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PubMed2005

Formation of conjugate adducts in the reactions of malonaldehyde-acetaldehyde and malonaldehyde-formaldehyde with guanosine.

The reactions of guanosine with malonaldehyde in buffered aqueous solutions in the presence of acetaldehyde or formaldehyde were studied. The reaction mixtures were analyzed by RP-HPLC. Two adducts were formed in the reaction of malonaldehyde and acetaldehyde and one in the reaction of malonaldehyde and formaldehyde. The products were isolated and purified by preparative C-18 chromatography and structurally characterized by UV absorbance, 1H NMR, and 13C NMR spectroscopy and mass spectrometry. The adducts formed in the reaction of malonaldehyde and acetaldehyde were identified as 7-(2,2-diformyl-1-methylethyl)-3-(beta-D-ribofuranosyl)pyrimido[1,2-a]-purin-10(3H)-one (M2AA-Guo I) and 2-(3,5-diformyl-4-methyl-1,4-dihydro-1-pyridyl)-9-(beta-D-ribofuranosyl)-purin-6(9H)-one (M2AA-Guo II). In the reaction of malonaldehyde and formaldehyde, the major product was identified as 7-formyl-3-(beta-D-ribofuranosyl)pyrimido[1,2-a]purin-10(8H)-one (M1FA-Guo). The highest yields of M2AA-Guo I and M2AA-Guo II, 7 and 2 mol %, respectively, were obtained in the reaction performed at pH 7.4 and 37 degrees C for 6 days, while M1FA-Guo was produced at a yield of 0.3 mol % after 3 days of reaction at pH 7.4 and 37 degrees C. The products are formed by reactions of malonaldehyde-acetaldehyde and malonaldehyde-formaldehyde condensation products with guanosine and are analogous to the previously identified condensation products formed with adenosine, cytidine, and proteins.

Acetaldehyde↗
PubMed1997

Determination of extent of formaldehyde-induced crosslinking in hard gelatin capsules by near-infrared spectrophotometry.

PURPOSE: To predict the degree of crosslinking from formaldehyde-stressed hard gelatin capsules (HGCs) using near-infrared spectrophotometry (NIR). METHODS: HGCs were exposed to a 150 ppb atmosphere of formaldehyde for 2.25, 4.60, 9.42, 16.0 and 24.0 hours. The capsules were filled with fresh amoxicillin, placed in a 90 degrees conical reflector cone, and scanned in a NIR spectrophotometer. Principal component regression (PCR) was employed to analyze the spectra of the intact capsules. Dissolution profiles were then obtained for each experimental group. RESULTS: The dissolution of amoxicillin from the capsules at pH 1.2 was found to decrease with increasing time of exposure to the formaldehyde atmosphere. A set of principal components (PCs) was formed by a linear combination of the absorbance values at each wavelength scanned. A good correlation was established (r2 = 0.963) when PC values from the NIR spectra of the HGCs were regressed against percentage of amoxicillin dissolved at 45 minutes, at pH 1.2. Water content of the capsules was found to be the largest determinant in the variation between HGC spectra at each exposure time. CONCLUSIONS: NIR spectrophotometry, combined with PCR, was successful at not only predicting dissolution of HGCs exposed to formaldehyde, but also at determining which wavelengths contributed most to spectral variation of these stressed HGCs.

Amoxicillin↗
PubMed1993

Three approaches to the analysis of trace formaldehyde in bulk and dosage from pharmaceuticals.

Trace-level determinations for the presence of formaldehyde in both bulk and dosage form pharmaceuticals were developed using three innovative strategies. One system adapted the chromotropic acid spot test for formaldehyde. This was accomplished spectrophotometrically over a linear detection range against authentic control samples. The other two chromatographic approaches necessitated rapid derivatization. One derivative was its corresponding oxime, formaldoxime, which was resolved on a gas chromatographic porous polymer column and sensed by a nitrogen-specific detector. The other derivative, sodium formate, was detected and quantified on an ion chromatograph using an anion-exchange column and a conductivity detector. The chromotropic acid technique was sensitive but not specific for formaldehyde. The chromatographic techniques required a high degree of water solubility. All were subject to interferences that could preclude their use for a particular application. None of the tested samples, which included a penicillin analogue, a pharmaceutical dosage from additive, a vitamin, and biological proteins, showed the presence of formaldehyde at trace levels.

