The genetics of position-effect variegation modifying loci in Drosophila melanogaster

The dose dependent effects of position-effect variegation (PEV) modifying genes were studied in chromosome arms 2L, 2R and 3R. Four groups of PEV modifying genes can be distinguished: haplo-abnormal suppressor and enhancer loci with or without a triplo-effect. Using duplications four triplo-abnormal suppressor and four triplo-abnormal enhancer functions were localized. In two cases we proved that these functions correspond to a converse haplo-abnormal one. Altogether 43 modifier loci were identified. Most of these loci proved not to display significant triplo-effects (35). The group of haplo-abnormal loci with a triplo-effect may represent genes which play an important role in heterochromatin packaging.

A sensitive direct enzyme immunoassay for cortisol in plasma and saliva

A sensitive enzyme immunoassay for cortisol in plasma and saliva without extraction has been developed. An antibody was raised in rabbits against cortisol-3-CMO-BSA and compared with anti-cortisol-21-HS-HSA. The enzyme label was a covalently linked cortisol-horseradish peroxidase conjugate. Solvent extraction was avoided by use of heat denaturation of transcortin and dilution of plasma 1:300. This assay had a limit of detection of 3 fmol/tube and satisfied the standard criteria of accuracy and precision. The test requires only a simple photometer. The normal values of cortisol in plasma and saliva before and after ACTH, dexamethasone or metyrapone application were determined. Saliva, being easily collected by a noninvasive, stress-free technique is an alternative to plasma. The cortisol concentrations were significantly increased in plasma and saliva of patients with Cushing's syndrome and decreased in patients with Addison's disease.

A simple solid phase enzyme immunoassay for aldosterone in plasma and saliva

A sensitive, solid phase enzyme immunoassay for the determination of aldosterone in plasma and saliva has been developed. For this purpose anti-aldosterone coated tubes were used. The enzyme marker was a covalently linked aldosterone/horseradish peroxidase conjugate. The assay had a limit of detection of 5 pg/assay tube. The test requires neither centrifuge nor gamma or beta counter, but only a simple photometer. The free/bound separation is based on the solid phase technique with a simple washing step. The normal values for aldosterone in plasma and saliva before and after ACTH application were determined. Saliva, being easily collected by a non-invasive, stress-free technique, is an alternative to plasma. The aldosterone levels in patients with Conn's syndrome were significantly increased in plasma and also in saliva.

Enzyme immunoassay of 17-hydroxyprogesterone in plasma, microfilter paper blood and saliva of newborns, children and patients with congenital adrenal hyperplasia

An enzyme immunoassay for the measurement of 17-hydroxyprogesterone (OHP) is described. The antigens, OHP-3-CMO-BSA and 11-deoxycortisol-21-hemisuccinate-BSA have been used to produce antisera in rabbits. The enzyme marker was horseradish peroxidase. Bound/free separation was achieved by the double antibody/polyethylene glycol method. The method was used for plasma samples, capillary blood dried on paper disc and for saliva. The normal values for OHP in newborns and children were determined. This method makes possible a selected screening program for congenital adrenal hyperplasia in the newborns.