-
Pediatric Emergency Care Oct 2002Methanol poisoning is an insidious event that can culminate in severe metabolic disturbances, permanent neurologic dysfunction, blindness, and death. Although numerous...
Methanol poisoning is an insidious event that can culminate in severe metabolic disturbances, permanent neurologic dysfunction, blindness, and death. Although numerous adult cases have been extensively reviewed, there is a paucity of reports about pediatric ingestions. We present a case of acute methanol intoxication in a 6-year-old male patient who presented with headache, nausea, altered mental status, and drowsiness. His blood methanol level was 350 mg/dL (109.4 mmol/L), despite the absence of any history or identifiable source of methanol. Treatment with ethanol, alkalinization, and hemodialysis resulted in full recovery without residua. Unusual facets of this case are the child's relatively older age, the extremely high methanol blood level, and, most remarkably, the complete lack of visual disturbances on routine ophthalmologic evaluation.
Topics: Child; Emergency Treatment; Humans; Male; Methanol; Poisoning
PubMed: 12395008
DOI: 10.1097/00006565-200210000-00009 -
Biomolecules Jul 2020The pits of Japanese apricot, Sieb. et Zucc., which are composed of stones, husks, kernels, and seeds, are unused by-products of the processing industry in Japan. The...
The pits of Japanese apricot, Sieb. et Zucc., which are composed of stones, husks, kernels, and seeds, are unused by-products of the processing industry in Japan. The processing of Japanese apricot fruits generates huge amounts of waste pits, which are disposed of in landfills or, to a lesser extent, burned to form charcoal. Mume stones mainly consist of cellulose, hemicellulose, and lignin. Herein, we attempted to solubilize the wood-like carapace (stone) encasing the pit by subcritical fluid extraction with the aim of extracting useful chemicals. The characteristics of the main phenolic constituents were elucidated by liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance (NMR) analyses. The degrees of solubility for various treatments (190 °C; 3 h) were determined as follows: subcritical water (54.9%), subcritical 50% methanol (65.5%), subcritical 90% methanol (37.6%), subcritical methanol (23.6%), and subcritical isopropyl alcohol (14.4%). Syringaldehyde, sinapyl alcohol, coniferyl alcohol methyl ether, sinapyl alcohol methyl ether, 5-(hydroxymethyl)-2-furfural, and furfural were present in the subcritical 90% methanol extract. Coniferyl and sinapyl alcohols (monolignols) are source materials for the biosynthesis of lignin, and syringaldehyde occur in trace amounts in wood. Our current findings provide a solubilization method that allows the main phenolic constituents of the pits to be extracted under mild conditions. This technique for obtaining subcritical extracts shows great potential for further applications.
Topics: Chromatography, Liquid; Industrial Waste; Liquid-Liquid Extraction; Mass Spectrometry; Methanol; Plant Extracts; Prunus; Waste Disposal Facilities
PubMed: 32679686
DOI: 10.3390/biom10071047 -
Alcoholism, Clinical and Experimental... Oct 1980After methanol administration to monkeys, an accumulation of formate in blood occurs coincident with the development of metabolic acidosis and a depletion of blood...
After methanol administration to monkeys, an accumulation of formate in blood occurs coincident with the development of metabolic acidosis and a depletion of blood bicarbonate. Formate metabolism in monkeys depends upon and is regulated by a folate-dependent system; therefore, the effect of folic acid pretreatment and 5-formyl tetrahydrofolic acid administration on methanol toxicity was investigated. Treatment of monkeys with repetitive doses of either sodium folate (48, 24, 12, and 4 hr prior to methanol) or 5-formyl tetrahydrofolic acid (2 mg/kg at 0, 4, 8, 12, and 18 hr after methanol) resulted in a marked decrease in the levels of blood formate and an absence of both metabolic acidosis and depletion of blood bicarbonate following methanol administration. Also, 5-formyl tetrahydrofolic acid reversed methanol toxicity once it was established in the monkey. The results indicate that folate compounds decrease formate accumulation after methanol by stimulating formate oxidation or utilization and suggest a possible use for folates in the treatment of certain cases of human methanol poisoning.