Chromatography, Gas↗
PubMed2002

Biodegradation of formaldehyde and its derivatives in industrial wastewater with methylotrophic yeast Hansenula polymorpha and with the yeast-bioaugmented activated sludge.

Methylotrophic yeast Hansenula polymorpha were shown to cooperate with activated sludge from biological wastewater treatment stations, enhancing substantially its potential to biodegrade formaldehyde in industrial wastewater. After integration with yeast cells the modified sludge retained its original structure and activity whereas its resistance to elevated formaldehyde concentrations was significantly improved. The applicability of the yeast in the utilization of formaldehyde derivatives, as exemplified by urotropine and trioxane, was also investigated. The treatment of urotropine-containing wastewater with methylotrophic yeast was found to be effective at acidic conditions (pH below 5.5). Trioxane was not degraded due to the stability of an ether bond which made themolecule recalcitrant to oxidation via methylotrophic pathway reactions. It is concluded that the yeast species may be applied to treat wastewater containing formaldehyde and some of its derivatives as either monocultures or as an integrated, specialized element of the activated sludge biocenosis.

Biodegradation, Environmental↗
PubMed2003

Presence of formaldehyde in topical corticosteroid preparations available on the Swedish market.

The aim of this study was to investigate the formaldehyde content of topical corticosteroid preparations available on the Swedish market. 73 samples were analysed with the chromotropic acid (CA) method for semi-quantitative formaldehyde determination and 30 samples with a high-performance liquid chromatographic method. These included 24 ointments, 28 creams, 1 lotion, 6 liniments, 2 gels, 9 solutions, 2 mousses and 1 oral paste. Formaldehyde was found in 5 creams and 1 ointment. Sources of formaldehyde in these preparations were discussed. Isopropanol was identified as a probable source of yellow discoloration, leading to false-negative results with the CA method.

Administration, Cutaneous↗
PubMed1999

A diffusive sampling device for the determination of formaldehyde in air using N-methyl-4-hydrazino-7-nitrobenzofurazan (MNBDH) as reagent.

A new method utilizing the diffusive sampling of formaldehyde in air has been developed. Formaldehyde is sampled with the use of a glass fiber filter impregnated with N-methyl-4-hydrazino-7-nitrobenzofurazan (MNBDH) and phosphoric acid. The formaldehyde hydrazone formed is desorbed from the filter with acetonitrile and determined by high-performance liquid chromatography (HPLC) with UV/visible detection at 474 nm. The sampling rate was determined to be 24.7 mL min-1 with a relative standard deviation of 7% for 48 experiments. The measured sampling rates were not dependent on the formaldehyde concentration (0.1-1.0 mg m-3), sampling time (15-482 min) or relative humidity (20-85%). The detection limit was 70 micrograms m-3 for a 15 min sampling period and 2 micrograms m-3 for an 8 h sampling period.

Air Pollution, Indoor↗
PubMed1994

A novel dye-linked formaldehyde dehydrogenase with some properties indicating the presence of a protein-bound redox-active quinone cofactor.

Dye-linked formaldehyde dehydrogenase from methylamine-grown Hyphomicrobium zavarzinii ZV 580, a tetramer of M(r) 210,000 with subunits of M(r) 54,000, was purified to homogeneity in five steps with 10% yield. The enzyme shows optimal affinity for, and activity with, formaldehyde (Km 67 microM) compared with other aldehydes. Pyridoxal phosphate, pyrroloquinoline quinone and other cofactors that would give the enzyme a distinctive absorption spectrum are absent. Slight changes are observed in the spectrum at 300-550 nm on oxidation of the enzyme with Wurster's Blue (WB) and reduction with formaldehyde. Titration of the native reduced enzyme with WB accounts for 2 mol of electrons per mol of tetrameric enzyme. The circumstantial evidence supporting the presence of a redox-active quinone cofactor bound to the polypeptide chain comprises a signal at g = 2.0049 in the X-band e.p.r. spectrum of the enzyme oxidized with WB, which disappears on reduction with formaldehyde, and a positive reaction of the native as well as the denatured and dialysed enzyme in the redox-cycling assay with glycinate and NitroBlue Tetrazolium (quinone staining). The oxidized enzyme is inhibited by equimolar amounts of phenylhydrazine, which is also a reductant. Hydrazone formation was absent with completely inhibited enzyme, according to photometric evidence. Likewise, the glycinate-dependent reduction of NitroBlue Tetrazolium was not affected by the inhibitor. It is concluded that an oxidation product of the hydrazine is the actual inhibitor which reacts with an amino acid residue of the active site rather than with the prospective quinone cofactor.

