Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CRESOL”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources
PubMed1998

Capillary gas chromatographic assay of camphor and m-cresol in dermatological creams.

Camphor and m-cresol mixtures are used in antiseptic and anti-itching creams. No compendial method exists for these preparations. This paper reports a capillary gas chromatographic method using FID detection with 2,6-di-tert-butyl-4-methylphenol as internal standard on a 30 m x 0.32 mm Supelcowax -10 column (0.25 micron film) with helium as carrier gas. Ramped temperature programming was applied. The method allows simultaneous quantitation of camphor and m-cresol in the presence of o- and p-cresols, calamine and zinc oxide. Overall percent recoveries (+/- SD, n = 9) of camphor, o-, p- and m-cresol from spiked placebo creams, at a labeled amount of 10 (w/w)% were 96.9 +/- 0.6, 98.2 +/- 0.6, 99.2 +/- 0.5 and 101.0 +/- 0.9%, respectively, and at a labeled amount of 1% were 96.7 +/- 0.6, 97.8 +/- 0.9, 97.8 +/- 0.6, and 100.3 +/- 1.0%, respectively. The recovery studies were carried out at +/- 30% of the labeled amounts. Linear peak area or height ratios were obtained (r > 0.999) for camphor, o-, p- and m-cresol covering a concentration range of 10-200% of the labeled amount. Linearity (r > 0.999) was also obtained for m-cresol when the relative concentration of o- and p-cresol was varied from 5 to 100% of the m-cresol concentration. The resolution between the 'critical pair' of p- and m-cresol was > or = 1.1. The limit of quantitation was 23 pg for m-cresol and 9.3 pg for camphor using an injection split of 1:50. The repeatability (%RSD) for all compounds were < 2% for peak area and < 1.4% for peak height ratios. System suitability and robustness of the method were established. The method was successively applied to the assay of available commercial products and allows assay of camphor and the three cresol isomers.

Antipruritics↗
PubMed2001

Effects of cresols (o-, m-, and p-isomers) on the bioenergetic system in isolated rat liver mitochondria.

It is known that o-, m- and p-cresols exert a toxic effect on rat liver cells. However, there is little information on the mechanism for the hepatotoxicity of cresols. We, therefore, investigated the effects of o-, m-, and p-cresols on the bioenergetic system using isolated rat liver mitochondria. When o-, m- or p-cresol was added to liver mitochondria with glutamate or succinate at concentrations of 0.3 to 6.0 mumol/mg protein, each cresol isomer reduced the rate of state 3 respiration dose-dependently. Three cresol isomers at 6.0 mumol/mg protein each inhibited state 3 respiration in liver mitochondria with glutamate or succinate by about 60 or 20%, respectively. The three isomers affected NAD- and succinate-linked respirations in liver mitochondria, by which the respiratory control ratio was dose-dependently attenuated. The inhibitory effects of o-, m- and p-cresols on the NAD-linked respiration were stronger than those on the succinate-linked respiration. However, three cresol isomers had little effect on the P/O ratio in liver mitochondria with glutamate or succinate. Three cresol isomers at 15 mumol/mg protein each induced the swelling in the absence of Ca2+ in medium and accelerated the swelling of liver mitochondria in the presence of Ca2+ in medium. These results indicate that o-, m- and p-cresols inhibit liver mitochondrial respiration and induce or accelerate the swelling of liver mitochondria, and suggest that liver mitochondria may be one of the targets for the hepatotoxic actions of cresols.

Animals↗
PubMed1999

4-chloro-m-cresol triggers malignant hyperthermia in susceptible swine at doses greatly exceeding those found in drug preparations.

