Biomedical subjects

A F Abbott

Publications and source records attributed to A F Abbott.

4 recordsLinked to original sources

PubMed1994

The effects of disease progression and zidovudine therapy on semen quality in human immunodeficiency virus type 1 seropositive men.

OBJECTIVE: To investigate the effects of disease progression and zidovudine antiretroviral therapy on semen parameters in human immunodeficiency virus type 1 (HIV-1) seropositive men. DESIGN: Cross-sectional analysis of semen parameters of 166 HIV-1 seropositive men in various stages of disease progression as defined by peripheral CD4+ cell count. Clinical symptoms and zidovudine therapy status were obtained from medical records and clinical interviews. PATIENTS: Human immunodeficiency virus type 1 seropositive men participating in clinical studies at the Fenway Community Health Center (Boston, MA), the University of San Francisco (San Francisco, CA), and Brown University (Providence, RI). MAIN OUTCOME MEASURES: Ejaculate volume; sperm concentration, motility, forward progression, morphology, total sperm count; seminal immature germ cell; and white blood cell (WBC) concentrations. RESULTS: Human immunodeficiency virus type 1 seropositive men that were not on zidovudine therapy and were in early disease stage (> 200 CD4+ cells/mm3) had normal semen parameters as defined by World Health Organization criteria. In contrast untreated men in advanced disease stage (< or = 200 CD4+ cells/mm3) had significant reductions in sperm concentration and total sperm count and an increased percentage of abnormal sperm forms. Men receiving zidovudine antiretroviral therapy, regardless of disease stage, had normal semen parameters similar to those of untreated early disease stage patients. Seminal WBC concentrations were not affected significantly by disease progression but were reduced in patients receiving zidovudine. CONCLUSION: Most HIV-1-infected men in this study had semen parameters consistent with fertility. Disease progression was associated with reduced semen quality, but this effect appeared to be abrogated by zidovudine therapy. Zidovudine was also associated with a significant reduction of WBC numbers in semen. As seminal WBC are principal HIV-1 host cells in ejaculates of HIV-1-infected men, this effect could explain recent laboratory and epidemiological evidence that zidovudine therapy is associated with a reduced prevalence of HIV-1 in semen and a lower rate of sexual transmission.

Acquired Immunodeficiency Syndrome↗

PubMed1994

Seminal white blood cells and recurrent abortion.

The incidence of leukocytospermia (> 1 million white blood cells/ml semen) and concentrations of white blood cell populations in semen from men whose partners experience unexplained recurrent spontaneous abortion by conventional testing criteria are described and compared to those of men whose partners have normal reproductive histories. Comparable seminal granulocyte and total white blood cell concentrations between groups suggest that couples with unexplained recurrent abortion do not have an abnormally high incidence of subclinical genital tract infections for which leukocytospermia could serve as a marker. However, a significantly higher prevalence of elevated CD4+ and CD8+ T lymphocyte concentrations in semen from men whose partners have cellular immunity to sperm antigens (i.e. produce embryotoxic factors in response to sperm antigen stimulation) warrants further investigation.

Abortion, Habitual↗

PubMed1994

Sperm morphology and recurrent abortion.

In 98 men whose partners experienced three or more spontaneous abortions, there were no significant differences in ejaculate volume, concentration of sperm, the percentage of total abnormal sperm, or the percentage of individual sperm defects as compared with normal WHO standards and 17 men fathering successful pregnancies. These data indicate that neither abnormal sperm concentration nor abnormal sperm morphology are significantly associated with recurrent spontaneous abortion.

Abortion, Habitual↗

PubMed1993

The role of complement component C3b and its receptors in sperm-oocyte interaction.

Previous studies have shown that human sperm that have undergone the acrosome reaction express a unique tissue-specific variant of the complement component 3 (C3)-binding molecule membrane cofactor protein (MCP, CD46) and that damaged or dead sperm activate the alternative pathway of complement and bind C3 catabolites. In this study we provide evidence that MCP on sperm that have undergone the acrosome reaction specifically binds dimeric C3b and that human sperm acrosomal proteases released during the acrosome reaction directly cleave C3, facilitating its binding to MCP. Furthermore, human and hamster oocytes can activate the alternative pathway of complement and also bind human C3 fragments. Monoclonal antibodies specific for complement receptors type 1 (CD35) and type 3 (CD11b/CD18) bind to the human oocyte plasma membrane, indicating that specific complement-binding molecules may play a role in the attachment of C3 catabolites to oocytes. Subsaturating concentrations of dimeric C3b (0.01-1 microM) promoted penetration of hamster oocytes by human sperm, whereas saturating doses (> 10 microM) inhibited this process. In addition, antibodies to both MCP and C3 significantly inhibited penetration of hamster oocytes by human sperm. These data provide evidence that regulated gamete-induced generation of C3 fragments and the binding of these fragments by selectively expressed receptors on sperm and oocytes may be an initial step in gamete interaction, leading to membrane fusion and fertilization.

Adult↗