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Sample records for hamster cricetulus griseus

  1. [Susceptibility of the Chinese hamster (Cricetulus griseus) to parasitic infection (3). Experimental infection with Hymenolepis nana or Trichuris muris to the cortisone treated Chinese hamster].

    PubMed

    Kutsumi, H; Miyamoto, K; Inaoka, T

    1989-07-01

    Susceptibility of Chinese hamster (Cricetulus griseus) of Asahikawa Colony (CHA) to Hymenolepis nana or Trichuris muris infection was compared in the feces-egg examination with that of mice as the control animals. Though CHA were resistant to the infection of H. nana, they were found to become susceptible to H. nana by the treatment with cortisone. A half number of CHA was infected with H. nana and the eggs were detected from each animal only in 4 or 6 days in the periods of examination more than 40 days. Mice with or without cortisone treatment were equally susceptible to H. nana infection. In another experiment, CHA with or without cortisone treatment were completely resistant to Trichuris muris infection. Mice, as the control animals, were found to be infected with T. muris in both of cortisone-treated and non-treated groups. Results from the fecal examination, it was confirmed that T. muris were expelled naturally from the animals on the weeks of 11 to 33 after infection.

  2. Synaptonemal complex karyotyping in spermatocytes of the Chinese hamster (Cricetulus griseus). I. Morphology of the autosomal complement in spread preparations.

    PubMed

    Moses, M J

    1977-03-16

    Using the Counce-Meyer spreading technique, in over 70 spermatocytes it was possible consistently to obtain whole, flattened nuclei containing complete sets of pachytene SCs. The SCs are visible in both the phase and electron microscopes. Each SC is morphologically intact, preferentially stained, and attached to the nuclear envelope by a dense, terminal plaque. It is thus possible to trace each SC for its entire length. Also, a structure representing the kinetochore is clearly visible in each autosomal SC. Karyotypes comparable to the somatic karyotype can be constructed by arranging SCs according to length and kinetochore position. The observed regularity of SC morphology implies structural stability sufficient to withstand the stresses imposed by the procedure.--A coarse network of closely packed nuclear annuli connecting SC attachment plaques often provides end-to-end associations and may tend to immobilize SCs during processing.--Three kinds of perturbation of SC structure are encountered. Twists in the SC frequently occur, but no regular pattern or correspondence with chiasma distribution is observed. SCs occasionally hook around each other without disruption, but in two instances the unpaired axis of the X apparently was interlocked within an autosomal SC. Streching of the SC is infrequent; it is conspicous when it occurs and is usaully associated with other obvious distortions of the nucleus.--Distinctive morphologies of the X and Y chromosomes facilitate their identification inall preparations.--During zygotene, autosomal synapsis, i.e., the formation of SCs from the pairing of single axial elements, initiates at distal ends and terminates at the kinetochore region; neither initiation nor termination is synchronous among all autosomes.

  3. Limits to sustainable energy budget during lactation in the striped hamster (Cricetulus barabensis) raising litters of different size.

    PubMed

    Zhao, Zhi-Jun; Chi, Qing-Sheng; Cao, Jing

    2010-08-01

    A female animal appears to approach an upper limit to the rate of sustained energy intake/metabolic rate (SusEI/MR) during lactation. However, different species of animals may respond differently to the sustainable limit. Here, we measured energy budget during lactation in female striped hamsters raising litters of natural size (Con), and females whose litter size was manipulated during early lactation to support fewer or more pups (minus pups, MP or plus pups, PP). The striped hamsters significantly decreased their body mass and increased food intake from early to late lactation; and MP females had lower weight loss and food intake than the control and PP females. Litter size of the PP group decreased significantly over the period of lactation, and pups were weaned at a similar weight to that of the controls. MP females supported a significantly lower litter mass throughout lactation compared with the control and PP females, but during late lactation the pups from the MP group were significantly heavier. Resting metabolic rate (RMR) did not differ significantly between the three groups and the gross energy intake during peak lactation was 5.0 ×, 4.2 × and 5.0 × RMR for the control, MP and PP females, respectively. Female striped hamsters reached a plateau in food intake at around 14 g/d during peak lactation, which might signify a limit of SusEI at 5.0 × RMR. However, it was not possible to determine whether the limitation on SusEI was imposed centrally by the capacity of the gastrointestinal tract to process food, peripherally by the capacity of the mammary gland to produce milk, or by the capacity of animals to dissipate heat.

  4. Helminth Infections of Meriones persicus (Persian Jird), Mus musculus (House Mice) and Cricetulus migratorius (Grey Hamster): A Cross-Sectional Study in Meshkin-Shahr District, Northwest Iran

    PubMed Central

    ZAREI, Zabiholah; MOHEBALI, Mehdi; HEIDARI, Zahra; DAVOODI, Jaber; SHABESTARI, Afshin; MOTEVALLI HAGHI, Afsaneh; KHANALIHA, Khadijeh; KIA, Eshrat Beigom

    2016-01-01

    Background: Rodents have important role as reservoirs of different parasites. The aim of this study was to determine helminth parasites of abundant rodents in Meshkin-Shahr, Ardabil Province northwest Iran. Methods: From April 2014 to March 2015; 205 rodents including 118 Meriones persicus, 63 Mus musculus and 24 Cricetulus migratorius were collected, using live traps. All rodents were dissected and their different tissues examined for infectivity with helminth parasites. Results: Overall, 74.2% of rodents were infected with helminth parasites. The rate of infectivity in M. persicus, M. musculus and C. migratorius was 82.2%, 61.9%, 66.7%, respectively. In general, among all 205 rodents, the species and infection rates of helminthes were as follows: Nematoda: Trichuris sp. (46.8%), Capillaria hepatica (18.1%), Syphacia frederici (14.2%), Aspicularis tetraptera (3.4%), Trichuris rhombomidis (2%), Heligmosomom sp. (2%), Streptopharagus kuntzi (0.5%), Spiruridae gen. sp. (0.5%); Cestoda: Hymenolepis nana fraterna (16.6%) Hymenolepis diminuta (7.3%) tetratiridium of Mesocestoides sp. (1%), Paranoplocephala sp. (0.5%), Cysticercus fasciolaris (0.5%), Taenia endothoracicus larva (0.5%), and Acanthocephala: Moniliformis moniliformis (18.5%). Conclusions: Variable species of helminthes circulate in the rodents of the study area. Presence of several zoonotic species highlights the potential risk of infections for public health. PMID:28096855

  5. Genotoxicity Assessment of Mixed Oligomers of Chlorotrifluoroethylene using a Battery of In Vitro and In Vivo/In Vitro Assays

    DTIC Science & Technology

    1990-11-01

    locus in Chinese hamster ovary ( CHO ) cells under...is functional in the female Chinese hamster ovary ( CHO ) cells , a single-step forward mutation from HGPRT + to HGPRT- in the functional X chromosome...this study were CHO cells . The hypodiploid CHO -K1 cell line was originally derived from the ovary of a female Chinese hamster (Cricetulus griseus)

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

    PubMed

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

    2016-01-01

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

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

    PubMed

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

    2016-05-01

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

  8. Griseochelin, a novel carboxylic acid antibiotic from Streptomyces griseus.

    PubMed

    Gräfe, U; Schade, W; Roth, M; Radics, L; Incze, M; Ujszászy, K

    1984-08-01

    Griseochelin, C33H60O7, isolated from an asporogenous strain of Streptomyces griseus represents a novel carboxylic acid antibiotic. The metabolite, which is active against Gram-positive bacteria, forms water-insoluble salts with mono- and divalent cations and binds alkaline-earth metal ions specifically in 2:1 (X2M) stoichiometry. Detailed spectral (IR, MS and NMR) studies provide full characterization of its constitution featuring a carboxylic acid function, a substituted tetrahydropyran ring, an allylic OH group which are accommodated within a tetrahydroxylated-octamethyl-C25 diene backbone.

  9. STREPTOMYCIN FORMATION BY INTACT MYCELIUM OF STREPTOMYCES GRISEUS

    PubMed Central

    Nomi, Ryosaku

    1963-01-01

    Nomi, Ryosaku (Rutgers, The State University, New Brunswick, N.J.). Streptomycin formation by intact mycelium of Streptomyces griseus. J. Bacteriol. 86:1220–1230. 1963.—A study was made of streptomycin formation by intact mycelium of Streptomyces griseus 107 grown in glucose-yeast extract medium. When mycelium harvested after 24, 48, and 72 hr was compared, the earliest growth showed the highest activity in producing streptomycin from glucose. The concentration of streptomycin in the mycelium was higher in the older growth. Calcium chloride had a remarkable effect in increasing streptomycin production from the precursors in the mycelium, especially when the mycelium was grown for 48 hr or longer. The effect of calcium chloride cannot be attributed to the precipitation of an excess of inorganic phosphate in the medium. Glucose, fructose, glycerol, lactic acid, glucosamine, streptidine, and inositol stimulated streptomycin formation, whereas gluconic acid, glucuronic acid, streptamine, and strepturea did not. When 24-hr-old mycelium was suspended and shaken in 0.5% glucose solution, the antibiotic precursors necessary to produce streptomycin were found mainly in the supernatant of the culture rather than in the mycelium. The supernatant included some substance which had a weak antibiotic activity. This substance was less basic than streptomycin and was transformed to streptomycin with a remarkable increase in antibiotic activity. PMID:14086093

  10. First isolation of Leptospira interrogans from Lycalopex griseus (South American gray fox) in Argentina shows new MLVA genotype.

    PubMed

    Scialfa, Exequiel; Brihuega, Bibiana; Venzano, Agustín; Morris, Winston Eduardo; Bolpe, Jorge; Schettino, Mateo

    2013-01-01

    To identify carriers of Leptospira spp. in Argentina, wild animals were trapped in Buenos Aires Province during three nights, capturing 12 Didelphis albiventris (white-eared opossum), six Chaetophractus villosus (big hairy armadillo), five Lycalopex griseus (South American gray fox), and two Conepatus chinga (Molina's hog-nosed skunk). All were tested by microscopic agglutination test, and five (two gray foxes, two armadillos, and one skunk) were positive for Leptospira interrogans serovars Canicola and Icterohaemorrhagiae, L. borgpetersenii serovar Castellonis, and L. kirschneri serovar Grippotyphosa, at titers of 1:50 and 1:100. Kidney tissue from all animals was cultured, and one isolate of L. interrogans from a gray fox was obtained. Hamsters inoculated with the isolate died after 6 days with no macroscopic lesions at necropsy. However, histologic examination revealed glomerulonephritis, interstitial nephritis, and pneumonia. The Leptospira strain from the South American gray fox was analyzed serologically and its pathogenicity was established. Genotyping through multiple-locus variable-number tandem repeat analysis showed that the strain was a new genotype related to the L. interrogans serogroup Icterohaemorrhagiae.

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

    PubMed

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

    2015-11-01

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

  12. Deoxysugar transfer during chromomycin A3 biosynthesis in Streptomyces griseus subsp. griseus: new derivatives with antitumor activity.

    PubMed

    Menéndez, Nuria; Nur-e-Alam, Mohammad; Fischer, Carsten; Braña, Alfredo F; Salas, José A; Rohr, Jürgen; Méndez, Carmen

    2006-01-01

    Chromomycin A3 is an antitumor drug produced by Streptomyces griseus subsp. griseus. It consists of a tricyclic aglycone with two aliphatic side chains and two O-glycosidically linked saccharide chains, a disaccharide of 4-O-acetyl-D-oliose (sugar A) and 4-O-methyl-D-oliose (sugar B), and a trisaccharide of D-olivose (sugar C), D-olivose (sugar D), and 4-O-acetyl-L-chromose B (sugar E). The chromomycin gene cluster contains four glycosyltransferase genes (cmmGI, cmmGII, cmmGIII, and cmmGIV), which were independently inactivated through gene replacement, generating mutants C60GI, C10GII, C10GIII, and C10GIV. Mutants C10GIV and C10GIII produced the known compounds premithramycinone and premithramycin A1, respectively, indicating the involvement of CmmGIV and CmmGIII in the sequential transfer of sugars C and D and possibly also of sugar E of the trisaccharide chain, to the 12a position of the tetracyclic intermediate premithramycinone. Mutant C10GII produced two new tetracyclic compounds lacking the disaccharide chain at the 8 position, named prechromomycin A3 and prechromomycin A2. All three compounds accumulated by mutant C60GI were tricyclic and lacked sugar B of the disaccharide chain, and they were named prechromomycin A4, 4A-O-deacetyl-3A-O-acetyl-prechromomycin A4, and 3A-O-acetyl-prechromomycin A4. CmmGII and CmmGI are therefore responsible for the formation of the disaccharide chain by incorporating, in a sequential manner, two D-oliosyl residues to the 8 position of the biosynthetic intermediate prechromomycin A3. A biosynthetic pathway is proposed for the glycosylation events in chromomycin A3 biosynthesis.

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

    PubMed

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

    2016-07-01

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

  14. Diet, dietary selectivity and density of South American Grey Fox, Lycalopex griseus, in Central Chile.

    PubMed

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

    2017-03-06

    The South American Grey Fox (Lycalopex griseus) is a canid widely distributed in southern South America, however some aspects of its biology are still poorly known. We studied the diet and density of L. griseus in the Lago Peñuelas Biosphere Reserve, in Central Chile. The trophic niche breadth was B = 6.16 (Bsta = 0.47) and prey diversity was H ' = 2.46 (Hmax' = 3.17, J' = 0.78). The highest proportions of prey consumed in the diet were Oryctolagus cuniculus (52.21%) and other mammals (32.78%). We compared these results with a latitudinal gradient of diet results for this species in Chile. L. griseus eats mostly mammals (> 90% of total prey), consuming the rodent Phyllotis darwini and reptiles in the Northern zone; O. cuniculus, Octodon degus and Abrocoma bennetti in the Central zone; Abrothrix spp. and lagomorphs in the Southern zone; and Lepus capensis and Ovis aries in the Austral zone. The estimated density of L. griseus in Lago Peñuelas NR was 1.3 foxes /km(2) . This article is protected by copyright. All rights reserved.

  15. The Mitochondrial Toxin Produced by Streptomyces griseus Strains Isolated from an Indoor Environment Is Valinomycin

    PubMed Central

    Andersson, M. A.; Mikkola, R.; Kroppenstedt, R. M.; Rainey, F. A.; Peltola, J.; Helin, J.; Sivonen, K.; Salkinoja-Salonen, M. S.

    1998-01-01

    Actinomycete isolates from indoor air and dust in water-damaged schools and children’s day care centers were tested for toxicity by using boar spermatozoa as an indicator. Toxicity was detected in extracts of four strains which caused a loss of sperm motility, and the 50% effective concentrations (EC50) were 10 to 63 ng (dry weight) ml of extended boar semen−1. The four strains were identified as Streptomyces griseus strains by 16S ribosomal DNA and chemotaxonomic methods. The four S. griseus strains had similar effects on sperm cells, including loss of motility and swelling of mitochondria, but we observed no loss of plasma membrane integrity or depletion of cellular ATP. None of the effects was observed with sperm cells exposed to extracts of other indoor actinomycete isolates at concentrations of ≥5,000 to 72,000 ng ml−1. The toxin was purified from all four strains and was identified as a dodecadepsipeptide, and the fragmentation pattern obtained by tandem mass spectrometry was identical to that of valinomycin. Commercial valinomycin had effects in sperm cells that were identical to the effects of the four indoor isolates of S. griseus. The EC50 of purified toxin from the S. griseus strains were 1 to 3 ng ml of extended boar semen−1, and the EC50 of commercial valinomycin was 2 ng ml of extended boar semen−1. To our knowledge, this is the first report of the presence of ionophoric toxin producers in an indoor environment and the first report of valinomycin-producing strains identified as S. griseus. PMID:9835560

  16. Chromate reduction by PVA-alginate immobilized Streptomyces griseus in a bioreactor.

    PubMed

    Poopal, Ashwini C; Laxman, R Seeta

    2009-01-01

    Microbial reduction of toxic Cr6+ to the less toxic Cr3+ is potentially a useful bioremediation process. Among the matrices tested for whole cell immobilization of an efficient chromate-reducing Streptomyces griseus strain, PVA-alginate was the most effective and was used for reduction of Cr(VI) in a bioreactor. Cr6+ reduction efficiency decreased as Cr6+ was increased from 2 to 12 mg l(-1) but increased with an increase in biomass concentration. However, increasing the flow rate from 2 to 8 ml h(-1) did not significantly affect Cr(6+) reduction. The reduction was faster in simulated effluent than in synthetic medium and complete removal of 8 mg Cr6+ l(-1) from effluent and synthetic medium occurred in 2 and 12 h, respectively. Our results indicate that immobilized S. griseus cells could be applied for the large-scale bioremediation of chromate-containing effluents and wastewaters.

  17. Cloning and characterization of a gene involved in aerial mycelium formation in Streptomyces griseus.

    PubMed Central

    Kudo, N; Kimura, M; Beppu, T; Horinouchi, S

    1995-01-01

    A-factor (2-isocapryloyl-3R-hydroxymethyl-gamma-butyrolactone) is essentially required for aerial mycelium formation and streptomycin production in Streptomyces griseus. A DNA fragment which induced aerial mycelium formation and sporulation in an A-factor-deficient mutant strain, S. griseus HH1, was cloned from this strain on a high-copy-number plasmid. Subcloning and nucleotide sequencing revealed that one open reading frame with 218 amino acids, named AmfC, served as a multicopy suppressor of the aerial mycelium-defective phenotype of the A-factor-deficient strain. The amfC gene did not restore A-factor or streptomycin production, indicating that amfC is involved in aerial mycelium formation independently of secondary metabolic function. Disruption of the chromosomal amfC gene in the wild-type S. griseus strain caused a severe reduction in the abundance of spores but no effect on the shape or size of the spores. The infrequent sporulation of the amfC disruptant was reversed by introduction of amfC on a plasmid. The amfC-defective phenotype was also restored by the orf1590 gene but not by the amfR-amfA-amfB gene cluster. Nucleotide sequences homologous to the amfC gene were distributed in all of 12 Streptomyces species tested, including Streptomyces coelicolor A3(2). The amfC homolog of S. coelicolor A3(2) was cloned and its nucleotide sequence was determined. The AmfC products of S. griseus and S. coelicolor A3(2) showed a 60% identity in their amino acid sequences. Introduction of the amfC gene of S. coelicolor A3(2) into strain HH1 induced aerial mycelium formation and sporulation, which suggests that both play the same functional role in morphogenesis in the strains. PMID:7592414

  18. Salinity selection and preference of the grey snapper Lutjanus griseus: field and laboratory observations.

    PubMed

    Serrano, X; Grosell, M; Serafy, J E

    2010-05-01

    Field observations were supplemented with laboratory experiments to reveal patterns of salinity selection and preference for grey snapper Lutjanus griseus (c. 21 cm total length, L(T)), an ecologically and economically important species in the south-eastern U.S.A. Fish abundance data were examined from a long-term field survey conducted in the mangrove habitats of Biscayne Bay, Florida, where salinities ranged from <1 to 40. First, regression analyses indicated significant, positive linear relationships with salinity for both L. griseus frequency of occurrence and concentration (density when present). These patterns are inconsistent with physiological expectations of minimizing energetic osmoregulatory costs. Next, the salinity preference and swimming activity of 11 L. griseus (ranging from 18 to 23 cm L(T)) were investigated using a newly developed electronic shuttlebox system. In the laboratory, fish preferred intermediate salinities in the range of 9-23. Swimming activity (measured in terms of spontaneous swimming speed) followed a parabolic relationship with salinity, with reduced activity at salinity extremes perhaps reflecting compensation for higher osmoregulatory costs. It is suspected that the basis of the discrepancy between laboratory and field observations for size classes at or near maturity ultimately relates to the reproductive imperative to move towards offshore (high-salinity) coral-reef habitats, a necessity that probably overrides the strategy of minimizing osmoregulatory energetic costs.

  19. Diet variation of a generalist fish predator, grey snapper Lutjanus griseus, across an estuarine gradient: trade-offs of quantity for quality?

    PubMed

    Yeager, L A; Layman, C A; Hammerschlag-Peyer, C M

    2014-08-01

    This study examined diet, prey quality and growth for a generalist fish predator, grey snapper Lutjanus griseus, at five sites across an estuarine gradient in the Loxahatchee River estuary, Florida, U.S.A. Lutjanus griseus diets shifted from dominance by low quality, intertidal crabs upstream to an increased reliance on higher quality shrimp, fishes and benthic crabs downstream. Frequency of L. griseus with empty stomachs was higher at downstream sites. Lutjanus griseus growth rates did not vary among sites. Results indicate that L. griseus may be able to compensate for lower quality prey upstream by consuming more, and thus individuals are able to maintain similar levels of energy balance and growth rates across the estuarine gradient. Elucidating mechanisms, such as compensatory feeding, that enable generalist species to remain successful across habitat conditions are critical to understanding their organismal ecology and may facilitate predictions about the response of generalists to landscape alteration.

  20. Pulmonary fungal infection caused by Neoscytalidium dimidiatum in a Risso's dolphin (Grampus griseus).

    PubMed

    Elad, Daniel; Morick, Danny; David, Dan; Scheinin, Aviad; Yamin, Gilad; Blum, Shlomo; Goffman, Oz

    2011-05-01

    Neoscytalidium dimidiatum was isolated from two 12-18 cm abscesses in the lung and the mediastinal lymph nodes of a stranded Risso's dolphin (Grampus griseus). Histopathologic examination of samples of these organs revealed the presence of hyphae and sclerotic body-like fungal elements. Photobacterium damselae subsp. damselae was recovered from the dolphin's organs which also were found to contain numerous Monorygma grimaldii cysts. No histopathological signs of morbillivirus infection were seen. To the best of our knowledge, this is the first report of N. dimidiatum infection in a sea mammal.

  1. Gait disturbances in dystrophic hamsters.

    PubMed

    Hampton, Thomas G; Kale, Ajit; Amende, Ivo; Tang, Wenlong; McCue, Scott; Bhagavan, Hemmi N; VanDongen, Case G

    2011-01-01

    The delta-sarcoglycan-deficient hamster is an excellent model to study muscular dystrophy. Gait disturbances, important clinically, have not been described in this animal model. We applied ventral plane videography (DigiGait) to analyze gait in BIO TO-2 dystrophic and BIO F1B control hamsters walking on a transparent treadmill belt. Stride length was ∼13% shorter (P < .05) in TO-2 hamsters at 9 months of age compared to F1B hamsters. Hindlimb propulsion duration, an indicator of muscle strength, was shorter in 9-month-old TO-2 (247 ± 8 ms) compared to F1B hamsters (272 ± 11 ms; P < .05). Braking duration, reflecting generation of ground reaction forces, was delayed in 9-month-old TO-2 (147 ± 6 ms) compared to F1B hamsters (126 ± 8 ms; P < .05). Hindpaw eversion, evidence of muscle weakness, was greater in 9-month-old TO-2 than in F1B hamsters (17.7 ± 1.2° versus 8.7 ± 1.6°; P < .05). Incline and decline walking aggravated gait disturbances in TO-2 hamsters at 3 months of age. Several gait deficits were apparent in TO-2 hamsters at 1 month of age. Quantitative gait analysis demonstrates that dystrophic TO-2 hamsters recapitulate functional aspects of human muscular dystrophy. Early detection of gait abnormalities in a convenient animal model may accelerate the development of therapies for muscular dystrophy.

  2. Purification of histidase from Streptomyces griseus and nucleotide sequence of the hutH structural gene.

    PubMed Central

    Wu, P C; Kroening, T A; White, P J; Kendrick, K E

    1992-01-01

    Histidine ammonia-lyase (histidase) was purified to homogeneity from vegetative mycelia of Streptomyces griseus. The enzyme was specific for L-histidine and showed no activity against the substrate analog, D-histidine. Histidinol phosphate was a potent competitive inhibitor. Histidase displayed saturation kinetics with no detectable sigmoidal response. Neither thiol reagents nor a variety of divalent cations had any effect on the activity of the purified enzyme. High concentrations of potassium cyanide inactivated histidase in the absence of its substrate or histidinol phosphate, suggesting that, as in other histidases, dehydroalanine plays an important role in catalysis. The N-terminal amino acid sequence of histidase was used to construct a mixed oligonucleotide probe to identify and clone the histidase structural gene, hutH, from genomic DNA of the wild-type strain of S. griseus. The cloned DNA restored the ability of a histidase structural gene mutant to grow on L-histidine as the sole nitrogen source. The deduced amino acid sequence of hutH shows significant relatedness with histidase from bacteria and a mammal as well as phenylalanine ammonia-lyase from plants and fungi. Images PMID:1537807

  3. Identification of transformation products arising from bacterial oxidation of codeine by Streptomyces griseus.

    PubMed Central

    Kunz, D A; Reddy, G S; Vatvars, A

    1985-01-01

    14-Hydroxycodeine and norcodeine were rigorously identified as products arising from codeine oxidation by Streptomyces griseus ATCC 10137. Both products were routinely detected in extracted culture filtrates after growth of cells in the presence of codeine for 1 week. Under these conditions, about 4 mol% of the codeine starting material was consumed, with norcodeine and 14-hydroxycodeine representing the only identifiable transformation products (molar ratio, 4:1, respectively). Extraction of a series of culture filtrates and purification of the pooled metabolites by thin-layer and high-pressure liquid chromatography led to the isolation of both biological products, the structures of which were verified by high-resolution mass spectrometry and proton nuclear magnetic resonance spectroscopy. The identities of both biological products were further confirmed by comparison of their spectral properties with those of authentic standards. This is the first report providing structural evidence for the biological formation of 14-hydroxycodeine from codeine and of codeine oxidation by S. griseus. PMID:3936418

  4. Differential Regulation of ftsZ Transcription during Septation of Streptomyces griseus

    PubMed Central

    Kwak, Jangyul; Dharmatilake, Amitha J.; Jiang, Hao; Kendrick, Kathleen E.

    2001-01-01

    Streptomyces has been known to form two types of septa. The data in this research demonstrated that Streptomyces griseus forms another type of septum near the base of sporogenic hyphae (basal septum). To understand the regulation of the septation machinery in S. griseus, we investigated the expression of the ftsZ gene. S1 nuclease protection assays revealed that four ftsZ transcripts were differentially expressed during morphological differentiation. The vegetative transcript (emanating from Pveg) is present at a moderate level during vegetative growth, but is switched off within the first 2 h of sporulation. Two sporulation-specific transcripts predominantly accumulated, and the levels increased by approximately fivefold together shortly before sporulation septa begin to form. Consistently, the sporulation-specific transcripts were expressed much earlier and more abundantly in a group of nonsporulating mutants that form their sporulation septa prematurely. Promoter-probe studies with two different reporter systems confirmed the activities of the putative promoters identified from the 5′ end point of the transcripts. The levels and expression timing of promoter activities were consistent with the results of nuclease protection assays. The aseptate phenotype of the Pspo mutant indicated that the increased transcription from Pspo is required for sporulation septation, but not for vegetative or basal septum formation. PMID:11489862

  5. Agricultural irrigation mediates climatic effects and density dependence in population dynamics of Chinese striped hamster in North China Plain.

    PubMed

    Yan, Chuan; Xu, Lei; Xu, Tongqin; Cao, Xiaoping; Wang, Fusheng; Wang, Shuqing; Hao, Shoushen; Yang, Hefang; Zhang, Zhibin

    2013-03-01

    Several studies show that climatic (extrinsic) factors can interact with density-dependent (intrinsic) factors to alter long-term population dynamics, yet there is a surprising lack of investigations of how anthropogenic disturbance modifies such dynamics. Such interactions could be especially important in agricultural systems subject to climate change. We investigated the effects of density dependence, climate, recurrent disturbance from flood irrigation and their interactions on the population dynamics of an important rodent pest, the Chinese striped hamster (Cricetulus barabensis), over 27 years in the croplands of the North China Plain. Strong density-dependent feedbacks occurred at both annual and seasonal scales. While warmer weather increased population sizes in nonbreeding seasons, this effect was counteracted by the negative effect of flood irrigation in breeding seasons. Precipitation showed significant positive effects in nonbreeding seasons, but negative effects in breeding seasons. There were important interactions between intrinsic dynamics, extrinsic dynamics and disturbance. Low temperature significantly increased the strength of density dependence in nonbreeding seasons, whereas intensification of flood irrigation area significantly increased the strength of density dependence but reduced the effect of summer precipitation in breeding seasons. Overall climate change is expected to increase population levels, but anthropogenic disturbance from flood irrigation will help prevent long-term population increases. The interactions between anthropogenic disturbance and both intrinsic and extrinsic (weather-driven) population dynamics caution that we need to consider anthropogenic disturbance as an integral component of population responses to climate change.

  6. Iminimycin A, the new iminium metabolite produced by Streptomyces griseus OS-3601.

    PubMed

    Nakashima, Takuji; Miyano, Rei; Iwatsuki, Masato; Shirahata, Tatsuya; Kimura, Toru; Asami, Yukihiro; Kobayashi, Yoshinori; Shiomi, Kazuro; Petersson, George A; Takahashi, Yōko; Ōmura, Satoshi

    2016-08-01

    A new natural product, designated iminimycin A, was isolated from the cultured broth of a streptomycin-producing microbial strain, Streptomyces griseus OS-3601, via a physicochemical screening method using HP-20, silica gel and ODS column chromatographies and subsequent preparative HPLC. Iminimycin A is an indolizidine alkaloid, containing of an unusual iminium group and a cyclopropane ring with a triene side chain. The absolute configuration of iminimycin A was elucidated by NMR studies and electronic circular dichroism analysis. Iminimycin A shows anti-bacterial activity against Bacillus subtilis, Kocuria rhizophila and Xanthomonas campestris pv. orizae, and cytotoxic activity against HeLa S3 and Jurkat cells with IC50 values of 43 and 36 μM, respectively.

  7. Aeromonas dhakensis pneumonia and sepsis in a neonate Risso's dolphin Grampus griseus from the Mediterranean Sea.

    PubMed

    Pérez, Lola; Abarca, M Lourdes; Latif-Eugenín, Fadua; Beaz-Hidalgo, Roxana; Figueras, M José; Domingo, Mariano

    2015-09-17

    A neonate Risso's dolphin Grampus griseus was found stranded alive on a beach in Catalonia, Spain. Rehabilitation attempts were unsuccessful and it died 2 d later, showing pneumonia and sepsis. A pure bacterial culture was obtained from all tissues and blood and identified as Aeromonas hydrophila using the API 20NE. However, sequencing the rpoD gene showed that the strain in fact belongs to A. dhakensis, making this the first report of fatal haemorrhagic-necrotizing pneumonia and sepsis due to this species in a marine mammal. The A. dhakensis strain GMV-704 produced β-haemolysis, possessed several virulence genes and showed sensitivity to several antimicrobials. This study provides a new potential host for A. dhakensis, and its potential virulence in dolphins and its presence in the marine environment may warrant considering this species a potential threat to marine mammals.

  8. The purification and properties of two staphylolytic enzymes from Streptomyces griseus

    PubMed Central

    Ward, J. B.; Perkins, H. R.

    1968-01-01

    1. Two staphylolytic enzymes have been purified from cultures of a soil isolate of Streptomyces griseus. 2. The purified enzymes were shown to be basic proteins of low molecular weight. Each enzyme released N-acetylmuramic acid reducing groups from the cell walls of Staphylococcus aureus. 3. The enzymes lysed whole staphylococci best at higher pH values and lower ionic strengths than when the substrate was isolated cell walls or purified mucopeptide. 4. Added teichoic acid did not inhibit the enzymes, but it formed an ethanol-precipitable complex with them. 5. The possibility that teichoic acid on the surface of whole cells prevents the access of the enzymes to their mucopeptide substrate is discussed. PMID:4976493

  9. A modular family 19 chitinase found in the prokaryotic organism Streptomyces griseus HUT 6037.

    PubMed Central

    Ohno, T; Armand, S; Hata, T; Nikaidou, N; Henrissat, B; Mitsutomi, M; Watanabe, T

    1996-01-01

    The specificity of chitinase C-1 of Streptomyces griseus HUT 6037 for the hydrolysis of the beta-1,4-glycosidic linkages in partially acetylated chitosan is different from that of other microbial chitinases. In order to study the primary structure of this unique chitinase, the chiC gene specifying chitinase C-1 was cloned and its nucleotide sequence was determined. The gene encodes a polypeptide of 294 amino acids with a calculated size of 31.4 kDa. Comparison of the amino acid sequence of the deduced polypeptide with that of other proteins revealed a C-terminal catalytic domain displaying considerable sequence similarity to the catalytic domain of plant class I, II, and IV chitinases which form glycosyl hydrolase family 19. The N-terminal domain of the deduced polypeptide exhibits sequence similarity to substrate-binding domains of several microbial chitinases and cellulases but not to the chitin-binding domains of plant chitinases. The previously purified chitinase C-1 from S. griseus is suggested to be generated by proteolytic removal of the N-terminal chitin-binding domain and corresponds to the catalytic domain of the chitinase encoded by the chiC gene. High-performance liquid chromatography analysis of the hydrolysis products from N-acetyl chitotetraose revealed that chitinase C-1 catalyzes hydrolysis of the glycosidic bond with inversion of the anomeric configuration, in agreement with the previously reported inverting mechanism of plant class I chitinases. This is the first report of a family 19 chitinase found in an organism other than higher plants. PMID:8752320

  10. Characterization of a novel sesquiterpene cyclase involved in (+)-caryolan-1-ol biosynthesis in Streptomyces griseus.

    PubMed

    Nakano, Chiaki; Horinouchi, Sueharu; Ohnishi, Yasuo

    2011-08-12

    Most terpenoids have been isolated from plants and fungi and only a few from bacteria. However, an increasing number of genome sequences indicate that bacteria possess a variety of terpenoid cyclase genes. We characterized a sesquiterpene cyclase gene (SGR2079, named gcoA) found in Streptomyces griseus. When expressed in Streptomyces lividans, gcoA directed production of a sesquiterpene, isolated and determined to be (+)-caryolan-1-ol using spectroscopic analyses. (+)-Caryolan-1-ol was also detected in the crude cell lysate of wild-type S. griseus but not in a gcoA knockout mutant, indicating that GcoA is a genuine (+)-caryolan-1-ol synthase. Enzymatic properties were characterized using N-terminally histidine-tagged GcoA, produced in Escherichia coli. As expected, incubation of the recombinant GcoA protein with farnesyl diphosphate yielded (+)-caryolan-1-ol. However, a small amount of another sesquiterpene was also detected. This was identified as the bicyclic sesquiterpene hydrocarbon (+)-β-caryophyllene by comparison with an authentic sample using GC-MS. Incorporation of a deuterium atom into the C-9 methylene of (+)-caryolan-1-ol in an in vitro GcoA reaction in deuterium oxide indicated that (+)-caryolan-1-ol was synthesized by a proton attack on the C-8/C-9 double bond of (+)-β-caryophyllene. Several β-caryophyllene synthases have been identified from plants, but these cannot synthesize caryolan-1-ol. Although caryolan-1-ol has been isolated previously from several plants, the enzyme responsible for its biosynthesis has not been identified previously. GcoA is thus the first known caryolan-1-ol synthase. Isolation of caryolan-1-ol from microorganisms is unprecedented.

  11. Cloning and characterization of the A-factor receptor gene from Streptomyces griseus.

    PubMed Central

    Onaka, H; Ando, N; Nihira, T; Yamada, Y; Beppu, T; Horinouchi, S

    1995-01-01

    A-factor (2-isocapryloyl-3R-hydroxymethyl-gamma-butyrolactone) and its specific receptor protein control streptomycin production, streptomycin resistance, and aerial mycelium formation in Streptomyces griseus. The A-factor receptor protein (ArpA) was purified from a cell lysate of S. griseus IFO 13350. The NH2-terminal amino acid sequences of ArpA and lysyl endopeptidase-generated fragments were determined for the purpose of preparing oligonucleotide primers for cloning arpA by the PCR method. The arpA gene cloned in this way directed the synthesis of a protein having A-factor-specific binding activity when expressed in Escherichia coli under the control of the T7 promoter. The arpA gene was thus concluded to encode a 276-amino-acid protein with a calculated molecular mass of 29.1 kDa, as determined by nucleotide sequencing. The A-factor-binding activity was observed with a homodimer of ArpA. The NH2-terminal portion of ArpA contained an alpha-helix-turn-alpha-helix DNA-binding motif that showed great similarity to those of many DNA-binding proteins, which suggests that it exerts its regulatory function for the various phenotypes by directly binding to a certain key gene(s). Although a mutant strain deficient in both the ArpA protein and A-factor production overproduces streptomycin and forms aerial mycelium and spores earlier than the wild-type strain because of repressor-like behavior of ArpA, introduction of arpA into this mutant abolished simultaneously its streptomycin production and aerial mycelium formation. All of these data are consistent with the idea that ArpA acts as a repressor-type regulator for secondary metabolite formation and morphogenesis during the early growth phase and A-factor at a certain critical intracellular concentration releases the derepression, thus leading to the onset of secondary metabolism and aerial mycelium formation. The presence of ArpA-like proteins among Streptomyces spp., as revealed by PCR, together with the presence of A

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

    PubMed

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

    2006-02-01

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

  13. Improved Production of Active Streptomyces griseus Trypsin with a Novel Auto-Catalyzed Strategy

    PubMed Central

    Zhang, Yunfeng; Ling, Zhenmin; Du, Guocheng; Chen, Jian; Kang, Zhen

    2016-01-01

    N-terminal sequences play crucial roles in regulating expression, translation, activation and enzymatic properties of proteins. To reduce cell toxicity of intracellular trypsin and increase secretory expression, we developed a novel auto-catalyzed strategy to produce recombinant trypsin by engineering the N-terminus of mature Streptomyces griseus trypsin (SGT). The engineered N-terminal peptide of SGT was composed of the thioredoxin, glycine-serine linker, His6-tag and the partial bovine trypsinogen pro-peptide (DDDDK). Furthermore, we constructed a variant TLEI with insertion of the artificial peptide at N-terminus and site-directed mutagenesis of the autolysis residue R145. In fed-batch fermentation, the production of extracellular trypsin activity was significantly improved to 47.4 ± 1.2 U·ml−1 (amidase activity, 8532 ± 142.2 U·ml−1 BAEE activity) with a productivity of 0.49 U·ml−1·h−1, which was 329% greater than that of parent strain Pichia pastoris GS115-SGT. This work has significant potential to be scaled-up for microbial production of SGT. In addition, the N-terminal peptide engineering strategy can be extended to improve heterologous expression of other toxic enzymes. PMID:26983398

  14. Organization and characterization of a biosynthetic gene cluster for bafilomycin from Streptomyces griseus DSM 2608

    PubMed Central

    2013-01-01

    Streptomyces griseus DSM 2608 produces bafilomycin, an antifungal plecomacrolide antibiotic. We cloned and sequenced an 87.4-kb region, including a polyketide synthase (PKS) region, methoxymalonate genes, flavensomycinate genes, and other putative regulatory genes. The 58.5kb of PKS region consisting 12 PKS modules arranged in five different PKS genes, was assumed to be responsible for the biosynthesis of plecomacrolide backbone including 16-membered macrocyclic lactone. All the modules showed high similarities with typical type I PKS genes. However, the starting module of PKS gene was confirmed to be specific for isobutyrate by sequence comparison of an acyltransferase domain. In downstream of PKS region, the genes for methoxymalonate biosynthesis were located, among which a gene for FkbH-like protein was assumed to play an important role in the production of methoxymalonyl-CoA from glyceryl-CoA. Further the genes encoding flavensomycinyl-ACP biosynthesis for the post-PKS tailoring were also found in the upstream of PKS region. By gene disruption experiments of a dehydratase domain of module 12 and an FkbH-like protein, this gene cluster was confirmed to be involved in the biosynthesis of bafilomycin. PMID:23663353

  15. Characterization of an 8-hydroxy-5-deazaflavin:NADPH oxidoreductase from Streptomyces griseus.

    PubMed

    Eker, A P; Hessels, J K; Meerwaldt, R

    1989-01-27

    An 8-hydroxy-5-deazaflavin-dependent oxidoreductase was isolated from the actinomycete Streptomyces griseus and purified 590-fold with 72% overall yield. The enzyme catalyzes electron transfer between 8-hydroxy-5-deazaflavins and NADPH. It seems to be more specific than methanogenic oxidoreductase as it has an absolute requirement for both the 5-deazaflavin structure and the presence of an 8-hydroxy group in the substrate. A molecular weight of 42,000 was found with gel permeation chromatography, while SDS gel electrophoresis indicated the presence of two identical subunits. Maximal enzymatic activity was found at 0.32 M NaCl and pH 5.9 for reduction of 8-hydroxy-5-deazaflavin and pH 7.9 for the reverse reaction. From the kinetic constants it was estimated that the main function of this oxidoreductase is probably to provide cells with reduced 8-hydroxy-5-deazaflavin to be used in specific reduction reactions. These results indicate the occurrence of 8-hydroxy-5-deazaflavin-dependent electron transfer in microorganisms not belonging to the archaebacteria.

  16. [Cardon dato (Stenocereus griseus, Cactaceae) fruit pulp as raw material for marmalade production].

    PubMed

    Emaldi, Unai; Nassar, Jafet M; Semprum, Carla

    2006-03-01

    This study aimed to examine the possibility of producing marmalades from the fruit pulp of the red and white varieties of card6n dato (Stenocereus griseus). We developed the formulations of the marmalades and evaluated their stability during three months of storage at room temperature. As first step, we characterized the fruits of the two color varieties, observing that despite the considerable difference between both color varieties, there were no significant differences in average weight, dimensions and proportion of pulp, skin and seeds. The pulp of the two color types had high pH (5.2) values and low contents of reductor sugars (3.59 g/ 100 g white variety 2.23 g/ 100 g red variety), non reductor sugars (0.75 g/ 100 g white variety and 2.03 g/ 100 g red variety), pectin (0.14 g/ 100 g white variety and 0.23 g/ 100 g red variety) and acids (7.67 g/ 100 g white variety and 0.15 g/ 100 g red variety). It is needed to include sugar, pectin, and citric acid in the marmalade formula. The first marmalades produced were gummy, a problem that we solved adding the acid from the beginning of the making process. During the three months of storage, the marmalades had good acceptance by the evaluators, this despite slight fluctuations observed in pH, solid contents, and acidity.

  17. Hearing abilities and sound reception of broadband sounds in an adult Risso's dolphin (Grampus griseus).

    PubMed

    Mooney, T Aran; Yang, Wei-Cheng; Yu, Hsin-Yi; Ketten, Darlene R; Jen, I-Fan

    2015-08-01

    While odontocetes do not have an external pinna that guides sound to the middle ear, they are considered to receive sound through specialized regions of the head and lower jaw. Yet odontocetes differ in the shape of the lower jaw suggesting that hearing pathways may vary between species, potentially influencing hearing directionality and noise impacts. This work measured the audiogram and received sensitivity of a Risso's dolphin (Grampus griseus) in an effort to comparatively examine how this species receives sound. Jaw hearing thresholds were lowest (most sensitive) at two locations along the anterior, midline region of the lower jaw (the lower jaw tip and anterior part of the throat). Responses were similarly low along a more posterior region of the lower mandible, considered the area of best hearing in bottlenose dolphins. Left- and right-side differences were also noted suggesting possible left-right asymmetries in sound reception or differences in ear sensitivities. The results indicate best hearing pathways may vary between the Risso's dolphin and other odontocetes measured. This animal received sound well, supporting a proposed throat pathway. For Risso's dolphins in particular, good ventral hearing would support their acoustic ecology by facilitating echo-detection from their proposed downward oriented echolocation beam.

  18. A small lytic polysaccharide monooxygenase from Streptomyces griseus targeting α- and β-chitin.

    PubMed

    Nakagawa, Yuko S; Kudo, Madoka; Loose, Jennifer S M; Ishikawa, Takahiro; Totani, Kazuhide; Eijsink, Vincent G H; Vaaje-Kolstad, Gustav

    2015-03-01

    The lytic polysaccharide monooxygenases (LPMOs) have received considerable attention subsequent to their discovery because of their ability to boost the enzymatic conversion of recalcitrant polysaccharides. In the present study, we describe the enzymatic properties of SgLPMO10F, a small (15 kDa) auxilliary activity (AA) family 10 LPMO from Streptomyces griseus belonging to a clade of the phylogenetic tree without any characterized representative. The protein was expressed using a Brevibacillus-based expression system that had not been used previously for LPMO expression and that also ensures correct processing of the N-terminus crucial for LPMO activity. The enzyme was active towards both α- and β-chitin and showed stronger binding and a greater release of soluble oxidized products for the latter allomorph. In chitinase synergy assays, however, SgLPMO10F worked slightly better for α-chitin, increasing chitin solubilization yields by up to 30-fold and 20-fold for α- and β-chitin, respectively. Synergy experiments with various chitinases showed that the addition of SgLPMO10F leads to a substantial increase in the (GlcNAc)2 :GlcNAc product ratio, in reactions with α-chitin only. This underpins the structural differences between the substrates and also shows that, on α-chitin, SgLPMO10F affects the binding mode and/or degree of processivity of the chitinases tested. Variation in the only exposed aromatic residue in the substrate-binding surface of LPMO10s has previously been linked to preferential binding for α-chitin (exposed Trp) or β-chitin (exposed Tyr). Mutation of this residue, Tyr56, in SgLPMO10F to Trp had no detectable effect on substrate-binding preferences but, in synergy experiments, the mutant appeared to be more efficient on α-chitin.

  19. Gender, Season and Management Affect Fecal Glucocorticoid Metabolite Concentrations in Captive Goral (Naemorhedus griseus) in Thailand

    PubMed Central

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

    2014-01-01

    Chinese goral (Naemorhedus griseus) are a threatened species in Thailand and the focus of captive breeding for possible reintroduction. However, little is known of their biology or what factors in the captive environment affect welfare. Our objective was to determine the impact of gender, season, and management on goral adrenal activity. We hypothesized that differences in fecal glucocorticoid concentrations would be related to animal density. Fecal samples were collected 3 days/week for 1 year from 63 individuals (n = 32 males, 31 females) at two facilities that house the majority of goral in Thailand: Omkoi Wildlife Sanctuary (Omkoi), an off-exhibit breeding center that houses goral in individual pens (16 pens; n = 8 males, 8 females) and in small family groups (8 pens; n = 8 males, 8 females); and the Chiang Mai Night Safari (NS), a zoo that maintains 31 goral (n = 17 males, 14 females) in one large pen. Glucocorticoid metabolite concentrations were higher in male than female goral at Omkoi throughout the year, and there was a seasonal effect on adrenal activity (p<0.05). Goral at Omkoi and NS were used to test the effect of animal density on fecal glucocorticoid excretion of goral housed in similar-sized enclosures. Overall, the highest levels were found at NS (n = 31 adults/pen; 27 m2 per animal) compared to Omkoi (n = 2 adults/pen; 400 m2 per animal) (p<0.05). Overall findings support our hypothesis that animal density and aspects of the captive environment impact adrenal steroid activity in captive goral. In addition, gender and season also had significant effects on glucocorticoid metabolite production. Potential stressors pertaining to the welfare of this species were identified, which will guide future efforts to improve management and create self-sustaining and healthy populations of this threatened species. PMID:24637886

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  2. Analysis of a gene that suppresses the morphological defect of bald mutants of Streptomyces griseus.

    PubMed Central

    McCue, L A; Kwak, J; Wang, J; Kendrick, K E

    1996-01-01

    When present in multiple copies, orf1590 restored sporulation to class IIIA bald mutants of Streptomyces griseus, which form sporulation septa and thick spore walls prematurely. The orf1590 alleles from class IIIA bald mutants restored sporulation upon introduction at a high copy number into those same mutants, and the nucleotide sequence of one of these alleles was identical to that of the wild-type strain. We conclude that overexpression of orf1590 suppresses the defect in class IIIA bald mutants. Previous nucleotide sequence and transcript analyses suggested that orf1590 could encode two related proteins, P56 and P49.5, from nested coding sequences. A mutation that prevented the synthesis of P56 without altering the coding sequence for P49.5 eliminated the function of orf1590, as did amino acid substitutions in the putative helix-turn-helix domain located at the N terminus of P56 and absent from P49.5. To determine the coding capacity of orf1590, we analyzed translational fusions between orf1590 and the neo gene from Tn5. Measurement of the expression of fusions to the wild-type and mutant alleles of orf1590 indicated that P56 was the sole product of orf1590 during vegetative growth. Attempts to generate a nonfunctional frameshift mutation in orf1590 were unsuccessful in the absence of a second-site bald mutation, suggesting that orf1590 may be required during vegetative growth by preventing early sporulation. Our results are consistent with the hypothesis that P56 at a high level delays the premature synthesis of sporulation septa and spore walls in class IIIA mutants. PMID:8631675

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

    PubMed

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

    2007-09-01

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

  4. Characterization of ssfR and ssgA, Two Genes Involved in Sporulation of Streptomyces griseus

    PubMed Central

    Jiang, Hao; Kendrick, Kathleen E.

    2000-01-01

    In the presence of cefoxitin, which inhibits septum formation during sporulation, Streptomyces griseus is unable to sporulate, retaining the sonication sensitivity of nonsporulating hyphae. Cefoxitin- and sonication-resistant mutant SKK2600 was isolated and showed many morphological differences from its parental strain. A 3.6-kb DNA fragment that complemented the mutations of SKK2600 contained two open reading frames (ORFs), either of which could complement SKK2600. One ORF, designated ssfR, encoded a protein containing a potential DNA-binding helix-turn-helix motif close to its N terminus. SsfR is similar to members of a large family of transcriptional regulators, particularly IclR of Escherichia coli. The second ORF was identified as ssgA, a previously described sporulation gene from S. griseus (S. Kawamoto and J. C. Ensign, Actinomycetology 9:136–151, 1995). A point mutation of C to T seven nucleotides upstream of the UGA stop codon of ssfR was responsible for the phenotype of isolated mutant strain SKK2600. Surprisingly, this mutation should not change the primary structure of SsfR. The ssfR and ssgA disruption mutants were constructed and showed the “white” mutant phenotype, with some growth medium dependence. In addition, the ssfR null mutant sporulated ectopically in phosphate starvation medium. PMID:10986257

  5. Molecular cloning and characterization of the obg gene of Streptomyces griseus in relation to the onset of morphological differentiation.

    PubMed Central

    Okamoto, S; Itoh, M; Ochi, K

    1997-01-01

    Morphological differentiation in microorganisms is usually accompanied by a decrease in intracellular GTP pool size, as has been demonstrated in bacillaceae, streptomycetaceae, and yeasts. The obg gene, which codes for a GTP-binding protein belonging to the GTPase superfamily of proteins, was cloned from Streptomyces griseus IFO13189. The gene is located just downstream of the genes for ribosomal proteins L21 and L27, encoded a protein of 478 amino acids (51 kDa), and possessed three consensus motifs which confer GTP-binding ability; Obg protein expressed in Escherichia coli bound GTP, as demonstrated using a UV cross-linking method. Introduction of multiple copies of obg into wild-type S. griseus suppressed aerial mycelium development in cells on solid media. However, no effect on streptomycin production was detected, indicating that Obg is involved in the regulation of the onset of morphological but not physiological differentiation. Multiple copies of obg also suppressed submerged spore formation in liquid culture. Southern hybridization studies indicated that genes homologous to obg exist widely in streptomycetes, and an obg homolog was successfully cloned from S. coelicolor A3(2). We propose that by monitoring the intracellular GTP pool size, the Obg protein is involved in sensing changes in the nutritional environment leading ultimately to morphological differentiation. PMID:8981995

  6. Multilocus sequence analysis of Streptomyces griseus isolates delineating intraspecific diversity in terms of both taxonomy and biosynthetic potential.

