Determination of formic acid tissue and fluid concentrations in three fatalities due to methanol poisoning

Three fatalities caused by methanol ingestion are reported. Admission blood methanol concentrations ranged from 0.28 to 4.6 g/L. Two patients had been admitted after a significant delay (>20 hours), and one patient was observed within 90 minutes following ingestion. Formic acid levels were determined in blood samples at admission and ranged from 302 to 680 mg/L. The patients died 44, 55, and 82 hours after poisoning. Formic acid determinations in postmortem tissues were performed by a gas chromatograph method. The authors found great variability in formic acid distribution among the patients and among organs.     

Variability of simulants used in recreating stab events

Formic acid (FA) concentration was measured in post-mortem blood and urine samples as methyl formate using a headspace in-tube extraction gas-chromatography-mass-spectrometry method. A total of 113 cases were analyzed, each including a blood and urine sample fortified with 1% sodium fluoride. The cases were divided into three groups: regular (n=59), putrefied (n=30), and methanol-positive (n=22) cases. There was no evidence of ante-mortem methanol consumption in the regular and putrefied cases. In regular cases, the mean (and median) FA concentrations were 0.04 g/l (0.04 g/l) and 0.06 g/l (0.04 g/l) in blood and urine, respectively. In putrefied cases, the mean (and median) FA concentrations were substantially higher, 0.24 g/l (0.22 g/l) and 0.25 g/l (0.15 g/l) in blood and urine, respectively. In three putrefied cases, FA concentration in blood exceeded 0.5 g/l, a level associated with fatal methanol poisoning. Ten putrefied cases were reanalyzed after 3-4 months storage, and no significant changes in FA concentrations were seen. These observations suggest that FA was formed by putrefaction during the post-mortem period, not during sample storage when sodium fluoride was added as a preservative. In methanol-positive cases, the mean (and median) FA concentrations were 0.80 g/l (0.88 g/l) and 3.4 g/l (3.3 g/l) in blood and urine, respectively, and the concentrations ranged from 0.19 to 1.0 g/l in blood and from 1.7 to 5.6 g/l in urine. The mean (and median) methanol concentrations in methanol-positive cases were 3.0 g/l (3.0 g/l) and 4.4 g/l (4.7 g/l) in blood and in urine, respectively. The highest methanol concentrations were 6.0 g/l and 8.7 g/l in blood and urine, respectively. No ethyl alcohol was found in the methanol-positive blood samples. Poor correlation was shown between blood and urine concentrations of FA. Poor correlations were also shown, in both blood and urine, between methanol and FA concentrations.     

The relationship of methanol and formate concentrations in fatalities where methanol is detected

An automated headspace gas chromatography method was developed for the determination of formate (formic acid) in postmortem specimens, based on the in situ sulfuric acid-methanol methylation of formic acid to methyl formate. Diisopropyl ether was used as an internal standard. The method was applied to over 150 postmortem cases where methanol was detected. Of the 153 cases presented, 107 deaths were attributed to acute methanol toxicity. In the vast majority of the remaining 46 deaths, the methanol was determined to be present as a postmortem or perimortem artifact, or was otherwise incidental to the cause of death. Of the 76 victims who were found dead and blood was collected by the medical examiner, all but one had a postmortem blood formate concentration greater than 0.50 g/L (mean 0.85 g/L; n = 74). The sole exception involved suicidal ingestion of methanol where the blood methanol concentration was 7.9 g/L (790 mg/100 mL) and blood formate 0.12 g/L. In 97% (72/74) of the cases where blood was available, the blood formate was between 0.60 and 1.40 g/L. In 31 of the 153 cases, the victim was hospitalized and blood obtained on admission or soon after was analyzed for methanol and formate during the subsequent death investigation; the vast majority (27/30) had antemortem blood formate concentrations greater than 0.50 g/L. Cases with samples taken prior to death with blood formate concentrations less than 0.5 g/L can readily be explained by active treatment such as dialysis. The blood formate method has also been useful in confirming probable perimortem or postmortem contamination of one of more fluids or tissues with methanol (e.g., windshield washer fluid or embalming fluid), where methanol ingestion was unlikely.     

