Manual fluorometry of phenylalanine from blood specimens collected on filter paper: a modified procedure.

Abstract:

:In this manual fluorometric method, blood samples are used that have been impregnated on the filter paper, a convenient collection technique that is widely used to screen newborns for phenylketonuria. The modified procedure, based on the method of McCaman and Robins [J. Lab Clin. Med. 59, 885 (1962)], includes elution of phenylalanine from specimens on filter paper, removal of proteins by precipitation with trichloroacetic acid at 0 degrees C, and then reaction with ninhydrin-peptide reagent for color development. The standard curve is linear to at least 200 mg/L and the CV is 6.3% for a phenylalanine concentration of 27 mg/L. The modified procedure is suitable both for early screening for phenylketonuria and for monitoring blood phenylalanine of phenylketonurics during dietary therapy.

journal_name

Clin Chem

journal_title

Clinical chemistry

authors

Wu JT,Wu LH,Ziter FA,Ash KO

subject

Has Abstract

pub_date

1979-03-01 00:00:00

pages

470-2

issue

3

eissn

0009-9147

issn

1530-8561

journal_volume

25

pub_type

杂志文章
  • Significance of serum 24,25-dihydroxyvitamin D in the assessment of vitamin D status: a double-edged sword?

    abstract:BACKGROUND:24,25-Dihydroxyvitamin D [24,25(OH)2D] in serum may be both a nuisance and nutritionally valuable. METHODS:We investigated the impact of 24,25(OH)2D3 on the performance of commercially available immunoassays for serum total 25-hydroxyvitamin D [25(OH)D] using (a) serum from a nationally representative sampl...

    journal_title:Clinical chemistry

    pub_type: 杂志文章,随机对照试验

    doi:10.1373/clinchem.2014.234955

    authors: Cashman KD,Hayes A,Galvin K,Merkel J,Jones G,Kaufmann M,Hoofnagle AN,Carter GD,Durazo-Arvizu RA,Sempos CT

    更新日期:2015-04-01 00:00:00

  • Plasma lipoprotein peroxidation potential: a test to evaluate individual susceptibility to peroxidation.

    abstract::Peroxidation of lipids is believed to play a key role in various degenerative diseases. However, few simple tests are able to detect individual susceptibility or resistance to peroxidation. Measurement of the basal concentrations of lipid peroxides in plasma is not satisfactory because they are so low. Therefore, we d...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:

    authors: Arshad MA,Bhadra S,Cohen RM,Subbiah MT

    更新日期:1991-10-01 00:00:00

  • Isoelectric focusing in agarose: classification of genetic variants of alpha 1-antitrypsin.

    abstract::Polyacrylamide has been the matrix of choice for isoelectric focusing owing to the virtual absence of electroendosmosis in this medium. Certain inherent limitations associated with polyacrylamide have prompted some investigators to use low-electroendosmosis agarose for isoelectric focusing, but with limited success th...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:

    authors: Buffone GJ,Stennis BJ,Schimbor CM

    更新日期:1983-02-01 00:00:00

  • Acetate intolerance and an inhibitor of acetate utilization in hemodialysis patients.

    abstract::Diminished ability to utilize acetate (acetate intolerance) developed in a male patient on chronic hemodialysis after five years of maintenance dialysis. His ability to utilize lactate was also subnormal. We studied acetate metabolism in vitro by isolating lymphocytes from the patient's blood before dialysis and measu...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:

    authors: Egan JD,Wells IC

    更新日期:1979-03-01 00:00:00

  • Time series modeling for quality control in clinical chemistry.

    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:

    authors: Alwan LC,Bissell MG

    更新日期:1988-07-01 00:00:00

  • Immunofluorometric demonstration and quantification of placental protein 5 in the absence of pregnancy.

    abstract::This time-resolved immunofluorometric assay (IFMA) developed for measurement of placental protein 5 (PP5) involves two antibodies: a monoclonal anti-PP5 antibody attached to a solid phase and an europium(III) chelate-labeled polyclonal anti-PP5 antibody as a tracer. The measuring range is 0.05-100 micrograms/L and the...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:

    authors: Bützow R,Alfthan H,Stenman UH,Suikkari AM,Bohn H,Seppälä M

    更新日期:1988-08-01 00:00:00

  • No influence of the MDR-1 C3435T polymorphism or a CYP3A4 promoter polymorphism (CYP3A4-V allele) on dose-adjusted cyclosporin A trough concentrations or rejection incidence in stable renal transplant recipients.

