Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Formaldehyde”

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 829 records · Page 46Linked to original sources
PubMed2003

The acute nephrotoxicity of systemically administered formaldehyde in rats.

AIM: The purpose of this study was to assess the acute nephrotoxicity of formaldehyde, as it is believed to be the toxic component of formocresol. METHODS: A sample of 24 Sprague-Dawley rats was used in the study and divided into 3 groups of 8 rats each. The following procedures were performed: group A) formaldehyde equivalent dose to 20 pulpotomies, injected into the main vein of each rat's tail; group B) formaldehyde equivalent dose to 100 pulpotomies injected; group C) control group with a saline solution injected. Blood analyses were performed after 24 and 48 hours to assess urea and creatinine levels. Urine samples were taken after 24 hours to analyse for LDH protein levels. Rats were sacrificed after 48 hours and histology samples of renal tissue were studied for any pathological defects. RESULTS: Evaluation of histological samples of kidney tissue did not show any inflammation or other tissue lesions. No significant differences were found, using an ANOVA test procedure, among the variables of LDH protein or creatinine levels after 24 and 48 hours. Significant differences were found between the levels of urea and creatinine after 48 hours between the control group and the other test groups. CONCLUSION: The use of formaldehyde at the usual clinical doses or with an amount equivalent to 100 pulpotomies did not produce renal tissue damage and the blood and urine factors analysed did not show significant changes after 48 hours in the experimental model used.

Animals↗
PubMed2003

[Assessing the content of formaldehyde in vermicelli in Changsha market].

In order to better supervise food safety for the residents, the extent of formaldehyde in vermicelli sold on Changsha market was assessed by the acetyl acetone colorimetry method. Results showed that among 106 samples, 61 were formaldehyde positive. The positive rate was 57.55% (61/106). The content of formaldehyde ranged from 0.011 mg/kg to 2.859 mg/kg, indicating severe contamination of vermicellis by formaldehyde in Changsha market and therefore, the food safety supervision work should be strengthened.

China↗
PubMedDate not supplied

[Results of a study on formaldehyde pollution as a cause of discomfort in public sector office workers].

Medical surveillance of Catania public sector employees who use video display terminals (VDTs) revealed complaints of eye and upper respiratory tract irritation, skin rash, headache, mental fatigue and reduced concentration in some of the workers. These were employed in three recently renovated offices and showed the above symptoms while at work. Investigations were performed to verify whether contaminants that may cause the above symptoms were present in the indoor air. In particular, levels of formaldehyde and CO2 were continuously monitored. CO2 levels were found to be higher in offices open to the general public as compared to other offices (including the three renovated ones). However, CO2 levels were never above 1,000 ppm. Formaldehyde was found in the indoor air of all three renovated offices in approximately equal concentrations, ranging from a minimum of 0,07 - 0,09 ppm to a maximum of 0,3 -0,4 ppm. In addition, a strong pungent odor typical of this substance was present in all three renovated offices but not in the others. Formaldehyde pollution must always be considered and assessed whenever new furnishings that may have required the use of glues that emit formaldehyde are brought into an indoor environment.

Air Pollution, Indoor↗
PubMed2004

[Allergy to formaldehyde].

The article presents a case of 56-year-old patient, female, who developed generalized urticaria following dental treatment. The wheals appeared four hours after she left the clinic. During stomatological treatment she was given parapaste, a complex drug, consisting of cinchocaine, eugenol, paraformaldehyde and glycerin. She was admitted to hospital and was treated with prednison and cetirizine. The symptoms resolved in one day and she was discharged. This was the second episode of urticarial reaction to after dental visit. In a previous case, several months earlier, she received parapaste and Scandonest, local anaesthetic. She visited an allergologist after three weeks and skin prick tests with common allergens were done. All were negative. Then the prick tests with the ingredients of parapaste were done resulting in 5 mm diameter wheal to the solution of formaldehyde. We performed RAST to formaldehyde - the result was confirming the presence of antibodies to formaldehyde in a third class. The diagnosis of sensitization to formaldehyde was made. The incidence of allergy to dental drugs was discussed.

