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 1,369 records · Page 76Linked to original sources

Formaldehyde-treated, heat-inactivated virions with increased human immunodeficiency virus type 1 env can be used to induce high-titer neutralizing antibody responses.

The lack of success of subunit human immunodeficiency virus (HIV) type 1 vaccines to date suggests that multiple components or a complex virion structure may be required. We hypothesized that the failure of current vaccine strategies to induce protective antibodies is linked to the inability of native envelope structures to readily elicit these types of antibodies. We have previously reported on the ability of a formaldehyde-treated, heat-inactivated vaccine to induce modest antibody responses in animal vaccine models. We investigated here whether immunization for HIV with an envelope-modified, formaldehyde-stabilized, heat-inactivated virion vaccine could produce higher-titer and/or broader neutralizing antibody responses. Thus, a clade B vaccine which contains a single point mutation in gp41 (Y706C) that results in increased incorporation of oligomeric Env into virions was constructed. This vaccine was capable of inducing high-titer antibodies that could neutralize heterologous viruses, including those of clades A and C. These results further support the development of HIV vaccines with modifications in native Env structures for the induction of neutralizing antibody responses.

AIDS Vaccines↗

Disinfection of heat-sensitive material by low-temperature steam and formaldehyde.

Steam under subatmospheric pressure at temperatures below 90 degrees C. rapidly killed nonsporing organisms after air had been removed by a high-vacuum pump. Most bacterial spores were killed but small proportions of the populations were very resistant. The destruction of spores was not logarithmic. The addition of formaldehyde vapour to the steam greatly increased its sterilizing power, with deep penetration into fabrics and destruction of spores. Penetration into wide tubes was good, but was poor in narrow tubes. Most fabrics, plastics, and instruments were unharmed. Low-temperature steam with formaldehyde is probably as efficient a sterilizing agent as ethylene oxide.

Formaldehyde↗

Formaldehyde induced anti-N: a possible cause of renal graft failure.

Treatment of human red cells with low concentrations of formaldehyde induces an antigenic change which makes them react very strongly with the anti-N sera found in certain patients treated by haemodialysis. This supports the idea that formaldehyde sterilisation of reusable home dialysers leads to the development of anti-N in these patients' sera. The clinical problems produced by this antibody are discussed together with ways of overcoming them.

Antibody Formation↗

Relationship between formaldehyde-related antibodies and cross-reacting anti-N-like antibodies in patients undergoing chronic haemodialysis.

An attempt was made to determine the sequence of events leading to the production of two distinct antibodies in patients with chronic renal failure who regularly undergo haemodialysis with formaldehyde-resterilizable dialysis units by Multipoint (UK) or Cordis (USA). A distinct pattern emerged-namely, the production of anti-formaldehyde red cells started about six months after the beginning of haemodialysis treatment. Only when the titre of these antibodies reached 64 or 128 another, apparently cross-reacting, antibody appeared which reacted like an anti-N antibody. A strong direct antiglobulin reaction was found to be positive for formalin-treated red cells after five minutes' contact with specific antibody, indicating a high affinity of the antibody fo the formalin-altered red cell.

Antibodies↗

Removal of formaldehyde and xylene fumes from histopathology laboratories: a functional approach to the design of extraction systems.

There have been many reports of the relative hazards of formaldehyde, xylene, and hot paraffin wax fumes in pathology laboratories. In contrast, there have been comparatively few describing efficient extraction systems for their removal. When the opportunity presented to design a new laboratory the efficient removal of these fumes was given a high priority. In designing the extraction systems described consideration was given to the physical properties of the fumes and the degree of freedom of use of the bench, with the object of achieving sub-threshold limit values for each area of exposure. The efficiency of removal of the formaldehyde and xylene was measured using infrared spectroscopy.

Air Conditioning↗

Detection of cytomegalovirus antigens and DNA in tissues fixed in formaldehyde.

Immunohistochemical techniques with monoclonal antibodies against cytomegalovirus (CMV) immediate early (IEA) and early antigens (EA), and in situ hybridisation, were used to detect CMV infection in routinely obtained, formaldehyde fixed and paraffin wax embedded tissues taken from bone marrow transplant patients, who had died form interstitial pneumonia. To improve the rates of detection of CMV-IEA and EA the wax embedded material was pretreated with 0.4% pepsin/HCl at 37 degrees C for 30 minutes. This pretreatment was also advantageous for in situ hybridisation. In the patients with histological evidence of CMV infection or positive viral culture from the lung tissue, or both, viral proteins and nucleic acids were detected in lung, as well as in other organs. Immunohistochemical techniques proved superior in heavily infected but necrotic tissues. In control patients (patients who had died from interstitial pneumonia without any evidence of CMV, or with no interstitial pneumonia at all) in situ hybridisation showed no positive signal, while immunohistochemical techniques showed only a few positive cells in lung tissue of one of nine patients. In addition to CMV-DNA analysis, formaldehyde-fixed, paraffin wax embedded tissue is amenable to immunohistochemical analysis with CMV monoclonal antibodies.

