Abstract:
OBJECTIVES:Newly presented solid-phase extraction methods (Solid Phase Disc Extraction, SPEC-Plus, Multi-Modal, and Solid Phase Micro Extraction, SPME have been checked with respect to their applicability to clinical toxicological analysis. In comparison with conventional liquid/liquid-extraction and a common mixed-phase column technology, their use in general screening and selective extraction methodology is discussed. DESIGN AND METHODS:Recovery studies were performed with urine-based samples including model substances, as well as drugs and metabolites from native urine samples. Chromatographic performance of the resulting extracts is presented in some examples. RESULTS:Liquid/liquid extraction, common mixed-phase column technique and the new SPEC-Plus, Multi-Modal disc extraction method gave the best recoveries with respect to broad-spectrum general screening. The purity of the concentrates was somewhat different, however. Solid-phase C18 and Solid-Phase Micro Extraction methodologies are better suited for selective drug extraction. In SPEC Disc or SPME extraction, the use of solvents is greatly reduced or omitted. Recovery of some volatile substances is enhanced. SPEC discs can be inserted directly into TLC chromatographic plates, SPME fibers into GC injection ports. CONCLUSIONS:The new solid-phase extraction technologies offer advantages in different respects: The mixed-phase disc extraction SPEC 1 Plus AR/MP3 Multi-Modal delivers promising results with respect to broad-spectrum general screening. Solvent consumption is low, throughput times are short, the extracts are clean, and recovery rates are good, comparable, or even higher than with common mixed-phase column techniques. The new SPME extraction method shows benefits in dedicated, selective extraction procedures (e.g., analysis of volatile substances such as amphetamines). Sampling is solvent-free, the handling is easy, and the yields of extraction are good, but only for selected substances. Broad-spectrum general screening still remains problematic with this technique. Further examinations have to be carried out including a larger number of drugs of toxicological relevance. Headspace sampling by SPME offers a good alternative to conventional mechanized sampling in the analysis of volatile substances in biological samples, omitting the need for expensive instrumentation.
journal_name
Clin Biochemjournal_title
Clinical biochemistryauthors
Degel Fdoi
10.1016/s0009-9120(96)00096-3subject
Has Abstractpub_date
1996-12-01 00:00:00pages
529-40issue
6eissn
0009-9120issn
1873-2933pii
S0009912096000963journal_volume
29pub_type
杂志文章abstract:OBJECTIVES:The aim was to study the influence of sampling time, food intake and sleep on tests used to screen for and monitor conditions of iron deficiency and overload. DESIGN AND METHODS:The 24 h variations of iron, transferrin, transferrin saturation (TS) and ferritin were studied in seven healthy individuals durin...
journal_title:Clinical biochemistry
pub_type: 临床试验,杂志文章
doi:10.1016/j.clinbiochem.2010.08.023
更新日期:2010-11-01 00:00:00
abstract::We investigated the effects of medium supplementation with increasing amounts of different fatty acids on HepG2 cell cholesterol biosynthesis and esterification. Up to 200 microM 16:0 led to an increase in cholesterol secretion/synthesis of 60%/40%; 18:1, 18:2, or 18:3 decreased secretion/synthesis by 35%/25%, 65%/65%...
journal_title:Clinical biochemistry
pub_type: 杂志文章
doi:10.1016/0009-9120(92)80008-5
更新日期:1992-10-01 00:00:00
abstract:OBJECTIVES:Characterization of beta-galactosidase in leukocytes and fibroblasts of heterozygotes for GM1 type I. DESIGN AND METHODS:Leukocyte and fibroblast beta-galactosidase activity was determined fluorimetrically using 4-methylumbelliferyl-beta-D-galactoside as an artificial substrate. Optimum pH, Km, Vmax and the...
journal_title:Clinical biochemistry
pub_type: 杂志文章
doi:10.1016/s0009-9120(00)00049-7
更新日期:2000-03-01 00:00:00
abstract:BACKGROUND:Several cases of biotin interference with laboratory testing have been reported in the literature. However, there are no publications discussing the extent of biotin use or plasma concentrations observed among the patient population. The objective of this study was to determine the prevalence of biotin consu...
