Effect of repeated Paecilomyces japonica treatment on rats / 대한수의학회지

Cordyceps is a fungus used as a traditional medicine in China, Japan, and Korea. Paecilomyces (P.) japonica is a new cordyceps that was recently cultivated on silkworm pupae in Korea. The present study evaluated the toxicological effects of P. japonica in rats. Forty rats were treated with oral doses of P. japonica (0, 20, 100, or 500 mg/kg/day) for 4 weeks. Twenty additional rats were treated with 0 or 500 mg/kg/day of P. japonica for 4 weeks and then maintained for 2 weeks without treatment. Clinical signs, body weight, food and water consumption, and organ weight as well as hematology, serum biochemistry, and histopathology data were examined. Body weight gain of the group treated with 500 mg/kg/day was significantly reduced. Microscopically, karyomegaly, single cell necrosis, and mitosis were observed in the renal tubular epithelium of all treated groups. In conclusion, P. japonica caused a reduction of body weight and renal injury in rats. The no observed adverse effect level (NOAEL) of P. japonica was less than 20 mg/kg/day.

Myxoid liposarcoma in a dog / 대한수의학회지

The pathological features of a mass in the back skin region of an 8-year-old castrated male dog are described herein. The cut section of the tumor was white to tan with a soft multilobulated mass containing hemorrhagic and necrotic foci and a mucinous-like composition. Microscopically, the tumor was composed of a mixture of lipocytes, lipoblasts, spindle cells and stellate cells and had a myxoid background. Oil red O staining revealed that the cytoplasm of neoplastic cells contained large numbers of lipid droplets. Immunohistochemically, tumor cells were positive for vimentin and S-100 protein. The skin mass was diagnosed as myxoid liposarcoma.

Expression of CD133, CD44, CK7, and OCT4 in Animal Cancers / 대한수의학회지

Cancers are mainly sustained by a small pool of neoplastic cells, known as cancer stem cells or tumor-initiating cells. These cells possess the ability to self-renew and proliferate, and are thus able to form the tumor. In the present study cells that correspond to cancer stem cells in mammary and liver cancers in animals were identified by the expression of CD133, CD44, CK7, and OCT4 using immunochemistry. As a result, we found with CD133+ and CD44+ cancer stem cell-like phenotypes in mouse and canine hepatocellular carcinoma and canine mammary gland tumors. However, CK7+ and OCT4+ cells were not identified in animal mammary and liver cancer. CD133+ and CD44+ cells are wellknown stem cell lines and play key roles in development and metastasis in human cancer. These findings suggest that cancer stem cells are involved in animal tumorigenesis and may provide insight into mechanisms in cancer development as well as cancer diagnostics.

Chordoma in the Tail of a Ferret / 한국실험동물학회지

A chordoma is an uncommon tumor that originates from the remnants of the notochord and most commonly involves the cranial and caudal regions of the axial skeleton. Chordoma has been described in laboratory animals such as dogs, rats, minks, and ferrets. This report describes a case of a chordoma in the tail of a ferret. Grossly, a grayish-white, expansile, subcutaneous soft-tissue mass was observed in the tail. Histopathologically, the mass was a loosely placed, nodular, unencapsulated neoplasm within the dermis. In the mass, tumor lobules were intermingled with fibrous tissues. Fibrous tissues contained abundant extracellular basophilic material that was consistent with mucin. The tumor was composed of a close pack of adipocyte-like vacuolated cells (physaliferous cells). The cells were centrally or eccentrically located round nuclei and eosinophilic cytoplasm with large vacuoles. Immunohistologically, neoplastic cells were positive for vimentin and S-100 protein. Based on histopathologic findings and special staining characteristics, this case was diagnosed as chordoma.

Involvement of the Fas and Fas ligand in testicular germ cell apoptosis by zearalenone in rat

Zearalenone (ZEA), a nonsteroidal estrogenic mycotoxin, is known to cause testicular toxicity in animals. In the present study, the effects of ZEA on spermatogenesis and possible mechanisms involved in germ cell injury were examined in rats. Ten-week-old Sprague-Dawley rats were treated with 5 mg/kg i.p. of ZEA and euthanized 3, 6, 12, 24 or 48 h after treatment. Histopathologically, spermatogonia and spermatocytes were found to be affected selectively. They were TUNEL-positive and found to be primarily in spermatogenic stages I-VI tubules from 6 h after dosing, increasing gradually until 12 h and then gradually decreasing. Western blot analysis revealed an increase in Fas and Fas ligand (Fas-L) protein levels in the ZEA-treated rats. However, the estrogen receptor (ER)alpha expression was not changed during the study. Collectively, our data suggest that acute exposure of ZEA induces apoptosis in germ cells of male rats and that this toxicity of ZEA is partially mediated through modulation of Fas and Fas-L systems, though ERalpha may not play a significant role.

Skin entrance dose for digital and film radiography in Korean dental schools / 대한구강악안면방사선학회지

PURPOSE: This study was aimed to compare skin entrance dose of digital radiography with that of film radiography and to show the dose reduction achievement with digital systems at 11 dental schools in Korea. MATERIALS AND METHODS: Forty six intraoral radiographic systems in 11 dental schools were included in this study. Digital sensors were used in 33 systems and film was used in 13 systems. Researchers and the volunteer visited 11 dental schools in Korea. Researchers asked the radiologic technician (s) at each school to set the exposure parameters and aiming the x-ray tube for the periapical view of the mandibular molar of the volunteer. The skin entrance doses were measured at the same exposure parameters and distance by the technician for each system with a dosimeter (Multi-O-Meter : Unfors instruments, Billdal, Sweden). RESULTS: The median dose was 491.2micronGy for digital radiography and 1, 205.0 microGy for film radiography. The skin entrance dose in digital radiography was significantly lower than that of film radiography (p< 0.05). CONCLUSIONS: Fifty-nine percent skin entrance dose reduction with digital periapical radiography was achieved over the film radiography in Korean dental schools.