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Biomedical subjects

H Yabuuchi

Publications and source records attributed to H Yabuuchi.

At least 127 records · Page 7Linked to original sources
PubMed1985

Ultrastructural study on a severe infantile sialidosis (beta-galactosidase-alpha-neuraminidase deficiency).

This study was undertaken to elucidate ultrastructural changes in a severe infantile sialidosis. The materials examined in this study consisted of biopsied rectal mucosa and autopsied small intestine, liver and kidney. In the biopsy sample, axons contained a number of pleomorphic electron dense bodies, and numerous membrane-bound vacuoles were found in Schwann's cells, fibroblasts, endothelial cells, lymphocytes and plasma cells. In autopsy samples, neurons in Auerbach's myenteric plexus of the small intestine were filled with a number of membranous cytoplasmic bodies, pleomorphic dense bodies and vesicles containing dense materials. Hepatocytes in the liver, and glomerular and tubular epithelial cells in the kidney were also extended by a number of membrane-bound vacuoles. These ultrastructural changes in severe infantile sialidosis closely resemble those in GM1-gangliosidosis type 1.

Biopsy↗
PubMed1985

Bone gamma-carboxyglutamic acid containing protein in the perinatal period.

We measured bone gamma-carboxyglutamic acid-containing protein (BGP), calcium (Ca), phosphorus (P), and alkaline phosphatase (Al-P) in paired maternal and cord sera, and urinary gamma-carboxyglutamic acid (gamma-Gla) in neonates. The circulating BGP was 41.21 +/- 2.47 ng/ml and 7.44 +/- 0.87 ng/ml in the cord (n = 15) and the maternal (n = 14) sera, respectively. The urinary gamma-Gla in the neonates was 147.68 +/- 10.75 mumol/g creatinine (n = 15). The cord serum BGP was significantly higher than the normal adult level. The maternal serum BGP was at the same level as in other adults. It is conceivable that the fetus may produce BGP during gestation, as the cord serum BGP level was significantly higher than the maternal level and there was no correlation between the cord and maternal serum BGP concentrations. The reason for the elevated circulating BGP level in the cord serum is not known, but increased bone turnover may be a factor. The cord serum BGP may include not only carboxylated but also non-gamma-carboxylated GP because of fetal vitamin K deficiency.

1-Carboxyglutamic Acid↗
PubMed1985

Decreased nuclear uptake of 1,25-dihydroxyvitamin D3 by duodenal mucosal cells in the X-linked hypophosphatemic mouse.

We have shown that there is a significant decrease in the nuclear uptake of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] by duodenal mucosal cells in the X-linked hypophosphatemic (Hyp) mouse. Duodenal mucosal cells prepared from control and Hyp mice were incubated with 1,25(OH)2[26,27-methyl-3H]D3 ([3H]-1,25(OH)2D3) for 30 min. to evaluate the time-course and perform saturation analysis. The results of time-course studies showed that saturation was attained in 30 min., reaching an average nuclear uptake of 10.4 fmol/tube in the control mice and 6.1 fmol/tube in the Hyp mice. The results of Scatchard analyses were as follows: dissociation constant (Kd) 5.71 X 10(-10) M and maximal binding sites 7.31 X 10(4) sites/cell in the control mice, and Kd 2.92 X 10(-10) M and maximal binding sites 4.88 X 10(4) sites/cell in the Hyp mice, the maximal binding sites of the latter showed a significant decrease (P less than 0.05) by Student's t test. In addition, there was no significant difference in the binding of [3H]-1,25(OH)2D3 to its residual cytosol receptors between the control and Hyp mice. On the basis of these data, we speculate that the reported resistance of Hyp mice to vitamin D may be due to decreased nuclear uptake of 1,25(OH)2D3 by their duodenal mucosal cells.

Animals↗
PubMed1985

Assay of glucocerebrosidase using a fluorescent analogue of glucocerebroside for the diagnosis of Gaucher disease.

