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J D Artiss

Publications and source records attributed to J D Artiss.

At least 19 recordsLinked to original sources
PubMed2000

A liquid-stable reagent for lactic acid levels. Application to the Hitachi 911 and Beckman CX7.

We evaluated the use of a new lactate oxidase-based reagent for the determination of serum and plasma lactic acid levels with the Hitachi 911 (Roche Diagnostics, Indianapolis, IN) and the Beckman CX7 (Beckman Instruments, Brea, CA). Evaluation studies demonstrated on-board stability of at least 3 months and a calibration stability of more than 5 months. Within- and between-day imprecision of this reagent was less than 2% for both applications. The reagent is free of the deleterious effects of triglyceride up to levels of 1,400 mg/dL (15.8 mmol/L), bilirubin to concentrations of 24.6 mg/dL (420 mumol/L), and hemoglobin, from lysed erythrocytes, to levels of more than 0.3 g/dL (3.0 g/L). When used on the Hitachi 911 for the determination of plasma lactate concentrations, the reagent correlates with the Dade aca III (Dade International, Deerfield, IL). When applied to the Beckman CX7 for the determination of serum lactate levels, the method correlates with the Beckman method.

Ampyrone↗
PubMed1997

Application of a sensitive and specific reagent for the determination of serum iron to the Bayer DAX48.

We describe a modification of a previously described serum iron procedure applied to the Bayer DAX48 (Bayer Diagnostics, Tarrytown, NY) automated chemistry analyzer. The iron-ligand used in this assay, 2-(5-nitro-2-pyridylazo)-5-(N-propyl-N-sulfopropylamine) phenol (nitro-PAPS), has a molar absorptivity of 94,000 L mol(-1) cm(-1), which is three to four times more sensitive than the more commonly used ligands. The increased sensitivity of the iron-ligand complex facilitates modification of a Ferene S method that requires a smaller sample volume while it maintains the precision of the assay. Because the reagent does not contain ascorbate, the "onboard" stability has been increased to more than 4 weeks. The reagent seems to be quite insensitive to icterus and hemolysis. Furthermore, the interference of turbidity caused by triglycerides, abnormal proteins, or fibrinogen, present in samples from patients undergoing anticoagulant therapy, seems to have been eliminated.

Azo Compounds↗
PubMed1996

Clinical laboratory investigation of the Sanofi ACCESS CK-MB procedure and comparison to electrophoresis and Abbott IMx.

This evaluation was undertaken to verify the application protocol for the CK-MB assay on the ACCESS Immunoassay Analyzer (Sanofi Diagnostics Pasteur, Chaska, MN). The results show that the ACCESS CK-MB assay total imprecision was 6.8% to 9.1%. Analytical linearity of the ACCESS CK-MB assay was excellent in the range of < 1-214 micrograms/L. A comparison of the ACCESS CK-MB assay with the IMx (Abbott Laboratories, Abbott Park, IL) method shows good correlation r = 0.990 (n = 108). Linear regression analysis yielded Y = 1.36X-0.3, Sx/y = 7.2. ACCESS CK-MB values also correlated well with CK-MB by electrophoresis with r = 0.968 (n = 132). The linear regression equation for this comparison was Y = 1.08X + 1.4, Sx/y = 14.1. The expected non-myocardial infarction range of CK-MB determined by the ACCESS system was 1.3-9.4 micrograms/L (mean = 4.0, n = 58). The ACCESS CK-MB assay would appear to be rapid, precise and clinically useful.

Adolescent↗
PubMed1993

Calcium determination in serum with stable alkaline Arsenazo III and triglyceride clearing.

