The photophysics of 2-cyanoindole probed by femtosecond spectroscopy

The photophysics of 2-cyanoindole (2-CI) in solution (water, 2,2,2-trifluoroethanol, acetonitrile‚ and tetrahydrofuran) was investigated by steady-state as well as time resolved fluorescence and absorption spectroscopy. The fluorescence quantum yield of 2-cyanoindole is strongly sensitive to the solvent. In water the quantum yield is as low as 4.4 × 10–4. In tetrahydrofuran, it amounts to a yield of 0.057. For 2-CI dissolved in water, a bi-exponential fluorescence decay with time constants of ∼1 ps and ∼8 ps is observed. For short wavelength excitation (266 nm) the initial fluorescence anisotropy is close to zero. For excitation with 310 nm it amounts to 0.2. In water, femtosecond transient absorption reveals that the fluorescence decay is solely due to internal conversion to the ground state. In aprotic solvents, the fluorescence decay takes much longer (acetonitrile: ∼900 ps, tetrahydrofuran: ∼2.6 ns) and intersystem crossing contributes.

Graphical abstract

ICSI outcomes in men undergoing TESE for azoospermia and impact of maternal age

This retrospective study compared clinical outcomes in men with obstructive and nonobstructive azoospermia after ICSI following testicular sperm extraction and the influence of maternal age. Fertilisation rates, embryo quality, pregnancy rates, miscarriage rates and live birth rates were evaluated. Men with obstructive azoospermia (OA) had significantly higher rates of diploid fertilisation and clinical pregnancy than men with nonobstructive azoospermia (NOA), but miscarriage rates and live birth rates were not significantly different. The higher rates of fertilisation, embryo quality and clinical pregnancy in men with OA were statistically significant when their female partners were <35 years but results were similar in both groups when female partners ≥35 years. Although the OA group had better overall quality embryos than the NOA group when maternal age was <35 years, embryologists can select the morphologically better embryos for transfer, eliminating the effect of embryo quality differences present in these two groups. Understanding more about factors that affect TESE/ICSI outcomes will not only help us predict patients' outcomes but it can help us educate and better counsel our patients.

Testis/sperm-specific histone 2B in the sperm of donors and subfertile patients: variability and relation to chromatin packaging

BACKGROUND

The compaction of human sperm chromatin is the result of replacement of approximately 85% of histones with protamines. Germ-line testis/sperm-specific histone 2B (TSH2B) has been detected in only approximately 30% of mature spermatozoa. Its level in the semen of subfertile patients varies; its function is unknown. We evaluated TSH2B in the sperm samples of 23 donors and 49 subfertile patients and assessed its association with chromatin compaction status.

METHODS

TSH2B level was measured using immunoblotting. Chromatin packaging quality was evaluated by staining with chromomycin A3 (CMA3) which marked spermatozoa with defective packaging. To assess both TSH2B and chromatin status in the same spermatozoon, CMA3 staining and TSH2B immunolocalization were performed sequentially.

RESULTS

A significant correlation (r = 0.55, P = 0.0027) was found between TSH2B level and percentage of CMA3-positive sperm in patient and donor semen samples. When individual spermatozoa were assessed for these parameters, 92% of TSH2B-containing cells were also CMA3 positive. Variation in the total sperm TSH2B level was less in donors than in patients.

CONCLUSIONS

CMA3 positive staining of TSH2B-containing individual spermatozoa and a significant correlation between the total TSH2B level and CMA3 percentage in semen samples suggest a structural role for TSH2B in sperm chromatin organization. Low variability of TSH2B level in donors implies a mechanism (however unknown) regulating this parameter.

Sperm DNA quality predicts intrauterine insemination outcome: a prospective cohort study

BACKGROUND

We aimed to investigate whether sperm DNA quality may predict intrauterine insemination (IUI) outcome.

METHODS

The study was designed in a prospective cohort fashion, at a tertiary centre for reproductive medicine. A total of 119 patients underwent 154 cycles of IUI. Parameters related to demography, cycle management and semen sample used for IUI were evaluated. Conventional semen parameters, morphology (strict criteria), sperm DNA fragmentation and stability [evaluated by terminal deoxynucleotidyl transferase-mediated dUDP nick-end labelling (TUNEL) and acridine orange staining under both acid and acid + heat denaturing conditions respectively] were measured. The main outcome measure was clinical pregnancy, defined as ultrasonographic visualization of intrauterine gestational sac(s).

RESULTS

Logistic regression analyses were done on six sets of data, including all cycles combined, cycles with washed samples, first cycle of each couple, first cycle of each couple with washed samples, cycles stimulated with gonadotrophins and finally gonadotrophin-stimulated cycles with washed samples. The number of pre-ovulatory follicles on day of hCG, the age of the woman and the percentage of sperm with acid- + heat-resistant DNA were the parameters that predicted IUI outcome in most of these data subsets. For the gonadotrophin-stimulated cycles, age of the man appeared as a predictor as opposed to that of the woman; and for the cycles within this subgroup, where the semen sample was washed, sperm DNA fragmentation and age of the man were the only two parameters to predict IUI outcome. No samples with >12% of sperm having DNA fragmentation resulted in pregnancy.

CONCLUSIONS

The number of follicles, age of the woman/man and sperm DNA quality may predict IUI outcome.

Cryopreservation of fractionated, highly motile human spermatozoa: effect on membrane phosphatidylserine externalization and lipid peroxidation

INTRODUCTION

This study investigated lipid peroxidation (LPO) and membrane integrity following cryopreservation-thawing.

METHODS

Infertile men (study group) and donors (control group) were examined. Purified populations of highly motile spermatozoa were cryopreserved using TEST-yolk buffer and glycerol (TYB-G) followed by quick thaw. LPO was measured by a spectrophotometric assay, with and without a ferrous ion promoter. Annexin V binding was used to assess membrane translocation of phosphatidylserine (PS).

