V. Hingorani

Phase I clinical trials with three formulations of anti-human chorionic gonadotropin vaccine

Comparative phase I clinical trials were carried out in 5 centres with three formulations of beta-hCG-based vaccines inducing antibodies against human chorionic gonadotropin. The objectives of these trials were to determine their relative immunogenicity, duration, reversibility and safety. A total of 116 tubal ligated women volunteers were enrolled in the study and 101 subjects were followed-up for one year or more until the antibody titres declined to near zero levels. Every woman receiving the vaccine produced anti-hCG and anti-tetanus antibodies. Clinical examination carried out at intervals of 4-6 weeks revealed no abnormality. No serious side effects or adverse reactions were reported with any of the formulations during primary immunization with three monthly injections of the vaccine. Eleven women, however, demonstrated hypersensitivity to test dose at the time of the booster injection. The reaction was to tetanus toxoid; gonadotropin subunits conjugated to another carrier did not evoke any such reaction. Progesterone in bleeds taken at midluteal phase, as well as complete progesterone and estradiol done in two immunized women, indicated normal ovulatory cycles. Immunization with these formulations had no significant effect on haematological, clinical chemistry and other metabolic parameters. In summary, the results indicate that none of the three beta-hCG-based contraceptive vaccines had any adverse effects clinically, on endocrine status and metabolic parameters. Formulations A and B induced comparatively higher anti-hCG titres than M. Thus, further work can be undertaken to study the efficacy of these vaccines in humans for preventing pregnancy.

Analysis of menstrual records of women immunized with anti-hcg vaccines inducing antibodies partially cross-reactive with hLH

Menstrual data of 13 control subjects and 88 subjects immunized with three beta-hCG-based vaccine formulations were analysed. Immunization did not change the menstrual regularity; bleeding days were normal (3-7 days) and 89% of the menstrual cycles were within the normal range of 22-35 days. Irregular (short or long) cycles were observed in both immunized and control groups. These were, however, unrelated to prevailing anti-hCG antibody titres or to cross-reactivity of antibodies with hLH.

Long-term contraception by steroid-releasing implants. II A preliminary report on long-term contraception by a single silastic implant containing norethindrone acetate (ENTA) in women

n A preliminary report on the long-term contraceptive effectiveness and acceptability of a single subdermal silastic implant containing norethindrone acetate (ENTA) is presented. The 4 types of implants used varied in length, wall thickness, and amount of ENTA; implant A contained 20-25 mg ENTA, implant B contained 30-35 mg ENTA, implant C contained 45-50 mg ENTA as was longer than all the other implants, and implant D contained 40 mg ENTA and had a greater wall thickness than all the other implants. 213 women volunteers received a single implant and were followed for a total of 909 cycles. 2 of 13 women receiving implant A, 2 of 39 women receiving implant B, 3 of 76 women receiving implant C, and none of the 85 women receiving implant D became pregnant. Implant D had the longest expected life-span (10 months). Menstrual irregularities were fewest with implants A (23%) and D (20%), and greatest with implant C (42%). there were no complaints of nausea, insomnia, tender breasts, or loss of libido. 4 patients with implant B and 6 patients with implant C had the capsules removed for medical reasons. More detailed studies of implant D are in progress.n

Discriminatory effect of anti-Pr-β-hCG-TT antibodies on the neutralization of the biological activity of placental and pituitary gonadotropins

n In 2 test systems, serum from monkeys and human subjects immunized with an anti-human chorionic gonadotropin (hCG) vaccine, Pr-beta-hCG-TT, were analyzed for their capacities to neutralize hCG/luteinizing hormone (LH)-induced biological effects. hCG-induced ovulation was completely blocked by the monkey antiserum in mice, but the same amount of antiserum, and even 2-fold greater concentrations, did not reduce the number of ovulating animals when primed with ovine LH. Competency of both the immunized monkey and human sera to neutralize the hCG-induced testosterone production in Leydig cells was shown. All monkey and 7/12 human sera did not interfere with the human LH action on Leydig cells. 5 human sera, however, showed varying degrees of inhibition of human LH-induced sterodogesnesis by this sensitive Leydig cell bioassay. Nevertheless, these subjects maintained regular menstrual cycles, and serum progesterone levels during the luteal phase were consistent with ovulation. Normal hormone profiles were constructed from a subject whose serum had shown a fairly high degree of cross-reaction with human LH by the Leydig cell bioassay when estradiol, human LH, and progesterone levels were determined on different days throughout the menstrual cycle.n

Clinical profile and toxicology studies on four women immunized with Pr-β-HCG-TT

Four women in child bearing age group were immunized with the vaccine Pr-β-HCG-TT. All of them responded to active isoimmunization by production of anti-HCG and anti-TT antibodies. All subjects were followed up for one year. A thorough clinical examination was done at monthly visits and nothing abnormal was detected. Laboratory examination included (i) Hepatic function (serum bilirubin, alkaline phosphatase, serum transaminases GOT and GPT, LDH isoenzymes, cholinesterase), (ii) Renal function tests (urine routine and microscopic examination, blood urea and serum creatinine and urinary creatinine, (iii) Metabolic studies (blood glucose, serum proteins, serum cholesterol, and free fatty acids), (iv) Endocrinal study (protein-bound-iodine, insulin tolerance test serum progesterone and endometrial biopsy) and (v) Haematological investigations (haemoglobin, total and differential leucocyte count, erythrocyte sedimentation rate, platelet reticulocyte count and peripheral smear). No abnormality of any kind has been noticed so far, thus indicating that active isoimmunization with Pr-β-HCG-TT has no adverse or undesirable side effects.

