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J M Hicks

Publications and source records attributed to J M Hicks.

At least 37 records · Page 2Linked to original sources
PubMed1990

A dry-strip immunometric assay for digoxin on the Ames Seralyzer.

We evaluated the Ames Seralyzer III with a new reagent and drystrip test for assay of digoxin. Assay precision was acceptable in the therapeutic range. Within-run imprecision (coefficient of variation, n = 20) was 7% at 0.9 ng/ml (1.2 nM) and 3.5% at 1.9 ng/ml (2.4 nM); run-to-run imprecision was 7.6% at 0.8 ng/ml (1.0 nM) and 5.7% at 2.1 ng/ml (2.7 nM). The method is very reproducible and is linear between 0.5 and 4.3 ng/ml (0.6-5.5 nM). The assay performed well with patient samples, with Abbott TDx used as the reference procedure. Bilirubin up to 16 mg/dl (273 microM) and hemoglobin up to 11 g/l do not cause interference. Digoxin-like immunoreactive factors cause minimal interference. Some digoxin metabolites such as monodigitoxoside, bis-digitoxoside, and digoxigenin cross-react with the digoxin antibody. Patients on spironolactone have falsely increased digoxin values. The new digoxin assay is easy to perform and uses 30 microliters serum; the result can be reported in 15-20 min.

Antibody Specificity↗
PubMed1989

Evaluation of colorimetric dipstick test to detect alcohol in saliva: a pilot study.

The Alco Screen Saliva Dipstick is an inexpensive, easy-to-use, colorimetric test that gives a semiquantitative estimation of the blood alcohol value by measuring the relative concentration of salivary alcohol. To evaluate its accuracy, we compared the results from tests with the Alco dipstick with values from simultaneously measured blood alcohol tests in 53 patients who were suspected of having ingested alcohol. The correlation between Alco dipstick results and blood alcohol values was strong (r [Spearman's rho], + .91). When the blood alcohol concentration was 0.1 g/dL or more, the Alco dipstick test was 90.9% sensitive, 71.4% specific, and 92% efficient. At Alco dipstick values of 0.02 and 0.05 g/dL, however, semiquantitative concordance was unsatisfactory. Nevertheless, even at the 0.05-g/dL value of salivary alcohol, the test was still valuable as a screen of de facto alcohol ingestion. Definitive diagnosis of relative alcohol intoxication requires confirmatory breath or blood alcohol concentrations by standard methodologies.

Adolescent↗
PubMed1989

High-dose caffeine suppresses postoperative apnea in former preterm infants.

Thirty-two former preterm infants (less than or equal to 44 weeks postconceptual age) undergoing inguinal hernia repair were prospectively studied. General inhalational anesthesia with neuromuscular blockade was used. No barbiturates or opioids were given. Infants were randomly divided into two groups. Group 1 received iv caffeine 10 mg/kg immediately after induction of anesthesia. Group 2 received iv saline. Respiratory pattern, heart rate, and SpO2 were monitored using an impedance pneumograph and a pulse oximeter, respectively, for at least 12 h postoperatively. Tracings were analyzed for evidence of apnea, periodic breathing, and/or bradycardia by a pulmonologist unaware of the drug given. None of the patients who received caffeine developed postoperative bradycardia, prolonged apnea, or periodic breathing, and none had postoperative SpO2 less than 90%. In the control group 13 (81%) developed prolonged apnea 4-6 h postoperatively. Fifty percent of the patients had SpO2 less than 90% at the time. This study shows that iv caffeine 10 mg/kg is effective in the control of apnea in otherwise healthy expremature infants between 37 and 44 weeks of postconceptual age. It is still recommended, however, that all infants at risk be monitored for at least 12 h for apnea and bradycardia following general anesthesia.

Anesthesia, General↗
PubMed1987

Another physician's office analyzer: the Abbott "Vision" evaluated.

We evaluated the Abbott Vision system, to assess its suitability for use in the physician's office setting. We compared results from Vision for all the available analytes (alkaline phosphatase, urea nitrogen, cholesterol, creatinine, glucose, uric acid, and triglycerides) with results from the Kodak Ektachem 400 and 700. For all analytes, standard curve linearity, assessed with various dilutions of an analyte-supplemented serum pool, was within the ranges claimed by the manufacturer. Within-run precision (CV) for assays of these analytes ranged from 0.9% to 4.7%, run-to-run precision from 1.1% to 7.3%. Comparisons with other methods were generally very good except for a bias in results for blood urea nitrogen and alkaline phosphatase. Hemolysis (hemoglobin at 2.0 and 3.0 g/L) interferes with results for cholesterol, glucose, triglycerides, and uric acid in serum and whole blood. Bilirubin at 82 mg/L interferes with results for creatinine and triglycerides; at 120 mg/L it interferes with cholesterol, glucose, and uric acid results; and at 170 mg/L it interferes with alkaline phosphatase results. Triglycerides up to 5000 mg/L do not interfere with any of the tests. Calibration of the analyzer was stable for one month. We also compared the performance of a skilled operator with that of an unskilled operator and a physician.

