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Biomedical subjects

J Krahn

Publications and source records attributed to J Krahn.

18 recordsLinked to original sources
PubMed1993

Falsely elevated enzyme-multiplied immunoassay serum valproic acid results in 12 patients.

A split sample study of 69 patients' serum for valproic acid analysis by enzyme-multiplied immunoassay technique (EMIT) and by gas-liquid chromatography revealed falsely elevated EMIT values in 12 patients. Of the 69 serum samples, 28 were also assayed by fluorescence polarization immunoassay and all results agreed with those of gas-liquid chromatography. Five of the 12 patients with elevated EMIT values were included in this subgroup. The unidentified interfering substance appears to be a heat-labile, high-molecular-weight compound, possibly a protein complex that can persist in blood for several months following discontinuation of the drug.

Adolescent↗
PubMed1990

Excess serum osmolality gap after ingestion of methanol.

Two cases of methanol ingestion and one case of combined methanol and ethylene glycol ingestion are presented to illustrate the large differences that exist between the serum osmolality gap and the measured methanol (plus ethylene glycol) concentration(s) before treatment of these poisonings. After treatment with intravenous ethanol and hemodialysis was initiated, the differences disappeared in all three cases. We speculate that one or more metabolites with osmotic activity are formed in cases of methanol intoxication where no ethanol has also been consumed. The possible identity of these compounds is discussed.

Acid-Base Equilibrium↗
PubMed1988

Comparison of screening methods in a diabetes prevalence survey among northern Indians.

The use of medical records, fasting plasma glucose, 2-hour post-challenge glucose and glycosylated hemoglobin is compared in a population diabetes screening survey among Indians in northern Ontario and Manitoba. As expected, screening identified additional diabetics not previously known to the health care system. Glycosylated hemoglobin was highly correlated with fasting glucose and could discriminate between diabetics and non-diabetics, although not those with impaired glucose tolerance. In multiple regression models more significant predictors were identified and a larger proportion of the overall variance accounted for when log hemoglobin instead of log fasting glucose was used as the dependent variable. In a subsample of subjects, no additional diabetics were identified when both 2-hour and fasting criteria were used, compared to fasting plasma glucose alone.

Adult↗
PubMed1987

Variables affecting resolution of lung phospholipids in one-dimensional thin-layer chromatography.

Resolution of the confusion in the literature about the separation of lung phospholipids in thin-layer chromatographic systems has awaited a systematic study of the variables that potentially affect this separation. In this study I show that: incorporation of ammonium sulfate into silica gel "GHL" has a dramatic effect on separation of lung phospholipids; this effect is equally dramatic but different in activated and nonactivated gels; when it picks up moisture, ammonium sulfate-activated gel very rapidly loses its ability to resolve lecithin from phosphatidylinositol; in gel containing ammonium sulfate, small amounts of phosphatidylethanolamine are hydrolyzed to lyso-phosphatidylethanolamine.

Ammonium Sulfate↗
PubMed1983

Evaluation of the Dupont aca bromocresol purple albumin method.

The bromocresol purple (BCP) albumin method on the DuPont aca was evaluated by determining the accuracy and precision of the method. A split sample comparison was performed against the electroimmunoassay (EIA) method as well as the bromocresol green (BCG) method on the DuPont aca and the Technicon SMA 12/60. The BCP method was found to have more than adequate precision and its accuracy is as good as the EIA method. The BCP method will give results which are approximately 9 g/L lower than end point BCG methods. Problems have been identified with some of the commercial materials that could be used to standardize the BCP method, since different commercial preparations of human serum albumin do not react in identical fashion in the BCP and EIA methods. For this reason caution should be exercised when standardizing the BCP method.

Animals↗
PubMed1978

[A case of malignant hyperthermia unrelated to anaesthesia (author's transl)].

Narcots and muscle relaxants are proven causes of malignant hyperthermia. Alcohol and a large number of drugs are capable of inducing myopathic changes which resemble malignant hyperthermia. The case of a 47-year-old man is reported who presented with the clinical symptoms of maligant hyperthermia. The similarity in the course of the disturbance, the clinical and chemical findings and the changes in the morphological features of the muscle suggested that the abnormally high body temperature had been induced by psychotropic durgs in a pre-disposed patient with an history of chronic alcoholism.

Alcoholism↗