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Kautzleben Michael - - 2004
The anticoagulant r-hirudin lepirudin is eliminated exclusively via the kidneys. We examined the C-terminal amino acid degradation of lepirudin by the proximal kidney tubulus cells in humans as well as the antithrombotic efficacy of the metabolites and quantified the metabolite portions. In vitro metabolites of lepirudin were produced by adding ...
Proudfoot A T - - 2004
This Position Paper was prepared using the methodology agreed by the American Academy of Clinical Toxicology (AACT) and the European Association of Poisons Centres and Clinical Toxicologists (EAPCCT). All relevant scientific literature was identified and reviewed critically by acknowledged experts using set criteria. Well-conducted clinical and experimental studies were given ...
Sondossi M - - 2004
The purpose of this investigation was to examine the capacity of the biphenyl catabolic enzymes of Comamonas testosteroni B-356 to metabolize dihydroxybiphenyls symmetrically substituted on both rings. Data show that 3,3'-dihydroxybiphenyl is by far the preferred substrate for strain B-356. However, the dihydrodiol metabolite is very unstable and readily tautomerizes ...
Ponce G - - 2004
The TaqIA1 allele of the dopamine receptor gene D2 (DRD2) has been associated with alcoholism, as well as with other addictive behaviours. The exact nature of how the presence of this allele can be a vulnerability factor in the development of alcoholism remains unclear. In this study we found that ...
Parvex P - - 2003
Children with fully recessive (Type I/I) cystinuria have a high risk of stone formation in the first decade of life. To assess the tendency for cystine to precipitate in individual urine samples, we developed an in vitro assay in which radiolabelled cystine (4mM) was dissolved in urine at 37 degrees ...
Carlsson S - - 2003
Dietary and endogenous nitrates are excreted in urine, and during infection with nitrate-reducing bacteria they are reduced to nitrite. At a low pH nitrite is converted to a variety of nitrogen oxides that are toxic to bacteria. We hypothesized that acidification of nitrite-rich infected urine would result in the killing ...
Muñoz Jose A - - 2003
An ICPMS method for the determination of phytic acid in human urine based on the total phosphorus measurement of purified extracts of phytic acid is described. Pretreatment of the sample is required to avoid interference in the ICPMS detection from other phosphorus compounds accompanying phytic acid in urine such as ...
Chace Donald H - - 2003
BACKGROUND: Over the past decade laboratories that test for metabolic disorders have introduced tandem mass spectrometry (MS/MS), which is more sensitive, specific, reliable, and comprehensive than traditional assays, into their newborn-screening programs. MS/MS is rapidly replacing these one-analysis, one-metabolite, one-disease classic screening techniques with a one-analysis, many-metabolites, many-diseases approach that ...
Nakazawa Takahiro - - 2003
As a part of our search for the active metabolite from the bark of Magnolia officinalis (Magnoliaceae), the aqueous extract was orally administered to rats, and metabolites in the urine were analysed by a high-performance liquid chromatograph equipped with a photodiode array detector. When the extract was given to rats, ...
Hoffer L John - - 2003
BACKGROUND: N-acetyl-L-tyrosine (NAT) is commonly used in place of tyrosine in parenteral nutrition, but human studies carried out to date indicate considerable amounts of it are excreted unchanged in the urine. NAT retention has not been well studied in parenterally fed adults. METHODS: NAT retention was measured in 13 adults ...
Sperlingová I - - 2004
The reference material was prepared by freeze-drying pooled urine samples obtained from healthy persons occupationally exposed to styrene. The concentrations of mandelic acid (MA), phenylglyoxylic acid (PGA), and hippuric acid (HA) in urine were determined by three modes of high-performance liquid chromatography (HPLC). For isochronous stability testing the urinary mandelic ...
Chen L-J - - 2003
(R)-(+)-Menthofuran is a metabolite of (R)-(+)-pulegone, the chief constituent of pennyroyal oil. Menthofuran has been shown to account for a significant percentage of pulegone toxicity through further metabolism to a reactive intermediate, an enonal (2-Z-(2'-keto-4'-methylcyclohexylidene)propanal). Hydration of the enonal followed by a 1,4-dehydration and rearrangement gives rise to diastereomeric (-)-mintlactone ...
Jones K - - 2003
2-Butoxyethanol is a glycol ether widely used in printing inks, varnishes and cleaning fluids. As skin absorption can be significant, biological monitoring is useful in monitoring worker exposure. A number of analytes and matrices have been used previously, including 2-butoxyethanol in blood and free and total 2-butoxyacetic acid in urine. ...
