Abstract：
:We evaluated the density-gradient ultracentrifugation method in a swinging-bucket rotor (Anal Biochem 111, 149-157, 1981) in a slightly modified version for isolation and determination of high-density lipoprotein (HDL) subfractions. We prestained the serum with Coomassie Brilliant Blue R, which did not change the hydrated densities of the lipoproteins, and after only 2.2 X 10(8) gav . min obtained an equilibrium distribution of the lipoproteins along the gradient. The density distribution of the HDL of 120 sera obtained from apparently healthy persons and from patients with different types of hyperlipoproteinemia was bimodal. The HDL2 could be isolated in the density range 1.072-1.098 kg/L and the HDL3 at 1.100-1.176 kg/L, the latter fraction being more heterogeneous. At a solvent density of 1.100 we obtained similar results for HDL2-and HDL3-cholesterol by ultracentrifugation in two different fixed-angle rotors with tube angles of 15 degrees or 35 degrees. Independent of the rotor and the ultracentrifugation technique, subfractionation at d = 1.100 resulted in more distinct stained entities than ultracentrifugation at d = 1.125. In the swinging-bucket rotor procedure, interference by sinking pre-beta-lipoproteins was minimized because, having hydrated densities between 1.058 and 1.075, they could be removed without aspirating the HDL2. The method is both accurate and precise. For HDL2- and HDL3-cholesterol determined in a thawed frozen serum pool, CVs were 8.8 and 6.3%, respectively (n = 18).
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Demacker PN,van Sommeren-Zondag DF,Stalenhoef AF,Stuyt PM,van't Laar Asubject
Has Abstractpub_date
1983-04-01 00:00:00pages
656-63issue
4eissn
0009-9147issn
1530-8561journal_volume
29pub_type
杂志文章abstract：:We have developed an HPLC method for measuring carbamylated hemoglobin (CarHb), based on the quantification of valine hydantoin formed from the released NH2-terminal carbamyl valine residue after acid hydrolysis of hemoglobin. In uremia, CarHb is produced by nonenzymatic post-translational modification of the terminal...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-04-01 00:00:00
abstract：:We report spectrophotometric methods for quantifying sodium and potassium in serum and plasma without sample pretreatment or solvent-extraction steps. The methods are based on novel chromogenic ionophores characterized by molecular structures highly preorganized for binding, which result in exceptionally high sensitiv...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-09-01 00:00:00
abstract：BACKGROUND:Band 5 tartrate-resistant acid phosphatase (TrACP; EC 3. 1.3.2) consists of two isoenzymes, bands 5a and 5b, of which band 5b TrACP is considered to be derived from bone. However, no kinetic method for the specific measurement of band 5b TrACP in serum is available. Our aim was to develop a kinetic assay met...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：2000-04-01 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：:We describe the measurement of human immunoglobulins IgG, IgA, and IgM in diluted sera, with diluted commercial monospecific antisera, with use of a 36-place centrifugal analyzer (RotoChem IIa; American Instrument Co., Silver Spring, MD 20920). The assay involves a two-point kinetic turbidimetric technique. The change...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-04-01 00:00:00
abstract：:We assessed the accuracy and precision of seven commercial kits for serum ferritin. The concentration of ferritin as determined by these assays for a liver ferritin reference standard, a human heart ferritin standard, and normal sera correlated highly, but the absolute values varied widely. Use of an international ref...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-02-01 00:00:00
abstract：:We describe the influence of autoantibodies that bind creatine kinase BB (CK-BB) on the methods for MB isoenzyme. If these autoantibodies are present in patients' sera, they cause the formation of macro CK type 1 (immunoglobulin-linked CK-BB). In some of these cases they can bind not only endogenous CK-BB but also CK-...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1985-07-01 00:00:00
abstract：:We describe a process for preparing a cholesterol-rich lipoprotein extract from bovine serum. The material is used to enhance cholestrol concentration up to 3.5 g/liter in a clear control material from human serum. The optical clarity of the enriched serum is only slightly affected by lyophilization and reconstitution...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1976-08-01 00:00:00
abstract：:Both cellulose acetate electrophoresis and citrate agar electrophoresis were performed on 834 blood samples collected on filter paper in Jamaica and shipped for testing to the National Hemoglobinopathy Standardization Laboratory at the U.S. National Center for Disease Control. Additionally, 30 blood samples collected ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1976-05-01 00:00:00
abstract：:Measurement of alpha-fetoprotein concentration and acetylcholinesterase activity in amniotic fluid can be used to identify chromosomal defects as well as neural tube defects. In seven cases of trisomy 21 and one case of partial trisomy 3, alpha-fetoprotein concentrations were below the reference range but values for a...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1985-04-01 00:00:00
abstract：:We have reported (Clin Chem 29: 42-44, 1983) that prestaining with Remazol Brilliant Blue permits direct visualization of serum components on disc electrophoresis, and apparently purifies the proteins well. Here we have cut out the bands corresponding to the prestained albumin and transferrin after disc electrophoresi...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-07-01 00:00:00
abstract：BACKGROUND:Gas6 is a vitamin K-dependent antiapoptotic protein that has been implicated in cardiovascular pathophysiology. We report the development and validation of an ELISA for Gas6, and the variation of plasma Gas6 with hormonal status in a study designed to evaluate the effect of oral contraception on plasma marke...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2007.089102
更新日期：2007-10-01 00:00:00
