrPC spectroscopically and immunologically, has been studied using multidimensional NMR; initial results were published [James et al. (1997) Proc. Natl. Acad. Sci. U.S.A. 94, 10086-10091]. We now report refinement with better definition revealing important structural and dynamic features which can be related to biological observations pertinent to prion diseases. Structure refinement was based on 2778 unambiguously assigned nuclear Overhauser effect (NOE) connectivities, 297 ambiguous NOE restraints, and 63 scalar coupling constants (3JHNHa). The structure is represented by an ensemble of 25 best-scoring structures from 100 structures calculated using ARIA/X-PLOR and further refined with restrained molecular dynamics using the AMBER 4.1 force field with an explicit shell of water molecules. The rPrP(90-231) structure features a core domain (residues 125-228), with a backbone atomic root-mean-square deviation (RMSD) of 0.67 A, consisting of three alpha-helices (residues 144-154, 172-193, and 200-227) and two short antiparallel beta-strands (residues 129-131 and 161-163). The N-terminus (residues 90-119) is largely unstructured despite some sparse and weak medium-range NOEs implying the existence of bends or turns. The transition region between the core domain and flexible N-terminus, i.e., residues 113-128, consists of hydrophobic residues or glycines and does not adopt any regular secondary structure in aqueous solution. There are about 30 medium- and long-range NOEs within this hydrophobic cluster, so it clearly manifests structure. Multiple discrete conformations are evident, implying the possible existence of one or more metastable states, which may feature in conversion of PrPC to PrPSc. To

  8. Factors other than genotype account largely for the phenotypic variation of the pulmonary valve in Syrian hamsters.

    PubMed

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

    2012-07-01

    Understanding of the aetiology of congenitally anomalous pulmonary valves remains incomplete. The aim of our study, therefore, was to elucidate the degree to which the phenotypic variation known to exist for the pulmonary valve relies on genotypic variation. Initially, we tested the hypothesis that genetically alike individuals would display similar valvar phenotypes if the phenotypic arrangement depended entirely, or almost entirely, on the genotype. Thus, we examined pulmonary valves from 982 Syrian hamsters belonging to two families subject to systematic inbreeding by crossing siblings. Their coefficient of inbreeding was 0.999 or higher, so they could be considered genetically alike. External environmental factors were standardized as much as possible. A further 97 Syrian hamsters from an outbred colony were used for comparative purposes. In both the inbred and outbred hamsters, we found valves with a purely trifoliate, or tricuspid, design, trifoliate valves with a more or less extensive fusion of the right and left leaflets, bifoliate, or bicuspid, valves with fused right and left leaflets, with or without a raphe located in the conjoined arterial sinus, and quadrifoliate, or quadricuspid, valves. The incidence of the different valvar morphological variants was similar in the outbred and inbred colonies, except for the bifoliate pulmonary valves, which were significantly more frequent in the hamsters from one of the two inbred families. Results of crosses between genetically alike hamsters revealed no significant association between the pulmonary valvar phenotypes as seen in the parents and their offspring. The incidence of bifoliate pulmonary valves, nonetheless, was higher than statistically expected in the offspring of crosses where at least one of the parents possessed a pulmonary valve with two leaflets. Our observations are consistent with the notion that the basic design of the pulmonary valve, in terms of whether it possesses three or two leaflets

  9. The influence of natural short photoperiodic and temperature conditions on plasma thyroid hormones and cholesterol in male Syrian hamsters

    NASA Astrophysics Data System (ADS)

    Vaughan, M. K.; Brainard, G. C.; Reiter, R. J.

    1984-09-01

    Adult male Syrian hamsters were subjected to 1, 3, 5, 7 or 11 weeks of either natural winter conditions or rigorously controlled laboratory conditions (LD 10∶14; 22 ± 2‡C). Although both groups of hamsters gained weight over the course of the experiment, hamsters housed indoors were significantly heavier after 5 weeks of treatment compared to their outdoors counterparts. Animals housed under natural conditions exhibited a significant decrease in circulating levels of thyroxine (T4) and a rapid rise in triiodothyronine (T3) levels; the free T4 and free T3 index (FT4I and FT3I) mirrored the changes in circulating levels of the respective hormones. Laboratory-housed animals had a slight rise in T4 and FT4I at 3 weeks followed by a slow steady decline in these values; T3 and FT3I values did not change remarkably in these animals. Plasma cholesterol declined steadily over the course of the experiment in laboratory-maintained animals but increased slightly during the first 5 weeks in animals under natural conditions. Since the photoperiodic conditions were approximately of the same duration in these 2 groups, it is concluded that the major differences in body weight, thyroid hormone values and plasma cholesterol are due to some component (possibly temperature) in the natural environment.

  10. Evaluation of apoptogenic adenovirus type 5 oncolytic vectors in a Syrian hamster head and neck cancer model.

    PubMed

    Vijayalingam, S; Kuppuswamy, M; Subramanian, T; Strebeck, F F; West, C L; Varvares, M; Chinnadurai, G

    2014-06-01

    Human adenovirus (HAdV) vectors are intensely investigated for virotherapy of a wide variety of human cancers. Here, we have evaluated the effect of two apoptogenic HAdV5 vectors in an immunocompetent Syrian hamster animal model of head and neck cancer. We established two cell lines of hamster cheek pouch squamous cell carcinomas, induced by treatment with 9,10-dimethyl-1,2-benzanthracene. These cell lines, when infected with HAdV5 mutants lp11w and lp11w/Δ55 K (which are defective in the expression of either E1B-19 K alone or both E1B-19 K and E1B-55 K proteins) exhibited enhanced apoptotic and cytotoxic responses. The cheek pouch tumor cells transplanted either subcutaneously at the flanks or in the cheek pouches of hamsters readily formed tumors. Intratumoral administration of HAdV5-E1B mutants efficiently suppressed the growth of tumors at both sites. Histological examination of orthotopic tumors revealed reduced vascularity and the expression of the viral fiber antigen in virus-administered cheek pouch tumors. These tumors also exhibited increased caspase-3 levels, suggesting that virus-induced apoptosis may contribute to tumor growth suppression. Our results suggest that the apoptogenic HAdV5 vectors may have utility for the treatment of human head and neck cancers. PMID:24874842

  11. Evaluation of apoptogenic adenovirus type 5 oncolytic vectors in a Syrian hamster head and neck cancer model

    PubMed Central

    Subramanian, T.; Strebeck, Frank F.; West, Cheri L.; Varvares, Mark; Chinnadurai, G.

    2015-01-01

    Human adenovirus (HAdV) vectors are intensely investigated for virotherapy of a wide variety of human cancers. Here, we have evaluated the effect of two apoptogenic HAdV5 vectors in an immunocompetent Syrian hamster animal model of head and neck cancer. We established two cell lines of hamster cheek pouch squamous cell carcinomas, induced by treatment with 9, 10-dimethyl-1, 2-benzanthracene (DMBA). These cell lines, when infected with HAdV5 mutants lp11w and lp11w/Δ55K (which are defective in the expression of either E1B-19K alone or both E1B-19K and E1B-55K proteins) exhibited enhanced apoptotic and cytotoxic responses. The cheek pouch tumor cells transplanted either subcutaneously at the flanks or in the cheek pouches of hamsters readily formed tumors. Intra-tumoral administration of HAdV5 E1B mutants efficiently suppressed the growth of tumors at both sites. Histological examination of orthotopic tumors revealed reduced vascularity and the expression of the viral fiber antigen in virus-administered cheek pouch tumors. These tumors also exhibited increased caspase-3 levels, suggesting virus-induced apoptosis may contribute to tumor growth suppression. Our results suggest that the apoptogenic HAdV5 vectors may have utility for the treatment of human head and neck cancers. PMID:24874842

  12. 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

  13. Morphological transformation of Syrian hamster embryo cells by low doses of fission neutrons delivered at different dose rates

    SciTech Connect

    Jones, C.A.; Sedita, B.A. ); Hill, C.K. . Cancer Research Lab.); Elkind, M.M. . Dept. of Radiology and Radiation Biology)

    1991-01-01

    Both induction of cell transformation and killing were examined with Syrian hamster embryo (SHE) fibroblasts exposed to low doses of JANUS fission-spectrum neutrons delivered at high (10.3 cGy/min) and low (0.43 and 0.086 cGy/min) dose rates. Second-passage cells were irradiated in mass cultures, then cloned over feeder cells. Morphologically transformed colonies were identified 8-10 days later. Cell killing was independent of dose rate, but the yield of transformation was greater after low-dose-rate irradiations. Decreasing the neutron dose-rate from 10.3 to 0.086 cGy/min resulted in a two- to threefold increase in the yield of transformation for neutron exposures below 50 cGy, and enhancement which was consistently observed in repetitive experiments in different radiosensitive SHE cell preparations. 43 refs., 5 figs., 1 tab.

  14. 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.

  15. The Syrian hamster embryo cells transformation assay identifies efficiently nongenotoxic carcinogens, and can contribute to alternative, integrated testing strategies.

    PubMed

    Benigni, Romualdo; Bossa, Cecilia; Tcheremenskaia, Olga; Battistelli, Chiara Laura; Giuliani, Alessandro

    2015-02-01

    The long-term carcinogenesis bioassays have played a central role in protecting human health, but for ethical and practical reasons their use is dramatically diminishing and the genotoxicity short-term tests have taken the pivotal role in the pre-screening of chemical carcinogenicity. However, this strategy cannot detect nongenotoxic carcinogens. Since up to 25% of IARC human carcinogens are recognized to have nongenotoxic mechanisms of action, the risk they pose to human health cannot be disregarded, and it is urgent to fill the gap in the tools for alternative testing. In this paper, we analyze from different perspectives the ability of Cell Transformation Assays to identify nongenotoxic carcinogens, and we conclude that the Syrian hamster embryo cells test is able to identify nongenotoxic carcinogens with 80-90% efficiency, and thus, can play an important role in integrated, alternative testing strategies. PMID:25813724

  16. Oral Probiotic Microcapsule Formulation Ameliorates Non-Alcoholic Fatty Liver Disease in Bio F1B Golden Syrian Hamsters

    PubMed Central

    Bhathena, Jasmine; Martoni, Christopher; Kulamarva, Arun; Tomaro-Duchesneau, Catherine; Malhotra, Meenakshi; Paul, Arghya; Urbanska, Aleksandra Malgorzata; Prakash, Satya

    2013-01-01

    The beneficial effect of a microencapsulated feruloyl esterase producing Lactobacillus fermentum ATCC 11976 formulation for use in non-alcoholic fatty liver disease (NAFLD) was investigated. For which Bio F1B Golden Syrian hamsters were fed a methionine deficient/choline devoid diet to induce non-alcoholic fatty liver disease. Results, for the first time, show significant clinical benefits in experimental animals. Examination of lipids show that concentrations of hepatic free cholesterol, esterified cholesterol, triglycerides and phospholipids were significantly lowered in treated animals. In addition, serum total cholesterol, triglycerides, uric acid and insulin resistance were found to decrease in treated animals. Liver histology evaluations showed reduced fat deposits. Western blot analysis shows significant differences in expression levels of key liver enzymes in treated animals. In conclusion, these findings suggest the excellent potential of using an oral probiotic formulation to ameliorate NAFLD. PMID:23554890

  17. Relative biological effectiveness of accelerated heavy ions for induction of morphological transformation in Syrian hamster embryo cells.

    PubMed

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

    1998-09-01

    Syrian hamster embryo cells were used to study the morphological transformation induced by accelerated heavy ions with different linear energy transfer (LET) ranging from 13 to 400 keV/micron. Exponentially growing cells were irradiated with 12C or 28Si ion beams generated by the Heavy Ion Medical Accelerator in Chiba (HIMAC), then inoculated to culture dishes. Morphologically altered colonies were scored as transformants. 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 X-rays first increased with LET, reached a maximum value of about 7 at 100 keV/micron, then decreased with the further increase of LET. Our findings confirmed that high LET heavy ions are much more effective than X-rays for the induction of in vitro cell transformation. PMID:9868868

  18. Effect of photoperiod on the rate of 3H-thymidine incorporation of epididymal principal cells in adult Syrian hamsters

    SciTech Connect

    Johnson, L.; Bartke, A. )

    1991-04-01

    Photoperiod-induced cycles of gonadal regression and recrudescence in the Syrian hamster were used to determine if epididymal growth in adults involves mitotic activity of principal cells. In Experiment 1, the following groups of adult hamsters were examined: induced recrudescing (5L:19D (5 hr light and 19 hr dark) for 13 wk followed by 14L:10D for at least 3 wk), spontaneous recrudescing (5L:19D for 25 wk), and active gonadal state (14:10D). In Experiment 2, adult hamsters were divided into the following groups: induced recrudescing, active, and regressed (5L:19D for 16 wk). Hamsters received subcutaneous injections of 0.5 microCi 3H-thymidine/g body weight three times/wk for 3 wk. The epididymis was fixed in a glutaraldehyde followed by osmium, embedded in Epon 812, and sectioned at 1 micron. Slides were dipped in Kodak NTB-3 emulsion, exposed for 2 or 3 months, developed, and evaluated for isotopic labeling of principal and basal cell nuclei by scoring 500 to 1,000 nuclei. In Experiment 1, the percentages of labeled principal cell nuclei for the induced recrudescing, spontaneous recrudescing, and active groups were 26 {plus minus} 2%, 23 {plus minus} 5%, and 9 {plus minus} 1%, respectively. Considering the intermittent availability of 3H-thymidine during 21 days, this represents daily recruitment of 6.3%, 5.6%, and 2.2%, respectively. In Experiment 2, the percentages of labeled principal cell nuclei for induced recrudescing, active, and regressed groups were 12 {plus minus} 4%, 3 {plus minus} 1%, and 4 {plus minus} 1%, respectively. There was no effect of photoperiod on labeling pattern of basal cells (1.5 {plus minus} 0.6%, 1.2 {plus minus} 0.1%, 0.4 {plus minus} 0.1% for the three photoperiod groups, respectively).

  19. Inhibiting intestinal NPC1L1 activity prevents diet-induced increase in biliary cholesterol in Golden Syrian hamsters.

    PubMed

    Valasek, Mark A; Repa, Joyce J; Quan, Gang; Dietschy, John M; Turley, Stephen D

    2008-10-01

    Niemann-Pick C1-like 1 (NPC1L1) facilitates the uptake of sterols into the enterocyte and is the target of the novel cholesterol absorption inhibitor, ezetimibe. These studies used the Golden Syrian hamster as a model to delineate the changes in the relative mRNA expression of NPC1L1 and other proteins that regulate sterol homeostasis in the enterocyte during and following cessation of ezetimibe treatment and also to address the clinically important question of whether the marked inhibition of cholesterol absorption alters biliary lipid composition. In hamsters fed a low-cholesterol, low-fat basal diet, the abundance of mRNA for NPC1L1 in the small intestine far exceeded that in other regions of the gastrointestinal tract, liver, and gallbladder. In the first study, female hamsters were fed the basal diet containing ezetimibe at doses up to 2.0 mg.day(-1).kg body wt(-1). At this dose, cholesterol absorption fell by 82%, fecal neutral sterol excretion increased by 5.3-fold, and hepatic and intestinal cholesterol synthesis increased more than twofold, but there were no significant changes in either fecal bile acid excretion or biliary lipid composition. The ezetimibe-induced changes in intestinal cholesterol handling were reversed when treatment was withdrawn. In a second study, male hamsters were given a diet enriched in cholesterol and safflower oil without or with ezetimibe. The lipid-rich diet raised the absolute and relative cholesterol levels in bile more than fourfold. This increase was largely prevented by ezetimibe. These data are consistent with the recent finding that ezetimibe treatment significantly reduced biliary cholesterol saturation in patients with gallstones. PMID:18718997

  20. Lifetime carcinogenesis studies of chrysotile asbestos (CAS No. 12001-29-5) in syrian golden hamsters (feed studies). Technical report series

    SciTech Connect

    Not Available

    1990-07-01

    Carcinogenesis studies of 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. 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 to 253. Starting at 6 weeks of age, male and female hamsters in the intermediate range chrysotile/DMH study were given oral doses of DMH (4 mg/kg) every other week for a total of 5 doses. There was no adverse effect on body weight gain or survival by either form of asbestos or by asbestos in combination with DMH. Under the conditions of these studies, neither short range chrysotile nor intermediate range chrysotile asbestos was carcinogenic when ingested at 1% levels in the diet by male and female Syrian golden hamsters. While there were increases in the rates of adrenal cortical adenomas in male and female hamsters exposed to intermediate range chrysotile asbestos compared with pooled control groups, these incidence rates were not different when compared with the concurrent control groups. Additionally, the biologic importance of adrenal tumors in the absence of target organ (gastrointestinal tract) neoplasia is questionable.

  1. Whole and fractionated yellow pea flours modulate insulin, glucose, oxygen consumption, and the caecal microbiome in Golden Syrian hamsters.

    PubMed

    Marinangeli, Christopher P F; Krause, Denis; Harding, Scott V; Rideout, Todd C; Zhu, Fuqin; Jones, Peter J H

    2011-12-01

    The objective was to evaluate the effects of whole and fractionated yellow peas on circulating lipids, glucose and insulin levels, energy expenditure, and body composition, as well as to assess their prebiotic actions in Golden Syrian hamsters. Forty-five hamsters consumed a hypercholesterolemic diet for 28 days, then were randomly assigned to 1 of 3 groups: control (CON), whole pea flour (WPF), and fractionated pea flour (hulls only) (FPF). WPF and FPF were incorporated into the diets, replacing 10% of the cornstarch. WPF and FPF feeding produced negligible effects on circulating cholesterol and triglyceride levels. However, both WPF (56.76 ± 9.22 pmol·L⁻¹, p = 0.002) and FPF (89.27 ± 19.82 pmol·L⁻¹, p = 0.032) reduced circulating insulin levels compared with the CON group (131.70 ± 17.70 pmol·L⁻¹). Moreover, FPF decreased (p = 0.03) circulating glucose levels (6.26 ± 0.51 mmol·L⁻¹) compared with CON (8.27 ± 0.81 mmol·L⁻¹). Energy expenditure analysis revealed that hamsters consuming WPF demonstrated a higher (p = 0.036) oxygen consumption (2.00 ± 0.31 mL O₂·g⁻¹ lean body mass) vs. the CON group (1.56 ± 0.089 mL O₂·g⁻¹ lean body mass). Analysis of caecal digesta showed that WPF produced shifts in the abundance of microbial taxa with the most predominant changes occurring within the phylum Firmicutes. Yellow peas and their constituents should be investigated as future functional food ingredients that help prevent and manage lifestyle-related diseases such as diabetes and obesity. PMID:22026418

  2. GABAA Receptor Activation in the Lateral Septum Reduces the Expression of Conditioned Defeat and Increases Aggression in Syrian Hamsters

    PubMed Central

    McDonald, Mark M.; Markham, Chris M.; Norvelle, Alisa; Albers, H. Elliot; Huhman, Kim L.

