Evaluation and review of ways to differentiate sources of ethanol in postmortem blood

Alcohol and toxicological factors influencing fatal falls from height in the Greater Tokyo Area: a retrospective study

Falls from height pose a significant public health concern in urban regions, including the highly urbanized Greater Tokyo Area. The Japanese population is characterized by high rates of suicide and psychoactive drug usage, underscoring the importance of investigating these attributes in falls from height. This study aimed to retrospectively analyze the alcohol and toxicological aspects influencing falls from height in the Greater Tokyo Area between 2014 and 2022 and compare the findings with existing reports on other populations. In total, 75 cases of falls from height and 159 cases of natural deaths were included. Consistent with previous findings, Fisher's exact test revealed a predominance of males (66.67%, 50/75) and young adults (57.33%, 43/75) in falls from height. Multivariate logistic regression analysis identified antidepressant usage as the most significant risk factor within the target population, while younger individuals under alcohol influence constituted another high-risk group. Notably, contradictory to other populations, female individuals involved in fatal falls in the Greater Tokyo Area exhibited a higher frequency of alcohol consumption than males (48.00%, 12/25 vs. 26.00%, 13/50), and most of them were associated with suicide (83.33%, 10/12). These findings elucidate the population characteristics that pose a high risk for fatal falls from height in Japan and can serve as a reference for other Asian populations residing in similar megacities.

Alpha-methyltryptamine and 5-(2-methylaminopropyl)-benzofuran (5-MAPB) fatal co-intoxication: case report and review of literature

The scientific literature contains little reliable data regarding new psychoactive substances and designer drugs, making it difficult to assess toxic blood levels and potentially lethal threshold. Here, we report a fatal co-intoxication involving two uncommon drugs ‒ alpha-methyltryptamine (AMT) and 5-(2-methylaminopropyl)-benzofuran (5-MAPB) ‒ combined with exposure to benzodiazepines, ephedrine, and norephedrine. AMT and 5-MAPB were quantified using ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC/MS-MS), revealing concentrations of AMT 4690 ng/mL and 5-MAPB 101 ng/mL in postmortem peripheral blood. We additionally reviewed the literature to help interpret the likely roles of these molecules in the occurrence of death.

Preanalytical factors influencing the results of ethanol analysis in postmortem specimens

Excessive drinking and drunkenness are underlying factors in many fatal accidents, which make the quantitative determination of ethanol in postmortem (PM) specimens an essential part of all unnatural death investigations. The same analytical methods are used to determine ethanol in blood taken from living and deceased persons although the interpretation of the results is more complicated in medical examiner cases owing to various preanalytical factors. The biggest problem is that under anaerobic conditions ethanol can be produced naturally in decomposed bodies by microbial activity and fermentation of blood glucose. Ways are needed to differentiate antemortem ingestion of ethanol from PM synthesis. One approach involves the determination of ethanol in alternative specimens, such as bile, cerebrospinal fluid, vitreous humor and/or urine, and comparison of results with blood alcohol concentration (BAC). Another approach involves the analysis of various alcohol biomarkers, such as ethyl glucuronide, ethyl sulfate and/or phosphatidylethanol or the urinary metabolites of serotonin 5-hydroxytryptophol/5-hydroxyindoleacetic acid (5-HTOL/5-HIAA). If ethanol had been produced in the body by microbial activity, the blood samples should also contain other low-molecular volatiles, such as acetaldehyde, n-propanol and/or n-butanol. The inclusion of 1-2% w/v sodium or potassium fluoride, as an enzyme inhibitor, in all PM specimens is essential to diminish the risk of ethanol being generated after sampling, such as during shipment and storage prior to analysis. Furthermore, much might be gained if the analytical cut-off for reporting positive BAC was raised from 0.01 to 0.02 g% when PM blood is analyzed. During putrefaction low BACs are more often produced after death than high BACs. Therefore, when the cadaver is obviously decomposed, a pragmatic approach would be to subtract 0.05 g% from the mean analytical result. Any remaining BAC is expected to give a more reliable indication of whether alcohol had been consumed before death.

