Nancy J. Alexander

Defective calcium influx and acrosome reaction (spontaneous and progesterone-induced) in spermatozoa of infertile men with severe teratozoospermia *

OBJECTIVEnTo evaluate the acrosome reaction and its prerequisite, a calcium influx, in spermatozoa of infertile men with a high incidence of abnormal sperm forms.nnnDESIGNnProspective, controlled study.nnnSETTINGnAcademic tertiary assisted reproduction center.nnnPATIENTSnPatients (n = 14) were allocated in the study after semen evaluation showed teratozoospermia (< 14% normal sperm forms) as diagnosed by strict criteria.nnnINTERVENTIONSnAfter swim-up separation of the motile fraction, acrosome reactions were evaluated using Pisum sativum agglutinin (both spontaneously and exogenously induced with P and the calcium ionophore A23187, both at 10 microM); the intracellular-free [Ca2+]i was assessed by the fluorescent fura-2 indicator (basal and after P).nnnRESULTSnPatients did not show the typical P-induced wave of [Ca2+]i that was observed in controls but rather a blunted response, no response at all, or abnormal basal [Ca2+]i levels. The percent of basal acrosome reaction was significantly lower for patients versus controls postswim-up, and at 1 hour and 3 hours. Furthermore, there was a significant difference in the response of acrosome reaction to P both at 1 hour and 3 hours, with patients showing almost no response at all. However, patients acrosome reaction response to the calcium ionophore was similar to those of fertile men.nnnCONCLUSIONnInfertile patients with a high incidence of abnormal sperm forms as diagnosed by strict criteria have a low incidence of spontaneous acrosome reaction and a diminished P-stimulated acrosome reaction, whereas the nonspecific response to a calcium ionophore is conserved. Parallel abnormalities of [Ca2+]i were observed in patients, suggesting that these sperm populations may have a defective nongenomic P sperm receptor and/or abnormalities of other membrane transduction systems.

Fertility drugs and ovarian cancer: red alert or red herring?

Whittemore and colleagues from the Collaborative Ovarian Cancer Group (COCG) have published a combined analysis of three epidemiologic studies of the association between ovarian cancer and the use of fertility drugs.

Steroid specificity of the human sperm membrane progesterone receptor

The aim of this study was to evaluate the effect of several abeopregnane, steroidal heterocycles (A/B-transandrostano [2,3-d]isoxazole, and 17-spiroandrostano[2,3-c]furazan), and 6 alpha, 11 beta, 16 alpha-trisubstituted 19-norpregnadienedione on the influx of extracellular Ca2+ in human sperm. These steroidal compounds had minimal genomic progestational, androgenic, or estrogenic activity with the exception of 16 alpha-ethyl-6 alpha-methyl-11 beta-(4-N,N-dimethylaminophenyl)-19- norpregna-4,9-diene-3,20-dione which was four times more progestational than progesterone. Some of the steroidal compounds, e.g., 16 alpha-ethyl-6 alpha-methyl-11 beta-(4-N,N-dimethylaminophenyl)-19-nor- pregna-4,9-diene-3,20-dione and 2,3,4,5-tetrahydrospiro[furan-2 beta, 17-androstano] [2,3-c]furazan produced an influx of Ca2+ into human spermatozoa. These studies indicate that high (10 microM) concentrations of certain steroidal compounds are selective for the sperm membrane progesterone receptor, since most of them have minimal genomic activity. The steroidal compounds that elicited an influx of Ca2+ caused an initial high influx but were not as potent as progesterone, since no effects were observed below 1 microM, whereas progesterone at 1 microM produced a maximum effect. Progesterone as well as the steroidal compounds caused a modest increase in the number of acrosome-reacted spermatozoa. Molecular modeling revealed that 5 alpha-dihydro-2,3-fused and 4,4-dimethyl-5-ene-2,3-fused steroidal heterocycles possessing different conformations compared to that of progesterone are responsible for elevation of Ca2+. In conclusion, a unique non-genomic progesterone receptor is present on human spermatozoa and several steroidal compounds that do not have progestational effects may activate this sperm membrane receptor, resulting in Ca2+ influx.

Heterosexual spread of HIV infection

Sexual transmission is the most common route of spread of human immunodeficiency virus (HIV), with heterosexual transmission of HIV infection accounting for 90% of those infected in 1992 and over 75% of the 10–12 million of those infected to date worldwide. Yet, heterosexual transmission is poorly understood. Since HIV can be transmitted from HIV-infected people who are asymptomatic as well as from those who have the acquired immunodeficiency syndrome (AIDS), we must better define the potential for transmission of HIV from HIV-infected individuals as well as the factors which influence the susceptibility of HIV-uninfected individuals.

