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The annual number of suicides in Japan totaled around 23,000 in 1997 and abruptly increased to around 31,000 in 1998. This figure has remained high since then. This abrupt increase in the number of suicides was primarily due to an increase in suicides occasioned by economic concerns. The association between various economic factors and suicide must be studied in detail and over the long term in order to ascertain the association between economic concerns and suicide. This study examined the relative poverty rate and the suicide rate in Japan over 30 years and discussed the association between those two rates. The results suggest that the relative poverty rate may be associated with the suicide rate for both sexes. This association is true for men in particular. The organizations and professionals involved in implementing suicide prevention measures should be cognizant of the current findings and consider formulating additional specific measures.

In the present study, we used micro-Raman spectroscopy with high-resolution analysis to discriminate between bloodstains from infants and bloodstains from adults. Raman peaks were detected at 674, 754, 976, 1002, 1105, 1127, 1176, 1248, 1340, 1368, 1390, 1560, and 1611 cm1; these peaks were derived from hemoglobin, albumin, and glucose. However, a peak was obtained at 1105 cm1, which was assigned to histidine; this peak was observed only for bloodstains from adults. Human adult hemoglobin (HbA) is composed of an a2b2 tetramer structure, whereas human fetal hemoglobin (HbF) is composed of an a2c2. Therefore, the lack of a Raman peak at 1105 cm1in bloodstains from infants indicates the possibility of two histidine substitutions (His116Ile and His143Ser) in the y chain of HbF. This study discriminates between bloodstains from infants and bloodstains from adults using micro-Raman spectroscopy, with beneficial implications in forensic science.

The measurement of blood carboxyhemoglobin (CO-Hb) is important to determine the cause of death. The AVOXimeter 4000 (AVOX), a portable CO-oximeter, has the advantages of a low purchase price and operating cost, ease of operation, and rapid results. Little information is available on the usefulness of AVOX in the forensic sample, and the previous study investigated only six samples. Therefore, in this study, we confirmed the usefulness of the AVOX through a comparison of its results with data previously obtained using the double wavelength spectrophotometric method in autopsies. Regression analysis was performed between CO-Hb levels measured by the AVOX and those measured by the conventional double wavelength spectrophotometric method in postmortem blood samples: a significant correlation was observed. This study suggests the usefulness of the AVOX to analyze postmortem blood, and the AVOX is suitable for routine forensic analysis and can be applied at the crime scene.

We devised a simple DNA extraction procedure suitable for STR typing of urine sample. Use of a commercially available DNA/RNA extraction kit equipped with a silica-gel-based membrane made it possible to omit the recovery of urinary nucleated cells by sedimentation before the extraction. Successful genotyping of the TH01, HumTPO and multiplex STRs was achieved using aliquots of urine as small as 100 microL. Furthermore, application of this DNA extraction procedure to frozen urine samples provided STR allele results comparable to results obtained from fresh samples. Therefore, this extraction procedure is considered to be effective for STR typing of urine samples in both the frozen and aqueous state. Furthermore, addition of sodium azide to fresh urine samples prolonged their storage duration even at room temperature.

We describe the use of deoxyribonuclease I (DNase I) polymorphism for individualization of semen in body fluid stain mixtures, as a means of providing new and more useful information to practicing forensic biologists as a genetic marker. We have already reported that human DNase I isozyme patterns from different subjects are classifiable into ten groups. Isoelectric focusing of DNase I isozymes on polyacrylamide gel (IEF-PAGE, pH 3.5 to 5) was accomplished using a 0.5 mm thick gel. Pretreatment of semen samples with neuraminidase enhanced the isozyme band resolution and sensitivity. Activity detection using the dried agarose film overlay (DAFO) procedure was reliable, sensitive and simple, with high resolution, and the phenotypes of DNase I were determined in semen stains of about 0.3 microL stored at room temperature for up to a year in most of the samples tested. The DNase I types in semen stains were correlated with the types found in the corresponding blood and urine samples, although most of the vaginal fluid samples had no typable DNase I activity. This is considerably advantageous for seminal individualization from body fluid mixture stains in criminal cases. An evaluation of DNase I typing by IEF-PAGE and DAFO was also performed on casework samples submitted to our laboratory, and the results showed that DNase I was expected to be one of the most useful individualization marker of semen in practical application.

We have confirmed for the first time, both biochemically and immunologically, the existence of deoxyribonuclease I (DNase I) in human liquid sweat. Isoelectric focusing of sweat samples on polyacrylamide gels (pH 3.5 to 5), followed by dried agarose film overlay detection, was used to determine the phenotypes of sweat DNase I. Because this detection method not only had high sensitivity, but also high band resolution, it was possible to determine DNase I types from sweat samples of 50 to 100 μL. Pretreatment of sweat samples with sialidase was essential for typing to enhance markedly the sensitivity accompanied by simplification of the isozyme pattern. The DNase I types in all sweat samples were consistently related to the types found in corresponding blood, urine, and semen samples. DNase I typing could, therefore, provide a novel discriminant characteristic in the forensic examination of sweat.