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Biomedical subjects

Z Tun

Publications and source records attributed to Z Tun.

At least 19 recordsLinked to original sources
PubMed2001

Examination of Y-STR mutations in sex chromosomal abnormality in forensic cases.

The Y-STR typing was carried out on eight DNA samples (three from criminal cases) demonstrating Klinefelter's syndrome. STR types in the X chromosome were randomly distributed. However, some Y-STR markers were distributed within the normal range but restricted to only one or two specific alleles, that is, some specific haplotypes were found in Klinefelter's syndrome. In addition, a single nucleotide polymorphism in DYS390 (transversion of G to A at the 28th position downstream of tandem repeats) was detected in Klinefelter samples. This Y-STR polymorphism and restricted Y-STR alleles in Klinefelter's syndrome is not known, but it might be related to the genesis of Klinefelter's syndrome. We also found that extended standard haplotypes of these samples are extremely rare in the normal population, according to the Y-STR haplotype reference database (YHRD). The extended standard haplotype database in a Japanese population is also reported. In 100 unrelated Japanese, 89 haplotypes were observed, and the haplotype diversity was calculated to be 0.9866.

Crime↗
PubMed2001

Identifying sex chromosome abnormalities in forensic DNA testing using amelogenin and sex chromosome short tandem repeats.

Forensic DNA laboratories worldwide have begun using multiplexed STR systems to decrease analysis time and increase sample throughput. The loci used in these systems are basically "nonsense" regions of human DNA. However, due to the chromosome on which some of these loci are located, various genetic abnormalities can sometimes be detected. This paper will show one such abnormality--Klinefelter's Syndrome--and the process used to show the possibility of this defect in two undiagnosed males using peak height ratios at the Amelogenin locus, and X-Y STRs.

Amelogenin↗
PubMed2001

DNA testing of Klinefelter's syndrome in a criminal case using XY chromosomal STR multiplex-PCR.

We report genetic typing of Klinefelter's syndrome applied to casework in forensic DNA testing. In this case, by using extracted DNA from body samples (muscle and bones), we could identify two distinct X alleles in two out of three X-STR loci (HPRTB and ARA), in addition to Y alleles (DYS390, DYS393). The extra X was found to have originated from father, and the victim turned out to have 47XXY Klinefelter's syndrome. The victim was a 30-year-old male, born from relatively elderly parents as a second child. His father was a severe alcoholic and had been malnourished for more than 20 years at the moment of his birth. He exhibited slight mental retardation as a child, and belonged to a criminal group as an adult. The method presented here was useful to accurately diagnose sex chromosomal abnormality instead of conventional chromosomal analysis and Xg blood group typing. A subtype of this syndrome, 48 XXXY or mosaic, for example, could be identified if the intensity of the overlapped X bands were calculated.

Adult↗
PubMed2000

A model for diffraction from MCM-41 materials

A model involving only a small number of parameters provides a convenient way of interpreting diffraction patterns from MCM-41 materials. Each parameter of the model has a clear physical meaning, and this approach is clearly superior to extracting pore structure information by fitting Gaussians to an observed diffraction pattern.

Journal Article↗
PubMed2000

A novel mutation of the KAL1 gene in monozygotic twins with Kallmann syndrome.

OBJECTIVE: Kallmann syndrome is defined by the association of hypogonadotropic hypogonadism and anosmia. The KAL1 gene is responsible for the X-linked form of Kallmann syndrome. In this study we describe monozygotic twins with Kallmann syndrome due to the same mutation in the KAL1 gene. DESIGN: We studied male monozygotic twins with Kallmann syndrome. METHODS: We analyzed the KAL1 gene using the PCR-direct sequencing method. The twins' mother was examined for the identified mutation. RESULTS: We identified a 14 bp deletion from codon 419 in exon 9 (Pro419del14) in both KAL1 genes of the twins. This was a novel mutation in the KAL1 gene and was responsible for Kallmann syndrome. As Pro419del14 was not detected in the mother of the twins, Pro419del14 was a germline mutation originating from them. These monozygotic twins showed different LH and FSH responses to LH-RH stimulation and different phenotypes such as complications, physiques and psychiatric characters. CONCLUSIONS: We report an identical KAL1 gene mutation in the monozygotic twins with Kallmann syndrome. As these monozygotic twins showed different phenotypes in some respects, we suggest that factors other than mutations in the KAL1gene affect the symptomatic features of Kallmann syndrome.