Bilirubin↗
PubMed1986

Hemoglobin, electrolytes, and other major clinical laboratory analytes as measured with a physician's office analyzer, the Kodak DT60.

We evaluated the Kodak DT60 analyzer, to assess its suitability for use in the physician's office setting. The DT60 Analyzer is based on the same multilayer film technology as used in the Ektachem 400 and 700. We compared results obtained with DT60 for all the analyses currently available for use in this instrument (Na+, K+, Cl-, glucose, urea nitrogen, uric acid, total bilirubin, total protein, amylase, cholesterol, and triglycerides) with results from a Kodak Ektachem 700 Analyzer and from other laboratory procedures. Results for hemoglobin were compared with those from a Coulter Counter Analyzer. For all analytes, linearity of the standard curve for various dilutions of Ektachem calibrators was within the manufacturer's claims. CVs for within-run precision ranged from 0.8% to 5.4%, run-to-run CVs ranged from 1.6% to 7.5%. Except for amylase, comparisons with other methods were generally very good. The only interference we observed was that of hemoglobin in the bilirubin assay. Calibration was stable for longer than one month. We also compared the performance of a skilled operator with that of an unskilled operator and of a physician.

Autoanalysis↗
PubMed1985

Rhabdomyolysis: two pediatric case reports.

We report two pediatric cases of rhabdomyolysis. This disease involves the destruction of skeletal muscle, which can present with myalgia and a brown-pigmented urine. The first patient presented with acute renal failure, hypertension, and hyponatremia. The second patient was pyrexic, hypernatremic, and hypokalemic, and later developed hypertension. Evidence of rhabdomyolysis in both patients included dark, o-tolidine-positive urine, granular casts in the urinary sediment, and grossly increased activities of creatine kinase (greater than 60 000 U/L) in serum. An uncommonly recognized entity in the pediatric age group, rhabdomyolysis often presents as an acute disease with severe onset but can be diagnosed with relatively simple laboratory tests.

Adolescent↗
PubMed1985

In situ monitoring.

In situ monitoring has been increasingly accepted during the past five years. This approach has been applied to measurement of gas tensions such as pO2 and pCO2, to pH and ions, to the assessment of jaundice by measurement of bilirubin, and to analysis for 14CO2 after administration of labeled antipyrine and aminopyrine, for evaluation of hepatic damage. Various techniques have been developed for in situ monitoring: transcutaneous measurements, implantable sensors, ingestible radio-sensitive pills, and breath analysis. Here I review some of these approaches and their limitations. These limitations include the sparsity of circumstances under which the technique can be applied and the probable increase in health-care costs.

Bilirubin↗
PubMed1985

Ektachem multilayer dry-film assay for ammonia evaluated.

We evaluated the Kodak Ektachem multilayer dry-film method for ammonia. Within-day precision (CV) was 5.9% and 2.7% at ammonia concentrations of 53 and 654 mumol/L, respectively. Between-run precision (CV) was 7.8% and 7.3% at 51 and 109 mumol/L, respectively. Correlation with a manual ion-exchange chromatography-Berthelot reaction-based method (x) was good (y = 0.96x - 1.37; r = 0.984; SEE = 9.16). The response of the method varies linearly with ammonia concentration up to 900 mumol/L. Bilirubin less than or equal to 270 mg/L, triglycerides less than or equal to 6.0 g/L, and slight hemolysis did not interfere. The concentration of ammonia in plasma of 120 healthy adults was 16-53 mumol/L (nonparametric central 95 percentiles).

Ammonia↗
PubMed1984

Beta-blocking autoantibodies in pediatric bronchial asthma.

We have used the inhibition of binding of a potent beta antagonist, iodohydroxybenzylpindolol, to canine lung-plasma membrane beta-adrenergic receptors as a test for beta-blocking autoantibodies in the sera of 376 mildly and severely asthmatic children. This binding inhibition assay, coupled with a variant test in which the binding assay was performed on selected sera (binding values below 2 SD from the mean) before and after immunodepletion of the sera (removal of IgG and IgA), permitted the conclusion that about 5% of the juvenile asthmatic population studied produce beta-blocking autoantibodies.

Adrenergic beta-Antagonists↗