PubMed Health⌕ Search

Biomedical subjects

A Kitano

Publications and source records attributed to A Kitano.

At least 91 records · Page 5Linked to original sources
PubMed1987

Altered kinetic properties of the branched-chain alpha-keto acid dehydrogenase complex due to mutation of the beta-subunit of the branched-chain alpha-keto acid decarboxylase (E1) component in lymphoblastoid cells derived from patients with maple syrup urine disease.

Branched-chain alpha-keto acid dehydrogenase (BCKDH) complexes of lymphoblastoid cell lines derived from patients with classical maple syrup urine disease (MSUD) phenotypes were studied in terms of their catalytic functions and analyzed by immunoblotting, using affinity purified anti-bovine BCKDH antibody. Kinetic studies on three cell lines derived from patients with the classical phenotype showed sigmoidal or near sigmoidal kinetics for overall BCKDH activity and a deficiency of the E1 component activity. An immunoblot study revealed a markedly decreased amount of the E1 beta subunit accompanied by weak staining of the E1 alpha subunit. The E2 and E3 component exhibited a cross-reactive peptide. Thus, in at least some patients with MSUD, mutations of the E1 beta subunit might provide an explanation for the altered kinetic properties of the BCKDH complex.

3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)↗
PubMed1987

Heterogeneous phenotypes of mitochondrial encephalomyopathy in a single kindred.

Five patients with mitochondrial disorders in a single family showed marked heterogeneity of clinical signs and symptoms. Two patients had the syndrome of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes; one had blepharoptosis, seizures, and diabetes insipidus; and two had a nonspecific encephalomyopathic disorder. This family supports the concept of a "mitochondrial cytopathy."

Acidosis, Lactic↗
PubMed1986

The leading cord method of colonofiberscopy.

Although the colonofiberscope has undergone various modifications and improvements, the insertion principle remains unchanged; that is, pushing and rotation and the elasticity of the scope itself are inevitable. It often is difficult to maintain proper balance among these dynamic factors; imbalance prevents deep insertion. Over-elongation of the scope leads to insertion failure, particularly if there are adhesions of the sigmoid colon, overextension of the colon, or transverse colon ptosis. Our "leading cord" method is an excellent aid to colonofiberscopy. It can be inserted from the clamp hole of a conventional fiberscope and hardened to straighten the scope, thereby permitting deep insertion. With this technique the region from the rectum to the descending colon, as well as a ptosed transverse colon, can be straightened. Our clinical experience indicates that the rate of successful insertions in colonofiberscopy will be increased considerably with this complementary device.

Colonoscopes↗
PubMed1986

Mitochondrial cytopathy with lactic acidosis, carnitine deficiency and DeToni-Fanconi-Debré syndrome.

We reported a 6-year-old girl with mitochondrial cytopathy with lactic acidosis. The patient developed hypotonia, hearing loss, mental retardation, short stature, cataracta, hypoparathyroidism, DeToni-Fanconi-Debré syndrome and carnitine deficiency. Histological examination disclosed ragged red fibers and moderate lipid storage in skeletal muscle tissue and several structural abnormalities of mitochondria both in muscle tissue and proximal renal tubules. Biochemical examination of muscle tissue revealed a partial deficiency of pyruvate dehydrogenase complex and normal activities of cytochrome c oxidase, succinate cytochrome c reductase and NADH cytochrome c reductase. This is the first report of mitochondrial cytopathy representing DeToni-Fanconi-Debré syndrome associated with partial deficiency of pyruvate dehydrogenase complex and normal cytochrome c oxidase activity.

Acidosis, Lactic↗
PubMed1986

Factor VIII concentrate-responsive thrombocytopenia, hemolytic anemia, and nephropathy. Evidence that factor VIII:von Willebrand factor is involved in its pathogenesis.

A 4-year-old Japanese girl had a congenital disorder that was characterized by recurrent thrombocytopenia, hemolytic anemia, hematuria, and proteinuria, which were repeatedly improved by the infusion of factor VIII concentrate. She developed the similar symptoms within 1 h after 1-desamino-8-D-arginine vasopressin (DDAVP) administration. Coagulation studies 30 and 60 min after DDAVP infusion showed a disappearance of large factor VIII:von Willebrand factor (VIII:vWF) multimers, which was the same abnormality that was observed at acute episodes. There were no significant changes in the plasma levels of 6-keto-prostaglandin F1 alpha and thromboxane B2 before and after DDAVP infusion. These results provide further support that VIII:vWF is directly involved in the pathogenesis of this congenital disorder.

Anemia, Hemolytic↗
PubMed1986

Epithelial dysplasia of the rabbit colon induced by degraded carrageenan.