    PubMed

    Rong, Xiaoying; Liu, Ning; Ruan, Jisheng; Huang, Ying

    2010-08-01

    Systematics can provide a fundamental framework for understanding the relationships and diversification of organisms. Multilocus sequence analysis (MLSA) has shown great promise for an elaborate taxonomic grouping of streptomycete diversity. To evaluate the practical significance of MLSA as a valuable systematic tool for streptomycetes, we examined six endophytic Streptomyces griseus isolates and two S. griseus reference strains possessing obvious antagonistic activities and identical 16S rRNA gene sequences, using both housekeeping genes and secondary metabolic genes. All the eight strains contained PKS-I and NRPS genes, but not PKS-II genes, and showed similar diversity in both the MLSA phylogeny based on five housekeeping genes (atpD, gyrB, recA, rpoB and trpB) and fingerprinting of KS-AT genes. We also inferred a phylogeny based on concatenated amino acid sequences of representative KS-AT genes from the strains, which displayed a topology correlated well with those of housekeeping-gene MLSA and KS-AT fingerprinting. The good congruence observed between phylogenies based on the different datasets verified that the MLSA scheme provided robust resolution at intraspecific level and could predict the overall diversity of secondary metabolic potential within a Streptomyces species, despite somewhat of a discrepancy with antimicrobial data. It is therefore feasible to apply MLSA to dissecting natural diversity of streptomycetes for a better understanding of their evolution and ecology, as well as for facilitating their bioprospecting.

  7. Effects of geolocation archival tags on reproduction and adult body mass of sooty shearwaters (Puffinus griseus)

    USGS Publications Warehouse

    Adams, J.; Scott, D.; McKechnie, S.; Blackwell, G.; Shaffer, S.A.; Moller, H.

    2009-01-01

    We attached 11 g (1.4% body-mass equivalent) global location sensing (GLS) archival tag packages to tarsi of 25 breeding sooty shearwaters (Puffinus griseus, titi) on Whenua Hou (Codfish Island), New Zealand during the chick-rearing period in 2005. Compared with chicks reared by non-handled adults that did not carry tags, deployment of tags on one or both adult parents ultimately resulted in 35% reduction in chick body mass and significantly reduced chick skeletal size preceding fledging (19 April). However, body mass between chick groups was not significantly different after controlling for skeletal size. Effects on chicks were more pronounced in six pairs where both parents carried tags. Chick mass was negatively related to the duration that adults carried tags. In this study, none of the chicks reared by pairs where both parents were tagged, 54% of chicks reared by pairs where one parent was tagged, and 83% of chicks reared by non-handled and non-tagged parents achieved a previously determined pre-fledging mass threshold (564 g; Sagar & Horning 1998). Body mass of adults carrying tags and returning from transequatorial migration the following year were 4% lighter on average than non-tagged birds, but this difference was not statistically significant. Reduced mass among chicks reared by adults carrying tags during the chick-provisioning period indicated that adults altered "normal" provisioning behaviours to maintain their own body condition at the expense of their chicks. Population-level information derived from telemetry studies can reveal important habitat-linked behaviours, unique aspects of seabird foraging behaviours, and migration ecology. Information for some species (e.g., overlap with fisheries) can aid conservation and marine ecosystem management. We advise caution, however, when interpreting certain data related to adult provisioning behaviours (e.g., time spent foraging, provisioning rates, etc.). If effects on individuals are of concern, we suggest

  8. Directed Student Inquiry: Modeling in Roborovsky Hamsters

    ERIC Educational Resources Information Center

    Elwess, Nancy L.; Bouchard, Adam

    2007-01-01

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

  9. Risso's dolphin (Grampus griseus) stranding on the coast of Israel (eastern Mediterranean). Autopsy results and trace metal concentrations.

    PubMed

    Shoham-Frider, Efrat; Amiel, Shlomi; Roditi-Elasar, Mia; Kress, Nurit

    2002-08-05

    The stranding of Risso's dolphin (Grampus griseus) on the Mediterranean coast of Israel is reported in this study. High concentrations of trace metals (Hg, Cd, Zn, Fe and Se) were found in the various tissues analyzed, while Cu and Mn concentrations were naturally low. The specimen was found alive, but died a day later. The cause of death was attributed to bacterial bronchopneumonia in combination with endotoxemia, resulting in disseminated intravascular coagulation. Plastic bags found in its stomach contributed to the dolphin's poor physical condition. No connection was found between the high concentrations of trace metals in the internal organs and the cause of death. It is assumed that the high concentrations were a result of the high trophic level of this species, its diet and its advanced age. Anthropogenic influence could not be assessed due to the sparse database of trace metals for this species, in particular knowledge of the natural levels.

  10. Epidemiological studies on intestinal helminth parasites of the patagonian grey fox (Pseudalopex griseus) in Tierra del Fuego, Patagonia Argentina.

    PubMed

    Zanini, Fabián; Laferrara, Miguel; Bitsch, Matías; Pérez, Héctor; Elissondo, Maria Celina

    2006-03-31

    The present work was performed to study the intestinal helminths of the patagonian grey fox (Pseudalopex griseus) and to obtain information about its possible role in the sylvatic life cycle of Echinococcu granulosus in Tierra del Fuego, Patagonia Argentina. Eighty-one foxes were captured and subject to post-mortem analysis. Thirty-one foxes (38.3%) harboured helminths. A total of six helminth species were recovered. Only one adult of E. granulosus was found in the studied samples. The current study is the first report of the intestinal helminths of the patagonian grey fox in Tierra del Fuego, Argentina and showed that this specie is probably not an important reservoir host for E. granulosus.

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

    PubMed Central

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

    2000-01-01

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

  12. Taste reactivity in the hamster.

    PubMed

    Brining, S K; Belecky, T L; Smith, D V

    1991-06-01

    Taste reactivity, which was first described in the rat, consists of ingestive and aversive response components, the latter seen mostly to bitter-tasting stimuli. The present experiment characterized the hamster's taste reactivity to an array of stimuli (sugars: 1 M sucrose, d-fructose and d-glucose; sodium salts: 1 M NaCl, Na2SO4 and NaNO3; acids: 30 mM HCl, tartaric acid and citric acid; bitter-tasting stimuli: 100 mM quinine hydrochloride and nicotine sulfate and 10 mM denatonium benzoate). These 12 stimuli were chosen to represent 3 examples each of stimuli that taste sweet, salty, sour, or bitter to humans; they were presented in random order via an intraoral fistula, one stimulus each day per animal (n = 10). Infusions of 0.6 ml were delivered over a 1-min period from a syringe pump. Orofacial and somatic motor responses were recorded on videotape for later analysis and were also coded online into a computer. Ingestive responses included forward and lateral tongue protrusions and aversive responses included gaping, chin rubbing, forelimb flailing, fluid rejection, increased locomotion, and aversive posturing. Each stimulus group produced a characteristic pattern of these behaviors, with sugars eliciting only ingestive behaviors and the bitter stimuli evoking predominantly aversive responses. Both sodium salts and acids produced ingestive responses, as seen previously in the rat, although these stimuli also elicited aversive behaviors in the hamster, including apes. The patterns of responses were characterized using multivariate procedures; the stimuli fell into distinct groups that were separated primarily along an hedonic dimension.

  13. Spontaneous endomyometrial neoplasms in aging Chinese hamsters

    SciTech Connect

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

    1980-05-01

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

  14. Induction of lyme arthritis in LSH hamsters

    SciTech Connect

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

    1988-09-01

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

  15. Neurobehavioural development of the golden hamster.

    PubMed

    Da Silva, V A; Smart, J L; Freire, E M; Paumgartten, F J

    1989-01-01

    The aim of this study was to establish a developmental profile for the golden hamster by using a systematic sequence of test procedures. One experimentally naive litter was tested each day from 0 to 25 days of postnatal age. The appearance of developmental landmarks (physical features and reflexes), spontaneous behaviour in an open field, homing behaviour and rota rod performance were studied. Infant mortality through infanticide was recorded in undisturbed and tested hamsters. The results indicated that most of the tests employed in the present study can be applied usefully in the evaluation of the neurobehavioural development of the golden hamster. The developmental profile for this species is described in detail. In comparison to rats and mice, hamsters display accelerated development of a number of characteristics, most notably incisor eruption and vaginal opening. Infanticide, the most troublesome problem in studies in which hamster litters must be disturbed, did not occur after day 3. As most reflexes and sensory abilities develop after this age, hamster pups can be used successfully in behavioural teratology evaluation.

  16. [Feeding habits and trophic ecology of the fish Lutjanus griseus (Pisces: Lutjanidae) associated with submerged vegetation in Laguna de Términos, Campeche, Mexico].

    PubMed

    Guevara, Emma; Alvarez, Hernán; Mascaró, Maite; Rosas, Carlos; Sánchez, Alberto

    2007-01-01

    In Campeche, Mexico, the Laguna de Términos has Thalassia testudinum beds inhabited by the grey snapper, Lutjanus griseus (Linnaeus 1758). Along one year, we collected 994 individuals and 672 had food in their stomachs; we recorded number, weight, and frequency oftrophic groups, and the index of relative importance. Dominant food components were Farfantepenaeus duorarum and Palemonetes octaviae, Eucinostomus gula (Cuvier 1830) and Libinia dubia. Salinity and temperature were related to the number of individuals collected and with greater fish consumption by large L. griseus. The trophic niche breadth index was calculated for six size-classes of fish. The smallest and the largest fish had the lowest index values, whereas medium-size snappers had higher values. This snapper has a preference for habitats with submerged vegetation. The percentage of fish with food in their stomachs was higher during dark hours, providing evidence of the nocturnal habits of this fish.

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

    PubMed

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

    2011-04-01

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

  18. Identification and Utility of FdmR1 as a Streptomyces Antibiotic Regulatory Protein Activator for Fredericamycin Production in Streptomyces griseus ATCC 49344 and Heterologous Hosts▿ †

    PubMed Central

    Chen, Yihua; Wendt-Pienkowski, Evelyn; Shen, Ben

    2008-01-01

    The fredericamycin (FDM) A biosynthetic gene cluster, cloned previously from Streptomyces griseus ATCC 49344, contains three putative regulatory genes, fdmR, fdmR1, and fdmR2. Their deduced gene products show high similarity to members of the Streptomyces antibiotic regulatory protein (SARP) family (FdmR1) or to MarR-like regulators (FdmR and FdmR2). Here we provide experimental data supporting FdmR1 as a SARP-type activator. Inactivation of fdmR1 abolished FDM biosynthesis, and FDM production could be restored to the fdmR1::aac(3)IV mutant by expressing fdmR1 in trans. Reverse transcription-PCR transcriptional analyses revealed that up to 26 of the 28 genes within the fdm gene cluster, with the exception of fdmR and fdmT2, were under the positive control of FdmR1, directly or indirectly. Overexpression of fdmR1 in S. griseus improved the FDM titer 5.6-fold (to about 1.36 g/liter) relative to that of wild-type S. griseus. Cloning of the complete fdm cluster into an integrative plasmid and subsequent expression in heterologous hosts revealed that considerable amounts of FDMs could be produced in Streptomyces albus but not in Streptomyces lividans. However, the S. lividans host could be engineered to produce FDMs via constitutive expression of fdmR1; FDM production in S. lividans could be enhanced further by overexpressing fdmC, encoding a putative ketoreductase, concomitantly with fdmR1. Taken together, these studies demonstrate the viability of engineering FDM biosynthesis and improving FDM titers in both the native producer S. griseus and heterologous hosts, such as S. albus and S. lividans. The approach taken capitalizes on FdmR1, a key activator of the FDM biosynthetic machinery. PMID:18556785

  19. Serotoninergic system in hamster skin.

    PubMed

    Slominski, Andrzej; Pisarchik, Alexander; Semak, Igor; Sweatman, Trevor; Szczesniewski, Andre; Wortsman, Jacobo

    2002-10-01

    We have cloned the tryptophan hydroxylase cDNA from hamster pituitary and demonstrated its expression in the skin, melanotic and amelanotic melanomas, spleen, heart, and the eye. We further demonstrated that skin, melanomas, spleen, pituitary, and eye but not heart expressed arylalkylamine N-acetyltransferase mRNA. The cutaneous expression of the arylalkylamine N-acetyltransferase gene was accompanied by enzymatic activity for the conversion of serotonin and tryptamine to N-acetylserotonin and N-acetyltryptamine, respectively. There was marked regional variation in the serotonin N-acetyltransferase activity, which was higher in ear skin than in corpus skin, and was lower in melanomas than in normal skin. Serotonin N-acetyltransferase activity was significantly inhibited by Cole bisubstrate at low concentration (

  20. 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.

  1. Histopathology of Lyme arthritis in LSH hamsters

    SciTech Connect

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

    1989-05-01

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

  2. Effects of arsenic deprivation in hamsters.

    PubMed

    Uthus, E O

    1990-01-01

    An experiment was conducted to ascertain the effects of arsenic deprivation in hamsters. Male weanling Golden Syrian hamsters were fed a casein-corn-based diet containing approximately 12 ng arsenic/g. Controls were fed 1 microgram arsenic/g of diet, as Na2HAsO4.7 H2O. After 6 weeks arsenic deprivation elevated heart weight/body weight ratio and the concentration of liver zinc and decreased the concentrations of the plasma amino acids alanine, glycine, phenylalanine and taurine. Although no biological role has been found for arsenic, the findings indicate that the hamster is a suitable animal for arsenic deprivation studies and support the hypothesis that arsenic may have a physiological role that influences methionine/methyl metabolism.

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2014-01-01

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

  5. Intracellular distribution of estradiol and estrogen binding sites in the uterus and oviducts of the green monkey (cercopithecus griseus)

    SciTech Connect

    Alekseeva, M.L.; Fanchenko, N.D.; Novikov, E.A.; Shchedrina, R.N.

    1986-03-01

    This paper describes a comparative investigation of changes in estradoil (E/sub 2/) and progesterone (P) concentrations in the blood plasma and concentrations of E/sub 2/ and estrogen binding sites (EBS) in the uterus and oviducts of C. griseus in the course of the menstrual cycle. A 0.25 aqueous solution of sucrose, 10mM Tris-HC1 buffer containing 1.5 mM EDTA, a 0.1M phosphate buffer containing 0.01% and 0.1% gelatin, antisera against E/sub 2/-17beta and P, labeled 3 /SUB H/ -E/sub 2/-17beta and /sup 3/H-P (specific radioactivity 104 and 96 Ci/nmole respectively), and their unlabeled analogs, 0.5, 1, and 5% suspensions of activated charcoal in buffer with the addition of 0.1% gelatin, and scintillation fluid consisting of 0.5% PPO and 0.05% POPOP in toluene were used. Indirect evidence shows the absence of any additional intracellular mechanisms affecting translocation of activated cytoplasmic estrogenreceptor complexes into the nucleus.

  6. tmRNA of Streptomyces collinus and Streptomyces griseus during the growth and in the presence of antibiotics.

    PubMed

    Palecková, Petra; Bobek, Jan; Mikulík, Karel

    2009-01-01

    Streptomycetes are soil microorganisms with the potential to produce a broad spectrum of secondary metabolities. The production of antibiotics is accompanied by a decrease in protein synthesis, which raises the question of how these bacteria survived the transition from the primary to the secondary metabolism. Translating ribosomes incapable to properly elongate or terminate polypeptide chain activate bacterial trans-translation system. Abundance and stability of the tmRNA during growth of Streptomyces collinus and Streptomyces griseus producing kirromycin and streptomycin, respectively, was analysed. The level of tmRNA is mostly proportional to the activity of the translational system. We demonstrate that the addition of sub-inhibitory concentrations of produced antibiotics to the cultures from the beginning of the exponential phase of growth leads to an increase in tmRNA levels and to an incorporation of amino acids into the tag-peptides at trans-translation of stalled ribosomes. These findings suggest that produced antibiotics induce tmRNA that facilitate reactivation of stalled complex of ribosomes and maintain viability. The effect of antibiotics that inhibit the cell-wall turnover, DNA, RNA or protein synthesis on the level of tmRNA was examined. Antibiotics interfering with ribosomal target sites are more effective at stimulation of the tmRNA level in streptomycetes examined than those affecting the synthesis of DNA, RNA or the cell wall.

  7. Nonphotic phase shifting in hamster clock mutants.

    PubMed

    Mrosovsky, N; Salmon, P A; Menaker, M; Ralph, M R

    1992-01-01

    Golden hamsters with the tau mutation were kept in the dark and induced to become active through confinement to a novel running wheel for 3 hr. The response of the mutants to this nonphotic phase-shifting stimulus differed from that of wild-type hamsters. The mutants showed larger phase shifts, and their phase response curves differed in shape, with an advance portion at about circadian time 24, a phase at which wild types show delays. The results establish that the tau mutation, in addition to its already known effects, alters the response of the circadian system to nonphotic events.

  8. 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.

  9. 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.

  10. Disparities in activity levels and learning ability between Djungarian hamster (Phodopus sungorus) and Roborovskii hamster (Phodopus roborovskii).

    PubMed

    Ikeda, Hiromi; Nagasawa, Mao; Yamaguchi, Takeshi; Minaminaka, Kimie; Goda, Ryosei; Chowdhury, Vishwajit S; Yasuo, Shinobu; Furuse, Mitsuhiro

    2017-03-01

    The Djungarian hamster and the Roborovskii hamster belong to the same genus of Phodopus. However, the Djungarian hamster is tame and shows sedative behavior, while Roborovskii hamster is not tame and shows high levels of locomotor activity. Hyperactivity occurs in animals with tameless behavior. Tameness or tamelessness behavior is very important because tameness helps for breeding and controlling as well as it enables a strong human-animal bond. In the present study, we examined the relationships between activity levels and cognitive function in Djungarian and Roborovskii hamsters. Three types of behavioral tests were performed to analyze their activity levels, memory and leaning ability. The levels of L- and D-amino acids and monoamines in the brain were then determined. Roborovskii hamsters showed significantly higher locomotor activity than Djungarian hamsters. Memory ability was not significantly different between the two hamsters, but Roborovskii hamsters showed lower learning ability. Brain levels of D-serine which is related to enhancement in memory and learning ability, were significantly higher in Djungarian hamsters, but the reverse was true for brain dopamine and serotonin levels. These results suggest that these differences in brain metabolism may be related to the behavioral differences between the two hamsters.

  11. Severe glomerular disease in juvenile grey snapper Lutjanus griseus L. in the Gulf of Mexico caused by the myxozoan Sphaerospora motemarini n. sp.

    PubMed

    Holzer, Astrid S; Pecková, Hanka; Patra, Sneha; Brennan, Nathan P; Yanes-Roca, Carlos; Main, Kevan L

    2013-12-01

    In the eastern Gulf of Mexico, off the coast of Florida, grey snapper, Lutjanus griseus was found to be infected with the myxozoan parasite Sphaerospora motemarini n. sp., with high prevalence (83%) and intensity of infection occuring in age-0 fish, and with parasite levels decreasing with age (age-1 snapper 40%; age-2 snapper 0%). The morphological, molecular and phylogenetic characterisation of the myxozoan showed that it is a member of the typically marine, polysporoplasmid Sphaerospora spp. which form a subclade within the Sphaerospora sensu stricto clade of myxozoans, which is characterised by large expansion segments in their SSU rDNA sequences. Presporogonic stages of S. motemarini n. sp. were detected in the blood, using PCR. Pseudoplasmodia and spores were found to develop in the renal corpuscles of the host, causing their massive expansion. Macroscopic and histopathological changes were observed in age-0 fish and show that S. motemarini n. sp. causes severe glomerulonephritis in L. griseus leading to a compromised host condition, which makes it more susceptible to stress (catch-and-release, predators, water quality) and can result in mortalities. These results are discussed in relation to the exploitation of grey snapper populations by commercial and recreational fisheries and with the observed increased mortalities with temperature along the coast of Florida. In the future, we would like to determine prevalence and intensity of infection with S. motemarini n. sp. in juvenile L. griseus in different areas of the Gulf of Mexico in order to be able to estimate the temperature dependence of S. motemarini n. sp. proliferation and to be able to predict its distribution and severity during climatic changes in the Gulf.

  12. Severe glomerular disease in juvenile grey snapper Lutjanus griseus L. in the Gulf of Mexico caused by the myxozoan Sphaerospora motemarini n. sp.

    PubMed Central

    Holzer, Astrid S.; Pecková, Hanka; Patra, Sneha; Brennan, Nathan P.; Yanes-Roca, Carlos; Main, Kevan L.

    2013-01-01

    In the eastern Gulf of Mexico, off the coast of Florida, grey snapper, Lutjanus griseus was found to be infected with the myxozoan parasite Sphaerospora motemarini n. sp., with high prevalence (83%) and intensity of infection occuring in age-0 fish, and with parasite levels decreasing with age (age-1 snapper 40%; age-2 snapper 0%). The morphological, molecular and phylogenetic characterisation of the myxozoan showed that it is a member of the typically marine, polysporoplasmid Sphaerospora spp. which form a subclade within the Sphaerospora sensu stricto clade of myxozoans, which is characterised by large expansion segments in their SSU rDNA sequences. Presporogonic stages of S. motemarini n. sp. were detected in the blood, using PCR. Pseudoplasmodia and spores were found to develop in the renal corpuscles of the host, causing their massive expansion. Macroscopic and histopathological changes were observed in age-0 fish and show that S. motemarini n. sp. causes severe glomerulonephritis in L. griseus leading to a compromised host condition, which makes it more susceptible to stress (catch-and-release, predators, water quality) and can result in mortalities. These results are discussed in relation to the exploitation of grey snapper populations by commercial and recreational fisheries and with the observed increased mortalities with temperature along the coast of Florida. In the future, we would like to determine prevalence and intensity of infection with S. motemarini n. sp. in juvenile L. griseus in different areas of the Gulf of Mexico in order to be able to estimate the temperature dependence of S. motemarini n. sp. proliferation and to be able to predict its distribution and severity during climatic changes in the Gulf. PMID:24533325

  13. Characterization of the S1 binding site of the glutamic acid-specific protease from Streptomyces griseus.

    PubMed Central

    Stennicke, H. R.; Birktoft, J. J.; Breddam, K.

    1996-01-01

    The glutamic acid-specific protease from Streptomyces griseus (SGPE) is an 18.4-kDa serine protease with a distinct preference for Glu in the P1 position. Other enzymes characterized by a strong preference for negatively charged residues in the P1 position, e.g., interleukin-1 beta converting enzyme (ICE), use Arg or Lys residues as counterions within the S1 binding site. However, in SGPE, this function is contributed by a His residue (His 213) and two Ser residues (Ser 192 and S216). It is demonstrated that proSGPE is activated autocatalytically and dependent on the presence of a Glu residue in the -1 position. Based on this observation, the importance of the individual S1 residues is evaluated considering that enzymes unable to recognize a Glu in the P1 position will not be activated. Among the residues constituting the S1 binding site, it is demonstrated that His 213 and Ser 192 are essential for recognition of Glu in the P1 position, whereas Ser 216 is less important for catalysis out has an influence on stabilization of the ground state. From the three-dimensional structure, it appears that His 213 is linked to two other His residues (His 199 and His 228), forming a His triad extending from the S1 binding site to the back of the enzyme. This hypothesis has been tested by substitution of His 199 and His 228 with other amino acid residues. The catalytic parameters obtained with the mutant enzymes, as well as the pH dependence, do not support this theory; rather, it appears that His 199 is responsible for orienting His 213 and that His 228 has no function associated with the recognition of Glu in P1. PMID:8931145

  14. Seasonal Sexual Segregation by Monomorphic Sooty Shearwaters Puffinus griseus Reflects Different Reproductive Roles during the Pre-Laying Period

    PubMed Central

    Hedd, April; Montevecchi, William A.; Phillips, Richard A.; Fifield, David A.

    2014-01-01

    Tracking technology has revolutionized knowledge of seabird movements; yet, few studies have examined sex differences in distribution and behavior of small to medium-sized, sexually-monomorphic seabirds. Application of bird-borne geolocation-immersion loggers revealed seasonal segregation in the sexually-monomorphic Sooty Shearwater Puffinus griseus, mainly in the pre-laying period, when there were clear differences in reproductive roles. Shearwaters first returned to the Falkland Islands on 27 Sept±8 d; males, on average, 8 d earlier than females. Prior to egg-laying, distribution at sea, colony attendance and behaviour depended on sex. Males foraged locally over the southern Patagonian Shelf and Burdwood Bank, spending mainly single days at sea and intervening nights in the burrow. Females, who flew for more of the day during this time, foraged in more distant areas of the northern Patagonian Shelf and Argentine Basin that were deeper, warmer and relatively more productive. Attendance of females at the colony was also more variable than that of males and, overall, males were present for significantly more of the pre-laying period (38 vs. 19% of time). Sex differences were reduced following egg-laying, with males and females using similar foraging areas and making trips of similar mean duration in incubation (7.6±2.7 d) and chick-rearing (1.4±1.3 d). Congruence continued into the non-breeding period, with both sexes showing similar patterns of activity and areas of occupancy in the NW Atlantic. Thus, seasonal changes in reproductive roles influenced patterns of sexual segregation; this occurred only early in the season, when male Sooty Shearwaters foraged locally, returning regularly to the colony to defend (or maintain) the burrow or the mate, while females concentrated on building resources for egg development in distant and relatively more productive waters. PMID:24416429

  15. Pathologic findings in Western gray squirrels (Sciurus griseus) from a notoedric mange epidemic in the San Bernardino Mountains, California☆

    PubMed Central

    Stephenson, Nicole; Swift, Pam; Villepique, Jeffrey T.; Clifford, Deana L.; Nyaoke, Akinyi; De la Mora, Alfonso; Moore, Janet; Foley, Janet

    2013-01-01

    Notoedric mange, caused by the contagious, burrowing mite Notoedres centrifera, has been associated with several large-scale population declines of western gray squirrels (Sciurus griseus) and has been a significant obstacle to population recovery in Washington State where the species is listed as threatened. In 2009, residents and wildlife rehabilitators in the isolated San Bernardino Mountains of southern California reported a dramatic die-off of western gray squirrels, in what had been a previously dense and robust population. Individuals were observed suffering from abnormal neurologic behaviors (ataxia and obtundation) and severe skin disease. Full necropsy of five squirrels from the epidemic showed that all had moderate to severe infestation with mange mites and severe dermatitis characterized by hyperkeratosis, acanthosis, intralesional mites, intracorneal pustules and superficial bacteria. Mites from affected squirrels were evaluated by light and electron microscopy and identified as N. centrifera based on morphologic criteria. Additionally, the internal transcribed spacer-2 region of the mite was cloned, sequenced and accessioned in GenBank. The cause for the abnormal neurologic behavior was not confirmed on post-mortem examination. However, we hypothesize that mange can cause incoordination and obtundation as a result of malnutrition and dehydration, and intense pruritis may induce abnormal or erratic behavior that could be mistaken for neurologic signs. While we have characterized the severe impact this disease can have on individual animals, more work is needed to understand the impact on squirrel populations, particularly in view of the anecdotal reports of dramatic population declines that may take decades to recover. PMID:24533345

  16. Bioactivation of diethylstilbestrol by the Syrian hamster kidney

    SciTech Connect

    Adams, S.P.

    1987-01-01

    Male Syrian golden hamsters chronically exposed to diethylstilbestrol (DES) develop renal adenocarcinomas with an incidence approaching 100%. The ability of the hamster kidney to bioactivate DES was assessed using hamster kidney slices. The male hamster renal cortex has a 2- to 5-fold greater capacity to irreversibly bind ({sup 3}H)DES as compared with female hamster renal cortex and with male hamster renal medulla. Incubation of the tissue under anaerobic conditions inhibited the metabolism and irreversible binding of ({sup 3}H)DES. Gel electrophoresis analysis of covalently modified proteins revealed several radioactive peaks indicating that specific adduct formation had occurred. The cytochrome P-450 inhibitors SKF 525-A, metyrapone, carbon monoxide, butylated hydroxytoluene, and dicumarol decreased the irreversible binding of ({sup 3}H)DES to renal cortical protein by 38 to 72%.

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

    PubMed Central

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

    2015-01-01

    Marine actinobacteria are known to be a rich source for novel metabolites with diverse biological activities. In this study, a potential extracellular L-asparaginase was characterised from the Streptomyces griseus NIOT-VKMA29. Box-Behnken based optimization was used to determine the culture medium components to enhance the L-asparaginase production. pH, starch, yeast extract and L-asparagine has a direct correlation for enzyme production with a maximum yield of 56.78 IU mL−1. A verification experiment was performed to validate the experiment and more than 99% validity was established. L-Asparaginase biosynthesis gene (ansA) from Streptomyces griseus NIOT-VKMA29 was heterologously expressed in Escherichia coli M15 and the enzyme production was increased threefold (123 IU mL−1) over the native strain. The ansA gene sequences reported in this study encloses several base substitutions with that of reported sequences in GenBank, resulting in altered amino acid sequences of the translated protein. PMID:26206135

  18. A mutation at proline-115 in the A-factor receptor protein of Streptomyces griseus abolishes DNA-binding ability but not ligand-binding ability.

    PubMed Central

    Onaka, H; Sugiyama, M; Horinouchi, S

    1997-01-01

    A-factor (2-isocapryloyl-3R-hydroxymethyl-gamma-butyrolactone) and its specific receptor protein (ArpA) are required for streptomycin production and aerial mycelium formation in Streptomyces griseus. A mutant strain HO1 that produced streptomycin and formed aerial mycelium and spores was derived from an A-factor-deficient mutant, S. griseus HH1. The phenotypes of mutant HO1 were found to result from a single amino acid replacement of ArpA; the proline residue at position 115 in the wild-type ArpA was replaced by serine, yielding mutant ArpA (P115S). The mutant ArpA (P115S) was still able to form a homodimer and possessed A-factor-binding ability but lost the ability to bind DNA. The properties of P115S suggest that ArpA consists of two independently functional domains, one for A-factor binding and one for DNA binding, and that proline-115 plays an important role in DNA binding. This is in agreement with the idea that A-factor binding to the COOH-terminal domain of ArpA causes a subtle conformational change of the distal NH2-terminal DNA-binding domain, resulting in dissociation of ArpA from DNA. PMID:9098075

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

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

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

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

    PubMed

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

    2015-07-24

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

  1. Tumor-related gene changes in immunosuppressive Syrian hamster cholangiocarcinoma.

    PubMed

    Juasook, Amornrat; Aukkanimart, Ratchadawan; Boonmars, Thidarut; Sudsarn, Pakkayanee; Wonkchalee, Nadchanan; Laummaunwai, Porntip; Sriraj, Pranee

    2013-10-01

    The results of a previous study demonstrated that prednisolone enhanced cholangiocarcinogenesis. Therefore, to clarify molecular changes during immunosuppressive cholangiocarcinogenesis, Syrian hamsters were divided into 8 groups: uninfected controls; immunosuppressed Syrian hamsters using prednisolone (P); normal Syrian hamsters administered N-nitrosodimethylamine (ND); immunosuppressed Syrian hamsters administered N-nitrosodimethylamine (NDis); normal Syrian hamsters infected with Opisthorchis viverrini (OV); immunosuppressed Syrian hamsters infected with O. viverrini (OVis); normal Syrian hamsters infected with O. viverrini and administered N-nitrosodimethylamine (CCA); and immunosuppressed Syrian hamsters infected with O. viverrini and administered N-nitrosodimethylamine (CCAis). Syrian hamster livers were used for analysis of tumor-related gene expression and immunohistochemistry through cytokeratin 19 (CK19) and proliferating cell nuclear antigen (PCNA) staining. The tumor-related gene expression results show that CCAis groups at all time points exhibited upregulation of COX-2, IL-6, SOD1, CAT and iNOS and downregulation of p53, which correlated with the predominant expression of CK19 and PCNA in liver tissue. These results suggest that prednisolone enhances cholangiocarcinoma development, which was confirmed by molecular changes.

  2. Isolation and characterization of tryptophan transaminase and indolepyruvate C-methyltransferase. Enzymes involved in indolmycin biosynthesis in Streptomyces griseus.

    PubMed

    Speedie, M K; Hornemann, U; Floss, H G

    1975-10-10

    Two enzymes, tryptophan transaminase and indolepyruvate C-methyltransferase, which are active in the initial steps of the biosynthetic pathway of the antibiotic indolmycin, have been detected and partially purified from cell-free extracts of Streptomyces griseus. The transaminase has been purified 3-fold by ammonium sulfate fractionation. At this stage of purification, it catalyzes the alpha-ketoglutarate and pyridoxal phosphate-dependent transamination of L-tryptophan, 3-methyltryptophan, L-pphenylalanine, and L-tyrosine. The C-methyltransferase catalyzes the transfer of a methyl group from S-adenosylmethionine to position 3 of the aliphatic side chain of indolepyruvate. No cofactors are required. The C-methyltransferase has been purified 110-fold by ammonium sulfate fractionation, Sephadex G-150 gel filtration, DEAE-Sephadex column chromotography, and Bio-Gel A-5m gel filtration. The enzyme has a broad pH optimum of 7.5 to 8.5. A molecular weight of 55,000 +/- 5,000 has been determined by Sephadex G-200 gel filtration with reference proteins and a molecular weight of 58,000 +/- 8,000 has been determined by sucrose density gradient centrifugation. The enzyme is relatively stable at temperatures of 0-5 degrees but is destroyed by freezing or by heating. The C-methyltransferase is inhibited strongly by the thiol reagents p-chloromercuribenzoate and N-ethylmaleimide. The Zn2+ and Fe2+ chelators 1,10-phenanthroline and 2,2'-bipyridine also inhibit the enzyme activity but EDTA does not. Michaelis-Menten constants have been determined for the 110-fold purified enzyme as 1.2 X 10(-5) M for S-adenosylmethionine and 4.8 X 10(-6) M for indolepyruvate. The enzyme activity in the crude extract is inhibited competitively by indolmycin (Ki equals 2.3 mM) and L-tryptophan (Ki equals 0.17 mM), but these effects are not observed after the enzyme has been passed through the Sephades G-150 column during purification. The crude extract is capable of methylating phenylpyruvate and p

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

    PubMed Central

    Casto, Bruce C.

    1969-01-01

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

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

    EPA Science Inventory

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

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

    PubMed Central

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

    2009-01-01

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

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

    PubMed

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

    2007-10-01

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

  7. A gene cluster involved in aerial mycelium formation in Streptomyces griseus encodes proteins similar to the response regulators of two-component regulatory systems and membrane translocators.

    PubMed Central

    Ueda, K; Miyake, K; Horinouchi, S; Beppu, T

    1993-01-01

    Mutants of Streptomyces griseus deficient in A-factor production are sporulation negative, since A-factor is an essential hormonal regulator for the induction of morphological and physiological differentiation in this bacterium. A DNA fragment which induced aerial mycelium formation and sporulation in an A-factor-deficient mutant strain, S. griseus HH1, was cloned from this mutant strain. Subcloning experiments and nucleotide sequencing showed that two open reading frames, ORF1 with 656 amino acids and ORF2 with 201 amino acids, were required in order to induce sporulation. The amino acid sequence of ORF1 significantly resembled that of the Escherichia coli HlyB protein, a member of a family of bacterial membrane proteins engaged in ATP-dependent secretion mechanisms. Conserved features of this surface translocator family, such as the transmembrane structure predicted by their hydropathy profiles and the amino acid sequence forming an ATP-binding fold, were also conserved in ORF1. The ORF1 gene appeared to constitute a transcriptional unit with an additional upstream gene encoding ORF3, which was greatly similar to ORF1 in size and amino acid sequence. The other protein, ORF2, showed significant end-to-end homology with the E. coli uhpA product, a regulatory protein for the uptake of sugar phosphates. Like UhpA as a response regulator of a bacterial two-component regulatory system, ORF2 contained a helix-turn-helix DNA-binding domain at its COOH-terminal portion and an Asp residue (Asp-54) probably to be phosphorylated at its NH2-terminal portion. An amino acid replacement from Asp-54 to Asn resulted in the loss of the ability of ORF2 to induce sporulation in strain HH1. Images PMID:8458843

  8. Circadian rhythms accelerate wound healing in female Siberian hamsters.

    PubMed

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

    2017-03-15

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

  9. A role for glucose in hypothermic hamsters

    NASA Technical Reports Server (NTRS)

    Resch, G. E.; Musacchia, X. J.

    1976-01-01

    Hypothermic hamsters at a rectal temperature of 7 C showed a fivefold increase in survival times from 20 to 100.5 hr when infused with glucose which maintained a blood level at about 45 mg/100 ml. A potential role for osmotic effects of the infusion was tested and eliminated. There was no improvement in survival of 3-O-methylglucose or dextran 40-infused animals. The fact that death eventually occurs even in the glucose-infused animal after about 4 days and that oxygen consumption undergoes a slow decrement in that period suggests that hypothermic survival is not wholly substrate limited. Radioactive tracer showed that localization of the C-14 was greatest in brain tissue and diaphragm, intermediate in heart and kidney, and lowest in skeletal muscle and liver. The significance of the label at sites important to respiration and circulation was presented.

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

    NASA Technical Reports Server (NTRS)

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

    1972-01-01

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

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

    PubMed

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

    2016-09-01

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

  12. Histaminergic regulation of seasonal metabolic rhythms in Siberian hamsters.

    PubMed

    I'anson, Helen; Jethwa, Preeti H; Warner, Amy; Ebling, Francis J P

    2011-06-01

    We investigated whether histaminergic tone contributes to the seasonal catabolic state in Siberian hamsters by determining the effect of ablation of histaminergic neurons on food intake, metabolic rate and body weight. A ribosomal toxin (saporin) conjugated to orexin-B was infused into the ventral tuberomammillary region of the hypothalamus, since most histaminergic neurons express orexin receptors. This caused not only 75-80% loss of histaminergic neurons in the posterior hypothalamus, but also some loss of other orexin-receptor expressing cells e.g. MCH neurons. In the long-day anabolic state, lesions produced a transient post-surgical decrease in body weight, but the hamsters recovered and maintained constant body weight, whereas weight gradually increased in sham-lesioned hamsters. VO(2) in the dark phase was significantly higher in the lesioned hamsters compared to shams, and locomotor activity also tended to be higher. In a second study in short days, sham-treated hamsters showed the expected seasonal decrease in body weight, but weight remained constant in the lesioned hamsters, as in the long-day study. Lesioned hamsters consumed more during the early dark phase and less during the light phase due to an increase in the frequency of meals during the dark and decreased meal size during the light, and their cumulative food intake in their home cages was greater than in the control hamsters. In summary, ablation of orexin-responsive cells in the posterior hypothalamus blocks the short-day induced decline in body weight by preventing seasonal hypophagia, evidence consistent with the hypothesis that central histaminergic mechanisms contribute to long-term regulation of body weight.

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

    PubMed

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

    2013-10-01

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

  14. [Induction of protective antiamebic immunity in hamsters with heterologous antigens].

    PubMed

    Jiménez Cardoso, J M; Jiménez, E; de Jesús Bernal, M; Kumate, J

    1989-01-01

    Two hundred and twenty-five Syrian golden hamsters were used. Twenty five of them served as the control group. All other hamsters were intradermal immunized, once a week for four weeks, with a mixture of amebic proteins, mixed with complete Freund adjuvant, obtained from 5 x 10(5) homogenized dead amebic trophozoites from five different strains. Each group of hamsters (five groups of 40 animals each) were immunized with one of the following strains: E. histolytica HM-531, HJ-1, HM1-IMSS, E. chattoni PM-4 and PM-5. All hamsters, including those from the control group, were later inoculated with 0.2 mL equivalent to 1 x 10(5) live trophozoites from the different strains grown in axenic TYI-S-33 medium. Inoculation was performed by direct injection into the liver. The hamsters were sacrificed eight days later and their livers examined. All non-immunized animals showed extensive gross hepatic nodular abscesses. The liver of immunized hamsters showed mild to moderate lesions: the histopathological striking feature was non-specific granulomata. It is concluded that the immunized animals inoculated with homologous stock showed protective immunity to amebic infections. In other cases, immunity was seen though they were inoculated with a heterologous stock.

  15. Regulation of tonic gonadotropin release in prepubertal female hamsters

    SciTech Connect

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

    1982-04-01

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

  16. Ocular pathological changes in hamsters experimentally infected with Schistosoma mansoni.

    PubMed

    Ismail, H I H; Ashour, D S; Abou Rayia, D M; Ali, A L

    2016-11-01

    Ocular lesions have been reported in patients with schistosomiasis; however, the problem with studying schistosomal infection of the human eye is that biopsies are almost impossible to take, and histopathological examination of suspicious lesions can only be undertaken post-mortem or after enucleation. This work aimed to study the possible effects and pathogenesis of schistosomiasis on the eye. This study involved 55 hamsters; five hamsters remained non-infected and the remaining 50 hamsters were infected with Schistosoma mansoni cercariae. Infected hamsters were sacrificed on weeks 8, 12, 16 and 20 post-infection (pi). Eye sections were prepared and stained for histopathological and immunohistochemical studies. Histopathological changes detected in hamsters infected after 16 and 20 weeks included looseness and oedema of the innermost retinal layers together with hyperplastic polypoid growth. Neither eggs nor granulomata were detected in eye sections throughout the experimental period. Deposition of S. mansoni antigen was revealed in 35% of infected hamsters. Later, on weeks 16 and 20 pi, moderate subepithelial conjuctival deposits and marked subchoroidal and scleral deposition were detected. In conclusion, the deposition of schistosomal antigen and immune complexes may play a pivotal role in the ocular changes that occur in schistosomiasis, even in the absence of detectable Schistosoma eggs. Schistosomiasis should be suspected in cases with unexplained ophthalmological findings, especially in endemic areas.

  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. 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.

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

    SciTech Connect

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

    1980-09-01

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

  20. Metabolic initiation of differentiation and secondary metabolism by Streptomyces griseus: significance of the stringent response (ppGpp) and GTP content in relation to A factor.

    PubMed Central

    Ochi, K

    1987-01-01

    I investigated the significance of the intracellular accumulation of guanosine 5'-diphosphate 3'-diphosphate (ppGpp) and of the coordinated decrease in the GTP pool for initiating morphological and physiological differentiation of Streptomyces griseus, a streptomycin-producing strain. In solid cultures, aerial mycelium formation was severely suppressed by the presence of excess nutrients. However, decoyinine, a specific inhibitor of GMP synthetase, enabled the cells to develop aerial mycelia in the suppressed cultures at concentrations which only partially inhibited growth. A factor (2S-isocapryloyl-3S-hydroxymethyl-gamma-butyrolactone) added exogenously had no such effect. Decoyinine was also effective in initiating the formation of submerged spores in liquid culture. The ability to produce streptomycin did not increase but decreased drastically on the addition of decoyinine. This sharp decrease in streptomycin production was accompanied by a decrease in intracellular accumulation of ppGpp. A relaxed (rel) mutant was found among 25 thiopeptin-resistant isolates which developed spontaneously. The rel mutant had a severely reduced ability to accumulate ppGpp during a nutritional shift-down and also during postexponential growth and showed a less extensive decrease in the GTP pool than that in the rel+ parental strain. The rel mutant failed to induce the enzymes amidinotransferase and streptomycin kinase, which are essential for the biosynthesis of streptomycin. The abilities to form aerial mycelia and submerged spores were still retained, but the amounts were less, and for both the onset of development was markedly delayed. The decreased ability to produced submerged spores was largely restored by the addition of decoyinine. This was accompanied by an extensive GTP pool decrease. The rel mutant produced A factor normally, indicating that synthesis of A factor is controlled neither by ppGpp nor by GTP. Conversely, a mutant defective in A-factor synthesis accumulated

  1. 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.

  2. Caloric density affects food hoarding and intake by Siberian hamsters.

    PubMed

    Wood, A D; Bartness, T J

    1996-01-01

    Siberian hamsters respond to food deprivation or restriction by increasing their food hoarding and do so proportionately to the degree of body mass (fat) loss. These data suggest that Siberian hamsters integrate their internally stored energy as body fat with their externally stored energy as hoarded food such that when internal energy stores are decreased, external stores are increased. The purpose of the present experiments was to test whether the caloric value of the food hoard is regulated. This was accomplished by challenging the hamsters with diets of varying caloric density and assessing whether their hoarded food is changed accordingly. Specifically, in Experiment 1 hamsters were switched from the control food pellets to a diet where the caloric density was increased by creating a high fat diet (HFD). In Experiment 2, the caloric density of the control diet was decreased by diluting it with cellulose such that 25% and 50% (kcal/wt) reduced calorie diets (RCDs) were created. HFD-fed hamsters decreased their food hoarding, increased their body mass, and decreased the grams of food eaten, but not enough to compensate exactly for the increased caloric density of the diet. When refed the control diet, food hoarding increased to pre-HFD levels as body mass and food intake decreased. RCD feeding resulted in caloric density-dependent effects on all measures. Food hoarding and intake (grams and calories) increased when hamsters were given the 25% RCD and did so to an even greater degree when given the 50% RCD. Thus, Siberian hamsters responded to increases or decreases in the caloric density of their food by attempting to regulate the number of calories hoarded and eaten; however, the adjustments in food hoarding: 1) were not precise, 2) were largely opposite of food intake, 3) tended to be inversely related to body mass and 4) were caloric density dependent.

  3. Toxic element concentrations in the bottlenose (Tursiops truncatus), striped (Stenella coeruleoalba) and Risso's (Grampus griseus) dolphins stranded in eastern Adriatic Sea.

    PubMed

    Bilandžić, Nina; Sedak, Marija; Ðokić, Maja; Ðuras Gomerčić, Martina; Gomerčić, Tomislav; Zadravec, Manuela; Benić, Miroslav; Prevendar Crnić, Andrea

    2012-09-01

    Concentrations of cadmium (Cd), arsenic (As), mercury (Hg) and lead (Pb) were measured in muscle, liver and kidney of three cetacean species, the bottlenose (Tursiops truncatus), striped (Stenella coeruleoalba) and Risso's (Grampus griseus) dolphins from the Croatian waters of the Adriatic Sea. In all three dolphin species Cd levels decreased in tissues in the order: kidney > liver > muscle, while As and Pb decreased in the order: liver > kidney > muscle for striped and Risso's dolphins, but with the order reversed for liver and kidney in the bottlenose dolphin for Pb. Levels of Hg consistently followed the order: liver > muscle > kidney, with mean concentrations in the liver being 11-34 times higher than in the other tissues. The highest mean concentrations of trace elements were measured in Risso's dolphins at 14.9 μg/g wet weight, for Cd in the kidney, and concentrations in the liver of 2.41, 1,115 and 0.63 μg/g for As, Hg and Pb, respectively. Statistically significant differences between the three dolphin species were determined for Cd, Hg and Pb in liver tissues, for As in muscle and for Cd in kidney. Significant correlations of metals between tissues were determined in all three species. The results presented give an indication of the environmental condition with regard to the content of toxic metals along the eastern coast of the Adriatic Sea.

  4. Humoral and cellular response to infection with Echinostoma revolutum in the golden hamster, Mesocricetus auratus.

    PubMed

    Mabus, J; Huffman, J E; Fried, B

    1988-06-01

    Laboratory hamsters (Mesocricetus auratus) were infected with Echinostoma revolutum (Trematoda). Immunoelectrophoretic studies of hamster serum showed no demonstrable antibody response to E. revolutum. Histopathologic examination of intestinal tissue of infected hamsters showed erosion of intestinal villi and lymphocytic infiltration as the primary host response. Spleens from infected hamsters were hyperplastic during the first 3 weeks of infection and atrophic from 4 to 8 weeks postinfection. Hamsters were unable to acquire a resistance to E. revolutum infection. Lack of resistance was demonstrated in hamsters where the parasite infection was no longer detected based on the absence of eggs in the faeces; these hamsters were then reinfected. Hamsters treated with the anthelmintic oxyclozanide were also reinfected with E. revolutum.

  5. Treatment of disseminated histoplasmosis in hamsters.

    PubMed

    Finquelievich, J L; Negroni, R; Iovannitti, C; Bava, A J

    1989-02-01

    A comparative study between itraconazole, ketoconazole and amphotericin B in the treatment of experimental histoplasmosis in hamsters was carried out. Seventy five animals were inoculated intracardiacally with the yeast-phase of Histoplasma capsulatum. They were divided in 5 groups: 1) treated with itraconazole by gavage (g) at a daily dose of 16 mg/kg; 2) treated with ketoconazole by (g) at a daily dose of 80 mg/kg; 3) treated with amphotericin B intraperitoneally (i.p.) at 6 mg/kg every other day; 4) control animals receiving distilled water i.p. and 5) control animals receiving P.E.G. 200 by (g). All the treatments were started one week after the challenge inoculation and they were given for 21 days. The results were evaluated by autopsy of all the animals one week after the end of the treatments. The following determinations were taken into account: microscopic examinations of spleen, liver and lungs and cultures of the spleen with determination of colony forming units/g. All the antifungal drugs used in this study were able to cause negative microscopic examinations of the liver, spleen and lungs; but only amphotericin B produced culture negative results. Itraconazole and ketoconazole presented 66% and 86% of positive cultures respectively, nevertheless the C.F.U. were lower than those obtained in control groups. In these experimental conditions amphotericin B seems to be more active than the azolic compounds and itraconazole is slightly superior to ketoconazole at a lower dose.

  6. Establishment and persistence of photoperiodic memory in hamsters

    PubMed Central

    Prendergast, Brian J.; Gorman, Michael R.; Zucker, Irving

    2000-01-01

    Long summer days unequivocally stimulate, and short winter days inhibit reproduction in Siberian hamsters. By contrast, intermediate-duration day lengths (12.5–14 h long) either accelerate reproductive development or initiate regression of the reproductive apparatus. Which of these outcomes transpires depends on an animal's photoperiodic history, suggesting that hamsters must encode a representation of prior photoperiods. The duration of nocturnal melatonin secretion is the endocrine representation of day length, but nothing is known about how long it takes to establish photoperiodic histories or how long they endure. Hamsters exposed for 2 or more weeks to long summer day lengths acquired a long-day photoperiodic history that determined subsequent reproductive responses to intermediate-duration day lengths and melatonin signals. The memory for long-day lengths persisted in pinealectomized hamsters for 6.5 weeks, faded significantly after 13 weeks, and was functionally absent after 20 weeks. These findings indicate that hamsters are influenced only by relatively recent day lengths and melatonin signals and ignore earlier ones that might cause them to misinterpret the salience of current day lengths. PMID:10792054

  7. Circadian regulation of cortisol release in behaviorally split golden hamsters.

    PubMed

    Lilley, Travis R; Wotus, Cheryl; Taylor, Daniel; Lee, Jennifer M; de la Iglesia, Horacio O

    2012-02-01

    The master circadian clock located within the hypothalamic suprachiasmatic nucleus (SCN) is necessary for the circadian rhythm of glucocorticoid (GC) release. The pathways by which the SCN sustains rhythmic GC release remain unclear. We studied the circadian regulation of cortisol release in the behaviorally split golden hamster, in which the single bout of circadian locomotor activity splits into two bouts approximately 12 h apart after exposing the animals to constant light conditions. We show that unsplit control hamsters present a single peak of cortisol release that is concomitant with a single peak of ACTH release. In contrast, split hamsters show two peaks of cortisol release that are approximately 12 h appart and are appropriately phased to each locomotor activity bout but surprisingly do not rely on rhythmic release of ACTH. Our results are consistent with a model in which the circadian pacemaker within the SCN regulates the circadian release of GC via input to the hypothalamo-pituitary-adrenal axis and via a second regulatory pathway, which likely involves sympathetic innervation of the adrenal and can operate even in the absence of ACTH circadian rhythmic release. Furthermore, we show that although the overall 24-h cortisol output in split hamsters is lower than in unsplit controls, split hamsters release constant low levels of ACTH. This result suggests that the timing, rather than the absolute amount, of cortisol release is more critical for the induction of negative feedback effects that regulate the hypothalamo-pituitary-adrenal axis.

