Role of tyrosine phosphorylation in sperm capacitation / acrosome reaction

Capacitation is an important physiological pre-requisite before the sperm cell can acrosome react and fertilize the oocyte. Recent reports from several laboratories have amply documented that the protein phosphorylation especially at tyrosine residues is one of the most important events that occur during capacitation. In this article, we have reviewed the data from our and other laboratories, and have constructed a heuristic model for the mechanisms and molecules involved in capacitation/acrosome reaction

Reduction of fertility in female rabbits and mice actively immunized with a germ cell antigen (GA-1) from the rabbit

Female rabbits and mice were actively immunized against germ cell antigen (GA-1) of 63 kDa molecular mass isolated from rabbit sperm and testis. There was a significant (P P < 0.01) reduction in fertility as seen by mean 7-9 day implants+/-S.D. per mated mouse actively immunized with GA-1 whether through the intraperitoneal route (GA-1, 1.2+/-1.6; controls, 8.0+/-3.4) or through the subcutaneous/intramuscular route (GA-1, 3.8+/-3.4; controls, 10.1+/-3.9). The antisera from these actively immunized animals were negative for sperm agglutinating and immobilizing antibodies. In the Western blot enzyme-immunobinding procedure, the antisera showed specific binding to a single protein of 63 kDa. The incidence of fertilization of eggs recovered from rabbits inseminated with anti-GA-1 antibodies-treated sperm was not significantly different from control rabbits. The percentage of fertilized eggs obtained from rabbits inseminated with anti-GA-1 antibodies-treated sperm that reached the blastocyst stage upon in vitro incubation, however, was significantly less than that for embryos obtained from rabbits inseminated with control serum-treated sperm. Incubation of normal fertilized eggs in vitro with the antibodies did not affect development. Neither antiserum nor immune uterine fluid reacted with 4-day blastocysts in the indirect immunofluorescence technique. It is concluded that active immunization with GA-1 results in post-fertilization reduction of fertility in rabbits and mice by inhibiting early embryonic development.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25986/1/0000052.pd

Core outcome sets for trials of interventions to prevent and to treat multimorbidity in adults in low and middle-income countries:the COSMOS study

INTRODUCTION: The burden of multimorbidity is recognised increasingly in low- and middle-income countries (LMICs), creating a strong emphasis on the need for effective evidence-based interventions. Core outcome sets (COS) appropriate for the study of multimorbidity in LMICs do not presently exist. These are required to standardise reporting and contribute to a consistent and cohesive evidence-base to inform policy and practice. We describe the development of two COS for intervention trials aimed at preventing and treating multimorbidity in adults in LMICs.METHODS: To generate a comprehensive list of relevant prevention and treatment outcomes, we conducted a systematic review and qualitative interviews with people with multimorbidity and their caregivers living in LMICs. We then used a modified two-round Delphi process to identify outcomes most important to four stakeholder groups (people with multimorbidity/caregivers, multimorbidity researchers, healthcare professionals and policymakers) with representation from 33 countries. Consensus meetings were used to reach agreement on the two final COS.REGISTRATION: https://www.comet-initiative.org/Studies/Details/1580.RESULTS: The systematic review and qualitative interviews identified 24 outcomes for prevention and 49 for treatment of multimorbidity. An additional 12 prevention and 6 treatment outcomes were added from Delphi round 1. Delphi round 2 surveys were completed by 95 of 132 round 1 participants (72.0%) for prevention and 95 of 133 (71.4%) participants for treatment outcomes. Consensus meetings agreed four outcomes for the prevention COS: (1) adverse events, (2) development of new comorbidity, (3) health risk behaviour and (4) quality of life; and four for the treatment COS: (1) adherence to treatment, (2) adverse events, (3) out-of-pocket expenditure and (4) quality of life.CONCLUSION: Following established guidelines, we developed two COS for trials of interventions for multimorbidity prevention and treatment, specific to adults in LMIC contexts. We recommend their inclusion in future trials to meaningfully advance the field of multimorbidity research in LMICs.PROSPERO REGISTRATION NUMBER: CRD42020197293.</p

Development of contraceptive vaccines for humans using antigens derived from gametes (spermatozoa and zona pellucida) and hormones (human chorionic gonadotrophin): current status

Contraceptive research has entered a new phase of development with the advent of hybridoma and DNA recombinant technologies. During the past 5 years, significant advances have been made in this area and now it seems that realistic prospects exist for the development of contraceptive vaccines for use in humans and animals (veterinary, wild and domestic), applicable to both the female and male sexes. Contraceptive vaccines will be valuable supplements to the presently available methods of family planning, and, due to high specificity, the occurrence of limited side-effects if any, low cost and infrequent administration, contraceptive vaccines may have greater acceptability than the currently available methods. Mammalian reproduction starts with the unison of gametes contributed by the male and female partners. Both spermatozoon and oocyte have antigens on the cell surface that are unique, tissue-specific, immunogenic and accessible to antibodies, and binding of the antibodies to these antigens can cause inhibition of gamete function, resulting in a failure of fertilization. Fertilization is followed by embryogenesis, with the early embryo producing several proteins, some of which, eg. human chorionic gonadotrophin (HCG), have a vital role in the establishment and maintenance of early pregnancy. Again, these proteins are accessible to antibodies, and their immunoneutralization can cause anti-fertility effects with loss of early embryo. Thus, the antigens derived from proteins on spermatozoa, oocyte and early embryo, especially HCG, constitute interesting molecules for the development of contraceptive vaccines. The aim of the present article is to review the current status of development of contraceptive vaccines based on antigens derived from sperm cell, oocyte zona pelluci-da and HCG, and to discuss their relative merits and future development