Aldehyde Oxidoreductases↗
PubMed1999

Comparison of cytokine secretion profiles provoked in mice by glutaraldehyde and formaldehyde.

BACKGROUND: Glutaraldehyde and formaldehyde are commonly used sterilizing agents that are known skin sensitizers. There is some controversy, however, regarding their capacity to cause respiratory allergy. The authors have demonstrated previously that topical exposure of mice to chemical contact allergens such as 2,4-dinitrochlorobenzene (DNCB) or respiratory allergens such as trimellitic anhydride (TMA) induces characteristic cytokine secretion profiles consistent with the selective activation of T helper1 (TH1)- and TH2-type cells, respectively. OBJECTIVE: To investigate the quality of immune response provoked following topical exposure of mice to these materials. METHODS: BALB/c strain mice were exposed topically to 50% formaldehyde or to various concentrations of glutaraldehyde in acetone. Control animals were treated concurrently with the reference contact allergen DNCB (1% in acetone:olive oil [AOO]) or with the reference respiratory sensitizer TMA (10% in AOO). Thirteen days after the initiation of exposure, draining lymph node cells (LNCs) were cultured for 12-120h and cytokine content of supernatants analysed by cytokine-specific enzyme-linked immunosorbent assay. RESULTS: DNCB-alpha and formaldehyde-activated LNCs produced high levels of the TH1-type cytokine interferon gamma, but little of the TH2-type products interleukins 4 and 10. TMA- and glutaraldehyde-stimulated LNCs displayed the converse TH2-type pattern of cytokine expression. CONCLUSIONS: These data are consistent with glutaraldehyde, but not formaldehyde, having significant potential to cause allergic sensitization of the respiratory tract.

Administration, Topical↗
PubMed1984

The effect of formaldehyde or glutaraldehyde application to lucerne before ensiling on silage fermentation and silage N digestion in sheep.

The primary growth of lucerne (Medicago sativa) was ensiled after treatment with either formic acid alone (4.1 litres/t; silage F) or with formic acid and either formaldehyde (30.5 g/kg crude protein (nitrogen X 6.25; CP); silage FF), glutaraldehyde (44.2 g/kg CP; silage FG) or a mixture of the two aldehydes at approximately half their individual application rates (silage FFG). Compared with formic acid alone, both formaldehyde and glutaraldehyde reduced protein breakdown and carbohydrate fermentation during ensiling. The extent of protein protection afforded within the silo was similar for the two aldehydes, whereas formaldehyde was more effective in restricting carbohydrate fermentation. The effect of treatment FFG on silage fermentation was confounded by the silo bag bursting and the development of a clostridial-type fermentation. All aldehyde treatments reduced silage soluble-N content but N disappearance when the silages were incubated in polyester bags in the rumen was high for all silages and reductions due to the aldehydes were small. Silage digestion was studied in four mature sheep each fitted with a rumen cannula and re-entrant cannulas in the proximal duodenum and distal ileum. The apparent digestibility of organic matter (OM) in the whole tract was reduced (P less than 0.05) to a similar extent by both aldehydes, whereas rumen OM digestion was reduced (P less than 0.05) more by glutaraldehyde than by formaldehyde. The effects on digestion appeared to be due to the action of the aldehydes on the foods rather than to any adverse influences of the aldehydes on the metabolism of the rumen microbes because, although rumen ammonia levels were lower (P less than 0.05) when the aldehyde-treated silages were given, rumen casein-degrading activity, the degradation of different feedstuffs when incubated in polyester bags in the rumen and microbial N flow at the duodenum did not differ (P greater than 0.05) between silages. All aldehyde treatments decreased (P less than 0.05) the apparent digestibility of N in the whole tract. Silage N degradability in the rumen was also decreased (P less than 0.05) from 0.82 for silage F to 0.67, 0.60 and 0.62 for silages FF, FG and FFG respectively, and consequently non-ammonia-N (NAN) flow at the duodenum increased (P less than 0.05). The aldehydes did not adversely affect the apparent digestibility of NAN in the small intestine, and net NAN absorption from the small intestine increased from 8.8 g/d with silage F to 11.4, 15.3 and 14.2 g/d with silages FF, FG and FFG respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Aldehydes↗
PubMed1975

