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Sample records for gold hamster mesocricetus

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

    SciTech Connect

    Dolan, Cheryl E.

    2004-08-30

    The research described in this dissertation consists of four major areas: (1) sequence analysis of protamine 2 from Muroid rodents to identify potential zinc-binding domain(s) of protamine 2; (2) structural studies of the protamine 2-zinc complex from Syrian Gold hamster sperm and spermatids to elucidate the role of zinc during spermiogenesis; (3) structural studies of an unique protamine 2-zinc complex from chinchilla sperm; and (4) Nuclear Magnetic Resonance (NMR) studies of soluble complexes of hairpin oligonucleotides with synthetic arginine-rich peptides or protamine 1 isolated from bull sperm. First, zinc was quantitated in spermatids and sperm by Proton-Induced X-ray Emission (PIXE) to determine whether zinc is present in the early stages of spermiogenesis. The PIXE results revealed the zinc content varies proportionately with the amount of protamine 2 in both spermatid and sperm nuclei. An exception was chinchilla sperm containing twice the amount of protamine 2 than zinc. Further analyses by PIXE and X-ray Absorption Spectroscopy (XAS) of zinc bound to protamines isolated from hamster sperm confirmed the majority of the zinc is bound to protamine and identified the zinc ligands of protamine 2 in hamster spermatids and sperm in vivo. These studies established that zinc is bound to the protamine 2 precursor in hamster spermatids and the coordination of zinc by protamine 2 changes during spermiogenesis. Finally, the sequence analysis combined with the XAS results suggest that the zinc-binding domain in protamine 2 resides in the amino-terminus. Similar analyses of chinchilla sperm by XAS were performed to clarify the unusual PIXE results and revealed that chinchilla has an atypical protamine 2-zinc structure. Two protamine 2 molecules coordinate one zinc atom, forming homodimers that facilitate the binding of protamine 2 to DNA and provide an organizational scheme that would accommodate the observed species-specific protamine stoichiometry in mammalian sperm

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

    PubMed

    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.

  3. 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.

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

    SciTech Connect

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

    1987-02-01

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

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

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

    PubMed Central

    Nelson, D E; Takahashi, J S

    1991-01-01

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

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

    PubMed

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

    2016-03-01

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

  20. Photoperiodic regulation of melatonin membrane receptor (MT1R) expression and steroidogenesis in testis of adult golden hamster, Mesocricetus auratus.

    PubMed

    Mukherjee, Arun; Haldar, Chandana

    2014-11-01

    Photoperiodic modulation of melatonin membrane receptor (MT1R) expression in testis has never been reported for any seasonal breeder. Thus, the aim of the present study was to investigate the expression dynamics of MT1R in testis and its interaction with testicular steroidogenesis in a long-day breeder, Mesocricetus auratus. Hamsters were exposed to different photoperiodic conditions i.e. critical- (CP; 12.5L:11.5D); short-day- (SD; 8L:16D) and long-day- (LD; 16L:8D) for 10 weeks wherein testicular steroidogenesis, local melatonin synthesis and the expression of MT1R were analyzed. SD induced melatonin suppressed testicular steroidogenesis as evident from regressed testicular histoarchitecture, decreased expression of AR, StAR, LH-R, P₄₅₀SCC and enzyme activities of 3β- and 17β-HSD. Differential photoperiodic regulation of MT1R expression in testis suggests its involvement in photoperiodic signal transduction for seasonal adjustment of reproduction. Increased S-NAT (Serotonin N-acetyl transferase) activity and local testicular melatonin under SD condition suggest an inhibitory effect of the local melatonergic system on testicular steroidogenesis. Completely opposite responses were recorded for all the parameters analyzed when hamsters were exposed to CP or LD conditions. In conclusion, we may suggest that photoperiod via regulating circulatory and local melatonin level as well as MT1R expression in testes fine tunes the steroidogenesis and thereby, the reproductive status of male golden hamster.

  1. [Diminution of antifungal activity of fluconazole associated with ibuprofen and piroxicam in experimental histoplasmosis of hamsters (Mesocricetus auratus)

    PubMed

    Finquelievich, Jorge Luis; Iovannitti, Cristina; Landaburu, Fernanda; Raffin, Gabriel; SanJuan, Norberto; Elías-Costa, Maria Rosa; Negroni, Ricardo

    2002-03-01

    The aim of this study was to determine if tha association of non-steroid antiinflammatory drugs (piroxicam and ibuprofen) with fluconazole, affects the antifungal activity of the azole compound, in an experimental model histoplasmosis in hamsters (Mesocricetus auratus). Sixty hamsters were intracardially inoculated with 4x10(6) yeasts of Histoplasma capsulatum var. capsulatum. Treatments began one week after the challenge and continued for three weeks. The hamsters were divided in six groups of ten animals each and received the following treatment: 1- fluconazole 8 mg/kg/day; 2- ibuprofen 20 mg/kg/day; 3- piroxicam 20 mg/kg/day; 4- fluconazole+ibuprofen; 5- fluconazole+piroxicam and 6- only received the solvent of these drugs. One week after ending the treatment, all the animals were sacrified and the evaluation of the treatments was based on the results of blood cultures, on the determination of colony forming units per gram of spleen, and the histopathologic studies of the same organ. The animals treated with fluconazole plus ibuprofen or piroxicam showed more colony colony forming units per gram (3.9x10(7) and 3.3x10(7)) when compared with the animals treated with fluconazole alone (0.9x10(7)). The histopathologic results of the hamsters that received fluconazole showed well-organized granulomas with few yeast-like elements inside the macrophages. In contrast, those which received fluconazole associated with antiinflammatory drugs presented lax granulomas containing numerous yeast-like elements. These findings let us to conclude that non-steroids antiinflammatory drugs diminish the antifungal efficacy of fluconazole in this animal model.

  2. Photoperiod and reproductive condition are associated with changes in RFamide-related peptide (RFRP) expression in Syrian hamsters (Mesocricetus auratus).

    PubMed

    Mason, Alex O; Duffy, Sean; Zhao, Sheng; Ubuka, Takayoshi; Bentley, George E; Tsutsui, Kazuyoshi; Silver, Rae; Kriegsfeld, Lance J

    2010-06-01

    To conserve scarce energetic resources during winter, seasonal breeders inhibit reproduction and other nonessential behavioral and physiological processes. Reproductive cessation is initiated in response to declining day lengths, a stimulus represented centrally as a long-duration melatonin signal. The melatonin signal is not decoded by the reproductive axis directly, but by an unidentified neurochemical system upstream of gonadotropin-releasing hormone (GnRH). The dorsomedial nucleus of the hypothalamus (DMH) has been implicated in seasonal changes in reproductive function in Syrian hamsters (Mesocricetus auratus), although the specific-cell phenotype decoding photoperiodic information remains unknown. RFamide-related peptide (RFRP; the mammalian homolog of the gonadotropin-inhibitory hormone (GnIH) gene identified in birds) has emerged as a potent inhibitory regulator of the reproductive axis and, significantly, its expression is localized to cell bodies of the DMH in rodents. In the present study, the authors explored the relationship between RFRP expression, photoperiod exposure, and reproductive condition/hormonal status. In male hamsters that respond to short days with reproductive inhibition, RFRP-ir and mRNA expression are markedly reduced relative to long-day animals. Replacement of testosterone in short-day animals did not affect this response, suggesting that alterations in RFRP expression are not a result of changing sex steroid concentrations. A subset of the hamster population that ignores day length cues and remains reproductively competent in short days (nonresponders) exhibits RFRP-ir expression comparable to long-day hamsters. Analysis of cell body and fiber density suggests a potential interplay between peptide production and release rate in differentially regulating the reproductive axis during early and late stages of reproductive regression. Together, the present findings indicate that photoperiod-induced suppression of reproduction is

  3. A new plateau in the dose-survival-time response of the golden hamster (Mesocricetus auratus) from whole body irradiation.

    PubMed

    Tsubouchi, S; Matsuzawa, T

    1981-07-01

    The survival time of golden hamsters (Mesocricetus auratus) after whole-body 60Co-gamma-irradiation in the range of 600 to 200 000 rad was investigated. The two plateaus of the dose-survival curve which correspond to bone marrow and gastrointestinal death are similar to those of other species such as mice, rats and mongolian gerbils. A new plateau occurring 40-57 hours after doses of 30 000 to 60 000 rad, where there is a little reduction in survival time, has been found. It is in addition to the well recognized central nevous system (CNS) syndrome. This plateau is observed only in golden hamsters, presumably because of their relatively high resistence to CNS syndrome. Experiments involved partial body irradiation of the animals indicate that the target is in the cephalic one-third of abdomen. The new segment may well indicate a new type of acute somatic radiation injury different from the well known bone marrow, gastrointestinal and CNS syndromes.

  4. Formation of cartilaginous foci in the central fibrous body of the heart in Syrian hamsters (Mesocricetus auratus).

    PubMed

    Durán, A C; López, D; Guerrero, A; Mendoza, A; Arqué, J M; Sans-Coma, V

    2004-09-01

    The formation of cartilage in the mammalian heart has been studied in the aortic and pulmonary valves. The chondrogenetic process that takes place in the cardiac skeleton is still unknown. The present study was designed to illustrate the ontogeny of cartilaginous foci occurring in the central fibrous body of the Syrian hamster (Mesocricetus auratus) heart. Hearts from 472 animals aged 0-708 days were examined using histological, histochemical and immunohistochemical techniques. Cartilage was present in the central fibrous body of 118 (25%) specimens. A further 104 hamsters were used for the detection of calcific deposits in the central fibrous body. Six (5.8%) showed calcified cartilage. The first sign related to chondrogenesis was the presence of small groups of cells embedded in a type II collagen-positive extracellular matrix. These cellular groups, which can appear as early as 2 days after birth, differentiate into hyaline cartilage or, less frequently, into fibrocartilage. The highest production of cartilaginous foci takes place between days 40 and 80. Thereafter, formation of new foci is uncommon. This indicates that appearance of cartilage in the central fibrous body of the heart is not a consequence of cardiac aging. The cartilaginous foci seem to act as pivots resisting mechanical tensions generated during the cardiac cycle. Deposition of calcium in the extracellular matrix of the foci can be regarded as a reinforcement of the cartilaginous tissue.

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

    PubMed

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

    2011-02-01

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

  6. Membrane phospholipid fatty acid composition regulates cardiac SERCA activity in a hibernator, the Syrian hamster (Mesocricetus auratus).

    PubMed

    Giroud, Sylvain; Frare, Carla; Strijkstra, Arjen; Boerema, Ate; Arnold, Walter; Ruf, Thomas

    2013-01-01

    Polyunsaturated fatty acids (PUFA) have strong effects on hibernation and daily torpor. Increased dietary uptake of PUFA of the n-6 class, particularly of Linoleic acid (LA, C18:2 n-6) lengthens torpor bout duration and enables animals to reach lower body temperatures (T(b)) and metabolic rates. As previously hypothesized, this well-known influence of PUFA may be mediated via effects of the membrane fatty acid composition on sarcoplasmic reticulum (SR) Ca(2+-)ATPase 2a (SERCA) in the heart of hibernators. We tested the hypotheses that high proportions of n-6 PUFA in general, or specifically high proportions of LA (C18:2 n-6) in SR phospholipids (PL) should be associated with increased cardiac SERCA activity, and should allow animals to reach lower minimum T(b) in torpor. We measured activity of SERCA from hearts of hibernating and non-hibernating Syrian hamsters (Mesocricetus auratus) in vitro at 35 °C. Further, we determined the PL fatty acid composition of the SR membrane of these hearts. We found that SERCA activity strongly increased as the proportion of LA in SR PL increased but was negatively affected by the content of Docosahexaenoic acid (DHA; C22:6 n-3). SR PL from hibernating hamsters were characterized by high proportions of LA and low proportions of DHA. As a result, SERCA activity was significantly higher during entrance into torpor and in torpor compared to inter-bout arousal. Also, animals with increased SERCA activity reached lower T(b) during torpor. Interestingly, a subgroup of hamsters which never entered torpor but remained euthermic throughout winter displayed a phenotype similar to animals in summer. This was characterized by lower proportions of LA and increased proportions of DHA in SR membranes, which is apparently incompatible with torpor. We conclude that the PUFA composition of SR membranes affects cardiac function via modulating SERCA activity, and hence determines the minimum T(b) tolerated by hibernators.

  7. 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.

  8. Changes in Testicular Interstitial Connective Tissue of Hamsters (Mesocricetus auratus) During Ageing and After Exposure to Short Photoperiod.

    PubMed

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

    2016-02-01

    The testicular interstitium of Syrian hamster (Mesocricetus auratus) was studied during ageing and in testicular regression after exposure to a short photoperiod, in relation to the interstitial cells and their connective tissue. This tissue was assessed histochemically using Masson's trichrome technique and the expression of Heat Shock Protein 47 (HSP-47) and collagen IV (α5) was assessed in Leydig cells. Finally, an ultrastructural analysis of some cells of the testicular interstitium was made. Leydig cells were positive for HSP-47 and collagen IV (α5). Ageing did not change the parameters studied while the short photoperiod altered the synthetic activity of Leydig cells. The positivity index of these cells for HSP-47 was significantly higher in the regressed testis, but was lower for collagen IV (α5). During ageing no change were observed. Ultrastructural Leydig cells showed a discontinuous basal lamina that did not change during ageing. The basal lamina was not identified in Leydig cells regressed by exposure to a short photoperiod. In conclusion; the intertubular connective tissue suffers little change with age. By contrast, in the testis regressed after exposure to a short photoperiod the studied parameters related to the intertubular connective tissue were altered. These changes are probably related with the low synthetic activity of regressed Leydig cell.

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

    PubMed

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

    2014-05-01

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

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

    PubMed Central

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

    2014-01-01

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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

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

    PubMed

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

    2016-01-01

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

  18. 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.

  19. 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.

  20. 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.

  1. Adolescent anabolic/androgenic steroids: Aggression and anxiety during exposure predict behavioral responding during withdrawal in Syrian hamsters (Mesocricetus auratus).

    PubMed

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

    2013-11-01

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

  2. 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.

  3. 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.

