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Biomedical subjects

R H Gadsden

Publications and source records attributed to R H Gadsden.

At least 37 records · Page 2Linked to original sources
PubMed1982

Computerized calculation with osmolality and its automatic comparison with observed serum ethanol concentration.

The need to obtain blood alcohol levels in the differential diagnosis of the acutely intoxicated or unconscious patient often presents an emergency situation. By simultaneously determining the measured osmolality, the calculated osmolality, and the enzymatically-assayed ethanol level, the presence of alcohols other than ethanol can be recognized rapidly. A computer program has been written in FORTRAN to perform the necessary calculations, check for internal consistency, and alert the technologist if a disparity occurs.

Adult↗
PubMed1982

Improved one-dimensional thin-layer chromatography of phospholipids in amniotic fluid.

With this extraction procedure and chromatographic method, six amniotic fluid phospholipids [phosphatidylcholine (lecithin), sphingomyelin, phosphatidylinositol, phosphatidylserine, phosphatidylethanolamine, and phosphatidylglycerol] are completely resolved in less than 70 min from the time the specimen is received. The mobile phase (chloroform/petroleum ether/methanol/acetic acid, 5/3/1.6/1, by vol) is used with commercially available 7.5 X 10 cm silica-gel plates. The phospholipids are made visible by immersing the plate in cupric acetate/phosphoric acid. Lecithin/sphingomyelin (L/S) ratios are determined densitometrically. Rf values are well reproducible for both samples and standards, as are L/S ratios, and the method is simple and inexpensive. The relation between L/S ratios (for 100 specimens of amniotic fluid measured by this method) and fetal status is consistent with other reports. We confirm phosphatidylglycerol to be a sensitive indicator of fetal lung maturity: when it was detectable in amniotic fluid, the newborn invariably showed no symptoms of the respiratory distress syndrome.

Amniotic Fluid↗
PubMed1982

Sample preparation and liquid-chromatographic analysis for tricyclic antidepressants in serum.

We report two separate sample-preparation procedures and a "high-pressure" liquid-chromatographic method for quantitating nine tricyclic antidepressant drugs: trimipramine, doxepin, amitriptyline, imipramine, desmethyldoxepin, nortriptyline, desipramine, maprotiline, and protriptyline. The drugs are extracted from 1 mL of serum by a single manual hexane extraction or by using DuPont's PREP I Automated Sample Processor. The drugs from either process are chromatographed on a mu-Bondapak-CN column with a mobile phase of acetonitrile/methanol/Na2HPO4, 5 mmol/L (60/15/25 by vol), pH 7.0, at a flow rate of 2.0 mL/min. Absorbance at 254 nm is linear with drug concentration from 25 to 1000 mg/L for each drug. With the manual extraction procedure the detection limit was 10 mg/L, absolute recovery 20-44%, within-run precision (CV) 10.1%, and run-to-run precision 11.1%. The performance of automated sample extraction was better, with a detection limit of 5 mg/l, absolute recovery 72-97%, within-run precision 6.1%, and run-to-run precision 6.6%.

Antidepressive Agents, Tricyclic↗
PubMed1981

Appearance of a sixth lactate dehydrogenase isoenzyme (LDH6) in a previously health patient.

We gave described a previously healthy patient with marked metabolic acidosis secondary to alcohol ingestion. An abnormal LDH isoenzyme (LDH6) located on the cathodic side of LDH5 after several episodes of shock was found in the patient's serum. We believe that the presence of LDH6 may occur as a result of shock from any cause and signifies a poor prognosis. The origin of LDH6 remains unknown.

Acidosis↗
PubMed1980

A computerized system for describing the tests offered by a clinical laboratory.

A system has been developed which allows for the easy display of information concerning tests performed in the clinical laboratory. The system is designed for use at nursing stations as well as in the clinical laboratory. The information which can be displayed includes: 1) general information, such as sample type, tube type and minimum sample volume; (2) price charged for the test; (3) special instructions, such as sample transportation, hours when test is available, and sample collection information; (4) normal or reference values for the results. The programs are written in FORTRAN IV and, together with the data files, require 422 kilobytes of storage space.

Clinical Laboratory Techniques↗
PubMed1977

Some effects of dieldrin and mirex on Ehrlich ascites tumor cells in vivo and in vitro.

The effects of dieldrin and mirex on Ehrlich ascites tumor cells were assessed, using certain in vivo (in mice) and in vitro measurements. Mirex retarded the development of Ehrlich ascites tumor in vivo, but dieldrin did not. Effects of dieldrin on de nova RNA purine synthesis from formate in vivo were slight, while mirex inhibited the synthesis of both RNA purines. Dieldrin inhibited the in vitro incorporation if thymidine, uridine, and L-leucine into DNA, RNA, and protein, respectively, but mirex was virtually without effect.

Animals↗
PubMed1977

Combined gel filtration, biuret/copper method compared with an immunochemical method for urinary protein measurement.

We compared an immunochemical method specific for plasma proteins with a chemical method, in which interfering substances are separated by gel filtration and "total" urinary protein is determined by the biuret reaction followed by reaction of protein-bound copper with diethyldithiocarbamate after a second gel filtration to remove nonprotein-bound copper. More than 250 24-h urine samples were analyzed by each method. There was linear agreement and a correlation of 0.96 between the two methods, but urinary protein values determined by the immunochemical method, especially for patients with multiple myeloma, were lower than by the chemical method.

Chromatography, Gel↗
PubMed1977

Evaluation of Ames' "Clini-Tek".

Reproducibility of reading "N-Multistix" dipsticks by a semi-automated urinalysis instrument (Ames' "Clini-Tek") has been described for artifically prepared samples. Glucose, ketone, urobilinogen, and nitrite showed high reproducibility (greater than 90%) for reading multiple samples at predetermined analyte concentrations. Determination of proteinuria showed the lowest proportion of false positives (2-3%) and false negatives (0%). Determination of hemoglobinuria and bilirubinuria by dipsticks were the least reproducible. Urobilinogen showed no interference from bilirubin in concentrations up to 32 mg/liter. Precision was high for results for quality-control capsules provided by the manufacturer.

Autoanalysis↗
PubMed1977

Semi-automated vs. visual reading of urinalysis dipsticks.

Semi-automated reflectance readings of urinalysis dipsticks showed better precision than visual readings in the case of artificially prepared urine samples containing glucose, ketone, and protein. Actual pathological specimens containing glucose, protein, and nitrite also showed that instrumental readings were better than visual. Results of repeated visual readings spread over three different color blocks for certain concentrations of glucose, ketone, and protein, whereas repeated instrumental readings were never spread greater than two color blocks. Subjectivity can be reduced by semi-automated dipstick urinalysis.

Acetoacetates↗