Factors associated with mortality among hospitalized patients with COVID-19 disease treated with convalescent plasma.

The use of convalescent plasma (CP) for hospitalized patients with SARS-CoV-2 infection might be a useful option in certain settings. Soon after the outbreak of COVID-19, the National Ministry of Health of Argentina recommended the use of CP transfusion for hospitalized patients with COVID-19 disease. Between 1 June and 3 October 2020, 480 patients, excluding those on invasive mechanical ventilation (IMV), received at least one CP infusion in the province of Santa Fe. We aimed to find factors associated with mortality among this cohort of patients. The median age was 60 years (interquartile range: 49-69 years) and 320 (66.7%) were males. Most of these patients (93.75%) received a single CP infusion, 82.1% and 95.6% before day 4 and day 7 of hospitalization, respectively. Anti-SARS-CoV-2 titers were determined in the CP units administered using Elecsys Anti-SARS-CoV-2 S assay. At 28 days of follow-up, 250 patients were discharged (52.1%), 131 (27.3%) remained hospitalized without and 16 (3.3%) with oxygen requirement, 27 (5.6%) were on IMV, and 56 (11.7%) had died. In the multivariate logistic regression analysis, the factors significantly associated with 28-day mortality were (i) requirement of IMV, (ii) the administration of CP after the third day of hospitalization, (iii) age, and (iv) number of comorbidities. The qualitative and quantitative analyses of antibodies against SARS-CoV-2 in the infused CP were not associated with mortality. Our findings may imply a seemingly favorable effect of CP administration among patients with severe COVID-19 disease when infused sooner after hospitalization.IMPORTANCEThe use of convalescent plasma (CP) could be an option for patients with severe COVID-19, especially in poor-resource countries where direct antiviral drugs are not commercially available. Currently, the U.S. Food and Drug Administration limits the CP administration for outpatients and inpatients with COVID-19 who are immunocompromised and only if high levels of anti-SARS-CoV-2 antibodies are confirmed in the CP unit. Although most of the randomized clinical trials failed to show a clear-cut benefit of CP in hospitalized patients with severe COVID-19, other studies have shown that if given early in the course of the disease, it might be a useful therapeutic option. In this retrospective study, we demonstrated that early treatment (within 3 days of hospitalization) was significantly associated with reduced 28-day mortality compared with those patients treated beyond day 3. The results from our study add up to the scientific evidence on the use of CP as a relatively safe, cheap, and possibly effective therapy in certain patients suffering from severe SARS-CoV-2 infection.

Mechanisms involved in the contraceptive effects of ulipristal acetate.

The use of emergency contraception (EC) methods is increasing worldwide as it constitutes an effective way to prevent unplanned pregnancy after unprotected sexual intercourse. During the last decade, ulipristal acetate (UPA), a selective progesterone receptor modulator, has emerged as the most effective EC pill, and it is now recommended as first-line hormonal treatment for EC in several countries. Its principal mechanism of action involves inhibition or delay of follicular rupture, but only when administered during the follicular phase before the luteinizing hormone (LH) peak. However, considering the high efficacy of UPA, it is possible that it also exerts contraceptive effects besides ovulation. In the present review, we summarize and discuss the existing evidence obtained on the effect of UPA on sperm function and post-ovulatory events as potential additional mechanisms to prevent pregnancy. The bulk of evidence collected so far indicates that UPA would not affect gamete function; however, it could impair embryo-uterine interaction. Thus, besides the described effects on ovarian function, UPA contraceptive effectiveness might also be attributed to post-ovulatory effects, depending on the moment of the female cycle in which the drug is administered.

