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Biomedical subjects

K Hayasaka

Publications and source records attributed to K Hayasaka.

At least 73 records · Page 4Linked to original sources
PubMed1999

Prader-Willi syndrome in a child with XYY.

We report a 26-month-old boy with XYY syndrome, with the complication of Prader-Willi syndrome (PWS) due to uniparental maternal disomy of chromosome 15. To our knowledge, this is the first case of XYY syndrome and PWS. Clinical findings were fully compatible with the diagnostic criteria for PWS. Molecular analysis revealed a maternal heterodisomy of chromosome 15, indicating that non-disjunction of chromosome 15 had occurred at maternal meiosis I, and that the non-disjunction of chromosome Y and of chromosome 15 had occurred independently.

Child, Preschool↗
PubMed1999

Intermittent jaundice in patients with acute leukaemia: a common mutation of the bilirubin uridine-diphosphate glucuronosyltransferase gene among Asians.

The Gly71Arg mutation of the hepatic bilirubin UDP glucuronosyl-transferase (B-UGT) gene associated with Gilbert syndrome prevails among Japanese and its gene frequency is 0.13. Among 20 patients with acute leukaemia, 4 patients showed intermittent unconjugated hyperbilirubinaemia during the course of combined chemotherapy. The Gly71Arg mutation was detected in all 4 patients with hyperbilirubinaemia, but was not found in 16 patients without hyperbilirubinaemia. Two of them were heterozygotes and one was a homozygote for the Gly71Arg mutation, and the other was a compound heterozygote of the Gly71Arg mutation and TA insertion mutation in the TATA box of the B-UGT gene. In addition to the complications leading to hyperbilirubinaemia, including liver damage due to drugs, viral infections or tumour cell infiltrations and alloimmune haemolysis, carrier status for the Gly71Arg mutation should be considered in a patient with leukaemia showing intermittent hyperbilirubinaemia during the course of chemotherapy, especially among Japanese, Koreans and Chinese owing to its prevalence in those populations.

Acute Disease↗
PubMed1999

MR findings in primary retroperitoneal schwannoma.

OBJECTIVE: To evaluate the MR findings in primary retroperitoneal schwannoma. MATERIAL AND METHODS: Seven cases of primary retroperitoneal schwannoma, in whom the diagnosis was confirmed histopathologically, were analyzed retrospectively. The following items were reviewed at MR imaging: tumor diameter, margin, homogeneity, signal intensity as compared to normal renal parenchyma, presence/absence of infiltration into adjacent organs, and, in 1 and 4 cases, the enhancement on Gd-dynamic images and post-contrast T1-weighted images, respectively. RESULTS: Tumor diameter was 5.5 +/- 3.1 cm, ranging from 2.5 to 10 cm in the 6 benign schwannomas, and 12 cm in 1 malignant. The tumor margin was regular in all of the benign cases and irregular in the malignant one. The malignant case showed infiltration into the liver and duodenum. Four of the benign schwannomas showed a homogeneous, and 2 presented a heterogeneous pattern, while the malignant schwannoma was heterogeneous. On T1-weighted images, the benign schwannomas were hypointense in 4 cases, isointense in 1 and mixed in 1, while on T2-weighted images, they were hyperintense in 5 and mixed in 1. The malignant case showed mixed intensity on both T1- and T2-weighted images. On enhanced T1-weighted images, capsular, septal enhancement was noted in 2 cases, overall enhancement in 2, and, on Gd-dynamic images, late enhancement was shown. CONCLUSION: On MR imaging, primary retroperitoneal schwannomas show different signal intensity characteristics, including cystic degeneration. There are, however, no specific characteristics of these tumors.

Aged↗
PubMed1999

Deletion and nonsense mutations of the connexin 32 gene associated with Charcot-Marie-Tooth disease.

Two patients with a mild to moderate phenotype of Charcot-Marie-Tooth disease were identified to carry the mutations of the connexin (Cx) 32 gene. One of the patient had a novel nonsense mutation of tryptophan at amino acid 132 and the other had a deletion of the Cx 32 gene. Our study indicated that a loss of Cx 32 function contributes to a major pathogenesis of X-linked Charcot-Marie-Tooth disease.

Adult↗
PubMed1999

Antibody mimicking an anti-E antibody that binds to patient's E negative red cells.

We have reported a rare case of auto anti-E antibody with specificity mimicking alloantibody with E specificity. A patient whose red cells typed as R1R1 and who had a positive direct antiglobulin test was admitted to our hospital. After standard serologic testing was performed, flow cytometry, Western blot analysis and differential allogenic adsorption test were used to verify whether antibody binds to the patient's red cells and normal red cells. A high titer anti-E antibody was detected transiently from the patient's serum and eluate. An indirect antiglobulin test using red cells treated by cysteine-activated papain and dithiothreitol (ZZAP) and chloroquine showed that both the patient's serum and eluate bound an apparent anti-E antibody to E negative patient's red cells. Fluorescence activated cells sorter (FACS) and Western blot analysis verified that the patient's red cells lacked E antigen. Further, it was clarified that the antibody does not bind to any E negative normal red cells by differential allogenic adsorption test. These results provide evidence that an antibody mimicking an E alloantibody can bind to patient's own E negative red cells but not to allogenic E negative red cells.

