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1.
Djungarian hamsters were examined for the susceptibility to Neospora caninum infection. After 29 Djungarian hamsters were intraperitoneally inoculated with 5 x 10(6) N. caninum tachyzoites of JPA1 strain, some animals showed symptoms such as ataxia, and many tissue cysts were detected in the brain and a cyst in the muscular tunics of stomach. Especially, more than 100 cysts per head were observed after 5 weeks post inoculation. It is suggested that the Djungarian hamster is a model useful to examine neosporosis.  相似文献   

2.
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.  相似文献   

3.
Four Djungarian hamsters ( Phodopus sungorus campbelli ) were examined because of insidious globe enlargement, visual impairment and secondary altered behavior. Buphthalmos, deep anterior chambers, widely dilated pupils and poor to absent pupillary light reflexes were evident bilaterally in all four animals. Pale retinae and atrophic optic nerve heads were observed in the oldest hamsters. Light microscopic findings, including uveal atrophy, retinal atrophy (especially the inner retina), and a relative decrease in ganglion cells and optic nerve atrophy, were consistent with glaucoma. The etiology was unclear, but a genetic predisposition cannot be excluded.  相似文献   

4.
Djungarian (Phodopus sungorus) and Chinese (Cricetulus griseus) hamster IFN-gamma genes were cloned and sequenced. The Djungarian and Chinese hamster genes were both 525bp nucleotides, resulting in 174 amino acids in full length with a predicted molecular weight (MW) of 19,560 dal and 19,775 dal, respectively. The first 23 amino terminal amino acids consisted of a hydrophobic signal sequence when cleavaged, which would result in a mature 151 amino acid polypeptide with a predicted MW of 17,115 dal in the Djungarian hamster IFN-gamma and 17,255 dal in the Chinese hamster one.  相似文献   

5.
Interleukin 10 (IL-10) genes of Djungarian, Chinese, and Syrian hamsters were cloned. The clones of IL-10 consisted of 537 bp nucleotides and 178 amino acids in full length, and the nucleotide and amino acid sequences exhibited a high degree of homology with those of the mouse and human. Since the number and position of signal sequences, N-glycosylations and cysteine sites in the IL-10 amino acid sequences of the hamsters were the same as those of the mouse, we suggest that the IL-10 molecular structures of the hamster are closer to that of the mouse than human.  相似文献   

6.
A 2.5‐year‐old intact male Roborovski hamster (Phodopus roborovskii) was presented with a large subcutaneous mass overlying the abdomen, affecting the animal's ambulation and access to different compartments of the cage through narrow tubing. Ultrasound examination delineated a well‐circumscribed mass in the subcutis of the caudoventral abdominal region. The mass was surgically excised and on cytologic examination showed, in a background of blood, a small population of individually arranged oval to spindle‐shaped cells that exhibited a moderate degree of anisokaryosis, coarsely stippled chromatin, one or more prominent nucleoli, and lightly basophilic well‐defined cytoplasmic processes. Histologically, the mass was composed of interlacing streams and bundles of pleomorphic spindle cells (ganglion‐like cells) with variable amounts of collagenous stroma. The neoplastic cells exhibited moderate features of malignancy. These cells stained intensely with vimentin, but not with any other markers, including antibodies to cytokeratin AE1/AE3, S100 protein, desmin, smooth muscle actin, synaptophysin, neurofilament, and androgen receptor. Based on histologic features, the mass was diagnosed as an atypical fibrosarcoma. This is the first report of an atypical fibrosarcoma in a Roborovski hamster and one of few reports of atypical fibrosarcoma in domesticated hamsters overall.  相似文献   

7.
Spontaneous subcutaneous extraskeletal osteosarcoma was diagnosed in the subcutaneous tissue of two Djungarian hamsters. Histologically, the tumour was characterized by multiple nests of osseous and cartilaginous components within a proliferation of pleomorphic cells. No abnormality was observed in any skeletal bones and no change suggesting tumorous growth was observed in any other sites. This is the first report of extraskeletal osteosarcomas in Djungarian hamsters.  相似文献   

