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Biomedical subjects

M Morimoto

Publications and source records attributed to M Morimoto.

At least 433 records · Page 24Linked to original sources
PubMed1975

Purification and characterization of kynurenine--2-oxoglutarate aminotransferase from the liver, brain and small intestine of rats.

1. Kynurenine-2-oxoglutarate aminotransferase (isoenzyme 1) was purified to homogeneity from the liver, brain and small intestine of rats by the same procedure. The three enzyme preparations had nearly identical pH optima, substrate specificities and molecular weights. Isoenzyme 1 was active with 2-oxoglutarate but not with pyruvate as amino acceptor, and utilized a wide range of amino acids as amino donors. Amino acids were effective in the following order to activity: L-aspartate greater than L-tyrosine greater than L-phenylalanine greater than L-tryptophan greater than 5-hydroxy-L-tryptophan greater than L-kynurenine. The molecular weight was approximately 88 000 as determined by sucrose-density-gradient centrifugation. The pH optimum was between 8.0 and 8.5. On the basis of substrate specificity, substrate inhibition, subcellular distribution and polyacrylamide-disc-gel electrophoresis, it is suggested that liver, brain and small intestinal kynurenine-2-oxoglutarate aminotransferase (isoenzyme 1) is identical with mitochondrial tyrosine-2-oxoglutarate aminotransferase and also with mitochondrial aspartate-2-oxoglutarate aminotransferase. 2. An additional kynurenine-2-oxoglutarate aminotransferase (isoenzyme 2) was purified from the liver. This enzyme was specific for 2-oxoglutarate and L-kynurenine. Sucrose-density-gradient centrifugation gave a molecular weight of approximately 100 000. The pH optimum was between 6.0 and 6.5. This enzyme was not detected in the brain or small intestine.

Animals↗
PubMed1975

Restoration of voice after laryngeal surgeries.

Some aspects of speech deficiency in Japanese-speaking patients who had undergone surgeries for laryngeal malignancy were studied. Surgical procedures included reconstructive surgeries after total laryngectomy and conservation surgeries. A series of listener-judgments and some acoustic analyses of speech were made. The recorded voices of the patients were more or less hoarse. The median speaking pitch varied greatly from patient to patient, and often assumed an unusual value. The average articulation score for five Japanese vowels was computed for each subject. The score varied from patient to patient, and was thought to be useful in quantitatively evaluating speech quality. It was shown that certain glottal consonants such as /h/ can be affected by laryngeal surgeries. It was emphasized that the larynx should be regarded not only as a generator or a vibrator, but also as an articulator which produces consonants. The listening tests also revealed that the intonation pattern of Japanese two-syllable nouns can be influenced by laryngeal surgeries, and that distinction among certain words may become impossible as a result. This type of speech problem may require serious consideration in some language environments.

Environment↗
PubMed1975

Subcellular distribution and properties of kynurenine pyruvate transaminase in rat kidney.

Kynurenine transaminase activity in rat kidney was found in both the mitochondrial and supernatant fractions. These fractions contained (a) kynurenine pyruvate transaminase, which showed a preference for pyruvate as amino acceptor, and had a pH optimum between 8.0 and 8.5, and (b) kynurenine 2-oxoglutarate transaminase, with a preference for 2-oxoglutarate and a pH optimum between 6.0 and 6.5. The apparent Km value of the former enzyme for L-kynurenine was much lower than that of the latter enzyme.

Cytosol↗
PubMed1975

Menière's disease and diphenidol. A critical analysis of symptoms and equilibrium function tests.

In 24 patients with Ménière's disease, chemotherapy using Diphenidol (1,1-diphenyl-4-piperidino-l-butanol hydrochloride), a non-phenothiazinic antiemetic agent, was carried out using the double-blind technique in the cross-over design. The prevalence and intensity of symptoms at the three stages were recorded every three weeks according to fixed scales which were graded: vertigo, unsteadiness, tinnitus, nausea, headache, and shoulder stiffness. The hearing was measured by tone audiometry. Equilibrium function tests were also performed every three weeks and these included the electronystagmographical procedure to determine caloric response and the ARG-Tilt tests. Both symptoms and the results of equilibrium function tests, showed a higher incidence of improvement during the period of Diphenidol administration than during that of placebo. The difference was statistically significant with respect to vertigo, dizziness or unsteadiness, and general condition subjectively, as well as caloric response and ARG-Tilt tests. The Diphenidol effect consisted of an improvement of imbalance, both in the peripheral and in the central vestibular system through its neural and circulatory action. Only 8% of the patients dropped out and no side effects were observed in this series. Both the feasibility of the graded symptom scales and the utility of each parameter obtained from the equilibrium function tests are discussed in connection with testing of the drug in various stages of the disease.

Audiometry↗
PubMed1975

A new folded pharyngeal flap. Preliminary report.

In an attempt to minimize postoperative scar contracture and shrinkage after a pharyngeal flap operation, a folded flap operation was devised. This operation was performed on 14 patients with velopharyngeal inadequacy. A superiorly-based flap was elevated from the posterior pharyngeal wall and was folded with the mucosa outside. The flap-velum connection was made through raw surfaces produced on each lateral ridge of the flap and the two penetrating incisions on the sides of the soft palate. In none of the cases did detachment of the flap or any other complications occur. This rather simple technique which aims to prevent scar contracture of the flap will permit further elaboration of the flap design-depending on the extent of velopharyngeal incompetence.

Cleft Palate↗
PubMed1974

Subcellular distribution and properties of kynurenine transaminase in rat liver.

Kynurenine transaminase activity in rat liver was found in both the mitochondrial and supernatant fractions. The mitochondrial and supernatant fractions contained (a) kynurenine-pyruvate transaminase, which showed a preference for pyruvate as amino acceptor and a pH optimum between 8.0 and 8.5, and (b) kynurenine-alpha-oxoglutarate transaminase, with a preference for alpha-oxoglutarate and a pH optimum between 6.0 and 6.5. Possible roles of these enzymes in tryptophan metabolism in the liver are discussed.

Alcohol Oxidoreductases↗