BACKGROUND: Chlorocresols are used as preservatives in numerous commercial drugs that have been shown to induce myoplasmic Ca2+ release; the most potent isoform is 4-chloro-m-cresol. The aims of this study were to (1) examine the in vivo effects of 4-chloro-m-cresol on swine susceptible to malignant hyperthermia and (2) contrast in vivo versus in vitro dose-response curves. METHODS: Susceptible swine (weight: 38.5 kg+/-3.55 kg) were anesthetized and monitored for variations in physiological responses, including end-tidal CO2, heart rate, blood pressure, blood chemistry, and temperatures. In the first animals studied, 4-chloro-m-cresol, at equivalent cumulative doses of 0.14, 0.28, 0.57, 1.14, 2.27, 4.54, and 9.08 mg/kg (n = 3; 12.5, 25, 50, 100, 200, 400, and 800 micromol) were administered, and in a second group, larger doses were used: 1.14, 3.41, 7.95, 17.04 (n = 4), and/or 35.22 (n = 1) mg/kg (100, 300, 700, 1,500, and/or 3,100 micromol). For comparison, in vitro rectus abdominis muscle preparations obtained from normal and susceptible swine were exposed to 4-chloro-m-cresol, at cumulative concentrations of 6.25, 12.5, 25, 50, 100, 200, 400, 800, and 1,600 micromol; standard caffeine and halothane contracture testing was also performed. RESULTS: Episodes of malignant hyperthermia were not triggered in response to administration of low doses of 4-chloro-m-cresol, but transient cardiovascular reactions (e.g., tachycardia, arrhythmias, and hypotension) were observed. Subsequently, episodes in these animals were triggered when halothane (0.87; 1 MAC) and succinylcholine (2 mg/kg) were given. Animals administered the higher doses of 4-chloro-m-cresol all had fulminant episodes of malignant hyperthermia that were fatal, when equivalent cumulative concentrations were greater than 1,500 micromol. The levels of 4-chloro-m-cresol in the plasma rapidly decreased: e.g., 5 min postadministration of the 1,500-micromol dose, the mean plasma level was only 52+/-18 micromol (n = 4). Hemolysis was detected following 4-chloro-m-cresol administration at concentrations > 200 micromol. In vitro, muscle from susceptible animals elicited contractures > 200 mg at 50-micromol bath concentrations of 4-chloro-m-cresol (n = 29), whereas normal muscle did not elicit such contractures until bath concentrations were > 800 micromol (n = 10). CONCLUSIONS: 4-chloro-m-cresol is a trigger of malignant hyperthermia in susceptible swine, but only when serum concentrations are far above those likely to be encountered in humans. A relatively low concentration of 4-chloro-m-cresol, 50 micromol, is sufficient to activate sarcoplasmic [Ca+2] release in vitro (e.g., contractures); this same bolus dose administered in vivo (0.57 mg/kg) has minimal effects due to the rapid decrease in its plasma levels.

Animals↗
PubMed2003

Formation of DNA adducts in HL-60 cells treated with the toluene metabolite p-cresol: a potential biomarker for toluene exposure.

We have examined DNA adduct formation in myeloperoxidase containing HL-60 cells treated with the toluene metabolite p-cresol. Treatment of HL-60 cells with the combination of p-cresol and H(2)O(2) produced four DNA adducts 1: (75.0%), 2: (9.1%), 3: (7.0%) and 4: (8.8%) and adduct levels ranging from 0.3 to 33.6 x 10(-7). The levels of DNA adducts formed by p-cresol were dependent on concentrations of p-cresol, H(2)O(2) and treatment time. In vitro incubation of p-cresol with myeloperoxidase and H(2)O(2) produced three DNA adducts 1: (40.5%), 2: (28.4%) and 3: (29.7%) with a relative adduct level of 0.7x10(-7). The quinone methide derivative of p-cresol (PCQM) was prepared by Ag(I)O oxidation. Reaction of calf thymus DNA with PCQM produced four adducts 1: (18.5%), 2: (36.4%), 3: (29.0%) and 5: (16.0%) with a relative adduct level 1.6x10(-7). Rechromatography analyses indicates that DNA adducts 1-3 formed in HL-60 cells treated with p-cresol and after myeloperoxidase activation of p-cresol were similar to those formed by reaction of DNA with PCQM. This observation suggests that p-cresol is activated to a quinone methide intermediate in each of these activation systems. Taken together, these results suggest PCQM is the reactive intermediate leading to the formation of DNA adducts in HL-60 cells treated with p-cresol. Furthermore, the DNA adducts formed by PCQM may provide a biomarker to assess occupational exposure to toluene.

Animals↗
PubMed2002

Scavenging property of three cresol isomers against H2O2, hypochlorite, superoxide and hydroxyl radicals.