Relationship between the concentration of ethanol and methanol in blood samples from Swedish drinking drivers

Headspace gas chromatography was used to determine the concentration of ethanol and methanol in blood samples from 519 individuals suspected of drinking and driving in Sweden where the legal alcohol limit is 0.50 mg/g in whole blood (11 mmol/l). The concentration of ethanol in blood ranged from 0.01 to 3.52 mg/g with a mean of 1.83 +/- 0.82 mg/g (+/- S.D.). The frequency distribution was symmetrical about the mean but deviated from normality. A plot of the same data on normal probability paper indicated that it might be composed of two subpopulations (bimodal). The concentration of methanol in the same blood specimens ranged from 1 to 23 mg/l with a mean of 7.3 +/- 3.6 mg/l (+/- S.D.) and this distribution was markedly skew (+). The concentration of ethanol (x) and methanol (y) were positively correlated (r = 0.47, P less than 0.001) and implies that 22% (r2) of the variance in blood-methanol can be attributed to its linear regression on blood-ethanol. The regression equation was y = 3.6 + 2.1 x and the standard error estimate was 0.32 mg/l. This large scatter precludes making reliable estimates of blood-methanol concentration from measurements of blood-ethanol concentration and the regression equation. But higher blood-methanol concentrations are definitely associated with higher blood-ethanol in this sample of Swedish drinking drivers. Frequent exposure to methanol and its toxic products of metabolism, formaldehyde and formic acid, might constitute an additional health risk associated with heavy drinking in predisposed individuals. The determination of methanol in blood of drinking drivers in addition to ethanol could indicate long-standing ethanol intoxication and therefore potential problem drinkers or alcoholics.     

Fatal methanol intoxication with different survival times--morphological findings and postmortem methanol distribution

Three corresponding cases of fatal methanol intoxication with different survival times were investigated ante-mortem and postmortem. Ante-mortem serum methanol concentrations were determined during treatment in hospital for 4 days. Furthermore, postmortem distribution of methanol in various tissues and fluids was measured after autopsy. Morphological and toxicological findings are discussed based on the literature. The morphological findings correlated with the different survival times. The results of the toxicological analyses were partly in keeping with previously published data. Interestingly, very high methanol levels were determined in brain with very low concentrations in femoral venous blood. These results may have implications for postmortem toxicological analysis, brain death diagnosis and organ explanation for transplantation.     

Diagnostic implication of blood and urine morphine content in alcohol intoxication

A total of 198 cases of acute parenteral poisoning with opiates are characterized. The range of concentrations of opiates metabolites in the blood and urine, main causes of death due to opiate poisoning in alcohol intoxication are analysed. Opiates toxicity was assessed with the logit-regression method and dose-effect curves valid for analysis of relationships between probability of death and opiate metabolites concentration in blood and urine. Correlation between probability of death and detection of morphine and ethanol in biological media of the victims is considered. Concentrations of morphine in blood and urine definitely indicating opiates poisoning in alcohol intoxication as a cause of death are determined.     

389例不同年份的中毒尸检资料对比分析

本文报告近16年来(1983～1998)本教研室检验的中毒尸检158例,并与本教研室1983年以前26年(1957～1982)的中毒尸检231例进行对比分析.发现中毒毒物的种类在近16年虽然仍以有机磷农药为主,但敌敌畏中毒在90年代后则明显减少,相反新型有机磷农药及其它新型农药则逐渐增加;杀鼠剂、醇类、麻醉品及毒品呈明显增多趋势,而金属盐类毒物则减少较明显.90年代后,杀鼠剂投毒及医源性或非法行医所致药物中毒案例显著增多.     

