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T Arinami

Publications and source records attributed to T Arinami.

At least 109 records · Page 6Linked to original sources
PubMed1995

Mid-trimester fetal sex determination from maternal peripheral blood by fluorescence in situ hybridization without enrichment of fetal cells.

To determine the fetal sex on 30 women who were 16-20 weeks pregnant, about 100,000 maternal blood nucleated cells were analysed by means of fluorescence in situ hybridization (FISH) with a Y-chromosome-specific DNA probe. Cells with the hybridization signal were detected in 12 of the 30 women. All the 12 mothers gave birth to a male child. Of the other 18 women who had no Y-positive cells in the peripheral blood, 14 gave birth to a female child and four gave birth to a male child. These false-negative results probably occurred because the number of cells examined was inadequate. The data obtained in this study suggest that fetal sex determination using maternal peripheral blood with FISH is possible and that this diagnostic method will be clinically useful when more cells are analysed.

Blood Cells↗
PubMed1995

Fetal nucleated cells in maternal peripheral blood after delivery in cases of fetomaternal hemorrhage.

OBJECTIVE: To determine how long fetal nucleated cells can be detected in maternal peripheral blood after delivery in cases of fetomaternal hemorrhage, using fluorescence in situ hybridization or polymerase chain reaction. METHODS: Nucleated cells with Y chromosomes were analyzed in 90 blood samples using fluorescence in situ hybridization with a Y-chromosome-specific DNA probe. The samples were obtained from 15 mothers (gravida 1), who were delivered of normal male neonates at University of Tsukuba Hospital, Japan, with fetomaternal hemorrhage 1 and 7 days, and 1, 3, 6, and 12 months after delivery. The 15 mothers were selected if fetal cells were detected above the ratio of one fetal cell per 3000 mothers' cells at 1 day after delivery. Polymerase chain reaction amplifying two different Y-specific fragments (a 102 base-pair fragment in the pHY10 vector, which was a highly repetitive sequence, and a single-copy, Y-specific 198 base-pair fragment) was also carried out for the analysis of genomic DNA from the same samples. RESULTS: Seven days and 1 month after delivery, Y-positive cells were detected in nine and four of 15 samples, respectively. No cells with the hybridization signal were detected in any of the 45 samples obtained 3 months or more after delivery. When we performed the polymerase chain reaction experiment amplifying the single-copy Y-specific fragment, none of the 45 samples after 3 months or more showed the expected band. However, from the same 45 samples, four obtained from different mothers showed positive results by amplification of the fragment in the pHY10 vector. Because multiple samples taken from these mothers before the collection of the positive samples showed negative results in the three experiments, these findings strongly suggest that the observed positive results were false-positives. CONCLUSION: Fetal nucleated cells in maternal peripheral blood become undetectable 3 months after delivery in most, if not all, cases of fetomaternal hemorrhage.

False Positive Reactions↗
PubMed1994

Longitudinal changes in IQ among fragile X females: a preliminary multicenter analysis.

Longitudinal declines in IQ among fragile X [fra(X)] males have been reported previously by several investigators. Remarkably little is known about longitudinal changes in IQ scores among fra(X) females. Previously, one cross-sectional study showed a significant negative correlation between age and IQ scores. However, a recent investigation of girls with fra(X) syndrome noted longitudinal increases in IQ scores in 8 of 11 individuals. Therefore, the purpose of this preliminary multicenter study was to determine: (1) the characteristics of longitudinal changes in IQ among fra(X) females; and (2) whether these changes were comparable to those which have been observed among fra(X) males. IQ test and retest scores for 11 fra(X) females were obtained from 3 centers: Greenwood, South Carolina; Ibaraki, Japan; and Leuven, Belgium. To ensure high reliability, only test-retest scores from the Wechsler and Stanford-Binet tests were used. Age of subjects at initial testing ranged from 5 to 35 years. Mean intertest interval was 4.5 years. In contrast to a report of longitudinal increases, we found 9/11 (82%) subjects demonstrated decreases in IQ scores. Mean decline was 9 points. Females over 18 years of age showed little or no change in IQ scores. Decreases in scores appeared to be related to initial IQ score. Females in the earlier longitudinal report were higher functioning than those in our study, which may account for the observed difference in direction of change; or, change in IQ score may be related to size of the fra(X) mutation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Comparison between the cytogenetic test for fragile X and the molecular analysis of the FMR-1 gene in Japanese mentally retarded individuals.