Formocresol has long been used for pulpotomy of primary teeth and as an intracanal medicament. Little is known, however, about the pharmacological effect of tricresols. This study showed that three cresol isomers, o-cresol, m-cresol and p-cresol, are H2O2 scavengers with a 50% inhibitory concentration (IC50) of 502, 6.7 and 10.16 microM, respectively. o-, m- and p-cresol were also shown to be effective scavengers of superoxide radicals generated by xanthine/xanthine oxidase with an IC50 of 282, 153 and > 4000 microM, respectively, as analyzed by luminometer. o-, m- and p-cresol showed protective effects on the DNA breaks generated by H2O2/FeCl2 and FeCl3/ascorbate/H2O2 systems at concentrations ranging from 70 microM to 1.43 mM, o-, m- and p-cresol also showed differential protective effects against DNA breaks induced by 0.17% NaOCl with 100% inhibitory concentration (IC100) of about 10, 1 and 10 mM, respectively. In addition, reaction with 3% H2O2 and 0.17% NaOCl completely prevented NaOCl-induced DNA breaks. The results indicate that the three cresol isomers are effective ROS scavengers and may prevent ROS induced damage when used as pulpotomy agents or as intracanal medicaments. Owing to the difference in the position of the functional hydroxyl group in the three cresol isomers, m-cresol is the most effective ROS scavenger. Concomitant use of H2O2 for root canal irrigation may diminish both the tissue dissolving capacity of NaOCl and NaOCl-induced DNA damage.

Acridines↗
PubMed2006

Photodegradation of o-cresol in water by the H2O2/UV process.

Photodegradation of o-cresol in water has been investigated using hydrogen peroxide as an oxidant along with ultra violet lamps. The synergistic effect of H(2)O(2) and UV light was found to be effective to decomposition of o-cresol in water. The effects of wave length of UV light, initial concentration of o-cresol, hydrogen peroxide dose and initial solution pH on photodegradation rate of o-cresol were systematically examined. Degradation of o-cresol with UV-C lamps (wavelength of 254 nm) was more significant than that with near-UV black light lamps (wavelength of 352 nm). The optimal solution pH was around 5 being the natural pH of the solution. The efficiency of o-cresol degradation increased as initial o-cresol concentration decreased. There was the optimal H2O2 dose being around 150 mM when the initial o-cresol concentration was 0.93 mM. Based on the experimental results, a kinetic model for the photodegradation of o-cresol by H(2)O(2)/UV has been developed. The model could simulate the experimental results reasonably.

Cresols↗
PubMed1973

Metabolism of phenol and cresols by mutants of Pseudomonas putida.

Mutant strains of Pseudomonas putida strain U have been obtained which are deficient in enzymes of the degradative pathways of phenol and cresols. Mutant strains deficient in catechol 2, 3-oxygenase accumulated the appropriate catechol derivative from cresols. A mutant strain which would not grow on either phenol or a cresol was shown to be deficient in both 2-hydroxymuconic semialdehyde hydrolase and a nicotinamide adenine dinucleotide, oxidized form, (NAD(+))-dependent aldehyde dehydrogenase. When this strain was grown in the presence of phenol or a cresol, the appropriate product of meta fission of these compounds accumulated in the growth medium. A partial revertant of this mutant strain, which was able to grow on ortho- and meta-cresol but not para-cresol, was shown to have regained only the hydrolase activity. This strain was used to show that the products of meta ring fission of the cresols and phenol are metabolized as follows: (i) ortho- and meta-cresol exclusively by a hydrolase; (ii) para-cresol exclusively by a NAD(+)-dependent aldehyde dehydrogenase; (iii) phenol by both a NAD(+)-dependent dehydrogenase and a hydrolase in the approximate ratio of 5 to 1. This conclusion is supported by the substrate specificity and enzymatic activity of the hydrolase and NAD(+)-dependent aldehyde dehydrogenase enzymes of the wild-type strain. The results are discussed in terms of the physiological significance of the pathway. Properties of some of the mutant strains isolated are discussed.

Adipates↗
PubMed2004

P-cresol, a uremic retention solute, alters the endothelial barrier function in vitro.

Patients with chronic renal failure (CRF) exhibit endothelial dysfunction, which may involve uremic retention solutes that accumulate in blood and tissues. In this study, we investigated the in vitro effect of the uremic retention solute p-cresol on the barrier function of endothelial cells (HUVEC). P-cresol was tested at concentrations found in CRF patients, and since p-cresol is protein-bound, experiments were performed with and without physiological concentration of human albumin (4 g/dl). With albumin, we showed that p-cresol caused a strong increase in endothelial permeability after a 24-hour exposure. Concomitant with this increase in endothelial permeability, p-cresol induced a reorganization of the actin cytoskeleton and an alteration of adherens junctions. These molecular events were demonstrated by the decreased staining of cortical actin, associated with the formation of stress fibers across the cell, and by the decreased staining of junctional VE-cadherin. This decrease in junctional VE-cadherin staining was not associated with a reduction of membrane expression. Without albumin, the effects of p-cresol were more pronounced. The specific Rho kinase inhibitor, Y-27632, inhibited the effects of p-cresol, indicating that p-cresol mediates the increase in endothelial permeability in a Rho kinase-dependent way. In conclusion, these results show that p-cresol causes a severe dysfunction of endothelial barrier function in vitro and suggest this uremic retention solute may participate in the endothelium dysfunction observed in CRF patients.