Mani Ali R - - 2003
Reactive nitrogen species, such as peroxynitrite, can nitrate tyrosine in proteins to form nitrotyrosine. Nitrotyrosine is metabolized to 3-nitro-4-hydroxyphenylacetic acid (NHPA), which is excreted in the urine. This has led to the notion that measurement of urinary NHPA may provide a time-integrated index of nitrotyrosine formation in vivo. However, it ...
Yoshida Kaoru - - 2003
Our long-term oral administration of dimethylarsinic acid (DMAV) in rats revealed that three unidentified metabolites, M-1, M-2, and M-3, were detected in urine and feces. DMAV and trimethylarsine oxide (TMAO) were converted to M-2 and M-3 and M-1 by Escherichia coli strain A3-6 isolated from the ceca of DMAV-administered rats, ...
Kohri Toshiyuki - - 2003
After intravenous administration of (-)-epicatechin gallate to Wistar male rats, its biliary metabolites were examined. Deconjugated forms of (-)-epicatechin gallate metabolites were prepared by beta-glucuronidase/sulfatase treatment and purified by HPLC. Five compounds were subjected to FAB-MS and NMR analyses. These metabolites were shown to be (-)-epicatechin gallate, 3'-O-methyl-(-)-epicatechin gallate, 4'-O-methyl-(-)-epicatechin ...
Sprague Christopher L - - 2003
Epidemiological studies have indicated that 1,3-butadiene exposure is associated with an increased risk of leukemia. In human liver microsomes, 1,3-butadiene is rapidly oxidized to butadiene monoxide, which can then be hydrolyzed to 3-butene-1,2-diol (BDD). In this study, BDD and several potential metabolites were characterized in the urine of male B6C3F1 ...
Senda C - - 2003
1. The study was performed to isolate and characterize a glucuronic acid conjugate of mexiletine that releases mexiletine on acid hydrolysis from urine samples obtained from healthy volunteers following a single oral dose of mexiletine. 2. The [M-H]- ion of the isolated metabolite was observed at m/z 398 in the ...
Hofmann Ute - - 2003
Enzyme deficiencies in pyrimidine metabolism are associated with a risk for severe toxicity against the antineoplastic agent 5-fluorouracil. To assess whether urinary levels of pyrimidines and their metabolites can be used for predicting patients' individual phenotype, a new gas chromatographic-tandem mass spectrometric method was developed which allows the simultaneous determination ...
Wang I-Jen - - 2003
Maple syrup urine disease (MSUD) is a rare inborn error of the branched chain amino acid metabolism, which can be classified as classical, intermediate, intermittent, and thiamine responsive types. We report a 16-day-old boy who suffered from difficult feeding, persistent metabolic acidosis, and tricycling movement of the lower legs. Status ...
Fleming David E - - 2003
The existence of intracrystalline proteins and amino acids in calcium oxalate monohydrate was demonstrated by X-ray synchrotron diffraction studies. Their presence has implications for the destruction of calcium oxalate crystals formed in the urinary tract and the prevention of kidney stones. INTRODUCTION: Although proteins are present in human kidney stones, ...
Hardt Jochen - - 2003
OBJECTIVES: Pyrethroids are applied as insecticides throughout the world. Human metabolism of pyrethroids results in urinary metabolites that are suitable for biological monitoring. The aim of the study was to evaluate individual exposure due to occupational application of pyrethroids as a precondition for the assessment of health risks. METHODS: Thirty-six ...
Vermeulen Martijn - - 2003
Cruciferous vegetables contain glucosinolates, which are degraded to isothiocyanates. These are easily absorbed, conjugated to glutathione, and excreted into the urine as their corresponding mercapturic acids. We have developed and validated a solid phase extraction-high-performance liquid chromatography-electrospray ionization mass spectrometry/mass spectrometry method for the specific analysis of individual isothiocyanate mercapturic ...
Li Ke - - 2003
9-Nitro-20(S)-camptothecin is a novel anticancer drug. In this study, metabolites of 9-nitro-20(S)-camptothecin in rats were identified. Rats were dosed with the drug, and the metabolites in the bile were isolated and collected by high-performance liquid chromatography using a gradient elution. By LC/MSn(n =1-3), the biliary metabolites in addition to the ...
