Abstract：
BACKGROUND:Cleavage of conjugates is an important step in toxicological analysis, especially of urine samples. The aim of this study was to combine the advantages and to reduce the disadvantages of acid hydrolysis and conventional enzymatic hydrolysis procedures. METHODS:beta-Glucuronidase (GRD; EC 3.2.1.31) and arylsulfatase (ARS; EC 3.1.6.1) were purified and coimmobilized on an agarose gel matrix and packed into columns. RESULTS:In columns packed with GRD and ARS, the test conjugates 4-nitrophenyl glucuronide and 4-nitrophenyl sulfate added into urine could be completely cleaved within 25 min. Even the relatively stable morphine conjugates could be completely hydrolyzed within 60 min in authentic urine samples. Therefore, an incubation time of 1 h is recommended. Enzyme inhibition by matrix or by rather high concentrations of acetaminophen conjugates was tested and found to be up to 50%. However, a large excess of GRD and ARS was used. The immobilizate columns could be reused for at least 70 incubations and had a storage stability of at least 12 weeks. Carryover of analytes in reused columns could be avoided by rinsing with 200 mL/L methanol in acetate buffer. Thus, five drugs known to be contaminants added in very high concentrations into urine could be completely removed from the columns. A study on the applicability in systematic toxicological analysis showed that 120 different drugs and/or their metabolites could be detected in 35 different authentic urine samples. CONCLUSIONS:Use of immobilized and column-packed GRD and ARS is an efficient alternative for the cleavage of urinary conjugates in clinical toxicology.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Toennes SW,Maurer HHsubject
Has Abstractpub_date
1999-12-01 00:00:00pages
2173-82issue
12eissn
0009-9147issn
1530-8561journal_volume
45pub_type
杂志文章abstract：BACKGROUND:The American Diabetes Association task force on standardization of insulin assays in 1996 showed wide variation in assay bias. Newer assays are specific for insulin, with several now available on automated immunoassay analyzers. METHODS:In 2004, we compared 11 commercially available insulin assays by analyz...
journal_title：Clinical chemistry
pub_type： 杂志文章,多中心研究
doi：10.1373/clinchem.2006.077784
更新日期：2007-05-01 00:00:00
abstract：:3-Hydroxy-3-methylglutaric aciduria was detected in a newborn. The progress of the dietary therapy for the disorder was monitored by dual-column "high-performance" liquid chromatography with a computer-controlled photodiode array spectrophotometric detector. This procedure is a quick way to detect and monitor the prog...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-01-01 00:00:00
abstract：BACKGROUND:Hyperhomocysteinemia (HHcy) has been linked to impaired left ventricular function and clinical class in patients with chronic heart failure. We hypothesized that HHcy stimulates myocardial brain natriuretic peptide (BNP) expression and induces adverse left ventricular remodeling. METHODS:We randomized 50 ra...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2006.077859
更新日期：2007-04-01 00:00:00
abstract：:This enzyme immunoassay procedure for pregnancy-associated plasma protein type A involves a "sandwich"-type system in microtitration plates. One can detect 0.27 mg of the protein per liter of serum, with a between-batch CV of 10.2%, and the antiserum used does not cross react with any of the other placentally derived ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-11-01 00:00:00
abstract：:HbCO in blood sampled from 20 mothers and newborns immediately after birth was measured with a new, simple gas-chromatographic method for CO. The mean ratio of HbCO to total hemoglobin for 13 non-smoking mothers did not differ significantly from that for their infants (mean 0.38%, SD 0.26% vs 0.38%, SD 0.13%), but the...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-01-01 00:00:00
abstract：:We examined the relationship in a large-living population between the concentration of triglycerides in plasma from fasting persons and the concentration of very-low-density lipoprotein cholesterol (VLDL-C) as determined after preparative ultracentrifugation. Data from individuals in the Framingham Heart Study who wer...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1981-12-01 00:00:00
abstract：:A coated microtiter-well, enzyme-linked immunometric assay for quantifying immunoreactive trypsinogen in dried blood spots was modified to use time-resolved fluorescence of europium in place of end-point enzymatic color development as the quantification step. The streptavidin-horseradish peroxidase and color developme...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1993-02-01 00:00:00