Antigens, Viral↗

Use of buffered formaldehyde in the enzymatic digestion of inflamed mucosa.

Mucosal inflammation is associated with altered expression of cell membrane molecules. Disaggregation of tissue for flow cytometry may introduce artefactual changes. In an attempt to prevent the induction of artefacts, cells were fixed prior to isolation. The addition of 0.1% buffered formaldehyde to the collagenase/dispase digestion of mucosal biopsy specimens from patients with inflammatory bowel disease enhances detection of CD3, CD11b, CD16, CD63, and CD14. No significant effect was noted for CD19, CD67 or CD45. The expression of CD3, CD11b and CD45 correlated with the degree of endoscopic inflammation. Dilute buffered formaldehyde may be a useful adjunct to the enzymatic isolation of cells from mucosal specimens, by protecting surface antigens from digestion or alterations in expression.

Adult↗

Bactericidal properties of peracetic acid and hydrogen peroxide, alone and in combination, and chlorine and formaldehyde against bacterial water strains.

The bactericidal properties of peracetic acid, hydrogen peroxide, chlorine, and formaldehyde were compared in vitro using a rapid micromethod. A combination of peracetic acid and hydrogen peroxide was also tested to assess interactions. The activities of these agents, which are widely used as disinfectants, were evaluated against water isolates and culture collection strains. Peracetic acid and chlorine exhibited an excellent antimicrobial activity, with a relatively rapid destruction of 10(5) bacteria/mL. The time-dependent bactericidal activities of hydrogen peroxide and formaldehyde were the lowest. The combination of peracetic acid and hydrogen peroxide, tested by a checkerboard micromethod, was found to be synergistic. The minimal bactericidal concentration was established in terms of time for a given mixture of peracetic acid and hydrogen peroxide. Determination of bactericidal concentrations showed that synergy was maintained with increasing contact time. Concentrations for minimal times of treatment by chemicals that provided interesting activities in vitro were tested for disinfection of ultrafiltration membranes. The bactericidal activities of peroxygen compounds were confirmed and synergism was maintained in working conditions. Chlorine showed a loss of efficacy when used on membranes.

Chlorine↗

Modification of biological activities of Ricinus communis agglutinin by cross-linking with formaldehyde.

Formaldehyde treatment of Ricinus communis agglutinin, a nonmitogenic toxic 120 000 molecular weight (MW) lectin, yielded two distinct protein fractions: one was heterogeneous and contained high molecular weight lectin polymers (greater than 120 000), and the other was a homogeneous 120 000 MW protein. Both fractions lost their cytotoxicity after formaldehyde treatment and stimulated thymidine incorporation into lymphocytes. Binding of both treated lectin fractions to lymphocytes exhibited positive cooperativity, whereas binding of untreated lectin did not.

Adult↗

Vasoactive effects of methylamine in isolated human blood vessels: role of semicarbazide-sensitive amine oxidase, formaldehyde, and hydrogen peroxide.

It is hypothesized that methylamine (MA) and semicarbazide-sensitive amine oxidase (SSAO) activity are involved in the cardiovascular complications in human diabetics. To test this, we 1) determined the acute vasoactive effects of MA (1-1,000 micromol/l) in uncontracted and norepinephrine (NE; 1 micromol/l)-precontracted human blood vessels used for coronary artery bypass grafts [left internal mammary artery (LIMA), radial artery (RA), and right saphenous vein (RSV)]; 2) tested whether MA effects in LIMA and RSV were dependent on SSAO activity using the SSAO inhibitor semicarbazide (1 mmol/l, 15 min); 3) determined the effects of MA metabolites formaldehyde and hydrogen peroxide in LIMA and RSV; 4) tested whether the MA response was nitric oxide, prostaglandin, or hyperpolarization dependent; 5) measured the LIMA and RSV cGMP levels after MA exposure; and 6) quantified SSAO activity in LIMA, RA, and RSV. In NE-precontracted vessels, MA stimulated a biphasic response in RA and RSV (rapid contraction followed by prolonged relaxation) and dominant relaxation in LIMA (mean +/- SE, %relaxation: 55.4 +/- 3.9, n = 30). The MA-induced relaxation in LIMA was repeatable, nontoxic, and age independent. Semicarbazide significantly blocked MA-induced relaxation (%inhibition: 82.5 +/- 4.8, n = 7) and SSAO activity (%inhibition: 98.1 +/- 1.3, n = 26) in LIMA. Formaldehyde (%relaxation: 37.3 +/- 18.6, n = 3) and H(2)O(2) (%relaxation: 55.6 +/- 9.0, n = 9) at 1 mmol/l relaxed NE-precontracted LIMA comparable with MA. MA-induced relaxation in LIMA was nitric oxide, prostaglandin, and possibly cGMP independent and blocked by hyperpolarization. We conclude that vascular SSAO activity may convert endogenous amines, like MA, to vasoactive metabolites.