Actins↗
PubMed1997

P-Cresol, a uremic compound, enhances the uptake of aluminum in hepatocytes.

In the end-stage renal disease patient, certain uremic compounds could influence the cellular accumulation of aluminum (Al). In this study, we examined the effect of 15 uremic ultrafiltrate fractions obtained by HPLC on the uptake and toxicity of Al in mouse hepatocytes (MH) in culture, a model system in which Al is taken up bound to transferrin (Tf). Uremic fractions 4 to 8, 12, 14, and 15 increased cellular Al uptake and aspartate aminotransferase release and decreased cell growth when Tf-Al, not Al citrate, was added to culture media. Compounds that have been extracted previously from these ultrafiltrate fractions (p-cresol, xanthine, tryptophan, hippuric acid, and o-hydroxyhippuric acid) were then tested for their effect on Al uptake and toxicity in MH at concentrations found in uremic serum. Significant Al uptake by MH was observed only when p-cresol was added together with Tf-Al. Time-response curves showed increased Al uptake and toxicity at p-cresol concentrations of 3 mg/dl in culture media. Dose-response curves confirmed that Al uptake and cell toxicity were proportional to p-cresol from 1.5 mg/dl to 3 mg/dl in culture media. p-Cresol was not toxic to MH in the absence of Tf-Al in media. p-Cresol increased Tf-associated Al uptake only because there was no effect on Al uptake when Al citrate was substituted, and studies with Tf-I125-Al in the presence of this compound showed increased Tf-I125 taken up by MH. p-Cresol did not increase Tf saturation with Al. p-Cresol also increased Tf-Al uptake in Friend erythroleukemia and neuroblastoma cells in culture. Our studies suggest that p-cresol and uremic fractions 4 to 8, 12, 14, and 15 increase the uptake and toxicity of Al in cultured MH. These compounds may play a role in the accumulation and toxicity of Al in the liver of end-stage renal disease patients and possibly in all cells that express Tf receptors.

Aluminum↗
PubMed1999

Cresol metabolism by the sulfate-reducing bacterium Desulfotomaculum sp. strain Groll.

The metabolism of cresols under sulfate-reducing conditions was investigated in Desulfotomaculum sp. strain Groll. This strain grows on a variety of aromatic compounds, including para- and meta- but not ortho-cresol. Degradation of p-cresol proceeded by oxidation reactions of the methyl group to yield p-hydroxybenzoate, which was then dehydroxylated to benzoate. The aromatic intermediates expected for this pathway, p-hydroxybenzyl alcohol, p-hydroxybenzaldehyde, p-hydroxybenzoate, and benzoate, were readily metabolized by strain Groll. Utilization of these intermediates generally preceded and inhibited the degradation of p-cresol. p-Hydroxybenzoate and benzoate were detected in culture fluid as metabolites of p-cresol. p-Hydroxybenzaldehyde and p-hydroxybenzoate were detected in cultures degrading p-hydroxybenzyl alcohol. Enzyme activities responsible for utilization of p- and m-cresol, induced by growth on the respective cresol, were detected in cell-free extracts of strain Groll. The compounds detected in culture fluids and the enzyme activities detected in cell-free extracts indicate that the pathways for the degradation of p- and m-cresol converge on benzoate, followed by metabolism to benzoyl-coenzyme A (CoA). Strain Groll can utilize both cresol isomers under sulfate-reducing conditions by similar reactions, but the enzyme activities catalyzing these transformations of the two isomers appear distinct.

Anaerobiosis↗
PubMed1998

Concentrated cresol intoxication.

