Abstract:
:A simple HPLC method for the determination of caffeine and theophylline in plasma is described. Separation of theobromine, paraxanthine, theophylline, beta-hydroxyethyltheophylline and caffeine is obtained using a mobile phase of 1% acetic acid/methanol (83:17, v/v) and a Waters Associates NOVA-PAK C18 column protected by a Guard-PAK precolumn module containing a Guard-PAK CN cartridge. Rapid sample preparation is achieved by solid-phase extraction columns (Bond-Elut C18, 1 mL capacity) which provide excellent recovery values for both drugs. The cost per sample using this approach can be minimised by column regeneration and re-use. Results obtained for theophylline are in good agreement with values determined by other techniques.
journal_name
Ann Clin Biochemjournal_title
Annals of clinical biochemistryauthors
Pickard CE,Stewart AD,Hartley R,Lucock MDdoi
10.1177/000456328602300410subject
Has Abstractpub_date
1986-07-01 00:00:00pages
440-6eissn
0004-5632issn
1758-1001journal_volume
23 ( Pt 4)pub_type
杂志文章abstract:BACKGROUND:We evaluated the recently released chemiluminescence assay for 25-hydroxy vitamin D (25-OHD) on the Immunodiagnostic Systems iSYS (IDS-iSYS) automated analyser. METHODS:The IDS-iSYS comparison was performed using patient samples previously measured for 25-OHD by a validated liquid chromatography-tandem mass...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1258/acb.2011.011018
更新日期:2012-03-01 00:00:00
abstract::The application of a DC plasma emission spectrometer to the measurement of copper, zinc and magnesium in serum and urine is reported. Each assay requires only a simple dilution in 1% nitric acid. Comparisons with standard atomic absorption techniques showed good analytical agreement, especially for copper and magnesiu...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456328502200512
更新日期:1985-09-01 00:00:00
abstract:BACKGROUND:Combined lipid and glucose point-of-care testing (POCT) devices could facilitate widespread population screening for cardiovascular disease (CVD) and diabetes as part of the NHS Vascular Risk Assessment and Management Program (NHS Health Checks). An evaluation of the Cholestech LDX and CardioChek PA POCT ana...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/0004563213482890
更新日期:2014-01-01 00:00:00
abstract::Most UK clinical laboratories use alkaline phosphatase (ALP) methods similar to that proposed by the International Federation of Clinical Chemistry (IFCC), based on the use of 2-amino-2-methyl-1-propanol (AMP) buffer. We present evidence of significant differences in results produced by apparently similar commercial A...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456329803500117
更新日期:1998-01-01 00:00:00
abstract::A recently introduced turbidimetric immunoassay using shell/core particles for determination of myoglobin (Turbiquant Myoglobin, Behringwerke, Marburg, Germany) was evaluated on the Behring Turbitimer analyzer. Intra-assay CV varied between 1.0% and 3.2%; interassay CV was between 2.0% and 3.6%. Linear results were ob...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456329102800509
更新日期:1991-09-01 00:00:00
abstract::We describe a new electrochemical method for the determination of erythrocyte acetylcholinesterase activity (EC 3.1.1.7) and plasma cholinesterase (EC 3.1.1.8) activity, based on the measurements of pH variation due to release of acetic acid from acetylcholine. The major advantages of the differential pH procedure are...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456328602300509
更新日期:1986-09-01 00:00:00
abstract:BACKGROUND:Glycated haemoglobin (HbA1c) concentration is lower relative to glyacemic control in diabetic patients on haemodialysis. However, it is unknown as to whether this is also true for diabetic patients with end-stage renal disease but not on haemodialysis. METHODS:Correlations between HbA1c or glycated albumin ...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1258/acb.2011.011161
更新日期:2012-01-01 00:00:00
abstract::The analytical and biological components of variation of total cholesterol, high density lipoprotein (HDL) cholesterol, HDL3 cholesterol, HDL2 cholesterol and apolipoproteins A-I and B in serum were assessed in 12 apparently healthy individuals. All analytes showed marked individuality and therefore conventional popul...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456328902600314
更新日期:1989-05-01 00:00:00