  4. Formation of cartilage in congenital bicuspid aortic valves of Syrian hamsters (mesocricetus auratus).

    PubMed

    Sans-Coma, V; López, D; Durán, A C; Guerrero, A; Fernández-Gallego, T; Fernández, M C; Arqué, J M

    2005-07-01

    The formation, topographical location and calcification of cartilage in congenital bicuspid aortic valves of 235 Syrian hamsters aged 0--173 days were studied by histological, histochemical and immunohistochemical techniques. In all animals the aortic valve was bicuspid; it had two leaflets, ventral and dorsal, each supported by its own aortic sinus. In 141 valves, a more or less developed raphe was located in the ventral sinus. The remaining 94 valves were devoid of any raphe. The first sign of valvular chondrogenesis was the presence of small groups of cells embedded in a type II collagen-positive extracellular matrix. These cellular groups, which appeared as early as 2 days after birth, became converted into hyaline cartilage or fibrocartilage. A considerable proportion (67%) of the valvular cartilages developed within the first 6 weeks of life. The cartilaginous tissue was capable of forming anywhere along the attachments of the valve leaflets to their supporting sinuses. However, statistical analyses substantiated the observation that the bases of the sinuses and raphes were the valvular regions particularly prone to the development of cartilage. At these sites, the cartilage was usually hyaline and often became calcified. The findings were consistent with the assumption that intense mechanical stimulation plays an important role in the formation of the valvular cartilage. Moreover, these findings supplied new evidence that in the cardiac semilunar valves of Syrian hamsters, cartilage formation does not involve the aggregation of large numbers of cells before their differentiation into chondrocytes. The valvular hyaline cartilages appear to act as competent pivots, resisting mechanical tensions generated during the cardiac cycle. Deposition of calcium in the matrix can be regarded as a reinforcement process of the cartilaginous tissue. Finally, it is hypothesized that the formation of cartilage in the aortic valves of hamsters prevents dystrophic calcification

  5. Quantification of fecal estradiol and progesterone metabolites in Syrian hamsters (Mesocricetus auratus).

    PubMed

    Chelini, M O M; Souza, N L; Rocha, A M; Felippe, E C G; Oliveira, C A

    2005-11-01

    Alternative methods to the utilization of laboratory animal blood and its by-products are particularly attractive, especially regarding hamsters due to their small size and difficulties in obtaining serial blood samples. Steroid hormone metabolite quantification in feces, widely used in studies of free-ranging or intractable animals, is a non-invasive, non-stressor, economical, and animal saving technique which allows longitudinal studies by permitting frequent sampling of the same individual. The present study was undertaken to determine the suitability of this method for laboratory animals. Estradiol and progesterone metabolites were quantified by radioimmunoassay in feces of intact, sexually mature female Syrian hamsters during the estrous cycle (control) and in feces of superovulated females. Metabolites were extracted by fecal dilution in ethanol and quantified by solid phase radioimmunoassay. Median estrogen and progesterone concentrations were 9.703 and 180.74 ng/g feces in the control group, respectively. Peaks of estrogen (22.44 +/- 4.54 ng/g feces) and progesterone (655.95 +/- 129.93 ng/g feces) mean fecal concentrations respectively occurred 12 h before and immediately after ovulation, which is easily detected in this species by observation of a characteristic vaginal postovulatory discharge. Median estrogen and progesterone concentrations (28.159 and 586.57 ng/g feces, respectively) were significantly higher in superovulated animal feces (P < 0.0001). The present study demonstrated that it is possible to monitor ovarian activity in Syrian hamsters non-invasively by measuring fecal estradiol and progesterone metabolites. This technique appears to be a quite encouraging method for the development of new endocrinologic studies on laboratory animals.

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

    PubMed Central

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

    2012-01-01

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

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

    PubMed

    Petrulis, Aras

    2009-06-25

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

  8. Reduced mate preference for dominant over subordinate males in old female Syrian hamsters (Mesocricetus auratus).

    PubMed

    Place, Ned J; Vernon, Dianne M; Johnston, Robert E

    2014-10-01

    Why some females choose to mate with a 'preferred' male, whereas others choose to mate with an 'inferior' male is not always clear. Generally, the choosiness of females is thought to decline with advanced age, but relatively few studies have investigated this concept, and reports of this phenomenon in mammals are lacking. To address this deficiency, young and old female golden hamsters were evaluated for their preference for dominant vs. subordinate males. Females observed male dyads as a dominance relationship was established. Dominant and subordinate males were then placed within enclosures at the opposite ends of a Y-maze, and the first approach, scent marking, and time spent near each male were evaluated in young and old females during pro-oestrus-a time when females solicit visits by prospective mates by leaving vaginal and flank scent marks. Whereas the proportion of time spent near the dominant male was significantly greater than random for both young and old females, the proportions of vaginal and flank scent marks left for the dominant male were significantly greater than random for young females, but not for old females. Overall, these results are consistent with a decline in the preference for dominant males by old female hamsters.

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

    PubMed

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

    2012-02-28

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

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

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

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

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

    PubMed Central

    Petrulis, Aras

    2008-01-01

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

  12. History-dependent changes in entrainment of the activity rhythm in the Syrian hamster (Mesocricetus auratus).

    PubMed

    Chiesa, Juan J; Anglès-Pujolràs, Montserrat; Díez-Noguera, Antoni; Cambras, Trinitat

    2006-02-01

    The authors have studied the activity rhythm of Syrian hamsters exposed to square LD cycles with a 22-h period (T22) with the aim of testing the effects of the previous history on the rhythmic pattern. To do so, sequential changes of different lighting environments were established, followed by the same LD condition. Also, the protocol included T22 cycles with varying lighting contrasts to test the extent to which a computational model predicts experimental outcomes. At the beginning of the experiment, exposure to T22 with 300 lux and dim red light occurring respectively at photophase and scotophase (LD300/dim red) mainly generated relative coordination. Subsequent transfer to cycles with approximately 0.1-lux dim light during the scotophase (LD300/0.1) promoted entrainment to T22. However, a further reduction in light intensity to 10 lux during the photophase (LD10/0.1) generated weak and unstable T22 rhythms. When, after that, animals were transferred again to the initial LD300/dim red cycles, the amplitude of the rhythm still remained very low, and the phases were very unstable. Exposure to constant darkness partially restored the activity rhythm, and when, afterwards, the animals were submitted again to LD300/dim red cycles, a robust T22 rhythm appeared. The results demonstrate history-dependent changes in the hamster circadian system because the locomotor activity pattern under the same T22 cycle can show relative coordination or unstable or robust entrainment depending on the prior lighting condition. This suggests that the circadian system responds to environmental stimuli depending on its previous history. Moreover, computer simulations allow the authors to predict entrainment under LD300/0.1 cycles and indicate that most of the patterns observed in the animals due to the light in the scotophase can be explained by different degrees of coupling among the oscillators of the circadian system.

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

    PubMed

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

    2015-06-01

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

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

    PubMed

    Roosa, Kristen A; Place, Ned J

    2015-12-01

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

  15. Happy hamsters? Enrichment induces positive judgement bias for mildly (but not truly) ambiguous cues to reward and punishment in Mesocricetus auratus.

    PubMed

    Bethell, Emily J; Koyama, Nicola F

    2015-07-01

    Recent developments in the study of animal cognition and emotion have resulted in the 'judgement bias' model of animal welfare. Judgement biases describe the way in which changes in affective state are characterized by changes in information processing. In humans, anxiety and depression are characterized by increased expectation of negative events and negative interpretation of ambiguous information. Positive wellbeing is associated with enhanced expectation of positive outcomes and more positive interpretation of ambiguous information. Mood-congruent judgement biases for ambiguous information have been demonstrated in a range of animal species, with large variation in the way tests are administered and in the robustness of analyses. We highlight and address some issues using a laboratory species not previously tested: the Syrian hamster (Mesocricetus auratus). Hamsters were tested using a spatial judgement go/no-go task in enriched and unenriched housing. We included a number of controls and additional behavioural tests and applied a robust analytical approach using linear mixed effects models. Hamsters approached the ambiguous cues significantly more often when enriched than unenriched. There was no effect of enrichment on responses to the middle cue. We discuss these findings in light of mechanisms underlying processing cues to reward, punishment and true ambiguity, and the implications for the welfare of laboratory hamsters.

  16. Syrian hamsters (Mesocricetus auratus) with simultaneous intestinal Giardia sp., Spironucleus sp., and trichomonad infections.

    PubMed

    Sheppard, Barbara J; Stockdale Walden, Heather D; Kondo, Hirotaka

    2013-11-01

    A commercial facility producing hamsters with a history of infection by dwarf tapeworm (Hymenolepis nana) submitted 15 animals for necropsy and postmortem parasitological and microscopic examination. No tapeworms were detected grossly or microscopically. Fecal examination including gastrointestinal mucosal smears demonstrated mixed intestinal bacteria and low numbers of Giardia sp. Histologic examination of small intestine demonstrated filling of the small intestinal crypts by large numbers of 7-9 µm × 3 µm, rod to crescent or teardrop-shaped flagellates consistent with Spironucleus sp. These organisms had two 1-µm, basophilic, oval nuclei and multiple superficial flagella-like structures. Much larger 10-15 µm × 8-10 µm, oval to pear-shaped organisms were also present in lower numbers and usually located with the crypts. These larger flagellates had multiple flagella and a basophilic rod-shaped nucleus. The larger flagellates included Giardia sp., which had an intimate interface with the surface of the mucosal epithelium, bilaterally symmetry, and binucleation. Lower numbers of trichomonads were also present and were distinguished by an undulating surface membrane and a single nucleus. The mucosa was hyperplastic and moderately inflamed. Although the tapeworm infection was resolved, diagnosis of multiple intestinal flagellates by fecal examination is complicated by the varying sensitivity and diagnostic accuracy of different types of fecal analysis for different flagellate types. Key differences in the morphology and location of the different types of flagellates as observed by histology of intestinal tissues provide important additional diagnostic information to distinguish trichomonads, Spironucleus sp., and Giardia sp.

  17. Role of progesterone in mediating stress-related litter deficits in the golden hamster (Mesocricetus auratus).

    PubMed

    Pratt, N C; Lisk, R D

    1991-05-01

    Primiparous females were mated to proven breeders and half received a subcutaneous implantation of a progesterone-filled silastic capsule on Day 3 which was removed on Day 14. The other half of the group received no treatment. Blood samples were taken from all individuals on Days 3, 7, 11 and 14. The females were paired for brief periods on Days 4, 5 and 6 with a conspecific matched for treatment group, age, weight and stage of pregnancy. Controls were exposed to a novel area instead of a conspecific. Within each of the pairs, one female was consistently dominant to the other. At parturition, all pups were counted, sexed and weighed. Among the untreated group, there were no significant differences between litter sizes or sex ratios (defined as percentage male) produced by control and dominant females. Subordinate females produced significantly smaller litters than control or dominant dams and significantly lower sex ratios than dominant dams. Subordinates produced fewer males than control or dominant dams, but there were no differences in the number of females produced. Among animals given progesterone implants, there were no significant reductions in litter size or sex ratio produced by subordinate dams compared with control or dominant dams. This study showed that female golden hamsters exposed to social subordination early in pregnancy produced smaller and more female-biased litters, and that these effects were accompanied by a significant reduction in circulating progesterone concentrations. When subordinate females were given supplementary doses of progesterone before exposure to stress, they did not show significant litter deficits.(ABSTRACT TRUNCATED AT 250 WORDS)

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

    SciTech Connect

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

    1985-11-01

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

  19. 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

  20. Corticotropin-releasing factor type II (CRF-sub-2) receptors in the bed nucleus of the stria terminalis modulate conditioned defeat in Syrian hamsters (Mesocricetus auratus).

    PubMed

    Cooper, Matthew A; Huhman, Kim L

    2005-08-01

    In Syrian hamsters (Mesocricetus auratus), social defeat produces a subsequent increase in submissive and defensive behavior and a loss of normal territorial aggression, which the authors have called conditioned defeat. In this study, the authors investigated the effect of blocking corticotropin-releasing factor (CRF) Type I and Type II receptors on conditioned defeat. Intracerebroventricular infusion of the CRF-sub-2 receptor antagonist antisauvagine-30 prior to testing significantly reduced conditioned defeat compared with vehicle controls, whereas the CRF-sub-1 receptor antagonist CP-154,526 had no effect. Also, infusion of antisauvagine-30 into the bed nucleus of the stria terminalis (BNST) 15 min, but not immediately, prior to testing reduced conditioned defeat in a dose-dependent manner. The authors' results provide evidence that CRF-sub-2 receptors in the BNST, but not CRF-sub-1 receptors, are an important component in the neural circuitry regulating conditioned defeat.

  1. Effect of 2-deoxy-D-glucose induced metabolic stress on testicular steroidogenesis and antioxidant status in golden hamster, Mesocricetus auratus: Role of photoperiod.

    PubMed

    Mukherjee, Arun; Haldar, Chandana

    2015-12-01

    The driving force underlying the evolution of reproductive seasonality is the marked seasonal fluctuation in energy availability. It is well established that photoperiod regulates testicular steroidogenesis through modulation of circulatory and local melatonin levels and MT1R expression in golden hamster. However, photoperiodic variation in energy availability and its impact on testicular steroidogenesis and antioxidant status has never been investigated for any seasonal breeder. Therefore, the aim of the present study is to elucidate the role of photoperiod in modulation of metabolic stress induced variation in steroidogenesis and antioxidant status in testes. We experimentally reduced energy availability via administration of 2-deoxy-d-glucose (2-DG), a synthetic glucose analog, in critical- (CP), long- (LD) and short-day (SD) exposed golden hamsters, Mesocricetus auratus and examined testicular steroidogenesis and antioxidant status. Administration of 2-DG decreased testicular steroidogenesis and antioxidant enzyme activity in CP and LD experienced hamsters as compared to CP- and LD-control groups. Moreover, a decrease in the plasma- and local-melatonin level and MT1R expression in testes with a simultaneous increase in plasma corticosterone level was noted following 2-DG administration in CP and LD exposed hamsters. In contrast, no significant effect of 2-DG administration was observed on the parameters investigated under SD condition. Therefore, it can be suggested that the reduction in energy availability under CP and LD condition suppressed testicular steroidogenesis and increased oxidative damage in testis whereas SD induced melatonin might have buffered the 2-DG induced suppression of testicular steroidogenesis and maintained testicular antioxidant status.

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

    PubMed

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

    2014-05-01

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

  3. Lectin histochemistry as a tool to identify apoptotic cells in the seminiferous epithelium of Syrian hamster (Mesocricetus auratus) subjected to short photoperiod.

    PubMed

    Seco-Rovira, V; Beltrán-Frutos, E; Ferrer, C; Sánchez-Huertas, M M; Madrid, J F; Saez, F J; Pastor, L M

    2013-12-01

    Lectins have been widely used to study the pattern of cellular glycoconjugates in numerous species. In the process of cellular apoptosis, it has been observed that changes occur in the membrane sugar sequences of these apoptotic cells. The aim of our work was to identify which lectins, out of an extensive battery of the same (PNA, SBA, HPA, LTA, Con-A, UEA-I, WGA, DBA, MAA, GNA, AAA, SNA), show affinity for germinal cells in apoptosis, at what stage of cell death they do so and in which germinal cell types they can be detected. For this, we studied testis sections during testicular regression in Syrian hamster (Mesocricetus auratus) subjected to short photoperiod. Several lectins showed an affinity for the glycoconjugate residues of germ cells in apoptosis: Gal β1,3-GalNAcα1, α-d-mannose, N-acetylgalactosamine and l-fucose. Furthermore, lectin specificity was observed for some specific germinal cells and in certain stages of apoptosis. It was also observed that one of these lectins (PNA) showed affinity for Sertoli cells undergoing apoptosis. Therefore, we conclude that the use of lectin histochemistry could be a very useful tool for studying apoptosis in the seminiferous epithelium because of the specificity shown towards germinal cells in pathological or experimentally induced epithelial depletion models.

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

    PubMed

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

    2014-10-13

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

  5. The effects of day length, hibernation, and ambient temperature on incisor dentin in the Turkish hamster (Mesocricetus brandti).

    PubMed

    Batavia, Mariska; Nguyen, George; Zucker, Irving

    2013-05-01

    Dentin is deposited on a circadian basis, and daily layers manifest as bands on the medial surfaces of rodent incisors. Hibernation alters dentin deposition, and a distinct hibernation mark has been described on incisor surfaces of several rodent species; the factors that influence the morphology of this mark are poorly understood. We tested the effects of day length, torpor expression, and ambient temperature on incisor surface morphology in Turkish hamsters housed in one of four conditions: long days (LDs) at 22 °C, short days (SDs) at 22 °C, SDs at 5 °C, and SDs at 13 °C. Body temperature was monitored continuously with implanted radio transmitters, and teeth examined postmortem. Teeth of SD hamsters had narrower, less distinct circadian increments than those of LD hamsters, but the width of ultradian increments was similar in both photoperiods. Hibernation at both 5 and 13 °C was associated in most specimens with very narrow, sharply defined dentin increments and increased tooth heterogeneity. Hamsters in SDs at 5 °C that did not hibernate lacked characteristic hibernation increments. At 5 °C, but not 13 °C, the number and cumulative width of hibernation increments were related to number and cumulative duration of periodic arousals. Our results suggest that incremental deposition of dentin in rodent incisors may be a useful trait for characterizing hibernation behavior in both evolutionary and historical contexts.

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

    PubMed

    Karakaş, A; Kaya, Aliye; Gündüz, B

    2010-12-01

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

  7. Anomalous origin of the left coronary artery from the right side of the aortic valve in Syrian hamsters (Mesocricetus auratus).