Ethyl sulfate in blood shows the potential to distinguish alcoholic death and postmortem alcohol instillation

Alcohol is often found in the blood of the deceased. To cover up the true cause of victim's death, postmortem instillation of alcohol occurs in some criminal cases. Explaining the finding of alcohol is extremely vital in forensic practice. This study aims to evaluate whether ethyl glucuronide (EtG) and ethyl sulfate (EtS) in blood and vitreous humor (VH) can be used to distinguish alcoholic death and postmortem alcohol instillation. Saline or 12.6 g/kg ethanol (antemortem alcohol poisoning group) was introduced into rabbits' stomachs 2 h before sacrificed. Same amount of ethanol was introduced into rabbits' stomachs at 0 h, 0.5 h, 1 h and 2 h after death in four subgroups of postmortem alcohol instillation group, respectively. Cardiac blood and VH were collected at 10 min, 4 h, 10 h and 24 h after death in blank and antemortem alcohol poisoning group, and after instillation of alcohol in postmortem alcohol instillation group. Blood was also collected at 34 h. Ethanol and EtG levels in blood and VH and EtS in VH in antemortem alcohol poisoning group were overlapped with those in postmortem alcohol instillation group. The contents of EtG and EtS in blood in antemortem alcohol poisoning group (mean ≥ 7.833 μg/mL for EtG and ≥ 19.990 μg/mL for EtS) were much higher than those in postmortem alcohol instillation group (mean ≤ 0.118 μg/mL for EtG and ≤ 0.091 μg/mL for EtS), but apparent decomposition was observed in EtG, which might lead to misinterpretation. Blood EtS showed better stability and could be used to distinguish alcoholic death and postmortem alcohol instillation.

Determination of Ethyl Glucuronide and Ethyl Sulfate in Dried Blood Spots by UHPLC-MS-MS: Method Validation and Assessment of Ethanol Exposure in Postmortem Samples from Road Traffic Victims

The determination of ethyl glucuronide (EtG) and ethyl sulfate (EtS) in blood has been proposed in clinical and forensic applications to identify recent alcohol consumption. Also, there is a growing interest on the use of dried blood spots (DBS) in toxicological analysis, allowing increased stability of the analytes and simplifying sample transportation and storage. This study presents the development and validation of a method for quantifying EtG and EtS in DBS using ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS-MS). The DBS samples were extracted with a mixture of methanol and acetonitrile (80:20 v/v) and analyzed using UHPLC-MS-MS with electrospray source in negative mode, after separation with a fluoro-phenyl stationary phase. Validation was performed according to the Scientific Working Group for Forensic Toxicology (SWGTOX) guidelines, with calibrations ranging from 0.10 to 18 µg/mL for EtG and 0.02 to 6 µg/mL for EtS. The analytes were stable in DBS stored from -20 to 45°C for 21 days. The method was successfully applied to capillary and venous DBS samples from 20 volunteers after ethanol ingestion and to DBS samples from 99 fatal victims of road traffic injuries. Capillary DBS was comparable to venous DBS and fresh whole blood in Passing-Bablok and Bland-Altman analysis, with correlation coefficients >0.91 (P < 0.001) for all comparisons. In postmortem application, the DBS EtG and EtS analysis indicated positive exposure to ethanol in 72.7% of the cases (EtG: 0.10-24.0 µg/mL and EtS: 0.03-4.11 µg/mL). The identification of ethanol consumption from blood alcohol concentrations (BACs) and EtG/EtS in DBS was in agreement in 98.6% of positive and 96.3% of negative cases (kappa 0.877, P < 0.001), indicating a high level of concordance with BAC in assessing alcohol use in postmortem samples.

Forensic Aspects of a Fatal Intoxication Involving Acetaminophen, Citalopram and Trazodone: A Case Report

We report the case of a young man, a former heroin addict, found dead at home by the Police Forces in an advanced state of decomposition. Numerous blisters and unpacked tablets of medications were found all over the bed and on the floor of the room. Multiple injuries to the face, left arm and neck of the deceased were noted. The latter damages were attributed to post-mortem dog bites, since no indications of a possible defense against the animal were observed. The autopsy findings were unremarkable. Toxicological investigations performed on peripheral blood and urine by gas chromatography-mass spectrometry (GC-MS) technique showed the presence of acetaminophen, citalopram and trazodone. Combined drug intoxication was proposed as the cause of death since acetaminophen and trazodone concentrations were comparable with the ones found in fatal cases. Moreover, citalopram concentration in peripheral blood was above the toxic range and in accordance with levels found in fatalities due to poly-drug intoxication.

