PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “THIOGLYCOLLIC ACID”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 541 records · Page 30Linked to original sources
PubMed2003

Transfer of arachidonic acid from lymphocytes to macrophages.

The incorporation and oxidation of arachidonic acid (AA) by rat lymphocytes (LY), the transfer of AA from LY to rat macrophages (Mphi) in co-culture, and the subsequent functional impact on Mphi phagocytosis were investigated. The rate of incorporation of [1-14C]AA by untreated-LY and TG (thioglycolate treated)-LY (TG-LY) was 158 +/- 8 nmol/10(10) LY per h for both untreated-LY and TG-LY. The oxidation of AA was 3.4-fold higher in TG-LY as compared with untreated cells. LY from TG-injected rats had a 2.5-fold increase in the oxidation of palmitic (PA), oleic (OA), and linoleic (LA) acids. After 6 h of incubation, [14C] from AA was distributed mainly into phospholipids. The rate of incorporation into total lipids was 1071 nmol/10(10) cells in untreated-LY and 636 nmol/10(10) cells in TG-LY. [14C]AA was transferred from LY to co-cultured Mphi in substantial amounts (8.7 nmol for untreated and 15 nmol per 10(10) for TG cells). Exogenously added AA, PA, OA, and LA caused a significant reduction of phagocytosis by resident cells. Mphi co-cultured with AA-preloaded LY showed a significant reduction of the phagocytic capacity (about 40% at 35 microM). LY preloaded with PA, LA, and OA also induced a reduction in phagocytic capacity of co-cultured Mphi. TG treatment abolished the AA-induced inhibition of phagocytosis in Mphi co-cultured with TG-LY. Therefore, the transfer of AA between leukocytes is a modulated process and may play an important role in controlling inflammatory and immune response.

Animals↗
PubMed2000

Value of lysozyme agar incorporation and alkaline thioglycollate exposure for the environmental recovery of Clostridium difficile.

Clostridium difficile is an increasingly prevalent nosocomial pathogen. Environmental contamination by spores is believed to be a major factor propagating the spread of C. difficile. Various approaches including the use of bile salts have been described to enhance the recovery of C. difficile from clinical and environmental specimens. We found that lysozyme (5 mg/L) incorporated into a selective medium containing bile salts significantly increased the recovery of C. difficile from swabs of 197 environmental sites (11% versus 24% samples positive, P< 0.01). Furthermore, in a separate series of experiments additional use of cooked meat broth enrichment significantly enhanced the recovery of C. difficile (35% versus 45%, P = 0.009). Conversely, we found that pre-exposure to alkaline thioglycollate did not improve the yield of C. difficile. Lysozyme incorporation markedly increases the recovery of C. difficile from environmental samples probably by stimulation of spore germination. Our findings suggest that previous attempts to determine the level of environmental C. difficile contamination have markedly underestimated the true prevalence of this pathogen.

Agar↗
PubMed1987

Role of fatty acid oxidation in control of meal pattern.

To characterize the role of fatty acid oxidation in the control of food intake, we investigated the effect of 2-mercaptoacetate, which inhibits fatty acid oxidation, on meal patterns and cumulative food intake in rats. Rats were fed either a medium fat (MF, 18% fat) or a low fat (LF, 3.3% fat) diet. Mercaptoacetate (400 mumole/kg body wt), intraperitoneally injected in the middle of the bright or at the onset of the dark phase of the diurnal lighting cycle, increased cumulative food intake in MF rats by shortening the latency to eat after injection and the duration of the subsequent intermeal interval (IMI) without affecting the size of the first meal. Mercaptoacetate, injected in the middle of the bright phase, reduced the latency to eat but did not affect the duration of the subsequent IMI or cumulative food intake in LF rats. A higher dose of mercaptoacetate (600 mumole/kg body wt), initially increased and later decreased cumulative food intake in MF rats. The initial increase in food intake was due to shorter IMIs; the subsequent decrease in food intake was due to smaller meals after mercaptoacetate injection than after control injection. The results indicate that a drop in fatty acid oxidation caused by mercaptoacetate triggers a meal. This implicates fatty acid oxidation in the maintenance of postprandial satiety.