Acreditación de los laboratorios de Andrología en la República Argentina / Accreditation of Andrology laboratories in Argentina / Credenciamento dos laboratórios de Andrologia na República Argentina

La acreditación de laboratorios especializados en Andrología tiene como objetivo promover, mejorar y asegurar la calidad del servicio. Las especialidades requieren de la participación de expertos que asesoren a los organismos autónomos que efectúan las auditorías de tercera parte. El objetivo del trabajo es comunicar la experiencia de trabajo cooperativo llevado a cabo por una sociedad científica, la Sociedad Argentina de Andrología (SAA) y el Programa de Acreditación de Laboratorios (PAL) de la Fundación Bioquímica Argentina (FBA) para el aseguramiento de la calidad de la prestación bioquímica en el área andrológica. Con tal fin se firmó un convenio marco y específico de colaboración para la acreditación de laboratorios especializados en Andrología. La FBA llevaría a cabo la logística del proceso, con su plantel de auditores, aplicando como instrumento el Manual de Acreditación MA3 y la SAA proveería asesoramiento científico. Junto con las autoridades del PAL se elaboró un documento que especifica los apartados correspondientes al MA3 capítulo Nº 4 Anexo Nº 4, "Estándares para la acreditación de laboratorios especializados". Se realizó capacitación para la elaboración de la documentación y formación de los auditores en la especialidad. Esta experiencia demuestra que el trabajo cooperativo entre organizaciones permite alcanzar logros a favor de la seguridad del paciente.

Laboratory accreditation aims to promote, improve and ensure the quality of the service. The specialties require the participation of experts who advise the autonomous bodies that carry out third-party audits. The objective is to communicate the experience of cooperative work carried out by a scientific society, the Sociedad Argentina de Andrología (SAA) (Argentine Society of Andrology) and the Laboratory Certification Programme (PAL for its name in Spanish) of Fundación Bioquímica Argentina (FBA) (Argentine Biochemistry Foundation) for quality assurance of the biochemical work in the andrology area. To reach this goal, a framework and specific collaboration agreement was signed for the certification of specialized laboratories in Andrology. The FBA will carry out the logistics of the process, with its auditors' staff, applying the MA3 Accreditation Manual as an instrument, and the SAA will provide scientific advice. Together with the PAL authorities, a document was drawn to specify the sections corresponding to the MA3 chapter No. 4 Annex No. 4, "Standards for the certification of specialized laboratories". Training was carried out to prepare the documentation and the auditors in the specialty were trained as well. This experience has proven that cooperative work between organizations can achieve results favouring the patient's safety.

O credenciamento dos laboratórios visa promover, melhorar e garantir a qualidade do serviço. As especialidades requerem a participação de profissionais que assessoram os órgãos autônomos que realizam auditorias de terceiros. O objetivo é comunicar a experiência do trabalho cooperativo realizado por uma sociedade científica, a Sociedade Argentina de Andrologia (SAA) e o Programa de Credenciamento (PAL) da Fundação Bioquímica Argentina (FBA) para garantir a qualidade do trabalho bioquímico na área andrológica. Para esse fim, foi assinado um acordo-quadro e específico de cooperação para o credenciamento de laboratórios especializados em Andrologia. A FBA iria executar a logística do processo, com a sua equipe de auditores, por meio do Manual de Credenciamento MA3 como instrumento e a SAA como um instrumento e a SAA forneceria assessoramento científico. Junto com as autoridades do PAL foi elaborado um documento especificando as seções relativas ao MA3 capítulo Nº 4 Anexo Nº 4, "Normas para a credenciamento de laboratórios especializados". O treinamento foi realizado para a elaboração da documentação e formação dos auditores na especialidade. Essa experiência tem demonstrado que o trabalho cooperativo entre organizações permite atingir resultados positivos para a segurança do paciente.

A single post-ovulatory dose of ulipristal acetate impairs post-fertilization events in mice.

Ulipristal acetate (UPA) is a selective progesterone receptor modulator used for emergency contraception that has proven to be highly effective in preventing pregnancy when taken up to 120 h after unprotected sexual intercourse. Even though it may act mainly by delaying or inhibiting ovulation, additional effects of UPA on post-fertilization events cannot be excluded. Therefore, the aim of this study was to determine whether a single post-ovulatory dose of UPA could prevent pregnancy using the mouse as a pre-clinical model. Mated females received a single dose of UPA (40 mg/kg) on Day E1.5 or E2.5 (E0.5: copulatory plug detection) and post-fertilization events were evaluated. Our studies revealed that UPA administration produced a significant decrease in the number of conceptuses compared to control. Moreover, UPA-treated females exhibited a lower number of early implantation sites on Day E5.5, despite normal in vivo embryo development and transport to the uterus at E3.5. Administration of UPA produced histological and functional alterations in the uterine horns, i.e., a dyssynchronous growth between endometrial glands and stroma, with non-physiological combination of both fractions compared to controls, and a completely impaired ability to respond to an artificial decidualization stimulus. Altogether, our results show that the administration of a single post-ovulatory dose of UPA impairs mouse pregnancy probably due to an effect on embryo-uterine interaction, supporting additional effects of the drug on post-fertilization events. Although these studies cannot be performed with human samples, our results with the mouse model provide new insights into the mechanism of action of UPA as an emergency contraception method.

