Alkylated benzothiophene desulfurization by Rhodococcus sp. strain T09. (65/1894)

A benzothiophene desulfurizing bacterium was isolated and identified as Rhodococcus sp. strain T09. Growth assays revealed that this strain assimilated, as the sole sulfur source, various organosulfur compounds that cannot be assimilated by the well-studied dibenzothiophene-desulfurizing Rhodococcus sp. IGTS8. The cellular growth rate of strain T09 for the alkylated benzothiophenes depended on the alkylated position and the length of the alkyl moiety.  (+info)

Antitumor effect and potentiation of cytotoxic drugs activity in human cancer cells by ZD-1839 (Iressa), an epidermal growth factor receptor-selective tyrosine kinase inhibitor. (66/1894)

Transforming growth factor alpha (TGF-alpha) is an autocrine growth factor for human cancer. Overexpression of TGF-alpha and its specific receptor, the epidermal growth factor receptor (EGFR), is associated with aggressive disease and poor prognosis. The EGFR has been proposed as a target for anticancer therapy. Compounds that block ligand-induced EGFR activation have been developed. ZD-1839 (Iressa) is a p.o.-active, quinazoline derivative that selectively inhibits the EGFR tyrosine kinase and is under clinical development in cancer patients. The antiproliferative activity of ZD-1839 alone or in combination with cytotoxic drugs differing in mechanism(s) of action, such as cisplatin, carboplatin, oxaliplatin, paclitaxel, docetaxel, doxorubicin, etoposide, topotecan, and raltitrexed, was evaluated in human ovarian (OVCAR-3), breast (ZR-75-1, MCF-10A ras), and colon cancer (GEO) cells that coexpress EGFR and TGF-alpha. ZD-1839 inhibited colony formation in soft agar in a dose-dependent manner in all cancer cell lines. The antiproliferative effect was mainly cytostatic. However, treatment with higher doses resulted in a 2-4-fold increase in apoptosis. A dose-dependent supra-additive increase in growth inhibition was observed when cancer cells were treated with each cytotoxic drug and ZD-1839. The combined treatment markedly enhanced apoptotic cell death induced by single-agent treatment. ZD-1839 treatment of nude mice bearing established human GEO colon cancer xenografts revealed a reversible dose-dependent inhibition of tumor growth because GEO tumors resumed the growth rate of controls at the end of the treatment. In contrast, the combined treatment with a cytotoxic agent, such as topotecan, raltitrexed, or paclitaxel, and ZD-1839 produced tumor growth arrest in all mice. Tumors grew slowly for approximately 4-8 weeks after the end of treatment, when they finally resumed a growth rate similar to controls. GEO tumors reached a size not compatible with normal life in all control mice within 4-6 weeks and in all single agent-treated mice within 6-8 weeks after GEO cell injection. In contrast, 50% of mice treated with ZD-1839 plus topotecan, raltitrexed, or paclitaxel were still alive 10, 12, and 15 weeks after cancer cell injection, respectively. These results demonstrate the antitumor effect of this EGFR-selective tyrosine kinase inhibitor and provide a rationale for its clinical evaluation in combination with cytotoxic drugs.  (+info)

Further evidence that 5-HT-induced relaxation of pig pulmonary artery is mediated by endothelial 5-HT(2B) receptors. (67/1894)

The endothelial 5-HT receptor mediating relaxation of pig pulmonary artery has been characterized using the selective 5-HT(2B) receptor agonist BW 723C86 and a variety of structurally diverse 5-HT receptor antagonists. If arterial rings with intact endothelium were precontracted with prostaglandin F(2alpha) (3 microM), BW 723C86 caused concentration-dependent relaxation with a pEC(50)=8.21+/-0.03 and E(max)=89+/-4% relative to 5-HT. The relaxant responses to BW 723C86 were inhibited by the 5-HT(2B) receptor antagonist SB 204741, the 5-HT(2B/2C) receptor antagonist SB 206553 and the antimigraine drug pizotifen, yielding pA(2) values of 6.68, 7.20 and 8.32, respectively. The pA(2) values against BW 723C86 were similar to those determined against 5-HT. The relaxant effect of 5-HT was antagonized by a variety of 22 compounds of diverse chemical structures. Based on the calculated mean pA(2) values the order of the most potent antagonists was ritanserin (9.38) > methysergide (8. 86) > pizotifen (8.47) >/= methiothepin (8.32) > LY 53857 (7.84) >/= amoxapine (7.80) >/= loxapine (7.73) >/= metergoline (7.64) >/= mianserin (7.51) >/= rauwolscine (7.39). Compounds with weak blocking potency were yohimbine (6.37), spiperone (5.88) and ketanserin (5.85). Correlation analysis between the affinities of the antagonists in pig pulmonary artery and those from radioligand binding studies at human and rat 5-HT(2B) receptors showed a highly significant correlation (r=0.95 and 0.84, P<0.002 and <0.005). Correlation with 5-HT(2C) receptors was much lower (r=0.57, P=0.035), and no correlations were obtained with 5-ht(6) and 5-HT(7) receptors. It is concluded that the 5-HT receptor mediating endothelium-dependent relaxation of pig pulmonary artery is of the 5-HT(2B) subtype.  (+info)

