Bruce Hobson

A RAPID LUTEINIZING HORMONE RADIOIMMUNOASSAY FOR THE PREDICTION OF OVULATION

A rapid luteinizing hormone (LH) radioimmunoassay (total time 4 h) has been developed and used to measure the preovulatory LH surge in 22 patients. Ovulation, assessed by laparoscopy or mini laparotomy, did not occur until at least 32 h after the start of the LH surge. This rapid LH radioimmunoassay provides a simple method of predicting ovulation for the correct timing of oocyte collection or artificial insemination.

HORMONAL PATTERNS IN CONCEPTUAL CYCLES AND EARLY PREGNANCY

Androstenedione, testosterone, progesterone and human chorionic gonadotrophin (HCG) in plasma and total oestrogens, luteinizing hormone (LH) and HCG in urine were measured in five women during conceptual cycles and in early pregnancy. There were increased levels in plasma and urine of all the hormones measured between 12 to 48 days after ovulation except progesterone. The concentration of this hormone in plasma decreased during this time. The possible sources of these hormones in early pregnancy are discussed.

TWO CASES OF HYDATIDIFORM DEGENERATION OF THE PLACENTA WITH FETAL ABNORMALITY AND TRIPLOID CHROMOSOME CONSTITUTION

Triploidy is a fairly common cause of abortion in the first trimester. It is uncommon for such a pregnancy to continue beyond this time. Two cases of triploidy with hydatidiform degeneration of the placenta and fetal abnormality where the pregnancies continued to 29 and 25 weeks are reported. The concentration of HCG in these abnormal placentae was high and the patients excreted larger than normal amounts of it. Severe pre‐eclampsia and anaemia occurred. Other cases in the literature are reviewed.

Chromatographic Studies on a Chorionic Gonadotropic Activity in the Placenta of the Rat, Mouse and Hamsterx

Acetone-ether extracts of rat, mouse and hamster placentae were fractionated by molecular sieve chromatography on Sephadex G-200. The fractions were tested for immunoreactivity in human chorionic gonadotropin (hCG), hCG-beta-subunit and alpha-subunit radio-immunoassay systems. The elution profiles were compared with those of similar chromatographic studies of a human placental extract and of purified preparations of hCG and its subunits. The results indicate that rodent placentae have a chorionic gonadotropin and that this hormone in the rat, mouse and hamster is structurally similar to hCG with its alpha- and beta-subunits. Extracts of rat and hamster placentae had a gonadotropic activity similar in concentration to that found in normal human placentae at term. Until now, it has been difficult to find an animal model for studying how the production of chorionic gonadotropin is regulated. Our results suggest that rodents may be suitable for such an investigation.

ROUTINE PREGNANCY DIAGNOSIS AND QUANTITATIVE ESTIMATION OF CHORIONIC GONADOTROPHIN USING FEMALE XENOPUS LAEVIS

THE Edinburgh University Pregnancy Diagnosis Laboratory was started in 1930 by Professor Crew; 840 requests for pregnancy tests were received in the first year. From this modest beginning has grown an organization dealing annually with more than 21,000 tests. During the first 7 years the AschheimZondek and Friedman tests were used exclusively. In 1937 Crew, impressed by favourable reports of other workers-Bellerby (1934), Shapiro and Zwarenstein (1934)--compared Xenopus laevis as a test animal with the mouse and rabbit, confirming (Crew, 1939) the good results obtained by Landgrebe (1939). Crew proposed that the toad test be known as the Hogben test after Professor Hogben who originally showed that Xenopus would respond to injected gonadotrophin by ovulation and oviposition. As Xenopus was unquestionably reliable it was decided gradually to replace the mouse and rabbit with the toad. Outbreak of hostilities prevented this and not until 1948 was the new laboratory equipped to carry out the Hogben test. In spite of numerous publications on Xenopus laevis very few workers are able to maintain the toad in good condition and consistently get accurate results. As there is no single paper containing up-to-date information on the use of Xenopus, we think the experience gained from maintaining a stock of 6,000 toads and performing more than 100,000 pregnancy tests in the past 5

DYSGERMINOMA OF THE OVARY AND GONADOTROPHIN EXCRETION

years should be available to workers who wish to make use of this animal. MATERIALS AND METHODS

THE EXCRETION OF CHORIONIC GONADOTROPHIN IN NORMAL PREGNANCY AND IN WOMEN WITH HYDATIDIFORM MOLE

DYSCERMINOMA of the ovary is a comparatively rare tumour which occurs characteristically in young women and is frequently associated with congenital abnormalities of sex differentiation (Saxen and Hakama, 1964; Meyer, 1931). Like the seminoma i n the male, the dysgerminoma is thought to arise from primitive mesenchymal cells which fail to develop beyond their embryonic state. Dysgerminomas have not generally been considered to be associated with abnormal hormone production except when they co-existed with choriocarcinoma. Dixon and Moore (1953) found that 14 out of 3 15 seminomas contained either teratomatous or choriocarcinomatous elements. Conversely cases have been described of dysgerminomas in association with choriocarcinoma (Santesson, 1947; Liebert and Stent, 1960; Pedowitz et a/., 1955; Neigus, 1955). In some of these cases large quantities of gonadotrophin have been excreted and this has resulted in a positive “pregnancy test”. The association of a positive pregnancy test with a “pure” dysgerminoma has only been reported rarely (Black-Schaffer and Kambe, 1952; Hain, 1949; Burge, 1949; Moreton and Desjardins, 1947; Schomaker et al., 1947). Neigus (1 955) concluded that the dysgerminoma cell was incapable of producing hormones and that the source of the gonadotrophin must either ke the pituitary or teratomatous elements which had been overlooked. This communication describes a dysgerminoma of the ovary occurring in a girl of sixteen. Extensive pathological examination of the tumour was carried out as well as pre-operative