Expression profile and distribution of Annexin A1, A2 and A5 in human semen.

Annexins (ANXAs) have been identified in different seminal components mainly by proteomic methods. The presence and distribution of Annexin A1, A2 and A5 (ANXA1, ANXA2, ANXA5) in human semen was analysed and the corresponding mRNAs studied in spermatozoa. All three ANXAs were present in prostasomes and spermatozoa, but only ANXA1 in prostasomes-free seminal plasma. Immunofluorescence showed ANXA1 and ANXA5 in the sperm head, mid-piece and flagellum. The amount of mRNAs corresponding to ANXA1 and A2 decreased with increasing levels of the corresponding proteins indicating a probable regulation of their expression at the translational level during spermatogenesis. Additionally, DNA fragmentation was assessed by the sperm chromatin dispersion test. Lower amounts of ANXA1 and A2 with higher levels of the corresponding mRNAs were noted in poor quality semen samples. ANXA5 was detected in spermatozoa from all semen samples, but no particular trend was noted. The corresponding mRNA were detected both in excellent and poor quality semen samples. Results showed that ANXA1 and A2 expressions appear to be related with DNA fragmentation suggesting their possible use as new biomarkers for sperm DNA quality. ANXA5's natural presence in spermatozoa suggest that revision of high-quality sperm selection by binding to this protein is needed.

Study of the effect of ulipristal acetate on human sperm ability to interact with tubal tissue and cumulus-oocyte-complexes.

OBJECTIVE: Ulispristal acetate (UPA) is a selective progesterone receptor modulator widely used for emergency contraception (EC). The described main mechanism of action is by inhibiting or delaying ovulation; however, the postovulatory effects of the drug are still on debate. Therefore, the aim of this study was to determine whether UPA could interfere with human sperm fertilizing ability. STUDY DESIGN: Human motile spermatozoa were incubated under capacitating conditions with or without UPA, and then used to inseminate human tubal explants, mouse cumulus-oocyte complexes and zona-free hamster eggs. The ability of UPA to interact with human sperm progesterone (P)-binding sites was investigated by incubating the cells with fluorescent-labeled P and analyzing them by fluorescence microscopy. RESULTS: UPA did not affect the ability of human sperm to bind to human tubal tissue explants surface or to penetrate the mouse cumulus mass and the zona-free hamster eggs. In addition, concentrations of UPA much higher than those present in the plasma of EC pill users were required to bind to human sperm P-binding sites. CONCLUSIONS: Our study supports a lack of an agonist or antagonist action of UPA on different functional parameters associated with the fertilizing ability of human sperm. IMPLICATIONS: This study provides new functional evidence supporting that the contraceptive action of UPA is not related to effects on human sperm cells, contributing to a better understanding of the mechanism of action of UPA as EC.

Effects of ulipristal acetate on sperm DNA fragmentation during in vitro incubation.

OBJECTIVE: Ulipristal acetate (UPA) acts as an emergency contraceptive by inhibiting ovulation. This study explores possible additional effects on the fragmentation of sperm DNA during in vitro incubation. METHODS: Motile spermatozoa from healthy donors were selected by swim-up and incubated under capacitating conditions in control medium or with UPA (1, 10, 100, 1,000 or 10,000 ng/ml). In some experiments, 200 µM of H2O2 were added to induce oxidative stress. The sperm chromatin dispersion test was performed to analyse DNA integrity (400 cells; 1000×). Lipid peroxidation (thiobarbituric acid assay), induced-acrosome reaction (AR) and sperm vitality (Eosin Y) were also evaluated in spermatozoa exposed to UPA and/or H2O2. RESULTS: During sperm incubation, the percentage of fragmented DNA increased significantly, from 15.0 ± 1.3 to 41.0 ± 4.5% (p < 0.001). In the presence of UPA, DNA fragmentation decreased significantly (p < 0.05), in a dose-dependent manner. At 100 and 1000 ng/ml, UPA also counteracted the effect of H2O2 and prevented DNA fragmentation. No effect on sperm vitality, lipid peroxidation or induced-AR was found with any treatment. CONCLUSIONS: During in vitro sperm capacitation DNA fragmentation increased but the latter was counteracted in the presence of UPA, which possibly acted as a scavenger of reactive oxygen species produced by spermatozoa.

