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PubMed1979

[Effect of formaldehyde and its aminomethylol derivatives on E. coli strains with various defects of the DNA repair systems].

It was shown that aminomethylol compounds formed during reaction of formaldehyde with amino acids and formaldehyde as well exert a pronounced lethal action on E. coli strains with various defects of the DNA repair systems. The correlation between the extent of the DNA depurination caused by in vitro action of diverse aminomethylol derivatives and the inactivation of bacteria by these derivatives is revealed. The data obtained suggest that the inactivating effect of formaldehyde and its aminomethylol derivatives seems likely to be due to the formation of depurinized groups in bacterial DNA rather than to dimerization of purine bases.

DNA Repair↗
PubMedDate not supplied

Assessment of the systemic distribution and toxicity of formaldehyde following pulpotomy treatment: Part one.

This report, the first of a two-part study, was undertaken to quantitate the systemic distribution of formaldehyde from a pulpotomy site, and to compare this level to doses that elicit overt systemic pathology. Maxillary first molars of rats were pulpotomized and treated with 14C-labeled formaldehyde, for 5 minutes. Additionally, four groups of rats were infused with 10, 20, 30, or 50 percent of the first quantity applied to the site. The data show that approximately 30 percent of the 14C-formaldehyde placed in the pulp chamber was distributed systemically; 50 percent to 59 percent was expired as CO2; and 2 percent was excreted.

Animals↗
PubMed1985

[Transmissible formaldehyde resistance in Serratia marcescens].

It was possible to isolate a strain of Serratia marcescens from fresh clinical bacterial isolates which was 4-6 times more resistant against formaldehyde than other strains. It was shown that the strain harbours two plasmids with molecular sizes of 58- and 90 Mdal. It was demonstrated by conjugation-, transformation- and plasmid-curing experiments that the formaldehyderesistance is plasmid mediated and transferable to E. coli. It was shown by labelling with 14C-formaldehyde that the resistant strains bind much more formaldehyde than the sensible strains.

Disinfectants↗
PubMedDate not supplied

Gas chromatographic determination of formaldehyde in coffee via thiazolidine derivative.

Thiazolidine formed from trace quantities of formaldehyde in an aqueous solution containing cysteamine at pH 8 was extracted with chloroform and subsequently analyzed by a gas chromatograph equipped with a fused silica capillary column and a thermionic nitrogen-phosphorus specific detector. Recoveries of formaldehyde from the aqueous solutions at levels lower than 1 ppm were slightly over 100%. Quantitative analysis of formaldehyde in commercial brewed and instant coffees showed 3.4-4.5 ppm in the brewed and 10-16.3 ppm in the instant coffee.

Aldehydes↗
PubMed1985

Effects of formaldehyde, acetaldehyde, benzoyl peroxide, and hydrogen peroxide on cultured normal human bronchial epithelial cells.

The effects of several aldehydes and peroxides on growth and differentiation of normal human bronchial epithelial cells were studied. Cells were exposed to formaldehyde, acetaldehyde, benzoyl peroxide (BPO), or hydrogen peroxide (HPO). The effect of each agent on the following parameters was measured: (a) clonal growth rate; (b) squamous differentiation; (c) DNA damage; (d) ornithine decarboxylase activity; (e) nucleic acid synthesis; (f) aryl hydrocarbon hydroxylase activity; and (g) arachidonic acid and choline release. None of the agents were mitogenic, and their effects were assessed at concentrations which reduced growth rate (population doublings per day) to 50% of control. The 50% of control concentrations for the 6-h exposure were found to be 0.065 mM BPO, 0.21 mM formaldehyde, 1.2 mM HPO, and 30 mM acetaldehyde. BPO-exposed cells were smaller than controls (median cell planar area, 620 sq microns versus 1150 sq microns), and acetaldehyde-exposed cells were larger than controls (median cell planar area, 3200 sq microns). All agents increased the formation of cross-linked envelopes and depressed RNA synthesis more than DNA synthesis. HPO caused DNA single-strand breaks, while formaldehyde and BPO caused detectable amounts of both single-strand breaks and DNA-protein cross-links. Other effects included increased arachidonic acid and choline release due to HPO. The similarities and differences of the effects of these aldehydes and peroxides to those caused by tumor promoters are discussed.