    PubMed

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

    2006-05-01

    This study describes the coronary artery distribution patterns associated with the anomalous origin of the left coronary artery from the right side of the aortic valve in Syrian hamsters. The hearts of 15 affected animals were examined by means of a corrosion-cast technique, histology and scanning electron microscopy. The hamsters belonged to a laboratory inbred colony with a high incidence of coronary artery anomalies and bicuspid aortic valves. The aortic valve was tricuspid in eight hamsters and bicuspid in the other seven. In all cases, the right coronary artery was normal, whereas the left main coronary artery trunk arose from the right aortic sinus or from the right side of the ventral aortic sinus when the aortic valve was bicuspid. In 12 specimens, the left main trunk crossed the infundibular septum and then divided into the left circumflex branch and the obtuse marginal branch. In another specimen, the course of the left main trunk was ventral to the right ventricular outflow tract; in the remaining two, it surrounded the aorta dorsally. In man, some of these distribution patterns may cause myocardial ischaemia and sudden death. The present findings prove that the origin of the left coronary artery from the right aortic sinus occurs in primitive mammals such as the Syrian hamster, suggesting that the defect may occur in other mammalian species. Its possible occurrence should be borne in mind in domestic animals, especially in those with signs of myocardial ischaemia after strenuous activity.

  8. Photoperiodic modulation of thyroid hormone receptor (TR-α), deiodinase-2 (Dio-2) and glucose transporters (GLUT 1 and GLUT 4) expression in testis of adult golden hamster, Mesocricetus auratus.

    PubMed

    Verma, Rakesh; Haldar, Chandana

    2016-12-01

    Phenomenon of seasonal reproduction is being regulated by changes in day length or photoperiod. The molecular mechanism underlying the event of photoperiodic regulation of testis and thyroid functions along with glucose uptake transporters has never been reported for golden hamster, M. auratus. The present study was performed to investigate the effect of photoperiod on the expression of key thyroid hormone receptor (TR-α), deiodinase-2 (Dio-2) and glucose uptake transporters (GLUT-1 & GLUT-4) in testicular germ cell and Leydig cells, and its correlation with the testicular androgen receptor (AR), germ cell proliferation factor (PCNA) and cell survival factor (Bcl-2) in testis of adult golden hamster, Mesocricetus auratus. Hamsters were exposed to different photoperiodic regimes i.e. critical photoperiod (CP), short day (SD) and long day (LD) for 10weeks. LD induces upregulation of thyroidal and gonadal activity as evident by active thyroid gland and testicular histoarchitecture, peripheral total thyroid (tT3, tT4) and testosterone hormone profiles when compared with SD exposed hamsters. Further, LD increased the expression of testicular TR-α, Dio-2, GLUT-1, GLUT-4 along with testicular AR and glucose content thereby enhancing germ cell proliferation and survival as reflected by increased PCNA and Bcl-2 expression when compared to SD exposed hamsters. Thus, it can be suggested that testicular thyroid hormone status is being regulated by photoperiod and is possibly involved in seasonal adaptation to reproductive phenomenon of golden hamster.

  9. Colocalization of serotonin and vesicular glutamate transporter 3-like immunoreactivity in the midbrain raphe of Syrian hamsters (Mesocricetus auratus).

    PubMed

    Mintz, Eric M; Scott, Tamara J

    2006-02-13

    Vesicular glutamate transporter 3 (VGLUT3) expression has been specifically localized to brain regions rich in serotonergic cells. It has been suggested that this transporter may contribute to the regulation of extracellular glutamate concentrations via a nonsynaptic mechanism. In this study, we examine the colocalization of vesicular glutamate transporter 3 immunoreactivity with serotonin immunoreactivity in the dorsal and median raphe nuclei of Syrian hamsters. Brain sections from adult hamsters were fluorescently labeled for serotonin-ir and VGLUT3-ir and examined using confocal microscopy. The results indicate that most serotonergic cells of the midbrain raphe also expressed vesicular glutamate transporter 3. In addition, nonserotonergic cells in these brain regions also show immunoreactivity for the transporter. These data confirm previous findings of vesicular glutamate transporter 3 expression in serotonergic and nonserotonergic neurons in rats. These findings suggest that the location of vesicular glutamate transporter 3 may be as much a function of neuroanatomical location as of the neurochemical identity of the expressing neurons.

  10. Immunosuppression-Induced Susceptibility of Inbred Hamsters (Mesocricetus auratus) to Lethal-Disease by Lymphocytic Choriomeningitis Virus Infection

    DTIC Science & Technology

    1987-01-01

    and in human , , Lassa fever virus infections [20]. The role of antibody in recovery from infections with viruses such as LCMV. Lassa . and Pichinde...is not clear. Certainly the appearance of antibodies measured by IFAT in the LCMV-infected hamster or in Lassa .-. - fever virus infections [17. 19...Lvmphocvtit choriomeninEzitis virus and other arenaviruses . Springer. Berlin Heidelber New York. pp 113-120 9. Gee SR. Chan MA. (lark DA. Rawls WE (1981

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

    PubMed

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

    2015-01-01

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

  12. Transcription factor dynamics in pineal gland and liver of the Syrian hamster (Mesocricetus auratus) adapts to prevailing photoperiod.

    PubMed

    Maronde, Erik; Pfeffer, Martina; Glass, Yuri; Stehle, Jörg H

    2007-08-01

    The anticipation of day length and duration of darkness is necessary and advantageous for animals to survive and requires a photoperiodic memory. In the Syrian hamster this adaptation to photoperiod is mirrored by seasonal changes in the animal's reproductive state and its liver metabolism. Both events are linked to season-dependent alterations of the nocturnally elevated synthesis of the pineal hormone melatonin. To decipher molecules that are involved in this temporal gating, hamsters were exposed to long photoperiod (16 hr light:8 hr darkness; LP), or short photoperiod (8 hr light:16 hr darkness; SP). Dynamics in gene expression was investigated in the pineal gland [inducible cAMP early repressor (ICER)], and in the liver (ICER; C/EBPdelta; clock genes) using immunochemistry and reverse transcriptase PCR. While in the pineal, ICER rhythms tightly follow the prior duration of light and dark with decreasing levels at the beginning of the dark period in both LP and SP, ICER is not rhythmic in liver. In the liver, clock genes and their protein products reflect differences in photoperiodic history, with enhanced rhythm amplitudes of PER, CRY, CLOCK, and BMAL1 under SP conditions. Thus, in the Syrian hamster transcription factor expression patterns lock onto the prevailing photoperiod in two peripheral oscillators, the pineal gland and the liver, to function as mediators of suprachiasmatic nucleus-derived information on environmental light and dark. This tissue-specific gating in gene transcription represents a strategy to ameliorate consequences of altering environmental lighting conditions on endocrine and metabolic parameters that endow a strong circadian bias.

  13. The cooling tube: A novel small animal model of systemic hypothermia in awake Syrian Golden Hamsters (mesocricetus auratus).

    PubMed

    Goedeke, Jan; Apelt, Nadja; Kamler, Markus

    2015-01-01

    Hypothermia is increasingly used as a therapeutic strategy in a diversity of clinical scenarios. Its impact on mammalian physiology, particularly on the microcirculatory changes of critical organ systems, are, however, incompletely understood. Close examination of the literature reveals a marked paucity of small animal models of rapid systemic hypothermia. All published models introduce important microvascular confounders by investigating either local cooling processes or using anaesthetised animals. Here we present the first rapid systemic hypothermia model in an awake hamster. We developed a waterstream cooled copper tube system for standardized systemic temperature control. With this novel system core body temperature (Tc) in 14 awake animals could be precisely stabilised at temperatures of 30°C and 18°C (7 animals, respectively) within 10-20 min. Rewarming was achieved over 10-15 min. Tolerance of the procedure was excellent. Hamsters did not show any behavioural changes in the mild hypothermia group. In the deep hypothermia group 6 of 7 animals regained normal behaviour within 2-11 hs. As hypothermia was induced in dorsal skinfold chamber bearing animals this model seems suitable for investigation of microcirculatory purposes.Advantages over previously established experimental hypothermia models are significant. Amongst these, the possibility of visualization of microcirculation, the lack of microcirculation confounding factors such as anaesthetic drugs, the ability for precise Tc control and rapid induction of hypothermia are prominent.

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

    PubMed Central

    Fernández-Vargas, Marcela; Johnston, Robert E.

    2015-01-01

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

  15. Ultrasonic vocalizations in golden hamsters (Mesocricetus auratus) reveal modest sex differences and nonlinear signals of sexual motivation.

    PubMed

    Fernández-Vargas, Marcela; Johnston, Robert E

    2015-01-01

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

  16. The posteromedial cortical amygdala regulates copulatory behavior, but not sexual odor preference, in the male Syrian hamster (Mesocricetus auratus).

    PubMed

    Maras, P M; Petrulis, A

    2008-10-15

    In rodent species, the expression of reproductive behavior relies heavily on the perception of social odors, as well as the presence of circulating steroid hormones. In the Syrian hamster, chemosensory and hormonal cues are processed within an interconnected network of ventral forebrain nuclei that regulates many aspects of social behavior. Within this network, the posteromedial cortical amygdala (PMCo) receives direct projections from the accessory olfactory bulbs and contains a dense population of steroid receptor-containing neurons. Consequently, the PMCo may be important for generating odor-guided aspects of reproductive behavior, yet little is known regarding the role of this nucleus in regulating these behaviors. Thus, the present study tested male hamsters with site-specific electrolytic lesions of the PMCo for their (a) sexual odor preference in a Y-maze apparatus, (b) sexual odor discrimination in a habituation-dishabituation task, and (c) copulatory behavior when paired with a sexually receptive female. PMCo-lesioned males preferred to investigate female odors over male odors and were able to discriminate between these odor sources. However, PMCo lesions were associated with several alterations in the male copulatory pattern. First, PMCo-lesioned males displayed increased investigation of the female's non-anogenital region, suggesting that the PMCo may be involved in directing appropriate chemosensory investigation during mating. Second, PMCo lesions altered the temporal pattern of the mating sequence, as PMCo-lesioned males took longer than Sham-lesioned males to reach sexual satiety, as indicated by the delayed expression of long intromissions. This delayed onset of satiety was associated with an increased number of ejaculations compared with Sham-lesioned males. Importantly, these data provide the first direct evidence for a functional role of the PMCo in regulating male reproductive behavior.

  17. Effects of European mistletoe (Viscum album L. subsp. album) extracts on activity rhythms of the Syrian hamsters (Mesocricetus auratus).

    PubMed

    Karakas, Alper; Turker, Arzu Ucar; Gunduz, Bulent

    2008-01-01

    Antitumor drugs may have some significant nervous system side-effects such as disrupted sleep, eating and drinking patterns. European Mistletoe has been investigated for many decades for its potential use against cancer. To test the hypothesis that the non-antineoplastic effects of mistletoe might be mediated by the actions on the circadian timing system, we have applied mistletoe extracts and vehicle and have measured locomotor activity, feeding and drinking rhythms under constant darkness. Four groups (vehicle, 20 mg kg(-1) ip injection, 40 mg kg(-1) ip injection and 6 g kg(-1) oral administration) were performed for both heat-treated and freeze-dried extracts. None of the administrations changed the locomotor activity, feeding and drinking rhythms in the groups except for 40 mg kg(-1) freeze-dried injected group. The locomotor activity levels decreased in 40 mg kg(-1) freeze-dried extract injected group. These results suggest that, side-effects of mistletoe on circadian timing system of the Syrian hamster depend on the dose and the preparation method of the extract.

  18. Gonadotropin-inhibitory hormone reduces sexual motivation but not lordosis behavior in female Syrian hamsters (Mesocricetus auratus).

    PubMed

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

    2013-08-01

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

  19. A comparison of enzyme activity mutation frequencies in germ cells of mice (Mus musculus) and golden hamsters (Mesocricetus auratus) after exposure to 2 + 2 Gy gamma-irradiation.

    PubMed

    Pretsch, W; Neuhäuser-Klaus, A; Favor, J

    2000-01-01

    The radiation-induced germ cell mutation rate has been investigated in two species of mammals. Mice and golden hamsters of both sexes were exposed to 2 + 2 Gy gamma-irradiation with a 24 h fractionation interval and mated to untreated partners. In mice, specific locus mutations were examined as positive controls and the obtained mutation rates (per locus and gamete x10(-5)) were 51.4, 10.1, 13.6 and 17.4 for irradiated post-spermatogonia, spermatogonia and 1-7 and >7 days post-treatment oocytes, respectively. Offspring of mice and golden hamsters were screened for activity alterations of 10 erythrocyte enzymes coded by at least 14 loci. The observed mutation rates per locus per gamete x10(-5) for treated post-spermatogonial stages, spermatogonia and oocytes 1-7 and >7 days post-treatment were 6.5, 1.5, 8.8 and 7.0, respectively, for mice and 16.7, 0, 7.6 and 0, respectively, for golden hamsters. There is a significant difference for mutation rates in mouse oocytes 1-7 days post-treatment compared with the control. No differences in the frequencies of mutations in the various germ cell stages could be observed between mice and golden hamsters. A critical assumption for the extrapolation of experimental mutagenesis studies to humans is that no species effects exist in sensitivity to mutation induction by irradiation. Our results do not contradict this assumption.

  20. B-cell and T-cell lymphomas and other associated diseases induced by an infectious DNA viroid-like agent in hamsters (Mesocricetus auratus).

    PubMed Central

    Coggin, J. H.; Bellomy, B. B.; Thomas, K. V.; Pollock, W. J.

    1983-01-01

    Five epidemics of diffuse, poorly differentiated lymphocytic, immunoblastic, and plasmacytoid lymphoma induced by an infectious, horizontally transmitting viroidlike agent have occurred in two hamster facilities. Incidence summaries and pathologic characteristics of the lymphomas induced in LSH and LVG hamsters are presented. An elevated leukocyte count with a marked increase in neutrophils and a significant decrease in small mononuclear lymphocytes was detected in 5-week-old but not in 10- or 25-week-old LVG hamsters born in the facility contaminated with the lymphoma-inducing agent. Three-week-old LVG hamsters exposed to the contaminated facility showed no similar hematologic change at 5 weeks of age or 5 weeks of exposure. Several associated syndromes, including an intussusception disease, pyelonephritis, inflammatory bowel disease, and body warts associated with the presence of the causative viroidlike agent in the contaminated colonies are described. Details of the epidemiology of the disease, karyology, viral studies, and correlation with several epidemics in other laboratories are presented. Images Figure 1 Figure 3 Figure 4 PMID:6600884

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

    PubMed

    Takahashi, Makoto; Ueno, Yoshikazu; Fujita, Kazuo

    2015-11-01

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

  2. Influence of histological degree of seminiferous tubular degeneration and stage of seminiferous cycle on the proliferation of spermatogonia in aged Syrian hamster (Mesocricetus auratus).

    PubMed

    Bernal-Mañas, C M; Cortes, S; Morales, E; Horn, R; Seco-Rovira, V; Beltran-Frutos, E; Ferrer, C; Canteras, M; Pastor, L M

    2014-08-01

    The ageing testis is associated with germ loss in the seminiferous epithelium and a decrease in spermatogonia proliferation. In this work, we study whether the stages of the seminiferous epithelium cycle and/or the degree of histological tubular degeneration resulting from ageing is related with this decrease in spermatogonia proliferation. Eleven hamsters were used, five aged 6 months and six aged 24 months. In both groups, the proliferative activity was studied by BrdU immunostaining. The number of BrdU-positive and BrdU-negative cells was measured, providing the overall proliferation index in adult and aged testes. The mean number of BrdU-positive cells was also determined for each degree of histological degeneration of seminiferous epithelium, and a spermatogonia proliferation index was obtained for each stage of the seminiferous cycle. Ageing caused an overall decrease in the BrdU-positive cell percentage and a decrease in the number of BrdU-positive cells in the tubular sections with hypospermatogenesis, the sloughing of germ cells and maturation arrest, these changes being similar in both young and old animals. The spermatogonia proliferation index was only seen to be significantly lower in ageing hamster in stages VII-VIII of the seminiferous epithelium cycle. In conclusion, the overall decrease in proliferation observed in aged seminiferous epithelium is correlated with an increase in the number of degenerated sections of the seminiferous tubules, and this decrease is a phenomenon which occurs in specific stages of the seminiferous cycle.