The prevalence of the fragile X syndrome has been estimated by the results of population studies in which the disease was mostly diagnosed by cytogenetic examinations. To examine the reliability of the cytogenetic analysis for the estimation of the prevalence of the fragile X syndrome, the CGG repeat in the FMR-1 gene was assayed by Southern blot hybridization and polymerase chain reaction (PCR) in an institutionalized group of mentally retarded individuals consisting of 305 males and 129 females. The data thus obtained were compared with the cytogenetic data. The DNA analysis detected 7 full mutations among the alleles of the 296 unrelated males and 2 full mutations among the alleles of the 129 unrelated females. These findings were consistent with the cytogenetic data. No premutation was found in 554 X chromosomes in the unrelated mentally retarded patients nor 826 X chromosomes in unrelated control individuals. The distribution of the CGG repeat number in the normal range was not significantly different between the mentally retarded individuals and the control individuals. These data suggest that the estimates of the prevalence of the fragile X syndrome based on cytogenetic data in the population studies are almost reliable. Based on the finding that no premutations were found in this study, a small difference in the prevalence of the fragile X syndrome between Caucasians and Japanese is suggested.

Adolescent↗
PubMed1994

Association of dopamine D2 receptor molecular variant with schizophrenia.

We have examined a variant of the dopamine D2 receptor gene (Ser311-->Cys) in 156 Japanese schizophrenic patients and 300 controls. The allele frequency of Cys311 was significantly higher in the whole patient group (0.054), among patients with onset before age 25 (0.090), and among those with a family history (0.135) than in the controls (0.018). 3 patients were homozygous for Cys311. The patients with Cys311 showed significantly less severe thought disorder and negative symptoms of schizophrenia than those without Cys311. The Cys311 variant of the D2 receptor may be a genetic risk factor for some types of schizophrenia.

Adolescent↗
PubMed1994

Dose-dependent association of apolipoprotein E allele epsilon 4 with late-onset, sporadic Alzheimer's disease.

We examined the apolipoprotein E (apo E) genotypes in 47 patients with late-onset sporadic Alzheimer's disease (mean age at onset +/- standard deviation, 72.2 +/- 6.4 years), 8 with late-onset familial Alzheimer's disease (75.5 +/- 5.1 years), 18 with early-onset sporadic Alzheimer's disease (52.8 +/- 4.7 years), and 10 with early-onset familial Alzheimer's disease (52.0 +/- 6.8 years) in Japan and compared them with genotypes in control subjects. In late-onset sporadic Alzheimer's disease, apo E-epsilon 4 frequency increased significantly (epsilon 4 frequency: 0.34 vs 0.095 in controls, p < 0.0001), and the odds ratio, which represents the strength of association between Alzheimer's disease and apo E-epsilon 4, markedly increased with increasing dose of apo E-epsilon 4 gene (3 [95% confidence interval, 2-6] in one dose; 43 [95% confidence interval, 12-154] in two doses). This study also suggested that apo E-epsilon 4 is associated with both late-onset (epsilon 4: 0.31) and early-onset familial Alzheimer's disease (epsilon 4: 0.35). In contrast, we found no association between apo E-epsilon 4 and early-onset sporadic Alzheimer's disease (epsilon 4: 0.08). These results indicate that the risk of developing late-onset sporadic Alzheimer's disease is markedly dependent on the dose of apo E-epsilon 4, while apo E-epsilon 4 does not appear to be a major risk factor for early-onset sporadic Alzheimer's disease.

Aged↗
PubMed1994

Apolipoprotein E5 and E7 in apparently healthy Japanese males: frequencies and relation to plasma lipid levels.