RESULTS

Pre-freeze LPO was significantly higher in the study than in the control group (P = 0.03). In both groups, LPO measurements after thawing were significantly higher than the pre-freeze samples not exposed to TYB-G (P = 0.002 and P = 0.001 respectively). However, when the pre-freeze samples with TYB-G were compared with the post-thaw samples (all exposed to TYB-G), these differences were not significant. There was a significant increase in PS externalization following cryopreservation in both groups (P = 0.02 and P = 0.003 respectively). In donors, pre-freeze LPO concentrations had a significant positive correlation with thawed spermatozoa depicting PS externalization (r = 0.77, P = 0.04).

CONCLUSION

Although patients had higher basal LPO than donors, LPO did not differ between fresh and cryopreserved-thawed fractionated motile spermatozoa. Freezing-thawing was associated with translocation of PS to the external membrane leaflet.

Outcome of intracytoplasmic sperm injection in azoospermic patients: stressing the liaison between the urologist and reproductive medicine specialist

OBJECTIVES

To analyze the outcome of intracytoplasmic sperm injection (ICSI) cycles in infertile couples in whom the main diagnosis of infertility was azoospermia of obstructive and nonobstructive origin.

METHODS

Eighty-three consecutive ICSI cycles were carried out with retrieved testicular or epididymal spermatozoa, 60 cycles in 32 patients with obstructive azoospermia and 23 cycles in 12 patients with nonobstructive azoospermia. Fifty-four testicular biopsies (testicular sperm extraction) and 18 epididymal aspirations (microepididymal sperm aspiration) were performed.Results. Motile spermatozoa were recovered in 65 cycles (90.3%). In another 3 (4.2%), nonmotile spermatozoa were retrieved. In 4 patients (5.5%), sperm could not be recovered. In 11 cycles, frozen sperm from a previous procedure were used. A significantly lower fertilization rate (64% versus 73%, P = 0.02), clinical pregnancy rate (13% versus 47%, P <0.001), and good embryo quality rates (35% versus 56%, P = 0.009) were observed in patients with nonobstructive azoospermia. In patients with obstructive azoospermia, no significant differences were observed when the outcome was analyzed on the basis of the sperm origin (ie, from testicular sperm extraction or microepididymal sperm aspiration).

CONCLUSIONS

When combining testicular sperm extraction or microepididymal sperm aspiration with ICSI in patients with obstructive azoospermia, the results in terms of fertilization, implantation, and pregnancy rates were similar to those found in patients with nonazoospermic obstruction who underwent ICSI with ejaculated sperm. Patients with nonobstructive azoospermia had lower fertilization, embryo quality, and pregnancy rates than did those with obstructive azoospermia, probably because of severe defects in spermatogenesis, leading to poor gamete quality. The urologist and reproductive endocrinologist now have an excellent therapeutic option to offer men with previously intractable infertility.

Cryopreservation-thawing of fractionated human spermatozoa and plasma membrane translocation of phosphatidylserine

OBJECTIVE(S)

[1] To evaluate sperm membrane damage during cryopreservation-thawing by the assessment of phosphatidylserine (PS) translocation and [2] to examine the relationship between reactive oxygen species (ROS) and cryopreservation-related alterations.

DESIGN

Prospective cohort study.

SETTING

University-based center.

PATIENT(S)

Men consulting for infertility and fertile donors (controls).

INTERVENTION(S)

Semen processing was performed by density gradient separation followed by cryopreservation and thawing.

MAIN OUTCOME MEASURE(S)

Membrane PS translocation was evaluated with annexin V binding, generation of ROS was detected by chemiluminescence, and motion parameters were assessed by computer analysis.

RESULT(S)

Annexin V binding was detected in the prefreeze fractions with high and low sperm motility. In the patient group, there were significantly higher postthaw levels of annexin V binding in both fractions when compared with prefreezing values. However, such induction of PS translocation was significantly higher in the fractions with high sperm motility. Significantly higher ROS levels were detected in prefreeze samples of the fractions with low sperm motility.

CONCLUSION(S)

In the population of men studied, [1] cryopreservation-thawing was associated with induction of membrane PS translocation; [2] postthaw ROS levels were lower than before freezing; and [3] neither annexin V binding results nor the generation of ROS were able to accurately predict sperm cryosurvival rates.

Effects of hydrogen peroxide on DNA and plasma membrane integrity of human spermatozoa

OBJECTIVE

To evaluate the effects of oxidative stress on DNA and plasma membrane integrity of human spermatozoa.

DESIGN

Prospective cohort study.

SETTING

University-based, tertiary-care infertility center.

PATIENT(S)

Men (n = 10) undergoing infertility investigation.

INTERVENTION(S)

Purified populations of sperm with high motility were separated using Percoll density gradients. Then, spermatozoa were incubated with 0, 10, 100, and 200 microM hydrogen peroxide (H(2)O(2)) under capacitating conditions.

MAIN OUTCOME MEASURE(S)

Motion parameters were assessed by computer analysis. Genomic integrity was examined by the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) assay. Plasma membrane integrity was evaluated by the annexin V-binding assay, a measure of phosphatidylserine translocation.

RESULT(S)

Under basal conditions, there was a significant and negative relationship between sperm motility and the percentages of sperm with DNA fragmentation and membrane translocation of phosphatidylserine. After a 2-h incubation, there was a significant, dose-dependent effect of H(2)O(2) on motion parameters (decrease) and DNA fragmentation (increase). The percentage of annexin V(-) live (normal) cells declined significantly as the level of oxidative stress increased. Although the percentages of annexin V(+) live cells (sperm depicting translocation of phosphatidylserine) and necrotic cells increased at the highest H(2)O(2) levels, these changes were not significant.

CONCLUSION(S)

In vitro sperm incubation with H(2)O(2) induces DNA fragmentation in a dose-dependent fashion. The sublethal effects of oxidative stress on motion parameters were not significantly associated with membrane translocation of phosphatidylserine.

