Abstract：
:A new enzymic method is described for the determination of creatine in urine by continuous-flow analysis. The measurement is accomplished by transforming creatine to formaldehyde in reactions catalyzed by creatinase (creatine amidinohydrolase) and sarcosine dehydrogenase. The formaldehyde is reacted with 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole to form a purple product, which is measured colorimetrically. The method gives a linear standard curve for creatine concentrations up to 100 mg/L. Precision and analytical recovery are excellent, and results correlate well with those by the more-difficult Folin method, which currently is most often used for this analysis.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Yasuhara M,Fujita S,Furukawa I,Arisue K,Kohda K,Hayashi Csubject
Has Abstractpub_date
1981-11-01 00:00:00pages
1888-91issue
11eissn
0009-9147issn
1530-8561journal_volume
27pub_type
杂志文章abstract：:Nitric oxide is a soluble gas continuously synthesized by the endothelium. This substance has a wide range of biological properties that maintain vascular homeostasis, including modulation of vascular dilator tone, regulation of local cell growth, and protection of the vessel from injurious consequences of platelets a...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：
更新日期：1998-08-01 00:00:00
abstract：BACKGROUND:Massively parallel sequencing has recently been used in noninvasive prenatal diagnosis. The current costs of this technology are still relatively expensive, however, and sample throughput is still relatively low when it is used as a molecular diagnostic tool. Rather than nonselectively sequencing the genome,...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2010.154336
更新日期：2011-01-01 00:00:00
abstract：BACKGROUND:The Dutch project "Calibration 2000" aims at harmonization of laboratory results via calibration by development of matrix-based secondary reference materials. We considered the selection, preparation, and characterization of 34 potential reference materials (PRMs). METHODS:Sixteen PRMs were prepared either ...
journal_title：Clinical chemistry
pub_type： 杂志文章,多中心研究
doi：
更新日期：2002-09-01 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 describe a sensitive beta-endorphin (beta-EP) radioimmunoassay specific for beta-EP 1-31 applied to human ventricular and lumbar cerebrospinal fluid (CSF). Specificity was documented by reversed-phase HPLC of CSF pools. Simultaneous ventricular and lumbar CSF samples from 13 patients suspected of having normal-pres...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-06-01 00:00:00
abstract：:Ornithine carbamoyltransferase (EC 2.1.3.3) activity is a sensitive, specific indicator of hepatocellular injury. This paper describes development of an improved automated procedure for measurement of this activity. Triethanolamine-ethylenediaminetetraacetate is used as a buffer, and activity is determined by measurin...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1975-05-01 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：BACKGROUND:The recent discovery of the presence of circulating cell-free fetal DNA in maternal plasma opens up new prenatal diagnostic applications and provides new avenues for clinical investigation. It is of research and potential diagnostic interest to determine whether fetal trisomy 21 may be associated with quanti...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章,多中心研究
doi：
更新日期：1999-10-01 00:00:00
abstract：:Using results from patients, we studied several methods for long-term (years) monitoring of the analytical stability of various chemistry tests. For each test, we obtained on a bimonthly basis histograms of > or = 200 to approximately 2000 data points and determined the median, mean, and mean of those data points in t...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1996-06-01 00:00:00
abstract：BACKGROUND:Cardiac troponin T (cTnT) is the preferred biomarker for the diagnosis of acute myocardial infarction (AMI). It has been suggested that cTnT is present predominantly in fragmented forms in human serum following AMI. In this study, we have used a targeted mass spectrometry assay and epitope mapping using West...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2016.261511
更新日期：2017-02-01 00:00:00
abstract：:We have studied factors affecting biological variation in total plasma alkaline phosphatase in a population of 32 329 apparently healthy subjects four years old or older. Quantification of the bone and liver isoenzymes after thermal denaturation made it possible to specify the contributions of each isoenzyme to variat...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1983-04-01 00:00:00
abstract：:Erythrocyte protoporphyrin content is increased in several human and veterinary disorders in which heme synthesis is disrupted. The nature of the defect determines whether zinc protoporphyrin, unchelated (free) protoporphyrin, or both are present in the erythrocytes. Extraction of the protoporphyrin into acetone/water...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1981-02-01 00:00:00
abstract：:The biological variability of total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and calculated low-density lipoprotein cholesterol (LDL-C) was determined in three serial (monthly) capillary and venous specimens from 83 subjects. The analytes were quantified with a desktop analyz...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1996-12-01 00:00:00
