Search Results

You are looking at 1 - 5 of 5 items for

  • Author: J. S. BIGGS x
Clear All Modify Search
Restricted access

J. S. BIGGS

Acid hydrolysis is widely used in the estimation of urinary oestrogens. Its main advantages over enzymic hydrolysis are its speed and simplicity. Its main disadvantage is a loss of 10–20% of oestrone and oestriol, depending on the dilution of the urine. The losses of oestradiol and less stable oestrogen metabolites may be much greater (Brown, 1965).

The conditions for acid hydrolysis must be chosen to produce complete hydrolysis of conjugates with minimal destruction of oestrogens. Boiling under reflux for 1 hr. with 15 vol. of conc. HCl/100 vol. urine has been found to be a satisfactory compromise and has been widely adopted. In laboratory practice this step is inconvenient as well as slow. In routine assays boiling large numbers of urine samples under reflux is dangerous, gives rise to unpleasant smells and uses a good deal of valuable bench space.

Hydrolysis under pressure was described by Frandsen (1963) as a

Restricted access

J. S. BIGGS

Oestriol concentrations in amniotic fluid have been investigated by several workers as a possible means of assessing foeto-placental function (Berman, Kalchman, Chattoraj & Scommegna, 1968; Michie & Livingstone, 1969). Certain basic data are required, however, in working with any biological fluid and although information is available for storage effects on urinary oestriol (Leon, Bulbrook & Greenwood, 1959) more information is needed for amniotic fluid. This paper describes an investigation of the effects of storage at different temperatures, of filtration and of the influence of glucose concentration on amniotic fluid oestriol using a gas-liquid chromatographic (GLC) method.

Amniotic fluid was obtained at surgical induction of labour in patients in the 40th or 41st weeks of normal pregnancy. For the study of storage effects, 450 ml. of amniotic fluid was obtained from one patient and immediately divided into three parts. The first was stored in a stoppered flask at room temperature (22°),

Restricted access

G. J. S. Tan, R. Tweedale and J. S. G. Biggs

The effects of oxytocin on dispersed luteal cells from human corpora lutea of the menstrual cycle were studied. Oxytocin at a concentration of 4 mi.u./ml produced a slight increase in basal progesterone production. However, higher oxytocin concentrations (400 and 800 mi.u./ml) markedly inhibited both basal and human chorionic gonadotrophin-induced progesterone production. These data provide evidence for an effect of oxytocin on the human corpus luteum. In view of the inhibitory action of oxytocin, increased secretion of this hormone may be important in the demise of the corpus luteum at the end of the menstrual cycle.

Restricted access

G. J. S. Tan and J. S. G. Biggs

The effects of prolactin on steroidogenesis were studied in dispersed luteal cells prepared from human corpora lutea of the menstrual cycle. Prolactin, at concentrations of 0·1–1000 ng/ml, had no effect on progesterone production by luteal cells during short-term incubation (3 h). However, in two out of five corpora lutea, higher concentrations of prolactin (100 and 1000 ng/ml) significantly reduced the oestradiol-17β production induced by human chorionic gonadotrophin (hCG; 10 i.u./ml); lower doses of prolactin had little effect. In the remaining corpora lutea, prolactin failed to affect either basal or hCG-induced production of oestradiol-17β. These results are discussed in relation to the mechanism by which prolactin influences human ovarian function.

Restricted access

J. S. BIGGS, A. KLOPPER and G. R. WILSON

SUMMARY

A method is described for estimating oestriol in amniotic fluid. The main steps of the method are acid hydrolysis, chemical purification and methylation, chromatography on alumina columns, acetylation and estimation by gas chromatography. A radioactive internal standard is employed to correct for losses during assay. Data on the reliability of the method are given.