Anti-Inflammatory Agents↗
PubMed2004

[Study of direct fluorophotometric and flow-injection fluorophotometric methods based on the inhibitory effect for the determination of trace formaldehyde].

Sulfite reacts with o-phthalaldehyde in the presence of ammonium forming the highly fluorescing isoindole-1-sulfonate in neutral or weakly acid solution, and formaldehyde has inhibitory effect on it. Based on this principle, the authors developed the direct fluorophotometric and flow-injection fluorophotometric methods for the determination of trace formaldehyde. The maximum excitation wavelength and the maximum emission wavelength are 320 and 390 nm respectively. With the direct fluorophotometric method, formaldehyde in the concentration range of 0.10-1.60 microg x mL(-1) can be determined with a detection limit of 0.046 microg x mL(-1). With the flow-injection fluorophotometric method, formaldehyde in the concentration range of 0.10-2.00 microg x mL(-1) can be determined with a detection limit of 0.085 microg x mL(-1). The methods were applied respectively to the analysis of river water with satisfactory results.

Flow Injection Analysis↗
PubMed2005

[Functional activity of blood and liver cells under formaldehyde intoxication via inhalation].

The influence of formaldehyde (of 5 and 10 mg/m3) on the state of the antioxidant system the blood and liver of rats, the activity of pentose phosphate pathway enzymes, and weight of immune organs was investigated. Formaldehyde intoxication led to activation of lipid peroxidation processes in red blood cells and hepatocytes. In the liver cells these changes were accompanied by activation of the antioxidant and detoxification systems. Formaldehyde depleted thiamine diphosphate in the liver, and this effect was not dose-dependent. The number of blood cells remained unchanged. Formaldehyde at the concentration of 10 mg/m3 exerted the negative effect on the thymus. This effect may be related to stimulation of lipid peroxidation.

Administration, Inhalation↗
PubMed2005

[Photocatalytic degradation of low level formaldehyde on TiO2 porous film].

Photocatalytic degradation of low level formaldehyde in the gas phase was studied in a intermittent recirculation photocatalytic reaction system with TiO2 porous film photocatalyst coated on stainless steel mesh. The effects of carrier of the photocatalyst, coating cycle of the photocatalyst, the initial concentration of formaldehyde and the illumination source were investigated respectively. The study of the aging stability of the photocatalyst was carried out as well. Results show that the degradation efficiency of formaldehyde increased with the increase of mesh number. The degradation efficiency also increased with the increase of carrier number, but the influence of carrier number on the degradation efficiexcy was gradually weakened with increasing carrier number. The activity of the photocatalyst firstly increased and then decreased when coating cycle increased from 1 cycle to 6 cycles. When initial concentration was in the range of 1.34 - 10.72 mg/m3, the change of formaldehyde concentration markedly increased with the increase of initial concentration, but the degradation efficiency increased and subsequently decreased with increasing initial concentration. The degradation efficiency with germicidal light was approximately 19.0% higher than that with black light holding same power, and the enhancement in light intensity could approximately increase the degradation efficiency by 20.5%. Finally, the experiment on the longevity of the photocatalyst indicated that the photocatalyst had the good photocatalytic activity after being used for 4 cycles.

Air Pollution, Indoor↗
PubMed2005

[Development and performance evaluation for a solid phase adsorption gas sampler of formaldehyde in indoor air].

OBJECTIVE: We developed a solid phase adsorption gas sampler, which is suitable for collection and analysis of indoor air formaldehyde. METHODS: This solid phase adsorption gas sampler is composed of two parts, a support part made of a glass tube covered silica-gel stopper on ports, an absorbent part in glass tube made of surface denatured synthetic fibre coated formaldehyde absorbent. We evolved its performance, and established an method for sampling and determination formaldehyde in indoor air with the gas sampler. RESULTS: For the solid phase adsorption gas sampler, the collection efficiency was 98.7%, and the desorption efficiency was 98.6%. The variation coefficients of sampling was 4.02% (n = 10). The above method was compared with the standard method (GB/T 16129-1995 ), the results showed no significant difference between the two methods. CONCLUSION: This solid phase adsorption gas sampler can be used for sampling and determination formaldehyde in indoor air.

