Clinical Chemistry

King, J, Stanton

doi: 10.1093/clinchem/17.10.971pmid: N/A

Abstract Current theories of renal stone formation are reviewed, together with the resulting proposals for treatment, with emphasis on the idiopathic, recurrent formation of calcium oxalate stones. Factors influencing the initiation and development of stones are discussed. inhibitors, composition, calcium, magnesium, phosphate, sodium, solubilizers, genetic influences, oxalate metabolism, calcium-binding protein, organic matrix This content is only available as a PDF. © 1971 The American Association of Clinical Chemists, Inc. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Harris, Eugene, K;DeMets, David, L

doi: 10.1093/clinchem/17.10.983pmid: N/A

Abstract Intra- and interindividual components of variation in ionized calcium among normal individuals have been estimated. The basic data were means of duplicate analyses of total serum calcium, total serum protein, and serum albumin from 68 normal subjects, 10-12 weekly samples per person. The McLean-Hastings equation was used to estimate [Ca2+]. Use of observed albumin/globulin ratios, instead of an assumed constant, had negligible effect on mean [Ca2+] or components of variation. The interindividual component of variation in [Ca2+] was found to be the same as that in total calcium: 3%. Average intraindividual variation (0.045-0.05 mmol/liter), appeared to be entirely attributable to analytical deviations in total protein and total calcium determinations. Thus, in the average normal individual, no physiologic variation in [Ca2+] could be detected. Results agreed with recent data on [Ca2+] measured by calcium ion-selective electrodes. variance, inter- and intraindividual variation, homeostasis, A/G ratio, total serum calcium, hormonic control, ion-selective electrodes This content is only available as a PDF. © 1971 The American Association of Clinical Chemists, Inc. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Helman, Edith, Zak;Blevins, Eleanor, J;Gleason, Irene, O

doi: 10.1093/clinchem/17.10.988pmid: N/A

Abstract Light-scattering measurements (nephelometry) of serum after filtration through appropriate filters is a rapid method for physically determining triglyceride concentrations and lipoprotein phenotypes. A correlation coefficient of greater than 0.9 was obtained when aliquots of the same specimen were tested for triglycerides by light scattering in an Aminco-Bowman Spectrophotofluorometer and by a chemical (Van Handel and Zilversmit) method. Lipoprotein phenotyping by agarose gel electrophoresis and by light-scattering measurement corresponded excellently. In equivocal cases, nephelometric results agreed better with the triglyceride and cholesterol data than did the electrophoretic method. colorimetry-nephelometry relationships, Fredrickson’s phenotypes This content is only available as a PDF. © 1971 The American Association of Clinical Chemists, Inc. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Dunckley, J, V

doi: 10.1093/clinchem/17.10.992pmid: N/A

Abstract An atomic absorption spectrophotometric method is described for estimating gold in diluted serum. Matrix effects are compensated by adding protein to the working standards. chrysotherapy, rheumatoid arthritis This content is only available as a PDF. © 1971 The American Association of Clinical Chemists, Inc. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Lopez,, A;Vial,, R;Gremillion,, L;Bell,, L

doi: 10.1093/clinchem/17.10.994pmid: N/A

Abstract An automated method is described for simultaneously determining cholesterol in serum β- and pre-β-lipoprotein fractions. This fast, reproducible, accurate method depends on the ability of β- and pre-β-lipoproteins to form insoluble complexes with polyanionic polysaccharides such as heparin. Values obtained by this method and by similar manual methods described in the literature agree well. This method is extremely useful in mass screening for hyperlipidemias; in certain cases it may be more useful than the determination of only cholesterol or triglycerides. AutoAnalyzer, complexes with heparin, hyperlipidemias, mass screening This content is only available as a PDF. © 1971 The American Association of Clinical Chemists, Inc. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Clarke, A, E;Denborough, M, A

doi: 10.1093/clinchem/17.10.998pmid: N/A

Abstract Chlorpromazine causes precipitation both of the glycoprotein and protein components of bile in vitro. The reaction depends on an electrostatic interaction between the negatively charged carboxyl groups on the bile components and the positively charged amine groups on the drug molecules in solution. The optimum conditions for the interaction between chlorpromazine and bile components have been established, and the suggestion is made that this precipitation may be responsible in part, for cholestatic jaundice associated with the administration of chlorpromazine. blood-group specific glycoproteins, cholestatic jaundice, sialic acids, phenothiazines This content is only available as a PDF. © 1971 The American Association of Clinical Chemists, Inc. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Radde, I, C;Höffken,, B;Parkinson, D, K;Sheepers,, J;Luckham,, A