For the diagnosis of homozygotes and heterozygotes of Gaucher disease, glucocerebrosidase (glucocerebroside beta-D-glucoside glucohydrolase, EC 3.2.1.45) activity in lymphocytes was measured using a fluorescent analogue of glucocerebroside, 1-0-glucosyl-2-N-(dimethylaminonaphthalene-5-sulfonyl)-sphingosine as substrate. The activity in lymphocytes from homozygotes of Gaucher disease was found to be reduced markedly. This method is proved to be simple, sensitive, and specific as an assay of glucocerebrosidase activity for the diagnosis of Gaucher disease.

Clinical Enzyme Tests↗
PubMed1985

[Therapeutic effect of cefotaxime in the field of pediatrics].

Cefotaxime (CTX) was administered to 130 children with various bacterial infections of 41 to 400 mg/kg/day for 2 to 21 days. The clinical effect of CTX was very satisfactory in respiratory tract infection, urinary tract infection and meningitis. The overall clinical effect was excellent in 59, good in 39, fair in 17 and failure in 8 with effective rate of 79.7%. During this therapy, side effects were seen in 3 cases, diarrhea in 1 and rash in 2. Abnormal laboratory findings were seen in 5 cases, elevation of GOT in 1, GOT, GPT and A1-P in 1, GOT, GPT and T. Bil. in 1, elevation of BUN, increase of number of basophils and albuminuria in 1 and observation of albuminuria in 1. The above results demonstrate that CTX is a clinically useful antibiotic for the therapy of pediatric infections.

Adolescent↗
PubMed1984

Diagnosis of Tay-Sachs disease by estimation of beta-N-acetylhexosaminidase activity using a radiolabeled hyaluronic acid-derived trisaccharide substrate.

We have prepared a new radiolabeled substrate (N-[3H]acetylglucosamine-glucuronic acid-N-[3H]acetylglucosamine), from hyaluronic acid, for an assay of beta-N-acetylhexosaminidase activity. Using this substrate, we found a striking deficiency of beta-N-acetylhexosaminidase activity in cultured skin fibroblasts and in liver homogenates from patients with Tay-Sachs disease. DEAE-cellulose chromatography at pH 6.0 revealed that both isoenzymes A and B of beta-N-acetylhexosaminidase from normal liver participated in the catabolism of hyaluronic acid. There were, however, major differences in substrate specificities between isoenzymes A and B. Our results indicate that this substrate should be useful for enzymatic diagnosis of Tay-Sachs disease.

Cells, Cultured↗
PubMed1984

Use of a fluorescent analogue of galactocerebroside for assay of galactocerebroside beta-galactosidase activity in skin fibroblasts from patients with Krabbe's disease.

In order to diagnose Krabbe's disease (globoid cell leukodystrophy) or its carrier state in patients, galactocerebroside beta-galactosidase (galactosylceramidase) activity in cultured skin fibroblasts was measured with high-performance liquid chromatography using a fluorescent analogue of galactocerebroside, 1-O-galactosyl-2-N-(1-dimethylaminonaphthalene-5-sulfonyl)-sphingosine, as substrate. The enzyme activities in skin fibroblasts of the patients were found to be dramatically reduced when compared with those of controls. The assay can be adopted for diagnostic use in place of assays using radioisotope-labeled natural substrate.

Cells, Cultured↗
PubMed1984

The effects of sucrose loading on lysosomal hydrolases.