    2012-01-01

    Exposure to social stressors can cause profound changes in an individual’s physiology and behavior. In Syrian hamsters, even a single social defeat results in conditioned defeat, which includes an abolishment of territorial aggression and the emergence of high levels of submissive behavior. The purpose of the current study was to determine whether the lateral septum (LS) is a component of the putative neural circuit underlying conditioned defeat. Experiment 1 explored the possibility that plasticity in the LS is necessary for the induction of conditioned defeat. Infusions of the protein synthesis inhibitor, anisomycin, prior to defeat training, however, failed to alter conditioned defeat during testing on the following day, suggesting that synaptic plasticity in the LS is not critical for defeat-induced suppression of aggression. Experiment 2 tested whether the LS is necessary for the expression of conditioned defeat. Infusions of the GABAA agonist muscimol into the LS prior to testing significantly increased aggression and decreased submission in previously defeated animals suggesting that the LS is an important component of the neural circuit mediating the expression of both aggression and submission in conditioned defeat. Experiment 3 examined whether the effects of muscimol on aggression were dependent on prior social defeat. Non-defeated animals receiving muscmol infusions prior to testing with a non-aggressive intruder displayed significantly more aggression than did hamsters receiving control injections. Thus, these data suggest that the activation of GABAA receptors in the LS increases aggression regardless of whether or not a hamster has previously experienced social defeat. PMID:22265703

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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.

  8. 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

  9. Transplacental induction of peripheral nervous tumor in the Syrian golden hamster by N-nitroso-N-ethylurea. A new animal model for von Recklinghausen's neurofibromatosis.

    PubMed Central

    Nakamura, T.; Hara, M.; Kasuga, T.

    1989-01-01

    Multiple peripheral nervous tumors were induced in 45 of 60 (75.0%) Syrian golden hamsters by transplacental administration of N-ethyl-N-nitro-sourea. Moreover, melanomas, pheochromocytomas, and Wilms' tumors developed in six (10.0%), three (5.0%), and 13 (21.7%) animals, respectively. The histologic, immunohistochemical, and electron microscopic findings of the peripheral nervous tumors were similar to those of human neurofibroma, and their growth pattern and distribution resembled those of human von Recklinghausen's neurofibromatosis (VRNF). The occurrence of melanoma, pheochromocytoma, and proliferative foci of melanin-containing cells in neurofibroma suggests that the targets of ENU in hamsters are the neural crest-derived cells. With its high incidence of Wilms' tumor, the hamster with ENU-induced tumors is considered to be a good animal model for human neurocristopathy, including VRNF. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:2551169

  10. 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…

  11. 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

  12. 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...

  13. Epiberberine reduces serum cholesterol in diet-induced dyslipidemia Syrian golden hamsters via network pathways involving cholesterol metabolism.

    PubMed

    Zou, Zong-Yao; Hu, Yin-Ran; Ma, Hang; Feng, Min; Li, Xue-Gang; Ye, Xiao-Li

    2016-03-01

    This study aimed to evaluate the cholesterol-lowering effect of epiberberine in dyslipidemia Syrian golden hamsters induced by high fat and high cholesterol (HFHC) diet and its regulation mechanism on some key genes involved in cholesterol metabolism. Hamsters were divided into six groups: normal control group (NC), HFHC group, simvastatin (Sim) and three doses of epiberberine group. The body weight, organs weight and serum lipid levels, as well as total cholesterol (TC) and total bile acids (TBA) levels in liver and feces were determined. Furthermore, the antidyslipidemia effect of epiberberine on key genes involved in cholesterol biosynthesis, uptake, conversion and elimination such as 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), low density lipoprotein receptor (LDL receptor), 7-alpha-hydroxylase (CYP7A1) and apical sodium dependent bile acid transporter (ASBT) were investigated. The results showed that epiberberine at high dosage significantly reduced serum TC, low density lipoprotein cholesterol (LDL-c) and TBA levels by 20.2%, 22.3% and 43.8%, respectively, and increased TBA and TC levels in feces. Epiberberine inhibited HMGCR mRNA and protein expressions and slightly reduced the protein level of ASBT, as well as dramatically up-regulated mRNA and protein expressions of CYP7A1 and LDL receptor. These findings suggested that the antidyslipidemia effects of epiberberine can be achieved via inhibiting the synthesis of cholesterol, promoting the uptake and conversion of TC in liver and increasing the excretion of TC and TBA in feces. Thus, epiberberine should be considered as one of the promising natural drugs for the treatment of dyslipidemia. PMID:26593426

  14. Effects of incubation in an atmosphere of 20% CO2 in air on the Syrian hamster embryo clonal transformation assay.

    PubMed

    Przygoda, R T; Takayama, K; Traul, K A; Tummey, A

    1985-01-01

    An atmosphere containing 10% CO2 has been generally accepted as optimal for the growth of Syrian hamster embryo cells in a clonal transformation assay. Data presented in this paper show that 10% CO2 may not be the optimum environment for this assay. Using 10 or 20% (analytically measured) CO2 in air (1 atm pressure), hamster embryo cell pools were examined for clonal growth characteristics and transformability using five known carcinogens and a single noncarcinogenic compound. At 10% CO2, only 2 of 11 pools were transformed by the five carcinogens but not by the noncarcinogen. At 20% CO2, six of seven pools were transformed by the five carcinogens and not by the noncarcinogen. Further, the transformation frequencies were found to be greater in cultures incubated in an atmosphere consisting of 20% CO2 in air. The data also show that 20% CO2 increased the cloning efficiency of these cells. A comparison of the 10 and 20% CO2 data to results reported from other laboratories suggests that conflicting interlaboratory results with this assay system may be due, in part, to variations of CO2 concentrations. In some instances, the CO2 levels indicated by incubator flow meters vary considerably from analytically determined CO2 values. To prevent these CO2 discrepancies and their resultant effects on transformation and cloning efficiency, methods for monitoring the CO2 environment other than flow meters are recommended. The observation of increased cloning efficiencies and transformation rates strongly suggests that culture incubation at 20% CO2 is a preferred environment for the conduct of this assay. PMID:3936836

  15. Prolactin messenger ribonucleic acid levels, prolactin synthesis, and radioimmunoassayable prolactin during the estrous cycle in the Golden Syrian hamster

    SciTech Connect

    Massa, J.S. ); Blask, D.E. )

    1990-01-01

    The purpose of this study was to observe the molecular dynamics of pituitary prolactin (PRL) gene expression during the estrous cycle of the Golden Syrian hamster. PRL messenger ribonucleic acid (mRNA) levels, PRL synthesis were measured in the morning on each day of the cycle. We observed that all of these PRL indices declined or did not change from Day 2 to Day 3 of the cycle. From Day 3 to Day 4 however, PRL mRNA levels increased 33-38% and media {sup 3}H-PRL increased 32-42%, while there were no significant changes in pituitary {sup 3}H-PRL, or RIA-PRL in the media or pituitary. From Day 4 to Day 1 (estrus) there was reciprocal change in the levels of {sup 3}H-PRL in the pituitary vs. the media, with the former increasing 37-50% and the latter decreasing 25-32%. Pituitary RIA-PRL did also increased 45-64% from Day 4 to Day 1 while media RIA-PRL did not change. These data are consistent with the following hypothesis: On the morning of proestrus(Day 4) in the hamster, PRL mRNA levels are elevated compared to those on Day 3, signaling an increase in PRL synthesis. This newly synthesized PRL is shunted into a readily releasable pool on the morning of Day 4 (contributing to the afternoon surge of serum PRL), and into a preferentially stored pool by the morning of Day 1.

  16. In vitro comet and micronucleus assays do not predict morphological transforming effects of silica particles in Syrian Hamster Embryo cells.

    PubMed

    Darne, Christian; Coulais, Catherine; Terzetti, Francine; Fontana, Caroline; Binet, Stéphane; Gaté, Laurent; Guichard, Yves

    2016-01-15

    Crystalline silica particles and asbestos have both been classified as carcinogenic by the International Agency for Research on Cancer (IARC). However, because of the limited data available, amorphous silica was not classifiable. In vitro, the carcinogenic potential of natural crystalline and amorphous silica particles has been revealed by the Syrian Hamster Embryo (SHE) cell transformation assay. On the other hand, the genotoxic potential of those substances has not been investigated in SHE cells. And yet, genotoxicity assays are commonly used for hazard evaluation and they are often used as in vitro assays of reference to predict a possible carcinogenic potential. The main objective of this study was to compare the genotoxic potential and the carcinogenic potential of different crystalline and amorphous silica particles in SHE cells. Three silica samples of different crystallinity were used: natural amorphous silica, partially crystallized silica and quartz silica particles. Their genotoxicity were tested through the in vitro micronucleus assay and the comet assay in SHE, and their carcinogenic potential through the SHE transformation assay. In addition, silica samples were also tested with the same genotoxicity assays in V79 hamster-lung cells, a common in vitro model for particle exposure. Results obtained in the micronucleus and the comet assays show that none of the silica was capable of inducing genotoxic effects in SHE cells and only the amorphous silica induced genotoxic effects in V79 cells. However in the SHE cell transformation assays, the partially crystallized and quartz silica were able to induce morphological cell transformation. Together, these data suggest that, in vitro, the short-term genotoxic assays alone are not sufficient to predict the hazard and the carcinogenic potential of this type of particles; SHE transformation assay appears a more reliable tool for this purpose and should be included in the "in vitro battery assays" for hazard

  17. 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

  18. Pulmonary retention and tissue distribution of {sup 239}Pu nitrate in F344 rats and syrian hamsters inhaling carbon tetrachloride

    SciTech Connect

    Benson, J.M.; Barr, E.B.; Lundgren, D.L.; Nikula, K.J.

    1994-11-01

    Carbon tetrachloride (CCl{sub 4}) has been used extensively in the nuclear weapons industry, so it is possible that nuclear plant workers have been exposed to CCl{sub 4} and plutonium compounds. Potential for future exposure exists during {open_quotes}cleanup{close_quotes} operations at weapon production sites such as the Hanford, Washington, and Rocky Flats, Colorado, facilities. The current Threshold Limit Value for CCl{sub 4} is 5 ppm; however, concentrations of CCl{sub 4} occurring in the nuclear weapons facilities over the past 40-50 y are unknown and may have exceeded this value. The pilot study described in this report is designed to determine whether subchronic inhalation of CCl{sub 4} by CDF{sup register}(F-344)/CrlBR rats and Syrian golden hamsters, at concentrations expected to produce some histologic changes in liver, alters the hepatic retention and toxic effects of inhaled {sup 239}Pu nitrate {sup 239}Pu(NO{sub 3}){sub 4}.

  19. Biodistribution of an oncolytic adenovirus after intracranial injection in permissive animals: a comparative study of Syrian hamsters and cotton rats

    PubMed Central

    Sonabend, AM; Ulasov, IV; Han, Y; Rolle, CE; Nandi, S; Cao, D; Tyler, MA; Lesniak, MS

    2008-01-01

    Conditionally replicative adenoviruses (CRAds) are often evaluated in mice; however, normal and cancerous mouse tissues are poorly permissive for human CRAds. As the cotton rat (CR) is a semipermissive animal and the Syrian hamster (SH) is a fully permissive model for adenoviral replication, we compared them in a single study following intracranial (i.c.) injection of a novel glioma-targeting CRAd. Viral genomic copies were quantified by real-time PCR in brain, blood, liver and lung. The studies were corroborated by immunohistochemical, serological and immunological assays. CR had a multiple log higher susceptibility for adenoviral infection than SH. A similar amount of genomic copies of CRAd-Survivin-pk7 and human adenovirus serotype 5 (AdWT) was found in the brain of CR and in all organs from SH. In blood and lung of CR, AdWT had more genomic copies than CRAd-Survivin-pk7 in some of the time points studied. Viral antigens were confirmed in brain slices, an elevation of serum transaminases was observed in both models, and an increase in anti-adenoviral antibodies was detected in SH sera. In conclusion, CR represents a sensitive model for studying biodistribution of CRAds after i.c. delivery, allowing for the detection of differences in the replication of CRAd-Survivin-pk7 and AdWT that were not evident in SH. PMID:19011597

  20. Ability of fourteen chemical agents used in dental practice to induce chromosome aberrations in Syrian hamster embryo cells.

    PubMed

    Hikiba, Hirohito; Watanabe, Eiko; Barrett, J Carl; Tsutsui, Takeki

    2005-01-01

    To assess the genotoxicity of 14 chemical agents used in dental practice, the ability of these agents to induce chromosome aberrations was examined using Syrian hamster embryo (SHE) cells. Statistically significant increases in the frequencies of chromosome aberrations were induced in SHE cells treated with 7 of 10 chemical agents used as endodontic medicaments, that is, carbol camphor, m-cresol, eugenol, guaiacol, zinc oxide, hydrogen peroxide, and formaldehyde. The other 3 chemical agents, that is, thymol, glutaraldehyde, and iodoform, did not increase the levels of chromosome aberrations. Of the 4 chemical agents that are used as an antiseptic on the oral mucosa, chromosome aberrations were induced by iodine, but not by the other 3 antiseptics, benzalkonium chloride, benzethonium chloride, and chlorhexidine. Among the 6 chemical agents exhibiting a negative response in the assay, only thymol induced chromosome aberrations in the presence of exogenous metabolic activation. Our results indicate that chemical agents having a positive response in the present study are potentially genotoxic to mammalian cells and need to be studied further in detail. PMID:15665446

  1. Alterations in cellular differentiation, mitogenesis, cytoskeleton and growth characteristics during Syrian hamster embryo cell multistep in vitro transformation.

    PubMed

    Isfort, R J; Cody, D B; Doersen, C J; Kerckaert, G A; Leboeuf, R A

    1994-10-01

    In vitro Syrian hamster embryo (SHE) cell transformation is a neoplastic process that proceeds through several identifiable consecutive stages including in vitro morphological transformation (mt), acquisition of immortality (I+), acquisition of tumorigenicity (T+) and tumor-derived cells (I'TD). Eight transformed lineages consisting of cells at the mt, I+, T+ and I'TD stages were assayed for alterations in general markers of cell differentiation, mitogenic signaling pathways, cytoskeleton and cellular growth in 3D matrix. Alterations in cellular differentiation markers included a decrease in H19 gene expression and placental alkaline phosphatase enzymatic activity at the mt stage in all lineages examined with a complete absence of H19 gene expression and placental alkaline phosphatase enzymatic activity by the I'TD stage in a majority of transformed lineages. Changes in mitogenic signaling pathways included the production of autocrine growth factors and alterations in growth factor-induced immediate early gene expression by the I'TD stage of transformation in the majority of transformed lineages investigated. By the I'TD stage of transformation in most lineages, changes in both the cytoskeleton (including a decrease in tropomyosin-I gene expression) and the Matrigel growth characteristics of SHE cells were observed. PMID:7927892

  2. In Vivo Selection of Paromomycin and Miltefosine Resistance in Leishmania donovani and L. infantum in a Syrian Hamster Model.

    PubMed

    Hendrickx, S; Mondelaers, A; Eberhardt, E; Delputte, P; Cos, P; Maes, L

    2015-08-01

    In 2002 and 2006, respectively, miltefosine (MIL) and paromomycin (PMM) were licensed in the Indian subcontinent for treatment of visceral leishmaniasis; however, their future routine use might become jeopardized by the development of drug resistance. Although experimental selection of resistant strains in vitro has repeatedly been reported using the less relevant promastigote vector stage, the outcome of resistance selection on intracellular amastigotes was reported to be protocol and species dependent. To corroborate these in vitro findings, selection of resistance in Leishmania donovani and Leishmania infantum was achieved by successive treatment/relapse cycles in infected Syrian golden hamsters. For PMM, resistant amastigotes were already obtained within 3 treatment/relapse cycles, while their promastigotes retained full susceptibility, thereby sharing the same phenotypic characteristics as in vitro-generated PMM-resistant strains. For MIL, even five treatment/relapse cycles failed to induce significant susceptibility changes in either species, which also corresponds with the in vitro observations where selection of an MIL-resistant phenotype proved to be quite challenging. In conclusion, these results argue for cautious use of PMM in the field to avoid rapid emergence of primary resistance and highlight the need for additional research on the mechanisms and dynamics of MIL resistance selection. PMID:26014955

  3. In Vivo Selection of Paromomycin and Miltefosine Resistance in Leishmania donovani and L. infantum in a Syrian Hamster Model

    PubMed Central

    Hendrickx, S.; Mondelaers, A.; Eberhardt, E.; Delputte, P.; Cos, P.

