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Biomedical subjects

H Yabuuchi

Publications and source records attributed to H Yabuuchi.

At least 109 records · Page 6Linked to original sources
PubMed1986

Neurological manifestations in xeroderma pigmentosum.

Xeroderma pigmentosum is an unusual neurocutaneous disorder. Recent studies have classified patients with xeroderma pigmentosum into 10 groups by somatic cell hybridization methods. In this report we describe 32 patients with Group A xeroderma pigmentosum, including 1 patient with an atypical case, who were assessed for neurological complications. Of these patients, 17 had microcephaly, 13 short stature, and 21 mental retardation. In patients over 7 years of age, sensorineural deafness and spinocerebellar signs such as nystagmus, dysarthria, tremor, and ataxia were frequently observed; no patients below 7 years of age had such neurological complications. Electroencephalographic studies revealed abnormal slow and low voltage background activity. Two patients had focal abnormal discharges, one of whom developed versive seizures. Cranial computed tomographic scans revealed abnormalities, including ventricular dilatation, cerebral atrophy, cerebellar and brainstem atrophy, and cranial bone thickening. A patient with an atypical case of Group A xeroderma pigmentosum had less skin and neurological involvement, and higher levels of postultraviolet colony-forming ability and host cell reactivation than did a typical Group A case. It is possible that these less severe cytological findings are responsible for the less severe skin lesions and neurological complications noted clinically.

Adolescent↗
PubMed1986

Pathological study on a severe sialidosis (alpha-neuraminidase deficiency).

A 56-day-old infant with alpha-neuraminidase deficiency, whose clinical features included severe edema of extremities and ascites which resembled those in severe infantile sialidosis, was autopsied. Perforation, whose pathogenesis was unclear, was found on the descending portion of the duodenum. Light and electron microscope studies showed that neurons in the cerebral and cerebellar corticies, and the thoracic spinal cord contained membrane-bound vacuoles but no membranous cytoplasmic bodies. Zebra bodies were found only in the neurons of the spinal cord. The neurons in the paraganglion and in the Auerbach's myenteric plexus were also distended with numerous membrane-bound vacuoles. Hepatocytes, endothelial cells and Kupffer cells in the liver and glomerular and tubular epithelial cells in the kidney were swollen with a number of vacuoles, although the patient showed none of the clinical features of renal involvement. These pathological changes were similar to those in nephrosialidosis reported by Le Sec et al. [Arch Fr Pediatr 35:819-829 (1978)].

Cerebral Cortex↗
PubMed1986

Trial of inactivated Japanese encephalitis vaccine in children with underlying diseases.

Two shots of inactivated Japanese encephalitis (JE) vaccine were given to children, 139 with underlying diseases and 42 healthy, and their antibody responses were studied by the neutralization test. Before vaccination, most of the vaccinees did not have antibody against JE virus. One month after the second vaccination, they were all seroconverted and showed considerably high neutralizing titres. One healthy child developed fever on the day of vaccination without any severe symptoms afterwards, and no side reactions were observed in the handicapped children. These results suggest that the current JE vaccine is safe and can induce a strong immune response even in handicapped children.

Antibodies, Viral↗
PubMed1986

Increased incidence of herpes zoster in normal children infected with varicella zoster virus during infancy: community-based follow-up study.

We surveyed outbreaks of varicella zoster virus (VZV) and herpes zoster virus, involving 31 outbreaks of chicken pox, in a semiclosed institution in Osaka Japan during the 34 years between 1949 and 1984. Eight hundred forty-nine infants and children who had had clinical varicella during the first 4 years of life and those who had resided in the institution at least 12 to 144 months after the onset of varicella were included in the study. Nine cases of zoster were observed among children who had acquired varicella during the first year of life, but there was no case of zoster in those who had acquired varicella after 1 year of age. In 61,800 person-months of observation, the overall incidence rate of zoster was calculated as 0.15 per 1000 person-months for the population at risk. The incidence rate in children infected with VZV when younger than 2 months was 1.0 per 1000 person-months during the first decade of life. This rate was significantly (P less than 0.005) greater than that (0.19 per 1000 person-months) in children who had varicella when they were 2 to 11 months of age. These observations suggest that zoster occurs at a significantly shorter interval if VZV infection is acquired during infancy. More than 85% of subjects with prior infection were intimately reexposed to epidemic varicella during their residency in the institution, before having zoster. Epidemic reexposure to varicella during follow-up resulted in enhancement of preexisting immunologic reactivity, but did not prevent subsequent zoster in the population studied.