In order to determine the frequencies of apolipoproteins (apo) E5 and E7 and their relation to plasma lipid levels, apo E phenotypes were determined in 608 healthy Japanese male adults by two-dimensional gel electrophoresis. Apo E5 and E7 were observed in 2.8% of the subjects, in addition to the three common apo E isoforms, E2, E3, and E4. Apo E5 was divided into two subtypes based on the migration rate on SDS/PAGE, E5f is the type with faster migration and E5s slower migration. The gene frequencies were: the epsilon 3 allele, 0.841; the epsilon 4 allele, 0.095; the epsilon 2 allele, 0.049; the epsilon 7 allele, 0.009; the epsilon 5 allele encoding apo E5f (the epsilon 5f allele), 0.004; and the epsilon 5 allele encoding apo E5s (the epsilon 5s allele), 0.001. The five individuals with apo E5f and the eleven with apo E7 were heterozygotes and normocholesterolemic. Also plasma apo B and apo E levels were not increased in any subjects with apo E5f or apo E7. The data suggests that apo E5f and E7 are not rare in the Japanese population but that neither apo E5f nor E7 are associated with hypercholesterolemia in most of the heterozygotes.

Adult↗
PubMed1994

Fetal nucleated cells in maternal peripheral blood after delivery.

OBJECTIVE: The purpose of this study was to determine the frequency of fetal nucleated cells and their serial changes in maternal peripheral blood after delivery. STUDY DESIGN: A total of 135 blood samples were investigated by means of fluorescence in situ hybridization by observing cells with Y chromosomes. Polymerase chain reaction amplifying two different Y-specific fragments were also carried out for genomic deoxyribonucleic acid from the same samples. RESULTS: The mean frequency of the Y-positive cells detected by fluorescence in situ hybridization in mothers who gave birth to male children was about 1 in 17,500 1 day after delivery. The frequency of these cells decreased with time, dropping below detectable levels 3 months after delivery. The frequency estimated by polymerase chain reaction experiments was significant and positively correlated with those found by fluorescence in situ hybridization. CONCLUSION: Fetal nucleated cells in maternal peripheral blood decrease in frequency with time after delivery. These cells disappear from maternal circulation 3 months after delivery in most, if not all, mothers.

Adult↗
PubMed1994

Plasminogen with type-I mutation in the Chinese Han population.

A functionally inactive plasminogen (PLG) variant, PLG M5, is polymorphic in the Japanese population and has a codon 601 mis-sense mutation (GCT for Ala to ACT for Thr), designated type-I mutation. The present study aimed to reveal whether the plasminogen with type-I mutation is present in the Chinese Han population. Among 104 healthy Chinese students, phenotype PLG AM5 was found in three subjects (2.9%), while 100 subjects were phenotype A and one was phenotype AA3. In the three subjects with PLG AM5, plasma concentrations of immunoreactive PLG were normal but PLG activities were decreased. Analysis using PCR and dot-blot hybridization with allele-specific oligonucleotide probes revealed the presence of the type-I mutation in the PLG gene of all three subjects with PLG AM5. The data indicate that PLG with type-I mutation is present in the Chinese Han population, possibly at a polymorphic frequency.

Asian People↗
PubMed1994

[Analysis of the dopamine D2 receptor gene].

The methods, such as Southern blot hybridization, PCR-direct sequencing and PCR-SSCP, to detect sequence variants in the human dopamine D2 receptor (DRD2) gene were described. To study the association of a missense variant of the DRD2 gene resulting in Ser311-->Cys, which was detected by PCR-direct sequencing in schizophrenics, the genotypes of controls and schizophrenics were determined by the methods of PCR-dot blot hybridization, PCR amplification of specific alleles and artificially introduced PCR-RFLP.

Base Sequence↗
PubMed1993

A structural polymorphism of human dopamine D2 receptor, D2(Ser311-->Cys).