    2015-01-01

    In 2002 and 2006, respectively, miltefosine (MIL) and paromomycin (PMM) were licensed in the Indian subcontinent for treatment of visceral leishmaniasis; however, their future routine use might become jeopardized by the development of drug resistance. Although experimental selection of resistant strains in vitro has repeatedly been reported using the less relevant promastigote vector stage, the outcome of resistance selection on intracellular amastigotes was reported to be protocol and species dependent. To corroborate these in vitro findings, selection of resistance in Leishmania donovani and Leishmania infantum was achieved by successive treatment/relapse cycles in infected Syrian golden hamsters. For PMM, resistant amastigotes were already obtained within 3 treatment/relapse cycles, while their promastigotes retained full susceptibility, thereby sharing the same phenotypic characteristics as in vitro-generated PMM-resistant strains. For MIL, even five treatment/relapse cycles failed to induce significant susceptibility changes in either species, which also corresponds with the in vitro observations where selection of an MIL-resistant phenotype proved to be quite challenging. In conclusion, these results argue for cautious use of PMM in the field to avoid rapid emergence of primary resistance and highlight the need for additional research on the mechanisms and dynamics of MIL resistance selection. PMID:26014955

  4. 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

  5. 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

  6. Evaluation with mTHPC of early squamous cell carcinomas of the cheek pouch mucosa of Golden Syrian hamsters as a model for clinical PDT of early cancers in the upper aerodigestive tract, the esophag

    NASA Astrophysics Data System (ADS)

    Glanzmann, Thomas M.; Theumann, Jean-Francois; Forrer, Martin; Braichotte, Daniel; Wagnieres, Georges A.; van den Bergh, Hubert; Andrejevic-Blant, Snezana; Savary, Jean-Francois; Monnier, Philippe

    1995-03-01

    Golden Syrian hamsters are evaluated as an animal model for light induced fluorescence (LIF) photodetection and phototherapy of early squamous cell carcinomas of the upper aerodigestive tract, the esophagus, and the traecheo-bronchial tree. Carcinomas of this type are induced on the hamster cheek pouch mucosa by the application of the carcinogen 7,12-DMBA. For phototherapeutic experiments on the animals we utilized meso-(tetrahydoxyphenyl) chlorin (mTHPC). This drug is currently in phase I and II clinical trials for ENT patients presenting superficial `early' squamous cell carcinomas. By means of LIF we measured in vivo the kinetics of the uptake and removal of mTHPC in the normal and tumoral cheek mucosa and in the skin. The photodynamic therapy (PDT) reaction of the tissue after excitation of the photosensitizer with laser light at 652 nm was studied. Both pharmacokinetics and PDT efficacy are compared between animal model and clinical results with special emphasis on selectivity between normal and tumoral mucosa. These first experiments show that this tumor model in the hamster cheek pouch seems to be suitable for testing new photosensitizers preceding their clinical application as well as for optimization of the multiple parameters of clinical PDT.

  7. Morphological transformation and effect on gap junction intercellular communication in Syrian hamster embryo cells as screening tests for carcinogens devoid of mutagenic activity.

    PubMed

    Rivedal, E; Mikalsen, S O; Sanner, T

    2000-04-01

    A large fraction of chemicals observed to cause cancer in experimental animals is devoid of mutagenic activity. It is therefore of importance to develop methods that can be used to detect and study environmental carcinogenic agents that do not interact directly with DNA. Previous studies have indicated that induction of in vitro cell transformation and inhibition of gap junction intercellular communication are endpoints that could be useful for the detection of non-genotoxic carcinogens. In the present work, 13 compounds [chlordane, Arochlor 1260, di(2-ethylhexyl)phthalate, 1,1,1-trichloro-2, 2-bis(4-chlorophenyl)ethane, limonene, sodium fluoride, ethionine, o-anisidine, benzoyl peroxide, o-vanadate, phenobarbital, 12-O-tetradecanoylphorbol 13-acetate and clofibrate] have been tested for their ability to induce morphological transformation and affect intercellular communication in Syrian hamster embryo cells. The substances were selected on the basis of being proven or suspected non-genotoxic carcinogens, and thus difficult to detect in short-term tests. The data show that nine of the 13 compounds induced morphological transformation, and seven of the 13 inhibited intercellular communication in hamster embryo cells. Taken together, 12 of the 13 substances either induced transformation or caused inhibition of communication. The data suggest that the combined use of morphological transformation and gap junction intercellular communication in Syrian hamster embryo cells may be beneficial when screening for non-genotoxic carcinogens. PMID:10793297

  8. Effect of selenium supplementation on histopathology of vitamin E deficiency in the syrian golden hamster

    SciTech Connect

    Hinton, D.E.; Banks, M.A.; Martin, W.G.

    1986-03-01

    Male hamsters (N-40) were placed on a semi-purified torula yeast diet (< 0.05 ppm Se) containing 0.1 ppm added Se (as Na/sub 2/SeO/sub 3/) at age 6-8 weeks, then assigned to either vitamin E deficient (< 1 I.U./100 g, DS) or sufficient (1.5 I.U./100 g CS) diets and pair-fed. Body weights were recorded at 3 week intervals. At 65, 92, 120 and 180 days on diet (dod) two pairs of hamsters were sacrificed by injection of 10 cc/kg Brevital sodium. Blood samples were obtained from the inferior vena cava. Organs were removed, weighted, fixed, routinely processed and stained with hematoxylin and eosin. DS began to lose weight relative to CS at 75 dod. At 92 dod DS plasma ..cap alpha..-tocopherol decreased (DS = 4.3 +/- 1.2, CS = 36.7 +/- 4.4 ..mu..g/ml, p < 0.01), while at 180 dod, RBC hemolysis did not significantly differ (DS = 19.2 +/- 11.3, CS = 3.9 +/-2.7%, p < 0.10). A previous study indicated that dietary vitamin E plus Se deficiencies resulted in depressed growth (70 dod), increased RBC hemolysis (90 dod), muscle degeneration (120 dod), hepatocellular hypertrophy (180 dod) and acinar cell atrophy of the pancreas (170 dod). At 180 dod, Se-supplemented vitamin E deficient hamsters did not display muscle degeneration, hypertrophy of the liver or atrophy of the pancreas, but did have testicular atrophy. None of the DS animals died.

  9. 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

  10. Sex differences in the photoperiodic regulation of RF-Amide related peptide (RFRP) and its receptor GPR147 in the syrian hamster.

    PubMed

    Henningsen, Jo B; Poirel, Vincent-Joseph; Mikkelsen, Jens D; Tsutsui, Kazuyoshi; Simonneaux, Valérie; Gauer, François

    2016-06-15

    RF-(Arg-Phe) related peptides (RFRP-1 and -3) are considered to play a role in the seasonal regulation of reproduction; however, the effect of the peptides depends on species and gender. This study aimed at comparing the RFRP system in male and female Syrian hamsters over long and short photoperiods to investigate the neuroanatomical basis of these differential effects. The neuroanatomical distribution of RFRP neurons and fibers, revealed using an antiserum recognizing RFRP-1 and -3, as well as GPR147 mRNA, are similar in male and female Syrian hamsters. RFRP neurons are mainly found in the medial hypothalamus, whereas RFRP projections and GPR147 mRNA are observed in the preoptic area, anteroventral-periventricular nucleus, suprachiasmatic nucleus, paraventricular nucleus, bed nucleus of the stria terminalis, ventromedial hypothalamus, habenular nucleus, and arcuate nucleus. The number of RFRP neurons is higher in females than in males, and in both sexes, the number of RFRP neurons is reduced in short photoperiods. GPR147 mRNA levels are higher in females than in males and are downregulated in short photoperiods, particularly in females. Interestingly, the number of RFRP-positive fibers in the anteroventral-periventricular nucleus is higher only in females adjusted to a short photoperiod. Our results suggest that the RFRP system, which is strongly regulated by photoperiod in both male and female Syrian hamsters, is particularly important in females, with a distinct role in the anteroventral-periventricular nucleus, possibly in the regulation of the preovulatory luteinizing hormone surge via kisspeptin neurons. PMID:26518222

  11. Natural Immunity to Ebola Virus in the Syrian Hamster Requires Antibody Responses.

    PubMed

    Prescott, Joseph; Falzarano, Darryl; Feldmann, Heinz

    2015-10-01

    Most ebolaviruses can cause severe disease in humans and other primates, with high case fatality rates during human outbreaks. Although these viruses have been studied for almost 4 decades, little is know regarding the mechanisms by which they cause disease and what is important for protection or treatment after infection. Because of the sporadic nature of the outbreaks and difficulties accessing the populations affected by ebolaviruses, little is also known about what constitutes an appropriate immune response to infection in humans that survive infection. Such knowledge would allow a targeted approach to therapies. In contrast to humans, rodents are protected from disease on infection with ebolaviruses, although adapted versions of some of the viruses are lethal in mice, hamsters and guinea pigs. Using the recently described hamster model, along with T-cell depletion strategies, we show that CD4(+) T cells are required for natural immunity to Ebola virus infection and that CD4-dependent antibody responses are required for immunity in this model. PMID:25948862

  12. Contribution of Chymase-Dependent Angiotensin II Formation to the Progression of Tubulointerstitial Fibrosis in Obstructed Kidneys in Hamsters

    PubMed Central

    Fan, Yu-Yan; Nishiyama, Akira; Fujisawa, Yoshihide; Kobori, Hiroyuki; Nakano, Daisuke; Matsuura, Junji; Hase, Naoki; Hitomi, Hirofumi; Kiyomoto, Hideyasu; Urata, Hidenori; Kohno, Masakazu

    2009-01-01

    Recent studies indicate a role of chymase in the regulation of angiotensin II (AngII) formation in cardiovascular and renal tissues. We investigated a possible contribution of chymase to AngII formation and to renal fibrosis in unilateral ureteral obstruction (UUO). Eight-week-old Syrian hamsters were subjected to UUO and treated with vehicle, the specific chymase inhibitor (CI) 4-[1-(4-methyl-benzo[b]thiophen-3-ylmethyl)-1H-benzimidazol-2-ylsulfanyl]-butyric acid (50 mg/kg, twice a day, p.o.), or the selective AT1-receptor blocker olmesartan (10 mg/kg per day, p.o,) for 14 days. UUO-induced renal interstitial fibrosis was associated with increases in renal mRNA levels of α-smooth muscle actin (SMA), type I collagen, and transforming growth factor (TGF)-β. The UUO hamsters showed markedly higher AngII contents and increased AT1-receptor mRNA level in the obstructed kidney than sham-operated ones. In contrast, angiotensin-converting enzyme (ACE) protein expression was significantly lower in UUO hamsters. In UUO hamsters, treatment with CI or olmesartan significantly decreased AngII levels in renal tissue and mRNA levels of α-SMA, type I collagen, and TGF-β and ameliorated tubulointerstitial injury. On the other hand, neither CI nor olmesartan changed systolic blood pressure, renal ACE, and AT1-receptor protein levels. These data suggest that chymase-dependent intrarenal AngII formation contributes to the pathogenesis of interstitial fibrosis in obstructed kidneys of hamsters. PMID:19721329

  13. Use of the Syrian hamster embryo cell transformation assay for carcinogenicity prediction of chemical currently being tested by the National Toxicology Program in rodent bioassays

    SciTech Connect

    Kerckaert, G.A.; LeBoeuf, R.A.; Isfort, R.J.; Brauninger, R.

    1996-10-01

    The Syrian hamster embryo (SHE) cell transformation assay was used to predict the carcinogenicity of 26 chemicals currently being tested in the rodent bioassay by the National Toxicology Program as part of its program titled {open_quotes}Strategies for Predicting Chemical Carcinogenesis in Rodents.{close_quotes} Of these 26 chemicals, 17 were found to be positive in the SHE cell transformation assay while 9 were negative. Carcinogenicity predictions were made for these chemicals, based upon the SHE cell transformation assay results. Our predictions will be compared with the rodent bioassay results as they become available. 11 refs., 2 tabs.

  14. A method of producing carcinoma in upper aerodigestive tree and esophagus of the Syrian golden hamster using wounding and instillation of N-methylnitrosourea.

    PubMed

    Estensen, Richard D; Anderson, W Robert; Galbraith, Arthur R; Hartle, Donna E; Jordan, Margaret M; Ondrey, Frank G; Wattenberg, Lee W

    2007-08-01

    Details of a method for producing carcinoma of the aerodigestive tree of the Syrian golden hamster and the use of this model to evaluate putative agents for chemoprevention of these carcinomas are described. The method produces a majority of squamous carcinomas of the trachea and glottis that follow squamous metaplasia of respiratory epithelium. In addition, seen are adenocarcinomas arising in glands of the respiratory tree. Squamous carcinomas of the digestive epithelium arise in primary squamous epithelium. These tumors of digestive epithelium have a growth pattern that differs from that of the respiratory epithelium in that they grow and invade without filling the epithelial layer with tumor cells. PMID:17684140

  15. Protection of signal processing at low temperature in baroreceptive neurons in the nucleus tractus solitarius of Syrian hamsters, a hibernating species

    PubMed Central

    Sekizawa, Shin-Ichi; Horwitz, Barbara A.; Horowitz, John M.

    2013-01-01

    We previously described synaptic currents between baroreceptor fibers and second-order neurons in the nucleus tractus solitarius (NTS) that were larger in Syrian hamsters than in rats. This suggested that although electrical activity throughout the hamster brain decreased as brain temperature declined, the greater synaptic input to its NTS would support continued operation of cardiorespiratory reflexes at low body temperatures. Here, we focused on properties that would protect these neurons against potential damage from the larger synaptic inputs, testing the hypotheses that hamster NTS neurons exhibit: 1) intrinsic N-methyl-d-aspartate receptor (NMDAR) properties that limit Ca2+ influx to a greater degree than do rat NTS neurons and 2) properties that reduce gating signals to NMDARs to a greater degree than in rat NTS neurons. Whole cell patch-clamp recordings on anatomically identified second-order NTS baroreceptive neurons showed that NMDAR-mediated synaptic currents between sensory fibers and second-order NTS neurons were larger in hamsters than in rats at 33°C and 15°C, with no difference in their permeability to Ca2+. However, at 15°C, but not at 33°C, non-NMDAR currents evoked by glutamate released from baroreceptor fibers had significantly shorter durations in hamsters than in rats. Thus, hamster NMDARs did not exhibit lower Ca2+ influx than did rats (negating hypothesis 1), but they did exhibit significant differences in non-NMDAR neuronal properties at low temperature (consistent with hypothesis 2). The latter (shorter duration of non-NMDAR currents) would likely limit NMDAR coincidence gating and may help protect hamster NTS neurons, enabling them to contribute to signal processing at low body temperatures. PMID:24068050

  16. 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

  17. A biologically based model of growth and senescence of Syrian hamster embryo (SHE) cells after exposure to arsenic.

    PubMed Central

    Liao, K H; Gustafson, D L; Fox, M H; Chubb, L S; Reardon, K F; Yang, R S

    2001-01-01

    We modified the two-stage Moolgavkar-Venzon-Knudson (MVK) model for use with Syrian hamster embryo (SHE) cell neoplastic progression. Five phenotypic stages are proposed in this model: Normal cells can either become senescent or mutate into immortal cells followed by anchorage-independent growth and tumorigenic stages. The growth of normal SHE cells was controlled by their division, death, and senescence rates, and all senescent cells were converted from normal cells. In this report, we tested the modeling of cell kinetics of the first two phenotypic stages against experimental data evaluating the effects of arsenic on SHE cells. We assessed cell division and death rates using flow cytometry and correlated cell division rates to the degree of confluence of cell cultures. The mean cell death rate was approximately equal to 1% of the average division rate. Arsenic did not induce immortalization or further mutations of SHE cells at concentrations of 2 microM and below, and chromium (3.6 microM) and lead (100 microM) had similar negative results. However, the growth of SHE cells was inhibited by 5.4 microM arsenic after a 2-day exposure, with cells becoming senescent after only 16 population doublings. In contrast, normal cells and cells exposed to lower arsenic concentrations grew normally for at least 30 population doublings. The biologically based model successfully predicted the growth of normal and arsenic-treated cells, as well as the senescence rates. Mechanisms responsible for inducing cellular senescence in SHE cells exposed to arsenic may help explain the apparent inability of arsenic to induce neoplasia in experimental animals. PMID:11748027

  18. Sex differences in motivational responses to dietary fat in Syrian hamsters.

    PubMed

    Shannonhouse, John L; Grater, Danielle M; York, Daniel; Wellman, Paul J; Morgan, Caurnel

    2015-08-01

    Women are more likely than men to exhibit motivational disorders (e.g., anhedonia and anxiety) with limited treatment options, and to overconsume high-fat "comfort foods" to improve motivational disruptions. Unfortunately, neurobiological underpinnings for sex differences in motivational disruptions and their responses to dietary fat are poorly understood. To help bridge these fundamental knowledge gaps, we assessed behavioral and neurobiological responses to dietary fat in a hamster model of female-biased motivational lability. Relative to social housing, social separation reduced hedonic drive in a new behavioral assay, the reward investigational preference (RIP) test. Fluoxetine or desipramine treatment for 21, but not 7, days improved RIP test performance. Pharmacologic specificity in this test was shown by non-responsiveness to diazepam, tracazolate, propranolol, or naltrexone. In the anxiety-related feeding/exploration conflict (AFEC) test, social separation worsened latency to eat highly palatable food under anxiogenic conditions, but not in home cages. Social separation also reduced weight gain, food intake, and adiposity while elevating energy expenditure, assessed by caloric efficiency and indirect calorimetry. Furthermore, chronic high-fat feeding improved anhedonic and anxious responses to separation, particularly in females. In the motivation-influencing nucleus accumbens, females, but not males, exhibited a separation-induced anxiety-related decrease in Creb1 mRNA levels and an anhedonia-related decrease in ΔFosb mRNA levels. Consistent with its antidepressant- and anxiolytic-like effects on behavior, high-fat feeding elevated accumbal Creb1 and ΔFosb mRNA levels in females only. Another accumbal reward marker, Tlr4 mRNA, was elevated in females by high-fat feeding. These results show that social separation of hamsters provides a novel model of sex-dependent comorbid anhedonia, anxiety, and anorexia, and implicate accumbal CREB, ΔFosB, and TLR4

  19. Sex Differences in Motivational Responses to Dietary Fat in Syrian Hamsters

    PubMed Central

    Shannonhouse, John L.; Grater, Danielle M.; York, Daniel; Wellman, Paul J.; Morgan, Caurnel

