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PubMed1978

An assay procedure for inositol pentaphosphate in avian erythrocytes.

A method to determine the concentration of inositol pentaphosphate (IP5) in chicken erythrocytes is described. Lysates of washed erythrocytes were treated with trichloroacetic acid to remove protein and were chromatographed on Dowex-1 chloride columns. After eluting the other organic phosphates with .3 N HCl, IP5 was eluted with .5 N HCl and quantitated by phosphorus assay. The mean for 12 chickens was 15.4 +/- 2.71 micromoles/g hemoglobin. The method should be useful for the assay of large numbers of samples.

Animals↗

PubMed2005

Resolution of liver fibrosis in chronic CCl4 administration in the rat after discontinuation of treatment: effect of silymarin, silibinin, colchicine and trimethylcolchicinic acid.

The purpose of this work was to obtain a suitable model of fibrosis, in which spontaneous reversion was minimal, to study the ability of silymarin, silibinin, colchicine and trimethylcolchicinic acid (TMCA) to reverse it. Reversal of liver fibrosis was studied in male Wistar rats after one, two or three months of CCl(4) administration (0.4 g/kg intraperitoneally, three times per week), by discontinuation of the toxin for 2 months. Silymarin (50 mg/kg), silibinin (50 mg/kg), colchicine (10 microg/rat) and trimethylcolchicinic acid (100 microg/rat) were administered daily, by gavage, after 3 months of CCl(4) administration. Collagen content was determined by measuring hydroxyproline in liver samples; glycogen, was determined utilizing the anthrone reagent; Mallory's trichromic stains of liver sections were performed. The best scheme of treatment was obtained when CCl(4) was administered during three months (collagen increased 6 times). Discontinuation of the toxin for two months produced a significant but relative small reduction of fibrosis (collagen was still 4.5 times over control). Colchicine, TMCA, silymarin or silibinin treatment showed no significant fibrolitic effect. This scheme of treatment may be an excellent tool to study the ability of drugs to reverse fibrosis. The hepatoprotective properties of silymarin, silibinin, colchicine and trimethylcolchinic acid may be irrelevant to reverse established cirrhosis.

Alanine Transaminase↗

PubMed1991

Presence of an extracellular glycosyltransferase in human dental plaque.

1. Glycosyltransferase activity incorporating 14C-radioactivity from [14C]sucrose into endogenous acceptor was demonstrated in human dental plaque. 2. The enzyme was localized in dental plaque into two forms: (a) associated form to bacteria (pellet 10,000 g) and (b) released as an extracellular form (supernatant 10,000 g). 3. The reaction product was insoluble in 95% ethanol, soluble in trichloroacetic acid, and it was a mixture of saccharides with different sizes, as was demonstrated by column chromatography. 4. Exogenous activity with Dextran T-10 as substrate was also demonstrated, and it represented 9% of the total endogenous activity. 5. Characterization of the extracellular glycosyltransferase, and comparative results with glycosyltransferase secreted by oral bacteria in cultures medium are discussed.

Bacteria↗

PubMed2001

The [15N]methacetin liver function test characterizes multicomponent exposure of children in industrially polluted regions.

The [15N]methacetin urine test for assessing disturbances of the cytochrome P450-aided oxygenation of xenobiotics in the human liver has been approved in several environmental health studies. A recent longitudinal study of kindergarten children near chemical and mining companies undergoing fundamental restructuring showed high, seasonally fluctuating SO2 burden which was well correlated with alterations in the mean liver states of the children. At one point the correlation disappeared, together with indications of large amounts of chlorinated compounds overflowing locally at nighttime. This was finally proven by analyzing urine samples from the children for trichloroacetic acid (TCA). Chlorinated ethanes and ethenes-the precursors of TCA-seemed to dominate the air pollution and to affect the hepatic detoxification capacity. We concluded that the methacetin liver function test reflects multicomponent exposure, including acute monopolization by a dominant pollutant for a time.

Acetamides↗

PubMed1978

A simple sensitive method, applicable to small polypeptides, for the determination of proteins in polyacrylamide gels after isoelectric focusing.

A simple method is described for the determination of polypeptides and proteins in polyacrylamide gels after isoelectric focusing. Precipitates formed in trichloroacetic acid, under controlled conditions, are quantified densitometrically by measuring the proportion of light scattered. The procedure is of particular value in its applicability to smaller polypeptides, with mol.wts. of 3000-6000, which are not fixed adequately in gels by other procedures currently in use. The working range, over which polypeptide concentration is proportional to the effective absorbance, is approx. 1-30 microgram per component.

