Abstract:
BACKGROUND:Measurement of hemoglobin A1c (HbA1c) in the blood is integral to and essential for the treatment of patients with diabetes mellitus. HbA1c reflects the mean blood glucose concentration over the preceding 8 to 12 weeks. Although the clinical value of HbA1c was initially limited by large differences in results among various methods, the investment of considerable effort to implement standardization has brought about a marked improvement in analysis. CONTENT:The focus of this review is on the substantial progress that has been achieved in enhancing the accuracy and, therefore, the clinical value of HbA1c assays. SUMMARY:The interactions between the National Glycohemoglobin Standardization Program and manufacturers of HbA1c methods have been instrumental in standardizing HbA1c. Proficiency testing using whole blood has allowed accuracy-based assessment of methods in individual clinical laboratories that has made an important contribution to improving the HbA1c measurement in patient samples. These initiatives, supported by the efforts of the IFCC network, have led to a continuing enhancement of HbA1c methods.Many of the factors that previously influenced HbA1c results independently of blood glucose have been eliminated from most modern methods. These include carbamylation, labile intermediates, and common hemoglobin variants. Nevertheless, some factors (e.g., race and aging) may alter HbA1c interpretation, but whether these differences have clinical implications remains contentious. HbA1c has a fundamental role in the diagnosis and management of diabetes. Ongoing improvements in HbA1c measurement and quality will further enhance the clinical value of this analyte.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Little RR,Rohlfing C,Sacks DBdoi
10.1373/clinchem.2018.296962subject
Has Abstractpub_date
2019-07-01 00:00:00pages
839-848issue
7eissn
0009-9147issn
1530-8561pii
clinchem.2018.296962journal_volume
65pub_type
杂志文章,评审abstract::Ethchlorvynol is a commonly abused sedative hypnotic. I report here a seven-day study of serum ethchlorvynol concentrations in a patient who had received an extreme overdose. These concentrations were correlated with the patient's response to stimuli. Serum ethchlorvynol concentrations were logarithmically related to ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1975-06-01 00:00:00
abstract::The serum pancreolauryl test has limited sensitivity for detecting mild pancreatic insufficiency. The aim of this study was to optimize the serum pancreolauryl test so as to increase the probability of positive results in patients with chronic pancreatitis. The study had three parts. First, the sampling time was optim...
journal_title:Clinical chemistry
pub_type: 临床试验,杂志文章
doi:
更新日期:1998-04-01 00:00:00
abstract:BACKGROUND:Hyperglycosylated human chorionic gonadotropin (hCG-h) contains larger and more complex carbohydrate chains than regular human chorionic gonadotropin (hCG). hCG-h is thought to be the major form of hCG produced by testicular cancers and it has been suggested to play a key role in tumor invasion, but studies ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2012.183723
更新日期:2012-07-01 00:00:00
abstract::We have improved the protocol for RNA quantification by using RNase protection. Instead of precipitation and extraction with phenol and chloroform, we use a faster and more reliable precipitation based on guanidinium thiocyanate (GdSCN). The internal standard is produced by in vitro transcription of a DNA template con...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1995-11-01 00:00:00
abstract::Determination of the ratio of testosterone to epitestosterone (T/E) in urine is used to detect testosterone administration in athletes, with a ratio > 6 considered as evidence of an offense. We show that administration of ketoconazole, which inhibits testosterone biosynthesis, may be useful for differentiating between...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1993-09-01 00:00:00
abstract::Two major components of rRNA (18S and 28S rRNA) were separated by electrophoresis in injection-molded acrylic chips with a microchannel 100 microm in width, 40 microm in depth, and with 1 cm of separation distance. Microchannels were filled with 4 g/L hydroxypropylmethylcellulose as sieving polymer and 5 mg/L ethidium...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1998-11-01 00:00:00
abstract::To evaluate their potential usefulness in the differential diagnosis of Cushing's syndrome, we estimated the urinary excretion rates of the following non-metabolized, unbound steroid hormones: pregnenolone, progesterone, 17-OH-pregnenolone, 17-OH-progesterone, dehydroepiandrosterone (DHEA), androstenedione, testostero...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-01-01 00:00:00