Effect of exposure to ulipristal acetate on sperm function.

OBJECTIVE: A pill containing ulipristal acetate (UPA) is used for emergency contraception (EC). Considering that, following its intake, spermatozoa may be exposed to UPA in the female genital tract we intended to evaluate sperm functions after incubation with this compound. METHODS: Motile spermatozoa were selected by swim-up and were incubated under capacitating conditions with UPA (at concentrations of 1, 10, 100, 1,000, and 10,000 ng/ml) or control medium. The main outcome measures were sperm vitality, sperm protein tyrosine phosphorylation (TyrP), spontaneous acrosomal reaction (AR), and human follicular fluid (hFF)-induced AR. RESULTS: Sperm vitality and TyrP pattern were similar between spermatozoa exposed to UPA or control. In addition, spontaneous AR ranged from 14.0 ±1.5% to 18.0 ±1.9% after exposure to UPA or control medium without significant differences, and UPA did not prevent hFF-induced AR. CONCLUSIONS: Incubation of sperm with UPA at concentrations around the expected plasma levels after ingestion of this EC pill (˜100-200 ng/ml) did not modify the signal transduction of TyrP involved in sperm capacitation. Moreover, UPA showed no agonist effect on progesterone receptors because it did not induce AR. Considering that progesterone in hFF is essential for AR induction, and UPA did not prevent the hFF-induced AR, an antagonist action of UPA on the AR is unlikely.

Peritoneal fluid modifies the response of human spermatozoa to follicular fluid.

The aim of this study was to elucidate the mechanism involved in the acrosome reaction (AR) induced by follicular fluid (FF) in spermatozoa previously exposed to peritoneal fluid (PF). The influence of progesterone was also investigated. Semen samples were from 18 normozoospermic donors. PF samples were from 13 women with unexplained infertility and from a woman treated with synthetic progestagen. FF samples were collected from six women undergoing IVF/embryo transfer and pooled. Motile spermatozoa were capacitated overnight and a kinetic and inhibition study on the FF-induced AR was performed. Spermatozoa pretreated with PF were challenged with either FF or progesterone. The ability of progesterone- and progestagen-supplemented PF to induce AR was analysed. Enzyme-digested PF was also tested. Pre-incubation with PF for 60 min completely prevented the FF-induced AR; spermatozoa treated with PF were unable to respond to FF or progesterone and this effect was not reversible. Progesterone- and progestagen-supplemented PF stimulated the AR relative to controls. Enzyme-digested PF did not have an inhibitory capacity. These data strongly suggest that there are one or more inhibitory proteins in PF that interact with spermatozoa so as to prevent access of progesterone to its receptor and thus inhibit the occurrence of the AR. The oviduct, or Fallopian tube, provides a place for spermatozoa and egg transport and storage, fertilization and early embryo development. If ovulation has not occurred, spermatozoa may reside in the oviduct for several hours or even a few days, awaiting oocyte arrival. It is assumed that fluids present in the female genital tract may have a role in synchronizing the timing required to guarantee the success of fertilization. We previously observed that the peritoneal fluid that bathes the peritoneal cavity is a suitable medium for sperm survival and we also reported that this fluid could stabilize spermatozoa. In this study we show further evidence that the exposure to peritoneal fluid modifies the response of spermatozoa to oocyte signals.

Human tubal secretion can modify the affinity of human spermatozoa for the zona pellucida.

