Kimiharu Iwadate

Toxicological analysis of 17 autopsy cases of hydrogen sulfide poisoning resulting from the inhalation of intentionally generated hydrogen sulfide gas

Although many cases of fatal hydrogen sulfide poisoning have been reported, in most of these cases, it resulted from the accidental inhalation of hydrogen sulfide gas. In recent years, we experienced 17 autopsy cases of fatal hydrogen sulfide poisoning due to the inhalation of intentionally generated hydrogen sulfide gas. In this study, the concentrations of sulfide and thiosulfate in blood, urine, cerebrospinal fluid and pleural effusion were examined using GC/MS. The sulfide concentrations were blood: 0.11-31.84, urine: 0.01-1.28, cerebrospinal fluid: 0.02-1.59 and pleural effusion: 2.00-8.59 (μg/ml), while the thiosulfate concentrations were blood: 0-0.648, urine: 0-2.669, cerebrospinal fluid: 0.004-0.314 and pleural effusion: 0.019-0.140 (μmol/ml). In previous reports, the blood concentration of thiosulfate was said to be higher than that of sulfide in hydrogen sulfide poisoning cases, although the latter was higher than the former in 8 of the 14 cases examined in this study. These results are believed to be strongly influenced by the atmospheric concentration of hydrogen sulfide the victims were exposed to and the time interval between exposure and death.

Sudden death involving inhalation of 1,1-difluoroethane (HFC-152a) with spray cleaner: Three case reports

Spray cleaner is a cleaning product containing compressed 1,1-difluoroethane (HFC-152a) to blow dust off electric devices and other sensitive equipment; however, it is also inhaled to induce euphoria. This report describes three cases of death involving HFC-152a inhalation with spray cleaner under different circumstances. In case 1, death was during inhalation for euphoria with which led to having frostbite. In case 2, death may have been associated with suicidal intention. Case 3 was also considered an accidental autoerotic death. In all three cases, HFC-152a was detected at 99.2-136.2mg/l in blood samples, 94.5-191.9 mg/l in urine samples and 3.6-18.4 mg in the gastric contents according to gas chromatography with flame ionization detection. To prevent death associated with HFC-152a inhalation from spray cleaner, the danger of the sudden death should be announced to people, given the ready availability of commercial products containing HFC-152a.

Immunohistochemical Analysis of the Ubiquitin Proteasome System and Autophagy Lysosome System Induced After Traumatic Intracranial Injury: Association With Time Between the Injury and Death

AbstractThis study aimed to analyze how the ubiquitin proteasome system (UPS) or autophagy lysosome system (autophagy) are induced in brain tissues at different intervals after traumatic intracranial injury in humans. Injured cerebral cortices of 36 forensic autopsy cases were analyzed by immunohistochemistry using antibodies as the UPS marker (ubiquitin and lysine 48-linked polyubiquitin chains [K48]) and autophagy marker (lysine 63-linked polyubiquitin chains [K63], p62/sequestome 1 and microtubule-associated protein 1 light chain 3 [LC3]). The number of neurons and glial cells with cytoplasmic inclusions that stained positive for ubiquitin, K48, and p62 began to increase within 1 hour after intracranial injury, particularly at contusion sites. From 3.5 hours onward, an increase in cytoplasmic inclusions that stained positive for K63 and LC3 began to be detected. LC3-positive cytoplasmic inclusions were not identified after 37 days; however, the increased immunoreactivity to ubiquitin and anti-K48 antibody was maintained for 7 months. These results suggest that the UPS is activated earlier and lasts longer than autophagy, that autophagy is activated for a relatively short term (between a few hours and approximately 1 month), and that the activation occurs especially in severely damaged brain tissues following head trauma in humans.

Infant death associated with maternal methamphetamine use during pregnancy and delivery: A case report

The case described in this report is of a male infant who was found dead in a closet. His mother delivered the infant in the kitchen, left him wrapped in a towel, and called emergency medical services 4days after the delivery. At the autopsy, the growth suggests a full-term delivery, significant pathological findings were not observed, and the infant was estimated to be stillborn. After the autopsy, the police investigation discovered that the mother used a stimulant during the pregnancy and shortly before the rupture of the membrane. Toxicological analysis showed 1.60mg/L of methamphetamine in the blood, strongly suggesting that the fetal death was associated with this acute intoxication. Thus far, only a few cases of infant deaths have been reported in association with methamphetamine intoxication. The present case showed the highest blood concentration of methamphetamine compared to the past infant cases with this intoxication.

Single tooth tells us the date of birth

The atmospheric carbon-14 (14C) concentration remained relatively stable until 1955, but then rapidly increased after 1955 by nuclear bomb tests, peaked in 1963, and decreased thereafter. Recently, Spalding et al. proposed epoch-making method for determining date of birth (DOB) using the tooth enamel 14C incorporated during enamel formation. However, because the 14C level analyzed in one tooth gives two possible age ranges (up-slope or down-slope of the bomb curve), a variety of teeth that formed in different periods are required for estimating DOB in this method. Enamel formation in a tooth moves from the incisal (occlusal) side to the cervical side. Taking advantage of this characteristic, we have first succeeded in specifying the age range from only single tooth by measuring 14C in the incisal (occlusal) and cervical regions of the enamel separately. To date, no method of determining DOB or age estimation from single tooth enamel has been made. Furthermore, this method of dividing tooth into smaller parts could be useful for producing a more accurate DOB. Our new method is a powerful tool for identification when we can use only extremely few specimens in forensic casework.

