Biomedical subjects
Publications and source records attributed to M Nata.
Genotype and distribution of allele frequencies at 17 STRs were studied in 526 unrelated Japanese individuals using the PowerPlex 16 system and the AmpFlSTR Identifiler.
A 16-year-old girl with short stature, short neck, shield chest, and cubitus valgus was studied. FISH analyses of her structurally altered X chromosome showed a der(X)- (wcpX+,TelXp/Yp++,SHOX++,STS++,KAL-, 37A12-,DXZ1+,XIST++,97L7++,300O13-,404F- 18-,417G15-,404F18-,140A-,TelXq/Yq-). These results, together with the high-resolution banding analysis, indicated her karyotype to be 46,X,der(X)(Xpter-->Xp22.3::Xq22.3--> cen-->Xq22.3::Xp22.3-->Xpter). The der(X) was an isochromosome, consisting of duplicated terminal short arms and duplicated proximal long arms. This in turn suggested that the chromosome was formed through pericentric inversion of an X chromosome, followed by isochromosome formation through sister chromatid exchange at Xp, close to the centromere. Replication R-banding analysis showed that the abnormal X chromosome was late replicating. Analysis of digestion patterns with a methylation-sensitive restriction endonuclease of the phosphoglycerate kinase 1 gene, located in Xq13.3, indicated that its inactivation patterns were completely skewed.
To investigate X chromosome inactivation (XCI) patterns in 45,X/46.XX mosaics, genomic DNA was extracted from peripheral blood samples of 15 female subjects who showed different proportions of 45,X cell clones. XCI patterns were analyzed using two assays. The first assay was the BstXI restriction endonuclease detection of an X-linked phosphoglycerate kinase (PGK) gene polymorphism following digestion of the DNA with methylation-sensitive HpaII, or with methylation-insensitive AfaI as a control. The second assay was the detection of a CAG triplet repeat polymorphism in the X-linked androgen receptor (AR) gene after sodium bisulfite treatment. Of the 15 subjects, 11 were informative due to heterozygosity for at least one of the polymorphisms (6 were heterozygous for the PGK polymorphism and 9 were heterozygous for the AR polymorphism). Four of the 11 informative subjects (36%) showed extremely skewed XCI for at least one of the polymorphisms, which was a much higher incidence than previously reported for normal females. Moreover, 3 of these 4 women had proportions of 45,X cell clones greater than 20%. Although our results may be due to several possible cytogenetic or molecular mechanisms, the most likely explanation is that cases of 45,X/46,XX that contain relatively high levels of 45,X cell clones probably arose due to structural aberrations of the X chromosome undetectable by conventional karyotyping.
A 35-year-old woman, a chronic alcoholic, died from an intracerebral haematoma 10 hr after she fell downstairs. Some subcutaneous bleeding was seen on the head and face, but there were no new skull fractures and surface contusions of the brain. She appeared to have few predisposing conditions for non-traumatic cerebral haemorrhage. In addition, the haematoma was mainly located "lateral" to the basal ganglia, not where hypertensive bleeding most commonly occurs, and subdural and haemorrhage in the corpus callosum was found with subdural/and subarachnoid haemorrhage. We concluded that on falling a shearing strain from a rotating force produced the intracerebral haemorrhage, but without skull fractures and surface contusions of the brain. She had been admitted to a neurosurgical hospital just 11 months before this incident because of an epidural haemorrhage with left temporal bone fracture. Mild thrombocytopenia was found during that hospitalization. In this report, this abnormality was thought to have some relation to the formation of the huge haematoma occurring after the intracerebral bleeding started.
Diatom concentrations in seawater were examined monthly at four aquatic areas. Diatom concentrations inside a bay showed a monthly variation, but these were detectable. On the other hand, in the open sea around the continental shelf break, there were few diatoms in any season. When a person drowns in the open sea, the diatom test cannot be expected to function reliably.
Interleukin-6 (IL-6) has been considered as an important mediator of inflammation. Clinically it is a well-known marker of the severity of injury following major trauma. In this study, the levels of IL-6 in body serum were applied to a traumatic death index. Of ninety victims 55 were men and 35 women, with a mean age of 53.4+/- 19 (S.D.) years. The cases were classified as traumatic deaths (38 cases), non-traumatic deaths other than natural causes of deaths (36 cases), and deaths due to natural causes (16 cases). All samples were collected within 2 days after death. The mean values of IL-6 levels of the traumatic, non-traumatic and disease groups were 8608.97, 2205.65, and 3266.64 pg/ml, respectively. Some cases in non-traumatic and disease cases were beyond 10 000 pg/ml, however, the mean value of the traumatic group was statistically higher than that of the other two groups. Even though several cases had high levels of IL-6 in spite of instantaneous death, the results showed that IL-6 levels are helpful in the diagnosis of traumatic shock.
