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PubMed1982

[Chromosome damages in human lymphocytes as affected by formaldehyde. I. Formaldehyde treatment of lymphocytes in culture].

The cytogenetic activity of formaldehyde was studied in human lymphocytes in vitro. High concentrations of formaldehyde (0.01 mg/ml, 2.5, and 5 mg/l) inhibit mitotic activity of cells to induce polyploidy and chromosome aberrations with high frequency at G2-stage of mitotic cycle. In comparatively low concentrations formaldehyde does not inhibit cell proliferation, and induces chromosome aberrations at G1-S-stages, but not at G2-stage of mitotic cycle. Specific effect of formaldehyde on the distribution of damages pro genome and pro chromosome was also observed.

Cells, Cultured↗
PubMed2000

Sensitive fluorimetric determination of formaldehyde by the co-quenching effect of formaldehyde and sulfite on the fluorescence of tetra-substituted amino aluminium phthalocyanine.

A novel and sensitive fluorimetric method was developed for the determination of formaldehyde based on the co-quenching effect of formaldehyde and sulfite on the fluorescence of tetra-substituted amino aluminium phthalocyanine. Formaldehyde in the concentration range 0.040-1.19 micrograms ml-1 can be determined with a limit of detection of 7.5 ng ml-1. The relative standard deviation for nine replicate measurements of 80.0 ng ml-1 formaldehyde is 1.8%. The method was applied to the analysis of real samples with satisfactory results.

Journal Article↗
PubMed1999

Measurement of formaldehyde as dimedone adduct and potential formaldehyde precursors in hard tissues of human teeth by overpressured layer chromatography.

Simple, automatic overpressured layer chromatographic methods for the parallel determination of endogenous formaldehyde in the form of dimedone adduct and potential formaldehyde generators (betaines) in hard tissues of human teeth are described together with an efficient densitometric evaluation. These simple procedures involve the special preparation of teeth and extraction of formaldehyde, of different binding force in teeth, with methanol containing dimedone, and the isolation of betaines with an aqueous solution of methanol.

Automation↗
PubMed1987

Generation of formaldehyde by N-demethylation of antipyrine. Detection of formaldehyde in bile by 13C-NMR spectroscopy.

The importance of NMR spectroscopy as a tool to investigate metabolic events in vitro and in vivo becomes more and more evident. Particularly 13C-NMR spectroscopy is able to deliver a wide range of information regarding the chemistry of xenobiotics in vivo. We studied the N-demethylation of N-methyl-13C-labelled antipyrine using an isolated perfused rat liver with a fluorocarbon suspension (FC 43) as oxygen carrier. Bile was collected in different fractions during the experiment. On the vascular side metabolite formation was monitored by continuous flow NMR spectroscopy. In bile the metabolic events were detected by standard NMR techniques. The bile spectra exhibit, among others, a signal at 84.2 ppm, indicating formaldehyde hydrate derived from the N-methyl group of antipyrine by an oxidative metabolic pathway. Neither formaldehyde hydrate nor other oxidation products could be detected in the vascular perfusate. The biliary excretion of considerable amounts of formaldehyde during the N-demethylation of antipyrine might have toxicological consequences for the intra- and extrahepatic bile ducts.

Animals↗
PubMed1986

Residual formaldehyde in steam-formaldehyde sterilized materials.

The amounts of residual formaldehyde and paraformaldehyde present in polymeric materials after steam-formaldehyde sterilization in a commercial sterilizer were determined. Appreciable amounts of residue were detected in ethylene-vinyl alcohol copolymer (EVOH), polyamide-6 (PA-6) and natural rubber (NR). These polymers all have a relatively low contact angle with water which indicated that the wettability of a material is an important parameter in determining amount of residue. The residue present in EVOH and in PA-6,6 filter material appeared to be toxic in the HFL-test (a screening test for acute toxicity). This indicated that a more thorough investigation into the possible toxicological consequences of the use of some steam-formaldehyde sterilized materials is necessary.

Biocompatible Materials↗
PubMed1986

Studies on the actions of glutaraldehyde, formaldehyde, and mixtures of glutaraldehyde and formaldehyde on tissue proteins.

The effects of aldehyde fixation on tissue proteins was studied using SDS-polyacrylamide gel electrophoresis. Fixation with low concentrations of formaldehyde or glutaraldehyde had only a slight effect on the protein banding pattern. On the other hand, most of the original protein bands were absent after a short treatment with mixtures of formaldehyde and glutaraldehyde. Spectral absorption measurements showed a stronger absorption at both gamma = 280 nm and gamma = 235 nm with the glutaraldehyde-formaldehyde mixture than with glutaraldehyde alone.