    abstract:BACKGROUND:A substantial proportion of the variability in the absorption and clearance of cyclosporin A (CsA) after oral administration has been attributed to variability in liver cytochrome P-450 3A4 (CYP3A4) activity and intestinal P-glycoprotein (P-gp) concentration. A polymorphism in the CYP3A4 promoter region, ter...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:

    authors: von Ahsen N,Richter M,Grupp C,Ringe B,Oellerich M,Armstrong VW

    更新日期:2001-06-01 00:00:00

  • Differential reactivity of two homogeneous LDL-cholesterol methods to LDL and VLDL subfractions, as demonstrated by ultracentrifugation and HPLC.

    abstract:BACKGROUND:The analytical and clinical performance of homogeneous LDL-cholesterol assays has been reported, but their reactions with subfractions of LDL and VLDL have not been described in detail. METHODS:We evaluated reaction selectivity of two homogeneous LDL-cholesterol assays, LDLk (Kyowa Medex) and LDLd (Daiichi ...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:

    authors: Usui S,Kakuuchi H,Okamoto M,Mizukami Y,Okazaki M

    更新日期:2002-11-01 00:00:00

  • Evaluation of the IFCC-recommended procedure for serum aspartate aminotransferase as modified for use with the centrifugal analyzer.

    abstract::The IFCC-recommended procedure for aspartate aminotransferase (EC 2.6.1.1) was adapted to the centrifugal analyzer and evaluated during five years. The main hindrance to widespread use of the recommended method is the need for pre-incubation with pyridoxal phosphate. The present method includes a 10-min pre-incubation...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:

    authors: Bruns DE,Savory J,Titheradge AC,Cross RE,Wills MR

    更新日期:1981-01-01 00:00:00

  • Zinc in plasma, neutrophils, lymphocytes, and erythrocytes as determined by flameless atomic absorption spectrophotometry.

    abstract::Zinc is determined in neutrophils and lymphocytes (isolated from whole blood on discontinuous gradients of Ficoll-Hypaque) and in microliter quantities of plasma and erythrocytes by flameless atomic absorption spectrophotometry with greater sensitivity than with conventional flame atomic absorption spectrophotometry. ...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:

    authors: Whitehouse RC,Prasad AS,Rabbani PI,Cossack ZT

    更新日期:1982-03-01 00:00:00

  • Telomeres and telomerase: biological and clinical importance.

    abstract::We review the present knowledge of telomeres and telomerase with special attention to their role in cell proliferation, cellular senescence, and human aging. We summarize the functional aspects of telomerase in cancer, as well as its role as a useful diagnostic and prognostic tumor marker, and discuss possible approac...

    journal_title:Clinical chemistry

    pub_type: 杂志文章,评审

    doi:

    authors: Dahse R,Fiedler W,Ernst G

    更新日期:1997-05-01 00:00:00

  • Chemical and immunochemical measurement of total iron-binding capacity compared.

    abstract::Radiometric, colorimetric, and two immunochemical methods for measuring total iron-binding capacity are compared. We evaluated the procedures on the basis of precision, applicability to a pediatric population, and accuracy as assessed by analytical recovery of purified transferrin. The immunoephelometric assay for tra...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:

    authors: Buffone GJ,Lewis SA,Iosefsohn M,Hicks JM

    更新日期:1978-10-01 00:00:00

  • New enzymatic assay for glycohemoglobin.

    abstract:BACKGROUND:Previous methods to measure glycohemoglobin (GHb) have been time-consuming or imprecise; we therefore developed a new enzymatic assay for GHb. METHODS:Blood cells were first hemolyzed, and hemoglobin was digested with protease to yield fructosyl amino acid. Fructosyl amino acid oxidase acts on the fructosyl...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:10.1373/49.2.269

    authors: Sakurabayashi I,Watano T,Yonehara S,Ishimaru K,Hirai K,Komori T,Yagi M

    更新日期:2003-02-01 00:00:00

  • In vitro effects of a novel hemoglobin-based oxygen carrier on routine chemistry, therapeutic drug, coagulation, hematology, and blood bank assays.