No structural change of the dopamine D2 receptor (DRD2) has been reported so far, though the DRD2 gene has been suggested to be one of the candidate genes for mental disorders. Herein we report one missense nucleotide mutation from C to G resulting in a substitution of serine with cystein at the codon 311 located in the third intracellular loop of the DRD2 that was found in the analyses of the sequence of the DRD2 gene in 50 schizophrenics. The allele frequency, 0.04, of this Cys311 allele in 50 schizophrenics was slightly increased compared with that, 0.023, in 110 controls though the difference was not significant. The schizophrenics with Cys311 tended to have a lower age of onset and a positive family history of schizophrenia.

Alleles↗
PubMed1993

Autosomal dominant hypoalphalipoproteinemia due to a completely defective apolipoprotein A-I gene.

Primary hypoalphalipoproteinemia is associated with atherosclerosis and exhibits significant familial aggregation. To reveal the presence of autosomal dominant hypoalphalipoproteinemia due to a completely defective apolipoprotein A-I gene, the apolipoprotein A-I gene was analyzed in a Japanese family with low levels of HDL cholesterol and apolipoprotein A-I. An insertion of a C in the region of the seven C run between codons 3 and 5 was detected in the apolipoprotein A-I gene. The heterozygous state for the mutation was associated with approximately 50% of the normal HDL cholesterol levels and of the normal apolipoprotein A-I levels. The data suggest that a part of familial hypoalphalipoproteinemia might be an autosomal dominant trait due to a completely defective apolipoprotein A-I gene.

Adult↗
PubMed1993

Association between severity of alcoholism and the A1 allele of the dopamine D2 receptor gene TaqI A RFLP in Japanese.

The allelic association of TaqI A restriction fragment length polymorphism (RFLP) of the dopamine D2 receptor gene with alcoholism was examined in 78 Japanese alcoholics and compared with Japanese controls. A significantly higher frequency of the A1 allele (0.42) was found in 100 Japanese unscreened controls compared with those reported in white populations. Among 70 alcoholics whose severities were determined, the A1 allele was present in 77% of 43 more severe alcoholics and in 59% of 27 less severe alcoholics. The A1 allele was present significantly less frequently in the alcoholics at the age of 60 or older (42%), compared with those under the age of 60 (74%). In the subjects under the age of 60, the A1 allele was present in 83% of the 35 more severe alcoholics, being significantly more frequent than in 60% of the 35 nonalcoholic controls. All of the 7 alcoholics homozygous for the A1 allele were classified as severe. The average severity of alcoholism increased in the order A2/A2, A1/A2, and A1/A1 genotypes. These data suggest that the A1 allele is associated with severe alcoholism in the Japanese population and that the effect is related to or has a linkage disequilibrium with a genetic factor that has a small but not negligible additive effect on alcoholism.

Age Factors↗
PubMed1993

Data on the CGG repeat at the fragile X site in the non-retarded Japanese population and family suggest the presence of a subgroup of normal alleles predisposing to mutate.

The fragile X mutation is the result of amplification in the repeat number of p(CGG)n in FMR-1; alleles with more than 52 repeats have been shown to be so unstable as to mutate in the repeat number in almost every transmission. To improve our understanding of mutations in normal alleles of FMR-1, the following studies were carried out in the Japanese population: a study on length variation in the repeat to determine the allele distribution of the repeat length in a non-retarded population, family studies to observe new mutations in normal allele, and haplotype analyses with microsatellite markers flanking the repeat to confirm estimated mutation rates and founder chromosomes in the fragile X syndrome. Analysis of the p(CGG)n in 370 unrelated males detected 24 distinct alleles with repeats of 18-44. A comparison with previously reported data suggests the presence of racial/ethnic differences in the allele distribution. No premutation allele was found in 824 unrelated X chromosomes examined by the polymerase chain reaction and Southern blot analysis. Family studies detected one new mutation in a total of 303 meioses. However, the mutation rate was not in accordance with the expected or observed heterozygosities in the population or with linkage disequilibrium observed between the repeat numbers and the haplotypes of the markers flanking the CGG. The haplotype in the chromosome in which the new mutation was found was the same as that frequently found in the Japanese fragile X chromosomes, and the variance in the CGG repeat number was wider in chromosomes with the haplotypes frequently found in the fragile X chromosome than in those with the other haplotypes. These observations suggest that a subgroup is present in normal alleles and that this subgroup is more liable to mutate than others.

