Biomedical subjects

C K Brazil

Publications and source records attributed to C K Brazil.

4 recordsLinked to original sources

PubMed2001

Sperm morphology, motility, and concentration in fertile and infertile men.

BACKGROUND: Although semen analysis is routinely used to evaluate the male partner in infertile couples, sperm measurements that discriminate between fertile and infertile men are not well defined. METHODS: We evaluated two semen specimens from each of the male partners in 765 infertile couples and 696 fertile couples at nine sites. The female partners in the infertile couples had normal results on fertility evaluation. The sperm concentration and motility were determined at the sites; semen smears were stained at the sites and shipped to a central laboratory for an assessment of morphologic features of sperm with the use of strict criteria. We used classification-and-regression-tree analysis to estimate threshold values for subfertility and fertility with respect to the sperm concentration, motility, and morphology. We also used an analysis of receiver-operating-characteristic curves to assess the relative value of these sperm measurements in discriminating between fertile and infertile men. RESULTS: The subfertile ranges were a sperm concentration of less than 13.5 x 10(6) per milliliter, less than 32 percent of sperm with motility, and less than 9 percent with normal morphologic features. The fertile ranges were a concentration of more than 48.0 x 10(6) per milliliter, greater than 63 percent motility, and greater than 12 percent normal morphologic features. Values between these ranges indicated indeterminate fertility. There was extensive overlap between the fertile and the infertile men within both the subfertile and the fertile ranges for all three measurements. Although each of the sperm measurements helped to distinguish between fertile and infertile men, none was a powerful discriminator. The percentage of sperm with normal morphologic features had the greatest discriminatory power. CONCLUSIONS: Threshold values for sperm concentration, motility, and morphology can be used to classify men as subfertile, of indeterminate fertility, or fertile. None of the measures, however, are diagnostic of infertility.

Adult↗

PubMed1994

Sperm-immunobead binding decreases with in vitro incubation.

OBJECTIVE: To characterize the stability of the sperm-immunobead association over time. DESIGN: Prospective evaluation of sperm-immunobead binding, using direct and indirect assays. SETTING: Male Infertility Clinic, University of California, Davis, Davis, California. PATIENTS: Eleven men with sperm surface antibodies and 25 men with serum antisperm antibodies volunteered. MAIN OUTCOME MEASURES: Repeated assessment of sperm-immunobead binding over time. RESULTS: Serum immunoglobulin (Ig)G decreased a mean of 42.6% over 30 minutes, and serum IgA decreased a mean of 22.7% over 30 minutes. Semen-derived IgG binding fell a mean of 59.9% and semen-derived IgA fell a mean of 27.0% over 25 to 40 minutes. CONCLUSIONS: Sperm-immunobead coincubation results in a decrease in the number of sperm bound to immunobeads.

Antibodies↗

PubMed1993

Detection of altered acrosomal physiology of cryopreserved human spermatozoa after sperm residence in the female reproductive tract.

At least some of the spermatozoa that remain motile following cryopreservation have sustained sublethal damage that reduces their functional capacity in vivo. Although it is believed that acrosomal damage is partly responsible for impaired sperm function in vivo, direct evidence for this hypothesis is lacking because spermatozoa have not been collected from the female reproductive tract for evaluation. In the study reported here, cervical mucus was collected from women 24 h after artificial insemination by cervical cup. For both cryopreserved and nonfrozen inseminates, spermatozoa within the cervical mucus and spermatozoa that migrated out of mucus into culture medium (t = 1 h) were viable and had intact acrosomes. However, although nonfrozen spermatozoa did not initially respond to induction of the acrosome reaction with follicular fluid, a significant proportion of cryopreserved spermatozoa did respond. These results demonstrate that cryopreservation increases the acrosomal lability of spermatozoa residing in the female reproductive tract. An in vitro test was developed to detect this form of cryodamage. Sperm-free mucus was collected before insemination and spermatozoa from the inseminate were allowed to swim into this column of mucus in vitro. Spermatozoa recovered from this mucus sample were compared with spermatozoa from the paired sample collected from the cervix 24 h later. This in vitro test could detect acrosomal lability in cryopreserved semen samples, and this approach may prove valuable for studying sublethal cryodamage to the acrosome.

Acrosome↗

PubMed1984

Human sperm function in the ejaculate following vasectomy.

Semen specimens were obtained for analysis from nine men immediately before vasectomy and 3 days following the vasectomy procedure. After vasectomy there was a significant decrease in seminal sperm concentration, percentage of sperm motility, and mean swimming speed. In seven of nine cases the spermatozoa did not survive overnight incubation in capacitation media, and in no case was penetration of zonafree hamster oocytes observed 3 days after vasectomy.

Animals↗