journal_title:Clinical biochemistry
pub_type: 杂志文章
doi:10.1016/j.clinbiochem.2018.07.004
更新日期:2018-09-01 00:00:00
abstract::The clinical role of HER-2/neu, a 185 kD epithelial transmembranous protein, has evolved after the approval of the anti-HER-2/neu targeted monoclonal antibody trastuzumab (Herceptin) for the therapy of metastatic breast cancer. The extracellular domain of HER-2/neu undergoes proteolytic cleavage from the full-length p...
journal_title:Clinical biochemistry
pub_type: 杂志文章,评审
doi:10.1016/s0009-9120(03)00026-2
更新日期:2003-06-01 00:00:00
abstract:OBJECTIVES:Cortisol metabolism is controlled by 11beta-hydroxysteroid dehydrogenase (11beta-HSD) isoenzymes, which interconvert cortisol and cortisone. Accurate measurement of the cortisol and cortisone concentrations and their ratio provide useful information about 11beta-HSD activity. METHODS:Cortisol and cortisone ...
journal_title:Clinical biochemistry
pub_type: 杂志文章
doi:10.1016/j.clinbiochem.2004.01.005
更新日期:2004-05-01 00:00:00
abstract:OBJECTIVE:Prostate-specific antigen (PSA) samples from five commercial sources were compared with PSA from the European Commission Community Bureau of Reference, known as CRM 613, using liquid chromatography-mass spectrometry (LC-MS) and matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS). DESIGN ...
journal_title:Clinical biochemistry
pub_type: 杂志文章
doi:10.1016/j.clinbiochem.2004.10.016
更新日期:2005-02-01 00:00:00
abstract:OBJECTIVES:Leptin is a multifunctional polypeptide produced primarily by adipocytes and associated with the occurrence of obesity and insulin resistance. Tumor necrosis factor-alpha (TNF-alpha), a polypeptide cytokine produced primarily by mononuclear phagocytes, plays a key role in the initiation of the inflammatory r...
journal_title:Clinical biochemistry
pub_type: 杂志文章
doi:10.1016/s0009-9120(02)00314-4
更新日期:2002-06-01 00:00:00
abstract:OBJECTIVES:This study explored the relationship between oxidative stress biomarkers and stability of carotid plaque. We decided to analyze the broad range of parameters describing oxidative stress in patients with carotid stenosis. DESIGN AND METHODS:124 consecutive patients undergoing carotid endarterectomy were enro...
journal_title:Clinical biochemistry
pub_type: 杂志文章
doi:10.1016/j.clinbiochem.2013.05.057
更新日期:2013-08-01 00:00:00
abstract:OBJECTIVES:An overview of biochemical markers of bone metabolism is presented along with indications for their clinical utilization. DESIGN AND METHODS:The structure, cyclical metabolism, and hormone regulation of bone is reflected by markers of resorption, formation and/or turnover. Markers of resorption representing...
journal_title:Clinical biochemistry
pub_type: 杂志文章,评审
doi:10.1016/s0009-9120(97)00113-6
更新日期:1997-12-01 00:00:00
abstract:OBJECTIVES:To develop immunofluorometric procedures for measuring BRCA1 protein in various biological fluids and tissue extracts. DESIGN AND METHODS:Five commercially available monoclonal and polyclonal antibodies against BRCA1 were evaluated for developing competitive and non-competitive immunofluorometric procedures...
journal_title:Clinical biochemistry
pub_type: 杂志文章
doi:10.1016/s0009-9120(97)00042-8
更新日期:1997-07-01 00:00:00
abstract::The concentrations in serum of total and ionised calcium, phosphate, magnesium, albumin and alkaline phosphatase activity were measured in patients when hyperthyroid and again when euthyroid. Significant declines in the mean values of ionised calcium, phosphate and alkaline phosphatase activity and significant increas...
journal_title:Clinical biochemistry
pub_type: 杂志文章
doi:10.1016/s0009-9120(89)80035-9
更新日期:1989-10-01 00:00:00
abstract::MicroRNAs are endogenous non-coding RNAs that post-transcriptionally regulate gene expression by specifically binding the target mRNA and by consequently inducing its degradation. miRNAs can be released into the circulation where they remain stable and they can be measured. Their changes reflect individual biologic ad...