Alleles↗
PubMed1993

Fetal nucleated cells in maternal peripheral blood: frequency and relationship to gestational age.

To determine the frequency of fetal nucleated cells in maternal peripheral blood during different stages of pregnancy, 50 primigravidas were investigated by determining the frequency of cells with the Y chromosome using fluorescence in situ hybridization (FISH) of Y-specific repetitive sequences of the DYZ1 family. Polymerase chain reaction (PCR) amplifying the same part of the DYZ1 used as the probe in FISH and a single-copy Y-specific fragment was also carried out for genomic DNA from the same samples. Cells with the hybridization signal were detected by FISH at and after 15 weeks of pregnancy in all pregnant women who gave birth to boys. The ratio of cells with the signal to those without the signal ranged from 1 in 144,000 to 1 in 4,000 with a tendency to increase as the pregnancy advanced. The frequency of fetal cells estimated by the PCR experiments was significantly and positively correlated with that found by FISH. The present study suggests that fetal nucleated cells increase in maternal peripheral blood with advancing gestation, from less than 1 in 100,000 nucleated cells in the first trimester to around 1 in 10,000 at term. These frequencies were much lower than those reported by cytological methods.

Blood Cell Count↗
PubMed1993

Topographic pattern of the rearrangement of the dystrophin gene in Japanese Duchenne muscular dystrophy.

To compare the frequency and distribution of rearrangements in the dystrophin gene in Duchenne muscular dystrophy (DMD) between Japanese DMD patients and those in North America and Europe, Southern blot analyses of the dystrophin gene were carried out in 88 probands classified as DMD. Gene rearrangements were found in 61 (69%) subjects, and they were composed of partial gene deletions in 53 (60%) probands and partial duplications in 7 (8%) probands. A total deletion of the gene was found in 1 (1%) patient. Among 53 patients with deletions, 34 (64%) had breakpoints between introns 44 and 52 and 7 (13%) had breakpoints between introns 2 and 11. Both the frequency and the distribution of gene rearrangements found in this study were similar to those reported in North America and Europe. These data suggest that there are no ethnic or racial differences in the frequency and distribution of rearrangements thought to be caused by similar mechanisms in the dystrophin gene in all human racial groupings.

Adolescent↗
PubMed1993

High degree of genetic polymorphism in apolipoprotein(a) associated with plasma lipoprotein(a) levels in Japanese and Chinese populations.

We have developed a sensitive, high-resolutin method for the analysis of the apolipoprotein(a) [apo(a)] isoforms using sodium dodecyl sulfate (SDS)-agarose/gradient polyacrylamide gel electrophoresis. In an analysis of the genetic polymorphism of apo(a) isoforms and their relationship with plasma lipoprotein(a) [Lp(a)] levels in Japanese and Chinese, this method identified 25 different apo(a) isoforms and detected one or two apo(a) isoforms in more than 99.5% of the individuals tested. The apparent molecular weights of the apo(a) isoforms ranged from 370 kDa to 950 kDa, and 22 of the 25 different apo(a) isoforms had a higher molecular weight than of apo B-100. Studies on Japanese families confirmed the autosomal codominant segregation of apo(a) isoforms and the existence of a null allele at the apo(a) locus. The observed frequency distribution of apo(a) isoform phenotypes fit the expectations of the Hardy-Weinberg equilibrium in both the Japanese and Chinese populations. Our data indicate the existence of at least 26 alleles, including a null allele, at the apo(a) locus. The frequency distribution patterns of the apo(a) isoform alleles in Japanese and Chinese were similar to each other and also similar to that of apo(a) gene sizes reported in Caucasian American individuals. The average heterozygosity at the apo(a) locus was 92% in Japanese and 93% in Chinese. A highly significant inverse correlation was observed between plasma Lp(a) levels and the size of apo(a) isoforms in both the Japanese (r = 0.677, P = 0.0001) and the Chinese (r = -0.703, P = 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Alleles↗