FURTHER OBSERVATIONS ON THE EXCRETION OF CHORIONIC GONADOTROPHIN BY WOMEN WITH HYDATIDIFORM MOLE

INTRODUCTION IT has been shown that women with hydatidiform moles excrete abnormally large amounts of chorionic gonadotrophin (C.G.) (Zondek, 1929; Aschheim, 1930). For this reason dilution tests have been used to distinguish a pregnancy from a mole or chorionepithelioma. Zondek (193 I) suggested that a level of 50,000 “mouse units” or more of gonadotrophin per litre of urine, an amount normally sufficient to produce a positive reaction when injected in a dilution of 1 in 100, indicated the presence of either a mole or chorionepithelioma. Despite evidence to the contrary, there is still a general impression that urines from patients with such abnormalities of the chorioplacental system will always give a positive “pregnancy test” in a dilution of 1 in 100, a view held by some clinicians and pathologists. It is now well established that not only may the level of C.G. excreted during a normal pregnancy be more than 50,000 mouse units but also weakly positive and even negative biological reactions may be obtained with urine concentrates from molar and epithelioma cases (Hobson, 1952). Although information is available about C.G. excretion in molar and epithelioma cases, few of the data are comparable, most reports emphasizing clinical and pathological aspects of the cases. Where quantitative assays have been made the results are expressed in “animal units”. The only comprehensive investigation is that of Hamburger (1944), one of the few workers to express his findings in International Units, despite the availability of an International Standard Preparation since 1939. That biological tests are only occasionally of diagnostic value is perhaps due to the lack of comparable information about C.G. excretion in hydatidiform mole, chorionepithelioma and pregnancy. This lack of knowledge is understandable when the infrequent occurrence of moles, variously estimated as 1 in 2,500 pregnancies (Novak, 1952), 1 in 2,334 (Sherman, 1935), or 1 in 1,300 (Cosgrove, 1938), and the even rarer occurrence of chorionepithelioma is remembered. Because of the difficulties of obtaining such material few workers have been able to assay the C.G. in body fluids from a large number of cases. This department has such facilities, for in addition to doing many thousands of “pregnancy” tests we also do about 1,000 semi-quantitative estimations annually. Semi-quantitative estimations or dilution tests are usually asked for when the presence of a mole is suspected. The results of these tests, together with the case history of the patient, may be used by the clinician in an attempt to differentiate between doubtful pregnancy and a possible pathological condition. The purpose of the following investigation, based largely upon material obtained during routine testing, has been to provide precise information regarding urinary C.G. excretion from a large number of patients with hydatidiform mole, and to compare C.G. levels with those obtaining at all stages of pregnancy.

PREGNANCY DIAGNOSIS USING THE PREGNOSTICON HAEMAGGLUTINATION INHIBITION TEST

THE excretion of chorionic gonadotrophin (C.G.) during normal and molar pregnancy was investigated recently (Hobson, 1955). Information about the excretion of C.G. by women is limited and in view of the continued use of biological tests as aids to the diagnosis of hydatidiform mole, it was felt that a further contribution to the subject would be valuable. Data have been collected about the duration of molar pregnancies, and the ovarian changes associated with them. Some information has been obtained about the concentration of C.G. in hydatidiform moles.

THE EXCRETION OF CHORIONIC GONADOTROPHIN BY WOMEN WITH CHORIOADENOMA AND CHORIOCARCINOMA

SEVEN years ago the first reports on various new immunological methods for detecting human chorionic gonadotrophin (HCG) in the urine and serum of the pregnant woman appeared (Brody and Carlstrom, 1960; McKean, 1960; Wide and Gemzell, 1960). In 1961 the first commercial immunological test, a two-stage agglutination test, was marketed by the Ortho Pharmaceutical Corporatioil. Since then commercially produced immunological “slide” and “tube” tests have gradually replaced the biological tests for pregnancy (Hobson, 1966). Four years ago, this laboratory investigated six commercially prepared immunological tests for pregnancy, and almost 4,000 urines were tested (Barr, 1963; Hobson, 1963a, b). When the results of these various tests were compared with the clinical diagnosis their accuracy was between 83.0 and 97.4 per cent. Although Pregnosticon was one of the most reliable tests it was 2.0 per cent less accurate than the Hogben test currently in use. The manufacturers of Pregnosticon modified the test system, decreased the sensitivity of the method, and this produced a marked improvement in accuracy and the almost complete elimination of false positive reactions. A further trial in this laboratory with Pregnosticon showed that an accuracy of 99.0 per cent could be achieved. I n August, 1964, the Hogben test was replaced in this laboratory by the haemagglutination inhibition test Pregnosticon and in the last three years more than 66,000 of these immunological tests have been done. This report is concerned with the results of tests done during the two years ending July, 1966.