Effects of postmortem interval, putrefaction, diabetes, and location of death on the analysis of ethyl glucuronide and ethyl sulfate as ethanol biomarkers of antemortem alcohol consumption

This study evaluated the forensic value of ethanol biomarkers ethyl glucuronide (EtG) and ethyl sulfate (EtS) under different conditions, including diabetes mellitus, drug abuse, and advanced decomposition. In addition, we explored whether ethanol, EtG, or EtS formation occurred in patients who died as a result of diabetes mellitus. Fifty-two routine postmortem cases were divided into three groups. Group 1 included only the post-mortem cases in which at least blood samples were available (n=47). Group 2 included all cases with positive BAC (n=28). Group 3 included the cases with negative BAC while information surrounding the cases suspected antemortem alcohol consumption and cases that tested negative for ethanol but positive for EtG and EtS. We analyzed multiple bodily fluid specimens, including the vitreous humor, for ethanol biomarker analysis and accurately identified antemortem ethanol consumption or postmortem ethanol synthesis. We also determined the utility of urine samples for analyzing ethanol and its metabolites in putrefaction cases. If no urine sample was available at autopsy due to urination before death or diabetes-associated glucosuria, vitreous humor samples were an appropriate alternative for ethanol biomarker testing. We observed postmortem ethanol synthesis in diabetic individuals even with a short postmortem interval (PMI), however, glucose did not increase postmortem ethanol production in individuals with diabetes under appropriate preservation. The shorter the PMI, the better the ethanol source can be determined. Postmortem ethanol production occurred in all body fluid specimens analyzed herein, including the vitreous humor. EtG and EtS levels were stable and provided accurate insight into ethanol sources, even in cases of postmortem ethanol production. While the present study focused on the use of vitreous humor for the analysis, it is expected such samples may not be available in cases of advanced decay. In cases where no other bodily fluid specimens are available, solid tissue specimens are highly preferred.

Modeling Postmortem Ethanol Production/Insights into the Origin of Higher Alcohols

The forensic toxicologist is challenged to provide scientific evidence to distinguish the source of ethanol (antemortem ingestion or microbial production) determined in the postmortem blood and to properly interpret the relevant blood alcohol concentration (BAC) results, in regard to ethanol levels at death and subsequent behavioral impairment of the person at the time of death. Higher alcohols (1-propanol, 1-butanol, isobutanol, 2-methyl-1-butanol (isoamyl-alcohol), and 3-methyl-2-butanol (amyl-alcohol)) are among the volatile compounds that are often detected in postmortem specimens and have been correlated with putrefaction and microbial activity. This brief review investigates the role of the higher alcohols as biomarkers of postmortem, microbial ethanol production, notably, regarding the modeling of postmortem ethanol production. Main conclusions of this contribution are, firstly, that the higher alcohols are qualitative and quantitative indicators of microbial ethanol production, and, secondly that the respective models of microbial ethanol production are tools offering additional data to interpret properly the origin of the ethanol concentrations measured in postmortem cases. More studies are needed to clarify current uncertainties about the origin of higher alcohols in postmortem specimens.

Modeling microbial ethanol production by S. aureus, K. pneumoniae, and E. faecalis under aerobic/anaerobic conditions - applicability to laboratory cultures and real postmortem cases

A quite intriguing subject being intensively researched in the forensic toxicology field is the source of postmortem determined blood ethanol concentration: antemortem ingestion or postmortem microbial production. Our previous research on microbial ethanol production has reported a quantitative relationship between the ethanol and the higher alcohols and 1-butanol produced by Escherichia coli, Clostridium perfrigens, and Clostridium sporogenes. In this contribution, we continue our research reporting on the following: (i) the patterns of ethanol, higher alcohols, and 1-butanol production by the microbes Klebsiella pneumoniae, Staphylococcus aureus, and Enterococcus faecalis (all being aerobic/facultative anaerobic species, common corpse's colonizers, and ethanol producers), under controlled laboratory conditions, (ii) the mathematical modeling, with simple mathematical equations, of the correlation between ethanol concentration and the other studied alcohols' concentrations, by performing multiple linear regression analysis of the results, and (iii) the applicability of the constructed models in microbial cultures developed under different temperature than that used to build the models, in denatured blood cultures and in real postmortem cases. The aforementioned alcohols were proved to be all indicators of ethanol production, both in qualitative and quantitative terms. 1-Propanol was the most significant alcohol in modeling microbial ethanol production, followed by methyl-butanol. The K. pneumoniae's models achieved the best scoring in applicability (E < 40%) compared to the S. aureus and E. faecalis models, both at laboratory microbial cultures at 37 °C and real postmortem cases. Overall, a noteworthy accuracy in estimating the microbial ethanol in cultures and autopsy blood is achieved by the employed simple linear models.

