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Biomedical subjects

Y Takase

Publications and source records attributed to Y Takase.

At least 109 records · Page 6Linked to original sources

Surgical treatment for carcinoma at the confluence of the major hepatic ducts.

During the period of November 1976 through October 1984, we have treated 46 patients with carcinoma at the confluence of the major hepatic ducts. Curative resection of the tumor (where no carcinoma cells at the margin of the resected portion were found macroscopically and microscopially), was performed upon ten patients, palliative resections were done in 11, palliative resection and intraoperative radiotherapy (IOR) in ten, bile duct drainage and IOR in three, and percutaneous transhepatic cholangiodrainage in 12. Among the ten patients who underwent curative operation, five are living six to 104 months after operation while the remaining five died four to 72 months postoperatively. Of the 11 patients who underwent palliative resection, five are alive two to 22 months after operation and six died between four and 20 months after operation. For the ten patients with carcinoma in the advanced stages, palliative resection with IOR was performed. Eight patients died 20 days to 16 months after operation while two patients are alive 13 and 14 months after the procedure. Of the three patients who underwent drainage of the bile duct and IOR, two died three months after operation and one patient survived 34 months. Twelve patients underwent drainage of the bile duct only and all died after 13 months. To perform a curative operation for carcinoma located at the confluence of major hepatic ducts, it is necessary to resect the right or left lobe, including the caudate lobe, in many instances. For the patients with carcinoma in the advanced stages, the possibility of long term survival period after operation exists through the use of the combined techniques of IOR and palliative resection of the tumor.

Adult↗

Pathological studies on esophageal varices treated with injection sclerotherapy.

Injection sclerotherapy is one of the most effective treatments for esophageal varices. To investigate the fate of esophageal varices embolized with a sclerosant (ethanolamine oleate), we have examined at autopsy the esophageal wall of 14 patients with esophageal varices. When the sclerosant was injected into the varices, at first thrombi formed. After two weeks, granulation tissue appeared and the thrombi were gradually replaced. The granulation tissues were organized slowly after 3 months and in the organized granulation tissue, microscopic recanalization of vessels were seen in 8 out of 9 cases. There was no recurrence of the original varices and de novo varices occurred in one patient. These observations indicate that the varices embolized with ethanolamine oleate become organized in three months after the treatment, and accordingly the esophageal varices are cured. It became also clear that recurrence of the original varices did not occur after the organization.

Adult↗

In vitro antibacterial properties of AT-2266, a new pyridonecarboxylic acid.

AT-2266, 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-1,8-naphthyridine-3 -carboxylic acid, is a new pyridonecarboxylic acid derivative with broad and potent antibacterial activity. It inhibited some gram-positive bacteria, such as staphylococci and Bacillus subtilis, and most gram-negative bacteria, including Serratia marcescens, Pseudomonas aeruginosa, Haemophilus influenzae, and Campylobacter jejuni, at concentrations of 0.1 to 0.78 microgram/ml, and most gram-positive bacteria, glucose-nonfermenters, and Mycoplasma pneumoniae at concentrations of 1.56 to 12.5 micrograms/ml. Most of the clinical isolates tested were as susceptible to AT-2266 as were laboratory strains. The antibacterial potency of AT-2266 was higher than those of pipemidic acid and nalidixic acid and similar to that of norfloxacin. AT-2266 was not cross-resistant with antibiotics and inhibited most highly nalidixic acid-resistant bacteria at concentrations of 1.56 to 3.13 micrograms/ml. Its activity was barely affected by the addition of horse serum or sodium cholate but weakened by lowering the medium pH or increasing the inoculum size. AT-2266 was bactericidal at concentrations near its minimal inhibitory concentrations. Frequencies of mutants resistant to 10 micrograms of AT-2266 per ml were lower than 4.0 x 10(-9).

Anti-Bacterial Agents↗

Activity of AT-2266 compared with those of norfloxacin, pipemidic acid, nalidixic acid, and gentamicin against various experimental infections in mice.

