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At least 595 records · Page 33Linked to original sources
PubMed1982

Early pregnancy factor as a monitor for fertilization in women wearing intrauterine devices.

Measurement of early pregnancy factor (EPF) by the rosette inhibition test was performed on serum samples from 14 women using intrauterine devices (IUDs). Serial blood samples taken during the luteal phase of 23 cycles demonstrated in six of the cycles a transient appearance of EPF during the 6- to 8-day period following ovulation. In contrast, no EPF activity was found in sera obtained from women in whom fertilization was prevented, either by sexual abstinence or tubal ligation. These observations support the postulate that the IUD functions by the prevention of implantation of the fertilized ovum, rather than by preventing fertilization.

Adult↗
PubMed1980

Fertility impairment in females--present status.

Various approaches towards the control of fertility in females have been discussed. The salient observations made in the field of reproductive physiology which may generate new leads for the development of agents capable of inhibiting pregnancy, are described. The discussion concerning the oestrogen and progesterone receptors is directed towards designing new antifertility agents. The different areas of fertility control covered in this survey are of importance for basic and applied research.

Cervix Mucus↗
PubMedDate not supplied

Analysis of serum-mediated immunosuppression in normal pregnancy, abortion and contraception.

Blood samples were obtained from pregnant women, threatened pregnancies, abortions, from women taking oral contraceptive drugs and normal controls. The measurement of immunoglobulins, G, A, M and E was done in all samples. The mean levels were normal in all cases, excepting the IgG levels which in normal pregnancies were decreased. Analysing the effect of these sera on the "in vitro' response of peripheral blood lymphocytes to PHA, a strong inhibition could be observed with the serum of normal pregnant women, with that of aborted pregnancies, that of women taking oral contraceptives and to a lesser extent with that of threatened pregnancies. Abortion experiments demonstrate that a large part of this inhibitory effect was attributable to the PZP factor. On the other hand, inhibitory sera failed to inhibit the "in vitro' production of MIF or the capacity of lymphocytes to form E-rosettes. A specific effect of PZP on the release of mitogenic factor by stimulated lymphocytes is suggested.

Abortion, Spontaneous↗
PubMed1993

[The influence of prostate-specific antigen p30 on human fertility].

The influence of prostate-specific antigen p30 on human fertility was studied with purified p30, domestic anti-p30 monoclonal and polyclonal antibodies. The results showed that the anti-p30 antibody presented in human serum had no negative effect upon human fertility and the anti-p30 antibody produced by heteroimmunization did not interfere with the process of human fertility in vitro. All these imply that it is unsuitable to recommend p30 as a contraceptive vaccine antigen.

Contraception, Immunologic↗
PubMedDate not supplied

Functional characterization of the primate sperm acrosomal antigen (PSA-63).

Monoclonal antibody (HS-63) raised in mice against human ejaculated sperm, polyclonal antibodies raised in rabbits against the cognate mouse testicular antigen (MSA-63; or Fab) and polyclonal antibodies raised in the rabbit against recombinant fusion proteins (GST-63) showed acrosomal localization in permeabilized rhesus monkey and human ejaculated sperm. Tail localization of the cognate primate sperm antigen (PSA-63) was also seen with intact MSA-63 antibodies and Fab fragments. The ability of these antibodies to inhibit sperm binding to the zona pellucida was measured with hemizona binding assays (HZAs). HS-63 (1.2 mg/ml) inhibited rhesus monkey sperm binding (mean +/- SEM) to homologous hemizonae (treatment, 15.5 +/- 3.3; control, 58.9 +/- 9.4; P < 0.025), whereas comparable concentrations of protein from nonimmunized mouse preparations were inactive (ascites fluid, 67.6 +/- 43.5; no ascites fluid, 72.0 +/- 44.6). Intact MSA-63 antibodies inhibited (up to 99%) monkey sperm-zona binding in a concentration-dependent manner. Moreover, inhibition in this case by intact MSA-63 antibody was limited to capacitated sperm. Similarly, intact MSA-63 antibodies inhibited (up to 85%) human sperm binding to homologous zonae in an antibody concentration-dependent manner. Fab fragments derived from MSA-63, when present in insemination mixtures (0.5 mg/ml), inhibited (P < 0.01) primate sperm binding to homologous hemizonae (monkey, 9.6 +/- 3; human sperm 9.4 +/- 2) compared with matched hemizona controls (monkey, 117 +/- 29; human, 20.4 +/- 3). Furthermore, rhesus monkey sperm-zona binding was reduced by 84% in the presence of rabbit anti-GST-63 antibodies.(ABSTRACT TRUNCATED AT 250 WORDS)

Acrosome↗
PubMed1995

[Immuno-contraceptive vaccines].