The addition of 88 mM sucrose to the culture medium of human skin fibroblasts from normal subjects caused remarkable increase in the intracellular lysosomal hydrolase activities. The mechanism of this induction by sucrose loading was carefully studied with several fibroblast strains of different inherited lysosomal storage disorders. In single lysosomal hydrolase defect such as GM1-gangliosidosis, mannosidosis and Sandhoff disease, no induction of the deficient hydrolase was found with 88 mM sucrose loading. In contrast, sucrose loading caused normalization of intracellular lysosomal hydrolase activities in I-cell disease fibroblasts and cytoplasmic inclusion materials disappeared. Subsequent investigations reveal that I-cell disease cells are classified into three subgroups by the degree of hydrolase induction by sucrose loading; a high responding, an intermediate responding and a no-response group. The heterogeneity may be based upon different induction by sucrose loading of the enzyme, probably the residual phosphotransferase which is involved in the processing steps of lysosomal enzyme molecules. With the addition of mannose-6-phosphate and 10 mM NH4Cl to cultured skin fibroblasts, it was shown that sucrose loading caused increased synthesis of lysosomal enzyme proteins. The result of the test with 2,4-dinitrophenol suggests that sucrose is indeed pinocytosed by cultured human skin fibroblasts and localized in lysosomes and that this event is the essential factor to trigger the induction of lysosomal hydrolases. Simultaneous loading of both invertase and sucrose in cultured cells caused no induction of alpha-mannosidase activity. This result indicates that invertase is also pinocytosed, reaches the lysosomes and hydrolyzes sucrose in the lysosomes. Lysosomal overloading with sucrose resulted in induction of lysosomal hydrolases and invertase blocked the induction of alpha-mannosidase activity. However, some induction still exists in beta-galactosidase and alpha-fucosidase activity. Thus it is very likely that the induction of lysosomal hydrolases demands a complicated process. In this article, we investigated the effects of sucrose on the lysosomal hydrolases in cultured human skin fibroblasts of several inherited lysosomal storage disorders and normal subjects and discuss the possible mechanism of the induction of lysosomal hydrolase activities by sucrose loading.

2,4-Dinitrophenol↗
PubMed1984

Activity of renal 25-hydroxyvitamin D3-1 alpha-hydroxylase in a case of X-linked hypophosphataemic rickets.

In 1974, a 2-year-old boy was diagnosed as having X-linked hypophosphataemic rickets (XLH) because of severe rickets and hypophosphataemia. The vitamin D metabolite concentrations, blood and urine chemistry and renal 25-hydroxyvitamin D3 (25OHD3)-1 alpha-hydroxylase were measured in 1982 (about 2 weeks after withdrawal of medication). 1 alpha-hydroxylase was 392 pg/mg tissue/20 min in the patient, which was high compared with aged-matched controls (69.7 +/- 28.5 pg/mg tissue/20 min, mean +/- SD, n = 7). Our present studies showed that the 1 alpha-hydroxylase activity in the patient with XLH was elevated. Therefore, the normal or low 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) concentrations in XLH patients could be due to accelerated catabolism of 1,25-(OH)2D3 or abnormally regulated 25OHD3-1 alpha-hydroxylase in response to hypophosphataemia, although significantly elevated above that in normal controls.

25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗
PubMed1984

Seroepidemiologic behavior of varicella zoster virus infection in a semiclosed community after introduction of VZV vaccine.

A survey of varicella and measles has been made in a semiclosed institution housing infants and children in Osaka since 1950. Live measles and varicella vaccines were introduced into the institution in 1974 and 1975, respectively. Nine of 10 measles outbreaks occurred during the 24 years before use of measles vaccine, and only one occurred during the 9 years after introduction of measles vaccine. In contrast, the incidence of varicella outbreaks has not been reduced after introduction of varicella vaccine, although the rate of immune individuals in the population against varicella has been kept at 74.2% for the 8 years since 1975, which was higher than that against measles (65.8%) during the same period. All successfully vaccinated children, however, were resistant to clinical varicella, and the number of clinical cases has been markedly reduced. Using the fluorescent antibody to membrane antigen and varicella zoster virus skin testing, the kinetics of secretory, humoral, and cellular immune responses to VZV was examined in vaccinated and naturally infected subjects and found to be comparable in both groups during repeated exposure to varicella epidemics. These results suggest that the seroepidemiologic behavior of varicella would not be significantly altered after introduction of varicella vaccine, in contrast to that of measles since general use of measles vaccine.