Consistency between self-reported alcohol consumption and biological markers among patients with alcohol use disorder - A systematic review

BACKGROUND

No systematic review has yet examined the consistency between self-reports of alcohol consumption and alcohol biomarkers among patients in treatment for alcohol use disorders (AUD). Therefore, we aimed to provide an overview of the consistency between self-reported alcohol intake and biomarkers among patients in treatment for AUD.

METHODS

The electronical databases MEDLINE, PsycINFO, EMBASE, Cochrane Database of Systematic Reviews (CDSR) and CENTRAL were searched for all original studies that examined the validity of self-reported alcohol consumption using a biological marker in samples of patients with AUD. Eligible studies were included in a qualitative synthesis of the outcomes. Quality assessment was conducted with the quality assessment tool for Observational Cohort and Cross-sectional studies, developed by The National Heart, Lung and Blood Institute.

RESULTS

The search identified 7672 hits, and 11 papers comprising 13 eligible studies were included. All the identified studies revealed inconsistencies between self-reporting and biomarkers. Under-reporting was the most common type of inconsistency across short-, intermediate- and long-term biomarkers. For short-term markers, under-reporting was indicated in 7 studies (n = 15-585) in a range from 5.5%-56.0% of the patients, and over-reporting in 2 studies (n = 34-65) in a range from 5.9%-74.1%. Only under-reporting was reported for intermediate-term, direct markers and was indicated in 2 studies (n = 18-54) in a range from 5.0%-50.0% of the patients. Although the results for long-term biomarkers were not reported consistently across the studies, under-reporting was indicated in 3 studies (n = 73-1580) in a range from 0.1%-40.0% of the patients, and over-reporting in 2 studies (n = 15-1580) in a range from 13.0%-70.6%. Correlations between self-reported alcohol consumption and biological markers were strongest for the intermediate-term direct markers, ranging from moderate to strong. For short-term and long-term markers, the correlations were mostly weak. Most of the studies were quality rated as fair.

CONCLUSION

The findings indicate that inconsistency between self-reported alcohol consumption and biomarkers may occur in a considerable proportion of patients with AUD. However, further studies applying more sensitive, specific, and easily assessable biological markers are warranted to confirm this preliminary synthesis. PROSPERO registration no.: CRD42018105308.

Modeling postmortem ethanol production by C. albicans: Experimental study and multivariate evaluation

In previous research, we modeled the ethanol production by certain bacteria under controlled experimental conditions in an attempt to quantify the production of microbial postmortem ethanol in cases where other alcohols were co-detected. This contribution on the modeling of postmortem ethanol production by Candida albicans is complementary to these previous studies. Τhis work aimed to study ethanol, higher alcohols (1-propanol, isobutanol, 2-methyl-1-butanol and 3-methyl-1-butanol), and 1-butanol production by Candida albicans: (i) in different culture media (Brain Heart Infusion, BHI and, Sabouraud Dextrose Broth, SDB), (ii) under mixed aerobic/anaerobic or strict anaerobic conditions, and (iii) at different temperatures (37 °C, 25 °C and, 4 °C), and develop simple mathematical models, resulted from fungal cultures at 25 °C, to predict the microbially produced ethanol in correlation with the other alcohols. The applicability of the models was tested in the C. albicans cultures in BHI and SDB media at 37 °C, in denatured human blood at 25 °C, acidic and neutral with different concentrations of additional glucose, in acidic denatured blood diluted with dextrose solution and in blood from autopsy cases. The received results indicated that the C. albicans models could apply in cases where yeasts have been activated in blood with elevated glucose levels. Overall, the in vitro ethanol production by C. albicans in blood depended on temperature, time, glucose (or carbohydrate) content, pH of the medium and endogenous changes in the medium composition through time. Our results showed that methyl-butanol is the most significant indicator of fungal ethanol production, followed by the equally important isobutanol and 1-propanol in qualitative and quantitative terms.