Air Pollutants↗
PubMed1977

Formaldehyde formation as a metabolite of methoxyflurane.

The production of formaldehyde as a metabolite of enzymatic biotransformation of methoxyflurane was observed in vitro in hepatic microsomal preparations derived from Japanese monkeys, rabbits and Wistar strain rats. Production rates of formaldehyde were 0.80-2.50 n moles/mg protein/min in the induced group which was pretreated with phenobarbitone, and 0.15-0.68 n moles/mg protein/min in the non-induced group. This reaction needed the presence of NADPH and oxygen. Formaldehyde production was almost completely inhibited by addition of 25% CO. Further degradation of formaldehyde did not occur in microsomal suspension. No detectable species difference was observed among the animals used in this study. These results indicate that the biotransformation of methoxyflurane is preceded by interaction with cytochrome p-450 in hepatic microsomes in the presence of NADPH and oxygen.

Animals↗
PubMed2006

[The bronchial response to inhaled formaldehyde].

INTRODUCTION: Formaldehyde is an ubiquitous indoor chemical polutant. Occupational exposure to high concentrations has revealed its irritant and allergenic potential. Nevertheless, domestic exposure to low concentrations may also have an effect on respiratory health in a non-specific way, just as has been found for other pollutants. STATE OF KNOWLEDGE: Potentiation of the response to allergens has been observed in animals and children. This effect has also been found on respiratory symptoms, with a 39% increase in the risk of asthma for a domiciliary exposure of more than 60 microgrammes.m(-3). We have recently been able to show, in a study with asthmatics sensitised to house dust mite, that the response to allergen provocation was increased following a 30 minutes exposure to 100 microgrammes.m(-3) formaldehyde. VIEWPOINT AND CONCLUSIONS: All the data show that mild exposure to formaldehyde in the home is sufficient to provoke sensitisation and also an aggrevation of symptoms in patients with allergic asthma. Taking into account the published evidence it is advisable that the concentrations of formaldehyde in domestic products should be made known in order to improve domiciliary air quality.

Air Pollution, Indoor↗
PubMed2006

Pulmonary function in persons who are professionally exposed to formaldehyde fumes.

The present study examines long-term effects of occupational exposure to formaldehyde fumes on lung function. Forced spirometry and diffusing lung capacity were measured in 16 health-service professionals (8 medical doctors and 8 laboratory technicians) working at the pathoanatomic laboratory for at least 4 years with daily exposure 8 +/- 1 hours. Control group employed 16 males, which were matched by age and stature to members of the exposed group. Only non-smokers were included in the study. Spirometric parameters in study participants exposed to formaldehyde fumes compared to control group were not significantly different indicating absence of restrictive and/or obstructive deterioration of lung function in exposed group. The only parameter differing in two groups was blood volume of pulmonary capillaries (Vc') which was significantly larger in a group exposed to formaldehyde fumes. The possibility that the hyperemic lung reaction is the consequence of the exposure to formaldehyde fumes should be further explored.

Adult↗
PubMed2006

[Effects of formaldehyde on the activity of superoxide dismutases and glutathione peroxidase and the concentration of malondialdehyde].

This review focus on the effects of formaldehyde on the activity of superoxide dismutases (SOD), glutathione peroxidase (GSH-Px) and the concentration of malondialdehyde (MDA) in recent years. It is showed formaldehyde having effect on lipid peroxidation by many studies of animal experiment and occupational group, it can decrease the activity of SOD and GSH-Px, increase the concentration of MDA, there are dose-response relationship between those lipid peroxidation index and the concentration of formaldehyde too. In future study, the animal experiment and the people's late effect of low dose formaldehyde exposure should be pay more attention.

