Multielement assays of bovine tissue specimens by inductively coupled argon plasma emission spectroscopy.

Inductively coupled argon plasma spectroscopy was used to generate multielement profiles of bovine serum (n = 607), liver (n = 229), and kidney (n = 90) samples submitted to the Animal Health Diagnostic Laboratory at Michigan State University, East Lansing. The presented frequency distribution histograms of element concentrations in the different samples provided a data base for diagnostic interpretations and illustrated some of the advantages, as well as limitations, of inductively coupled argon plasma for this purpose.

The effect of a phenylalanine and tyrosine restricted diet on elemental balance studies and plasma aminograms of patients with disseminated malignant melanoma.

Previous studies indicate dietary phenylalanine and tyrosine restriction may be of value in managing advanced cancer patients. To further evaluate this approach, we performed a 60-day study in which four patients with advanced malignant melanoma received formula diets via nasogastric tube containing only 8 mg total phenylalanine and tyrosine per kg lean body mass per day. Two of three patients completing elemental balance studies were in negative nitrogen, potassium, and phosphorus balance, suggesting an essential nutrient deficiency. Three patients tolerated the diet well, but one was non-compliant. Although no serious toxicity developed, serum albumin, total iron binding capacity and cholesterol significantly decreased (p less than 0.01) in the three complaint patients. Fasting plasma phenylalanine and tyrosine values did not significantly change during the study, but two-hour postprandial plasma phenylalanine and tyrosine concentrations fell below normal and were significantly lower than preprandial levels (p less than 0.01). There were no tumor responses.

Platelet X-ray microanalysis in patients with chronic renal failure.

The platelet element content was determined by semiquantitative X-ray microanalysis in 6 patients with chronic renal failure. The patients showed a different degree of thrombocytopathy expressed by impaired adhesiveness, epinephrine-induced aggregation and platelet factor 3 availability. The microanalysis indicated significantly increased quantities of phosphorus and copper in patients' platelets. Sodium and zinc showed a decrease in about half of the patients, whereas iron was significantly increased in at least 50% of the patients. Magnesium and potassium did not show any difference from the control. The results of sulfur, chlorine and calcium did not reveal a consistent pattern.

Using multivariate analysis on multielemental data.

In the search for correlation between elements or among the analyzed samples, much time and effort can be devoted to the examination of multielemental data when the elements are taken two at a time, especially when the number of analyzed elements is relatively large. By representing the samples as points in an n-dimensional space, in which the coordinates are proportional to the elemental content, an overall view of all the available information may be obtained by visualization of the interrelationships among the points through several of the multivariate analysis methods that have been described. Such visualization is a useful step in the classification of samples into groups, particularly so when no a priori group criteria existed. The true significance of the grouping often becomes evident when other known information is superimposed on the multielemental analysis plots. Indeed, though it is not an essential part of the evaluation process, the importance of visualization of multiparameter data has been stressed most strongly(10), because in this way, the area for further intensive statistical analysis can be clearly demarcated.

Altered serum element concentrations due to laboratory usage of Vacutainer tubes.

Aliquots of a pooled serum sample (bovine) were agitated in Vacutainer tubes (serum or clot tubes) for 0, 2, 8 and 32 hr to determine if Vacutainer tubes had any effect on serum trace element concentrations. The sera were analyzed for Ca, Cu, Fe, Mg, Na and Zn by the inductively coupled argon plasma emission spectrometer. The Zn concentration in sera was significantly increased over time, and the Cu and Fe concentrations were significantly decreased. Most of these artifacts became apparent within the first 2 hrs of exposure to the Vacutainer tubes. Changes in Cu, Mg and Na concentrations were not detected.