Assessment of sperm cryodamage and strategies to improve outcome

Sperm cryopreservation still represents a valuable clinical aid in the management of infertility. Its current principal indications include (1) donor sperm insemination; (2) freezing before cancer therapy to maintain reproductive capacity; (3) patient's convenience; and (4) because of the outstanding success with ICSI, even patients with different degrees of oligo-asthenoteratozoospermia can now be offered the use of frozen/thawed sperm for oocyte micromanipulation. Although sperm cryopreservation/thawing and results of insemination and IVF have been consistently good using donor semen, results of infertile men (with or without various degrees of oligoasthenoteratozoospermia) have yielded remarkably lower rates of survival and pregnancy. Freezing/thawing techniques have not been subjected to major changes in the last years, Furthermore, the exact nature of sperm cryodamage still remains to be elucidated. Various aspects of sperm freezing are revisited here (1) development of new technical approaches for cryopreservation; (2) analysis of the stimulatory effect of putative cryoprotectant additives; (3) the use of intrauterine insemination-ready processed samples; and (4) selection and optimization of end-points for analysis of cryodamage. It is expected that advances in such areas will improve significantly the cryopreservation/thawing outcome particularly as related to semen samples of subfertile men.

Semen treatment with progesterone and/or acetyl-L-carnitine does not improve sperm motility or membrane damage after cryopreservation-thawing

OBJECTIVE

To assess the effects of progesterone and acetyl-L-carnitine used before semen cryopreservation-thawing on sperm motility parameters and plasma membrane integrity.

DESIGN

Prospective cohort study.

SETTING

Academic tertiary center.

PATIENT(S)

Subfertile men undergoing semen evaluation.

INTERVENTION(S)

Before cryopreservation, spermatozoa were incubated with water-soluble progesterone (1 and 10 microM), acetyl-L-carnitine (2.5, 5, 10, and 20 mM), or both (progesterone, 1 microM; and acetyl-L-carnitine, 5 mM).

MAIN OUTCOME MEASURE(S)

Postthaw change of motility parameters (computer-assisted measurements) and vitality-membrane integrity (examined with eosin-Y staining and annexin V-Cy3 binding assay).

RESULT(S)

There were no statistically significant differences between control samples and samples treated with progesterone and/or acetyl-L-carnitine for cryosurvival rate, motility parameters, or membrane integrity. The percentages of postthaw cells identified as live showed significantly different results with use of the eosin-Y staining and annexin V binding assay.

CONCLUSION(S)

Neither progesterone nor acetyl-L-carnitine seemed to prevent cryodamage assessed by motility changes or membrane integrity in human spermatozoa of subfertile men. Annexin V binding, a reflection of membrane translocation of phosphatidylserine, provided more distinct information about postfreezing membrane integrity changes than eosin-Y staining.

Analysis of DNA fragmentation, plasma membrane translocation of phosphatidylserine and oxidative stress in human spermatozoa

The objectives of this cross-sectional observational study were: (i) to detect DNA damage and plasma membrane translocation of phosphatidylserine in purified sperm populations of high and low motility, and (ii) to analyse their relationship with the endogenous generation of reactive oxygen species. Ejaculates from infertile men were examined following gradient centrifugation. The main outcome measures were: sperm motion parameters (assessed with a computer analyser), generation of reactive oxygen species (measured by chemiluminescence), DNA damage (detected by terminal deoxynucleotidyl transferase-mediated dUDP nick-end labelling and monoclonal antibody labelling of single-stranded DNA) and translocation of membrane phosphatidylserine (examined with annexin V staining). DNA fragmentation and membrane translocation of phosphatidyl-serine were observed in the fractions with low and high sperm motility in all patients. The fractions with low sperm motility had significantly higher proportion of cells with DNA damage and production of reactive oxygen species than the fractions with high sperm motility (P < 0.005). DNA fragmentation was significantly and positively correlated with the generation of reactive oxygen species (r = 0.42; P = 0.02).

IN CONCLUSION

(i) spermatozoa from infertile men display translocation of membrane phosphatidylserine as diagnosed by annexin V positive staining; (ii) DNA damage (fragmentation and presence of single-stranded DNA) can be detected in ejaculated spermatozoa from infertile men in fractions with low and high sperm motility, and (iii) there is a relationship between DNA damage and oxidative stress.

Intra- and inter-laboratory variability in the assessment of sperm morphology by strict criteria: impact of semen preparation, staining techniques and manual versus computerized analysis

We designed prospective studies to compare manual and computerized analysis of sperm morphology by strict criteria using different semen processing and staining techniques. A total of 54 semen samples were studied; slides were prepared from each subject from liquefied semen and after washing, and stained with Diff-Quik or Papanicolaou. An intra-laboratory, blind assessment was performed manually (two observers) and using a computerized analyser (two readings). This demonstrated a very good correlation between manual analysis of liquefied and washed samples with both staining techniques [intraclass coefficient (ICC) = 0.93 and 0.83]. Greater agreement was observed between computerized readings (washed samples) of Diff-Quik (ICC = 0.93) than of Papanicolaou-stained slides (ICC = 0.66). An excellent intra-laboratory correlation was observed for within-computer readings (ICC = 0.93). There was moderate agreement between inter-laboratory computer readings (two centres, ICC = 0.72). Although there was lower inter-laboratory agreement for manual and manual versus computer readings, overall results of all manual and computer analyses showed good agreement (ICC = 0.73). Diff-Quik staining is reliable for both manual (liquefied) and computer (washed) analysis of strict sperm morphology. Intra- and inter-computer analyses using this method reached satisfactory levels of agreement. There is still high inter-laboratory variability for the manual method.

Modulation of sperm tail protein tyrosine phosphorylation by pentoxifylline and its correlation with hyperactivated motility

OBJECTIVE

To assess the effect of pentoxifylline on human sperm functions that are crucial to fertilization.

DESIGN

Prospective, controlled study.

SETTING

Academic tertiary care institute.