Acetaldehyde↗
PubMed1977

[Sterilization of plastic culture boxes by formaldehyde vapour (author's transl)].

Various experiments showed that plastic culture boxes may be sterilized by formaldehyde vapour in an exsiccator. Detectable quanties of formaldehyde were no longer found to be present when the dishes had been stored at room temperature for 24 hours after sterilization. A striking fature in these experiments consisted in the fact that colonies failed to grow on those agar plates, the surfaces of which had been in contact with formaldehyde vapour. The dishes used should be meticulously cleaned as studies showed that complete sterilization was not achieved when bacteria were present in or on agar. When Petri dishes cleansed in alcohol and then sterilized were used in assessing aerobic bacterial counts in minced meat by the mixed plate technique, significantly higher average numbers of colonies were recorded than was the case when commercially available sterilized Petri dishes were used. When the streak plate method was adopted, however, no significant differences were observed. When all the required manoeuvres are performed with meticulous care, the method is a practicable one ensuring that plastic culture boxes may be used again several times.

Formaldehyde↗
PubMedDate not supplied

[Effect of formaldehyde on the enzymatic activity of RNAase A].

Even a small amount of formaldehyde is shown to induce a drop in the RNase A enzymatic activity. This drop is rapid from the start and then begins to be slower. A supposition was made on nature of the enzyme activity. Comparison of the effects of formaldehyde on the enzymatic and the destabilizing activity of RNase A was made. The effect of formaldehyde on the enzymatic activity does not correlate with its effect on the ability of RNase to destabilize the DNA double helix.

Catalysis↗
PubMedDate not supplied

[Use of the reaction product of beta-alanine and formaldehyde in the kinetic method of determining defects in secondary structure].

It is shown that the kinetics of DNA despiralization in the presence of beta-alanine--formaldehyde reaction product (beta-ALA-FORM) can be described in terms of theory of DNA despiralisation by "slowly reacting agents". Conditions are determined in which beta-ALA-FORM product can be used to establish the concentration of defects in DNA secondary structure. Possible advantages are discussed of using the new agent in the kinetic method of determining DNA defects as compared to formaldehyde, in particular in analysis of DNA complexes with proteins. The data obtained throw some light on the nature of the interaction between beta-alanine and formaldehyde in slightly acidic solutions and with the excess of aminoacid.

Alanine↗
PubMed1983

[Dependency of a microbiological test of a formaldehyde gas sterilization procedure on the shape of objects to be sterilized].

During the last decade, a number of procedures have been developed by different firms for the sterilization of heat-sensitive instruments using a mixture of formaldehyde and water vapor at a temperature of approximately 60 degrees C as means of sterilization. Instruments to be sterilized by this technique as e.g. sounds and catheters normally have long narrow cavities. Therefore, the formaldehyde gas sterilization procedures have to be tested primarily for their capability of achieving a sufficient microbicidal effect within those cavities. For this purpose, the bioindicators are placed into special test pieces. The test pieces commonly in use differ widely in their construction, shape, and size. They mostly consist of some hollow cylinder with an attached capillary or a tube (see Table 1). The authors demonstrated by means of models that the variety of test pieces in use meant that the sterilization procedures had to meet quite different requirements. The models consisted of flexible tubes differing in diameter and length and were connected to short glass tubes. These glass tubes having identical or wider inner diameters than the flexible tubes served as receptacles containing the bioindicators. Spores of Bacillus stearothermophilus served as test organisms. The spores were suspended in defibrinated sheep blood and dried on filter paper. The efficiency of the sterilization technique was measured in terms of the relative number of indicator strips with surviving germs (i.e. non-sterilized indicators) after treatment of the test pieces with the formaldehyde gas. At first, the test results were examined as to their dependency on the length of the flexible tubes. These tubes were 3 mm wide and 5 to 100 cm long, each being sealed at one end and with the bioindicators placed near the sealed end. The percentage of indicators with surviving germs increased with the length of the tubes. After the sterilization process, nearly all indicators (92%) contained in the 1 m tubes proved to be non-sterile (see Table 2). The same results were obtained with tubes open at both ends, with the bioindicators located in the middle section of the tubes (see Table 3). Using tubes of 1 m length, the dependency of the test results on the inner diameter of the test pieces was demonstrated. While all indicators placed into tubes of 3 mm inner diameter still contained surviving germs, those in the tubes of 9 mm inner diameter were all sterile (see Table 4).(ABSTRACT TRUNCATED AT 400 WORDS)