Animals↗
PubMed1987

Tubular lysosome morphology and distribution within macrophages depend on the integrity of cytoplasmic microtubules.

Pinocytosis of the fluorescent dye lucifer yellow labels elongated, membrane-bound tubular organelles in several cell types, including cultured human monocytes, thioglycolate-elicited mouse peritoneal macrophages, and the macrophage-like cell line J774.2. These tubular structures can be identified as lysosomes by acid phosphatase histochemistry and immunofluorescence localization of cathepsin L. The abundance of tubular lysosomes is markedly increased by treatment with phorbol 12-myristate 13-acetate (10 ng/ml). When labeled by pinocytosis of microperoxidase and examined by electron microscopic histochemistry, the tubular lysosomes have an outside diameter of approximately 75 nm and a length of several micrometers; they radiate from the cell's centrosphere in alignment with cytoplasmic microtubules and intermediate filaments. Incubation of phorbol myristate acetate-treated macrophages at 4 degrees C or in medium containing 5 microM colchicine or nocodazole at 37 degrees C leads to disassembly of microtubules and fragmentation of the tubular lysosomes. Return of the cultures to 37 degrees C or removal of nocodazole from the medium leads to reassembly of microtubules and the reappearance of tubular lysosomes within 10-20 min. We conclude that microtubules are essential for the maintenance of tubular lysosome morphology and that, in macrophages, a significant proportion of the lysosomal compartment is contained within these tubular structures.

Animals↗
PubMed1989

In vitro protection by erdosteine against oxidative inactivation of alpha-1-antitrypsin by cigarette smoke.

Direct exposure in vitro of the protein alpha 1-antitrypsin (alpha 1-AT; human neutrophil elastase inhibitor, alpha 1-proteinase inhibitor) to gas phase cigarette smoke causes a loss of elastase-inhibitory capacity (EIC). This effect appears to be related to the formation of reactive oxygen species in the smoke that inactivate alpha 1-AT by oxidizing the methionine terminal amino acid. Reducing agents such as glutathione and ascorbic acid prevent this inactivation. In the present investigation erdosteine, a novel thiol derivative, which contains two blocked SH groups with potential reducing properties, was tested in vitro for its capacity to protect human alpha 1-AT. For the purpose, the compound, previously hydrolyzed with bicarbonate-carbonate buffer or with microsomal enzymes was put in contact with alpha 1-AT and exposed to gas phase cigarette smoke. The EIC of alpha 1-AT was then measured by incubating the samples with leukocyte elastase and, subsequently, by titrating the residual elastolytic activity against a synthetic substrate. Under these conditions erdosteine effectively protected alpha 1-AT against the smoke injury and, after alkaline hydrolysis, it appeared to be as active as glutathione and ascorbic acid (EC50 being respectively 6.4, 7.2 and 6.2 mM). This evidence suggests that the erdosteine SH groups, which can become free, may have an important role in the mechanism of action, by blocking highly reactive oxygen-free radicals. Erdosteine may have a therapeutic application in preventing oxidative lung damage induced by cigarette smoke.

Ascorbic Acid↗
PubMed1993

Macrophage-conditioned medium and beta-VLDLs enhance cholesterol esterification in SMCs and HSFs by LDL receptor-mediated and other pathways.