We describe an analytical procedure for determining serum calcium, using the ligand Arsenazo III in an aqueous alkaline medium. The choice of pH for the proposed technique differs from current procedures, which are for the most part carried out in a slightly acidic medium. An acidic medium avoids interference from magnesium, but is spectrophotometrically suboptimal for this pH-dependent reaction: the molar absorptivity of the Arsenazo III complex with calcium at acid pH is 13,787 L mol-1 cm-1, about one-half of that at a more optimal alkaline pH (26,574 L mol-1 cm-1). We have included a clearing technique in the reagent to avoid spectral aberrations from hypertriglyceridemic samples. alpha-Cyclodextrin absorbs the nonesterified fatty acids liberated from triglycerides by a microbial lipase. This modification may also be helpful for binding nonesterified fatty acids, which are known to interfere with calcium procedures by forming calcium soaps and thus preventing the reaction with intended ligands. The use of 8-hydroxyquinoline sulfonate as the magnesium-masking agent facilitates the use of alkaline pH. The less-water-soluble alternative, 8-hydroxyquinoline, commonly used as a precipitating agent for several methods, is difficult to solubilize in the alkaline reagent and tends to precipitate when complexed to magnesium. Finally, the use of alkaline pH results in a prolonged (> or = 6 weeks) shelf life for the reagent.

Arsenazo III↗
PubMed1991

Fluorometric determination of phosphatidylcholine as a measure of phospholipid methylation.

The successive methylation of phosphatidylethanolamine to phosphatidylcholine (phospholipid methylation) has been measured by the incorporation of S-[methyl-3H]adenosylmethionine or colorimetric assay of phosphatidylcholine extracted from adipocyte plasma membranes. A fluorometric assay for phosphatidylcholine was developed to measure phospholipid methylation. This assay is 10 times more sensitive than the colorimetric assay and demonstrates no significant interference with other methylated phospholipids. The fluorometric assay was used to determine a biphasic insulin dose response in adipocyte plasma membranes. This fluorometric assay for phosphatidylcholine represents an alternative method for monitoring phospholipid methylation, especially when increased sensitivity is required.

Adipose Tissue↗
PubMed1989

Phosphatidylglycerol in amniotic fluid. Comparison of an "ultrasensitive" immunologic assay with TLC and enzymatic assay.

Phosphatidylglycerol (PG) in amniotic fluid is recognized as a good indicator of fetal lung maturity and is unaffected by moderate amounts of blood or meconium contamination. A rapid immunologic agglutination assay, Ultrasensitive AmnioStat-FLM (FLM), was compared with two-dimensional thin-layer chromatography (TLC) and an enzymic, colorimetric procedure (E-PG). Eighty amniotic fluid specimens were analyzed. FLM results were reported as high (H), intermediate (I), or low positive (L). TLC was compared with FLM:H (n = 27), mean 0.14 (fraction of total phospholipids); I (n = 7), mean 0.11; L (n = 9), mean 0.03; negative results had no detectable PG by TLC. In 33 cases E-PG was compared with FLM:H (n = 9), mean 7.0 mumol/L; I (n = 5), mean 8.1 mumol/L; L (n = 3), mean 3.0 mumol/L; negative (n = 16), mean 3.2 mumol/L. Records were reviewed in 70 cases. Thirty cases were excluded: sample to delivery time was greater than 72 hours; steroids were given or sepsis was documented. Fetal lung immaturity was clinically present in six cases: respiratory distress syndrome in three cases and transient tachypnea of the newborn (TTN) in three cases. One false positive result was identified (TTN, FLM:H). FLM sensitivity for fetal lung maturity was 85.3%, specificity was 83.3%, and the positive predictive value for fetal lung maturity was 96.7%. FLM is a fast, reliable indicator of fetal lung maturity.

Agglutination Tests↗
PubMed1987

A method for the sequential colorimetric determination of serum triglycerides and cholesterol.

A simple spectrophotometric method for the sequential determination of triglycerides and cholesterol from a single serum sample was developed. In this two-stage procedure, the triglycerides and cholesterol esters are first hydrolysed to glycerol and free cholesterol respectively, with simultaneous scavenging of the liberated free fatty acids, a technique that ensures clarity of the sample. The glycerol is subsequently reacted to result in an intense red chromogen with a peak absorption maximum at 510 nm following a series of enzymic reactions. In the second stage, addition of cholesterol oxidase leads to oxidation of free cholesterol generated from the cholesterol esters in the first stage and the free cholesterol normally present in the sample, yielding in a similar fashion the identical red chromogen whose absorbance is also measured at 510 nm. Results obtained with the proposed method demonstrate good correlation with established individual procedures for triglycerides and cholesterol.

