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PubMed1985

[Comparative investigations on the precipitation behavior of various protein precipitates in organs and tissues].

The differences of the non-precipitable N-quota in blood plasma, liver, intestine, and muscles after treatment with various precipitants reveal data on the height of protein precipitation in the corresponding body fraction. Organs of hens treated with picric acid (1%), trichloroacetic acid (10%), and sulphosalicylic acid were used for the protein precipitation. Because of contradictory literature data as to the most suitable concentration of sulphosalicylic acid a preliminary determination of the most favourable acid concentration was necessary. The application of a 5% solution of sulphosalicylic acid gave the highest precipitation rate depending on the analyzed organs. In the succession picric acid, trichloroacetic acid, and sulphosalicylic acid nitrogen increases in the soluble supernatant. Furthermore, dependences of the protein precipitation on the kind of the analyzed organs were indicated.

Animals↗

PubMed2005

[Adsorption performance of haloacetic acids onto 5 GACs from water].

Adsorption performance of 5 GACs were compared on two abundant haloacetic acids (HAAs) as disinfection by-products (dichloroacetic acid and trichloroacetic acid). The adsorption behaviours of the two HAAs were well correlated with Langmuir equation. When the two HAAs co-existed, trichloroacetic acid tended to be adsorbed more easily. The adsorption capacity of a foreign GAC-A for dichloroacetic acid was 4.4-5.7 times that of domestic GACs, and 3.8 times that of another foreign GAC-B, while the adsorption capacity of a foreign GAC-A for trichloroacetic acid was 4.0-5.4 times that of domestic GACs, and 2.6 times that of another foreign GAC-B. The equilibrium study of competitive adsorption between dichloroacetic acid and trichloroacetic acid on GAC-A demonstrates that the relative adsorption capacity of HAAs has a linear increase with their relative equilibrium concentration. The adsorption capacity for trichloroacetic acid is sensitive to changes at its equilibrium concentration greater than that for dichloroacetic acid.

Adsorption↗

PubMed1986

Extraction of adenine nucleotides from cultured endothelial cells.

The goal of this work was to find a method suitable for the extraction of adenine nucleotides from cultured vascular endothelial cells. Extraction of cell monolayers with 80% methanol in water yielded extracts with a higher content of ATP than did extraction of cells with perchloric acid, trichloroacetic acid, or boiling water. The optimal extraction solution was 80% methanol with 0.5 mM ethylene glycol bis(beta-aminoethyl ether) N,N'-tetraacetic acid (EGTA) or EDTA, heated to 70 degrees C immediately before use. Extraction of nucleotides by this solution was rapid and the recovery of exogenous ATP added during the extraction process was generally greater than 90%. An aqueous methanol or ethanol solution may be applicable for the extraction of nucleotides and other metabolites from cultured animal cells, dispersed cells, and frozen, powdered tissues.

Adenine Nucleotides↗

PubMed1986

Mild interaction of proteins with butyl and hydroxyl groups on the surface of polymer gels TSK HW-65 and butyl toyopearl 650-M.

Interaction of bovine serum albumin (BSA) with butyl and hydroxyl groups on adsorbent gel surfaces was investigated by using TSK HW-65 and Butyl Toyopearl 650-M gels. It was found that BSA was adsorbed on the gel not only from highly concentrated ammonium sulphate but also from dilute perchloric acid, trichloroacetic acid, etc. Some eluent modifiers, such as organic solvents (30% aqueous methanol or acetonitrile), salt solutions (0.18-0.2 M phosphate) and hydrogen-bond breaking reagents (3-7 M urea, 10 M ethylene glycol, 0.1% triethylamine) were found to be effective in facilitating the elution of trapped BSA from the gel. The conformational change of BSA in these solutions was slight except for urea, and it was reversibly recovered after removal of the modifier from the aqueous solutions, except for the hydrogen-bond breaking reagents.

Adsorption↗

PubMed1996

Enantioseparation of 3-phenylacetylamino-2,6-piperidinedione and related chiral compounds.

This paper reports HPLC methodology for the first successful enantiomeric separations of 3-phenylacetylamino-2,6-piperidinedione (PAP), a naturally occurring peptide derivative used for inhibiting the growth of cancer tissues. The chiral separation of four related hydrolysates is also described. A commercially available tris-4-methylbenzoate cellulose (Chiralcel OJ) column was used as the chiral stationary phase, operated in the normal-phase, mode. The results demonstrated that hydrolyzed products of PAP, each of which has a carboxylic acid functionality present in its structure, eluted in a reasonable time and are enantiomerically resolved only when a trace amount of organic acid is present in the mobile phase. Different alcohols (ethanol and isopropanol) and acid additives (trifluoroacetic acid, trichloroacetic acid and acetic acid) were evaluated. In general, for the separation of the acidic enantiomers, ethanol is superior to isopropanol and stronger acids enhance the resolution more effectively. However, chiral separation of PAP could only be accomplished with isopropanol in the mobile phase and no acidic additive was needed.

