PubMed Health⌕ Search

Biomedical subjects

Masahiro Tada

Publications and source records attributed to Masahiro Tada.

13 recordsLinked to original sources

[Chemotherapy in advanced gastric cancer--to ensure timely and appropriate switch to subsequent treatment options].

Since irinotecan, S-1, docetaxel, and paclitaxel were approved, therapeutic options for chemotherapy in the treatment of gastric cancer have increased. It is suggested that the efficient use of the primary drugs prolongs life in the treatment of progressive colorectal cancer. Also, physicians have discussed ways to take full advantage of the drugs in the treatment of gastric cancer. In first-line treatment in other countries, combination therapy usually includes the administration of two drugs, while in Japan, where therapies based on S-1 have been developed, the most appropriate strategy must be determined after reporting the results of phase III trials in 2007. In the clinic, treatment must be selected on the basis of solid evidence in consideration of the organ dysfunction associated with progressive gastric cancer. The timing of any changes in the treatment should be considered because the cancer easily metastasizes to the peritoneum. Throughout the world, various regimens have been developed that replace cisplatin with oxaliplatin or mainly use oral fluoropyrimidine. Molecular target drugs, now being evaluated in phase II trials, will also be used in the treatment of gastric cancer in the near future. Novel therapies will be developed in Asia and Japan where the incidence of gastric cancer is high.

Antineoplastic Combined Chemotherapy Protocols↗

Rate enhancement of Diels-Alder reactions in aqueous perfluorinated emulsions.

A marked acceleration property for the Diels-Alder reaction was observed in an aqueous micellar system composed of perfluorohexane and lithium perfluorooctanesulfonate. The reaction rate increased with the concentration of the equimolar mixture of PFH and LiFOS, and the rate in 500 mM PFH and 500 mM LiFOS was about 100-fold greater than that in water without the fluorous field. After completion of the reaction, the products were simply extracted from the aqueous reaction mixture using n-hexane. [reaction: see text].

Alkanesulfonic Acids↗

Efficient ortho-oxidation of phenol and synthesis of anti-MRSA and anti-VRE compound abietaquinone methide from dehydroabietic acid.

A quinone methide diterpene: abietaquinone methide, which possesses potent anti-methicillin-resistant Staphylococcus aureus (MRSA) and anti-vancomycin-resistant Enterococcus (VRE) activities, was synthesized via efficiently ortho-oxidation of ferruginol derived from industrially available dehydroabietic acid. ortho-Oxidation of phenols was developed to give mono esters of catechols using a stable diacyl peroxide, bis(4-chlorobenzoyl) peroxide (m-chlorobenzoyl peroxide: mCBPO) which was synthesized from meta-chlorobenzoic acid. Efficient one pot ortho-oxidation reaction of phenol with an adduct of meta-chloroperbenzoic acid (mCPBA) with dicyclohexylcarbodiimide (DCC) was also reported.

Abietanes↗

[Capecitabine].

Capecitabine, an oral fluoropyrimidine carbamate, is adopted worldwide. As the treatment for metastatic colorectal cancer, capecitabine showed at least comparable efficacy with a favorable safety profile to bolus 5-FU/LV. In a large phase III trial (Xeloda Adjuvant Chemotherapy Trial: X-ACT), as the adjuvant treatment of patients with resected stage III colon cancer, capecitabine showed at least comparable disease-free survival, overall survival, and relapse-free survival with a favorable safety profile to bolus 5-FU/LV. Additionally, capecitabine-based combination regimens with oxaliplatin or irinotecan are now under evaluation. In phase II studies, capecitabine has shown the promising results in combination therapy. In Japan, capecitabine has been evaluated since 1994. In a recent phase II study, which evaluated the global dose as first-line treatment for metastatic colorectal cancer, the response rate was 35% (95% CI 23.1-48.4). The median time to disease progression was 169 days and the median overall survival was 617 days. Hand-foot syndrome (HFS), a characteristic adverse event of capecitabine, was observed in 73.3% of the patients, but the grade 3/4 was observed in 13.3% of the patients and only one patient discontinued the treatment due to HFS. An immediate approval of capecitabine in Japan is expected.

Antimetabolites, Antineoplastic↗

Use of local electroporation enhances methotrexate effects with minimum dose in adjuvant-induced arthritis.

