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 1,567 records · Page 87Linked to original sources
PubMed1997

Fate of gelatin-resorcinol-formaldehyde/glutaraldeyde adhesive on femoral vessel morphology.

Several clinical reports have demonstrated that gelatin-resorcinol-formaldehyde/glutaraldehyde (GRFG) glue can be useful in the repair of acute aortic dissection; however, the cellular and extracellular events that follow GRFG application, as well as the mechanisms responsible for the long-term strength and adhesive properties of GRFG, remain unclear. Accordingly, the present study examined the long-term effects of GRFG adhesive application on femoral vessel extracellular structure and composition. The left and right femoral artery and vein were sterilely exposed in adult rats, and GRFG (2 mL) was applied between and around one pair of vessels. An equivalent amount of sterile saline was applied to the contralateral vessels to serve as an intrinsic control. At either 1 (n = 6) or 2 (n = 6) months postoperatively, the lower extremities were perfusion fixed and harvested to preserve the native anatomy and cytoarchitecture of the femoral region. Gross examination of the specimens revealed no evidence of necrosis or wound breakdown. Tissue blocks (4 microm) were then sectioned perpendicular to the treated vessel region and subjected to histomorphometric analysis using computer-assisted microscopy. The perivascular capsule area, relative content of fibrillar collagen, and number of nucleated cells within the interstitial space were computed. At 1 and 2 months following the application of GRFG adhesive, perivascular capsular size increased by 42 and 221%, respectively. Perivascular interstitial collagen content increased by 21% at 1 month and by 50% at 2 months. The nucleated cell number increased by 107% at 1 month and by 166% at 2 months. This cellular infiltrate appeared to be of fibroblastic morphology. Thus, a potential contributory mechanism to the long-term strength and adhesive capacities of GRFG adhesive may be extracellular remodeling and not the intrinsic properties of GRFG glue itself.

Animals↗
PubMed1997

Analysis of chromatin structure by in vivo formaldehyde cross-linking.

Recent advances leave no doubt that higher order chromatin structures play a fundamental role in many developmentally important mechanisms of gene regulation. In particular analyses in genetic model systems like yeast and Drosophila uncovered novel proteins that are involved in the regulation of chromatin structures. Many of these proteins do not bind directly to DNA but interact in large multimeric complexes. To identify the DNA elements regulated by these multiprotein complexes, alternative approaches to the standard methods of DNA-protein analysis had to be devised. Here we present a method that preserves the architecture of the higher order chromatin structures by cross-linking cells in vivo with formaldehyde. An immunoprecipitation strategy is then used to identify the DNA targets of chromosomal proteins of interest. This method can be applied to study the distribution of proteins at high resolution over extended chromosomal regions.

Animals↗
PubMed1998

Antigen retrieval in formaldehyde-fixed human brain tissue.

Microwave-stimulated antigen retrieval has become a widely accepted method in both pathology and research laboratories. Since the introduction of the method in 1991, many groups have tried to optimize and standardize it. This review describes the present state of the art. A standard method for microwave-stimulated antigen retrieval in formaldehyde-fixed paraffin-embedded and nonembedded tissue is presented that results, in general, in very good staining for antibodies used in neuroscience. However, there are still a few antigens that are retrieved not at all or not in an optimal manner. Factors of importance for microwave antigen retrieval are the pH of the retrieval solution and, related to the pH, the temperature and duration of heating. These factors are discussed.

Antigens↗
PubMed1986

Perfused and ventilated guinea-pig lung: a method for evaluating xenobiotic effects on arachidonic acid using formaldehyde.

