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PubMed1984

The action of lanthanum ions and formaldehyde on the proton-pumping function of bacteriorhodopsin.

The photochemical cycle and the proton-pumping function of bacteriorhodopsin modified with lanthanum and formaldehyde has been studied. In both preparations, the M412 leads to BR570 transition time has been found to increase considerably. The deceleration of the photochemical cycle has been shown to be accompanied by inhibition of the millisecond phase of the photoelectrical response of bacteriorhodopsin membranes associated with phospholipid-impregnated collodion film. Photoelectrogenic activity measured with permeable ion probe in proteoliposomes was also inhibited. Effects of lanthanum were reversed by EDTA. Formation of M412 was slightly accelerated and the microsecond electrogenic phase was not affected by lanthanum and by formaldehyde. It is concluded that lanthanum, but not formaldehyde, can be used as a specific reversible inhibitor of the second half of the bacteriorhodopsin photocycle and of the associated H+ uptake on the cytoplasmic side of the halobacterial membrane. Possible mechanisms of these effects are discussed.

Anions↗

PubMed2004

Formaldehyde scavenging from peritoneal dialysis solutions using reduced aminothiol compounds.

BACKGROUND: Aldehydes were identified in clinical solutions, including peritoneal dialysis (PD) and cryoprotection solutions, which were used to freeze cells, tissues and embryos. Aldehydes are associated with increased cellular injury and may contribute to peritoneal membrane damage that occurs in patients on peritoneal dialysis. Recently, it was demonstrated that aldehydes could be 'scavenged' from these solutions by using aminothiol compounds. Although aldehydes were removed during the scavenging process, the kinetics of scavenging and the products formed were not characterized. METHODS: Proton nuclear magnetic resonance (NMR) spectroscopy was used to investigate formaldehyde scavenging from an artificial PD solution supplemented with aminothiol compounds, cysteamine or l-cysteine. Artificial PD solutions were formulated on the basis of commercial PD solutions and consisted of 132 mmol/L NaCl, 0.25 mmol/L MgCl2, 1.25 mmol/L CaCl2, and buffered with lactate (4.0 mmol/L) and lacked d-glucose. Formaldehyde scavenging was a two-step process involving an intermediate step followed by the formation of stable thiazolidine compounds. These included the derivatives of cysteamine and l-cysteine; thiazolidine and thiazolidine-4-carboxylic acid, respectively. CONCLUSION: Scavenging with aminothiol compounds masked the destructive carbonyl group (C = O) of formaldehyde and formed a compound that has antioxidant properties. The addition of aminothiol compounds may improve the biocompatibility of commercial PD solutions.

Cysteamine↗

PubMed1961

Some inhibitors of histamine-induced and formaldehyde-induced inflammation in mice.

The swelling and capillary hyperpermeability of the mouse foot in response to an injection of formaldehyde, and the increased capillary permeability to an intradermal injection of histamine, have been investigated. Cortisone, mepyramine and sodium salicylate were effective in reducing histamine-induced inflammation, sodium salicylate being less active in the adrenalectomized animal. In formaldehyde-induced inflammation, however, cortisone was ineffective whereas sodium salicylate was effective in the intact mouse, but not in the adrenalectomized animal. Certain aryloxypropionates and anti-esterases were also active in reducing the severity of the formaldehyde-induced inflammation.

Analgesics↗

PubMed1999

Gastric outlet obstruction as a late complication of formaldehyde ingestion: a case report.

A patient who ingested formaldehyde in a suicide attempt is described. Although early clinical and endoscopic manifestations appeared relatively mild, after several weeks the patient developed signs and symptoms suggestive of gastric outlet obstruction that eventually required surgical intervention. Formaldehyde ingestion has only rarely been described in the literature. Formaldehyde is a corrosive that can produce late sequelae, similar to the more common ingestion of acids and alkali.

Administration, Oral↗

PubMed1984

Guinea pig maximization tests with formaldehyde releasers. Results from two laboratories.

The guinea pig maximization test was used to evaluate the sensitizing potential of formaldehyde and 6 formaldehyde releasers (Forcide 78, Germall 115, Grotan BK, Grotan OX, KM 200 and Preventol D2). The tests were carried out in 2 laboratories (Copenhagen and Stockholm), and although we intended the procedures to be the same, discrepancies were observed, possibly due to the use of different animal strains, test concentrations and vehicles. The sensitizing potential was in general found to be stronger in Stockholm compared to Copenhagen: formaldehyde sensitized 50% of the guinea pigs in Copenhagen and 95% in Stockholm. For Grotan BK, the corresponding rates were 20% and 74%. Forcide 78, KM 200 and Preventol D2 sensitized 20% to 25% of the animals in Copenhagen, while Germall 115 and Grotan OX sensitized 60% to 70% of the animals in Stockholm.