Adult↗
PubMed1999

Simultaneous detection of multiple STR loci on sex chromosomes for forensic testing of sex and identity.

The forensic usefulness of X and Y chromosomal STR loci has recently been demonstrated. One quadruplex-PCR, using 2 X- and 2 Y-STRs (STRX1/HPRTB and DYS390/ DYS393), and 2 duplex-PCRs, each using an X- and a Y-STR (ARA/DYS390 and ARA/DYS393), and detection of PCR products by using an automated DNA sequencer are reported herein. This approach allows us to determine not only the sex of the donor of a sample, but also the X- and/or Y-STR genotypes of the sample. A male biological specimen yields 4 amplified products in quadruplex-PCR and 2 amplified fragments in duplex-PCRs, whereas a female biological specimen yields only 2 amplified fragments of X-STR in quadruplex-PCR and one fragment, also of X-STR, in duplex-PCRs. Our study thus provides useful information for many activities in forensic practice, such as identity testing, paternity testing, especially of deficiency cases, compilation of population data, and sex determination of a biological sample from a single PCR.

Alleles↗
PubMed1998

Detection and analysis of four polymorphic markers at the human monoamine oxidase (MAO) gene in Japanese controls and patients with Parkinson's disease.

Monoamine oxidase (MAO), which exists in two forms (MAOA and MAOB), plays an important role in the oxidative metabolism of neurotransmitters such as dopamine, and has been implicated in the etiology of Parkinson's disease (PD). Individual variations in the activity of these enzymes appear to be genetically determined, and these genetic variations appear to be predominantly mediated by the MAO locus. Here, we detected and analyzed four polymorphic markers in the MAO gene using a polymerase chain reaction method in 228 Japanese controls (102 males and 126 females) and 68 patients with PD (30 males and 38 females). Although the analysis of the MAOA marker demonstrated no overall association between its alleles and PD, a significant difference in the frequency of one particular MAOA allele between controls and patients with PD was found. Moreover, in a comparison of the distribution of the full haplotypes at the MAOA locus, there was a significant difference in the frequency of one particular haplotype between male controls and patients with PD. In the MAOB polymorphism, there was no difference in the distribution of alleles between them. These findings support the hypothesis that the MAOA gene may affect the susceptibility of individuals to PD among MAOA polymorphic loci.

Adult↗
PubMed1998

Comparison of a hypervariable segment in the human dopamine D4 receptor (DRD4) gene between the Japanese and Mongolian populations.

Amplifiable length polymorphism (AmpFLP) genotyping and direct sequencing of a hypervariable segment in the human dopamine D4 receptor (DRD4) gene were performed from genomic DNA of 100 unrelated Japanese and Mongolian individuals. The 4-repeat allele (314 bp) was the most prevalent and appeared at 0.88 and 0.82 in the Japanese and Mongolian populations, respectively. Homogeneity test of distribution showed no significant deviation from the observed frequencies of genotypes between the Japanese and Mongolian populations, but sequence analysis of the 4-repeat allele indicated that there could be ethnic differences between the two populations at the nucleotide level. The DRD4 allele and genotype frequencies in 10 patients with Parkinson's disease did not differ from those in the control Japanese population. In one Parkinsonian patient, however, a nucleotide change in one of the 4-repeat alleles was discovered. These results suggest that there could be ethnic and/or individual differences in the specific nucleotide changes within the repeat sequence because some alleles with the same number of repeat units had sequence variations. Thus, the DRD4 polymorphism exists at two levels and therefore could be a useful marker for forensic identification and anthropological studies.

Alleles↗
PubMed1997

An electrocution death of an infant who had received an electric shock from an uncovered oval shaped lamp switch in his mouth while in a hospital.

A male infant aged one year and nine months was found dead on a bed after admission to hospital with suspected pneumonia. The patient apparently put an uncovered oval shaped lamp switch (pendant switch) into his mouth and died of electric shock after contacting the exposed wires of the switch (100 V, 60 Hz alternating current). There were extensive first- to fourth-degree burns on the inner surface of the both lips. Because the histological findings were consistent with electric burns and the burns showed vital reactions, electric shock was judged to be the cause of death. The pendant switch is normally a very convenient piece of bedside equipment for inpatients. However, when the patient is an infant who naturally puts all the objects into the mouth, such a switch should be placed out of reach, and it should be certain that the cap is not loose.