Bilirubin↗
PubMed1987

Problems with measurements caused by high concentrations of serum solids.

There have been numerous reports of spectrophotometric and volume problems caused by elevated levels of lipids in blood. The offending lipids, primarily triglycerides, not only cause turbidity leading to optical aberrations when added to analytical reagents, but also result in short-sampling errors leading to the measurement of inaccurate volumes of sample. Numerous methods have been developed to clear the lipemia, including ultracentrifugation organic solvent extraction, chemical precipitation and, most recently, enzymic hydrolysis. Although the latter procedures eliminate the optical problems, they do not deal with the volume dilution error created by the triglycerides. In turn, corrective mathematics have been developed to compensate for the inaccurate pipetting caused by the elevated lipids in a sample; however, these empirical calculations are not truly accurate at high concentrations of total lipids. This monograph will describe the problems caused by the presence of elevated lipids and the means available for treating them.

Blood Chemical Analysis↗
PubMed1986

Stimulation of phosphatidylcholine synthesis by insulin and ATP in isolated rat adipocyte plasma membranes.

Added individually or together, insulin and/or ATP significantly and rapidly increased the concentration of phosphatidylcholine in an enriched plasma membrane preparation from rat adipocytes. The increase in phosphatidylcholine synthesis mediated by insulin or ATP was suppressed by the phospholipid methyltransferase inhibitor, S-adenosylhomocysteine. These results suggest that the activity of phospholipid methyltransferase from adipocyte plasma membranes may be increased by phosphorylation and that insulin may further increase the activity of the phosphorylated phospholipid methyltransferase by an alternative pathway.

Adenosine Triphosphate↗
PubMed1986

On-line clarification for the measurement of serum glucose in hyperlipidemic specimens.

The optical aberrations due to the presence of the turbidity caused by hyperlipidemia has been eliminated in two serum glucose procedures. This has been accomplished by incorporating lipase and alpha-cyclodextrin into the two glucose reagents. The hydrolytic action of the lipase generates water soluble glycerol and insoluble fatty acids. By including the chemical scavenger alpha-cyclodextrin into the reagent the fatty acids are solubilized and thus the production of a second turbidity is avoided. Because the clearing reagents are incorporated into the glucose reagents, this is an on-line process and no additional labor is required to clear the sample-reagent mixture. Furthermore, no additional time is required as the clearing occurs in the same period of time that it takes for the indicator reactions to reach equilibrium.

Blood Glucose↗
PubMed1986

Enzymic clearing of lipaemic serum following total parenteral nutrition: determination of neonatal bilirubin as a model.

Bilirubin determinations in the newborn infant are one of the many analytical tests that can yield misleading results when the specimen is either iatrogenically or naturally lipaemic. Incorporation of a recently reported enzymic clarification system into a commercially available test kit enables one to conveniently and accurately quantify both total and direct bilirubin within the present procedural characteristics of the Bilirubin Stat Analyser Photometer. This instrument measures the former directly with bichromatic spectrophotometry and the latter with a conventional diazo-type reaction. The proposed modification of existing reagents allows one to apply the assay to samples with as much as, and possibly more than 16 g/l of triglycerides which has been introduced into the vascular circulation as intravenous total parenteral nutrition.

Bilirubin↗
PubMed1986

Potential problems in serum protein electrophoresis.

Potential problems are described that one could encounter in carrying out an electrophoretic procedure including its ancillary phases of visualization (staining) and quantification (densitometry). Endpoint-like measurements for separated isoenzymes may provide artifactual kinetic values as well, because stain measurement is fixed at a single time whereas reagent blanking in the electrophoretic medium is substituted for the conventional serum initial absorbance readings of test-tube determinations. Truncation of separated electrophoretic zones or opacity of an electrophoretic anti-convection medium such as uncleared cellulose acetate may also interfere with absolute quantification procedures.

Albumins↗