abstract：BACKGROUND:With the gradual reopening of economies and resumption of social life, robust surveillance mechanisms should be implemented to control the ongoing COVID-19 pandemic. Unlike RT-qPCR, SARS-CoV-2 whole genome sequencing (cWGS) has the added advantage of identifying cryptic origins of the virus, and the extent o...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1093/clinchem/hvaa187
更新日期：2020-11-01 00:00:00
abstract：:The values of apolipoproteins (apo) A-I and B were determined in a population sample of hospital outpatients with a standardized method to verify if the cutpoints calculated in a cross-sectional study in the US are usable with other populations. We also tested the apolipoproteins' ability to discriminate between healt...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1998-01-01 00:00:00
abstract：:We present a unified approach to the use of linear models and matrix least squares with the intention of providing a better understanding of the techniques themselves and of the statistics that arise from these techniques as they are used in clinical chemistry. Emphasis is placed on the importance of appropriate exper...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-06-01 00:00:00
abstract：:To understand the regulation of immunity one must understand the processes and the consequences of the activation of the lymphoid cell, its clonal proliferation, and the ultimate differentiation of the progeny into the effector elements that constitute the immune system. By use of polyclonal mitogens, individual T-cel...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-12-01 00:00:00
abstract：BACKGROUND:Genotyping methods that reveal single-nucleotide differences are useful for a wide range of applications. We used digestion of 3-way DNA junctions in a novel technology, OneCutEventAmplificatioN (OCEAN) that allows sequence-specific signal generation and amplification. We combined OCEAN with peptide-nucleic-...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2006.068817
更新日期：2006-10-01 00:00:00
abstract：:Two hundred patients with liver disease were re-studied after six to eight years. The initial routine diagnosis (mainly based on morphological criteria) was confirmed in almost 80% of cases of chronic liver disease. In chronic active hepatitis, agreement was found in 86%. An alternative classification based on cluster...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1982-05-01 00:00:00
abstract：BACKGROUND:Late enhancement MRI (LE-MRI) and cardiac troponin I (cTnI) are sensitive methods to detect subclinical myocardial injury. We sought to investigate the relation between plasma concentrations of cTnI measured with a high-sensitivity assay (hs-cTnI) and the development of unrecognized myocardial infarctions (U...
journal_title：Clinical chemistry
pub_type： 杂志文章,随机对照试验
doi：10.1373/clinchem.2014.222430
更新日期：2014-10-01 00:00:00
abstract：BACKGROUND:Diagnosis of mitochondrial disorders usually requires a muscle biopsy to examine mitochondrial function. We describe our diagnostic procedure and results for 29 patients with mitochondrial disorders. METHODS:Muscle biopsies were from 43 healthy individuals and 29 patients with defects in one of the oxidativ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2005.062414
更新日期：2006-05-01 00:00:00
abstract：:We compared the effects of freezing serum on the determination of high-density lipoprotein (HDL) subfractions by two dual-precipitation methods, heparin and manganese chloride/dextran sulfate (HM/DS) (Gidez et al., J Lipid Res 1982;23:1206-23) and DS/DS (Warnick et al., Clin Chem 1982;28:1574), and by ultracentrifugat...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1994-09-01 00:00:00
abstract：BACKGROUND:Plasma creatinine concentration and calculated creatinine clearance are of limited value as glomerular filtration rate (GFR) markers in patients with decompensated liver cirrhosis. We assessed plasma cystatin C as an indicator of GFR in such patients. METHODS:We studied 36 patients with decompensated liver ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2002-06-01 00:00:00
abstract：:We describe a two-site time-resolved immunofluorometric assay for guinea pig vascular permeability factor (VPF) for quantifying VPF in different biological fluids. Antibody against the carboxy terminus (C-IgG) is immobilized on microtiter wells, and antibody against the amino terminus (N-IgG) is labeled with Eu(3+)-ch...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-01-01 00:00:00