Animals↗
PubMed2006

[Photocatalytic degradation of formaldehyde and VOCs in air on the porous nickel mesh coated with nanometer TiO2].

Three different metal ions doped TiO2 photocatalysts, which were prepared by the sol-gel method, were immobilized to porous nickel mesh by coating. The photocatalytic degradation activity of the supported photocatalyst on formaldehyde and volatile organic compounds (VOCs) was investigated. The results show that the nanometer TiO2 has an anatase structure. The photocatalytic degradation rate of formaldehyde and VOCs of 1.5% La3+ doped TiO2 coated on porous nickel mesh at 90 min are: 94% and 87%, higher than undoped TiO2: 83% and 72%, Fe3+ doped TiO2: 62% and 62%, Ag+ doped TiO2: 86% [Chinese character: see text] 81%. The orders of photocatalytic degradation rate on formaldehyde and VOCs with different content of La3+ doped TiO2 are as follows: 1.5% > 1% > 2% > undoped, 1.5% is the optimum La3+ doped content. Decreasing circular wind speed and using 254 nm or 365 nm ultraviolet wavelength will not influence the photocatalytic degradation rate of formaldehyde and VOCs.

Air Pollutants↗
PubMedDate not supplied

Pulmonary effects of formaldehyde exposure--an environmental-epidemiological study.

A comparative study of effects of formaldehyde on respiratory system was carried out among systematically selected anatomy and histopathology department workers of three medical colleges of Vidarbha. A group of persons, not exposed to formaldehyde served as control group. Analysis of air samples revealed that the concentration of formaldehyde at study group work places was significantly more than the control group work places. The respiratory symptoms such as productive cough, breathlessness and tightness of chest were significantly more frequent among formaldehyde exposed persons. The lung function parameters showed a significant decrease among exposed as compared to non-exposed group.

Air Pollutants, Occupational↗
PubMed1991

Formaldehyde-resistance in Enterobacteriaceae and Pseudomonas aeruginosa: identification of resistance genes by DNA-hybridization.

A 4.1. Kb large DNA fragment of a E. coli plasmid pVU 3695, on which the genes for formaldehyde-resistance are located, was used as a DNA probe to identify bacteria that carry this segment among formaldehyde-resistant bacteria. It was shown by Southern Blot-, Dot Blot-, and Colony Blot- Hybridization studies that the DNA of all formaldehyde-resistant E. coli, Serratia marcescens, Enterobacter cloacae, Citrobacter freundii and Klebsiella pneumoniae strains tested hybridize with the DNA probe from E. coli. In contrast the E. coli DNA probe does not hybridize with the DNA from formaldehyde-resistant Pseudomonas aeruginosa strains.

Blotting, Southern↗
PubMed1991

[The suitability of commercial bioindicators with spores of B. stearothermophilus for the testing of formaldehyde gas sterilizers].

Commercially available biological indicators with spores of B. stearothermophilus were investigated by the Hygiene-Institutes of Kiel and Lubeck. The objective was to find out if those indicators to which sheep blood was added subsequently correspond to the formaldehyde resistance required by. DIN 58948, part 14 (DIN 58948, part 13). Both working groups determined unanimously that the indicators of one producer showed a resistance too low compared to the remaining biological indicators showing a much higher resistance than required. Even biological indicators manufactured strictly in accordance to the testing standard were more resistant than demanded. This also corresponded to the commercially available untreated spores. On the other hand, practice showed that the biological indicators investigated within this study can be easily killed by formaldehyde sterilizers if they respond to the technical standard. In order to realize the testing of these sterilizers with indicators of a generally accepted resistance we propose either to demand for an equivalently higher formaldehyde resistance or to set up a killing period for the spore resistance from 150 to 240 min until experimentally important data are available. Concerning the blood containing indicators the results of both working groups differed considerably within the limits of formaldehyde efficiency whereas this was not the case with untested commercially available spores. As the addition of thinned blood did not cause an increase in resistance we recommend, in the interest of standardized investigative conditions, not to use it.