Lipoxygenase as well as cyclooxygenase pathways of arachidonic acid (AA) metabolism are involved in antigen-induced bronchoconstriction in ovalbumin-sensitized guinea-pig lungs. Chemical lung challenge induced by aerosol containing formaldehyde (5 ppm up to 20 ppm) was effective in increasing thromboxane (TX) B2 release in a dose-dependent manner, without affecting leukotriene (LT) release. This suggests that xenobiotics acting by non-immunologic mechanisms on bronchial mucosa may stimulate the cyclooxygenase pathway of AA metabolism, which, in turn, might cause bronchial and/or lung parenchymal effects of pathophysiological relevance.

Animals↗
PubMed1979

Distribution patterns of formaldehyde-induced fluorescence of hypothalamic monoamines.

In a circumscribed area of the preoptic periventricular nucleus of a male rat, formaldehyde-induced monoamine fluorophores modified by treatment with HCl vapors were investigated microfluorometrically (measurement of excitation peak ratio 370 : 320 nm) in all fluorescent terminals and preterminals. Microfluorometric recordings of an individual fluorescent structure were performed without UV irradiation of neighboring fluorophores. Recorded data were sampled and corrected by a microcomputer (Wang PCS II). 19 neuronal processes (axons) contained noradrenaline fluorophores; 11 contained dopamine fluorophores; 6 exhibited uncharacteristic excitation peak ratios; and in 19 recordings technical problems did not allow identification of the fluorophore content.

Animals↗
PubMed1987

Comparative studies of DNA cross-linking reactions following methylene dimethanesulphonate and its hydrolytic product, formaldehyde.

The technique of alkaline elution was employed to study the interactions of methylene dimethane sulphonate (MDMS) and formaldehyde (HCHO) with DNA from Yoshida lymphosarcoma cells treated with these agents. MDMS and HCHO produced a proteinase sensitive filter retention which indicated the presence of DNA-protein cross-links. MDMS also produced some proteinase K-resistant filter retention which was believed to indicate DNA-interstrand cross-linking, whilst only single-strand breaks could be detected following treatment with HCHO. Co-incubation with semicarbazide prevented all DNA-protein cross-links induced by MDMS and HCHO as well as single-strand breaks, most obvious following HCHO treatment. Semicarbazide also reduced HCHO-induced cytotoxicity in the Yoshida lymphosarcoma cell line, while no significant alteration in MDMS-induced cytotoxicity was observed. These results suggest that HCHO-induced DNA-protein cross-links and single-strand breaks do not contribute to MDMS-induced cytotoxicity, and therefore the small but significant level of MDMS-induced DNA-interstrand cross-links is the most likely cytotoxic lesion of this agent.

Animals↗
PubMed1990

Towards microfluorometric quantitation of polyamines in situ. Relationship between cellular polyamine concentration and fluorescence yield of the formaldehyde fluorescamine method.

Two different fluorescence cytochemical methods, the formaldehyde-fluorescamine (FF) method and the orthophthalaldehyde (OPT) method as well as an immunocytochemical method have been developed for the localization of spermidine and spermine. Of these three methods, the FF-method is the most easy to perform. We have studied the relationship between fluorescence intensity induced by the FF-method and cellular polyamine levels measured by HPLC in MCF-7 cells and HeLa cells. The experiments were designed to obtain different cell concentrations of polyamines. Cells grown on microscope slides in Petri-dishes were partly depleted of spermidine by two days inhibition of their ornithine decarboxylase activity using alpha-difluoromethylornithine. One hr before harvest the cells were exposed to different concentrations (0-30 microM) of spermidine. Microfluorometric results and chemical determinations of spermidine and spermine were obtained from each separate slide. The cellular total polyamine (spermidine + spermine) concentration on the slides varied between 4 and 15 nmol per mg protein (MCF-7 cells) and 5 and 26 nmol per mg protein (HeLa cells) and the corresponding microfluorometric results between 60 and 115 arbitrary units (MCF-7 cells) and 80 and 160 arbitrary units (HeLa cells). Simple regression analysis showed a good linear relationship between cellular polyamine concentration and FF-fluorescence yield. The correlation coefficient for MCF-7 cells was 0.86 and for HeLa cells 0.82, significance of the correlations was p less than or equal to 0.0001. Our results add further credence to the specificity of the FF-method and indicate that the method may be useful for microfluorometric quantitation of polyamines in situ.