  8. 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.

  9. 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.

  10. Hamster and Murine Models of Severe Destructive Lyme Arthritis

    PubMed Central

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

    2012-01-01

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

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

    PubMed Central

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

    1996-01-01

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

  12. Tamoxifen inhibits estrogen-induced hepatic injury in hamsters.

    PubMed

    Coe, J E; Ross, M J

    1988-01-01

    Estrogens have an unusual toxic effect on the liver of two hamster species, the Armenian and the Chinese hamster. The hepatotoxicity was detectable clinically by hyperbilirubinemia and confirmed histologically by the presence of hepatic degenerative-regenerative changes. Administration of tamoxifen with estrogen [either ethynyl estradiol or diethylstilbestrol (DES)] completely abrogated the hepatotoxic effects, suggesting that estrogen receptor (ER) was necessary for estrogen to damage liver. In Armenian hamsters, estrogens decreased hepatic synthesis of female protein (FP); tamoxifen also abolished this DES effect and resulted in a net increase in serum FP levels. DES administration produced higher serum bilirubin levels and lower serum FP levels in females than in males. Paradoxically, tamoxifen blocked these DES effects more effectively and efficiently in females than in males. Estrogens did not injure uteri of Armenian and Chinese hamsters and were nontoxic to livers of other hamsters species, such as Syrian and Turkish. This model provides another perspective of the acute cellular derangement that can be effected by estrogen-ER complex and may indicate a yet unknown mode of ER action.

  13. 9 CFR 3.36 - Primary enclosures used to transport live guinea pigs and hamsters.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

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

  14. 9 CFR 3.36 - Primary enclosures used to transport live guinea pigs and hamsters.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

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

  15. 9 CFR 3.36 - Primary enclosures used to transport live guinea pigs and hamsters.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

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

  16. 9 CFR 3.36 - Primary enclosures used to transport live guinea pigs and hamsters.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

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

  17. 9 CFR 3.36 - Primary enclosures used to transport live guinea pigs and hamsters.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

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

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

    PubMed

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

    2013-01-15

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

  19. Comparison of two Egyptian strains of Schistosoma mansoni in hamsters.

    PubMed

    Soliman, G N; el Assal, F M; Mansour, N S; Garo, K

    1986-01-01

    In human infection with Schistosoma mansoni from Beni-Suef, the eggs were encountered more frequently in the urine of patients than in infection with S. mansoni from Giza, where eggs were passed into the stool. A comparative study of the two strains of S. mansoni from Beni-Suef and Giza has been carried out in golden hamster. Consistent strain differences were observed. The Beni-Suef strain proved to have lower worm recovery and different egg distribution patterns in tissues of infected hamsters. Worms of both sexes of this strain were larger in size and required a longer period to reach maturity. Hence, the prepatent period was prolonged. Significant differences between the two strains were also noted in the number of eggs per worm. A lower mortality rate and a longer survival time were encountered in hamsters infected with the Beni-Suef strain.

  20. 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

  1. Hyperprolactinemia does not promote testicular recrudescence in photoregressed Siberian hamsters.

    PubMed

    Whitten, R D; Youngstrom, T G; Bartness, T J

    1993-07-01

    Serum prolactin (PRL) concentrations, as well as body, epididymal white adipose tissue (EWAT), and testes weights, decrease in Siberian hamsters (Phodopus sungorus sungorus) following short-photoperiod exposure. Previously, we have shown that lesions of the suprachiasmatic nucleus of the hypothalamus (SCNx) block regression of the testes and decreases in body weight and EWAT caused by short day-like, timed daily subcutaneous melatonin infusions in pinealectomized Siberian hamsters and elevate dramatically serum PRL concentrations. We also have shown that SCNx, as well as lesions of the paraventricular nucleus of the hypothalamus (PVNx) and an area immediately ventral to the PVN (subPVN), promote accelerated testicular recrudescence, increases in EWAT and body weights, and increases in serum PRL concentrations, in short-day (SD)-housed, photoregressed Siberian hamsters. The stimulation of the testes seen in these previous studies could have been due to the lesion-induced increases in serum PRL concentrations. Therefore, the purpose of the present experiment was to test whether experimentally induced hyperprolactinemia could stimulate testicular recrudescence. This was accomplished by giving photoregressed, SD-housed Siberian hamsters chronic subcutaneous infusions of ovine PRL (oPRL) to mimic either long-day- or lesion-induced serum concentrations of hamster prolactin (hPRL). No increase in testes, body, or EWAT weights were observed following 5 weeks of oPRL infusions in either group compared with their vehicle-infused counterparts. These data suggest that hyperprolactinemia was not solely responsible for the stimulation of testicular recrudescence in SCNx or PVNx photoregressed, or SCNx pinealectomized hamsters receiving timed melatonin infusions seen previously.

  2. Maternal entrainment of tau mutant hamsters.

    PubMed

    Viswanathan, N; Davis, F C

    1992-01-01

    Maternal entrainment of the circadian wheel-running activity rhythm was examined in Syrian hamsters heterozygous for a single gene mutation (tau) that affects the free-running period of circadian rhythms. Heterozygous tau pups were born to and raised by wild-type mothers under constant dim light. The pups' wheel-running activity was recorded after weaning on postnatal day 18 or 24. Pups weaned on day 18 had an average free-running period of 21.70 hr, demonstrating that the tau phenotype was fully expressed at this age. Using the activity onset of the postnatal free-running rhythms as a phase reference, we estimated the phase relationships between the pups and their mothers on days 18 and 24. In contrast to results with wild-type pups, the activity rhythms of tau pups were not in phase with the rhythms of their wild-type mothers; that is, activity onsets of mothers and pups did not coincide. The pups did, however, show synchrony among themselves, indicating that they had been exposed to a synchronizing signal sometime during development. It is likely that this synchronizing signal was provided by the mothers, since pups from different litters showed phase relationships similar to those of their mothers. Thus the mothers provided a signal that was sufficient to cause entrainment, despite the 2-hr difference in free-running period between the mothers and pups. Although the pups' activity rhythms appeared to have been entrained by the mothers, they were clearly free-running by postnatal day 18. The mechanism for entrainment is lost during the course of development, despite continued interaction between the mothers and pups.

  3. Hamster thecal cells express muscle characteristics

    SciTech Connect

    Self, D.A.; Schroeder, P.C.; Gown, A.M.

    1988-08-01

    Contraction of the follicular wall about the time of ovulation appears to be a coordinated event; however, the cells that mediate it remain poorly studied. We examined the theca externa cells in the wall of hamster follicles for the presence of a functional actomyosin system, both in developing follicles and in culture. We used a monoclonal antibody (HHF35) that recognizes the alpha and gamma isoelectric variants of actin normally found in muscle, but not the beta variant associated with non-muscle sources, to evaluate large preovulatory follicles for actin content and composition. Antibody staining of sectioned ovaries showed intense circumferential reactivity in the outermost wall of developing follicles. Immunoblots from two-dimensional gels of theca externa lysates demonstrated the presence of the two muscle-specific isozymes of actin. Immunofluorescence of cultured follicular cells pulse-labeled with (3H) thymidine (for autoradiographic detection of DNA replication) revealed the presence, in many dividing cells, of actin filaments aligned primarily along the longitudinal axis of the cells. In cultures exposed to the calcium ionophore A23187 (10(-4) M) for varying periods (5 min to 1 h), contraction of many individual muscle-actin-positive cells was observed. Immunofluorescence of these cells, fixed immediately after ionophore-induced contraction, revealed compaction of the actin filaments. Our findings demonstrate that the cells of the theca externa contain muscle actins from an early stage and that these cells are capable of contraction even while proliferating in subconfluent cultures. They suggest that follicular growth may include a naturally occurring developmental sequence in which a contractile cell type proliferates in the differentiated state.

  4. 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.

  5. Lesions of potato sprout and extracted potato sprout alkaloid toxicity in Syrian hamsters.

    PubMed

    Baker, D; Keeler, R; Gaffield, W

    1987-01-01

    Hamsters were gavaged either dried potato sprout material, alkaloid extract of potato sprouts, or the marc from which the alkaloid fraction was extracted and then were examined for gross and microscopic lesions. Nine of 10 hamsters receiving dried potato sprout material and 3 of 5 hamsters receiving alkaloid extract had severe gastric and intestinal mucosal necrosis which was most severe in the glandular stomach, duodenum and proximal jejunum. All control hamsters gavaged with water and all hamsters gavaged with the potato sprout marc survived to the time of euthanasia and did not have gross or microscopic lesions.

  6. Fecal inoculum can be used to determine the rate and extent of in vitro fermentation of dietary fiber sources across three lemur species that differ in dietary profile: Varecia variegata, Eulemur fulvus and Hapalemur griseus.

    PubMed

    Campbell, J L; Williams, C V; Eisemann, J H

    2002-10-01

    To estimate fermentative capacity among lemur species, four fiber substrates were tested across three species, Eulemur fulvus, Hapalemur griseus and Varecia variegata. The substrates, cellulose, beet pulp, citrus pulp and citrus pectin, ranged in composition from completely insoluble fiber (IF) to completely soluble fiber (SF), respectively. The lemurs consumed a nutritionally complete biscuit formulated for primates [85 g/100 g diet dry matter (DM)] and locally available produce (15 g/100 g diet DM). Feces were then collected and used to inoculate fermentation tubes prefilled with fiber substrates and an anaerobic growth medium. Dry matter disappearance (DMD), and acetate, propionate, butyrate, and total short-chain fatty acid (SCFA) production were measured in tubes subjected to 6, 12, 24 or 48 h of fermentation. Results were fitted to a logistic growth model. The maximal production (MP) time at which production or disappearance is at one-half maximum (t(50)) and the fermentation rate at 3 h were calculated. The maximal disappearance of DM differed among substrates (citrus pectin > citrus pulp > beet pulp; P < 0.0001) and species (E. fulvus > H. griseus > V. variegata; P < 0.001). V. variegata reached t(50) for acetate and total SCFA production faster than H. griseus or E. fulvus (P < 0.02). Three-hour production rates of acetate and total SCFA were also greater for V. variegata for citrus pulp and citrus pectin (P < 0.01). Few species differences were observed for beet pulp. Results provide evidence for differences in fermentative capacity and suggest that fiber solubility and fermentability should be considered when assessing the nutritional management of lemurs.

  7. Efficient Gene Targeting in Golden Syrian Hamsters by the CRISPR/Cas9 System

    PubMed Central

    Meng, Qinggang; Shi, Bi; Bunch, Thomas D.; White, Kenneth L.; Kong, Il-Keun; Wang, Zhongde

    2014-01-01

    The golden Syrian hamster is the model of choice or the only rodent model for studying many human diseases. However, the lack of gene targeting tools in hamsters severely limits their use in biomedical research. Here, we report the first successful application of the CRISPR/Cas9 system to efficiently conduct gene targeting in hamsters. We designed five synthetic single-guide RNAs (sgRNAs)—three for targeting the coding sequences for different functional domains of the hamster STAT2 protein, one for KCNQ1, and one for PPP1R12C—and demonstrated that the CRISPR/Cas9 system is highly efficient in introducing site-specific mutations in hamster somatic cells. We then developed unique pronuclear (PN) and cytoplasmic injection protocols in hamsters and produced STAT2 knockout (KO) hamsters by injecting the sgRNA/Cas9, either in the form of plasmid or mRNA, targeting exon 4 of hamster STAT2. Among the produced hamsters, 14.3% and 88.9% harbored germline-transmitted STAT2 mutations from plasmid and mRNA injection, respectively. Notably, 10.4% of the animals produced from mRNA injection were biallelically targeted. This is the first success in conducting site-specific gene targeting in hamsters and can serve as the foundation for developing other genetically engineered hamster models for human disease. PMID:25299451

  8. Echolocation clicks of two free-ranging, oceanic delphinids with different food preferences: false killer whales Pseudorca crassidens and Risso's dolphins Grampus griseus.

    PubMed

    Madsen, P T; Kerr, I; Payne, R

    2004-05-01

    Toothed whales (Odontoceti, Cetacea) navigate and locate prey by means of active echolocation. Studies on captive animals have accumulated a large body of knowledge concerning the production, reception and processing of sound in odontocete biosonars, but there is little information about the properties and use of biosonar clicks of free-ranging animals in offshore habitats. This study presents the first source parameter estimates of biosonar clicks from two free-ranging oceanic delphinids, the opportunistically foraging Pseudorca crassidens and the cephalopod eating Grampus griseus. Pseudorca produces short duration (30 micro s), broadband (Q=2-3) signals with peak frequencies around 40 kHz, centroid frequencies of 30-70 kHz, and source levels between 201-225 dB re. 1 micro Pa (peak to peak, pp). Grampus also produces short (40 micro s), broadband (Q=2-3) signals with peak frequencies around 50 kHz, centroid frequencies of 60-90 kHz, and source levels between 202 and 222 dB re. 1 micro Pa (pp). On-axis clicks from both species had centroid frequencies in the frequency range of most sensitive hearing, and lower peak frequencies and higher source levels than reported from captive animals. It is demonstrated that sound production in these two free-ranging echolocators is dynamic, and that free-ranging animals may not always employ biosonar signals comparable to the extreme signal properties reported from captive animals in long-range detection tasks. Similarities in source parameters suggest that evolutionary factors other than prey type determine the properties of biosonar signals of the two species. Modelling shows that interspecific detection ranges of prey types differ from 80 to 300 m for Grampus and Pseudorca, respectively.

  9. Calorimetric study of the energetics of pregnancy in golden hamsters.

    PubMed

    Quek, V S; Trayhurn, P

    1990-10-01

    The energetics of pregnancy have been assessed in the golden hamster, using continuous whole body indirect calorimetry to determine energy expenditure throughout gestation. Energy intake was unchanged during pregnancy, either on a daily or cumulative basis. The total energy expenditure per animal was, however, significantly higher (14%) in pregnant hamsters than in virgin control animals. The increase in total expenditure was the result of increases in daily energy expenditure over the last one-third of gestation (mean increase 21%), the period during which the energy costs associated with fetal growth are highest. The respiratory quotient (RQ) of the control hamsters was approximately 0.95, but in the pregnant group there was a progressive reduction over the second half of gestation, and by parturition the RQ had fallen to 0.80. The changes in RQ indicate that there is a switch toward the oxidation of fat, away from the oxidation of carbohydrate, in the later stages of pregnancy. Measurements of body lipid suggest that the fall in RQ in the second half of pregnancy is the result of a net utilization of maternal fat reserves; 42% of maternal body lipid was lost during pregnancy, with most of the loss occurring over the final one-third of gestation. Because energy expenditure is increased (relative to virgin controls) without any change in energy intake, it is evident that the efficiency of energy utilization (energy gain per unit of energy intake) is not increased during pregnancy in the golden hamster.

  10. The virulence of some strains of BCG for golden hamsters*

    PubMed Central

    Bunch-Christensen, K.; Ladefoged, A.; Guld, J.

    1968-01-01

    Although the injection of a large dose of BCG causes progressive, fatal disease in the Syrian golden hamster, not all BCG strains are equally active in this respect. It has been suggested that a strain to be used for vaccinating human beings should not be too weakly virulent in the hamster. Nine BCG strains, some of them widely used for BCG production, were compared with regard to their virulence for hamsters. Five of the strains were found to be of about the same high virulence; the other 4 were less virulent. Of the strains derived from the BCG that was used with success in the BCG trial conducted in Great Britain more than 15 years ago, some are more virulent for hamsters than others. It is suggested that virulence is easily lost but not gained when strains are maintained in vitro. Thus, less virulent strains would have deviated from the original protective strain, and for this reason may be less acceptable for vaccine production. PMID:4893582

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

    PubMed

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

    2003-01-01

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

  12. Development of Taenia pisiformis in golden hamster (Mesocricetus auratus).

    PubMed

    Toral-Bastida, Elizabeth; Garza-Rodriguez, Adriana; Jimenez-Gonzalez, Diego E; Garcia-Cortes, Ramon; Avila-Ramirez, Guillermina; Maravilla, Pablo; Flisser, Ana

    2011-07-25

    The life cycle of Taenia pisiformis includes canines as definitive hosts and rabbits as intermediate hosts. Golden hamster (Mesocricetus auratus) is a rodent that has been successfully used as experimental model of Taenia solium taeniosis. In the present study we describe the course of T. pisiformis infection in experimentally infected golden hamsters. Ten females, treated with methyl-prednisolone acetate were infected with three T. pisiformis cysticerci each one excised from one rabbit. Proglottids released in faeces and adults recovered during necropsy showed that all animals were infected. Eggs obtained from the hamsters' tapeworms, were assessed for viability using trypan blue or propidium iodide stains. Afterwards, some rabbits were inoculated with eggs, necropsy was performed after seven weeks and viable cysticerci were obtained. Our results demonstrate that the experimental model of adult Taenia pisiformis in golden hamster can replace the use of canines in order to study this parasite and to provide eggs and adult tapeworms to be used in different types of experiments.

  13. Rudimentary coronary artery in Syrian hamsters (Mesocricetus auratus).

    PubMed

    Durán, A C; Arqué, J M; Fernández, B; Fernández, M C; Fernández-Gallego, T; Rodríguez, C; Sans-Coma, V

    2009-08-01

    Congenital underdevelopment of one or more main branches of the coronary arteries has been reported in man, but not in non-human mammals. In man, this defective coronary artery arrangement may cause myocardial ischaemia and even sudden death. The main goal of this study was to describe the coronary artery distribution patterns associated with the presence of a markedly underdeveloped (rudimentary) coronary artery in Syrian hamsters. Moreover, an attempt was made to explain the morphogenesis of these patterns, according to current knowledge on coronary artery development. Eleven affected hamsters belonging to a laboratory inbred family were examined by means of internal casts of the heart, great arterial trunks and coronary arteries. The aortic valve was tricuspid (normal) in seven hamsters and bicuspid in the other four. A rudimentary coronary artery arose from the right side of the aortic valve in four specimens, from the left side of the aortic valve in a further three, and from the dorsal aortic sinus in the remaining four. In all cases, a second, well-developed coronary artery provided for all the coronary blood flow. Except for the existence of a rudimentary coronary artery, the present anomalous coronary artery distribution patterns are similar to coronary artery patterns reported in Syrian hamsters, dogs and humans in association with a solitary coronary ostium in aorta. We suggest that an unusual prolonged time interval in the development of the embryonic coronary stems might be a key factor in the formation of coronary arteries displaying significantly dissimilar developmental degrees.

  14. Voluntary exercise increases gonadotropin secretion in male Golden hamsters.

    PubMed

    Pieper, D R; Ali, H Y; Benson, L L; Shows, M D; Lobocki, C A; Subramanian, M G

    1995-07-01

    To determine the effect of voluntary exercise and food restriction on reproductive hormone secretion, 48 adult male hamsters were placed in cages with (EX) or without (SED) running wheels. One-half of the animals in each exercise group was fed ad libitum, and the other half was food restricted to reduce their body weight to 90 g over 4 wk. After 10 wk, the EX ad libitum-fed group had much larger testes and much higher serum follicle-stimulating hormone and testosterone levels than the other three groups, but these values in the EX food-restricted hamsters were similar to those in the SED food-restricted group. In experiment 2, 20 adult male hamsters were castrated and later implanted with silicone rubber capsules containing testosterone. Two weeks after implantation of the capsules, the serum follicle-stimulating hormone levels were higher in the EX than in the SED group of testosterone-treated hamsters, but not in animals receiving blank capsules. These data suggest that exercise increases gonadotropin secretion by inhibiting the negative feedback of testosterone.

  15. Hamsters predisposed to sucrose-induced cholesterol gallstones (LPN strain) are more resistant to excess dietary cholesterol than hamsters that are not sensitive to cholelithiasis induction.

    PubMed

    Souidi, M; Combettes-Souverain, M; Milliat, F; Eckhardt, E R; Audas, O; Dubrac, S; Parquet, M; Férézou, J; Lutton, C

    2001-06-01

    We compared the effects of cholesterol feeding in male hamsters from two strains with different propensities to sucrose-induced cholelithiasis; Laboratoire de Physiologie de la Nutrition (LPN) hamsters are predisposed to developing biliary cholesterol gallstones, whereas Janvier (JAN) hamsters are not. When fed a basal control diet, LPN hamsters had a lower cholesterolemia (-21%, P = 0.01) than JAN hamsters, and a higher activity of 3-hydroxy-3-methyl glutaryl coenzyme A reductase in liver (+148%, P = 0.018) and intestine (+281%, P < 0.0001). After feeding the same diet enriched with 0.3% cholesterol for 5 wk, cholesterolemia increased more dramatically in JAN hamsters (+235%, P < 0.001) than in LPN hamsters (+108%, P < 0.001), as did the liver concentration of cholesterol, which reached 152.30 +/- 13.00 and 44.41 +/- 9.06 micromol/g, respectively. Only JAN hamsters displayed hepatomegaly, with an increased cholesterol saturation index of the gallbladder bile (+100%, P < 0.01), due to the cholesterol challenge. In liver, cholesterol feeding reduced cholesterol 7alpha-hydroxylase activity and mRNA level, and stimulated sterol 27-hydroxylase and oxysterol 7alpha-hydroxylase activities. Hepatic levels of LDL receptor decreased by approximately 60% in both strains, whereas HDL receptor scavenger class B type 1 (SR-BI) levels were unaffected by dietary cholesterol. The greater resistance of LPN hamsters to the hypercholesterolemic diet can be explained by a lower capacity to store cholesterol in the liver and greater efficiency in reducing the activity of 3-hydroxy-3-methyl glutaryl coenzyme A reductase in response to cholesterol feeding [from 11263 to 261 pmol/(min x organ) in LPN hamsters and from 4530 to 694 pmol/(min x organ) in JAN hamsters]. These results highlight the usefulness of this two-strain model, which offers some analogy with the inverse association between the predisposition to cholelithiasis and the risk of atherosclerosis in humans.

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

    PubMed

    Askew, Alicia; González, Fernando

    2014-12-01

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

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

    NASA Technical Reports Server (NTRS)

    Musacchia, X. J.

    1972-01-01

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

  18. Syrian hamster tumor model to study oncolytic Ad5-based vectors.

    PubMed

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

    2012-01-01

    Oncolytic (replicating) adenovirus (Ad) vectors are emerging as a promising form of a cancer therapy agent. There has been a need for an appropriate animal model to study oncolytic Ad since human Ad -replication is usually species specific. We have shown that Syrian (golden) hamsters are an appropriate animal model to study human Ad5-based vectors. Syrian hamsters are immunocompetent, and they allow human Ad5 replication in normal tissues as well as in Syrian hamster cancer cells. The development of the Syrian hamster as a model to study oncolytic Ad vectors has opened avenues to explore the role of host immune response and preexisting immunity in Ad vector efficacy and toxicity/biodistribution following Ad vector administration. Since most of the normal tissues in the Syrian hamster are permissive for human Ad5 replication, Ad vectors can be studied in the context of orthotopic cancer model developed in Syrian hamsters.

  19. Internalization of ricin in Chinese hamster ovary cells.

    PubMed Central

    Ray, B; Wu, H C

    1981-01-01

    Internalization of ricin into Chinese hamster ovary cells has been investigated. Combined treatment with galactose and pronase at 0 degrees C resulted in a complete release of surface-bound [125I]ricin into the media. Galactose-pronase-resistant cell-bound [125I]ricin represents internalized ricin molecules inside the cells. The internalization process is time, temperature, and concentration dependent. The pH optimum of internalization of ricin is about pH 7. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis has revealed that intact ricin molecules are internalized. Neither reduction nor proteolytic processing of ricin is required for the entry of ricin into Chinese hamster ovary cells. PMID:6965107

  20. Echinostoma trivolvis: mating behavior of adults raised in hamsters.

    PubMed

    Nollen, P M

    1993-01-01

    Echinostoma trivolvis adults grown in golden hamsters were treated in vitro with [3H]-tyrosine to label sperm and transplanted to uninfected hamsters alone or with four to six unlabeled adults. After 4-5 days, worms were recovered, processed for autoradiography, and observed for silver grains over their seminal receptacles. Of 11 worms transplanted singly, 6 (55%) self-inseminated. In multiple-worm situations, 7 of 12 (58%) labeled worms self-inseminated, and in the process the 12 labeled worms inseminated only 5 of 35 (14%) possible unlabeled worms. E. trivolvis adults self-inseminated when isolated and both self- and cross-inseminated in groups, suggesting an unrestricted mating pattern. These results were compared with the mating patterns of other digenetic trematodes.

  1. Metabolism and excretion of orally administered arsenobetaine in the hamster

    SciTech Connect

    Yamauchi, H.; Kaise, T.; Yamamura, Y.

    1986-03-01

    Arsenobetaine, one of the trimethylarsenic compounds (TMA), occurs abundantly in seafoods. The urinary excretion pattern of arsenic in man following oral ingestion of TMA contained in fishes once only indicates that the most portion of the TMA is excreted in urine. These experiments in humans have used fish arsenic but no authentic arsenobetaine. From previous experiments in mice, rats and rabbits using/sup 73/As-labeled arsenobetaine, it was reported that arsenobetaine is not converted in vivo into any other chemical species of arsenic. The metabolic and excretory patterns of arsenic compounds in the hamster seem to be similar to those in humans. In the present study, the authors examined arsenobetaine-treated hamsters for what chemical species of arsenic this arsenic compound (arsenobetaine) would be metabolized into in vivo and also for its excretory patterns in urine and feces with time.

  2. 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

  3. Oxidative metabolites of diethylstilbestrol in the fetal Syrian golden hamster

    SciTech Connect

    Maydl, R.; Metzler, M.

    1984-12-01

    /sup 14/C-Diethylstilbestrol was administered orally, intraperitoneally, and intrafetally to 15-day pregnant hamsters at a dose of 20 mg/kg body weight, and the radioactivity was determined in the fetus, placenta, and maternal liver after 6 hours. Significant amounts of radioactivity were found in these tissues in every case, indicating maternal-fetal and fetal-maternal transfer of diethylstilbestrol. Part of the radioactivity found in the tissues could not be extracted even after excessive washing. This implied the presence of reactive metabolites. In the fetal and placental extracts, eight oxidative metabolites of diethylstilbestrol were identified by mass fragmentography as hydroxy- and methoxy-derivatives of diethylstilbestrol, pseudodiethylstilbestrol, and dienestrol. The presence of oxidative metabolites in the hamster fetus and the covalent binding to tissue macromolecules are possibly associated with the fetotoxic effects of diethylstilbestrol.

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

    NASA Technical Reports Server (NTRS)

    Musacchia, X. J.

    1973-01-01

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

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

    PubMed

    Shen, G X; Angel, A

    1995-07-01

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

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

    PubMed Central

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

    2006-01-01

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

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

    SciTech Connect

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

    1987-01-01

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

  8. Food hoarding is increased by food deprivation and decreased by leptin treatment in Syrian hamsters.

    PubMed

    Buckley, Carolyn A; Schneider, Jill E

    2003-11-01

    Compensatory increases in food intake are commonly observed after a period of food deprivation in many species, including laboratory rats and mice. Thus it is interesting that Syrian hamsters fail to increase food intake after a period of food deprivation, despite a fall in plasma leptin concentrations similar to those seen in food-deprived rats and mice. In previous laboratory studies, food-deprived Syrian hamsters increased the amount of food hoarded. We hypothesized that leptin treatment during food deprivation would attenuate food-deprivation-induced increases in hoarding. Baseline levels of hoarding were bimodally distributed, with no hamsters showing intermediate levels of hoarding. Both high (HH) and low hoarding (LH) hamsters were included in each experimental group. Fifty-six male hamsters were either food deprived or given ad libitum access to food for 48 h. One-half of each group received intraperitoneal injections of leptin (4 mg/kg) or vehicle every 12 h during the food-deprivation period. Within the HH group, the hoarding score increased significantly in food-deprived but not fed hamsters (P < 0.05). Leptin treatment significantly decreased hoarding in the food-deprived HH hamsters (P < 0.05). The LH hamsters did not increase hoarding regardless of whether they were food deprived or had ad libitum access to food. These results are consistent with the idea that HH hamsters respond to energetic challenges at least in part by changing their hoarding behavior and that leptin might be one factor that mediates this response.

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

    SciTech Connect

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

    1981-02-01

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

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

    PubMed

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

    2014-06-22

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

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

    SciTech Connect

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

    2003-04-01

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

  12. 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

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

    PubMed Central

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

    2014-01-01

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

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

    SciTech Connect

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

    1990-03-01

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  16. Diet affects resting, but not basal metabolic rate of normothermic Siberian hamsters acclimated to winter.

    PubMed

    Gutowski, Jakub P; Wojciechowski, Michał S; Jefimow, Małgorzata

    2011-12-01

    We examined the effect of different dietary supplements on seasonal changes in body mass (m(b)), metabolic rate (MR) and nonshivering thermogenesis (NST) capacity in normothermic Siberian hamsters housed under semi-natural conditions. Once a week standard hamster food was supplemented with either sunflower and flax seeds, rich in polyunsaturated fatty acids (FA), or mealworms, rich in saturated and monounsaturated FA. We found that neither of these dietary supplements affected the hamsters' normal winter decrease in m(b) and fat content nor their basal MR or NST capacity. NST capacity of summer-acclimated hamsters was lower than that of winter-acclimated ones. The composition of total body fat reflected the fat composition of the dietary supplements. Resting MR below the lower critical temperature of the hamsters, and their total serum cholesterol concentration were lower in hamsters fed a diet supplemented with mealworms than in hamsters fed a diet supplemented with seeds. These results indicate that in mealworm-fed hamsters energy expenditure in the cold is lower than in animals eating a seed-supplemented diet, and that the degree of FA unsaturation of diet affects energetics of heterotherms, not only during torpor, but also during normothermy.

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

    NASA Astrophysics Data System (ADS)

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

    1990-04-01

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

  18. Dopa oxidase activity and ceruloplasmin in the sera of hamsters with melanoma.

    PubMed

    Vachtenheim, J; Pavel, S; Duchon, J

    1981-01-01

    Two simple spectrophotometric assays have been employed for the measurement of dopa oxidase activity and ceruloplasmin polyphenol oxidase activity in the sera from normal hamsters and hamsters bearing melanotic melanoma. Both activities were found to be augmented in tumor animals, the dopa oxidase activity much more prominently. The levels of the enzymes tested increased proportionally to the tumor mass.

  19. 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.

  20. 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

  1. CpG oligodeoxynucleotides with crude parasite antigens reduce worm recovery in Opisthorchis viverrini infected hamsters.

    PubMed

    Kaewraemruaen, Chamraj; Sermswan, Rasana W; Wongratanacheewin, Surasakdi

    2016-12-01

    Opisthorchis viverrini, a human liver fluke, is still an endemic parasitic infection in Thailand and nearly all countries in Southeast Asia. O. viverrini induces a chronic stage of infection in hamsters. During the first 2 weeks of infection, Th1 inducing cytokine, IL-12, increased but was down regulated in chronic infection. In this study it was found that unmethylated-CpG ODN (oligodeoxynucleotides) 1826 increased hamster mononuclear cell proliferation and stimulated IFN-γ production in vitro. The IFN-γ levels in hamster sera were significantly increased in hamsters injected with CpG ODN 1826 alone or plus crude somatic antigens (CSAg). Further investigation using the flow cytometer found that CD4(+)T cells and IFN-γ(+) CD4(+)T cells (Th1-like cells) in the hamster blood were significantly increased. The role of these cells in the protective responses in hamsters was evaluated by challenging with 25 metacercaria and observation for 3 months. The number of worms recovered was significantly reduced in the hamsters injected with CpG ODN 1826 with CSAg, but not in CpG ODN 1826 alone groups when compared to PBS control. The percent of reduction in hamsters against this parasite were 32.95% and 21.49% in the CpG ODN 1826 with CSAg and CpG ODN 1826 alone. This study indicates that CpG ODN 1826 plus parasite antigens elicit a Th1-like response that leads to the enhancement of worm reduction.

  2. 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 ...

  3. Phylogenetic conservation of immunoglobulin heavy chains: direct comparison of hamster and mouse Cmu genes.

    PubMed

    McGuire, K L; Duncan, W R; Tucker, P W

    1985-08-12

    We have analyzed the JH-Cmu locus of the Syrian hamster by DNA cloning and sequencing. The single Cmu gene is highly homologous to that of the mouse. The hamster equivalents of the JH and switch (S) recombination regions are arranged as in the mouse, but surprisingly are not highly conserved. Also unlike its close murine relative, the Smu regions among inbred hamster strains are not polymorphic. The complete nucleotide sequence of hamster and mouse Cmu genes have been compared to partial Cmu sequences of other species. Conservation within a portion of the 3' untranslated region may signify functional requirements for 3' end processing. Mutational frequencies within exons and introns of hamster and mouse do not support the theory that the rate of DNA transitions to transversions decreases with evolutionary distance.

  4. Spontaneous nonneoplastic lesions in control Syrian hamsters in three 24-month long-term carcinogenicity studies.

    PubMed

    McInnes, Elizabeth F; Ernst, Heinrich; Germann, Paul-Georg

    2015-02-01

    Information about the incidence of spontaneously occurring, nonneoplastic background findings in Syrian hamsters is essential if Syrian hamsters are to be used for toxicity studies. Male and female Syrian hamsters of the strain Han:AURA from the Fraunhofer Institute for Toxicology and Experimental Medicine (ITEM) breeding colony were maintained as control animals for carcinogenicity studies and were examined for the presence of nonneoplastic background findings either when they died or when the study was terminated. The nonneoplastic background lesions observed at an incidence of >50% (high), >25% (moderate), and >10% (low) in either male or female animals or in both sexes in one or more long-term studies are detailed. The results are compared to previous published reports of nonneoplastic, spontaneous background lesions in Syrian hamsters. Background information about the incidence of background lesions in Syrian hamsters on short- and long-term studies is useful to both toxicologists and toxicological pathologists.

  5. Suprachiasmatic nuclei may regulate the rhythm of leptin hormone release in Syrian hamsters (Mesocricetus auratus).

    PubMed

    Karakas, Alper; Gündüz, Bülent

    2006-01-01

    The suprachiasmatic nuclei (SCN) generate the circadian rhythm of many hormones. The hormone leptin is a metabolic signal that informs the brain about fat and energy stores of the body. We investigated whether the rhythm of leptin hormone release in Syrian hamsters is directly controlled by the SCN. Three experiments were performed: in the first, hamsters were SCN-lesioned; in the second, hamsters were exposed to different feeding regimes; and in the third, hamsters were adrenalectomized and implanted with cortisol capsules to maintain constant glucocorticoid release. Blood samples were collected before and after the experiments at different clock times and examined for leptin levels by enzyme-linked immunosorbant assay (ELISA). Different feeding regimes and constant glucocorticoid release did not alter the rhythm of leptin release; whereas, SCN lesions abolished the rhythm. The results of the present study suggest the rhythm in leptin release in Syrian hamsters may be controlled by the SCN.

  6. Developing a laboratory animal model for perinatal endocrine disruption: the hamster chronicles.

    PubMed

    Hendry, William J; Sheehan, Daniel M; Khan, Shafiq A; May, Jeffrey V

    2002-10-01

    At the biomedical, regulatory, and public level, considerable concern surrounds the concept that inappropriate exposure to endocrine-disrupting chemicals, especially during the prenatal and/or neonatal period, may disrupt normal reproductive tract development and adult function. The intent of this review was to 1. Describe some unique advantages of the hamster for perinatal endocrine disruptor (ED) studies, 2. Summarize the morphological and molecular consequences of exposure to the established perinatal ED, diethylstilbestrol, in the female and male hamster, 3. Present some new, histomorphological insight into the process of neonatal diethylstilbestrol-induced disruption in the hamster uterus, and 4. Introduce recent efforts and future plans to evaluate the potency and mechanism of action of other putative EDs in the hamster experimental system. Taken together, the findings indicate that the hamster represents a unique and sensitive in vivo system to probe the phenomenon of endocrine disruption. The spectrum of candidate endpoints includes developmental toxicity, neoplasia, and more subtle endpoints of reproductive dysfunction.

  7. Aquaporin-11 control of testicular fertility markers in Syrian hamsters.

    PubMed

    Shannonhouse, John L; Urbanski, Henryk F; Woo, Shih-Lung; Fong, Li An; Goddard, Scott D; Lucas, William F; Jones, Edward R; Wu, Chaodong; Morgan, Caurnel

    2014-06-25

    The present study sought novel changes to the hamster testicular transcriptome during modulation of fertility by well-characterized photoperiodic stimuli. Transition from long days (LD, 14 h light/day) to short days (SD, 10h light/day) triggered testicular regression (61% reduction of testis weight, relative to LD) in SD-sensitive (SD-S) hamsters within 16 weeks. After 22 weeks of SD exposure, a third cohort of hamsters became SD-refractory (SD-R), and exhibited testicular recrudescence (137% testis weight gain, relative to SD-S). Partial interrogation of the testicular transcriptome by annealing-control-primer-modified differential display PCR provided several candidates for regulation of testicular functions. Multiple linear regression modeling indicated the best correlation for aquaporin 11 (Aqp11) with changes in testis weight. Correlations were also strongest for Aqp11 with expression levels of reference cDNAs that control spermatogenesis (Hspa2 and Tnp2), steroidogenesis (Cox2, 3βHsd, and Srebp2), sperm motility (Catsper1, Pgk2, and Tnp2), inflammation (Cox2), and apoptosis (Bax and Bcl2). Moreover, siRNA-mediated knockdown of testicular Aqp11 mRNA and protein reduced Hspa2 and Tnp2 mRNA levels, and it increased 3βHsd mRNA levels. It also reduced mRNA levels for Sept12, which is a testis-specific inducer of spermatogenesis. These results suggest a central role for testicular Aqp11 signaling in the coordinate regulation of crucial components of fertility.

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

    PubMed

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

    2015-02-01

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

  9. The Hamster as a Model for Embryo Implantation

    PubMed Central

    Reese, Jeff; Wang, Hehai; Ding, Tianbing; Paria, B. C.

    2008-01-01

    Defects in preimplantation embryonic development, uterine receptivity, and implantation are the leading cause of infertility, pregnancy problems and birth defects. Significant progress has been made in our basic understanding of these processes using the mouse model, where implantation is ovarian estrogen-dependent in the presence of progesterone. However, an animal model where implantation is progesterone-dependent must also be studied to gain a full understanding of the embryo and uterine events that are required for implantation. In this regard, the hamster is a useful model and this review summarizes the information currently available regarding mechanisms involved in synchronous preimplantation embryo and uterine development for implantation in this species. PMID:18178492

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

    SciTech Connect

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

    2010-05-15

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

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

    SciTech Connect

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

    1980-01-01

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

  12. 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

  13. Social forces can impact the circadian clocks of cohabiting hamsters

    PubMed Central

    Paul, Matthew J.; Indic, Premananda; Schwartz, William J.

    2014-01-01

    A number of field and laboratory studies have shown that the social environment influences daily rhythms in numerous species. However, underlying mechanisms, including the circadian system's role, are not known. Obstacles to this research have been the inability to track and objectively analyse rhythms of individual animals housed together. Here, we employed temperature dataloggers to track individual body temperature rhythms of pairs of cohabiting male Syrian hamsters (Mesocricetus auratus) in constant darkness and applied a continuous wavelet transform to determine the phase of rhythm onset before, during, and after cohabitation. Cohabitation altered the predicted trajectory of rhythm onsets in 34% of individuals, representing 58% of pairs, compared to 12% of hamsters single-housed as ‘virtual pair’ controls. Deviation from the predicted trajectory was by a change in circadian period (τ), which tended to be asymmetric—affecting one individual of the pair in nine of 11 affected pairs—with hints that dominance might play a role. These data implicate a change in the speed of the circadian clock as one mechanism whereby social factors can alter daily rhythms. Miniature dataloggers coupled with wavelet analyses should provide powerful tools for future studies investigating the principles and mechanisms mediating social influences on daily timing. PMID:24500164

  14. Rift Valley fever virus infection in golden Syrian hamsters.

    PubMed

    Scharton, Dionna; Van Wettere, Arnaud J; Bailey, Kevin W; Vest, Zachary; Westover, Jonna B; Siddharthan, Venkatraman; Gowen, Brian B

    2015-01-01

    Rift Valley fever virus (RVFV) is a formidable pathogen that causes severe disease and abortion in a variety of livestock species and a range of disease in humans that includes hemorrhagic fever, fulminant hepatitis, encephalitis and blindness. The natural transmission cycle involves mosquito vectors, but exposure can also occur through contact with infected fluids and tissues. The lack of approved antiviral therapies and vaccines for human use underlies the importance of small animal models for proof-of-concept efficacy studies. Several mouse and rat models of RVFV infection have been well characterized and provide useful systems for the study of certain aspects of pathogenesis, as well as antiviral drug and vaccine development. However, certain host-directed therapeutics may not act on mouse or rat pathways. Here, we describe the natural history of disease in golden Syrian hamsters challenged subcutaneously with the pathogenic ZH501 strain of RVFV. Peracute disease resulted in rapid lethality within 2 to 3 days of RVFV challenge. High titer viremia and substantial viral loads were observed in most tissues examined; however, histopathology and immunostaining for RVFV antigen were largely restricted to the liver. Acute hepatocellular necrosis associated with a strong presence of viral antigen in the hepatocytes indicates that fulminant hepatitis is the likely cause of mortality. Further studies to assess the susceptibility and disease progression following respiratory route exposure are warranted. The use of the hamsters to model RVFV infection is suitable for early stage antiviral drug and vaccine development studies.

  15. [Immune response induced by phosphofructokinase from E. histolytica in hamsters].

    PubMed

    Jiménez Cardoso, J M; Jiménez, E; Kumate, J

    1991-01-01

    The enzymatic activity of inorganic pyrophosphate (PPi) dependent phosphofructokinase became manifest in the supernatant obtained by centrifugation in a homogenate of E. histolytica strain HMI-IMSS at 700,000 g. Partial purification of the enzyme was achieved by column chromatography with Ultrogel AcA-34. Ten protein elution spikes were obtained: five showed enzymatic activity. Elution spikes I and II attained the highest values of specific enzymatic activity 6.45 and 6.98 U/mg of protein, respectively. Next were spikes X and III with similar values 2.55 and 2.63 U/mg of protein, and spike IV presented the lowest value of 0.86 U/mg of protein. The five spikes were used to immunize hamsters which were challenged intrahepatically, four weeks later, with 3 x 10(5) trophozoites of E. histolytica. A control group of animals not immunized underwent intrahepatic challenge with the same number of amebae. The proteins with enzymatic activity contained in elution spikes I and II conferred immunologic protection in 100% of the animals, while elution spikes X and III were protective in 50 to 63%, and spike IV gave the lowest value of 37%. It can be assumed that there is an antienzyme antibody responsible for the absence of hepatic abscesses in the immunized hamsters.

  16. An Analysis of Hamster Afferent Taste Nerve Response Functions

    PubMed Central

    Frank, Marion

    1973-01-01

    Sensitivities to moderately intense stimuli representing four taste qualities to man were determined for 79 hamster chorda tympani fibers. Some fibers were very sensitive to sucrose, sodium chloride, or hydrochloric acid, but none were very sensitive to quinine. These sensitivities were not randomly distributed among fibers: the sucrose sensitivity was separated from and negatively correlated with the other sensitivities which were associated and positively correlated with each other. Moreover, there were a limited number of sensitivity patterns: (a) fibers responding best to sucrose responded second-best to salt, less to acid, not to quinine; (b) fibers responding best to salt either responded second-best to sucrose and not to acid or quinine; or second-best to acid, less to quinine, and not to sucrose; and (c) fibers responding best to acid responded second-best to salt, more to quinine, and less to sucrose than other fibers. Therefore, if four stimuli of different taste qualities are ordered from acceptable to unacceptable, neural response functions of most hamster chorda tympani taste fibers peak at one point. Sensitivities to nine other moderately intense stimuli which vary in quality to man were also determined for 46–49 of the fibers. Sensitivities to sweet stimuli were always associated with each other and separated from sensitivities to nonsweet stimuli. Sensitivities to nonsweet stimuli were all associated with each other; however, the strongest correlations were between sensitivities to stimuli of like quality, e.g., the three acids or the two sodium salts. PMID:4705639

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

    SciTech Connect

    Tamura, H.; Greenwald, G.S.

    1987-04-01

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

  18. Sex differences in Siberian hamster ultradian locomotor rhythms

    PubMed Central

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

    2014-01-01

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

  19. Comparison of rat and hamster hepatocyte primary culture/DNA repair assays

    SciTech Connect

    Kornbrust, D.J.; Barfknect, T.R.

    1984-01-01

    Previous studies have demonstrated marked differences in the capacity of hepatocytes from rats or hamsters to mediate the metabolic activation of chemical carcinogens to genotoxic (i.e., mutagenic) products. Thus far, very few investigations of species differences in DNA repair have been performed. Therefore, a comparison of the relative extent of DNA repair elicited by various genotoxic chemicals in rat and hamster hepatocyes was conducted, using the hepatocyte primary culture/DNA repair (HPC/DR) assay. Of the ll chemicals tested, eight were more potent in inducing DNA repair in hamster hepatocytes than in rat hepatocytes. Dimethylnitrosamine, diethylnitrosamine, 2-acetylaminofluorene, 9-aminoacridine, pararosaniline hydrochloride, 1-naphthylamine, benzidine and 1,2,3,4-diepoxybutane were all active in hamster hepatocytes at a concentration at least ten times less than the lowest effective concentration in rat hepatocytes. The direct-acting alkylating agent, methylmethane sulfonate, was equipotent inducing DNA repair in both rat and hamster hepatocytes, indicating that the differences in DNA repair observed for the other chemicals were probably not a result of species differences in DNA repair capacities. In contrast, 1-nitropyrene produced a greater DNA repair response in rat hepatocyes than hamster hepatocytes, while the bacterial mutagen 3-(chloromethyl)pyridine hydrochloride was inactive in both hepatocyte systems. These studies demonstrate the feasibility of using hamster hepatocytes in the HPC/DR assay and illustrate the utility of performing the assay with hepatocytes from more than one species.

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

    PubMed

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

    1995-09-12

    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.

  1. Hamster Weight Patterns Predict the Intensity and Course of Schistosoma haematobium Infection.

    PubMed

    Le, Thien-Linh P; Boyett, Deborah M; Hurley-Novatny, Amelia; Hsieh, Michael H

    2015-10-01

    Although Syrian golden hamsters are widely used as hosts for experimental infection by Schistosoma haematobium , surprisingly little is known about the course of infection and associated intensity (as defined by measures of parasite burden). As such, we sought to define inexpensive, simple, noninvasive, and accurate methods for assessing and predicting the severity of disease in S. haematobium -infected hamsters in order to prevent premature hamster sacrifice and unexpected morbidity and mortality. Through monitoring the weight and behavior of infected hamsters, we determined that the weight-loss patterns of infected hamsters are highly correlated with commonly used measures of the severity of infection (i.e., numbers of eggs passed in the stool, worm burdens, and total egg yields). In contrast, we found no significant correlation between hamster weight-loss patterns and egg yields from liver and intestinal tissues. Our findings suggest that a more complex relationship exists among worm burden, fecundity, and egg passage in the feces than previously appreciated. Regardless, our data may be useful for workers seeking to optimize harvests of S. haematobium eggs and worms from infected hamsters for downstream applications.

  2. Kinetics and pathogenicity of oral infection by equine herpesvirus-9 in mice and suckling hamsters.

    PubMed

    El-Nahass, E; El-Habashi, N; Abdelaziz, A A; Nayel, M; Kasem, S; Fukushi, H; Tuji, H; Hirata, A; Sakai, H; Yanai, T

    2012-01-01

    The pathogenesis and kinetics of oral infection by equine herpesvirus (EHV)-9 were studied in mice and hamsters. After oral inoculation of 10(5) plaque-forming units (PFU) of virus, 1-week-old suckling hamsters showed varying severity of neurological disease from 72 hours post inoculation (hpi) and all of these animals had died by 96 hpi. Four-week-old ICR mice inoculated orally with 4 × 10(4)PFU of virus showed no clinical signs, but they developed erosive and ulcerative gastritis from 36 hpi. Varying degrees of encephalitis were seen in infected mice and hamsters, and the hamsters also developed myelitis by 96 hpi. Immunohistochemistry performed on whole body sections of suckling hamsters revealed the kinetics of spread of the virus to the central nervous system. EHV-9 antigen was detected initially in macrophages of the oral and lingual submucosa. At 36 hpi virus antigen was detected in the nerve fibres and pseudounipolar neurons of the trigeminal ganglion and at 96 hpi antigen was present in the myenteric plexuses of the intestine. Virus antigen was also detected in the liver, lungs and heart of affected animals. EHV-9 DNA was detected by polymerase chain reaction in the brain, blood and spinal cord of suckling hamsters at 36, 48 and 96 hpi. These findings show that EHV-9 may spread via the trigeminal nerve when mice and hamsters are inoculated orally with virus.

  3. Bioavailability and disposition of 3H-solanine in rat and hamster.

    PubMed

    Groen, K; Pereboom-de Fauw, D P; Besamusca, P; Beekhof, P K; Speijers, G J; Derks, H J

    1993-09-01

    1. The toxicokinetics of [3H]-alpha-solanine after oral (p.o.) and intravenous (i.v.) administration in rat and hamster were studied, in order to decide which is the most appropriate model in risk assessment studies. The i.v. dose was 54 micrograms/kg; the oral dose was 170 micrograms/kg. 2. After i.v. administration, the toxicokinetics of total radioactivity in blood were comparable in rat and hamster. However, the clearance of total radioactivity from plasma was more effective in rat than in hamster. The half-lives of distribution and of the terminal phase of unchanged alpha-solanine were not different between rat and hamster, whereas the systemic and metabolic clearance were, respectively, about 1.6 and 2.7 times higher in rat than in hamster. The clearance of unchanged alpha-solanine is more effective than of total radioactivity. 3. After p.o. administration in rat and hamster, the mean bioavailability of total radioactivity is about 29 and 57%, respectively. The bioavailability of unchanged alpha-solanine is only 1.6 and 3.2%, respectively, when compared with i.v. administration. 4. T1/2el of alpha-solanine after p.o. administration was in rats a factor of four and in hamsters a factor of two shorter than after i.v. administration. A strong retention of radioactivity was seen in the hamsters after p.o. administration; only 40% of the dose was excreted within 7 days versus 90% in rat. 5. Based on these and toxicological data from literature, it was decided that the hamster is a more appropriate model in (sub)-chronic toxicity studies with alpha-solanine than the rat.

  4. The use of an intestinal thermode for studying thermoregulation of the golden hamster.

    PubMed

    Stefl, B

    1988-01-01

    Intestinal cooling induces a normal metabolic response compensating heat loss in the euthermic golden hamster. The hypothalamic and subcutaneous temperatures change unpredictably and the threshold hypothalamic temperature for the induction of cold thermogenesis, similarly as the sensitivity of the regulator related to changes in hypothalamic temperature vary considerably, however. It seems that the thermal input from the hypothalamus does not contribute significantly to the control of cold thermogenesis in euthermic golden hamsters during intestinal cooling. The use of an intestinal thermode itself is not suitable for quantitative studies of thermoregulation in the golden hamster.