Aldehydes↗
PubMed1996

Comparison of the conformation, hydrophobicity, and model membrane interactions of diphtheria toxin to those of formaldehyde-treated toxin (diphtheria toxoid): formaldehyde stabilization of the native conformation inhibits changes that allow membrane insertion.

Toxoids are inactivated protein toxins that are used in vaccines. The behavior of diphtheria toxin reacted with formaldehyde (diphtheria toxoid) was compared to that of diphtheria toxin in order to understand the nature of the changes that occur in toxoids upon protein reaction with formaldehyde. Despite the intramolecular cross-links in the toxoid, the conformations of the toxoid and the toxin were very similar in both the native and low pH-induced membrane-penetrating states as judged by fluorescence and hydrophobicity properties. However, the toxoid underwent thermal-, low-pH-, and guanidinium chloride-induced conformational changes only at more extreme conditions than needed to induce such changes in the toxin. This implies that formaldehyde modification stabilizes the native conformation relative to several conformations that involve different degrees of unfolding. The stabilization to conformational changes induced by low pH is particularly interesting because low pH induces partial unfolding of the toxin to a molten globule-like state. It was found that the toxoid only gained the ability to interact with model membrane vesicles at a lower pH than the toxin. Because low-pH-induced unfolding and membrane interaction are critical steps in the entry of diphtheria toxin into cells, the resistance of the toxoid to these changes may be linked to its lack of toxicity. The implications of these results for the construction of toxoids are discussed.

Binding Sites↗
PubMed2003

Formaldehyde-negative allergic contact dermatitis from melamine-formaldehyde resin.

Melamine-formaldehyde resin (MFR) is used as a textile finish, in tableware, in surface coatings, and in glues in the furniture and wood industry. MFR is considered to be an infrequent sensitizer. Contact allergy to MFR is often combined with formaldehyde allergy. Patients allergic to textile finish often react to MFR, although other finishes are nowadays more commonly used. Besides allergy to textile finish, allergic contact dermatitis from MFR has been described in workers in composite production and in an orthopaedic plaster technician. To our knowledge, there are no previous reports of contact allergy in the plywood industry from MFR. We describe 3 cases of occupational allergic contact dermatitis from MFR without contact allergy to formaldehyde, 1 in the plywood industry, 1 in the production of melamine-laminated chipboard and 1 in laboratory work.

Adult↗
PubMed2001

[Evaluation on the performance of formaldehyde analyzer with standard formaldehyde gas generated by diffusion tube].

The performance of portable formaldehyde analyzer was tested by a standard formaldehyde gas generation system, the gas was generated by diffusion tube. The evaluation included testing the zero, calibrating the drift, response times and the accuracy of the analyzer, and testing the effect of relative humidity. In compare with the standard method (AHMT method GB/T16129) testing in the fields, the overall relative uncertainty of the formaldehyde analyzer was 7%.

Air Pollutants↗
PubMed1992

[Determination of formaldehyde using the colorimetric method with acetylacetone. I. Determination of formaldehyde in selected cosmetic products].

Total formaldehyde content was determined by the colorimetric method with acetylacetone in shampoos and foam baths. The commercial products containing formaldehyde were fortified with a solution of this compound of various amounts. Recovery in this method was 91.7-98.7%. The method was found useful in routine determinations of formaldehyde in shampoos and foam baths and can be used by the State Sanitary Inspection.

Colorimetry↗
PubMed1989

Disinfection with gaseous formaldehyde. Third Part: Bactericidal and sporicidal effectiveness of gaseous formaldehyde and level of residues in dependence on concentration, temperature and relative humidity.