abstract::Using high-performance liquid chromatography and gas chromatography, we reevaluated the 24-h influence of a serotonin- and dopamine-rich diet on platelet serotonin and serotonin, 5-hydroxyindoleacetic acid (5-HIAA), and major catecholamine metabolites in the urine of 15 healthy adults. Although there were significant ...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1992-09-01 00:00:00
abstract::In this simple, quick procedure for determining copper in human serum and urine, the serum and urine specimens were analyzed directly after dilution with a solution of HNO3 and Triton X-100, 1 mL/L each. We calibrated with aqueous standards for quantitation in Zeeman background atomic absorption spectrometry. By modif...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1993-09-01 00:00:00
abstract:BACKGROUND:The promise of targeted therapies in molecularly defined subsets of cancer has led to a transformation of the process of drug development in oncology. To target cancer successfully and precisely requires high-quality translational data. Such data can be generated by the use of biomarkers that answer key ques...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:10.1373/clinchem.2012.191072
更新日期:2013-01-01 00:00:00
abstract::Optimal reaction conditions for assaying human lactate dehydrogenase pyruvate-to-lactate were determined for isoenzymes 1 and 5 at 25, 30, and 37 degrees C. Three of the nine different buffers examined--imidazole, triethanolamine, and N-tris(hydroxymethyl)-methyl-2-aminoethane sulfonic acid--are satisfactory. Beta-NAD...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1978-02-01 00:00:00
abstract:BACKGROUND:Identifying markers of chronic kidney disease (CKD) that occur early in the disease process and are specific to loss of kidney function rather than other underlying causes of disease may allow earlier, more accurate identification of patients who will develop CKD. We therefore sought to identify diagnostic b...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2018.291104
更新日期:2019-03-01 00:00:00
abstract::We describe a direct radioimmunoassay for serotonin (5-hydroxytryptamine) in cerebrospinal fluid, platelet-poor plasma, and serum. We raised antisera in rabbits against serotonin diazotized to a conjugate of bovine albumin and D,L-p-aminophenylalanine. Polyethylene glycol, alone or in combination with anti-rabbit immu...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1982-04-01 00:00:00
abstract:BACKGROUND:Non-(1-84) parathyroid hormone (PTH) fragments are large C-terminal fragments of PTH with a partially preserved N-terminal structure. They differ from other C-terminal PTH fragments, which do not have an N-terminal structure and do not react in intact PTH assays. We aimed to identify the minimal N-terminal s...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2004.040485
更新日期:2005-01-01 00:00:00
abstract::We evaluated the enzymic mechanism by which 3-keto butylidene-beta-2-chloro-4-nitrophenyl maltopentaoside (3KB-G5-CNP) serves as a substrate for serum pancreatic (p-) and salivary (s-) amylases. In aliquots of the reaction mixture, three kinds of beta-2-chloro-4-nitrophenyl oligosaccharides (glucose, maltoside, and ma...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1991-08-01 00:00:00
abstract::This ultrafiltration technique allows determination of free drug in 50 microL of serum. We ultrafiltered sera containing the following drugs--valproic acid (and its major metabolites), phenobarbital, diazepam, indomethacin, phenytoin, furosemide, and chloramphenicol--using both the commercially available micropartitio...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1984-06-01 00:00:00
abstract::A highly sensitive two-site sandwich ELISA measuring total proinsulin immunoreactive material in serum or plasma was developed. The assay was based on two monoclonal antibodies, an anti-C-peptide antibody bound to a microtest plate and a biotin-labeled anti-insulin antibody. The detection limit (3 SD above zero value)...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1993-10-01 00:00:00
abstract:BACKGROUND:Previous studies have shown a single linear relationship between mean plasma glucose (MPG) and hemoglobin A(1c) (HbA(1c)). We examined the relationship in different treatment groups of patients with type 1 diabetes participating in the Diabetes Control and Complications Trial (DCCT). METHODS:Seven-point glu...