Animals↗

PubMed1986

Demonstration of contact sensitizers in resins and products based on phenol-formaldehyde.

12 phenol-formaldehyde resins were investigated with regard to the presence of 14 contact sensitizers by using high-pressure liquid chromatography. The allergens consisted of simple methylol phenols, dihydroxydiphenyl methanes, 4,4(1)-dihydroxy-(hydroxymethyl)-diphenyl methanes and 2,4(1)-dihydroxy-(hydroxymethyl)-diphenyl methanes. Four substances, 2,4-dimethylol phenol, 2,6-dimethylol phenol, 4,4(1)-dihydroxydiphenyl methane and 2,4(1)-dihydroxydiphenyl methane, were isolated from a resol resin and identified by mass-spectrometry and nuclear magnetic resonance spectrometry. The highest concentrations (up to 15% w/w) of allergens were noted for methylol phenols in resol resins based on phenol and formaldehyde. The corresponding novolak resins showed a high content of dihydroxydiphenyl methanes. There was great variation in concentration of the sensitizers between the resins. None of these sensitizers were demonstrated in the resin based on paratertiary-butyl phenol. Products based on phenol-formaldehyde resins were also investigated for the presence of allergens. Uncured impregnated paper for laminate production and uncured mineral wool contained the same concentrations of the sensitizers as some of the resins studied. The curing process decreased the content of all the allergens investigated in all products, but the sensitizers did not disappear, and they may thus be present in finished products.

Allergens↗

PubMed1986

The effect of 4 barrier creams on the absorption of water, benzene, and formaldehyde into excised human skin.

The effect of 4 barrier creams on the absorption of (3H)-water (14C)-benzene and (14C)-formaldehyde into excised human skin was studied. The control skin and the barrier cream treated skin were exposed to the test substance for 0.5 hr, whereupon the amount absorbed was determined. The results indicated that the experimental cream "Water barrier" reduced the absorption of water and benzene but not formaldehyde. Kerodex 71 cream slightly reduced the absorption of benzene and formaldehyde. The barrier creams Petrogard and "Solvent barrier" did not affect the absorption of any of the substances studied. The use of these creams against percutaneous absorption is questioned.

Benzene↗

PubMed1991

Formaldehyde is a significant allergen in women with hand eczema.

Among patients consecutively patch tested at St John's from 1984-1989, the prevalence rate of formaldehyde sensitivity was 2.2% for men and 3.7% for women. During these 6 years, 117 women were primarily sensitized by formaldehyde, of whom 61 (52%) had hand eczema. Exposure was occupational in 12% and domestic in 88%. Cleaning products were the main source of exposure in the domestic group. 20 women with hand eczema avoided formaldehyde and their hands healed in 2, greatly improved in 11 and were better in 7.

Allergens↗

PubMed1992

A comparative study of formaldehyde detection using chromotropic acid, acetylacetone and HPLC in cosmetics and household cleaning products.

Chromotropic acid and acetylacetone methods for qualitative determination of formaldehyde were tested in parallel on 48 commercial samples, with high-performance liquid chromotography (HPLC) implemented for quantitative measure. In addition, interference with the detection of formaldehyde was investigated by analyzing 12 other aldehydes and ketones, 7 essential oils and 3 polysorbates. Throughout this comparative study, the disadvantages of the chromotropic acid method, of which 2 variants were used, were delineated and we found that the acetylacetone test proved to be a more efficient screening method for formaldehyde detection in a clinical laboratory.

Chromatography, High Pressure Liquid↗

PubMed1999

Sensitizing potential of acetaldehyde and formaldehyde using a modified cumulative contact enhancement test (CCET).

The contact allergenic activity of acetaldehyde was investigated with a modified cumulative contact enhancement test (CCET) method in guinea pigs. Possible cross-reactivity between acetaldehyde and formaldehyde was also studied. In contrast to the original CCET protocol, we used sham-treated controls and the chemicals were tested with closed epicutaneous application at 1st challenge. The suitability of the method was verified with formaldehyde and the results were comparable with those previously found with the guinea pig maximization test (GPMT). For the 1st time, acetaldehyde was shown to be a contact allergen in predictive tests. No cross-reactivity was observed between acetaldehyde and formaldehyde. Acetaldehyde seems to be a rare sensitizer in man. However, its allergenic activity should be considered, since it might be present as an impurity in ethoxylated surfactants. As the CCET protocol involves topical induction and challenge, we regard the modified version as well suited to evaluation of the contact allergenic potential of chemicals.