Formaldehyde and paraformaldehyde study in funeral homes.

Formaldehyde is a toxic gas and classed as an upper respiratory irritant. The gas possesses distinctive physiological properties causing symptoms familiar to many formaldehyde workers, such as: burning of the eyes, lacrimation, and general irritation of the upper respiratory passages. To demonstrate this toxic action of formaldehyde a study was conducted in embalming rooms of funeral homes to determine the concentration and its effect on the embalmers at this level. The control measures in these establishments were also evaluated and found to be inadequate in some respects. Paraformaldehyde powders were sized and found to contain a respirable fraction. The results of the study show that these workers verified the fact that formaldehyde is an irritant at levels that are below the present Threshold Limit Value.

Air Pollutants, Occupational↗
PubMedDate not supplied

Pulmonary function in wood workers exposed to formaldehyde: a prospective study.

Employees exposed to formaldehyde in the woodworking industry (N = 47) and nonexposed control subjects (N = 20) were examined in 1980 by spirometry and the nitrogen washout technique. A transient impairment of lung function was noted over a work shift. Five years later, 21 subjects were still experiencing exposure to formaldehyde. A transient decrease in lung function was again found over a work shift, as evidenced by a reduction in forced mid-expiratory flow (FEF25-75) of 0.15 l/s and an increase in closing volume (CV%) of 3.0% in nonsmokers. Significant decreases in forced expired volume in 1 s as a percent of forced vital capacity (FEV1.0/FVC) and FEF25-75 were also noted over the 5 y in nonsmokers (0.4% and 0.2 l.s/y, respectively, after correction for normal aging). After 4 wk of no exposure (holidays), FEF25-75 and forced expired vital capacity (FVC, FEV1.0) returned to normal in the smoking group. Lung function in smokers improved less during the holiday. A dose-response relationship was found between exposure to formaldehyde and decrease in lung function. Thus, industrial exposure to formaldehyde causes transient lung function impairment over a work shift, with a cumulative effect over the years. The impairment, however, can be reversed with 4 wk of no exposure.

Adult↗
PubMed2005

Transcriptomic analysis of F344 rat nasal epithelium suggests that the lack of carcinogenic response to glutaraldehyde is due to its greater toxicity compared to formaldehyde.

Formaldehyde is cytotoxic and carcinogenic to the rat nasal respiratory epithelium inducing tumors after 12 months. Glutaraldehyde is also cytotoxic but is not carcinogenic to nasal epithelium even after 24 months. Both aldehydes induce similar acute and subchronic histopathology that is characterized by inflammation, hyperplasia, and squamous metaplasia. Because early aldehyde-induced lesions are microscopically similar, we investigated whether transcriptional patterns using cDNA technology could explain the different cancer outcomes. Treatments included 1-, 5-, or 28-day exposure by nasal instillation of formaldehyde solution (400 mM) or glutaraldehyde solution (20 mM). Animals were euthanized and the nasal respiratory epithelium removed for gene expression analysis and a subset of rats treated for 28 days was processed for microscopic examination. RNA was isolated and processed for expression assessment using Clontech Atlas Toxicology II Arrays. Both aldehydes induced hyperplasia, squamous metaplasia, and inflammatory infiltrates with scattered apoptotic bodies in the epithelium covering luminal surfaces of the nasoturbinate, maxilloturbinate, and nasal septum. A subset of 80 genes that were the most variant between the treated and control included the functional categories of DNA repair and apoptosis. Hierarchical clustering discriminated chemical treatment effects after 5 days of exposure, with 6 clusters of genes distinguishing formaldehyde from glutaraldehyde. These data suggest that although both aldehydes induced similar short-term cellular phenotypes, gene expression could distinguish glutaraldehyde from formaldehyde. The gene expression patterns suggest that glutaraldehyde's lack of carcinogenicity may be due to its greater toxicity from lack of DNA-repair, greater mitochondrial damage, and increased apoptosis.