Gonthier Marie-Paule - - 2003
Chlorogenic acid, the ester of caffeic acid with quinic acid, is one of the most abundant polyphenols in the human diet with coffee, fruits and vegetables as its major sources. Its antioxidant and anticarcinogenic properties have been well established in animal studies. However, little is known about its gut absorption ...
Renwick Andrew G - - 2003
The risk assessment of compounds added to foods or taken as supplements is usually based on hazard characterization studies performed in animal test species. A large default uncertainty factor, or margin or exposure, is usually required to allow for possible species differences and human variability in the toxicokinetics and toxicodynamics ...
McLean Stuart - - 2003
Glucuronuria is normal in marsupial folivores such as the koala (Phascolarrctos cinereus), which excretes 2-3 g glucuronic acid daily. Although this has long been attributed to the metabolites of Eucalyptus terpenes, we have found that these are mostly excreted in the unconjugated form. We now report on the aglycones that ...
Lee Stephen T - - 2003
The consumption of ponderosa pine (Pinus ponderosa), lodgepole pine (Pinus contorta), common juniper (Juniperus communis), and Monterey cypress (Cupressus macrocarpa) causes abortions in pregnant cattle. Recent studies have identified isocupressic acid (1) as the primary abortificient compound in these plants. In vitro and in vivo studies using rumen and blood ...
Balkman Cheryl E - - 2003
OBJECTIVE: To evaluate 3 methods for measuring urine bile acids (UBA) and compare their diagnostic performance with that of the serum bile acids (SBA) test and other routine screening tests in dogs with hepatic disorders. DESIGN: Prospective study. ANIMALS: 15 healthy dogs, 102 dogs with hepatic disorders, and 9 dogs ...
Bilecen Deniz - - 2003
This study describes for the first time results of a (19)F-MRS study on humans exposed to the fluorinated non-steroidal anti-inflammatory drug niflumic acid. The accumulation and elimination of this commercially available selective prostaglandin synthase inhibitor is studied after an oral bolus in the human liver, in blood plasma and in ...
Walker Valerie - - 2003
BACKGROUND: From investigations of a child with hyperprolinaemia type II, we demonstrated in vitro that pyridoxal phosphate forms a novel adduct with a proline metabolite, pyrroline-5-carboxylic acid, through Claisen condensation. Studies indicated that this was a previously unsuspected generic reaction of aldehydes and some ketones. We have subsequently found the ...
Blackledge C A - - 2003
Following the administration of 2-, 3- and 4-fluorobenzyl alcohols, the major metabolites detected in urine corresponded to the glycine conjugates of the corresponding benzoic acids. Little, or no, unchanged parent compound was detected in the samples. In addition to glycine-conjugated benzoic acids, a small proportion of the urinary metabolites for ...
Trainor D - - 2003
Urine bile acid (UBA) tests reflecting "average" serum bile acid (SBA) concentrations may have greater practical utility than paired SBA samples in cats. This study evaluated whether urine sulfated bile acids (USBAs), urine nousulfated bile acids (UNSBAs), or a combined approach had a clinical utility equivalent to SBAs. Routine serum ...
Mareska Michael C - - 2003
Glutaric acidemia type II (GA II) typically presents with profound metabolic acidosis, hypoketotic hypoglycemia, and mild dysmorphic features in newborns. Since its description, 11 patients with adult-onset GA II have been reported. A 23-year-old woman presented at 6 months gestation with preterm labor and weakness for 3 months. Her weakness ...
Leng Gabriele - - 2003
A prospective epidemiological study with respect to pyrethroid exposure was carried out combining clinical examination, indoor monitoring and biological monitoring. The results of the biological monitoring are presented. Biological monitoring was performed in 57 persons before (T1) as well as 1 day (T2), 3 days (T3), 4-6 months (T4), and ...
Mims DebraLynn - - 2003
The ability to quantify mixtures of bile acids using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry directly from urine has been demonstrated. Six cholic acid derivatives were selected for analysis: taurocholic acid (TCA), taurochenodeoxycholic acid (TCDCA), taurolithocholic acid (TLCA), glycocholic acid (GCA), glycochenodeoxycholic acid (GCDCA), and glycolithocholic acid (GCDCA). Urine ...
la Marca Giancarlo - - 2003
Quantification of orotic acid (uracil-6-carboxylic acid) in urine is an important tool to diagnose some inherited diseases, such as urea cycle disorder (OTCD) and hereditary orotic aciduria. New rapid analytical methods are necessary to provide high-throughput orotic acid analyses. A new analytical method has been developed for the rapid analysis ...