PATIENT(S)

Healthy male sperm donors.

INTERVENTION(S)

The effects of pentoxifylline (3.6 mM) on hyperactivated motility, sperm binding to the zona pellucida, and sperm protein tyrosine phosphorylation were evaluated.

MAIN OUTCOME MEASURE(S)

Hyperactivated motility was assessed by computer-assisted motion analysis, and tight binding of sperm to homologous zonae pellucidae was examined using the hemizona assay. Sperm protein phosphorylation was evaluated using indirect immunofluorescence with an antibody to phosphotyrosine (PY20).

RESULT(S)

Pentoxifylline significantly stimulated hyperactivated motility at 1 hour and 4 hours; it also significantly increased sperm binding to the zona pellucida and enhanced sperm tail tyrosine phosphorylation at 4 hours under capacitating conditions. There was a statistically significant correlation between hyperactivated motility and sperm tail protein phosphorylation.

CONCLUSION(S)

Pentoxifylline stimulates sperm functions that are essential to achieving fertilization under in vitro conditions in sperm obtained from fertile men. The enhancement of hyperactivated motility is associated with the stimulation of sperm tail tyrosine phosphorylation, suggesting a causal relation and the involvement of a modulatory effect after cyclic adenosine monophosphate-dependent phosphorylation of intermediate proteins.

Practical evaluation of standard-based low-cost video conferencing in telemedicine and epidemiological applications

The results of the evaluation of use of low-cost video conferencing systems (VCSs) in telemedicine is presented. Applications sharing, a new feature of these systems, recently has allowed high-quality computer-supported collaborative work (CSCW). The video conferencing (VCing) equipment used was Intel ProShare 200 v2.0a. It is representative of other low-cost VCSs. The areas of application are epidemiology and telemedicine (orthopaedics and radiology). Potential end users filled out 58 evaluation questionnaires concerning user profiles, contents and benefits of the sessions, organizational aspects, user friendliness, user acceptance, cost effectiveness, technical and multipoint related aspects. Although the end users had a lot of computer experience, their knowledge in VCSs was rather limited. The users assessed the system capable of being integrated into routine work, despite a high organizational impact. The VCS is user friendly, application sharing being used in almost every session. Audio quality was not always sufficient. The remote video was sufficient, as was the quality of medical images such as CT, MRI or X-ray. The user acceptance of the system was high. Multipoint sessions require a structured protocol to be effective. Some technical problems with MCUs (Multipoint Control Units) occurred. The use of low-cost standard VCSs in telemedicine is advisable and is a good substitute for real meetings.

Pentoxifylline stimulates various sperm motion parameters and cervical mucus penetrability in patients with asthenozoospermia

Pentoxifylline (PTX) was incubated in vitro with human spermatozoa to examine its effects on sperm motility characteristics and bovine cervical mucus penetrability (BCMP). Sperm motion parameters were assessed by computer-assisted motion analysis (CASA) using HTM-IVOS and BCMP was evaluated using the Penetrak kit. In vitro incubation with PTX (1 mg ml-1; 3.6 mM, 30 min) did not significantly change percentage motility, average path velocity (VAP), straight-line velocity (VSL) or beat cross frequency (BCF) of spermatozoa from normozoospermic or asthenozoospermic samples. However, it significantly increased curvilinear velocity (VCL), amplitude of lateral head displacement (ALH) and hyperactivated motility (HA), and significantly decreased linearity (LIN) of spermatozoa from both samples. Pentoxifylline was found to increase BCMP scores for spermatozoa from asthenozoospermic samples, but did not affect scores for spermatozoa from normozoospermic samples. Bovine cervical mucus penetrability (BCMP) was found to be positively and significantly correlated with the percentage motility of both non-PTX-treated and PTX-treated spermatozoa for asthenozoospermic samples. These results demonstrated that PTX enhanced several motion sperm parameters as well as BCMP in asthenozoospermic samples and suggest a potential use of the methylxanthine in infertile patients with motility defects undergoing artificial insemination.

Plasma membrane integrity of cryopreserved human sperm: an investigation of the results of the hypoosmotic swelling test, the water test, and eosin-Y staining

OBJECTIVE

[1] To examine the relationship between sperm membrane integrity and motion parameters before and after cryopreservation; [2] to determine the capacity of the membrane integrity tests to predict the outcome of cryopreservation in fertile and infertile men; and [3] to examine the degree of agreement between tail and head membrane integrity of testicular and ejaculated immotile sperm cryopreserved for intracytoplasmic sperm injection.

DESIGN

Prospective study.

SETTING

Academic tertiary care institution.

PATIENT(S)

Fertile donors and normozoospermic oligozoospermic, and asthenozoospermic subfertile men.

INTERVENTION(S)

Semen samples were cryopreserved and thawed for analysis.

MAIN OUTCOME MEASURE(S)

Sperm membrane integrity and computer-assisted motion parameters.

RESULT(S)

The hypoosmotic swelling test and water test had a significant and positive correlation in the fresh and cryopreserved ejaculates of all groups. The results of the hypoosmotic swelling test correlated positively with the percent motility in the fresh ejaculates of fertile and subfertile men. None of the membrane integrity tests correlated with the cryosurvival rate in any group. In the ejaculated and testicular samples with no postcryopreservation motility, the simultaneous assessment of hypoosmotic swelling test and eosin showed that of 33% sperm exhibiting coiling with the hypoosmotic swelling test, only 9% were eosin negative, whereas 24% were eosin positive.

CONCLUSION(S)

[1] The water test may be a simpler replacement for the hypoosmotic swelling test; [2] none of the membrane integrity tests predicted sperm motility after cryopreservation; and [3] there was a high degree of disagreement between the hypoosmotic swelling test and eosin in the samples with no postcryopreservation motility.

Semen quality: is there a paternal effect on pregnancy outcome in in-vitro fertilization/intracytoplasmic sperm injection?

