• Parasites, Hosts and Diseases
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• v.52 no.6
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• pp.695-699
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• 2014

Chronic Opisthorchis viverrini-induced hepatobiliary disease is associated with significant leukocyte infiltration, including activated macrophages; however, the polarization of infiltrating macrophages remains to be fully characterized. In this study, we characterized macrophage polarization and phenotype in chronic O. viverrini-induced hepatobiliary disease in humans and hamsters using gene expression and histochemical analysis. Chronic O. viverrini infection and associated hepatobiliary diseases were associated with iron loaded M2-like macrophages in both humans and hamsters. This study provides suggestive evidence that iron loaded M2-like macrophages promote hepatobiliary disease in chronic O. viverrini infection.

• Development and Reproduction
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• v.16 no.1
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• pp.1-8
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• 2012

The reproduction of animals is a way to maintain their species and demands a large amount of energy. The golden hamsters are seasonal breeders whose reproductive activities are regulated by photoperiod (length of day time in a day). The photic information received is transported to the pineal gland via many steps. Melatonin produced by the pineal gland affects the reproductive neuroendocrine system to manage reproductive activities. The major regulator neurons, secreting gonadotropin-releasing hormone, integrate all kinds of information to govern the reproductive frame hypothalamuspituitary-gonad axis. The elements impinging on the neurons are recently outspread. Thus the present review is to briefly survey the elements discovered newly and subjected to the active research realm and their correlations, focusing on the regulation of reproduction in mainly male golden hamsters as a representative animal.

• Proceedings of the Zoological Society Korea Conference
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• 2001.10a
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• pp.191.2-191
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• 2001

No Abstract, See Full Text

• Development and Reproduction
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• v.7 no.1
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• pp.35-40
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• 2003

Gonadotropin releasing hormone(GnRH), which is secreted from the hypothalamus, has a pivotal role in the reproduction of mammals. Golden hamsters are seasonal breeding mammal and their sexual activity is determined by photoperiod(length of light per day). Long photoperiod(LP, $\leq$ 12.5 hours of light) maintains the reproductive activity and short photoperiod(SP, $\leq$ 12 hours of light) suppresses it. In order to investigate in detail, the sexual activity was individually examined in SP-housed male golden hamsters received a vector at three different concentrations which contains rat GnRH cDNA. The gonadal regression was significantly(P<0.05) accelerated by the highest concentrations of the vector at 8 and 10 weeks after the treatment in comparison to the other groups. In the light of pulsatile release of GnRH in maintaining reproductive activity, the vector containing GnRH cDNA might secrete the GnRH in a constant high level. These results suggest that the GnRH-containing vector might desensitize the anterior pituitary, leading to acceleration or testicular regression.

• Applied Microscopy
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• v.39 no.2
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• pp.191-197
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• 2009

This study investigated the effects to lowering hyperlipidemic levels in hamsters by feeding them naringin and onion extracts. The hyperlipidemic levels on all of the hamsters were raised by feeding them with high fat atherogenic diet (HFAD) containing 10% coconut oil and 0.05% cholesterol. The experimental groups were randomly assigned to 5 groups (normal, control, OEN, OES, and OESN) each 6 hamsters over a 40 days period. The control group (HFAD) received a 10% coconut oil and 0.05% cholesterol with basal diet, the OEN group which received an onion extract mixture contaning 50% water and 50% onion extract, the OES group which received 100% onion extract, the OESN group which received 100% onion extract combined with 1% naringin. Serum cholesterol and triglyceride levels significantly decreased in the naringin treated group while the HDL cholesterol level increased. On the other hand, the morphology of the mitochondria and nuclei found in the livers of the treated group given naringin were siginficantly different when compared to those group given high fat diets. In conclusion, onion extract with naringin decreased cholesterol levels in hamster's livers.

• Parasites, Hosts and Diseases
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• v.51 no.6
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• pp.695-701
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• 2013

Opisthorchis viverrini infection causes inflammation and liver injury leading to periductal fibrosis. Little is known about the pathological alterations in bile canaliculi in opisthorchiasis. This study aimed to investigate bile canalicular alterations in O. viverrini-infected hamsters and to examine the chemopreventive effects of curcumin on such changes. Hamsters were infected with O. viverrini and one group of animals was fed with 1% dietary curcumin supplement. Animals were examined during the acute infection phase, days 21 and 30 post-infection (PI) and chronic infection phase (day 90 PI). Scanning electron microscopy revealed that in the infected group fed with a normal diet, bile canaliculi became slightly tortuous by 30 day PI and more tortuous at day 90 PI. Transmission electron microscopy showed a reduction in microvilli density of canaliculi starting at day 30 PI, with a marked loss of microvilli at day 90 PI. These ultrastructral changes were slightly seen at day 21 PI, which was similar to that found in infected animals fed with 1% curcumin-supplemented diet. Notably, curcumin treatment prevented the reduction of microvilli density, reduced the dilation of bile canaliculi, and decreased the tortuosity of the bile canaliculi relative to non-infected animals on a normal diet at days 30 and 90 PI. These results suggest that curcumin reduces alteration of bile canaliculi and may be a promising agent to prevent the onset of bile duct abnormalities induced by O. viverrini infection.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6279-6284
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• 2015