  5. Short-day response in Djungarian hamsters of different circadian phenotypes.

    PubMed

    Schöttner, Konrad; Schmidt, Maren; Hering, Anke; Schatz, Juliane; Weinert, Dietmar

    2012-05-01

    In Djungarian hamsters (Phodopus sungorus) bred at the authors' institute, a certain number of animals show activity patterns incompatible with proper entrainment of their endogenous circadian pacemaker to the environmental light-dark (LD) cycle. Even though the activity-offset in these animals is stably coupled to "light-on," activity-onset is increasingly delayed, leading to a compression of the activity time (α). If α falls below a critical value, the circadian rhythm in these so called delayed activity-onset (DAO) hamsters starts to free-run and finally breaks down. Animals then show an arrhythmic activity pattern (AR hamsters). Previous studies revealed the mechanisms of photic entrainment have deteriorated (DAO) or the suprachiasmatic nucleus (SCN) does not generate a rhythmic signal (AR). The aim of the present study was to investigate the consequences that these deteriorations have upon photoperiodic time measurement. Animals were bred and kept under standardized housing conditions with food and water ad libitum and a 14L/10D (long day, LD) regimen. Locomotor activity was recorded continuously using passive infrared motion detectors. Body mass, testes size, and fur coloration were measured weekly or biweekly to further quantify the photoperiodic reaction. In a first experiment, adult male wild-type (WT), DAO, and AR hamsters were transferred initially to a 16L/8D cycle. After 3-4 wks, the light period was shortened symmetrically by 8 h. After 14 wks, none of the DAO and AR hamsters, and only 1 of 8 WT hamsters showed short-day (SD) traits. Therefore, in a second experiment, hamsters were transferred to SD conditions (8L/16D cycle) for 8 wks directly from standard LD conditions. In 6 of 7 WT hamsters, activity time expanded, body mass and testes size decreased, and fur coloration changed from summer to winter pelage. In contrast, none of the DAO and AR hamsters displayed an SD response. In a third experiment, DAO and AR hamsters were kept in constant

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

    NASA Astrophysics Data System (ADS)

    White, Gary

    2015-03-01

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

  7. Glutamine protects Chinese Hamster Ovary cells from radiation killing

    SciTech Connect

    Winters, R.; Matthews, R.; Ercal, N.; Krishnan, K. )

    1994-01-01

    Chinese Hamster Ovary (CHO) cells were propagated in vitro and exposed to varying doses of ionizing radiation. The surviving fraction of cells was determined, being found to be a function of the radiation dose. The cell survival curves obtained as a function of radiation dose were modified by the inclusion of varying doses of glutamine in the medium, with glutamine demonstrating a radioprotective effect. The radioprotectant effect of glutamine for CHO cells was more pronounced at higher radiation doses. These results support the idea that glutamine protects body systems such as the gut more directly as a radioprotector as opposed to a more indirect route, such as preventing bacterial translocation from the gut. 16 refs.

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

    SciTech Connect

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

    1987-02-01

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

  9. Testicular amyloidosis in hamsters experimentally infected with Leishmania donovani.

    PubMed Central

    Gonzalez, J. L.; Gallego, E.; Castaño, M.; Rueda, A.

    1983-01-01

    Thirty hamsters were inoculated intraperitoneally with Leishmania donovani. Testes were examined grossly and histologically by light and electron microscopy. Progressive testicular atrophy developed. Spermatogenic cells of the seminiferous tubules showed vacuolar degeneration and decreased in number leading to a total azoospermia in the final weeks of the pathological process. Lymphoplasmocytic infiltrates with macrophages containing leishmanias appeared in the intertubular space. Amyloid deposits in the intertubular space and tubular basement membrane were identified by optical and ultrastructural methods. It has been suggested that testicular amyloidosis may have a pathogenic mechanism related to a dysfunction of plasma cells and stimulation of the reticuloendothial system, due to the antigenic character of the parasite. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:6639870

  10. Uptake of indocyanine green by hamster sebaceous glands

    NASA Astrophysics Data System (ADS)

    McMillan, Kathleen; Lo, Kai-Ming; Wang, Zhi

    2001-05-01

    Photothermal injury to the sebaceous glands is a potential curative treatment for the common skin disease acne vulgaris. Accumulation of the exogenous chromophore indocyanine green in the sebaceous glands may be accomplished using an emulsion or liposomal formulation applied to the skin surface. An emulsion containing 0.09% by weight indocyanine green (ICG) was applied to the epidermis of hamster ears ex vivo and the flank organ in vivo. Fluorescence microscopy demonstrated selective accumulation of ICG in the underlying sebaceous glands. The concentration of ICG that may be expected to accumulate in sebaceous glands of humans was then estimated on the basis of the gland size and orifice area, for the case of topical application of a more concentrated 1% ICG liposomal formulation. Monte Carlo modeling and heat transfer calculations showed that the sebaceous glands containing the exogenous chromophore may be selectively damaged by pulsed 810 nm laser radiation in conjunction with cryogen spray cooling.

  11. X-ray microanalysis of hamster tracheal epithelium

    SciTech Connect

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

    1989-06-01

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

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

    PubMed

    Łopuch, Sylwia

    2009-05-01

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

  13. [Ingavirin treatment of experimental parainfluenza pneumonia in Syrian hamsters].

    PubMed

    Zarubaev, V V; Garshinina, A V; Kalinina, N A; Beliaevskaia, S V; Nebol'sin, V E; Kiselev, O I; Reĭkhart, D V

    2012-01-01

    Parainfluenza viruses affect the upper respiratory tract in all age group patients, in children aged 6 months to 3 years in particular. The most urgent task is to design drugs to treat parainfluenza. This investigation studied the antiviral activity of Ingavirin (2-(imidazole-4-yl) ethanamide of pentandioic-1,5 acid) on a model of parainfluenza infection in Syrian hamsters. The drug was shown to restrict the infectious process in animal lung tissue. This restriction manifested itself as reductions in the infectious titer of parainfluenza virus in the lung tissue, in the degree of pulmonary edema and tissue cell infiltration, and in virus-specific lesion of bronchial epithelial cells. The in vitro experiments demonstrated the ability of Ingavirin to diminish the infective activity of viral descendants. The finding allows one to consider Ingavirin to be a promising antiviral agent that is active against parainfluenza infection in vivo.

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  16. Plasticity in anterior hypothalamic vasopressin correlates with aggression during anabolic-androgenic steroid withdrawal in hamsters.

    PubMed

    Grimes, Jill M; Ricci, Lesley A; Melloni, Richard H

    2006-02-01

    In hamsters, adolescent anabolic-androgenic steroid (AAS) exposure facilitates offensive aggression, in part by altering the development and activity of anterior hypothalamic arginine vasopressin (AH-AVP). This study assessed whether these effects were lasting by examining aggression and AH-AVP during AAS withdrawal. Adolescent hamsters administered AAS were tested as adults for aggression at 1, 4, 11, 18, or 25 days of withdrawal, sacrificed the following day, and examined for AH-AVP afferent innervation using immunohistochemistry. Through Day 12 of withdrawal, aggression and AVP were significantly higher in AAS-treated hamsters than in controls. These differences were no longer observable by Day 19 of withdrawal, at which point the behavior and neurobiology of AAS-treated hamsters reverted to that observed in controls. These data indicate that adolescent AAS exposure has short-term, reversible effects on both aggression and AH-AVP, correlating AH-AVP with the aggressive/nonaggressive behavioral phenotype during AAS withdrawal.

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

    SciTech Connect

    Gale, T.F.

    1981-02-01

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

  18. 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.

  19. The daily melatonin pattern in Djungarian hamsters depends on the circadian phenotype.

    PubMed

    Schöttner, Konrad; Simonneaux, Valérie; Vuillez, Patrick; Steinlechner, Stephan; Pévet, Paul; Weinert, Dietmar

    2011-12-01

    Djungarian hamsters (Phodopus sungorus) bred at the Institute of Halle reveal three different circadian phenotypes. The wild type (WT) shows normal locomotor activity patterns, whereas in hamsters of the DAO (delayed activity onset) type, the activity onset is continuously delayed. Since the activity offset in those hamsters remains coupled to "light-on," the activity time becomes compressed. Hamsters of the AR (arrhythmic) type are episodically active throughout the 24 h. Previous studies showed that a disturbed interaction of the circadian system with the light-dark (LD) cycle contributes to the phenomenon observed in DAO hamsters. To gain better insight into the underlying mechanisms, the authors investigated the daily melatonin rhythm, as it is a reliable marker of the circadian clock. Hamsters were kept individually under standardized laboratory conditions (LD 14:10, T=22°C±2°C, food and water ad libitum). WT, DAO (with exactly 5 h delay of activity onset), and AR hamsters were used for pineal melatonin and urinary 6-sulfatoxymelatonin (aMT6s) measurement. Pineal melatonin content was determined at 3 time points: 4 h after "light-off" [D+4], 1 h before "light-on" [L-1], and 1h after "light-on" [L+1]). The 24-h profile of melatonin secretion was investigated by transferring the animals to metabolic cages for 27?h to collect urine at 3-h intervals for aMT6s analysis. WT hamsters showed high pineal melatonin content during the dark time (D+4, L-1), which significantly decreased at the beginning of the light period (L+1). In contrast, DAO hamsters displayed low melatonin levels during the part of the dark period when animals were still resting (D+4). At the end of the dark period (L-1), melatonin content increased significantly and declined again when light was switched on (L+1). AR hamsters showed low melatonin levels, comparable to daytime values, at all 3 time points. The results were confirmed by aMT6s data. WT hamsters showed a marked circadian pattern of

  20. Extramedullary plasmacytoma of the salivary gland in two Syrian hamsters (Mesocricetus auratus).

    PubMed

    Munday, J S; Richey, L J; Brown, C A; Rodriguez, N A; Kiupel, M

    2005-11-01

    Two Syrian hamsters developed marked swelling of the ventral neck. Histologic examination of both masses revealed that the submaxillary salivary glands were effaced by large numbers of neoplastic plasma cells. In one hamster, neoplastic cells had infiltrated the adjacent lymph node. The neoplastic cells expressed CD79a antigen and were negative for CD3, lambda, and kappa light chains. Ultrastructural features of neoplastic cells in the salivary gland of one hamster included abundant cytoplasmic rough endoplasmic reticulum profiles, and peripherally displaced nuclei that contained marginated heterochromatin, consistent with plasma cells. Salivary gland plasmacytomas are extremely rare in humans and have not previously been reported in nonhuman species. The occurrence of such neoplasms in two hamsters suggests that this species may be predisposed to developing tumors of this type.

  1. Capillary-to-fiber ratio of hind limb muscles in the male Syrian golden hamster.

    PubMed

    Swisher, Anne K; Alway, Stephen E; Yeater, Rachel

    2004-04-01

    The hamster has been the accepted model of emphysema since the 1970s, demonstrating disease-related effects on respiratory skeletal muscle. However, there is scant information available about the model's ability to replicate the peripheral skeletal muscle changes seen in human disease, such as alterations in capillarity. The present study described the capillary-to-fiber ratio (C/F) of normal hamster plantaris, gastrocnemius, and soleus muscles in eight animals. C/F was 1.72 +/- 0.38 for plantaris, 1.95 +/- 0.40 for gastrocnemius, and 2.22 +/- 0.43 for soleus. C/F of soleus was significantly greater (P < 0.01) than plantaris. The C/F of hamster hindlimb muscles varies from those seen in rat species, and having baseline data on hamsters makes it possible to determine the effects of emphysema on C/F in this model.

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

    PubMed

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

    2015-12-01

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

  3. Developmental Changes in the ECG of a Hamster Model of Muscular Dystrophy and Heart Failure

    PubMed Central

    Hampton, Thomas G.; Kale, Ajit; McCue, Scott; Bhagavan, Hemmi N.; VanDongen, Case

    2012-01-01

    Aberrant autonomic signaling is being increasingly recognized as an important symptom in neuromuscular disorders. The δ-sarcoglycan-deficient BIO TO-2 hamster is recognized as a good model for studying mechanistic pathways and sequelae in muscular dystrophy and heart failure, including autonomic nervous system (ANS) dysfunction. Recent studies using the TO-2 hamster model have provided promising preclinical results demonstrating the efficacy of gene therapy to treat skeletal muscle weakness and heart failure. Methods to accelerate preclinical testing of gene therapy and new drugs for neuromuscular diseases are urgently needed. The purpose of this investigation was to demonstrate a rapid non-invasive screen for characterizing the ANS imbalance in dystrophic TO-2 hamsters. Electrocardiograms were recorded non-invasively in conscious ∼9-month old TO-2 hamsters (n = 10) and non-myopathic F1B control hamsters (n = 10). Heart rate was higher in TO-2 hamsters than controls (453 ± 12 bpm vs. 311 ± 25 bpm, P < 0.01). Time domain heart rate variability, an index of parasympathetic tone, was lower in TO-2 hamsters (12.2 ± 3.7 bpm vs. 38.2 ± 6.8, P < 0.05), as was the coefficient of variance of the RR interval (2.8 ± 0.9% vs. 16.2 ± 3.4%, P < 0.05) compared to control hamsters. Power spectral analysis demonstrated reduced high frequency and low frequency contributions, indicating autonomic imbalance with increased sympathetic tone and decreased parasympathetic tone in dystrophic TO-2 hamsters. Similar observations in newborn hamsters indicate autonomic nervous dysfunction may occur quite early in life in neuromuscular diseases. Our findings of autonomic abnormalities in newborn hamsters with a mutation in the δ-sarcoglycan gene suggest approaches to correct modulation of the heart rate as prevention or therapy for muscular dystrophies. PMID:22629245

  4. Developmental Changes in the ECG of a Hamster Model of Muscular Dystrophy and Heart Failure.

    PubMed

    Hampton, Thomas G; Kale, Ajit; McCue, Scott; Bhagavan, Hemmi N; Vandongen, Case

    2012-01-01

    Aberrant autonomic signaling is being increasingly recognized as an important symptom in neuromuscular disorders. The δ-sarcoglycan-deficient BIO TO-2 hamster is recognized as a good model for studying mechanistic pathways and sequelae in muscular dystrophy and heart failure, including autonomic nervous system (ANS) dysfunction. Recent studies using the TO-2 hamster model have provided promising preclinical results demonstrating the efficacy of gene therapy to treat skeletal muscle weakness and heart failure. Methods to accelerate preclinical testing of gene therapy and new drugs for neuromuscular diseases are urgently needed. The purpose of this investigation was to demonstrate a rapid non-invasive screen for characterizing the ANS imbalance in dystrophic TO-2 hamsters. Electrocardiograms were recorded non-invasively in conscious ∼9-month old TO-2 hamsters (n = 10) and non-myopathic F1B control hamsters (n = 10). Heart rate was higher in TO-2 hamsters than controls (453 ± 12 bpm vs. 311 ± 25 bpm, P < 0.01). Time domain heart rate variability, an index of parasympathetic tone, was lower in TO-2 hamsters (12.2 ± 3.7 bpm vs. 38.2 ± 6.8, P < 0.05), as was the coefficient of variance of the RR interval (2.8 ± 0.9% vs. 16.2 ± 3.4%, P < 0.05) compared to control hamsters. Power spectral analysis demonstrated reduced high frequency and low frequency contributions, indicating autonomic imbalance with increased sympathetic tone and decreased parasympathetic tone in dystrophic TO-2 hamsters. Similar observations in newborn hamsters indicate autonomic nervous dysfunction may occur quite early in life in neuromuscular diseases. Our findings of autonomic abnormalities in newborn hamsters with a mutation in the δ-sarcoglycan gene suggest approaches to correct modulation of the heart rate as prevention or therapy for muscular dystrophies.

  5. Phase resetting in duper hamsters: specificity to photic zeitgebers and circadian phase.

    PubMed

    Manoogian, Emily N C; Leise, Tanya L; Bittman, Eric L

    2015-04-01

    The duper mutation in Syrian hamsters shortens the free-running period of locomotor activity (τDD) to about 23 h and results in a type 0 phase-response curve (PRC) to 15-min light pulses. To determine whether exaggerated phase shifts are specific to photic cues and/or restricted to subjective night, we subjected hamsters to novel wheel confinements and dark pulses during subjective day. Small phase shifts elicited by the nonphotic cue were comparable in mutant and wild-type (WT) hamsters, but dark pulses triggered larger shifts in dupers. To assess further the effects of the duper mutation on light-dark transitions, we transferred hamsters between constant light (LL) and constant dark (DD) or between DD and LL at various circadian phases. Duper hamsters displayed significantly larger phase shifts than WT hamsters when transferred from LL to DD during subjective day and from DD to LL during subjective night. The variability of phase shifts in response to all light/dark transitions was significantly greater in duper hamsters at all time points. In addition, most duper hamsters, but none of the WTs, displayed transient ultradian wheel-running patterns for 5 to 12 days when transferred from light to dark at CT 18. The χ(2) periodogram and autocorrelation analyses indicate that these ultradian patterns differ from the disruption of rhythmicity by SCN lesions or exposure to constant bright light. We conclude that the duper mutation specifically amplifies phase shifts to photic cues and may destabilize coupling of circadian organization upon photic challenge due to weakened coupling among components of the circadian pacemaker. Mathematical modeling of the circadian pacemaker supports this hypothesis.

  6. Rhythmic Melatonin Response of the Syrian Hamster Pineal Gland to Norepinephrine In Vitro and In Vivo

    DTIC Science & Technology

    1986-01-01

    melatonin production . NE appears to be the neurotransmitter for stimulation of pineal melatonin production in the Syrian hamster. The sensitivity rhythm and...these findings indicate similarity of these three species with regard to sympathetic control of melatonin production as revealed by neural lesions and...of melatonin production in humans. Hamster Melatonin Response to Norepinephrine 237 One purpose of the present study was to re-examine whether the

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

    PubMed Central

    Carlton, Elizabeth D.; Demas, Gregory E.

    2014-01-01

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

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

    PubMed

    Carlton, Elizabeth D; Demas, Gregory E

    2014-11-01

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

  9. Raloxifene improves vascular reactivity in pressurized septal coronary arteries of ovariectomized hamsters fed cholesterol diet.

    PubMed

    Chan, Yau-Chi; Leung, Fung Ping; Tian, Xiao Yu; Yung, Lai Ming; Lau, Chi Wai; Chen, Zhen Yu; Yao, Xiaoqiang; Laher, Ismail; Huang, Yu

    2012-02-01

    Although vascular effects of selective estrogen receptor modulators (SERMs) have been extensively examined in conduit arteries, whether SERMs could favorably modulate myogenic response in resistance arteries is unknown. The impact of raloxifene therapy and cholesterol diet on myogenic constriction during estrogen deficiency is unresolved. This study investigated changes in vascular reactivity and myogenic responses in female ovariectomized (Ovx) hamsters fed high-cholesterol diet (HCD) with and without chronic treatment of raloxifene. Functional studies were performed on hamster septal coronary arteries cannulated in a pressure myograph. Acetylcholine (ACh)-induced dilatation was reduced in arteries from cholesterol-fed Ovx hamsters, but not in those from cholesterol-fed hamsters, while pressure-induced myogenic constriction was unaffected. Chronic treatment with raloxifene restored ACh-induced dilatation in cholesterol-fed Ovx hamsters. U46619-induced constriction was increased in arteries from cholesterol-fed Ovx hamsters but not from cholesterol-fed control hamsters, which was normalized by chronic raloxifene treatment. The pressure-diameter relationship is presented as normalized diameter versus intraluminal pressure, while the effect of ACh or U46619 is expressed as percentage of tone at 80 mm Hg. Two-way analysis of variance (ANOVA) followed by Bonferroni post-tests were used for statistical evaluation among different treatment groups. P<0.05 was taken as statistically significant. The present results show that chronic treatment with raloxifene could benefit myogenically active coronary arteries by (i) restoring ACh-induced dilatation and (ii) reducing U46619-induced constriction without affecting pressure-induced myogenic responses in cholesterol-fed hamsters during estrogen deficiency. If such benefit can be observed in humans, raloxifene and other SERMs may be useful to preserve endothelial function and curtail vascular hypersensitivity in resistance

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

    PubMed

    Samuel, Arthur S; Subbiah, Madhuri; Shive, Heather; Collins, Peter L; Samal, Siba K

    2011-02-23

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

  11. Serum leptin, energy budget, and thermogenesis in striped hamsters exposed to consecutive decreases in ambient temperatures.

    PubMed

    Zhao, Zhi-Jun

    2011-01-01

    Leptin has been found to be a direct participant in the regulation of both energy intake and energy expenditure in small mammals showing seasonal declines in body mass (M(b)) and fat mass, but its roles in an animal exhibiting seasonally increased thermogenesis and unchanged M(b) remain unclear. Serum leptin levels, energy budget, and thermogenesis were measured in striped hamsters exposed to consecutive decreases in ambient temperatures ranging from 23° to -23°C. Cold-exposed hamsters had significant increases in gross energy intake (GEI), the rate of basal metabolism, nonshivering thermogenesis, and activity of cytochrome c oxidase (COX) in brown adipose tissue (BAT), compared with control hamsters, indicating a cold-induced elevation of thermogenesis. Body mass and fat content were decreased in cold-exposed animals, and serum leptin levels were increased in hamsters exposed to temperatures of -8°C and below in inverse proportion to body fat content. Serum leptin levels were positively correlated with GEI and BAT COX activity in cold-exposed hamsters, but no such relationships were observed in control animals. These findings suggest that cold-exposed hamsters increase food consumption to meet the energy requirements for increased BAT thermogenesis. The increases in serum leptin levels are likely involved in increased thermogenesis in hamsters under cold stress. Cold-exposed hamsters may become leptin resistant, which is associated with impaired regulation of food intake. This new natural model of leptin resistance may also provide insight into the dynamic long-term control of energy homeostasis for animals that do not exhibit seasonal decline in M(b).

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

    PubMed

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

    2015-09-01

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

  13. Hematologic assessment in pet rats, mice, hamsters, and gerbils: blood sample collection and blood cell identification.

    PubMed

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

    2015-01-01

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

  14. Plasmodium berghei-Hamster Cheek Pouch Model for the Study of Severe Malaria

    DTIC Science & Technology

    1988-11-21

    rCFILE COY ] Plasmodium berghei-llansler Cheek Pouch Model for the study of Severe Malaria Lfl C) David R. Franz, Wallace B. Baze, G. David Young...PROGRAM PROJECT TASK WORK UNIT ELEMENT NO. NO. NO. ACCESSION NO. 11. TITLE (Include Security Classification) Plasmodium bergehei-Hamster Cheek Pouch Model...CODES 18. SUBJECT TERMS (Continue on reverse if necesry and identify by block number) FIELD GROUP SUB-GROUP Hamster cheek pouch, Plasmodium berghei

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

    PubMed

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

    2009-03-02

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

  16. Daidzin inhibits mitochondrial aldehyde dehydrogenase and suppresses ethanol intake of Syrian golden hamsters.

    PubMed

    Keung, W M; Klyosov, A A; Vallee, B L

    1997-03-04

    Daidzin is the major active principle in extracts of radix puerariae, a traditional Chinese medication that suppresses the ethanol intake of Syrian golden hamsters. It is the first isoflavone recognized to have this effect. Daidzin is also a potent and selective inhibitor of human mitochondrial aldehyde dehydrogenase (ALDH-2). To establish a link between these two activities, we have tested a series of synthetic structural analogs of daidzin. The results demonstrate a direct correlation between ALDH-2 inhibition and ethanol intake suppression and raise the possibility that daidzin may, in fact, suppress ethanol intake of golden hamsters by inhibiting ALDH-2. Hamster liver contains not only mitochondrial ALDH-2 but also high concentrations of a cytosolic form, ALDH-1, which is a very efficient catalyst of acetaldehyde oxidation. Further, the cytosolic isozyme is completely resistant to daidzin inhibition. This unusual property of the hamster ALDH-1 isozyme accounts for the fact we previously observed that daidzin can suppress ethanol intake of this species without blocking acetaldehyde metabolism. Thus, the mechanism by which daidzin suppresses ethanol intake in golden hamsters clearly differs from that proposed for the classic ALDH inhibitor disulfiram. We postulate that a physiological pathway catalyzed by ALDH-2, so far undefined, controls ethanol intake of golden hamsters and mediates the antidipsotropic effect of daidzin.

  17. Reduced hamster usage and stress in propagating Leishmania chagasi promastigotes using cryopreservation and saphenous vein inoculation.

    PubMed

    Lei, Soi Meng; Ramer-Tait, Amanda E; Dahlin-Laborde, Rebecca R; Mullin, Kathleen; Beetham, Jeffrey K

    2010-02-01

    Leishmania chagasi, a causal agent of visceral leishmaniasis, requires passage through lab animals such as hamsters to maintain its virulence. Hamster infection is typically accomplished via cardiac puncture or intraperitoneal injection, procedures accompanied by risks of increased animal stress and death. The use of the hamster model also necessitates a regular supply of infected animals, because L. chagasi parasites newly isolated from an infected hamster can be grown in culture for only several weeks before loss of function/phenotype occurs. In an effort to decrease animal usage and animal stress, experiments were performed to assess a more gentle inoculation procedure (saphenous vein inoculation) and the use of cryopreserved parasite cells for research experiments. Of 81 hamsters inoculated by the saphenous vein, 80 became infected as determined ante mortem, by display of clinical symptoms of leishmaniasis (onset of symptoms at 105 +/- 22 days post-inoculation), and postmortem by the presence of parasites within the spleen. Splenic parasite load calculated for a subset (n = 34) of infected hamsters was 124 to 26,177 Leishmania donovani infection units. Cryopreserved, and never-stored, cells were equivalent in all properties evaluated, including developmental changes in morphology during culture, culture growth rates, parasite resistance to serum-mediated lysis, and expression of developmentally regulated surface proteins major surface protease and promastigote surface antigen.

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

    PubMed

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

    2013-09-01

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

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

    PubMed

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

    2012-10-01

    Because the circadian clock in the mammalian brain derives from a network of interacting cellular oscillators, characterizing the nature and bases of circadian coupling is fundamental to understanding how the pacemaker operates. Various phenomena involving plasticity in circadian waveform have been theorized to reflect changes in oscillator coupling; however, it remains unclear whether these different behavioral paradigms reference a unitary underlying process. To test whether disparate coupling assays index a common mechanism, we examined whether there is covariation among behavioral responses to various lighting conditions that produce changes in circadian waveform. Siberian hamsters, Phodopus sungorus, were transferred from long to short photoperiods to distinguish short photoperiod responders (SP-R) from nonresponders (SP-NR). Short photoperiod chronotyped hamsters were subsequently transferred, along with unselected controls, to 24-h light:dark:light: dark cycles (LDLD) with dim nighttime illumination, a procedure that induces bifurcated entrainment. Under LDLD, SP-R hamsters were more likely to bifurcate their rhythms than were SP-NR hamsters or unselected controls. After transfer from LDLD to constant dim light, SP-R hamsters were also more likely to become arrhythmic compared to SP-NR hamsters and unselected controls. In contrast, short photoperiod chronotype did not influence more transient changes in circadian waveform. The present data reveal a clear relationship in the plasticity of circadian waveform across 3 distinct lighting conditions, suggesting a common mechanism wherein individual differences reflect variation in circadian coupling.

  1. Gender effects of tall oil versus soybean phytosterols as cholesterol-lowering agents in hamsters.

    PubMed

    Ntanios, F Y; MacDougall, D E; Jones, P J

    1998-01-01

    To examine the effect of gender on the mechanisms of action of phytosterols extracted from tall oil (TO) and soybean (SB) on cholesterol and phytosterol metabolism, male and female hamsters were fed cholesterol-enriched diets containing 0.5 or 1% (w/w) TO or SB phytosterols for 90 days. Plasma lipoprotein cholesterol profile and tissue phytosterol and cholesterol biosynthesis levels were determined. Mean plasma total-cholesterol level in females fed 1% (w/w) SB was reduced (p<0.05) by 44%, while in males it was lowered (p<0.05) by 25% compared with their respective controls. Moreover, mean plasma total-cholesterol level was reduced (p<0.05) in male hamsters by -31% and female hamsters by -32% when fed 1% (w/w) TO. Cholesterol biosynthesis was higher (p<0.05) by twofold in groups fed TO at 0.5 and 1% (w/w) concentrations, compared with SB. Hamsters fed TO at 0.5 and 1% (w/w) levels also had higher (p<0.05) hepatic and enterocytic campesterol contents than SB-fed animals. These findings demonstrate gender differences in cholesterol metabolism in TO- and SB-fed hamsters. The results suggest that TO, conversely to SB phytosterol, is a more effective cholesterol-lowering agent in male, but not as much in female, hamsters, over a feeding period of 90 days.

  2. Arginine-vasopressin and the regulation of aggression in female Syrian hamsters (Mesocricetus auratus).

    PubMed

    Gutzler, Stephanie J; Karom, Mary; Erwin, W D; Albers, H E

    2010-05-01

    Arginine-vasopressin (AVP) is critical for the expression of a variety of social behaviors in many species. Previous studies have demonstrated that AVP regulates behaviors such as social communication and aggression in Syrian hamsters through the V1a receptor subtype. In male hamsters, AVP injected into the anterior hypothalamus (AH) stimulates aggression, while injection of a V1a receptor antagonist inhibits the behavior. The purpose of the present studies was to determine whether AVP influences aggression by its action in the AH in female hamsters. In the first experiment, we were surprised to find that injection of the V1a receptor antagonist, Manning compound, into the AH of intact female hamsters increased aggression. The second experiment confirmed the ability of the V1a receptor antagonist to increase aggression and found that the largest effects of the antagonist occurred at intermediate concentrations of the compound. The next experiment found that injection of AVP into the AH significantly reduced the latency to attack and the duration of aggression. Finally, we examined whether the effects of AVP and the V1a receptor antagonist on aggression differed in hamsters exposed to long 'summer-like' photoperiods or short 'winter-like' photoperiods, and found that their effects on aggression were not photoperiod dependent. In summary, contrary to what is observed in males, these data suggest that AVP in the AH may play an inhibitory role on aggression in female Syrian hamsters.

  3. Behavioural and endocrinological changes in Syrian hamsters (Mesocricetus auratus) under domestication.

    PubMed

    Krause, S; Schüler, L

    2010-12-01

    This study aimed to quantify differences in response to stress between two strains of Syrian hamsters to evaluate the consequences of domestication in this species by measuring behavioural traits in the open-field, adrenal gland masses (ADR), and faecal and blood corticosterone concentrations (CC). We studied a laboratory (lab)- and a wild-derived population (wild). The lab hamsters were significant heavier than the wild hamsters. The lab males had the highest ADR, and it was independent of their high body mass (BM). The ADR of lab females and wild hamsters was linearly dependent of BM. The lab males had the highest faecal and blood CC, whereas the lab females had the lowest CC. In the open field, the lab hamsters began later to groom, groomed shorter, groomed less frequently, began later to rear, reared longer and reared less frequently. In the lab population, females reared more often and groomed longer than males. The sex differences in the behaviours of the lab population and the differences between the populations mirror the differences neither in the ADR nor in the CC. The founder effect and the breeding history of lab Syrian hamsters are discussed as causes of the differences between the studied populations.

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

    SciTech Connect

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

    1994-09-01

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

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

    SciTech Connect

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

    1985-02-01

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

  6. Body weight as a determinant of clinical evolution in hamsters (Mesocricetus auratus) infected with Leishmania (Viannia) panamensis.

    PubMed

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

    2013-01-01

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

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

    PubMed

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

    2014-01-01

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

  8. Potential role of mast cells in hamster cheek pouch carcinogenesis.

    PubMed

    Aromando, Romina F; Pérez, Miguel A; Heber, Elisa M; Trivillin, Verónica A; Tomasi, Víctor H; Schwint, Amanda E; Itoiz, María E

    2008-11-01

    During the process of activation, mast cells release products stored in their granules. Tryptase, a protease released from mast cell granules after activation, induces tumor cell proliferation through the activation of PAR-2 (protease activated receptor 2) on the plasma membrane of carcinoma cells. Chemical cancerization (DMBA) of the hamster cheek pouch is the most accepted model of oral cancer. However, there are no reports on the activation of mast cells during experimental carcinogenesis or on the correlation between mast cell activation and cell proliferation. The aim of the present study was to evaluate the potential effect of mast cells on the proliferation of epithelial cells at different times during the cancerization process. Paraffin serial sections of cancerized, tumor-bearing pouches were stained with Alcian Blue-Safranin to identify the different degrees of mast cell activation. Immunohistochemistry was performed to identify BrdU-positive cells to study tumor cell proliferation. Mast cells were counted and grouped into two categories: inactive mast cells AB-S+++ (red) and active mast cells AB+++S- (blue). Mast cell counts were performed in tumor stroma, base of the tumor (connective tissue immediately below the exophytic tumor), connective and muscle tissue underlying the cancerized epithelium (pouch wall) and adventitious tissue underlying the pouch wall. There was a significant increase in the number of mast cells at the base of tumors (p<0.001) compared to the number of mast cells in the wall of the pouch and in tumor stroma. In normal non-cancerized pouches, inactive mast cells were prevalent both in the wall (AB:S=1:2.15; p<0.001) and in the adventitious tissue (AB:S=1:1.6; p<0.004) of the hamster cheek pouch. At most of the experimental times examined, the ratio of active/inactive mast cells (AB/S) in the wall approximated unity and even reverted. The ratio of mast cells was AB:S 1:1.05 at the base of the tumor and 1:0.24 in tumor stroma (p<0

  9. High virulence in hamsters of four dominant Leptospira serovars isolated from rats in the Philippines.

    PubMed

    Villanueva, Sharon Y A M; Saito, Mitsumasa; Tsutsumi, Yutaka; Segawa, Takaya; Baterna, Rubelia A; Chakraborty, Antara; Asoh, Tatsuma; Miyahara, Satoshi; Yanagihara, Yasutake; Cavinta, Lolita L; Gloriani, Nina G; Yoshida, Shin-ichi

    2014-02-01

    Leptospirosis is caused by pathogenic species of Leptospira. The aim of this study was to determine and characterize the pathogenicity of four dominant Leptospira isolates prevailing among rats in the Philippines. The isolates were Leptospira interrogans serovar Manilae strain K64, L. interrogans serovar Losbanos strain K37, L. interrogans serovar Ratnapura strain K5 and Leptospira borgpetersenii serovar Javanica strain K6. Pathogenicities were studied using hamsters, which reproduce severe human leptospirosis. The minimum lethal doses were 10(0) ( = 1) leptospires for K64, K37 and K5, and 10(1) leptospires for K6. Weight loss amongst the Leptospira-infected hamsters was observed from 1 day before death (K64-, K37- and K5-infected hamsters) to as much as 1 week before death for K6-infected hamsters. Similar and varied gross and microscopic lesions were observed amongst infected hamsters, even for strains belonging to the same species (i.e. L. interrogans). The most significant and common histopathological findings were congestion of the glomerulus, disarrangement of hepatic cords and erythrophagocytosis. Other findings were foamy splenic macrophages for K6, severe petechial pulmonary haemorrhage for K64, and hematuria and severe pulmonary congestion for K37. Immunostaining and culture revealed the presence of leptospires in different organs of the infected hamsters. Based on these results, Leptospira isolates from rats in the Philippines were shown to be highly virulent, causing pulmonary haemorrhage, severe hepato-renal damage and death in hamsters even at lower doses. The present findings on experimental leptospirosis support clinical data showing that patients with severe manifestations of leptospirosis, such as pulmonary haemorrhage, are increasing in the Philippines. These findings may serve as a basis to strengthen the early diagnosis and treatment of human leptospirosis.

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

    PubMed

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

    2011-01-01

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

  11. Apoptosis and molecular pathways in the seminiferous epithelium of aged and photoinhibited Syrian hamsters (Mesocricetus auratus).

    PubMed

    Morales, Eva; Ferrer, Concepcion; Zuasti, Adelina; Garcia-Borron, Jose C; Canteras, Manuel; Pastor, Luis M

    2007-01-01

    Aging and short photoperiod exposure induce germ cell apoptosis in the Syrian hamster; however, the specific germ cells affected and the molecular pathways triggered have not been elucidated. We analyzed germ cell apoptosis and the expression of the Fas/Fas-L system, Bcl-2 family, and p53 in aged and photoinhibited hamsters and compared with those young maintained in natural photoperiod. Aging increased apoptosis in spermatogonia and spermatocytes, but in photoinhibited hamster testes only an increase in apoptotic spermatocytes was observed. Apoptosis was higher in aged hamsters in stages I-IV, V-VI and VII-VIII. Aging increased apoptosis of spermatogonia in stages I-IV and V-VI. Apoptotic pachytene spermatocytes were significantly higher in stages I-IV, V-VI, and VII-VIII in aging. Apoptotic preleptotene and pachytene spermatocytes were higher in aging, but no differences were observed in leptotene-zygotene. Fas-L was expressed by Sertoli cells, of young, aged, and photoinhibited hamsters. Bcl-x(L) was strongly expressed in germ cells on young hamsters and slightly in aging and after short photoperiod exposure. Spermatocytes of photoinhibited hamsters were intensively stained with Fas, Bax, Bcl-xs/L, and p53. In conclusion, aging increases apoptosis in spermatogonia and spermatocytes, depending on the stage of the seminiferous epithelium cycle, whereas after a short photoperiod exposure only an increase in apoptotic spermatocytes is observed. The results suggest that Fas, Bcl-x(L), Bax, and p53 participate in germ cell apoptosis induction after short photoperiod exposure, whereas only Bcl-x(L) is involved in aging.

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

    PubMed

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

    2014-06-01

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

  13. Functional cooperation of xenoproteins after hamster-to-rat liver transplantation: With particular reference to hamster C3 and secretory component for rat IgA

    PubMed Central

    Celli, S.; Valdivia, L.A.; Kelly, R.H.; Demetris, A.J.; Fung, J.J.; Rao, A.S.; Pan, F.; Tsugita, M.; Starzl, T.E.

    2010-01-01

    Long-term survival after hamster-to-rat liver xenotransplantation has provided the opportunity to study the posttransplantation source of major serum proteins and the functional consequences of several different receptor-ligand interactions, where one or the other is a xenogeneic protein. We report here that serum albumin, α-1-antitrypsin, complement component 3, and other acute phase reactants switch from recipient to donor origin during the first week after transplantation while serum immunoglobulins remain largely that of recipient. Despite the disparate source of complement (hamster) and immunoglobulins (rat), these two proteins were able to cooperate effectively to produce lysis of sheep red blood cells. Moreover, rat IgA was successfully processed by hamster hepatocytes and biliary epithelial cells, being present in the bile of successful liver xenograft recipients within one day after transplantation. The ability of these liver xenograft recipients to survive long-term in conventional and viral-free animal facilities without grossly obvious morbidity or unusual susceptibility to stress, suggests that xenogeneic proteins are able to successfully interact with several different physiologic systems in the hamster-to-rat combination. PMID:21318076

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

    PubMed

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

    2012-01-01

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

  15. Chlorpromazine distribution in hamsters and mice bearing transplantable melanoma

    SciTech Connect

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

    1982-02-01

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

  16. Morphogenesis of callosal arbors in the parietal cortex of hamsters.

    PubMed

    Hedin-Pereira, C; Lent, R; Jhaveri, S

    1999-01-01

    The morphogenesis of callosal axons originating in the parietal cortex was studied by anterograde labeling with Phaseolus lectin or biocytin injected in postnatal (P) hamsters aged 7-25 days. Some labeled fibers were serially reconstructed. At P7, some callosal fibers extended as far as the contralateral rhinal fissure, with simple arbors located in the homotopic region of the opposite cortical gray matter, and two or three unbranched sprouts along their trajectory. From P7 to P13, the homotopic arbors became more complex, with branches focused predominantly, but not exclusively, in the supra- and infragranular layers of the homotopic region. Simultaneously, the lateral extension of the trunk axon in the white matter became shorter, finally disappearing by P25. Arbors in the gray matter were either bilaminar (layers 2/3 and 5) or supragranular. A heterotopic projection to the lateral cortex was consistently seen at all ages; the heterotopic arbors follow a similar sequence of events to that seen in homotopic regions. These observations document that callosal axons undergo regressive tangential remodeling during the first postnatal month, as the lateral extension of the trunk fiber gets eliminated. Radially, however, significant arborization occurs in layer-specific locations. The protracted period of morphogenesis suggests a correspondingly long plastic period for this system of cortical fibers.

  17. CXPD: Cloning and characterization of the Chinese hamster XPD gene

    SciTech Connect

    Kirchner, J.M.; Salazar, E.P.; Lamerdin, J.E.; Carrano, A.V.; Weber, C.A.

    1994-12-31

    The Chinese hamster Xeroderma Pigmentosum group D (CXPD) nucleotide excision repair gene was cloned from the V79 cell line, and its nucleotide sequence was determined. The -15 kb gene is comprised of 23 exons with a 2283 base open reading frame. The predicted 760 amino acid protein is 98%, 51%, and 54% identical to the human ERCC2/XPD, the S. cerevisiae RAD3, and the S. pombe rad15 proteins, respectively. The promoter region of the CXPD gene contains a pyrimidine-rich stretch similar to sequences found in the promoter regions of two other nucleotide excision repair genes, a GC box, a putative {alpha}-Pal transcription factor binding site, and two CAAT boxes. We are creating mutants in CHO cell lines corresponding to those found in the rad3ts, rem-1 and rem-2 mutant alleles of S. cerevisiae, which do not cause UV-sensitivity. After modification of cloned CXPD fragments by site-directed mutagenesis, the DNAs will be targeted into UV-sensitive CHO group 2 cell lines. We have identified the mutation in the single CXPD alleles of UV5 and UVL-13. SInce the mutations in these lines are sufficiently near the sites of the rad3ts and both rem mutations, we will introduce the altered DNAs into these group 2 cell lines and select for UV-resistance. These new CHO mutants may provide insights into possible roles of CXPD in DNA replication fidelity, and mismatch repair and may confirm the predicted essential function.

  18. Propylthiouracil, but not other antithyroid treatments, lengthens hamster circadian period

    SciTech Connect

    Morin, L.P. )

    1988-07-01

    Two experiments were performed to evaluate the role of the thyroid gland as a mediator of circadian rhythms in the hamster. In experiment 1, the antithyroid drug propylthiouracil (PTU) lengthened the circadian period ({tau}), increased thyroid weight, and eliminated detectable thyroxine (T{sub 4}) and triiodothyronine (T{sub 3}) from blood. A low-iodine diet greatly reduced T{sub 4} levels but had no effect on T{sub 3} or {tau}. Treatment with 500 {mu}Ci of {sup 131}I failed to alter any parameter of physiology or thythmicity measured. In this experiment, some animals in the low-iodine and PTU groups had greatly reduced testes sizes, and testses size was inversely correlated with change in {tau}. In experiment 2, T{sub 4} and T{sub 3} levels detected 11 wk after surgical thyroidectomy were significantly less than those found in sham-operated ammals, but concentrations of the two hormones varied widely across the thyroidectomized group. Thyroidectomy did not increase {tau} either 4 or 11 wk after surgery, nor was there evidence from individuals that level of thyroid function was associated with change in {tau}. The results from these experiments suggest that diminished thyroid function is not causal of lengthened circadian period.

  19. Cell engineering and cultivation of chinese hamster ovary (CHO) cells.

    PubMed

    Omasa, Takeshi; Onitsuka, Masayoshi; Kim, Wook-Dong

    2010-04-01

    Mammalian cell lines are important host cells for the industrial production of pharmaceutical proteins owing to their capacity for correct folding, assembly and post-translational modification. In particular, Chinese hamster ovary (CHO) cells are the most dependable host cells for the industrial production of therapeutic proteins. Growing demand for therapeutic proteins promotes the development of technologies for high quality and productivity in CHO expression systems. The following are fundamentally important for effective production. 1) Construction of cultivation process. The CHO-based cultivation process is well established and is a general platform of therapeutic antibody production. The cost of therapeutic protein production using CHO cells is equivalent to that using microbial culture. 2) Cell line development. Recent developments in omics technologies have been essential for the development of rational methods of constructing a cell line. 3) Cell engineering for post-translational steps. Improvement of secretion, folding and glycosylaiton is an important key issue for mammalian cell production systems. This review provides an overview of the industrial production of therapeutic proteins using a CHO cell expression system.

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

    SciTech Connect

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

    1981-10-01

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

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

    PubMed

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

    1998-01-01

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

  2. The circadian body temperature rhythm of Djungarian Hamsters (Phodopus sungorus) revealing different circadian phenotypes.

    PubMed

    Schöttner, Konrad; Waterhouse, Jim; Weinert, Dietmar

    2011-06-01

    Djungarian hamsters (Phodopus sungorus) of our breeding stock show three rhythmic phenotypes: wild type (WT) animals which start their activity shortly after "lights-off" and are active until "lights-on"; delayed activity onset (DAO) hamsters whose activity onset is delayed after "lights-off" but activity offset coincides with "lights-on"; and arrhythmic hamsters (AR) that are episodically active throughout the 24-h day. The main aim of the present study was to investigate whether the observed phenotypic differences are caused by an altered output from the suprachiasmatic nuclei (SCN). As a marker of the circadian clock, the body temperature rhythm purified from masking effects due to motor activity was used. Hamsters were kept singly under standardized laboratory conditions (L:D=14:10h, T: 22°C±2°C, food and water ad libitum). Body temperature and motor activity were monitored by means of implanted G2-E-Mitters and the VitalView(®) System (MiniMitter). Each phenotype showed distinctive rhythms of overt activity and body temperature, these two rhythms being very similar for each phenotype. Correcting body temperatures for the effects of activity produced purified temperature rhythms which retained profiles that were distinctive for the phenotype. These results show that the body temperature rhythm is not simply a consequence of the activity pattern but is caused by the endogenous circadian system. The purification method also allowed estimation of thermoregulatory efficiency using the gradients as a measure for the sensitivity of body temperature to activity changes. In WT and DAO hamsters, the gradients were low during activity period and showed two peaks. The first one occurred after "lights-on", the second one preceded the activity onset. In AR hamsters, the gradients did not reveal circadian changes. The results provide good evidence that the different phenotypes result from differences in the circadian clock. In AR hamsters, the SCN do not produce an

  3. Mesangial proliferative glomerulonephritis associated with progressive amyloid deposition in hamsters experimentally infected with Leishmania donovani.

    PubMed Central

    Oliveira, A. V.; Roque-Barreira, M. C.; Sartori, A.; Campos-Neto, A.; Rossi, M. A.

    1985-01-01

    In the present work, 42 golden hamsters (Mesocricetus auratus) were infected by intracardiac injection of 5 X 10(6) amastigote forms of Leishmania donovani. Another group of 28 animals served as uninfected controls. Six hamsters of the infected group and four hamsters of the control group were selected randomly and sacrificed at Days 7, 14, 21, 28, 35, 42, and 49 after inoculation. The kidneys were studied by light microscopy, immunofluorescence and electron microscopy. The levels of serum and urinary immunoglobulins were determined. None of the control hamsters had kidney lesions. Light-microscopically the kidneys of infected hamsters showed a marked mesangial proliferation from Day 7 after infection. These changes were more pronounced at Day 21, when a discrete infiltration of mononuclear cells was frequent. These glomerular changes diminished after Day 28 and were replaced by deposits of amyloid. In the beginning these deposits were in the mesangium and progressively became more extensive, involving capillary loops, Bowman's capsule, and interstitium. The immunofluorescence study showed L donovani antigens and hamster immunoglobulins, primarily in the mesangial areas, by Days 7-14 after infection. These deposits extended into contiguous loops from Day 21 to Day 28. In the last 2 weeks the fluorescent staining for L donovani antigens remained intensely positive, whereas the staining for hamster immunoglobulins became moderate to slightly positive. The ultrastructural study revealed mesangial proliferation, mesangial and paramesangial electron-dense deposits, and amyloidosis in the glomeruli of infected animals. The serum immunoglobulins increased from Day 7 after infection, reaching a peak at Day 21 and falling thereafter until Day 49 to near control values. Immunoglobulins were detected in the urine of infected hamsters at day 21, increasing in amount thereafter. Since L donovani antigens and immunoglobulins were identified in the glomerular lesions, it is

  4. Improvement of oxidative stress and immunity by melatonin: an age dependent study in golden hamster.

    PubMed

    Vishwas, Dipanshu Kumar; Mukherjee, Arun; Haldar, Chandana; Dash, Debabrata; Nayak, Manasa K

    2013-02-01

    Reactive oxygen species (ROS) have been proposed to play an important role in balancing the pro- and antioxidant homeostasis during aging. Melatonin has been suggested as an effective free radical scavenger that might have a role during the process of aging. We observed, that melatonin administration (25 μg/100 g body weight for 30 days) significantly augments the activity of anti-oxidative enzymes like superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) in the plasma, spleen and bone marrow (BM) of young (6 weeks), adult (30 weeks) and old aged (2.5 years) male golden hamster, Mesocricetus auratus. A sharp decline in generation of ROS was observed in peripheral blood mononuclear cells (PBMC) and splenocytes upon melatonin administration in different age group of hamsters. Reduction in the level of thiobarbituric acid-reactive substances (TBARS) and total nitrite and nitrate concentration as metabolites and indicators of nitric oxide (NO) in plasma, spleen and BM were observed along with night time (22:00 h) melatonin concentration in different age group of hamsters after administration of melatonin and compared to the control group (treated with 0.9% saline). General immune parameters like proliferation of splenocytes, PBMC and colony forming ability of GM-CFU were observed following melatonin treatment in different age group, although it was low only in aged hamsters compared to the young and adult. Our data indicates that the age related increase of oxidative load and simultaneously augments the general immunity in aged hamsters.

  5. Wheel running affects seasonal acclimatization of physiological and morphological traits in the Djungarian hamster (Phodopus sungorus).

    PubMed

    Scherbarth, Frank; Rozman, Jan; Klingenspor, Martin; Brabant, Georg; Steinlechner, Stephan

    2007-09-01

    Wheel running was previously shown to influence body mass and torpor in short-day-acclimatized Djungarian hamsters (Phodopus sungorus). To determine whether the exercise-induced effect on body mass depends on the annual phase, hamsters were exposed to the natural change in photoperiod and given access to a running wheel (RW), either before, in the middle of, or at the end of the descending body mass trajectory during seasonal acclimatization. Due to wheel running, the seasonal weight cycle was prevented or aborted by abruptly rising body mass, resulting in a weight appropriate for summer, despite exposure to short days. Torpor was inhibited, and testicular recrudescence was advanced, compared with controls. In contrast, the change into winter fur remained unaltered. Analysis of body composition and plasma leptin revealed a low body fat mass in RW hamsters, not only in winter but also in summer, suggesting a lack of seasonal adiposity. Chronic leptin infusion in winter only decreased body mass in RW individuals, although their relative body fat mass probably was even lower than in sedentary hamsters. A constantly low body fat mass is conceivably reflecting an exercise-dependent change in metabolism, consistent with increased bone mineral content and density in RW hamsters. Additionally, bone area was increased, again supported by elongated vertebral columns. Together, the results show a striking effect of wheel running on body composition and the seasonal pattern of body mass, and they suggest that the photoperiodic regulation of body mass is regulated differently than the reproductive and pelage responses.

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

    PubMed

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

    2015-03-01

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

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

    SciTech Connect

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

    1983-06-30

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

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

    NASA Astrophysics Data System (ADS)

    Steinlechner, S.; Heldmaier, G.

    1982-12-01

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

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

    SciTech Connect

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

    1987-05-01

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

  10. Hibernation patterns of Turkish hamsters: influence of sex and ambient temperature.

    PubMed

    Batavia, Mariska; Nguyen, George; Harman, Kristine; Zucker, Irving

    2013-02-01

    Turkish hamsters (Mesocricetus brandti) are a model organism for studies of hibernation, yet a detailed account of their torpor characteristics has not been undertaken. This study employed continuous telemetric monitoring of body temperature (T(b)) in hibernating male and female Turkish hamsters at ambient temperatures (T(a)s) of 5 and 13 °C to precisely characterize torpor bout depth, duration, and frequency, as well as rates of entry into and arousal from torpor. Hamsters generated brief intervals of short (<12 h), shallow test bouts (T(b) > 20 °C), followed by deep torpor bouts lasting 4-6 days at T(a) = 5 °C and 2-3 days at T(a) = 13 °C. Females at T(a) = 5 °C had longer bouts than males, but maintained higher torpor T(b); there were no sex differences at T(a) = 13 °C. Neither body mass loss nor food intake differed between the two T(a)s. Hamsters entered torpor primarily during the scotophase (subjective night), but timing of arousals was highly variable. Hamsters at both T (a)s generated short, shallow torpor bouts between deep bouts, suggesting that this species may be capable of both hibernation and daily torpor.