The objective of this study was to investigate the role of the spermatozoon (paternal effects) on implantation and pregnancy outcome in in-vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI). Male individuals of three types were analysed: infertile men with oligoasthenoteratozoospermia (OAT), infertile men with normozoospermia and fertile men (donors). Female counterparts were judged to have comparable egg quality within two groups studied, i.e. infertile women with pure mechanical (tubal) infertility and recipients of donor eggs. There were significantly higher differences in implantation and pregnancy rates in groups using donor spermatozoa and donor egg recipients. Analyses of key set groups revealed a trend toward a poorer implantation and pregnancy outcome when comparing OAT versus normozoospermic patients within IVF, but not within ICSI treatments, in couples with tubal infertility. In couples who were recipients of donor eggs, no differences were observed between OAT patients treated by ICSI and normozoospermic patients treated with IVF. No significant differences were observed in miscarriage rates within any groups studied. In conclusion, the poorer results observed in OAT patients undergoing IVF may be secondary to spermatozoal effects due to a high insemination concentration. Overall, there does not seem to be a significant effect of severe male infertility (OAT) on implantation and pregnancy outcome. However, this does not preclude that specific sperm aberrations may exert a negative effect on embryogenesis and therefore on implantation potential following assisted or in-vivo reproduction.

Comparison of various methods of processing human cryopreserved-thawed semen samples

We compared the efficacy of various methods of processing cryopreserved-thawed samples for the recovery of functionally adequate spermatozoa as assessed by the response to the sperm stress test (SST), an index of temperature activated sperm membrane lipid peroxidation, and immediate and delayed changes in sperm viability and motion parameters. Donor semen samples (n = 28) were cryopreserved-thawed and divided into six equal parts, one part was used as control and the remaining parts were used to compare five methods of sperm processing as follows: direct Percoll gradient processing, washing by one-step or stepwise addition of the washing medium followed by Percoll processing, and washing by one-step or stepwise addition of the washing medium. Additional samples (n = 10) were evaluated for the immediate and delayed (6 h at 37 degrees C) impact of one-step and stepwise washing (without Percoll separation). Compared with wash-only methods, samples processed using Percoll had a significantly higher SST score (P = 0.001), motility, rapid spermatozoa (>50 microm/s), curvilinear velocity and motility index (P < 0.001). Comparing various Percoll methods, direct Percoll processing resulted in the highest number of motile spermatozoa recovered (P < 0.00001) and a higher SST score based on curvilinear velocity (P = 0.001). Stepwise washing gave a significantly higher number of motile spermatozoa (P < 0.001) but with a significantly lower SST score based on the concentration of motile spermatozoa (P = 0.001), motility (P = 0.001) and motility index (P = 0.01). Sperm viability and motion parameters after 6 h of incubation showed no difference between one-step and stepwise washing. In conclusion, compared with wash-only methods, Percoll processed samples resulted in the recovery of spermatozoa with superior quality as assessed by SST and motion analysis. One-step washing of the samples gave an overall comparable recovery compared to the samples prepared stepwise. Having significantly higher SST scores, similar viability and the maintenance of motility, one-step washing may be a better method of processing thawed samples than the stepwise washing.

Increase of intracellular calcium is not a cause of pentoxifylline-induced hyperactivated motility or acrosome reaction in human sperm

OBJECTIVE

To investigate the effects of the phosphodiesterase inhibitor pentoxifylline on hyperactivated motility and acrosome reaction in human sperm and to determine whether its stimulatory effects occur via increased intracellular calcium levels.

DESIGN

Prospective study.

SETTING

Academic tertiary care facility.

PARTICIPANT(S)

Healthy male donors.

INTERVENTION(S)

The effects of pentoxifylline on hyperactivated motility, acrosome reaction, and intracellular calcium were studied and compared with the effects of progesterone. Thapsigargin, a known mobilizer of intracellular calcium, also was used as positive control.

MAIN OUTCOME MEASURE(S)

Hyperactivated motility was assessed by computer-assisted sperm motion analysis using the HTM-IVOS, acrosome reaction was evaluated with the fluorescent probe fluorescein isothiocyanate-labeled Pisum sativum agglutinin, and intracellular calcium was determined by fura-2 using spectrofluorometry.

RESULT(S)

Pentoxifylline significantly increased both hyperactivated motility and acrosome reaction. Enhancement of hyperactivated motility by pentoxifylline in the capacitation medium persisted for up to 5 hours after pentoxifylline was washed from the medium. It also enhanced the percentage of acrosome-reacted spermatozoa after 4 hours of incubation. These effects occurred in the presence of a marginally significant decrease in intracellular calcium.

CONCLUSION(S)

Pentoxifylline stimulates hyperactivated motility and acrosome reaction in spermatozoa from fertile men. Its stimulatory effects occur through mechanism(s) other than increase in intracellular calcium.

Investigation of some biochemical and functional effects of cryopreservation of human spermatozoa using an automated freezing-quick-thawing method

The objective of the present studies was to assess the functional integrity of the sperm plasma membrane and metabolic and motility characteristics of the recovered motile fraction of human spermatozoa subjected to an automated freezing/quick-thawing method. Sperm membrane features examined included progesterone-induced changes in intracellular levels of calcium ([Ca2+]i), as measured by the fluorescent fura-2 indicator, and the tight binding of spermatozoa to homologous zonae pellucidae as assessed by the hemizona assay (HZA). Basal [Ca2+]i intracellular adenosine triphosphate (ATP) and adenosine diphosphate (ADP) levels determined using chemiluminescence with luciferin-luciferase, and motility parameters determined using a computer-aided semen analyser (CASA) were studied concomitantly as an expression of metabolic/functional status. Ejaculates from fertile men (donors) were evaluated after swim-up separation of the motile fraction in both fresh and cryopreserved-thawed samples, and fractions of each ejaculate (fresh and frozen-thawed) were subjected to parallel measurements of the same parameters at the same time frame. Basal and progesterone-induced increase in [Ca2+]i, and ATP levels (up to 24 h) were similar in fresh and frozen-thawed samples. HZA results showed a modest (26%) although significant (p = 0.008) decrease in binding in frozen-thawed samples. The ratios of ATP/ADP in fresh and frozen-thawed samples were also found to be similar. Although post-thaw sperm motility was significantly lower than that of the fresh samples, comparison of the results indicated that the method was capable of preserving > 65% of motile spermatozoa in almost all of the samples cryopreserved. Additionally, the swim-up rescued a motile fraction in the frozen-thawed samples that was not significantly impaired with regard to motility, mean linear velocity or linearity as compared to the fresh fractions in the first 4 h. Our results show that this automated freezing-quick-thawing method results in a small reduction in sperm-zona binding capacity, and that the time-dependent decline in motility parameters observed for both fresh and cryopreserved-thawed samples cannot be related to ATP deficiency under the conditions of our experiments. These in-vitro results are coincident with the maintenance of fertilizing capacity for donor spermatozoa in the in-vitro fertilization (IVF) setting.