Antibodies, Viral↗
PubMed1984

Antiepileptic effect and serum levels of clorazepate on children with refractory seizures.

Clorazepate dipotassium is rapidly decarboxylated to yield desmethyl diazepam. The antiepileptic effect of clorazepate was studied in 29 epileptic children with refractory seizures. Their ages were ranged from one year 9 months to 20 years (mean 11 years 6 months). Serum clorazepate levels were also determined in 16 patients. The mean initial dose was 0.91 mg/kg/day, and the dose was increased up to 3 mg/kg/day. Within several days after initiation of clorazepate therapy, a decrease in seizure frequency was seen in patients in whom clorazepate was effective. Excellent results (decrease in seizure frequency by more than 80%) were obtained in 7 patients (24.1%), a moderate improvement with a 50 to 80% decrease was seen in 7 patients (24.1%), and a partial improvement with less than 50% decrease was seen in 7 patients (24.1%). No benefit was seen in 8 patients (27.7%). Serum clorazepate levels in patients with excellent results were 31 to 77 ng/ml (mean 55 ng/ml), those in patients with a moderate improvement were 130 to 225 ng/ml (mean 163 ng/ml), and those in patients with a partial improvement were 142 to 518 ng/ml (mean 273 ng/ml). Serum clorazepate levels in patients with no benefit were 34 to 97 ng/ml (mean 56 ng/ml). There was no direct relationship between serum clorazepate levels and clinical response. The results of this study indicate the efficacy of clorazepate for epileptic children with refractory seizures.

Adolescent↗
PubMed1984

Breath hydrogen test in infants and children with blind loop syndrome.

Breath hydrogen production after oral lactose loading was examined in infants and children with stagnant loop syndrome, blind loop syndrome, or both. All six infants under 3 years of age had bacteriological evidence of small intestinal colonization. The characteristics of the breath hydrogen test in this syndrome are: (a) extremely high basal excretion of breath hydrogen (after overnight fasting); (b) an earlier and greater breath hydrogen value (0.293 +/- 0.201 ml/min/m2: mean +/- SD) after oral lactose administration than formed in lactose malabsorption alone (0.050 +/- 0.041 ml/min/m2); and (c) the observation of a sustained hydrogen rise over several hours. This investigation demonstrated that the breath hydrogen test is a promising and noninvasive tool for diagnosing blind (or stagnant) loop syndrome.

Blind Loop Syndrome↗
PubMed1984

Total parenteral nutrition with a new amino acid solution for infants.

The currently available, commercially prepared amino acid mixtures for intravenous usage do not result in completely normal plasma amino acid patterns. Taking into consideration the known imbalances that occur with the commercial preparations, we designed a new amino acid solution (AF). This solution was prepared to contain a low concentration of those amino acids usually found in increased concentrations in plasma during the course of total parenteral nutrition (TPN) with a commercially prepared product (CF) and a high concentration of branched-chain amino acids and arginine. Plasma amino acid concentrations were determined for nine infants receiving CF (Group A) and eight infants receiving AF (Group B) as the protein source while on TPN for 5 days. These data were compared to 2-h postprandial values obtained from breast-fed, growing infants serving as controls. In comparison with controls, the plasma concentrations of threonine, glycine, methionine, phenylalanine, tryptophan, and lysine were higher in infants in group A, while those of taurine, alanine, valine, cystine, isoleucine, and proline were lower. In group B, the levels of valine and leucine were slightly higher, while those of alanine, cystine, tyrosine, histidine, and proline were lower. Mean nitrogen balances in groups A and B were + 112 and + 170 mg/kg/day, respectively. Therefore, our new amino acid solution may be better for infants receiving TPN.

Amino Acids↗