To assess the power and significance of the likelihood ratio (LR) and the identity-by-state scoring (IBS) methods for a pair of siblings, we performed computer simulations by use of 10 DNA markers (HLA-DQalpha, D1S80, and 8 short tandem repeat loci) that were frequently analyzed in paternity tests in Japan. The combined power of discrimination of these 10 markers in the Japanese population is 0.999 999 999 98. Pedigrees each consisting of 10,000 pair of full-siblings, half-siblings and unrelated individuals were generated and typed on all markers as random samples. Both the summation of log10 LR and IBS of each group had approximate standard normal distribution with significant differences between the means. Statistical studies showed that the LR method has 91% power to detect unrelated individuals and 38% power to detect half-siblings as not full-siblings with a 5% false-positive rate, whereas the IBS method does 87% and 42% powers, respectively. In 62% of full-siblings, in contrast with only 0.2% of unrelated individuals, the values of LR exceeded 100 which was equivalent to 0.99 of probability of full-sibship at 50% prior probability. The advantage of the LR method over IBS method was convincing especially for the detection of unrelated individuals as not half-siblings, however, the latter would be also informative for sib-pair tests if sufficient number of polymorphic markers are available.
We report a case of infant death due to scurvy, which is very rare in Japan. We initially had little knowledge of the disease and suspected that the bleeding in the body was caused by domestic violence. The case did not fall under the category of the battered child syndrome but the death was caused by ignorance with respect to child care. In addition the parents usually locked the child alone in a room during the day and this is probably a case of neglect.
To investigate X-chromosome inactivation (XCI) in human trophoblasts during early pregnancy, trophoblast genomic DNA was extracted and analyzed for a Bst XI restriction endonuclease site polymorphism in the X-linked phosphoglycerate kinase gene, after digestion with methylation-sensitive Hpa II (control samples were digested instead with Afa I). Six villous trophoblast DNA samples were informative for the polymorphism (ie, heterozygous) and were derived from women homozygous for the polymorphism. These samples were then evaluated for XCI. In five of the six samples with Hpa II predigestion, the sizes of the two heterozygous band peaks differed; maternal X-chromosome (X(M))-derived alleles showed smaller peak sizes than paternal X-chromosome (X(P))-derived alleles, but the differences varied in degree. In samples obtained by microdissection from formalin-fixed, paraffin-embedded tissues (30 samples from different anchoring villi, and 38 samples from different branch villi), monoclonal band patterns of X(P)-derived alleles were observed more frequently than those of X(M)-derived alleles, but almost half of the samples showed polyclonal patterns. Our results suggest that a skewing of XCI exists in the human trophoblast; however, the degree of nonrandomness due to predominant X(P) inactivation appears to be restricted. It is probable that transcription of the X inactivation center (XIC) begins earlier in mice than in humans.
Dental identification is a useful scientific method. In Japan, however, there are only a few forensic odontologists; moreover, until now, forensic dental services have only been offered by general dentists. These dentists may not be able to offer such forensic services during office time. For a quick comparison, the authors tried sending digital photos, taken with a 2-million-pixel digital camera, to dental offices via the Internet. If a dental office has Internet access, it is possible for dental charting to be sent directly to the autopsy room. Of course, digital images only provide the first outline. However, when antemortem dental records of the person in question are available at autopsy, a quick comparison can be made.
We describe a unique patient with complete androgen insensitivity syndrome and a 47,XXY karyotype. Androgen receptor assay using cultured pubic skin fibroblasts showed no androgen-binding capacity. Sequence analysis of the androgen receptor gene demonstrated two nonsense mutations, one in exon D and one in exon E. Microsatellite marker analysis showed that the patient is homozygous for all five Xq loci examined. The results suggest that the long-arms of the two X chromosomes are identical, i.e., uniparental isodisomy at least for Xq, and carry the same mutations in the androgen receptor gene. This explains how complete androgen insensitivity syndrome occurred in this 47,XXY individual.
Allele frequencies for the eight STR loci Hum-CSF1P0, F13A01, F13B, FES/FPS, LPL, TH01, TPOX and VWA were investigated in Japanese and Chinese populations. No significant deviations from Hardy-Weinberg equilibrium could be found for all loci. In the Japanese population VWA, CSF1PO, TH01, FES/FPS and TPOX were found to be useful for forensic applications and in the Chinese population, VWA, CSF1PO, TH01 and TPOX were found to be useful. Allele distributions were similar between both populations except for FES/FPS.
We present a German Y-chromosome short tandem repeat (STR)-haplotype database consisting of the loci DYS19, DXYS156-Y, subtypes of DYS389, DYS390, DYS391, DYS392 and as well as DYS393. 104 haplotypes were observed in 179 unrelated Germans, the haplotype diversity is 98.06%. This database is a prerequisite for the forensic application of these new markers.