Administration, Intranasal↗
PubMedDate not supplied

Migration of melamine and formaldehyde from tableware made of melamine resin.

Migration of melamine and formaldehyde into food-simulating solvents from cups made of melamine resin was studied under various conditions. Little migration of melamine was observed in any unused cups kept at 60 degrees C for 30 min, room temperature (26 degrees C) for 1 h or cooled at -20 degrees C for several days. Migration of both compounds was strongly affected by heating and acidity. The highest migration of melamine into 4% acetic acid used as a food-simulating solvent was 42.9 +/- 7.2 ppm when the migration test was repeated seven times at 95 degrees C for 30 min. In this time, the migration of formaldehyde was 14.2 +/- 0.6 ppm into the solvent. The molecular ratio of the migration amount of formaldehyde to melamine decreased according to the formula Y = 9.15X-0.813 over seven repetitions of the test, and was maintained at about 1.6 between the 10th and 20th repetitions. The inner surface of the cups became tarnished during the repetition of the test and their roughness increased from 1 micron before the test to 2.5-5 microns after 20 repetitions of the test. Migration of melamine from the cups being used at a cafeteria was 0.4 +/- 0.5 ppm, but that of formaldehyde was undetectable when the cups were kept at 60 degrees C for 30 min with 4% acetic acid.

Chemical Phenomena↗
PubMed1992

Medical students' exposure to formaldehyde in a gross anatomy dissection laboratory.

The authors studied 150 first-year medical students exposed to formaldehyde during the dissection of cadavers in a gross anatomy laboratory. As a reference group, they used 189 third- and fourth-year medical students matched for sex, ethnic group, and age. Environmental and personal samples were collected to determine the exposure to formaldehyde among the first-year students. The mean concentration of formaldehyde in parts per million (ppm) in the area was 0.50 ppm (range = 0.40-0.60 ppm) and the personal sample was 0.74 ppm (range = 0.41-1.20 ppm). No significant differences were noted in the pre- and post-exposure mean FEV1 (forced expiratory volume in 1 second) and FVC (forced vital capacity) among the 22 randomly selected exposed male and female subjects. Significant differences, however, were observed in the exposed group for symptoms of decreased ability to smell, eye irritation, throat irritation, and dry mouth in comparison with the reference group. These symptoms were also significantly related to the time and place of occurrence. Medical schools should take more concrete measures to reduce students' exposure to formaldehyde. Meanwhile, although it is not now the practice in most medical schools, students should have ready access to goggles and respirators when working in dissection laboratories.

Air Pollutants, Occupational↗
PubMed2001

Personal exposure levels and microenvironmental concentrations of formaldehyde and acetaldehyde in the Helsinki metropolitan area, Finland.

Personal 48-hr exposures to formaldehyde and acetaldehyde of 15 randomly selected participants were measured during the summer/autumn of 1997 using Sep-Pak DNPH-Silica cartridges as a part of the EXPOLIS study in Helsinki, Finland. In addition to personal exposures, simultaneous measurements of microenvironmental concentrations were conducted at each participant's residence (indoor and outdoor) and workplace. Mean personal exposure levels were 21.4 ppb for formaldehyde and 7.9 ppb for acetaldehyde. Personal exposures were systematically lower than indoor residential concentrations for both compounds, and ambient air concentrations were lower than both indoor residential concentrations and personal exposure levels. Mean workplace concentrations of both compounds were lower than mean indoor residential concentrations. Correlation between personal exposures and indoor residential concentrations was statistically significant for both compounds. This indicated that indoor residential concentrations of formaldehyde and acetaldehyde are a better estimate of personal exposures than are concentrations in ambient air. In addition, a time-weighted exposure model did not improve the estimation of personal exposures above that obtained using indoor residential concentrations as a surrogate for personal exposures. Correlation between formaldehyde and acetaldehyde was statistically significant in outdoor microenvironments, suggesting that both compounds have similar sources and sinks in ambient urban air.