Topics: Animals; Female; Folic Acid; Formates; Hydrogen-Ion Concentration; Leucovorin; Macaca fascicularis; Male; Methanol; Oxidation-Reduction
PubMed: 7004236
DOI: 10.1111/j.1530-0277.1980.tb04835.x -
Molecules (Basel, Switzerland) Dec 2019Methanol is metabolized in the body to highly toxic formaldehyde and formate when consumed accidentally. Methanol has been typically analyzed with gas...
Methanol is metabolized in the body to highly toxic formaldehyde and formate when consumed accidentally. Methanol has been typically analyzed with gas chromatography-flame ionization detector (GC-FID). However, its retention time may overlap with other volatile compounds and lead to confusion. Alternative analysis of methanol using gas chromatography/mass spectrometry (GC/MS) also has limitations due to its similar molecular weight with oxygen and low boiling point. In this study, methanol and internal standard of deuterium-substituted ethanol were derivatized with 3,4-dihydro-2H-pyran under acid catalysis using concentrated hydrochloric acid. The reaction products including 2-methoxytetrahydropyran were extracted with solid-phase microextraction followed by GC/MS analysis. This method was successfully applied to measure the lethal concentration of methanol in the blood of a victim with a standard addition method to overcome the complex matrix effect of the biospecimen. Identification of the metabolite formate by ion chromatography confirmed the death cause to be methanol poisoning. This new method was a much more convenient and reliable process to measure methanol in complex matrix samples by reducing sample pretreatment effort and cost.
Topics: Benzenesulfonates; Gas Chromatography-Mass Spectrometry; Humans; Methanol; Pyrans
PubMed: 31877660
DOI: 10.3390/molecules25010041 -
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing... Jul 2020
Topics: Administration, Inhalation; Humans; Inhalation Exposure; Methanol; Poisoning; Renal Dialysis
PubMed: 32746583
DOI: 10.3760/cma.j.cn121094-20190927-00412 -
Bulletin Der Schweizerischen Akademie... Dec 1947
Topics: Drug-Related Side Effects and Adverse Reactions; Methanol
PubMed: 18902684
DOI: No ID Found -
Rapid Communications in Mass... Jan 2017The incubation of CPAQOP (1-[(2R)-2-[[4-[3-chloro-4-(2-pyridyloxy)anilino]quinazolin-5-yl]oxymethyl]-1-piperidyl]-2-hydroxy) with human liver microsomes generated...
Methanol adducts leading to the identification of a reactive aldehyde metabolite of CPAQOP in human liver microsomes by ultra-high-performance liquid chromatography/mass spectrometry.
RATIONALE
The incubation of CPAQOP (1-[(2R)-2-[[4-[3-chloro-4-(2-pyridyloxy)anilino]quinazolin-5-yl]oxymethyl]-1-piperidyl]-2-hydroxy) with human liver microsomes generated several metabolites that highlighted the hydroxyacetamide side chain was a major site of metabolism for the molecule. The metabolites were derived predominantly from oxidative biotransformations; however, two unexpected products were detected by liquid chromatography/ultraviolet/mass spectrometry (LC/UV/MS) and identified as methanol adducts. This observation prompted further LC/MS investigations into their formation.
METHODS
Three separate incubations of CPAQOP were conducted in human liver microsomes; Naïve, fortified with methoxyamine and fortified with glutathione. Separation was achieved via ultra-high-performance liquid chromatography with either methanol or acetonitrile gradients containing formic acid. MS analysis was conducted by electrospray ionisation LTQ Orbitrap mass spectrometry acquiring accurate mass full scan, data-dependent MS and all ion fragmentation.