Bacteriological Techniques↗
PubMed1984

Formaldehyde toxicity. Part II. Review of acute and chronic effects on health.

Inhaled formaldehyde has acute effects on the respiratory tract, central nervous system, skin and eyes and also chronic effects on the respiratory tract, particularly on pulmonary function. Formaldehyde has also been associated with adverse reproductive and mutagenic effects, and there is evidence of carcinogenic effects from two important animal studies. Some data, largely indirect, suggest a carcinogenic risk for man. The reactions of some international scientific bodies to the accumulated data are noted, and steps taken by a number of countries to control formaldehyde exposure in the workplace and other environments are discussed.

Acute Disease↗
PubMed1984

[Sterilization with formaldehyde vapors in a hypobaric procedure: microbiologic and toxicologic aspects].

The use of formaldehyde gas is an alternative for the sterilization of thermolabile instruments. A report is given on the effectivity of a sterilization medium the production of which is not dependent on any imports, and on the suitability of sterile packaging materials produced in the GDR for this process. In further studies the formaldehyde residue on catheters and tubing used in urology following sterilization is measured. The question of whether formaldehyde residue on catheters is of toxicological significance is examined.

Aged↗
PubMed1984

[What should be the length and inner diameter of the testing device for microbiological efficacy testing of formaldehyde gas sterilization methods?].

The series of tests described in a preceding publication (Spicher and Borchers, 1983) has been continued in a modified way. This time, the dependency of the microbiological test results of a formaldehyde gas sterilization procedure on length and inner diameter of the tubes serving as test pieces was examined. The tubes were 1 or 2 m in length with an inner diameter of 1 or 2 mm. The tests were performed with four different preparations of bioindicators. Spores of Bac. stearothermophilus served as test germs. The preparations differed in the type of suspension used for the preparation of the bioindicators: distilled water, diluted blood (10%), undiluted blood, 10% albumin solution. The spore suspensions had been dried on linen thread. During the test procedure, the bioindicators were located near the sealed end of the tube. After completion of the sterilization procedure, the bioindicators were examined for viable germs. In tubes of identical length, the frequency of indicators carrying viable germs was always higher in those of 1 mm than in those of 2 mm inner diameter. In tubes of identical inner diameter, the frequency of indicators carrying viable germs in those of 2 m length was always higher than in those of 1 m length. This regularity was independent of the type of bioindicators used. The bioindicators for the preparation of which a 10% albumin solution had been employed showed the highest resistance. A somewhat lower resistance was found for the bioindicators prepared with undiluted blood. The bioindicators for which the spores had been suspended in diluted blood proved to have the lowest resistance. If the spores had been suspended in distilled water, the resistance of the bioindicators was a little lower than that of those suspended in undiluted blood, but was higher than that of the dried spores with diluted blood. The test results confirm the effectiveness of the method proposed earlier, i.e. to deposit the bioindicators in special test pieces (e.g. tubes or sounds) for the microbiological testing of formaldehyde gas sterilization procedures. These test pieces must be at least as long and as narrow as the longest and narrowest cavity of the object to be sterilized (tubes, catheters). In order to standardize the microbiological testing of formaldehyde gas sterilization procedures and to guarantee a certain minimum efficiency, the bioindicator as well as the test piece and its size (length and inner diameter) should be standardized.(ABSTRACT TRUNCATED AT 400 WORDS)

Culture Media↗
PubMed1983

[DNA replication in mammalian cells acted on by chemical, physical and biological factors. I. DNA damage and replication in LL line cells treated with formaldehyde].

