Biomedical subjects

C C Coddington

Publications and source records attributed to C C Coddington.

58 records · Page 4Linked to original sources

PubMedDate not supplied

Hemizona assay (HZA) demonstrates effects of characterized mouse antihuman sperm antibodies on sperm zona binding.

Characterized antihuman sperm monoclonal antibodies from mice were evaluated using the hemizona assay (HZA) to determine whether sperm:zona binding was effected. The seven monoclonal antibodies were characterized using human sperm in agglutination, immobilization, and penetration assays. Semen was provided by four fertile men and used in the HZA to determine if the presence of a monoclonal antibody would affect tight binding of the sperm to the zona pellucida. Pre-incubation of MA-14 for 1 h with the sperm induced a 33-54% reduction of the number of tightly bound sperm. This antibody reacts to an antigen located on the acrosome and midpiece. Experiments in which there was no pre-incubation of the antibody with sperm, resulted in no significant reduction in the number of sperm bound in the HZA. These findings suggest that an anti-human sperm antibody produced in mice can modulate sperm:zona binding. Reduction in zona binding could indicate a cause of immune-related infertility and this test may be useful in selecting an antigen for contraceptive vaccine development.

Acrosome↗

PubMedDate not supplied

Hemizona assay: evaluation of fertility potential in patients with vasectomy reversal.

Approximately 40 to 60% of men who undergo a successful vasovasostomy have "functional failure" or failure to conceive even though active sperm are present. Factors of this functional failure include sperm abnormalities (oligoasthenoteratospermia) and antisperm antibodies. Nine male patients 32 to 43 years of age who underwent vasovasostomy were included in the study group. These patients demonstrated ductal patency 3 to 6 months after surgery. After attempts at fertility with their spouses failed, the couples underwent urological and gynecological evaluation. Semen parameters were recorded and further evaluation was performed using immobilizing and agglutination antibodies as well as direct immunobead test and the hemizona assay (HZA). Semen parameters presented varying levels of sperm concentration, percent motility, and morphology (strict). Antisperm antibodies were present in 4 of the 9 patients. Three of 4 patients with antibodies and 4 of 5 patients without antibodies benefitted from hemizona assay results in that it either supported a desired therapy or gave objective data that would dictate more aggressive therapy. Six men had a hemizona index of > 35%, predictive of adequate zona bind capability. Using these individual situations combined with gynecologic findings, recommendations are made as to identifying realistic options and therapeutic recommendations.

Adult↗

PubMedDate not supplied

Functional aspects of human sperm binding to the zona pellucida using the hemizona assay.

The hemizona assay (HZA) has facilitated investigations of sperm function in relation to zona pellucida binding. In this study, the authors examined: 1) the association between hyperactivated sperm motility and HZA binding; 2) the binding kinetics and efficiency of sperm from subfertile men; and 3) the influence of sperm freezing and thawing on binding capacity. For each HZA, a nonviable human oocyte was cut into equal zona hemispheres. The mean number of bound sperm and the incidence of hyperactivation were significantly greater for samples of sperm from fertile men compared with sperm from subfertile men (P less than 0.05). Subfertile sperm had a binding curve that paralleled the curve for fertile sperm, although the magnitude of binding was markedly reduced. Freezing and thawing of sperm from fertile samples impaired their capacity to bind to the zona pellucida. The HZA binding efficiency was reduced by 30%, although the binding curves for fresh versus frozen samples remained parallel.

Biological Assay↗

PubMedDate not supplied

Hemizona index (HZI) demonstrates excellent predictability when evaluating sperm fertilizing capacity in in vitro fertilization patients.

The objective of this work was to assess the power of the hemizona assay to predict in vitro fertilization (IVF) results using receiving operating characteristics (ROC) analysis. In a tertiary medical center setting, 94 couples undergoing IVF were included in the study comparing their fertilization results to sperm function during the hemizona assay. Using ROC analysis, fertilization in IVF (mature oocytes only) was compared to performance of the sperm in the sperm-zona pellucida binding test as expressed by hemizona index (HZI; [number of test sperm bound/number of control sperm bound] x 100). The IVF results were as follows: 32 patients had no fertilization (0%), 55 patients fertilized all of the oocytes (100%), and 7 patients fertilized between 14% and 85% of the oocytes. Modified ROC analysis was used to determine the best threshold for fertilization success or failure, depending upon how the data are viewed. A HZI of 40-43 separated the 100% fertilization group from the other groups, with a true positive rate of 87% and a true negative of 83%. Conversely, a HZI of 4-5 separated the 0% fertilization versus partial or total fertilization, with a true positive rate of 100% and true negative rate of 71%. Sperm performance in the hemizona assay as measured by the HZI reflects performance in IVF and benefits couple evaluation and counseling.

Female↗