Thioglycolate-elicited mouse peritoneal macrophages were incubated for 24 hours in serum-free Dulbecco-Vogt medium containing 0.5% fatty acid-poor bovine serum albumin. This conditioned medium, designated MP medium, was used for experiments with bovine aortic smooth muscle cells (SMCs) or human skin fibroblasts (HSFs). Dulbecco-Vogt medium of the same albumin content but without macrophages served as a control medium. In SMCs labeled from plating the [3H]cholesterol and incubated with hypercholesterolemic rabbit beta-very-low-density lipoprotein (beta-VLDL) in Dulbecco-Vogt medium for 24 hours, there was an increase in cellular [3H]cholesteryl ester (CE) content compared with cells incubated without lipoprotein. When MP medium was used for the incubation of SMCs with beta-VLDL, cellular [3H]cholesteryl ester content increased threefold compared with cells incubated with Dulbecco-Vogt medium. A smaller increase in cholesterol esterification in the presence of MP medium was also encountered with low-density lipoprotein (LDL). The MP medium-induced increase in [3H]cholesterol esterification was not evident up to 6 hours of incubation. Similar results were also obtained with HSFs. The increase in [3H]cholesterol esterification with MP medium in the presence of beta-VLDL was also elicited in cells obtained from LDL receptor-negative donors with familial hypercholesterolemia (FH-HSF), even though in these cells significantly less [3H]cholesteryl ester was formed in the presence of beta-VLDL. MP medium contains numerous agents that could be responsible for the increase in cellular [3H]cholesteryl ester induced by lipoproteins. The first considered was lipoprotein lipase, but lack of inhibition of the MP medium effect by antiserum to lipoprotein lipase did not support this possibility.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

A comparison of technetium-99m-thiodiglycolic acid and iodine-123-hippuran in the evaluation of equivocal upper urinary tract obstruction.

In a comparative trial, 21 patients (mean age 43 (range 19-66) years) with dilated upper urinary tracts underwent diuresis renography with both 123I-hippuran and the experimental agent. 99Tcm-thiodiglycolic acid (TDG). Deconvolution analysis of the derived renograms was also performed and the transit times were calculated. Excellent agreement was found between results with the two radiopharmaceuticals. There was complete agreement in interpretation of the response to diuresis with both agents and 84% agreement in the transit time estimations. Good images were produced with both agents and 99Tcm-TDG is considered to be a useful alternative to 123I-hippuran.

Adult↗
PubMed1983

Dissociation between phagocytosis and phagosome-lysosome fusion.

The acridine orange technique was used to explore phagosome-lysosome fusion (P-L fusion) in thioglycollate-elicited rat peritoneal macrophages. Sheep red blood cells were coated with IgG or IgM plus complement, or treated with neuraminidase, tannic acid or glutaraldehyde; then both their capacity to be ingested by macrophages and their ability to induce P-L fusion after ingestion were assayed. Their capacity to be engulfed by macrophages was similar, but glutaraldehyde-treated erythrocytes were far more efficient than the other particles in triggering P-L fusion. Hence, both processes must be driven by different mechanisms. No correlation was found between the surface charge of test particles (as assayed by cell electrophoresis) and their ability to trigger phagocytosis or P-L fusion. However, glutaraldehyde-treated erythrocytes were found to be more hydrophobic than the other particles, as previously reported. Hence, particle hydrophobicity might favor P-L fusion. The implication of these findings are discussed.

Animals↗
PubMed1997

Evidence for the transfer in culture of [14C]-labelled fatty acids from macrophages to lymphocytes.

[14C]-labelled palmitic acid (PA), oleic acid (OA), linoleic (LA) and arachidonic (AA) acids were transferred from macrophages (M phi) to lymphocytes (LY) when equal numbers of the two cell types were co-cultured. The relative degree and amounts of the fatty acids transferred from M phi to LY are as follow: AA (368.57 +/- 21.62) = OA (274.52 +/- 15.41) > LA (42.11 +/- 8.31) = PA (36.53 +/- 2.45). The transfer units are nmol/10(10) M phi/10(10) LY and the values are mean +/- SEM for 7 experiments. The [14C]-radioactivity transferred was mainly directed to the phospholipid fraction of the lymphocytes (85% by PA, 86% by LA, 83% by OA and 79% by AA). In the same order as above, phosphatidylcholine was the phospholipid moiety most heavily labelled (82% by PA, 71% by LA, 66% by OA and 47% by AA). The amount of [14C]-radioactivity transferred to stimulated lymphocytes of thioglycollate treated animals remained unchanged for LA, PA and AA but reduced for OA (71%). The significance of these observations for the immune functions of the cells and resolution of the question of whether some of the [14C]-isotope transfer involves a component of exchange or is unequivocally net fatty acid mass transfer are still being investigated.