Adult↗

Carbon-tetrachloride-induced urinary excretion of formaldehyde, malondialdehyde, acetaldehyde and acetone in rats.

Previous studies have demonstrated that the hepatotoxin carbon tetrachloride rapidly promotes lipid peroxidation and inhibits microsomal calcium sequestration, microsomal glucose-6-phosphatase activity and cytochrome P-450. Due to its profound effects on lipid peroxidation, we have examined the oral administration of 2.5 ml/kg carbon tetrachloride on the urinary excretion of the lipid metabolites formaldehyde, malondialdehyde, acetaldehyde and acetone. Urine samples were collected up to 48 h after treatment. The urinary metabolites were identified and quantitated by gas chromatography-mass spectrometry and high-pressure liquid chromatography. Time-dependent increases in the urinary excretion of the four metabolites were observed after carbon tetrachloride administration. At 48 h after treatment, the increases in the excretion of malondialdehyde, formaldehyde, acetaldehyde and acetone were approximately 55, 78, 57 and 268%, respectively, relative to control values. The data were expressed in nanomoles per kilogram body weight per 4.5 h. The results clearly demonstrate that carbon tetrachloride increases the urinary excretion of four lipid metabolites which may serve as noninvasive biomarkers of xenobiotic-induced lipid peroxidation.

Acetaldehyde↗

Follicular contact dermatitis due to formaldehyde.

2 patients with textile contact dermatitis due to formaldehyde developed follicular, papular lesions. Histologically these papules showed eczematous changes in the follicular epidermis and mononuclear cell infiltrates in the dermis around the involved follicle. The skin between the papules was intact. It is suggested that the concept of "dermal" contact sensitivity does not fit for the explanation of papular dermatitis due to formaldehyde.

Adolescent↗

Effects of formaldehyde fixation on basilar artery caliber.

The external diameters of rat and rabbit basilar arteries were determined before and after formaldehyde fixation in relaxed and drug constricted vessels. Fixation usually resulted in an immediate vessel constriction followed by partial relaxation after several hours. However, the results were inconstant from vessel to vessel and from area to area of the same vessel. It is concluded that morphologic as well as morphometric assessment of formaldehyde-fixed basilar arteries is unreliable.

Animals↗

Reversible pulmonary responses to formaldehyde. A study of clinical anatomy students.

Epidemiologic studies of irritants are difficult to perform using standard epidemiologic methods for several reasons, including the reversible nature of the health outcomes, the selection of sensitive individuals from the study population, and the wide heterogeneity in normal responses to irritants. This study examined the feasibility of using repeated measurements of peak expiratory flow (PEF) and reported symptoms to study respiratory irritants and their effects in students exposed to formaldehyde during a clinical anatomy laboratory course. We studied 24 physical therapy students dissecting cadavers for 3 h per week over a 10-wk period. Formaldehyde exposures in the breathing zone ranged from 0.49 to 0.93 ppm (geometric mean +/- geometric SD, 0.73 +/- 1.22). Irritant symptoms increased strongly over the course of the average laboratory period, but this effect was stronger at the beginning than at the end of the semester. PEF measured before each laboratory session declined over the semester by an average of about 10 L/min (2% of baseline), a trend that was statistically significant in random-effects regression models. After 14 wk away from the laboratory, the group's mean baseline PEF had returned to its preexposure level. Mean PEF also declined over each laboratory period, although this effect was attenuated over the course of the semester. Other important predictors of cross-laboratory PEF decrements were asthma and reporting throat irritation during the laboratory. It appears that mild irritant effects can be detected in naive subjects using a repeated monitoring design and relatively simple instrumentation.

Adult↗

Formaldehyde: an experimental multipotential carcinogen.