    2015-01-01

    Women are more likely than men to exhibit motivational disorders (e.g., anhedonia and anxiety) with limited treatment options, and to overconsume high-fat “comfort foods” to improve motivational disruptions. Unfortunately, neurobiological underpinnings for sex differences in motivational disruptions and their responses to dietary fat are poorly understood. To help bridge these fundamental knowledge gaps, we assessed behavioral and neurobiological responses to dietary fat in a hamster model of female-biased motivational lability. Relative to social housing, social separation reduced hedonic drive in a new behavioral assay, the reward investigational preference (RIP) test. Fluoxetine or desipramine treatment for 21, but not 7, days improved RIP test performance. Pharmacologic specificity in this test was shown by non-responsiveness to diazepam, tracazolate, propranolol, or naltrexone. In the anxiety-related feeding/exploration conflict (AFEC) test, social separation worsened latency to eat highly palatable food under anxiogenic conditions, but not in home cages. Social separation also reduced weight gain, food intake, and adiposity while elevating energy expenditure, assessed by caloric efficiency and indirect calorimetry. Furthermore, chronic high-fat feeding improved anhedonic and anxious responses to separation, particularly in females. In the motivation-influencing nucleus accumbens, females, but not males, exhibited a separation-induced anxiety-related decrease in Creb1 mRNA levels and an anhedonia-related decrease in ΔFosb mRNA levels. Consistent with its antidepressant- and anxiolytic-like effects on behavior, high-fat feeding elevated accumbal Creb1 and ΔFosb mRNA levels in females only. Another accumbal reward marker, Tlr4 mRNA, was elevated in females by high-fat feeding. These results show that social separation of hamsters provides a novel model of sex-dependent comorbid anhedonia, anxiety, and anorexia, and implicate accumbal CREB, ΔFosB, and TLR4

  20. Tumor incidence was not related to the thickness of visceral pleural in female Syrian hamsters intratracheally administered amphibole asbestos or manmade fibers

    SciTech Connect

    Adachi, Shuichi; Kawamura, K.; Takemoto, Kazuo ); Kimura, Kikuzi )

    1992-06-01

    Histological observations were performed on female Syrian hamsters 2 years after the intratracheal administration of amphibole asbestos, amosite, and crocidolite to evaluate the tumorigenicity of six types of fine manmade fibers (reported previously). A mesothelioma and a lung tumor were induced in 20 animals administered amosite, but no tumors were found in the crocidolite group. Because this incidence is not higher than that of manmade fibers, such as basic magnesium sulfate fiber (9 tumor-bearing hamsters in 20 hamsters (9/20)), metaphosphate fiber (5/20), calcium sulfate fiber (3.20), and fiberglass (2/20), it is suggested that some types of manmade fibers have a greater ability than asbestos to induce tumors. Moreover, as a specific observation in manmade fiber groups, tumors were induced at intracelial organs rather than at the pleural cavity. On the other hand, the average thickness of visceral pleura was higher in all asbestos and manmade fiber groups than in the control (2.9 {mu}m), for instance, 36.95 {mu}m in potassium titanate fiber group, 15.90 {mu}m crocidolite group, 13.00 {mu}m basic magnesium sulfate fiber group, and 10.45 {mu} in the rockwool group. Although both pleural thickening and mesotherlioma were known as peculiar lesions in asbestos-exposed people, it might also be suggested that these lesions could be induced by different mechanisms from the result that there was no relation between the pleural thickening and mesothelioma incidence in hamsters.

  1. Cycles of Transient High-Dose Cyclophosphamide Administration and Oncolytic Adenovirus Vector Intratumoral Injection for Long Term Tumor Suppression in Syrian Hamsters

    PubMed Central

    Dhar, Debanjan; Toth, Karoly; Wold, William S.M.

    2014-01-01

    Immune responses against oncolytic adenovirus (Ad) vectors are thought to limit vector anti-tumor efficacy. In Syrian hamsters, which are immunocompetent and whose tumors and normal tissues are permissive for replication of Ad5-based oncolytic Ad vectors, treating with high-dose cyclophosphamide to suppress the immune system and exert chemotherapeutic effects enhances Ad vector anti-tumor efficacy. However, long term cyclophosphamide treatment and immunosuppression can lead to anemia and vector spread to normal tissues. Here we employed three cycles of transient high-dose cyclophosphamide administration plus intratumoral injection of the oncolytic Ad vector VRX-007 followed by withdrawal from cyclophosphamide. Each cycle lasted 4-6 weeks. This protocol allowed the hamsters to remain healthy so the study could be continued for ~100 days. The tumors were very well suppressed throughout the study. With immunocompetent hamsters, the vector retarded tumor growth initially, but after 3-4 weeks the tumors resumed rapid growth and further injections of vector were ineffective. Preimmunization of the hamsters with Ad5 prevented vector spillover from the tumor to the liver yet still allowed for effective long term anti-tumor efficacy. Our results suggest that a clinical protocol might be developed with cycles of transient chemotherapy plus intratumoral vector injection to achieve significant anti-tumor efficacy while minimizing the side effects of cytostatic treatment. PMID:24722357

  2. Bioavailability of PCDDs and PCDFs of fly ash after semi-chronic oral ingestion by guinea pig and Syrian golden hamster

    SciTech Connect

    van den Bery, M.; de Vroom, E.; Olie, K.; Hutzinger, O.

    1986-01-01

    Groups of guinea pigs and syrian golden hamster were fed 2.5% HCl pre-treated fly ash from the electrostatic precipitator of a municipal incinerator during one, two, and three months, respectively, in the diet. The livers were analyzed for tetra-, penta-, and hexa-chlorinated dibenzo(p)dioxines (PCDDs) and dibenzofurans (PCDFs). In the livers of the hamsters 2,3,7,8-substituted PCDDs and PCDFs were the major isomers retained. In the livers of the guinea pigs 2,3,7,8 substituted PCDDs and PCDF congeners were retained, but also a number of otherwise substituted PCDFs. The PCDF congener which had the highest retention in the livers of guinea pigs was 1,2,3,7,8-PnCDF, 11.3% after 95 days. In the livers of the hamsters highest retention was found for 2,3,4,7,8-PnCDF, 8.4% after 95 days. For most 2,3,7,8-substituted PCDDs and PCDFs the retention in the livers of the guinea pigs and hamsters was not significantly different during the whole period, which could indicate a bioconcentration approaching a linear relationship to the administered dose. Constant relative concentrations in the livers were found for the 2,3,7,8-substituted penta- and hexa-chlorinated PCDDs and PCDF in both species during the three time periods.

  3. 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

  4. Bird-feeding ticks transstadially transmit Borrelia burgdorferi that infect Syrian hamsters.

    PubMed

    Anderson, J F; Magnarelli, L A; Stafford, K C

    1990-01-01

    Bird-feeding Ixodes dammini ticks were documented for the first time to successfully molt and transstadially pass Borrelia burgdorferi spirochetes that were indistinguishable by sodium dodecyl sulfate-polyacrylamide gel electrophoresis from the type B31 strain. Forty-six of 73 blood-engorged larvae and 50 of 66 fully-fed nymphs, removed from wild-caught birds, successfully molted. Borreliae were isolated from 21 of 78 partially- and fully-fed larvae off birds, including six specimens that molted. Spirochete-positive cultures also were obtained from 35 of 60 partially- and fully-fed nymphs that had fed from birds, including 20 nymphs that molted into adult ticks. Transstadially passed borreliae by bird-feeding larval and nymphal I. dammini were infectious to hamsters, leading us to suggest that these ticks are capable of subsequently transmitting infectious spirochetes to mammals, including humans. An isolated of B. burgdorferi, recovered from a bird-feeding larval Ixodes dentatus, was indistinguishable by sodium dodecyl sulfate-polyacrylamide gel electrophoresis from the B31 strain. This isolate, unlike another from I. dentatus off a cottontail rabbit (Sylvilagus floridanus), had a protein band with a molecular weight of approximately 31,000 that reacted with murine monoclonal antibodies H3TS and H5332 in western blot analysis. Thus, closely related borreliae are present in both I. dentatus and I. dammini. PMID:2304189

  5. [Effect of chronic social stress on lipid metabolism in golden Syrian hamsters].

    PubMed

    Zahaĭko, A L; Voronina, L M; Kaliman, P A; Strel'chenko, K V

    2008-01-01

    The changes of total lipids, lipoproteins and their fractions, free fatty acids, triacylglyceroles, free and esterified cholesterol levels and parameters of its metabolism in the blood serum and liver, glucose-6-phosphate dehydrogenase and lysosomal lipase activity in the liver, and also post-heparin lipases activity in blood of hamsters with chronic social stress are investigated. Is has been shown, that in stressed animals the prevalence in early terms of chronic stress lipolysis above lipogenesis is observed. In later terms of chronic stress the lipogenesis activation is also observed which, alongside with active lipolysis, can cause hyperlipidemia in blood. The latter phenomenon is obviously more characteristic of males, while in females the main source of fatty acids in blood is probably lipolysis in the liver. Proatherogenic redistribution of lipoprotein fractions, which was observed at chronic stress, becomes complicated by changes of their transformations processes under blood lipases action, in particular, lipases disbalance: by increasing of hepatic lipase activity without lipoprotein lipase activity increase. The increase of CETP activity in HDL, which is observed at stress, can be accompanied by atherogenic LDLB accumulation in the blood plasma. The chronic social stress is proatherogenic owing to lipid and lipoprotein metabolism changes, which lead to the shift of balance during lipids transport and their use by tissues. PMID:19140458

  6. 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

  7. 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

  8. Dopamine D2 Receptors Act Upstream of AVP in the Latero-Anterior Hypothalamus to Modulate Adolescent Anabolic/Androgenic Steroid-Induced Aggression in Syrian Hamsters

    PubMed Central

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

    2015-01-01

    In pubertal male Syrian hamsters, exposure to anabolic/androgenic steroids (AAS) during adolescence facilitates a high level of offensive aggression modulated by the enhanced development and activity of the vasopressin (AVP) and dopamine (DA) neural systems within the latero-anterior hypothalamus (LAH), i.e., a brain region implicated in the control of aggression. The present studies provide a detailed report of the pharmacologic interactions between AVP and DA D2 receptor signaling within the LAH in the control of adolescent AAS-induced offensive aggression. Male Syrian hamsters were treated with AAS throughout adolescence and tested for aggression after local infusion of the DA D2 receptor antagonist eticlopride (ETIC) alone, or in combination with AVP in the LAH in an effort to determine the influence of DA D2 receptors relative to AVP-receptor mediated aggression mechanisms. As previously shown, ETIC infusion into the LAH suppressed adolescent AAS-induced aggressive responding; however, the AAS-induced aggressive phenotype was rescued by the co-infusion of AVP into the LAH. These behavioral data indicate that interactions between AVP and DA neural systems within the LAH modulate the control of aggression following adolescent exposure to AAS and that DA D2 receptor signaling functions upstream of AVP in the LAH to control this behavioral response. PMID:25798632

  9. Syngeneic syrian hamster tumors feature tumor-infiltrating lymphocytes allowing adoptive cell therapy enhanced by oncolytic adenovirus in a replication permissive setting.

    PubMed

    Siurala, Mikko; Vähä-Koskela, Markus; Havunen, Riikka; Tähtinen, Siri; Bramante, Simona; Parviainen, Suvi; Mathis, J Michael; Kanerva, Anna; Hemminki, Akseli

    2016-05-01

    Adoptive transfer of tumor-infiltrating lymphocytes (TIL) has shown promising yet sometimes suboptimal results in clinical trials for advanced cancer, underscoring the need for approaches improving efficacy and safety. Six implantable syngeneic tumor cell lines of the Syrian hamster were used to initiate TIL cultures. TIL generated from tumor fragments cultured in human interleukin-2 (IL-2) for 10 d were adoptively transferred into tumor-bearing hamsters with concomitant intratumoral injections of oncolytic adenovirus (Ad5-D24) for the assessment of antitumor efficacy. Pancreatic cancer (HapT1) and melanoma (RPMI 1846) TIL exhibited potent and tumor-specific cytotoxicity in effector-to-target (E/T) assays. MHC Class I blocking abrogated the cell killing of RPMI 1846 TIL, indicating cytotoxic CD8(+) T-cell activity. When TIL were combined with Ad5-D24 in vitro, HapT1 tumor cell killing was significantly enhanced over single agents. In vivo, the intratumoral administration of HapT1 TIL and Ad5-D24 resulted in improved tumor growth control compared with either treatment alone. Additionally, splenocytes derived from animals treated with the combination of Ad5-D24 and TIL killed autologous tumor cells more efficiently than monotherapy-derived splenocytes, suggesting that systemic antitumor immunity was induced. For the first time, TIL of the Syrian hamster have been cultured, characterized and used therapeutically together with oncolytic adenovirus for enhancing the efficacy of TIL therapy. Our results support human translation of oncolytic adenovirus as an enabling technology for adoptive T-cell therapy of solid tumors. PMID:27467954

  10. Lack of Effects of Recombinant Human Bone Morphogenetic Protein2 on Angiogenesis in Oral Squamous Cell Carcinoma Induced in the Syrian hamster Cheek Pouch.

    PubMed

    Zaid, Khaled Waleed; Nhar, Bander Mossa; Ghadeer Alanazi, Salman Mohammed; Murad, Rashad; Domani, Ahmad; Alhafi, Awadh Jamman

    2016-01-01

    Recombinant human bone morphogenetic protein2 (rhBMP2 ), a member of the TGF? family, has been used widely in recent years to regenerate defects of the maxillary and mandible bones. Such defects are sometimes caused by resection of oral squamous cell carcinoma (OSCC) yet the biologic effects of rhBMP2 on these carcinomas are not fully clear. The objective of this study was to determine histologically whether rhBMP2 produces adverse effects on angiogenesis during induction of OSCC, a biologic process critical for tumor formation in an experimental model in the buccal pouch of golden Syrian hamsters. Buccal cavities were exposed to painting with 0.5% DMBA in liquid paraffin three times a week for 14 weeks, then biopsies were taken. Division was into 2 groups: a study group of 10 hamsters receiving 0.25?g/ml of rhBMP2 in the 3rd and 6th weeks; and a control group of 10 hamsters which did not receive any additional treatment. VEGF expression and microvessel density were measured but no differences were noted between the two groups. According to this study, rhBMP2 does not stimulate angiogenesis during induction of OCSSs. PMID:27510004

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

    PubMed Central

    Stephens, Amanda M; Sanders, Timothy H

    2015-01-01

    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, beginning when animals were 7 wk old. Plasma triacylglycerol and aortic cholesteryl ester concentrations did not significantly change during the study. Total plasma cholesterol (75.9–127.9 mg/dL), LDL- (3.2–12.2 mg/dL), and HDL- (53.8–98.9 mg/dL) cholesterols increased over the 24wk study. Aortic total cholesterol increased from 9.72 to 12.20 μg/mg protein, whereas aortic cholesteryl ester, a measure of atherosclerosis development, was less than 0.18 μg/mg protein throughout the study. The expression of hepatic endothelin 1, peroxisome proliferator-activated receptor α , and hepatic cholesterol 7-α-hydroxylase mRNA did not change throughout the study, indicating that fatty acid β-oxidation and cholesterol metabolism remained consistent. The mRNA expression of ATP-binding cassette, subfamily B member 11 increased between wk 0 and 8 but then remained unchanged, suggesting increased requirements for cholesterol in early growth. These results indicate that the consumption of a STD does not increase atherosclerotic disease risk factors in golden Syrian hamsters through 31 wk of age. PMID:26224433

  12. Long-term exposure of Syrian hamsters and Osborne-Mendel rats to aerosolized 0. 45-. mu. M mean-diameter fibrous glass

    SciTech Connect

    Smith, D.M.; Ortiz, L.W.; Archuleta, R.F.

    1982-01-01

    Male Syrian hamsters and female Osborne-Mendel rats were exposed for 24 months to one of two levels of an aerosolized fine-diameter fibrous glass (0.45-..mu..m mean diameter). The high-level exposure had a mass concentration of approx. 3 mg/m/sup 3/ (3000 fibers/cm/sup 3/) and the low-level exposure, approx. 0.3 mg/m/sup 3/ (300 fibers/cm/sup 3/). At the higher level, approximately 500 fibers/cm/sup 3/ were longer than 10 ..mu..m. After the 24-month exposure, the animals were maintained for the rest of their lives. Sham and unmanipulated cage controls were included for each species. No significant detrimental biological effects were observed in the hamsters. In fact, the exposed hamsters significantly outlived both the sham and cage controls. Several of the rats in the study are still alive. To date, no unusual changes have been observed in either pulmonary or extrapulmonary tissues of the rats.

  13. Inhibitory effect of 1α-hydroxyvitamin D3 on N-nitrosobis(2-oxopropyl)amine-induced cholangiocarcinogenesis in Syrian hamsters.

    PubMed

    Kawaura, Akihiko; Tanida, Noritoshi; Akiyama, Junichi; Nonaka, Kouji; Mizutani, Masatoshi; Sawada, Kenji; Nakagawa, Kimie; Tsugawa, Naoko; Izumi, Keisuke; Ii, Kunio; Okano, Toshio; Takeda, Eiji

    2011-06-01

    Sixty-three male 5-week-old Syrian hamsters received the carcinogen N-nitrosobis(2-oxopropyl)amine (BOP) s.c. in 5 weekly injections (the first, 70 mg/kg body, and the remaining, 20mg/kg each). The hamsters that received BOP were given intragastric administration of 0.2 ml of medium chain triglyceride (MCT) with or without 0.04 μg of 1α-hydroxyvitamin D3 [1α(OH)D3] through a feeding tube for 12 weeks. Thus, 3 groups were assigned:Group 1;BOP alone (n=20), Group 2;BOP+MCT (n=18) and Group 3;BOP+1α(OH)D3 (n=25). The mean body weight of Group 3 was lower than those of Groups 1 and 2 at the end of the experiment (p<0.001,Tukey-Kramer HSD test). At the end of week 12, all surviving hamsters were put to sleep. The incidences of liver tumors were 80%, 72% and 32% in Groups 1, 2 and 3, respectively. The incidence of tumors in Group 3 was significantly lower than in Group 1 and Group 2 (p<0.05, χ2-test). All tumors were cholangiocarcinoma. These results indicated that BOP-induced cholangiocarcinogenesis was suppressed by the supplemental administration of 1α(OH)D3. PMID:21709717

  14. Does the Precision of a Biological Clock Depend upon Its Period? Effects of the Duper and tau Mutations in Syrian Hamsters

    PubMed Central

    Bittman, Eric L.