Colonic mucosal lesions, characterized by crypt abscesses and mononuclear cell infiltration, which resemble human ulcerative colitis can be induced in rabbits by short-term (7 to 8 weeks) administration of carrageenan according to our method. In this study experimental epithelial dysplasia of the colon was induced by the p.o. administration of lambda-degraded carrageenan for a much longer period of time. Fifteen rabbits, sensitized i.m. with the same substance 1 week before, were subjected to 12 or 28 months of treatment with 1% carrageenan solution in drinking water. Histological examination disclosed chiefly mild inflammatory changes of the colonic mucosa in all animals and a focal but high-grade dysplasia (nonpolypoid) involving the mucosal epithelium in three of the five animals treated for 28 months. The present observations suggested that epithelial dysplasia of the colon may be caused in association with inflammation and that the pathological condition produced by us can be a useful model of carcinoma in situ possibly resulting from inflammation.

Animals↗
PubMed1985

Zinc status of untreated histidinemic children.

In order to study zinc status in histidinemia, serum and hair zinc concentrations were measured in 40 untreated children with histidinemia (age 2 months-5 years). In 20 children (greater than 2 years of age) zinc content and carbonic anhydrase activity of erythrocytes and urinary excretion of zinc were also studied. The amount of zinc excreted was elevated in histidinemic children and showed a positive correlation with the urinary histidine concentration (gamma = 0.57, p less than 0.005). The means of serum zinc concentration, erythrocyte zinc concentration, and erythrocyte carbonic anhydrase activity were all similar in the histidinemic and the control children. Hair zinc concentration of histidinemic children was compared with that of controls of five different age groups: less than 5 months, 5-18 months, 18 months-2 years, 2-4 years, and 4-5 years. In all of these age groups, hair zinc content was similar. The incidence of low-hair-zinc level (less than 80 micrograms/g) in histidinemic children greater than 5 months of age (9 of 34) was significantly higher than in controls (18 of 180, p less than 0.05). The observation suggested the possibility that untreated histidinemia may cause chronic mild zinc deficiency in some histidinemic children.

Ammonia-Lyases↗
PubMed1984

Pyruvate dehydrogenase subcomplex with lipoamide dehydrogenase deficiency in a patient with lactic acidosis and branched chain ketoaciduria.

The overall and three component activities of pyruvate dehydrogenase complex were measured in the liver and muscle from a patient who died at 1.9 years with increased concentrations of serum lactate, alpha-ketoglutarate and branched chain amino acids. The component activities of both lipoate acetyltransferase and pyruvate dehydrogenase were similar to those of normal controls, but the overall pyruvate dehydrogenase complex activity was 11 to 30% of controls and lipoamide dehydrogenase activity was not detected. The overall activity was significantly increased by the addition of lipoamide dehydrogenase purified from human liver. Immunochemical studies carried out with antibody prepared against lipoamide dehydrogenase from rat liver, could detect no immunoreactive material in liver and muscle homogenates from the patient, suggesting that the deficiency of lipoamide dehydrogenase activity was due to the lack of enzyme protein.

Acetyltransferases↗
PubMed1983

Four-hydroxyphenylpyruvic acid oxidase deficiency with normal fumarylacetoacetase: a new variant form of hereditary hypertyrosinemia.

Enzymatic studies on the liver of an infant are described-a case of hypertyrosinemia without hepatic dysfunction. His parents were siblings and the mother had hypertyrosinemia. Excessive amounts of 4-hydroxyphenylpyruvic acid (pHPP), 4-hydroxyphenylacetic acid (pHPL), and 4-hydroxyphenylacetic acid (pHPA) were found to be excreted in the patient's urine as well as in the urine of the mother and the inhibitor of porphobilinogen synthetase was not found. Soluble tyrosine aminotransferase (s-TAT), separated from that of the mitochondrial form (m-TAT) by DE 52 column chromatography, was normal in the patient's liver, both quantitatively and qualitatively. The activities of fumarylacetoacetase in the patient's liver and in the peripheral leucocytes from the parents were normal. The activity of pHPP oxidase in the patient's liver was approximately 5% of the control and the enzyme had a high Km value for pHPP (controls: 0.06 +/- 0.01 mM, patient: 0.23 +/- 0.03 mM). From these results, the patient was thought to be different from previously described types of tyrosinemia and perhaps representative of a new variant form. This is the first report concerning 4-hydroxyphenylpyruvic acid oxidase deficiency alone. Mild metal retardation and mild hypertyrosinemia may be offered as typical clinical features of the disease.

4-Hydroxyphenylpyruvate Dioxygenase↗
PubMed1982

Sural nerve lesions in a case of hypertyrosinemia.

A sural nerve obtained three hours after death from a patient with hypertyrosinemia due to 4-hydroxyphenylpyruvic acid oxidase deficiency was examined. The diameter of the myelinated fibers, as seen on the histogram, was similar to those in an age matched control. However, the number of smaller fibers was greater. Electron-microscopically, the findings of de- and hypomyelination were noted, and occasional dense bodies and multimembranous bodies were seen in some axoplasms. Since his mother was also suffering from hypertyrosinemia, the serum tyrosine level during the fetal and newborn infant periods seemed to be constantly elevated, which may have caused the abnormalities of nerve fibers observed in the present case.

4-Hydroxyphenylpyruvate Dioxygenase↗