doi: 10.1093/clinchem/17.10.1002pmid: N/A

Abstract We have evaluated the effects of the following on ion-specific electrode measurement of calcium ion activity in plasma: blood or plasma was stored in various ways for various periods of time, or exposed to air, or small amounts of heparin were added to the blood. Blood may be stored for as long as 120 min at room temperature before calcium ion activity changes measurably, but plasma stored for 20 min already has a slightly increased pH and decreased Ca ion activity. If plasma is frozen or refrigerated anaerobically after being collected, calcium ion activity is not measurably altered, but storage at room temperature is not suitable. If as much as 30 USP units of heparin is added per milliliter of blood and the blood is exposed to air for 1 min, calcium ion activity is unaltered, which allows rapidly processed samples to be used. Therefore, blood obtained by heel- or finger-prick may appropriately be used to measure calcium ion activity, particularly in newborns and infants. ion-specific flow-through electrode, rats, effects on blood Ca2+of storage, air exposure, heparin, magnesium, normal values, samples from infants This content is only available as a PDF. © 1971 The American Association of Clinical Chemists, Inc. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Muir, G, G;Ryan,, M

doi: 10.1093/clinchem/17.10.1007pmid: N/A

Abstract This method for the hydrolysis of estrogens completes the automated analysis of estrogens in pregnancy urine described by Muir, Ua Conaill, and Ryan [Steroids 13, 719 (1969)]. Pregnancy urines can be processed from the sampling of urine to the recording of fluorescence intensity in 30 min, at a rate of 20 samples per hour. The presence of glucose does not decrease the apparent hydrolysis products. fluorometry, AutoAnalyzer This content is only available as a PDF. © 1971 The American Association of Clinical Chemists, Inc. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Wright, Walter, R;Rainwater, John, C;Tolle, Lawrence, D

doi: 10.1093/clinchem/17.10.1010pmid: N/A

Abstract A colorimetric enzymatic assay system for glucose was evaluated. The system uses hexokinase (ATP:D-hexose 6-phospho-transferase; EC 2.7.1.1) and glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate:NADP oxidoreductase; EC 1.1.1.49) coupled with a PMS-INT reaction (phenazine methosulfate; 2-p-iodophenyl-3-p-nitrophenyl-5-phenyl tetrazolium chloride). The precision, range of linearity, reproducibility of standard curve, and stability of reagents after reconstitution are excellent. The method is specific for glucose in the presence of mannose, fructose, galactose, xylose, and ribose. Uric acid, urea, ascorbic acid, reduced glutathione, or creatinine at abnormally high concentrations do not interfere. Good correlations (with unselected hospital sera) were obtained in parallel assays by ferricyanide (AutoAnalyzer), o-toluidine (manual), and hexokinase (manual) procedures. Results obtained by the neocuproine (SMA-12/30) method in the parallel assays were significantly different from results obtained by the other three procedures. intermethod comparison, "GlucoStrate", "Glytel" This content is only available as a PDF. © 1971 The American Association of Clinical Chemists, Inc. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Frings, Christopher, S;Queen,, Cecelia;Foster, Lowell, B

doi: 10.1093/clinchem/17.10.1016pmid: N/A

Abstract The increasing abuse of drugs makes it imperative to have rapid, selective methods for their detection. Methods for amphetamines in which methyl orange is used as a reagent are subject to interference by a number of drugs. In the present modified, improved method, amphetamines combine with methyl orange to form a chromogen that follows Beer’s law at 515 nm to amphetamine concentrations of 10 mg/100 ml. Most interfering drugs are removed by pre-extraction into chloroform at pH 5.5. Of over 40 commonly used drugs, including organic bases and alkaloids, only amphetamine, dextroamphetamine, methamphetamine, and pentazocine HCl ("Talwin") react to produce a chromogen in this method. Recovery of amphetamine added to serum and urine is essentially 100%, as compared with aqueous standards taken through the entire procedure. The coefficient of variation is 8.9%. The method described, far more (but not completely) selective for amphetamines than previous methyl orange methods, is rapid, precise, and sensitive, which makes the method valuable in drug abuse screening programs—for which the speed is even greater, because only information on the qualitative presence or absence of amphetamines is required. methyl orange—drug complex, specificity, drug-abuse screening, extraction This content is only available as a PDF. © 1971 The American Association of Clinical Chemists, Inc. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)