Terminal deoxynucleotidyl transferase(TdT)-mediated dUTP-digoxigenin nick end labeling (TUNEL) assay is useful to detect apoptotic cells in situ. We examined by hematoxylin-eosin (H-E) and TUNEL assay whether or not postmortem delay affects the development of apoptotic signals of cells in various organs. Wistar Imamichi rats were radiated by X-ray and sacrificed six hours after radiation. The spleen, thymus, adrenal and testis were excised and kept in a moist chamber at room temperature. Each tissue was fixed after different time intervals 0, 6, 12, 24 hours and paraffin-embedded sections were made. In the no-radiation group, a few of TUNEL positive cells were observed in the spleen, thymus and testis sections, but not in the adrenal. No increase in the number of apoptotic cells was observed with postmortem delay. In the radiation group, we observed in the spleen and thymus, much increase in the number of TUNEL positive cells, of which nuclei were clearly and deeply stained, corresponding to the area where shrinking nuclei were observed in H-E section. In testis sections, there was a little increase in the number of positively stained cells, and no change was observed in H-E section. With postmortem delay, the margin of the TUNEL positive cells changed from clear to indistinct, and the positive area was spread around. Our results show that it is difficult to distinguish apoptotic cells from postmortem change. It is possible, however, to detect TUNEL positive cell together with postmortem changes as the spread of the TUNEL positive area after 24 hours postmortem delay. It is important to consider the effect of the postmortem change when we adapt TUNEL assay to autopsy cases.
Simple and rapid detection of HLA-DRB polymorphism has been performed using AMPLICOR HLA-DRB Typing Kit. We tried to apply this kit to various forensic samples. When DNA was extracted from the forensic samples using conventional phenol-chloroform method, addition of 7.5 mM MgCl2 was required to PCR amplification. HLA-DRB types were detected from DNA more than 0.1 ng by PCR amplification. Typing of unrelated 50 Japanese showed 38 different patterns, of which 30 patterns occurred once in the group. A total of 16 serotypes were deduced from the HLA-DRB DNA types. Out of them, high frequency serotypes were DR4 (24%), DR9 (18%) and DR15/16 (14%). This kit was very useful in forensic cases such as rape and in paternity cases. When we tried to detect HLA-DRB types from a single hair shaft of 3 cm in length, we were successful in detection from only one of five persons.
OBJECTIVE: To describe a woman with Turner syndrome with ring X chromosome mosaicism who had a child who possessed the same ring X chromosome. DESIGN: Polymorphisms of genes located on the X chromosome from genomic DNA of the mother, father, and the child were evaluated. PATIENT(S): The mother's karyotype was 45,X [48]/46,X,r(X)(p22.3q27) [2], and the child's karyotype was 45,X[33]/46,X,r(X)(p22.3q27) [17]. INTERVENTION(S): Polymerase chain reaction was used to amplify short tandem repeats from the loci of the hypoxanthine phosphoribosyltransferase gene and the androgen receptor gene. RESULT(S): Alleles for both genes in the child originated from both parents in a heterozygous fashion. The alleles originating from the mother originated from the ring X chromosome. However, the amount of amplified DNA was less than that of a normal X chromosome. CONCLUSION(S): The ring X chromosome of the mother was most likely transmitted to the newborn. Thus, an ovum with the ring X chromosome can be fertile and can produce a viable zygote.
We report a study of polymorphism for seven short tandem repeat (STR) loci in Japanese and Chinese populations. Among 104 to 134 individuals in the both population samples, eight alleles were revealed for locus PLA2, thirteen for D3S1359, eleven for FGA, eight for D8S315 (kw38), ten for D8S1132, five for CYP19, and seven for D3S2459. They correspondingly constituted 10 to 39 genotypes therein. For most of the STRs, there was only a single allele active as the most frequent one among the others, except locus D3S1359 in Chinese samples (two alleles, 206 bp and 210 bp, frequency = 0.273 each). Also, the population genotype configurations were locus specific, varying in the patterns of commonest genotypes on each locus, e.g., one pattern for loci CYP19, D3S1359, and D8S315, one and two for loci PLA2 and D3S2459, two for locus D8S1132, and one and four for locus FGA. The distributions of observed genotypes were in Hardy-Weinberg Equilibrium. Furthermore, the seven STRs were exhibited highly polymorphic and informative for the both populations, and the alleles could be easily separated in electrophoresis and correctly interpreted with side-to-side allelic ladders. Together, the results suggest that the tri- and tetra-meric STRs are useful genetic markers for forensic practice.
The PCR-direct sequence method was applied to ABO genotyping. At the 261st nucleotide of the genes of A and B glycosyltrasferase, it was easily detected that the nucleotide was guanine in AA, AB and BB genotypes and that the nucleotide was ademine in only OO. In AO and BO, substitution of A to G was confirmed by the dye primer method, but it was difficult to detect correctly by the dye terminator method. At the 297th, nucleotide substitution between A and B alleles was confirmed by the both methods. As this position, O allele was subdivided into three types, OAOA, OGOG and OAOG. At the 703rd, nucleotide substitution between A and B alleles was easily detected by the both methods. The PCR-direct sequence method was suitable to confirm the nucleotide substitution or deletion directly and to prevent the mistyping by other methods.