journal_title:Clinical chemistry
pub_type: 杂志文章,随机对照试验
doi:10.1373/clinchem.2006.079756
更新日期:2007-05-01 00:00:00
abstract:BACKGROUND:Measurements of the ionic current flowing through nanometer-scale pores (nanopores) have been used to analyze single DNA and RNA molecules, with the ultimate goal of achieving ultrafast DNA sequencing. However, attempts at purely electronic measurements have not achieved the signal contrast required for sing...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2007.091231
更新日期:2007-11-01 00:00:00
abstract::We report a continuous-flow fluorometric method for total urinary estrogens that involves the Kober reaction, with extraction of the reaction product into dichloroethane containing trichloroacetic acid as described by Hahnel and Jones [Clin. Chim. Acta 16, 185 (1967)]. The dichloroethane extraction gives greater stabi...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1977-10-01 00:00:00
abstract::The Arg-to-Trp substitution at codon 3500 in the apolipoprotein (apo) B-100 gene is established as a cause of familial defective apo B-100 (FDB), a functional mutation, resulting in reduced LDL receptor binding and manifest hypercholesterolemia. In a search for similar mutations in 163 Malaysians, we screened the puta...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1997-06-01 00:00:00
abstract::In this new radioimmunoassay system for determination of amatoxins in urine and plasma, a novel chemical approach is used for antigen and 125I-tracer production, based on a detoxified alpha-amanitin derivative (aldoamanitin). Total assay time, including data processing, is less than 100 min. The lowest detectable conc...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1986-09-01 00:00:00
abstract::We compared results obtained with the Beckman Creatinine Analyzer (Beckman Instruments, Inc.) to those with the GEMSAEC Centrifugal Analyzer (Electro-Nucleonics, Inc.) and with a manual method for determination of creatinine in serum and urine. Linearity, stability, recovery, and precision were evaluated. Interference...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1979-06-01 00:00:00
abstract::Two-dimensional protein maps of biopsies from normal mucosa, tubular adenomas (polyps), and colonic carcinomas in humans have been studied in order to obtain information on the possible precancerous role of intestinal polyps. The maps are complex and several hundred protein spots are seen after staining with Coomassie...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1982-04-01 00:00:00
abstract::In assessing interference from bilirubin, the use of a synthetic soluble derivative (ditaurobilirubin, DTB) is recommended as a surrogate for the natural conjugates (Bc). We compared the interference effect of unconjugated bilirubin (Bu), Bc, and DTB, using six mechanized methods for serum creatinine measurement. No s...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1991-02-01 00:00:00
abstract:BACKGROUND:The lead mobilization test reflects the mobilizable and likely toxicologically active fraction of the lead body burden. We propose a safe and convenient protocol for this test, to assess concomitant copper and zinc excretion and to determine the size of the chelatable lead pool in nonoccupationally exposed a...
journal_title:Clinical chemistry
pub_type: 临床试验,杂志文章
doi:10.1373/clinchem.2005.051128
更新日期:2006-01-01 00:00:00
abstract::Throughout the 1970s, controversy centered both on immunoassay "sensitivity" per se and on the relative sensitivities of labeled antibody (Ab) and labeled analyte methods. Our theoretical studies revealed that RIA sensitivities could be surpassed only by the use of very high-specificity nonisotopic labels in "noncompe...
journal_title:Clinical chemistry
pub_type: 杂志文章,评审
doi:
更新日期:1991-11-01 00:00:00
abstract::Crystalline preparations of diiodotyrosine contain trace quantities of thyroxine that can be detected by several competitive radioassays and by chromatography on Sephadex. Spontaneous coupling of diiodotyrosine to thyroxine during iodination of tyrosine and coprecipitation of hormone with diiodotyrosine crystals are l...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1978-10-01 00:00:00
abstract::A 56-year-old Samoan man with a documented history of hypertension, who presented with atrial fibrillation and hypotension, quickly developed renal failure with a serum urea nitrogen of 1.370 g/L and a serum creatinine of 92 mg/L. After hydration of the patient, the creatinine value became normal in two days, the urea...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:
更新日期:1979-11-01 00:00:00
abstract:BACKGROUND:Galectin-3 has emerged as a potential useful novel biomarker for heart failure and cardiovascular disease (CVD). However, it remains unclear whether galectin-3 is associated with recurrent cardiovascular events during long-term follow-up of patients with stable coronary heart disease (CHD) after adjustment f...
journal_title:Clinical chemistry
pub_type: 杂志文章
doi:10.1373/clinchem.2016.257550
更新日期:2016-10-01 00:00:00