Male and female Sprague-Dawley rats of different ages at the start of the experiments (12 day embryos, and 7 and 25 weeks old) were administered fromaldehyde in drinking water at different doses (2,500 or 1,500, 1,000, 500, 100, 50, 10, 0 ppm). An increased incidence of leukemias and of gastro-intestinal tumors was observed in formaldehyde treated rats. Gastro-intestinal tumors are exceptionally rare in the rats of the colony used. These results, together with the ones obtained by other Authors on rats exposed by inhalation to formaldehyde, indicate that this compound is an experimental multipotential carcinogen. The experimental results presented in this report give scientific support to the epidemiological observation of a higher incidence of leukemias and of gastro-intestinal cancers among the people occupationally exposed.

Animals↗

Cytofluorometric quantitation of 5-hydroxytryptamine in mast cells: an improved technique for the formaldehyde condensation reaction.

A simple technique for the condensation of cellular 5-hydroxytryptamine (5-HT) with formaldehyde gas is described. The technique, which is especially suited for quantitative cytofluormetric studies, involves the generation of formaldehyde gas from dry paraformaldehyde in a closed reaction vessel with the addition of a measured quantity of water. The fluorescence yield of 5-HT was tested at various humidities. Optimal results were obtained with the addition of 100 mg water to a 1000 ml reaction vessel containing 6 g of dry paraformaldehyde. A major advantage of the method if the fact that the humidity during the reaction can be precisely controlled. The fluorescence yield of 5-HT, tested over a 50 day period showed excellent reproducibility. The stoichiometry of the reaction was tested by comparison of cytofluormetic data with that obtained by analysing the 5-HT content of pooled mast cells with an independent biochemical method. A highly satisfactory correlation (r = 0.96) was obtained within the range of 0.1 to 4 pg of 5-HT per cell. The limit of sensitivity of the cytofluorometric method was found to be of the order of 10(-13) g, and was determined by the fluorescence blank of the mast cells. This contributes to between 10 and 30 per cent of the total fluorescence emission from mast cells containing about 0.2 pg of 5-HT.

Animals↗

Microfluorimetric scanning of sympathetic nerve fibers. An improved method to quantitate formaldehyde induced fluorescence of biogenic amines.

A two dimensional scanning procedure was developed for studying quantitative aspects of formaldehyde induced fluorescence (FIF) from noradrenaline containing nerve fibers. A computer (PDP 12) controlled scanning device was equipped with a cooled photomultiplier, a 0.5 micron scanning stage and a 0.5 micron measuring spot. Photodecomposition was reduced by a high scanspeed (100/sec) and a small excitation field. Digitized images were obtained with a high resolution. Data (10,000/scan) of large scan areas (2500 micron2) in the iris of the rat were transformed into fluorescence histograms, which allowed statistical evaluation. Visible changes induced in the histochemical preparation by administration of drugs (reserpine, L-Dopa) were reflected in characteristic changes in the histograms. A minor reduction in noradrenaline content, which was too small to be detected by visual observation of the microscopical image and by classical microfluorimetric methods, did evoke a significant change in the histograms. It is concluded that microfluorimetric scanning is a very sensitive technique for detecting changes of formaldehyde induced fluorescence from neuronal networks.

Adrenergic Fibers↗

Demonstration of catecholamine and resorcinolamine derivatives as formaldehyde-induced fluorescence in protein models.

We assessed in protein droplet models the potential use of the formaldehyde condensation method for histochemical demonstration of a wide range of catecholamines and resorcinolamines. The experiments showed that all of the amines tested, except salbutamol and carbuterol, formed fluorophores, and that the fluorescence was specific [i.e., there was no fluorescence in the absence of formaldehyde, the fluorescence was quenched by water, and the fluorophores were subject to photodecomposition by the exciting (405-nm) light]. Peak wavelengths of the emission spectra were 480-485 nm for fluorophores of resorcinolamine derivatives. The fluorescence intensity of the catecholamines was greater than that of the resorcinolamines. Fluorophore formation was not hindered by substitution of t-butyl, phenylisoprophyl, or p-hydroxyphenylisopropyl on the amino-N in catecholamines (t-butylnorepinephrine, Cc24, Cc25, respectively) or resorcinolamines (terbutaline, Th1161, fenoterol, respectively), and fluorophores also formed for catecholamines with the amino-N in a ring structure (rimiterol) or with a long alkyl chain substituted on the amino-N (hexoprenaline). Our study showed that fluorescence microphotometry can be used to detect a range of drugs that are catecholamines or resorcinolamines, and hence it should be possible to use this technique to study the properties of dissipation of these amines in tissues.

Amines↗