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K Hiyama

Publications and source records attributed to K Hiyama.

At least 91 records · Page 5Linked to original sources
PubMed1992

Length of telomeric repeats in neuroblastoma: correlation with prognosis and other biological characteristics.

Telomeres are the physical ends of eukaryotic chromosomes. In view of reports of the reduction of telomeric repeats in human malignant tumors, we measured the lengths of telomeric repeats in 55 primary neuroblastomas. The average lengths of telomeric repeats in these tumors fell in a wide range (from 1.1 kb to more than 23 kb) relative to those in ganglioneuromas and normal peripheral mononuclear cells. The reduction of telomeric repeats was significantly correlated with advanced stages of tumor development, poor prognosis, and increased S-phase fractions in tumor cells. On the other hand, three cases of Stage IV-S tumors showed the reduction of telomeric repeats and low percentage of S-phase fractions. These Stage IV-S patients had a good prognosis with spontaneous regression of metastatic tumors.

Adolescent↗
PubMed1992

[Analysis of oncogenes and suppressor genes in lung cancer and bronchial lesions from high risk group].

The authors investigated methods for analysis of oncogenes and tumor suppressor genes in lung cancers and bronchial lesions from high risk patients (retired poison gas factory workers). Amplifications of C-, L-, N-myc, length of terminal repeat array (TRA), mutations of p53 gene, p53 mRNA and K-ras genes were analysed in frozen specimens of surgically resected lung cancers. Various lesions including dysplasia, squamous metaplasia, goblet cell metaplasia, and basal cell hyperplasia were detected in the bronchial epithelium of biopsied specimens from retired poison gas factory workers. Analysis of p53 gene and k-ras gene mutations was performed on these formalin fixed, paraffin embedded samples, but no evidence of mutation has been found to date.

Bronchi↗
PubMed1991

Neuroblastoma with DNA amplification and rearrangement in the N-myc gene region.

We detected a rearrangement in the N-myc gene region in a neuroblastoma from a 9-month-old girl. In this case, the N-myc gene was amplified 50-fold in the primary tumor, the lymph node metastasis, and the hepatic metastasis. The rearrangement was detected only in the primary tumor and the lymph node metastasis, whereas N-myc RNA and protein expression were detected only in the primary tumor and the hepatic metastasis. Both the rearranged N-myc gene and the normal N-myc gene were amplified 25-fold, and the rearrangement occurred 723 nucleotides downstream from the 3' end of exon 3. The cell line (NH-6) derived from the primary tumor showed N-myc gene amplification without this rearrangement. These results suggest the following: (a) the primary tumor had a least two clones; (b) the rearrangement interrupted N-myc gene expression; and (c) oncogenesis preceded N-myc gene amplification.

Adrenal Gland Neoplasms↗
PubMed1991

The length polymorphism in the 5' flanking region of the human beta-globin gene with denaturing gradient gel electrophoresis in a Japanese population.

The ATTTT repeat polymorphism located approximately 1,400 base pairs (bp) upstream from the beta-globin structural gene was analyzed by denaturing gradient gel electrophoresis (DGGE) of RNA:DNA duplexes. A study of 81 unrelated Japanese from Hiroshima revealed a sequence heteromorphism in this site. The alleles with five and six repeats of the ATTTT unit, which have been reported, were found in polymorphic proportions. Two unreported alleles were also detected, the first, in two persons, characterized by seven repeats and the other, in a single person, having an A-to-G nucleotide substitution in the fifth repeat.

Cell Line↗
PubMed1991

Immunohistochemical analysis of N-myc protein expression in neuroblastoma: correlation with prognosis of patients.

We have analyzed N-myc gene amplification and N-myc protein expression in 41 primary neuroblastomas. In this series, 22 patients are currently alive and disease-free, whereas 19 patients have died or are alive with progressive disease. All tumor samples were obtained at operation. N-myc gene amplification was detected by Southern blot analysis, and N-myc protein expression was detected using Bouin-fixed, paraffin-embedded tissue sections and immunohistochemical staining with anti-N-myc gene products serum. N-myc protein expression was detected in all 9 tumors with N-myc gene amplification (greater than or equal to 10 N-myc gene copies). Among 19 patients with poor prognosis, N-myc gene amplification was detected in 8 (42%) and N-myc protein expression in 18 (95%); neither was detected in 20 of the 22 patients who survived free of disease. We conclude that the immunohistochemical detection of N-myc protein expression is one of the most unfavorable prognostic factors in neuroblastoma patients.

Adrenal Gland Neoplasms↗
PubMed1990

N-myc gene amplification and other prognosis-associated factors in neuroblastoma.

The correlation between N-myc gene amplification and heretofore known prognosis-associated factors was studied in 23 cases of neuroblastoma, comprising a total of 29 tumors (23 primary and six metastatic), examined in and after 1983. DNAs were extracted from tumor tissues preserved at -70 degrees C and digested with the restriction enzyme EcoRI. Southern blotting analysis was performed on these DNAs with the N-myc probe labelled with alpha-32P-dCTP. Prognosis-associated factors studied were age at diagnosis, stage, primary site, histological type, blood biochemistry tests, and catecholamine metabolites in urine. Amplification of N-myc gene was observed only in the cases in which primary site was the adrenal gland, but the relation to the stage, histological type, and prognosis was not as apparent as reported by other investigators. However, the amounts of catecholamine metabolites were low in the cases with amplification, and this suggests immaturity of catecholamine metabolism in the tumor with N-myc gene amplification.

Blotting, Southern↗
PubMed1990

Detection of deletions, insertions and single nucleotide substitutions in cloned beta-globin genes and new polymorphic nucleotide substitutions in beta-globin genes in a Japanese population using ribonuclease cleavage at mismatches in RNA:DNA duplexes.