The inhibition of DNA synthesis and the appearance of single-strand breaks and/or alkali-labile sites in DNA and DNA-membrane cross-links were observed after formaldehyde treatment of cultured LL-line cells. It was shown that supercoiling of cell chromatin is not affected under these conditions. The initiation of DNA replication after the exposure with 10(-4) M formaldehyde occurs also without disturbance. Under the higher concentration of formaldehyde (10(-3) M), DNA elongation was inhibited. It is suggested that cross-linking of DNA with other molecules and structures for example membranes, stabilizes DNA supercoiling (chromatine). This conformational stability is essential for normal initiation of DNA replication, although the parenteral DNA contains many lesions in its primary and secondary structures.

Animals↗
PubMedDate not supplied

[Sterilization of rubber medical equipment with formaldehyde].

The sterilizing procedure of medical rubber pieces have been studied. The gas sterilizer GK-100 has been used the chamber of which was loaded with rubber pieces and with rubber pieces in combination with plastic. The map of the temperature field has been build, and the effect of the exposure and temperature as well as the packaging density in the chamber on sterility of the test-pieces has been derived. The period of formaldehyde neutralization by ammonia has been measured, the action of formaldehyde on physical and mechanical properties of the rubber has been also studied. On the basis of the obtained data the sterilization procedure with formaldehyde for medical rubber pieces has been developed.

Equipment and Supplies↗
PubMed1983

[Sterile packing materials for formaldehyde sterilization].

Apart from the already widely applied sterilization by ethylene oxide, the sterilization by gaseous formaldehyde is another reliable procedure for the sterilization of thermolabile instruments. An essential advantage of the sterilization by gaseous formaldehyde over the so-called wet sterilization is that it can be performed in a recontamination-proof sterile packing. Packing materials produced in the GDR, the germ-tightness and toxicological safety of which were already known, were tested to evaluate their suitability for sterilization by gaseous formaldehyde. An appropriate packing variant was found and tested for microbiological reliability.

Equipment and Supplies↗
PubMed1984

[Characteristics of aniline, lead nitrate, carbon tetrachloride and formaldehyde as modifiers of chemical carcinogenesis].

The modifying effect of aniline, lead nitrate, carbon tetrachloride and formaldehyde on nitrosodimethylamine-induced blastogenesis was studied in chronic experiments on 750 CBA X C57 / Bl6 female mice. A mixture of carcinogen with aniline or formaldehyde given in drinking water for 39 weeks produced a significantly higher tumor incidence. A similar, though statistically insignificant, effect was registered for a mixture of carcinogen and lead citrate or carbon tetrachloride. It is emphasized that aniline and formaldehyde are capable of modifying effect at levels 10 times maximum allowable concentrations.

Aniline Compounds↗
PubMed1983

Nasal cancer in a worker exposed to formaldehyde.

Formaldehyde has not been established as a human carcinogen. Toxicological studies have, however, demonstrated that formaldehyde causes squamous cell carcinoma of the nasal cavity in rats. A case of squamous cell carcinoma of the nasal cavity occurred in a 57-year-old man who had 25 years of occupational exposure to low concentrations of formaldehyde in the textile-finishing industry.

Carcinoma, Squamous Cell↗
PubMed1983

Occupational exposure to formaldehyde in a medical center autopsy service.

The formaldehyde exposures occurring in the autopsy service of a medical complex were evaluated as part of a study to detect genetically harmful effects of chemical exposures. Determination of time-weighted average (TWA) exposures and characterization of the patterns of exposure experienced by individuals with different work responsibilities in this occupational setting were sought. Both general area and breathing zone samples were evaluated. Estimated weekly time-weighted average exposures for pathologists, residents and technicians were determined to be between 0.61 and 1.32 parts per million with little difference between work roles. While the averages were similar, the patterns of exposure of technicians and physicians were different. Technicians were exposed to a baseline level of formaldehyde for a prolonged period of time. In contrast, physicians were exposed for shorter times but experienced higher levels during specific tasks, particularly tissue-sectioning and examination. Evaluations of work procedures and environmental conditions in autopsy services are recommended to reduce personnel exposure to formaldehyde vapor.

Academic Medical Centers↗