The highest rate of inactivation of Staphylococcus aureus (ATCC 6538), Streptococcus faecium (ATCC 6057) and spores of Bacillus subtilis var. niger (DSM 675) was observed at a relative humidity (RH) of 90-95%. At a RH of 60% D 0.75 mg HCHO l-1 air at 45 degrees C-values of 35 min and over 65 min were determined for S. aureus and for B. subtilis spores which decreased to D = 2.9 min and D = 20 min respectively at a RH of 90%. At 45 degrees C, an optimal formaldehyde (HCHO) concentration for the inactivation of S. aureus was within the range of 0.75 to 1.5 mg HCHO l-1 air, with D-values of 2.9 to 1.8 min respectively and for Bacillus subtilis spores from 1.5 to 3.2 mg HCHO l-1 air with D-values of 10.9 to 4.0 min respectively. The most effective bactericidal and sporicidal activity of HCHO was observed at temperatures ranging from 40 to 45 degrees C. The higher the exposure temperature the lower were the HCHO residues on 100 cm2 aluminium plates with a structured lacquer. Exposure to formaldehyde concentrations of 0.4 mg l-1 air for 60 minutes resulted in lower residual formaldehyde of 5.9, 5.6, 4.7 and 4.5 micrograms HCHO 100 cm-2 sample surface at 30, 35, 40 and 45 degrees C, respectively. In contrast, after exposures to 3.2 mg HCHO l-1 air residues of 48.5, 43.4, 35.6 and 30.6 micrograms HCHO 100 cm-2 were found at the same temperatures.

Bacillus subtilis↗
PubMed1984

[Orienting studies of the formaldehyde residue in urologic instruments following sterilization with formaldehyde gas].

At an orientating investigation the formaldehyde residue at catheters and tubing was defined after formaldehyde gas sterilisation and a varying dependence of the residue of the concentration of the agent solution, the sterilisation time and the tube resp. catheter material was found. The formaldehyde residues lay in the region of micrograms/cm2. They are higher as in the judgement of the equipment producer. The necessity of the investigation of toxicological importance of the residue is mentioned.

Formaldehyde↗
PubMed1994

[Formaldehyde determination using the colorimetric method with acetylacetone. II. Formaldehyde determination in cosmetic emulsions and certain household products].

Total formaldehyde content was determined by the colorimetric method with acetylacetone in cosmetic emulsions and household products. The commercial products not containing formaldehyde were fortified with 150 micrograms of the investigated compound. Recovery in this method was 93.3-102.6%. The method was found useful in routine determinations of formaldehyde in cosmetics and household products and can be used by the State Sanitary Inspections.

Chromatography, High Pressure Liquid↗
PubMed1998

Airway response to formaldehyde inhalation in asthmatic subjects with suspected respiratory formaldehyde sensitization.

The aim of the study was to characterize the mechanism of formaldehyde (FM)-induced nasal and bronchial response in asthmatic subjects with suspected FM allergy. Ten subjects purported to have FM rhinitis and asthma and 10 healthy subjects submitted to an inhalation provocation in an exposure chamber with FM at a dose of 0.5 mg/m3 over 2 hr. Spirometry at rest and following bronchial provocation with histamine (PC20) were recorded before and after FM inhalation. In addition, FM-specific serum IgE antibodies were measured and cellular, biochemical, and mediator changes were assessed in nasal lavage before, and immediately after, provocation and at 4 hr and 24 hr later. Provocation with FM caused only transient symptoms of rhinitis in both groups. None of the subjects supposed to have occupational asthma developed clinical symptoms of bronchial irritation. No specific IgE antibodies to FM were detected in persons with occupational exposure to FM. No differences in the nasal response to FM were found between subjects reporting to have occupational allergic respiratory diseases and healthy subjects (P > 0.05). In summary, inhaled formaldehyde at a level as low as 0.5 mg/m3 did not induce a specific allergic response either in the upper or in the lower part of the respiratory tract. Moreover, there is no difference in nasal response to FM in asthmatic subjects occupationally exposed to FM and healthy subjects.

Administration, Inhalation↗
PubMed1987

Immunologic studies of subjects with asthma exposed to formaldehyde and urea-formaldehyde foam insulation (UFFI) off products.

There has been concern in recent years as to the health hazards of exposure to potentially carcinogenic or immunotoxic substances in the environment. This study was done to determine the effects of exposure to urea-formaldehyde foam insulation (UFFI) off products on various hematologic and immunologic parameters in subjects with asthma: complete blood count and differential, erythrocyte sedimentation rate, lymphocyte subpopulations (E-rosetting, T3, T4, T8, B73.1, and Fc receptor positive lymphocytes and large granular lymphocytes), lymphocyte response to phytohemagglutinin and formalin-treated red blood cells (Form-RBC), serum antibody against the Thomsen-Friedenreich RBC antigen and against Form-RBC, and natural killer (NK), interferon (IFN)-boosted NK (IFN-NK), and antibody-dependent cell-mediated cytotoxicity. Four control subjects with asthma from conventionally insulated homes (control group) and 23 subjects with asthma from UFFI-insulated homes (home group) were exposed to placebo, formaldehyde, dust, and UFFI off gas at levels ordinarily found in UFFI-containing homes for four separate periods in an environmental chamber. Immunologic testing was carried out before the exposure series and 1 day after completion 7 days later as part of an investigation of respiratory and possible allergic effects of such exposure. Data from the UFFI-insulated home group were not significantly different from data of the normal conventionally insulated home control group for any of the variables studied, either before or after UFFI exposure. Paired t tests comparing data from each of the two groups before and after UFFI exposure demonstrated minimal but statistically significant increases in percent eosinophils and T8 positive cells in the UFFI-insulated home group only. Although NK, relative NK, and IFN-NK were normal in all groups, IFN-NK assays by use of a low concentration of alpha-interferon demonstrated a statistically significant decrease in NK response to IFN in both the control and UFFI-insulated home groups after UFFI exposure. These differences were not observed at optimum levels of IFN stimulation. These data indicate that long-term exposure to UFFI off products in the home apparently had no effect on the immunologic parameters studied. Short-term exposure resulted in minor immunologic changes in this subject population.

