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Biomedical subjects

P Sandel

Publications and source records attributed to P Sandel.

At least 19 recordsLinked to original sources
PubMed1981

Cluster-oriented discriminant analysis; taxonomic classification of the thyroid function.

A computer assisted procedure for the diagnosis of thyroid diseases, based on seven clinical chemical parameters, is proposed. The population studied consisted of 592 consecutive outpatients with a tentative diagnosis of thyroid disease. Thyroxine, triiodothyronine, T3 uptake test, TSH before and after TRH application, its difference and thyroxine binding globulin have been determined. The patients were clinically examined and in each case a Tc-scintigram was obtained. As a first step, 20 biochemical patterns were defined by cluster analysis (pattern cognition). T check how good in grouping process was, linear discriminant analysis was applied after which the reclassification rates were very satisfactory. The clusters found corresponded well to the pathophysiological situations with some exceptions. As a second step, patients were assigned to these patterns by use of the derived discriminant functions (pattern recognition). The proposed method seems to have some advantages over other diagnostic models published hitherto.

Alpha-Globulins↗
PubMed1978

[Radioimmunoassay of beta2-microglobulin in monoclonal gammopathies (author's transl)].

Serum concentration of beta2m were measured by radioimmunoassay in 78 healthy subjects and 80 patients with monoclonal gammopathies. The beta2m levels of normal sera were normally distributed with a mean concentration of 1610 microgram/l. 77% of values were between 1200 and 2000 microgram/l. The serum beta2m levels of patients with monoclonal gammopathies were significantly higher than those of the healthy subjects, but there was no significant difference when comparing the Ig class or the light-chain type. Urinary beta2m excretion of patients with monoclonal gammopathies (3--5400 microgram/l) were slightly higher than normal (15--113 microgram/l). Serum beta2m levels did not correlate with the serum levels of monoclonal immunoglobulins. This supports the hypothesis of the mutual independence of beta2m and Ig production.

Adolescent↗
PubMed1978

Performance of various mathematical methods for computer-aided processing of radioimmunoassay results.

Interpolation and regression methods are available for computer aided determination of radioimmunological end results. We compared the performance of 6 algorithms (weighted and unweighted linear logit log regression; quadratic logit log regression, smoothing spline interpolation with a large and small smoothing factor, respectively, and polygonal interpolation and the manual curve fitting on the basis of three radioimmunoassays with different reference curve characteristics (digoxin, estriol, human chorionic somatomammotrophin (HCS)). Great store was set by the accuracy of the approximation at the intermediate points on the curve, i.e. those points that lie midway between two standard concentrations. These concentrations were obtained by weighing and inserted as unknown samples. In the case of digoxin and estriol the polygonal interpolation provided the best results, while the weighted logit log regression proved superior in the case of HCS.

Computers↗
PubMed1978

[Studies of activity kinetic of isoenzyme CK-MB in serum after myocardial infarction (author's transl)].

We investigated the activity kinetics of CK-total and CK-MB in 83 patients with proven myocardial infarctions. Serial serum samples were taken at intervals of 2--6 h. The activity of isoenzym CK-MB was determined by means of the immunological inhibition method. CK-MB activity was determined in all patients. The mean peak activity of CK-MB was 65 U/l (range: 9-241 U/l). At the time of peak CK-MB activity the mean percentage CK-MB activity was 13.2% (range: 3.4--21.7%). The CK-MB activity reached its peak at 17.4 h (range: 3.0--32.5 h) after the onset of retrosternal pain. This is 1.4 h after peak CK-total activity. The mean disappearance rate constant for CK-MB (n = 31) was found to be 9.3 X 10(-4) U/min with a large individual variation. This value corresponds to a half life of 12.5 h (CK-total: 15.5 h). The determination of CK-MB activity is therefore only of diagnostic significance within 48 h of possible myocardial occurrence. Moreover, isoenzyme CK-MB is not found exclusively in myocardium. For this reason it is better to use the percentage CK-MB activity in the differential diagnosis of myocardial infarction. With 80% of the patients this value is greater than 6% within 36 h of proven myocardial infarction.

Circadian Rhythm↗
PubMed1977

[Effect of total fasting on serum protein concentrations (author's transl)].

During a period of total fasting restricted to three weeks, haptoglobin, transferrin and beta1A-globin showed a marked, continuous decline. The complement was finally distinctly below the reference range. Macroglobulins and coeruloplasmin rised until the tenth day and decreased thereafter. IgG globulin remained essentially unchanged while immunoglobulins gammaA and gammaM showed an increase. On account of the considerable fluctuations observed in the protein fractions fasting in this form at least beyond a period of 21 days does not seem justified.

Blood Proteins↗
PubMed1975

[A prognostic index in acute myocardial infarction: discrimination analysis of clinical parameters on admission to hospital (author's transl)].

In 301 patients admitted to an intensive-care unit because of acute myocardial infarction a prognostic analysis was undertaken, based on 21 parameters (history, condition on admission, laboratory results) and related to ultimate outcome. Although some parameters were singly of prognostic value, discrimination analysis markedly improved predictive value. A prognostic index was constructed from seven easily available parameters: age, pulmonary congestion, leucocytosis, peripheral vasoconstriction, systolic blood pressure, site of infarct and hypertension. For those in a low-risk class (index less than 60, death-rate up to 5%), duration of stay in the intensive-care unit may be shortened and rehabilitation measures accelerated. Those at moderate risk (index 60-90, death-rate up to 25%) require careful monitoring. The highest risk classes (index 90-120, death-rate up to 90%; and index more than 120, death-rate more than 90%) require specially intensive and long-term monitoring, and various procedures for assisted circulation and possible cardiacsurgical intervention should be considered from the outset.

Acute Disease↗