Acrylic Resins↗

PubMed1997

Proline is a protein solubilizing solute.

The effect of proline on the prevention of trichloroacetic acid (TCA)-induced protein precipitation is studied. It is found that proline at high concentrations (> 4.0 M) completely prevents TCA-induced precipitation of hen egg white lysozyme. Other osmolytes such as ethylene glycol, glycerol and sucrose fail to prevent the TCA-induced precipitation of lysozyme. Viscosity and 1-anilino-8-naphthalene sulphonic acid binding experiments suggest that proline at high concentration forms an ordered supramolecular assembly. Proline is shown to increase the solubility of protein due to formation of such higher order assemblies. A model of the supra-molecular assembly of proline is proposed and a possible in vivo role of the increased levels of proline under water stress is discussed.

Animals↗

PubMed1977

Galactosyltransferase activity of the microvillous surface of human placental syncytial trophoblast.

The syncytial trophoblast has previously been shown to have minimal intrasyncytial galactosyltransferase activity at term. The biochemical and autoradiographic study reported here shows that the microvillous surface of term human placental syncytial trophoblast has a galactosyltransferase activity capable of transferring 3H-galactose from uridine diphosphate-D-galactose-1-3H to trichloroacetic-acid precipitable, endogenous acceptors. This capability of resynthesizing cleaved galactose moieties in the glycocalyx, without dependence on cytoplasmically located galactosyltransferases, would allow for reinstatement of the original surface molecular configuration without requiring synthesis and insertion of a completely new membrane molecule. It is suggested that the surface galactosyltransferase might function to repair damage to syncytial trophoblast glycocalyx induced by the enzymes in maternal blood.

Autoradiography↗

PubMed2005

Direct electrochemistry and electrocatalysis of heme proteins entrapped in agarose hydrogel films in room-temperature ionic liquids.

The electrochemistry and electrocatalysis of a number of heme proteins entrapped in agarose hydrogel films in the room-temperature ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF(6)]) have been investigated. UV-vis and FTIR spectroscopy show that the heme proteins retain their native structure in agarose film. The uniform distribution of hemoglobin in agarose-dimethylformamide film was demonstrated by atomic force microscopy. Cyclic voltammetry shows that direct electron transfer between the heme proteins and glassy carbon electrode is quasi-reversible in [bmim][PF(6)]. The redox potentials for hemoglobin, myoglobin, horseradish peroxidase, cytochrome c, and catalase were found to be more negative than those in aqueous solution. The charge-transfer coefficient and the apparent electron-transfer rate constant for these heme proteins in [bmim][PF(6)] were calculated from the peak-to-peak separation as a function of scan rate. The heme proteins catalyze the electroreduction of trichloroacetic acid and tert-butyl hydroperoxide in [bmim][PF(6)]. The kinetic parameter I(max) (maximum current at saturation concentration of substrate) and the apparent K(m) (Michaelis-Menten constant) for the electrocatalytic reactions were evaluated.

Biosensing Techniques↗

PubMed1993

Inositol phosphates in rat atria and the importance of the extraction procedure.

The nature of the inositol phosphates present in adult rat left atria have been examined. Trichloroacetic acid extracts of [3H] inositol-labelled left atria contained the 1 (or 3)-, 2- and 4-isomers of inositol monophosphate, inositol-1,4-bisphosphate, and inositol-1,4,5-trisphosphate. Addition of noradrenaline increased all of these isomers. However, even in the presence of noradrenaline, there was no evidence for the presence of inositol-1,3,4,5-tetrakisphosphate or its dephosphorylation products including inositol-1,3,4-trisphosphate and the 1,3- and 3,4-isomers of inositol bisphosphate. Total accumulation of inositol phosphates in the presence of LiCl was 98% accounted for by dephosphorylation of inositol-1,4,5-trisphosphate and its cyclic isomer. These data indicate that, in intact left atria, metabolism of inositol-1,4,5-trisphosphate is by dephosphorylation and that significant activity of the phosphorylation pathway is not present. When extractions were performed using either acidified chloroform-methanol or perchloric acid, other [3H] inositol-labelled compounds were detected in atrial extracts. One of these chromatographed with ATP and might be mistaken for inositol-1,3,4-trisphosphate if co-chromatography with ATP was used to identify that compound. Another compound had a similar, but not identical chromatographic profile to inositol-1,3,4,5-tetrakisphosphate and is thus likely to be mistaken for that compound. In addition, perchloric acid extraction caused phosphate group migration generating extra isomers of the inositol phosphates and other unidentified [3H]-labelled compounds. Such extraction artifacts are likely especially problematic in studies of intact heart tissue because of the time required to effectively homogenize the tissue. These findings demonstrate the need for caution in interpreting data relating to estimations of inositol phosphates in intact heart tissue.