  3. Tributyltin-mediated hepatic, renal and testicular tissue damage in male Syrian hamster (Mesocricetus auratus): a study on impact of oxidative stress.

    PubMed

    Kanimozhi, V; Palanivel, K; Akbarsha, M A; Kadalmani, B

    2016-01-01

    Organotin compounds are a versatile group of organometallic chemicals that are used in a variety of industrial and agricultural applications. Tributyltin (TBT), a common organotin, brings about severe spermatotoxic and organotoxic effects. However, information about the adverse effects of TBT on liver, kidney and testis is scanty. Hence, the present study was undertaken to elucidate the TBT-mediated oxidative stress-induced impairments in these organs. Administration of TBT through oral route at increasing doses of 50, 100 and 150 ppm for 65 days to male Syrian hamsters resulted in drastically decreased activities of antioxidant enzymes superoxide dismutase, catalase and glutathione peroxidase and decreased mean levels of non-enzymatic antioxidants (reduced glutathione, vitamin C, and vitamin E) followed by a dramatic increase in the levels of lipid peroxidation in the liver, kidney and testis as compared to the control animals. Significantly high levels of serum urea, creatinine, uric acid and bilirubin were observed in TBT-treated hamsters. Also, TBT treatment induced drastic histopathological changes in the liver, kidney and testis combined with remarkable changes in serum levels of tissue injury marker enzymes Aspartate transaminases, Alkaline phosphatase and Alanine transaminase. These data affirm that exposure to TBT can lead to oxidative stress-induced damage to liver, kidney and testis.

  4. Lesions that functionally disconnect the anterior and posterodorsal sub-regions of the medial amygdala eliminate opposite-sex odor preference in male Syrian hamsters (Mesocricetus auratus).

    PubMed

    Maras, P M; Petrulis, A

    2010-02-17

    In many rodent species, such as Syrian hamsters, reproductive behavior requires neural integration of chemosensory information and steroid hormone cues. The medial amygdala (MA) processes both of these signals through anatomically distinct sub-regions; the anterior region (MeA) receives substantial chemosensory input, but contains few steroid receptor-labeled neurons, whereas the posterodorsal region (MePD) receives less chemosensory input, but contains a dense population of steroid receptors. Importantly, these sub-regions have considerable reciprocal connections, and the goal of this experiment was therefore to determine whether interactions between MeA and MePD are required for male hamsters' preference to investigate female over male odors. To functionally disconnect MeA and MePD, males received unilateral lesions of MeA and MePD within opposite brain hemispheres. Control males received either unilateral lesions of MeA and MePD within the same hemisphere or sham surgery. Odor preferences were measured using a 3-choice apparatus, which simultaneously presented female, male and clean odor stimuli; all tests were done under conditions that either prevented or allowed contact with the odor sources. Under non-contact conditions, males with asymmetrical lesions investigated female and male odors equally, whereas males in both control groups preferred to investigate female odors. Under contact conditions, all groups investigated female odors longer than male odors, although males with asymmetrical lesions displayed decreased investigation of female odors compared to sham males. These data suggest that MeA-MePD interactions are critical for processing primarily the volatile components of social odors and highlight the importance of input from the main olfactory system (MOS) to these nuclei in the regulation of reproductive behavior. More broadly, these results support the role of the MA in integrating chemosensory and hormone information, a process that may underlie

  5. Testicular histomorphometry and the proliferative and apoptotic activities of the seminiferous epithelium in Syrian hamster (Mesocricetus auratus) during regression owing to short photoperiod.

    PubMed

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

    2015-05-01

    During the non-breeding season some animals exhibit testicular atrophy, decreased testicular weight and reduced seminiferous tubule diameter accompanied by depletion of the seminiferous epithelium. Some cellular factors involved in this depletion are changes in germ cell proliferation and apoptosis. In the Syrian hamster this depletion has been studied histologically and in terms of the involvement of proliferation and apoptosis in the seminiferous epithelium of fully regressed testes. The objectives of this study included the histomorphometrical characterization of the testis and the determination of the proliferative and apoptotic activity of germ cells in the seminiferous epithelium during testicular regression owing to short photoperiod. The study was performed using conventional light microscopy (hematoxylin and eosin), proliferating cell nuclear antigen and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP in situ nick end labelling staining, image analysis software, and transmission electron microscopy in three established regression groups: mild regression (MR), strong regression (SR), and total regression (TR). Morphometrically a gradual decrease in total tubular area and in the testicular, tubular, and epithelial volumes was observed during testicular regression. Interstitial and luminal volumes decreased from the MR group onwards. The tubular length decreased from MR to SR. As regards spermatogonial proliferation, only an initial decrease in proliferative activity was observed, whereas apoptotic germ cell activity increased throughout regression. The number of germ cells studied decreased throughout the process of testicular regression. In conclusion, testicular regression in Syrian hamster comprises two histomorphometrical phases, the first involving a decrease in seminiferous tubular diameter and volume and the second involving shortening of the seminiferous tubule and a decrease in interstitial volume. At the cellular level, there is an

  6. Copious urinary excretion of a male Syrian hamster (Mesocricetus auratus) salivary gland protein after its endocrine-like release upon β-adrenergic stimulation.

    PubMed

    Dubey, Ved Prakash; Srikantan, Subramanya; Mohammad, Mahabub Pasha; Rajan, Wenson David; De, Prabir Kumar

    2013-06-01

    Salivary glands, although widely considered as typically exocrine, may also release specific proteins in an endocrine manner. However, endocrine release of salivary gland proteins is not generally acknowledged since the evidences are not easily demonstrable. Submandibular salivary glands (SMG) of male Syrian hamsters express male-specific secretory proteins (MSP; which are lipocalins) visible in SDS-PAGE of SMG extracts, as major bands and also detectable in immunoblots of whole-saliva and urine as low MSP crossreactions. We report here that MSP is localized in acinar cells of SMG and acute treatment with isoproterenol (IPR; non-specific β1/β2-adrenergic agonist) results in considerable release of MSP in SMG-saliva. Moreover, acute IPR treatment markedly depletes SMG-MSP in a dose- and time-dependent manner. However, MSP depleted from SMG, far exceeds that recovered in SMG-saliva. Blood, submandibular lymph nodes and kidney of IPR-treated males showed MSP crossreactions and SDS-PAGE of their urine revealed profuse MSP excretion; this was undetectable in IPR-treated-SMG-ablated males, confirming that a substantial amount of MSP depleted from SMG after IPR treatment enters circulation and is excreted in urine. Treatments with specific β1- or β2-adrenergic agonists also reduced SMG-MSP levels and resulted in copious urinary excretion of MSP. Co-treatments with specific β1/β2-blockers indicated that above effects of IPR, β1- and even β2-agonists are very likely mediated by β1-adrenoceptors. MSP's detection by SDS-PAGE in urine after β-agonist treatment is a compelling and easily demonstrable evidence of release into circulation of a salivary gland protein. The possible means (endocrine-like or otherwise) of MSP's release into circulation and significance of its presence in saliva, blood and urine of male hamsters are discussed.

  7. Neuronal composition of the magnocellular division of the medial preoptic nucleus (MPN mag) is sex specific in the Syrian hamster (Mesocricetus auratus).

    PubMed

    Richendrfer, Holly A; Swann, Jennifer M

    2010-09-10

    The magnocellular division of the medial Preoptic nucleus (MPN mag) plays a critical role in the regulation of male sexual behavior in the hamster. Results from previous studies indicated that the number of neurons in the MPN mag is greater in males than females but failed to find significant differences in the volume of the nucleus suggesting that other elements in the nucleus may be greater in the female. The results of the present study, using NeuN to identify neurons, are in line with this hypothesis. The data show that (1) neurons in the MPN mag display two distinct phenotypes, those with a single nucleolus and those with multiple nucleoli; (2) the percentage of each phenotype is sex specific, differing over the course of development and (3) there is no sex difference in the number of glial cells at any age. Sex differences in the numbers of each type are correlated with developmental milestones and suggest that morphological changes are influenced by changes in circulating gonadal steroids during development.

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

    PubMed

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

    2016-05-01

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

  9. 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+...

  10. 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...

  11. 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.

  12. 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.

  13. Gold

    USGS Publications Warehouse

    Kirkemo, Harold; Newman, William L.; Ashley, Roger P.

    1998-01-01

    Through the ages, men and women have cherished gold, and many have had a compelling desire to amass great quantities of it -- so compelling a desire, in fact, that the frantic need to seek and hoard gold has been aptly named "gold fever." Gold was among the first metals to be mined because it commonly occurs in its native form -- that is, not combined with other elements -- because it is beautiful and imperishable, and because exquisite objects can be made from it.

  14. 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

  15. 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.

  16. Chromosomal evolution of Arvicolinae (Cricetidae, Rodentia). I. The genome homology of tundra vole, field vole, mouse and golden hamster revealed by comparative chromosome painting.

    PubMed

    Sitnikova, Natalia A; Romanenko, Svetlana A; O'Brien, Patricia C M; Perelman, Polina L; Fu, Beiyuan; Rubtsova, Nadezhda V; Serdukova, Natalya A; Golenishchev, Feodor N; Trifonov, Vladimir A; Ferguson-Smith, Malcolm A; Yang, Fengtang; Graphodatsky, Alexander S

    2007-01-01

    Cross-species chromosome painting has become the mainstay of comparative cytogenetic and chromosome evolution studies. Here we have made a set of chromosomal painting probes for the field vole (Microtus agrestis) by DOP-PCR amplification of flow-sorted chromosomes. Together with painting probes of golden hamster (Mesocricetus auratus) and mouse (Mus musculus), the field vole probes have been hybridized onto the metaphases of the tundra vole (Microtus oeconomus). A comparative chromosome map between these two voles, golden hamster and mouse has been established based on the results of cross-species chromosome painting and G-banding comparisons. The sets of paints from the field vole, golden hamster and mouse identified a total of 27, 40 and 47 homologous autosomal regions, respectively, in the genome of tundra vole; 16, 41 and 51 fusion/fission rearrangements differentiate the karyotype of the tundra vole from the karyotypes of the field vole, golden hamster and mouse, respectively.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. 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.

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

    PubMed

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

    2016-05-16

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

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Adolescent anabolic-androgenic steroid exposure alters lateral anterior hypothalamic serotonin-2A receptors in aggressive male hamsters.

    PubMed

    Schwartzer, Jared J; Ricci, Lesley A; Melloni, Richard H

    2009-05-16

    Chronic anabolic-androgenic steroid (AAS) treatment during adolescence facilitates offensive aggression in male Syrian hamsters (Mesocricetus auratus). Serotonin (5-HT) modulates aggressive behavior and has been shown to be altered after chronic treatment with AAS. Furthermore, 5-HT type 2 receptors have been implicated in the control of aggression. For example, treatment with 5-HT(2A) receptor antagonists suppress the generation of the offensive aggressive phenotype. However, it is unclear whether these receptors are sensitive to adolescent AAS exposure. The current study assessed whether treatment with AAS throughout adolescence influenced the immunohistochemical localization of 5-HT(2A) in areas of the hamster brain implicated in the control of aggression. Hamsters were administered AAS (5.0 mg/kg) each day throughout adolescence, scored for offensive aggression, and then examined for differences in 5-HT(2A)-immunoreactivity (5-HT(2A)-ir). When compared with non-aggressive oil-treated controls, aggressive AAS-treated hamsters showed significant increases in 5-HT(2A)-ir fibers in the lateral portion of the anterior hypothalamus (LAH). Further analysis revealed that AAS treatment also produced a significant increase in the number of cells expressing 5-HT(2A)-ir in the LAH. Together, these results support a role for altered 5-HT(2A) expression and further implicate the LAH as a central brain region important in the control of adolescent AAS-induced offensive aggression.

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

    PubMed

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

    2015-12-01

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

  17. Repeated anabolic-androgenic steroid treatment during adolescence increases vasopressin V(1A) receptor binding in Syrian hamsters: correlation with offensive aggression.

    PubMed

    DeLeon, Katrina R; Grimes, Jill M; Melloni, Richard H

    2002-09-01

    Repeated anabolic-androgenic steroid treatment during adolescence increases hypothalamic vasopressin and facilitates offensive aggression in male Syrian hamsters (Mesocricetus auratus). The current study investigated whether anabolic-androgenic steroid exposure during this developmental period influenced vasopressin V(1A) receptor binding activity in the hypothalamus and several other brain areas implicated in aggressive behavior in hamsters. To test this, adolescent male hamsters were administered anabolic steroids or sesame oil throughout adolescence, tested for offensive aggression, and examined for differences in vasopressin V(1A) receptor binding using in situ autoradiography. When compared with control animals, aggressive, adolescent anabolic steroid-treated hamsters showed significant increases (20-200%) in the intensity of vasopressin V(1A) receptor labeling in several aggression areas, including the ventrolateral hypothalamus, bed nucleus of the stria terminalis, and lateral septum. However, no significant differences in vasopressin V(1A) receptor labeling were found in other brain regions implicated in aggressive responding, most notably the lateral zone from the medial preoptic area to anterior hypothalamus and the corticomedial amygdala. These data suggest that adolescent anabolic steroid exposure may facilitate offensive aggression by increasing vasopressin V(1A) receptor binding in several key areas of the hamster brain.

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

    NASA Astrophysics Data System (ADS)

    Lenkiewicz, Zofia; Dabrowska, Barbara; Schiffer, Zofia

    1989-12-01

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

  19. Plasma corticosterone elevation inhibits the activation of nuclear factor kappa B (NFKB) in the Syrian hamster pineal gland.

    PubMed

    Ferreira, Z S; Bothorel, B; Markus, R P; Simonneaux, V

    2012-05-01

    We evaluated how the mild stress-induced increase in endogenous corticosterone affected the pineal gland in Syrian hamsters (Mesocricetus auratus). The animals were maintained under constant light for 1 day, instead of a cycle of 14:10-h, to increase the circulating corticosterone levels during the daytime. The nuclear translocation of nuclear factor kappa B (NFKB), which is the pivotal transcription factor for stress and injury, presented a daily rhythm in normal animals. NFKB nuclear content increased linearly from the onset of light [Zeitgeber Time 0 (ZT0)] until ZT11 and decreased after ZT12 when the plasma corticosterone peak was detected in normal animals. However, the 24-h profiles of the two curves were different, and they did not clearly support an exclusive relationship between corticosterone levels and NFKB content. Therefore, we tested the effect of increased endogenous corticosterone through inducing mild stress by maintaining daytime illumination for one night. This stressful condition, which increased daytime corticosterone levels, resulted in a daytime decrease in NFKB nuclear content, and this was inhibited by mifepristone. Overall, this study shows that NFKB has a daily rhythm in Syrian hamster pineal glands and, by increasing endogenous corticosterone with a stressful condition, NFKB activity is regulated. Therefore, this study suggests that the pineal gland in the Syrian hamster is a sensor of stressful conditions.

