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Biomedical subjects

K Sukegawa

Publications and source records attributed to K Sukegawa.

At least 91 records · Page 5Linked to original sources
PubMed1991

Gene deletions in Japanese patients with Duchenne and Becker muscular dystrophies: deletion study and carrier detection.

Fifty unrelated Japanese patients with Duchenne and Becker muscular dystrophy (DMD and BMD) have been studied through use of the dystrophin cDNA probes. The 14-kb dystrophin cDNA was subdivided into six subclones, and Hind III-digested DNAs were analyzed by Southern blotting. Of 50 unrelated patients, 20 showed a deletion of one or several of the exon-containing Hind III fragments (40.0%). These corresponded to 50% (11/22) of BMD patients and 32.1% (9/28) of DMD patients, and the position and extent of deletions were mapped and proven to be more heterogeneous in DMD than in BMD. Both ends of deletions detected by probe 1-2a were common to all six BMD patients, and the 5' ends of deletions in probe 5b-7 were also common to four BMD patients. The phenotypic-specific deletion in Japanese BMD patients existed in the 5' end of the DMD gene, although an apparently similar deletion produced a wide range of clinical courses (BMD phenotype). Three out of eight females in DMD/BMD families were diagnosed as carriers through use of the junctional fragment and dosage analyses of dystrophin cDNA.

Adolescent↗
PubMed1991

Mucopolysaccharidosis type VII: characterization of mutations and molecular heterogeneity.

We identified two different exonic point mutations causing beta-glucuronidase (beta G1) deficiency in two Japanese patients with mucopolysaccharidosis type VII (MPSVII). Enzyme assay of lysates of the lymphocytes and cultured fibroblasts showed little residual activity. The beta G1-specific mRNA levels were normal, as determined by northern blot analysis. Mutated cDNA clones, including the entire coding sequence, were isolated using the polymerase chain reaction (PCR) products derived from beta G1-deficient fibroblasts. Sequence analysis of the full-length mutated cDNAs showed C----T transitions, which resulted in a single Ala619----Val change (case 1, a 24-year-old male) and a Arg382----Cys change (case 2, a 7-year-old female). The former change was revealed by a loss of the cleavage site for the Fnu4HI in the mutated cDNA. On the basis of the loss of Fnu4HI restriction site, the patient (case 1) was a homozygote with this mutation. The mutational change in patient 2 was confirmed by direct sequencing and by demonstrating heterozygosity for the mutation in her parents. The Ala619----Val and Arg382----Cys mutations each disrupt a different domain which is highly conserved among human, rat, and Escherichia coli beta G1s. Each of these two amino acid changes reduced the beta G1 activity of the corresponding mutant beta G1 expressed following transfection of COS cells with expression vectors harboring the mutated cDNAs.

Adult↗
PubMed1990

Molecular basis of mucopolysaccharidosis type VII: replacement of Ala619 in beta-glucuronidase with Val.

We have identified a mutation causing beta-glucuronidase (beta Gl) deficiency in a 6-year-old girl with mucopolysaccharidosis type VII. Enzyme assay of lysates of a girl's lymphocytes or cultured fibroblasts showed little residual activity and a normal beta Gl-specific mRNA level, as revealed by Northern-blot analysis. Sequencing of the full-length mutated cDNA revealed a C----T transition, an event causing a single Ala619----Val change (we designated this variant beta GGifu). This change is detected by loss of the cleavage site for the enzyme Fnu4HI in the mutated cDNA. On the basis of the loss of Fnu4HI restriction site, the patient was shown to be a homozygote with the beta GGifu mutation and her parents and brother were heterozygotes. This mutation disrupts a functional domain consisting of a region of sequence highly conserved among human, rat and bacterial beta Gls, and it reduces the enzyme activity, as tested by transfection of COS cells with expression vectors harboring the mutated cDNA.

Alanine↗
PubMed1990

Non-existence of a tight association between a 444leucine to proline mutation and phenotypes of Gaucher disease: high frequency of a NciI polymorphism in the non-neuronopathic form.

A 444leucine to proline mutation detected by a NciI polymorphism in the human glucocerebrosidase gene was studied to investigate the correlation of the three clinical phenotypes of Gaucher disease with this mutation in 11 Japanese patients with Gaucher disease (type I, 8 patients; type II, 1 patient; type III, 2 patients) and to determine the feasibility of the use of genomic probe DNA for carrier detection and prenatal diagnosis in 8 Japanese families with Gaucher disease and agreeable to family study (type I, 6 families; type III, 2 families). The homoallelic 444leucine to proline mutation was found only in patients with type I disease. Of the 8 type I patients, 5 had the homoallelic mutation and 2 had one mutant allele. One patient with type II disease did not have this mutant allele. Of the 2 type III patients, one had a single mutant allele whereas the other exhibited no mutation of this kind. These results suggest that the 444leucine to proline mutation is very common in the type I (non-neuronopathic form) disease and is not tightly associated only with neuronopathic types of Gaucher disease in Japanese patients. These findings seem to conflict with others showing that this mutation is partially responsible for the occurrence of neuronopathic Gaucher disease. Thus, the NciI polymorphism will not be useful for the diagnosis of subtypes of Gaucher disease. Carrier detection was feasible in three families with type I disease of the 8 families analyzed by the NciI polymorphism.