Identification of the actinomycete 16S ribosomal RNA gene by polymerase chain reaction in oral inflammatory lesions

OBJECTIVESnTo examine the histopathological characteristics of inflammatory lesions containing Actinomyces based on DNA sequencing. Furthermore, case reports of actinomycosis in the maxillofacial region are summarized by a review of the literature.nnnSTUDY DESIGNnThe study comprised 12 cases of inflammatory lesions containing Actinomyces as diagnosed by DNA analysis. The average age of the subjects was 59xa0±xa015xa0years (6 males; 6 females).nnnRESULTSnThe distribution of causative bacteria was: Actinomyces israelii in 9 cases, Actinomyces gerencseriae in 2 cases, and Actinomyces naeslundii in 1 case. Four cases diagnosed by DNA sequencing were positive for Druse, a known morphological diagnostic characteristic of actinomycosis, and 8 cases lacked typical colony formation.nnnCONCLUSIONSnDNA analysis using paraffin-embedded samples is effective for both early and accurate diagnosis of oral lesions containing Actinomyces.

A novel method for the diagnosis of drowning by detection of Aeromonas sobria with PCR method

The acid digestion method has been widely used for the diagnosis of death by drowning, but it is not always sensitive. However, there has been no definitive method to replace acid digestion until now. We speculate that bacteria are more useful markers than plankton for the diagnosis of death by drowning. In this study, from the preserved blood samples of 32 freshwater drowning cases, specific DNA fragments of Aeromonas sobria, one of the most common aquatic bacteria, were examined using PCR. The DNA fragments of the bacterium were detected from 27 of 32 cases with first round PCR or nested-PCR. The remaining 5 cases in which bacterial DNA was not detected had longer storage periods for the blood samples and shorter time intervals from drowning to death. These results indicate that the present method can be applied to the diagnosis of death by drowning.

Investigation of oxyhemoglobin and carboxyhemoglobin ratios in right and left cardiac blood for diagnosis of fatal hypothermia and death by fire

Few large-scale investigations have looked at the oxyhemoglobin ratio (%O2-Hb) or the carboxyhemoglobin ratio (%CO-Hb) in fatal hypothermia and death by fire as applicable to forensic medicine. We therefore retrospectively examined right and left cardiac blood samples for both %O2-Hb and %CO-Hb in 690 forensic autopsy cases. We therefore sought to establish reference values for the above forensic diagnoses, to compare %O2-Hb in fatal hypothermia with or without cardiopulmonary resuscitation (CPR), and to compare the relationship between %CO-Hb and smoking history. All %O2-Hb and %CO-Hb data were obtained during or immediately after autopsies using a portable CO-oximeter. Death by carbon monoxide (CO) intoxication and death by fire were excluded from the analysis involving smoking history. In fatal hypothermia, %O2-Hb in the left cardiac blood was significantly higher than that in the right cardiac blood, providing important evidence for fatal hypothermia. Furthermore, %O2-Hb in the left cardiac blood increases with CPR but that in the right cardiac blood increases in parallel. No correlation was observed between rectal temperature and %O2-Hb in the right and left cardiac blood, indicating that it is unlikely that postmortem cooling increases %O2-Hb in cardiac blood. %CO-Hb in smokers was significantly higher than that in non-smokers, although the number of cigarettes smoked did not appear to be significant. When assessing death by fire, we identified that %CO-Hb of >10% was a reliable marker of antemortem CO inhalation, regardless of smoking history.

The effect of temperature on the mechanical aspects of rigor mortis in a liquid paraffin model

Rigor mortis is an important phenomenon to estimate the postmortem interval in forensic medicine. Rigor mortis is affected by temperature. We measured stiffness of rat muscles using a liquid paraffin model to monitor the mechanical aspects of rigor mortis at five temperatures (37, 25, 10, 5 and 0°C). At 37, 25 and 10°C, the progression of stiffness was slower in cooler conditions. At 5 and 0°C, the muscle stiffness increased immediately after the muscles were soaked in cooled liquid paraffin and then muscles gradually became rigid without going through a relaxed state. This phenomenon suggests that it is important to be careful when estimating the postmortem interval in cold seasons.

Potential medical adverse events associated with death: a forensic pathology perspective

OBJECTIVEnTo determine the incidence of potential medical adverse events among patients undergoing forensic autopsy, and to present the characteristics of potential medical adverse events.nnnDESIGNnRetrospective review of consecutive autopsy records.nnnSETTINGnDepartment of Forensic Medicine, the Jikei University School of Medicine, Tokyo, Japan.nnnPARTICIPANTSnA total of 3355 forensic autopsy cases between 1983 and 2006.nnnMAIN OUTCOME MEASURESnIncidence of potential medical adverse events identified in decedents undergoing forensic autopsy, classified by actual occurrence as confirmed, equivocal and negative cases; proportion of potential diagnostic, performance and system errors among potential medical adverse events.nnnRESULTSnOf 291 autopsies (8.7%) with potential medical adverse events, 66 cases (22.7%) were confirmed, 42 cases (14.4%) were negative and 183 cases (62.9%) were equivocal. Confirmed cases consisted of potential diagnostic errors in 49 cases (74.2%) and performance errors in 17 cases (25.8%). Equivocal cases included 99 cases associated with potential diagnostic errors (54.1%) and 60 cases associated with potential system errors (32.8%). In 38 of the confirmed cases (57.5%), serious exacerbation of patient condition occurred outside the medical facility.nnnCONCLUSIONSnPotential medical adverse events are not uncommon in decedents undergoing forensic autopsy. They are particularly associated with potential diagnostic errors. Forensic autopsy may provide information that could be used to improve care and reduce deaths due to potential medical adverse events.