abstract::The most widely used methods for the assay of total bilirubin in serum are based on a coupling reaction with various diazo dyes in the presence of an accelerating agent. The 'direct' reaction, without accelerator, gives a good estimate of the conjugated and protein bound (delta) species of bilirubin only if carefully ...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章,评审
doi:10.1177/000456329102800202
更新日期:1991-03-01 00:00:00
abstract::Background The clinical utility of serum thyroglobulin in the follow-up of patients with differentiated thyroid carcinoma may be compromised by the presence of endogenous antithyroglobulin antibodies. To prevent interference by antithyroglobulin antibodies several groups have developed real-time PCR-based assays for q...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/0004563216671538
更新日期:2017-09-01 00:00:00
abstract::Plasma creatine kinase (CK) activity and lean body mass (LBM) (by anthropometry) were measured in 120 women (20-82 years) and 70 men (20-82 years). Plasma CK activity and LBM was higher in men than in women. In men plasma CK activity was significantly correlated (product moment correlation coefficient) with LBM and ne...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456328802500411
更新日期:1988-07-01 00:00:00
abstract::We have evaluated the clinical relevance of monitoring acute phase proteins in severe urinary tract infection. Body temperature, white blood cell count, erythrocyte sedimentation rate, serum amyloid A protein (SAA), C-reactive protein (CRP), alpha-1-antichymotrypsin (ACT) and alpha-1-acid glycoprotein (AGP) were deter...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456329303000308
更新日期:1993-05-01 00:00:00
abstract::Two cases of hypercholesterolaemic patients are presented in whom raised plasma creatine kinase was noted during treatment with statins. The plasma creatine kinase failed to fall following cessation of therapy. Further investigation revealed the aetiology of the raised plasma creatine kinase to be due to previously un...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1258/000456303322326542
更新日期:2003-09-01 00:00:00
abstract::Hypoglycaemia is an uncommon manifestation of hypopituitarism in non-diabetic adults. A 47-year-old woman with Cushing's disease was treated with bilateral adrenalectomy and pituitary radiotherapy following unsuccessful trans-sphenoidal surgery. Twenty years later, she presented with a tonic-clonic seizure and recurre...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:
更新日期:2005-01-01 00:00:00
abstract::Free and total reduced concentrations of D-penicillamine have been measured in the plasma of rheumatoid arthritis patients by HPLC and electro-chemical detection. A reverse-phase ion-pair separation in conjunction with a dual porous graphite electrode satisfied the requirements of robustness, sensitivity, selectivity ...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456328802500210
更新日期:1988-03-01 00:00:00
abstract::The last 10 years have witnessed radical changes in the definition and diagnosis of the acute coronary syndrome (ACS), including myocardial infarction, as a result of the introduction of sensitive and specific markers of myocardial damage, the cardiac troponins. One barrier to the universal acceptance of these markers...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章,评审
doi:10.1258/000456304322664645
更新日期:2004-01-01 00:00:00
abstract:BACKGROUND:It is important to explain target proteins for the understanding of the pathogenesis of vitreoretinal diseases. In a previous study, we identified more than 100 proteins including seven angiogenic-modulated factors in vitreous humours (VHs). Although there have been many reports of expressed protein profiles...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1258/acb.2007.007151
更新日期:2008-05-01 00:00:00
abstract:BACKGROUND:In humans, leptin circulates in a free form and is also bound to macromolecules. The aim of the present study was to compare a rapid acid-ethanol precipitation (AEP) method of measuring bound leptin with the more laborious gel exclusion chromatography (GEC) reference procedure. Serum samples collected from h...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1258/000456303763046157
更新日期:2003-03-01 00:00:00
abstract::Improvement in the control of diabetic patients is aided by a knowledge of blood glucose levels during a 'normal' (non-hospitalised) day. We have devised a 5 microliter capillary tube collection system as a 'kit' for home use by diabetics. Blood collected into 5 microliter capillary tubes is washed into a protein prec...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456328101800507
更新日期:1981-09-01 00:00:00