RESULTS
No methanol adducts were detected by MS when acetonitrile was used in the mobile phase instead of methanol, verifying that a metabolite was reacting with methanol on column. Although this reactive metabolite could not be isolated or structurally characterised by LC/MS directly, product ion spectra of the methanol adducts confirmed addition of methanol on the hydroxyacetamide side chain. Additional experiments using methoxyamine showed the disappearance of the two methanol adducts and appearance of a methoxyamine adduct, confirming the presence of an aldhyde. Product ion spectra of the methoxyamine adduct confirmed addition of methoxyamine to the hydroxyacetamide side chain.
CONCLUSIONS
The proposed bioactivation of CPAQOP occurred via the reactive aldehyde intermediate, which readily reacted with methanol in the mobile phase to form a pair of isomeric hemiacetal methanol adducts. In acidified methanol the equilibrium favoured the methanol adduct and in acidified acetonitrile it favoured the hydrate; therefore, the reactive aldehyde metabolite was not detected and could not be structurally characterised directly. Copyright © 2016 John Wiley & Sons, Ltd.
Topics: Aldehydes; Chromatography, High Pressure Liquid; Glutathione; Humans; Hydroxylamines; Mass Spectrometry; Methanol; Microsomes, Liver; Piperidines
PubMed: 27943491
DOI: 10.1002/rcm.7772 -
Sensors (Basel, Switzerland) Jun 2022Micro-direct-methanol fuel cells (μDMFCs) use micro-electro mechanical system (MEMS) technology, which offers high energy density, portable use, quick replenishment,...
Micro-direct-methanol fuel cells (μDMFCs) use micro-electro mechanical system (MEMS) technology, which offers high energy density, portable use, quick replenishment, and free fuel reforming and purification. However, the μDMFC is limited by a short effective service life due to the membrane electrode's deterioration in electrochemical reactions. This paper presents a health status assessment and remaining useful life (RUL) prediction approach for μDMFC under dynamic operating conditions. Rather than making external observations, an internal characterization is used to describe the degradation indicator and to overcome intrusive influences in operation. Then, a Markov-process-based usage behavior prediction mechanism is proposed to account for the randomness of real-world operation. The experimental results show that the proposed degradation indicator alleviates the reduction in μDMFC output power degradation behavior caused by the user loading profile. Compared with the predictions of RUL using traditional external observation, the proposed approach achieved superior prognostic performance in both accuracy and precision.
Topics: Methanol; Micro-Electrical-Mechanical Systems; Prognosis
PubMed: 35684838
DOI: 10.3390/s22114217 -
Nordisk Medicin Oct 1955
Topics: Ethanol; Methanol
PubMed: 13280116
DOI: No ID Found -
Analytical Cellular Pathology... 2016Many studies have reported that methanol toxicity to primates is mainly associated with its metabolites, formaldehyde (FA) and formic acid. While methanol metabolism and...
Many studies have reported that methanol toxicity to primates is mainly associated with its metabolites, formaldehyde (FA) and formic acid. While methanol metabolism and toxicology have been best studied in peripheral organs, little study has focused on the brain and no study has reported experimental evidence that demonstrates transformation of methanol into FA in the primate brain. In this study, three rhesus macaques were given a single intracerebroventricular injection of methanol to investigate whether a metabolic process of methanol to FA occurs in nonhuman primate brain. Levels of FA in cerebrospinal fluid (CSF) were then assessed at different time points. A significant increase of FA levels was found at the 18th hour following a methanol injection. Moreover, the FA level returned to a normal physiological level at the 30th hour after the injection. These findings provide direct evidence that methanol is oxidized to FA in nonhuman primate brain and that a portion of the FA generated is released out of the brain cells. This study suggests that FA is produced from methanol metabolic processes in the nonhuman primate brain and that FA may play a significant role in methanol neurotoxicology.
Topics: Animals; Brain; Formaldehyde; Injections, Intraventricular; Macaca mulatta; Male; Methanol; Oxidation-Reduction; Time Factors
PubMed: 27066393
DOI: 10.1155/2016/4598454