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Biomedical subjects

H Yabuuchi

Publications and source records attributed to H Yabuuchi.

At least 163 records · Page 9Linked to original sources
PubMed1983

Heterogeneity in mucolipidosis II (I-cell disease).

Normalization of multiple deficiency of intracellular lysosomal hydrolases in I-cell disease (ICD) fibroblasts by sucrose loading has been reported (Kato et al. (1982) J. Biol. Chem. 257, 7814). Further studies revealed that the effects of sucrose on the induction of hydrolases in seven ICD strains examined in this study were characteristic in each strain. The results may indicate that ICD strains can be classified into subgroups by the degree of enzymic induction. Moreover, this speculation seems to be supported by the normalization of electrophoretic patterns of beta-hexosaminidase in ICD fibroblasts after sucrose loading.

Ammonium Chloride↗
PubMed1983

Induction of beta-galactosidase in beta-galactosidase-alpha-neuraminidase deficiency: effects of leupeptin and sucrose.

beta-Galactosidase was normalized by a serine-thiol protease inhibitor, leupeptin with concentration of 10 micrograms/ml in cultured skin fibroblasts from patients with beta-galactosidase-alpha-neuraminidase deficiency (beta-Gal-/Neu-). The induction of this enzyme was not observed in normal cells. Because the enzymic activity of cathepsin B1 increased significantly both in beta-Gal-/Neu- and normal cells by leupeptin loading, the restoration of beta-galactosidase in beta-Gal-/Neu- cells can not be explained by the theory that leupeptin inhibited intracellular degradation of beta-galactosidase molecules. The effects of leupeptin and sucrose on lysosomal hydrolase induction were compared.

Cathepsin B↗
PubMed1983

Neutralizing antibody responses to Japanese encephalitis vaccine in children.

Two shots of the current Japanese encephalitis (JE) vaccine were given to children and their immune responses to the Nakayama strain (the vaccine strain) and two wild strains (JaGAr-01 and E-50) of JE virus were examined by neutralizing (N) antibody titrations. Seventy vaccinees had no N antibody to JE virus before the first vaccination and were bled one month after the second vaccination. The N antibody responses to the JaGAr-01 and E-50 strains were found to be similar and to be less than that to the Nakayama strain after the second vaccination: the geometric mean titers (GMT) of N antibodies to the JaGAr-01 and E-50 strains (as logarithms) were 1.87 and 1.75, respectively, while the GMT to the Nakayama strain was 2.89. The seroconversion rates to the Nakayama, JaGAr-01 and E-50 strains were 70/70 (100%), 69/70 (99%) and 68/70 (97%), respectively, after the second vaccination. Twenty-seven of the 70 vacciness were also bled before the second vaccination. Most of them showed a considerably high N antibody response against the Nakayama strain and only one vaccinee failed to show seroconversion after the first vaccination. However, the antibody response to the E-50 strain appeared to be rather low and 9 of 25 vaccinees did not show any seroconversion. Similarly 3 of 25 failed to show any seroconversion against the JaGAr-01 strain. These results indicate that at the initial immunization two shots, at least, of the current JE vaccine are necessary to stimulate effective immune responses to wild strains of JE virus.

Aging↗
PubMed1982

Organic acid metabolism in a patient with ornithine transcarbamylase deficiency.

Serum and urinary organic acids in a 9-year-old girl with ornithine transcarbamylase deficiency were investigated. The urinary excretion of alpha-ketoglutarate (alpha-KG) and citrate were abnormally high. An inverse linear correlation was found between the plasma ammonium and alpha-KG levels when the plasma ammonium level was less than 200 micrograms/dl, but not at higher levels, suggesting that on overloading with ammonium, its route of metabolism and compensating mechanism are not functionally normal. After administration of NH4Cl, plasma and urinary levels of alpha-KG, pyruvate and citrate increased, but the urinary succinate level decreased slightly. After oral administration of citrate the plasma alpha-KG level increased and the ammonium level decreased transiently. Our results suggest that administration of citrate or alpha-KG is not effective for reducing hyperammonemia in ornithine transcarbamylase deficiency.

Ammonia↗
PubMed1982

Normalization of intracellular lysosomal hydrolases in I-cell disease fibroblasts with sucrose loading.

I-cell disease (ICD) is an hereditary inborn error of metabolism by lysosomal storage due to the multiple lysosomal hydrolases deficiency. Many inclusion materials are seen by phase contrast microscopy in cultured skin fibroblasts from the patients with ICD. We recently reported that the addition of 88 mM sucrose to the medium of cultured human skin fibroblasts from normal subjects induced several lysosomal hydrolases, but did not induce deficient hydrolases in lysosomal enzyme deficiencies (Kato, T., Okada, S., Ohshima, T., Inui, K., Yutaka, T., and Yabuuchi, H. (1981) Biochem. Int. 3, 551-556). This time sucrose loading was applied to the cultured skin fibroblasts from the patients with ICD. Incubation with 88 mM sucrose for more than 10 days exhibited significant effects. Biochemically, the activities of deficient hydrolases reached their normal levels, and morphologically, typical inclusion materials disappeared. These results indicate that sucrose enhanced synthesis of normal lysosomal enzymes and lysosome functions were normalized in ICD fibroblasts.