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

    PubMed

    Jefimow, Małgorzata; Wojciechowski, Michał S

    2014-02-01

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

  12. Validation of assays to monitor immune responses in the Syrian golden hamster (Mesocricetus auratus).

    PubMed

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

    2011-05-31

    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.

  13. Partial lipectomy, but not PVN lesions, increases food hoarding by Siberian hamsters.

    PubMed

    Wood, A D; Bartness, T J

    1997-03-01

    We tested the inverse relationship between body fat and food hoarding in Siberian hamsters by decreasing or increasing body fat through partial surgical lipectomy (LIPX) or by making obesity-inducing lesions of the paraventricular nucleus of the hypothalamus (PVNx), respectively. We asked three questions. 1) Is food hoarding increased after body fat loss due to LIPX? 2) Is food hoarding decreased after PVNx? 3) Does PVNx affect the hoarding response to LIPX? Hamsters housed in a simulated burrow system increased food hoarding after LIPX followed by a decrease to pre-LIPX levels as body fat was partially compensated through an increase in the mass of their unoperated fat pads. PVNx hamsters had increased body mass and food intake but did not have decreased food hoarding, nor was food hoarding increased by LIPX in PVNx hamsters. The partial body fat compensation by LIPX + PVNx hamsters suggests that the damaged PVN did not cause a general failure to sense energy deficits but did affect the ability to integrate internal and external energy stores.

  14. Induction of renal and hepatic mixed function oxidases in the hamster and guinea pig.

    PubMed

    Smith, J H; Rush, G F; Hook, J B

    1986-02-01

    A marked species difference exists in the induction of renal and hepatic mixed function oxidase (MFO) activity between rats and rabbits. However, little is known about MFO induction in these organs from other laboratory animals. Male Golden Syrian hamsters and male Hartley guinea pigs were administered phenobarbital (PB) or beta-napthoflavone (BNF) at 70 and 40 mg/kg, respectively, as daily i.p. injections for 4 days. Polybrominated biphenyl (PBB) (Firemaster BP-6) was given as a single i.p. injection (50 mg/kg). Hamster hepatic microsomal ethoxyresorufin-O-deethylase (EROD) and benzphetamine-N-demethylase (BPND) were selectively induced by BNF and PB, respectively. PBB administration induced both hamster hepatic EROD and BPND. In contrast, hepatic microsomal MFO activity from the guinea pig was inducible by PB, PBB and BNF. Renal microsomal MFO activity in both species was inducible by BNF and PBB as arylhydrocarbon hydroxylase and EROD were induced approximately 10-fold. On the other hand, hamster BPND was induced by PB whereas guinea pig MFO activity was unaffected. Total renal cytochrome P-450 content was not affected by any of these inducers in either species. These data demonstrate selective patterns of induction in both hamster and guinea pig liver and kidney suggesting the involvement of multiple forms of cytochrome P-450.

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

    PubMed

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

    2007-04-01

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

  16. Comparison of Pavlovian serial conditional discrimination in rats and hamsters in the same experimental situation.

    PubMed

    Bueno, J L; Figueiredo, T H; Mello, F M

    2001-12-01

    The present study compares behavioral changes between two distinct rodent groups, hamsters (Mesocricetus auratus) and Wistar rats, when submitted in the same homogeneous experimental situations to a serial conditional discrimination procedure which involves water deprivation and the processing of temporal variables. Both hamsters and rats acquired serial positive conditional discrimination as indicated by higher frequencies of magazine-oriented behavior during the tone followed by reinforcement (T+) and preceded by the feature stimulus light (L) and during the empty interval, than during the tone alone not followed by reinforcement (T-). Rats' frequencies of magazine-oriented behavior were high during T+ and T-, initially during training, and decreased during T- as the training progressed. However, the hamsters' frequencies of magazine-oriented behavior started very low and increased only during T+ as the training progressed. Comparison of the frequencies of magazine-oriented behavior during the empty interval in relation to the frequencies during the preceding L period showed that rats' frequencies remained very high and hamsters' frequencies increased during training. These results suggest that rats and hamsters have different behavioral strategies for the acquisition of a conditional discrimination. The results of the comparisons made in these experiments support the view of the importance of an ecological psychology approach to the understanding of complex learning in animals.

  17. Dopamine Mediates Testosterone-Induced Social Reward in Male Syrian Hamsters

    PubMed Central

    Sisk, Cheryl L.

    2013-01-01

    Adolescent maturation of responses to social stimuli is essential for adult-typical sociosexual behavior. Naturally occurring developmental changes in male Syrian hamster responses to a salient social cue, female hamster vaginal secretions (VS), provide a good model system for investigating neuroendocrine mechanisms of adolescent change in social reward. Sexually naïve adult, but not juvenile, males show a conditioned place preference (CPP) to VS, indicating that VS is not rewarding before puberty. In this series of experiments, the authors examined the roles of testosterone and dopamine receptor activation in mediating the adolescent gain in positive valence of VS. Experiment 1 showed that testosterone replacement is necessary for gonadectomized adult hamsters to form a CPP to VS. Experiment 2 showed that testosterone treatment is sufficient for juvenile hamsters to form a CPP to VS, and that the dopamine receptor antagonist haloperidol blocks formation of a CPP to VS in these animals. Experiments 3 and 4 demonstrated that the disruption of VS CPP with low doses of haloperidol is the result of a reduction in the attractive properties of VS and not attributable to aversive properties of haloperidol. Together, these studies demonstrate that the unconditioned rewarding properties of a social cue necessary for successful adult sociosexual interactions come about as the result of the pubertal increase in circulating testosterone in male hamsters. Furthermore, this social reward can be prevented by dopamine receptor antagonism, indicating that hypothalamic and/or mesocorticolimbic dopaminergic circuits are targets for hormonal activation of social reward. PMID:23372017

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

    PubMed

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

    2016-11-01

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

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

    SciTech Connect

    Stinson, S.F.; Saffiotti, U.

    1986-03-01

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

  20. Effect of azaline B on follicular development and functions in the hamster

    PubMed Central

    Chakraborty, Prabuddha; Roy, Shyamal K.

    2014-01-01

    The usefulness of azaline B, a GnRH antagonist, in suppressing gonadotropin secretion in the golden hamster was examined by examining follicular development, steroidogenesis and expression of steroidogenic enzymes. Serum levels of P and E declined significantly, while FSH or LH was undetectable in azaline B-treated hamsters. FSH significantly increased serum E levels, whereas LH upregulated serum P levels. The formation of antral follicles ceased in azaline-treated hamsters, but was reversed by FSH with or without LH supplement. FSH also activated the primordial follicle pool resulting in increased formation of primary and preantral follicles. Further, an increasing trend in the formation of preantral follicles in response to E or E + P, and the formation of antral follicles in response to E + P treatment was evident. The level of Cyp11a1 mRNA increased markedly in LH− or LH + FSH-treated hamsters, whereas FSH with or without LH upregulated Cyp17a1, Cyp19a1 and Fshr mRNA expression. E without or with P also upregulated ovarian Cyp19a1 mRNA expression. The expression of enzyme protein corroborated the mRNA data. In summary, azaline B is an efficient GnRH antagonist in the hamster, and will be useful in studying the selective effect of gonadotropins on ovarian functions without disrupting the physiological functions of other hormones in ovarian cells. PMID:25462584

  1. Propagation of Asian isolates of canine distemper virus (CDV) in hamster cell lines

    PubMed Central

    Sultan, Serageldeen; Lan, Nguyen Thi; Ueda, Toshiki; Yamaguchi, Ryoji; Maeda, Ken; Kai, Kazushige

    2009-01-01

    Backgrounds The aim of this study was to confirm the propagation of various canine distemper viruses (CDV) in hamster cell lines of HmLu and BHK, since only a little is known about the possibility of propagation of CDV in rodent cells irrespective of their epidemiological importance. Methods The growth of CDV in hamster cell lines was monitored by titration using Vero.dogSLAMtag (Vero-DST) cells that had been proven to be susceptible to almost all field isolates of CDV, with the preparations of cell-free and cell-associated virus from the cultures infected with recent Asian isolates of CDV (13 strains) and by observing the development of cytopathic effect (CPE) in infected cultures of hamster cell lines. Results Eleven of 13 strains grew in HmLu cells, and 12 of 13 strains grew in BHK cells with apparent CPE of cell fusion in the late stage of infection. Two strains and a strain of Asia 1 group could not grow in HmLu cells and BHK cells, respectively. Conclusion The present study demonstrates at the first time that hamster cell lines can propagate the majority of Asian field isolates of CDV. The usage of two hamster cell lines suggested to be useful to characterize the field isolates biologically. PMID:19835588

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

    PubMed

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

    2005-10-01

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

  3. Cryopreservation of hamster oocytes: effects of vitrification or freezing on human sperm penetration of zona-free hamster oocytes.

    PubMed

    Critser, J K; Arneson, B W; Aaker, D V; Ball, G D

    1986-08-01

    Three experiments were conducted for evaluation of the efficacy of conventional freezing or vitrification of hamster oocytes for use in a human sperm penetration assay (hSPA). In experiment 1, oocytes were cryopreserved and evaluated for survival on the basis of morphologic criteria. Survival of vitrified oocytes and that of frozen oocytes were not different, whereas all cryopreserved groups had lower survival than noncryopreserved controls. In experiment 2, oocytes were conventionally frozen or vitrified and evaluated in an hSPA. Vitrified oocytes had a lower frequency of sperm penetration than frozen oocytes, and all cryopreserved groups had lower penetration rates than untreated controls. In experiment 3, oocytes were exposed to the cryoprotectant used to vitrify (VS1) or freeze (DMSO) but not cooled prior to evaluation in an hSPA. Exposure to DMSO but not VS1 reduced hSPA values. It is concluded from these experiments that while all cryopreserved oocytes do not survive, at current stages of development conventionally frozen oocytes perform better than vitrified oocytes in the hSPA and losses associated with conventional freezing procedures may be related to cryoprotectant exposure, whereas vitrification losses are more probably due to events associated with rapid cooling and/or warming of the oocytes.

  4. 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.

  5. Fish oil induced hyperlipidemia and oxidative stress in BioF1B hamsters is attenuated by elderberry extract.

    PubMed

    Dubey, Pratibha; Jayasooriya, Anura P; Cheema, Sukhinder K

    2012-06-01

    We have previously reported fish oil induced hyperlipidemia in BioF1B hamsters compared with Golden Syrian (GS) hamsters. Elderberry (Sambucus nigra L.) extract is abundant in anthocyanins and is believed to exert cardioprotective effects primarily by virtue of its hypolipidemic and antioxidant potential. In the current study, high-fat fish oil feeding increased oxidative stress in BioF1B hamsters compared with GS hamsters; this increase was associated with increased levels of omega-3 polyunsaturated fatty acids in plasma and liver. We then investigated whether cosupplementation with anthocyanin-rich elderberry extract would reverse fish oil induced hyperlipidemia and reduce lipid peroxidation in BioF1B hamsters. Plasma and hepatic lipids decreased significantly when hamsters were fed diets containing elderberry extract along with fish oil. Both plasma and liver thiobarbituric acid reactive substances showed significant reductions upon cosupplementation with elderberry extract in fish oil fed BioF1B hamsters. Our findings demonstrate that cosupplementation with elderberry extract reverses hyperlipidemia and lipid peroxidation observed with dietary fish oil alone in BioF1B hamsters.

  6. Short-day-like body weight changes do not prevent fat pad compensation after lipectomy in Siberian hamsters.

    PubMed

    Mauer, M M; Bartness, T J

    1997-01-01

    Long-day (LD)-housed Siberian hamsters show compensatory increases in white adipose tissue (WAT) weight after lipectomy, whereas hamsters exposed to short days (SDs) for a long duration (22 wk) do not. We tested whether SD-induced body weight changes prevent fat pad compensation after lipectomy. In experiment 1, hamsters with lesions of the paraventricular nucleus of the hypothalamus (PVNx) rapidly increased body weight similarly to 22-wk SD-exposed hamsters. In experiment 2, LD-housed hamsters were food restricted for 22 wk and then pair fed with SD-housed hamsters for 12 wk to produce body weight changes mimicking those of ad libitum-fed SD-exposed animals. Epididymal WAT (EWAT) lipectomy (EWATx) of PVNx or food-restricted hamsters elicited compensatory increases in retroperitoneal and inguinal WAT (RWAT and IWAT) weights. Unlike other fat pads, EWAT was less affected by food restriction or PVNx than by SD exposure. In general, food restriction decreased adipocyte number, whereas SD exposure decreased adipocyte size. PVNx increased RWAT adipocyte size and IWAT adipocyte number. These results suggest that the lack of body fat compensation by EWATx hamsters exposed to SDs for a long duration is due to SD-associated responses other than body weight changes per se.

  7. Lack of tumorigenic activity of 1,1-dimethylhydrazine in Syrian golden hamsters treated by subcutaneous injection.

    PubMed

    Jeong, J Y; Kamino, K

    1993-02-01

    Syrian golden hamsters were treated throughout their lifespan by weekly subcutaneous injections of 1,1-dimethylhydrazine (1,1-DMH) at doses of 0, 8, 17 and 35 mg/kg body weight. In contrast to our previous study using European hamsters, no treatment-related tumors occurred in this study.

  8. Water molecules participate in proteinase-inhibitor interactions: crystal structures of Leu18, Ala18, and Gly18 variants of turkey ovomucoid inhibitor third domain complexed with Streptomyces griseus proteinase B.

    PubMed Central

    Huang, K.; Lu, W.; Anderson, S.; Laskowski, M.; James, M. N.

    1995-01-01

    Crystal structures of the complexes of Streptomyces griseus proteinase B (SGPB) with three P1 variants of turkey ovomucoid inhibitor third domain (OMTKY3), Leu18, Ala18, and Gly18, have been determined and refined to high resolution. Comparisons among these structures and of each with native, uncomplexed SGPB reveal that each complex features a unique solvent structure in the S1 binding pocket. The number and relative positions of water molecules bound in the S1 binding pocket vary according to the size of the side chain of the P1 residue. Water molecules in the S1 binding pocket of SGPB are redistributed in response to the complex formation, probably to optimize hydrogen bonds between the enzyme and the inhibitor. There are extensive water-mediated hydrogen bonds in the interfaces of the complexes. In all complexes, Asn 36 of OMTKY3 participates in forming hydrogen bonds, via water molecules, with residues lining the S1 binding pocket of SGPB. For a homologous series of aliphatic straight side chains, Gly18, Ala18, Abu18, Ape18, and Ahp18 variants, the binding free energy is a linear function of the hydrophobic surface area buried in the interface of the corresponding complexes. The resulting constant of proportionality is 34.1 cal mol-1 A-2. These structures confirm that the binding of OMTKY3 to the preformed S1 pocket in SGPB involves no substantial structural disturbances that commonly occur in the site-directed mutagenesis studies of interior residues in other proteins, thus providing one of the most reliable assessments of the contribution of the hydrophobic effect to protein-complex stability. PMID:8535235

  9. Trypanosoma cruzi: characterization of reinfection and search for tissue tropism in hamsters (Mesocricetus auratus).

    PubMed

    Cabrine-Santos, M; Lages Silva, E; Chapadeiro, E; Ramírez, L E

    2001-11-01

    Tissue tropism, the role of reinfection in the development of Chagas' disease, and the selection of subpopulations of Trypanosoma cruzi were evaluated in hamsters inoculated with the VIC strain of T. cruzi. Adult allogeneic male hamsters were inoculated once or reinoculated by the intraperitoneal route up to four times with 2000 blood trypomastigotes. Animals were studied by blood culture, histopathology, immunohistochemistry, and molecular techniques (PCR and low-stringency single specific primer-PCR). Homogeneity of the T. cruzi population observed in different tissues suggests that selective tropism of the VIC strain extends only to various muscle tissues in hamsters and that reinfection is not a factor in the development of the inflammatory processes, although it may aggravate it, possibly due to an increase in tissue parasitism, which might induce autoimmune mechanisms. Reinfection did not induce selection of subpopulations in the tissue or in the blood.

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

    SciTech Connect

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

    2012-07-01

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

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

    PubMed Central

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

    2016-01-01

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

  12. Running-wheel activity and body composition in golden hamsters (Mesocricetus auratus).

    PubMed

    Gattermann, Rolf; Weinandy, René; Fritzsche, Peter

    2004-09-15

    Running wheels are frequently used in behavioural and physiological experiments. The function of wheel-running activity in laboratory animals is controversial. In the present long-term study, the influence of this activity was evaluated in male golden hamsters over a period of 52 weeks. Four months after the start of the experiment, hamsters with access to running wheels were significantly heavier than those without these wheels. In addition, food consumption nearly doubled. The absolute values of fat-free mass (FFM), total body water (TBW) and crude fat mass (CFM) increased. However, in contrast to these absolute differences, the relative values were never different and general body composition was therefore unaffected by running-wheel activity. Different organ masses were established for absolute values of kidneys, testes and epididymis; possible effects on reproduction are discussed. The present data indicating improved physical condition leads to the assumption that a running wheel is a useful enrichment, enhancing animal welfare in the golden hamster.

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

    NASA Astrophysics Data System (ADS)

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

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

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

    SciTech Connect

    Gale, T.F.

    1982-10-01

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

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

    SciTech Connect

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

    1989-01-01

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

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

    PubMed

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

    2016-12-15

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

  17. The hamster model for identification of specific antigens of Taenia solium tapeworms.

    PubMed

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

    2011-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

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

  19. Early stage biliary and intrahepatic migration of Opisthorchis viverrini in the golden hamster.

    PubMed

    Nithikathkul, C; Tesana, S; Sithithaworn, P; Balakanich, S

    2007-03-01

    In Thailand, infection with the liver fluke Opisthorchis viverrini is a serious health problem, with over 8.6 million human infections each year. Early stage biliary intrahepatic migration and infection of O. viverrini in the Syrian golden hamster were used to study the growth and development of this fluke. Fifty metacercariae of O. viverrini were introduced into each hamster by gastric intubation. Worms were found to migrate rapidly from the stomach to the gall bladder and hepatic duct, where they remained in relatively constant numbers until the end of week 8. Sexual development of worms was rapid, with full development of the uterus and testes by one and one half weeks and the appearance of eggs in the uterus by the beginning of the third week of infection. Worm growth as indicated by body length had ceased by week 8. Hamsters demonstrated development of a full reproductive cycle with in three to four weeks, and this generation continued until 8 weeks.

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

    PubMed

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

    2015-06-01

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

  1. Histopathological studies of aortic dissection in streptozotocin-induced diabetic APA hamsters.

    PubMed

    Horiuchi, Keiko; Takatori, Atsushi; Inenaga, Toshiaki; Ohta, Etsuko; Ishii, Yoshiyuki; Kyuwa, Shigeru; Yoshikawa, Yasuhiro

    2005-07-01

    Syrian hamsters of the APA strain (APA hamsters) are known to show continuous diabetes accompanied by its complications, such as glomerulosclerosis and atherosclerosis, following a single injection of streptozotocin (SZ). Recently, we observed Stanford type B aortic dissection in three diabetic APA hamsters and histopathological analysis was performed. The histopathologic observations in the false lumen, such as proliferation of granulation tissues, neointima and pseudoneointima, corresponded to the non-thrombosed type of human aortic dissection, and blood clots of the thrombosed type were similar to the remodeling structures of aortic dissection found in human cases. Thus, this model may be useful for investigating the etiology and pathogenesis of aortic dissection accompanying diabetes mellitus in humans.

  2. Efficacy of an inactivated vaccine for equine herpesvirus type 1 in a novel hamster model.

    PubMed

    Skinner, G R; Davies, J

    2000-01-01

    A vaccine designated F.EHV1(S(-))BHK, which was prepared by formaldehyde treatment of equine herpesvirus type 1 (EHV1)-infected baby hamster kidney cells, stimulated neutralising antibodies in hamsters and rabbits and protected new-born hamsters against a lethal challenge with EHV1 by vaccination of their pregnant mothers. The preparative method was then modified to eliminate virus particles and intraparticulate DNA, producing a vaccine designated Bg.F.EHV1(S(-))BHK. this modification stimulated neutralising antibodies with evidence of in vivo inactivation of the virus above non-specific levels in a mouse model. There were no adverse effects from these vaccines in rodent or rabbit species.

  3. Cholecystokinin-33 acutely attenuates food foraging, hoarding and intake in Siberian hamsters

    PubMed Central

    Teubner, Brett J.W.; Bartness, Timothy J.

    2009-01-01

    Neurochemicals that stimulate food foraging and hoarding in Siberian hamsters are becoming more apparent, but we do not know if cessation of these behaviors is due to waning of excitatory stimuli and/or the advent of inhibitory factors. Cholecystokinin (CCK) may be such an inhibitory factor as it is the prototypic gastrointestinal satiety peptide and is physiologically important in decreasing food intake in several species including Siberian hamsters. Systemic injection of CCK-33 in laboratory rats decreases food intake, doing so to a greater extent than CCK-8. We found minimal effects of CCK-8 on food foraging and hoarding previously in Siberian hamsters, but have not tested CCK-33. Therefore, we asked: Does CCK-33 decrease normal levels or food deprivation-induced increases in food foraging, hoarding and intake? Hamsters were housed in a wheel running-based foraging system with simulated burrows to test the effects of peripheral injections of CCK-33 (13.2, 26.4, or 52.8 μg/kg body mass), with or without a preceding 56 h food deprivation. The highest dose of CCK-33 caused large baseline reductions in all three behaviors for the 1st h post injection compared with saline; in addition, the intermediate CCK-33 dose was sufficient to curtail food intake and foraging during the 1st h. In food deprived hamsters, we used a 52.8 μg/kg body mass dose of CCK-33 which decreased food intake, hoarding, and foraging almost completely compared with saline controls for 1 h. Therefore, CCK-33 appears to be a potent inhibitor of food intake, hoarding, and foraging in Siberian hamsters. PMID:20025915

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

    PubMed

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

    1996-08-02

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

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

    SciTech Connect

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

    2000-08-25

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

  6. 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.

  7. Short days and exogenous melatonin increase aggression of male Syrian hamsters (Mesocricetus auratus).

    PubMed

    Jasnow, Aaron M; Huhman, Kim L; Bartness, Timothy J; Demas, Gregory E

    2002-08-01

    Many nontropical rodent species rely on photoperiod as a primary cue to coordinate seasonally appropriate changes in physiology and behavior. Among these changes, some species of rodents demonstrate increased aggression in short, "winter-like" compared with long "summer-like" day lengths. The precise neuroendocrine mechanisms mediating changes in aggression, however, remain largely unknown. The goal of the present study was to examine the effects of photoperiod and exogenous melatonin on resident-intruder aggression in male Syrian hamsters (Mesocricetus auratus). In Experiment 1, male Syrian hamsters were housed in long (LD 14:10) or short (LD 10:14) days for 10 weeks. In Experiment 2, hamsters were housed in long days and half of the animals were given daily subcutaneous melatonin injections (15 microg/day in 0.1 ml saline) 2 h before lights out for 10 consecutive days to simulate a short-day pattern of melatonin secretion, while the remaining animals received injections of the vehicle alone. Animals in both experiments were then tested using a resident-intruder model of aggression and the number of attacks, duration of attacks, and latency to initial attack were recorded. In Experiment 1, short-day hamsters underwent gonadal regression and displayed increased aggression compared with long-day animals. In Experiment 2, melatonin treatment also increased aggression compared with control hamsters without affecting circulating testosterone. Collectively, the results of the present study demonstrate that exposure to short days or short day-like patterns of melatonin increase aggression in male Syrian hamsters. In addition, these results suggest that photoperiodic changes in aggression provide an important, ecologically relevant model with which to study the neuroendocrine mechanisms underlying aggression in rodents.

  8. Glutamate and the aggression neural circuit in adolescent anabolic steroid-treated Syrian hamsters (Mesocricetus auratus).

    PubMed

    Carrillo, Maria; Ricci, Lesley A; Melloni, Richard H

    2011-10-01

    Adolescent exposure to anabolic androgenic steroids (AAS) alters the development and activity of the glutamate neural system in the latero-anterior hypothalamus (LAH) in hamsters (Mesocricetus auratus); that is, an important neural component of the adolescent AAS-induced aggressive response. In this article, we used retrograde tracing to investigate glutamate-specific alterations in the connections between the LAH and several other nuclei implicated in adolescent AAS-induced aggression. Briefly, hamsters were treated with AAS or sesame-oil control during adolescence and then microinjected with retrograde tracer into the medial amygdala (MeA), lateral septum (LS), or bed nucleus of the stria terminalis (BNST). Brains were then processed for vesicular glutamate transporter 2 (VGLUT2) and examined for AAS-induced changes in the number VGLUT2 cells containing retrograde tracer (VGLUT2/tracer) within the LAH. It is interesting to note that while aggressive AAS-treated hamsters injected retrograde tracer into the MeA showed a significant reduction in the number of VGLUT2/tracer cells in the LAH, aggressive AAS-treated hamsters injected tracer into the BNST showed a significant increase in the number of VGLUT2/tracer cells in the LAH when compared with controls. Last, AAS hamsters injected with tracer into the LS had a comparable number of LAH-VGLUT2/tracer cells to controls. The current results indicate that glutamate likely functions as the major aggression output system from the LAH and that adolescent AAS treatment significantly alters the neural circuitry modulating aggression. Moreover, increases in the number of glutamate projections from the LAH to the BNST in AAS hamsters identify the BNST as an area particularly important for the regulation of AAS-induced aggression.

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

    PubMed

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

    2017-01-01

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

  10. Cholecystokinin-33 acutely attenuates food foraging, hoarding and intake in Siberian hamsters.

    PubMed

    Teubner, Brett J W; Bartness, Timothy J

    2010-04-01

    Neurochemicals that stimulate food foraging and hoarding in Siberian hamsters are becoming more apparent, but we do not know if cessation of these behaviors is due to waning of excitatory stimuli and/or the advent of inhibitory factors. Cholecystokinin (CCK) may be such an inhibitory factor as it is the prototypic gastrointestinal satiety peptide and is physiologically important in decreasing food intake in several species including Siberian hamsters. Systemic injection of CCK-33 in laboratory rats decreases food intake, doing so to a greater extent than CCK-8. We found minimal effects of CCK-8 on food foraging and hoarding previously in Siberian hamsters, but have not tested CCK-33. Therefore, we asked: Does CCK-33 decrease normal levels or food deprivation-induced increases in food foraging, hoarding and intake? Hamsters were housed in a wheel running-based foraging system with simulated burrows to test the effects of peripheral injections of CCK-33 (13.2, 26.4, or 52.8 microg/kg body mass), with or without a preceding 56 h food deprivation. The highest dose of CCK-33 caused large baseline reductions in all three behaviors for the 1st hour post-injection compared with saline; in addition, the intermediate CCK-33 dose was sufficient to curtail food intake and foraging during the 1st hour. In food-deprived hamsters, we used a 52.8 microg/kg body mass dose of CCK-33 which decreased food intake, hoarding, and foraging almost completely compared with saline controls for 1h. Therefore, CCK-33 appears to be a potent inhibitor of food intake, hoarding, and foraging in Siberian hamsters.

  11. Both soybean and kudzu phytoestrogens modify favorably the blood lipoprotein profile in ovariectomized and castrated hamsters.

    PubMed

    Guan, Lei; Yeung, Sai Ying Venus; Huang, Yu; Chen, Zhen-Yu

    2006-06-28

    The present study compared the hypolipidemic activity of kudzu phytoestrogens with that of soybean phytoestrogen in estrogen- and androgen-deficient hamsters. In the first experiment, ovariectomized hamsters (n = 37) were randomly divided into four groups (n = 9-10 each group). The first group was the control group, whereas the second group had the time-releasing estradiol-17beta subcutaneous (pellet) implants as a positive control. The third and fourth groups were orally administered soybean or kudzu phytoestrogen extracts (30 mg/kg of body weight) per day. In the second experiments, the first group of male hamsters (n = 9) received a sham operation, whereas the other three groups of male hamsters (n = 9 each) were castrated. The castrated control group received orally distilled water, whereas the second and third castrated groups were orally given 30 mg/kg soybean or kudzu phytoestrogen extracts. The results for the first experiment showed that the ovariectomized hamsters orally given soybean and kudzu phytoestrogen extracts had significantly decreased serum total cholesterol (TC) and non-high-density lipoprotein cholesterol (non-HDL-C) with HDL cholesterol (HDL-C) being unaffected. The data from the second experiment demonstrated that administration of soybean but not kudzu phytoestrogen extracts decreased significantly serum TC. However, administration of kudzu phytoestrogens caused redistribution of cholesterol among lipoproteins, leading to a significant decrease in the ratio of non-HDL-C to HDL-C. It was concluded that both soybean and kudzu phytoestrogens could modify favorably lipoprotein profiles in ovariectomized and castrated hamsters.

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

    PubMed

    Kabithe, Esther W; Place, Ned J

    2008-03-01

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

  13. Cryopreservation and In Vitro culture of Preimplantation Embryos in Djungarian Hamster (Phodopus sungorus).

    PubMed

    Brusentsev, E Yu; Abramova, T O; Rozhkova, I N; Igonina, T N; Naprimerov, V A; Feoktistova, N Yu; Amstislavsky, S Ya

    2015-08-01

    Although embryo cryobanking was applied to Syrian golden and to Campbell's hamsters, no attempt has been made at freezing embryos in Djungarian hamsters. Four-cell stage embryos were flushed from the reproductive ducts of pregnant females before noon of the third-day post coitum and frozen in 0.25-ml straws according to standard procedures of slow cooling. A mixture of permeating (ethylene glycol) and non-permeating (sucrose) cryoprotectants was used. The thawing was performed by incubating at RT for 40 s followed by 40 s in a water bath at 30.0°C. Most (66.7%) of the non-frozen four-cell embryos developed up to the morula stage in rat one-cell embryo culture medium (R1ECM). The use of hamster embryo culture medium (HECM) yielded fewer morulas (18.2%) during the same 24-h period of culture. The rate of embryo's surviving the freezing-thawing procedures, as estimated by light microscopy, was 60.7-68.8%. After 24-h culturing in R1ECM, 64.7% of frozen-thawed four-cell embryos developed and all of them reached the morula stage. Supplementation of R1ECM with GM-CSF (2 ng/ml) improved the rate of Djungarian hamster frozen-thawed embryo development: 100% of the four-cell stage embryos developed, 50% of them achieved the morula stage, and 50% developed even further and reached the blastocyst stage within 24 h of culturing. This study reports the world's first successful transfer of frozen-thawed Djungarian hamster embryos yielding term pups. Taken together, the results of this study demonstrate the possibility of applying some key reproductive technologies, that is, embryo freezing/cryopreservation and in vitro culture, to Djungarian hamsters.

  14. Periodic variation in R-R intervals and cardiovascular autonomic regulation in young adult Syrian hamsters.

    PubMed

    Mongue-Din, H; Salmon, A; Fiszman, M Y; Fromes, Y

    2009-03-01

    Several hamster strains are commonly used as models for cardiomyopathic phenotypes evolving toward heart failure. However, little is known about heart rate variability (HRV) in this species. Prolonged surface ECG recording, a prerequisite to HRV studies, can be obtained either by telemetry or by restraints. Here, we performed long time ECG recording using telemetry on young adult Syrian hamsters and we analyzed time series of interbeat intervals. Standard statistics showed that the mean of normal R-R intervals slightly increased with age, with standard deviation of normal R-R intervals remaining stable over time. However, time domain analysis using Poincaré plots revealed dynamic changes in the HRV. Analysis of frequency domains revealed that the ratio of spectral components (low frequency/high frequency) exhibited a maturation pattern. Thus refined analysis of HRV revealed a more complex pattern than common statistical analysis would translate. Unlike other rodents, hamsters display a great spontaneous variability of their heart rate. As the complexity canvas of HRV might be the consequence of extracardiac regulation factors, we assessed the sympathovagal balance in both time and frequency domain of heart rate. Pharmacological tests revealed that both sympathetic and vagal tones contribute to HRV in Syrian hamsters. Thus Syrian hamsters have a broad intrinsic HRV with large influences of the neurovegetative system. However, the influence of the previous beat seems to prevail over the autonomic oscillators. These animals present a high sensitivity to artificially altered cardiac regulation and might be great models for the diagnosis of early alterations in the HRV related to pathology. Therefore, Syrian hamsters represent a unique model for HRV studies.

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

    PubMed

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

    2014-12-01

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

  16. Injected phytosterols/stanols suppress plasma cholesterol levels in hamsters.

    PubMed

    Vanstone, C A.; Raeini-Sarjaz, M; Jones, P J.H.

    2001-10-01

    Although plant sterols are known to suppress intestinal cholesterol absorption, whether plasma and hepatic lipid levels are influenced through non-gut related internal mechanisms has not been established. To examine this question 50 male hamsters were divided into 5 groups and fed semi-purified diets containing 20% energy as fat and 0.25% (w/w) cholesterol ad libitum for 60 days. The control group (i) received diet alone, while four additional groups consumed the diet plus one of four equivalent phytosterol mixtures (5 mg/kg/day) given either as (ii) tall oil phytosterols/stanols mixed with diet (oralSA), (iii) tall oil phytosterols/stanols subcutaneously injected (subSA), (iv) soybean oil phytosterols alone mixed with diet (oralSE), or (v) soybean oil subcutaneous injected phytosterols alone (subSE). The control group and both orally supplemented groups also received placebo subcutaneous sham injections. Neither food consumption, body weight, nor liver weight differed across treatment groups. Subcutaneous administration of SA and SE decreased plasma total cholesterol levels by 21% and 23% (p < 0.0001) and non-apolipoprotein-A cholesterol concentrations by 22% and 15% (p < 0.0002), respectively, compared to control. HDL cholesterol and TG concentrations remained unchanged across all groups, except for a decline of 25% (p < 0.0001) in HDL concentration in the subSE group versus control. Plasma campesterol levels were lower (p < 0.05) in the subSA group relative to all other groups. Plasma campesterol:cholesterol and campesterol:sitosterol ratios were, however, higher (p < 0.0001) for both the oral and subSE groups. Hepatic cholesterol levels were higher (p < 0.0001) in the oral and subSE phytosterol groups by 30% and 31%, respectively, relative to control. We conclude that low doses of subcutaneously administered plant sterols reduce circulating cholesterol levels through mechanisms other than inhibiting intestinal cholesterol absorption.

  17. Crossed and uncrossed retinal projections to the hamster circadian system.

    PubMed

    Muscat, Louise; Huberman, Andrew D; Jordan, Cynthia L; Morin, Lawrence P

    2003-11-24

    The hamster suprachiasmatic nucleus (SCN), site of the circadian clock, has been thought to be equally and completely innervated by each retina. This issue was studied in animals that had received an injection of the tracer cholera toxin subunit B (CTb) conjugated to Alexa 488 into the vitreous of one eye, with CTb-Alexa 594 injected into the other. Retinal projections to the SCN and other nuclei of the circadian system were simultaneously evaluated by using confocal laser microscopy. Each retina provides completely overlapping terminal fields throughout each SCN. Although SCN innervation by the contralateral retina is slightly denser than that from the ipsilateral retina, there are distinct SCN regions where input from one side is predominant, but not exclusive. A dense terminal field from the contralateral retina encompasses, and extends dorsally beyond, the central SCN subnucleus identified by calbindin-immunoreactive neurons. Surrounding the dense terminal field, innervation is largely derived from the ipsilateral retina. The densest terminal field in the intergeniculate leaflet is from the contralateral retina, which completely overlaps the ipsilateral projection. Most nuclei of the pretectum receive innervation largely, but not solely, from the contralateral retina, although the olivary pretectal nucleus has very dense patches of innervation derived exclusively from one retina or the other. Retina-dependent variation in terminal field density within the three closely examined nuclei may indicate areas of specialized function not previously appreciated. This issue is discussed in the context of the melanopsin-containing retinal ganglion cell projections to several nuclei in the circadian visual system.

  18. Hypothalamic neuropeptide systems and anticipatory weight change in Siberian hamsters.

    PubMed

    Adam, C L; Mercer, J G

    2001-01-01

    Seasonal animals are able both to programme changes in body weight in response to annual changes in photoperiod (anticipatory regulation) and to correct changes in body weight caused by imposed energetic demand (compensatory regulation). Experimental evidence from the Siberian hamster suggests that seasonally appropriate body weight is continually reset according to photoperiodic history, even when actual body weight is driven away from this target weight by manipulation of energy intake. These characteristics constitute the "sliding set point" of seasonal body weight regulation. To define the mechanisms and molecules underlying anticipatory body weight regulation, we are investigating the involvement of hypothalamic systems with an established role in the compensatory defence of body weight. Weight loss or restricted growth induced by short days (SD) results in low circulating leptin compared with long day (LD) controls. However, this chronic low leptin signal is read differently from acute low leptin resulting from food deprivation; leptin receptor gene expression in the hypothalamic arcuate nucleus (ARC) is lower in SD, whereas food deprivation increases expression levels, suggesting changes in sensitivity to leptin feedback. SD alterations in mRNA levels for a number of hypothalamic neuropeptide and receptor genes appear counter-intuitive for a SD body weight trajectory. However, early increases in ARC cocaine-and amphetamine-regulated transcript (CART) gene expression in SDs could be involved in driving body weight loss or growth restriction. The sites of photoperiod interaction with energy balance neuronal circuitry and the neurochemical encoding of body weight set point require full characterisation. Study of anticipatory regulation in seasonal animals offers new insight into body weight regulation across mammalian species, including man.

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

    PubMed Central

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

    2016-01-01

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

  2. Novel object recognition of Djungarian hamsters depends on circadian time and rhythmic phenotype.

    PubMed

    Müller, Lisa; Fritzsche, Peter; Weinert, Dietmar

    2015-05-01

    Circadian rhythms have been shown to influence learning and memory. In this study, cognitive functions of Djungarian hamsters revealing different circadian phenotypes were evaluated using a novel object recognition (NOR) task. Wild type (WT) animals show a clear and well-synchronized daily activity rhythm, whereas DAO hamsters are characterized by a delayed activity onset. The phenomenon is caused by a diminished ability of photic synchronization. In arrhythmic (AR) hamsters, the suprachiasmatic nuclei (SCN) do not generate a circadian signal at all. The aim of this study was to investigate consequences of these deteriorations for learning and memory processes. Hamsters were bred and kept under standardized housing conditions with food and water ad libitum and a 14 L/10 D lighting regimen. Experimental animals were assigned to different groups (WT, DAO and AR) according to their activity pattern obtained by means of infrared motion sensors. Activity onset of DAO animals was delayed by 3 ± 0.5 h. NOR tests were performed in an open arena and consisted of habituation, training (two identical objects) and test sessions (one of the two objects being replaced). The training-test interval was 60 min. Tests were performed at different Zeitgeber times (ZT 0 = light-on). Every hamster was tested at all times with an interval of one week between experiments. As activity onset of DAO animals is delaying continuously day by day, they could be tested at only three times (ZT 13, ZT 16 and ZT 19). The times animals did explore the novel and the familiar objects were recorded, and the discrimination index as a measure of cognitive performance was calculated. Behavioral analyzes revealed that, WT hamsters were able to discriminate between familiar and novel objects at ZT 13, ZT 16 and ZT 19, i.e. one hour before and during their activity period. In accordance with their delayed activity onset, DAO hamsters could discriminate between objects only at ZT 16 and ZT 19

  3. The Syrian Hamster Pineal Gland Responds to Isoproterenol in Vivo at Night

    DTIC Science & Technology

    1987-01-01

    pineal gland transmitter. Proc Nat Acad Sci USA protect against acute stress-induced 70:2411 increase in N-acetyltransferase (EC 2.3.1.5.) activity ...Society Printed in U.S.A. A THE SYRIAN HAMSTER PINEAL GLAND RESPONDS TO ISOPROTERENOL IN VIVO AT NIGHT George M. Vaughan 1 and Russel J. Reiter 2 1US...then kept in light for 2 h, pineal melatonin was equally low 0 • after ISO or vehicle injection. The Syrian hamster pineal gland can respond in vivo

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

    PubMed

    Schöttner, Konrad; Hauer, Jane; Weinert, Dietmar

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

  7. Animal Models of Leptospirosis: Of Mice and Hamsters

    PubMed Central

    Gomes-Solecki, Maria; Santecchia, Ignacio; Werts, Catherine

    2017-01-01

    Pathogenic Leptospira sp. are spirochetal bacteria responsible for leptospirosis, an emerging worldwide zoonosis. These spirochetes are very successful pathogens that infect a wide range of hosts such as fish, reptiles, birds, marsupials, and mammals. Transmission occurs when chronically infected animals excrete live bacteria in their urine, contaminating the environment. Leptospira sp. enter their hosts through damaged skin and mucosa. Chronically infected rats and mice are asymptomatic and are considered as important reservoirs of the disease. Infected humans may develop either a flu-like, usually mild illness with or without chronic asymptotic renal colonization, or a severe acute disease with kidney, liver, and heart failure, potentially leading to death. Leptospirosis is an economic burden on society due to health-care costs related to elevated morbidity of humans and loss of animals of agricultural interest. There are no effective vaccines against leptospirosis. Leptospira sp. are difficult to genetically manipulate which delays the pace of research progress. In this review, we discuss in an historical perspective how animal models have contributed to further our knowledge of leptospirosis. Hamsters, guinea pigs, and gerbils have been instrumental to study the pathophysiology of acute lethal leptospirosis and the Leptospira sp. genes involved in virulence. Chronic renal colonization has been mostly studied using experimentally infected rats. A special emphasis will be placed on mouse models, long thought to be irrelevant since they survive lethal infection. However, mice have recently been shown to be good models of sublethal infection leading to chronic colonization. Furthermore, congenic and transgenic mice have proven essential to study how innate immune cells interact with the pathogen and to understand the role of the toll-like receptor 4, which is important to control Leptospira sp. load and disease. The use of inbred and transgenic mouse models opens

  8. Sequences homologous to retrovirus-like genes of the mouse are present in multiple copies in the Syrian hamster genome.

    PubMed Central

    Lueders, K K; Kuff, E L

    1981-01-01

    The genome of M. musculus contains many copies of DNA sequences homologous to the 35S RNA of intracisternal type-A particles (IAP) (1,2). A major class of IAP genes has been identified and isolated from a mouse library in Charon 4A (3). Cloned mouse IAP genes were used as probes to study homologous sequences in the DNA of other species. Sequences related to mouse IAP genes were detected in the DNAs from a variety of animal cells. DNAs from rat, gerbil, and hamster cells all gave strong reactions which could be localized to discrete restriction fragments on genomic blots. The reaction of Syrian hamster DNA was particularly strong. Fragments derived from different parts of the IAP gene all reacted with Syrian hamster DNA, and the reactive restriction fragments in the Syrian hamster DNA could be ordered with reference to the known restriction map of the IAP genes. The data suggest that sequences related to mouse IAP genes make up a 7 Kb unit in the Syrian hamster genome. Since the majority of the hamster sequences are quite divergent from those in the mouse, the ease with which they are detected suggests that they must be reiterated in the hamster genome. Images PMID:7198224

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

    PubMed

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

    2014-11-01

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

  10. Effects of sex and scotorefractory state on obesity induced by photostimulation and serum leptin in Siberian hamsters (Phodopus sungorus).

    PubMed

    Cudney, Sarah E; Place, Ned J

    2012-12-01

    The rising prevalence of obesity is associated with an increasing incidence of heart disease, diabetes and other health risks. In addition, severe cases of obesity are associated with an even greater risk of morbidity and mortality. Therefore, animal models of morbid obesity are required to better elucidate the underlying mechanisms. Our investigations in the Siberian hamster (Phodopus sungorus) suggest that pronounced obesity can be reliably induced in this species without relying on genetic manipulation or overly fatty and palatable foods. In a prior study on reproductive aging in female Siberian hamsters, we incidentally observed marked obesity in a group of hamsters that were exposed to a particular photoperiodic regime. In short day (SD) lengths, Siberian hamsters inhibit their reproductive physiology and reduce food intake and body mass. However, hamsters become refractory to SD after 15-20weeks and revert to the long day (LD) phenotype. In the previous study, refractory animals appeared to be particularly sensitive to photostimulation (transfer to LD), in terms of increasing body mass. To test the hypothesis that refractoriness to SD predisposes hamsters to severe obesity, we photostimulated females and males in different states of SD responsiveness (inhibited or refractory). We determined that photostimulation during the SD-refractory state is particularly effective in inducing pronounced obesity and high serum leptin concentration in female hamsters. We propose that this experimental framework is a useful model to investigate the factors and signals that create a predisposition to excessive food intake and body mass, without having to rely on genetic or dietary manipulations.

  11. Immunosuppressive prednisolone enhances early cholangiocarcinoma in Syrian hamsters with liver fluke infection and administration of N-nitrosodimethylamine.

    PubMed

    Juasook, Amornrat; Boonmars, Thidarut; Wu, Zhiliang; Loilome, Watcharin; Veteewuthacharn, Kulathida; Namwat, Nissana; Sudsarn, Pakkayanee; Wonkchalee, Orasa; Sriraj, Pranee; Aukkanimart, Ratchadawan

    2013-01-01

    Chronic infection with Opisthorchis viverrini for many years has been associated with the development of hepatobiliary diseases including cholangiocarcinoma. It is well known that inflammation is a key component of the tumor microenvironment, and that chronic inflammation plays an important role in tumorigenesis. Therefore, in this study cholangiocarcinogenesis was induced in Syrian hamsters in order to observe the cancer-related inflammation. The Syrian hamsters were divided into 5 groups: uninfected controls; normal Syrian hamsters infected with O. viverrini (OV); immunosuppressed Syrian hamsters infected with O. viverrini (OVis); normal Syrian hamsters infected with O. viverrini and administered N-nitrosodimethylamine (CCA); and immunosuppressed Syrian hamsters infected with O. viverrini and administered N-nitrosodimethylamine (CCAis). Syrian hamster livers were later observed for gross pathology and histopathological changes; COX2 was analyzed by immunohistochemical staining. We found a decreased number of inflammatory cells surrounding the hepatic bile duct in the OVis group, but not in the OV and CCAis groups. However, in the CCAis group (with suppressed immunity) early appearance and greater severity of cholangiocarcinoma were observed; gross pathological examination revealed many cancer nodularities on the liver surface, and histopathological studies showed the presence of cancer cells, findings which correlated with the predominant expression of COX2. The present study suggests that host immune responses are intended to ameliorate pathology, and they are also crucially associated with pathogenesis in O. viverrini infection; the unbalancing of host immunity may enhance cancer-related inflammation.

  12. De novo assembly, annotation, and characterization of the whole brain transcriptome of male and female Syrian hamsters

    PubMed Central

    McCann, Katharine E.; Sinkiewicz, David M.; Norvelle, Alisa; Huhman, Kim L.

    2017-01-01

    Hamsters are an ideal animal model for a variety of biomedical research areas such as cancer, virology, circadian rhythms, and behavioural neuroscience. The use of hamsters has declined, however, most likely due to the dearth of genetic tools available for these animals. Our laboratory uses hamsters to study acute social stress, and we are beginning to investigate the genetic mechanisms subserving defeat-induced behavioural change. We have been limited, however, by the lack of genetic resources available for hamsters. In this study, we sequenced the brain transcriptome of male and female Syrian hamsters to generate the necessary resources to continue our research. We completed a de novo assembly and after assembly optimization, there were 113,329 transcripts representing 14,530 unique genes. This study is the first to characterize transcript expression in both female and male hamster brains and offers invaluable information to promote understanding of a host of important biomedical research questions for which hamsters are an excellent model. PMID:28071753

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

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

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

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

    PubMed

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

    1990-01-16

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

  15. Response of gut microbiota to fasting and hibernation in Syrian hamsters.

    PubMed

    Sonoyama, Kei; Fujiwara, Reiko; Takemura, Naoki; Ogasawara, Toru; Watanabe, Jun; Ito, Hiroyuki; Morita, Tatsuya

    2009-10-01

    Although hibernating mammals wake occasionally to eat during torpor, this period represents a state of fasting. Fasting is known to alter the gut microbiota in nonhibernating mammals; therefore, hibernation may also affect the gut microbiota. However, there are few reports of gut microbiota in hibernating mammals. The present study aimed to compare the gut microbiota in hibernating torpid Syrian hamsters with that in active counterparts by using culture-independent analyses. Hamsters were allocated to either torpid, fed active, or fasted active groups. Hibernation was successfully induced by maintaining darkness at 4 degrees C. Flow cytometry analysis of cecal bacteria showed that 96-h fasting reduced the total gut bacteria. This period of fasting also reduced the concentrations of short chain fatty acids in the cecal contents. In contrast, total bacterial numbers and concentrations of short chain fatty acids were unaffected by hibernation. Denaturing gradient gel electrophoresis of PCR-amplified 16S rRNA gene fragments indicated that fasting and hibernation modulated the cecal microbiota. Analysis of 16S rRNA clone library and species-specific real-time quantitative PCR showed that the class Clostridia predominated in both active and torpid hamsters and that populations of Akkermansia muciniphila, a mucin degrader, were increased by fasting but not by hibernation. From these results, we conclude that the gut microbiota responds differently to fasting and hibernation in Syrian hamsters.

  16. EFTEM cytochemistry and sexual dimorphism of secretory granules in male and female hamster submandibular glands.

    PubMed

    Moriguchi, Keiichi; Utsumi, Michiya; Ohno, Norikazu

    2011-05-01

    After glutaraldehyde fixation followed by osmium tetroxide postfixing, the secretory granules of acinar cells in male hamster submandibular glands (SGs) exhibit a characteristic bipartite substructure, with an electron-lucid rim and a more electron-dense central core. In female hamsters, the reverse is seen, with the larger portion of the granules forming an electron-lucid core and an outer electron-dense crescent rim. In the present study of endogenous peroxidase (PO) activity of male and female hamster SGs, secretory granules in the acinar cells were studied by DAB cytochemical technique. Individual granules showed bipartite substructure with the PO activity in a positive center core and unreacted lucid rim in both the male and the female acinar cells. Through isolation of granular fractions, the male and the female granules exhibited the same bipartite structure. We also examined the relation between the PO activity and counterstained areas in male and female hamster SGs, and the secretory granules of acinar cells by using EFTEM. In the male SG, the secretory granules exhibited the characteristic bipartite substructure to carry out parallel-EELS, nitrogen reflecting the presence of DAB moieties and uranium from counterstaing the presence the central core but not in the rim. On the other hand, the female bipartite secretory granules of the SG, exhibit the nitrogen reflecting the presence in the central core and uranium in the rim.

  17. 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…

  18. Histopathology and Distribution of Viral Antigens in Hamsters Infected with Virulent and Benign Venezuelan Encephalitis Viruses

    PubMed Central

    Jahrling, P. B.; Scherer, W. F.