Deoxyribonucleases, Type II Site-Specific↗
PubMed1990

Gene deletions in Japanese patients with Duchenne and Becker muscular dystrophy.

Thirty-eight unrelated Japanese patients with Duchenne and Becker muscular dystrophy (DMD and BMD) have been investigated with the DMD cDNA probes. The 14-kb DMD cDNA was subdivided into 6 subclones and HindIII-digested DNAs were analyzed by Southern blotting. Out of 38 unrelated patients, 14 showed a deletion of one or several of the exon-containing HindIII fragments (36.8%). These corresponded to 50% (9/18) of BMD patients and 25% (5/20) of DMD patients, and the position and extent of deletions were mapped and proved to be more heterogeneous in DMD than in BMD. Both ends of deletions detected in probe 1-2a were common to all six BMD patients without the maintenance of reading frame of messenger RNA, and 5' ends of deletions in probe 5b-7 were also common but maintained in frame in three BMD patients. The phenotypic-specific deletion in Japanese BMD patients has existed in the 5' end of the DMD gene, although its apparently similar deletion produced a wide range of clinical courses (BMD phenotype). There was no tight correlation between clinical severity and presence or absence of deletion in DMD or BMD.

Adolescent↗
PubMed1990

[Molecular basis of mucopolysaccaridosis type VII (beta-glucuronidase deficiency)].

We have identified several mutations causing beta-glucuronidase (beta Gl) deficiency in three cases with mucopolysaccaridosis type VII (MPS VII). Enzyme assay of lysates of these lymphocytes or cultured fibroblasts showed little residual activity and that the beta Gl-specific mRNA levels were normal, as revealed by Northern blot analysis. Mutated cDNA clones including the entire coding sequencing were isolated from a library in case 1 and PCR (polymerase chain reaction) products in case 2 and 3 derived from cultured fibroblasts. Sequencing of the full-length mutated cDNA revealed C----T transitions, an event causing a single Ala619----Val change (cases 1 and 2) and Arg382----Cys and Pro649----Leu changes (case 3). The former change is detected by loss of the cleavage site for the enzyme Fnu 4 HI in the mutated cDNA. On the basis of the loss of Fnu 4 HI restriction site, the patients (cases 1 and 2) were shown to be a homozygote with this mutation and the parents and brother in case 1 were heterozygotes. The Ala619----Val and Arg382----Cys mutations disrupt a functional domain consisting of a region of sequence highly conserved among human, rat and bacterial beta Gl's, and they lower the enzyme activity, as tested by transfection of COS cells with expression vectors harboring the mutated cDNA. However the Pro649----Leu mutation does not lower the enzyme activity.

Amino Acid Sequence↗
PubMed1989

Restriction fragment length polymorphism analysis in healthy Japanese individuals and Japanese families with Gaucher disease.

We analysed the restriction fragment length polymorphism (RFLP) of 30 unrelated, healthy Japanese individuals and the members of seven Japanese families with Gaucher disease (5 Type I, 2 Type III) with the cDNA for human glucocerebrosidase, to investigate the frequency of the RFLP among healthy Japanese individuals and to determine the feasibility of the use of this probe DNA for carrier detection and prenatal diagnosis in Japanese families with Gaucher disease. In the Pvu II polymorphism, the common allele reported by Sorge et al was the rare allele for healthy Japanese individuals. The frequency of the common allele (+) in Japanese was 0.75 and the rare allele (-) was 0.25. The RFLP study was informative for carrier detection in the family in which both parents were heterozygous for the Pvu II polymorphism. Even in the family in which only one parent was heterozygous, carrier detection was feasible by combining the clinical history and the RFLP, although prenatal diagnosis was not feasible. The Kpn I polymorphism was not detected. It is necessary for precise carrier detection and prenatal diagnosis to investigate other restriction endonucleases which reveal the RFLP.

DNA↗
PubMed1986

Metabolism of sphingomyelin in cultured skin fibroblasts from patients with different types of Niemann-Pick disease.