Cells, Cultured↗
PubMed1982

A case report of congenital hypomyelination.

A 3 year, 11 month-old Japanese male with congenital hypomyelination is described. Clinical features are delay of motor development, generalized muscle hypotonia and weakness, absent tendon reflexes due to peripheral neuropathy, and normal mental development. Electrophysiologically, nerve conduction velocities could not be measured. Histological examination of the right sural nerve revealed total of absence myelin of most of the myelinated fibers. Electronmicroscopically, there was a concentric network of lamellae formed by double-layered sheets of basement membranes with fragments of Schwann cell cytoplasm around the myelinated fibers, so called "onion-bulbs". These peculiar features were similar to those in the cases reported by Lyon, (1969); Kennedy et al., (1977); Karch et al., (1975); and Anderson et al. (1973).

Biopsy↗
PubMed1982

Serum calcium regulating hormones in the perinatal period.

To clarify perinatal vitamin D metabolism, we measured 25-hydroxyvitamin D (25OHD), 24,25-dihydroxyvitamin D [24,25(OH)2D], 1,25-dihydroxyvitamin D [1,25(OH)2D], calcium (Ca), phosphorus (P), parathyroid hormone (PTH), and human calcitonin (CT) in paired maternal, cord, and infant serum. Cord serum 25OHD was significantly lower than the maternal level, and cord serum 24,25(OH)2D was also significantly below the maternal concentrations. Maternal, cord, and infant serum 1,25(OH)2D, on the other hand, was significantly higher than the normal adult level. The serum PTH was low, but the CT concentration was high in the cord. Cord serum Ca and P levels were significantly higher than maternal. The reason for the elevated circulating 1,25(OH)2D level in the perinatal period is uncertain, and we speculate that the possible factors are gonadal steroids, placental lactogen, prolactin, and CT. In addition, serum 24,25(OH)2D and 1,25(OH)2D concentrations are under some control by the fetus.

Adult↗
PubMed1982

Biochemical characterization of 1,25(OH)2D3 receptors in chick embryonal duodenal cytosol.

This study presents measurements of serum vitamin D metabolites, calcium and phosphorus as well as measurements of the equilibrium dissociation constant for duodenal 1,25(OH)2D3 receptor in 15-, 18-, 19-, and 20-day chick embryos in comparison to that in 1- and 118-day-old chicks and to vitamin D-deficient chicks. The present results showed that: (a) serum 1,25(OH)2D and 24,25(OH)2D levels rise from 15 and 18 to days 19 and 20 of embryonic development while serum phosphate levels are stable; (b) serum calcium levels rise at hatching to adult levels; (c) the duodenal 1,25(OH)2D3 receptor is detectable in 15-day-old embryo and has a Kd similar to that of 118-day-old vitamin D-replete chicks; and (d) the activity of 1,25(OH)2D3 receptor in chick duodenal cytosol is maximal at hatching.

Animals↗
PubMed1982

Immunologic and epidemiologic aspects of varicella infection acquired during infancy and early childhood.

The development of varicella zoster infection was studied in a population of infants under one year of age during three outbreaks of varicella in a semi-closed domiciliary institution for infants in Japan. Over a period of four years, many residents ranging in age from 27 days to 32 months were tested for cutaneous reactivity to VZV antigen, and VZV-specific antibody activity before, during, and after each outbreak of varicella. Of these, 85 subjects developed clinical varicella, with an overall attack rate of 100% for all susceptible subjects. All the infants under 2 months of age were infected following such exposure, despite the presence of pre-existing maternal antibody. The degree of cutaneous involvement appeared to be milder (less than 20 vesicles) in infants less than 2 months of age, and severe cutaneous disease (with over 300 eruptions or confluent rash) occurred more frequently in subjects 2 to 11 months of age. Pre-existing antibody did not prevent development of illness, or alter the degree of antibody or cellular immune response to subsequent infection. However, the peak cutaneous reactivity to VZV antigen after infection was found to be significantly lower in infants under 2 months of age.

Antibodies, Viral↗
PubMed1982

Cerebral blood flow changes in orthostatic dysregulation fainters.