    1973-01-01

    Lethalities and virulences of Venezuelan encephalitis (VE) viruses for hamsters were found to correlate with severity of histopathologic lesions in hematopoietic and brain tissues. Highly virulent strains (subtype I) destroyed marrow and lymphoid cells rapidly and produced intestinal wall damage; focal brain hemorrhages and destruction of Purkinje cells also occurred within the 4 to 5 days between subcutaneous inoculation and death. Like subtype I virus, a slightly less virulent strain (subtype II) also caused necrosis of bone marrow and brain lesions, but only minimal lymphoid cell damage occurred. The less virulent subtype III VE virus, which killed hamsters between 4 and 14 days after inoculation, usually caused no lesions in hematopoietic tissues, and deaths were related chiefly to hemorrhagic brain lesions and necrosis of Purkinje cells. Two VE viruses, benign for hamsters (the TC-83 attenuated vaccine strain and subtype IV), usually caused no necrosis of hematopoietic or brain tissues; focal extravasations of blood and swollen glial cells were found in brains of the rare hamsters that died. The degrees of necrosis seen in tissues stained with hematoxylin and eosin correlated with the quantities of viral antigens detected by fluorescent antibody, except in pancreas and small intestinal smooth muscle and glands, where antigens of subtype I virus were present without morphologic damage. ImagesFig 5-6Fig 7-8Fig 9Fig 10Fig 11Fig 12Fig 13Fig 14Fig 15Fig 16Fig 1-4 PMID:4578265

  19. Anabolic-androgenic steroid exposure during adolescence and aggressive behavior in golden hamsters.

    PubMed

    Melloni, R H; Connor, D F; Hang, P T; Harrison, R J; Ferris, C F

    1997-03-01

    Anabolic androgenic steroid (AAS) abuse by adolescents represents a significant health care risk due to the potential for long-term negative physical and psychological sequelae, including increased aggressive behavior. The current experiments examined the effects of AAS use in young male adolescent hamsters (Mesocricetus auratus) and their consequences on aggressive behavior. It was hypothesized that AAS administration during adolescence predisposes hamsters to heightened levels of aggressive behavior (i.e., offensive aggression). To test this hypothesis adolescent male hamsters were administered high doses of synthetic AAS to mimic a 'heavy use' self-administration regimen used by athletes. Immediately following the exposure to AAS hamsters were tested for aggressive behavior using a resident-intruder model. Animals treated with high doses of AAS during their adolescent development showed heightened measures of offensive aggression i.e., decreased latency to bite and increased total number of attacks and bites) during the test period, while measures of total activity (total contact time) between the animals remained unchanged. AAS-treated males did not differ in body weight from controls, suggesting that the increased aggression was not due to increased body mass. The results of this study show that exposure to AAS during adolescence facilitates aggressive response patterns, but does not alter body weight.

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

    SciTech Connect

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

    2009-06-03

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

  1. Age- and dose-dependent transplacental carcinogenesis by N-nitrosoethylurea in Syrian golden hamsters.

    PubMed

    Diwan, B A; Rehm, S; Rice, J M

    1996-01-01

    Syrian golden hamsters have a very short period (15 days) of gestation. The implantation of the blastocyst occurs on day 5, embryogenesis proceeds very rapidly thereafter and neural tube closure is completed by day 9. In the present study the effects of two different doses of N-nitrosoethylurea (NEU) administered at various stages of gestation were quantitatively evaluated in Syrian golden hamsters. NEU at either 0.2 or 0.5 mmol/kg was administered transplacentally as a single i.p. injection to pregnant hamsters on gestation days 7, 8, 9, 10, 11, 12, 13, or 14. The incidence, latency period and multiplicity of tumors varied with the dose of NEU and the stage of development at the time of NEU administration. Although tumors of the peripheral nervous system predominated, a variety of other tumors, including melanomas and visceral tumors of epithelial and mesenchymal origin, were also observed in hamster offspring exposed transplacentally to NEU. Sensitivity to transplacental carcinogenesis was maximal during late gestation and very low before day 9.

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

    SciTech Connect

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

    1984-01-01

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies were conducted to address conditioned flavour aversion (CFA) and place avoidance learning in hamsters given injections of alkaloid extracts from tall larkspur (Delphinium barbeyi), to determine if larkspur had reinforcing or negative properties sufficient to cause place avoidance or preferen...

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

    SciTech Connect

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

    1991-03-15

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

  5. Experimental investigations in hamsters and rabbits with DNA extracted from human uterine tumors.

    PubMed

    Nastac, E; Athanasiu, P; Predescu, E; Stoian, M; Hozoc, M; Perju, A

    1980-01-01

    Experimental inoculation of a DNA preparation extracted from a fragment of non-irradiated human uterine cervix carcinoma was followed by the appearance of neoplasia in four hamsters and of lymphosarcoma in one rabbit. Similar DNA preparations obtained from three cases of irradiated human uterine cervix carcinoma and from a human uterine fibroma proved to have no biological activity.

  6. Ectopic origin of coronary arteries from the aorta in Syrian hamsters (Mesocricetus auratus).

    PubMed

    Durán, A C; Fernández, B; Fernández, M C; López-García, A; Arqué, J M; Sans-Coma, V

    2012-01-01

    An ectopic origin of the coronary artery from the aorta beyond the sinotubular junction, a condition commonly referred to as 'coronary artery high take-off', has been described in man and C57BL/6 mice. The present paper reports this congenital coronary artery anomaly in the Syrian hamster (Mesocricetus auratus). Hearts from 14 individuals, aged 53-350 days, were examined by means of a corrosion-cast technique, scanning electron microscopy or histological and immunohistochemical techniques. In 11 hamsters, the right coronary artery was the ectopic vessel. In the other three animals there was a solitary coronary ostium in the aorta. In all cases, the ectopic coronary artery originated at an acute angle and a valve-like ridge was in front of the coronary artery ostium. The ectopic arteries examined microscopically showed an intramural trajectory within the aortic wall. In the hearts with a solitary ostium in the aorta, the left main coronary artery coursed between the aorta and the pulmonary artery. In man, all of these anomalous conditions place the individual at risk of myocardial ischaemia and sudden death. However, none of the affected hamsters had clinical signs of disease. Intimal thickenings of increasing size with age were present in the intramural coronary artery segment of eight hamsters aged 106 days or older, examined histologically. The present findings fit with the notion that coronary arteries with acute angle take-off and an intramural course are subjected to unusual wear and tear, leading to tissue changes in the vessel wall.

  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.

  8. 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.

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

    PubMed

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

    2013-10-01

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

  10. A review of respiratory system anatomy, physiology, and disease in the mouse, rat, hamster, and gerbil.

    PubMed

    Kling, Melissa A

    2011-05-01

    The purpose of this article is to provide for practitioners a comprehensive overview of respiratory diseases, both infectious and noninfectious, in the mouse, rat, hamster, and gerbil. The information presented will also be useful for veterinarians pursuing board certification. Anatomy and physiology are briefly addressed, as those two facets alone could encompass an entire article for these species.

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

    PubMed

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

    2011-08-01

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

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

    PubMed

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

    2016-09-01

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

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

    PubMed

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

    2015-04-01

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

  14. 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...

  15. The hamster (Mesocricetus auratus) as an experimental model of toxocariasis: histopathological, immunohistochemical, and immunoelectron microscopic findings.

    PubMed

    da Silva, Ana Maria Gonçalves; Chieffi, Pedro Paulo; da Silva, Wellington Luiz Ferreira; Kanashiro, Edite Hatsumi Yamashiro; Rubinsky-Elefant, Guita; Cunha-Neto, Edécio; Mairena, Eliane Conti; De Brito, Thales

    2015-03-01

    Toxocariasis is a globally distributed parasitic infection caused by the larval stage of Toxocara spp. The typical natural hosts of the parasite are dogs and cats, but humans can be infected by the larval stage of the parasite after ingesting embryonated eggs in soil or from contaminated hands or fomites. The migrating larvae are not adapted to complete their life cycle within accidental or paratenic hosts like humans and laboratory animals, respectively, but they are capable of invading viscera or other tissues where they may survive and induce disease. In order to characterize hamsters (Mesocricetus auratus) as a model for Toxocara canis infection, histopathological and immunohistochemistry procedures were used to detect pathological lesions and the distribution of toxocaral antigens in the liver, lungs, and kidneys of experimentally infected animals. We also attempted to characterize the immunological parameters of the inflammatory response and correlate them with the histopathological findings. In the kidney, a correlation between glomerular changes and antigen deposits was evaluated using immunoelectron microscopy. The hamster is an adequate model of experimental toxocariasis for short-term investigations and has a good immunological and pathological response to the infection. Lung and liver manifestations of toxocariasis in hamsters approximated those in humans and other experimental animal models. A mixed Th2 immunological response to T. canis infection was predominant. The hamster model displayed a progressive rise of anti-toxocaral antibodies with the formation of immune complexes. Circulating antigens, immunoglobulin, and complement deposits were detected in the kidney without the development of a definite immune complex nephropathy.

  16. [An initial investigation on the in vitro culture system of primordial germ cells in golden hamsters].

    PubMed

    Li, Hong; Zhang, Hao; Liang, Ying; Zhan, Li; Wu, Desheng

    2006-06-01

    To establish the in vitro culture system of primordial germ cells (PGCs) of golden hamsters, PGCs of hamster were isolated from genital ridge of embryos at 10. 5th dpc (day post coitum), obtained by enzyme-mechanical method, and cultured on feeder cells. Then the PGCs were identified by alkaline phosphatase (ALP) activity staining. In order to induce the PGCs to differentiate in vitro, we removed the differential inhibition factors in the conditioned medium and observed the formation of embryoids and differentiated cells from three layers. The result showed that the pluripotent primordial germ cells could be successfully obtained from the golden hamsters at 10. 5th dpc by the enzyme-mechanical method and that PGCs were identified by both their strong positive reaction in ALP activity staining test and their differentiation into three-layer derived cells in vitro. The result suggests that the establishment of in vitro PGCs culture system of golden hamsters will provide new cell source for biomedical engineering.

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

    PubMed Central

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

    2016-01-01

    Statement of the Problem: Oral mucositis (OM) is a common side effect of anti-cancer drugs and needs significant attention for its prevention. Purpose: This study aimed to evaluate the healing effects of olive leaf extract on 5-fluorouracil-induced OM in golden hamster. Materials and Method: OM was induced in 63 male golden hamsters by the combination of 5-fluorouracil injections (days 0, 5 and 10) and the abrasion of the cheek pouch (days 3 and 4). On day 12, hamsters were received topical olive leaf extract ointment, base of ointment, or no treatment (control) for 5 days. Histopathology evaluations, blood examinations, and tissue malondialdehyde level measurement were performed 1, 3 and 5 days after treatments. Results: Histopathology score and tissue malondialdehyde level were significantly lower in olive leaf extract treated group in comparison with control and base groups (p= 0.000). Significant decreases in white blood cell, hemoglobin, hematocrit , and mean corpuscular volume and an increase in mean corpuscular hemoglobin concentration were observed in olive leaf extract treated group in comparison with control and base groups (p< 0.05). Conclusion: Our findings demonstrated that daily application of olive leaf extract ointment had healing effect on 5-fluorouracil induced OM in hamsters. Moreover, the beneficial effect of olive leaf extract on OM might be due to its antioxidant and anti-inflammatory properties. PMID:27942549

  18. Adaptive changes in individual acyl-CoA esters from hamster BAT during cold acclimation.

    PubMed

    Donatello, S; Spennetta, T; Strieleman, P; Woldegiorgis, G; Shrago, E

    1988-02-01

    Long-chain fatty acyl-CoA esters (LCFACoAE) were extracted from freeze-clamped powdered brown adipose tissue (BAT) obtained from thermoneutral control and cold-acclimated hamsters and the CoA esters individually separated by high-performance liquid chromatography. LCFACoAE of carbon chain length C12 to C20 were identified by increasing column retention time in the following order: C12:0, C14:1, C14:0, C16:1, C18:2, C16:0, C18:1, C18:0, and C20:4. The mean total LCFACoAE concentrations were 235 +/- 40 nmol/g protein for the control hamsters and 648 +/- 105 nmol/g protein for the 22-day cold-acclimated hamsters. A rapid fourfold increase in the levels of C16:0, C18:0, and C18:1 occurred within hours after initiation of the cold temperature, whereas the concentrations of the other six LCFACoAE either increased only slightly or remained unchanged. Almost 50% of the total LCFACoAE in the BAT of cold-acclimated hamsters was made up of C16:0, C18:0, and C18:1. These results, which demonstrate some dynamic changes in adipose tissue LCFACoAE, are consistent with their proposed role in the initiation and maintenance of BAT thermogenesis.

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

    SciTech Connect

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

    2007-03-16

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

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

    PubMed

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

    2016-01-01

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

  1. 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+...

  2. 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...

  3. 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...

  4. Photoperiodic regulation of adrenal hormone secretion and aggression in female Syrian hamsters

    PubMed Central

    Gutzler, Stephanie J.; Karom, Mary; Erwin, W. Daniel; Albers, H. Elliott

    2009-01-01

    Seasonal changes in the length of the daily photoperiod induce significant changes in social behavior. Hamsters housed in winter-like short photoperiods (SP) can express significantly higher levels of aggression than hamsters housed in long photoperiods (LP) that mimic summer. The mechanisms responsible for increasing aggressiveness in SP-exposed female hamsters are not well understood but may involve seasonal changes in the endocrine system. In experiment 1, the effects of SP exposure on the circulating levels of three adrenal hormones were determined. Short photoperiod exposure was found to significantly depress the circulating levels of cortisol and the adrenal androgen dehydropiandrosterone (DHEA) but significantly increased the circulating levels of the sulfated form of DHEA, DHEAS. Experiment 2 examined the effects of gonadal hormones on several different measures of aggression including its intensity in females housed in both long and short photoperiod. Exposure to SP resulted in high levels of aggression regardless of the endocrine state of the animal or the measure used to quantify aggression. In contrast, administration of estradiol to hamsters housed in LP significantly reduced aggression. The data of the present study support the hypothesis that SP-housed females are more aggressive than LP-housed females because SP exposure renders females insensitive to the aggression-reducing effects of ovarian hormones. PMID:19716370

  5. Aortic ER stress in streptozotocin-induced diabetes mellitus in APA hamsters.

    PubMed

    Kurokawa, Masaki; Hideshima, Makoto; Ishii, Yoshiyuki; Kyuwa, Shigeru; Yoshikawa, Yasuhiro

    2009-04-01

    Atherosclerosis is thought to be associated with endoplasmic reticulum (ER) dysfunction and the accumulation of unfolded proteins. In this study, we examined the relationship between atherosclerosis and ER stress and the effect of sodium 4-phenylbutyrate (4-PBA), a kind of chemical chaperone, on atherosclerosis in streptozotocin-induced diabetic APA hamsters. Male, 8-week-old, APA hamsters were injected with streptozotocin (30 mg/kg body weight) to induce diabetes mellitus, and ER stress was evaluated immunohistochemically or by semi-quantitative RT-PCR analysis using ER stress markers such as calreticulin and GPR78. Control hamsters were injected with citrate buffer and were similarly analyzed. In the aorta of control animals, a weak ER stress was detected, and 4-PBA treatment decreased the calreticulin- and GRP78-positive areas and also reduced the mRNA levels of calreticulin and GRP78. On the other hand, strong ER stress was detected at the lesser curvature of the aortic arch of streptozotocin-induced diabetic APA hamsters. However, 4-PBA treatment failed to lessen the ER stress in the aorta and had no effect on improvement of the atherosclerotic lesions. These results may provide an explanation for the complex etiology of atherosclerosis accompanied by diabetes mellitus and various other clinical phenotypes of atherosclerosis.

  6. Interactions with heterospecific males do not affect how female Mesocricetus hamsters respond to conspecific males

    PubMed Central

    delBarco-Trillo, Javier; Johnston, Robert E.

    2012-01-01

    Reproductive interference includes any interspecific interaction that reduces the fitness of one or both species involved. There are several types of reproductive interference, but they normally involve the direct cost of interacting or mating with heterospecifics. An indirect cost of interacting with heterospecific individuals is a consequent reduction in successful interactions with conspecifics. We tested the hypothesis that being aggressive towards a heterospecific individual will diminish sexual responses towards conspecifics in later encounters. We used two species of Mesocricetus hamsters (Syrian and Turkish hamsters), whose interspecific interactions have previously been determined. We exposed or both exposed and paired Syrian hamster females with a conspecific or a heterospecific male. Five minutes later, we paired all females with a conspecific male and measured the latency to lordosis, the duration of lordosis and any incidence of aggression. We found that (1) interactions with heterospecific males did not affect how females responded to conspecific males in later encounters and (2) previous pairing of female subjects with either conspecific or heterospecific males promoted a faster sexual response by females in subsequent interactions with conspecific males. Thus, aggressive interactions of Syrian hamster females with heterospecific males, contrary to our initial hypothesis, had a positive effect on subsequent interactions with conspecific males. PMID:23439800

  7. Albino and pink-eyed dilution mutants in the Russian dwarf hamster Phodopus campbelli.

    PubMed

    Robinson, R

    1996-01-01

    The coat color mutant genes albino (c) and pink eyed dilution (p) are described in the dwarf hamster species Phodopus campbelli. Both genes are inherited as redessive to normal. Tests for linkage between the two genes gave negative results. The apparent absence of linkage is contrasted with linkage between homologous alleles c and p in other species of rodents.

  8. Persistent changes of corticostriatal plasticity in dt(sz) mutant hamsters after age-dependent remission of dystonia.

    PubMed

    Avchalumov, Y; Volkmann, C E; Rückborn, K; Hamann, M; Kirschstein, T; Richter, A; Köhling, R

    2013-10-10

    Abnormal plasticity in the cortico-basal ganglia-thalamocortical loop has been suggested to represent a key factor in the pathophysiology of dystonia. In a model of primary paroxysmal dystonia, the dt(sz) mutant hamster, previous experiments have shown a strongly increased long-term potentiation (LTP) in comparison to non-dystonic control hamsters. These basal changes, i.e. in the absence of dystonia, were found in young animals at an age of 5 weeks, when the age-dependent dystonia in dt(sz) mutant reaches highest severity. In the present study we examined in corticostriatal slices (1) whether the increases in synaptic plasticity can be modulated by stressful stimuli which induce dystonic episodes in young mutant hamsters, and (2) whether increases of LTP persist after spontaneous remission of dystonia in animals older than 10 weeks. The present data show that in slices of young mutant hamsters the extent of LTP was not influenced by the presence of dystonia: In comparison to age-matched control hamsters, LTP was increased in mutant hamsters independent of preceding stressful stimulation. After remission of dystonia, i.e., in older dt(sz) mutant hamsters >10 weeks, only LTP could be elicited, while in preparations from age-matched control hamsters, either LTP or long-term depression developed, depending on previous behavioral challenge. We conclude that in mature brain, corticostriatal connections have the potential for changes in metaplasticity, while in dt(sz) mutant hamsters this metaplasticity is persistently infringed even though stress-inducible dystonic symptoms are lost.

  9. An Endocannabinoid Signaling System Modulates Anxiety-like Behavior in Male Syrian Hamsters

    PubMed Central

    Moise, Anna M.; Eisenstein, Sarah A.; Astarita, Giuseppe; Piomelli, Daniele; Hohmann, Andrea G.

    2009-01-01

    Rationale An endocannabinoid signaling system has not been identified in hamsters. Objective We examined the existence of an endocannabinioid signaling system in Syrian hamsters using neuroanatomical, biochemical and behavioral pharmacological approaches. Method The distribution of cannabinoid receptors was mapped and membrane fatty-acid amide hydrolase (FAAH) activity and levels of fatty-acid amides were measured in hamster brain. The impact of cannabinoid CB1 receptor blockade and inhibition of FAAH was evaluated in the elevated plus maze, rota-rod test and models of unconditioned and conditioned social defeat. Results A characteristic heterogeneous distribution of cannabinoid receptors was detected in hamster brain using [3H]CP55,940 binding and autoradiography. The FAAH inhibitor URB597 inhibited FAAH activity (IC50 = 12.8 nM) and elevated levels of fatty-acid amides (N-palmitoyl ethanolamine (PEA) and N-oleoyl ethanolamine (OEA)) in hamster brain. Anandamide levels were not reliably altered. The cannabinoid agonist WIN55,212-2 (1– 10 mg/kg i.p.) induced CB1-mediated motor ataxia. Blockade of CB1 with rimonabant (5 mg/kg i.p.) induced anxiogenic-like behavior in the elevated plus maze. URB597 (0.1–0.3 mg/kg i.p.) induced CB1-mediated anxiolytic-like effects in elevated plus maze, similar to the benzodiazepine diazepam (2 mg/kg i.p.). Diazepam (2–6 mg/kg i.p.) suppressed the expression, but not the acquisition, of conditioned defeat. By contrast, neither URB597 (0.3–3.0 mg/kg i.p.) nor rimonabant (5 mg/kg i.p.) altered unconditioned or conditioned social defeat or rota-rod performance. Conclusions Endocannabinoids engage functional CB1 receptors in hamster brain to suppress anxiety-like behavior and undergo enzymatic hydrolysis catalyzed by FAAH. Our results further suggest that neither unconditioned nor conditioned social defeat in the Syrian hamster is dependent upon cannabinoid CB1 receptor activation. PMID:18545985

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

    PubMed

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

    2006-06-01

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

  11. Use of the Syrian hamster as a new model of ebola virus disease and other viral hemorrhagic fevers.

    PubMed

    Wahl-Jensen, Victoria; Bollinger, Laura; Safronetz, David; de Kok-Mercado, Fabian; Scott, Dana P; Ebihara, Hideki

    2012-12-14

    Historically, mice and guinea pigs have been the rodent models of choice for therapeutic and prophylactic countermeasure testing against Ebola virus disease (EVD). Recently, hamsters have emerged as a novel animal model for the in vivo study of EVD. In this review, we discuss the history of the hamster as a research laboratory animal, as well as current benefits and challenges of this model. Availability of immunological reagents is addressed. Salient features of EVD in hamsters, including relevant pathology and coagulation parameters, are compared directly with the mouse, guinea pig and nonhuman primate models.

  12. Possible ameliorative effects of antioxidants on propionic acid / clindamycin - induced neurotoxicity in Syrian hamsters

    PubMed Central

    2013-01-01

    Background Propionic acid (PA) found in some foods and formed as a metabolic product of gut bacteria has been reported to mimic/mediate the effects of autism. The present study was undertaken to compare the effect of orally administered PA with that of clindamycin-induced PA-microbial producers in inducing persistent biochemical autistic features in hamsters. The neuroprotective potency of carnosine and carnitine supplements against PA toxicity was also investigated. Methods The following groups were studied. 1. Control group, which received phosphate buffered saline orally, 2. Propionic acid treated group which were given PA at a dose of 250 mg/kg body weight/day for 3 days orally, 3. Clindamycin treated group which received a single dose of the antibiotic orogastrically at a dose of 30 mg/kg on the day of the experiment, 4. Carnosine-treated group which were given carnosine at a dose of 10 mg/kg body weight/day orally for one week, 5. Carnitine treated group given 50 mg/kg body weight/day carnitine orally daily for one week. Group 6. Carnosine followed by PA, Group 7. Carnitine followed by PA. Dopamine, adrenaline and noradrenaline, serotonin and Gamma amino-butyric acid (GABA) were measured in the cortex and medulla of the nine studied groups. Results PA administration caused significant decrease in the neurotransmitters in the brains of treated hamsters while clindamycin caused a significant decrease only in dopamine in hamster brains (cortex and medulla) and GABA in the cerebral cortex of the treated hamsters. Administration of carnosine and carnitine which are known antioxidants caused no significant changes in the levels of neurotransmitters when administered alone to hamsters. However when administered with PA both carnosine and carnitine restored the altered neurotransmitters to near normal levels. Conclusion Carnosine and carnitine may be used as supplements to protect against PA neurotoxicity. PMID:24188374

  13. Cytokine response in the intestinal mucosa of hamsters infected with Taenia solium.

    PubMed

    Avila, Guillermina; Aguilar, Laura; Romero-Valdovinos, Mirza; Garcia-Vazquez, Francisco; Flisser, Ana

    2008-12-01

    Taenia solium grows in experimentally infected hamsters. An inflammatory reaction in the intestinal mucosa surrounding the scolex of the worms is produced. We searched for mRNA of Th1 and Th2 cytokines by in situ hybridization in intestinal biopsies. Hamsters were infected with T. solium cysticerci and necropsied on different days post infection (d.p.i.). Tissue from the small intestine was taken from the area surrounding the tapeworm scolex, fixed, and processed for histology. Antisense probes for the detection of interferon (IFN)-gamma, interleukin (IL)-4, IL-5, and IL-13 were used. Kinetics of each cytokine was defined through detection on specific mRNA by counting the number of positive infected hamsters and of positive cells per 100 enterocytes on different d.p.i. IFN-gamma was detected as of d.p.i. 2; all animals were positive on d.p.i. 4 and 8; and on d.p.i. 16, only 20% were still positive. IL-13 had a pattern similar to IFN-gamma, but all hamsters remained positive until d.p.i. 16 when the experiment was terminated. IL-4 was positive in 40% of infected hamsters on d.p.i. 6. On d.p.i. 8, IL-5 was only detected in 20% but increased to 100% by d.p.i. 16. These data suggest that tapeworms induce a mixed Th1/Th2 response with a polarization toward Th2 at 2 weeks post infection, which may influence the expulsion of worms.

  14. Pathology of acute inhalation exposure to 3-methylfuran in the rat and hamster

    SciTech Connect

    Haschek, W.M.; Morse, C.C.; Boyd, M.R.; Hakkinen, P.J.; Witschi, H.P.

    1983-01-01

    The acute inhalation toxicity of 3-methylfuran (3MF) was investigated in SPF Fischer-derived and CD/CR rats, and golden Syrian hamsters by determination of the 2-week LC/sub 50/, and by histologic examination of animals killed 1, 3, and 14 days following a 1-hr exposure to 148 and 322 ..mu..mole 3MF/liter for CD/CR rats and hamsters, respectively. The Fischer-derived rat was more sensitive to 3MF-induced lethality than the CD/CR rat with an LC/sub 50/ in the male rat of 81 ..mu..mole/liter-1 hr as compared to 222 ..mu..mole/liter-1hr. No sex difference was found. The hamster was relatively resistant with no lethality at 322 ..mu..mole 3MF/liter-2 hr. Pulmonary damage was present in both species. In the hamster, selective necrosis of nonciliated bronchiolar epithelial (Clara) cells was seen at 1 day with virtually complete regeneration by 14 days whereas in the rat the bronchiolar epithelial damage was more extensive and was followed by scattered peribronchiolar fibrosis and epithelial mucous metaplasia suggestive of ''small airway disease'' of man. Relatively selective 3MF-induced necrosis of olfactory epithelium occurred in the nasal mucosa of both species. Resolution of this lesion was seen by 14 days in the hamster. In the rat, however, the necrosis was much more extensive and was followed by partially occlusive fibrosis of the nasal cavity as seen at 14 days. 3MF also induced centrilobular hepatic necrosis in both species. In the rat, lymphocyte necrosis in the thymus and spleen, and esophageal necrosis was also seen.

  15. Pathology of acute inhalation exposure to 3-methylfuran in the rat and hamster

    SciTech Connect

    Haschek, W.M.; Morse, C.C.; Boyd, M.R.; Hakkinen, P.J.; Witschi, H.P.

    1983-12-01

    The acute inhalation toxicity of 3-methylfuran (3MF) was investigated in SPF Fischer-derived and CD/CR rats, and golden Syrian hamsters by determination of the 2-week LC50, and by histologic examination of animals killed 1, 3, and 14 days following a 1-hr exposure to 148 and 322 mumole 3MF/liter for CD/CR rats and hamsters, respectively. The Fischer-derived rat was more sensitive to 3MF-induced lethality than the CD/CR rat with an LC50 in the male rat of 81 mumole/liter-1 hr as compared to 222 mumole/liter-1 hr. No sex difference was found. The hamster was relatively resistant with no lethality at 322 mumole 3MF/liter-2 hr. Pulmonary damage was present in both species. In the hamster, selective necrosis of nonciliated bronchiolar epithelial (Clara) cells was seen at 1 day with virtually complete regeneration by 14 days whereas in the rat the bronchiolar epithelial damage was more extensive and was followed by scattered peribronchiolar fibrosis and epithelial mucous metaplasia suggestive of ''small airway disease'' of man. Relatively selective 3MF-induced necrosis of olfactory epithelium occurred in the nasal mucosa of both species. Resolution of this lesion was seen by 14 days in the hamster. In the rat, however, the necrosis was much more extensive and was followed by partially occlusive fibrosis of the nasal cavity as seen at 14 days. 3MF also induced centrilobular hepatic necrosis in both species. In the rat, lymphocyte necrosis in the thymus and spleen, and esophageal necrosis was also seen.

  16. Effects of unsaturated fatty acids on torpor frequency and diet selection in Djungarian hamsters (Phodopus sungorus).

    PubMed

    Diedrich, Victoria; Steinlechner, Stephan; Scherbarth, Frank

    2014-12-15

    Essential polyunsaturated fatty acids (PUFA) have been shown to play a beneficial role in hibernating mammals. High amounts of dietary PUFA led to an earlier hibernation onset, deeper and longer hibernation bouts and a higher proportion of hibernating animals in several species. In contrast, the relevance of dietary PUFA for daily heterotherms exhibiting only brief and shallow torpor bouts is less well studied. Therefore, diets differing in PUFA composition were used to examine the effects on the frequency of spontaneous daily torpor in Djungarian hamsters (Phodopus sungorus). In contrast to earlier studies, we were interested in whether the ratio of n-6 to n-3 PUFA affects torpor expression, and in comparison with a diet rich in monounsaturated fatty acids (MUFA). Although we found a positive effect on torpor frequency in hamsters fed a diet rich in n-6 PUFA compared with the groups fed diets either rich in n-3 PUFA or MUFA, the latter two groups did not show unusually low torpor frequencies. The results of the additional diet choice experiment indicated that hamsters in short photoperiod select food with only a slight excess of n-6 PUFA compared with n-3 PUFA (ratio of 1 to 1.5). However, there was no significant difference in torpor frequency between the diet choice group and hamsters fed on standard chow with a sevenfold excess of n-6 PUFA. In summary, the present data strongly indicate that the dietary composition of unsaturated fatty acids plays a minor role in the occurrence of spontaneous daily torpor in Djungarian hamsters.

  17. The mucosal response of hamsters exposed to weekly repeated infections with the hookworm Ancylostoma ceylanicum.

    PubMed

    Alkazmi, L M M; Behnke, J M

    2013-09-01

    An experiment was carried out to assess mucosal changes in hamsters exposed to weekly repeated low-intensity infections with the hookworm Ancylostoma ceylanicum. The experiment included control groups of naïve, uninfected hamsters and groups that received a single-pulse primary infection. Changes in the intestinal architecture and in the density of inflammatory cells in the mucosa, including mast cells, goblet cells, Paneth cells and eosinophils were examined in relation to changes in hookworm burdens. As in the single-pulse primary infection, hamsters exposed to repeated infections responded with marked changes in the intestinal architecture and in mucosal populations of inflammatory cells. However, there were distinct differences in the kinetics of the responses to these two types of infection (primary single-pulse and repeated). The reduction in villous height and the increase in crypt depth in animals exposed to repeated infections were both initially slower but eventually equalled and exceeded the responses in hamsters given a chronic primary infection, despite the presence of fewer adult worms in the former. Similarly, changes in the mitotic figures of epithelial cells in the mucosa and the mast cell response were both initially slower and less intense in repeatedly infected hamsters, but eventually exceeded the response to primary infection. Furthermore, the eosinophil response was found to be initially greater in repeated infections and overall more persistent. In contrast, both goblet and Paneth cell responses were less marked in repeatedly infected animals compared to those carrying a primary infection. These results are discussed in the context of host protective resistance to infection with A. ceylanicum.

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

    SciTech Connect

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

    1981-10-01

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

  19. New insights into melatonin/CRH signaling in hamster Leydig cells.

    PubMed

    Rossi, Soledad P; Matzkin, María E; Terradas, Claudio; Ponzio, Roberto; Puigdomenech, Elisa; Levalle, Oscar; Calandra, Ricardo S; Frungieri, Mónica B

    2012-08-01

    We have previously described that melatonin inhibits androgen production in hamster testes via melatonin subtype 1a (mel1a) receptors and the local corticotrophin-releasing hormone (CRH) system. This study attempted to determine the initial events of the melatonin/CRH signaling pathway. In Leydig cells from reproductively active Syrian hamsters, Western blotting, reverse transcription quantitative polymerase chain reaction (RT-qPCR) and a colorimetric assay demonstrated that melatonin and CRH activate tyrosine phosphatases and subsequently reduce the phosphorylation levels of extracellular signal-regulated kinase (erk) and c-jun N-terminal kinase (jnk), down-regulate the expression of c-jun, c-fos and steroidogenic acute regulatory (StAR), and inhibit the production of testosterone. These effects were prevented by a highly selective CRH antagonist, thus indicating that melatonin does not exert a direct role. Specific mitogen-activated protein kinase kinase (MEK) and jnk blockers inhibited expression of c-jun, c-fos, StAR and the production of testosterone, confirming that these are events triggered downstream of erk and jnk. In Leydig cells from photoperiodically regressed adult hamsters, CRH inhibited the production of androstane-3α,17β-diol (3α-diol), the main androgen produced, through the same signaling pathway. Testicular melatonin concentration was 3-4-fold higher in reproductively inactive hamsters than that detected in active animals. Since melatonin, CRH, and their receptors are present not only in hamster testes but also in testicular biopsies of infertile men, we can conjecture about the relevance of this previously uncharacterized pathway in human fertility disorders. In summary, our study identifies crucial intracellular events triggered by melatonin/CRH in the testis that lead to a down-regulation of the steroidogenic process.

  20. Temperature modifies potentiation but not depotentiation in bidirectional hippocampal plasticity of Syrian hamsters (Mesocricetus auratus).

    PubMed

    Bronson, Nathan W; Piro, John B; Hamilton, Jock S; Horowitz, John M; Horwitz, Barbara A

    2006-07-07

    Previous studies have shown that one form of neuroplasticity, population spike (PS) potentiation, can be established in the hamster hippocampus at temperatures above 20 degrees C. Here, we tested three related hypotheses; namely, that in Syrian hamsters: (1) PS potentiation can be elicited below 20 degrees C and that at any constant temperature, potentiation can be described by a pair of sigmoidal functions matched to input/output curves; (2) potentiation can be partially reversed by depotentiation (a second and distinctive form of neuroplasticity); and (3) tetanus evokes long-term potentiation in slices from animals housed under conditions corresponding to various stages of the annual hibernation cycle. To test these hypotheses, we measured PS amplitudes and fEPSP slopes in CA1 pyramidal cells in hippocampal slices. We found that sigmoidal functions before and after tetanus showed PS enhancement at 18 degrees C and a larger enhancement at 28 degrees C, thereby supporting hypothesis 1. We also found that low-frequency stimulation reduced the amplitude of the potentiated PS by approximately 29% at both 18 degrees C and 28 degrees C, consistent with hypothesis 2; and that slices from nonhibernating hamsters on long and short photoperiods and from hamsters in hibernation all showed at least 40% increases in fEPSP slope following tetanus at a slice temperature of 23 degrees C, supporting hypothesis 3. Thus, bidirectional plasticity is present in hamsters. That is, both potentiation and depotentiation were readily evoked at 28 degrees C; potentiation was muted, while depotentiation (the reversal of the potentiation) remained robust at 18 degrees C. Moreover, potentiated responses could be elicited in slices from animals housed under diverse conditions.

  1. Immunohistochemical characterization of 5-HT(3A) receptors in the Syrian hamster forebrain.

    PubMed

    Carrillo, Maria; Ricci, Lesley A; Schwartzer, Jared J; Melloni, Richard H

    2010-05-06

    The Syrian hamster (Mesocricetus auratus) has been extensively used as an animal model to investigate neuronal networks underlying various behaviors where 5-HT(3A) receptors have been found to play a critical role. To date, however, there is no comprehensive description of the distribution of 5-HT(3A) receptors in the Syrian hamster brain. The current study examined the localization of 5-HT(3A) receptors across the neuraxis of the Syrian hamster forebrain using immunohistochemistry. Overall, 5-HT(3A) receptors were widely and heterogeneously distributed across the neuraxis of the Syrian hamster brain. Notably, the most intense 5-HT(3A) immunolabeling patterns were observed in the cerebral cortex and amygdala. In addition, high variability in receptor density and expression patterns (i.e., perikarya, fibers and/or neuropilar puncta) was observed within the majority of brain areas examined, indicating that the role this receptor has in the modulation of a particular neural function differs depending on brain region. In some regions (i.e., nucleus accumbens) differences in the immunolabeling pattern between rostral, medial and caudal portions were also observed, suggesting functional heterogeneity of this receptor within a single brain region. Together, these results and the localization of this receptor to brain areas involved in the regulation of sexual behavior, aggression, circadian rhythm, drug abuse and anxiety implicate 5-HT(3A) receptors in the modulation of various behaviors and neural functions in the Syrian hamster. Further, these results underscore the importance of evaluating 5-HT(3A) receptors as a pharmacological target for the treatment of various psychopathological disorders.

  2. Separate origin of the main components of the left coronary artery in Syrian hamsters (Mesocricetus auratus).

    PubMed

    Durán, A C; Arqué, J M; Fernández, B; Fernández, M C; Fernández-Gallego, T; Sans-Coma, V

    2007-08-01

    This study describes a rare congenital coronary artery anomaly in the Syrian hamster; namely, the separate origin of the obtuse marginal and left circumflex arteries which are the main components of the left coronary artery. The hearts of nine affected animals were examined by means of a corrosion-cast technique and histology. The hamsters belonged to a laboratory inbred family with a high incidence of coronary artery anomalies and bicuspid aortic valve. The aortic valve was tricuspid in three hamsters and bicuspid in the other six hamsters. In all cases, the right coronary artery was normal, whereas the left coronary artery main trunk was absent. The present anomalous coronary artery patterns could be classified into two main entities: (i) ectopic origin of the obtuse marginal artery from the right aortic sinus or from the right coronary artery, with the left circumflex artery arising from the left side of the aortic valve; and (ii) ectopic origin of both the obtuse marginal artery from the right aortic sinus or from the right coronary artery and left circumflex artery from the dorsal aortic sinus. In all cases, the obtuse marginal artery coursed to the right side of the heart through the ventral wall of the right ventricular outflow tract. When the left circumflex artery arose from the dorsal aortic sinus, it formed an acute angle with the aortic wall. This report seems to be the first to describe the separate origin of the main components of the left coronary artery in a non-human mammalian species. In man, the congenital coronary artery and aortic valve defects reported herein may entail the risk of clinical complications. However, none of the affected hamsters showed signs of disease.

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

    PubMed

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

    2016-07-15

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

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

    PubMed

    Demas, Gregory E

    2010-04-01

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

  5. T-1032, a novel phosphodiesterase type 5 inhibitor, increases the survival of cardiomyopathic hamsters.

    PubMed

    Inoue, Hirotaka; Yano, Koji; Noto, Tsunehisa; Takagi, Michino; Ikeo, Tomihiro; Kikkawa, Kohei

    2002-05-17

    To evaluate the influence of T-1032 (methyl2-(4-aminophenyl)-1,2-dihydro-1-oxo-7-(2-pyridylmethoxy)-4-(3,4,5-trimethoxyphenyl)-3-isoquinoline carboxylate sulfate), a potent and relatively selective phosphodiesterase 5 inhibitor, on chronic heart failure, we examined the acute hemodynamic profile of T-1032 and its chronic effect on the survival of Bio 14.6 cardiomyopathic hamsters. In the acute study, T-1032 (1, 10, 100 microg/kg) was administered intravenously by means of a dose-escalating procedure in 55-week-old hamsters. T-1032 significantly reduced both the right and left ventricular end-diastolic pressure in a dose-dependent manner. T-1032 modestly reduced the systemic arterial pressure at the highest dose (100 microg/kg i.v.). T-1032 did not change the heart rate or left ventricular dp/dt(max). In the survival study, chronic administration of T-1032 (50 and 500 ppm in a diet) increased survival, and the survival rate was 24.2%, 45.4% and 48.5% in the control, 50 and 500 ppm-treated groups, respectively. The median survival was 55, 58 and 58 weeks in control, 50 and 500 ppm-treated groups, respectively. Analysis of the survival curves revealed that T-1032 (500 ppm) significantly increased the survival of these hamsters (P<0.05 vs. control). It was concluded that T-1032 had beneficial hemodynamic effects on heart failure in Bio 14.6 cardiomyopathic hamsters, and the favorable hemodynamic changes induced by T-1032 were partly related to the increase in the survival of these hamsters. Phosphodiesterase type 5 inhibitors may have therapeutic potential for the treatment of chronic heart failure.

  6. Reduction in cholesterol absorption is enhanced by stearate-enriched plant sterol esters in hamsters.

    PubMed

    Rasmussen, Heather E; Guderian, David M; Wray, Curtis A; Dussault, Patrick H; Schlegel, Vicki L; Carr, Timothy P

    2006-11-01

    Consumption of plant sterol esters reduces plasma LDL cholesterol concentration by inhibiting intestinal cholesterol absorption. Commercially available plant sterol esters are prepared by esterifying free sterols to fatty acids from edible plant oils such as canola, soybean, and sunflower. To determine the influence of the fatty acid moiety on cholesterol metabolism, plant sterol esters were made with fatty acids from soybean oil (SO), beef tallow (BT), or purified stearic acid (SA) and fed to male hamsters for 4 wk. A control group fed no plant sterol esters was also included. Hamsters fed BT and SA had significantly lower cholesterol absorption and decreased concentrations of plasma non-HDL cholesterol and liver esterified cholesterol, and significantly greater fecal sterol excretion than SO and control hamsters. Cholesterol absorption was lowest in hamsters fed SA (7.5%), whereas it was 72.9% in control hamsters. Cholesterol absorption was correlated with fecal sterol excretion (r = -0.72, P < 0.001), liver cholesterol concentration (r = 0.88, P < 0.001), and plasma non-HDL cholesterol concentration (r = 0.85, P < 0.001). A multiple regression model that included each sterol ester type vs. cholesterol absorption indicated that intake of steryl stearate was the only dietary component that contributed significantly to the model (R2 = -0.75, P < 0.001). Therefore, our results demonstrate that BT and SA are more effective than SO in reducing cholesterol absorption, liver cholesterol, and plasma non-HDL cholesterol concentration, suggesting that cardioprotective benefits can be achieved by consuming stearate-enriched plant sterol esters.

  7. Effects of microwave exposure on the hamster immune system. I. Natural killer cell activity

    SciTech Connect

    Yang, H.K.; Cain, C.A.; Lockwood, J.; Tompkins, W.A.

    1983-01-01

    Hamsters were exposed to repeated or single doses of microwave energy and monitored for changes in core body temperature, circulating leukocyte profiles, serum corticosteroid levels, and natural killer (NK) cell activity in various tissues. NK cytotoxicity was measured in a /sup 51/Cr-release assay employing baby hamster kidney (BHK) targets or BHK infected with herpes simplex virus. Repeated exposure of hamsters at 15 mW/cm2 for 60 min/day had no significant effect on natural levels of spleen-cell NK activity against BHK targets. Similarly, repeated exposure at 15 mW/cm2 over a 5-day period had no demonstrable effect on the induction of spleen NK activity by vaccinia virus immunization, that is, comparable levels of NK were induced in untreated and microwave-treated animals. In contrast, treatment of hamsters with a single 60-min microwave exposure at 25 mW/cm2 caused a significant suppression in induced spleen NK activity. A similar but less marked decrease in spleen NK activity was observed in sham-exposed animals. Moreover, the sham effects on NK activity were not predictable and appeared to represent large individual animal variations in the response to stress factors. Depressed spleen NK activity was evident as early as 4 h postmicrowave treatment and returned to normal levels by 8 h. Hamsters exposed at 25 mW/cm2 showed an elevated temperature of 3.0-3.5 degrees C that returned to normal within 60 min after termination of microwave exposure. These animals also showed a marked lymphopenia and neutrophilia by 1 h posttreatment that returned to normal by 8-10 h. Serum glucocorticosteroids were elevated between 1 aNd 8 h after microwave treatment. Sham-exposed animals did not demonstrate significant changes in core body temperature, peripheral blood leukocyte (PBL) profile, or glucocorticosteroid levels as compared to minimum-handling controls.

  8. Aerobic exercise improves microvascular dysfunction in fructose fed hamsters.

    PubMed

    Boa, B C S; Costa, R R; Souza, M G C; Cyrino, F Z G A; Paes, L S; Miranda, M L; Carvalho, J J; Bouskela, E

    2014-05-01

    Fructose is a major diet component directly related to severe damages to the microcirculation and to diseases such as obesity, diabetes and hypertension to which physical activity is pointed out as an important non-pharmacological treatment since its positive effects precede anthropometric improvements. In this study we have investigated the effects of a light/moderate aerobic exercise training (AET) on microcirculatory dysfunction elicited by carbohydrate overload during a period of 5 months. Male hamsters (Mesocricetus auratus) whose drinking water was substituted (F) or not (C) by 10% fructose solution, during 20 weeks, associated or not to AET in the last 4 weeks (EC and EF subgroups) had their microcirculatory function evaluated on the cheek pouch preparation, glucose and insulin tolerance (GTT and ITT) tested. Arterial blood was collected for pO2, pCO2, HCO3(-), pH, total CO2, saturated O2 and lactate determinations. Liver fragments were observed using an electron microscope. Microcirculatory responses to acetylcholine [Ach, an endothelium-dependent vasodilator; 10(-8)M - *123.3±7.5% (C), 119.5±1.3% (EC), *98.1±3.2% (F) and 133.6±17.2% (EF); 10(-6)M - *133.0±4.1% (C), 135.6±4.3% (EC), *103.4±4.3% (F) and 134.1±5.9% (EF); 10(-4)M - *167.2±5.0% (C), 162.8±5.4% (EC), *123.8±6.3% (F) and 140.8±5.0% (EF)] and to sodium nitroprusside [SNP, an endothelium-independent vasodilator; 10(-8)M - 118.8±6.8% (C), 114.0±5.0% (EC), 100.2±2.9% (F), 104.9±4.4% (EF); 10(-6)M - 140.6±11.7% (C), 141.7±5.5% (EC), 125.0±4.7% (F), 138.3±2.8% (EF); 10(-4)M - 150.4±10.9% (C), 147.9±6.5% (EC), 139.2±7.3% (F), 155.9±4.7% (EF)] and macromolecular permeability increase induced by 30 min ischemia/reperfusion (I/R) procedure [14.4±3.5 (C), 30.0±1.9 (EC), *112.0±8.8 (F) and *22.4±0.9 leaks/cm(2) (EF)] have shown that endothelium-dependent vasodilatation was significantly reduced and I/R induced macromolecular permeability augmented in sedentary fructose (F

  9. The bed nucleus of the stria terminalis in the Syrian hamster (Mesocricetus auratus): absence of vasopressin expression in standard and wild-derived hamsters and galanin regulation by seasonal changes in circulating sex steroids.

    PubMed

    Bolborea, M; Ansel, L; Weinert, D; Steinlechner, S; Pévet, P; Klosen, P

    2010-02-03

    The bed nucleus of the stria terminalis (BNST) is a nucleus of the forebrain highly sensitive to sex steroids and containing vasopressin neurons implicated in several social- and reproduction-related behaviours such as scent-marking, aggression, pair bonding and parental behaviour. Sexually dimorphic vasopressin expression in BNST neurons has been reported in almost all rodents, with the notable exception of the Syrian hamster. In this species, vasopressin expression is completely absent in the BNST. Because almost all Syrian hamsters used in research are derived from a very small breeding stock captured in 1930, we compared commercially available Syrian hamsters with a recently captured, wild-derived breeding stock. We checked for vasopressin expression using in situ hybridization and immunohistochemistry. Vasopressin expression in BNST neurons was completely absent in both breeding stocks, confirming the absence of BNST vasopressin expression in Mesocricetus auratus and ruling out a breeding artefact. Because vasopressin expression in BNST neurons appears to be strictly dependent on circulating sex steroids, the absence of vasopressin expression in Syrian hamster BNST neurons might be due to an insensitivity of these neurons to sex steroids. BNST vasopressin neurons also express galanin. Although galanin expression in the BNST is not sexually dimorphic in the Syrian hamster, it appears to be regulated by sex steroids. In the Djungarian hamster, photoperiodically driven seasonal variations of circulating sex steroids result in a seasonal rhythm of galanin expression in BNST neurons. We analysed the sex steroid dependence of galanin expression in the Syrian hamster. Castration and short photoperiod-induced sexual quiescence both resulted in downregulation of galanin mRNA in cell bodies (BNST) and immunoreactivity in the fibres (lateral septum). Testosterone supplementation of short photoperiod-adapted animals was able to restore galanin expression. Thus Syrian

  10. Positive action of propionyl-L-carnitine on mechanical performance of papillary muscle from Syrian hamsters with hereditary dilated cardiomyopathy.

    PubMed

    Maresca, P; Mancinelli, R; Corsico, N; Arrigoni-Martelli, E; Manni, E

    1995-12-20

    Propionyl-L-carnitine has been shown to exert a beneficial effect on cardiac function in different experimental models of cardiomyopathy in the rat, most likely by improving cardiac metabolism and energy production. We have previously shown that, in a strain of hamsters with hereditary dilated cardiomyopathy (BIO TO.2), the mechanical activity of papillary muscle (length-tension, velocity of shortening, shortening, work and power relationship) is significantly depressed when compared to the same parameter in normal hamsters (BIO F1.B). The repeated oral treatment with propionyl-L-carnitine (60 mg/kg per os for 7 weeks) to BIO TO.2 hamsters had a significant positive inotropic effect, as indicated by an increase in developed tension up to the levels observed in papillary muscles from normal hamsters. This action is most likely associated with metabolic effects similar to those observed in rats.

  11. Transcriptome Sequencing and Development of an Expression Microarray Platform for Liver Infection in Adenovirus Type 5-Infected Syrian Golden Hamsters

    PubMed Central

    Ying, Baoling; Toth, Karoly; Spencer, Jacqueline F.; Aurora, Rajeev; Wold, William S.M.

    2015-01-01

    The Syrian golden hamster is an attractive animal for research on infectious diseases and other diseases. We report here the sequencing, assembly, and annotation of the Syrian hamster transcriptome. We include transcripts from ten pooled tissues from a naïve hamster and one stimulated with lipopolysaccharide. Our data set identified 42,707 non-redundant transcripts, representing 34,191 unique genes. Based on the transcriptome data, we generated a custom microarray and used this new platform to investigate the transcriptional response in the Syrian hamster liver following intravenous adenovirus type 5 (Ad5) infection. We found that Ad5 infection caused a massive change in regulation of liver transcripts, with robust up-regulation of genes involved in the antiviral response, indicating that the innate immune response functions in the host defense against Ad5 infection of the liver. The data and novel platforms developed in this study will facilitate further development of this important animal model. PMID:26319212

  12. The Syrian Golden Hamster Estrous Cycle: Unique Characteristics, Visual Guide to Staging, and Comparison with the Rat.

    PubMed

    Chanut, Franck J A; Williams, Ann M

    2016-01-01

    The Syrian hamster, Mesocricetus auratus, is a suitable rodent species for standard regulatory toxicity studies. However, little is published about the female Syrian hamster reproductive system. It has unique anatomic features that differ from the other rodent species. In the hamster, the upper cervix is composed of 2 canals and the vagina shows 2 lateral pouches where keratin debris accumulates. These pouches must be distinguished from the vagina in order to stage the estrous cycle properly. The microscopic changes occurring during all the estrous cycle stages show some differences with the other rodents, the lower cervix and upper vagina presenting the more dramatic changes. The aim of this work was to produce a practical guide to staging the cycle and to highlight some of the differences between the rat and hamster reproductive system.

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

    SciTech Connect

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

    1986-10-01

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

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

    PubMed

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

    2015-05-01

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

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

    PubMed Central

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

    2015-01-01

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

  16. Androgen and estradiol levels in plasma and amniotic fluid of late gestational male and female hamsters: uterine position effects.