Benzeneacetamides↗

PubMed1987

Determination of dosulepin and its metabolite: application of high-performance liquid chromatography with electrochemical detection.

Dosulepin, 11-(3-dimethylaminopropylidene)-6,11-dihydrodibenzo [b,e]thiepin hydrochloride, is a thio analogue of amitriptyline and is used for the treatment of anxiety and affective disorders. The present study developed a simple and sensitive procedure for the determination of this compound and its metabolite, northiaden, by a combination of high-performance liquid chromatography with electrochemical detection. Hydrodynamic voltammograms demonstrated an optimal applied potential at 1300 mV for both dosulepin and northiaden. A mobile phase consisting of 0.1 M acetate buffer-acetonitrile-perchloric acid-trichloroacetic acid (50:50:2:1.5) provided the best separation of the drugs. The extraction procedure, which used a heptane-isoamyl alcohol (99:1) mixture, was successfully applied with a recovery of over 90%. A preliminary pharmacokinetic study was performed by the proposed method.

Animals↗

PubMed2000

Trichloroethylene degradation by Ralstonia sp. KN1-10A constitutively expressing phenol hydroxylase: transformation products, NADH limitation, and product toxicity.

Ralstonia sp. KN1-10A, which was constructed by inserting the tac promoter upstream of the phenol hydroxylase (PH) gene in the chromosomal DNA of the wild-type strain, Ralstonia sp. KN1, is a useful recombinant strain for eliminating trichloroethylene (TCE) from contaminated sites because it exhibits constitutive TCE oxidation activity. During TCE degradation by Ralstonia sp. KN1-10A, noxious chlorinated compounds, such as dichloroacetic acid, trichloroacetic acid, 2,2,2-trichloroethanol, and chloral, were not detected, and more than 95% of chlorine in TCE was released as chloride ions. Among the possible TCE transformation products, only carbon monoxide was detected, and its conversion percentage was 7 mol%. The addition of formate, which Ralstonia sp. KN1-10A could use as an exogenous electron donor, did not enhance the TCE degradation performance, suggesting that NADH depletion did not limit the degradation. The phenol degradation activity of Ralstonia sp. KN1-10A that previously degraded TCE was not markedly lower than that of cells not exposed to TCE, suggesting that Ralstonia sp. KN1-10A was not susceptible to product toxicity associated with TCE degradation. Furthermore, to clarify the mechanisms underlying TCE degradation by PH from Ralstonia sp. KN1, this enzyme was compared with another enzyme, a hybrid aromatic ring dioxygenase exhibiting a high TCE degradation activity in Escherichia coli and Pseudomonas sp. The initial TCE degradation rate of Ralstonia sp. KN1 (pKTP100), which produced PH, was 1 50 lower than that of Ralstonia sp. KN1 (pKTF200), which produced the hybrid aromatic ring dioxygenase. However, because of its lower product toxicity, the strain producing PH could degrade 2.3 times more TCE than that generated by the strain producing the hybrid aromatic ring dioxygenase.

Journal Article↗

PubMed1990

Mechanism of acid-induced folding of proteins.

We have previously shown [Goto, Y., Calciano, L. J., & Fink, A. L. (1990) Proc. Natl. Acad. Sci. U.S.A. 87, 573-577] that beta-lactamase, cytochrome c, and apomyoglobin are maximally unfolded at pH 2 under conditions of low ionic strength, but a further decrease in pH, by increasing the concentration of HCl, refolds the proteins to the A state with properties similar to those of a molten globule state. To understand the mechanism of acid-induced refolding of protein structure, we studied the effects of various strong acids and their neutral salts on the acid-unfolded states of ferricytochrome c and apomyoglobin. The conformational transition of cytochrome c was monitored at 20 degrees C by using changes in the far-UV CD and in the Soret absorption at 394 nm, and that of apomyoglobin was monitored by changes in the far-UV CD. Various strong acids (i.e., sulfuric acid, perchloric acid, nitric acid, trichloroacetic acid, and trifluoroacetic acid) refolded the acid-unfolded cytochrome c and apomyoglobin to the A states as was the case with HCl. For both proteins neutral salts of these acids caused similar conformational transitions, confirming that the anions are responsible for bringing about the transition. The order of effectiveness of anions was shown to be ferricyanide greater than ferrocyanide greater than sulfate greater than thiocyanate greater than perchlorate greater than iodide greater than nitrate greater than trifluoroacetate greater than bromide greater than chloride.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2001

Reduction of haloacetic acids by Fe0: implications for treatment and fate.

