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Biomedical subjects

J R Swanson

Publications and source records attributed to J R Swanson.

31 records · Page 2Linked to original sources
PubMed1981

Colorimetric method for free fatty acids in serum validated by comparison with gas chromatography.

We compared results by a simplified colorimetric copper-soap method for serum free fatty acids (Clin, Chem. 19: 419, 1973, modified) with those by a gas--liquid chromatographic method. The modified method requires only 100 microliters of sample, its standard curve is linear from 0.1 to 4.0 mmol/L (reference interval for adults: 0.2 to 0.8 mmol/L), and it is suitable for use with newborns. Comparison with the gas--liquid chromatographic method (n = 51) over a wide concentration range gave a correlation coefficient of 0.989. Between-run CVs varied from 4 to 10%, analytical recoveries from 97 to 104%. Triglycerides, salicylates, hemoglobin, and anticoagulants (except citrate) do not interfere, but bilirubin and phospholipids give small positive interferences. The colorimetric assay is used, along with other routine tests, to assess lipid status and estimate kernicterus risk in neonatal intensive-care patients receiving lipid nutrition parenterally.

Adult↗
PubMed1980

Effect of dimethyl sulfoxide on serum osmolality.

Consecutive values for serum osmolality measured in a patient exceeded (548 mOsm) the previously reported pathological range and, indeed, exceeded that generally considered compatible with life. The patient was receiving large amounts of intravenous dimethyl sulfoxide as part of an experimental protocol to control intracranial pressure resulting from trauma. This compound increases serum osmolality linearly with respect to concentration over the range considered therapeutically significant, 0 to 10 mL/L. The mechanism of its effect on osmolality readings is discussed. It does not interfere with any values for those routine measurements made by continuous-flow (SMAC, Technicon).

Adult↗
PubMed1977

Ultraviolet spectrometry of serum triglycerides by a totally enzymic method adapted to a centrifugal analyzer.

We described a micromethod for determining serum triglycerides (triacylglycerols) with the centrifugal analyzer. This technique is based on the procedure of Bublitz and Kennedy [J. Biol. Chem. 211, 951 (1954)]. The enzymic hydrolysis requires 10 min at 30 degrees C. Twenty-six serum triglyceride assays can be done in about 30 min. Concentration and absorbance are linearly related up to 5.0 mmol/liter, but higher concentrations can be assayed by changing conditions slightly. Day-to-day reproducibility for the method was satisfactory (CV, 2.7 to 8.4%). Comparison of this method and two other methods for triglycerides, the automated Hantzsch condensation method and a commercial enzymic method (Calbiochem), gave correlation coefficients of 0.976 and 0.990, respectively. Results are unaffected by the presence of endogenous serum ADP, pyruvic acid, phosphatases, or ATPase.

Centrifugation↗
PubMed1976

Serum creatine phosphokinase in normal newborns.

Serum creatine phosphokinase (CPK) activity in 70 normal newborns was found to be significantly higher than the normal values found in adults or older children, and in some cases reached a level up to 10 times normal. It declined to near normal activity during the first 4 days and to normal level of activity by age 6-10 weeks. No clear correlation between birth trauma and increase in serum CPK activity was shown. CPK activity in cord blood was lower than in venous and capillary blood. Because of the increased CPK activity found in normal newborns, screening for Duchenne-type muscular dystrophy should be postponed for a few weeks after delivery.

Age Factors↗
PubMed1975

A prospective evaluation of the lecithin/sphingomyelin ratio and the rapid surfactant test in relation to fetal pulmonary maturity.

Fetal lung maturity was correlated to the results of amniatic fluid analysis in 578 samples obtained over a 2 1/2 year interval. Lecithin/sphingomyelin (L/S) ratios obtained by planimetric and densitometric methods were compared to the rapid surfactant test (RST). Both the planimetric L/S ratio (P L/S) and the densitometric L/S ratio (D L/S) correlated positively in a highly significant fashion with the RST. Both RST and D L/S were reliable in predicting fetal lung maturity (99 to 100 per cent, respectively). The RST was the most reliable test for fetal lung immaturity (69 per cent). Therefore, this series indicates that the RST could be used as a primary method with the D L/S being useful as an additional indicator of fetal maturity when the RST was intermediate, or the sample contaminated with blood and/or meconium.

Amniotic Fluid↗
PubMed1975

Serum biochemical and electrophoretic values from four deer species and from pronghorn antelope.

Serums from 4 species of deer and 1 species of antelope were analyzed for various components in order to define an animal disease model for sickle cell disease in people. Animal species included black-tailed deer (Odocoileus hemionus columbianus), mule deer (Odocoileus hemionus), sika deer (Cervus nippon nippon), fallow deer (Dama dama), and pronghorn antelope (Antilocapra americana). The mean serum values for total bilirubin, total protein, albumin, creatinine, urea nitrogen, and electrolytes were similar in all species and were in the normal range for human beings. Cholesterol and uric acid values for all animals were lower than those for people. Alkaline phosphatase values in the 4 cervid species were higher than in the pronghorn antelope. Values for glutamic oxalacetic transaminase were lower in the cervids than in the pronghorn antelope. Lactic dehydrogenase values were similar in the 5 species. High activities for glutamic oxalacetic transaminase and lactic dehydrogenase in the 5 species probably related to muscle mass and great muscular activity.

Alkaline Phosphatase↗
PubMedDate not supplied

Early CK-MB elevations predict ischemic events in stable chest pain patients.

OBJECTIVE: To demonstrate that creatine kinase-MB fraction (CK-MB) elevations within three hours of presentation in the emergency department (ED) are associated with subsequent ischemic events in clinically stable chest pain patients. METHODS: Prospective cohort study at two university- affiliated teaching hospitals. Participants were consenting ED chest pain patients 25 years old or older without evidence of rhythm or hemodynamic instability (n = 449). Exclusions included ST-segment elevation > or = 0.1 mV in > or = 2 electrocardiogram leads, chest wall trauma, abnormal x-ray studies, and incomplete data collection. Measurements included presenting and three-hour CK-MB levels, presenting ECG, initial clinical impression of coronary care unit need, and clinical follow up. Monitored adverse events included myocardial ischemia necessitating coronary angioplasty or cardiac bypass surgery, recurrent in-hospital myocardial infarction, bradycardia requiring pacing, emergent cardioversion, cardiogenic shock, ventricular fibrillation, and death. RESULTS: Overall, nine (2%) of 449 patients experienced an ischemic event within the first 48 hours. All nine patients required either coronary angioplasty or bypass surgery. Four (44%) of the nine patients with 48-hour ischemic events had elevated CK-MB levels. Of 23 patients who had complications within one week of ED presentation, seven (30%) had elevated ED CK-MB levels. An elevated CK-MB level was associated with an ischemic event both within 48 hours (risk ratio 9.5; 95% CI 2.7-33.7) and within one week (risk ration 5.2; 95% CI 2.3-11.7). CONCLUSIONS: An elevated CK-MB level within three hours of ED presentation is associated with a subsequent ischemic event in the clinically stable chest pain patient without ST-segment elevation. However, the ED CK-MB identifies only a minority or otherwise low-risk patients who develop ischemic events; other markers for diagnosing myocardial ischemia in the ED are needed.

Adult↗