Antibodies, Anti-Idiotypic↗
PubMed1999

[A sporadic case of Charcot-Marie-Tooth disease type 1 A associated with a duplication in chromosome 17 p11.2-p12].

Charcot-Marie-Tooth disease type 1A (CMT1A) is an autosomal dominant demyelinating peripheral neuropathy. Most patients with CMT1A including sporadic cases have been found to have a 1.5 megabase tandem DNA duplication in chromosome 17 p11.2-p12 (CMT1A duplication). We reported a 7-year-old girl with sporadic CMT 1 associated with the CMT1A duplication. The diagnosis of CMT 1 was based on the symmetrical distal muscle weakness, per cavus deformity, reduced motor and sensory nerve conduction velocities, and segmental de- and remyelinatin on sural nerve biopsy. To detect the CMT 1A duplication, peripheral myelin protein 22 (PMP-22) cDNA and a polymorphic marker in this region, VAW409 R3, were employed as probes for Southern blot analysis. Sporadic cases of autosomal dominant-CMT type 1 can not be clinically differentiated from recessive-CMT1. Testing for the CMT1A duplication is an important first step even in the molecular diagnosis of sporadic CMT1.

Charcot-Marie-Tooth Disease↗
PubMed1998

Four novel mutations of the connexin 32 gene in four Japanese families with Charcot-Marie-Tooth disease type 1.

DNA-based mutation analysis on the connexin 32 gene was performed in 49 families with Charcot-Marie-Tooth disease (CMT) type 1 but without duplication involving the chromosomal region, 17p12-p11.2. Mutations were identified in five of the 49 families, and four of the five mutations were hitherto undescribed: Va137Met, Glu57His, Arg142Glu, Val177Ala. X-linked CMT sometimes lacks evidence for X-linked transmission and cannot be differentiated from CMT type 2, especially in females with mildly decreased nerve conduction velocity. Therefore, molecular analysis is useful for molecular pathology of their disease.

Adolescent↗
PubMed1998

Novel mutations of the glutaryl-CoA dehydrogenase gene in two Japanese patients with glutaric aciduria type I.

We identified three different point mutations in the glutaryl-CoA dehydrogenase (GCDH) gene in two unrelated Japanese patients with glutaric aciduria type I (GA-I). One patient was a homozygote for Arg355His and the other a compound heterozygote for Ser305Leu and Met339Val. Arg355His and Met339Val are mutations hitherto undescribed, and all three mutations are predicted to alter the secondary structure of GCDH. Molecular analysis is useful for definite diagnosis and/or prenatal diagnosis of GA-I.

Amino Acid Metabolism, Inborn Errors↗
PubMed1998

Novel breakpoints of the EWS gene and the WT1 gene in a desmoplastic small round cell tumor.

We report here a 15-year-old boy with an intraabdominal desmoplastic small round cell tumor (DSRCT). Cytogenetic analysis of the tumor cells showed the chromosomal translocation (11;22). Reverse-transcriptase polymerase chain reaction and sequencing analysis revealed a chimeric transcriptional message of the EWS gene exon 10 fused to the WT1 gene exon 8. The typical chimeric transcript seen in DSRCT is an in-frame fusion of EWS exon 7 to WT1 exon 8. The tumor in this case had a novel and longer chimeric transcript, which should be a potent transcription factor. Genetic analysis is a very powerful and specific aid in the differential diagnosis of small round cell tumors.

Abdominal Neoplasms↗
PubMed1998

Muscular dystrophy associated with extra-abdominal desmoid tumor showing aberrant chromosome 1 [46,XX,add(1)(p36)].

We report on a 2-year-old girl with probable limb-girdle muscular dystrophy associated with an extra-abdominal desmoid tumor of the right mandible. This association is previously undescribed. The tumor was totally removed. Cytogenetic analysis of the tumor showed a clonal karyotypic abnormality: 46,XX,add(1)(p36) in 3 of 20 cells analyzed. Since an association of a neoplasm with limb-girdle muscular dystrophy has previously been reported in 3 cases, the two abnormalities are likely related causally. The chromosome abnormality in our patient may play a role in the occurrence of her desmoid tumor.

Child, Preschool↗
PubMed1998

Clustering of CMT1A duplication breakpoints in a 700 bp interval of the CMT1A-REP repeat.

The CMT1A-REP repeat is proposed to mediate unequal crossover leading to a 1.5 Mb duplication in chromosome 17p11.2-12 associated with Charcot-Marie-Tooth neuropathy type 1A (CMT1A). There is an apparent recombinational "hotspot" in the CMT1A-REP repeat since the majority of crossover breakpoints for CMT1A are located within a 1.7 kb interval. Further to characterize the crossover breakpoint region, we constructed PCR primers that specifically amplify the duplication breakpoint junctions in a series of Japanese and Caucasian CMT1A patients. We mapped the breakpoints in 89% of patients within a 700 bp interval of the CMT1A-REP repeat. This 700 bp region is 1.3 kb telomeric to a previously described mariner-like transposable element. Our observations further define the location of crossovers for CMT1A and provide additional evidence that this region is a recombinational "hotspot" within the CMT1A-REP repeat.