8.
As the comparative study was carried out on the susceptibility by the pursuit of parasitemia among the Djungarian, Syrian, and Chinese hamsters as well as BALB/c mice infected with the Syrian hamster-adapted Babesia microti strain, and Djungarian hamsters showed the highest parasitemia among them. Then, the other hematological parameters were pursued in the Djungarian hamsters infected with the hamster-adapted B. microti strain. Remarkable symptoms observed were hemoglobinuria clinically, anemia hematologically, and splenomegaly macroscopically during all over the observation period for 24 weeks post infection (PI). Parasitemia began to rise at 2 weeks and peaked at 4 weeks PI. After that, parasitemia decreased gradually but was maintained with a level of about 10% on average until 24 weeks PI at the end of the experiment. A decrease in the RBC count, Hb, and PCV, and an increase in the reticulocyte and WBC counts due to the development of immature neutrophils, lymphocytes and monocytes were recognized together with a rise of parasitemia. The hamsters had macrocytic hypochromic anemia due to the increase of MCV and the decrease of MCHC in the growth phase of the parasite. It was considered that the Djungarian hamsters will be useful for the infection examination, isolation, maintenance, and passage of B. microti in laboratory.  相似文献   

9.
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.  相似文献   

10.
'Granular cell' tumor observed in the malar subcutis of a Djungarian hamster was examined to determine its cellular origin. Histologically, the tumor consisted of a solid growth of oval or spindle-shaped large cells with abundant cytoplasm filled with eosinophilic granules that were periodic acid-Schiff-positive and diastase-resistant. Immunohistochemically, the tumor cells were positive to anti-vimentin and anti-desmin antibodies and a few cells showed positivity to anti-actin antibody as well. They did not react to myoglobin, S-100 protein, and glial fibrillary acidic protein (GFAP). Electron microscopic studies revealed that the tumor cells had pinocytotic vesicles, dense plaque and microfilaments. The first granular cell variant of myogenic tumor reported here in Djungarian hamsters was differentiated from granular cell tumor of Schwann cell origin.  相似文献   

11.
A two‐and‐a‐half year‐old male Chinese hamster (Cricetulus griseus) was referred for evaluation of an intraorbital mass involving the right eye. Based on ophthalmic examination and ultrasonography, a diagnosis of intraocular neoplasia was made. Enucleation of the affected eye was performed. The mass was histologically diagnosed as a primary malignant intraocular signet‐ring cell melanoma. No signs of recurrence were detected, and the hamster remained clinically healthy until it died 6 months after surgery. This case report attempts to contribute to the limited body of knowledge available in the literature on primary intraocular neoplasms in hamsters.  相似文献   

12.
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.  相似文献   

13.
Traditionally, urbanization has been seen as a negative phenomenon for biota. However, changes in the environmental parameters induced by urbanization might be favorable for some species. Over the past half‐century, the common hamster has actively populated cities, establishing populations in some European, Russian and Kazakhstan cities. Based on integrative methods, we investigated free‐range common hamsters inhabiting Simferopol from 2015 to 2018 to reveal possible adaptations to the urbanized environment across several parameters, including lifespan, hibernation period, reproductive activity and body mass. Results show that in urban areas, the common hamster demonstrates an extremely short hibernation period compared to other localities, possibly due to enhanced food resources from urban forestry (walnuts, locus and hazelnut), allowing the species to start breeding very early (February) and finish as late as October. We present the first evidence of polyandry for this species: mating of receptive females with several males and subsequent confirmation of multiple paternity. Despite high reproductive potential, the lifespan of the common hamster in urban conditions is generally very short (less than 1 year). We speculate that in the process of synurbization, the common hamster's innate plasticity across many life history traits permits it to successfully colonize throughout a wide range of habitats, with the ability to form novel adaptations to urban environments.  相似文献   

