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Biomedical subjects

M Takai

Publications and source records attributed to M Takai.

At least 127 records · Page 7Linked to original sources

Release of prostaglandins from the passively distended wall of guinea pig small intestine.

The effects of the radial distension of the intestinal wall and the increased intraluminal pressure on the liberation of prostaglandins (PGs) were studied with the isolated guinea pig ileum. Both procedures were accompanied by an increased output of a prostaglandin-like substance and the release was proportional to the degree of distension or intraluminal pressure. Thin-layer chromatography coupled with bioassay suggested that this substance may be a mixture of PGF2 alpha, PGE2 and PGE1. The existence of the former two types of PGs were prominent. The distension-induced release of PG-like substance was assumed to be not mediated by nerve excitation since tetrodotoxin failed to inhibit the release. The increased output of the PG-like substance was not maintained after distension of the intestinal wall, despite continued application of stimulus, indicating that actual tissue deformation is an essential condition leading to increased PG output. It is concluded that distension of the intestinal wall to its circumferential direction is an appropriate stimulus for the release of PG-like substance from the small intestine. The present results favor the view that prostaglandins may participate in the peristaltic activity.

Animals↗

[Pharmacological properties of procaterol, a newly synthetized, specific beta 2-adrenoceptor stimulant. Part I. Effects on the CNS (author's transl)].

Effects of procaterol (PRO) on the CNS were investigated in comparison with those of salbutamol (SAL) and isoproterenol (ISO). PRO, 15 to 50 mg/kg given subcutaneously suppressed spontaneous movement in mice, rats and rabbits and with a large dose, 1000 mg/kg, the animals became quiet and immobile. In dogs, PRO produced similar symptoms and in addition, there was nausea and vomiting. The animals recovered within 3--8 hours. ID50's in depressing spontaneous movement were 20.2 and 245 mg/kg for PRO, 51.1 and 133 mg/kg for SAL and 2.37 and 143 mg/kg for ISO, respectively, both by the subcutaneous and oral routes of administration. Methamphetamine induced increase in motility and fighting behavior was also suppressed by PRO when similar doses were given. PRO had no effect on coordinating movement, halothane anesthesia, drug and electric stimulation induced convulsions and body temperature, and there was no muscle relaxant action. However, PRO in large doses prolonged sleeping time with hexobarbital. The analgesic effect of PRO was not observed with Haffner's and Landall Selitto's methods but acetic acid induced writhing was suppressed by PRO. PRO had little effect on spontaneous EEGs either cortical or from deep structures, and EEG arousal responses. The effects of PRO on the CNS were slight and nonspecific, and similar to those of SAL and ISO.

Adrenergic beta-Agonists↗

Usnic acid derivatives as potential antineoplastic agents.

Usnic acid, a lichen antibiotic, showed low-level activity in the Lewis lung carcinoma test system. In an effort to produce new agents of potential use in the treatment of lung cancer, derivatives of the natural product were synthesized and evaluated with a cytotoxicity assay. Structure--activity analysis of the cytotoxicity data indicated the importance of the lipophilicity and the beta-triketone moiety of usnic acid on cytotoxicity. No significant increases in survival of test animals over controls were shown by any of the synthetic compounds in the P388 leukemia or the Lewis lung carcinoma test systems.

Animals↗

[Pharmacological properties of procaterol, a newly synthesized, specific beta 2-adrenoceptor stimulant. Part II. Effects on the peripheral organs (author's transl)].

Pharmacological properties of procaterol (PRO) in the peripheral organs were examined in comparison with those of sulbutamol (SAL) and isoproterenol (ISO). PRO slightly enhanced twitch tension of the tibialis anterior muscle but affected little the mono- and poly-synaptic spinal reflexes and ganglionic transmission. PRO depressed spontaneous contractions of the isolated ileum, non-pregnant and pregnant uterus and also the gastrointestinal and uterine movements in vivo. PRO prolonged the time of peroral charcoal transport in the intestine. Potencies of PRO in producing these effects were between those of ISO and SAL except those on the uterus in which PRO was more potent than ISO and SAL. Pro depressed gastric and bile secretion but had no effect on pancreatic secretion. ISO, PRO and SAL reduced resistance of the common carotid, femoral and renal arteries and the relative potencies of PRO and SAL to ISO were significantly less in the renal artery than in the other arteries. In accelerating heart rate in conscious rats and dogs, PRO (p.o. or s.c.) was almost equipotent to SAL. Urine flow, GFR, RPF, free water and osmolar clearance and also excretion of electrolytes were reduced by PRO with the concomitant fall of systemic blood pressure. PRO has no effect on blood coagulation and hemolysis but inhibited carrageenin edema and an increase in permeability of blood vessels induced by acetic acid. PRO had no alpha-adrenolytic, cholinolytic and anti-histaminic effects.

Adrenergic beta-Agonists↗

Purification and properties of a soluble polymer of glucose from cultures of Acetobacter xylinum.

A soluble nondialyzable polymer of glucose was isolated and purified by selective ethanol and ammonium sulfate precipitation from the supernatant of a culture of Acetobacter xylinum which was actively producing cellulose. This polymer was heterogeneous in size with an average sedimentation constant S20,w, of the most abundant fraction of 11.1. On drying from dilute solution in water, the polymer(s) showed extended linear fibrils or aggregates of such fibrils by transmission electron microscopy. The infrared spectrum resembled closely that of cellulose II. Preparations of the lyophilized polymer were amorphous by X-ray diffraction. Composition and structure of the polymer were established by enzymatic digestion, acid hydrolysis before paper chromatography, and methylation followed by gas-liquid chromatography. Glucose was the only component of the polymer. There were few, if any, alpha 1 leads to 4 linkages between glucose residues. The polymer(s) is a linear chain of glucose units linked beta 1 leads to 4 with single glucose residues as branches at position 2 of every third glucose on the average. The possibility that this branched glucose polymer is an intermediate in cellulose biosynthesis is examined.

Chemical Phenomena↗

The rare red cell phenotype Lan negative in Japanese.

Two patients and a healthy blood donor were found to be Lan negative and to have anti-Lan in their sera. These are the first three examples of the Lan-negative phenotype to be described in Japanese. The families of two of the propositi were studied: the parents of both were first cousins and one of the propositi had a Lan-negative sibling. No Lan-negative examples were found in 15,000 Japanese donors screened with anti-Lan.

Adult↗

Clinical outcome of intraoperative pelvic hyperthermochemotherapy for patients with Dukes' C rectal cancer.

In attempts to prevent local recurrence after curative resection for rectal cancer, intraoperative pelvic hyperthermochemotherapy (IOPHC) was prescribed for 27 patients with Dukes' C cancer. The procedures used were as follows: immediately after amputation or resection of the rectum with extended lymphadenectomy, the pelvic cavity was filled with physiological saline containing 40 micrograms/ml mitomycin C, which was warmed at 45 degrees C for 90 min with an apparatus devised for IOPHC. Thirty-five patients who underwent surgery alone for Dukes' C rectal cancer within the same period served as controls. There was a local recurrence in three patients in the IOPHC group (11.1%), and in 13 in the control group (37.1%). With regard to hepatic or pulmonary metastasis, there was no difference between the two groups. There was no morbidity in the IOPHC treatment except for a large volume of exudate from the pelvic cavity. Thus, IOPHC can be considered as one option for limiting local recurrence after surgical resection of an advanced rectal cancer.

Aged↗