Results of studies on birth control vaccines accomplished by many research groups within the WHO Special Programe of Research, Development and Research Training in Human Reproduction has been reviewed. The mostly investigated contraceptive vaccines contain human chorionic gonadotropin, and therefore structure, biological role and immunogenicity of the hormone were presented. Also, vaccines obtained on the basis of subunit beta of the human chorionic gonadotropin, its heterodimer with subunit beta of ovine lutropin or C-terminal peptide of beta subunit were described. Results of two phases of clinical trials with immuno-contraceptive vaccines were presented. The use of contraceptive vaccines for treatment of some trophoblastic tumors and the idea of using contraceptive recombinant vaccines were also mentioned.

Animals↗
PubMed1996

Molecular genetics of the zona pellucida: implications for immunocontraceptive strategies.

Successful immunocontraceptive agents must prevent fertilization without compromising the health of the individual exposed to immunization. The zona pellucida, which surrounds all mammalian eggs and is unique to the female gamete, represents a potential target for immunocontraception. Mouse and human zonae pellucidae are composed of three glycoproteins, designated ZP1, ZP2 and ZP3. The genes are conserved and the transcripts that encode the zona proteins have been characterized in both species. In mice, the expression of the zona genes is oocyte specific. The recent elucidation of the primary structure of the zona proteins in a number of species has provided critical information for the rational design of a contraceptive vaccine. We and others have demonstrated that both passive and active immunization strategies that target individual zona proteins can prevent fertilization. Although various contraceptive strategies have been tested in a laboratory setting, the applicability of these protocols to humans remains to be determined. The recent revolution in transgenesis coupled with the cloning of the human zona pellucida genes provide the means to produce animal models for testing immunocontraceptive strategies that target human zona proteins. These models could provide a system for the initial evaluation of vaccine candidates prior to trials in primates.

Animals↗
PubMed1996

Molecular biology approaches to evaluate species variation in immunogenicity and antigenicity of zona pellucida proteins.

Immunocontraception using the glycoproteins of the mammalian zona pellucida (ZP) has held great promise because antibodies specific to ZP antigens would inhibit fertility and not be abortive. It has been shown, however, that some ZP proteins will elicit adverse effects since immunization may affect ovarian follicular development. These effects vary among different mammalian species as well as on the source of the ZP immunogen. Therefore, the use of molecular biology has been essential in identifying specific ZP protein(s) that inhibit fertility without altering ovarian follicular development and in defining the relationships of ZP proteins among different species. Use of recombinant ZP proteins has allowed us to begin to dissect antigenic domains of ZP proteins and to evaluate their potential roles in the fertilization process. Recent studies using recombinant rabbit ZP proteins to immunize cynomolgus monkeys (Macaca fascicularis) have shown that the 55 kDa ZP protein will elicit antibodies that inhibit sperm binding while not altering ovarian function, in contrast to immunization with a recombinant truncated protein of the 75 kDa ZP protein which causes ovarian dysgenesis. The rabbit 55 kDa protein is the homologue of the pig ZP3 alpha sperm receptor and the human ZPB protein but is distinct from the mouse ZP3 sperm receptor. Expression of this protein using the baculovirus expression system has further shown that the 55 kDa protein binds to capacitated rabbit spermatozoa over the acrosomal region and induces the acrosome reaction. Antibodies against this recombinant form of the ZP also inhibit rabbit spermatozoa from binding to rabbit egg in vitro. These studies demonstrate the need to determine the structure and function of ZP proteins of different mammalian species to evaluate their potential for contraceptive vaccines.

Animals↗
PubMed1996

Influence of autoimmune ovarian disease pathogenesis on ZP3 contraceptive vaccine design.

Zona pellucida (ZP) glycoproteins possess sperm receptor-binding activities. Antibodies against ZP can block sperm-egg interaction and thereby prevent fertilization. The feasibility of developing a safe contraceptive vaccine based on the ZP has been hampered by the finding that active immunization with autologous or heterologous ZP proteins results in infertility that is associated with ovarian dysfunction. A mouse model was used to investigate mechanisms of the ovarian pathology that is induced by active immunization with a 13mer peptide derived from mouse ZP3 (mZP3(330-342)). This peptide includes one native B-cell epitope and two nested T-cell epitopes. Ovarian pathology could be transferred into naive recipients by CD4+ T cells, but not by antibodies, from immunized mice, suggesting the importance of T cells in the mechanism of ovarian pathogenesis. Moreover, immune responses, as well as disease induction, were restricted to H-2a,k,u,s,axb haplotypes. On the basis of this mouse model, a strategy to generate a contraceptive anti-ZP antibody response without a pathogenic T-cell response, irrespective of H-2 haplotype, is described. The B-cell epitope was modified by amino acid substitution to eliminate the overlapping oophoritogenic T-cell epitope, and was linked to a promiscuous foreign T-cell epitope, bovine RNase94-104. The resultant chimaeric peptide (CP2) induced anti-ZP antibodies in 100% of the eight strains of inbred mice with different H-2 haplotypes without significant disease induction. An antifertility trial in B6AF1 female mice immunized with CP2 showed that the anti-ZP antibody was associated with a reduction in fertility. This infertility was reversed with a decline in anti-ZP antibody titre. Preliminary data show that this strategy of vaccine design may also be applied to primates.

Amino Acid Sequence↗