• Journal of Veterinary Clinics
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• v.39 no.3
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• pp.126-130
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• 2022

A 17-month-old intact male Djungarian hamster (Phodopus sungorus) was presented with an axillary mass. Fine needle aspiration cytology of the mass showed a malignant epithelial cell tumor. Histopathological examination of the surgically removed mass confirmed a complex apocrine gland adenocarcinoma. Twenty days postoperatively, the mass recurred in the same area, and the patient died while waiting for the second surgical removal. This is the first report of the cytology, histopathology, and postoperative recurrence of apocrine gland adenocarcinoma in a Djungarian hamster.

• Journal of Veterinary Clinics
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• v.41 no.1
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• pp.65-70
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• 2024

Ten cutaneous masses from Djungarina hamsters (Phodopus sungorus) were diagnosed as nine atypical fibromas and one fibrosarcoma derived from cutaneous ganglion cell-like cells. Among these patients, nine were male and one was female. Histologically, these abnormal masses were composed of spindle-shaped or polygonal neoplastic 'ganglion cell-like' cells with abundant amphophilic vacuolated cytoplasm. Immunohistochemically, these neoplastic cells were stained for vimentin, S100, and neuron-specific enolase. Out of 9 males, 3 showed positive reactions to the androgen receptor. This report provides a detailed histologic and immunohistochemical characterization of atypical fibroma, fibrosarcoma, and the tumorigenesis of ganglion cell-like cells in Djungarian hamsters.

• Journal of Photoscience
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• v.9 no.2
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• pp.252-254
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• 2002

Djungarian hamsters show distinct seasonal rhythms in several physiological parameters. One of them is daily torpor that occurs in winter with decreased body temperature (about 1O-20$^{\circ}$C) during daytime. Daily torpor is induced by short-day photoperiod, food restriction and castration. But the mechanism to induce daily torpor has not been clarified. In the present study, we tried to clarify the process of daily torpor induction in detail. Adult male hamsters were kept in long photoperiod and high temperature (LP-HT) before the experiment and, thereafter, the animals were transferred to short photoperiod and low temperature (SP-LT), and they were kept in this condition for about six months. The daily rhythms of locomotor activity and body temperature were recorded every three-minutes by using the Minimitter telemetry system. Locomotor activity and body temperature showed very closely synchronized rhythms. All animals under LP-HT showed daily rhythms with higher locomotor activity and body temperature in nighttime than in daytime. Under SP-LT, there were two types of animals with and without showing daily torpor. Thus, they have individual differences in the response to SP -LT.