  20. Experimental coccidioidomycosis in hamsters. Disease kinetics and death curve in relation to infective dose.

    PubMed

    Finquelievich, J L; Iovannitti, C; Negroni, R; Elías Costa, M R

    2000-10-01

    A study of experimental coccidioidomycosis in hamsters (Mesocricetus auratus) is presented. Two experiments were conducted on 75 animals inoculated intracardially with the mycelial form of Coccidioides immitis. The first research (experiment I) studied the kinetics of experimental disease in 15 hamsters inoculated with 300 C. immitis arthroconidia. The parameters studied were: (a) presence of macroscopic lesions in the brain, lungs, liver, spleen and kidneys; (b) microscopic identification of spherules in wet mount preparations of these specimens; (c) samples from all organs cultured at 37 degrees C on Sabouraud glucose agar; (d) blood cultures drawn every 24 h during the first week and subsequently every 48 h and (e) histopathological studies of all organs. The second experiment (experiment II) determined the relationship between the inoculum size and death curve in six groups of 10 animals each, which had received doses of 10, 50, 100, 150, 200 and 300 arthroconidia, respectively. On day 14 post-inoculation, all the animals underwent skin tests and 1 ml of blood was obtained by cardiac puncture to detect antibodies. Disseminated disease with persistent fungaemia developed in all the studied animals. Coccidioides immitis was recovered from all organs, with the lungs being the first to present disease. Death occurred in all groups, regardless of the dose of arthroconidia and 83.3% died between day 22 and day 28 post-infection. The use of this model is proposed for the biological standardization of antigens, the study of prophylactic measures and the "in vivo" evaluation of new antifungal treatments.

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

  3. 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.

  4. Variation in intake of sweet and bitter solutions by inbred strains of golden hamsters.

    PubMed

    Frank, Marion E; Wada, Yumiko; Makino, Junshiro; Mizutani, Makoto; Umezawa, Hidehiko; Katsuie, Yasutomi; Hettinger, Thomas P; Blizard, David A

    2004-07-01

    Variation in intake of sweet and bitter solutions by inbred strains of laboratory mice has helped identify genes related to taste behaviors; but similar information is not available for golden hamsters (Mesocricetus auratus ), a species used much in taste research. Thus, 6-hour, 1-bottle intake by water-replete hamsters of 7 inbred strains was measured for water and 2 concentrations of sucrose, maltose, D-phenylalanine (D-Phe), and sodium saccharin, which are sweet; and quinine.HCl, L-phenylalanine (L-Phe), caffeine, and sucrose octaacetate (SOA), which are bitter to humans. Difference scores (DIF), calculated as solution intake minus mean baseline water intake (mL) for each animal, were evaluated by analysis of variance. Compared to ACN, CN, APA, APG, and CBN, five strains with similar DIF for all compounds, GN, an ancestral strain of ACNT, and ACNT preferred sucrose, caffeine, and SOA more strongly; ACNT also preferred saccharin and maltose more strongly and rejected quinine more strongly. Narrow sense heritabilities for the 6 compounds for which strain differences were revealed ranged from 0.31 to 0.57. Genetic correlations indicated the strain variations in intake of sucrose, saccharin, SOA, and caffeine were coupled; a statistical association with several possible interpretations. Intakes of the two amino acids, preferred D-Phe and aversive L-Phe, did not reveal strain differences, and heritability ranged from 0.13 to 0.23 for the two optical isomers. Thus, although, compared to mice, genetic variation in laboratory hamsters may be small, genetic differences that influence taste behaviors in existing strains may help identify relevant genes.

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

    PubMed

    Ferraro, J S

    1988-01-01

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

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

    NASA Technical Reports Server (NTRS)

    Ferraro, J. S.

    1988-01-01

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

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

    PubMed

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

    2015-09-01

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

  8. The medial preoptic area is necessary for sexual odor preference, but not sexual solicitation, in female Syrian hamsters.

    PubMed

    Martinez, Luis A; Petrulis, Aras

    2013-04-01

    Precopulatory behaviors that are preferentially directed towards opposite-sex conspecifics are critical for successful reproduction, particularly in species wherein the sexes live in isolation, such as Syrian hamsters (Mesocricetus auratus). In females, these behaviors include sexual odor preference and vaginal scent marking. The neural regulation of precopulatory behaviors is thought to involve a network of forebrain areas that includes the medial amygdala (MA), the bed nucleus of the stria terminalis (BNST), and the medial preoptic area (MPOA). Although MA and BNST are necessary for sexual odor preference and preferential vaginal marking to male odors, respectively, the role of MPOA in odor-guided female precopulatory behaviors is not well understood. To address this issue, female Syrian hamsters with bilateral, excitotoxic lesions of MPOA (MPOA-X) or sham lesions (SHAM) were tested for sexual odor investigation, scent marking, and lordosis. MPOA-X females did not investigate male odors more than female odors in an odor preference test, indicating that MPOA may be necessary for normal sexual odor preference in female hamsters. This loss of preference cannot be attributed to a sensory deficit, since MPOA-X females successfully discriminated male odors from female odors during an odor discrimination test. Surprisingly, no deficits in vaginal scent marking were observed in MPOA-X females, although these females did exhibit decreased overall levels of flank marking compared to SHAM females. Finally, all MPOA-X females exhibited lordosis appropriately. These results suggest that MPOA plays a critical role in the neural regulation of certain aspects of odor-guided precopulatory behaviors in female Syrian hamsters.

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

    SciTech Connect

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

    1981-12-01

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

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

    PubMed Central

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

    2007-01-01

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

  11. Parasite Burden in Hamsters Infected with Two Different Strains of Leishmania (Leishmania) infantum: “Leishman Donovan Units” versus Real-Time PCR

    PubMed Central

    Moreira, Nádia das Dores; Vitoriano-Souza, Juliana; Roatt, Bruno Mendes; Vieira, Paula Melo de Abreu; Ker, Henrique Gama; de Oliveira Cardoso, Jamille Mirelle; Giunchetti, Rodolfo Cordeiro; Carneiro, Cláudia Martins; de Lana, Marta; Reis, Alexandre Barbosa

    2012-01-01

    To develop and test new therapeutics and immune prophylaxis strategies for visceral leishmaniasis (VL), understanding tissue parasitism evolution after experimental infection with Leishmania infantum is important. Experimental infection in a hamster model (Mesocricetus auratus) reproduces several typical aspects of canine and human VL that are closely related to the inoculum’s route. We quantified the parasitism in the liver and spleen of hamsters experimentally infected by various routes (intradermal, intraperitoneal, and intracardiac [IC]) and different strains of L. infantum (MHOM/BR/74/PP75 and Wild) and compared two different methodologies to evaluate tissue parasitism (Leishman Donovan units [LDU] and real-time qPCR). In addition, the quantification of specific total-IgG in the serum of uninfected and infected hamsters was determined by ELISA. The animals were followed for 1, 3, 6 and 9 months post-infection for survival analysis. We found that infection with the Wild strain by the IC route resulted in higher mortality. Positive antibody (IgG) responses were detected with higher peaks at 6 and 9 months in the IC group inoculated with PP75 strain. However, in animals infected with the Wild strain the IgG levels were elevated in all infected groups during all the time evaluated. We also observed by LDU analysis that the IC route lead to higher parasitism in the liver and spleen with both strains. Furthermore, qPCR showed higher sensitivity for identifying animals with low parasitic burden. In conclusion, qPCR can be useful for assessing parasitism in the spleen and liver of a hamster model infected with L. infantum independent of the route of infection, and this technique may become an essential tool for assessing parasite density in the hamster model after experimental treatment or immunization with potential vaccine candidates. PMID:23112869

  12. Cytokine, antibody and proliferative cellular responses elicited by Taenia solium calreticulin upon experimental infection in hamsters.

    PubMed

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

    2015-01-01

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

  13. DEVELOPMENTAL AND WITHDRAWAL EFFECTS OF ADOLESCENT AAS EXPOSURE ON THE GLUTAMATERGIC SYSTEM IN HAMSTERS

    PubMed Central

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

    2011-01-01

    In the Syrian hamster (Mesocricetus auratus) glutamate activity has been implicated in the modulation of adolescent anabolic-androgenic steroid (AAS)-induced aggression. The current study investigated the time course of adolescent AAS-induced neurodevelopmental and withdrawal effects on the glutamatergic system and examined whether these changes paralleled those of adolescent AAS-induced aggression. Glutamate activity in brain areas comprising the aggression circuit in hamsters and aggression were examined following 1, 2, 3 and 4 weeks of AAS treatment or 1, 2, 3 and 4 weeks following the cessation of AAS exposure. In these studies glutamate activity was examined using vesicular glutamate transporter 2 (VGLUT2). The onset of aggression was observed following 2 weeks exposure to AAS and continued to increase showing maximal aggression levels after 4 weeks of AAS treatment. This aggressive phenotype was detected after 2 weeks of withdrawal from AAS. The time-course of AAS-induced changes in latero anterior hypothalamus (LAH)-VGLUT2 closely paralleled increases in aggression. Increases in LAH-VGLUT2 were first detected in animals exposed to AAS for 2 weeks and were maintained up to 3 weeks following the cessation of AAS treatment. AAS treatment also produced developmental and long-term alterations in VGLUT2 expression within other aggression areas. However, AAS-induced changes in glutamate activity within these regions did not coincide with changes in aggression. Together, these data indicate that adolescent AAS treatment leads to alterations in the glutamatergic system in brain areas implicated in aggression control, yet only alterations in LAH-glutamate parallel the time course of AAS-induced changes in the aggressive phenotype. PMID:21500881

  14. Developmental and withdrawal effects of adolescent AAS exposure on the glutamatergic system in hamsters.

    PubMed

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

    2011-06-01

    In the Syrian hamster (Mesocricetus auratus) glutamate activity has been implicated in the modulation of adolescent anabolic-androgenic steroid (AAS)-induced aggression. The current study investigated the time course of adolescent AAS-induced neurodevelopmental and withdrawal effects on the glutamatergic system and examined whether these changes paralleled those of adolescent AAS-induced aggression. Glutamate activity in brain areas comprising the aggression circuit in hamsters and aggression levels were examined following 1, 2, 3, and 4 weeks of AAS treatment or 1, 2, 3, and 4 weeks following the cessation of AAS exposure. In these studies glutamate activity was examined using vesicular glutamate transporter 2 (VGLUT2). The onset of aggression was observed following 2 weeks exposure to AAS and continued to increase showing maximal aggression levels after 4 weeks of AAS treatment. This aggressive phenotype was detected after 2 weeks of withdrawal from AAS. The time-course of AAS-induced changes in latero-anterior hypothalamus (LAH)-VGLUT2 closely paralleled increases in aggression. Increases in LAH-VGLUT2 were first detected in animals exposed to AAS for 2 weeks and were maintained up to 3 weeks following the cessation of AAS treatment. AAS treatment also produced developmental and long-term alterations in VGLUT2 expression within other aggression areas. However, AAS-induced changes in glutamate activity within these regions did not coincide with changes in aggression. Together, these data indicate that adolescent AAS treatment leads to alterations in the glutamatergic system in brain areas implicated in aggression control, yet only alterations in LAH-glutamate parallel the time course of AAS-induced changes in the aggressive phenotype.

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

    PubMed

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

    2014-08-15

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

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

    PubMed Central

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

    2015-01-01

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

  17. Ultrastructure of spermatogonia and spermatocyte lobules in Taenia solium strobilae (Cestoda, Cyclophyllidea, Taeniidae) from golden hamsters.

    PubMed

    Willms, Kaethe; Caro, Jose Antonio; Robert, Lilia

    2003-08-01

    Golden hamsters ( Mesocricetus auratus) were infected with Taenia solium metacestodes dissected from infected pig meat. Adult worms were collected from hamster intestines of animals killed 5-60 days post-infection (dpi), incubated in RPMI 1640 medium with or without colchicine, fixed and processed for transmission electron microscopy (TEM). Sections for light microscopy from 40 different blocks with scolex, immature and mature proglottids were photographed. Thin sections were cut from 25 selected blocks, examined and photographed with TEM. Metaphase mitosis figures were observed in the subtegument of the germinative tissue and interpreted as germ cell precursors. In immature proglottids (20 dpi), discrete cell clusters of three to four cells surrounded by a thin cytoplasmic envelope were identified along the inner border of the lateral excretory ducts. These were also observed in more mature proglottids (40-60 dpi) as clusters of eight cells enclosed in a cytoplasmic envelope, with nuclei of spermatogonia exhibiting the synaptolems of primary meiotic cells. In mature proglottids from 45 dpi, a large number of spermatocyte lobules were found, exhibiting different stages of spermatogenesis from primary spermatocytes to mature filiform spermatids with a single axoneme, annular nucleus and spiral cortical microtubules, similar to spermatozoa described for type III spermiogenesis of species of the family Taeniidae. All mature spermatocyte lobules were enclosed in a highly organized cellular envelope and surrounded by a basal lamina. The envelopes contained a number of distinct organelles, seen in cross-section as discrete lattices of microtubules located between two layers of plasma membrane, as well as thickened furled cytoplasm with numerous strands of rough endoplasmic reticulum and pockets of microtubules.

  18. Gold Rush!

    ERIC Educational Resources Information Center

    Brahier, Daniel J.

    1997-01-01

    Describes a mathematical investigation of gold--how it is weighed, stored, used, and valued. For grades 3-4, children estimate the value of treasure chests filled with gold coins and explore the size and weight of gold bars. Children in grades 5-6 explore how gold is mined and used, and how the value of gold changes over time. (PVD)

  19. Repeated anabolic/androgenic steroid exposure during adolescence alters phosphate-activated glutaminase and glutamate receptor 1 (GluR1) subunit immunoreactivity in Hamster brain: correlation with offensive aggression.

    PubMed

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

    2007-06-04

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-04-01

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

  2. Schistosoma mansoni infection of Syrian golden hamsters: the host humoral immune response in relation to the adult worm burdens after primary infection.

    PubMed

    Yong, W K; Das, P K; Dachlan, Y P

    1983-01-01

    Seven-week-old female Syrian golden hamsters (Mesocricetus auratus) showed different degrees of susceptibility to Schistosoma mansoni, as assessed by the percentage of cercariae recovered as adult worms 6 weeks after infection. Plasma of the low (A), medium (B) and high (C) susceptibility groups were tested immunochemically. No differences were observed in the concentrations of albumin, alpha 1-, alpha 2-, beta- and gamma-globulins as measured by cellulose acetate electrophoresis. However, a significantly higher percentage of animals in groups A and B than in group C had an S. mansoni specific "beforked" IgG precipitin band and specific antibodies against a worm tegumental antigen preparation (AWT). Conversely, more animals in group C made antibodies against a "denuded" worm-body antigen preparation (AWB) than in groups A and B. However, by using the enzyme-linked immunosorbent assay, no significant differences in antibody titres against AWT, AWB and a total worm antigen (AVA) were observed in the animals in groups A, B and C. Upon consideration of the immunochemical data in relation to the distribution pattern of susceptibility to infection, we propose that the intensity of S. mansoni infection in the hamster is a polygene-controlled phenomenon and depends upon the presentation of differing parasite antigenic component(s) to the host.

  3. Adolescent exposure to anabolic/androgenic steroids and the neurobiology of offensive aggression: a hypothalamic neural model based on findings in pubertal Syrian hamsters.

    PubMed

    Melloni, Richard H; Ricci, Lesley A

    2010-06-01

    Considerable public attention has been focused on the issue of youth violence, particularly that associated with drug use. It is documented that anabolic steroid use by teenagers is associated with a higher incidence of aggressive behavior and serious violence, yet little is known about how these drugs produce the aggressive phenotype. Here we discuss work from our laboratory on the relationship between the development and activity of select neurotransmitter systems in the anterior hypothalamus and anabolic steroid-induced offensive aggression using pubertal male Syrian hamsters (Mesocricetus auratus) as an adolescent animal model, with the express goal of synthesizing these data into an cogent neural model of the developmental adaptations that may underlie anabolic steroid-induced aggressive behavior. Notably, alterations in each of the neural systems identified as important components of the anabolic steroid-induced aggressive response occurred in a sub-division of the anterior hypothalamic brain region we identified as the hamster equivalent of the latero-anterior hypothalamus, indicating that this sub-region of the hypothalamus is an important site of convergence for anabolic steroid-induced neural adaptations that precipitate offensive aggression. Based on these findings we present in this review a neural model to explain the neurochemical regulation of anabolic steroid-induced offensive aggression showing the hypothetical interaction between the arginine vasopressin, serotonin, dopamine, gamma-aminobutyric acid, and glutamate neural systems in the anterior hypothalamic brain region.