journal_title:Clinical biochemistry
pub_type: 杂志文章,评审
doi:10.1016/j.clinbiochem.2016.09.017
更新日期:2016-12-01 00:00:00
abstract::The use of alcohol and tobacco is prevalent among pregnant women despite the well-known adverse effects of these substances imposed on the developing fetus and immense public health education efforts. Confirmation of gestational exposures to these compounds have relied mostly on maternal self-reporting, which is often...
journal_title:Clinical biochemistry
pub_type: 杂志文章,评审
doi:10.1016/j.clinbiochem.2004.01.010
更新日期:2004-06-01 00:00:00
abstract::The toxicity of carbon monoxide has been recognized for long throughout history and is unquestionably the leading cause of unintentional poisoning deaths in the Western countries. The severity of poisoning is dependent upon environmental and human factor. The leading pathophysiological mechanism resides in the ability...
journal_title:Clinical biochemistry
pub_type: 杂志文章,评审
doi:10.1016/j.clinbiochem.2012.06.004
更新日期:2012-11-01 00:00:00
abstract:OBJECTIVES:Oxidative stress increases postmenopausally, an effect attributed to aging. Increase in body weight generally accompanies menopause. Obesity per se also seems to increase oxidative stress. The question is whether postmenopausal increase in oxidative stress is related to body weight, or is only a function of ...
journal_title:Clinical biochemistry
pub_type: 杂志文章
doi:10.1016/j.clinbiochem.2009.03.019
更新日期:2009-07-01 00:00:00
abstract::The effect of altered thyroid function on serum fructosamine concentrations was investigated in 31 untreated hyperthyroid patients, 18 short-term hypothyroid patients (i.e., 20 days after withdrawal of thyroid hormone suppressive therapy for thyroid cancer), 7 untreated long-term hypothyroid patients, and 25 age-match...
journal_title:Clinical biochemistry
pub_type: 杂志文章
doi:10.1016/0009-9120(88)90007-0
更新日期:1988-06-01 00:00:00
abstract:OBJECTIVES:The purpose of this study is to assess the usefulness of the concentration of cystatin C (Cys-C) in serum for predicting the clearance of vancomycin (CLvcm) compared with the serum concentration of creatinine (SCr) in the elderly. METHODS:Thirty-nine serum samples were obtained from 24 elderly patients (65 ...
journal_title:Clinical biochemistry
pub_type: 杂志文章
doi:10.1016/j.clinbiochem.2007.01.008
更新日期:2007-04-01 00:00:00
abstract:OBJECTIVES:The purpose of this study was to measure the extent of lipid peroxidation and the status of antioxidants in patients with Hodgkin's disease. DESIGN AND METHODS:Glutathione peroxidase (GPX) and superoxide dismutase (SOD) activities, and malondialdehyde (MDA), selenium, zinc and copper content have been measu...
journal_title:Clinical biochemistry
pub_type: 杂志文章
doi:10.1016/s0009-9120(00)00062-x
更新日期:2000-04-01 00:00:00
abstract:OBJECTIVES:The change in DNA methylation patterns can be used to distinguish between normal and cancer cells. The aim of the present study was to examine the 5' CpG island methylation patterns of the cancer-testis antigen (CT antigen) gene family, MAGE-As, in hepatocellular carcinoma (HCC), and to develop the DNA demet...
journal_title:Clinical biochemistry
pub_type: 杂志文章
doi:10.1016/j.clinbiochem.2006.01.014
更新日期:2006-03-01 00:00:00
abstract:OBJECTIVE:To review screening for cancer in high risk families. METHODS AND RESULTS:Screening for hereditary cancer involves three steps: it is first necessary to identify families at high risk by examining the number and sites of cancer in a family. Special attention is given to cancers appearing at an early age, to ...
journal_title:Clinical biochemistry
pub_type: 杂志文章,评审
doi:10.1016/0009-9120(95)00022-2
更新日期:1995-08-01 00:00:00
abstract::The synthesis and characterisation of a new colorimetric reagent for iron, 3-(2-pyridyl)-5,6-bis(2-furyl)-1,2,4-triazine are described. Peak assignments and chemical shifts of the high resolution 13C nmr spectrum are given. The reagent forms a tris iron(II) complex with epsilon max of 32000 Lcm-1 mol-1 at 577 nm. The ...