Antibody response to Pr-β-HCG-TT vaccine in human subjects

Abstract The ability of Pr-β-HCG-TT vaccine to elicit anti-HCG antibodies have been investigated in four human subjects who were in reproductive age and of proven fertility. All subjects responsed positively by formation of anti-HCG and anti-tetanus toxoid antibodies. The anti-HCG antibodies were detectable after a lag period of 6 to 8 weeks and plateau levels were attained at about five months after primary immunization with the vaccine. The anti-HCG antibody titers though declining were still high in three subjects after nearly 11 months of immunization. In one of the subjects the titers declined to near zero levels after 16 months indicating the reversibility of antibody response with this vaccine. The antibodies reacted immunologically with the whole HCG molecule and were competent to neutralize the biological activity of HCG in radioligand receptor assay.

Evaluation of 15 (S)15 methyl-PGF2α methyl ester suppositories with a two dose schedule for termination of early pregnancy

Abstract The abortifacient effectiveness of 15-methyl-PGF 2α vaginal suppositories in two dose schedules, was tested in forty women for termination of 30–56-day pregnancies. The dose schedule consisted of 1.0 mg or 1.5 mg vaginal suppositories administered 3 hourly for the maximum of 4 suppositories. Success rates were 70 per cent and 65 per cent, respectively. Incidence of vomiting and diarrhea was comparatively higher with the 1.5 mg schedule. Estimation of serum progesterone and HCG was done before the administration of suppositories and two weeks later. A significant decline in the serum progesterone and HCG levels, two weeks post-treatment, occurred in successful cases and further confirmed the effectiveness of the therapy.

Influence of HCG and tetanus toxoid injections on the antibody titers in a subject immunized with Pr-β-HCG-TT

N.D., a subject immunized 11 months earlier with Pr-β-HCG-TT in whom the anti-HCG titers were on the decline, was injected with 2,000 IU and 4,000 IU of HCG intramuscularly at 24-hour intervals. The anti-HCG titers in blood fell in response to HCG administration but remained above zero. No evidence for the presence of free HCG was found in circulation. HCG administration did not alter the anti-tetanus toxoid titers. The anti-HCG titers in the blood sample drawn 21 days after the load test showed a return to nearly about the initial values. No clear cut booster effect of HCG injection on anti-HCG titers was noted. On the other hand injection of tetanus toxoid vaccine increased the antitetanus toxoid antibodies in the subject.

BIOSYNTHESIS OF OESTROGENS AND THEIR INTER‐CONVERSION IN HUMAN PLACENTAE FROM NORMAL AND TOXAEMIC PREGNANCIES

In vitro biosynthesis of oestrogens in microsomal and 10000 g supernatant fractions of placentae, ten each, from normal and toxaemic pregnancies has been investigated. Dehydroepiandrosterone sulphate (DHAS), dehydroepiandrosterone (DHA) and androstenedione were used as substrates and their conversion to oestrone and oestradiol studied. In all the placental preparations the relative efficiency of the conversion of these androgens to oestrogens, though differing greatly between subcellular fractions as well as between normal and toxaemic placentae, was invariably in the order of DHAS > DHA > androstenedione. The conversion of these androgen precursors to oestrone and oestradiol was reduced in toxaemia compared with the normal placenta. Moreover, formation of oestradiol was much more reduced than that of oestrone. The free oestradiol level in the serum was also found to be lower in toxaemic pregnancies as compared with the normal range. The inter‐conversions of oestrogens further showed a significantly reduced conversion of oestrone to oestradiol in toxaemic placentae compared with normal placentae. The results may explain the lowered blood oestradiol levels observed in toxaemia of pregnancy and thus provide an explanation of the usefulness of the estimation of the oestradiol level as an index of feto‐placental function.

Hormonal changes in patients undergoing therapeutic abortion with prostaglandin F2α, 15(S)-15-methyl-prostaglandin F2α and hypertonic saline

Abstract Intra-amniotic PGF 2α and extra-amniotic 15(S)-15-methyl-PGF 2α (15-methyl-PGF 2α ) when administered to women for induction of abortion decreased the serum progesterone, HPL and estradiol-17β levels. These hormones, estimated by specific radioimmunoassays, showed a greater and somewhat faster decline with extra-amniotic 15-methyl-PGF 2α than with intra-amniotic PGF 2α . Interestingly, in one case (FMP) where 15-methyl-PGF 2α failed to terminate pregnancy, no change in the hormonal patterns were observed. Similarly, in another case (CP) where two doses of PGF 2α failed to terminate pregnancy, no change in the estradiol level was observed. However, after the third dose, a sharp fall in the estradiol level occurred which was followed by abortion. On the other hand, intra-amniotic hypertonic saline caused a sharp fall in the estradiol level only. The decrease in progesterone and HPL by saline was rather slow and inconsistent as compared to prostaglandins. The contribution of the changes in serum hormonal levels to the understanding of the mechanism of action of these abortifacients is discussed.