Breast Neoplasms↗
PubMed1985

Selective destruction by formaldehyde fixation of an H-2Kb serological determinant involving lysine 89 without loss of T-cell reactivity.

In preparation for functional analyses, a study of the binding of H-2Kb-specific monoclonal antibodies (mAb) to formaldehyde (FOR)-fixed H-2b spleen or tumor cells revealed that three of nine mAb tested had lost reactivity with the FOR-fixed cells, whereas the reactivity of the other mAb generally did not diminish. Comparison of the reactivity of these mAb on untreated H-2Kbm mutant cells and on FOR-treated H-2Kb cells suggests that for three mAb the total loss of reactivity on the latter could be a consequence of the alteration by FOR of lysine 89, which is substituted by alanine in mutant bm3. H-2Kb-specific alloreactive polyclonal or monoclonal CTL, all of which had retained reactivity with bm3 target cells, had also retained reactivity with FOR-fixed H-2b cells as indicated by cold target inhibition studies. The H-2Kb-specific CTL were probably reactive with "conformational" determinants of H-2Kb, which are dependent on the integrity of both the alpha 1 and the alpha 2 domains of the H-2Kb molecule. Results are compatible with FOR treatment selectively affecting a serological determinant in the alpha 1 domain without affecting conformational-type CTL determinants.

Amino Acid Sequence↗
PubMed1977

Ocular melanomas: formaldehyde-induced fluorescence in relation to mortality.

Some ocular malignant melanomas contain enough cysteinyldopa to make them fluorescent when treated with formaldehyde. In 32 ocular malignant melanomas, such fluorescence was seen in 19 cases, which had a slightly, but not significantly, worse prognosis than the 13 cases with no fluorescence. The mixed type of malignant melanoma showed fluorescence significantly more often than the B type. Fluorescence histochemistry thus gives a biochemical classification of the tumor, but not a malignancy prognosis.

Adult↗
PubMed1987

Fungi associated with urea-formaldehyde foam insulation in Canada.

Sixty-eight fungal taxa were identified from samples of urea-formaldehyde foam insulation taken from Canadian residences. Mesophilic taxa were predominant, with Penicillium spp., Trichoderma harzianum and Paecilomyces variotii observed most frequently. Extensive or conspicuous growth also was seen for Hormoconis resinae, Stachybotrys chartarum and Trichoderma viride in some samples. The potential for these fungi to have contributed to the adverse health effects reported in some homes containing UF-foam insulation is discussed.

Canada↗
PubMed1975

Oxidation of methanol, formaldehyde and formate by catalase purified from methanol-grown Hansenula polymorpha.

Catalase has been partially purified from cell-free extracts of methanol-grown Hansenula polymorpha and its peroxidative properties were studied. It was shown that the enzyme is capable of oxidizing methanol, formaldehyde and formate in the presence of hydrogen peroxide. The physiological significance of these reactions in the transduction of energy from the oxidation of methanol in yeasts is discussed.

Ascomycota↗
PubMed1977

Effects of picric acid-formaldehyde fixation on the LH(HCG) receptors' binding activity in the rat testis. A histochemichal model for qualitative and quantitative studies.

PAF (picric acid-formaldehyde) fixation of rat testis for a short time at 0-4 degrees C was found to give satisfactory histological results and to preserve most of the specific binding activity of LH(HCG) receptors. Investigations of the characteristics of the hormone-receptor reaction after mild PAF fixation indicated that this reaction was not substantially affected in hormne receptor affinity and its own specificity; only the capacity of the receptors was lowered by about 20%. A histochemical model is presented whose main features are: fixation of testis tissue in PAF; freezing in liquid nitrogen and cutting in the cryostat; radiolabelled hormone-receptor binding reaction performed on the sections; autoradiography to reveal the binding reaction. The utility of the method for qualitative and quantitative receptor studies and its possible application to biopsy and surgical specimens, are discussed.