  4. Directed Student Inquiry: Modeling in Roborovsky Hamsters

    ERIC Educational Resources Information Center

    Elwess, Nancy L.; Bouchard, Adam

    2007-01-01

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

  5. Phenotypic plasticity of male Schistosoma mansoni from the peritoneal cavity and hepatic portal system of laboratory mice and hamsters.

    PubMed

    Mati, V L T; Freitas, R M; Bicalho, R S; Melo, A L

    2015-05-01

    Morphometric analysis of Schistosoma mansoni male worms obtained from AKR/J and Swiss mice was carried out. Rodents infected by the intraperitoneal route with 80 cercariae of the schistosome (LE strain) were killed by cervical dislocation at 45 and 60 days post-infection and both peritoneal lavage and perfusion of the portal system were performed for the recovery of adult worms. Characteristics including total body length, the distance between oral and ventral suckers, extension of testicular mass and the number of testes were considered in the morphological analysis. Changes that occurred in S. mansoni recovered from the peritoneal cavity or from the portal system of AKR/J and Swiss mice included total body length and reproductive characteristics. Significant morphometric alterations were also observed when worms recovered from the portal system of both strains of mice were compared with the schistosomes obtained from hamsters (Mesocricetus auratus), the vertebrate host in which the LE strain had been adapted and maintained by successive passages for more than four decades. The present results reinforce the idea that S. mansoni has high plastic potential and adaptive capacity.

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

    PubMed Central

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

    2015-01-01

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

  7. 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.

  8. Spontaneous endomyometrial neoplasms in aging Chinese hamsters

    SciTech Connect

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

    1980-05-01

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

  9. 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.

  10. 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

  11. 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.

  12. 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 (

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

    SciTech Connect

    Lam, C.K.C.

    1982-11-01

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

  14. Chromosomal evolution of Arvicolinae (Cricetidae, Rodentia). II. The genome homology of two mole voles (genus Ellobius), the field vole and golden hamster revealed by comparative chromosome painting.

    PubMed

    Romanenko, Svetlana A; Sitnikova, Natalia A; Serdukova, Natalya A; Perelman, Polina L; Rubtsova, Nadezhda V; Bakloushinskaya, Irina Yu; Lyapunova, Elena A; Just, Walter; Ferguson-Smith, Malcolm A; Yang, Fengtang; Graphodatsky, Alexander S

    2007-01-01

    Using cross-species chromosome painting, we have carried out a comprehensive comparison of the karyotypes of two Ellobius species with unusual sex determination systems: the Transcaucasian mole vole, Ellobius lutescens (2n = 17, X in both sexes), and the northern mole vole, Ellobius talpinus (2n = 54, XX in both sexes). Both Ellobius species have highly rearranged karyotypes. The chromosomal paints from the field vole (Microtus agrestis) detected, in total, 34 and 32 homologous autosomal regions in E. lutescens and E. talpinus karyotypes, respectively. No difference in hybridization pattern of the X paint (as well as Y paint) probes on male and female chromosomes was discovered. The set of golden hamster (Mesocricetus auratus) chromosomal painting probes revealed 44 and 43 homologous autosomal regions in E. lutescens and E. talpinus karyotypes, respectively. A comparative chromosome map was established based on the results of cross-species chromosome painting and a hypothetical ancestral Ellobius karyotype was reconstructed. A considerable number of rearrangements were detected; 31 and 7 fusion/fission rearrangements differentiated the karyotypes of E. lutescens and E. talpinus from the ancestral Ellobius karyotype. It seems that inversions have played a minor role in the genome evolution of these Ellobius species.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Gold Coating

    NASA Technical Reports Server (NTRS)

    1997-01-01

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

  20. Enhanced detection of early-stage oral cancer in vivo by optical coherence tomography using multimodal delivery of gold nanoparticles

    PubMed Central

    Kim, Chang Soo; Wilder-Smith, Petra; Ahn, Yeh-Chan; Liaw, Lih-Huei L.; Chen, Zhongping; Kwon, Young Jik

    2010-01-01

    Contrast in optical coherence tomography (OCT) images can be enhanced by utilizing surface plasmon resonant gold nanoparticles. To improve the poor in vivo transport of gold nanoparticles through biological barriers, an efficient delivery strategy is needed. In this study, the improved penetration and distribution of gold nanoparticles were achieved by microneedle and ultrasound, respectively, and it was demonstrated that this multimodal delivery of antibodyconjugated PEGylated gold nanoparticles enhanced the contrast in in vivo OCT images of oral dysplasia in a hamster model. PMID:19566301

  1. Enhanced detection of early-stage oral cancer in vivo by optical coherence tomography using multimodal delivery of gold nanoparticles

    NASA Astrophysics Data System (ADS)

    Kim, Chang Soo; Wilder-Smith, Petra; Ahn, Yeh-Chan; Liaw, Lih-Huei L.; Chen, Zhongping; Kwon, Young Jik

    2009-05-01

    Contrast in optical coherence tomography (OCT) images can be enhanced by utilizing surface plasmon resonant gold nanoparticles. To improve the poor in vivo transport of gold nanoparticles through biological barriers, an efficient delivery strategy is needed. In this study, the improved penetration and distribution of gold nanoparticles were achieved by microneedle and ultrasound, respectively, and it was demonstrated that this multimodal delivery of antibody-conjugated PEGylated gold nanoparticles enhanced the contrast in in vivo OCT images of oral dysplasia in a hamster model.

  2. 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%.

  3. Gold Nanoantennas

    SciTech Connect

    2012-01-01

    An array of gold nanoantennas laced into an artificial membrane enhances the fluorescence intensity of three different molecules when they pass through plasmonic hot spots in the array. Watch for the blue, green and red flashes. The photobleaching at the end of each fluorescence event (white flashes) is indicative of single molecule observations.

  4. 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.

  5. Biomineralization of gold: biofilms on bacterioform gold.

    PubMed

    Reith, Frank; Rogers, Stephen L; McPhail, D C; Webb, Daryl

    2006-07-14

    Bacterial biofilms are associated with secondary gold grains from two sites in Australia. 16S ribosomal DNA clones of the genus Ralstonia that bear 99% similarity to the bacterium Ralstonia metallidurans-shown to precipitate gold from aqueous gold(III) tetrachloride-were present on all DNA-positive gold grains but were not detected in the surrounding soils. These results provide evidence for the bacterial contribution to the authigenic formation of secondary bacterioform gold grains and nuggets.

  6. Is It Real Gold?

    ERIC Educational Resources Information Center

    Harris, Harold H.

    1999-01-01

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

  7. 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

  8. 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...

  9. 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

  10. Polystyrene microspheres as a specific marker for the diagnosis of aspiration in hamsters.

    PubMed

    Avital, Avraham; Shapiro, Eli; Doviner, Victoria; Sherman, Yoav; Margel, Shlomo; Tsuberi, Merav; Springer, Chaim

    2002-10-01

    The diagnosis of recurrent aspiration in young children is problematic because there is no specific gold standard test to be used. In the present work, normal saline or a suspension of white polystyrene microspheres in normal saline was instilled into hamsters' trachea (n = 42), and bronchoalveolar lavage (BAL) cytology, microsphere index (total microspheres/100 macrophages), and lung histology were followed for 90 d. Naive animals (n = 6) had no tracheal instillation. On Days 1, 3, 10, 32, 60, and 90 after tracheal instillation, animals were killed (saline-instilled animals, n = 3; and microsphere-instilled animals, n = 4), and BAL was performed. There was a marked inflammatory response in BAL on Day 1 after tracheal instillation of saline or microsphere suspension. White microspheres were clearly identified within alveolar macrophages in all studied days. Microsphere numbers showed a 50% disappearance rate of 10 d. A mild peribronchial inflammation was noted in lung histology only on Day 1 after instillation. Microspheres were not detected in extrapulmonary organs. We conclude that polystyrene microspheres instilled in hamsters' trachea can be easily identified in BAL macrophages for as long as 3 mo and could potentially be used as a sensitive, specific, and stable marker for the diagnosis of aspiration.

  11. Long-term intake of soyabean phytosterols lowers serum TAG and NEFA concentrations, increases bile acid synthesis and protects against fatty liver development in dyslipidaemic hamsters.

    PubMed

    Laos, Sirle; Caimari, Antoni; Crescenti, Anna; Lakkis, Jamileh; Puiggròs, Francesc; Arola, Lluís; del Bas, Josep Maria

    2014-09-14

    Various human trials and pre-clinical studies have suggested that dietary plant sterols possess hypotriacylglycerolaemic properties apart from their cholesterol-lowering properties. We hypothesised that phytosterols (PS) might attenuate triacylglycerolaemia by interfering with the deleterious effects of cholesterol overload in the liver. In the present study, twenty hamsters (Mesocricetus auratus) with diet-induced combined hyperlipidaemia were fed a high-fat diet (HFD, n 10) or a HFD supplemented with soyabean PS (n 10) for 40 d. In parallel, a healthy group was fed a standard diet (n 10). PS normalised fasting plasma cholesterol concentrations completely after 20 d and were also able to normalise serum TAG and NEFA concentrations after 40 d. HFD feeding caused microvesicular steatosis and impaired the expression of key genes related to fatty acid oxidation such as PPARA, carnitine palmitoyltransferase-Iα (CPT1A) and phosphoenolpyruvate carboxykinase 1 (PCK1) in the liver. PS treatment completely protected against HFD-induced steatosis and resulted in a normalised hepatic gene expression profile. The protection of the hepatic function by PS was paralleled by increased faecal cholesterol excretion along with a 2-fold increase in the biliary bile acid (BA):cholesterol ratio. The present study supports the conclusion that long-term consumption of PS can reduce serum TAG and NEFA concentrations and can protect against the development of fatty liver via different mechanisms, including the enhancement of BA synthesis. The results of the present study place these compounds as promising hepatoprotective agents against fatty liver and its derived pathologies.

  12. The bed nucleus of the stria terminalis is critical for sexual solicitation, but not for opposite-sex odor preference, in female Syrian hamsters.

    PubMed

    Martinez, Luis A; Petrulis, Aras

    2011-11-01

    Successful reproduction in vertebrates depends critically upon a suite of precopulatory behaviors that occur prior to mating. In Syrian hamsters (Mesocricetus auratus), these behaviors include vaginal scent marking and preferential investigation of male odors. The neural regulation of vaginal marking and opposite-sex odor preference likely involves an interconnected set of steroid-sensitive nuclei that includes the medial amygdala (MA), the bed nucleus of the stria terminalis (BNST), and the medial preoptic area (MPOA). For example, lesions of MA eliminate opposite-sex odor preference and reduce overall levels of vaginal marking, whereas lesions of MPOA decrease vaginal marking in response to male odors. Although BNST is densely interconnected with both MA and MPOA, little is known about the role of BNST in female precopulatory behaviors. To address this question, females received either bilateral, excitotoxic lesions of BNST (BNST-X) or sham lesions (SHAM), and were tested for scent marking and for investigatory responses to male and female odors. Whereas SHAM females vaginal marked more to male odors than female odors on two days of the estrous cycle, BNST-X females marked at equivalent levels to both odors. This deficit is not due to alterations in social odor investigation, as both BNST-X and SHAM females investigated male odors more than female odors. Finally, BNST lesions did not generally disrupt the cyclic changes in reproductive behaviors that occur across the estrous cycle. Taken together, these results demonstrate that BNST is critical for the normal expression of solicitational behaviors by females in response to male odor stimuli.

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

    PubMed

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

    2015-03-01

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

  14. The role of the medial preoptic area in appetitive and consummatory reproductive behaviors depends on sexual experience and odor volatility in male Syrian hamsters

    PubMed Central

    Been, Laura E.; Petrulis, Aras

    2010-01-01

    In Syrian hamsters (Mesocricetus Auratus), the expression of reproductive behavior requires the perception and discrimination of sexual odors. The behavioral response to these odors is mediated by a network of ventral forebrain nuclei, including the medial preoptic area (MPOA). The role of MPOA in male copulatory behavior has been well-studied, but less is known about the role of MPOA in appetitive aspects of male reproductive behavior. Furthermore, many previous studies that examined the role of MPOA in reproductive behavior have used large lesions that damaged other nuclei near MPOA or fibers of passage within MPOA, making it difficult to attribute post-lesion deficits in reproductive behavior to MPOA specifically. Thus, the current study used discrete, excitotoxic lesions of MPOA to test the role of this nucleus in opposite-sex odor preference and copulatory behavior in both sexually-naïve and sexually-experienced males. Lesions of MPOA eliminated preference for volatile, opposite-sex odors in sexually-naïve, but not sexually-experienced, males. When, however, males were allowed to contact the sexual odors, preference for female odors remained intact. Surprisingly, lesions of MPOA caused severe copulatory deficits only in sexually-naïve males, suggesting previous reports of copulatory deficits following MPOA lesions in sexually-experienced males were not due to damage to MPOA itself. Together, these results demonstrate that the role of MPOA in appetitive and consummatory aspects of reproductive behavior depends on the type of access to sexual odors and the sexual experience of the male. PMID:20732389

  15. 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.

  16. Hypothalamic over-expression of VGF in the Siberian hamster increases energy expenditure and reduces body weight gain.

    PubMed

    Lewis, Jo E; Brameld, John M; Hill, Phil; Cocco, Cristina; Noli, Barbara; Ferri, Gian-Luca; Barrett, Perry; Ebling, Francis J P; Jethwa, Preeti H

    2017-01-01

    VGF (non-acronymic) was first highlighted to have a role in energy homeostasis through experiments involving dietary manipulation in mice. Fasting increased VGF mRNA in the Arc and levels were subsequently reduced upon refeeding. This anabolic role for VGF was supported by observations in a VGF null (VGF-/-) mouse and in the diet-induced and gold-thioglucose obese mice. However, this anabolic role for VGF has not been supported by a number of subsequent studies investigating the physiological effects of VGF-derived peptides. Intracerebroventricular (ICV) infusion of TLQP-21 increased resting energy expenditure and rectal temperature in mice and protected against diet-induced obesity. Similarly, ICV infusion of TLQP-21 into Siberian hamsters significantly reduced body weight, but this was due to a decrease in food intake, with no effect on energy expenditure. Subsequently NERP-2 was shown to increase food intake in rats via the orexin system, suggesting opposing roles for these VGF-derived peptides. Thus to further elucidate the role of hypothalamic VGF in the regulation of energy homeostasis we utilised a recombinant adeno-associated viral vector to over-express VGF in adult male Siberian hamsters, thus avoiding any developmental effects or associated functional compensation. Initially, hypothalamic over-expression of VGF in adult Siberian hamsters produced no effect on metabolic parameters, but by 12 weeks post-infusion hamsters had increased oxygen consumption and a tendency to increased carbon dioxide production; this attenuated body weight gain, reduced interscapular white adipose tissue and resulted in a compensatory increase in food intake. These observed changes in energy expenditure and food intake were associated with an increase in the hypothalamic contents of the VGF-derived peptides AQEE, TLQP and NERP-2. The complex phenotype of the VGF-/- mice is a likely consequence of global ablation of the gene and its derived peptides during development, as well

  17. Hypothalamic over-expression of VGF in the Siberian hamster increases energy expenditure and reduces body weight gain

    PubMed Central

    Brameld, John M.; Hill, Phil; Cocco, Cristina; Noli, Barbara; Ferri, Gian-Luca; Barrett, Perry; Ebling, Francis J. P.; Jethwa, Preeti H.

