Mathematical models for the processing of data from binding radioassays; transformations and approximations

Ohne Zusammenfassung

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Mathematical models for the processing of data from binding radioassays; transformations and approximations

     

Eine modellnahe Ausgleichsfunktion für die radiometrische Insulinbestimmung durch Rücktitration freier Antikörper

In the radiometric estimation of insulin with ¹²⁵I insulin radioreagent first an equilibrium is established between insulin antibodies and insulin of the test samples. Thereafter ¹²⁵I insulin binds to free antibodies in a kinetically controlled reaction. The bound activity may be fitted to the equations of this model without contradictions. But they were proved to be not useful for practical data evaluation. A modelnear equations is given, the three parameter of which may be estimated by iterative nonlinear regression analysis without complications.     

Radioimmltnoassay Determinations of p-Hydroxiphenformin and of Apparent Phenformin in Human Plasma or Serum

Abstract

Sensitive radioimmunoassay procedures are described for measuring p-hydroxyphenformin and apparent phenformin in human plasma or serum. The p-hydroxyphenformin procedure, which requires advance phenformin analysis, offers excellent accuracy. The determinations of apparent phenformin are influenced by the phenformin and p-hydroxyphenformin contents of the samples. Over a period of four months, the methods showed a precision associated with relative standard deviations of 12% for apparent phenformin and 13% for p-hydroxyphenformin.     

Radioimmunoassay of Triazolam

Abstract

Two radioimmunoassay (RIA) assay methods (I, II) have been developed for triazolam (T, U-33,030) in serum and plasma. The parameters of equilibration time, serum blank, antibody specificity, extraction efficiency, and drug-binding to glass were studied. Of the various triazolam analogs tested for cross reactivity, only the hydroxy metabolites interfered significantly. At the levels normally found in plasma or serum, a background blank was encountered from constituents such as fatty acids, lysolecithin, lecithin, and cholesterol. However, serum or plasma samples could be analyzed with (I) by constructing standard curves in which blank serum from the same subject was used. An alternate method (II) was found which simultaneously extracted and precipitated the interferences. Both methods could be employed for analysis of plasma or serum samples. However, II detects T metabolites less efficiently than I. The within day and between day coefficients of variation for method I were found to be 5.7% and 3.9% respectively at the 8 ng/ml level. Method I is suitable for measuring large numbers of samples where blank subject serum can be obtained and where detection of T metabolites in addition to T would not present a problem.     

Problems in automation of serum cortisol radioimmunoassay

Conclusions A fully automatable method for the cortisol RIA has been developed which requires no prior extraction using an antibody in an assay-system at pH 4.0. The use of ¹²⁵I-labelled tracer has abolished the need for scintillation fluid and its attendant quench and radioactive waste problems. The capacity of this method is very high because of the automation. The first clinlinal results have shown that this method is reliable, reproducible and gives comparable values with those from the ³H-assay. The fact that no centrifugation is needed, that 3 samples are counted simultaneously and that the capacity is over 1000 tubes per working day makes this method attractive to a routine laboratory with high through put of serum cortisol samples. From the theoretical stand point, this method is adaptable to almost any commercially available automatlin or semi-automatlin assay system.Supported by the Deutsche Forschungsgemeinschaft (SFB 51) and Bundesministerium für Forschung und Technologie.     

Radioimmunoassay of Plasma Dehydroepiandrosterone

Abstract

This report describes a radioimmunoassoy method for measurement of unconjugated dehydroepiandrosterone (DHEA) in plasma. Utilizing a highly specific DHEA antiserum combined with a one step celite microcolumn chromatographic system, we have measured this steroid accurately in small aliquots of plasma from both male and female subjects. The mean value for both male and nonpregnant females was 2.7 ng/ml. The values for third trimester pregnant females ranged from 0.5 ng/ml to 12.5 ng/ml. When plasma DHEA was measured over a complete menstrual cycle, the levels were higher during the early and latter parts of that cycle than at midcycle. One male subiect, studied over a 24 hour period for diurnal variation, demonstrated highest DHEA levels during the early morning.     

小剂量SmCl3对大鼠甲状腺结构和功能的影响

应用放射免疫测定研究了大白鼠经腹腔注射，灌胃和静脉注射小剂量ＳｍＣｌ３，０．０５ｍｇ／ｋｇ后，血清中甲状腺激素和促甲状腺激素浓度的变化；并在电镜观察了甲状腺和腺垂体促甲状腺激素细胞的超微结构。