Animals↗
PubMed1997

Meiothermus cerbereus sp. nov., a new slightly thermophilic species with high levels of 3-hydroxy fatty acids.

Strains of Meiothermus cerbereus sp. nov. were isolated from the hot springs within the Geysir geothermal area of Iceland. The strains of Meiothermus cerbereus produce red-orange-pigmented colonies, have an optimum growth temperature of about 55 degrees C, and have higher levels of 3-OH fatty acids than the strains of the other species of the genus Meiothermus. These strains, unlike all other strains of the species of the genus Meiothermus examined previously, required cysteine, thiosulfate, or thioglycolate for growth in liquid Thermus medium, but not in the corresponding medium solidified with agar. Several strains belonging to Meiothermus silvanus, isolated from Geysir, also required reduced sulfur compounds for growth in liquid medium, leading to the hypothesis that this requirement is not a taxonomic characteristic of the new species. The new species represented by strains GY-1T and GY-5 can be distinguished from the other species of the genus Meiothermus by biochemical characteristics, fatty acid composition, DNA-DNA reassociation values, and 16S ribosomal DNA sequence. The type strain for Meiothermus cerbereus is GY-1 (= DSM 11376).

Base Composition↗
PubMed2006

Characterization of the bifunctional glycosyltransferase/acyltransferase penicillin-binding protein 4 of Listeria monocytogenes.

Multimodular penicillin-binding proteins (PBPs) are essential enzymes responsible for bacterial cell wall peptidoglycan (PG) assembly. Their glycosyltransferase activity catalyzes glycan chain elongation from lipid II substrate (undecaprenyl-pyrophosphoryl-N-acetylglucosamine-N-acetylmuramic acid-pentapeptide), and their transpeptidase activity catalyzes cross-linking between peptides carried by two adjacent glycan chains. Listeria monocytogenes is a food-borne pathogen which exerts its virulence through secreted and cell wall PG-associated virulence factors. This bacterium has five PBPs, including two bifunctional glycosyltransferase/transpeptidase class A PBPs, namely, PBP1 and PBP4. We have expressed and purified the latter and have shown that it binds penicillin and catalyzes in vitro glycan chain polymerization with an efficiency of 1,400 M(-1) s(-1) from Escherichia coli lipid II substrate. PBP4 also catalyzes the aminolysis (d-Ala as acceptor) and hydrolysis of the thiolester donor substrate benzoyl-Gly-thioglycolate, indicating that PBP4 possesses both transpeptidase and carboxypeptidase activities. Disruption of the gene lmo2229 encoding PBP4 in L. monocytogenes EGD did not have any significant effect on growth rate, peptidoglycan composition, cell morphology, or sensitivity to beta-lactam antibiotics but did increase the resistance of the mutant to moenomycin.

Acyltransferases↗
PubMed1992

Murine alpha 1,3-galactosyltransferase. A single gene locus specifies four isoforms of the enzyme by alternative splicing.