Asian People↗
PubMed1998

Spondyloepiphyseal dysplasia with accumulation of glycoprotein in the chondrocytes: spondyloepiphyseal dysplasia, Stanescu type.

OBJECTIVE: To clarify the phenotype in a bone dysplasia termed "spondyloepiphyseal dysplasia with accumulation of glycoprotein in the chondrocytes" by Stanescu et al. DESIGN AND PATIENTS: Subjects comprised two definitive cases of one family and one probable case of another family. Histologic examination in one patient warranted the diagnosis of the first family, whereas the diagnosis of the second family was based solely on clinical and radiologic grounds. RESULTS: Pedigrees revealed an autosomal dominant mode of transmission. All three patients shared painful large joints with joint restriction, progressive contracture with osseous expansion of the finger joints, and normal height despite the presence of a short trunk. Moderate platyspondyly, hypoplastic ilia, epiphyseal flattening with metaphyseal splaying of the tubular bones, and most characteristically, broad, elongated femoral necks with striking coxa valga were identical in all patients, but the patient of the second family showed severe brachydactyly unlike the other two patients. Histologic examination revealed PAS-positive, amylase-resistant intracytoplasmic inclusion bodies in the chondrocytes, corresponding to dilated rough endoplasmic reticulum filled with moderately electron-dense materials found by electron microscopy. CONCLUSION: The manifestations of our patients are sufficiently characteristic to constitute a distinct entity.

Adolescent↗
PubMed1998

Multiple sulphatase deficiency and haemophagocytic syndrome.

A 3-year-old boy with multiple sulphatase deficiency, complicated by a haemophagocytic syndrome, recovered with conventional treatment. Haemophagocytic syndrome can be a complication of many disorders including metabolic diseases, frequently triggered by intracellular viral and bacterial infections or even by drug administration.

Child, Preschool↗
PubMed1998

Novel mutations of the peripheral myelin protein 22 gene in two pedigrees with Dejerine-Sottas disease.

Peripheral myelin protein 22 (PMP22), a membrane glycoprotein, plays a significant role in the formation and/or maintenance of compact myelin in the peripheral nervous system. We studied two pedigrees with Dejerine-Sottas disease and identified two novel mutations in the PMP22 gene: one a 2-bp deletional mutation at nucleotide positions 426 and 427 of exon 4 (this is predicted to alter the reading frame at leucine 80 and thus to lead to frame-shifted translation), and the other a guanine to thymine substitution at nucleotide position 636 leading to a cysteine substitution for glycine 150. Both mutations were located in the putative transmembrane domains reported in many cases of Charcot-Marie-Tooth neuropathy, Dejerine-Sottas disease, and hereditary neuropathy with liability to pressure palsies. The results suggest an important role for the putative transmembrane domains of PMP22 in its function.

Adult↗
PubMed1998

Anti-angiogenic effect of TGFbeta in aqueous humor.

Neovascularization is mediated by various factors in ocular tissues. Recent studies have emphasized the role of vascular endothelial growth factor in the induction of angiogenesis. We have previously reported that aqueous humor (AH) suppressed vascular endothelial cell growth and angiogenesis. We speculated that the anti-angiogenic effect of AH is mediated by transforming growth factor beta (TGFbeta). In order to clarify the presence of TGFbeta in bovine AH, we applied it on the heparin-sepharose affinity column and prepared two fractions (bound and unbound fractions). We measured TGFbeta concentration in each fraction and examined how the anti-TGFbeta antibody decreased the inhibitory effect of AH on human umbilical vein endothelial cell growth and on in vitro angiogenesis. We found the presence of TGFbeta2, but not TGFbeta1, in the heparin bound fraction, and the inhibitory effect was detected in the heparin-bound fraction. Anti-TGFbeta antibody completely and dose-dependently extinguished the inhibitory effect of AH. We propose that the inhibitory effect of AH on endothelial cell growth and in vitro angiogenesis are both mediated by TGFbeta2. Our results indicate TGFbeta2 is normally present in AH and protects the eye tissue against abnormal neovascularization.

Animals↗
PubMed1998

Brainstem lesion in Aicardi-Goutières syndrome.

Aicardi-Goutières syndrome is characterized by the calcification of basal ganglia, leukodystrophy, and lymphocytosis in cerebrospinal fluid. No brainstem lesion has been described. We report a Japanese girl who presented with delayed development and microcephalus at early infancy. Magnetic resonance imaging revealed T2-weighted high intensity in the cerebral white matter and brainstem, and nerve conduction velocity was delayed in the central nervous system, indicating that she manifested dysmyelination in the brainstem white matter similar to that in the cerebral white matter.

Basal Ganglia Diseases↗