OBJECTIVE: To study the effect of the human tubal tissue conditioned medium (CM) on sperm parameters related to sperm-zona pellucida interaction. DESIGN: Controlled experimental laboratory study. SETTING: Research laboratory. SUBJECT(S): Semen samples from donors with normozoospermia. Human tubal tissue obtained from women undergoing hysterectomies. Human follicular fluids (hFF) and oocytes collected from patients undergoing IVF-ET. INTERVENTION(S): Incubation of spermatozoa with CM proteins obtained from human tubal tissue culture; sperm binding to the zona pellucida assessment. MAIN OUTCOME MEASURE(S): Explants' viability was assessed by tissue DNA analysis. Sperm ability to interact with zona was tested with use of the whole oocyte test. Expression of d-mannose binding sites was assessed with use of a fluorescent probe on mannose coupled to bovine serum albumin. Human FF-induced acrosome reaction was assessed by the Pisum sativum technique. RESULT(S): Although treatment with 0.8 microg/microL of CM allowed sperm binding to the zona and the expression of d-mannose binding sites comparable with sperm in control medium, with 3.2 microg/mL of CM resulted in a significant decrease of both parameters. No effect of CM on spontaneous or hFF-induced acrosome reaction or in sperm viability was observed. CONCLUSION(S): The results indicate that the incubation of spermatozoa in the presence of CM reduces sperm affinity for the zona pellucida. This effect can be partly explained by the decreased expression of d-mannose binding sites on the sperm surface.

D-Mannose-binding sites are putative sperm determinants of human oocyte recognition and fertilization.

The aim of the present study was to further evaluate the participation of D-mannose in the process of human sperm-egg interaction. Zona pellucida binding competitive assays in the presence of D-mannose were carried out using discarded oocytes from IVF. Spermatozoa were capacitated and D-mannose-binding site (MBS) expression, sperm viability and follicular fluidinduced acrosome reaction (AR) were evaluated. MBS were visualized using a fluorescein-neoglycoprotein probe. The capacity of free D-mannose and mannosylated albumin to induce the AR was also tested. MBS and the IVF outcome were also analysed. The involvement of D-mannose in sperm binding to the zona pellucida was verified by the inhibitory effect produced when the sugar was present during binding assays. MBS expression increased during capacitation, in parallel with the ability to undergo the induced AR. Mannosylated albumin, but not the free sugar, induced the AR. In acrosome-reacted spermatozoa, the MBS was located at the plasma membrane, as shown by confocal analysis. No significant difference in the increase in MBS expression was observed among the different IVF groups of patients. The data show that D-mannose is involved in the sperm-zona pellucida interaction, and that the expression of MBS on the sperm surface occurs during the acquisition of in-vitro sperm fertilizing ability.

In vivo assessment of the human sperm acrosome reaction and the expression of glycodelin-A in human endometrium after levonorgestrel-emergency contraceptive pill administration.

BACKGROUND: The objectives were firstly to assess acrosome reaction (AR) status of spermatozoa following uterine flushing, secondly to measure levonorgestrel (LNG) levels in serum and in uterine flushing fluid and finally to measure endometrial glycodelin-A expression after administration of LNG as a form of emergency contraception (EC). METHODS: Forty-eight experiments were conducted on 15 regularly menstruating women. Four groups were formed based on different intercourse to treatment interval and treatment to recovery of spermatozoa and the biopsies. RESULTS: Twenty-four and forty-eight hours after treatment, there were 14.5 +/- 3.9 x 10(6) and 17.3 +/- 6.8 x 10(6) sperm recovered from the uterus, respectively. There were no differences between the AR rate and the endometrial glycodelin-A staining intensity in an LNG or placebo treated cycles. The LNG in uterine flushing medium represented 1.38% of the values observed in serum 24 h after the LNG intake. CONCLUSIONS: Twenty-four and forty-eight hours after administration of EC, neither the proportion of AR sperm, nor the glycodelin-A level was influenced by 1.5 mg of LNG. LNG did not impair the cervical mucus either because viable spermatozoa were found in the genital tract 36-60 h after coitus and 24-48 h after LNG intake. The mechanism of action of LNG as EC remains unknown.

Comparative concentrations of steroid hormones and proteins in human peri-ovulatory peritoneal and follicular fluids.

