abstract：:To determine the molar absorptivities of beta-NADH and beta-NAD at 260 nm, we purified the reduced form of the coenzyme by repeated anion-exchange chromatography. A NADH preparation was so obtained for which the 260 nm/340 nm absorbance ratio was 2.265. When calculated with epsilon 340 beta-NADH = 6.22 times 10-3 for ...

journal_title：Clinical chemistry

authors： Haid E,Lehmann P,Ziegenhorn J

更新日期：1975-06-01 00:00:00

abstract：:Several aspects of mass spectrometry and gas chromatography-mass spectrometry are reviewed, including ionization methods, repetitive scanning, selected ion monitoring, and stable isotope measurement. I discuss the application of these and other mass spectrometry methods to the investigation of compound classes relevan...

journal_title：Clinical chemistry

authors： Lawson AM

更新日期：1975-06-01 00:00:00

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

authors： Pochopien DJ

更新日期：1975-06-01 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

authors： Clayson KJ,Fine JS,Strandjord PE

更新日期：1975-05-01 00:00:00

abstract：:We measured immunoglobulins in the sera of 33 patients on days 1, 3, 6, 10, and 17 and three to four weeks after surgical operations (mostly hysterectomy or appendectomy) or (six patients) after spinal injury. In the absence of infection or blood transfusion, IgG usually decreased slightly and transiently after hyster...

journal_title：Clinical chemistry

authors： Fuller JM,Keyser JW

更新日期：1975-05-01 00:00:00

abstract：:We describe a modification of the MacGee method [Anal. Chem. 42, 421 (1970)] for rapid determination of phenytoin (diphenylhydantoin) in plasma by gas-liquid chromatography, in which an ethylaing reagent is used instead of the more common methylating reagents. With this modification, several N-methylated antiepileptic...

journal_title：Clinical chemistry

authors： Friel P,Troupin AS

更新日期：1975-05-01 00:00:00

abstract：:I describe a micro-scale method for determining lead in whole blood by utilizing a graphite furnace. Sample pretreatment consists of fivefold dilution with a dilute surfactant. The method is directly calibrated with lead standards prepared in dilute HNO3. To eliminate a small, nonspecific absorption signal from the...

journal_title：Clinical chemistry

authors： Fernandez FJ

更新日期：1975-04-01 00:00:00

abstract：:Determination of zinc in blood plasma by flameless atomic absorption spectrometry is discussed, with particular reference to the protocol required for the successful use of the Varian-Techtron Carbon Rod Atomizer. Cup aging is shown to be an important factor in limiting the precision of this analytical technique and ...

journal_title：Clinical chemistry

authors： Chooi MK,Todd JK,Boyd ND

更新日期：1975-04-01 00:00:00

abstract：:Comparison of two methods for determining a substance is a common procedure in clinical chemistry. Almost without exception, normal theory statistics are used with the tacit assumption that the data under test show gaussian distributions. Experience has led us to question this assumption for populations of differences...

journal_title：Clinical chemistry

authors： Wu GT,Twomey SL,Thiers RE

更新日期：1975-03-01 00:00:00

abstract：:This communication describes and evaluates an improved routine methodology for quantitating clinical proteinuria. Based on investigations of Piscator and of Savory et al., a modified Tsuchiya's reagent (ethanolic HCI-phosphotungstic acid) is used to precipitate proteins at 56 degrees C, followed by biuret spectrophoto...

journal_title：Clinical chemistry

authors： Rice EW

更新日期：1975-03-01 00:00:00

abstract：:Sensitivity, stability, and specificity of the color-producing reaction of hydrogen peroxide with bezidine, leuco-malachite green, or o-dianisidine were tested in numerous systems containing hemoglobin and other hemoproteins. Use of urea or low temperature (to minus 12 degrees C), or both, was highly beneficial, espec...

journal_title：Clinical chemistry

authors： Ahlquist DA,Schwartz S

更新日期：1975-03-01 00:00:00

abstract：:In radioimmunoassay of digoxin by the dextran-coated charcoal method, duration of the incubation period for the antigen-antibody reaction and time allowed for dextran-coated charcoal to absorb the free antigen are critical factors. We compared effects of prolonged periods of absorption on results obtained with five co...

journal_title：Clinical chemistry

authors： Kuno-Sakai H,Sakai H

更新日期：1975-02-01 00:00:00

abstract：:An enzymatic, fluorometric method is described for determination of serum urea on silicone-rubber pads. In this method, the reagents are lyophilized on the surface of the pads, NADH on one side and a mixture of urease, glutamate dehydrogenase, and alpha-ketoglutarate on the other. The rate of disappearance of NADH flu...

journal_title：Clinical chemistry

authors： Kuan JC,Lau KY,Guilbault GG

更新日期：1975-01-01 00:00:00