Acetaldehyde↗

PubMed2003

Risk assessment of formaldehyde in typical office buildings in Taiwan.

Our study conducts a series of investigations in five office buildings chosen according to the types of construction, ventilation, and building age. Formaldehyde was measured by continuous photoacoustic Multi-Gas monitor Type 1302 (Brüel & Kjaer). The 8-h average concentrations in working hours were used to estimate the lifetime cancer probability (LCP) and chronic non-carcinogenic hazard index (HI). The carcinogenic effect of formaldehyde estimate by LCP (70 years old) is about 2.06 x 10(-4) to 1.75 x 10(-3) after adjusting their working time. The levels of risk are 100-1000 times of the acceptable carcinogenic risk. A similar trend is observed for the levels of HI calculated. Many studies have suggested that exposure to high levels of formaldehyde may cause nasal cancer and other health effects. Therefore, promoting the labeling system for low emission materials to protect consumers from exposure to excessive emissions and helping the industry to develop low emission materials is evidently urgent and deserves greater efforts.

Air Pollution, Indoor↗

PubMed2006

Variations of formaldehyde and VOC levels during 3 years in new and older homes.

UNLABELLED: Indoor air organic compounds were continuously monitored during 3 years in new and older homes which were voluntarily selected throughout countries. The levels of volatile organic compounds (VOCs) in the new homes decreased markedly after 1 year, and steady emissions of VOCs were obtained in the initial months. Formaldehyde and a-pinene related to wooden materials need a longer flushing period than the other compounds in the new homes. The levels of the indoor air organic compounds in the older homes showed no significant fluctuation during the 3-year period. Decreases of the indoor-produced compounds in the new homes did not depend upon the ventilation systems. The results indicate that the indoor-produced compounds in the new homes will be more influenced by the aging decreases of emission source strengths than ventilation systems. The quantitative information on the trend of the indoor air organic compound levels will be useful for the risk assessment of indoor exposure to those compounds, and also for Japanese IAQ guidelines. PRACTICAL IMPLICATIONS: The initial levels of VOCs in the new homes decreased dramatically and were close to the mean values for the older homes after one year. The results suggest that steady emissions of VOCs are obtained within initial months. However, formaldehyde and a-pinene did not follow the trend for VOCs, particularly in the wooden framed houses. The results tend to suggest that formaldehyde and a-pinene related to wooden materials will need more long a flushing period than other compounds in the new homes. Decreasing tendency of indoor air organic compound levels in the new homes did not appear to show any dependency upon the ventilation systems over the whole period. Absence of data for ventilation rates in the houses dose not permit interpretation of the relation between ventilation rates and indoor air organic compound levels with statistical certainty, but the results suggest that indoor air organic compound levels in the homes will be more influenced by emission source strengths than ventilation systems. The levels of indoor air organic compounds in the new homes are sufficiently decreased according to the ageing decreases of organic compounds when the home is ventilated with adequate quantities.

Air Pollutants↗

PubMed1986

The in vitro permeability of human skin to benzene, ethylene glycol, formaldehyde, and n-hexane.

The permeability of human skin to benzene, ethylene glycol, formaldehyde, and n-hexane was studied using excised skin in a flow-through diffusion cell. The rate of resorption was determined by measuring the amount of substance found in the receptor fluid beneath the skin at steady-state. The rates of resorption (microgram X cm-2 X hr-1) were: benzene 99. ethylene glycol 118, formaldehyde from a concentrated solution of formalin 319, formaldehyde from a solution of 10% formalin in phosphate buffer 16.7, and n-hexane 0.83. The amount of substance in the skin at steady-state and after 0.5 hr of exposure was also determined. For all substances, the sum of the amount in the receptor medium and in the skin at steady-state, were larger than the amount obtained by multiplying the resorption rate by the time of exposure. For benzene, ethylene glycol and n-hexane the amount absorbed during the first half-hour of exposure was considerable larger than the amount resorbed during a same unit of time at steady-state. These data call attention to the fact that the absorption rate is higher before steady state is attained.

Benzene↗

PubMed1974

Generation of formaldehyde from methenamine: effect of pH and concentration, and antibacterial effect.

Using an in vitro system that simulates the dynamics of the urinary tract, we have shown that concentrations of formaldehyde >/= 25 mug/ml can be achieved in urine containing >/= 0.6 mg of methenamine per ml at pH </= 5.7 or >/= 1 mg/ml at pH </= 5.85. Exposure to this concentration of formaldehyde for 2 h produced a measurable antibacterial effect. These studies suggest that an effective bacteriostatic level of formaldehyde is likely to be achieved with currently used dosages of methenamine when the urine pH is less than 5.7 to 5.85.