Animals↗
PubMed1980

Microspectrograpic analysis of formaldehyde-induced fluorescence in the quail adenohypophysis after injection of L-dopa and 5-hydroxytryptophan.

The spectral distribution of the formaldehyde-induced fluorescence emitted by model solutions and by adenohypophpyses after intraperitoneal injection of L-dopa or 5-hydroxytryptophan was analyzed microspectrographically. Based on previously reported studies and on present findings, it seems that dopamine is stored in the strongly fluorescent cells after injection of L-dopa, and that a compound closely related to 5-hydroxytryptophan. A non-specific, granular fluorescence appeared after 5-hydroxytryptophan and, to a lesser extend, L-dopa treatment. It probably represents autofluorescence of lysosomes, which are numerous in these circumstances.

5-Hydroxytryptophan↗
PubMed1986

Conditions for the immunohistochemical demonstration of complement factor C3 in formaldehyde-fixed and paraffin-embedded renal tissues.

Paraffin sections of formaldehyde-fixed renal biopsies were labeled for complement C3 by a polyclonal rabbit antibody to human complement C3, by the peroxidase-antiperoxidase complex (PAP) and the avidin-biotin peroxidase complex (ABC) techniques, respectively. All tissues had C3 deposits according to direct immunofluorescence on fresh frozen sections. Staining for muramidase was introduced as an intrinsic control for the degree of tissue proteolysis after the necessary trypsin digestion prior to the immunoenzyme labeling. The results indicated that even minute deposits of C3 could be detected in paraffin sections by the ABC method, which was more sensitive than the PAP technique; the ABC method allowed a maximal dilution of 1:2,400 of the primary antibody as compared to 1:800 for the PAP technique.

Animals↗
PubMed1976

Feulgen-Naphthol Yellow S cytophotometry of liver cells. The effect of formaldehyde induced shrinkage on nuclear Naphthol Yellow S binding.

1. In isolated liver cells, fixed in 4 per cent formaldehyde (NFS) for Feulgen-Naphthol Yellow S (F-NYS) staining of DNA and protein, nuclear shrinkage increases the nuclear concentration of solids to 46 per cent (w/v) before the start of the NYS staining. 2. When a fixative mixture of methanol:acetic acid:formalin (85:5:10 by volume; MAF) is used, the concentration of nuclear solids during NYS staining remain at a physiological level of 19 per cent. 3. By exposing liver cells to NFS for 10 to 120 seconds before fixation in MAF, increasing nuclear shrinkage can be induced with increasing pretreatment in NFS. Nuclear NYS binding decreases in parallel with the decreasing nuclear volume in cells thus treated. As the shrinkage induced reduction in NYS binding may vary with the net charge of nuclear non-histone proteins, MAF fixation must be preferred for quantitative determinations of nuclear non-histone protein in F-NYS stained, isolated cells. 4. Fixation in MAF offers the same advantages as NFS fixation as regards the small loss of proteins during the Feulgen staining procedure and the excellent reproducibility of the F-NYS staining. Storage of MAF fixed cells in the fixative for a few days does not alter their F-NYS staining properties. 5. In MAF fixed, F-NYS stained cells there is no NYS binding to histone basic amino acid residues.