Phase I, dose-finding, and pharmacokinetic study of raltitrexed combined with oxaliplatin in patients with advanced cancer. (68/1894)

PURPOSE: To determine the maximum-tolerated dose (MTD) and the dose-limiting toxicities (DLTs) of the raltitrexed plus oxaliplatin combination regimen, to explore its safety and pharmacokinetics, and to assess its antitumor activity in patients with advanced solid tumors. PATIENTS AND METHODS: Forty-eight patients received the combination of raltitrexed plus oxaliplatin. Raltitrexed was administered as a 15-minute infusion followed by oxaliplatin as a 2-hour infusion 1 hour later, repeated every 3 weeks. Seven dose levels were explored, ranging from 2 to 3.75 mg/m(2) and from 85 to 130 mg/m(2) for raltitrexed and oxaliplatin, respectively. The pharmacokinetics of both raltitrexed and oxaliplatin was assessed at the last three dose levels. RESULTS: Forty-six patients were assessable for toxicity. Severe toxicities usually occurred from dose level V (raltitrexed 3 mg/m(2) and oxaliplatin 130 mg/m(2)). This combination was not myelosuppressive, eliciting only sporadic grades 3 and 4 neutropenia and/or thrombocytopenia without complications. There was no alopecia. DLTs were asthenia and nausea/vomiting, despite systematic antiemetic prophylaxis. Dose level VI (raltitrexed 3.5 mg/m(2) and oxaliplatin 130 mg/m(2)) was deemed to be the MTD. Eight confirmed partial responses were observed: six patients with malignant mesothelioma (both pretreated and nonpretreated), one with fluorouracil-refractory pancreatic carcinoma, and one with renal carcinoma. Evaluation of the pharmacokinetics of both drugs did not suggest any drug interaction. CONCLUSION: The combination of raltitrexed and oxaliplatin given as consecutive short infusions every 3 weeks seems to be an acceptable regimen that allows a dose-intensity as high as the sum of the recommended doses of each agent given alone. The dose recommended for further phase II studies is raltitrexed 3 mg/m(2) and oxaliplatin 130 mg/m(2) every 3 weeks. Promising antitumor activity has been observed in patients with malignant mesothelioma.  (+info)

A comparison of latanoprost and dorzolamide in patients with glaucoma and ocular hypertension: a 3 month, randomised study. Ireland Latanoprost Study Group. (69/1894)

AIMS: To compare the effects on intraocular pressure (IOP) and side effects of monotherapy with either latanoprost or dorzolamide in patients with glaucoma or ocular hypertension. METHODS: 224 patients with open angle glaucoma or ocular hypertension were recruited to a 3 month open labelled study. Previous glaucoma medications were washed out and the patients were randomised to receive either latanoprost 0.005% once daily or dorzolamide 2% three times daily. RESULTS: Of 224 patients 213 were included in the analysis of efficacy. After 3 months, latanoprost reduced mean baseline diurnal IOP from 27.2 (SD 3.0) mm Hg by 8.5 (3.3) mm Hg. The corresponding figures for dorzolamide were 27.2 (3.4) and 5.6 (2.6) mm Hg. The difference of 2.9 mm Hg (95% CI: 2.3-3.6) was highly significant (p<0.001, ANCOVA). Latanoprost reduced IOP at peak by 8.6 mm Hg (32%) compared with 6.2 mm Hg (23%) for dorzolamide, and the difference of 2.4 mm Hg was significant (p<0.001, ANCOVA). The corresponding figures at trough were 8.1 mm Hg (31%) for latanoprost and 4.7 mm Hg (17%) for dorzolamide, a significant difference of 3.4 mm Hg (p<0.001, ANCOVA). Both drugs were well tolerated systemically and locally. CONCLUSION: Latanoprost was superior to dorzolamide in reducing the IOP, judged both from the effect on IOP at peak and trough and by the effect on diurnal IOP.  (+info)

Oxaliplatin and raltitrexed combined with leucovorin-modulated 5-fluorouracil i.v. bolus every two weeks: a dose finding study in advanced previously treated colorectal carcinoma. Southern Italy Cooperative Oncology Group. (70/1894)