AT-2266 (1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-1, 8-naphthyridine-3-carboxylic acid) showed marked activity in vivo when administered orally to mice bearing systemic, pulmonary, dermal, or urinary tract infections due to variety of organisms. The activity of AT-2266 was uniformly higher than those of norfloxacin, pipemidic acid, and nalidixic acid against all of the infections. The activity of AT-2266 administered orally was almost comparable to that of gentamicin administered subcutaneously against urinary tract infections due to gram-negative organisms but was generally lower against other infections. AT-2266 exhibited significant activity against infections due to gentamicin-resistant and nalidixic acid-resistant organisms.

Animals↗

Pharmacokinetics of AT-2266 administered orally to mice, rats, dogs, and monkeys.

The pharmacokinetics of AT-2266 (1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-1,8-naphthyridine- 3-carboxylic acid) were studied in various experimental animals and compared in a number of aspects with those of norfloxacin. Both agents were administered orally. The mean peak plasma levels of AT-2266 in mice, rats, and dogs (given a single dose of 50 mg/kg for mice and rats and 25 mg/kg for dogs) were 2.39, 1.63, and 5.00 mug/ml, respectively, with elimination half-lives of 2.24, 2.81, and 5.76 h. The respective mean plasma levels of norfloxacin at similar dosages were 0.510, 0.410, and 0.700 mug/ml; elimination half-lives were 1.40, 2.35, and 6.06 h. In dogs repeatedly dosed with 25 mg of AT-2266 per kg every 12 h, the mean peak plasma levels after the third and fifth doses were about 1.4 times those after the first dose. The binding rates of AT-2266 and norfloxacin to plasma of mice, rats, and dogs and to human serum ranged from 27.6 to 40.2% and 39.8 to 44.2%, respectively. In rats receiving a single dose of 50 mg/kg, the respective mean peak levels of AT-2266 in plasma, lung, muscle, and kidney were 2.47, 4.60, 5.35, and 33.9 mug/ml or g, whereas those of norfloxacin were 0.234, 0.390, 0.272, and 2.05 mug/ml or g. AT-2266 was widely distributed in tissues of dogs and monkeys after repeated dosage. The respective 24-h recoveries of AT-2266 from urine of mice, rats, and dogs after single doses of 50, 50, and 25 mg/kg were 56.6, 40.5, and 64.1%, and recoveries of norfloxacin at these doses were 4.40, 2.91, and 5.34%. The respective 24-h recoveries of AT-2266 from bile and feces of rats given a single dose of 50 mg/kg were 2.47 and 52.7%. Bioautography of plasma and urine indicated that AT-2266 was metabolized to but a slight degree. The results indicate that AT-2266 is better than norfloxacin in oral absorption and similar to the latter in stability to metabolic inactivation.

Administration, Oral↗

Lithotomy of intrahepatic and choledochal stones with Yag laser.

Eight patients with intrahepatic bile duct stones and three with choledochal stones were treated by Yag laser using a choledochofiberscope. A choledochoscope was inserted through a T-tube fistula in five patients or a percutaneous transhepatic cholangiodrainage fistula in six patients. In one patient, right partial lobectomy of the liver was performed after most of the stones were withdrawn, since some stones in the extremely narrow bile duct had not been removed. Most of the intrahepatic bile duct stones and choledochal stones will be withdrawn using the Yag laser and a choledochofiberscope, when they were bilirubin stones.

Adult↗

Studies on contact hypersensitivity in the guinea pig.

A method to determine the quantitative induction and challenge of the allergenicity of externally applied toiletories and cosmetics, including their components, is described. The experiment used oil-soluble cinnamic aldehyde and water-soluble formalin as allergens, and guinea pigs as the experimental animals. A high sensitization method resulted, carried out as follows. A 24-h closed patch is attached to the skin every other day over a period of 2 weeks (a total of 4 applications). Freund's complete adjuvant is administered intradermally just before the 3rd application of the patch. The challenge step is performed by directly applying the test material. This method was compared with other allergenicity evaluation methods. As a result, this method was found to be in no way inferior in sensitization performance to the other methods. The method was used on perfume mixtures and tested for its evaluation effectiveness. It proved to be satisfactory.

Animals↗