Male infertility: the focus shifts to sperm manipulation.

Few systemic approaches for treatment of the infertile male are available. Therefore, the focus has shifted to studies of sperm maturation in the female tract, tests of sperm function, and assisted reproduction. New methods of sperm evaluation allow a better determination of those samples that will and will not fertilize ova. These methods include the strict morphology examination, biochemical approaches such as evaluation of creatine Idnase levels, and the hemizona assay. Computer assisted semen analysis has not yet proved important for diagnosis but has provided important research information. For example, the drug pentoxifylline significantly increases velocity and has also been shown to enhance in vitro fertilization. The term subfertile is extensively used in the literature but its clear definition and the prognosis for subfertile men have not been established. Approaches that may increase fertilization rates include reducing the gamete culture volume and removal of cumulus oophorus. Assisted reproductive technologies for patients with ejaculatory dysfunction have also been expanded. The use of improved semen processing techniques, advanced oocyte retrieval, and well-timed intrauterine insemination are enabling physicians to use decreasing numbers of viable sperm to achieve pregnancies.

Vasectomy, serum assays, and coronary heart disease symptoms and risk factors

We compared three serum assays (two antisperm antibody assays and one assay for circulating immune complexes) and a number of CHD-related variables in 69 vasectomized (V) and 126 non-vasectomized (NV) participants in the Portland Center for the Multiple Risk Factor Intervention Trial. Significant differences between the V and NV men were found in sperm agglutination (SA) and sperm immobilization (SI) titers, as well as in several CHD risk factors, symptoms, and treatments; men in the V group had higher titers for SA and SI, smoked more, and had lower diastolic and systolic blood pressure than men in the NV group. Differences between V and NV in SA and SI activity remained even after we controlled for any effects that CHD risk factors, symptoms, and treatments may have had on the serum assays. Antibody development tended to decrease with age-at-vasectomy and increase with time-post-vasectomy. In the case of SA the antibodies clearly increased with time-post-vasectomy.

Quantitation of vaginally administered nonoxynol-9 in premenopausal women

A feasibility study was performed in 11 healthy nonpregnant premenopausal women to determine a method for collection and recovery of vaginally administered nonoxynol-9. We also determined if nonoxynol-9 could be quantitated in vaginal lavage fluid obtained 2 h after instillation of a standard precoitol dose of a foam formulation of nonoxynol-9. Samples were analyzed in batch using a validated normal phase high-performance liquid chromatography (HPLC) method. Two hours after instillation of one dose of Delfen Contraceptive Foam (100 mg), the quantity of nonoxynol-9 collected ranged from 10.8 to 67.8 mg (mean: 35.4 mg). This corresponds to a recovery of 11.70%, of the administered dose. Quantitation of vaginally administered nonoxynol-9 is both practical and feasible. These data represent a critical first step in the evaluation of the safety and effectiveness of nonoxynol-9-containing products in the prevention of sexually transmitted diseases.

HIV quantitation in spiked vaginocervical secretions: lack of non-specific inhibitory factors

The objective of this study was to assess the effect of menstrual phase on the ability to quantitate HIV-1 in vaginocervical secretions (VCS) through reconstruction experiments with HIV seronegative VCS collected throughout the menstrual cycle. Measurement of HIV-1 inoculated into both fresh and frozen VCS was undertaken by quantitative micro co-culture, p24 antigen assay and polymerase chain reaction (PCR) for both HIV-1 RNA and pro-viral DNA. Two laboratories carried out these assays over a range of viral concentrations. The study involved a randomized factorial design and the factors were: (1) diluents (phases of the menstrual cycle and controls); (2) laboratories; (3) stock concentrations; and (4) frozen versus fresh VCS samples. Each assay was assessed independently using a random effects analysis of variance (ANOVA) model. No statistical differences due to menstrual cycle were seen in the assay results of p24 antigen (P = 0.08), PBMC culture (P = 0.74), plasma culture (P = 0.13), cell-free RNA (P = 0.44), cell-associated RNA (P = 0.58) and cell-associated DNA (P = 0.43). Inter-laboratory differences were statistically significant for cell-free RNA (P < 0.001), cell-associated DNA (P < 0.001) and p24 (P < 0.001). It is concluded that VCS obtained throughout the menstrual cycle from HIV-uninfected women lacks intrinsic inhibitory factors which could limit detection and quantification by antigen, culture or nucleic acid-based technologies for HIV-1 in VCS throughout the menstrual cycle. Using a standardized collection procedure, we suggest that variation in HIV quantity over time, when reported in VCS of infected women, should be attributed to HIV-associated biologic factors, rather than non-specific or other technical factors.