We have reported the characterization of a cDNA (clone 31A) encoding bovine alpha 1,3-galactosyltransferase (alpha 1,3-GT) (Joziasse, D. H., Shaper, J. H., Van den Eijnden, D. H., Van Tunen, A. J., and Shaper, N. L. (1989) J. Biol. Chem. 264, 14290-14297). With the goal of isolating a full-length cDNA encoding murine alpha 1,3-GT we screened a cDNA library with clone 31A and isolated a 3.4-kilobase (kb) alpha 1,3-GT clone (4A). The murine coding sequence is 78% similar to that of the bovine alpha 1,3-GT cDNA, but the "stem" region (defined as the region that links the single transmembrane domain to the catalytic domain) of the murine alpha 1,3-GT encoded by clone 4A, is 31 amino acids shorter than the corresponding region of the bovine alpha 1,3-GT. To screen for heterogeneity in the murine alpha 1,3-GT transcripts, we carried out a polymerase chain reaction (PCR) analysis on mouse C127 cDNA. Four distinct transcripts were detected, which predict four isoforms of the alpha 1,3-GT polypeptide that differ only in the length of their stem region. To determine how the four different transcripts are generated from a single gene, we have established the genomic organization for murine alpha 1,3-GT. The full-length mRNA spans at least 35 kb of genomic DNA and is distributed over nine exons that range in size from 36 base pairs (bp) to approximately 2600 bp. The protein coding region is distributed over six exons, and the 5'-untranslated sequence is distributed over three exons. Comparison of the genomic DNA sequence with that of the four different mRNAs indicates that these transcripts are produced by alternative splicing of the murine pre-mRNA according to a cassette model. A tissue survey using RNA-PCR revealed the presence of four different alpha 1,3-GT transcripts in all mouse tissues and cell lines examined to date, with the notable exception of male germ cells. Additionally, although alpha 1,3-GT levels increased upon thioglycollate-induced activation of mouse peritoneal macrophages, the ratio of the alpha 1,3-GT isoforms was essentially unchanged. Similar results were obtained upon retinoic acid-induced differentiation of murine F9 teratocarcinoma cells. Lastly, a similar PCR analysis of bovine cDNA produced only a single DNA fragment, corresponding to bovine cDNA clone 31A.

Amino Acid Sequence↗
PubMed1977

[Utilization of inorganic sulfur sources by Staphylococcus aureus strains].

Staphylococcus aureus strains of different host-adapted variants (Meyer 1966) have been tested for their ability to use inorganic sulfur sources. All the 25 strains tested were able to utilize sodium sulfide as sulfur source in a medium similar to that described by Kloos and Pattee (1965). Using S. aureus strain 116/74 grown in a medium containing Na2-35S as the only sulfur source we studied incorporation and insertion of inorganic sulfide into sulfur containing amino acids. In disintegrated and fractionated cellular material we could find 35S labelled homocystine and methionine as major compounds, and cystine, cysteic acid, homocysteic acid, and beta-sulphopyruvate as minor compounds. The occurrence of homocystine and the sulfonic acids in bacterial proteins is rather uncommon.

Bacterial Proteins↗
PubMed1994

Macrophage recognition of saccharide chains on the erythrocytes damaged by iron-catalyzed oxidation.

Mouse erythrocytes oxidized with an iron catalyst ADP/Fe3+ chelate attached to the monolayers of mouse resident and thioglycollate-induced peritoneal macrophages in the absence of serum, indicating that the macrophages recognized the oxidized erythrocytes. The recognition was partially prevented when the oxidized cells were treated with dithiothreitol, suggesting that disulfide formation is involved, in part, in the generation of the membrane sites recognized by macrophages. Phosphatidylserine is unlikely to be the determinant on the oxidized cells because it was not detected on the outer surface of the oxidized cells. The recognition by resident macrophages was effectively inhibited by N-acetylneuramin lactose, N-acetylneuraminic acid, glycophorin A, and disialoganglioside GD1a, but poorly by lactose, asialoglycophorin A, and monosialoganglioside GM1. In addition, the recognition was partially inhibited by L-fucose and human lactoferrin. The recognition by thioglycollate-induced macrophages was not inhibited by glycophorin A but was partially inhibited by L-fucose, lactoferrin, and oligosaccharides from band 3 glycoprotein. Enzymatic cleavage of the poly-N-acetyllactosaminyl saccharide chains of band 3 and lactoferrin resulted in a loss of the inhibitory activity. These results suggest that sialosaccharide chains of ADP/Fe(3+)-oxidized erythrocytes, possibly those on glycophorin A, are mainly involved in the recognition by resident macrophages, and poly-N-acetyllactosaminyl saccharide chains, possibly those on band 3, are partly involved in the recognition both by resident and thioglycollate-induced macrophages. Oxidation of erythrocytes may induce change in these membrane glycoproteins, like aggregation, which renders their saccharide chains susceptible to the macrophage recognition.

Adenosine Diphosphate↗