The changes in blood flow of both the internal carotid and the vertebral artery during orthostatic test with or without fainting attack were studied in 25 healthy children and 30 patients with orthostatic dysregulation (OD). In healthy children and non-fainted OD patients, no change in blood flow occurred in either the internal carotid artery or the vertebral artery during orthostatic test. On the other hand, a significant decrease in blood flow of the internal carotid artery and/or the vertebral artery occurred during fainting of OD patients. These data suggest that three mechanisms might be involved in fainting of OD patients; a decrease in blood flow of the internal carotid artery, the vertebral artery and a decrease in blood flow of both these arteries.

Adolescent↗
PubMed1982

Internal carotid blood flow velocity in children with cerebral palsy by Doppler Ultrasound method.

Cerebral blood flow assessed noninvasively by Doppler ultrasound technique in 30 children with cerebral palsy. The average maximal blood velocity (A/L) and end-diastolic blood velocity (d) of internal carotid artery were measured before and during brief digital compression of contralateral common carotid artery. Both A/L and d values in children with cerebral palsy were significantly lower than those observed in normal healthy children. In 13 children with spastic hemiplegia, no significant difference in either A/L or d was seen between the non-affected side and affected side both before and during brief digital compression. This data suggests that mean cerebral blood flow decreases in our children with cerebral palsy, and that no lateralization of the decrease in hemispheric cerebral circulation in hemiplegic children may explain by supposing the existence of generalized bilateral brain damage in those subjects.

Adolescent↗
PubMed1982

Antiepileptic effects of clobazam in children.

Many benzodiazepines used as anticonvulsants have nitrogen radicals in positions 1 and 4. Clobazam has nitrogen radicals in positions 1 and 5. We studied the antiepileptic effect of clobazam in 36 patients with intractable epilepsies in childhood. Their ages were 1 year 1 month to 16 years 5 months (mean 8 years). The mean initial dose was 0.33 mg/kg of daily doses and increased up to 0.71 mg/kg. Nine cases (primary generalized epilepsy 2/2, secondary generalized epilepsy 7/29) were completely free from seizures, and another 9 (secondary generalized epilepsy 8/29, partial epilepsy 1/5) experienced a decrease of 50% or more in seizure frequency. Seizure frequency did not change in 16, and increased in the other 2 (secondary generalized epilepsy 2/29). The antiepileptic effects were observed on the first day to 10th day after clobazam treatment. There were recurrences of seizures in 4 out of 9 patients with complete control of seizures, 1 month alter in 3 and 10 months later in one. Mean serum clobazam level of 7 improved cases was 73 ng/ml and that of 3 cases with no response was 94 ng/ml. Although mild clinical side effects such as drowsiness were observed transiently in 17 cases, no abnormality was found in laboratory investigations performed.

Adolescent↗
PubMed1982

Antibody response to varicella-zoster virus after natural or vaccine-induced infection.

The development of serum and nasopharyngeal antibody responses to varicella-zoster virus (VZV) was studied in groups of children after naturally acquired varicella or after immunization with the Oka strain of live attenuated VZV vaccine administered in varying doses via respiratory inhalation or subcutaneous injection. Natural infection, subcutaneous immunization, and respiratory inhalation of large doses of VZV vaccine consistently resulted in the development of VZV-specific IgG antibody responses in serum. Although the serum IgG antibody responses persisted for at least eight to 12 months (to date) after either form of infection, the antibody activity appeared to be four- to eight-fold higher after natural infection than after immunization. Transient IgG antibody responses were observed in serum after respiratory inhalation of smaller doses of VZV vaccine. Natural infection, but not VZV vaccine, was associated with the development of serum and nasopharyngeal IgA responses to VZV in most subjects.

Adolescent↗
PubMed1982

Failure of p-aminobenzoic acid screening test to diagnose pancreatic insufficiency in Shwachman's syndrome.

The 6-h urine recovery of p-aminobenzoic acid (PABA) following the administration of a standard dose of N-benzoyl-L-tyrosyl-p-aminobenzoic acid (BTPABA) was performed in 13 control subjects and two siblings with Shwachman's syndrome. The control subjects showed a recovery of 67 +/- 12.1% (mean +/- 1 SD) of the administered dose, consistent with previously reported values. Unexpectedly, the recovery of PABA in two siblings with Shwachman's syndrome was found to be 67 and 63%, respectively. The values are well within the normal range. In these siblings, fecal chymotrypsin activities were very low when measured with N-acetyl-L-tyrosyl-ethyl ester (ATEE) as substrate, but were normal when BTPABA was the substrate. The duodenal juice of the younger affected child following pancreozymin-secretin stimulation showed very low chymotrypsin activity against ATEE, BTPABA, and N-benzoyl-L-tyrosyl-ethyl ester. These findings suggest that there may be BTPABA-splitting activity in the lower bowel of these siblings with Shwachman's syndrome. This activity might be that of enteric bacteria or of the intestinal mucosa.

4-Aminobenzoic Acid↗