To predict the fate of haloacetic acids (HAAs) in natural or engineered systems, information is needed concerning the types of reactions that these compounds undergo, the rates of those reactions, and the products that are formed. Given that many drinking water distribution systems consist of unlined cast iron pipe, reactions of HAAs with elemental iron (Fe0) may play a role in determining the fate of HAAs in these systems. In addition, zerovalent iron may prove to be an effective treatment technology for the removal of HAAs from chlorinated drinking water and wastewater. Thus, batch experiments were used to investigate reactions of four trihaloacetic acids, trichloroacetic acid (TCAA), tribromoacetic acid (TBAA), chlorodibromoacetic acid (CDBAA), and bromodichloroacetic acid (BDCAA), with Fe0. All compounds readily reacted with Fe0, and investigation of product formation and subsequent disappearance revealed that the reactions proceeded via sequential hydrogenolysis. Bromine was preferentially removed over chlorine, and TBAA was the only compound completely dehalogenated to acetic acid. In compounds containing chlorine, the final product of reactions with Fe0 was monochloroacetic acid. Halogen mass balances were 95-112%, and carbon mass balances were 62.6-112%. The pseudo-first-order rate constants for trihaloacetic acid degradation were as follows: BDCAA (10.6 +/- 3.1 h-1) > CDBAA (1.43 +/- 0.32 h-1) approximately TBAA (1.41 +/- 0.28 h-1) >> TCAA (0.08 +/- 0.02 h-1).

Acetic Acid↗

PubMed1986

Sampling and analytical methods for the determination of monochloroacetic acid in air.

A personal sampling and analytical method has been developed for the determination of monochloroacetic acid (MCA) vapor in air. The sampling procedure is the collection of MCA with a solid sorbent sampling tube packed with silica gel. The MCA is leached from the exposed sorbent into distilled, deionized water and quantitated by ion chromatographic analysis. The method has been validated in the concentration range of 0.35 to 29 mg/m3 in 3-L air samples. The capacity of the silica gel is in the range of 3 to 4 mg of MCA per 100 mg of sorbent, which allows for up to 8 hr of sampling at concentrations greater than 40 mg/m3. There are no significant interferences from glycolic acid, acetic acid, dichloroacetic acid, trichloroacetic acid, fluoride and chloride compounds, or water vapor. The effects on the analytical data due to variations in the temperature and humidity of the test atmosphere, sample storage time and chromatographic parameters have been found to be minimal.

Acetates↗

PubMed1991

Validated methods for degrading hazardous chemicals: some halogenated compounds.

Two techniques were investigated for degrading a number of halogenated compounds of commercial and research importance. Reductive dehalogenation with nickel-aluminum alloy in potassium hydroxide solution was used to degrade iodomethane, chloroacetic acid, trichloroacetic acid, 2-chloroethanol, 2-bromoethanol, 2-chloroethylamine, 2-bromoethylamine, 1-bromobutane, 1-iodobutane, 2-bromobutane, 2-iodobutane, 2-bromo-2-methylpropane, 2-iodo-2-methylpropane, 3-chloropyridine, fluorobenzene, chlorobenzene, bromobenzene, iodobenzene, 4-fluoroaniline, 2-chloroaniline, 3-chloroaniline, 4-chloroaniline, 4-fluoronitrobenzene, 2-chloronitrobenzene, 3-chloronitrobenzene, 4-chloronitrobenzene, benzyl chloride, benzyl bromide, alpha,alpha-dichlorotoluene, and 3-aminobenzotrifluoride. The products were generally those obtained by replacing the halogen with hydrogen although concomitant reduction of the other groups was also observed. Bibenzyl was produced during the reduction of benzyl chloride, benzyl bromide, and alpha,alpha-dichlorotoluene. Refluxing with ethanolic potassium hydroxide was used to degrade iodomethane, chloroacetic acid, 2-fluoroethanol, 2-chloroethanol, 2-bromoethanol, 1-chlorobutane, 1-bromobutane, 1-iodobutane, 2-bromobutane, 2-iodobutane, 2-bromo-2-methylpropane, 2-iodo-2-methylpropane, benzyl chloride, benzyl bromide, 1-bromononane, 1-chlorodecane, and 1-bromodecane. The products were the corresponding ethyl ethers. 2-Methylaziridine was cleaved with nickel-aluminum alloy in potassium hydroxide solution to a mixture of isopropylamine and n-propylamine. In all cases, the compounds were completely degraded and only nonmutagenic reaction mixtures were produced.