Adolescent↗
PubMed1986

Kappa-chain gene rearrangement in an apparent T-lineage lymphoma.

We describe a 10-yr-old boy with T-lineage non-Hodgkin's lymphoma. He had a mediastinal mass, swollen supraclavicular lymph nodes, and pleural effusion. A supraclavicular lymph node biopsy under light microscopy showed a malignant lymphoma of diffuse lymphoblastic type. Most of the cells taken from the malignant pleural effusion expressed T cell-associated antigens such as Leu-1 and OKT 8. To confirm these antigens as T-lineage lymphoma, we examined genomic DNA from malignant cells obtained from the pleural effusion. As was expected, T cell receptor beta-chain gene rearrangements were demonstrated. However, when the immunoglobulin gene organization was analyzed, we detected rearrangements in both the heavy- and kappa-chain genes. To our knowledge, this is the first case in which kappa-chain gene rearrangement was detected in apparent T-lineage cells. These findings provide important information relating to determination of the cellular lineage of lymphoid malignancy.

Child↗
PubMed1986

Effect of 1,25-dihydroxyvitamin D3 on insulin secretion: direct or mediated?

In order to clarify the role of vitamin D (D) in regulating insulin secretion, we studied the effect of long term (10 days) and short term (3 days) supplementation with D and/or calcium (Ca) on insulin secretion from the isolated, perfused pancreas of D- and Ca-deficient rats. The influence of the nutritional state induced by D deficiency was also evaluated. The long term supplementation of either D, Ca, or both restored the body weight and improved insulin secretion induced by high glucose concentration to the same extent; thus, no significant difference in insulin secretion was found between the D-only-supplemented group and the Ca-only-supplemented group. When the insulin secretion was compared in D-deplete vs. D-replete rats given the same amount of Ca, insulin secretion was significantly higher in D-replete animals, although plasma Ca levels were also higher. In short term experiments, insulin release was significantly augmented to a similar extent in D- or Ca-replete rats as compared with D- and Ca-deficient rats, despite no significant change in body weight. In a separate experiment, the pancreas from D-deficient rats was perfused with or without 1,25-dihydroxyvitamin D3 [1,25-OH)2D3] to observe its acute effect on insulin release. The perfusion with 1,25-(OH)2D3 did not affect insulin release. This result suggests that impaired insulin secretion in D-deficient rats is caused by a decrease in Ca in the body fluid and possibly by the lack of D effect on the pancreas.

Animals↗
PubMed1986

Further heterogeneity of childhood common acute lymphoblastic leukemia.

In an attempt to look further at the problem of heterogeneity, we have studied the immunoglobulin (Ig) gene organization in leukemic cells from 20 children with acute lymphoblastic leukemia (common ALL). Nineteen cases were divided into two subgroups: 12 cases with rearrangement of the Ig heavy (H) chain genes and 7 cases with rearrangement of both the Ig H and light (L) chain genes. No Ig gene rearrangement was found in one case. These findings indicate that there is more heterogeneity among patients with common ALL than has previously been believed.

Antigens, Neoplasm↗
PubMed1986

Volume regulation in leukemic and lymphoma cells in children and determination of cell lineage.

Among normal lymphocytes, T cells can readjust their volume rapidly following initial swelling in a hypotonic medium, whereas B cells do not have this ability. Based on this finding, we examined the volume regulation of malignant cells from 40 patients with lymphocytic and nonlymphocytic malignancies. The T lineage cells were able to regulate their volume in response to hypotonic stress, whereas B lineage cells were not able to do so. In contrast to lymphoid lineage cells, nonlymphocytic leukemia cells as well as undifferentiated cells did not show a consistent tendency in their volume regulation. These results showed that the difference in the ability to regulate cell volume in response to hypotonic stress is available as a marker for identifying the cellular lineage of lymphoid malignancies.

Acute Disease↗
PubMed1986

Protection of mumps in children with various underlying diseases: application of a live attenuated mumps and trivalent measles-rubella-mumps (MRM) vaccines in these children.