    2017-01-01

    VGF (non-acronymic) was first highlighted to have a role in energy homeostasis through experiments involving dietary manipulation in mice. Fasting increased VGF mRNA in the Arc and levels were subsequently reduced upon refeeding. This anabolic role for VGF was supported by observations in a VGF null (VGF-/-) mouse and in the diet-induced and gold-thioglucose obese mice. However, this anabolic role for VGF has not been supported by a number of subsequent studies investigating the physiological effects of VGF-derived peptides. Intracerebroventricular (ICV) infusion of TLQP-21 increased resting energy expenditure and rectal temperature in mice and protected against diet-induced obesity. Similarly, ICV infusion of TLQP-21 into Siberian hamsters significantly reduced body weight, but this was due to a decrease in food intake, with no effect on energy expenditure. Subsequently NERP-2 was shown to increase food intake in rats via the orexin system, suggesting opposing roles for these VGF-derived peptides. Thus to further elucidate the role of hypothalamic VGF in the regulation of energy homeostasis we utilised a recombinant adeno-associated viral vector to over-express VGF in adult male Siberian hamsters, thus avoiding any developmental effects or associated functional compensation. Initially, hypothalamic over-expression of VGF in adult Siberian hamsters produced no effect on metabolic parameters, but by 12 weeks post-infusion hamsters had increased oxygen consumption and a tendency to increased carbon dioxide production; this attenuated body weight gain, reduced interscapular white adipose tissue and resulted in a compensatory increase in food intake. These observed changes in energy expenditure and food intake were associated with an increase in the hypothalamic contents of the VGF-derived peptides AQEE, TLQP and NERP-2. The complex phenotype of the VGF-/- mice is a likely consequence of global ablation of the gene and its derived peptides during development, as well

  18. 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.

  19. 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.

  20. 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.

  1. 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.

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

    PubMed

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

    2007-02-01

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

  3. 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.

  4. [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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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...

  20. 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...

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

    Code of Federal Regulations, 2014 CFR

    2014-01-01

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

  2. 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...

  3. 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...

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Lesions of the posterior bed nucleus of the stria terminalis eliminate opposite-sex odor preference and delay copulation in male Syrian hamsters: role of odor volatility and sexual experience

    PubMed Central

    Been, Laura E.; Petrulis, Aras

    2010-01-01

    In Syrian hamsters (Mesocricetus auratus), the expression of reproductive behavior requires the perception of social odors. The behavioral response to these odors is mediated by a network of ventral forebrain nuclei, including the posterior bed nucleus of the stria terminalis (pBNST). Previous studies have tested the role of pBNST in reproductive behavior, but the use of large, fiber-damaging lesions in these studies make it difficult to attribute post-lesion deficits to pBNST specifically. Thus, the current study used discrete, excitotoxic lesions of pBNST to test the role of pBNST in opposite-sex odor preference and copulatory behavior in both sexually-naïve and sexually-experienced males. Lesions of pBNST decreased sexually-naïve males’ investigation of volatile female odors, resulting in an elimination of opposite-sex odor preference. This elimination of preference was not due to a sensory deficit, as males with pBNST lesions were able to discriminate between odors. When, however, subjects were given sexual experience prior to pBNST lesions, their preference for volatile opposite-sex odors remained intact post-lesion. Similarly, when sexually-naïve or sexually-experienced subjects were allowed to contact the social odors during the preference test, lesions of pBNST decreased males’ investigation of female odors, but did not eliminate preference for opposite-sex odors, regardless of sexual experience. Finally, lesions of pBNST delayed the copulatory sequence in sexually-naïve, but not sexually-experienced, males such that they took longer to mount, intromit, ejaculate, and display long intromissions. Together, these results demonstrate that pBNST plays a unique and critical role in both appetitive and consummatory aspects of male reproductive behaviors. PMID:20597978

  13. 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

  14. GOLD PLATING PROCESS

    DOEpatents

    Seegmiller, R.

    1957-08-01

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

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. Dark field optical imaging reveals vascular changes in an inducible hamster cheek pouch model during carcinogenesis

    PubMed Central

    Hu, Fangyao; Morhard, Robert; Murphy, Helen A.; Zhu, Caigang; Ramanujam, Nimmi

    2016-01-01

    In this study, we propose a low-cost cross-polarized dark field microscopy system for in vivo vascular imaging to detect head and neck cancer. A simple-to-use Gabor-filter-based image processing technique was developed to objectively and automatically quantify several important vascular features, including tortuosity, length, diameter and area fraction, from vascular images. Simulations were performed to evaluate the accuracies of vessel segmentation and feature extraction for our algorithm. Sensitivity and specificity for vessel segmentation of the Gabor masks both remained above 80% at all contrast levels when compared to gold-standard masks. Errors for vascular feature extraction were under 5%. Moreover, vascular contrast and vessel diameter were identified to be the two primary factors which affected the segmentation accuracies. After our algorithm was validated, we monitored the blood vessels in an inducible hamster cheek pouch carcinogen model over 17 weeks and quantified vascular features during carcinogenesis. A significant increase in vascular tortuosity and a significant decrease in vessel length were observed during carcinogenesis. PMID:27699096

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. 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.

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

    NASA Technical Reports Server (NTRS)

    Musacchia, X. J.

    1973-01-01

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

  10. Chalcogenide centred gold complexes.

    PubMed

    Gimeno, M Concepción; Laguna, Antonio

    2008-09-01

    Chalcogenide-centred gold complexes are an important class of compounds in which a central chalcogen is surrounded by several gold atoms or gold and other metals. They have special characteristics such as unusual geometries, electron deficiency and properties such as luminescence or non-linear optical properties. The best known species are the trinuclear [E(AuPR3)3]+, 'oxonium' type species, that have high synthetic applicability, not only in other chalcogen-centred species, but in many other organometallic derivatives. The aurophilic interactions play an important role in the stability, preference for a particular geometry and luminescence properties in this type of derivatives (critical review, 117 references).

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. Gold nanoprobes for theranostics

    PubMed Central

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

    2011-01-01

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

  20. Gold-bearing skarns

    USGS Publications Warehouse

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

    1991-01-01

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

  1. Getting the Gold Treatment

    NASA Technical Reports Server (NTRS)

    2002-01-01

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

  2. Gold in minerals and the composition of native gold

    USGS Publications Warehouse

    Jones, Robert Sprague; Fleischer, Michael

    1969-01-01

    Gold occurs in nature mainly as the metal and as various alloys. It forms complete series of solid solutions with silver, copper, nickel, palladium, and platinum. In association with the platinum metals, gold occurs as free gold as well as in solid solution. The native elements contain the most gold, followed by the sulfide minerals. Several gold tellurides are known, but no gold selenides have been reported, and only one sulfide, the telluride-sulfide mineral nagyagite, is known. The nonmetallic minerals carry the least gold, and the light-colored minerals generally contain less gold than the dark minerals. Some conclusions in the literature are conflicting in regard to the relation of fineness of native gold to its position laterally and vertically within a lode, the nature of the country rocks, and the location and size of nuggets in a streambed, as well as to the variation of fineness within an individual nugget.

  3. 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.

  4. 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...

  5. 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.

  6. 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).

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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 ...

  12. In vivo liberation of gold ions from gold implants. Autometallographic tracing of gold in cells adjacent to metallic gold.

    PubMed

    Danscher, Gorm

    2002-05-01

    For some years, the implantation of small pieces of gold has been used as an unauthorised remedy for osteoarthritis and pain. The aim of the present study was to evaluate whether gold ions are released from gold implants. Pieces of pure gold were placed in the connective tissue of skin, bone and brains of anaesthetised animals. Ten days to several months later the animals were anaesthetised and killed by transcardial perfusion. Tissue blocks containing the gold pieces were cut, and the sections were silver-enhanced by autometallography. It was found that gold ions are released from the implanted gold and diffuse out into the surrounding tissue. The gold-containing cells in connective tissues were macrophages, mast cells and fibroblasts. In the brain, gold accumulated in astrocytes and neurons. Proton-induced X-ray emission spectroscopy analysis of the tissue surrounding gold implants confirmed that gold ions are liberated. The findings suggest that the gold implant technique, on a local scale, mimics systemic treatment with a gold-containing drug.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. Biorecovery of gold

    USGS Publications Warehouse

    Eisler, R.

    2003-01-01

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

  19. 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

  20. 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}.

  1. 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.

  2. Gold-bismuth clusters.

    PubMed

    Martínez, Ana

    2014-08-07

    Metal clusters have interesting characteristics, such as the relationship between properties and size of the cluster. This is not always apparent, so theoretical studies can provide relevant information. In this report, optimized structures and electron donor-acceptor properties of AunBim clusters are reported (n + m = 2-7, 20). Density functional theory calculations were performed to obtain optimized structures. The ground states of gold clusters formed with up to seven atoms are planar. The presence of Bi modifies the structure, and the clusters become 3-D. Several optimized geometries have at least one Bi atom bonded to gold or bismuth atoms and form structures similar to NH3. This fragment is also present in clusters with 20 atoms, where the formation of Au3Bi stabilizes the structures. Bismuth clusters are better electron donors and worse electron acceptors than gold clusters. Mixed clusters fall in between these two extremes. The presence of Bi atoms in gold clusters modifies the electron donor-acceptor properties of the clusters, but there is no correlation between the number of Bi atoms present in the cluster and the capacity for donating electrons. The effect of planarity in Au19Bi clusters is the same as that in Au20 clusters. The properties of pure gold clusters are certainly interesting, but clusters formed by Bi and Au are more important because the introduction of different atoms modifies the geometry, the stability, and consequently the physical and chemical properties. Apparently, the presence of Bi may increase the reactivity of gold clusters, but further studies are necessary to corroborate this hypothesis.

  3. Chemistry for oncotheranostic gold nanoparticles.

    PubMed

    Trouiller, Anne Juliette; Hebié, Seydou; El Bahhaj, Fatima; Napporn, Teko W; Bertrand, Philippe

    2015-06-24

    This review presents in a comprehensive ways the chemical methods used to functionalize gold nanoparticles with focus on anti-cancer applications. The review covers the parameters required for the synthesis gold nanoparticles with defined shapes and sizes, method for targeted delivery in tumours, and selected examples of anti-cancers compounds delivered with gold nanoparticles. A short survey of bioassays for oncology based on gold nanoparticles is also presented.

  4. Derivatized gold clusters and antibody-gold cluster conjugates

    DOEpatents

    Hainfeld, James F.; Furuya, Frederic R.

    1994-11-01

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

  5. Derivatized gold clusters and antibody-gold cluster conjugates

    DOEpatents

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

    1994-11-01

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

  6. Earth's continental crustal gold endowment

    NASA Astrophysics Data System (ADS)

    Frimmel, H. E.

    2008-03-01

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

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

    PubMed

    Vavelidis, M; Andreou, S

    2008-04-01

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

  8. 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

  9. 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.

  10. [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.

  11. 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

  12. 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.

  13. 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

  14. GOLD PRESSURE VESSEL SEAL

    DOEpatents

    Smith, A.E.

    1963-11-26

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

  15. Digging for Gold

    ERIC Educational Resources Information Center

    Waters, John K.

    2012-01-01

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

  16. 'Cascade Gold' raspberry

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  17. Gold Nanoparticle Microwave Synthesis

    SciTech Connect

    Krantz, Kelsie E.; Christian, Jonathan H.; Coopersmith, Kaitlin; Washington, II, Aaron L.; Murph, Simona H.

    2016-07-27

    At the nanometer scale, numerous compounds display different properties than those found in bulk material that can prove useful in areas such as medicinal chemistry. Gold nanoparticles, for example, display promise in newly developed hyperthermia therapies for cancer treatment. Currently, gold nanoparticle synthesis is performed via the hot injection technique which has large variability in final particle size and a longer reaction time. One underdeveloped area by which these particles could be produced is through microwave synthesis. To initiate heating, microwaves agitate polar molecules creating a vibration that gives off the heat energy needed. Previous studies have used microwaves for gold nanoparticle synthesis; however, polar solvents were used that partially absorbed incident microwaves, leading to partial thermal heating of the sample rather than taking full advantage of the microwave to solely heat the gold nanoparticle precursors in a non-polar solution. Through this project, microwaves were utilized as the sole heat source, and non-polar solvents were used to explore the effects of microwave heating only as pertains to the precursor material. Our findings show that the use of non-polar solvents allows for more rapid heating as compared to polar solvents, and a reduction in reaction time from 10 minutes to 1 minute; this maximizes the efficiency of the reaction, and allows for reproducibility in the size/shape of the fabricated nanoparticles.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Gold Nanoparticles Cytotoxicity

    NASA Astrophysics Data System (ADS)

    Mironava, Tatsiana

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

  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. Spiky gold nanoshells.

    PubMed

    Sanchez-Gaytan, Brenda L; Park, So-Jung

    2010-12-21

    We report a high-yield synthetic method for a new type of metal nanostructure, spiky gold nanoshells, which combine the morphological characteristics of hollow metal nanoshells and nanorods. Our method utilizes block copolymer assemblies and polymer beads as templates for the growth of spiky nanoshells. Various shapes of spiky metal nanoshells were prepared in addition to spherical nanoshells by using block copolymer assemblies such as rod-like micelles, vesicles, and bilayers as templates. Furthermore, spiky gold shells encapsulating magnetic nanoparticles or quantum dots were prepared based on the ability of block copolymers to self-assemble with various types of nanoparticles and molecules. The capability to encapsulate other materials in the core, the shape tunability, and the highly structured surface of spiky nanoshells should benefit a range of imaging, sensing, and medical applications of metal nanostructures.

  7. Radioactive gold ring dermatitis

    SciTech Connect

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

    1990-08-01

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

  8. 'Pot of Gold'

    NASA Technical Reports Server (NTRS)

    2004-01-01

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

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. [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.

  16. 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.

  17. 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

  18. Gold-gold junction electrodes:the disconnection method.

    PubMed

    Dale, Sara E C; Vuorema, Anne; Ashmore, Ellen M Y; Kasprzyk-Horden, Barbara; Sillanpää, Mika; Denuault, Guy; Marken, Frank

    2012-02-01

    The formation of gold-gold junction electrodes for application in electroanalysis is described here based on electro-deposition from a non-cyanide gold plating bath. Converging growth of two hemispherical gold deposits on two adjacent platinum microelectrodes (both 100 µm diameter in glass, ca. 45 µm gap) followed by careful etching in aqueous chloride solution was employed. During growth both gold hemispheres "connect" and during etching "disconnection" is evident in a drop in current. Gold-gold junctions with sub-micron gaps are formed and applied for the electroanalytical detection of sub-micromolar concentrations of hydroquinone in 0.1 M phosphate buffer pH 7 (E(rev) = 0.04 V vs. SCE) and sub-micromolar concentration of dopamine in 0.1 M phosphate buffer pH 7 (E(rev) = 0.14 V vs. SCE). The potential future uses in analysis and limitations of gold-gold junction electrodes are discussed.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

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

    PubMed

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

    2015-12-01

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

  5. 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

  6. 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.

  7. 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.

  8. 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

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

    PubMed Central

    Carlton, Elizabeth D.; Demas, Gregory E.

    2014-01-01

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

  10. 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.

  11. 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

  12. 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.

  13. 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).

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. Industry Forum Navy Gold Coast

    DTIC Science & Technology

    2014-08-13

    NAVFAC Southwest Lora E. Morrow Deputy for Small Business NAVFAC Southwest NAVFAC Southwest Industry Forum Navy Gold Coast August...REPORT DATE 13 AUG 2014 2. REPORT TYPE 3. DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Industry Forum Navy Gold Coast 5a...S) 12. DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release; distribution unlimited 13. SUPPLEMENTARY NOTES NDIA 27th Navy Gold Coast

  19. 31 CFR 100.4 - Gold coin and gold certificates in general.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

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

  20. 31 CFR 100.4 - Gold coin and gold certificates in general.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  1. 31 CFR 100.4 - Gold coin and gold certificates in general.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Gold coin and gold certificates in... EXCHANGE OF PAPER CURRENCY AND COIN In General § 100.4 Gold coin and gold certificates in general. Gold coins, and gold certificates of the type issued before January 30, 1934, are exchangeable, as...