Value of sperm morphology assessed by strict criteria for prediction of the outcome of artificial (intrauterine) insemination

The purpose of this study was to investigate the relationship between sperm parameters and the outcome of artificial (intrauterine) insemination (IUI). One hundred and twenty-six patients undergoing 395 consecutive IUI cycles in a 1-year period in our institution were studied. In all cases, controlled ovarian stimulation and hCG-timed IUI were performed, followed by progesterone supplementation of the luteal phase. In 86 patients, (243 cycles) the husband's sperm was utilized, whereas in 40 couples (152 cycles), donor sperm was used due to severe male factor infertility. Among the sperm parameters of the original ejaculate, % normal morphology (assessed by strict criteria) was the most significant predictor of pregnancy (stepwise regression analysis, P = 0.003). Using logistic regression, morphology was the best predictor of pregnancy (r = 0.12); linearity of movement significantly enhanced the predictive value of morphology alone (r = 0.17, P = 0.004). Overall, the pregnancy rates were significantly higher (P = 0.01) in cases with > or = 14% normal morphology (15% per cycle) compared to cases with < 14% normal morphology (7% per cycle). This threshold level for morphology is in agreement with previously published IVF results. These results underscore the significance of sperm morphology assessed by strict criteria as a predictor of pregnancy outcome in the IUI setting.

Impact of cryopreservation on spermatozoa from infertile men: implications for artificial insemination

The objective of this study was to evaluate the effect of cryopreservation-thawing on the quality of sperm from men with subfertile semen parameters. Twenty-seven patients with teratozoospermia, six of whom also had asthenozoospermia, were studied and their sperm parameters were compared to those of fertile donors (n = 71) in their fresh, post-thaw, and washed samples. After thawing, the percentage decrease in motility was significantly greater in patients than in donors, but the motility yield (post-thaw motility/prethaw motility) reached an average of 58% in the patient group vs. 68% in the donors (p = .02). No single characteristic of the fresh samples from patients or donors could significantly predict post-thaw outcome. For the patient group, however, multiple regression analysis provided a cutoff sperm concentration (50 x 10(6)/mL) and motility (40%) below which a very poor post-thaw recovery was obtained. The frozen-thawed-washed specimens had significantly higher velocity than the frozen-thawed samples, both in patients and donors. The results suggest that some patients with teratoasthenozoospermia yield acceptable sperm parameters after freezing-thawing-washing, and therefore these ejaculates could be used individually (or pooled) in artificial insemination.

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

OBJECTIVE

To evaluate the acrosome reaction and its prerequisite, a calcium influx, in spermatozoa of infertile men with a high incidence of abnormal sperm forms.

DESIGN

Prospective, controlled study.

SETTING

Academic tertiary assisted reproduction center.

PATIENTS

Patients (n = 14) were allocated in the study after semen evaluation showed teratozoospermia (< 14% normal sperm forms) as diagnosed by strict criteria.

INTERVENTIONS

After 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).

RESULTS

Patients 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.

CONCLUSION

Infertile 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.

Validation of the hemizona assay (HZA) in a monkey model. II. Kinetics of binding and influence of cryopreserved-thawed spermatozoa

We compared fresh and frozen-thawed cynomolgus monkey spermatozoa tight binding to the zona pellucida under hemizona assay (HZA) conditions. Monkey oocytes were recovered after superovulation and stored in salt solution. Matching hemizonae were obtained by micromanipulation. Semen, obtained by electroejaculation, was used fresh or was cyropreserved, thawed, and washed by swim-up separation. At the standard initial dilution of 500,000 motile sperm/ml (or 5 x 10(4) motile sperm/hemizona), binding was significantly higher for fresh sperm (P = 0.00004). For frozen-thawed samples, there was a linear increase in the number of tightly bound sperm with increasing sperm concentration (r = 0.95). At 1.5 x 10(6) motile sperm/hemizona, binding of frozen-thawed spermatozoa was similar to that of fresh at a standard concentration. Kinetic studies showed peak binding at 1 hr of gametes coincubation. We conclude that, in this monkey model, the HZA is a valuable bioassay for evaluation of sperm binding to the zona pellucida, the initial requisite for fertilization and embryo development.

Functional and morphological features of spermatozoa microaspirated from the epididymal regions of cynomolgus monkeys (Macaca fascicularis)

In most species examined to date, spermatozoa mature during transit through the epididymis to become functionally competent to swim progressively, fertilize oocytes, and produce viable offspring. In the studies presented here, the status of spermatozoa obtained from the regions of the epididymis of the cynomolgus monkey (Macaca fascicularis) was examined. Epididymal fluid was collected by microaspiration from the caput, corpus, and cauda regions. The spermatozoa obtained were evaluated for morphology, motion parameters, and tight zona pellucida binding and were compared to spermatozoa collected by electroejaculation. Epididymal and ejaculated sperm differed morphologically only in the location of the cytoplasmic droplet. Motile sperm recovered by swim-up procedure exhibited a significantly higher proportion of sperm with more distal cytoplasmic droplets than the original aspirated samples (p < 0.02). Poor duration of movement was most noticeable for corpus spermatozoa, and to a lesser degree for cauda spermatozoa, when the motion parameters of velocity, linearity, and amplitude of the lateral head were examined. Zona pellucida binding was decreased only for sperm microaspirated from the caput region; sperm obtained from the corpus and cauda regions bound comparably to those collected via electroejaculation. These results suggest that by the time cynomolgus sperm reach the corpus region of the epididymis, they are functionally competent for tight zona binding. However, these nonhuman primate sperm may not complete the metabolic changes requisite for sustained sperm motility until reaching the most distal regions of the epididymis.