A live attenuated mumps and trivalent measles-rubella-mumps (MRM) vaccines have been applied to 887 and 148 children with various underlying diseases at the vaccine clinic of Osaka University Hospital between 1975 and 1985, respectively. Clinical reactions after mumps vaccination occurred in only 7 children (0.8%) and those after MRM vaccination in 28 children (19%), but their underlying diseases were not deteriorated by either vaccination. Clinical follow up study revealed that 2 of the 430 children immunized with mumps vaccine had contracted the disease during 7 year period and 2 of the 123 children immunized with MRM vaccine had contracted clinical mumps or rubella during 3 year period. The seroconversion rates after mumps vaccination were 70% and 61% by the hemagglutination inhibition (HI) test and neutralization (NT) test, respectively, while 94% by the fluorescent antibody to membrane antigen (FAMA) test. Those after MRM vaccination were 87% for measles, 96% for rubella by the HI test and 89% for mumps by the FAMA test. Serological follow up study revealed that antibodies elicited by mumps vaccination were sustained without substantial decline for at least 7 years. These results suggest that a live attenuated mumps and MRM vaccines are safe and effective in children with various underlying diseases.

Antibodies, Viral↗
PubMed1986

Enzyme-linked immunosorbent assay for detection of serum antibody in children vaccinated with Japanese encephalitis vaccine.

Serum antibodies in children who had been vaccinated with Japanese encephalitis (JE) vaccine were measured by enzyme-linked immunosorbent assay (ELISA) and neutralization (N) and hemagglutination-inhibition (HI) tests. Of 20 serum samples obtained after two shots of JE vaccine in the first year, all but one showed positive titers in the ELISA and N test, but five showed negative titers in the HI test. All 12 serum samples obtained after booster immunization with JE vaccine in the second year showed positive and considerably higher titers in all three tests. Moreover, a high correlation was found between the ELISA, N and HI titers. These results indicate that the ELISA is useful for detecting antibodies in subjects immunized with JE vaccine.

Antibodies, Viral↗
PubMed1986

Abnormal relationship between serum phosphate concentration and renal 25-hydroxycholecalciferol-1-alpha-hydroxylase activity in X-linked hypophosphatemic mice.

C57BL/6J Hyp/Y mice (Hyp-mice, X-linked hypophosphatemic mice) were fed diets containing various concentrations of phosphate and calcium to produce serum phosphate concentrations from very low to normal. We measured the renal 25-OHD3-1 alpha-hydroxylase activity and compared it to that of C57BL/6J normal male mice. The enzyme activity in control diet Hyp-mice was not different from that in control diet normal mice, but it was considerably lower than that in hypophosphatemic normal mice. In spite of a very low serum phosphate concentration, 25-OHD3-1 alpha-hydroxylase activity was reduced in the low-phosphate diet Hyp-mice. In order to normalize serum phosphate concentration without decreasing the serum calcium concentrations, Hyp-mice were fed a high-phosphate and high-calcium diet. In this situation the enzyme activity was stimulated and was significantly higher than that of control diet normal mice and was also significantly increased compared to that of high-phosphate diet Hyp-mice, which had a hypocalcemia. Our data show that there is a positive correlation between the serum phosphate concentration and renal 25-OHD3-1 alpha-hydroxylase activity in Hyp-mice, which is opposite to the negative correlation between serum phosphate and 25-OHD3-1 alpha-hydroxylase present in normal mice. This supports the concept of deranged control of renal vitamin D metabolism in hypophosphatemic rickets.

Animals↗
PubMed1986

Effects of phenobarbital on lipid peroxidation in vitamin-E-deficient rats.

Increased serum lipid peroxide (LPO) and decreased vitamin E (VE) levels have been reported in epileptic children after long-term anticonvulsant therapy. The present study was designed to examine the acute effects of phenobarbital (PB) on lipid peroxidation in VE deficient rats. Five-day treatment with PB (75 mg/kg/day, IP) caused a significant increase in liver LPO levels (P less than 0.01), a decrease in plasma LPO levels (P less than 0.02), and a significant decrease in liver VE levels (P less than 0.05). It is suggested that PB plays an important role in lipid peroxidation in the liver by interfering with VE metabolism.

Animals↗