    2012-01-01

    Mutations which alter the feedback loops that generate circadian rhythms may provide insight into their insensitivity to perturbation robustness) and their consistency of period (precision). I examined relationships between endogenous period, activity and rest (τDD, α and ρ) in Syrian hamsters using two different mutations, duper and tau, both of which speed up the circadian clock. I generated 8 strains of hamsters that are homozygous or heterozygous for the tau, duper, and wild type alleles in all combinations. The endogenous period of activity onsets among these strains ranged from 17.94+0.04 to 24.13±0.04 h. Contrary to predictions, the variability of period was unrelated to its absolute value: all strains showed similar variability of τDD when activity onsets and acrophase were used as phase markers. The τDD of activity offsets was more variable than onsets but also differed little between genotypes. Cycle variation and precision were not correlated with τDD within any strain, and only weakly correlated when all strains are considered together. Only in animals homozygous for both mutations (super duper hamsters) were cycle variation and precision reduced. Rhythm amplitude differed between strains and was positively correlated with τDD and precision. All genotypes showed negative correlations between α and ρ. This confirms the expectation that deviations in the duration of subjective day and night should offset one another in order to conserve circadian period, even though homeostatic maintenance of energy reserves predicts that longer intervals of activity or rest would be followed by longer durations of rest or activity. Females consistently showed greater variability of the period of activity onset and acrophase, and of α, but variability of the period of offset differed between sexes only in super duper hamsters. Despite the differences between genotypes in τDD, ρ was consistently more strongly correlated with the preceding than the succeeding

  15. Effect of Saw Palmetto Supplements on Androgen-Sensitive LNCaP Human Prostate Cancer Cell Number and Syrian Hamster Flank Organ Growth.

    PubMed

    Opoku-Acheampong, Alexander B; Penugonda, Kavitha; Lindshield, Brian L

    2016-01-01

    Saw palmetto supplements (SPS) are commonly consumed by men with prostate cancer. We investigated whether SPS fatty acids and phytosterols concentrations determine their growth-inhibitory action in androgen-sensitive LNCaP cells and hamster flank organs. High long-chain fatty acids-low phytosterols (HLLP) SPS ≥ 750 nM with testosterone significantly increased and ≥500 nM with dihydrotestosterone significantly decreased LNCaP cell number. High long-chain fatty acids-high phytosterols (HLHP) SPS ≥ 500 nM with dihydrotestosterone and high medium-chain fatty acids-low phytosterols (HMLP) SPS ≥ 750 nM or with androgens significantly decreased LNCaP cell number (n = 3; p < 0.05). Five- to six-week-old, castrated male Syrian hamsters were randomized to control (n = 4), HLLP, HLHP, and HMLP SPS (n = 6) groups. Testosterone or dihydrotestosterone was applied topically daily for 21 days to the right flank organ; the left flank organ was treated with ethanol and served as the control. Thirty minutes later, SPS or ethanol was applied to each flank organ in treatment and control groups, respectively. SPS treatments caused a notable but nonsignificant reduction in the difference between left and right flank organ growth in testosterone-treated SPS groups compared to the control. The same level of inhibition was not seen in dihydrotestosterone-treated SPS groups (p < 0.05). Results may suggest that SPS inhibit 5α-reductase thereby preventing hamster flank organ growth. PMID:27272436

  16. Effect of Saw Palmetto Supplements on Androgen-Sensitive LNCaP Human Prostate Cancer Cell Number and Syrian Hamster Flank Organ Growth

    PubMed Central

    Opoku-Acheampong, Alexander B.; Penugonda, Kavitha; Lindshield, Brian L.

    2016-01-01

    Saw palmetto supplements (SPS) are commonly consumed by men with prostate cancer. We investigated whether SPS fatty acids and phytosterols concentrations determine their growth-inhibitory action in androgen-sensitive LNCaP cells and hamster flank organs. High long-chain fatty acids-low phytosterols (HLLP) SPS ≥ 750 nM with testosterone significantly increased and ≥500 nM with dihydrotestosterone significantly decreased LNCaP cell number. High long-chain fatty acids-high phytosterols (HLHP) SPS ≥ 500 nM with dihydrotestosterone and high medium-chain fatty acids-low phytosterols (HMLP) SPS ≥ 750 nM or with androgens significantly decreased LNCaP cell number (n = 3; p < 0.05). Five- to six-week-old, castrated male Syrian hamsters were randomized to control (n = 4), HLLP, HLHP, and HMLP SPS (n = 6) groups. Testosterone or dihydrotestosterone was applied topically daily for 21 days to the right flank organ; the left flank organ was treated with ethanol and served as the control. Thirty minutes later, SPS or ethanol was applied to each flank organ in treatment and control groups, respectively. SPS treatments caused a notable but nonsignificant reduction in the difference between left and right flank organ growth in testosterone-treated SPS groups compared to the control. The same level of inhibition was not seen in dihydrotestosterone-treated SPS groups (p < 0.05). Results may suggest that SPS inhibit 5α-reductase thereby preventing hamster flank organ growth. PMID:27272436

  17. 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

  18. Cucumis melo ssp. Agrestis var. Agrestis Ameliorates High Fat Diet Induced Dyslipidemia in Syrian Golden Hamsters and Inhibits Adipogenesis in 3T3-L1 Adipocytes

    PubMed Central

    Shankar, Kripa; Singh, Sumit K.; Kumar, Durgesh; Varshney, Salil; Gupta, Abhishek; Rajan, Sujith; Srivastava, Ankita; Beg, Muheeb; Srivastava, Anurag Kumar; Kanojiya, Sanjeev; Mishra, Dipak K.; Gaikwad, Anil N.

    2015-01-01

    Background: Cucumis melo ssp. agrestis var. agrestis (CMA) is a wild variety of C. melo. This study aimed to explore anti-dyslipidemic and anti-adipogenic potential of CMA. Materials and Methods: For initial anti-dyslipidemic and antihyperglycemic potential of CMA fruit extract (CMFE), male Syrian golden hamsters were fed a chow or high-fat diet with or without CMFE (100 mg/kg). Further, we did fractionation of this CMFE into two fractions namely; CMA water fraction (CMWF) and CMA hexane fraction (CMHF). Phytochemical screening was done with liquid chromatography-mass spectrometry LC- (MS)/MS and direct analysis in real time-MS to detect active compounds in the fractions. Further, high-fat diet fed dyslipidemic hamsters were treated with CMWF and CMHF at 50 mg/kg for 7 days. Results: Oral administration of CMFE and both fractions (CMWF and CMHF) reduced the total cholesterol, triglycerides, low‐density lipoprotein cholesterol, and very low‐density lipoprotein-cholesterol levels in high fat diet-fed dyslipidemic hamsters. CMHF also modulated expression of genes involved in lipogenesis, lipid metabolism, and reverse cholesterol transport. Standard biochemical diagnostic tests suggested that neither of fractions causes any toxicity to hamster liver or kidneys. CMFE and CMHF also decreased oil-red-O accumulation in 3T3-L1 adipocytes. Conclusion: Based on these results, it is concluded that CMA possesses anti-dyslipidemic and anti-hyperglycemic activity along with the anti-adipogenic activity. SUMMARY The oral administration of Cucumis melo agrestis fruit extract (CMFE) and its fractions (CMWF and CMHF) improved serum lipid profile in HFD fed dyslipidemic hamsters.CMFE, CMWF and CMHF significantly attenuated body weight gain and eWAT hypertrophy.The CMHF decreased lipogenesis in both liver and adipose tissue.CMFE and CMHF also inhibited adipogenesis in 3T3-L1 adipocytes. Abbreviation used: CMA: Cucumis melo ssp. agrestis var. agrestis, CMFE: CMA fruit extract, CMWF

  19. 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

  20. CARCINOGENIC POTENTIAL OF ROTENONE: SUBCHRONIC ORAL AND PERITONEAL ADMINISTRATION TO RATS AND CHRONIC DIETARY ADMINISTRATION TO SYRIAN GOLDEN HAMSTERS

    EPA Science Inventory

    Three long-term studies were performed to evaluate the carcinogenic potential of the pesticide rotenone in hamsters and rats. Rotenone was administered orally to Wistar rats and by intraperitoneal injection to Sprague-Dawley rats, which were maintained and observed for 14 and 18 ...

  1. Enhanced morphological transformation of early passage Syrian hamster embryo cells cultured in medium with a reduced bicarbonate concentration and pH.

    PubMed

    LeBoeuf, R A; Kerchaert, G A

    1987-05-01

    Recent studies from our laboratory have demonstrated that clonal cell proliferation of early passage Syrian hamster embryo (SHE) cells is optimal at a bicarbonate concentration in the culture medium of 8.9 mM (pH 6.65-6.75) under the experimental conditions reported. The purpose of the studies reported here was to examine whether morphological transformation induced by benzo[a]pyrene (BP) was enhanced under optimal culture conditions for SHE cell proliferation. Culture media of pH 6.70, 7.11 and 7.34 under incubator conditions of 10% CO2 in air were obtained by the addition of 0.75 (8.9 mM), 2.25 (26.8 mM) and 3.75 g/l (44.6 mM) of NaHCO3 respectively to a modified formulation of Dulbecco's modified Eagles medium. The frequency of morphological transformation of SHE cells was increased at 8.9 mM bicarbonate (pH 6.70) relative to media containing 26.8 or 44.6 mM bicarbonate (pH 7.11 and 7.34 respectively). Additionally, the isolate of embryo cells and lot of fetal bovine serum used supported transformation induced by BP at 8.9 mM bicarbonate (pH 6.70), but did not with media of higher bicarbonate concentration and pH. The duration of cell culture and the no. of colonies per plate influenced the amount of increase of morphological transformation observed at 8.9 mM bicarbonate relative to media of higher bicarbonate concentration. Initial studies have shown that a fraction of morphologically transformed colonies generated at reduced bicarbonate concentration were tumorigenic in newborn hamsters. These results are discussed in terms of the potential utility of low bicarbonate concentration cultured SHE cells for transformation studies. PMID:3581427

  2. Investigation of a potential cotumorigenic effect of the dioxides of nitrogen and sulfur, and of diesel-engine exhaust, on the respiratory tract of Syrian golden hamsters

    SciTech Connect

    Heinrich, U.; Mohr, U.; Fuhst, R.; Brockmeyer, C. )

    1989-05-01

    Syrian golden hamsters (480 males and 480 females) allocated into 24 groups were exposed 19 hours per day and 5 days per week for 6, 10.5, 15, or 18 months to total diesel exhaust, diesel exhaust without particles, a mixture of nitrogen dioxide (5 parts per million (ppm)2) and sulfur dioxide (10 ppm), or clean air. Two exposure groups from each test atmosphere were also treated by a single subcutaneous injection of either 3 mg or 6 mg of diethylnitrosamine/kg of body weight to evaluate an enhancing effect of diethylnitrosamine on exposure-related changes. Morphological evaluation was done by histopathology. Minor changes of the larynx and trachea were investigated by scanning electron microscopy, which showed a loss of ciliated cells in all exhaust-exposed groups. After exposure to diesel exhaust with or without particles, focal metaplasia and dysplasia of the respiratory epithelium were seen in the oldest animals by scanning electron microscopy. In the same specimens, attached mucous droplets indicated changes in mucous cells and mucous viscosity. Only the exposure to total diesel exhaust significantly increased the tumor rate in the upper respiratory tract of male hamsters treated with 6 mg of diethylnitrosamine per kg of body weight. At the lower diethylnitrosamine dose, no exposure-related effects on the tumor rates could be observed. The results from this study and from our other inhalation experiments appear to be insufficiently conclusive to demonstrate that diesel-engine exhaust should be classified as a cocarcinogen or enhancer for the test system used.

  3. Development of an enzyme-linked-receptor assay based on Syrian hamster β2-adrenergic receptor for detection of β-agonists.

    PubMed

    Cheng, Guyue; Li, Feng; Peng, Dapeng; Huang, Lingli; Hao, Haihong; Liu, Zhenli; Wang, Yulian; Yuan, Zonghui

    2014-08-15

    β-Adrenergic agonists (β-agonists) are illegally used in animal husbandry, threatening the health of consumers. To realize multianalyte detection of β-agonists, a β2-adrenergic receptor (β2-AR) was cloned from Syrian hamster lung and heterogeneously expressed by Spodoptera frugiperda (Sf9) cells. The recombinant β2-AR was purified from intracellular soluble proteins of infected Sf9 cells, and was utilized to establish an enzyme-linked-receptor assay (ELRA) to detect a group of β-agonists simultaneously. This assay was based on direct competitive inhibition of binding of horseradish peroxidase-labeled ractopamine to the immobilized β2-AR proteins by β-agonists. The IC50 and limit of detection values for ractopamine were 30.38μgL(-1) and 5.20μgL(-1), respectively. Clenbuterol and salbutamol showed 87.7% and 58.5% cross-reactivities with ractopamine, respectively. This assay is simple, rapid, and environmentally friendly, showing a potential application in the screening of β-agonists in animal feeds. PMID:24853343

  4. X-ray structural and molecular dynamical studies of the globular domains of cow, deer, elk and Syrian hamster prion proteins.

    PubMed

    Baral, Pravas Kumar; Swayampakula, Mridula; Aguzzi, Adriano; James, Michael N G

    2015-10-01

    Misfolded prion proteins are the cause of neurodegenerative diseases that affect many mammalian species, including humans. Transmission of the prion diseases poses a considerable public-health risk as a specific prion disease such as bovine spongiform encephalopathy can be transferred to humans and other mammalian species upon contaminant exposure. The underlying mechanism of prion propagation and the species barriers that control cross species transmission has been investigated quite extensively. So far a number of prion strains have been characterized and those have been intimately linked to species-specific infectivity and other pathophysiological manifestations. These strains are encoded by a protein-only agent, and have a high degree of sequence identity across mammalian species. The molecular events that lead to strain differentiation remain elusive. In order to contribute to the understanding of strain differentiation, we have determined the crystal structures of the globular, folded domains of four prion proteins (cow, deer, elk and Syrian hamster) bound to the POM1 antibody fragment Fab. Although the overall structural folds of the mammalian prion proteins remains extremely similar, there are several local structural variations observed in the misfolding-initiator motifs. In additional molecular dynamics simulation studies on these several prion proteins reveal differences in the local fluctuations and imply that these differences have possible roles in the unfolding of the globular domains. These local variations in the structured domains perpetuate diverse patterns of prion misfolding and possibly facilitate the strain selection and adaptation. PMID:26320075

  5. Equivalency of endothelial cell growth supplement to irradiated feeder cells in carcinogen-induced morphologic transformation of Syrian hamster embryo cells

    SciTech Connect

    Evans, C.H.; DiPaolo, J.A.

    1982-01-01

    Endothelial cell growth supplement (ECGS), an extract of bovine neural tissue with growth-promoting properties for human endothelial and epithelial cells and for mouse BALB/c fibroblast-like cells, can be substituted for feeder cells in a quantitative 7-day Syrian hamster embryo cell colony in vitro model of carcinogenesis. Inclusion of 50 or 100 micrograms ECGS/ml medium throughout the 7-day growth period produced results equal to those obtained with feeder cells. The frequency and morphology of normal fibroblast colonies and carcinogen-induced morphologically transformed cell colony growth in the presence of ECGS were similar to those in the presence of feeder cells. A positive dose-response relationship in transformation by benzo(a)pyrene occurred. The frequency of transformed colonies following UV irradiation and treatment of the cells with the cocarcinogenic tumor promoter 12-O-tetradecanoylphorbol 13-acetate was greatly augmented, and lymphotoxin, a lymphokine with anticarcinogenic activity, reduced transformation. Thus ECGS can substitute for feeder cells in supporting in vitro transformation and eliminates a potential complex source of variability for studies where interaction(s) with feeder cells are a consideration. The mechanics of this model system was simplified, and its versatility for the study of physiologic, carcinogenic, and other pathophysiologic processes was broadened.

  6. The Syrian hamster embryo (SHE) cell transformation system: a biologically relevant in vitro model--with carcinogen predicting capabilities--of in vivo multistage neoplastic transformation.

    PubMed

    Isfort, R J; LeBoeuf, R A

    1995-01-01

    Neoplastic transformation is a multistep process that can be modeled in vitro using Syrian hamster embryo (SHE) cells. SHE cells multistage transformation involves several intermediate stages, including morphological transformation, immortality, acquisition of tumorigenicity, and malignant progression. Analysis of the molecular alterations that occur at each stage indicated that morphological transformation results from both carcinogen-induced irreversible chromosomal/genetic mutations and reversible genetic events, including altered DNA methylation. Morphological transformation results from a block in the cellular differentiation of progenitor and determined stem-like cells in the SHE cell population via alternation in the expression of the H19 tumor suppressor gene and other genes. Immortality results from genetic mutations in growth factor responsiveness, including loss of growth suppression by TGF beta and autocrine growth factor production, and genomic stability, resulting in genomic instability and an increased mutation rate. Acquisition of tumorigenicity involves loss of tumor suppressor gene function, altered mitogenic signal transduction, mutation of oncogenes, acquisition of anchorage independent growth, and chromosomal aberrations. Malignant progression is associated with alterations in extracellular matrix growth characteristics, alterations in cytoskeleton structure, elevated fibrinolytic activity, secretion of proteases, and changes in extracellular matrix protein secretion. Together, these changes model the alterations observed during in vivo neoplastic transformation and possibly explain why the SHE assay, as a carcinogen screening tool, is able to identify carcinogens with a 80 to 85% accuracy. PMID:9012585

  7. 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

  8. Effects of low-dose radiation on gene expression in Syrian hamster embryo cells: Comparison of JANUS neutrons and gamma rays

    SciTech Connect

    Woloschak, G.E.; Chang-Liu, C.M.