journal_title:Clinical biochemistry
pub_type: 杂志文章
doi:10.1016/s0009-9120(84)90613-1
更新日期:1984-10-01 00:00:00
abstract:BACKGROUND:Vitamin B12 insufficiency/deficiency is common in mixed patient populations. However there is no single marker which can reliably diagnose B12 insufficiency/deficiency. Elevated concentrations of methylmalonic acid (MMA) are considered the most representative marker of metabolic vitamin B12 insufficiency, bu...
journal_title:Clinical biochemistry
pub_type: 杂志文章
doi:10.1016/j.clinbiochem.2013.08.006
更新日期:2014-01-01 00:00:00
abstract:OBJECTIVES:Recurrent miscarriage (RM) is a challenging medical problem because of its unknown pathogenesis and etiology in most of the cases. Recent studies suggest the role of persistent environmental pollutants such as organochlorine pesticides (OCPs) in the etiology of RM. The present study was conducted to investig...
journal_title:Clinical biochemistry
pub_type: 杂志文章
doi:10.1016/j.clinbiochem.2009.09.019
更新日期:2010-01-01 00:00:00
abstract:OBJECTIVES:Galectin-3 might serve as a biomarker of human metabolic alterations. We measured serum levels of galectin-3 in patients with nonalcoholic fatty liver disease (NAFLD) and examined their association with clinical and histological phenotypes. DESIGN AND METHODS:Serum levels of galectin-3 were assayed in 71 pa...
journal_title:Clinical biochemistry
pub_type: 杂志文章
doi:10.1016/j.clinbiochem.2011.05.015
更新日期:2011-08-01 00:00:00
abstract:OBJECTIVES:Low-normal thyroid function may relate to increases in plasma cholesterol and triglycerides, but effects on lipoprotein subfractions are largely unknown. Associations of alterations in lipoprotein metabolism and functionality with low-normal thyroid function could be more pronounced in Type 2 diabetes mellit...
journal_title:Clinical biochemistry
pub_type: 杂志文章
doi:10.1016/j.clinbiochem.2015.01.015
更新日期:2015-05-01 00:00:00
abstract:OBJECTIVES:Non-invasive prenatal aneuploidy testing (NIPT) by next-generation sequencing of circulating cell-free DNA in maternal plasma relies on chromosomal ratio (chrratio) measurements to detect aneuploid values that depart from euploid ratios. Diagnostic performances are known to depend on the fraction of fetal DN...
journal_title:Clinical biochemistry
pub_type: 杂志文章
doi:10.1016/j.clinbiochem.2018.06.015
更新日期:2018-09-01 00:00:00
abstract::A study conducted on 228 diabetic patients has shown a significant positive association between serum gamma-glutamyl transpeptidase (GGT) and triglyceride levels. Both fall with treatment, the most marked reduction occurring in patients on insulin. We suggest that the association between serum GGT and triglyceride lev...
journal_title:Clinical biochemistry
pub_type: 杂志文章
doi:10.1016/s0009-9120(76)80059-8
更新日期:1976-08-01 00:00:00
abstract::An ion-exchange chromatographic procedure is described which facilitates the determination of beta-chain aminoterminal modified glycated hemoglobin. The procedure includes an erythrocyte lysis reagent which eliminates the labile aldimine component (pre-A1c) and a two-stage elution step which separates HbA, 1a + b from...
journal_title:Clinical biochemistry
pub_type: 杂志文章
doi:10.1016/s0009-9120(85)80020-5
更新日期:1985-02-01 00:00:00
abstract:INTRODUCTION:Vitamin B12 deficiency is mostly caused by insufficient gastro-intestinal absorption and in rare conditions by Transcobalamin (TC) deficiency. Unsaturated Transcobalamin (apoTC) can be measured by a binding assay using radiolabeled cobalamin. The Active B12 test analyzes saturated Transcobalamin (holoTC) a...
journal_title:Clinical biochemistry
pub_type: 杂志文章
doi:10.1016/j.clinbiochem.2017.08.009
更新日期:2017-12-01 00:00:00