Sperm creatine phosphokinase M-isoform ratios and fertilizing potential of men: a blinded study of 84 couples treated with in vitro fertilization

OBJECTIVE

To examine the value of sperm creatine phosphokinase M-isoform (CK-MM) measurements toward predicting fertilizing potential of men.

DESIGN

In 84 in vitro fertilization (IVF) couples without knowing the semen parameters, reproductive history or the outcome of the IVF cycles, we determined the sperm CK-MM ratios (the proportion of sperm CK-MM versus CK-MM+CK-BB). Husbands with less than 10% or greater than or equal to 10% CK-MM ratios were classified as "low likelihood for fertilization" (CKMM-Infertile, n = 22) or "high likelihood for fertilization" (CKMM-Fertile, n = 62), respectively.

RESULTS

Both the CKMM-Infertile and CKMM-Fertile groups (CK-MM ratios: 4.9% +/- 0.6% versus 31.1% +/- 1.8%) were in the normospermic range (31.5 +/- 6.9 versus 78.4 +/- 5.9 x 10(6) sperm/mL and 45.6% +/- 5.0% versus 54.0% +/- 2.0% motility). The fertilization rates (6.2 versus 4.9 oocytes inseminated) were 14.2% versus 53.4%, and 72.7% versus 25.8% of the couples failed to achieve any oocyte fertilization. All 14 pregnancies (16.7% rate) occurred in the CKMM-Fertile group. The pregnancy rate in the 62 CKMM-Fertile couples was 22.6%, and considering only the 46 CKMM-Fertile women in whom oocyte fertilization occurred, it was 30.4%. Among the 22 CKMM-Infertile men, 9 were normospermic and 9 of the 62 CKMM-Fertile men were oligospermic. Within the CKMM-Fertile group, 12 and 2 of the 14 pregnancies occurred by the 53 normospermic and 9 oligospermic men (22.6% versus 22.2% rate).

CONCLUSIONS

Sperm CK-MM ratios, a measure of normal sperm development, predict fertilizing potential independently from sperm concentrations. Sperm CK-MM ratios also detect unexplained male infertility (infertile men with normospermic semen), a diagnosis that until now could not be substantiated.

Successful fertilization and pregnancy outcome in in-vitro fertilization using cryopreserved/thawed spermatozoa from patients with malignant diseases

Cryopreservation of spermatozoa before treatment is the only proven effective method available to circumvent the sterilizing effect of therapy in some patients with malignant diseases. Because of impaired sperm quality after freezing and thawing in-vitro fertilization/embryo transfer (IVF/ET) was indicated in 10 patients (12 cycles) during 1986-1990. The patient's mean age was 33.4 +/- 1.6 years. The following diagnoses were made: seminoma (1), testicular carcinoma (3), leiomyosarcoma of the prostate (1), Wegener's granulomatosis (1), non-Hodgkin's (1) and Hodgkin's lymphoma (3). When motile spermatozoa could be recovered after thawing, the total fraction of motile spermatozoa after swim-up separation ranged from 0.2 to 4.2 x 10(6) spermatozoa/ml (eight patients, nine cycles). In all these cases, insemination was performed with multiple oocytes per dish. Fertilization was achieved when swim-up recovered a mean of 1.8 +/- 0.5 x 10(6) spermatozoa/ml and when insemination was performed with at least a calculated concentration of motile spermatozoa of 1 x 10(5) spermatozoa/oocyte. The fertilization rate of preovulatory oocytes was 60%. Four patients achieved a pregnancy: two of them delivered a single healthy baby, one delivered triplet healthy babies and one had a preclinical abortion. In two patients (three cycles), no motile spermatozoa were recovered after thawing, and micromanipulation of oocytes for assisted fertilization was performed. Although fertilized oocytes were transferred, those couples did not achieve a pregnancy. Patients with lymphopathies had the best results, whilst those with testicular neoplasms had the poorest outcome, thus suggesting a poor gametogenic function in the non-affected testis. These results give hope to some patients with malignant diseases to maintain their reproductive capacity through sperm banking and IVF/ET.

Cryopreserved/thawed semen for in vitro fertilization: results from fertile donors and infertile patients

We evaluated the in vitro fertilization (IVF) outcome in 54 cycles using cryopreserved/thawed semen from fertile donors. Controls were other IVF patients matched by time frame, female age, stimulation protocol, number of pre-embryos transferred, and absence of a male factor using freshly ejaculated normal semen samples. In the study group and controls, respectively, post-thaw swim-up motility was 83.1% and 89.5%; fertilization rate of preovulatory oocytes (91.8%, 95.7%) and ongoing pregnancy rate (PR) per transfer (21.1%, 25.0%) were similar. The excellent fertilization rate with frozen/thawed semen was achieved through high-concentration insemination (0.5 x 10(6) motile sperm/mL). With use of frozen/thawed samples from infertile men (normal and subfertile samples), PR was similar but fertilization rate was lower. Cryopreserved semen is a valuable option for infertile couples in IVF therapy.