Hazardous Substances↗

PubMedDate not supplied

Preliminary evaluation of the Abbott TDx for screening of D-methamphetamine in whole blood specimens.

The Abbott TDx Urine Amphetamine/Methamphetamine II fluorescence polarization immunoassay technique was applied to the determination of D-methamphetamine in hemolyzed whole blood. The assay was found to have 100% cross-reactivity with D-methamphetamine and only an 8% cross-reactivity with L-methamphetamine. Whole blood was fortified with D-methamphetamine at concentrations ranging from 25 to 1000 ng/mL. These whole blood calibrators were used to evaluate the following sample preparation techniques: direct, diluted and buffer, and precipitated using methanol, acetone, sulfosalicylic acid, trichloroacetic acid, and zinc sulfate. Calibrators and samples were prepared by mixing 200 microL of whole blood and 200 microL precipitation reagent and centrifuging at 10,000 rpm for 5 min (9600 x g). A 50-microL aliquot of the supernatant was used for the assay. Using the zinc sulfate precipitation, blood calibration curves showed a linear range of 25-1000 ng/mL. The within-run precision for the 25-, 60-, and 200-ng/mL D-methamphetamine blood controls showed percent coefficients of variation of 17.8, 17.0, and 5.4, respectively. The TDx results were compared to RIA and GC/MS assays for the methamphetamine controls and for eight positive case specimens and found reliable for the screening of hemolyzed whole blood.

Cross Reactions↗

PubMed1978

An electron microscopic study of the location of peptidoglycan in group A and C streptococcal cell walls.

The morphological appearance of deproteinized Group A and C streptococcal walls after treatment by different procedures extracting teichoic acids and polysaccharides (formamide, hydrochloric acid, nitrous acid, trichloroacetic acid, sulphuric acid, sodium hydroxide and sodium deoxycholate) was compared with the content of teichoic acids and polysaccharides remaining in the treated walls. All procedures extracted teichoic acids almost completely, but polysaccharides were extracted to various degrees. The ultrastructural appearance of walls after these extractions still exhibited the triple-layered wall profile; only a reduction of thickness of the wall and of electron density of the layers occurred. There was no direct correlation between the reduction of rhamnose content and thickness of walls. The ultrastructural localization of peptidoglycan in the streptococcal walls was explored by means of the indirect immunoferritin technique using anti-peptidoglycan antibodies isolated from anti-Group A-variant antisera. Ferritin particles were bound predominantly to filamentous structures which protruded from both surfaces of peptidoglycan fragments and isolated walls. Peptidoglycan was also detected on the filamentous protrusions of whole cocci. These results contradict models of the streptococcal wall in which peptidoglycan forms the innermost layer and support a mosaic structure in which peptidoglycan forms a network of the peptidoglycan-polysaccharide complex.

Antibodies, Bacterial↗

PubMed2004

Therapy of cutaneous human Papillomavirus infections.

Human Papillomaviruses (HPV) are double-stranded DNA viruses, which result in a variety of clinical manifestations according to type. The most common cutaneous lesions include warts located on the skin and genitalia. Because there is currently no cure for HPV infection, treatment focuses on the alleviation of signs and symptoms. Unfortunately, therapy has not been proved to affect transmissibility. Traditional treatment modalities have focused on the destruction of infected tissue through a variety of techniques. These include podophyllin resin, podophyllotoxin, salicylic acid, trichloroacetic acid, bichloroacetic acid, cryotherapy, laser, and surgical techniques. None of these modalities have been proved to be superior. More recently, immunomodulatory compounds with antiviral properties have demonstrated superior efficacy with clearance rates up to 77% and low recurrence rates. Most importantly, clinical trials of vaccines to prevent acquisition of oncogenic HPV are demonstrating marked safety and efficacy.

Humans↗

PubMed1994

Measuring urinary protein with the new BioRad reagent kit: evaluation and comparison with five other methods.

Total urinary protein was measured by five methods: BioRad Total Protein Test (TPT), pyrogallol red, benzethonium chloride, sulfosalicylic acid, trichloroacetic acid, and the results compared to those obtained by a method combining preparative ultrafiltration and the biuret reaction. TPT was linear to 1.5 g protein/l, the detection limit 0.0135 g/l, and it was 3-5 times more sensitive than the other methods. Within-day precision (CV) was 4.3%, (0.60 g/l), the day-to-day precision was 4.5%. The protein contents of 35 selected urine samples assigned to one of five groups according to their electrophoretic pattern were assayed by the five methods. No method accurately measured physiological proteinuria, but the values for light chain (Bence Jones), glomerular, tubular and overload proteinurias measured by TPT did not differ significantly from the biuret value. The other methods differed significantly for at least three groups. Alpha 1 acid glycoprotein slightly inhibited TPT, but peptones, amino acids, antibiotics or normal urine constituents had little or no effect. The TPT method has been automated (Kone Progress); normal 24-h urinary protein excretion was 36 mg/day (range 12-114), the protein creatinine ratio was 34 mg/g (12-106 mg/g).