Drug Resistance, Microbial↗
PubMed1989

[Formaldehyde chamber disinfection: not suitable for respirators and anesthesia equipment].

After formaldehyde-chamber-disinfection of respirators considerable quantities of formaldehyde deposit (presumably deep adsorption) within the devices. When the apparatuses are re-employed the respired air contains more than 1,000 (in individual cases more than 4,000) micrograms/m3. Thus all limits are exceeded by far. The liberation of the formaldehyde deposited in considerable amounts comes off according to an exponential equation dependent on the time of employment slowly, that with following chamber disinfections the quantities of formaldehyde in the apparatuses are still increased and still higher loadings of the respired gas occur. Even after employing them for a long time either non-stop or intermittently "saturated" respirators can not be used again. The disinfection according to the principle of the Aseptor-chamber or its imitations has to be refused for respirators and similar medical technical devices, e.g. incubators.

Anesthesia, General↗
PubMed1985

Contact sensitizers in resins based on phenol and formaldehyde.

A paratertiary-butyl phenol-formaldehyde resin is present in the routine patch test series of the International Contact Dermatitis Research Group. This resin was not sufficient to trace patients with contact allergy to resins based on phenol and formaldehyde (P-F-R). A particular resol resin (P-F-R-2) was demonstrated to be a good tracer of patients with P-F-R hypersensitivity. 2-methylol phenol (2-MP), 4-methylol phenol (4-MP) and 2,4,6-trimethylol phenol (2,4,6-MP) were, besides formaldehyde, known sensitizers in P-F-R. The sensitizing potentials were confirmed both in humans and in guinea pigs. Eleven new contact sensitizers in P-F-R were established. A consistently performed patch testing, including testing with serial dilutions of each sensitizer, facilitated comparisons and conclusions concerning (a) assessment of irritancy/allergenicity, (b) determination of highest acceptable contaminations, (c) evaluation of clinical relevance and (d) choice of substances for cross-reactivity testing. Six theoretically possible substances in P-F-R, 3-methylol phenol, 2,4-dimethylol phenol, 2,6-dimethylol phenol, 2,21-dihydroxydiphenyl methane (2,21-HPM), 4,41-dihydroxydiphenyl methane (4,41-HPM) and 2,41-dihydroxydiphenyl methane (2,41-HPM), were established as contact sensitizers and also demonstrated and identified in P-F-R-2. Five sensitizers were isolated from P-F-R-2 and identified to be 4,4-dihydroxy-3-(hydroxymethyl)-diphenyl methane (4,41-H-3-HPM), 4,41-dihydroxy-3,31-di-(hydroxymethyl)-diphenyl methane (4,41-H-3,31-HPM), 4,4-dihydroxy-3,5-di-(hydroxymethyl)-diphenyl methane (4,41-H-3,5-HPM), 2,41-dihydroxy-3,31-di-(hydroxymethyl)-diphenyl methane and 2,4-dihydroxy-31,51-di-(hydroxymethyl)-diphenyl methane. Nine sensitizers, 2-MP, 4-MP, 2,4,6-MP, 2,21-HPM, 4,41-HPM, 2,41-HPM, 4,41-H-3-HPM, 4,41-H-3,31-HPM and 4,41-H-3,5-HPM, were investigated using guinea pigs for sensitizations. The guinea pig maximization test was modified to increase standardization, enable a blind evaluation and also statistical comparisons between test animals and appropriate control animals. All 9 substances, except 4,41-HPM and 2,41-HPM, were established as contact sensitizers in guinea pigs. The 4,41-H-HPM were the most potent allergens. Phenol-formaldehyde resins and products based on P-F-R were investigated for the presence of 14 contact sensitizers. The concentrations varied and the highest concentrations were demonstrated for simple methylol phenols in P-F-R of the resol type.(ABSTRACT TRUNCATED AT 400 WORDS)

Allergens↗