甲醇中毒机制的研究进展

甲醇经口或皮肤吸收入血后造成中毒者双目失明甚至死亡等严重后果的案件时有发生。甲醇及其代谢产物甲醛、甲酸均可对机体产生严重毒性作用,引起代谢性酸中毒、视力障碍及神经症状。目前对于甲醇中毒机制的研究主要集中在甲醇氧化代谢过程中形成的甲醛、甲酸及大量自由基直接或间接地造成组织细胞缺氧,结构及生物特性改变,自由基及抗氧化系统、蛋白酶及蛋白酶抑制系统平衡被打破,而造成体内一系列中毒改变。     

Electroretinogram and Histopathologic Changes of the Retina after Methanol Intoxication

In order to study the functional and structural alterations of the retina in SD rat model after methanol intoxication,35 rats were divided randomly into five groups administrated with saline,3-day high dose,7-day high dose,3-day low dose and 7-day low dose methanol separately.The retinal function of each group was assessed by flash electroretinogram(F-ERG) 3 and 7 days after methanol poisoning.The microstructure and ultrastructure of the retina were observed at the same time.The high-dose methanol intoxication induced irreversible retinal functional and structural damages 3 days after poisoning,which included prolonged latency and reduced amplitude of the Max-reaction of F-ERG.These injuries were aggravated 7 days after poisoning.Meanwhile,the latency and amplitude of the Cone-reaction of F-ERG were also affected 3 days after poisoning,but there were no further worsening tendency 7 days after poisoning.The retinal histological analysis showed cellular edema,heteromorphy and disarrangement,tissular loosen of the inner nuclear layer and photoreceptors layer.The mitochondrial damage began at the photoreceptors layer and developed further into the inner nuclear layer.The low-dose methanol intoxication only caused transient damage of the retina.Our results showed that the function and structure of the photoreceptor and inner nuclear layer were the primary target of methanol intoxication and that the rod cells were more sensitive to methanol intoxication than the cone cells.The mitochondrial damage developed from outer layer to inner layer of the retina.     

Forensic medical significance of enzymatic products of ethanol oxidation in cadaveric brain

The concentrations of ethanol, acetaldehyde, and the oxidizing enzymes alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (AIDH) were measured in neuronal cytoplasm, limbic cortical capillaries, and cardiovascular center of the medulla oblongata. The measurements were carried out by histochemical methods, gas-liquid chromatography, etc. The results were processed with consideration for the degree and stage of ethanol intoxication in case of death from ethanol poisoning and asphyxia in hanging. Increase of ethanol concentration in the blood was associated with a decrease and then increase in the brain concentrations of ADH and with an increase of AIDH concentration. Enzymatic changes predominated in capillary walls; the minimum shifts were observed in the neuronal cytoplasm of the cerebral limbic cortex, which confirms the neurohumoral nature of detoxication regulation. Lethal ethanol poisoning could occur during any stage of ethanol intoxication. The detected changes in ethanol, acetaldehyde, and metabolizing oxidoreductases in brain tissue can be used for forensic medical diagnosis of ethanol poisoning.     

Identification and quantitation of xenobiotics by 1H NMR spectroscopy in poisoning cases

In order to analyse a wide range of xenobiotics and their metabolites present in biological fluids, NMR spectroscopy can be used. A large variety of xenobiotics (therapeutic agents, pesticides, solvents, alcohols) can be characterized and quantitated directly, without sample preparation. NMR investigations were applied to acute poisoning cases, involving drugs such as salicylates and valproic acid (VPA). In a salicylate poisoning case, the three major metabolites of acetylsalicylic acid have been detected in crude urine, and rapid identification of lysine revealed the origin of the intoxication, namely lysine acetylsalicylate (Aspegic). Valproic acid as its glucuronide was identified in urine samples from two poisoned patients. 1H NMR was also used to identify and quantitate paraquat (Gramoxone) in urine owing to its two aromatic signals at 8.49 and 9.02 ppm, in two acutely poisoned patients (183 and 93 mg/l). An intentional poisoning case with tetrahydrofuran (THF) was also investigated. Serum and urine samples were collected. THF was characterized by its resonances at 1.90 and 3.76 ppm, and quantified at 813 and 850 mg/l in the two biological fluids, respectively. Moreover, two other compounds were detected: lactate and gamma-hydroxybutyric acid (GHB). 1H NMR spectroscopic analysis of serum samples from three poisoned patients revealed methanol in one case and ethylene glycol in the two others. Moreover, in the same spectrum, the corresponding metabolites formate and glycolate were found. Compared with the reference chromatographic or spectrophotometric methods, requiring time-consuming extraction and/or derivatization steps, NMR spectroscopy allows the determination of many exogenous and endogenous compounds, without any pre-selection of the analytes.     