Antibody Formation↗
PubMed1979

A steady-state-kinetic model for formaldehyde dehydrogenase from human liver. A mechanism involving NAD+ and the hemimercaptal adduct of glutathione and formaldehyde as substrates and free glutathione as an allosteric activator of the enzyme.

The steady-state kinetics of formaldehyde dehydrogenase from human liver have been explored. Non-linearities were obtained in v-versus-v[S] plots. It was necessary and sufficient to consider two reactants of the equilibrium mixture of formaldehyde, glutathione and their hemimercaptal adduct for a complete description of the kinetics. A random sequential reaction scheme is proposed in which adduct and beta-NAD+ are the substrates. In addition, glutathione can bind to an allosteric regulatory site and only the glutathione-containing enzyme is considered productive. Various alternative reaction models were examined but no simple alterative was superior to the model chosen. The discrimination was largely based on results of non-linear regression analysis. Several S-substituted glutathione derivatives were tested as activators or inhibitors of the enzyme, but all were without effect. Thio-NAD+, nicotinamide--hypoxanthine dinucleotide and 3-acetylpyridine-adenine dinucleotide could substitute for beta-NAD+ as the nucleotide substrate. alpha-NAD+ and ADP-ribose were competitive inhibitors with respect to beta-NAD+ and non-competitive with glutathione and the adduct. When used simultaneously, the inhibitors were linear competitive versus each other, indicating a single nucleotide-binding site or, if more than one, non-co-operative binding sites.

Aldehyde Oxidoreductases↗
PubMed1995

Biological indicators for low temperature steam and formaldehyde sterilization: the effect of defined media on sporulation, growth index and formaldehyde resistance of spores of Bacillus stearothermophilus strains.

Preliminary screening was carried out on spores of 29 strains of Bacillus stearothermophilus to determine their potential as biological indicator organisms for low temperature steam and formaldehyde sterilization. Each strain was sporulated on four chemically defined media. Fourteen strains produced satisfactory sporulation on one or more of the media but there was considerable variation in the extent of sporulation. The growth index of the spores, which was dependent on both the strain of organism and the sporulation medium, ranged from 1% to 90%. The spores were appraised on the basis of their resistance to inactivation by 0.5% w/v formaldehyde in aqueous solution at 70 degrees C. The survivor curves obtained could be characterized into five types on the basis of the shape of the curve. Only five strains of Bacillus stearothermophilus produced spores with the characteristics of high resistance, linear semi-logarithmic survivor curve and high growth index that would be required of a potential biological indicator organism.

Culture Media↗
PubMed1988

Epidemiology of chronic occupational exposure to formaldehyde: report of the Ad Hoc Panel on Health Aspects of Formaldehyde. Universities Associated for Research and Education in Pathology, Inc.

An independent, international panel of scientists reviewed and evaluated the relevant literature on occupational and environmental exposure to formaldehyde and subsequent epidemiology of cancer in exposed populations. Studies of topical sites (respiratory tract and skin) were considered separately from non-topical sites (other major organ systems) and individual assessments were made of evidence of site-specific cancer risk within the broader categories. In addition to the studies per se, the Panel also took into account critiques and reviews of the published reports. The Panel concluded that: 1) for no malignancy in man is there convincing evidence of a relationship with formaldehyde exposure and 2) furthermore, that if a relationship does exist, the excess risk, in absolute terms, must be small. An apparent lack of consistency among the studies in site-specific cancer risk and uncertainty resulting from unresolved confounding by known risk factors were identified by the Panel as significant obstacles to more definitive conclusions.

Epidemiologic Methods↗