Despite the fact that both peritoneal (PF) and follicular (FF) fluids have a common ovarian origin, FF is a natural inducer of sperm acrosome reaction (AR) while PF is not. To better understand these effects, concentrations of oestradiol, progesterone and proteins in peri-ovulatory PF and FF were determined and compared. PF was aspirated by laparoscopy at the peri-ovulatory stage from women with unexplained infertility. FF was collected from patients undergoing IVF and pooled. PF and FF were tested for the presence of antisperm antibodies. Oestradiol and progesterone were measured by enzyme immunoassay, and total protein concentration was determined and analysed. The AR was determined in spermatozoa that were exposed to PF alone, progesterone-supplemented PF, progesterone, control medium, or ethanol. No antisperm antibodies were found in any fluid tested. Oestradiol and progesterone and concentrations in PF were significantly lower than in FF. Protein concentration was also significantly lower in PF than in FF, but no differences were observed between the electrophoretic patterns. When capacitated spermatozoa were exposed to progesterone-supplemented PF there was a significant increase in the percentage of AR with respect to those in PF, control medium or ethanol. These results suggest that the lack of AR-stimulating activity of PF was related to its lower progesterone concentration compared with FF.

Doses of levonorgestrel comparable to that delivered by the levonorgestrel-releasing intrauterine system can modify the in vitro expression of zona binding sites of human spermatozoa.

BACKGROUND: The levonorgestrel-releasing intrauterine system (LNG-IUS) exerts its contraceptive effect by interfering with sperm transport through the female genital tract and with ovulation. However, the possibility cannot be discarded that the device exerts a direct effect on sperm function, thus, helping prevent fertilization. OBJECTIVES: The purpose of this study is to evaluate whether LNG at doses comparable to that measured in the uterus during the use of the LNG-IUS affects the detection of D-mannose binding sites or zona pellucida (ZP) receptors on human spermatozoa. The association with acrosomal status was also investigated. METHODS: Seventeen semen samples from fertile men were used, and spermatozoa were separated using a Percoll gradient and incubated for 22 h at 37 degrees C under 5% CO(2) in air. Capacitated spermatozoa were exposed for 30 min to 1,000 or 10,000 ng/mL of LNG or control medium. D-Mannose binding sites were detected using commercial D-mannosylated bovine serum albumin conjugated with fluorescein isothiocyanate, and the percentage of specific patterns (II and III) was recorded. The acrosome reaction was evaluated using the Pisum sativum technique. RESULTS: Levonorgestrel releasing significantly increased (p < .001) the percentage of spermatozoa with D-mannose receptors localized in pattern III, and this increase was dose dependent and a significant increase (p < .001) in the percentage of acrosome-reacted spermatozoa. Double staining confirmed an association between the location of the zona receptor and acrosomal status. RESULTS: The in vitro exposure of capacitated spermatozoa to the assayed doses of LNG increased the proportion of spermatozoa with fewer chances of interacting with the ZP. Further studies should be carried out to confirm whether this mechanism is part of the contraceptive action of the LNG-IUS.

The in vitro effect of emergency contraception doses of levonorgestrel on the acrosome reaction of human spermatozoa.

INTRODUCTION: The aim of this study was to evaluate the effect of three concentrations of levonorgestrel (LNG) comparable to the levels found in serum following ingestion of LNG as emergency contraception (EC) on the acrosome reaction (AR) of capacitated and noncapacitated spermatozoa of fertile men. MATERIALS AND METHODS: A total of 24 semen samples from three fertile men were evaluated. The spermatozoa were selected by Percoll gradient. Twelve samples were subsequently incubated with human tubal fluid medium supplemented with bovine serum albumin (HTF/BSA) for 20 h under capacitating conditions. The capacitated spermatozoa and the spermatozoa from the remaining 12 samples were exposed to LNG at 1, 10 and 100 ng/mL, to follicular fluid (FF) (20 %v/v) and to HTF medium. The ratio of live to dead spermatozoa was assessed after 1, 2 and 3 h of incubation at 37 degrees C and 5% CO2. After 30 min of exposure to the different LNG concentrations, aliquots were divided into two parts. In the first part, spermatozoa were immediately stained with Hoescht 33258 and fluorescein isothiocyanate-pisum sativum agglutinin (FITC-PSA) in order to assess AR rate and to repeat evaluation of the live-to-dead ratio. After 3 h of incubation, the remaining part of the aliquots were submitted to the same procedures. Each concentration of LNG was then compared with FF and HTF medium as positive and negative controls, respectively. RESULTS: The results showed that in vitro exposure to the three different LNG concentrations did not induce AR. CONCLUSION: This study failed to show any in vitro effect on AR of LNG concentrations similar to those found in serum following intake of LNG as EC. If this effect exists or if there is any other that influences sperm fertilizing capacity, in vitro experiments are probably not an appropriate way of testing it.