Postmortem determination of the biological distribution of formic acid in methanol intoxication.

Two 25-year-old men were fatally intoxicated with methanol. The formic acid levels in their blood, urine, and organs were determined postmortem by headspace gas chromatography. The postmortem concentrations of formic acid in the two patients were the following: 0.32 and 0.23 mg/mL in blood, 2.27 and 0.47 mg/mL in urine, 0.11 and 1.17 mg/g in the brain, 0.54 and 0.51 mg/g in the liver, and 0.13 and 1.19 mg/g in the kidneys. The total amounts of formic acid in the gastric contents were 108 and 23.2 mg.     

Methyl alcohol poisoning in Trabzon (Turkey)

The aim of this retrospective study was to examine methyl alcohol intoxications in Trabzon (Turkey) and to determine any relations between the laboratory results and histopathologic changes. A total of 4492 forensic autopsies were performed from 1998 to 2008. Thirteen of the cases (0.3%) were because of methanol poisoning, and all were men. Their ages ranged from 25 to 62 years. The blood methanol concentrations ranged widely, from 15 to 482 mg/dL. In six cases, poisoning was because of consumption of the alcoholic beverage "Raki," while in five cases, poisoning was because of the ingestion of cologne. The products consumed were unknown in the other two cases because of insufficient history and data records. Mortality because of methanol poisoning may be prevented/decreased with the implementation of some precautions, such as public education regarding the harms of methyl alcohol, routine monitoring of the vendors that sell alcoholic beverages and cologne, and appropriate legal retribution for the illegal production of methanol.     

The forensic medical diagnosis of intoxication of alcohol surrogates by morphological findings

The pathomorphology of intoxication of alcohol surrogates is described. A high frequency rate of DIC-syndrome is shown for the condition. A majority of thrombi accumulates at places with the highest concentrations of toxic substances as well as at those places, through which poisoning substances are brought out of the body, i.e. in the liver (since toxic substances are introduced perorally) and kidneys. Thrombi were detected in all internals, including the brain, in lethal intoxication. The immediate toxic effect from methanol and from higher spirits can matter in the genesis of changes, including acute swelling and chromatolysis with subsequent cell death. Exclusively cerebral or coagulopathic-cerebral types of thanatogenesis were registered in studied case of intoxication.     

Fatalities due to methyl alcohol intoxication in Turkey: an 8-year study

The aim of this study is to examine methyl alcohol poisoning cases from the medico-legal point of view. The records of the Morgue Department of Council of the Forensic Medicine were reviewed retrospectively for all methyl alcohol poisonings for the period of 27.10.1992 and 30.05.2001. The victim's age, sex, death year, death place, methyl alcohol blood levels, the source of methyl alcohol, accompanying laboratory results and histopathologic tissue changes were recorded. The number of deaths due to the methyl alcohol poisoning was 271 during that period of time. Two hundred and forty-two of the (89.3%) total 271 methyl alcohol fatalities were men and 29 (10.7%) of were women. The largest age group was 36-40 years old, followed by 41-45. The methyl alcohol blood concentrations ranged widely from 50 to 755 mg for per 100 ml. There were 222 cases (81.9%) with the methyl alcohol blood concentrations over 100 mg/dl. Twenty-nine (10.7%) victims were poisoned through the consumption of cologne and three of them with alcoholic beverage named "Raki". Consumed products were not known in all other cases because of insufficient patient history and data. As a conclusion, regarding the distribution according to years, mortality due to methyl alcohol intoxication in our country have been proceeding on a certain level. In order to decrease the mortality due to methyl alcohol intoxication, some precautions should be developed that could prevent the production and consumption of alcoholic beverages illegally produced.     