    1992-07-01

    Past work by or group and others has shown the modulation of specific genes following exposure of cells to ionizing radiation. Many classes of genes have been found to be modulated in response to ionizing radiation, including those encoding cytoskeletal elements, cell growth arresting proteins, cytokines, and cellular oncogenes. The functions of this specific modulation of gene expression are currently being investigated by several groups: it has been suggested that gene modulation in response to radiation plays a role in the cellular repair of DNA damage, cell survival, or cellular transformation. Several groups have examined induction of nuclear proto-oncogenes following exposure to DNA-damaging agents. In all experiments, we examined modulation of gene expression by ionizing radiations in Syrian hamster embryo (SHE) fibroblasts, which are normal diploid cells that can be neoplastically transformed by low doses of ionizing radiations. Cells plated in 100-mm Petri plates containing 10 ml of medium were irradiated with {sup 60}C {gamma}-rays or fission-spectrum neutrons (0.85 MeV) from the JANUS reactor. All irradiations were performed at 37{degrees}C on cycling cells; equitoxic doses of neutrons and {gamma}-rays were selected on the basis of survival data.

  9. Effects of low-dose radiation on gene expression in Syrian hamster embryo cells: Comparison of JANUS neutrons and gamma rays

    SciTech Connect

    Woloschak, G.E.; Chang-Liu, C.M.

    1992-01-01

    Past work by or group and others has shown the modulation of specific genes following exposure of cells to ionizing radiation. Many classes of genes have been found to be modulated in response to ionizing radiation, including those encoding cytoskeletal elements, cell growth arresting proteins, cytokines, and cellular oncogenes. The functions of this specific modulation of gene expression are currently being investigated by several groups: it has been suggested that gene modulation in response to radiation plays a role in the cellular repair of DNA damage, cell survival, or cellular transformation. Several groups have examined induction of nuclear proto-oncogenes following exposure to DNA-damaging agents. In all experiments, we examined modulation of gene expression by ionizing radiations in Syrian hamster embryo (SHE) fibroblasts, which are normal diploid cells that can be neoplastically transformed by low doses of ionizing radiations. Cells plated in 100-mm Petri plates containing 10 ml of medium were irradiated with {sup 60}C {gamma}-rays or fission-spectrum neutrons (0.85 MeV) from the JANUS reactor. All irradiations were performed at 37{degrees}C on cycling cells; equitoxic doses of neutrons and {gamma}-rays were selected on the basis of survival data.

  10. Modulation of in vitro transformation and the early and late modes of DNA replication of uv-irradiation Syrian hamster cells by caffeine

    SciTech Connect

    Doniger, J.; DiPaolo, J.A.

    1981-09-01

    The effect of caffeine on post-uv DNA replication was studied to determine its relevance to carcinogenesis. The level of uv-induced transformed colonies of Syrian hamster embryo cells (HEC) was increased up to fivefold when caffeine was added to cells between 0 and 6 h post-uv. The greatest increase was observed when the interval between uv irradiation and caffeine addition was 4 h. Two modes of DNA replication occurred after uv irradiation. During the early mode (0 to 3 h post-uv) the size of nascent strands, as measured by alkaline sucrose sedimentation, was smaller than those in nonirradiated cells, whereas during the late mode they recovered to normal size. Caffeine inhibited the rate of elongation of nascent strands during the early mode. When caffeine was added immediately after uv irradiation, the conversion of the early mode to the late mode was inhibited. Studies on the effects of caffeine have now been extended to the late mode. While caffeine has little effect with the fd elements beginning from the 10th day after irradiation is connected with their proliferation but not with the migration out from lymphoid organs.

  11. A mechanistic evaluation of the Syrian hamster embryo cell transformation assay (pH 6.7) and molecular events leading to senescence bypass in SHE cells.

    PubMed

    Pickles, Jessica C; Pant, Kamala; Mcginty, Lisa A; Yasaei, Hemad; Roberts, Terry; Scott, Andrew D; Newbold, Robert F

    2016-05-01

    The implementation of the Syrian hamster embryo cell transformation assay (SHE CTA) into test batteries and its relevance in predicting carcinogenicity has been long debated. Despite prevalidation studies to ensure reproducibility and minimise the subjective nature of the assay's endpoint, an underlying mechanistic and molecular basis supporting morphological transformation (MT) as an indicator of carcinogenesis is still missing. We found that only 20% of benzo(a)pyrene-induced MT clones immortalised suggesting that, alone, the MT phenotype is insufficient for senescence bypass. From a total of 12 B(a)P- immortalised MT lines, inactivating p53 mutations were identified in 30% of clones, and the majority of these were consistent with the potent carcinogen's mode of action. Expression of p16 was commonly silenced or markedly reduced with extensive promoter methylation observed in 45% of MT clones, while Bmi1 was strongly upregulated in 25% of clones. In instances where secondary events to MT appeared necessary for senescence bypass, as evidenced by a transient cellular crisis, clonal growth correlated with monoallelic deletion of the CDKN2A/B locus. The findings further implicate the importance of p16 and p53 pathways in regulating senescence while providing a molecular evaluation of SHE CTA -derived variant MT clones induced by benzo(a)pyrene. PMID:27169376

  12. 3,2'-Dimethyl-4-aminobiphenyl-DNA adduct formation in tumor target and nontarget organs of rapid and slow acetylator Syrian hamsters cogenic at the NAT2 locus.

    PubMed

    Feng, Y; Jiang, W; Deitz, A C; Hein, D W

    1996-10-01

    DNA adduct formation is an important step in initiation of the carcinogenic process. 3,2'-Dimethyl-4-aminobiphenyl (DMABP) is a well-documented multiorgan carcinogenic aromatic amine in rodents. In the present study, DMABP-DNA adduct levels were measured in rapid (Bio. 82.73/H-Pat(r)) and slow (Bio. 82.73/H-Pat(s)) acetylator Syrian hamsters congenic at the NAT2 locus following a single injection of 33 or 100 mg/kg body wt DMABP. Two DNA adducts, N-(deoxyguanosin-8-yl)-DMABP and 5-(deoxyguanosin-N2-yl)-DMABP, were identified and quantitated by 32P-postlabeling assay. After injection of 33 mg/kg, DMABP-DNA adducts were detected in urinary bladder at 6, 18, 24, and 48 hr with adduct levels increasing up to 48 hr postinjection. DMABP-DNA adducts were not detected in liver, colon, and heart. After injection of 100 mg/kg, DMABP-DNA adducts were detected in urinary bladder, liver, prostate, colon, and heart at 48 hr postinjection. DMABP-DNA adduct levels were significantly higher in urinary bladder (primary tumor target organ) than in the other organs of both rapid and slow acetylator congenic hamsters. N-(deoxyguanosin-8-yl)-DMABP levels were significantly higher in liver and prostate than in colon and heart of rapid and slow acetylator congenic hamsters, whereas 5-(deoxyguanosin-N2-yl)-DMABP levels were significantly higher in prostate than in colon and heart of rapid and slow acetylator congenic hamsters. DMABP-DNA adduct levels in each tissue examined did not differ significantly between rapid and slow acetylator hamsters following either 33 or 100 mg/kg injection. The tissue-dependent differences in DMABP-DNA adduct levels observed in the Syrian hamster differ from those reported in the rat and are consistent with previous studies that show DMABP induces primarily urinary bladder tumors in the Syrian hamster. PMID:8887447

  13. Melatonin and 6-methoxy-2-benzoxazolinone (6-MBOA) alter the response of the male Syrian hamster to natural photoperiod

    NASA Astrophysics Data System (ADS)

    Vaughan, M. K.; Little, J. C.; Powell, D. C.; Puig-Domingo, M.; Reiter, R. J.

    1988-06-01

    Adult male hamsters bearing either a blank beeswax, 6-methoxy-2-benzoxazolinone (6-MBOA), or melatonin pellet were exposed to 8 weeks (Oct. 6 Dec. 6) of natural autumn decreasing photoperiod (<11 h light) and temperature conditions (mean 10°C for last 4 weeks) or to a 14 h light/10 h dark (14L∶10D) photoperiod and controlled temperature (20°C). Melatonin but not 6-MBOA pellets partially prevented the combined effects of short photoperiod and cold temperatures on the testes and accessory organs. However, both 6-MBOA-and melatonin-treated hamsters maintained outdoors had significantly higher pituitary follicle stimulating hormone (FSH) values compared to their respective indoor-treated controls or to the animals kept outdoors and treated with a blank beeswax pellet. When one compares the various effects of 6-MBOA and melatonin (2 mg/month) on the reproductive system of the male hamster, 6-MBOA is not as effective as melatonin in altering reproductive responses to short photoperiod and cool temperatures at the dose administered.

  14. Effects of dietary palmitoleic acid on plasma lipoprotein profile and aortic cholesterol accumulation are similar to those of other unsaturated fatty acids in the F1B golden Syrian hamster.

    PubMed

    Matthan, Nirupa R; Dillard, Alice; Lecker, Jaime L; Ip, Blanche; Lichtenstein, Alice H

    2009-02-01

    The lower susceptibility of palmitoleic acid (16:1) to oxidation compared to PUFA may confer functional advantages with respect to finding acceptable alternatives to partially hydrogenated fats, but limited data are available on its effect on cardiovascular risk factors. This study investigated the effect of diets (10% fat, 0.1% cholesterol, wt:wt) enriched with macadamia [monounsaturated fatty acid (MUFA)16:1], palm (SFA,16:0), canola (MUFA,18:1), or safflower (PUFA,18:2) oils on lipoprotein profiles and aortic cholesterol accumulation in F1B Golden Syrian hamsters (n = 16/group). After 12 wk, 8 hamsters in each group were killed (phase 1). The remaining hamsters fed palm oil were changed to a diet containing coconut oil, while hamsters in the other diet groups continued on their original diets for an additional 6 wk (phase 2). With minor exceptions, the time course and dietary SFA source did not alter the study outcomes. Macadamia oil-fed hamsters had lower non-HDL cholesterol and triglyceride concentrations compared with the palm and coconut oil-fed hamsters and higher HDL-cholesterol compared with the coconut, canola, and safflower oil-fed hamsters. The aortic cholesterol concentration was not affected by dietary fat type. The hepatic cholesterol concentration was higher in the unsaturated compared with the saturated oil-fed hamsters. RBC membrane and aortic cholesteryl ester, triglyceride, and phospholipid fatty acid profiles reflected that of the dietary oil. These data suggest that an oil relatively high in palmitoleic acid does not adversely affect plasma lipoprotein profiles or aortic cholesterol accumulation and was similar to other unsaturated fatty acid-rich oils. PMID:19106316

  15. Single-Dose Replication-Defective VSV-based Nipah Virus Vaccines Provide Protection from Lethal Challenge in Syrian Hamsters

    PubMed Central

    Lo, Michael K.; Bird, Brian H.; Chattopadhyay, Anasuya; Drew, Clifton P.; Martin, Brock E.; Coleman, Joann D.; Rose, John K.; Nichol, Stuart T.; Spiropoulou, Christina F.

    2013-01-01

    Nipah virus (NiV) continues to cause outbreaks of fatal human encephalitis due to spillover from its bat reservoir. We determined that a single dose of replication-defective vesicular stomatitis virus (VSV)-based vaccine vectors expressing either the NiV fusion (F) or attachment (G) glycoproteins protected hamsters from over 1000 times LD50 NiV challenge. This highly effective single-dose protection coupled with an enhanced safety profile makes these candidates ideal for potential use in livestock and humans. PMID:24184127

  16. Low-level X-radiation effects on functional vascular changes in Syrian hamster cheek pouch epithelium during hydrocarbon carcinogenesis

    SciTech Connect

    Lurie, A.G.; Coghill, J.E.; Rippey, R.M.

    1985-07-01

    Effects of repeated low-level X radiation on functional microvascular changes in hamster cheek pouch epithelium during and following carcinogenesis by 7,12-dimethylbenz(a)anthracene (DMBA) were studied. Hamsters were treated with either radiation, DMBA, radiation + DMBA, or no treatment. Animals were sacrificed at 3-week intervals from 0 to 39 weeks after treatments began. Pouch vascular volume and permeability changes were studied by fractional distributions of radiotracers and were analyzed by a variety of statistical methods which explored the vascular parameters, treatment types, elapsed time, presence of the carcinogen, and histopathologic changes. All treatments resulted in significant changes in vascular volume with time, while only DMBA treatments alone resulted in significant changes in vascular permeability with time. As in prior studies, there were significant vascular volume differences between DMBA and DMBA + radiation groups of tumor-bearing cheek pouches. Radiation significantly affected DMBA-associated vascular volume and permeability changes during carcinogenesis. Several possible explanations for the relationship of these changes to the enhancement of DMBA carcinogenesis are discussed.

  17. Immediate post-defeat infusions of the noradrenergic receptor antagonist propranolol impair the consolidation of conditioned defeat in male Syrian hamsters.

    PubMed

    Gray, Cloe Luckett; Krebs-Kraft, Desiree L; Solomon, Matia B; Norvelle, Alisa; Parent, Marise B; Huhman, Kim L

    2015-12-01

    Social defeat occurs when an animal is attacked and subjugated by an aggressive conspecific. Following social defeat, male Syrian hamsters fail to display species-typical territorial aggression and instead exhibit submissive or defensive behaviors even when in the presence of a non-aggressive intruder. We have termed this phenomenon conditioned defeat (CD). The mechanisms underlying CD are not fully understood, but data from our lab suggest that at least some of the mechanisms are similar to those that mediate classical fear conditioning. The goal of the present experiment was to test the hypothesis that noradrenergic signaling promotes the consolidation of CD, as in classical fear conditioning, by determining whether CD is disrupted by post-training blockade of noradrenergic activity. In Experiment 1, we determined whether systemic infusions of the noradrenergic receptor antagonist propranolol (0, 1.0, 10, or 20mg/kg) given immediately after a 15 min defeat by a resident aggressor would impair CD tested 48 h later. Hamsters that were given immediate post-training infusions of propranolol (1.0, but not 10 or 20mg/kg) showed significantly less submissive behavior than did those given vehicle infusions supporting the hypothesis that there is noradrenergic modulation of the consolidation of a social defeat experience. In Experiment 2, we demonstrated that propranolol (1.0mg/kg) given immediately, but not 4 or 24h, after defeat impaired CD tested 48 h after defeat indicating that the window within which the memory for social defeat is susceptible to beta-adrenergic modulation is temporary. In Experiment 3, we examined whether central blockade of noradrenergic receptors could recapitulate the effect of systemic injections by giving an intracerebroventricular infusion of propranolol immediately after defeat and examining the effect on CD 24h later. Centrally administered propranolol (20 μg/3 μl but not 2 μg/3 μl) was also effective in dose-dependently reducing

  18. Distribution and photodynamic effect of meta-tetrahydroxyphenylchlorin (mTHPC) in the pancreas and adjacent tissues in Syrian golden hamsters

    NASA Astrophysics Data System (ADS)

    Mlkvy, Peter; Messmann, Helmut; Stewart, J. C.; Pauer, M.; Millson, Charles E.; MacRobert, Alexander J.; Bown, Stephen G.

    1995-03-01

    Experimental study has been carried out using metatetrahydroxyphenylchlorin (m-THPC) in female Syrian golden hamsters. For quantitative fluorescence study, using a CCD camera, the dose of 1.0 mg/kg bodyweight of mTHPC was given intracaval and animals were sacrificed 1 and 4 hours and 1, 2, 3, 4, 5, 6 days afterwards and specimens from the pancreas, stomach, duodenum, gallbladder, aorta and vena cava were examined. A sensitizing dose of 0.3 mg/kg and 0.1 mg/kg respectively was given for PDT, which followed after 2 and 4 days and animals were sacrificed after 1, 2, 3, 4 and 7 days. The treated areas included the pancreas, antral part of the stomach, duodenum and wedge of lesser omentum. In the treated pancreas necrosis up to 3 - 4 mm, marked ulceration in treated duodenum up to 3 - 4.5 mm and in the stomach up to 2 - 2.5 mm in diameter were observed. No macroscopic and histological signs of necrosis were seen in bile duct and major blood vessels. Sealed duodenal perforation occurred in all treated animals with 0.3 mg/kg sensitizing dose and was not observed in 0.1 mg/kg dose with protected duodenum during PDT. Using breaks during PDT (3 X 1; 3 X 3 minutes, respectively) approximately 30% increase of pancreatic necrosis has been observed. In this model, only the duodenum is at risk of irreversible damage. The risk to normal organs in this region is similar to that of photofrin and sulphonated aluminum phtalocyanine. mTHPC is a promising photosensitizer for tumors in the region of the pancreas, although care is required in the region of the duodenum.

  19. 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

  20. 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

  1. Miniaturization of cytotoxicity tests for concentration range-finding studies prior to conducting the pH 6.7 Syrian hamster embryo cell-transformation assay.

    PubMed

    Plöttner, Sabine; Käfferlein, Heiko U; Brüning, Thomas

    2013-08-15

    The Syrian hamster embryo (SHE) cell-transformation assay (SHE assay) is a promising alternative method to animal testing for the identification of potential carcinogens in vitro. Prior to conducting the SHE assay the appropriate concentration range for each test chemical must be established, with a maximum concentration causing approximately 50% cytotoxicity. Concentration range-finding is done in separate experiments, which are similar to the final SHE assay but with less replicates and more concentrations. Here we present an alternative for the cytotoxicity testing by miniaturization of the test procedure by use of 24-well plates and surpluses from feeder-cell preparations as target cells. In addition, we integrated the photometry-based neutral red (NR) assay. For validation of the assay, incubations with dimethyl sulf-oxide, p-phenylenediamine-2HCl, aniline, o-toluidine-HCl, 2,4-diaminotoluene, and 2-naphthylamine were carried out in the miniaturized approach and compared with the standard procedure in terms of calculating the relative plating efficiencies (RPEs). To directly compare both methods, concentrations that produced 50% cytotoxicity (IC50) were calculated. Excellent associations were observed between the number of colonies and NR uptake. For all test substances a concentration-dependent, concomitant decrease of NR uptake in the miniaturized approach and RPEs in the standard test was observed after a 7-day incubation. The results from both test setups showed a comparable order of magnitude and the IC50 values differed by a factor <2 (1.4-1.9), depending on the substance in question. Overall, the miniaturized approach should be considered an improved alternative for cytotoxicity testing in the SHE assay, as it saves valuable SHE cells and speeds-up the time, to obtain test results more rapidly. PMID:23830925

  2. 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

  3. Transcriptomic effects of di-(2-ethylhexyl)-phthalate in Syrian hamster embryo cells: an important role of early cytoskeleton disturbances in carcinogenesis?