abstract：BACKGROUND:Monogenic autoinflammatory diseases are caused by pathogenic variants in genes that regulate innate immune responses, and are characterized by sterile systemic inflammatory episodes. Since symptoms can overlap within this rapidly expanding disease category, accurate genetic diagnosis is of the utmost importa...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1093/clinchem/hvaa024
更新日期：2020-04-01 00:00:00
abstract：:We describe the performance of an RIA for the measurement of prostate-specific antigen (PA). Between-assay precision (CV) for control sera with various analyte concentrations was as follows: mean = 1.67 micrograms/L, CV = 7.1%; mean = 4.47 micrograms/L, CV = 5.6%; mean = 7.15 micrograms/L, CV = 5.5% (n = 19 each). Ana...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1984-05-01 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：:Endotoxin, the lipopolysaccharide cell wall constituent of Gram-negative bacteria, produces symptoms of the Gram-negative sepsis syndrome. By measuring endotoxin in blood from septic patients it may be possible to select a subpopulation of patients in which mortality can be prevented by treatment with anti-endotoxin a...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1994-08-01 00:00:00
abstract：:Urinary polyamines were measured by a fluorometric thin-layer chromatographic technique in samples collected daily throughout a single menstrual cycle by each of 13 healthy women. Polyamine excretion fluctuated considerably, but excretion of putrescine, spermidine, and spermine combined was consistently greatest durin...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1978-05-01 00:00:00
abstract：:Imferon (Merrell-National), an iron-dextran complex, is widely used in patients with iron deficiency. It is present in the circulation in appreciable amounts for two to three weeks after administration and interferes with all tested colorimetric iron assays, both with and without deproteinization. The amount of the pl...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1980-04-01 00:00:00
abstract：BACKGROUND:MALDI-TOF mass spectrometry (MS) is set to make inroads into clinical chemistry because it offers advantages over other analytical platforms. These advantages include low acquisition and operating costs, ease of use, ruggedness, and high throughput. When coupled with innovative front-end strategies and appli...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2015.239491
更新日期：2016-01-01 00:00:00
abstract：BACKGROUND:5α-Reductase 2 deficiency (5ARD) is a known cause of 46,XY disorders of sex development (DSD). Traditionally, the diagnosis relies on dihydrotestosterone (DHT) measurement, but the results are often equivocal, potentially leading to misdiagnosis. We reviewed alternative approaches for diagnosis of 5ARD. MET...
journal_title：Clinical chemistry
pub_type： 杂志文章,评审
doi：10.1373/clinchem.2012.196501
更新日期：2013-05-01 00:00:00
abstract：BACKGROUND:The susceptibility of plasma lipids to oxidation is thought to be a factor contributing to atherogenic risk. Various groups have studied the in vitro oxidizability of isolated LDL and examined the effects of conventional antioxidants. The drawbacks associated with the isolation of LDL for evaluation of in vi...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2005.051078
更新日期：2005-11-01 00:00:00
abstract：BACKGROUND:Coffee consumption has been associated with several risk factors for coronary heart disease, including increased cholesterol, increased blood pressure, and increased plasma total homocysteine (tHcy). tHcy is determined by several B-vitamins. However, reports about the association between coffee intake and B-...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2008.103465
更新日期：2008-09-01 00:00:00
abstract：:We present a rate-determination method for analyzing glucose. A glucose enzyme electrode serves as the sensor and is made by placing a gel-immobilized layer of glucose oxidase over the tip of a Clark-type O2 electrode. The electrode membrane is made of Teflon and is derivatized by etching with a suspension of colloida...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1980-01-01 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：: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：: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：:Autocorrelation of clinical chemistry quality-control (Q/C) measurements causes one of the basic assumptions underlying the use of Levey-Jennings control charts to be violated and performance to be degraded. This is the requirement that the observations be statistically independent. We present a proposal for a new app...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-07-01 00:00:00
abstract：BACKGROUND:Altered germline expression of genes may represent a powerful marker of genetic or epigenetic predisposition to cancer or other diseases. METHODS:We developed and validated a method of nonfluorescent primer extension that uses a single dideoxynucleotide and denaturing HPLC (DHPLC) to analyze the relative al...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2009.126300
更新日期：2009-09-01 00:00:00
abstract：BACKGROUND:Cardiovascular mortality is markedly higher in Russia than in Western Europe and the US. Little is known about indicators of atherosclerotic risk in the Russian population. To our knowledge, this is the first study of apolipoprotein (apo) AI and B in Russia based on the WHO-IFCC standard. METHODS:We measure...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2003.023853
更新日期：2004-02-01 00:00:00