abstract：:A new method for quantifying specific amino acids in small volumes of plasma and whole blood has been developed. Based on isotope-dilution tandem mass spectrometry, the method takes only a few minutes to perform and requires minimal sample preparation. The accurate assay of both phenylalanine and tyrosine in dried blo...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1993-01-01 00:00:00
abstract：:To determine when a change in serial measurements of prothrombin time in patients receiving oral anticoagulant therapy (ACT) is a statistically significant biological change necessitating dose adjustment, one must know the size of the "critical difference" in statistical terms (i.e., probabilities). In a cohort of 32 ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1995-03-01 00:00:00
abstract：:Because of uncertainty as to the molecular weight of transferrin, a previous comparison [Von der Heul et al., Clin. Chim. Acta 38, 347 (1972)] between transferrin content of serum and total iron-binding capacity cannot be definitive. We found a conversion factor for expressing the maximum amount of iron bound by 1 mg ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-07-01 00:00:00
abstract：:Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is a recessively inherited defect in the mitochondrial beta-oxidation of fatty acids. A single nucleotide change, the A985 --> G transition, in the MCAD gene accounts for approximately 90% of all the disease-causing mutations in the patients. We have used PCR to am...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1998-01-01 00:00:00
abstract：:I describe the automation/mechanization of several areas of sample processing at SmithKline Beecham Clinical Laboratories. By analyzing and implementing new systems for conveyance and sorting of incoming specimens, specimen processing, within-laboratory specimen delivery, specimen storage and retrieval, and client res...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-09-01 00:00:00
abstract：:We combined the amplification refractory mutation system (ARMS) and fluorescence polarization (FP) to give a homogeneous genomic DNA genotype analysis method. Oligonucleotide probes labeled with the fluorescein dyes fluorescein isothiocyanate and 5-([4,6-dichlorotriazin-2-yl]amino)fluorescein and the rhodamine dye 6-c...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1997-08-01 00:00:00
abstract：BACKGROUND:Recurrent pregnancy loss, (RPL) affecting 1%-2% of couples, is defined as ≥3 consecutive pregnancy losses before 20-week' gestation. Women with RPL are routinely screened for etiological factors, but routine screening of male partners is not currently recommended. Recently it has been suggested that sperm qu...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2018.289348
更新日期：2019-01-01 00:00:00
abstract：:We report another patient with a circulating alkaline phosphatase/immunoglobulin complex in his blood, and describe a simple method of demonstrating such complexes. On electrophoresis on cellulose acetate, the complex was relatively slow moving and there was no activity in the normal bone/liver isoenzyme region. When ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1980-10-01 00:00:00
abstract：:We compared the performance of an automated assay of creatine kinase MB isoenzyme (CK-MB) mass (Stratus) with that of a CK-MB enzymatic assay routinely used at our institutions. Both of these assays use the same CK-MB-specific monoclonal antibody to immunocapture CK-MB, thus providing a direct means of comparing a mas...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-10-01 00:00:00
abstract：:We investigated glycosylated hemoglobin S by means of chromatography on Bio-Rex 70. The selected elution conditions were similar to those described by Trivelli et al. (N Engl J Med 284: 353-357, 1971), except for modified ionic strength and accurate temperature control. This enabled us to isolate a minor hemoglobin fr...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1985-04-01 00:00:00
abstract：:Of 98 patients' specimens examined for alkaline phosphatase (EC 3.1.3.1) isoenzymes by electrophoresis on cellulose acetate membrane after incubation with neuraminidase, 50 showed only a single liver or bone isoenzyme staining band; in 15 of these, the tissue origin of the fraction could not be accurately identified f...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1985-07-01 00:00:00
abstract：:This assay was developed to measure apolipoprotein (apo) B in blood samples spotted onto filter paper. The long-term aim is to detect young families with the dominantly inherited familial hypercholesterolemia, during current neonatal screening programs. The interassay CV was 5.6%, and apo B concentrations correlated c...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-06-01 00:00:00