    PubMed Central

    2011-01-01

    Background Di-(2-ethylhexyl)-phthalate (DEHP) is a commonly used plasticizer in polyvinylchloride (PVC) formulations and a potentially non-genotoxic carcinogen. The aim of this study was to identify genes whose level of expression is altered by DEHP by using a global wide-genome approach in Syrian hamster embryo (SHE) cells, a model similar to human cells regarding their responses to this type of carcinogen. With mRNA Differential Display (DD), we analysed the transcriptional regulation of SHE cells exposed to 0, 12.5, 25 and 50 μM of DEHP for 24 hrs, conditions which induced neoplastic transformation of these cells. A real-time quantitative polymerase chain reaction (qPCR) was used to confirm differential expression of genes identified by DD. Results Gene expression profiling showed 178 differentially-expressed fragments corresponding to 122 genes after tblastx comparisons, 79 up-regulated and 43 down-regulated. The genes of interest were involved in many biological pathways, including signal transduction, regulation of the cytoskeleton, xenobiotic metabolism, apoptosis, lipidogenesis, protein conformation, transport and cell cycle. We then focused particularly on genes involved in the regulation of the cytoskeleton, one of the processes occurring during carcinogenesis and in the early steps of neoplastic transformation. Twenty one cytoskeleton-related genes were studied by qPCR. The down-regulated genes were involved in focal adhesion or cell junction. The up-regulated genes were involved in the regulation of the actin cytoskeleton and this would suggest a role of cellular plasticity in the mechanism of chemical carcinogenesis. The gene expression changes identified in the present study were PPAR-independent. Conclusion This study identified a set of genes whose expression is altered by DEHP exposure in mammalian embryo cells. This is the first study that elucidates the genomic changes of DEHP involved in the organization of the cytoskeleton. The latter genes

  4. The induction of transformed-like morphology and enhanced growth in Syrian hamster embryo cells grown at acidic pH.

    PubMed

    LeBoeuf, R A; Kerckaert, G A

    1986-09-01

    The effect of the pH, Na+ concentration and osmolality of the culture medium on early passage Syrian hamster embryo (SHE) clonal cell proliferation was examined. The pH of the medium was adjusted from 6.49 to 7.45 by addition of different amounts of NaHCO3 to the medium and incubating the cell cultures in a fixed atmosphere of 10% CO2/90% air. Our results indicate that clonal SHE cell proliferation is optimal at pH 6.65-6.80 while plating efficiency is independent of pH between 6.65 and 7.45. Adjustment of Na+ to that concentration in the medium (3450 p.p.m., 0.15 M) of the greatest NaHCO3 addition caused a moderate depression of cell proliferation over the entire pH series. Adjusting the osmolality of the culture medium to a constant value of 338 mOsm/kg did not alter the pH effect on cell proliferation. The pH of the medium also affected cellular and colony morphology. Below pH 6.90 there was an increase in the number of colonies which exhibited a transformed-like morphology ('altered' colonies). The 'altered' phenotype was characterized by a multilayered, criss-cross pattern of growth throughout the colony. This phenotype was stable upon sub-cloning into pH 6.65 medium but was reversible if sub-cloned into pH 7.36 medium. The induction of 'altered' colonies at low pH could be partially suppressed by Na+ or osmolality adjustment. These results are discussed in terms of optimizing growth conditions for SHE cells in order to enhance their usefulness for cell transformation studies. The induction of 'altered' colonies by low pH is also discussed relative to the involvement of pH regulation in tumor-promoter and growth-factor action on cells in culture. PMID:3742717

  5. 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...

  6. Background diet and fat type alters plasma lipoprotein response but not aortic cholesterol accumulation in F1B golden syrian hamsters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dietary modification alters plasma lipoprotein profiles and atherosclerotic lesion progression in humans and some animal models. Variability in response to diet induced atherosclerosis has been reported in hamsters. Assessed was the interaction between background diet composition and dietary fat typ...

  7. Acetylator genotype-dependent formation of 2-aminofluorene-hemoglobin adducts in rapid and slow acetylator Syrian hamsters congenic at the NAT2 locus.

    PubMed

    Feng, Y; Rustan, T D; Ferguson, R J; Doll, M A; Hein, D W

    1994-01-01

    Arylamine-hemoglobin adducts are a valuable dosimeter for assessing arylamine exposures and carcinogenic risk. The effects of age, sex, time-course, dose, and acetylator genotype on levels of 2-aminofluorene-hemoglobin adducts were investigated in homozygous rapid (Bio. 82.73/H-Patr) and slow (Bio. 82.73/H-Pats) acetylator hamsters congenic at the polymorphic (NAT2) acetylator locus. Following administration of a single ip dose of [3H]2-aminofluorene, peak 2-aminofluorene-hemoglobin adduct levels were achieved at 12-18 hr and retained a plateau up to 72 hr postinjection in both rapid and slow acetylator congenic hamsters. 2-Aminofluorene-hemoglobin adduct levels did not differ significantly between young (5-6 weeks) and old (32-49 weeks) hamsters or between male and female hamsters within either acetylator genotype. 2-Aminofluorene-hemoglobin adduct levels increased in a dose-dependent manner (r = 0.95, p = 0.0001) and were consistently higher in slow versus rapid acetylator congenic hamsters in studies of both time-course and dose-effect. The magnitude of the acetylator genotype-dependent difference was a function of dose; 2-aminofluorene-hemoglobin adduct levels were 1.5-fold higher in slow acetylator congenic hamsters following a 60 mg/kg 2-aminofluorene dose (p = 0.0013) but 2-fold higher following a 100 mg/kg 2-aminofluorene dose (p < 0.0001). These results show a specific and significant role for NAT2 acetylator genotype in formation of arylamine-hemoglobin adducts, which may reflect the relationship between acetylator genotype and the incidence of different cancers from arylamine exposures. PMID:8291051

  8. Effect of vitamin E deficiency on pancreatic tumors induced by N-nitrosobis(2-oxopropyl)amine (BOP) in the syrian golden hamster

    SciTech Connect

    Banks, M.A.; Martin, W.G.; Hinton, D.E.

    1986-03-05

    Male hamsters (N=100) were injected i.p. with 40 mg/kg BOP at 8 wk, then assigned to a vitamin E deficient (< 1 I.U./100g, D) or sufficient (150 I.U./100g, C) semi-purified diet and pair-fed. To prevent interaction with Se, diets were torula yeast based (< 0.05 ppm Se). After 120 d on diet (dod), the hamsters were fed the C diet for the remainder of the trial. A previous study indicated that this dietary regimine prevented mortality due to vitamin E depletion to at least 420 dod. At 90 dod two pairs of hamsters were sacrificed to confirm E deficiency. RBC hemolysis increased in D (D=87.1 +/- 6.5%, C=43.9 +/- 4.4%, p < 0.05) and plasma ..cap alpha..-tocopherol decreased (D=22.5 +/- 3.8, C=43.9 +/- 4.7 ..mu..g/ml, p < 0.05). D hamsters lost weight relative to C from 60-185 dod only. Moribund hamsters were sacrificed. Gross examination revealed nodules in liver and pancreas of animals dying at greater than or equal to 33 wk post-injection. At 52 wk, 50% of D had died and the remaining D hamsters were sacrificed. Mortality (50%) was delayed by 8 wk in C. From 33-52 wk, D:C mortality was 1.6. This suggests that dietary vitamin E deficiency decreased the latency period for onset of tumors. Histological examination showed pancreatic tumors and associated lesions, including cystic foci, cystadenomas and adenocarcinomas.

  9. 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

  10. 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

  11. 7, 12 dimethylbenz(a)anthracene(DMBA)-induced "early" Squamous Cell carcinoma in the Golden Syrian hamster: evaluation of an animal model and comparison with "early" forms of human Squamous Cell car

    NASA Astrophysics Data System (ADS)

    Andrejevic-Blant, Snezana; Savary, Jean-Francois; Fontolliet, Charlotte; Monnier, Philippe

    1995-03-01

    To improve our knowledge on PDT of human early squamous cell carcinomas of the upper aero-digestive tract and to evaluate new photosensitizers, we have set up the Syrian hamster as an animal model. A 0.5% oily solution of DMBA was applied topically to the left buccal pouch mucosa 3 times weekly. The contralateral buccal pouch served as control. Groups of 5 animals were sacrificed at 6, 8, 10 and 12 weeks from the first applications. Tissue samples of the buccal mucosa were analyzed by histopathologic and immunohistochemical techniques and compared with preneoplastic and neoplastic changes which are seen in the human carcinogenesis of the upper aero-digestive tract. After 6 to 9 weeks from the beginning of the application, we observed different degrees of epithelial dysplasia and after 10 weeks microinvasive carcinomas. The sequence of dysplastic changes to early carcinoma was reproducible in different groups of animals, and they were closely comparable with the human forms of `early' squamous cell cancer. Hyper- and dyskeratosis were present at all stages of tumor development. We are particularly interested in (mu) -invasive tumor forms appearing 10 weeks after the first application because they are potentially amenable to photodynamic therapy.

  12. Involvement of PSMD10, CDK4, and Tumor Suppressors in Development of Intrahepatic Cholangiocarcinoma of Syrian Golden Hamsters Induced by Clonorchis sinensis and N-Nitrosodimethylamine

    PubMed Central

    Uddin, Md. Hafiz; Choi, Min-Ho; Kim, Woo Ho; Jang, Ja-June; Hong, Sung-Tae

    2015-01-01

    Background Clonorchis sinensis is a group-I bio-carcinogen for cholangiocarcinoma (CCA). Although the epidemiological evidence links clonorchiasis and CCA, the underlying molecular mechanism involved in this process is poorly understood. In the present study, we investigated expression of oncogenes and tumor suppressors, including PSMD10, CDK4, p53 and RB in C. sinensis induced hamster CCA model. Methods Different histochemical/immunohistochemical techniques were performed to detect CCA in 4 groups of hamsters: uninfected control (Ctrl.), infected with C. sinensis (Cs), ingested N-nitrosodimethylamine (NDMA), and both Cs infected and NDMA introduced (Cs+NDMA). The liver tissues from all groups were analyzed for gene/protein expressions by quantitative PCR (qPCR) and western blotting. Principal Findings CCA was observed in all hamsters of Cs+NDMA group with well, moderate, and poorly differentiated types measured in 21.8% ± 1.5%, 13.3% ± 1.3%, and 10.8% ± 1.3% of total tissue section areas respectively. All CCA differentiations progressed in a time dependent manner, starting from the 8th week of infection. CCA stroma was characterized with increased collagen type I, mucin, and proliferative cell nuclear antigen (PCNA). The qPCR analysis showed PSMD10, CDK4 and p16INK4 were over-expressed, whereas p53 was under-expressed in the Cs+NDMA group. We observed no change in RB1 at mRNA level but found significant down-regulation of RB protein. The apoptosis related genes, BAX and caspase 9 were found downregulated in the CCA tissue. Gene/protein expressions were matched well with the pathological changes of different groups except the NDMA group. Though the hamsters in the NDMA group showed no marked pathological lesions, we observed over-expression of Akt/PKB and p53 genes proposing molecular interplay in this group which might be related to the CCA initiation in this animal model. Conclusions/Significance The present findings suggest that oncogenes, PSMD10 and CDK4

  13. The RNA polymerase II of an alpha-amanitin-resistant Chinese hamster ovary cell line.

    PubMed

    Lobban, P E; Siminovitch, L; Ingles, C J

    1976-05-01

    Amal, an alpha-amanitin-resistant mutant of the Chinese hamster ovary cell line, contains an RNA polymerase activity which elutes from DEAE-Sephadex at a salt concentration characteristic of an RNA polymerase II, but which is not sensitive to alpha-amanitin at levels where the polymerase II of wild-type cells is strongly inhibited. This result suggests that Amal owes its amanitin-resistant phenotype to a mutation affecting one of its genes for RNA polymerase II. To test this hypothesis, we purified the enzyme from Amal and then compared its properties with those of the wild-type enzyme. The mutant enzyme is indeed a polymerase II, and is over 600 times less sensitive to alpha-amanitin and more thermolabile than the wild-type enzyme. PMID:954093

  14. Sex-dependent differences in the disposition of 2,4-dichlorophenoxyacetic acid in Sprague-Dawley rats, B6C3F1 mice, and Syrian hamsters.

    PubMed

    Griffin, R J; Godfrey, V B; Kim, Y C; Burka, L T

    1997-09-01

    2,4-Dichlorophenoxyacetic acid (2,4-D), a widely used broadleaf herbicide, is under investigation in a study of peroxisome proliferators. To supplement that study, male and female rats, mice, and hamsters were dosed with 14C-2,4-D orally at 5 and 200 mg/kg and tissue distributions were determined. Blood, liver, kidney, muscle, skin, fat, brain, testes, and ovaries were examined. At early time points tissues from female rats consistently contained higher amounts of radioactivity than did corresponding tissues from males (up to 9 times). By 72 hr, tissue levels were equivalent and males and females had excreted equal amounts of radioactivity. This sex difference was absent in mice. In hamsters, males had higher tissue levels than females. Taurine, glycine, and glucuronide conjugates of 2,4-D were excreted along with parent. Metabolite profiles differed between species qualitatively and quantitatively; however, differences between sexes were minimal. Plasma elimination curves were generated in male and female rats after iv and oral administration. Kinetic analysis revealed significant differences in elimination and exposure parameters consistent with a greater ability to clear 2,4-D by male rats relative to females. This suggests that at equivalent doses, female rats are exposed to higher concentrations of 2,4-D for a longer time than males and may be more susceptible to 2,4-D-induced toxicity. These sex-dependent variations in the clearance of 2,4-D in rats and hamsters may indicate a need for sex-specific models to accurately assess human health risks. PMID:9311622

  15. Subchronic inhalation of carbon tetrachloride alters the tissue retention of acutely inhaled plutonium-239 nitrate in F344 rats and syrian golden hamsters

    SciTech Connect

    Benson, J.M.; Barr, E.B.; Lundgren, D.L.

    1995-12-01

    Carbon tetrachloride (CCl{sub 4}) has been used extensively in the nuclear weapons industry, so it is likely that nuclear plant workers have been exposed to both CCl{sub 4} and plutonium compounds. Future exposures may occur during {open_quotes}cleanup{close_quotes} operations at weapons productions sites such as the Hanford, Washington, and Rocky Flats, Colorado, facilities. Inhalation of 20 and 100 ppm CCl{sub 4} by hamsters reduces uptake of {sup 239}Pu solubilized from lung, shunting the {sup 239}Pu to the skeleton.

  16. Modifying effects of 1,2-dichloropropane on N-nitrosobis(2-oxopropyl)amine-induced cholangiocarcinogenesis in male Syrian hamsters.

    PubMed

    Gi, Min; Fujioka, Masaki; Yamano, Shotaro; Shimomura, Eri; Kanki, Masayuki; Kawachi, Satoko; Tachibana, Hirokazu; Tatsumi, Kumiko; Fang, He; Ishii, Naomi; Kakehashi, Anna; Wanibuchi, Hideki

    2015-01-01

    Based on the findings of epidemiological studies in Japan that occupational exposure to 1,2-dichloropropane (1,2-DCP) was associated with increased cholangiocarcinomas, 1,2-DCP has recently been classified as being carcinogenic to humans (Group 1). However, the cholangiocarcinogenicity of 1,2-DCP has not been demonstrated experimentally, and it was negative for cholangiocarcinogenicity in rats and mice. The present study determined the effects of 1,2-DCP on N-nitrosobis(2-oxopropyl)amine (BOP)-induced cholangiocarcinogenesis in male hamsters. We found that 1,2-DCP did not enhance the development of BOP-induced atypical biliary hyperplasia and did not induce any lesions in liver bile duct when administered alone. Notably, 1,2-DCP had no effect on the proliferative activity of bile duct epithelial cells regardless of BOP-initiation. These results demonstrate that 1,2-DCP lacks promoting effects on BOP-induced cholangiocarcinogenesis and suggest the possibility that 1,2-DCP is not cholangiocarcinogenic to the hamster in the present model. In addition, 1,2-DCP also lacks promoting effects on pancreatic, lung, and renal carcinogenesis. As the occurrence of occupational cholangiocarcinomas in Japan might be attributed to exposure to multiple chemicals, the results of the present study indicate that it will be necessary to determine the cholangiocarcinogenic effects of concurrent exposure of 1,2-DCP and the other halogen solvents to which workers with cholangiocarcinomas were exposed. PMID:26354381

  17. Experimental scrapie in golden Syrian hamsters: temporal comparison of in vitro cell-fusing activity with brain infectivity and histopathological changes.

    PubMed Central

    Moreau-Dubois, M C; Brown, P; Rohwer, R G; Masters, C L; Franko, M; Gajdusek, D C

    1982-01-01

    Golden Syrain hamsters were inoculated intracerebrally with the hamster-adapted 263K strain of scrapie virus, and the evolution of in vitro cell fusing activity induced by brain suspensions was compared with brain infectivity titers and histological changes. Cell-fusing activity abruptly appeared 4 weeks after inoculation, 1 week before the earliest detectable histopathological changes, at an infectivity level of 7.6 log 50% lethal doses per g of brain. Cell-fusing activity was sustained throughout the remaining 4 weeks of the incubation period and the subsequent 1- to 3-week stage of clinical illness but did not increase with the logarithmic progression of infectivity, which reached a level of 11 log 50% lethal doses per g in the agonal stage of disease. Gliosis was most sensitively detected by a monoclonal antibody reacting with astrocyte intermediate filaments in an indirect immunofluorescence test, anticipating histological recognition of gliosis and spongiform change by 1 to 2 weeks. In vitro cell-fusing activity is thus one of the earliest known biological markers (apart from infectivity itself) of experimental scrapie infection. PMID:6809626

  18. Experimental paracoccidioidomycosis in the Syrian hamster: morphology, ultrastructure and correlation of lesions with presence of specific antigens and serum levels of antibodies.