abstract：:We evaluated plasma selenium concentrations in patients with euthyroid sick syndrome express by low serum triiodothyronine (T3) concentrations. Selenium status in these patients was compared with that found in patients with both untreated and treated hypothyroidism. Selenium concentrations in plasma were significantly...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-09-01 00:00:00
abstract：:Creatinine and specific gravity (relative density) measurements both allow differences in urine concentration to be taken into account in determining urine cotinine concentrations. In this study we demonstrate that the variance of urine cotinine measurements is reduced comparably when either creatinine or specific gra...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1994-04-01 00:00:00
abstract：:Reference values were determined for 23 plasma free amino acids from measurements done in 148 healthy children ranging from 0 to 18 years of age. Amino acid analysis was performed by ion-exchange chromatography. We propose a graphic form of presenting the age-specific distribution of plasma amino acid concentrations w...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1997-12-01 00:00:00
abstract：BACKGROUND:To address the continuing need for the standardization of clinical human cardiac troponin I (cTnI) assays, NIST, with the assistance of the AACC/IFCC Cardiac Troponin I Standardization Committee, has developed a new certified reference material, Standard Reference Material (SRM) 2921: Human Cardiac Troponin ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2005.051359
更新日期：2006-02-01 00:00:00
abstract：BACKGROUND:Epidemiologists have observed that blood donation is associated with decreased risk of type 2 diabetes and cardiovascular disease. METHODS:We investigated the relationship between iron stores and insulin sensitivity, after controlling for known confounding factors, and compared insulin sensitivity between b...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2004.046847
更新日期：2005-07-01 00:00:00
abstract：:We have modified the 63Ni radiochemical method of Ho (Anal Biochem 1970;36:105) for determination of free fatty acids (FFA) in plasma. Extracting 1 or 0.1 mL of plasma with Dole's mixture (J Biol Chem 1960;235:2595) and washing the "heptane" layer with two volumes of isopropanol/water/dilute (0.5 mol/L) H2SO4 (25/25/1...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1987-01-01 00:00:00
abstract：:We used enzyme immunoassay to measure apolipoprotein B concentration in human plasma. Pure lipoprotein B was isolated from serum samples of fasting normolipidemic subjects by sequential preparative ultracentrifugation and coated to a polystyrene tube surface by adsorption. Human serum samples and rabbit antiserum to h...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1978-03-01 00:00:00
abstract：BACKGROUND:The association of changes in oxidative and proinflammatory states with vascular function after diet and exercise intervention among obese children has not been previously explored. METHODS:In this 6-week diet and exercise intervention study in 35 obese children, age 12 to 18 years, we evaluated the relatio...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：10.1373/clinchem.2007.089953
更新日期：2008-01-01 00:00:00
abstract：:Changes in values for myoglobin, total creatine kinase (EC 2.7.3.2), and creatine kinase B-subunit in the serum of patients with thyroid disease are compared with values for these during the 24-h after myocardial infarction. Concentrations of all three of these muscle-derived proteins were significantly higher than no...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-01-01 00:00:00
abstract：:We measured the concentration of carboxyhemoglobin (HbCO) in blood samples from 32 neonates by spectrophotometry (IL282 CO-Oximeter) and gas chromatography, finding a strong positive correlation (r = 0.89) between the concentration of fetal hemoglobin (Hb F) and HbCO as measured by spectrophotometry, but not by gas ch...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-05-01 00:00:00
abstract：:Creatine kinase (CK) isoenzymes MM, MB, and BB are located primarily in the cell cytosol, and increased CKMB in plasma is the hallmark of myocardial infarction. However, whether CK is released with reversible ischemic injury remains controversial. Here, we assessed plasma CK activity--cytosolic and mitochondrial CK--i...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1997-03-01 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：:After extraction of the sample (on filter paper) in the counting vial, cortisol is assayed by adding 50 microL of horse serum containing tritiated cortisol, and 2 mL of toluene scintillator, shaking for 20 min, and counting the radioactivity in a liquid-scintillation counter at ambient temperature. The method can be a...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1987-07-01 00:00:00
abstract：:We describe a group of glycoproteins that are synthesized and released by human breast tumors maintained in organ culture and similar glycoproteins released by a human breast carcinoma cell line (BT-20). The electrophoretic mobility of these glycoproteins on cellulose acetate is consistent with increased glycoprotein-...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1977-11-01 00:00:00
abstract：:Genetic engineering of beta-galactosidase (EC 3.2.1.23) has led to the development of a new homogeneous assay system, CEDIA. The Z gene of the lac operon of Escherichia coli encodes a large enzymatically inactive polypeptide that spontaneously aggregates and folds to form active beta-galactosidase. Using recombinant D...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-09-01 00:00:00
abstract：:Using a cation-exchange chromatographic method, we found normal or subnormal values for glycosylated hemoglobin in a few diabetic patients with persistent hyperglycemia. Subsequent investigations revealed that these unexpected results had originated from black patients with diabetes. In view of common occurrence of ab...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1979-08-01 00:00:00
abstract：BACKGROUND:Data regarding the prognostic value of programmed cell death ligand 1 (PD-L1) expression on circulating tumor cells (CTCs) are lacking. However, CTCs could represent an alternative approach to serial biopsies, allowing real-time monitoring of cancer phenotype. METHODS:We evaluated, in a dedicated prospectiv...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1093/clinchem/hvaa121
更新日期：2020-08-01 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
