A human bladder cancer cell line resistant to adriamycin (ADM), T-24/ADM was established in vitro by exposing T-24 parent cells to a progressively higher concentration of the drug over an 18 month period. The T-24/ADM was 34.9 times more resistant to ADM than the T-24 parent. The T-24/ADM exhibited cross resistance to ADM derivatives, vinca alkaloid (vindesine, vincristine), etoposide and SN-38, but collateral sensitivity to methotrexate. The biological and biochemical characteristics of T-24/ADM were examined in terms of ADM-resistance. Although a flow cytometric analysis showed that Pglycoprotein is not expressed on the T-24/ADM cells, lower accumalation of the drug caused by decreased uptake and increased active efflux were observed. The cellular level of glutathione-S-transferase π was 1.8-fold higher than the parent cells and the activity of nuclear extracts of DNA topoisomerase II for T-24/ADM assayed by decatenation of kinetoplast DNA was lower, about one-half that of the T-24 parent. Confocal laser microscopy revealed the difference in intracellular distribution of ADM in T-24/ADM; in particular, the accumulation of the drug in the nucleus decreased. Additionally western blot analysis showed an enhanced expression of multidrug resistance-associated protein (MRP) in the T-24/ADM cells. This resistant cell may be used as an experimental system to elucidate the mechanism of ADM resistance and also as a model for developing new chemotherapeutic strategies against multi-drug resistant bladder cancer.
Enterococcus faecalis is a frequent cause of hospital-acquired infection. Two hundred fifty one E. faecalis isolates from patients with urinary tract infection at Okayama University Hospital over an 8-year period from 1991 through 1998 were collected. The presence of the asaI, cylA, aac (6')-aph (2''), and aph (3')-III genes was analyzed by PCR methods. Of the 251 isolates, 205 (81.7%) were positive for asaI. The 81.5% (167/205) of asaI-positive isolates also possessed either cylA or aminoglycoside resistance genes, compared to only 15.2% of (7/46) asaI-negative isolates (p<0.0001). The incidence of asaI gradually increased from 69.2% in 1991 to 90.7% in 1998. The number of isolates that contain asaI, cylA and aminoglycoside resistance gene (s) also increased. Pulsed-field gel electrophoresis (PFGE) analyses of 28 asaI-positive and hemolysin-producing isolates revealed 22 different banding patterns, including 6 pairs with similar patterns. The plasmid analyses of these isolates showed different patterns except for 1 pair with similar PFGE pattern. These results suggest that E. faecalis possessing the asaI gene may play an important role in the exchange of genetic information among enterococci in the urinary tract.
A typical highest thoracic artery with anterior, posterior, ascending and descending branches was reported. Discussion suggests that this artery, when developed, gives rise to the internal thoracic artery descening lateral to the scalenus anterior muscle, transverse cervical artery, descending scapular artery, lateral thoracic artery or subscapular artery.
The characteristics of ferric nitrilotriacetate (Fe-NTA)-induced rat renal cell carcinoma by intraperitoneal administration and the effects of hormones on the tumor have been studied in vivo. However, to our knowledge there have been no reports on the characteristics of the tumor cells. In this study, we established a tumor cell line from Fe-NTA induced rat renal tumor and investigated tumor cell characteristics. The tumor cell line RKFe was established from Fe-NTA induced rat renal tumor by collagenase digestion. RKFe showed epithelial morphology in culture, and had microvilli and basement membranes under electron microscopy. RKFe cells acquired tolerance to the cytotoxicity of Fe-NTA. They also grew in soft agar culture and formed tumors by the inoculation of cells into nude mice. Histologically, transplanted tumors showed poorly differentiated adenocarcinoma with several tubular structures. A subclone of RKFe, named RKFe-C6, showed metastasis to lungs. The RKFe cell line may be useful for studying the characteristics of Fe-NTA induced rat tumor cells.
We reported a patient of non-small cell lung cancer (adenocarcinoma) patient effectively treated with gemcitabine after the failure of previous treatment with cisplatin and vinorelbine. A single agent chemotherapy with gemcitabine was well tolerated, so that it can be a useful treatment for maintaining QOL among the patients with progressive disease of lung cancer. Its usefulness as a second-line chemotherapy for the treatment of non-small cell lung cancer should be investigated.