Increasing numbers of women birthing after 34 weeks in our hospital are receiving antenatal corticosteroids before 34 weeks. The long-term implications of this are not currently clear.
No abstract
FOR several years it has been recognised that the yields of oestrogenic material which can be obtained from human pregnancy urine by extraction with immiscible fat-solvents may be considerably increased by preliminary acidification of the urine [Marrian, 1930;1933;Doisy et al., 1930]. Zondek [1934, 1] did, indeed, state that such preliminary treatment was unnecessary to ensure complete extraction of the hormones, but later [1934, 2] revised his opinions as a result of work carried out by Borchardt et al. [1934]. The latter authors were responsible for the first systematic attempt to determine the optimum conditions for the liberation of oestrin from its combined state in human pregnancy urine. They showed that the amount of hormone that could be extracted by prolonged boiling with benzene was greatly increased by acidification of the urine to PH 3 0, and still further increased by the addition of hydrochloric acid to a concentration of 3-6 %.The present authors [1934] developed a colorimetric method, based on the Kober test [1931] for oestrin, for the separate quantitative estimation of oestrone and oestriol in ethereal extracts of human pregnancy urine. This method enabled a more complete study of the factors influencing the hydrolysis by acids of the " oestrin-esters " in urine to be made than would have been possible if only the biological test for oestrin had been available. It was shown that when pregnancy urine was acidified to PH 1-2 and then heated at 1000, there occurred a slow liberation of ether-soluble oestrin from the combined form, which reached a maximum after 16 hours. Heating for longer periods resulted in a decrease in the amount of ether-extractable oestrin, indicating that destruction of the liberated hormone had occurred. By heating the urine acidified to PH 1-2 in an autoclave at 15 lbs. pressure for 2-4 hours, a larger amount of ether-soluble oestrin was liberated than when the urine was heated at 1000. Autoclaving for longer periods destroyed the liberated oestrin. This work clearly showed that, as might be expected, the rate of hydrolysis of the "oestrin esters " in urine is considerably increased by an increase in temperature, and that destruction of the hormone may occur on prolonged heating in an acid aqueous medium.Few attempts have been made to effect liberation of the combined oestrin in urine by means other than that of hydrolysis with acids. Marrian [1933] found that keeping the urine until considerable bacterial decomposition had occurred was extremely effective as a means of liberating the combined oestrin, but that heating to 1000 at an alkaline reaction for short periods was ineffective. Both these findings were confirmed by Cohen and Marrian [1934].For two reasons it was clearly necessary to conduct a more detailed investigation of the factors involved in the hydrolysis of the " oestrin esters " in human pregnancy urine. In the first place, estimation of the oestrin content of urine ( 1577 )
IT is well known that both oestrone and oestriol when warmed with concentrated sulphuric acid give a green-fluorescing orange-coloured solution, thus resembling sterols and the bile acids. The colours given by the latter compounds are discharged by dilution with water, but as Kober [1931] showed, the oestrin colour on dilution with water is changed to a clear red, the green fluorescence being retained. His evidence suggested that this test was highly specific for oestrin. Kober also showed that the addition of phenol to the sulphuric acid eliminated the green fluorescence from, and intensified the red colour of, the finally diluted solution. He stated that under the conditions of his procedure, the intensity of the red colour bore a direct but not linear relationship to the amount of oestrin, and he claimed that by the use of this test it was possible to assay the oestrin content of impure extracts. The obvious desirability of a rapid chemical method for the quantitative determination of the oestrin content of human urines led the authors to investigate the value of the Kober test for such a purpose. EXPERIMENTAL. Modification8 introduced into the Kober technique. Kober suggested the following technique. About 5y of crystalline hormone (presumably oestrone) are heated to 100' for 2 minutes with 0-2 ml. of a mixture of equal parts2 of concentrated sulphuric acid and phenolsulphonic acid (o-+p-). The mixture is then cooled, and after the addition of 02 ml. of water is heated momentarily to boiling. Finally the solution is made up to 1 ml. with water and immediately cooled. After standing in the cold for 5-10 minutes, the colour is compared with that of a standard solution of acid cresol red (10 mg. in 100 ml.) in a colorimeter. Kober states that 5y of the hormone give a colour of the same intensitv as that of 25y of cresol red. Since the greater part of the oestrogenic material in human pregnancy urine is oestriol, most of the earlier experiments described here were carried out on l The names oestrone and oestriol are here used to designate the two oestrogenic substances present in human pregnancy urine which have been known previously as ketohydroxyoestrin and trihydroxyoestrin, theelin and theelol, etc. This new system of nomenclature has been approved by the majority of the interested English workers [Nature, 1933, 132, 205]. The name oestrin is used where it is desired to refer to the oestrogenic material in urine without specifying its exact chemical nature. 2 It is assumed here that Kober used equimolecular parts of sulphuric and phenolsulphonic acids.
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