Anti-Bacterial Agents↗

PubMed1994

Cloning and high-level expression of the glutathione-independent formaldehyde dehydrogenase gene from Pseudomonas putida.

A DNA fragment of 485 bp was specifically amplified by PCR with primers based on the N-terminal sequence of the purified formaldehyde dehydrogenase (EC 1.2.1.46) from Pseudomonas putida and on that of a cyanogen bromide-derived peptide. With this product as a probe, a gene coding for formaldehyde dehydrogenase (fdhA) in P. putida chromosomal DNA was cloned in Escherichia coli DH5 alpha. Sequencing analysis revealed that the fdhA gene contained 1,197-bp open reading frame, encoding a protein composed of 399 amino acid residues whose calculated molecular weight was 42,082. The transformant of E. coli DH5 alpha harboring the hybrid plasmid, pFDHK3DN71, showed about 50-fold-higher formaldehyde dehydrogenase activity than P. putida. The predicted amino acid sequence contained several features characteristic of the zinc-containing medium-chain alcohol dehydrogenase (ADH) family. Most of the glycine residues strictly conserved within the family, including a Gly-Xaa-Gly-Xaa-Xaa-Gly pattern in the coenzyme binding domain, were well conserved in this enzyme. Regions around both the catalytic and the structural zinc atoms were also conserved. Analyses of structural and enzymatic characteristics indicated that P. putida FDH belongs to the medium-chain ADH family, with mixed properties of mammalian class I and III ADHs.

Alcohol Dehydrogenase↗

PubMed2000

A novel operon encoding formaldehyde fixation: the ribulose monophosphate pathway in the gram-positive facultative methylotrophic bacterium Mycobacterium gastri MB19.

A 4.2-kb PstI fragment harboring the gene cluster of the ribulose monophosphate (RuMP) pathway for formaldehyde fixation was identified in the chromosome of a gram-positive, facultative methylotroph, Mycobacterium gastri MB19, by using the coding region of 3-hexulose-6-phosphate synthase (HPS) as the hybridization probe. The PstI fragment contained three complete open reading frames (ORFs) which encoded from the 5' end, a DNA-binding regulatory protein (rmpR), 6-phospho-3-hexuloisomerase (PHI; rmpB), and HPS (rmpA). Sequence analysis suggested that rmpA and rmpB constitute an operon, and Northern blot analysis of RNA extracted from bacteria grown under various conditions suggested that the expression of the two genes is similarly regulated at the transcriptional level. A similarity search revealed that the proteins encoded by rmpA and rmpB in M. gastri MB19 show high similarity to the unidentified proteins of nonmethylotrophic prokaryotes, including bacteria and anaerobic archaea. The clusters in the phylogenetic tree of the HPS protein of M. gastri MB19 and those in the phylogenetic tree of the PHI protein were nearly identical, which implies that these two formaldehyde-fixing genes evolved as a pair. These findings give new insight into the acquisition of the formaldehyde fixation pathway during the evolution of diverse microorganisms.

Aldehyde-Lyases↗

PubMed2001

Two-component system that regulates methanol and formaldehyde oxidation in Paracoccus denitrificans.

A chromosomal region encoding a two-component regulatory system, FlhRS, has been isolated from Paracoccus denitrificans. FlhRS-deficient mutants were unable to grow on methanol, methylamine, or choline as the carbon and energy source. Expression of the gene encoding glutathione-dependent formaldehyde dehydrogenase (fhlA) was undetectable in the mutant, and expression of the S-formylglutathione hydrolase gene (fghA) was reduced in the mutant background. In addition, methanol dehydrogenase was immunologically undetectable in cell extracts of FhlRS mutants. These results indicate that the FlhRS sensor-regulator pair is involved in the regulation of formaldehyde, methanol, and methylamine oxidation. The effect that the FlhRS proteins exert on the regulation of C(1) metabolism might be essential to maintain the internal concentration of formaldehyde below toxic levels.

Aldehyde Oxidoreductases↗

PubMed1975

Experiments on terminal disinfection by formaldehyde vapor in the case of smallpox.

The usually recommended terminal disinfection by formaldehyde vapor is unable to completely inactivate vaccinia viruses embedded in scabs. In view of our results, we recommend doubling the concentration of formaldehyde (10 g of formaldehyde per m3 of space) and prolonging the time of exposure to 24 h for terminal disinfection in the case of smallpox. Subsequent disinfection by scrubbing assumes special importance, since no complete inactivation of the scabs occurs.

Animals↗