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).

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 In one patient, right partial lobectomy of the liver was performed after most of the stones were withdrawn, since some stones in the extremely narrow bile duct had not been removed. Most of the intrahepatic bile duct stones and choledochal stones will be withdrawn using the Yag laser and a choledochofiberscope, when they were bilirubin stones.

Injection sclerotherapy of esophageal varices for patients undergoing emergency and elective surgery

From October 1977 to September 1981, 68 patients with esophageal varices (30 emergency cases of bleeding and 38 elective cases) were treated by injecting 5% ethanolamine oleate into varices, using an esophagofiberscope. Esophageal bleeding was successfully controlled in 29 of 30 patients who had emergency surgery. None of the 38 patients who underwent elective operation had bleeding after treatment. When recurrence occurred 1 or 2 years after treatment, the same procedure was repeated. Pleuritis occurred in one of the patients who had emergency surgery, and bleeding (300 to 400 ml) from the esophagocardial junction occurred in two patients who underwent elective operation. These patients were treatment conservatively.

[Tissue concentration of 5-FU following pre-operative administration of FT-207]

Forty patients with gastric cancer and 30 patients with colon cancer were administered FT-207 prior to the operation. The relation between a total dose (4-88g) and tissue concentration of 5-FU was investigated and the following results were obtained. (5-FU concentration was measured with the method of Gas chromatography mas fragmentography) 1) The relation between total doses of FT-207 (x) and concentration of 5-FU in the tissue (y) was demonstrated by the formula: y = 0.00317x + 0.025 (gastric cancer) r = 0.519, p = 0.0001 y = 0.0019x + 0.043 (colon cancer) r = 0.641, p = 0.0001 2) In most of the patients with rectal cancer who received radiation therapy prior to the operation, 5-FU concentration in the tissue was extremely low. 3) 5-FU concentration showed no difference between the normal and metastatic lymph nodes, or among the lymph node groups. Administration methods (oral intake or suppository) had no influence on the concentration of 5-FU. 4) Among the organs, 5-FU concentration was higher in the following orders: liver, normal mucosa, lymph node, tumor, normal serosa. 5) In five autopsy cases, 5-FU concentration of the tissue show a great difference among them, and some cases showed 10 times as high concentration as others in the tissue of every organ.

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.

Choledocholithotomy by Yag laser with a choledochofiberscope: case reports of two patients

The Neodymium-Yag laser was successfully used with a choledochofiberscope for choledocholithotomy in two patients. The bile duct stones were crushed with the Yag laser and removed or pushed into the duodenum without causing any injury. This procedure is highly recommended for treatment of some patients with bile duct stones.

Direct effects of endogenous pyrogen on medullary temperature-responsive neurons in rabbits

The effect of endogenous pyrogen (E.P.) injected directly into the tissue near the recording site were examined on the activities of the medullary temperature-responsive (TR) neurons in rabbits anesthetized with urethane. Endogenous pyrogen prepared from rabbit's whole blood was administered by a fine glass cannula (100-200 micrometer in diameter) in a fluid volume of 1 to 4 microliter. The cannula was fixed to the manipulator in parallel with a microelectrode and their tips were less than 0.05 mm apart. In rabbits with the intact preoptic/anterior hypothalamic (PO/AH) region, 4 warm-responsive neurons out of 7 were inhibited and 6 cold-responsive neuron out of 7 were excited by the direct administration of the E.P. In rabbits with lesions of the PO/AH, 5 warm-responsive neurons out of 9 were inhibited and 6 cold-responsive neurons out of 8 were facilitated by E.P. Antipyretics administered locally after the E.P. antagonized the pyretic effect, causing a return of the discharge of TR neuron to the control rate within 2.4 +/- 1.2 (mean +/- S.D.) min. The medullary TR neuron itself has the ability to respond to the E.P. and contributes to the development of fever.

A new device for barium-enema examination following colostomy

The authors developed a colostomy appliance for use during barium-enema examinations. It is 8 cm in diameter and 4 cm in height, and is made of acrylic resins. With the use of this device, 21 patients were fluoroscopically examined through the stoma; good contrast views of the lower intestinal tract were obtained in all cases without leakage of barium or air.

Pipemidic acid, a new antibacterial agent active against Pseudomonas aeruginosa: in vitro properties

Pipemidic acid, 8-ethyl-5,8-dihydro-5-oxo-2-(1-piperazinyl)-pyrido [2,3-d]pyrimidine-6-carboxylic acid, is a new derivative of piromidic acid. It is active against gram-negative bacteria including Pseudomonas aeruginosa as well as some gram-positive bacteria. Its potency is generally greater than that of piromidic acid and nalidixic acid. Cross-resistance is not observed between pipemidic acid and various antibiotics, and most of bacteria resistant to piromidic acid and nalidixic acid are moderately susceptible to pipemidic acid. The activity of pipemidic acid is scarcely affected by the addition of serum, sodium cholate, or change of medium pH, but is subject to the influence of inoculum size. Its action is bactericidal above minimal inhibitory concentrations.

Pipemidic acid: absorption, distribution, and excretion

Pipemidic acid was absorbed well by the oral route. Its peak levels in plasma ranged from 4 to 12 mug/ml at an oral dose of about 50 mg/kg in mice, rats, dogs, monkeys, and men. The protein binding of pipemidic acid was about 20% in dog plasma and about 30% in human serum. Pipemidic acid was distributed to most of the organs and tissues tested at the concentrations comparable to or higher than the plasma level. Its concentrations in bile and urine were much higher than the plasma level. About 25 to 88% of orally administered pipemidic acid was excreted into urine in a bacteriologically active form, the percentage depending on the animals and doses employed. The remainder was excreted into feces in men. The main active principle in vivo was unchanged pipemidic acid itself. The mean lethal dose of pipemidic acid after a single oral dose was more than 16,000 mg/kg in mice. No abnormalities were observed in mice orally receiving pipemidic acid once a day for 4 weeks at doses of 1,000, 2,000, and 4,000 mg/kg per day, and in rats orally receiving the drug once a day for 2 weeks at doses of 400 and 1,600 mg/kg per day.