Siegers Claudia - - 2003
Cystinol akut containing arbutin was developed as an antiseptic since it liberates hydroquinone in the urine. The in vivo release of hydroquinone from arbutin with or without addition of glusulase or an E. coli suspension was investigated in 4 volunteers. They ingested 6 dragees Cystinol akut (420 mg arbutin equivalent ...
Kuhara Tomiko - - 2002
To diagnose inborn errors of metabolism, it would be desirable to simultaneously analyze and quantify organic acids, purines, pyrimidines, amino acids, sugars, polyols, and other compounds using a single-step fractionation; unfortunately, no such method currently exists. The present article will be concerned primarily with a practical yet comprehensive diagnostic procedure ...
Khan Saeed R - - 2002
BACKGROUND: Cell membranes and their lipids play critical roles in calcification. Specific membrane phospholipids promote the formation of calcium phosphate and become a part of the organic matrix of growing calcification. We propose that membrane lipids also promote the formation of calcium oxalate (CaOx) and calcium phosphate (CaP) containing kidney ...
Shahjee Hanief M - - 2002
Using cytidine 2':3' cyclic monophosphate as a substrate, Km and k(cat) of ribonuclease-A in the presence of different concentrations of D-amino acids (Ala, Ser, Pro and Lys) and their L-isomers were measured at pH 6.0 and 25 degrees C. These kinetic parameters remained unchanged in the presence and absence of ...
Gonzalez-Reche Luis Mariano - - 2003
It was the aim of this study to ascertain whether xylenes form phenylmercapturic acids via aromatic epoxides in the human metabolism. Aromatic epoxides are suspected to exert mutagenic properties. Therefore we developed an LC/MS/MS procedure for the determination of these mercapturic acids. Using this method we were able to detect ...
Dlasková Zdenka - - 2003
In urine the level of thiodiglycolic acid (TDGA) is a sensitive indicator of exposure of the human organism to some physiologically active or toxic substances, gases and vapors. The determination of TDGA by use of a voltammetric method based on electroreduction of TDGA in acidic solution at the hanging mercury ...
Rechner Andreas R - - 2002
Berry extracts rich in anthocyanins have been linked to protective effects including the modulation of age-related neurological dysfunction and the improvement of the resistance of red blood cells against oxidative stress in vitro. In this study the bioavailability, metabolism and elimination of polyphenols from blackcurrant juice, rich in anthocyanins, flavonols, ...
Kirschbaum B - - 2002
AIMS: Inflammation results in the production of free radicals which damage proteins, lipids, and nucleic acids. The products of these reactions are cleared, in part, by the kidney and appear in the urine. In this study, urine fluorescence was measured in individuals with various nephropathies to determine the value of ...
Valkonen Sinikka - - 2002
The FIOH quality assurance programme for organic solvents and their metabolites consists of analyses for 2,5-hexadione, phenol, mandelic acid, methylenedianiline, methylhippuric acid, trans,trans-muconic acid and trichloroacetic acid in urine, and creatinine and relative density for standardisation. Four times a year two levels of spiked urine or urine specimens collected from ...
dos Santos Claudia Regina - - 2002
Urinary 2,5-hexanedione (2,5-HD) is used as a biomarker for biological monitoring of workers exposed to n-hexane. The purpose of this study was to compare two types of treatment of urine samples during clean-up (with and without acidic hydrolysis) and to study the exposure situation of workers exposed to n-hexane during ...
Poplawski N K - - 2002
OBJECTIVES: To determine the proportion of urine amino and organic acids screening tests (UMS) undertaken for patients referred with developmental delay or intellectual disability (DD/ID), and within the group with DD/ID, to determine the diagnostic yield, the proportion of diagnoses with a therapy and the associated recurrence risks. METHODS: A ...
Strickland Paul T - - 2002
Heterocyclic amines (HAs) are carcinogenic combustion products formed during the cooking of meat at moderate to high temperatures. PhIP is the most common HA formed in fried, grilled or broiled meat, and is a colon, breast, and prostate carcinogen in rodents. The major metabolites of PhIP detected in human urine ...
Arancibia Juan A - - 2002
First- and second-order multivariate calibration of fluorescence data have been compared as regards the determination of anti-inflammatories and metabolites in the biological fluids serum and urine. The simultaneous resolution of naproxen-salicylic acid mixtures in serum and naproxen-salicylic acid-salicyluric acid mixtures in urine was accomplished and employed for a discussion of ...
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