Allele frequencies of 31 autosomal short tandem repeat (auSTR) loci obtained using the Precision ID GlobalFiler™ NGS STR Panel v2 in 322 individuals from the Japanese population.

In human identification methods that target short tandem repeats (STRs), massively parallel sequencing (MPS) technology has made it possible to genotype at the level of the specific sequence itself. This allows for the detection of repeat unit variants and single nucleotide polymorphisms (SNPs) adjacent to the STRs. Using the GlobalFiler™ NGS STR Panel v2, Ion S5, and Converge software, this study constructed a Japanese database of 31 autosomal STRs (auSTRs) and two sex markers from 322 individuals. After excluding some sequence errors and stutters, a total of 31 novel alleles were identified. Additionally, using the allele frequencies of 31 auSTR loci, the match probabilities for the length-based and sequence-based data were calculated to be 1.433 × 10-34 and 9.163 × 10-38, respectively. These values are at least nine orders of magnitude higher than that obtained from 21 auSTR loci in the Japanese population using the conventional capillary electrophoresis method. The database generated in this study is expected to be implemented in forensic practice and used to solve difficult casework.

Evaluation of the Utility of Mitochondrial DNA Testing in Personal Identification Work in the Great East Japan Earthquake of 2011.

Although the Great East Japan Earthquake occurred on March 11, 2011, identification of victims is still ongoing. Typically, mitochondrial DNA (mtDNA) is performed when it is difficult to identify an individual using nuclear DNA. In Japan, samples from criminal investigations are subjected to nuclear DNA testing at the Scientific Research Institute belonging to each prefectural police headquarters, while all mtDNA tests were originally conducted at the National Research Institute of Police Science. However, the appraisal work using mtDNA became more time-consuming as the number of target samples increased. Because our department is capable of performing mtDNA testing, the Miyagi Prefectural Police requested that our department perform mtDNA testing. Specifically, we focused on 16 individuals as putative candidates for 11 unidentified human remains; efforts to identify these remains were performed using samples from 20 relatives. These efforts positively identified six victims. This included confirmation that one corpse had originally been identified incorrectly. Although disasters of a similar scale can strike Japan again, there are limited facilities that can consistently perform mtDNA testing. Expensive sequencing machines and properly trained operators are essential for mtDNA testing, but they cannot be established at the forensic departments of all medical schools. There is thus an urgent need to establish core facilities at appropriate sites, such as Tohoku University in the Tohoku Region, to build a mtDNA testing system suitable for the aftermath of any disaster.

The protein phosphatase 6 catalytic subunit (Ppp6c) is indispensable for proper post-implantation embryogenesis.

Ppp6c, which encodes the catalytic subunit of phosphoprotein phosphatase 6 (PP6), is conserved among eukaryotes from yeast to humans. In mammalian cells, PP6 targets IκBε for degradation, activates DNA-dependent protein kinase to trigger DNA repair, and is reportedly required for normal mitosis. Recently, Ppp6c mutations were identified as candidate drivers of melanoma and skin cancer. Nonetheless, little is known about the physiological role of Ppp6c. To investigate this function in vivo, we established mice lacking the Ppp6c phosphatase domain by crossing heterozygous mutants. No viable homozygous pups were born, indicative of a lethal mutation. Ppp6c homozygous mutant embryos were identified among blastocysts, which exhibited a normal appearance, but embryos degenerated by E7.5 and showed clear developmental defects at E8.5, suggesting that mutant embryos die after implantation. Accordingly, homozygous blastocysts showed significant growth failure of the inner cell mass (ICM) in in vitro blastocyst culture, and primary Ppp6c exon4-deficient MEFs showed greatly reduced proliferation. These results establish for the first time that the Ppp6c phosphatase domain is indispensable for mouse embryogenesis after implantation.

An autopsy case of death due to metabolic acidosis after citric acid ingestion.

A man in his 40s was found unconscious on a sofa in a communal residence for people with various disabilities. He appeared to have drunk 800 ml of undiluted citric acid from a commercial plastic bottle. The instructions on the label of the beverage specified that the beverage be diluted 20- to 30-fold before consumption. The patient was admitted to an emergency hospital with severe metabolic acidosis (pH, 6.70; HCO3(-), 3.6 mEq/L) and a low ionized calcium level (0.73 mmol/L). Although ionized calcium and catecholamines were continuously administered intravenously to correct the acidosis, the state of acidemia and low blood pressure did not improve, and he died 20 h later. Citric acid concentrations in the patient's serum drawn shortly after treatment in the hospital and from the heart at autopsy were 80.6 mg/ml and 39.8 mg/dl, respectively (normal range: 1.3-2.6 mg/dl). Autopsy revealed black discoloration of the mucosal surface of the esophagus. Microscopically, degenerated epithelium and neutrophilic infiltration in the muscle layer were observed. In daily life, drinking a large amount of concentrated citric acid beverage is rare as a cause of lethal poisoning. However, persons with mental disorders such as dementia may mistakenly drink detergent or concentrated fluids, as in our case. Family members or facility staff in the home or nursing facility must bear in mind that they should not leave such bottles in places where they are easily accessible to mentally handicapped persons.

Sudden, unexpected infant death due to pulmonary arterial hypertension.

A 3-year-old girl with no particular medical history complained of a stomachache and died on the way to the hospital. The autopsy revealed marked right ventricular hypertrophy and dilation with no other cardiac abnormalities. Microscopically, the pulmonary small arteries showed marked medial hypertrophy and varying degrees of intimal and adventitial thickening. We supposed that the cause of death was attributable to pulmonary arterial hypertension (PAH). PAH is a rare disease that can cause sudden, unexpected death at any age. Forensic pathologists should consider PAH in the differential diagnosis of sudden death.

Sex-related differences in the expression of mfGSTA2, a novel GST identified in cynomolgus monkey (Macaca fascicularis).

Glutathione S-transferase (GST) is one of the most important phase II drug-metabolizing enzymes, catalyzing the conjugation of electrophilic substrates to glutathione. Unlike in humans, a surprisingly limited number of GST genes have been identified in monkeys. The identification of additional GST genes in this model system would prove to be advantageous, because monkeys remain an important predictor of drug effects and toxicities in humans during preclinical studies. In this study, we report the identification and characterization of the following six cDNAs in cynomolgus monkeys: mfGSTA1, mfGSTA2, mfGSTM5, mfMGST1, mfGSTO1, and mfGSTZ1. These cDNAs encode GSTs highly homologous (approximately 95%) to human GST cDNAs. Among these, the mfGSTA1, mfGSTM5, mfMGST1, mfGSTO1, and mfGSTZ1 cDNAs correspond to a single human GST counterpart, whereas the mfGSTA2 cDNA is highly similar to human GSTA1 and GSTA2 cDNAs. An analysis of tissue samples indicates that these GST genes are predominantly expressed in the liver along with some extrahepatic expression as determined by real-time reverse transcriptase-polymerase chain reaction. It is interesting to note that mfGSTA2 is significantly differentially expressed between males and females in the jejunum, where a striking 8-fold higher expression level is observed in males. These results suggest that a potential sex difference in the metabolism of drugs may be mediated by mfGSTA2. This also provides a basis for the investigation of sex-dependent drug metabolism in monkeys.