Ichiro Matsuda

Leukocyte glutathione peroxidase deficiency in a male patient with chronic granulomatous disease

A male child with chronic granulomatous disease is described in whom glutathione peroxidase deficiency of leukocytes was identified. Stability and activity of G-6-PD and activity of NADPH oxidase were normal. The leukocytes of the parents showed intermediate activities of glutathione peroxidase, suggesting the possibility of autosomal recessive inheritance.

A solid-phase radioimmunoassay for human carbonic anhydrase B.

A sensitive and specific radioimmunoassay method for human erythrocyte carbonic anhydrase B was developed using a solid-phase technique. The assay was found to be sensitive for the detection of nanogram amounts of the enzyme in incubation mixtures. Iodination of it gave rise to a loss of antigenicity and a solid-phase assay technique using antibody-coated paper discs was employed in order to exclude the chemical modification or conformational changes of the enzyme. The levels of carbonic anhydrase B in the erythrocytes of newborn infants and in some biological fluids were determined.

Renal tubular acidosis and skeletal demineralization in patients on long-term anticonvulsant therapy

Three children ranging from seven to 12 years of age from unrelated families were given long-term anticonvulsant therapy including acetazolamide (Diamox). These children had rickets and renal tubular acidosis. Investigations have suggested (1) secondary hyperparathyroidism due to hypocalcemia of rickets and (2) prolonged acetazolamide therapy were responsible for acidosis as a result of reduction of bicarbonate reabsorption in the kidney. A clear-cut recovery from acidosis and rickets was seen in two patients following medication with high doses of vitamin D, an oral supplement of phosphorus, and discontinuance of acetazolamide therapy.

Prenatal diagnosis of I-cell disease

SummaryA pregnancy from a family in risk of I-cell disease was monitored. The fetus was diagnosed as having I-cell disease based on the findings that (1) lysosomal enzyme activities except for acid phosphatase and α glucosidase were clearly elevated in amniotic fluid and were reduced in cultivated amniotic fluid cells, and (2) cytoplasmic inclusions were seen in cultivated amniotic cells by phase contrast microscopy. The accuracy of prediction was confirmed by cultured skin fibroblast of the aborted fetus.

Hurler/Scheie genetic compound (mucopolysaccharidosis IH/IS) in Japanese brothers

Two brothers, aged 21 and 18 years, respectively, presented with Hurler‐like clinical features and normal intelligence. Both had severe dwarfism, characteristic facies, corneal opacities, hearing defect, cardiac enlargement, umbilical and inguinal hernias, and multiple skeletal changes. Both were found to excrete an excessive amount of mucopolysaccharide, shown to be dermatan sulfate and heparan sulfate in the proportion of 9:1. Metachromatic granules could not be found in the peripheral blood leukocytes of either patient. Cultured skin fibroblasts from the younger brother exhibited α‐L‐iduronidase deficiency. In view of these findings, they were diagnosed as Hurler/Scheie genetic compound heterozygotes. A lamellar corneal graft in the older brother remained clear for 4 years after operation.

α-l-Fucosidase and α-d-mannosidase activity in the white blood cells in the disease and carrier state of fucosidosis

Abstract α- l -Fucosidase and α- d -mannosidase activity in white blood cells from a patient with fucosidosis and her family members were studied. α- l -Fucosidase activity of the patient was completely lacking, whereas the α- l -mannosidase activity was increased and relative thermostability of this enzyme was also observed. Apparent K m value of α- d -mannosidase was similar in the patient and the control. When the ratio of α- l -fucosidase to α- d -mannosidase activity was calculated, the value of the parents was intermediate between that of the patient and the control.

Urinary acidification in children

Abstract Eleven children with normal renal function between the ages of 4–14 and with body surface area between 0.60–1.43 m2 were subjected to a short-term test of urinary acidification. Urine specimens were collected 2 hourly before and after 8 h of the oral administration of ammonium chloride, 0.1 g/kg body weight. Shortly after the treatment urinary pH decreased to 5.4 or less in all children and the excretion of titratable acid and ammonium increased as urinary pH decreased. The amount of excreted ammonium corrected by 1.73 m2 body surface area was found to be close to the normal value for adults. The evaluation of this test specially in children is discussed.

Ornithine transcarbamylase, an isoelectric point (pI) isozyme in human liver and its deficiency.

Abstract The crude extract of human liver ornithine transcarbamylase, obtained from a patient with hyperammonemia due to enzyme deficiency, was studied by the isoelectric focusing method. The activity of ornithine transcarbamylase in the patient at pH 8.0 was only slightly reduced. After electrolysis, two main peaks which were isoelectric at pH 3.2 and pH 4.4 were observed in the control, while only one peak at pH 2.8 was found in the patient.

Laurence-Moon-Biedl syndrome (?) and Prader-Willi syndrome (?) in a single family.

Mental retardation, hypogonadism, obesity, and abnormal blood sugar regulation were common findings in two siblings. In addition, the 17-year-old female patient showed short stature, muscular hypotonia in infancy, and small hands with tapering fingers suggesting Prader-Willi syndrome, and the 12-year-old male patient showed retinitis pigmentosa, normal height, and normal muscular tonicity suggesting Laurence-Moon-Biedl syndrome, though polydactyly was absent. Possible consideration was discussed.

Metabolic acidosis in patients receiving anticonvulsants

Blood pH, bicarbonate, PCO2, serum calcium, alkaline phosphatase and red cell carbonic anhydrase were measured in 37 selected patients receiving anticonvulsants. Patients with metabolic acidosis showed a high incidence of hypocalcemia with increased alkaline phosphatase and a significant reduction of carbonic anhydrase-B activity. High iPTH levels were found in 13 patients, but this was not correlated with acid-base balance status. Anticonvulsant drugs seemed to inactive carbonic anhydrase-B activity. Metabolic acidosis might be one of the factors causing a disturbance of calcium metabolism in these patients.