Cresol, a commonly used disinfectant, may cause gastrointestinal corrosive injury, central nervous system and cardiovascular disturbances, and renal and hepatic injury following intoxication. We report a case of acute severe cresol poisoning after a suicide attempt with ingestion of a cresol-soap solution used as a toilet disinfectant. A 44-y-old male was found unconscious after ingesting 300 ml of 50% cresol-soap solution. Endotracheal intubation, gastric lavage and activated charcoal were given immediately which reversed his conscious. He had dermal burns, esophageal and gastric erosion, pneumonia, mixed metabolic acidosis and respiratory aklalosis, renal and liver function impairment, leucocytosis and dark urine. Acute renal failure and hemolysis developed, but he recovered after hemodialysis and intensive supportive care. Urine levels of p-cresol, m-cresol, o-cresol and phenol were respectively 2083, 2059, 125 and 68 mg/g creatinine at 7 h post-ingestion. Though the amount cresol claimed ingested by the patient (150 g) far exceeded the reported lethal dose (30-60 g), and multiple complications developed after massive ingestion, this patient recovered. The renal, pulmonary and hematological effects in this patient might have resulted from the direct toxicity of cresol and its metabolites.

Adult↗
PubMed2005

Concerted effects of substituents in the reaction of .OH radicals with aromatics: the cresols.

The concerted effects of hydroxyl and methyl substituents in controlling the site of .OH radical attack on aromatics in aqueous solutions are explored using the cresols as typical examples. The distributions of dihydroxytoluenes produced in the radiolysis of aqueous solutions of the cresols containing ferricyanide as a radical oxidant were examined by capillary electrophoretic and liquid chromatographic methods. Because .OH is a strong electrophile, it adds preferentially at the electron-rich sites of an aromatic ring. As a result, the observed distributions of dihydroxytoluenes reflect the charge distributions in the cresols. It is shown that in the case of m-cresol the hydroxyl substituent has a dominant ortho-para directing effect similar to that observed for phenol. In o- and p-cresol, this effect is modified, indicating that the methyl substituent has a significant effect on the electronic structure of those cresols. Correlation of the charge distribution in the cresols indicated by the observed distribution of dihydroxytoluenes with the unpaired spin distribution in the corresponding methylphenoxyl radicals demonstrates that the electronic structures of o- and p-cresol and their corresponding phenoxyl radicals are similarly affected by hydroxyl and methyl substitution. Addition of .OH at the methyl-substituted positions of o- and p-cresol to produce o- and p-dienone is also reported. The observation of these dienones demonstrates that addition of .OH at the ipso positions of alkylated aromatics can be of considerable importance. Mass spectrometric studies show that these dienones have relatively higher proton affinities than their isomeric analogues.

Journal Article↗
PubMed1983

Hippuric acid and o-cresol in the urine of workers exposed to toluene.

Factory workers, 74 males and 56 females exposed predominantly to toluene up to 129 ppm, were examined for the urinary excretion of hippuric acid and o-cresol. The time-weighted averages (TWA) of toluene exposure were measured by personal sampling with carbon felt dosimeters. A preliminary study revealed that the concentrations of hippuric acid and o-cresol in urine increased during work and both reach their peaks at the end of the shift. Correlation coefficients between the TWA of toluene concentration in air and hippuric acid concentration in urine collected at the end of the shift were 0.803 for the 74 males, and 0.830 for the 56 females, while the counterpart correlation coefficients between toluene and o-cresol were 0.607 for the 74 males, and 0.627 for the 56 females, suggesting that hippuric acid is more reliable than o-cresol as an index of toluene exposure. In the urine samples (4 to 8 samples per subject) collected during 8-h worktime from 11 males and 13 females, the urinary levels of o-cresol increased as a function of exposure time in parallel with those of hippuric acid, and the correlation coefficients between o-cresol and hippuric acid were significant (r = 0.834 approximately 0.987; P less than 0.05) when the urine samples from the same subjects were examined. The comparison of the slopes of 24 regression lines between o-cresol and hippuric acid in urine revealed that the maximal slope was almost 8 times as large as the minimal one. From 8 female workers, five urine samples each were collected during 8-h worktime on two consecutive Mondays and analyzed for the two metabolites. The slopes of the regression lines between o-cresol and hippuric acid in the samples from the same subject were identical, regardless of variation in exposure intensity. The findings indicate that an individual difference exists in the pattern of toluene metabolism, and that the ratio between aliphatic and aromatic oxidation is presumably set congenitally. Possible toxicological significance is discussed.

Air Pollutants, Occupational↗
PubMed2005

Destruction of cresols by Fenton oxidation process.