OBJECTIVE: To investigate the effects of electrical pulses on the ability of methotrexate (MTX) to attenuate inflammation and subsequent joint destruction in rats with adjuvant-induced arthritis (AIA). METHODS: Rats in the experimental group received an intraperitoneal injection of MTX (0.125 mg/kg body weight), followed 30 minutes later by application of direct electrical pulses (50V, 8 Hz) to their left hind paws with an electroporation apparatus (M+/E+ group; n = 8). The procedure was repeated twice weekly for 3 weeks. Three control groups received the following treatments, respectively: MTX without electrical treatment (M+/E- group; n = 9), electrical treatment but no MTX (M-/E+ group; n = 10), or no electrical treatment and no MTX (M-/E- group; n = 9). Progression of AIA was monitored by joint swelling and radiologic and histologic changes in the ankle joint. RESULTS: Three weeks after injection of the adjuvant, and at the height of the arthritic reaction, the swelling and radiologic and histologic changes in the left hind paws in the M+/E+ rats were significantly reduced, as compared with changes observed in the control groups. CONCLUSION: These results demonstrate that application of electrical pulses in combination with use of systemic low-dose MTX can ameliorate local arthritic reactions. This response probably occurs because electrical stimulation promotes transient passage of MTX through pores in the cell membranes, with a resultant local increase in the concentration of the drug within the cells. These results point to a potential use of electrochemotherapy to increase the efficacy of MTX or other drugs in an arthritic joint that is refractory to treatment, without increasing the dose of the drug.

Animals↗

Open reduction of the dislocated hip in juvenile idiopathic arthritis: a case report.

An 8-year-old girl with systemic-onset juvenile idiopathic arthritis (JIA) required surgical reduction for a dislocated left hip joint following failure of skin traction for 1 week. Unaided walking was achieved by 3 months postoperatively. Incongruence and irregularity of the hip joint remained but may resolve with maturation. Joint laxity caused by synovitis, flexion/adduction contracture with pain, and acetabular dysplasia by growth disturbance apparently caused hip dislocation.

Journal Article↗

Synthesis and anti-barnacle activities of novel isocyanocyclohexane compounds containing an ester or an ether functional group.

Ten novel isocyanocyclohexane compounds that possess an oxygenic functional group at the 4-position were synthesized and evaluated for their antifouling activity against the larvae of the barnacle Balanus amphitrite with the aim of exploring the structure-activity relationships further. The anti-barnacle effect of the synthesized compounds was in the EC50 range of 0.0096-17.0 microg ml(-1). Some ester derivatives exhibited extremely high antifouling activities, and none of the synthesized isocyanocyclohexane compounds showed significant toxicity. The results suggest that the ester function is one of the important groups in the expression of potent antifouling activity in isocyano compounds.

Animals↗

Synthesis and anti-barnacle activities of novel 3-isocyanotheonellin analogues.

An antifouling active natural compound, 3-isocyanotheonellin, and its analogues were synthesized and evaluated for antifouling activity against the larvae of the barnacle Balanus amphirite in order to explore structure-activity relationships. The anti-barnacle effect of the 3-isocyanotheonellin analogues was in the EC50 range 0.18-7.20 micrograms ml-1. Some synthesized analogues exhibited potent antifouling activity as high as 3-isocyanothoenllin, and none of the synthesized isocyano compounds showed significant toxicity. The results of the present study suggest that an isocyano group and a hydrophobic site at a suitable position are important for potent antifouling activity without toxicity.

Animals↗

Anodic modification of proline derivatives using a lithium perchlorate/nitromethane electrolyte solution.

[reaction: see text] N-Acyliminium cation of prolines was efficiently generated to accumulate in an undivided cell at 0 degrees C by an anodic oxidation of N-acylprolines or alpha'-phenylsulfanylated N-acylproline derivatives in a lithium perchlorate/nitromethane solution. The iminium cation intermediates gave modified prolines by a reaction with nucleophiles under mild conditions.

Electrodes↗

Phase II study of paclitaxel with 3-h infusion in patients with advanced gastric cancer.

BACKGROUND: To increase the options for agents for gastric cancer chemotherapy, we performed a phase II clinical trial on the use of a 3-h infusion of paclitaxel to confirm its efficacy and the feasibility of its use in patients with advanced gastric cancer. METHODS: Thirty-two (32) patients with measurable metastatic gastric cancer were enrolled in this study. Seventeen patients (53%) had received prior chemotherapy for metastatic disease, 4 patients (13%) had adjuvant chemotherapy alone, and 11 patients (34%) were chemotherapy-naive. Paclitaxel was intravenously infused for 3 h, at a dose of 210 mg/m(2), once every 3 weeks. To prevent hypersensitivity reactions, standard premedication was administered to all patients. RESULTS: Nine (28%; 9/32 ) objective partial responses (PRs) were observed (95% confidence interval [CI], 14%-47%), and the remaining 23 patients showed stable (12 patients; 37.5%) and progressive disease (11 patients; 34.4%). The median time to response was 20 days (range, 14-38 days). The median response duration was 87 days (range, 50-103 days). The median survival of all patients was 234 days (range, 13-646+ days). The major adverse reactions were myelosuppression (grade 3/4 leukopenia and neutropenia were observed in 59% and 88% of the patients, respectively), alopecia, and peripheral neuropathy. Peripheral neuropathy was observed in 19 patients, however, most of the patients recovered after the completion of treatment. CONCLUSION: A 3-h infusion of paclitaxel is an effective therapy for advanced gastric cancer and is clinically well tolerated by the patients.

Adenocarcinoma↗