    abstract::Red blood cell (RBC) replacement solutions are being developed as alternatives to allogeneic RBC use in blood transfusions in the treatment of massive trauma, to achieve hemodynamic stability during elective surgery, and to increase oxygen-carrying capacity in anemia. Hemoglobin-based oxygen carrier (HBOC)-201 (Biopur...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:

    authors: Callas DD,Clark TL,Moreira PL,Lansden C,Gawryl MS,Kahn S,Bermes EW Jr

    更新日期:1997-09-01 00:00:00

  • Identification of a new metabolite of astilbin, 3'-O-methylastilbin, and its immunosuppressive activity against contact dermatitis.

    abstract:BACKGROUND:Astilbin is a flavonoid isolated from the rhizome of Smilax glabra. In a previous study, we revealed its unique immunosuppressive activity, a selective inhibition against activated T lymphocytes. This characteristic of astilbin is beneficial for the treatment of human immune diseases. METHODS:We incubated a...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:10.1373/clinchem.2006.077297

    authors: Guo J,Qian F,Li J,Xu Q,Chen T

    更新日期:2007-03-01 00:00:00

  • Non-enzymic glycation of individual plasma proteins in normoglycemic and hyperglycemic patients.

    abstract::Diabetic patients in poor glycemic control show increased glycation of total plasma proteins, but little is yet known about the relative extents to which the various individual proteins are glycated. Thus, we studied the non-enzymic glycation of several major plasma proteins and plasma protein fractions in normal and ...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:

    authors: Austin GE,Mullins RH,Morin LG

    更新日期:1987-12-01 00:00:00

  • Simultaneous quantitation of zinc protoporphyrin and free protoporphyrin in erythrocytes by acetone extraction.

    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:

    authors: Hart D,Piomelli S

    更新日期:1981-02-01 00:00:00

  • Determination of sodium and potassium with ion-selective electrodes.

    abstract::We compared different sample-handling techniques for measurement of Na+ and K+ with ion-selective electrodes (ISE). Imprecision was less for venous blood (with a minimum of heparin) than for plasma, serum, or capillary blood. The results for K+ were higher for serum than for whole blood, and higher for whole blood tha...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:

    authors: Fogh-Andersen N,Wimberley PD,Thode J,Siggaard-Andersen O

    更新日期:1984-03-01 00:00:00

  • Determination of vanillylmandelic acid with ion-pair chromatography and fluorescence detection.

    abstract::We describe a chromatographic procedure for sensitive (2.0 mumol/L), specific quantification of vanillylmandelic acid (VMA) in urine with iso-VMA as an internal standard. After rapid extraction from urine, the VMA is determined by isocratic reversed-phase ion-pair chromatography on a bonded C8 column and detection of ...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:

    authors: Lindgren K,Rodopoulos N

    更新日期:1986-04-01 00:00:00

  • Sandwich ELISA Using a Mouse/Human Chimeric CSLEX-1 Antibody.

    abstract:BACKGROUND:An assay using a mouse antisialyl Lewis X (sLeX) antibody (CSLEX-1) is used clinically for screening and monitoring patients with breast cancer in Japan. However, the IgM isoform of CSLEX-1 is not preferred for the assay because the bulkiness of IgM generally causes poor accessibility to the antigen. To solv...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:10.1373/clinchem.2016.260968

    authors: Yamashita J,Kobayashi I,Tatematsu K,Sezutsu H,Noda K,Ishihara H

    更新日期:2016-11-01 00:00:00

  • Detection of mucopolysaccharidosis type II by measurement of iduronate-2-sulfatase in dried blood spots and plasma samples.

    abstract:BACKGROUND:Mucopolysaccharidosis type II (MPS II) is a lysosomal storage disorder related to a deficiency in the enzyme iduronate-2-sulfatase (IDS). Clinical trials of enzyme replacement therapy are in progress, but effective treatment will require screening assays to enable early detection and diagnosis of MPS II. Our...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:10.1373/clinchem.2005.061838

    authors: Dean CJ,Bockmann MR,Hopwood JJ,Brooks DA,Meikle PJ

    更新日期:2006-04-01 00:00:00

  • Plasma protein abnormalities in nephrotic syndrome: effect on plasma colloid osmotic pressure and viscosity.

    abstract::The concentrations of 25 plasma proteins were measured in 22 patients with membranous nephropathy. For some large proteins, the plasma concentrations were increased; there were also large proteins with low plasma concentrations, but small or medium-sized proteins showed uniformly lower plasma concentration than the co...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:

    authors: Joven J,Clivillé X,Camps J,Espinel E,Simó J,Vilella E,Oliver A

    更新日期:1997-07-01 00:00:00

  • Carboxyhemoglobin, cotinine, and thiocyanate assay compared for distinguishing smokers from non-smokers.