Autoanalysis↗

PubMed1998

Evaluation of an acidic deproteinization for the measurement of ascorbate and dehydroascorbate in plasma samples.

The most popular pretreatment method of plasma samples for the measurement of ascorbate (AsA) and dehydroascorbate (DHA) has been an acidic deproteinization via metaphosphoric acid or trichloroacetic acid. In general, DHA is absent in plasma samples prepared from human blood in a conventional manner. However, when these plasma samples were subjected to acidic deproteinization, DHA was detected in the acidified sample solutions. In the present study, we demonstrate that the oxidation of AsA to DHA in the solutions was promoted by at least two mechanisms, one involving catalysis by ferric ion released from transferrin, and the other involving catalysis by plasma hemoglobin. In the acidified transferrin solution by trichloroacetic acid, an oxidation of AsA to DHA proceeded with standing time, whereas the oxidation was not observed in that by metaphosphoric acid. This oxidation appeared to be catalyzed by ferric ion released from transferrin. In contrast, plasma hemoglobin functioned as a catalyst for AsA oxidation in both metaphosphoric acid and trichloroacetic acid solutions. Therefore, DHA content in the trichloroacetic acid-treated plasma sample was markedly higher than that in the metaphosphoric acid-treated one. These results suggest that DHA detected in acidified plasma samples is an artifact resulting from AsA oxidation.

Adult↗

PubMed1999

The use of chemical peelings in the treatment of different cutaneous hyperpigmentations.

BACKGROUND: Several chemical agents including hydroquinone, retinoic acid, and azelaic acid are currently used in the treatment of cutaneous hyperpigmentations. Recently chemical peelings with kojic acid, glycolic acid, and trichloroacetic acid, either alone or in combination, have been introduced for treatment of hyperpigmentations. OBJECTIVE: The purpose of our study was to evaluate the efficacy of trichloroacetic acid as well as glycolic acid associated with kojic acid in the treatment of cutaneous hyperpigmentations. METHODS: Twenty patients with diffuse melasma were treated with a solution composed of 50% glycolic acid and 10% kojic acid whereas 20 patients with localized hyperpigmentations (lentigo) were treated with 15%-25% trichloroacetic acid. RESULTS: Complete regression of diffuse melasma was observed in 6 of 20 patients (30%), a partial regression in 12 of 20 patients (60%), and no regression in 2 of 20 patients (10%) treated with 50% glycolic acid and 10% kojic acid. Complete regression of localized hyperpigmentations was observed in 8 of 20 patients (40%), a partial regression in 10 of 20 patients (50%), and no regression in 2 of 20 patients (10%) treated with 15-25% trichloroacetic acid. CONCLUSIONS: Based on our findings, both peelings can be considered effective in the treatment of cutaneous hyperpigmentations.

Adult↗

PubMed2003

Vacancy ion-exclusion chromatography of haloacetic acids on a weakly acidic cation-exchange resin.

A new and simple approach is described for the determination of the haloacetic acids (such as mono-, di- and trichloroacetic acids) usually found in drinking water as chlorination by-products after disinfection processes and acetic acid. The new approach, termed vacancy ion-exclusion chromatography, is based on an ion-exclusion mechanism but using the sample solution as the mobile phase, pure water as the injected sample, and a weakly acidic cation-exchange resin column (TSKgel OApak-A) as the stationary phase. The addition of sulfuric acid to the mobile phase results in highly sensitive conductivity detection with sharp and well-shaped peaks, leading to excellent and efficient separations. The elution order was sulfuric acid, dichloroacetic acid, monochloroacetic acid, trichloroacetic acid, and acetic acid. The separation of these acids depends on their pKa values. Acids with lower pKa values were eluted earlier than those with higher pKa, except for trichloroacetic acid due to a hydrophobic-adsorption effect occurring as a side-effect of vacancy ion-exclusion chromatography. The detection limits of these acids in the present study with conductivity detection were 3.4 microM for monochloroacetic acid, 0.86 microM for dichloroacetic acid and 0.15 microM for trichloroacetic acid.

Acetates↗