abstract::Protoporphyrin and zinc-protoporphyrin were measured in the erythrocytes of normal subjects, workers exposed to lead and patients with iron deficiency and erythropoietic protoporphyria (EPP). Results showed significantly higher levels of zinc-protoporphyrin in the lead-exposed workers (P < 0.0001), patients with iron ...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456329803500313
更新日期:1998-05-01 00:00:00
abstract::The Myolex (Orion) and the RapiTex (Behringwerke) latex agglutination tests for the rapid detection of elevated levels of serum myoglobin were studied prospectively in patients suspected of acute myocardial infarction, who were admitted to hospital within 8 h of pain onset. Using admission blood samples drawn 3.4 +/- ...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456328902600309
更新日期:1989-05-01 00:00:00
abstract::Eleven unfit bank executives in sedentary employment exercised daily for 10 weeks according to the Canadian Air-Force 5BX Exercise Programme. Over this period no changes were observed in the glucose or insulin responses to a standard breakfast or to intravenous glucose, or in the glucose response to intravenous insuli...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456327901600115
更新日期:1979-03-01 00:00:00
abstract:BACKGROUND:Individuals who are unable to metabolize the short-acting muscle relaxant succinylcholine due to abnormal cholinesterase activity are currently investigated via spectrophotometry using artificial substrates and enzyme inhibitors. Methods have been described using succinylcholine as substrate but with measure...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1258/acb.2010.009169
更新日期:2010-05-01 00:00:00
abstract::The total cost of a haematology and clinical chemistry laboratory, including external and hospital costs, was studied in a district general hospital in The Netherlands. The main conclusion is that the number of samples analysed is the most important cost-setting factor, but that reduction in the number of requests doe...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456328402100206
更新日期:1984-03-01 00:00:00
abstract::Simultaneous localisation of the isoenzymes of alkaline phosphatase and gamma-glutamyl transferase was carried out on 173 serum samples from patients with hepatobiliary and bone disease to determine (i) if a better discrimination of the underlying pathology could be obtained by such an approach, and (ii) if the pathol...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456328001700104
更新日期:1980-01-01 00:00:00
abstract:BACKGROUND:Measurement of serum natriuretic peptides is recommended in patients with suspected heart failure. Assays for N-terminal pro-B-type natriuretic peptide (NT-proBNP) are available on several platforms and can be measured in serum or heparinized plasma. Siemens Healthcare Diagnostics do not recommend the use of...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1258/acb.2012.012053
更新日期:2012-09-01 00:00:00
abstract::Using a high-performance liquid chromatography method, we measured seven commonly prescribed benzodiazepines (chlordiazepoxide, nitrazepam, nordiazepam, oxazepam, lorazepam, temazepam and diazepam) in 100 urine samples obtained from patients attending the Leeds Addiction Unit. All of the urines selected for investigat...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456329703400110
更新日期:1997-01-01 00:00:00
abstract::The higher bias of serum cystine estimations by a HPLC method compared with those by ion exchange techniques is shown to be largely due to differences in the sample preparation procedures of the two techniques. The ion exchange methods utilised sulphosalicylic acid serum protein precipitation and post-column ninhydrin...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456328802500516
更新日期:1988-09-01 00:00:00
abstract::The fasting hyperinsulinaemia characteristic of obesity is due to pancreatic hypersecretion and is accompanied by a corresponding increase in plasma C-peptide concentrations. The exaggerated plasma insulin and C-peptide responses to oral glucose in obese subjects which is greater for insulin than C-peptide suggests th...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章
doi:10.1177/000456328902600502
更新日期:1989-09-01 00:00:00
abstract::The current search for new treatments to combat coronary heart disease (CHD) is centred on increasing HDL-cholesterol. The failure of the CETP inhibitor torcetrapib may force a rethink. This perspective briefly reviews the antiatherosclerotic properties of HDL and ways HDL-cholesterol concentration can be raised, but ...
journal_title:Annals of clinical biochemistry
pub_type: 杂志文章,评审
doi:10.1258/acb.2008.008133
更新日期:2009-01-01 00:00:00