The present study was used to probe the treatment of simulated wastewater containing cresols by Fenton process. Experiments were conducted in a batch reactor to examine the effects of operating variables like pH, hydrogen peroxide concentration (H(2)O(2)) and ferrous ion concentration (Fe(2+)) on chemical oxygen demand (COD) removal. The progress of the degradation reaction was monitored by the decrease in COD content in the treated solution. The optimal reacting conditions were experimentally determined and it was found to be [H(2)O(2)]=31.64 mM, [Fe(2+)]=0.90 mM for o- and p-cresol while 0.72 mM for m-cresol at pH=3.0+/-0.2. The degradation efficiency for cresol isomers was as high as 82% within 120 min at optimum conditions. A pseudo-first-order kinetic model was adopted to represent the Fenton oxidation for cresols. The mineralization rate for cresols obeys the following sequence: m->p->o-. Maximum degradation occurred at 30 degrees C for the temperature range of 20-50 degrees C studied. The global activation energy for the first-order reaction was estimated to be in the range of 12.90-16.25 kJ/mol. Air/nitrogen did not play an active role in completely mineralizing the organic intermediates at the experimental conditions adopted. Irrespective of the position of methyl group in o-, m- or p-position, the maximum dissolved organic carbon (DOC) removal efficiency was 42%. Only 2/5th of cresol was mineralized to CO(2) by Fenton process. The results showed that the cresols were completely oxidized and degraded into lower molecular weight aliphatic acids. Among the acids, acetic and oxalic acids were identified as the major products formed during the degradation.

Acetic Acid↗
PubMed2003

Multicentre evaluation of in vitro contracture testing with bolus administration of 4-chloro-m-cresol for diagnosis of malignant hyperthermia susceptibility.

BACKGROUND AND OBJECTIVE: The in vitro contracture test with halothane and caffeine is the gold standard for the diagnosis of susceptibility to malignant hyperthermia (MH). However, the sensitivity of the in vitro contracture test is between 97 and 99% and its specificity is 78-94% with the consequence that false-negative as well as false-positive test results are possible. 4-Chloro-m-cresol is potentially a more specific test drug for the in vitro contracture test than halothane or caffeine. This multicentre study was designed to investigate whether an in vitro contracture test with bolus administration of 4-chloro-m-cresol can improve the accuracy of the diagnosis of susceptibility to MH. METHODS: Three hundred and fifty-two patients from 11 European MH laboratories participated in the study. The patients were first classified as MH susceptible, MH normal or MH equivocal by the in vitro contracture test according to the European MH protocol. Muscle specimens surplus to diagnostic requirements were used in this study (MH susceptible = 103 viable samples; MH equivocal = 51; MH normal = 204). 4-Chloro-m-cresol was added to achieve a concentration of 75 micromol L(-1) in the tissue bath. The in vitro effects on contracture development and muscle twitch were observed for 60 min. RESULTS: After bolus administration of 4-chloro-m-cresol, 75 micromol L(-1), 99 of 103 MH-susceptible specimens developed marked muscle contractures. In contrast, only two of 204 MH-normal specimens showed an insignificant contracture development following 4-chloro-m-cresol. From these results, a sensitivity rate of 96.1% and a specificity rate of 99.0% can be calculated for the in vitro contracture test with bolus administration of 4-chloro-m-cresol 75 micromol L(-1). Forty-three patients were diagnosed as MH equivocal, but only specimens from 16 patients developed contractures in response to 4-chloro-m-cresol, indicating susceptibility to MH. CONCLUSIONS: The in vitro contracture test with halothane and caffeine is well standardized in the European and North American test protocols. However, this conventional test method is associated with the risk of false test results. Therefore, an improvement in the diagnosis of MH is needed. Regarding the results from this multicentre study, the use of 4-chloro-m-cresol could increase the reliability of in vitro contracture testing.

Biopsy↗
PubMed1966

The metabolism of cresols by species of Pseudomonas.