Animals↗

PubMed1995

The role of dermabrasion and chemical peels in the treatment of patients with xeroderma pigmentosum.

We describe our experience with two patients with xeroderma pigmentosum who underwent periodic trichloroacetic acid chemical peels. One also received a full-face dermabrasion. The effect of chemical peeling was more transient than dermabrasion but was associated with less morbidity. Both chemical peeling and dermabrasion provided a prophylactic effect against the development of skin malignancies; the latter had a more pronounced effect.

Adolescent↗

PubMed2000

Characterization of phage receptors in Streptococcus thermophilus using purified cell walls obtained by a simple protocol.

A simple protocol was designed and applied to obtain Streptococcus thermophilus purified cell walls. To identify the structures involved in phage adsorption, the cell walls of two Strep. thermophilus strains were treated with sodium dodecyl sulphate and proteinase K. These treatments did not reduce the adsorption of phages CYM and 0BJ to the cell walls of Strep. thermophilus YSD10 and Strep. thermophilus BJ15, respectively. However, phage binding was reduced when the cell envelopes were treated with mutanolysin or trichloroacetic acid 5%, suggesting that the phage receptor component is part of the peptidoglycan or a polymer closely linked to it. The ability of several saccharides to inactivate both phages was also assayed. These phage inhibition experiments suggested that the phage CYM adsorbed to a component involving glucosamine and rhamnose, while glucosamine and ribose interfered with the adsorption of phage 0BJ.

Adsorption↗

PubMed1991

Some aspects of chronic copper poisoning in sheep.

The variations in an analytical fraction of plasma copper, as well as those of direct and indirect plasma bilirubin, were studied for a period of twenty-three days in ten native crossbred sheep suffering from chronic copper poisoning. The findings of the experiment, which was begun just before the appearance of any acute symptoms, show that the proportion of the above fraction of plasma copper, characterized as "soluble in trichloroacetic acid" (STAPC), represents approximately 45% as a mean percentage of the total plasma copper (TPC), while in the controls it was 12%; further, the former proportion, despite progressive reduction in the absolute values on the respective concentrations, shows, at least during the course of the experiment, a relatively small decrease, while in the controls it remains constant. Further findings regarding direct and indirect plasma bilirubin are discussed.

Animals↗

PubMed2006

Composite system based on chitosan and room-temperature ionic liquid: direct electrochemistry and electrocatalysis of hemoglobin.

A novel polymer/room-temperature ionic liquid (RTIL) composite material based on chitosan (Chi) and 1-butyl-3-methyl-imidazolium tetrafluoroborate (BMIM.BF(4)) was explored. The composite system can be readily used as an immobilization matrix to entrap proteins and enzymes. Hemoglobin (Hb) was chosen as a model protein to investigate the composite system. A pair of well-defined quasireversible redox peaks of hemoglobin were obtained at the Chi-BMIM.BF(4)-Hb composite-film-modified glassy carbon (GC) electrode by direct electron transfer between the protein and the GC electrode. Dramatically enhanced biocatalytic activity was exemplified at the Chi-BMIM.BF(4)-Hb/GC electrode by the reduction of oxygen and trichloroacetic acid. Thermogravimetric analysis (TGA) suggests that the Chi-BMIM.BF(4)-Hb composite has higher thermal stability than Chi-Hb itself. The Chi-BMIM.BF(4)-Hb film was also characterized by UV-visible spectra, indicating excellent stability in solution and good biocompatibility for protein. The unique composite material based on polymer and ionic liquid can find wide potential applications in direct electrochemistry, biosensors, and biocatalysis.

Biocompatible Materials↗

PubMed1972

Binding of rat liver and hepatoma polyribosomes to stripped rough endoplasmic reticulum in vitro. Biological or an artifact?