The metabolism of [choline-methyl-14C]sphingomyelin in cultured skin fibroblasts from patients with different types of Niemann-Pick disease was measured 1 and 3 days after uptake from the media. The cell lines obtained from type A disease had more than 95% unhydrolyzed sphingomyelin in situ on day 3 while two cell lines obtained from type B had 36.3% and 43.3% unhydrolyzed sphingomyelin on day 3. The cell line derived from one patient with the transitory type disease had 48.1% unhydrolyzed sphingomyelin on day 3, and there was no significant difference in the sphingomyelinase activity measured in vitro or in degradation of sphingomyelin in situ between the type B and transitory type disease. In three cell lines from patients with type C disease, there was 18.5%, 29.6% and 31.1% unhydrolyzed sphingomyelin on day 3, which indicates that this type has a decreased ability to metabolize sphingomyelin. Cell from type E disease metabolized sphingomyelin normally.

Cells, Cultured↗
PubMed1985

Glycosaminoglycan excretion in random samples of urine.

The measurement of glycosaminoglycans (GAGs) on a single random urine specimen in 405 healthy individuals and in 79 patients with mucopolysaccharidoses (MPSs) is described. The uronic acid (UA) content of the precipitated GAGs was estimated by the method of Bitter and Muir. The results were expressed as uronic acid to creatinine (UA/C) ratio. We found that the UA/C ratio decreased with age but had a rather constant low value between the ages of 20 and 33 in healthy individuals. Except for most patients with Morquio syndrome, the UA/C ratio in random urine samples was higher in patients with MPSs than in healthy individuals.

Adolescent↗
PubMed1985

Screening test for urinary glycosaminoglycans and differentiation of various mucopolysaccharidoses.

The Ames MPS paper spot test and the cetylpyridinium chloride (CPC)-citrate turbidity test were used to detect urinary glycosaminoglycans (GAGs) as screening tests for the diagnosis of mucopolysaccharidoses (MPSs). The simplicity and reliability of these two methods were evaluated. The MPS paper spot test correlated more closely with the carbazole test than did the CPC-citrate turbidity test. The monodimensional electrophoresis of Cappelletti et al was also used to screen the subtypes of MPSs using differences in electrophoretic patterns. MPS VII cannot be distinguished from normal by its electrophoretic pattern, but can be detected by the MPS paper spot test. Therefore, the MPS paper spot test combined with monodimensional electrophoresis can detect these subtypes of MPSs (MPS I-II, III, IV, VI, VII). Since only 20 ml of random urine is needed and the result can be obtained with complete reliability in only 7 hours, this screening test appears to be useful for the early diagnosis of MPSs.

Adolescent↗
PubMed1983

Activities of sulfatases for the degradation of acidic glycosaminoglycans in cultured skin fibroblasts from two siblings with multiple sulfatase deficiency.

Cultured skin fibroblasts from two siblings with multiple sulfatase deficiency (MSD) were assayed for the activities of sulfatases known to degrade acidic glycosaminoglycans (AGAG). There were iduronate sulfatase, arylsulfatase B, heparan sulfate (HS) sulfatase, N-acetylgalactosamine-6-sulfate sulfatase, HS-derived N-acetylglucosamine-6-sulfate sulfatase, and two keratan sulfate (KS)-derived N-acetylglucosamine-6-sulfate sulfatases. The activities of sulfatases required for the degradation of HS were reduced to a greater extent than those for the degradation of dermatan sulfate (DS), and those of sulfatases associated with basic defect of Morquio disease type A were moderately decreased or normal. On the other hand, urinary excretion of AGAG in both patients was increased about 10-fold compared to controls, and especially, the excretion of HS and DS was increased about 150-fold and 50-fold, respectively. Keratan sulfate was not detected. The results suggest that in patients with MSD the degradation of HS might be affected to a greater extent than that of DS.

Cells, Cultured↗
PubMed1979

Sphingomyelinase activities in cultured skin fibroblasts from patients with Niemann-Pick Disease.

Sphingomyelinase activity in cultured skin fibroblasts from a fetus affected with infantile-type Niemann-Pick disease was 0.5% of control activity; the activities in cells from two patients with adult-type disease (Cases 2 and 3) were 5.0% and 59.0%. Sphingomyelinase activiy was separated into three peaks (I-III) by isoelectric focusing. The isoelectric points were 4.5, 4.9, and 5.2 for peaks I, II, and III, respectively. The three peaks in the Case 2 cells were drastically reduced; only a very small peak could be distinguished (pI of 4.7). On the other hand, three peaks were observed in the Case 3 cells. Peak I had a pI of 4.4, peak II a pI of 4.7, and peak III a pI of 5.2. Peak I was found at near normal level, but both peaks II and III were markedly reduced. Sphingomyelinase in the peak I fraction obtained from isoelectric focusing in Case 3 cells was found to have the same Km value as that in control cells.

Adult↗