    abstract::We compared cotinine, carboxyhemoglobin, and thiocyanate concentrations in blood sampled from 187 cigarette smokers and 181 non-smokers. All three differed significantly between smokers and non-smokers. Cotinine performed best as a test for assessing smoking status, with a sensitivity of 98% as compared with 94% for c...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:

    authors: Pojer R,Whitfield JB,Poulos V,Eckhard IF,Richmond R,Hensley WJ

    更新日期:1984-08-01 00:00:00

  • Comparison of specific gravity and creatinine for normalizing urinary reproductive hormone concentrations.

    abstract:BACKGROUND:Specific gravity (SG) may perform as well as creatinine (CR) correction for adjusting urinary hormone concentrations, as well as offer some advantages. We compared the two methods and applied them to US and Bangladeshi specimens to evaluate their use in different populations. METHODS:Pearson correlations be...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:10.1373/clinchem.2004.032292

    authors: Miller RC,Brindle E,Holman DJ,Shofer J,Klein NA,Soules MR,O'Connor KA

    更新日期:2004-05-01 00:00:00

  • Comparison of double- and single-isotope enzymatic derivative methods for measuring catecholamines in human plasma.

    abstract::We directly compared the reliability of a single-isotope enzymatic derivative technique for measurement of plasma catecholamines with that of the well-established double-isotope method. A significant (p less than 0.001) correlation was observed between measurements (n = 52) in the two assays, both for norepinephrine (...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:

    authors: Evans MI,Halter JB,Porte D Jr

    更新日期:1978-04-01 00:00:00

  • Immunopeptidometric assay for enzymatically active prostate-specific antigen.

    abstract:BACKGROUND:Determinations of certain forms of prostate-specific antigen (PSA) have been shown to increase the specificity for prostate cancer (PCa). One such variant, proteolytically active PSA, is a potentially useful tumor marker, but it is not specifically recognized by antibodies. Using phage display libraries, we ...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:10.1373/clinchem.2003.026146

    authors: Wu P,Zhu L,Stenman UH,Leinonen J

    更新日期:2004-01-01 00:00:00

  • Sodium activity, sodium concentration, and osmolality in plasma in acute and chronic renal failure.

    abstract::We compared the ionic activity of sodium, as measured with glass electrodes, with sodium concentration in 23 healthy persons, 15 persons with acute renal failure, and before and after dialysis in 46 patients with chronic renal failure. In healthy persons the mean (+/- SEM) sodium concentration was 139.1 +/- 0.6 mmol/L...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:

    authors: Langhoff E,Ladefoged J

    更新日期:1985-11-01 00:00:00

  • Radioimmunoassay of conjugated cholic acid, chenodeoxycholic acid, and deoxycholic acid from human serum, with use of 125I-labeled ligands.

    abstract::We describe a method for radioimmunoassay of conjugated cholic acid, chenodeoxycholic acid, and deoxycholic acid in serum. In the method, 125I-labeled bile acid conjugates are used as the tracers along with antibodies raised against individual bile acid-bovine serum albumin conjugates. Antibody-bound and free bile aci...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:

    authors: Mäentausta O,Jänne O

    更新日期:1979-02-01 00:00:00

  • Nonchromatographic radioimmunoassay of unconjugated estriol in plasma, with polyethylene glycol as precipitant.

    abstract::We describe a rapid, reliable radioimmunoassay for unconjugated estriol in plasma. Polyethylene glycol (Carbowax 6000) is used to separate antibody-bound and free steroid. The assay is sensitive (25 pg for standards), precise, and accurate. At high and low concentrations of estriol, intra-assay coefficients of variati...

    journal_title:Clinical chemistry

    pub_type: 杂志文章

    doi:

    authors: Schiller HS,Brammall MA

    更新日期:1976-03-01 00:00:00

  • Role of serotonin in the pathophysiology of depression: focus on the serotonin transporter.

    abstract::Considerable evidence has accrued in the last two decades to support the hypothesis that alterations in serotonergic neuronal function in the central nervous system occur in patients with major depression. These findings include the following: (a) reduced cerebrospinal fluid (CSF) concentrations of 5-hydroxyindoleacet...

    journal_title:Clinical chemistry

    pub_type: 杂志文章,评审

    doi:

    authors: Owens MJ,Nemeroff CB

    更新日期:1994-02-01 00:00:00