1. A comparison of rates of oxidation of various compounds by whole cells indicated that protocatechuate was a reaction intermediate when a non-fluorescent species of Pseudomonas oxidized p-cresol. In contrast, a fluorescent Pseudomonas oxidized 3-methylcatechol and 4-methylcatechol when grown with p-cresol, but did not oxidize protocatechuate. 2. Heat-treated extracts of the fluorescent Pseudomonas oxidized catechol, 3-methylcatechol and 4-methylcatechol to ring-fission products, the spectroscopic properties of which were recorded. Rates of enzymic degradation of these products were also measured. 3. Acetic acid and formic acid were obtained by the action of a Sephadex-treated extract on 3-methylcatechol and 4-methylcatechol respectively. In each case 0.8mol. of the carboxylic acid was formed from 1.0mol. of substrate. 4. Dialysed extracts converted 3-methylcatechol into acetaldehyde and pyruvate, with 4-hydroxy-2-oxovalerate as a reaction intermediate. 4-Methylcatechol was converted first into 4-hydroxy-2-oxohexanoate and then into propionaldehyde and pyruvate. 5. The ring-fission product of catechol was formed from phenol by a fluorescent Pseudomonas, that of 3-methylcatechol was formed from o-cresol and m-cresol, and the ring-fission product of 4-methylcatechol was given from p-cresol. Propionate was readily oxidized by these cells after growth with p-cresol, but this compound was not attacked when phenol, o-cresol or m-cresol served as source of carbon. 6. Cell extracts appeared to attack only one enantiomer of synthetic 4-hydroxy-2-oxohexanoate.

Acetaldehyde↗
PubMed2002

Contact allergy to o-cresol--a sensitizer in phenol-formaldehyde resin.

BACKGROUND: In patients hypersensitive to phenol formaldehyde resin (PFR) it is, for therapeutic and preventive reasons, important to know the identity of the primary sensitizing substances, their sensitizing capacity, as well as their cross-reaction patterns. When elucidating the issue of cross reactivity in patients with contact allergy to simple methylol phenols (MP), o-cresol was shown to be a contact sensitizer. Besides cross reactivity, contamination of one or more MP(s) in o-cresol as well as o-cresol being a sensitizer of its own in PFR were possible explanations of the simultaneous positive patch test reactions to MP and o-cresol. OBJECTIVE: The aim of this study was to investigate if the simultaneous allergic reactions to PFR and o-cresol could be explained by the presence of this substance in PFR. METHODS: Patch testing, high-pressure liquid chromatography (HPLC), nuclear magnetic resonance spectrometry (NMR), gas chromatography (GC), and mass spectrometry (MS) were used. RESULTS: o-Cresol was isolated from the specific PFR used in our standard patch test series and identified. The concentration in the resin was 0.066% wt/wt. CONCLUSION: The current study establishes o-cresol as a contact sensitizer in a PFR. The observed reactions to o-cresol could be on the basis of cross reactivity or primary sensitization.

Allergens↗
PubMed1993

Use of Fluorinated Compounds To Detect Aromatic Metabolites from m-Cresol in a Methanogenic Consortium: Evidence for a Demethylation Reaction.

Anaerobic sewage sludge was used to enrich a methanogenic m-cresol-degrading consortium. 6-Fluoro-3-methylphenol was synthesized and added to subcultures of the consortium with m-cresol. This caused the accumulation of 4-hydroxy-2-methylbenzoic acid. In a separate experiment, the addition of 3-fluorobenzoic acid caused the transient accumulation of 4-hydroxybenzoic acid. Inhibition with bromoethanesulfonic acid caused the accumulation of benzoic acid. Thus, the proposed degradation pathway was m-cresol --> 4-hydroxy-2-methylbenzoic acid --> 4-hydroxybenzoic acid --> benzoic acid. The m-cresol-degrading consortium was able to convert exogenous 4-hydroxybenzoic acid and benzoic acid to methane. In addition, for each metabolite of m-cresol identified, the corresponding fluorinated metabolite was detected, giving the following sequence: 6-fluoro-3-methylphenol --> 5-fluoro-4-hydroxy-2-methylbenzoic acid --> 3-fluoro-4-hydroxybenzoic acid --> 3-fluorobenzoic acid. The second step in each of these pathways is a novel demethylation which was rate limiting. This demethylation reaction would likely facilitate the transformation of the methyl group to methane, which is consistent with the results of a previous study that showed that the methyl carbon of m-[methyl-C]cresol was recovered predominantly as [C]methane (D. J. Roberts, P. M. Fedorak, and S. E. Hrudey, Can. J. Microbiol. 33:335-338, 1987). The final aromatic compound in the proposed route for m-cresol metabolism was benzoic acid, and its detection in these cultures merges the pathway for the methanogenic degradation of m-cresol with those for the anaerobic metabolism of many phenols.

Journal Article↗