Acetates↗
PubMed1982

Polyamine cytochemistry. Use of a novel o-phtalaldehyde method for visualizing spermidine and spermine. Comparisons to the formaldehyde-fluorescamine method.

o-Phtalaldehyde (OPT) reacts with a number of biologically important molecules, including the polyamines, spermidine and spermine. By systematically varying reaction conditions with respect to temperature, pH, concentration and length of exposure to the reagent, using both model systems and tissues, we have succeeded in constructing a cytochemical OPT-method specific for spermidine and spermine. The method detects cell types known to contain these polyamines, including growing and neoplastic cells. The staining pattern obtained with the OPT method is identical to that obtained with the formaldehyde-fluorescamine (FF) technique recently shown to be specific for spermidine and spermine. In contrast to the FF technique, the OPT method can be used for staining suspensions of isolated cells and may hence be employed in studies using fluorescence-activated cell sorting (FACS). Preliminary such studies show a pronounced decrease in cellular OPT-induced fluorescence, paralleled by a decrease in content of polyamines, after treatment with the polyamine biosynthesis inhibitor alpha-difluoromethylornithine (alpha DFMO). In contrast, cells simultaneously treated with alpha DFMO + spermidine show pronounced increases in their spermidine content and parallel increases in their OPT-induced fluorescence. Availability of methods selectively demonstrating polyamines at the cellular and subcellular level is expected to aid our understanding of polyamine functions in normal growth and cancer.

Aldehydes↗
PubMed1979

The formaldehyde-induced fluorescence of the developing hypogastric (main pelvic) ganglion of the rat. Short adrenergic neurons and the effect of testosterone.

The development of the hypogastric ganglion of normal and testosterone-treated rats was studied using formaldehyde-induced fluorescence (FIF) method. The fluorescence intensities were recorded microspectrofluorimetrically. In normally developing rats cytoplasmic FIF decreases and cell size increases with age. In normally developing rats cytoplasmic FIF decreases and cell size increases with age. In testosterone-treated animals FIF increases during 2--6 weeks compared to the controls. The differences between control and experimental rats were significant. The diameters were significantly longer in treated animals in three and four week old groups. Vacuolated neurons were seen earlier in testosterone-treated rats. No changes in FIF or in cell size were noticed in the superior cervical ganglion. The male sex steroid, testosterone evidently influences the catecholamine turnover and cellular growth during development in the male pelvic ganglion.

Animals↗
PubMed1987

Molecular consequences of two formaldehyde-induced mutations in the alcohol dehydrogenase gene of Drosophila melanogaster.

Adhfn23 and Adhfn24 are two formaldehyde-induced, homozygous-viable, alcohol dehydrogenase-null mutants that bear lesions in the gene that codes for the alcohol dehydrogenase (ADH; EC 1.1.1.1) of Drosophila melanogaster. Adhfn23 contains a 34-base pair deletion in the C-terminal coding region of the alcohol dehydrogenase structural gene. By immunological and molecular analysis, we show that the deletion shifts the translation reading frame and results in a prematurely truncated polypeptide product (10 amino acids shorter than wild type) that cross-reacts with antibody raised against ADH. The steady-state level of alcohol dehydrogenase mRNA present in this mutant is close (97%) to that in the wild type, but the steady-state level of alcohol dehydrogenase-like protein is 50% lower. Moreover, the rate of alcohol dehydrogenase synthesis in Adhfn23 flies is reduced to 60% of that found in the wild type. Hence both the rate of synthesis and the rate of degradation of alcohol dehydrogenase are affected. In contrast, Adhfn24 which contains an 11-base pair deletion in the N-terminal coding region of the ADH gene, synthesizes no immunodetectable protein, and the amount of alcohol dehydrogenase mRNA is less than half that of wild-type flies. As with Adhfn23, the deletion in Adhfn24 results in a change in the reading frame. Unlike Adhfn23, however, nucleic acid sequence data indicate that polypeptide chain elongation can proceed for a considerable distance (over 130 amino acids) beyond the deletion. Based upon antigenic binding-site predictions, the resultant aberrant protein (projected 195 amino acids in length) would share few antigenic sites with the alcohol dehydrogenase from the wild type, which may account for the lack of immunoprecipitable material in this mutant. The contrasting effects these two deletions have on the Drosophila ADH mRNA levels and ADH protein levels are discussed.

Alcohol Dehydrogenase↗