Colchicine Extract Suicidal Lethal Poisoning Confirmation Using High‐Resolution Accurate Mass Spectrometry: A Case Study

A case of suspected acute and lethal intoxication caused by colchicine has been reported. The woman was hospitalized after her suspicion of suicidal poisoning by a rare autumn crocus (Colchicum autumnale). Suspected colchicine poisoning was confirmed using a novel UHPLC method with a modern reversed‐phase stationary phase with a sub 2‐micron superficial porous particle size combined with a QTOF mass spectrometer. Sample preparation procedure included the addition of propiverine as internal standard, protein precipitation using methanol and solid phase extraction. High‐resolution MS only and targeted MS/MS modes are reported for the qualitative analysis and screening of other potential drugs of abuse in blood samples. All Ion MS mode was used for quantitative determination of colchicine afterward. The concentration of colchicine in the blood sample was approximately 41 ng/mL, and more than 200 μg/mL of the plant extract used for the suicide.     

A review of methadone deaths in Jefferson County,Alabama

Interpretation of the concentration of a drug is more difficult when a combination of drugs is present in a decedent's blood. An increase in deaths resulting from co-intoxication with methadone and a benzodiazepine led the authors to perform a retrospective study of cases examined at the Jefferson County Coroner/Medical Examiner Office. They found 101 deaths wherein methadone was detected in the blood. Based on the drugs detected in the blood, these 101 cases were grouped into four categories: (1) pure methadone intoxication, (2) intoxication with methadone and benzodiazepine, (3) intoxication with methadone and other drugs excluding benzodiazepine, and (4) intoxication with methadone, benzodiazepines, and other drugs. Methadone was the sole intoxicant in 15 cases, with a mean concentration of 0.27 mg/L. Benzodiazepines were the most frequently detected co-intoxicant (60 of 101 cases). Benzodiazepine was the only co-intoxicant in 30 cases, and the mean methadone concentration in those 30 cases was 0.599 mg/L. Higher levels of methadone may occur in acute intoxication with methadone and benzodiazepine because benzodiazepines compete with methadone for methadone receptors. Higher levels of methadone may occur with chronic abuse of methadone and benzodiazepines because over time, benzodiazepines inhibit the hepatic enzymes that metabolize methadone.     

Fatal brodifacoum rodenticide poisoning: autopsy and toxicologic findings.

This report details the pathologic and toxicologic findings in the case of a 15-year-old girl who deliberately and fatally ingested brodifacoum, a commonly used rodenticide. The mechanism of death, massive pulmonary hemorrhage, has not been previously reported. Brodifacoum was quantitated in liver, spleen, lung, brain, bile, vitreous humor, heart blood, and femoral blood using HPLC with fluorescence detection. The highest brodifacoum concentrations were detected in bile (4276 ng/mL) and femoral blood (3919 ng/mL). No brodifacoum was detected in brain or vitreous humor. A brodifacoum concentration of 50 ng/g was observed in frozen liver while formalin fixed liver exhibited a concentration of 820 ng/g. A very high blood:liver brodifacoum concentration ratio suggested acute poisoning but the historical and pathologic findings suggested a longer period of anticoagulation. Though most cases of brodifacoum poisoning in humans are non-fatal, this compound can be deadly because of its very long half-life. Forensic pathologists and toxicologists should suspect superwarfarin rodenticides when confronted with cases of unexplained bleeding. Anticoagulant poisoning can mimic fatal leukemia or infectious diseases such as bacterial sepsis, rickettsioses, plague, and leptospirosis. A thorough death scene investigation may provide clues that a person has ingested these substances.     

Distribution of malathion in body tissues and fluids.

Six cases of suspected poisoning were studied. The various body tissues and fluids of all the cases were analysed and malathion was found positive. The quantitative analysis was performed using high performance liquid chromatography. The distribution of malathion was studied in lungs, liver, kidneys, spleen, brain, heart, blood, muscles, urine and gastric contents.     

An autopsy analysis on 5 cases of poisoning death with tetramethylenedisulfotertramine

Pathological changes due to intoxication of tetramethylenedisulphotetramine (TETS) were studied. The results showed that the signs of asphyxia were obvious, so were the congestion and edema of the brain. The spotty and focal hemorrhages in brain stems, multiple myolysis of papillary muscles and contractionbands necrosis of myocardium were observed occasionally. The main clinical symptom of intoxication was frequent clinic--tonic convulsions, which were similar to the grandma epilepsy. The poisoned died mainly in 3 hours. The general poisoning symptoms, LD50, toxicological mechanism and medicolegal expertise were also reviewed.