In vitro effect of levonorgestrel on sperm fertilizing capacity and mouse embryo development.

The objectives of this study were to assess the expression of alpha-d-mannose binding sites in human spermatozoa, human sperm-oocyte interaction and the development of early stages of mouse embryo in the presence of levonorgestrel (LNG). Semen samples were obtained from 16 normozoospermic men. Spermatozoa were separated by Percoll gradient and incubated overnight for capacitation. The kinetic analysis of the expression of alpha-D-mannose binding sites was determined at 0, 4 and 22 h and in 22 h-capacitated spermatozoa that had been exposed to 1, 10 or 100 ng/mL of LNG or to a control medium for 30 min. Sperm binding sites for alpha-D-mannose were detected using commercial alpha-D-mannosylated bovine serum albumin conjugated with fluorescein isothiocyanate. To evaluate sperm-oocyte interaction, each oocyte was placed in a 100-microL droplet containing one of the three doses of LNG or control medium and inseminated with 1.0 x 10(5) motile spermatozoa/mL, after which the number of bound spermatozoa was evaluated. A total of 157 two-cell embryos recovered from eight mice was pooled and assigned randomly to treatment (1, 10 or 100 ng/mL of LNG) or control groups. There was a significant increase in the expression of specific alpha-d-mannose binding sites (Patterns II and III) during the incubation of spermatozoa under capacitating conditions. In the presence of LNG, results showed that there was no significant difference in the expression of specific alpha-d-mannose binding sites (Patterns II and III) at any LNG concentration tested compared with those spermatozoa in control medium. None of the LNG concentrations were capable of modifying the number of spermatozoa tightly bound to the human zona pellucida. There was no association between the presence or absence of LNG or the different doses of LNG evaluated and mouse embryo development. In conclusion, the hypothesis that in vitro exposure to LNG could interfere with sperm function and could contribute to the mechanism of action of this form of contraception was not confirmed but cannot be ruled out by the results of this study.

Effects of human oviductal in vitro secretion on spermatozoa and search of sperm-oviductal proteins interactions.

It has been suggested that oviductal proteins could be involved in modulating sperm function and fertilizing ability through as yet not well-known mechanisms. The objective of the study was to investigate the pattern of proteins secreted by human oviductal tissue cultures and the effects of their conditioned media (CM) on sperm function under capacitating conditions and in phosphate buffered saline (PBS). In addition, interactions between spermatozoa and oviductal proteins were examined. The oviductal tissue was obtained from pre-menopausal patients scheduled for hysterectomies because of uterine fibromyoma. Normozoospermic semen samples were obtained from healthy donors. Cultures of human fallopian tissue were carried out and CM were collected for analysis of the de novo production of [35S]-methionine-labelled proteins by SDS-PAGE. Motile spermatozoa were incubated under capacitating conditions and in PBS, with or without CM, and sperm fertilizing ability was assessed by ionophore-induced acrosome reaction (AR) and the acrosome reaction to ionophore challenge (ARIC) score. The ionophore-induced AR was evaluated by the Pisum sativum technique. Sixteen de novo produced proteins were detected in CM. One of these proteins (molecular weight 79 kDa) was detected in extracts from spermatozoa pre-incubated with CM. Sperm survival and motility were maintained in the presence of CM, although results showed a significant decrease in ARIC score (p < 0.05), with respect to controls. The presence of CM significantly decreased sperm fertilizing ability, without affecting sperm survival. These results suggest that the oviductal secretion could contribute to preserve sperm viability and motility, and to prevent a premature response of spermatozoa to AR inducers.