  2. 31 CFR 100.4 - Gold coin and gold certificates in general.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

  3. 31 CFR 100.4 - Gold coin and gold certificates in general.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Surface-stabilized gold nanocatalysts

    DOEpatents

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

    2009-12-08

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

  13. Experimental abrasion of detrital gold

    USGS Publications Warehouse

    Yeend, Warren E.

    1975-01-01

    The physical breakdown and abrasion rates of gold were studied using a tumbler to simulate natural high-energy environments. The gold fragments were tumbled for periods ranging from 30 to 240 h with different combinations of sand, cobbles, and water at velocities of 0.5 and 2.0 mi/h (0.85 and 3.22 km/h). With sand and gravel, the common bedload of the rivers that deposited the gold-bearing Tertiary sedimentary rocks of the Sierra Nevada, gold is abraded at rates of 0.015 to 0.007 percent (by weight) per hour of travel (at 0.5 mi/h or 0.845 km/h). Cobbles, rather than sand, are responsible for most of the physical changes and abrasion of the gold. Ten gold fragments tumbled for 120 h with cobbles and water (no sand) were broken down to 68 recoverable fragments and lost about 25 percent of their weight to particles smaller than could be recovered using conventional panning techniques. Gold tumbled for 120 h with sand and water lost less than 1 percent of its weight. Gold was abraded faster by wet sand than by dry sand. Velocity appears to be more important as a factor in abrasion of gold than travel distance a fourfold increase in velocity produced a tenfold increase in hourly abrasion rates of gold. Scanning electron microscope examination of the gold fragments after the tumbling experiments revealed differences in surface texture between fragments tumbled with (1) sand, (2) sand and cobbles, and (3) cobbles only.

  14. 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.

  15. When cyclopropenes meet gold catalysts

    PubMed Central

    Miege, Frédéric

    2011-01-01

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

  16. Antibody-gold cluster conjugates

    DOEpatents

    Hainfeld, J.F.

    1988-06-28

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

  17. 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

  18. 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.

  19. 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.

  20. 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

  1. [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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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.

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

    PubMed

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

    2015-03-01

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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

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

    PubMed

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

    2016-08-01

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

  3. 20th-Century Gold Rush.

    ERIC Educational Resources Information Center

    Wargo, Joseph G.

    1992-01-01

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

  4. 41 CFR 101-45.002 - Gold.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

  5. 41 CFR 101-45.002 - Gold.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  6. 41 CFR 101-45.002 - Gold.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

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

  7. 41 CFR 101-45.002 - Gold.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

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

  8. 41 CFR 101-45.002 - Gold.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Enhancement of gold recovery using bioleaching from gold concentrate

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

  15. Overcoming barriers in topical administration of gold nanoparticles for optical coherence tomography using multimodal delivery

    NASA Astrophysics Data System (ADS)

    Kim, Chang Soo; Wilder-Smith, Petra; Ahn, Yeh-Chan; Liaw, Lih-Huei L.; Chen, Zhongping; Kwon, Young Jik

    2010-02-01

    Optical coherence tomography (OCT) is a non-invasive and promising imaging modality with high resolution that is an order of magnitude higher than current diagnostic techniques. However, its use in detecting early-stage cancer is limited due to insufficient contrast level in biological tissue, which can be enhanced by harnessing contrast agents [e.g., gold nanoparticles (Au NPs)]. Enhanced penetration by creating micropassages and distribution by ultrasonic force (multimodal topical delivery) was proven to overcome two major barriers (stratum corneum and epithelial barriers) in topically administering Au NPs using an in vivo oral dysplasia hamster model (overall 150% enhanced OCT contrast). Expanded progress on a highly efficient and versatile Au NP-releasing polymer microneedle platform showed a promising next generation multi-modal delivery of Au NPs.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Colloidal Synthesis of Gold Semishells

    PubMed Central

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

    2012-01-01

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

  9. Gold, currencies and market efficiency

    NASA Astrophysics Data System (ADS)

    Kristoufek, Ladislav; Vosvrda, Miloslav

    2016-05-01

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

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. GOLD: The Genomes Online Database

    DOE Data Explorer

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

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

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

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

    • 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.

    • 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

    • Gold, coal and oil.

      PubMed

      Dani, Sergio U

      2010-03-01

      Jared Diamond has hypothesized that guns, germs and steel account for the fate of human societies. Here I propose an extension of Diamond's hypothesis and put it in other terms and dimensions: gold, coal and oil account not only for the fate of human societies but also for the fate of mankind through the bodily accumulation of anthropogenic arsenic, an invisible weapon of mass extinction and evolutionary change. The background is clear; arsenic species fulfill seven criteria for a weapon of mass extinction and evolutionary change: (i) bioavailability to all living organisms; (ii) imperceptibility; (iii) acute toxicity; (iv) bioaccumulation and chronic toxicity; (v) adverse impact on reproductive fitness and reproductive outcomes and early-age development and growth in a wide range of microbial, plant and animal species including man; (vi) widespread geographical distribution, mobility and ecological persistence on a centennial to millennial basis and (vii) availability in necessary and sufficient amounts to exert evolutionarily meaningful effects. The proof is becoming increasingly feasible as human exploitation of gold, coal and oil deposits cause sustainable rises of arsenic concentrations in the biosphere. Paradoxically, humans are among the least arsenic-resistant organisms because humans are long-lived, encephalized and complex social metazoans. An arsenic accumulation model is presented here to describe how arsenic accumulates in the human body with increasing age and at different provisionally safe exposure levels. Arsenic accumulates in the human body even at daily exposure levels which are within the lowest possible WHO provisional tolerance limits, yielding bodily arsenic concentrations which are above WHO provisional limits. Ongoing consequences of global scale arsenic poisoning of mankind include age-specific rises in morbidity and mortality followed by adaptive changes. The potential rise of successful forms of inborn resistance to arsenic in humans

    • 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

    • 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

    • 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

    • 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

    • Gold nanoparticle (AuNPs) and gold nanopore (AuNPore) catalysts in organic synthesis.

      PubMed

      Takale, Balaram S; Bao, Ming; Yamamoto, Yoshinori

      2014-04-07

      Organic synthesis using gold has gained tremendous attention in last few years, especially heterogeneous gold catalysis based on gold nanoparticles has made its place in almost all organic reactions, because of the robust and green nature of gold catalysts. In this context, gold nanopore (AuNPore) with a 3D metal framework is giving a new dimension to heterogeneous gold catalysts. Interestingly, AuNPore chemistry is proving better than gold nanoparticles based chemistry. In this review, along with recent advances, major discoveries in heterogeneous gold catalysis are discussed.

    • Modeling of gold production in Malaysia

      NASA Astrophysics Data System (ADS)

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

      2013-04-01

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

    • Monoclonal antibody "gold rush".

      PubMed

      Maggon, Krishan

      2007-01-01

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

    • Goldschlager allergy in a gold allergic patient.

      PubMed

      Guenthner, T; Stork, C M; Cantor, R M

      1999-08-01

      We describe the case of gold allergy after ingestion of GOLDSCHLAGER, a gold-containing liquor, in a patient with a previous allergy to gold jewelry. The patient was not aware that genuine gold particles were contained in the schnapps liquor and that ingestion could result in a reaction similar to that experienced by individuals sensitive to gold jewelry. Clinicians should be familiar with the presence of gold particles in GOLDSCHLAGER liquor and the potential for allergic reactions to occur in those so predisposed.

    • 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

    • 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

    • 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

    • 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

    • 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.

    • 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.

  1. 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.

  2. 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

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

    PubMed

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

    2014-01-22

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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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…

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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...

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Golden-Syrian hamsters have been used as an animal model to assess diet-induced atherosclerosis since the early 1980s. Advantages appeared to include a low rate of endogenous cholesterol synthesis, receptor-mediated uptake of LDL cholesterol, cholesteryl ester transfer protein activity, hepatic apo...

  3. [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.

  4. 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

  5. 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.

  6. 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.

  7. 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...

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Gold nanoparticles for photoacoustic imaging

    PubMed Central

    Li, Wanwan; Chen, Xiaoyuan

    2015-01-01

    Photoacoustic (PA) imaging is a biomedical imaging modality that provides functional information regarding the cellular and molecular signatures of tissue by using endogenous and exogenous contrast agents. There has been tremendous effort devoted to the development of PA imaging agents, and gold nanoparticles as exogenous contrast agents have great potential for PA imaging due to their inherent and geometrically induced optical properties. The gold-based nanoparticles that are most commonly employed for PA imaging include spheres, rods, shells, prisms, cages, stars and vesicles. This article provides an overview of the current state of research in utilizing these gold nanomaterials for PA imaging of cancer, atherosclerotic plaques, brain function and image-guided therapy. PMID:25600972

  10. Economic geology: Gold buried by oxygen

    NASA Astrophysics Data System (ADS)

    Gaillard, Fabrice; Copard, Yoann

    2015-03-01

    The Witwatersrand Basin in South Africa contains extraordinary amounts of gold. Thermodynamic calculations suggest that the gold may have accumulated there in response to a perfect storm of conditions available only during the Archaean.

  11. Recent Developments in Australian Gold Extraction.

    ERIC Educational Resources Information Center

    Thiele, Rodney B.

    1995-01-01

    Describes new technologies that have greatly improved the extraction efficiency of gold ore, including: altering plant layout to promote efficiency, engaging Filiblast forced oxidation and bioxidation systems, and updating the electrowinning procedure at the gold recovery stage. (JRH)

  12. Formation, structure, and orientation of gold silicide on gold surfaces

    NASA Technical Reports Server (NTRS)

    Green, A. K.; Bauer, E.

    1976-01-01

    The formation of gold silicide on Au films evaporated onto Si(111) surfaces is studied by Auger electron spectroscopy (AES) and low-energy electron diffraction (LEED). Surface condition, film thickness, deposition temperature, annealing temperature, and heating rate during annealing are varied. Several oriented crystalline silicide layers are observed.

  13. Single-crystalline gold nanoplates from a commercial gold plating solution.

    PubMed

    Li, Zhonghao; Lapeyre, Véronique; Ravaine, Valérie; Ravaine, Serge; Kuhn, Alexander

    2009-03-01

    A novel route was proposed to synthesize gold nanoplates using a commercial gold plating solution as the reactant. Single-crystalline gold nanoplates can be successfully synthesized by reacting gold plating solution with HCl. The as-prepared nanoplates are from several micrometers to tens of micrometers in size. The effects of reactant concentration and temperature on the morphology of the gold products were investigated. The size of the gold nanoplate increases with the decrease of the amount of gold plating solution, while irregular gold nanoparticles are formed as the HCl concentration becomes low. When the reaction temperature is as low as room temperature, nanoplates with a concavity form. Specifically, it is found that the Cl- plays an important role for the formation of these gold nanoplates. The formation mechanism of the gold nanoplates is studied in detail.

  14. Structural change from doping the gold cluster.

    PubMed

    Tang, Yiji; Wang, Shu-Guang; Li, Jia

    2011-05-01

    Doping gold clusters with a transition metal (M@Au(n)) causes structural change. To determine the mechanism by which these changes occur, the central gold atom of Au(5) was doped with its same row transition metals Pt, Ir, Os, Re, and W. Based on theoretical calculations, a similar trend was found in other gold clusters.

  15. Highly active thermally stable nanoporous gold catalyst

    SciTech Connect

    Biener, Juergen; Wittstock, Arne; Biener, Monika M.; Bagge-Hansen, Michael; Baeumer, Marcus; Wichmann, Andre; Neuman, Bjoern

    2016-12-20

    In one embodiment, a system includes a nanoporous gold structure and a plurality of oxide particles deposited on the nanoporous gold structure; the oxide particles are characterized by a crystalline phase. In another embodiment, a method includes depositing oxide nanoparticles on a nanoporous gold support to form an active structure and functionalizing the deposited oxide nanoparticles.

  16. Evaluation of the toxicity of intravenous delivery of auroshell particles (gold-silica nanoshells).

    PubMed

    Gad, Shayne C; Sharp, Kelly L; Montgomery, Charles; Payne, J Donald; Goodrich, Glenn P

    2012-01-01

    Gold nanoshells (155 nm in diameter with a coating of polyethylene glycol 5000) were evaluated for preclinical biocompatibility, toxicity, and biodistribution as part of a program to develop an injectable device for use in the photothermal ablation of tumors. The evaluation started with a complete good laboratory practice (GLP) compliant International Organization for Standardization (ISO)-10993 biocompatibility program, including cytotoxicity, pyrogenicity (US Pharmacopeia [USP] method in the rabbit), genotoxicity (bacterial mutagenicity, chromosomal aberration assay in Chinese hamster ovary cells, and in vivo mouse micronucleus), in vitro hemolysis, intracutaneous reactivity in the rabbit, sensitization (in the guinea pig maximization assay), and USP/ISO acute systemic toxicity in the mouse. There was no indication of toxicity in any of the studies. Subsequently, nanoshells were evaluated in vivo by intravenous (iv) infusion using a trehalose/water solution in a series of studies in mice, Sprague-Dawley rats, and Beagle dogs to assess toxicity for time durations of up to 404 days. Over the course of 14 GLP studies, the gold nanoshells were well tolerated and, when injected iv, no toxicities or bioincompatibilities were identified.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. Gold, Silver and Bronze Citations.

    ERIC Educational Resources Information Center

    American School & University, 2003

    2003-01-01

    Presents the gold, silver, and bronze winners of a competition, which judged the most outstanding learning environments at educational institutions nationwide. Jurors spent two days reviewing projects, focusing on concepts and ideas that made them exceptional. For each citation, the article offers information on the firm, client, total area, total…

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. Bimodal porous gold opals for molecular sensing

    NASA Astrophysics Data System (ADS)

    Chae, Weon-Sik; Yu, Hyunung; Ham, Sung-Kyoung; Lee, Myung-Jin; Jung, Jin-Seung; Robinson, David B.

    2013-11-01

    We have fabricated bimodal porous gold skeletons by double-templating routes using poly(styrene) colloidal opals as templates. The fabricated gold skeletons show a bimodal pore-size distribution, with small pores within spheres and large pores between spheres. The templated bimodal porous gold skeletons were applied in Raman scattering experiments to study sensing efficiency for probe molecules. We found that the bimodal porous gold skeletons showed obvious enhancement of Raman scattering signals versus that of the unimodal porous gold which only has interstitial pores of several hundred nanometers.

  14. Gold nephropathy in juvenile rheumatoid arthritis.

    PubMed

    Husserl, F E; Shuler, S E

    1979-01-01

    A 2-year-old girl was treated with gold salts for juvenile rheumatoid arthritis. Treatment had to be discontinued when persistent proteinuria was detected. As this case report indicates, close monitoring of the urine is mandatory during treatment with gold salts to detect early signs of toxicity: hematuria followed by casts and then proteinuria as therapy is continued. Histologic examination with electron microscopy will help to differentiate the different forms of gold toxicity. When the findings are consistent with gold-induced renal involvement, therapy should be discontinued. The gold nephropathy usually resolves in time, with no permanent renal damage.

  15. Gold recycling; a materials flow study

    USGS Publications Warehouse

    Amey, Earle B.

    2000-01-01

    This materials flow study includes a description of trends in consumption, loss, and recycling of gold-containing materials in the United States in 1998 in order to illustrate the extent to which gold is presently being recycled and to identify recycling trends. The quantity of gold recycled, as a percent of the apparent supply of gold, was estimated to be about 30 percent. Of the approximately 446 metric tons of gold refined in the United States in 1998, the fabricating and industrial use losses were 3 percent.

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

    PubMed Central

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

    2016-01-01

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

  17. 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.

  18. 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.

  19. 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.

  20. 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