14.
用多房棘球绦虫(Echinococcus multilocularis,Em)原头蚴继发感染一线仓鼠(坎培尔仓鼠Dwarf Campbells RussianHamster)、冬白仓鼠(倭仓鼠Phodopus sungoris sungoris)、金丝熊仓鼠(黄金鼠Mesocricetus auratus)、松鼠(Sciurusvulgaris)4种宠物鼠各4只。接种70 d后剖解各种宠物鼠1只,一线仓鼠、金丝熊仓鼠、松鼠未发现包囊泡,冬白仓鼠分离出包囊泡4.37 g,占体重的7.23%;接种95 d后4种宠物鼠的平均湿包囊泡重和包囊泡重占体重的百分比分别为:冬白仓鼠13.05g和33.03%,金丝熊仓鼠2.22 g和1.98%,松鼠2.28 g和3.54%,冬白仓鼠、金丝熊仓鼠和松鼠都出现成熟原头蚴,一线仓鼠未发现包囊泡。试验证明冬白仓鼠、金丝熊仓鼠和松鼠对多房棘球绦虫原头蚴较敏感,可以作为Em的中间宿主。  相似文献   

15.
Characteristic ganglion-like cell proliferation observed in the skin of Djungarian hamsters was investigated using 24 male and 24 female hamsters, 1-6 months of age, to examine the anatomic location of these ganglion-like cells and their morphologic features. One abdominal skin tumor composed of these cells and resembling proliferative fasciitis in humans was also examined. Skin ganglion-like cells were rarely observed in young animals but increased in number and extent with age, especially in males. These cells were frequently seen in the ventral and medial regions of the trunk and legs rather than in the dorsal and lateral regions. Light microscopic examination of these ganglion-like cells revealed abundant vesicular basophilic cytoplasm with delicate intracytoplasmic silver stain-positive fibrils. Ultrastructurally, these cells contained abundant rough endoplasmic reticulum and Golgi complexes with dilated cisternae; intracellular collagen fibrils were present within these cisternae. Heat shock protein 47, beta-tubulin, and androgen receptor were expressed in these cells. The morphologic features of cells of one tumor resembling human proliferative fasciitis were identical to those observed in ganglion-like cells. The results of the present study suggest that these ganglion-like cells are derived from intrinsic undifferentiated mesenchymal cells in the dermis or subcutaneous adipose tissue and that any tumor-like lesion they form should be regarded as an abnormal proliferative lesion of skin ganglion-like cells rather than as proliferative fasciitis or fibroma.  相似文献   

16.
A malignant basal cell tumor was found in the skin of the abdomen of a female Djungarian hamster of unknown age and weighing 40 g. Histologically, the tumor mass was composed of cells resembling the basal cells of the epidermis, and these cells exhibited solid type proliferation. In the tumor tissue and necrotic foci, horn cysts were observed. Immunohistochemically, cytokeratin was present in the tumor cells and horncysts. By electron microscopic examination, the tumor cells had scanty cell organelles and a few desmozomes. This paper describes a rare malignant basal cell tumor in a Djungarian hamster.  相似文献   

17.
REASONS FOR PERFORMING STUDY: Vaccination and challenge studies in ponies are the most relevant experimental system for predicting whether strains included in equine influenza vaccines are relevant, but they are difficult to perform. OBJECTIVES: In order to investigate the feasibility of using a small animal model, results of a cross-protection study in hamsters were compared with those from a previous pony challenge experiment. METHODS: Animals were immunised with inactivated vaccines containing one of 4 strains of equine influenza A H3N8 subtype virus isolated over a 26 year period (1963 to 1989), then challenged with a 1989 strain. RESULTS: Although there was no significant difference in titres of excreted virus between groups of vaccinated ponies, hamsters immunised with heterologous strains had significantly higher virus titres in the lung than hamsters vaccinated with the homologous strain. In both ponies and hamsters, the number of animals excreting virus was greater the earlier the isolation date of the vaccine strain, although this was only significant in the hamster study. CONCLUSIONS: Despite differences, the overall conclusion of both the pony and hamster models was that heterologous vaccines may be less effective than homologous vaccines at preventing virus excretion. POTENTIAL RELEVANCE: Further validation is required, but the hamster model shows potential for preliminary assessment of the effects of antigenic drift on vaccine efficacy.  相似文献   

