A comparison of swim-down and swim-up methods for the extraction of high motility sperm.

High quality motile sperm are essential for the success of the in vitro fertilization-embryo transfer program and related procedures, for the performance of sperm antibody assays, and other in vitro tests of sperm function. Two methods for the extraction of high motility sperm, swim-down and swim-up, were compared on 30 ejaculates, and sperm motility was assessed at intervals up to 18 hours. The swim-down method was simpler, shorter, and provided a significantly better recovery of sperm with sustained high motility than did the swim-up method.

An improved indirect enzyme-linked immunosorbent assay (ELISA) for the detection of antisperm antibodies.

An indirect enzyme-linked immunosorbent assay (ELISA) was used for the detection of antisperm antibodies which provides a sensitivity and ease of quantitation that is not available with conventional bioassay systems. A standardized protocol was developed in which washed whole sperm were coated onto polystyrene microelisa plates at a density of 1 X 10(5) sperm per well using a commercially available spray fixative. Urease was employed in the enzyme-antiimmunoglobulin conjugate to minimize nonspecific background reactions. Diluted positive and negative human sera were incubated at 37 degrees C and the results were read on an ELISA auto reader. Using mouse antihuman sperm antisera and sera from selected infertile patients, it was found that the ELISA method was significantly more sensitive than the sperm microimmobilization test and the microtray agglutination test. The results also confirmed that the ELISA detected a different spectrum of sperm antibodies compared with the other two techniques.

A simplified liquid nitrogen vapour method for the cryopreservation of human semen.

A simple manually operated liquid nitrogen vapour freezing apparatus has been developed for the cryopreservation of human semen. A test method using this apparatus was evaluated by comparison with a conventional freezing method using an ultra cold (-70 degrees C) freezer. Twenty different unselected fresh semen samples were analysed, diluted with cryoprotective medium and then divided into equal numbers of straws prior to freezing by the two methods. A comparison of the average sperm motility before freezing and after thawing using these two methods demonstrated a statistically significant superiority of the simplified test method.

Phase I clinical trial of a World Health Organisation birth control vaccine.

A birth control vaccine incorporating a synthetic peptide antigen representing the aminoacid sequence 109-145 of the C-terminal region of the beta subunit of human chorionic gonadotropin (hCG-beta) was submitted to a phase 1 clinical trial. Thirty surgically sterilised female volunteers, divided into five equal groups for different vaccine doses, received two intramuscular injections six weeks apart. Over a six-month follow-up there were no important adverse reactions, and potentially contraceptive levels of antibodies to hCG developed in all subjects. In the highest vaccine dose group, the results gave promise of a contraceptive effect of six months' duration.

PIP: A Phase I clinical trial of the immunogenicity and safety of a vaccine against the C-terminal region of the beta subunit of human chorionic gonadotropin (hCG-B) demonstrated a dose-related immune response. The antigen was a synthetic peptide of the C 109-145 region of hCG-B, conjugated to diphtheria toxoid, and administered in a water-soluble synthetic adjuvant in a saline-oil emulsion. This vaccine had been previously tested for toxicity in laboratory animals and for immunogenicity, safety and contraceptive effectiveness in baboons. 30 previously sterilized women were given 2 injections 6 weeks apart, ranging from 50 to 1000 mcg of the antigen. Each woman tested free of HLA B27 antigen and reacted negative to the diphtheria toxoid skin test. Based on calculated contraceptive antibody binding level of 0.52 nmol/l, all subjects mounted an effective antibody response for at least 6 months. 2 subjects in the group given 1000 mcg who were followed for 9 and 10 months maintained this level of antibody. 12 women showed an anamnestic response to diphtheria toxoid, while 8 did not. The only adverse reactions were mild, transient pain at the injection site. Several women who received unstable adjuvant experienced more severe myalgia. Menstrual changes appeared in 5 subjects: early menopause in 1, spotting in 3 and menorrhagia in 1 woman. Only transient positive findings were seen in some sera screened for autoantibodies. This preliminary trial indicates that anti-hCG vaccine is a hopeful reversible contraceptive.