Relationship between morphology and motion characteristics of human spermatozoa in semen and in the swim-up sperm fractions

In this study, the authors evaluated the morphology pattern and motion characteristics of human spermatozoa before and after swim-up separation. Samples were divided into two, morphologically different groups according to the percentage of normal sperm forms assessed by the strict criteria of the Norfolk laboratory: "good"(G) and "poor" (P) prognosis patterns. The percentages of normal forms, slightly abnormal forms, and severe head defects were significantly different in the two groups. Motile characteristics were analyzed by a computerized semen analyzer with constant parameter settings. Before swim-up there were no significant differences in semen volume, percentage of neck and tail defects, concentration, or percentage of motility and linearity, but the mean velocity was higher in group G. After swim-up the percentage of motility, total number of motile cells, and recovery rate were higher for group G, and the incidence of severe head defects correlated negatively with the percentage of cells with a velocity of greater than 80 microns/sec. The results suggest that patients with a high incidence of sperm head defects have impaired original velocity, and swim-up selects for velocity as well as normal forms and motility. Although motility and velocity improved substantially after swim-up, the recovery rate and percentage of motility were significantly lower in the P group.

Corrective measures and pregnancy outcome in in vitro fertilization in patients with severe sperm morphology abnormalities

Sperm morphology evaluated by new, strict criteria is a good predictor of outcome in in vitro fertilization (IVF). This study aimed (1) to determine whether the fertilization rate of preovulatory oocytes in patients with abnormal morphology can be improved by increasing insemination concentration at the time of IVF and (2) to evaluate the pregnancy outcome in patients with abnormal sperm morphology. Three groups were studied: (1) normal morphology, (2) good prognosis pattern, and (3) poor prognosis pattern. All other sperm parameters were normal. Group 3 had a lower overall fertilization rate, lower pregnancy rate/cycle, and lower ongoing pregnancy rate/cycle. Groups 2 and 3 showed a higher miscarriage rate, although not significantly different from group 1. By increasing insemination concentration from 2- to 10-fold, the fertilization rate in group 3 increased from 14.5% to 62.6%. However, pregnancy outcome did not improve. We conclude that patients with severe sperm head abnormalities have a lower ability to establish successful pregnancies, even though fertilization may be achieved.

Abnormal sperm morphology and other semen parameters related to the outcome of the hamster oocyte human sperm penetration assay

A new method for evaluation of sperm morphology using strict criteria is currently used in the andrology laboratory at the Eastern Virginia Medical School. A prospective study was designed to evaluate the following semen parameters in samples of all patients over a set period of time: sperm concentration and motility, and normal sperm morphology. These factors were correlated with results of the hamster zona-free oocyte/human sperm penetration assay (SPA). One hundred patients with a sperm concentration ranging from 2 to 219 X 10(6)/ml, a motile sperm fraction ranging from 6.9 to 87%, and normal sperm morphology ranging from 1 to 39%, were evaluated. The statistical analysis system general linear model was used to judge the influence of the different variables. There was a statistically significant relationship between the per cent of sperm with normal morphology and penetration rate in the SPA (P = 0.001). Outcome of the SPA was also correlated with in vitro fertilization, retrospectively, in 84 patients. Thirty-eight patients had an SPA less than 10%, with no fertilization in vitro in 13 patients (33.3%) and fertilization in 25 (66.7%). Forty-five had an SPA greater than 10% with fertilization in 37 (82.2%) and no fertilization in eight (17.8%) patients.

Correlation between sperm morphology, acrosin, and fertilization in an IVF program

Acrosin, a neutral proteinase, is located within the acrosome. The aim of this study was to evaluate acrosin concentrations in patients with severe damage of the sperm head and to determine whether acrosin concentration could predict the chances of fertilization in an IVF program. Sixty patients were accepted into this study, prospectively. The patients were divided into two groups, those with a normal morphology of less than 14% (group I, n = 33) and those with normal morphology less than 14% (group II, n = 27). All patients had a sperm concentration of less than 20 million sperm/ml and less than 30% progressively motile sperm. The acrosin assays were performed on the semen sample obtained on the day of IVF. Routine IVF insemination procedures were used, and only mature oocytes were considered. The only factor that showed a significant correlation of fertilization was normal morphology (p less that 0.01). The mean acrosin level was 73.4 /+- 38.6 mED/10 million sperm in group I and 70.9 /+- 42.7 mIU/10 million sperm in group II (no significant difference). The fertilization rate in group I was 45.4% and in group II, 77.7% p less than 0.002). Acrosin levels were not significantly different in patients with and without fertilization (72.0 /+- 42.1 and 73.6 /+- mIU/10 million sperm, respectively).

New method of evaluating sperm morphology with predictive value for human in vitro fertilization

A prospective study was planned to evaluate sperm morphology as a parameter to predict the fertilization outcome in an in vitro fertilization program. Couples applying to in vitro fertilization were admitted into this project when the sperm concentration was greater than 20 million per mL and motility greater than 30 per cent. Based on new strict criteria for evaluating normal sperm morphology, patients were divided prospectively into 2 groups. In group I (25 patients) normal sperm morphology was less than 14 per cent, and in group II (71 patients) normal sperm morphology was greater than 14 per cent, using a threshold established previously. Multiple regression analysis was used to evaluate different parameters: concentration, motility, and morphology against the dependent variables, fertilization, and cleavage. The only factor which was significantly correlated with fertilization and cleavage was normal sperm morphology (P less than 0.0001). The fertilization rate (per oocyte) and the cleavage rate were 49.4 per cent and 47.6 per cent in group I and 88.3 per cent and 87 per cent in group II (P less than 0.0001). The ongoing pregnancy rate per laparoscopy and per embryo transfer was 4 per cent and 5.5 per cent, respectively, in group I and 18.3 per cent and 18.5 per cent, respectively, in group II (no significant difference). This study demonstrates the value of analyzing sperm morphology using the criteria recommended in terms of predicting fertilization and perhaps pregnancy outcome. Patients can be better counseled and the probability of fertilization or no fertilization can be more accurately established. Furthermore a trend is shown in the pregnancy rate that may indicate the importance of the male genome in establishing a pregnancy.