18.
A total of 90 tumors from 85 domestic hamsters (70 Djungarian hamsters and 15 Syrian hamsters) were examined by histology. In the Djungarian hamsters, 64 neoplastic and 11 non-neoplastic lesions were identified, whereas 14 Syrian hamsters showed neoplastic disease, and one showed non-neoplastic disease. The Djungarian hamsters showed a high prevalence of neoplastic disease, similarly to laboratory Djungarian hamsters. In the Djungarian hamsters, almost all tumors were integumental, whereas hematopoietic tumors were the most common type in the Syrian hamsters. The most common integumental tumors in the Djungarian hamsters were mammary tumors, atypical fibromas and papillomas, and a spectrum of integumental tumors that have not been reported in laboratory Djungarian hamsters were identified. Most mammary tumors occurred in the females, whereas all atypical fibromas were observed in the males. In the Syrian hamsters, plasmacytomas and lymphomas were the most common tumors. The small number of Syrian hamsters in this study may reflect the low prevalence of spontaneous tumors seen in laboratory Syrian hamsters. The mean age of the affected hamsters was 19.8 months, which is relatively advanced. To our knowledge, this is the first comprehensive study of tumors in domestic hamsters.  相似文献   

19.
Irisin is mainly secreted by heart and skeletal muscle cells. It is an exercise‐induced protein that converts white adipose tissue to brown. Increased irisin expression was lead to weight loss and improved glucose tolerance. We investigated irisin immunoreactivity in various tissues of the dwarf hamsters (Phodopus roborovskii). Tissues were processed, embedded in paraffin, sectioned at 5 μm and stained immunohistochemically for irisin. In the retina, irisin was found almost all layers, except outer nuclear layer. Also, irisin immunoreactivity was observed in the skin, cornea, striated muscle, parotid gland, tongue, oesophagus, stomach and small intestine. The findings from this study support the notion that skeletal muscle is not the primary source of irisin.  相似文献   

20.
The life history of many animals includes periods of food shortage. Two behavioral strategies are involved in small mammals in response to food shortage: an increase in activity behavior, representing the increased foraging or migratory behavior, and a decrease in activity level, serving as a mechanism for conserving energy. However, it is uncertain whether animals adopt both strategies in response to food shortage, and whether hormone and neuroendocrine mechanisms are involved in both strategies. In the present study, changes in behavior and metabolic rate were examined in food‐deprived striped hamsters (Cricetulus barabensis). The effects of leptin supplement on activity behavior, metabolic rate and hypothalamic neuropeptide gene expression were also examined. The behavior of food‐deprived hamsters significantly changed with photoperiod phases: with increasing activity during the dark phase compared to those fed ad libitum, whereas decreasing activity and simultaneously increasing resting behavior during the light phase. Resting metabolic rate, body mass, and masses of fat depots and digestive tracts significantly decreased in food‐deprived hamsters compared with ad libitum controls. Leptin supplement tended to attenuate the increased activity in the dark phase. Gene expression of hypothalamic neuropeptide Y (NPY) was significantly upregulated in food‐deprived hamsters, while was significantly attenuated by exogenous leptin. These findings suggest that both behavior strategies are important behavioral adjustments in free‐living animals to cope with food shortage. Leptin and hypothalamic NPY gene expression may be involved in the adjustments of physiology and behavior in animals demonstrating a hyperactivity strategy in response to food shortage.  相似文献   

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