A descriptive study of solitary death in Yokohama City

Abstract Background The solitary death rate in Japan is expected to continue increasing because of its growing super-aged society and the rapid growth of home care in the country. To accurately determine the actual status of solitary deaths, we used a novel analysis method of combining vital statistics and ambulatory care information in Yokohama City. Methods Data of persons who died at home in 2013 were obtained from death certificate notifications. We also obtained the emergency transportation records that matched the cases of these death certificate notifications. Then, we gathered information regarding age, gender, marital status, and cause of death for the matched cases. Results There were 1890 “suspected unnatural deaths,” in which most solitary deaths could be included, among all citizens who died at home (n = 4847). We were able to match 1503 of these cases with emergency transportation records. These 1503 cases were divided into two groups, “solitary death” (n = 349) and “un-solitary death” (n = 1154) according to the postmortem interval until finding (PMI-f). Pearson’s χ 2 tests conducted for the two groups revealed that there were significant differences regarding the proportion of persons who were elderly, unmarried, male, and had a hepatic disease and senility. A logistic regression analysis also showed that an increased likelihood of a prolonged PMI-f was associated with males and an unmarried status with hepatic diseases. Conclusions Unmarried, male sex, and liver diseases are independent risks for solitary death in Yokohama City

Non-polyalanine repeat mutation in PHOX2B is detected in autopsy cases of sudden unexpected infant death.

BackgroundCongenital central hypoventilation syndrome (CCHS), which is caused by PHOX2B with phenotypic variations, has a point of controversy: CCHS is putatively involved in autopsy cases of sudden unexpected infant death (SUID) including sudden infant death syndrome.ObjectiveThe relation of CCHS to SUID cases was investigated by extensive genotyping of PHOX2B.MethodsWe analyzed 93 DNA samples of less than one-year-old SUID cases that were autopsied in our department. Unrelated adult volunteers (n = 942) were used as the control.ResultsNo polyalanine tract expansion was detected in the SUID cases. The allelic frequencies of repeat contractions and SNP (rs28647582) in intron 2 were not significantly different from that in those control group. Further extensive sequencing revealed a non-polyalanine repeat mutation (NPARM) of c.905A>C in a sudden death case of a one-month-old male infant. This missense mutation (p.Asn302Thr), registered as rs779068107, was annotated to 'Affected status is unknown', but it might be associated with the sudden death.ConclusionNPARM was more plausibly related to sudden unexpected death than expansions because of severe clinical complications. This finding indicates possible CCHS involvement in forensic autopsy cases without ante-mortem diagnosis

MicroRNA Stability in FFPE Tissue Samples: Dependence on GC Content

<div><p>MicroRNAs (miRNAs) are small non-coding RNAs responsible for fine-tuning of gene expression at post-transcriptional level. The alterations in miRNA expression levels profoundly affect human health and often lead to the development of severe diseases. Currently, high throughput analyses, such as microarray and deep sequencing, are performed in order to identify miRNA biomarkers, using archival patient tissue samples. MiRNAs are more robust than longer RNAs, and resistant to extreme temperatures, pH, and formalin-fixed paraffin-embedding (FFPE) process. Here, we have compared the stability of miRNAs in FFPE cardiac tissues using next-generation sequencing. The mode read length in FFPE samples was 11 nucleotides (nt), while that in the matched frozen samples was 22 nt. Although the read counts were increased 1.7-fold in FFPE samples, compared with those in the frozen samples, the average miRNA mapping rate decreased from 32.0% to 9.4%. These results indicate that, in addition to the fragmentation of longer RNAs, miRNAs are to some extent degraded in FFPE tissues as well. The expression profiles of total miRNAs in two groups were highly correlated (0.88 <<i>r</i> < 0.92). However, the relative read count of each miRNA was different depending on the GC content (<i>p</i><0.0001). The unequal degradation of each miRNA affected the abundance ranking in the library, and miR-133a was shown to be the most abundant in FFPE cardiac tissues instead of miR-1, which was predominant before fixation. Subsequent quantitative PCR (qPCR) analyses revealed that miRNAs with GC content of less than 40% are more degraded than GC-rich miRNAs (<i>p</i><0.0001). We showed that deep sequencing data obtained using FFPE samples cannot be directly compared with that of fresh frozen samples. The combination of miRNA deep sequencing and other quantitative analyses, such as qPCR, may improve the utility of archival FFPE tissue samples.</p></div

Amplification efficiency of target genes.

<p>*Dynamic range represents the range of Cq values between the highest and the lowest concentration of generated standard curves.</p><p>Amplification efficiency of target genes.</p

Amplification efficiency of target genes.

<p>*Dynamic range represents the range of Cq values between the highest and the lowest concentration of generated standard curves.</p><p>Amplification efficiency of target genes.</p

MiRNA deep sequencing results.

<p>MiRNA deep sequencing results.</p

Target miRNA characteristics.

<p>Target miRNA characteristics.</p

Detection of smRNAs in frozen tissues.

<p>Average Cq values (Y-axis) of 8 smRNAs with various postmortem intervals (X-axis) are shown. Cq values for the miRNAs (dashed lines) appear to be more stable than those of other classes of smRNAs (solid lines). The mean value and standard deviation for each candidate smRNA are shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0129338#pone.0129338.t003" target="_blank">Table 3</a>.</p