Extent of Mycobacterium bovis infection in dairy cattle herds subject to partial culling as determined by an interferon-gamma assay

The interferon-gamma (IFN-gamma) assay is employed as a complementary diagnostic test for bovine tuberculosis (BTB) in many countries. To simplify this assay, we established a 96-well plate format using the ESAT-6 and CFP-10 antigens and then employed it to determine the extent of Mycobacterium (M.) bovis infection in dairy herds with a history of BTB outbreaks in a country where only selective culling is practiced. The sensitivity and specificity of this IFN-gamma assay were 85.9% and 100%, respectively, based on comparison with the conventional single intradermal tuberculin test (SIDT). The IFN-gamma assay was also positive in 30.4% and 36.8% of SIDT-negative animals from herds with recent and remote BTB outbreaks, respectively. Of 14 SIDT-negative, IFN-gamma positive cattle, five (35.7%) were culture positive and an additional six were positive based on a polymerase chain reaction-based test for M. bovis. Therefore, the IFN-gamma assay has the potential to serve as a specific and sensitive test for M. bovis infection in dairy cattle. Further, the results indicated that a substantial portion of SIDT-negative animals in herds with previous BTB outbreaks were actually infected with M. bovis. Accordingly, the present selective-culling strategy may require modifications to include this more sensitive assay.

The Effect of Combination Therapy with Radiation and Selective Cyclooxygenase-2 Inhibitor on Xenografted Human Oral Cavity Squamous Cell Carcinoma in Nude Mice / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: It is known that tumor cells over-expressing COX-2 have resistance to many anticancer treatments. Among those treatments, along with surgery and chemotherapy, radiation therapy plays a significant role in the treatment of head and neck cancer. However, radiosensitivity of each cancer varies according to cancer types. Especially, the cancer over-expressing COX-2 is reported to have higher radioresistance to radiation therapy. The purpose of this study is to evaluate the effect of selective COX-2 inhibitor when combined with the radiation therapy, and to assess the possibility of clinical application of the selective COX-2 inhibitor for radiation therapy in the head and neck cancer. MATERIALS AND METHOD: The human oral cavity squamous carcinoma cells were cultured and xenografted in 40 athymic nude mice (1 x 10(7), left thigh, subcutaneous injection) and the mice were divided into 4 groups: the control group (10 mice), the radiation therapy group (10 mice, Group A), the Meloxicam injection group (10 mice, Group B), and the combination therapy group with radiation and Meloxicam (10 mice, Group C). The tumor volume was measured on every five days during the treatment and the tumor specimen was taken for immunohistochemical staining when the treatment was finished. The mean tumor volume, the apoptosis index and the proliferation index were measured. RESULTS: In the combination therapy group (Group C), the tumor growth rate was decreased compared to the radiation therapy group (Group A). Also, according to the result of the apoptosis index and the proliferation index measured using immunohistochemical staining, the combination therapy group presented a higher apoptosis index but a lower proliferation index than other groups. CONCLUSION: Meloxicam, selective COX-2 inhibitor, improves the efficacy of the radiation therapy for the human oral cavity squamous carcinoma and this effect was due to apoptosis modulation by selective COX-2 inhibitor.