Acetaldehyde↗
PubMed2002

Cigarette smoke and its formaldehyde component inhibit bradykinin-induced calcium increase in pig aortic endothelial cells.

Bradykinin-induced increase in the intracellular concentration of free calcium evokes an activation of the endothelial nitric oxide synthase (eNOS) enzyme, producing nitric oxide (NO). Cigarette smoke inhibits the eNOS-NO-cGMP signaling pathway. The pathomechanism of this deleterious effect of smoke on NO production is unknown. The aim of this study was to investigate the effect of gas phase smoke trapped in a buffer (smoke buffer, SB) on the bradykinin-induced calcium increase in cultured endothelial cells. FURA-2-AM was used to detect bradykinin-induced calcium increase. A sensitive, fluorescent method using O-phthaldialdehyde was used for the determination of intracellular reduced glutathione (GSH) and protein-thiol levels. SB caused a time- and concentration-dependent inhibition of bradykinin-induced calcium increase. Formaldehyde, a component of SB, inhibited bradykinin-induced calcium increase in concentrations characteristic for SB. SB decreased both the intracellular GSH (0.22 +/- 0.06 vs. 2.23 +/- 0.32 mumol/g protein, SB vs. control, p < .001) and protein-thiol levels (4.98 +/- 0.54 vs. 7.31 +/- 0.97 microEqu GSH/g protein, SB vs. control, p < .05) in the endothelial cells. Intracellular GSH and protein-thiol levels were not changed by 80 microM formaldehyde. GSH (4 mM) prevented the effect of SB (p < .001) and formaldehyde (p < .05) on the bradykinin-induced calcium increase. Our data support the premise that SB inhibits bradykinin-induced calcium increase. This inhibition is partially due to protein-thiol oxidation but may also be caused by the formaldehyde content of SB, which inhibits calcium increase in a protein-thiol-independent manner.

Animals↗
PubMedDate not supplied

Effects of sulfur dioxide and formaldehyde on particle clearance in the rat.

The effects of exposures to sulfur dioxide and formaldehyde atmospheres on the clearance of inhaled, insoluble tracer particles from the lungs of rats have been studied. The tracer particles employed were polystyrene latex microspheres radio-labeled with 51Cr. Following the deposition of the 1.9-micron activity median aerodynamic diameter (AMAD) particles, the rats were divided into 3 groups for a single 4-h exposure to purified air, 20 ppm sulfur dioxide, or 20 ppm formaldehyde. Early, presumably upper-respiratory-tract, clearance was monitored by analysis of radioactivity excreted in feces, while late, presumably deep-lung, clearance was followed by thoracic counting of the animals. Both the sulfur dioxide and formaldehyde atmospheres did significantly delay early clearance (p less than 0.1, two-tailed t-test). However, the late clearance rates of the two pollutant-exposed groups of rats were not significantly different from that of the purified air-exposed group of rats. Although sulfur dioxide had numerically greater effects than formaldehyde, the differences were not statistically significant at the p less than 0.1 level.

Air Pollutants↗
PubMed1991

Effects of acute exposure to formaldehyde on surface morphology of nasal epithelia in rats.

This study investigated the distribution of epithelial cells over the turbinates in the rat nasal cavity and their injury following exposure to formaldehyde. Rats were exposed to either purified air or 10 ppm formaldehyde for a period of 4 h. The noses removed from these rats were decalcified, sectioned midsagittally along the septum to expose the internal turbinates, and processed for examination by scanning electron microscopy. The distribution of the various cell types present was documented in the control rats. Observations obtained from the formaldehyde-exposed rats were compared to those in rats exposed to purified air. Changes were seen in the various regions of the turbinates in the form of ciliary destruction and cell separation (especially in the naso- and moxilloturbinates), cellular swelling (throughout the turbinates), mucus release by the goblet cells (in the nasoturbinate), and in some cases pores on the cell surface or between adjacent cells (evident in the middle meatus). The data from this study indicate that the degree of deleterious effects of formaldehyde on the nasal epithelia of rats is dependent upon cell type and location. Histological studies supported the scanning electron microscopic observations by demonstrating increased goblet cell volume, cell sloughing, and damaged cilia.

Administration, Inhalation↗