    PubMed

    Vomachka, A J; Lisk, R D

    1986-06-01

    Using radioimmunoassay we have measured the plasma and amniotic fluid levels of androgen and estradiol in male and female hamster fetuses nearing parturition. On Days 14 and 15 of gestation (day of birth = Day 16), plasma levels of androgen are higher in males than females while estradiol levels are equal. Amniotic fluid levels of these hormones, while lower than plasma, reflect the difference in androgen and the similarity in estradiol between sexes. Uterine position analysis on Day 14 suggests that female siblings located caudally suppress amniotic fluid androgen and elevate estradiol levels of male siblings. Comparison of Day 18 gestation male and female rat amniotic fluid androgen to Day 14 hamsters reveals that male rats are bathed in high levels of androgen. Female rats have lower levels which are not different from those of male hamsters. Female hamsters are exposed to little androgen. Relevance to behavioral sexual differentiation and the display of adult behavior is discussed.

  17. Treatment of spatial memory impairment in hamsters infected with West Nile virus using a humanized monoclonal antibody MGAWN1.

    PubMed

    Smeraski, Cynthia A; Siddharthan, Venkatraman; Morrey, John D

    2011-07-01

    In addition to functional disorders of paresis, paralysis, and cardiopulmonary complications, subsets of West Nile virus (WNV) patients may also experience neurocognitive deficits and memory disturbances. A previous hamster study has also demonstrated spatial memory impairment using the Morris water maze (MWM) paradigm. The discovery of an efficacious therapeutic antibody MGAWN1 from pre-clinical rodent studies raises the possibility of preventing or treating WNV-induced memory deficits. In the current study, hamsters were treated intraperitoneally (i.p.) with 32 mg/kg of MGAWN1 at 4.5 days after subcutaneously (s.c.) challenging with WNV. As expected, MGAWN1 prevented mortality, weight loss, and improved food consumption of WNV-infected hamsters. The criteria for entry of surviving hamsters into the study were that they needed to have normal motor function (forelimb grip strength, beam walking) and normal spatial reference memory in the MWM probe task. Twenty-eight days after the acute phase of the disease had passed, MGAWN1- and saline-treated infected hamsters were again trained in the MWM. Spatial memory was evaluated 48 h after this training in which the hamsters searched for the location where a submerged escape platform had been positioned. Only 56% of infected hamsters treated with saline spent more time in the correct quadrant than the other three quadrants, as compared to 92% of MGAWN1-treated hamsters (P⩽0.05). Overall these studies support the possibility that WNV can cause spatial memory impairment and that therapeutic intervention may be considered.

  18. Treatment of spatial memory impairment in hamsters infected with West Nile virus using a humanized monoclonal antibody MGAWN1

    PubMed Central

    Smeraski, Cynthia A.; Siddharthan, Venkatraman; Morrey, John D.

    2011-01-01

    In addition to functional disorders of paresis, paralysis, and cardiopulmonary complications, subsets of West Nile virus (WNV) patients may also experience neurocognitive deficits and memory disturbances. A previous hamster study has also demonstrated spatial memory impairment using the Morris water maze (MWM) paradigm. The discovery of an efficacious therapeutic antibody MGAWN1 from pre-clinical rodent studies raises the possibility of preventing or treating WNV-induced memory deficits. In the current study, hamsters were treated intraperitoneally (i.p.) with 32 mg/kg of MGAWN1 at 4.5 days after subcutaneously (s.c.) challenging with WNV. As expected, MGAWN1 prevented mortality, weight loss, and improved food consumption of WNV-infected hamsters. The criteria for entry of surviving hamsters into the study were that they needed to have normal motor function (forelimb grip strength, beam walking) and normal spatial reference memory in the MWM probe task. Twenty-eight days after the acute phase of the disease had passed, MGAWN1- and saline-treated infected hamsters were again trained in the MWM. Spatial memory was evaluated 48 hours after this training in which the hamsters searched for the location where a submerged escape platform had been positioned. Only 56% of infected hamsters treated with saline spent more time in the correct quadrant than the other three quadrants, as compared to 92% of MGAWN1-treated hamsters (P ≤ 0.05). Overall these studies support the possibility that WNV can cause spatial memory impairment and that therapeutic intervention may be considered. PMID:21554903

  19. Beneficial effect of berberine on hepatic insulin resistance in diabetic hamsters possibly involves in SREBPs, LXRα and PPARα transcriptional programs.

    PubMed

    Liu, Xuhan; Li, Guosheng; Zhu, Hua; Huang, Lan; Liu, Yali; Ma, Chunmei; Qin, Chuan

    2010-01-01

    The "lipotoxicity" hypothesis holds that fat-induced hepatic insulin resistance (FIHIR) may play a major role in the pathogenesis of type 2 diabetes. Berberine has been reported to have antidiabetic properties. However, the molecular mechanisms for this action are not fully clarified. Therefore, we will investigate the gene expression alterations involved in the therapeutic effect of berberine on FIHIR in diabetic hamsters and possible mechanisms. In this study, type 2 diabetic hamsters were induced by high-fat diet with streptozotocin injection. After 9 weeks of berberine-treatment, the gene expression alterations involved in the therapeutic molecular mechanisms of berberine on FIHIR will be studied by microarray technology and real time RT-PCR. Our study demonstrates berberine significantly improved fat-induced insulin resistance and diabetic phenotype in type 2 diabetic hamsters. The alterations of certain metabolism related genes and their main regulators: Liver X receptor (LXR) α, Peroxisome proliferator-activated receptor (PPAR) α and Sterol regulatory element-binding protein (SREBPs) are observed in the liver of treated and untreated diabetic hamsters. Compared with diabetic hamsters, the increased mRNA levels of LXRα and PPARα and the decreased mRNA levels of SREBPs are observed in berberine-treated diabetic hamster. The statistical significance of the expression of hepatic LXRα, SREBPs and PPARα and their certain target genes is found between treated and untreated diabetic hamsters. These results suggest that altered hepatic SREBPs, LXRα and PPARα transcriptional programs possibly involve in the therapeutic mechanisms of berberine on FIHIR in type 2 diabetic hamsters.

  20. Effects of trans-10,cis-12 conjugated linoleic acid on body fat and serum lipids in young and adult hamsters.

    PubMed

    Navarro, V; Miranda, J; Churruca, I; Fernández-Quintela, A; Rodríguez, V M; Portillo, M P

    2006-06-01

    The aim of the present work was to determine whether t-10, c-12 conjugated linoleic acid (CLA) feeding was able to reduce body fat accumulation and improve the serum lipid profile in adult hamsters fed an atherogenic diet, in order to compare these effects with those observed in young growing hamsters. Young and adult hamsters were fed semi-purified atherogenic diets supplemented with 0.5 % linoleic acid or 0.5% t-10, c-12 CLA for 6 weeks. Body weight and food intake were measured every two days. Adipose tissue from different anatomical locations, liver and gastrocnemious muscle were dissected and weighed. Cholesterol, triacylglycerols, non-esterified fatty acids and proteins were determined spectrophotometrically and water content by gravimetry. In young hamsters, no significant differences were found in food intake, final body weight and gastrocnemious muscle weight. White adipose tissue weights were reduced, liver weight was increased and cholesterol and triacyl-glycerols in both serum and liver were reduced. In adult hamsters, CLA feeding decreased food intake and adipose tissue weights. No changes were observed in other parameters. The present study demonstrates that age has an influence in hamster responsiveness to t-10, c-12 CLA because, although when this isomer is added to an atherogenic diet it reduces body fat accumulation in both young and adults hamsters, the lessening of the effects on serum lipids brought about by atherogenic feeding is only observed in young animals. Moreover, it is clear that liver is a target for CLA in young but not in adult hamsters.

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

    SciTech Connect

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

    1998-01-01

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

  2. Hydrogen gas attenuates embryonic gene expression and prevents left ventricular remodeling induced by intermittent hypoxia in cardiomyopathic hamsters.

    PubMed

    Kato, Ryuji; Nomura, Atsuo; Sakamoto, Aiji; Yasuda, Yuki; Amatani, Koyuha; Nagai, Sayuri; Sen, Yoko; Ijiri, Yoshio; Okada, Yoshikatsu; Yamaguchi, Takehiro; Izumi, Yasukatsu; Yoshiyama, Minoru; Tanaka, Kazuhiko; Hayashi, Tetsuya

    2014-12-01

    The prevalence of sleep apnea is very high in patients with heart failure (HF). The aims of this study were to investigate the influence of intermittent hypoxia (IH) on the failing heart and to evaluate the antioxidant effect of hydrogen gas. Normal male Syrian hamsters (n = 22) and cardiomyopathic (CM) hamsters (n = 33) were exposed to IH (repeated cycles of 1.5 min of 5% oxygen and 5 min of 21% oxygen for 8 h during the daytime) or normoxia for 14 days. Hydrogen gas (3.05 vol/100 vol) was inhaled by some CM hamsters during hypoxia. IH increased the ratio of early diastolic mitral inflow velocity to mitral annulus velocity (E/e', 21.8 vs. 16.9) but did not affect the LV ejection fraction (EF) in normal Syrian hamsters. However, IH increased E/e' (29.4 vs. 21.5) and significantly decreased the EF (37.2 vs. 47.2%) in CM hamsters. IH also increased the cardiomyocyte cross-sectional area (672 vs. 443 μm(2)) and interstitial fibrosis (29.9 vs. 9.6%), along with elevation of oxidative stress and superoxide production in the left ventricular (LV) myocardium. Furthermore, IH significantly increased the expression of brain natriuretic peptide, β-myosin heavy chain, c-fos, and c-jun mRNA in CM hamsters. Hydrogen gas inhalation significantly decreased both oxidative stress and embryonic gene expression, thus preserving cardiac function in CM hamsters. In conclusion, IH accelerated LV remodeling in CM hamsters, at least partly by increasing oxidative stress in the failing heart. These findings might explain the poor prognosis of patients with HF and sleep apnea.

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

    PubMed

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

    2015-03-01

    The Syrian golden hamster has been increasingly used to study viral hemorrhagic fever (VHF) pathogenesis and countermeasure efficacy. As VHFs are a global health concern, well-characterized animal models are essential for both the development of therapeutics and vaccines as well as for increasing our understanding of the molecular events that underlie viral pathogenesis. However, the paucity of reagents or platforms that are available for studying hamsters at a molecular level limits the ability to extract biological information from this important animal model. As such, there is a need to develop platforms/technologies for characterizing host responses of hamsters at a molecular level. To this end, we developed hamster-specific kinome peptide arrays to characterize the molecular host response of the Syrian golden hamster. After validating the functionality of the arrays using immune agonists of defined signaling mechanisms (lipopolysaccharide (LPS) and tumor necrosis factor (TNF)-α), we characterized the host response in a hamster model of VHF based on Pichinde virus (PICV(1)) infection by performing temporal kinome analysis of lung tissue. Our analysis revealed key roles for vascular endothelial growth factor (VEGF), interleukin (IL) responses, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling, and Toll-like receptor (TLR) signaling in the response to PICV infection. These findings were validated through phosphorylation-specific Western blot analysis. Overall, we have demonstrated that hamster-specific kinome arrays are a robust tool for characterizing the species-specific molecular host response in a VHF model. Further, our results provide key insights into the hamster host response to PICV infection and will inform future studies with high-consequence VHF pathogens.

  4. 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

  5. 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

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

    PubMed Central

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

    2016-01-01

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

  7. Effect of Gonadectomy on the Androgen-Dependent Behavior of Ganglion Cell-Like Cells in Djungarian Hamsters (Phodopus sungorus).

    PubMed

    Nakahira, Rei; Yoshida, Rumika; Michishita, Masaki; Ohkusu-Tsukada, Kozo; Takahashi, Kimimasa

    2016-02-01

    Ganglion cell-like (GL) cells reside in the dermis of the ventral skin of mature male Djungarian hamsters (Phodopus sugorus) and express androgen receptor (AR). To assess whether GL cells have androgen-dependent behavior, we evaluated the histologic changes of GL cells after gonadectomy. Five male and 5 female hamsters were gonadectomized at the age of 4 wk and necropsied 14 wk later. The number, distribution, and proliferative activity of GL cells in the thoracoabdominal and dorsal skins were evaluated histologically and compared with those of corresponding intact animals. GL cells were more numerous, were distributed throughout the skin more widely, and had higher proliferative activity in the intact male hamsters than in their gonadectomized counterparts. Similar trends regarding these 3 parameters were seen in ovariectomized compared with intact female hamsters and between intact male and intact female hamsters. These results suggest that the GL cells of Djungarian hamsters demonstrate sex-associated differences in their distribution and proliferative activity and that androgen may be involved in the development of these cells.

  8. Prolactin (PRL) induction of cyclooxygenase 2 (COX2) expression and prostaglandin (PG) production in hamster Leydig cells.

    PubMed

    Matzkin, María Eugenia; Ambao, Verónica; Carino, Mónica Herminia; Rossi, Soledad Paola; González, Lorena; Turyn, Daniel; Campo, Stella; Calandra, Ricardo Saúl; Frungieri, Mónica Beatriz

    2012-01-02

    Serum prolactin (PRL) variations play a crucial role in the photoperiodic-induced testicular regression-recrudescence transition in hamsters. We have previously shown that cyclooxygenase 2 (COX2), a key enzyme in the biosynthesis of prostaglandins (PGs), is expressed mostly in Leydig cells of reproductively active hamsters with considerable circulating and pituitary levels of PRL. In this study, we describe a stimulatory effect of PRL on COX2/PGs in hamster Leydig cells, which is mediated by IL-1β and prevented by P38-MAPK and JAK2 inhibitors. Furthermore, by preparative isoelectric focusing (IEF), we isolated PRL charge analogues from pituitaries of active [isoelectric points (pI): 5.16, 4.61, and 4.34] and regressed (pI: 5.44) hamsters. More acidic PRL charge analogues strongly induced COX2 expression, while less acidic ones had no effect. Our studies suggest that PRL induces COX2/PGs in hamster Leydig cells through IL-1β and activation of P38-MAPK and JAK2. PRL microheterogeneity detected in active/inactive hamsters may be responsible for the photoperiodic variations of COX2 expression in Leydig cells.

  9. Effects of growth and exercise on composition, structural maturation and appearance of osteoarthritis in articular cartilage of hamsters

    PubMed Central

    Julkunen, Petro; Halmesmäki, Esa P; Iivarinen, Jarkko; Rieppo, Lassi; Närhi, Tommi; Marjanen, Juho; Rieppo, Jarno; Arokoski, Jari; Brama, Pieter A; Jurvelin, Jukka S; Helminen, Heikki J

    2010-01-01

    Articular cartilage composition and structure are maintained and remodeled by chondrocytes under the influence of loading. Exercise-induced changes in the composition, structure, mechanical properties and tissue integrity of growing and aging hamster articular cartilage were investigated. Articular cartilage samples (n = 191) were harvested from the proximal tibiae of hamsters aged 1, 3, 6, 12 and 15 months. The hamsters were divided into runners and controls. The runners had free access to a running wheel between 1 and 3 months (runner groups 3-, 12- and 15-month-old hamsters) or 1 and 6 months (runner group 6-month-old hamsters) of age. Control animals were subjected to a sedentary lifestyle. Mechanical indentation tests and depth-wise compositional and structural analyses were performed for the cartilage samples. Furthermore, the integrity of articular cartilage was assessed using histological osteoarthritis grading. Exercise affected the collagen network organization after a 5-month exercise period, especially in the middle and deep zones. However, no effect on the mechanical properties was detected after exercise. Before the age of 12 months, the runners showed less osteoarthritis than the controls, whereas at 15 months of age the situation was reversed. It is concluded that, in hamsters, physical exercise at a young age enhances cartilage maturation and alters the depth-wise cartilage structure and composition. This may be considered beneficial. However, exercise at a young age demonstrated adverse effects on cartilage at a later age with a significant increase in the incidence of osteoarthritis. PMID:20646109

  10. Helicobacter mesocricetorum sp. nov., a Novel Helicobacter Isolated from the Feces of Syrian Hamsters

    PubMed Central

    Simmons, J. H.; Riley, L. K.; Besch-Williford, C. L.; Franklin, C. L.

    2000-01-01

    A spiral-shaped bacterium with bipolar, single, nonsheathed flagella was isolated from the feces of Syrian hamsters. The bacterium grew as a thin spreading film at 37°C under microaerobic conditions, did not hydrolyze urea, was positive for catalase and alkaline phosphatase, reduced nitrate to nitrite, did not hydrolyze hippurate, and was sensitive to nalidixic acid but resistant to cephalothin. Sequence analysis of the 16S rRNA gene and biochemical and phenotypic criteria indicate that the novel bacterium is a helicobacter. The novel bacterium is most closely related to the recently described mouse enteric helicobacter, Helicobacter rodentium. This is the first urease-negative Helicobacter species with nonsheathed flagella isolated from feces of asymptomatic Syrian hamsters. We propose to name this novel helicobacter Helicobacter mesocricetorum. The type strain is MU 97-1514 (GenBank accession number AF072471). PMID:10790105

  11. An affordance analysis of unconditioned lever pressing in rats and hamsters.

    PubMed

    Cabrera, Felipe; Sanabria, Federico; Jiménez, Ángel Andrés; Covarrubias, Pablo

    2013-01-01

    Two experiments were conducted to assess the effect of lever height on lever pressing that was not explicitly reinforced - i.e., operant-level responding. Two rodent species were used as subjects, rats (Experiment 1) and hamsters (Experiment 2), aiming to compare the behavioral support offered by one lever at various heights relative to the subjects' body size. Results showed that lever height had a substantial effect on response rate. The rate of lever pressing varied similarly for rats and hamsters as a function of lever height, when lever height was re-scaled relative to body size. The distribution of inter-response times showed that lever pressing was organized in bouts separated by pauses. This pattern of responding was accurately described in both experiments by a mixture of two exponential distributions. These findings support an analysis of affordances in non-human species.

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

    PubMed Central

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

    2016-01-01

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

  13. Maporal viral infection in the Syrian golden hamster: a model of hantavirus pulmonary syndrome.

    PubMed

    Milazzo, Mary Louise; Eyzaguirre, Eduardo J; Molina, Claudia P; Fulhorst, Charles F

    2002-11-15

    Hantavirus pulmonary syndrome (HPS) is a severe and often fatal rodent-borne zoonosis. Maporal (MAP) virus is a newly discovered hantavirus that originally was isolated from an arboreal rice rat captured in central Venezuela. The results of this study indicate that MAP virus in the Syrian golden hamster (Mesocricetus auratus) can cause a disease that is clinically and pathologically remarkably similar to HPS. The similarities include the time course of clinical disease, presence of virus-specific IgG at the onset of clinical disease, subacute pneumonitis, rapid onset of diffuse alveolar edema in the absence of necrosis, hepatic-portal triaditis, mononuclear-cellular infiltrate in lung and liver, widespread distribution of hantaviral antigen in endothelial cells of the microvasculature of lung and other tissues, and variable lethality. These similarities suggest that the MAP virus-hamster system is a useful model for studies of the pathogenesis of HPS and for the evaluation of potential therapeutic agents.

  14. Norepinephrine turnover in heart and spleen of 7-, 22-, and 34 C-acclimated hamsters

    NASA Technical Reports Server (NTRS)

    Jones, S. B.; Musacchia, X. J.

    1976-01-01

    The relationship of norepinephrine (NE) concentration and endogenous turnover rates in both myocardial and spleen tissues in the golden hamster is examined as a function of chronic exposure to either high or low ambient temperatures. Changes in myocardial and spleen NE turnover values are discussed in terms of functional alterations in sympathetic nerve activity and the importance of such changes in temperature acclimation. It is found that acclimation of hamsters to 7 C for 7-10 weeks results in decreased myocardial NE concentration and an apparent increase in myocardial NE turnover. In contrast, exposure to 34 C for 6-8 weeks results in increased myocardial NE concentration and an apparent decrease in NE turnover in both myocardial and spleen tissues. The implication of altered NE synthesis is that sympathetic nerve activity is reduced with heat acclimation and is enhanced with cold acclimation.

  15. Chinese hamster ovary cells contain transcriptionally active full-length type C proviruses.

    PubMed

    Lie, Y S; Penuel, E M; Low, M A; Nguyen, T P; Mangahas, J O; Anderson, K P; Petropoulos, C J

    1994-12-01

    We have isolated a genomic locus from Chinese hamster ovary (CHO) cells that contains a full-length provirus. Nucleotide sequence analysis indicates that it is a defective member of the rodent type C retrovirus family with an env region that is similar to those of mouse amphotropic retrovirus and subgroup B feline leukemia virus. We were able to demonstrate that this provirus is a member of a closely related family of full-length proviruses in CHO cells and Chinese hamster liver. Hybridization probes generated from this genomic clone were used to characterize type C retrovirus RNA expression in CHO cells. Full-length genomic RNA and subgenomic envelope mRNA were detected in CHO cell lines but not in the human-derived 293 cell line. Interestingly, we discovered that the site of retrovirus integration lies within a G repeat sequence belonging to the short interspersed element family of retroposons.

  16. 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.

  17. Investigation of Blue Bedding in Cages Housing Treatment-Naïve Hamsters.

    PubMed

    Shah, Vishal D; Walton, Betsy J; Culp, Amanda G; Castellino, Stephen

    2015-11-01

    During the acclimation phase of a preclinical safety study involving Syrian golden hamsters, some of the cages of treatment-naïve animals were noted to contain blue-tinged bedding; the urine of these hamsters was not discolored. We sought to understand the underlying cause of this unusual finding to ensure that the study animals were healthy and free from factors that might confound the interpretation of the study. Analysis of extracts from the blue bedding by using HPLC with inline UV detection and high-resolution mass spectrometry indicated that the color was due to the presence of indigo blue. Furthermore, the indigo blue likely was formed through a series of biochemical events initiated by the intestinal metabolism of tryptophan to an indoxyl metabolite. We offer 2 hypotheses regarding the fate of the indoxyl metabolite: indigo blue formation through oxidative coupling in the liver or through urinary bacterial metabolism.

  18. Superoxide Mediates the Toxicity of Paraquat for Chinese Hamster Ovary Cells

    NASA Astrophysics Data System (ADS)

    Bagley, Ann C.; Krall, Judith; Lynch, Robert E.

    1986-05-01

    The roles of superoxide and H2O2 in the cytotoxicity of paraquat were assessed in Chinese hamster ovary cells. Neither catalase nor superoxide dismutase inhibited the loss of ability to form colonies when added to the medium. When introduced into the cells, superoxide dismutase but not catalase inhibited the toxicity of paraquat. That superoxide dismutase acted by its known catalytic action is shown by the loss of inhibition when the enzyme was inactivated by H2O2 before being introduced into the cells. The lack of inhibition by catalase, by dimethyl sulfoxide, and by desferoxamine suggests that the toxicity is not mediated by a reaction between H2O2 and superoxide to engender the hydroxyl radical. Exposure of Chinese hamster ovary cells to paraquat may be a suitable means to determine the effects of superoxide anion in cultured cells and the ways in which cells can resist this toxic action.

  19. Lack of postmortem digestion of tapeworms in Golden hamsters experimentally infected with Taenia solium.

    PubMed

    Garza-Rodríguez, A; Maravilla, P; Mendlovic, F; Mata-Miranda, P; Robert, L; Flisser, A

    2007-04-10

    Taenia solium causes human neurocysticercosis, a public health problem in Mexico and other developing countries. Surprisingly, tapeworm carriers are very rarely found and in necropsy studies practically no tapeworms have been reported. In this paper we analyze the possibility that, after the death of the host, tapeworms could easily be destroyed in the intestine. Our experiments, performed in the hamster model, suggest that the absence of tapeworms in human intestine during necropsy is not due to postmortem digestion.

  20. Experimental Infection of Mice with Hamster Parvovirus: Evidence for Interspecies Transmission of Mouse Parvovirus 3

    PubMed Central

    Christie, Rachel D; Marcus, Emily C; Wagner, April M; Besselsen, David G

    2010-01-01

    Hamster parvovirus (HaPV) was isolated 2 decades ago from hamsters with clinical signs similar to those induced in hamsters experimentally infected with other rodent parvoviruses. Genetically, HaPV is most closely related to mouse parvovirus (MPV), which induces subclinical infection in mice. A novel MPV strain, MPV3, was detected recently in naturally infected mice, and genomic sequence analysis indicates that MPV3 is almost identical to HaPV. The goal of the present studies was to examine the infectivity of HaPV in mice. Neonatal and weanling mice of several mouse strains were inoculated with HaPV. Tissues, excretions, and sera were harvested at 1, 2, 4, and 8 wk after inoculation and evaluated by quantitative PCR and serologic assays specific for HaPV. Quantitative PCR detected viral DNA quantities that greatly exceeded the quantity of virus in inocula in multiple tissues of infected mice. Seroconversion to both nonstructural and structural viral proteins was detected in most immunocompetent mice 2 or more weeks after inoculation with HaPV. In neonatal SCID mice, viral transcripts were detected in lymphoid tissues by RT-PCR and viral DNA was detected in feces by quantitative PCR at 8 wk after inoculation. No clinical signs, gross, or histologic lesions were observed. These findings are similar to those observed in mice infected with MPV. These data support the hypothesis that HaPV and MPV3 are likely variants of the same viral species, for which the mouse is the natural rodent host with rare interspecies transmission to the hamster. PMID:20412687

  1. Neural-tube defects produced in Syrian hamsters by potato glycoalkaloids.

    PubMed

    Renwick, J H; Claringbold, W D; Earthy, M E; Few, J D; McLean, A C

    1984-12-01

    Keeler et al. (78) showed that potato sprouts could be teratogens for the central nervous system in the Syrian hamster. We demonstrate here the same teratogenic effect from a British cultivar, Arran Pilot. Most of the activity was traced to the two solanidine triglycosides, alpha-chaconine and, at a higher dose level, alpha-solanine. Some possible implications for the study of human neural-tube defects are considered.

  2. 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.

  3. Peripheral ghrelin injections stimulate food intake, foraging, and food hoarding in Siberian hamsters.

    PubMed

    Keen-Rhinehart, Erin; Bartness, Timothy J

    2005-03-01

    Fasting triggers many effects, including increases in circulating concentrations of ghrelin, a primarily stomach-derived orexigenic hormone. Exogenous ghrelin treatment stimulates food intake, implicating it in fasting-induced increases in feeding, a consummatory ingestive behavior. In Siberian hamsters, fasting also stimulates appetitive ingestive behaviors such as foraging and food hoarding. Therefore, we tested whether systemic ghrelin injections (3, 30, and 200 mg/kg) would stimulate these appetitive behaviors using a running wheel-based food delivery system coupled with simulated burrow housing. We also measured active ghrelin plasma concentrations after exogenous ghrelin treatment and compared them to those associated with fasting. Hamsters had the following: 1) no running wheel access, free food; 2) running wheel access, free food; or 3) foraging requirement (10 revolutions/pellet), no free food. Ghrelin stimulated foraging at 0-1, 2-4, and 4-24 h postinjection but failed to affect wheel running activity not coupled to food. Ghrelin stimulated food intake initially (200-350%, first 4 h) across all groups; however, in hamsters with a foraging requirement, ghrelin also stimulated food intake 4-24 h postinjection (200-250%). Ghrelin stimulated food hoarding 2-72 h postinjection (100-300%), most markedly 2-4 h postinjection in animals lacking a foraging requirement (635%). Fasting increased plasma active ghrelin concentrations in a time-dependent fashion, with the 3- and 30-mg/kg dose creating concentrations of the peptide comparable to those induced by 24-48 h of fasting. Collectively, these data suggest that exogenous ghrelin, similar to fasting, increases appetitive behaviors (foraging, hoarding) by Siberian hamsters, but dissimilar to fasting in this species, stimulates food intake.

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

    PubMed

    Bradley, Sean P; Prendergast, Brian J

    2014-06-01

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

  5. Concentration and chemical status of arsenic in the early placentas of arsenate-dosed hamsters

    SciTech Connect

    Hanlon, D.P.; Ferm, V.H.

    1987-04-01

    The authors determined the concentration and chemical status of arsenic in the placentas of hamsters following continuous exposure via the osmotic minipump to minimally and frankly teratogenic doses of arsenate. Close to 70% of the placental arsenic is bound to macromolecules, two-thirds of which is dialyzable. The remaining 30% of arsenic consists of low molecular weight species, predominantly inorganic arsenic. This mix is the same for minimally teratogenic and frankly teratogenic doses of arsenate.

  6. The effects of argon in the bioenergetics of the hamster and the rat

    NASA Technical Reports Server (NTRS)

    Tempel, G. E.; Musacchia, X. J.

    1974-01-01

    Oxygen consumption was examined in hamsters and rats exposed to normoxic mixtures of argon at 1 atm. In fasted and nonfasted animals, no marked change in O2 utilization was detectable at 22 C. However, at 7 C a significant decrease in oxygen consumption was observed where the animals were exposed in argon. The data are interpreted in terms of the greater thermal conductivity of nitrogen. The study was prompted by conflicting reports on the metabolic effects of argon and helium.

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

    PubMed

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

    2015-08-01

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

  8. 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.

  9. Cardiac and non-cardiac malformations produced by Mercury in hamsters. [None

    SciTech Connect

    Gale, T.F.

    1980-11-01

    The susceptibility of the developing mammalian embryo to the adverse effects of mercury is well documented. A variety of organic mercury compounds have been demonstrated to produce embryotoxic effects in experimental animals. HARADA recently summarized the reports of human intrauterine methylmercury poisoning, i.e., congenital Minamata disease, resulting from the ingestion of contaminated food. Ongoing studies in this laboratory have involved several different aspects of the embryotoxicity produced by inorganic mercury in hamsters including a dose response study, the interaction of mercuric acetate with cadmium and zinc, the effect of different routes of administration, the placental permeability of /sup 203/Hg and the embryotoxic response in several different hamster strains. Little is known regarding a human syndrome of congenital malformations characterized by ectopia cordis, internal cardiac defects and abnormalities of the diaphragm and ventral body wall. Most papers regarding this human syndrome are clinical reports describing the characteristics and management of specific cases; only speculative information is provided regarding etiology and possible embryopathic mechanisms. The observation that a similar syndrome, which will be designated CNC for cardiac and non-cardiac malformations, can be produced by mercury in hamsters prompted the present study. The specific goals of this study were 1) to study the effect of treating pregnant hamsters at different times during embryonic organogenesis to determine the time which produces the highest incidence of the CNC syndrome and whether different treatment times modify the morphological characteristics of the inclusive malformations and 2) to study the structural features of all mercury-induced external and internal abnormalities of the CNC syndrome in late gestation fetuses.

  10. Experimental infection of mice with hamster parvovirus: evidence for interspecies transmission of mouse parvovirus 3.

    PubMed

    Christie, Rachel D; Marcus, Emily C; Wagner, April M; Besselsen, David G

    2010-04-01

    Hamster parvovirus (HaPV) was isolated 2 decades ago from hamsters with clinical signs similar to those induced in hamsters experimentally infected with other rodent parvoviruses. Genetically, HaPV is most closely related to mouse parvovirus (MPV), which induces subclinical infection in mice. A novel MPV strain, MPV3, was detected recently in naturally infected mice, and genomic sequence analysis indicates that MPV3 is almost identical to HaPV. The goal of the present studies was to examine the infectivity of HaPV in mice. Neonatal and weanling mice of several mouse strains were inoculated with HaPV. Tissues, excretions, and sera were harvested at 1, 2, 4, and 8 wk after inoculation and evaluated by quantitative PCR and serologic assays specific for HaPV. Quantitative PCR detected viral DNA quantities that greatly exceeded the quantity of virus in inocula in multiple tissues of infected mice. Seroconversion to both nonstructural and structural viral proteins was detected in most immunocompetent mice 2 or more weeks after inoculation with HaPV. In neonatal SCID mice, viral transcripts were detected in lymphoid tissues by RT-PCR and viral DNA was detected in feces by quantitative PCR at 8 wk after inoculation. No clinical signs, gross, or histologic lesions were observed. These findings are similar to those observed in mice infected with MPV. These data support the hypothesis that HaPV and MPV3 are likely variants of the same viral species, for which the mouse is the natural rodent host with rare interspecies transmission to the hamster.

  11. In vivo metabolic activity of hamster suprachiasmatic nuclei: use of anesthesia

    SciTech Connect

    Schwartz, W.J.

    1987-02-01

    In vivo glucose utilization was measured in the suprachiasmatic nuclei (SCN) of Golden hamsters using the /sup 14/C-labeled deoxyglucose technique. A circadian rhythm of SCN metabolic activity could be measured in this species, but only during pentobarbital sodium anesthesia when the surrounding background activity of adjacent hypothalamus was suppressed. Both the SCN's metabolic oscillation and its time-keeping ability are resistant to general anesthesia.

  12. Effective cryopreservation of golden Syrian hamster embryos by open pulled straw vitrification.

    PubMed

    Fan, Z; Meng, Q; Bunch, T D; White, K L; Wang, Z

    2016-02-01

    Golden Syrian hamster embryos are difficult to cryopreserve due to their high sensitivity to cryoprotectants and in vitro handling. The objective of this study is to develop a robust open pulled straw (OPS) vitrification technique for cryopreserving hamster embryos at various developmental stages. We first systematically tested the concentrations of cryoprotectants and the exposure times of two-cell embryos to various vitrification solutions. We identified pretreatment of two-cell embryos with 10% (v/v) ethylene glycol (EG) + 10% (v/v) dimethylsulfoxide (DMSO) for 30 s followed by exposure in the vitrification solution, EDFS30 (containing 15% EG + 15% DMSO), for 30 s before plunging into liquid nitrogen (two-step exposure method) as the optimal OPS vitrification protocol. We then investigated the resourcefulness of this protocol for vitrifying hamster embryos at different developmental stages. The results showed that high blastocyst rates from embryos vitrified at two-cell, four-cell, eight-cell, or morula stage (62%, 78%, 80%, or 72%, respectively), but not those verified at pronuclear (0%) or blastocyst stage (24%; P < 0.05), were achieved by this protocol. When embryos vitrified at the two-cell stage were recovered and then directly transferred to recipient females, 29% of them developed to term, a development rate not significantly different (P > 0.05) from the 40% birth rate of the unvitrified controls. In conclusion, we have developed an effective two-step OPS vitrification protocol for hamster embryos.

  13. Effects of foraging effort on body fat and food hoarding in Siberian hamsters.

    PubMed

    Day, D E; Bartness, T J

    2001-02-15

    Food hoard size varies inversely with body fat levels in Siberian hamsters. If food hoarding only increases when body fat decreases, then hamsters foraging for their food should only increase food hoarding when foraging efforts decrease body fat ("lipostatic hypothesis"); however, if food hoarding increases whenever there is an energy flux away from fat storage, then it should increase regardless of significant body fat decreases ("metabolic hypothesis"). Female Siberian hamsters (Phodopus sungorus) earned food pellets after completion of a programmed number of wheel revolutions (Immobilized Wheel [free access to food], Free Wheel [wheel active, free food], and 10, 50, 100, and 200 revolutions/pellet). Hamsters were killed after 19 days and inguinal, retroperitoneal, and parametrial white adipose tissue (WAT) pads (IWAT, RWAT, and PWAT, respectively) were harvested and carcass composition determined. Food hoard size increased fourfold with the availability of running wheels alone (Free Wheel), increased threefold with low foraging levels (10 and 50 revolutions/pellet), but was nearly abolished at the highest foraging level (200 revolutions/pellet). Surplus food (earned, not eaten or hoarded) was significantly greatest at the lowest level of foraging. As foraging effort increased, PWAT mass decreased the most (<10 revolutions/pellet), while RWAT and IWAT mass only were decreased at the highest foraging effort. Carcass lipid content only was significantly decreased at the highest foraging effort, yet food hoarding was nearly abolished at that level. Collectively, these results demonstrate that body fat levels and food hoarding can be uncoupled with increases in foraging effort. J. Exp. Zool. 289:162-171, 2001.

  14. Efficient and Rapid Development of Transgenic Hamster Models of TSEs Using a Radical New Technology

    DTIC Science & Technology

    2007-09-01

    high scrapie susceptibility genotype VVRRQQ. All three lines of the mouse transgenics carrying sheep, human, and elk PrP have been now re-derived. We...have observed the first transmission of the disease from our standard scrapie -infected sheep brain inoculum to the transgenic mice with sheep PrP and...already been distributed. 15. SUBJECT TERMS Transgenic, Mouse, Hamster, TSE, Sheep Scrapie , TOSK, transposon 16. SECURITY CLASSIFICATION OF

  15. Pterocarpanquinone LQB-118 Induces Apoptosis in Leishmania (Viannia) braziliensis and Controls Lesions in Infected Hamsters

    PubMed Central

    Costa, Luciana; Pinheiro, Roberta O.; Dutra, Patrícia M. L.; Santos, Rosiane F.; Cunha-Júnior, Edézio F.; Torres-Santos, Eduardo C.; da Silva, Alcides J. M.; Costa, Paulo R. R.; Da-Silva, Silvia A. G.

    2014-01-01

    Previous results demonstrate that the hybrid synthetic pterocarpanquinone LQB-118 presents antileishmanial activity against Leishmania amazonensis in a mouse model. The aim of the present study was to use a hamster model to investigate whether LQB-118 presents antileishmanial activity against Leishmania (Viannia) braziliensis, which is the major Leishmania species related to American tegumentary leishmaniasis. The in vitro antileishmanial activity of LQB-118 on L. braziliensis was tested on the promastigote and intracellular amastigote forms. The cell death induced by LQB-118 in the L. braziliensis promastigotes was analyzed using an annexin V-FITC/PI kit, the oxidative stress was evaluated by 2′,7′-dichlorodihydrofluorescein diacetate (H2DCFDA) and the ATP content by luminescence. In situ labeling of DNA fragments by terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) was used to investigate apoptosis in the intracellular amastigotes. L. braziliensis-infected hamsters were treated from the seventh day of infection with LQB-118 administered intralesionally (26 µg/kg/day, three times a week) or orally (4,3 mg/kg/day, five times a week) for eight weeks. LQB-118 was active against the L. braziliensis promastigotes and intracellular amastigotes, producing IC50 (50% inhibitory concentration) values of 3,4±0,1 and 7,5±0,8 µM, respectively. LQB-118 induced promastigote phosphatidylserine externalization accompanied by increased reactive oxygen species production and ATP depletion. Intracellular amastigote DNA fragmentation was also observed, without affecting the viability of macrophages. The treatment of L. braziliensis-infected hamsters with LQB-118, either orally or intralesionally, was effective in the control of lesion size, parasite load and increase intradermal reaction to parasite antigen. Taken together, these results show that the antileishmanial effect of LQB-118 extends to L. braziliensis in the hamster model, involves the

  16. Hypolipidemic Effects of Alkaloids from Rhizoma Coptidis in Diet-Induced Hyperlipidemic Hamsters.

    PubMed

    He, Kai; Kou, Shuming; Zou, Zongyao; Hu, Yinran; Feng, Min; Han, Bing; Li, Xuegang; Ye, Xiaoli

    2016-05-01

    This study was conducted to evaluate the antihyperlipidemic activity of five major alkaloids in Rhizoma Coptidis using high-fat- and high-cholesterol-induced hyperlipidemic hamsters. Hyperlipidemic hamsters were treated with coptisine, berberine, jatrorrhizine, palmatine, epiberberine, and total Rhizoma Coptidis alkaloids with a dose of 46.7 mg/kg × day for 140 days. Serum total cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and total bile acids were examined after alkaloid treatment. The results showed that all therapy agents prevented body weight gain, reduced the serum total cholesterol, and increased the high-density lipoprotein cholesterol of hamsters. Berberine, jatrorrhizine, and total Rhizoma Coptidis alkaloids decreased the triglyceride level in hyperlipidemic hamsters, while coptisine, jatrorrhizine, palmatine, and total Rhizoma Coptidis alkaloids significantly suppressed the elevation of the low-density lipoprotein cholesterol level. The fecal excretion of bile acids was significantly elevated by berberine, coptisine, jatrorrhizine, palmatine, total Rhizoma Coptidis alkaloids, and orlistat. Notably, total Rhizoma Coptidis alkaloids possess a much stronger lipid-lowering effect than the pure Rhizoma Coptidis alkaloids. Quantitative reverse transcription-polymerase chain reaction analyses revealed that Rhizoma Coptidis alkaloids could retard the synthesis of cholesterol by downregulating the mRNA expression of 3-hydroxy-3-methyl glutaryl coenzyme A reductase and accelerate the clearance of lipids by upregulating the low-density lipoprotein receptor, cholesterol 7α-hydroxylase, and uncoupling protein-2 expression. These findings highlight the critical role of Rhizoma Coptidis alkaloids in hyperlipidemia treatment. Thus, they need to be considered in future therapeutic approaches.

  17. Effect of aging on brain respiration and carbohydrate metabolism of Syrian hamsters.

    PubMed

    Fox, J H; Parmacek, M S; Patel-Mandlik, K

    1975-01-01

    Syrian hamsters were used to study the effect of aging on brain slice respiration and metabolism. Young animals (average age 8 months) and old animals (average age 18 months) were incubated under standard conditions with the following parameters being measured: oxygen uptake, 14CO2 production, glucose utilization, lactate and pyruvate formation. No differences were found in the two groups. It is still very likely that subtle differences exist but can only be documented under conditions of metabolic stress.

  18. The ultrastructure of N-dibutylnitrosamine induced pulmonary tumours (adenocarcinomata) in European hamsters.

    PubMed Central

    Reznik-Schüller, H.; Mohr, U.

    1975-01-01

    N-dibutyl-nitrosamine induced pulmonary adenocarcinoma in European hamsters were studied electron microscopically. The tumours were composed of light and dark cells, which, due to their lamellar bodies, resembled alveolar epithelial cells Type II. As cells containing lamellar bodies also occasionally occurred with the epithelial lining of tumour associated peripheral bronchi, a possible bronchiolar origin of the neoplasms is discussed. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 PMID:1212352

  19. Asbestos-Induced Epithelial Changes in Organ Cultures of Hamster Trachea: Inhibition by Retinyl Methyl Ether

    NASA Astrophysics Data System (ADS)

    Mossman, B. T.; Craighead, J. E.; MacPherson, B. V.

    1980-01-01

    The epithelium of the hamster trachea in organ culture undergoes hyperplasia and squamous metaplasia after exposure to the amphibole types of asbestos, crocidolite and amosite. These changes are inhibited when the synthetic vitamin A analog, retinyl methyl ether, is incorporated into the culture medium. These findings suggest a possible use for retinoids in the prevention and treatment of respiratory tract disease associated with environmental exposure to asbestos.

  20. Daytime Unresponsiveness of the Human and Syrian Hamster Pineal to Adrenergic Stimulation

    DTIC Science & Technology

    1989-01-01

    et al., 1981; Li et al., 1988). Experimental animals have also been variably resistent to induction of changes in the melatonin rhythm if the light... melatonin content in burned rats and hamsters is essentially normal (Vaughan et al., 1985). Acute adverse stimuli, such as insulin -induced hyoglycemia...or excreted melatonin in humans during the day by a variety of influences (including naps, psychological stress, exercise, insulin hypoglycemia, and

  1. Induction of malignant peripheral nerve sheath tumors in European hamsters with 1,1-dimethylhydrazine (UDMH).

    PubMed

    Ernst, H; Rittinghausen, S; Wahnschaffe, U; Mohr, U

    1987-06-01

    A rate of up to 43% of malignant peripheral nerve sheath tumors (PNST) was induced in European hamsters (EH) after weekly s.c. administration of 1,1-dimethylhydrazine (UDMH). The overall neoplastic response in the treated EH was also elevated as compared to the untreated controls. Histologically, the malignant PNST were neurofibrosarcomas and melanotic as well as unpigmented schwannomas. The occurrence of melanotic schwannomas is briefly discussed with regard to the histogenesis of this rare tumor type.

  2. Immunization and challenge shown by hamsters infected with Opisthorchis viverrini following exposure to gamma-irradiated metacercariae of this carcinogenic liver fluke

    PubMed Central

    Papatpremsiri, A.; Junpue, P.; Loukas, A.; Brindley, P.J.; Bethony, J.M.; Sripa, B.; Laha, T.

    2016-01-01

    Here we report findings to optimize and standardize conditions to attenuate metacercariae of Opisthorchis viverrini by ionizing radiation to elicit protective immune responses to challenge infection. Metacercariae were gamma-irradiated and the ability of irradiated metacercariae to prevent patent infection of challenge metacercariae in hamsters was determined, as well as their ability to induce a host antibody response. Metacercariae irradiated in a dose-dependent manner, with 3, 5, 10, 12, 20, 25 and 50 Gray, were used to infect Syrian golden hamsters by stomach gavage to ascertain the effect of irradiation on ability of the worms to establish infection. In addition, other hamsters were infected with metacercariae irradiated with 20–50 Gray, followed by challenge with intact/wild-type (non-irradiated) metacercariae to determine the protective effect as established by the numbers of adult flukes, eggs of O. viverrini in hamster faeces and anti-O. viverrini antibody titres. Significantly fewer worms were recovered from hamsters immunized with metacercariae irradiated at 20, 25 and 50 Gray than from control hamsters infected with intact metacercariae or 0 Gray, and the worms showed damaged reproductive organs. Faecal egg numbers were decreased significantly in hamsters immunized with 25 and 50 Gray metacercariae of O. viverrini. Moreover, hamsters administered metacercariae that were protected elicited a robust, specific anti-fluke immunoglobulin G response compared to control hamsters, suggesting a role for antibody in protection elicited by radiation-attenuated metacercariae. PMID:25315797

  3. Immunization and challenge shown by hamsters infected with Opisthorchis viverrini following exposure to gamma-irradiated metacercariae of this carcinogenic liver fluke.

    PubMed

    Papatpremsiri, A; Junpue, P; Loukas, A; Brindley, P J; Bethony, J M; Sripa, B; Laha, T

    2016-01-01

    Here we report findings to optimize and standardize conditions to attenuate metacercariae of Opisthorchis viverrini by ionizing radiation to elicit protective immune responses to challenge infection. Metacercariae were gamma-irradiated and the ability of irradiated metacercariae to prevent patent infection of challenge metacercariae in hamsters was determined, as well as their ability to induce a host antibody response. Metacercariae irradiated in a dose-dependent manner, with 3, 5, 10, 12, 20, 25 and 50 Gray, were used to infect Syrian golden hamsters by stomach gavage to ascertain the effect of irradiation on ability of the worms to establish infection. In addition, other hamsters were infected with metacercariae irradiated with 20-50 Gray, followed by challenge with intact/wild-type (non-irradiated) metacercariae to determine the protective effect as established by the numbers of adult flukes, eggs of O. viverrini in hamster faeces and anti-O. viverrini antibody titres. Significantly fewer worms were recovered from hamsters immunized with metacercariae irradiated at 20, 25 and 50 Gray than from control hamsters infected with intact metacercariae or 0 Gray, and the worms showed damaged reproductive organs. Faecal egg numbers were decreased significantly in hamsters immunized with 25 and 50 Gray metacercariae of O. viverrini. Moreover, hamsters administered metacercariae that were protected elicited a robust, specific anti-fluke immunoglobulin G response compared to control hamsters, suggesting a role for antibody in protection elicited by radiation-attenuated metacercariae.

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

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

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

  5. Seasonal pelage changes are synchronized by simulated natural photoperiods in Siberian hamsters (Phodopus sungorus)

    PubMed Central

    Butler, Matthew P.; Zucker, Irving

    2013-01-01

    The extent to which changing day lengths synchronize the seasonal molt was assessed in nine cohorts of male and female Siberian hamsters (Phodopus sungorus) born into a simulated natural photoperiod (SNP) beginning 4 weeks before and ending 12 weeks after the summer solstice. Hamsters in early cohorts displayed rapid somatic and gonadal growth and early puberty, whereas those in later cohorts delayed puberty until the next spring. Despite the varying birth dates and puberty strategies, the seasonal pattern of change in pelage is much better predicted by calendar date than by age in both sexes. Males born over the course of 16 weeks first made the transition to the winter pelage during a 5 week interval beginning on October 25; the autumn molt, however, was not significantly synchronized by either age or calendar date. The autumn molt of females on the other hand began 2 weeks later, and was significantly synchronized to calendar date with no detectable age effects. In both sexes, the autumn molt lagged gonadal and somatic seasonal changes by many weeks. Date of birth did not affect the timing of the spring molt, which was significantly synchronized by calendar date in both sexes. Incrementally changing photoperiods exert a strong organizing effect on the seasonal molt by providing hamsters with timing cues that are absent in laboratory analyses that employ static day lengths and abrupt transitions from summer to winter day lengths, thereby extending and validating conclusions derived from previous analyses. PMID:19425044

  6. Identification and characterization of hamster stearoyl-CoA desaturase isoforms.

    PubMed

    Wang, Jian; Yu, Lan; Wang, He; Gao, Yunling; Schrementi, James P; Porter, Regina K; Yurek, David A; Kuo, Mingshang; Suen, Chen-Shian; Cao, Guoqing; Bean, James S; Kauffman, Raymond F; Qian, Yuewei

    2008-03-01

    Stearoyl-CoA desaturase (SCD) catalyzes the formation of monounsaturated fatty acids from saturated fatty acids. It plays a key role in lipid metabolism and energy expenditure in mammals. In mice, four SCD isoforms (SCD1-4) have been identified. Here we report the identification of cDNA sequences corresponding to SCD1, SCD2 and SCD3 of golden hamster. The deduced amino acid sequences of these hamster SCD (hmSCD) isoforms display a high degree of homologies to their mouse counterparts (mouse SCD). Polyclonal antibodies specific to rodent SCDs detected proteins of predicted size in the human embryonic kidney 293 cells transfected with hmSCD cDNAs. Microsome fractions prepared from these cells also displayed increased SCD activity versus cells transfected with vector alone. Real-time reverse transcription-polymerase chain reaction analysis revealed the highest expression of hmSCD1 in liver and adipose tissue, while the highest hmSCD2 expression was detected in the brain. Very low levels of hmSCD3 mRNA can be detected in the tissues tested. This report is the first description of three SCD isoforms in the hamster and will provide useful tools in the further study of fatty acids metabolism in this species.

  7. Mouse and hamster mutants as models for Waardenburg syndromes in humans.

    PubMed Central

    Asher, J H; Friedman, T B

    1990-01-01

    Four different Waardenburg syndromes have been defined based upon observed phenotypes. These syndromes are responsible for approximately 2% of subjects with profound congenital hearing loss. At present, Waardenburg syndromes have not been mapped to particular human chromosomes. One or more of the mouse mutant alleles, Ph (patch), s (piebald), Sp (splotch), and Mior (microphthalmia-Oak Ridge) and the hamster mutation Wh (anophthalmic white) may be homologous to mutations causing Waardenburg syndromes. In heterozygotes, phenotypic effects of these four mouse mutations and the hamster mutation are similar to the phenotypes produced by different Waardenburg syndrome mutations. The chromosomal locations and syntenic relationships associated with three of the four mouse mutant genes have been used to predict human chromosomal locations for Waardenburg syndromes: (1) on chromosome 2q near FN1 (fibronectin 1), (2) on chromosome 3p near the proto-oncogene RAF1 or 3q near RHO (rhodopsin), and (3) on chromosome 4p near the proto-oncogene KIT. Waardenburg syndromes show extensive intrafamilial phenotypic variability. Results of our studies with the hamster mutation Wh suggest that this variability may be explained in part by modifier genes segregating within families. Images PMID:2246770

  8. 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.