Burns, Electric↗
PubMed1996

Detection and analysis of the human D4 dopamine receptor gene (DRD4) sequence variant in the Japanese and Mongolian population.

A PCR-based Sma I restriction fragment length polymorphism (RFLP) in the human D4 dopamine receptor (DRD4) gene was investigated in 200 subjects each of Japanese and Mongolian populations. When compared to allele frequencies for Caucasians previously reported by Petronis et al., Japanese and Mongolian populations showed a decreased frequency of the allele which could not be digested with Sma I. The difference in allele distributions between these two ethnically defined populations (Japanese and Mongolians, and Caucasians) was statistically significant (p<0.05). This RFLP was suggested to be a racial difference between Asian and European populations. However, since the frequency of the non-digested allele was extremely low (1%) in the Asian populations, we cannot exclude the possibility that this allele represents a mutation. Sma I PCR-RFLP typing would not only be one of genetic markers, but might also be a specific marker for searching some neuropsychiatric abnormalities.

Alleles↗
PubMed1996

Determination of ester-type local anesthetic drugs (procaine, tetracaine, and T-caine) in human serum by wide-bore capillary gas chromatography with nitrogen-phosphorus detection.

A sensitive method for simultaneous determination of ester-type local anesthetic drugs (procaine, tetracaine, and T-caine) has been developed using wide-bore capillary gas chromatography with nitrogen-phosphorus detection (GC-NPD). The extraction procedure, the experimental conditions for heptafluorobutyryl (HFB) derivative formation, and the percentage of the ester-type local anesthetic drugs from the human serum are described. The HFB derivatives of ester-type local anesthetic drugs showed sensitivity of approximately 2-3 fold higher than that without derivatization. The detection limits of HFB derivatives of the ester-type local anesthetic drugs were approximately 60-70 pg on column. Recoveries from the human serum were 85-94%. This method could be used to determine concentrations as low as 24-28 ng/mliters of the ester-type local anesthetic drugs.

4-Aminobenzoic Acid↗
PubMed1996

Genetic polymorphism of the 3' VNTR region of the human dopaminergic function gene DAT1 (human dopamine transporter gene) in the Mongolian population.

The hypervariable region of the dopamine transporter gene (DAT1) was amplified from samples in the Mongolian population. This region includes a variable number of tandem repeats of a 40-bp core unit in the 3' untranslated region of DAT1. Vandenbergh et al. (1992) reported variability in the number of repeats of this 3' flanking region ranging from 3 to 11 times in white and black populations. We examined polymorphism at the DAT1 locus in 78 native Mongolian subjects. We found alleles with 7 to 13 repeats, which is different from the findings of Vandenbergh et al. (1992). The allele distribution of the Mongolian population is similar to that in the Japanese population, reported previously by Nakatome et al. (1995). Chi-square analysis showed a significant lack of homogeneity between our findings in Mongolian subjects and those reported previously in white and black populations. The DAT1 locus was estimated to have a heterozygosity index of 14.1%, and the polymorphic information content was calculated to be 0.16.

Base Sequence↗
PubMed1996

Rapid and clear detection of ABO genotypes by simultaneous PCR-RFLP method.

We reported a new approach of ABO genotyping by a polymerase chain reaction and restriction fragment length polymorphism method. Instead of amplifying the loci containing the positions of nucleotides 258 and 700 of cDNA of the A transferase separately, we successfully amplified these 2 loci together in one reaction mixture using 2 sets of primers. The amplified DNA products were digested at the same time with restriction enzymes Kpn I and Alu I. The digested DNA products were then separated by electrophoresis on polyacrylamide gel. In addition, we evaluated the influence of various amplification parameters (concentration of template DNA, primers, Taq DNA polymerase, MgCl2, and number of cycles). In particular, high Mg2+ concentration (3.5 mM) made effective amplification of this locus without producing any unspecific band. By using that optimized condition for PCR, together with a simultaneous approach, our study proved to be time saving, more economic, and convenient in interpreting the results.

ABO Blood-Group System↗