PURPOSE: To determine the maximum tolerated dose of oxaliplatin (L-OHP) given as a two-hour infusion followed by raltitrexed (Tomudex [TOM]) administered as a 15-min infusion on day 1, and bolus 5-fluorouracil (5-FU) modulated by a fixed dose of levo-folinic acid (LFA) 250 mg/m2 on day 2, recycling every two weeks, and to have preliminary evidence of activity of this combination in pretreated advanced colorectal cancer patients. PATIENTS AND METHODS: Fifty-two patients with advanced colorectal carcinoma previously treated with one (25 cases) or two or more lines of chemotherapy, including irinotecan (26 cases), and/or modulated 5-FU (40 cases) entered this study. Starting doses of L-OHP, TOM, and 5-FU were 85, 2.5 and 750 mg/m2, respectively. RESULTS: Seven dose levels were tested. Neutropenia was the main dose limiting toxicity of the dose escalation (8 of 13 cases). The recommended doses were 130 mg/m2 of L-OHP, and 3.0 mg/m2 of TOM on day 1, followed by 250 mg/m2 of LFA, and 1050 mg/m2 of 5-FU on day 2, every two weeks. Severe diarrhoea and stomatitis were rarely reported. Most patients complained of mild peripheral sensitive aeurotoxicity, which was related to the cumulative dose of L-OHP. Twelve patients were considered as having a major responses (one complete), and an additional eight patients showed a minor response; the median time to treatment failure was twenty-four weeks. CONCLUSIONS: With this regimen it is possible to give full doses of all three cytotoxic drugs every two weeks. Its activity and its manageable toxicity profile deserve further evaluation in pretreated advanced colorectal cancer patients.  (+info)

Regulation of cell invasion and morphogenesis in a three-dimensional type I collagen matrix by membrane-type matrix metalloproteinases 1, 2, and 3. (71/1894)

During tissue-invasive events, migrating cells penetrate type I collagen-rich interstitial tissues by mobilizing undefined proteolytic enzymes. To screen for members of the matrix metalloproteinase (MMP) family that mediate collagen-invasive activity, an in vitro model system was developed wherein MDCK cells were stably transfected to overexpress each of ten different MMPs that have been linked to matrix remodeling states. MDCK cells were then stimulated with scatter factor/hepatocyte growth factor (SF/HGF) to initiate invasion and tubulogenesis atop either type I collagen or interstitial stroma to determine the ability of MMPs to accelerate, modify, or disrupt morphogenic responses. Neither secreted collagenases (MMP-1 and MMP-13), gelatinases (gelatinase A or B), stromelysins (MMP-3 and MMP-11), or matrilysin (MMP-7) affected SF/HGF-induced responses. By contrast, the membrane-anchored metalloproteinases, membrane-type 1 MMP, membrane-type 2 MMP, and membrane-type 3 MMP (MT1-, MT2-, and MT3-MMP) each modified the morphogenic program. Of the three MT-MMPs tested, only MT1-MMP and MT2-MMP were able to directly confer invasion-incompetent cells with the ability to penetrate type I collagen matrices. MT-MMP-dependent invasion proceeded independently of proMMP-2 activation, but required the enzymes to be membrane-anchored to the cell surface. These findings demonstrate that MT-MMP-expressing cells can penetrate and remodel type I collagen-rich tissues by using membrane-anchored metalloproteinases as pericellular collagenases.  (+info)

A dose-finding study of raltitrexed (tomudex) with cisplatin and epirubicin in advanced gastro-oesophageal adenocarcinoma. (72/1894)

The standard treatment for advanced gastro-oesophageal cancer in the UK is epirubicin, cisplatin and continuous infusion 5-fluoruracil by an indwelling central venous catheter (ECF), which has significant morbidity. Raltitrexed (tomudex), a specific inhibitor of thymidylate synthase with a long plasma terminal half-life (50-100 h) has activity in gastro-intestinal tract malignancy. To reduce the Hickman line-associated morbidity of ECF; we have conducted a dose-finding study of tomudex combined with epirubicin and cisplatin. Twenty-four patients (22 males, two female), median age 63 years (range 21-75), ECOG performance status < or =2 with histologically proven, unresectable or metastatic gastric (14 patients), gastro-oesophageal junction (nine patients) or oesophageal (one patient) adenocarcinoma received treatment with 3-weekly cisplatin 60 mg m(-2), epirubicin 50 mg m(-2) and tomudex at doses of 2 mg m(-2), 2.5 mg m(-2) or 3 mg m(-2) in successive cohorts. Six patients were treated per dose level with no intra-patient dose escalation. Dose escalation occurred after six patients had completed at least one cycle of chemotherapy at the previous dose level. After defining the maximum tolerated dose a further six patients were treated at the preceding dose level to assess toxicity at the proposed phase II dose. A total of 102 cycles (50% completed 6 cycles) were administered. The dose-limiting toxicities are neutropenia and diarrhoea occurring in 2/6 patients at the 3 mg m(-2) dose level. Of those patients evaluable for response, there were eight partial and one complete response (overall response rate 38%). The median survival was 9.9 months. ECT is an active regimen in oesophagogastric adenocarcinoma. The recommended dose of tomudex for further study in combination with epirubicin and cisplatin is 2.5 mg m(-2).  (+info)