Opisthorchis viverrini (OV)-induced cholangiocarcinoma (CCA) is an important cancer in the Great Mekong region, particularly in Thailand. Limitations of treatment options and the lack of an effective diagnostic tool for early detection of CCA are major concerns for the control of this type of cancer. The aim of the study was to investigate anti-CCA activity of the ethanolic extract of Atractylodes lancea (Thunb.) DC., and the applicability of positron emission tomography-computed tomography (PET-CT) as a tool for detection and monitoring the progression of CCA in Opisthorchis viverrini (OV)/dimethylnitrosamine (DMN)-induced CCA hamsters. Male Syrian hamsters were used for toxicity tests and anti-CCA activity evaluation. Development of CCA was induced by initial feeding of 50 metacercariae of OV, followed by drinking water containing 12.5 ppm of DMN in hamsters. The ethanolic extract of A. lancea (Thunb.) DC. was administered orally for 30 days. PET-CT was performed every 4 weeks after initiation of CCA using 18F-fluorodeoxyglucose ($^{18}F-FDG$). Results from the present study suggest that the ethanolic extract of A. lancea (Thunb.) DC. rhizome exhibited promising anti-CCA activity and safety profile in the OV/DMN-induced hamster model. To successfully apply PET-CT as a tool for early detection of tumor development and progression, modification of radiolabeling approach is required to improve its specificity for CCA cells.

• Biomolecules & Therapeutics
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• v.1 no.1
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• pp.9-19
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• 1993

DA-125, a new anthracycline antibiotic, showed antitumor activity against animal tumors and human tumors. Therefore we studied the cardiotoxic potential of DA-125 in hamsters and rats as a part of safety research, and compared it with that of doxorubicin(DXR). In acute cardiotoxicity test model used hamsters DA-125 was administered intravenously at a dose of 6, 9, 12 mg/kg, and DXR at 3 mg/kg was given. The electrocardiogram(ECG) of hamsters was recorded for 30 minutes after administration. The DA-125 caused slight ECG alterations at a dose of 6 mg/kg. At a dose of 12 mg/kg DA-125 induced moderate to remarkable changes in ECG like decrease of heart rate, widening of PR interval and 07 interval, and A-V block in 3 out of 5 animals. The severity of ECG alteration at 12 mg/kg of DA-125 was similar to that at 3mg/kg of DXR and these changes caused by DA-125 and DXR recovered within 10 minutes after injection. In chronic cardiotoxicity test model used rats, DA-125 was administered intravenously once a week for three weeks at a dose of 6, 9mg/kg and DXR was given at a dose of 6mg/kg. Electrocardiogram was recorded every week from the start of administration to 2 weeks after the last administration and the animals were sacrificed for histological heart examination at 1 week or 2 weeks after the last administration. DA-125 did not cause any abnormal changes in ECG and in histological heart examination due to administration, but DXR caused widening of ST segment, QRS complex, and QT interval from 1 week after administration and these changes were continued to necropsy. These alterations in ECG were accompanied by cardiac histological lesions such as vacuolation in myocardiac cells, interstitial edema and necrosis of myocytes. These results suggest that DA-125 is less cardiotoxic than DXR.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3527-3531
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• 2016

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

• Development and Reproduction
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• v.17 no.1
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• pp.37-43
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• 2013

Cynomorium songaricum (CS) has been used in traditional Korean medicine in treating male impotence and sexual dysfunction. We investigated the effects of aqueous CS extract on the reproductive activity of golden hamsters whose spermatogenetic capacity is active in summer and inactive in winter. The animals were divided into 5 groups: long photoperiod (LP) control, short photoperiod (SP) control, and SP animals treated with low, middle, or high concentrations of CS. The animals were orally ingested with low (0.5 g/kg), middle (1.0 g/kg), or high (2.5 g/kg) concentrations of the aqueous extracts for 8 weeks on the daily basis. The control animals received the vehicle. As results, the LP control animals showed active testicular function but SP control animals displayed remarkably reduced testicular weights. The outcomes of the reproductive activity from low and middle concentrations of CS treatments were identical and marked as low dose. The consequences were a partial blocking of regressing activity by SP. On the other hand, the animals treated with high dose of CS extract showed remarkable significance in comparison to the SP control, indicative of a complete blocking effect of the CS on the regressing testes by SP. There were a dose-dependent effects of the CS on the sexual function. These results suggest that the CS extract promotes the male fertility by strengthening the spermatogenesis in the golden hamsters.