Exposed thiol groups do not appear to be related to the binding of (32)P-labelled polyribosomes to stripped rough endoplasmic reticulum in vitro. Treating stripped rough endoplasmic reticulum with GSSG did not diminish binding of polyribosomes, suggesting that binding in vitro has no correlation with the inhibition of protein synthesis in vitro reported by Kosower et al. (1971). Thiol reagents, which are known to dissociate ribosomes, did not significantly decrease binding of (32)P-labelled polyribosomes to stripped rough endoplasmic reticulum. Denaturing the protein of (32)P-labelled polyribosomes or stripped rough endoplasmic reticulum of liver or hepatoma with heat, trichloroacetic acid, or HClO(4) did not alter the binding in vitro. Therefore, the practice of measuring the binding of (32)P-labelled polyribosomes to stripped rough endoplasmic reticulum in vitro (Shires et al., 1971b) is an unsuitable indicator of biological significance in the intact cell.

Animals↗

PubMed1980

The fate of 99Mo-labelled sodium tetrathiomolybdate after duodenal administration in sheep: the effect on caeruloplasmin (EC 1.16.3.1) diamine oxidase activity and plasma copper.

1. The effect of acute duodenal infusion of 99Mo-labelled sodium tetrathiomolybdate on caeruloplasmin (ferroxidase; EC 1.16.3.1) was examined in sheep. The diamine oxidase activity of this enzyme with respect to two substrates, p-phenylenediamine and o-dianisidine (both at their apparent Km concentrations) was inhibited. 2. The 99Mo appeared rapidly in plasma and was at first present predominantly in a trichloroacetic acid insoluble form; inhibition of oxidase activity was related to the levels of TCA-insoluble Mo. The behaviour of the copper prosthetic groups of caeruloplasmin was altered since some plasma Cu precipitated with the protein fraction after TCA treatment. The appearance of TCA insoluble Cu was related to the level of TCA-insoluble 99Mo and corresponded to the inhibition of diamine oxidase activity.

Amine Oxidase (Copper-Containing)↗

PubMed1987

Studies on the mechanism of acetaldehyde-mediated inhibition of rat liver transaminases.

Incubation of mitochondria-depleted rat liver homogenates with 5 mmol/l acetaldehyde at 37 degrees C for 1 h inhibited both aspartate and alanine aminotransferases by 30%. Inhibition was prevented by decreasing temperature to 4 degrees C or by preincubating homogenates with cyanate but was unaffected by cyanamide and methylpyrazole which block acetaldehyde oxidation and reduction respectively. Cyanate-sensitive acetaldehyde-mediated inhibition of purified porcine heart transaminases was also demonstrated in the presence of rat liver homogenate but not in Tris/sucrose medium. Moreover, porcine transaminases were inhibited by trichloroacetic acid extracts of rat liver homogenates previously incubated with acetaldehyde but not by extracts of homogenates incubated with both acetaldehyde and cyanate. These findings suggest that acetaldehyde-mediated transaminase inhibition requires further non-oxidative metabolism of acetaldehyde. Since transaminase activities were not restored by addition of pyridoxal 5'-phosphate to the assay systems, acetaldehyde-induced transaminase inhibition does not appear to be mediated by displacement or depletion of this B6 coenzyme.

Acetaldehyde↗

PubMed2005

Genital warts: current and future management options.

Genital warts are a cosmetic nuisance. They are caused by low-risk human papillomavirus types, have no oncogenic potential and are not linked to cervical cancer. However, they often cause significant psychological morbidity. Treatments are aimed at eradicating the unsightly lesions and stimulating the immune system to generate clearance and prevent recurrence. Commonly used physical treatment methods include cryotherapy, trichloroacetic acid, laser, and electrocautery. However, many patients respond extremely well to home therapies with either podophyllotoxin or imiquimod. Patients prefer the comfort and dignity of home treatment, and this should be the first-line of treatment for the majority of patients. A routine screen for sexually transmitted infections is appropriate in most cases. Detailed explanation and reassurance are of paramount importance in reducing the psychological distress associated with this unpleasant genital condition.

Adjuvants, Immunologic↗

PubMed1987

Health and reproductive status of female workers in dry cleaning shops.

This study concerns 67 women working in 53 dry cleaning shops in the city of Rome. The survey includes data on work habits, health problems and reproductive histories. Exposure to the prevalent solvent used in dry cleaning (tetrachloroethylene) was evaluated by the trichloroacetic acid (TCA) concentration in the urine. Exposure was four times higher among dry cleaners than among women doing only ironing and among the controls. However, the TCA values were still low, thus suggesting ambient concentrations within the acceptable limits. The health of these women was satisfactory, and no overt reproductive pathology was detected. The methodological limitations and the small sample size, however, do not permit firm conclusions.

Adult↗