Taxol resistance and its reversal by synthetic isoprenoids in human bladder cancer cell line.

Purpose: We investigated the mechanism of action of reversal agents for taxol-resistance in bladder cancers.

Materials And Methods: We isolated a taxol-resistant cell line (KK47/TX30) from a human KK47 bladder cancer cell line (KK47/WT). We characterized KK47/TX30 cells and screened reversal agents for taxol-resistance.

Overexpression of cyclooxygenase-2 in high-grade human transitional cell carcinoma of the upper urinary tract.

Objective: To examine cyclooxygenase (COX)-2 expression (a key enzyme in the synthesis of prostaglandins, and involved in carcinogenesis of human epithelial tumours) in human transitional cell carcinomas (TCCs) of the renal pelvis and ureter, and to determine whether COX-2 expression correlates with the clinicopathological characteristics of the disease.

Materials And Methods: Specimens from 144 patients with TCC of the upper urinary tract who had undergone nephroureterectomy were analysed immunohistochemically, and 23 were also analysed by immunoblotting.

Results: Immunoblot analysis showed COX-2 immunoreactivity in 17 (74%) of 23 tumours, but not in normal transitional epithelium.

Reversal of P-glycoprotein-mediated paclitaxel resistance by new synthetic isoprenoids in human bladder cancer cell line.

We isolated a paclitaxel-resistant cell line (KK47/TX30) from a human bladder cancer cell line (KK47/WT) in order to investigate the mechanism of and reversal agents for paclitaxel resistance. KK47/TX30 cells exhibited 700-fold resistance to paclitaxel and cross-resistance to vinca alkaloids and topoisomerase II inhibitors. Tubulin polymerization assay showed no significant difference in the ratio of polymerized alpha- and beta-tubulin between KK47/WT and KK47/TX30 cells.

Expression of thymidine phosphorylase as an indicator of poor prognosis for patients with transitional cell carcinoma of the bladder.

Background: Thymidine phosphorylase (TP), which is identical to platelet-derived endothelial cell growth factor (PD-ECGF), stimulates chemotaxis of endothelial cells and is involved in the angiogenesis of human solid tumors.

Methods: The activity and expression of TP were examined in human transitional cell carcinomas (TCCs) of the bladder, and their association with clinicopathologic findings was determined. The activity of the enzyme in 37 TCCs and 12 adjacent nonneoplastic tissues was measured spectrophotometrically.

Expression of vascular endothelial growth factor in patients with testicular germ cell tumors as an indicator of metastatic disease.

Background: Angiogenesis is essential for tumor growth and metastasis. Vascular endothelial growth factor (VEGF) and thymidine phosphorylase (TP)/platelet-derived endothelial cell growth factor (PD-ECGF) are involved in increased angiogenic activity and disease progression in solid tumors. However, there is no information regarding the association of these angiogenic factors with clinicopathologic findings in testicular germ cell tumors (GCTs).

Natural killing activity is associated with progression of gastric cancer.

Previously, we proposed a new analysis of natural killing activity, in which an individual effector/target cell ratio was employed for comparison according to the peripheral number of effector cells. In 51 patients with gastric cancer, the activity was studied using that modified analysis. Natural killing activity was activated in patients with early cancer, where tumor-cell invasion was restricted to the mucosa or the submucosa, even though in well-differentiated adenocarcinoma with invasion of the mucosa alone, the activity remained at the level of controls.

A case of extragenital choriocarcinoma in the jejunum.

A case of extragenital choriocarcinoma which produces human chorionic gonadotropin (HCG) in the small intestine of a 48-yr-old Japanese women is reported. Only seven such cases have been reported. The patient complained of postprandial upper abdominal pain and vomiting of 5 months' duration.

Diabetes insipidus after traumata of two extremes in severity.

Two patients with post-traumatic diabetes insipidus (DI) are reported. One had suffered a fatal injury and the other a mild contusion without amnesia before DI developed. These two instances exemplify the wide spectrum of post-traumatic DI and, hence, the importance of ruling out DI even afer a mild closed-head injury.

Effect of somatostatin and its analogs on histamine-stimulated cAMP production in isolated guinea pig gastric glands.

The effect of somatostatin-14 (ss-14), somatostatin-28 (ss-28), and [D-trp8]somatostatin-14 ([ D-trp8]ss-14) on both histamine-stimulated cellular cAMP production and [3H]-cimetidine binding on plasma membranes in isolated guinea pig gastric glands was investigated. These three peptides partially inhibited (approximately 50% maximally) the increase of cAMP production stimulated by histamine. There was no inhibition of [3H]-cimetidine binding on plasma membranes from these isolated gastric glands.