Presentation on theme: "-Pregnancy test Urine (EVA test) -The Measurement of Urinary 17- Oxosteroids. 376 BCH Miss Tahani Al-Shehri."— Presentation transcript:
-Pregnancy test Urine (EVA test) -The Measurement of Urinary 17- Oxosteroids. 376 BCH Miss Tahani Al-Shehri
Pregnancy test HCG- Human chorionic gonadotropin, Mw 36,700, chemically a glycoprotein, 30% CHO and amino acid Normally person not pregnant has a secretion of this hormones but not detected Function of HCG Stimulate the biosynthesis of ovarian tissue Convert androgen (men) to estrogen (women ) on placenta Maintain pregnancy
Pregnancy test It can give +ve result in these case :- Hyperactivity of pituitary gland Functional abnormalities of placenta. Intrauterine fetal death.
The Measurement of Urinary 17- Oxosteroids. OBJECTIVES To measure the excretion of 17-oxosteroids in a 24- hour collection of urine.
INTRODUCTION AND PRINCIPLE Most of the products and metabolites of the androgen pathways in the adrenal and the testis, are in the form of 17-oxosteroids. The quantity of 17-oxosteroids (17-OS) excreted varies with Age Sex weight. In females, most of the 17-OS are derived from the adrenal gland In the male a considerable percentage (10-20%) is derived from the testis as metabolites of testosterone (not itself a 17-OS). The adrenal cortex and testis are both under the hormonal control of the anterior pituitary. Thus, changes in the 17-OS excretion in urine are found in disease involving the anterior pituitary, adrenal cortex and testis.
INTRODUCTION AND PRINCIPLE Decreased excretion of 17-OS is found when there is hypo-activity of the adrenal cortex, pituitary, or testis. Increased excretion of 17-OS in both sexes is normally associated with increased activity of the adrenal cortex High levels of 17-OS may be found in some tumors of the testis or ovaries. Steroids are normally excreted as water-soluble conjugates, glucuronides, and sulphates, since the steroids themselves have very low solubilities in water.
INTRODUCTION AND PRINCIPLE These conjugates must be hydrolyzed to liberate the free steroid, before extraction from the urine into an organic solvent, usually chloroform or ethylene dichloride. The extract is then washed to remove impurities, which interfere with the colorimetric assay and the oxo-steroids are estimated using Zimmerman's reagent. Zimmerman's reagent is an alkaline solution of n- dinitro-benzene, which slowly forms colored complexes with steroids containing CO.CH 2 groups.