    PubMed

    Iabuki, K; Montenegro, M R

    1979-07-16

    Male hamsters (134) received intratesticular injection of a live cerebriform culture of Paracoccidioides brasiliensis and were sacrificed from 6 hours up to 123 days onwards. Tissues from testis, lymph nodes, lungs, liver, spleen, kidneys and intestines were examined microscopically; presence of specific antigens was saught in lesions of testis, regional lymph nodes and liver by indirect immunofluorescence (IF); inoculation site lesions were studied electron microscopically and circulating specific antibodies measured by complement fixation and IF tests. Up to 24 hours inoculation site lesions showed fungi surrounded by PMNs; 48 hours latter macrophages accumulated forming loose nodules; epithelioid granulomata appeared after 5 days. Fungi, scarce in early lesions, increased in numbers up to the time when epithelioid granulomata dominated the picture; in young granulomata fungi were abundant and small; older granulomata contained rare, vacuolated fungi. Ultrastructurally the space between fungi and host-cells was larger around reproducing forms decreasing in size as the parasites grew larger and being a virtual slit around old degenerated fungi. Immunofluorescence studies revealed that fungal walls were brightly fluorescent; in early lesions macrophages surrounding fungi or free in the intersticium contained fluorescent antigenic material in the cytoplasm; similar macrophages were observed in draining lymph nodes as early as 18 hours after inoculation, and latter, in macrophage nodules and Kupffer cells in the liver; epithelioid and giant cells appear to block diffusion of antigens, since in epithelioid granulomata fluorescence was limited to fungal walls. Disseminated paracoccidioidomycosis occurred in 100% of animals after day 5 of infection. Besides specific lesions (containing fungi), antigens were identified by immunofluorescence in 'non specific' lesions in the liver (diffuse or nodular Kupffer cell hyperplasia) and in the lymph nodes (histiocytic hyperplasia

  19. Expression of secreted recombinant human insulin-like growth factor-II (IGF-II) in Chinese hamster ovary cells.

    PubMed

    Bekkari, H; Sekkat, D; Straczek, J; Hess, K; Belleville-Nabet, F; Nabet, P

    1994-07-29

    Chinese hamster ovary (CHO-KI) cells were cotransfected with a plasmid pcDNAI containing the human preproinsulin-like growth factor II cDNA linked downstream to the human cytomegalovirus promoter and with a plasmid containing the neomycin resistance gene (pMAM-neo). CHO neo+ were selected by growth in medium supplemented with G418 geneticin. After amplification, the neomycin-resistant clones were screened for IGF-II production. IGF-II produced was identified by dot blot and quantified by ELISA. The clones C24, C40 and C94 secreted IGF-II at about 350-400 ng per 10(6) cells per day. DNA analysis of C24 and C40 CHO cells by PCR demonstrated the presence of the IGF-II construct in the transfected cells, presumably integrated into the chromosomal DNA. IGF-II produced by CHO cells and purified by RP-HPLC was a mitogen for MCF-7 stimulating mitosis 2-fold. PMID:7765161

  20. Auto-inhibitory regulation of angiotensin II functionality in hamster aorta during the early phases of dyslipidemia.

    PubMed

    Pereira, Priscila Cristina; Pernomian, Larissa; Côco, Hariane; Gomes, Mayara Santos; Franco, João José; Marchi, Kátia Colombo; Hipólito, Ulisses Vilela; Uyemura, Sergio Akira; Tirapelli, Carlos Renato; de Oliveira, Ana Maria

    2016-06-15

    Emerging data point the crosstalk between dyslipidemia and renin-angiotensin system (RAS). Advanced dyslipidemia is described to induce RAS activation in the vasculature. However, the interplay between early dyslipidemia and the RAS remains unexplored. Knowing that hamsters and humans have a similar lipid profile, we investigated the effects of early and advanced dyslipidemia on angiotensin II-induced contraction. Cumulative concentration-response curves for angiotensin II (1.0pmol/l to 1.0µmol/l) were obtained in the hamster thoracic aorta. We also investigated the modulatory action of NAD(P)H oxidase on angiotensin II-induced contraction using ML171 (Nox-1 inhibitor, 0.5µmol/l) and VAS2870 (Nox-4 inhibitor, 5µmol/l). Early dyslipidemia was detected in hamsters treated with a cholesterol-rich diet for 15 days. Early dyslipidemia decreased the contraction induced by angiotensin II and the concentration of Nox-4-derived hydrogen peroxide. Advanced dyslipidemia, observed in hamsters treated with cholesterol-rich diet for 30 days, restored the contractile response induced by angiotensin II by compensatory mechanism that involves Nox-4-mediated oxidative stress. The hyporresponsiveness to angiotensin II may be an auto-inhibitory regulation of the angiotensinergic function during early dyslipidemia in an attempt to reduce the effects of the upregulation of the vascular RAS during the advanced stages of atherogenesis. The recovery of vascular angiotensin II functionality during the advanced phases of dyslipidemia is the result of the upregulation of redox-pro-inflammatory pathway that might be most likely involved in atherogenesis progression rather than in the recovery of vascular function. Taken together, our findings show the early phase of dyslipidemia may be the most favorable moment for effective atheroprotective therapeutic interventions. PMID:27063446

  1. Connections of the corticomedial amygdala in the golden hamster. II. Efferents of the ''olfactory amygdala''

    SciTech Connect

    Kevetter, G.A.; Winans, S.S.

    1981-03-20

    The anterior cortical (C1) and posterolateral cortical (C2) nuclei of the amygdala are designated the ''olfactory amygdala'' because they each receive direct projections from the main olfactory bulb. The efferents of these nuclei were traced after stereotaxic placement of 1-5 muCi tritiated proline in the corticomedial amygdala of the male golden hamsters. Following survival times of 12, 24, or 48 hours, 20 micron frozen sections of the brains were processed for light microscopic autoradiography. Efferents from C2 terminate in layers II and III of the olfactory tubercle and in layer Ib of pars ventralis and pars medialis of the anterior olfactory nucleus. Fibers from this nucleus also project to layers I and II of the infralimbic cortex and to the molecular layer of the agranular insular cortex. More posteriorly, fibers from C2 terminate in layer I of the dorsolateral entorhinal cortex, and in the endopiriform nucleus. From C1, efferent fibers travel in the stria terminalis and terminate in the precommissural bed nucleus of the stria terminalis and in the mediobasal hypothalamus. Efferents from C1 also innervate the molecular layer of C2, the amygdalo-hippocampal area, and the adjacent piriform cortex. Neurons in both C1 and C2 project to the molecular layer of the medial amygdaloid nucleus and the posteromedial cortical nucleus of the amygdala, the plexiform layer of the ventral subiculum, and the molecular layer of the lateral entorhinal cortex.

  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. 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.

  4. Effect of arousing stimuli on circulating corticosterone and the circadian rhythms of luteinizing hormone (LH) surges and locomotor activity in estradiol-treated ovariectomized (ovx+EB) Syrian hamsters.

    PubMed

    Legan, S J; Peng, X; Yun, C; Duncan, M J

    2015-06-01

    In most proestrous hamsters, novel wheel exposure phase advances activity rhythms and blocks the preovulatory LH surge, which occurs 2h earlier the next day. Because wheel immobilization does not prevent these effects we hypothesized that arousal alone blocks and phase advances the LH surge. Ovariectomized (ovx) hamsters received a jugular vein cannula and estradiol benzoate (EB) or vehicle was injected sc. The next day (Day 1), at zeitgeber time (ZT) 4-5 (ZT 12 = lights off), after obtaining a blood sample, each hamster was exposed to constant darkness (DD), and either remained in her home cage or was transferred to a new cage and exposed to a running wheel or a 2-hour arousal paradigm. Blood samples were obtained in dim red light and activity was recorded hourly until ~ZT 10-11 on Days 1 and 2. For the next 1-2 weeks, activity was monitored in DD. Plasma LH and corticosterone were assessed by RIA. Novel wheel exposure or arousal at ZT 4 greatly attenuated the Day 1 LH surge in ovx+EB hamsters, and phase advanced the Day 2 LH surge by about 2h. In proestrous hamsters, novel wheel exposure led to a prolonged (>2h) increase in corticosterone levels only when LH surges were blocked. Phase advances in activity rhythms were enhanced by estradiol and arousal. The results suggest that estradiol modulates the effectiveness of non-photic stimuli. The role of the increased activity of the hypothalamic-pituitary-adrenal axis associated with novel wheel-induced attenuation of LH surges in ovx+EB hamsters remains to be determined. PMID:25958077

  5. 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 ...

  6. 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...

  7. 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...

  8. Effect of 3-methoxybenzamide on the induction and development of hamster-pouch tumors

    SciTech Connect

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

    1987-01-01

    Data from this laboratory and others has suggested that inhibitors of poly(ADP-ribose) polymerase might be able to augment the action of chemical carcinogens. The purpose of this study was to see if one of these inhibitors, 3-methoxybenzamide (MBA), could enhance the carcinogenic effects of 7,12-dimethylbenz(a)anthracene (DMBA). Thirty-two female Syrian hamsters were divided into two equal experimental groups. The left buccal pouches of the animals in Group I were painted three times weekly, first with a solution of dimethylsulfoxide (DMSO) and then with a 0.5% solution of DMBA in mineral oil. In Group II the basic treatment was the same except that the DMSO contained MBA (2.5%). After a total of 50 treatments (16 1/2 weeks), the animals were sacrificed and autopsied. The data indicated that the hamsters in Group II had approximately twice as many tumors as the animals in Group I. The average size of the tumors in the two groups was essentially the same. Using the two-stage mechanism for tumorigenesis it would appear the MBA affected the initiating phase of DMBA-induced carcinogenesis.

  9. Treatment of nitrosamine-induced pancreatic tumors in hamsters with analogs of somatostatin and luteinizing hormone-releasing hormone

    SciTech Connect

    Paz-Bouza, J.I.; Redding, T.W.; Schally, A.V.

    1987-02-01

    Pancreatic ductal adenocarcinoma was induced in female Syrian golden hamsters by injecting N-nitrosobis(2-oxopropyl)amine (BOP) once a week at a dose of 10 mg per kg of body weight for 18 weeks. Hamsters were then treated with somatostatin analog (RC-160) or with (6-D-tryptophan)luteinizing hormone-releasing hormone ((D-Trp/sup 6/)LH-RH) delayed delivery systems. After 18 weeks of BOP administration, the hamsters were divided into three groups of 10-20 animals each. Group I consisted of untreated controls, group II was injected with RC-160, and group III was injected with (D-Trp/sub 2/)LH-RH. A striking decrease in tumor weight and volume was obtained in animals treated with (D-Trp/sup 6/)LH-RH or with the somatostatin analog RC-160. After 45 days of treatment with either analog, the survival rate was significantly higher in groups II and III (70%), as compared with the control group (35%). The studies, done by light microscopy, high-resolution microscopy, and electron microscopy, showed a decrease in the total number of cancer cells and changes in the epithelium, connective tissue, and cellular organelles in groups II and III treated with the hypothalamic analogs as compared to controls. These results in female hamsters with induced ductal pancreatic tumors confirm and extend the authors findings, obtained in male animals with transplanted tumors, that (D-Trp/sub 6/)LH-RH and somatostatin analogs inhibit the growth of pancreatic cancers.

  10. 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...

  11. 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.

  12. 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...

  13. 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...

  14. Inhaled ozone as a mutagen. II - Effect on the frequency of chromosome aberrations observed in irradiated Chinese hamsters.

    NASA Technical Reports Server (NTRS)

    Zelac, R. E.; Cromroy, H. L.; Bolch, W. E., Jr.; Dunavant, B. G.; Bevis, H. A.

    1971-01-01

    Exposure-adjusted break frequencies for chromosome aberrations produced in Chinese hamster circulating blood lymphocytes were the quantitative indicator of damage from 5 hrs of exposure to X-radiation and/or to ozone. Radiation produced 5.51 x 0.0001 breaks/cell rad for cells withdrawn 2 weeks after exposure, a reasonable value when compared with data from in vivo exposure of human lymphocytes and Chinese hamster bone marrow cells. Animals exposed to the two agents simultaneously exhibited more than 70% of the total breaks anticipated assuming the expected equal contributions to be additive. Extending to humans, at presently permitted levels, exposure to ozone would be much more detrimental than exposure to radiati*n.

  15. Antioxidative and antiatherogenic effects of flaxseed, α-tocopherol and their combination in diabetic hamsters fed with a high-fat diet

    PubMed Central

    HALIGA, RALUCA ECATERINA; MOCANU, VERONICA; BADESCU, MAGDA

    2015-01-01

    Oxidative stress has previously been shown to play a role in the pathogenesis of diabetes mellitus (DM) and its complications. In the present study, the effects of supplementation with dietary antioxidants, flaxseed and α-tocopherol were investigated in diabetic golden Syrian hamsters fed with a high-fat diet. Thirty-five golden Syrian hamsters were randomly divided into a control group (C) and four diabetic groups (DM, DM + flax, DM + E and DM + Flax + E). The hamsters received four different diets for a 20-week period, as follows: i) Groups C and DM received a high-fat diet (40% energy as fat), deficient in α-linolenic acid (ALA); ii) the DM + Flax group received a high-fat diet enriched with ground flaxseed 15 g/100 g of food, rich in ALA; iii) the DM + E group received a high-fat diet enriched with vitamin E, 40 mg α-tocopherol/100 g of food; and iv) the DM + Flax + E group received a high-fat diet enriched with flaxseed and vitamin E. The results of serum lipid and oxidative stress analysis suggested that the antiatherogenic effect of flaxseed, α-tocopherol and their combination added to a high-fat diet in diabetic hamsters was based primarily on their antioxidative role, demonstrated by decreased serum lipid peroxidation and increased liver glutathione content. Improvements of serum glucose and non-high-density lipoprotein cholesterol (HDL-C) levels were observed and may have contributed to the prevention of diabetic macroangiopathy evidenced in the histopathological examination. The antioxidant effect of flaxseed was similar to that of α-tocopherol in diabetic hamsters fed a high-fat diet and combined supplementation did not appear to bring more benefits than flaxseed alone. Moreover, the high dose of ground flaxseed alone may have a better cardioprotective effect than α-tocopherol in diabetic hamsters by reducing total cholesterol and non-HDL-C levels and increasing HDL-C levels. PMID:25574229

  16. The Syrian Movement into Upstate New York.

    ERIC Educational Resources Information Center

    McHenry, Stewart G.

    1979-01-01

    Factors associated with the chosen occupation (door to door peddling) of many Syrians account for the initial movement of Syrians into and throughout New York State in the early 1900s. Variations in Syrian population density are explained in this article. (Author/GC)

  17. 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.

  18. Hepatic Gene Expression Related to Lower Plasma Cholesterol in Hamsters Fed High Fat Diets Supplemented with Blueberry Pomace and Extract

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We analyzed plasma lipid profiles, and genes related to cholesterol and bile acid metabolism, and inflammation in livers as well as adipose tissue from Syrian Golden hamsters fed high-fat diets supplemented with blueberry (BB) pomace byproducts including 8% dried whole blueberry peels (BBPWHL), 2% d...

  19. 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.

  20. Morphologic changes in livers of hamsters treated with high doses of ursodeoxycholic acid: correlation with bile acids in bile.

    PubMed

    Mamianetti, A; Konopka, H F; Lago, N; Vescina, C; Scarlato, E; Carducci, C N

    1994-01-01

    The effects of high doses of ursodeoxycholic acid on bile acid composition and the liver morphology was examined in 60 male Syrian golden hamsters. The animals were allocated to five groups: I, control; II and IV received 0.5 g and 1 g of ursodeoxycholic acid per 100 g of standard diet respectively over 30 days and III and V received 0.5 g and 1 g of ursodeoxycholic acid per 100 g of standard diet respectively over 60 days. Bile acids were determined by high performance liquid chromatography. In all treated groups there was a significant increase in chenodeoxycholic and lithocholic acid in the bile. The mean glyco/tauro ratio was significantly higher than in the control group, reaching values > 1 for individual bile acids, except for lithocholic acid values which remained < 1. Under light microscopy, the livers of the hamsters showed damage which was dose/time related, namely portal inflammatory infiltrate, bile duct proliferation, cholestasis, fat infiltration and necrosis. Electron microscopy revealed pronounced changes starting with microvilli edema and extending to canalicular membrane destruction and necrosis. The changes observed in the relation glyco/tauro lithocholic acids, may be due to defence mechanisms to avoid hepatotoxicity. The hepatotoxicity resulting from ursodeoxycholic acid administration is presumed to be due primarily to lithocholic acid or some lithocholic acid metabolite. PMID:8058592

  1. 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.

  2. 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

  3. 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.

  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. 31 CFR 542.316 - Syria; Syrian.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Syria; Syrian. 542.316 Section 542.316... Syria; Syrian. The term Syria means the territory of Syria and any other territory or marine area, including the exclusive economic zone and continental shelf, over which the Government of Syria...

  6. 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

  7. 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

  8. Changes in cholesterol homeostasis modify the response of F1B hamsters to dietary very long chain n-3 and n-6 polyunsaturated fatty acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The plasma lipoprotein response of F1B Golden-Syrian hamsters fed diets high in very long chain (VLC) n-3 PUFA is paradoxical to that observed in humans. This anomaly is attributed, in part, to low lipoprotein lipase activity and dependent on cholesterol status. To further elucidate the mechanism(...

  9. Dietary supplementation of Chardonnay grape seed flour reduces plasma cholesterol concentration, hepatic steatosis, and abdominal fat content in high-fat diet-induced obese hamsters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mechanisms for the hypocholesterolemic and anti-obesity effects of grape seed flours derived from white and red winemaking processing were investigated. Male Golden Syrian hamsters were fed high-fat (HF) diets supplemented with 10% partially defatted grape seed flours from Chardonnay (ChrSd), Ca...

  10. Lower weight gain and hepatic lipid content in hamsters fed high fat diets supplemented with white rice protein, brown rice protein, and soy protein and their hydrolysates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The physiological effects of the hydrolysates from white rice, brown rice, and soy isolate were compared to the original protein source. White rice, brown rice, and soy protein were hydrolyzed with the food grade enzyme, alcalase2.4 L®. Male Syrian hamsters were fed high-fat diets containing eithe...