  9. A cowpox virus gene required for multiplication in Chinese hamster ovary cells.

    PubMed Central

    Spehner, D; Gillard, S; Drillien, R; Kirn, A

    1988-01-01

    Cowpox virus, in contrast to vaccinia virus, can multiply in Chinese hamster ovary cells. To study the genetic basis for this difference in host range, recombinants between vaccinia and cowpox viruses were isolated and their DNA restriction patterns were examined. The ability to multiply in Chinese hamster ovary cells could be correlated with the conservation of cowpox virus sequences mapping at the left end of the genome. This was further demonstrated by marker rescue of the host range phenotype with restricted cowpox virus DNA. Marker rescue with cloned restriction fragments of decreasing size enabled the fine localization of the host range function to a 2.3-kilobase-pair fragment. Nucleotide sequencing revealed that the fragment encoded a single major polypeptide of approximately 77,000 daltons. It is suggested that the role of the host range gene from cowpox virus is to prevent the early and extensive shutoff of protein synthesis that normally occurs in Chinese hamster ovary cells infected by vaccinia virus. Images PMID:2831390

  10. Daidzin and daidzein suppress free-choice ethanol intake by Syrian golden hamsters.

    PubMed

    Keung, W M; Vallee, B L

    1993-11-01

    Syrian Golden hamsters prefer and consume large and remarkably constant amounts of ethanol in a simple two-bottle free-choice regimen. Ethanol intake is significantly suppressed by zimelidine, bromocriptine, buspirone, and lithium carbonate, pharmacological agents that have been shown to be beneficial in controlling ethanol intake in alcohol-dependent humans. These results suggest that this ethanol-drinking animal model has high "predictive validity" and can be used effectively in the search for and identification of new agents for the treatment of alcohol abuse. The model has enabled us to confirm the putative antidipsotropic effect of Radix puerariae (RP), an herb long used in traditional Chinese medicine for the treatment of patients who abuse alcohol. A crude extract of RP at a dose of 1.5 g.kg-1 x day-1 significantly suppresses (> 50%) the free-choice ethanol intake of Golden hamsters. Moreover, two major constituents of RP, daidzein (4',7-dihydroxyisoflavone) and daidzin (the 7-glucoside of daidzein), were also shown to suppress free-choice ethanol intake. Daidzin and daidzein, at doses of 150 and 230 mg.kg-1 x day-1, respectively, suppress ethanol intake by > 50%. RP, daidzein, and daidzin treatment do not significantly affect the body weight and water or food intake of the hamsters. These findings identify a class of compounds that offer promise as safe and effective therapeutic agents for alcohol abuse.

  11. Chinese hamster ovary cell lysosomes retain pinocytized horseradish peroxidase and in situ-radioiodinated proteins

    SciTech Connect

    Storrie, B.; Sachdeva, M.; Viers, V.S.

    1984-02-01

    We used Chinese hamster ovary cells, a cell line of fibroblastic origin, to investigate whether lysosomes are an exocytic compartment. To label lysosomal contents, Chinese hamster ovary cells were incubated with the solute marker horseradish peroxidase. After an 18-h uptake period, horseradish peroxidase was found in lysosomes by cell fractionation in Percoll gradients and by electron microscope cytochemistry. Over a 24-h period, lysosomal horseradish peroxidase was quantitatively retained by Chinese hamster ovary cells and inactivated with a t 1/2 of 6 to 8 h. Lysosomes were radioiodinated in situ by soluble lactoperoxidase internalized over an 18-h uptake period. About 70% of the radioiodine incorporation was pelleted at 100,000 X g under conditions in which greater than 80% of the lysosomal marker enzyme beta-hexosaminidase was released into the supernatant. By one-dimensional electrophoresis, about 18 protein species were present in the lysosomal membrane fraction, with radioiodine incorporation being most pronounced into species of 70,000 to 75,000 daltons. After a 30-min or 2-h chase at 37 degrees C, radioiodine that was incorporated into lysosomal membranes and contents was retained in lysosomes. These observations indicate that lysosomes labeled by fluid-phase pinocytosis are a terminal component of endocytic pathways in fibroblasts.

  12. Expression of vasopressin receptors in hamster hypothalamus is sexually dimorphic and dependent upon photoperiod.

    PubMed Central

    Dubois-Dauphin, M; Theler, J M; Zaganidis, N; Dominik, W; Tribollet, E; Pévet, P; Charpak, G; Dreifuss, J J

    1991-01-01

    The distribution of vasopressin receptors was studied in the brain of a photoperiodic animal, the Siberian hamster. Attention was focused on [3H]vasopressin binding sites located in the hypothalamic ventromedial nucleus, medial tuberal nucleus, and ventral premammillary nucleus in males or females kept in long or short photoperiod conditions. Displacement experiments with structural analogs suggested that vasopressin receptors in the hamster hypothalamus are of the vasopressor (V1) type. Quantitative data obtained with a gaseous detector of beta-particles indicated that in the ventromedial nucleus and in the ventral premammillary nucleus of animals in long photoperiod, the number of beta-particles emitted per unit area was significantly greater in males than in females. In the ventromedial hypothalamic nucleus, in both males and females, the number of beta-particles emitted was significantly lower in short than in long photoperiod conditions. In the ventral premammillary nucleus, shortening of the photoperiod had a significant effect in reducing the amount of [3H]vasopressin bound in females, but not in males. These data suggest that, in the hamster, the control of the expression of vasopressin receptors differs among various hypothalamic nuclei and may depend on the sex and/or on the level of circulating gonadal steroids. Images PMID:1837144

  13. Selective blockade of the endothelin subtype A receptor decreases early atherosclerosis in hamsters fed cholesterol.

    PubMed Central

    Kowala, M. C.; Rose, P. M.; Stein, P. D.; Goller, N.; Recce, R.; Beyer, S.; Valentine, M.; Barton, D.; Durham, S. K.

    1995-01-01

    Recent studies suggest that endothelin and its receptors may be involved in atherogenesis. To test this hypothesis, cholesterol-fed hamsters were treated with a selective endothelin subtype A (ETA) receptor antagonist BMS-182874. Characterization of hamster atherosclerotic plaques indicated that they contained a fibrous cap of smooth muscle cells, large macrophage-foam cells, and epitopes of oxidized low density lipoprotein. Messenger RNA for both ETA and ETB receptors was detected in aortic endothelial cells, in medial smooth muscle cells, and in macrophage-foam cells and smooth muscle cells of the fibro-fatty plaques. BMS-182874 inhibited the endothelin-1-induced pressor response whereas the depressor effect was unaltered, suggesting that vascular ETA receptors were selectively blocked in vivo. In hyperlipidemic hamsters, BMS-182874 decreased the area of the fatty streak by reducing the number and size of macrophage-foam cells. The results indicated that ETA receptors and thus endothelin promoted the early inflammatory phase of atherosclerosis. Images Figure 1 Figure 2 Figure 3 Figure 5 PMID:7717449

  14. PARENT-OF-ORIGIN GROWTH EFFECTS AND THE EVOLUTION OF HYBRID INVIABILITY IN DWARF HAMSTERS

    PubMed Central

    Brekke, Thomas D.; Good, Jeffrey M.

    2015-01-01

    Mammalian hybrids often show abnormal growth, indicating that developmental inviability may play an important role in mammalian speciation. Yet it is unclear if this recurrent phenotype reflects a common genetic basis. Here we describe extreme parent-of-origin dependent growth in hybrids from crosses between two species of dwarf hamsters, Phodopus campbelli and P. sungorus. One cross type resulted in massive placental and embryonic overgrowth, severe developmental defects, and maternal death. Embryos from the reciprocal cross were viable and normal sized but adult hybrid males were relatively small. These effects are strikingly similar to patterns from several other mammalian hybrids. Using comparative sequence data from dwarf hamsters and several other hybridizing mammals, we argue that extreme hybrid growth can contribute to reproductive isolation during the early stages of species divergence. Next we tested if abnormal growth in hybrid hamsters was associated with disrupted genomic imprinting. We found no association between imprinting status at several candidate genes and hybrid growth, though two interacting genes involved in embryonic growth did show reduced expression in overgrown hybrids. Collectively, our study indicates that growth-related hybrid inviability may play an important role in mammalian speciation but that the genetic underpinnings of these phenotypes remain unresolved. PMID:25130206

  15. Preliminary protective capacity study of a Dicrocoelium dendriticum antigenic protein in hamsters.

    PubMed

    González-Lanza, C; Manga-González, M Y; Revilla-Nuín, B

    2006-11-01

    The purpose of this study was to evaluate the protective capacity of 130 kDa Dicrocoelium dendriticum protein in hamsters experimentally infected with this parasite. Forty hamsters divided into four groups of ten animals each were used: G1 (control), G2 (infected), G3 (immunized with Freund's adjuvant and infected), G4 (130 kDa protein vaccinated + adjuvant and infected). Infection with 40 metacercariae/hamster was carried out 4 weeks after the last immunization. Parasitological studies [number of eggs per gram (epg) and worm burden] and biochemical parameters (total proteins, albumin, and total bilirubin), hepatic enzymes [aspartate aminotransferase (AST) and alanine aminotransferase (ALT)], and total IgG levels were determined. A reduction in epg in G3 and G4 was observed 16 weeks postinfection with the higher reduction percentage in the latter (25.2%). No statistically significant differences were detected in the number of recovered worms among groups, although the mean was slightly less in G4 (12.2 +/- 2.08, mean +/- SE) than in G2 (15.4 +/- 2.90). In G4, global protection was 20.9% and an increase in AST and ALT levels was observed. Total IgG levels were similar in the three infected groups. The protection obtained was inadequate, so the antigen dose, immunization-infection period, adjuvants, and immunization route must be optimized.

  16. 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.

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

    SciTech Connect

    Cozzi, J.

    1994-09-01

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

  18. Single and multiple worm infections of Echinostoma caproni (Trematoda) in the golden hamster.

    PubMed

    Fried, B; Huffman, J E; Weiss, P M

    1990-03-01

    Six of 10 hamsters fed a single metacercarial cyst of Echinostoma caproni (single-worm infections) and 13 of 19 hamsters fed either 2 or 5 cysts (multiple-worm infections) were infected with adult echinostomes at necropsy 22 days post-infection. Considerable histopathological changes to the small intestine occurred in hamsters carrying single-worm infections. There were no differences in either mean length, width or wet weight of echinostomes in single- versus multiple-worm infections. The mean number of eggs/worm from single-worm infections (525) was significantly greater than that from multiple-worm infections (288). The average percentage of fully developed miracidia/worm from single worms (94%) was similar to that from worms in multiple infections (92-95%). Single worms of E. caproni were capable of self-fertilization and production of viable eggs. Miracidia derived from single worms were as capable of infecting laboratory-reared Biomphalaria glabrata and producing patent rediae as were those from multiple infections.

  19. Hog barn dust extract increases macromolecular efflux from the hamster cheek pouch.

    PubMed

    Rubinstein, Israel; Von Essen, Susanna G

    2006-07-01

    The purpose of this study was to determine whether short-term exposure to an aqueous extract of hog barn dust increases macromolecular efflux from the intact hamster cheek pouch and, if so, to begin to determine the mechanism(s) underlying this response. By using intravital microscopy, we found that suffusion of hog barn dust extract onto the intact hamster cheek pouch for 60 min elicited a significant, concentration-dependent leaky site formation and increase in clearance of FITC-labeled dextran (molecular mass, 70 kDa). This response was significantly attenuated by suffusion of catalase (60 U/ml), but not by heat-inactivated catalase, and by pretreatment with dexamethasone (10 mg/kg iv) (P < 0.05). Catalase had no significant effects on adenosine-induced increase in macromolecular efflux from the cheek pouch. Suffusion of hog barn dust extract had no significant effects on arteriolar diameter in the cheek pouch. Taken together, these data indicate that hog barn dust extract increases macromolecular efflux from the in situ hamster cheek pouch, in part, through local elaboration of reactive oxygen species that are inactivated by catalase. This response is specific and attenuated by corticosteroids. We suggest that plasma exudation plays an important role in the genesis of upper airway dysfunction evoked by short-term exposure to hog barn dust.

  20. Hydroxycinnamic acids do not prevent aortic atherosclerosis in hypercholesterolemic golden Syrian hamsters.

    PubMed

    Auger, Cyril; Laurent, Nathalie; Laurent, Caroline; Besançon, Pierre; Caporiccio, Bertrand; Teissédre, Pierre Louis; Rouanet, Jean-Max

    2004-03-26

    The protective effect of hydroxycinnamic acids, i.e. caffeic acid (CA) and sinapic acid (SA) present in wine, and chlorogenic acid (CHA) present in apple, compared to a red wine phenolic extract (RWPE) was investigated in hamsters fed an atherogenic diet for 12 weeks. Five groups of 8 hamsters fed such a diet received by force-feeding RWPE, CA or SA in water, mimicking a moderate consumption of alcohol-free red wine. Controls received water and CHA force-feeding was extrapolated from apple consumption. Plasma cholesterol concentration was lower in group that received RWPE (-22%) and hydroxycinnamic acids had no effect. Plasma apolipoprotein Apo-A1 concentration was not affected; consumption of RWPE only decreased Apo-B concentration (-46%). Liver superoxide dismutase activity was 33% lower and glutathione peroxidase activity was 67% greater in the group receiving RWPE compared to controls; there was no effect when CA, SA or CHA were given. All the phenolic compounds significantly increased plasma antioxidant capacity (about 28% on average) compared with controls. Aortic fatty streak area was significantly reduced in the group receiving RWPE (-30%) in comparison with controls and hydroxycinnamic acids. Our findings demonstrate that chronic ingestion of the nonalcoholic components of red wine, mainly polyphenols, prevent the development of atherosclerosis in hamster and that wine hydroxycinnamic acids are not the phenolic compounds involved in such a beneficial effect.

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

    SciTech Connect

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

    2009-05-10

    Hendra virus (HeV) and Nipah virus (NiV) are recently-emerged, closely related and highly pathogenic paramyxoviruses. We have analysed here the pathogenesis of the acute HeV infection using the new animal model, golden hamster (Mesocricetus auratus), which is highly susceptible to HeV infection. HeV-specific RNA and viral antigens were found in multiple organs and virus was isolated from different tissues. Dual pathogenic mechanism was observed: parenchymal infection in various organs, including the brain, with vasculitis and multinucleated syncytia in many blood vessels. Furthermore, monoclonal antibodies specific for the NiV fusion protein neutralized HeV in vitro and efficiently protected hamsters from HeV if given before infection. These results reveal the similarities between HeV and NiV pathogenesis, particularly in affecting both respiratory and neuronal system. They demonstrate that hamster presents a convenient novel animal model to study HeV infection, opening new perspectives to evaluate vaccine and therapeutic approaches against this emergent infectious disease.

  2. Inhibition and regression of tumors in hamster DMBA model following laser microvascular targeting

    NASA Astrophysics Data System (ADS)

    McMillan, Kathleen; Wang, Zhi; Shapshay, Stanley M.

    1998-07-01

    Vascular targeting is a recent approach to cancer therapy that aims at damaging tumor vasculature to induce tumor cell hypoxia and subsequent cell death. Squamous cell cancer arises in the superficial mucosal and cutaneous epithelial layers, and tumor microvasculature therefore may be particularly well suited for targeting by selective photothermolysis. An initial evaluation of the effect of selective eradication of microvasculature on tumor development was undertaken here using the chemically-induced hamster cheek pouch model and a 585 nm pulsed dye laser. In a first group of 6 hamsters, progression of premalignant mucosal lesions was compared between control and laser treatment groups, and laser-induced regression of established tumors was evaluated. In a second group of 12 hamsters, the number of laser treatments required to produce complete regression of tumors of the buccal mucosa was determined. The effect of the laser on tumors appearing on the skin in these animals was also investigated. These experiments showed that laser treatment inhibited tumor development and caused complete regression of established tumors 10 mm3 or smaller. Photothermal microvascular targeting may be useful in treating dyplasia and early tumors of the upper aerodigestive tract and skin, with fewer adverse sequelae than existing modalities.

  3. Hypolipidemic and Antioxidative Effects of Glossogyne tenuifolia in Hamsters Fed an Atherogenic Diet.

    PubMed

    Lee, Yi-Ning; Hsu, Guoo-Shyng Wang; Lin, Wan-Teng; Lu, Yi-Fa

    2016-05-01

    Glossogyne tenuifolia (GT) Cassini is a special herbal tea in the Penghu Islands, Taiwan, and has a long history of being used as an antipyretic, detoxifying, and anti-inflammatory remedy in folk medicine among local residents. The aim of this study was to investigate the effect of hot water extracts from GT on oxidative stress and lipid metabolism in animals. Five- to 6-week-old male Syrian hamsters were divided into four groups (n = 14) for different treatments, that is: control group (C), high-fat/cholesterol (HF) group, HF diet containing 0.5% (GT0.5) and 1.5% (GT1.5) GT extracts for 4 weeks. Hamsters fed with 0.5% GT powder as well as 1.5% GT powder exhibited reduced serum total cholesterol (TC), conjugated diene of low-density lipoprotein (LDL), and increased serum antioxidant capacity, but 1.5% GT powder was more potent at lowering serum LDL cholesterol and thiobarbituric acid reactive substance concentrations than 0.5% GT. GT extracts significantly lowered liver triacylglycerol (TG) concentration by diminishing activities of fatty acid synthase (FAS) and glucose-6-phosphate dehydrogenase (G-6-PDH). In addition, fecal excretion of cholesterol and bile acids were increased in GT extract groups. In conclusion, GT extracts increase the antioxidative capacity, decrease serum TC, inhibit the activities of FAS and G-6-PDH, and further reduce liver TG accumulation in hamster fed on atherogenic diets.

  4. Parent-of-origin growth effects and the evolution of hybrid inviability in dwarf hamsters.

    PubMed

    Brekke, Thomas D; Good, Jeffrey M

    2014-11-01

    Mammalian hybrids often show abnormal growth, indicating that developmental inviability may play an important role in mammalian speciation. Yet, it is unclear if this recurrent phenotype reflects a common genetic basis. Here, we describe extreme parent-of-origin-dependent growth in hybrids from crosses between two species of dwarf hamsters, Phodopus campbelli and Phodopus sungorus. One cross type resulted in massive placental and embryonic overgrowth, severe developmental defects, and maternal death. Embryos from the reciprocal cross were viable and normal sized, but adult hybrid males were relatively small. These effects are strikingly similar to patterns from several other mammalian hybrids. Using comparative sequence data from dwarf hamsters and several other hybridizing mammals, we argue that extreme hybrid growth can contribute to reproductive isolation during the early stages of species divergence. Next, we tested if abnormal growth in hybrid hamsters was associated with disrupted genomic imprinting. We found no association between imprinting status at several candidate genes and hybrid growth, though two interacting genes involved in embryonic growth did show reduced expression in overgrown hybrids. Collectively, our study indicates that growth-related hybrid inviability may play an important role in mammalian speciation but that the genetic underpinnings of these phenotypes remain unresolved.

  5. Structure of the dihydrofolate reductase gene in Chinese hamster ovary cells.

    PubMed

    Carothers, A M; Urlaub, G; Ellis, N; Chasin, L A

    1983-04-11

    Overlapping recombinant lambda 1059 phages carrying regions of the dhfr locus from the amplified Chinese hamster ovary (CHO) cell clone MK42 have been isolated. In addition, dhfr cDNAs from this cell line have been cloned into plasmid pBR322. Restriction analysis of these recombinant molecules has led to a map of the Chinese hamster dhfr gene. This gene has a minimum size of 26 kb and contains six exons as defined by hybridization to a combination of mouse and CHO cDNA probes. The latter probes reveal 3' exonic sequences that are not present in mouse cDNA. The CHO dhfr gene thus extends about 700 bp further 3' than in the mouse, consistent with the larger size of the hamster mRNA. At least five intervening sequences are present, of approximate sizes: 0.3, 2.5, 8.6, 2.6 and 9.4 kb. Four sequences from highly repeated families are situated in introns within the dhfr gene. The overall structure of this gene is strikingly similar to that of the mouse. Evolutionary conservation of interrupted gene structure among mammals thus extends to genes that code for household enzymes as well as specialized or structural proteins.

  6. Vaccination with a cocktail of Ancylostoma ceylanicum recombinant antigens leads to worm burden reduction in hamsters.

    PubMed

    Wiśniewski, Marcin; Łapiński, Maciej; Daniłowicz-Luebert, Emilia; Jaros, Sławomir; Długosz, Ewa; Wędrychowicz, Halina

    2016-09-01

    Hookworms, a group to which Ancylostoma ceylanicum belongs, are gastrointestinal nematodes that infect more than 700 million people around the world. They are a leading cause of anemia in developing countries. In order to effectively prevent hookworm infections research is conducted to develop an effective vaccine using recombinant antigens of the parasite. The aim of this study was to examine the influence of the hosts' on protection against ancylostomiasis and the shaping of the humoral immune response among Syrian hamsters after immunization with a cocktail of five A. ceylanicum recombinant antigens. Ace-ASP-3, Ace-ASP-4, Ace-APR-1, Ace-MEP-6 and Ace-MEP-7 were obtained in the pET expression system. Immunization with a vaccine cocktail resulted in a 33.5% worm burden reduction. The immunogenicity of the recombinant proteins were determined using ELISA. Statistical analysis showed that vaccinated hamsters developed stronger humoral responses to four of five recombinant antigens (the exception being Ace-ASP-3) compared to hamsters from the control group.

  7. Intestinal absorption and histomorphometry of Syrian hamsters (Mesocricetus auratus) experimentally infected with Lawsonia intracellularis.

    PubMed

    Vannucci, Fabio Augusto; Borges, Elizabeth Lage; de Oliveira, Juliana Saes Vilaça; Guedes, Roberto Mauricio Carvalho

    2010-10-26

    The objective of this study was to evaluate the intestinal absorption and histomorphometry of hamsters experimentally infected with Lawsonia intracellularis and correlate these parameters with severity of infection based on immunohistochemistry. Sixty hamsters were equally divided into control and inoculated groups which were orally infected with intestinal mucosa homogenate from pigs naturally infected with L. intracellularis. The intestinal absorption of glucose, sodium, potassium and chloride was evaluated in live animals (25 inoculated and 25 control) on day 26 after inoculation. In this procedure, a standard solution was infused into the cranial jejunum and collected at the terminal ileum. The experimental infection was confirmed by gross and histopathological examination and L. intracellularis antigen labeling by immunohistochemistry. Histomorphometry analysis demonstrated positive correlation between intestinal crypt depth and severity of infection based on immunohistochemistry. Infected animals had significantly lower intestinal absorption of glucose, potassium and chloride. These results indicate a lower intestinal absorption as an important mechanism of diarrhea in hamsters experimentally infected with L. intracellularis. Therefore, malabsorption should be considered as the main mechanism involved in the physiopathology of the diarrhea in L. intracellularis infected animals.

  8. Number of coronary ostia in Syrian hamsters (Mesocricetus auratus) with normal and anomalous coronary arteries.

    PubMed

    Durán, A C; Fernández, M C; Fernández, B; Fernández-Gallego, T; Arqué, J M; Sans-Coma, V

    2007-12-01

    Little attention is being paid to the presence of accessory coronary artery ostia in man and non-human mammals due to their limited clinical relevance. However, information about their frequency and the cardiac territories irrigated by the vessels arising from them is of interest to obtain an accurate survey of the establishment of the coronary artery system in each species. The aim here was to compare the incidence and significance of the accessory coronary ostia in Syrian hamsters with normal coronary arteries and several coronary anomalies characterized by the absence of a left coronary artery originating from the left aortic sinus. The hearts from 2829 hamsters were examined using a corrosion-cast technique, micro-dissection, histochemical techniques, and scanning electron microscopy. Overall, 148 specimens displayed accessory ostia. A limited number of them belonged to the conal artery which supplies the wall of the right ventricular outflow tract. The other accessory ostia led to the septal artery, a vessel which irrigates the most part of the interventricular septum. The incidence of accessory ostia in normal and anomalous coronary artery patterns was quite similar. This suggests that the morphogenetic deviations producing the coronary artery anomalies reported in this study do not alter the connections of the septal and conal arteries to the aorta. The present observations lead to the notion that in the Syrian hamster, the septal artery should be regarded as a third coronary artery.

  9. Puumala virus infection in Syrian hamsters (Mesocricetus auratus) resembling hantavirus infection in natural rodent hosts.

    PubMed

    Sanada, Takahiro; Kariwa, Hiroaki; Nagata, Noriyo; Tanikawa, Yoichi; Seto, Takahiro; Yoshimatsu, Kumiko; Arikawa, Jiro; Yoshii, Kentaro; Takashima, Ikuo

    2011-09-01

    The mechanism of hantavirus persistent infection in natural hosts is poorly understood due to a lack of laboratory animal models. Herein, we report that Syrian hamsters (Mesocricetus auratus) infected with Puumala virus (PUUV) at 4 weeks old show persistent infection without clinical symptoms for more than 2 months. IgG and IgM antibodies against the viral nucleocapsid protein and neutralizing antibody were first detectable at 14 days postinoculation (dpi) and maintained through 70 dpi. Viral RNA was first detected from 3 dpi in lungs and blood clots, and was detected in all tissues tested at 7 dpi. The viral RNA persisted for at least 70 days in the lungs, kidney, spleen, heart, and brain. The highest level of RNA copies was observed at 14 dpi in the lungs. Slight inflammatory reactions were observed in the lungs, adrenal glands, and brain. Immunohistochemical analysis revealed that PUUV antigen persisted until 56 dpi in the kidneys and adrenal glands. Infected hamsters showed no body weight loss or clinical signs. These results indicate that PUUV infection in hamsters is quite similar to the hantavirus infection of natural host rodents.

  10. Diet self-selection and food hoarding after food deprivation by Siberian hamsters.

    PubMed

    Day, D E; Mintz, E M; Bartness, T J

    Siberian hamsters (Phodopus sungorus) increase food hoarding, but not food intake, after a fast. Because the physiological mechanisms underlying these changes in food hoarding are virtually unknown, we sought insight into these mechanisms by allowing hamsters to self-select their diet from food sources varying in macronutrient composition and caloric density ("dietary wisdom"). Therefore, the effects of food deprivation length on diet self-selection were tested in adult female hamsters after adaptation to three composite diets: sunflower seeds (SS), pellet chow (PC), and rabbit chow (RC). One group initially was fasted for 32 h, the other for 56 h, and then each was refed. The remaining nonexperienced fast was instated after prefast body mass, food intake, and hoarding were recovered. Food hoarding, but not food intake, was increased regardless of fast length or sequence; moreover, the largest increase in food hoarding was on the first day of refeeding and was primarily reflected as increased SS hoarding. When the longer fast occurred first body mass loss was greater and the increased food hoard size was maintained for more days than when the longer fast came second. The order of food intake and hoarding preferences was not changed after a fast (SS > PC > RC), but the degree of food hoarding preference for SS was exaggerated. Collectively, these results support the notion that food hoarding increases with decreases in lipid stores, and show that when internal lipid stores are decreased, external lipid stores are preferentially increased.

  11. Food hoarding is increased by pregnancy, lactation, and food deprivation in Siberian hamsters.

    PubMed

    Bartness, T J

    1997-01-01

    Food hoarding by male Siberian hamsters (Phodopus sungorus sungorus) is increased only when body mass (fat) is decreased. Pregnancy and lactation result in marked decreases in lipid reserves (approximately 50%) in female Siberian hamsters. Therefore, the present experiments addressed the following questions: 1) Is food hoarding increased after food deprivation in female Siberian hamsters? and 2) How do food hoarding and food intake change during pregnancy, lactation, and their combination? During measurements in a simulated burrow system food hoarding increased after a 32-h fast (approximately 2- to 3-fold) to a level similar to that seen previously in males and was markedly increased during pregnancy (approximately 12- to 18-fold, lactation, and concurrent pregnancy and lactation (approximately 10- to 25-fold for each of the latter 2 conditions). Postfast food intake was not different from prefast baseline measures. Food intake was increased only during the last few days of pregnancy and was elevated throughout lactation. These impressive increases in the level of food hoarding during pregnancy, lactation and their combination suggest that food hoarding may play an important role in supplying easily accessible energy to subserve these reproductive conditions.

  12. 7 alpha-methyl-19-nortestosterone facilitates sexual behavior in the male Syrian hamster.

    PubMed

    Wood, R I; Bean, A R; Sundaram, K; Kumar, N; Bardin, C W

    1996-06-01

    Steroid hormones from the testes promote attraction to estrous females and facilitate copulation in the male Syrian hamster. We compared the ability of testosterone (T) and MENT, a potent synthetic androgen that does not undergo 5 alpha-reduction, to maintain sexual behavior in castrated males. Steroid treatment was initiated immediately after castration at three levels by means of Alzet osmotic pumps in sexually experienced adult male hamsters. Daily doses were 5, 25, or 100 micrograms T and 1, 5, or 25 micrograms MENT (n = 5/group). Additional castrated males (n = 5) remained untreated. Sexual behavior was recorded during two 10-min tests before, and at 2, 4, 6, and 8 weeks after orchidectomy. MENT and T maintained equivalent levels of behavior at each corresponding dose of androgen (high, medium, or low). The low dose of T or MENT failed to sustain mating behavior. Eight weeks after castration, males receiving the high and medium doses of androgens continued to express intromissions and ejaculations at gonadally intact levels. However, only males receiving the high dose showed anogenital investigation at the same level as intact males. From these data, we conclude that MENT sustains mating behavior in the male hamster, and that chemoinvestigatory behavior requires higher levels of androgens than those necessary for copulation.

  13. Effects of binary taste stimuli on the neural activity of the hamster chorda tympani

    PubMed Central

    1980-01-01

    Binary mixtures of taste stimuli were applied to the tongue of the hamster and the reaction of the whole corda tympani was recorded. Some of the chemicals that were paired in mixtures (HCl, NH4Cl, NaCl, CaCl2, sucrose, and D-phenylalanine) have similar tastes to human and/or hamster, and/or common stimulatory effects on individual fibers of the hamster chorda tympani; other pairs of these chemicals have dissimilar tastes and/or distinct neural stimulatory effects. The molarity of each chemical with approximately the same effect on the activity of the nerve as 0.01 M NaCl was selected, and an established relation between stimulus concentration and response allowed estimation of the effect of a "mixture" of two concentrations of one chemical. Each mixture elicited a response that was smaller than the sum of the responses to its components. However, responses to some mixtures approached this sum, and responses to other mixtures closely approached the response to a "mixture" of two concentrations of one chemical. Responses of the former variety were generated by mixtures of an electrolyte and a nonelectrolyte and the latter by mixtures of two electrolytes or two nonelectrolytes. But, beyond the distinction between electrolytes and nonelectrolytes, the whole-nerve response to a mixture could not be predicted from the known neural or psychophysical effects of its components. PMID:7411114

  14. Sunitinib Improves Some Clinical Aspects and Reverts DMBA-Induced Hyperplasic Lesions in Hamster Buccal Pouch

    PubMed Central

    de Souza, Fernanda Lopes; Oliveira, Mariana; Nunes, Marianne Brochado; Serafim, Lucas Horstmann; Azambuja, Alan Arrieira; Braga, Luisa Maria G. de M.; Saur, Lisiani; de Souza, Maria Antonieta Lopes; Xavier, Léder Leal

    2014-01-01

    Oral squamous cell carcinoma (OSCC) is a public health problem. The hamster buccal pouch model is ideal for analyzing the development of OSCC. This research analysed the effects of sunitinib (tyrosine kinase inhibitor) in precancerous lesions induced by 7,12-dimethylbenz(a)anthracene (DMBA) in this model. Thirty-four male hamsters, divided into six groups: control—C (n = 7), acetone—A (n = 12), carbamide peroxide—CP (n = 5 ), acetone and CP—A+CP (n = 8), 1% DMBA in acetone and CP—DA+CP (n = 6), and 1% DMBA in acetone and CP and 4-week treatment with sunitinib—DA+CP+S (n = 7). The aspects evaluated were anatomopathological features (peribuccal area, paws, nose, and fur), histological sections of the hamster buccal pouches (qualitatively analyzed), epithelium thickness, and the rete ridge density (estimated). Sunitinib was unable to attenuate the decrease in weight gain induced by DMBA; no increase in volume was detected in the pouch and/or ulceration, observed in 43% of the animals in the DA+CP group. DA+CP groups presented a significant increase in rete ridge density compared to the control groups (P < 0.01) which was reverted by sunitinib in the DA+CP+S group. Sunitinib seems to have important benefits in early stage carcinogenesis and may be useful in chemoprevention. PMID:24693453

  15. γ-Aminobutyric acid suppresses enhancement of hamster sperm hyperactivation by 5-hydroxytryptamine

    PubMed Central

    FUJINOKI, Masakatsu; TAKEI, Gen L.

    2016-01-01

    Sperm hyperactivation is regulated by hormones present in the oviduct. In hamsters, 5-hydroxytryptamine (5HT) enhances hyperactivation associated with the 5HT2 receptor and 5HT4 receptor, while 17β-estradiol (E2) and γ-aminobutyric acid (GABA) suppress the association of the estrogen receptor and GABAA receptor, respectively. In the present study, we examined the regulatory interactions among 5HT, GABA, and E2 in the regulation of hamster sperm hyperactivation. When sperm were exposed to E2 prior to 5HT exposure, E2 did not affect 5HT-enhanced hyperactivation. In contrast, GABA partially suppressed 5HT-enhanced hyperactivation when sperm were exposed to GABA prior to 5HT. GABA suppressed 5HT-enhanced hyperactivation associated with the 5HT2 receptor although it did not suppress 5HT-enhanced hyperactivation associated with the 5HT4 receptor. These results demonstrate that hamster sperm hyperactivation is regulated by an interaction between the 5HT2 receptor-mediated action of 5HT and GABA. PMID:27773888

  16. Immunization of hamsters against Clostridium difficile infection using the Cwp84 protease as an antigen.

    PubMed

    Péchiné, Séverine; Denève, Cécile; Le Monnier, Alban; Hoys, Sandra; Janoir, Claire; Collignon, Anne

    2011-10-01

    Clostridium difficile is a pathogen responsible for diarrhoea and colitis, particularly after antibiotic treatment. We evaluated the C. difficile protease Cwp84, found to be associated with the S-layer proteins, as a vaccine antigen to limit the C. difficile intestinal colonization and therefore the development of the infection in a clindamycin-treated hamster model. First, we evaluated the immune response and the animal protection against death induced by several immunization routes: rectal, intragastric and subcutaneous. Antibody production was variable according to the immunization routes. In addition, serum Cwp84 antibody titres did not always correlate with animal protection after challenge with a toxigenic C. difficile strain. The best survival rate was observed with the rectal route of immunization. Then, in a second assay, we selected this immunization route to perform a larger immunization assay including a Cwp84 immunized group and a control group. Clostridium difficile intestinal colonization and survival rate, as well as the immune response were examined. Clostridium difficile hamster challenge resulted in a 26% weaker and slower C. difficile intestinal colonization in the immunized group. Furthermore, hamster survival in the Cwp84 immunized group was 33% greater than that of the control group, with a significant statistical difference.

  17. Melatonin treatment counteracts the hyperthermic effect of lipopolysaccharide injection in the Syrian hamster.

    PubMed

    Bruno, Verónica A; Scacchi, Pablo A; Perez-Lloret, Santiago; Esquifino, Ana I; Cardinali, Daniel P; Cutrera, Rodolfo A

    2005-12-09

    The present study examined the acute response in body temperature to lipopolysaccharide (LPS) injection to Syrian hamsters at two time intervals during the light-dark cycle. Its modification by melatonin (MT) administration in the drinking water was also assessed. Hamsters were intraperitoneally (i.p.) implanted with a transmitter to measure core body temperature. MT was administered from day 8 post-surgery until the end of experiment. On day 16 after surgery, LPS or saline was injected i.p. at the beginning of the light phase (ZT 0) or of the scotophase (ZT 14). At ZT 0, LPS increased core body temperature, an effect that persisted for at least 5h and that was blunted by MT administration. At ZT 14, the hyperthermic effect of LPS was absent. Rather, at ZT 14 the animals showed increases in core body temperature following saline or LPS during the first 2h after injection only, which were significantly less intense in LPS-treated animals. MT administration blunted this difference. Five days after injection, hamsters that had received LPS at ZT 0 showed an increase in the mesor of core body temperature rhythm as compared to saline. This effect was suppressed by MT administration. The results demonstrate that MT prevents body temperature increase after LPS at ZT 0.

  18. Presence of SNAP-23 and syntaxin 4 in mouse and hamster peritoneal mast cells.

    PubMed

    Salinas, Eva; Rodríguez, Gonzalo; Quintanar, J Luis

    2007-01-01

    Mast cells (MCs) play a crucial role in inflammatory reactions. Their presence and number in the peritoneal cavity is important to overcome and enhance resistance to peritoneal infection. When MCs are activated they release a variety of biological mediators from their granules, such as histamine, that contribute to the appropriate and rapid local immune response. Granular content is released using a process of compound exocytosis, also termed degranulation. SNAP-23 and syntaxin 4 are plasma membrane proteins involved in degranulation of rat MCs. Their presence, however, has not been studied in MCs of other rodent species. The aim of the present study was to investigate using immunocytochemistry whether SNAP-23 and syntaxin 4 are present in peritoneal MCs of the mouse and hamster. In addition, the diameter, percentage and histamine content of these cells were also analyzed. Our results demonstrate that SNAP-23 and syntaxin 4 are present in the mouse and hamster peritoneal MCs, suggesting that proteins involved in the secretory process in MCs are conserved among species. Likewise, we conclude that peritoneal MCs of mouse and hamster are heterogeneous in size, percentage and histamine content.

  19. Circadian variations of prostaglandin E2 and F2 alpha release in the golden hamster retina.

    PubMed

    de Zavalía, Nuria; Fernandez, Diego C; Sande, Pablo H; Keller Sarmiento, María I; Golombek, Diego A; Rosenstein, Ruth E; Silberman, Dafne M

    2010-02-01

    Circadian variations of prostaglandin E2 and F2alpha release were examined in the golden hamster retina. Both parameters showed significant diurnal variations with maximal values at midnight. When hamsters were placed under constant darkness for 48 h, the differences in prostaglandin release between subjective mid-day and subjective midnight persisted. Western blot analysis showed that cyclooxygenase (COX)-1 levels were significantly higher at midnight than at mid-day, and at subjective midnight than at subjective mid-day, whereas no changes in COX-2 levels were observed among these time points. Immunohistochemical studies indicated the presence of COX-1 and COX-2 in the inner (but not outer) retina. Circadian variations of retinal prostaglandin release were also assessed in suprachiasmatic nuclei (SCN)-lesioned animals. Significant differences in retinal prostaglandin release between subjective mid-day and subjective midnight were observed in SCN-lesioned animals. These results indicate that hamster retinal prostaglandin release is regulated by a retinal circadian clock independent from the SCN. Thus, the present results suggest that the prostaglandin/COX-1 system could be a retinal clock output or part of the retinal clock mechanism.

  20. Photoperiodic changes in opiate binding and their functional implications in golden hamsters.

    PubMed

    Tubbiola, M L; Nock, B; Bittman, E L

    1989-11-27

    Daylength modulates gonadotropin secretion, gonadal steroid hormone feedback, sexual behavior and body weight in male golden hamsters. Endogenous opiates regulate each of these phenomena, and the ability of opiate receptor blockade to elevate serum LH secretion is photoperiod-dependent. We used in vitro autoradiography to localize and quantify effects of daylength in golden hamsters. Hamsters were exposed to stimulatory (14 h light: 10 h dark) or inhibitory (10 h light: 14 h dark) photoperiods for 10 weeks before specific [3H]naloxone binding was assessed. Short days significantly decreased binding in medial amygdala and the intercalated amygdaloid nucleus. This effect was reversed by superior cervical ganglionectomy. No significant effects of daylength were observed in other amygdaloid, hypothalamic or preoptic areas. Lesions of the medial amygdala decreased copulatory behavior, short day-induced weight loss, and anogenital chemoinvestigation but did not affect gonadal regression or other forms of chemoinvestigation. These lesions facilitated testosterone's negative feedback on luteinizing hormone in long days but did not interfere with the potentiation of negative feedback by short days.

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

    SciTech Connect

    Adachi, Shuichi; Takemoto, Kazuo ); Kimura, Kikuzi )

    1991-02-01

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

  2. Somatostatin Agonist Pasireotide Promotes a Physiological State Resembling Short-Day Acclimation in the Photoperiodic Male Siberian Hamster (Phodopus sungorus).

    PubMed

    Dumbell, R A; Scherbarth, F; Diedrich, V; Schmid, H A; Steinlechner, S; Barrett, P

    2015-07-01

    The timing of growth in seasonal mammals is inextricably linked to food availability. This is exemplified in the Siberian hamster (Phodopus sungorus), which uses the annual cycle of photoperiod to optimally programme energy expenditure in anticipation of seasonal fluctuations in food resources. During the autumn, energy expenditure is progressively minimised by physiological adaptations, including a 30% reduction in body mass, comprising a reduction in both fat and lean tissues. However, the mechanistic basis of this adaptation is still unexplained. We hypothesised that growth hormone (GH) was a likely candidate to underpin these reversible changes in body mass. Administration of pasireotide, a long-acting somatostatin receptor agonist developed for the treatment of acromegaly, to male hamsters under a long-day (LD) photoperiod produced a body weight loss. This comprised a reduction in lean and fat mass, including kidneys, testes and brown adipose tissue, typically found in short-day (SD) housed hamsters. Furthermore, when administered to hamsters switched from SD to LD, pasireotide retarded the body weight increase compared to vehicle-treated hamsters. Pasireotide did not alter photoperiod-mediated changes in hypothalamic energy balance gene expression but altered the expression of Srif mRNA expression in the periventricular nucleus and Ghrh mRNA expression in the arcuate nucleus consistent with a reduction in GH feedback and concurrent with reduced serum insulin-like growth factor-1. Conversely, GH treatment of SD hamsters increased body mass, which included increased mass of liver and kidneys. Together, these data indicate a role for the GH axis in the determination of seasonal body mass of the Siberian hamster.

  3. Testosterone induction of prostaglandin-endoperoxide synthase 2 expression and prostaglandin F(2alpha) production in hamster Leydig cells.

    PubMed

    Matzkin, María E; Gonzalez-Calvar, Silvia I; Mayerhofer, Artur; Calandra, Ricardo S; Frungieri, Mónica B

    2009-07-01

    We have previously observed expression of prostaglandin-endoperoxide synthase 2 (PTGS2), the key enzyme in the biosynthesis of prostaglandins (PGs), in reproductively active Syrian hamster Leydig cells, and reported an inhibitory role of PGF(2alpha) on hamster testicular steroidogenesis. In this study, we further investigated PTGS2 expression in hamster Leydig cells during sexual development and photoperiodic gonadal regression. Since PTGS2 is mostly expressed in pubertal and reproductively active adult hamsters with high circulating levels of LH and androgens, we studied the role of these hormones in the regulation/maintenance of testicular PTGS2/PGF(2alpha). In active hamster Leydig cells, LH/hCG and testosterone induced PTGS2 and PGF(2alpha) production, and their actions were abolished by the antiandrogen bicalutamide (Bi). These results indicate that LH does not exert a direct effect on PG synthesis. Testosterone also stimulated phosphorylation of the mitogen-activated protein kinase isoforms 3/1 (MAPK3/1) within minutes and hours, but the testosterone metabolite dihydrotestosterone had no effect on PTGS2 and MAPK3/1. Because Bi and U0126, an inhibitor of the MAP kinase kinases 1 and 2 (MAP2K1/2), abolished testosterone actions on MAPK3/1 and PTGS2, our studies suggest that testosterone directly induces PTGS2/PGF(2alpha) in hamster Leydig cells via androgen receptors and a non-classical mechanism that involves MAPK3/1 activation. Since PGF(2alpha) inhibits testosterone production, it might imply the existence of a regulatory loop that is setting a brake on steroidogenesis. Thus, the androgen environment might be crucial for the regulation of testicular PG production at least during sexual development and photoperiodic variations in hamsters.

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

    PubMed

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

    2012-11-01

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

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

    PubMed

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

    2015-11-13

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

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

    PubMed Central

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

    2011-01-01

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

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

    PubMed

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

    2011-07-01

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

  8. 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.

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

    PubMed

    Frye, Cheryl A; Rhodes, Madeline E

    2005-03-15

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

  10. Cutaneous Leishmaniasis in the Dorsal Skin of Hamsters: a Useful Model for the Screening of Antileishmanial Drugs

    PubMed Central

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

    2012-01-01

    Traditionally, hamsters are experimentally inoculated in the snout or the footpad. However in these sites an ulcer not always occurs, measurement of lesion size is a hard procedure and animals show difficulty to eat, breathe and move because of the lesion. In order to optimize the hamster model for cutaneous leishmaniasis, young adult male and female golden hamsters (Mesocricetus auratus) were injected intradermally at the dorsal skin with 1 to 1.5 x l07 promastigotes of Leishmania species and progression of subsequent lesions were evaluated for up to 16 weeks post infection. The golden hamster was selected because it is considered the adequate bio-model to evaluate drugs against Leishmania as they are susceptible to infection by different species. Cutaneous infection of hamsters results in chronic but controlled lesions, and a clinical evolution with signs similar to those observed in humans. Therefore, the establishment of the extent of infection by measuring the size of the lesion according to the area of indurations and ulcers is feasible. This approach has proven its versatility and easy management during inoculation, follow up and characterization of typical lesions (ulcers), application of treatments through different ways and obtaining of clinical samples after different treatments. By using this method the quality of animal life regarding locomotion, search for food and water, play and social activities is also preserved. PMID:22546739

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

    PubMed

    Beaulieu, A; Reebs, S G

    2009-01-01

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

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

    PubMed

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

    1999-10-01

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

  13. Effects of microwave exposure on the hamster immune system. III. Macrophage resistance to vesicular stomatitis virus infection

    SciTech Connect

    Rao, G.R.; Cain, C.A.; Tompkins, W.A.

    1984-01-01

    Exposure of hamsters to microwave (MW) energy (2.45 GHz, 25 mW/cm2, 1 h) resulted in activation of peritoneal macrophages (PM) to a viricidal state restricting the replication of vesicular stomatitis virus (VSV). The PM from MW-exposed hamsters were viricidal as early as 1 day after exposure and remained active for 5 days. Immunization of hamsters with vaccinia virus induced viricidal PM by 3 to 4 days and they remained active for 7 days. To test the hypothesis that thermogenic MW exposure results in the release of endotoxin across the intestinal epithelium which subsequently activates PM, hamsters were injected with lipopolysaccharide (LPS) and their viricidal activity was studied. Lipopolysaccharide in vitro (0.2 microgram) and in vivo (0.5 microgram) activated macrophages to a viricidal state. When administered in vivo, LPS (0.5 microgram) activated macrophages as early as 1 day and the activity remained for 3 days. While MW exposure of PM in vitro failed to induce viricidal activity, exposure of PM to LPS in vitro induced strong viricidal activity. This suggests that the in vivo response of PM to MW is an indirect one, which is consistent with the hypothesis that MW-induced PM viricidal activity may be mediated via LPS. In preliminary experiments, MW exposure resulted in extended survival time for hamsters challenged with a lethal dose of vesicular stomatitis virus, supporting the concept that MW-activated PM may be a useful therapeutic modality.

  14. Zaprinast, a phosphodiesterase 5 inhibitor, overcomes sexual dysfunction produced by fluoxetine, a selective serotonin reuptake inhibitor in hamsters.

    PubMed

    Frye, Cheryl A; Rhodes, Madeline E

    2003-02-01

    A high incidence of sexual dysfunction among women is reported in the clinical literature. Little experimental investigation has been initiated on the ability of phosphodiesterase (PDE) inhibitors to overcome deficits in sexual functioning because of selective serotonin reuptake inhibitors (SSRIs). The effects of fluoxetine, an SSRI, and zaprinast, a PDE-5 inhibitor, on the lateral displacement response (used as a measure of sensitivity to reproductively relevant stimuli) of hamsters in behavioral estrus were investigated. In Experiment 1, hamsters that were maximally sensitive to reproductively relevant stimuli because they were at the peak of behavioral estrus were administered fluoxetine (10 mg/kg, i.p.); they had significantly decreased lateral displacement responses compared to vehicle-administered hamsters. In Experiment 2, hamsters that were relatively less sensitive to sexual stimuli because they were at the termination of behavioral estrus were administered zaprinast (3 mg/kg; i.p.); they had significantly enhanced lateral displacement responses compared to responses seen following vehicle administration. In Experiment 3, fluoxetine-induced deficits in the lateral displacement of hamsters at the peak of behavioral estrus were overcome by the coadministration of zaprinast. These data confirm previous findings that sexual dysfunction can be induced by SSRIs and extend the current knowledge to suggest that administration of a PDE-5 inhibitor can override SSRI-induced deficits in sexual functioning.

  15. Detection of Schistosoma mansoni infection by TaqMan® Real-Time PCR in a hamster model.

    PubMed

    Espírito-Santo, Maria Cristina Carvalho; Alvarado-Mora, Mónica Viviana; Pinto, Pedro Luiz Silva; de Brito, Thales; Botelho-Lima, Lívia; Heath, Ashley Richard; Amorim, Maria Galli; Dias-Neto, Emmanuel; Chieffi, Pedro Paulo; Pinho, João Renato Rebello; Carrilho, Flair José; Luna, Expedito José Albuquerque; Gryschek, Ronaldo Cesar Borges

    2014-08-01

    An experimental study in hamsters was performed to evaluate the capability for detecting Schistosoma mansoni DNA in serum and fecal samples during the pre and post-egg-laying periods of infection using TaqMan® Real-Time PCR system (qPCR), was compared with the circumoval precipitin test (COPT) and the Kato-Katz technique, especially among individuals with low parasitic burden. Twenty-four hamsters were infected with cercariae. Three hamsters were sacrificed per week under anesthesia, from 7 days post infection (DPI) up to 56 DPI. A serum sample and a pool of feces were collected from each hamster. The presence of S. mansoni eggs in fecal samples was evaluated by Kato-Katz method and in the hamsters gutby histopathology. Detection of S. mansoni DNA was performed using qPCR and S. mansoni antibody using COPT. The first detection of eggs in feces by Kato-Katz method and S. mansoni DNA in feces by qPCR occurred 49 DPI. Nevertheless, S. mansoni DNA was detected in serum samples from 14 up to 56 DPI. COPT was positive at 35 DPI. The results not only confirm the reliability of S. mansoni DNA detection by qPCR, but also demonstrate that serum is a trustworthy source of DNA in the pre patent infection period.

  16. Male golden hamster in male reproductive toxicology testing: Assessment of protective activity of selenium in acute cadmium intoxication

    SciTech Connect

    Wiodarczyk, B.; Biernacki, B.; Minta, M.; Juszkiewicz, T.; Kozaczynski, W.

    1995-06-01

    The golden hamster has a short history as a laboratory animal. In spite of this, it has been extensively used as a subject for biomedical research. The hamster has also been utilized in toxicological evaluations, especially in teratology studies. Results of these investigations reveal that laboratory hamsters are very sensitive to many chemical compounds, including: drugs, food additives, industrial chemicals, heavy metals, and other environmental contaminants. The animals most frequently used in toxicological investigations are rats and mice. This is also true in male reproductive toxicology. Apparent differences in species sensitivity to chemical compounds suggest a need to examine a new species in this field of toxicology. A good example of chemical specific differences in species sensitivity is the testicular toxicity of 1,2-dibromo-3-chloropropane (DBCP), which was a testicular toxicant in humans and in rats, but it was not effective, even at relatively high dose levels, in the mouse. From our own vast experience in using hamsters in toxicological studies, we decided to use this laboratory animal in male reproductive toxicology screening tests. The purpose of this study was to determine the suitability of golden hamsters as an experimental animal species for male reproductive toxicology testing. To this effect we have chosen selenium and cadmium as test agents as they were well known for their spectacular effect on the male reproductive system. 13 refs., 1 tab.

  17. 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