The applicability of ribonuclease cleavage at mismatches in RNA:DNA duplexes (RNase cleavage method) for determining nucleotide variant rates has been examined in a Japanese population. DNA segments of various lengths obtained from 4 different regions of a normal and 3 thalassemic cloned human beta-globin genes were inserted into transcription vectors. Sense and antisense RNA probes uniformly labeled with 32P were prepared. When RNA probes of 771 nucleotides (nt) or less were hybridized with cloned DNAs and the resulting duplexes were treated with a mixture of RNases A and T1, the length of products agreed with theoretical values. Twelve possible mismatches were examined. Since both sense and antisense probes were used, uncleavable mismatches such as G:T and G:G which were made from one combination of RNA and DNA strands could be converted to the cleavable C:A and C:C mismatches, respectively, by using the opposite combination. Deletions and insertions of 1 (G), 4 (TTCT), 5 (ATTTT) and 10 (ATTTTATTTT) nt were easily detected. A polymorphic substitution of T to C at position 666 of the second intervening sequence (IVS2-666) of the beta-globin gene was detected using genomic DNAs from cell lines established from the peripheral B lymphocytes of 59 unrelated Japanese from Hiroshima or those amplified by polymerase chain reaction (PCR). The frequency of the gene with C at the IVS2-666 (allele C) was 0.48 and that of the gene with T (allele T) was 0.52. The associations of the 2 alleles were in agreement with Hardy-Weinberg proportions. No contradiction to Mendelian inheritance was observed in the results obtained from 11 family studies. Two new polymorphic substitutions of C to A and A to T were detected at nucleotide positions 1789 and 1945 from the capping site, respectively, using genomic DNAs amplified by PCR. The feasibility of the RNase cleavage method combined with PCR for large-scale screening of variation in chromosomal DNA is discussed.

Base Composition↗
PubMed1990

An improved method for the detection of genetic variations in DNA with denaturing gradient gel electrophoresis.

We have examined the feasibility of denaturing gradient gel electrophoresis (DGGE) of RNA:DNA duplexes to detect variations in genomic and cloned DNAs. The result has demonstrated that employment of RNA:DNA duplexes makes DGGE much more practical for screening a large number of samples than that of DNA:DNA heteroduplexes originally developed by Lerman et al. (1986), because preparation of RNA probes is easier than that of DNA probes. Three different 32P-labeled RNA probes were produced. Genomic or cloned DNAs were digested with restriction enzymes and hybridized to labeled RNA probes, and resulting RNA:DNA duplexes were examined by DGGE. The presence of mismatch(es) was detected as a difference in mobility of bands on the gel. The experimental conditions were determined using DNA segments from cloned normal and 3 thalassemic human beta-globin genes. The results of the experiments on the cloned DNAs suggest that DGGE of RNA:DNA duplexes will detect nucleotide substitutions and deletions in DNA. In the course of these studies, a polymorphism due to a single-base substitution at position 666 of IVS2 (IVS2-666) of the human beta-globin gene was directly identified using genomic DNA samples. A study of 59 unrelated Japanese from Hiroshima was made in which the frequency of the allele with C at IVS2-666 was 0.48 and that of the allele with T was 0.52. This approach was found to be very effective for the detection of heritable variation and should be a powerful tool for the detection of fresh mutations in DNA, which occur outside the known restriction sites.

DNA↗
PubMed1989

[Adult polysaccharide storage myopathy].

A first Japanese case of an adult polysaccharide storage myopathy (APSM) was reported. A 30-year-old Japanese male was admitted because of weakness of the lower limbs. The onset of the symptoms was at the age of 23. Neurologically he had moderate weakness of proximal limb muscles involving the lower limbs more than the upper and slightly decreased vibratory sense in the feet. His gait was waddling. The following laboratory values were obtained; SGOT 45 I.U., SGPT 83 I.U., CPK 218 I.U., UA 8.3 mg/dl. Ischemic exercise test of the forearm showed a normal rise of venous lactate. EMG revealed a mixture of myopathic and mild neurogenic patterns characterized by motor units of short duration and low amplitude with intermittent high amplitude potentials, fibrillation and fasciculation. There were also prominent myotonic discharges without clinical myotonia. MCV was normal, however sural nerve SCV was slightly slow (lt. 36/m, rt. 38 m/s). Muscle biopsy revealed vacuolar myopathy. Most vacuoles contained basophilic, PAS-positive, diastase-resistant and Lugol's iodine-negative material. With ATPase staining there was type 1 fiber predominance (84%), but the vacuoles were predominantly seen in type 2A fiber. In ultrastructural study, the storage material was located under the sarcolemma and in the areas of the intermyofibrillar network. No delimiting membranes were seen. At higher magnification, these masses were consisted of filaments. Therefore the storage material was considered to be unusual polysaccharide. Glycogen storage disease was suspected, however, biochemical study of the muscle specimen disclosed no enzymatic defect including branching enzyme.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Intra-axonal polysaccharide deposits in the peripheral nerve seen in adult polysaccharide storage myopathy.

This is the first report of an adult polysaccharide storage myopathy demonstrating polysaccharide deposits within the axons of the peripheral nerve. Histochemical and electron-microscopic studies revealed that the intra-axonal deposits were basophilic, PAS-positive, diastase-resistant, and composed of filamentous and granular material. The structural similarity among the polysaccharide deposits in our case, amylopectin-like materials in type IV glycogenosis, Lafora bodies, corpora amylacea, and polyglucosan bodies is discussed.

Adult↗