Influence of initial semen quality on the integrity of human sperm DNA following semen processing

OBJECTIVE: To examine and compare the effects of density-gradient centrifugation on the integrity of sperm DNA from the semen of both fertile and infertile men. DESIGN: Prospective, observational study. SETTING: University infertility clinic. PATIENTS: Forty-four nonazoospermic, infertile men and nine fertile controls. INTERVENTIONS: Semen samples were processed by density-gradient centrifugation. Sperm motility and sperm chromatin structure (evaluated by flow cytometry analysis of acridine orange-treated spermatozoa) were monitored before and after semen was processed. MAIN OUTCOME MEASURES: Sperm motility and DNA integrity. RESULTS: Following density-gradient centrifugation, mean sperm motility (+/-SEM) improved significantly compared to whole semen in samples from fertile and infertile men, respectively (71 +/- 6 vs. 49 +/- 7% and 56 +/- 3 vs. 44 +/- 3%, P<0.05). However, the percentage of sperm with denatured DNA increased compared to whole semen after processing of samples from infertile (25 +/- 3 vs. 15 +/- 2%, P<0. 01) but not fertile men (9 +/- 3 vs. 8 +/- 2%, P>0.05). CONCLUSIONS: Our data indicate that the potential detrimental effect of density-gradient centrifugation on sperm DNA integrity is related to the initial semen quality. These data urge us to examine our current sperm-processing techniques to minimize sperm DNA damage.     

Light and electron microscopic study of the effect of L-carnitine on the sperm morphology among sub fertile men

ObjectiveThis work was conducted to evaluate the effect of L-carnitine on sperm morphology in sub fertile patients who need enhance for intra cytoplasmic sperm injection (ICSI) as a method of infertility treatment.SettingAssisted Reproduction Unit, at the International Islamic Centre for Population Studies and Researchs (IICPSR), Al-Azhar University and Zoology Department Faculty of Science (Girl's Branch), Al-Azhar University.Materials and methodsAccording to the routine semen analysis, 85 patients were divided into:Group 1: Ten normal fertile men.Group 2: 25 oligozoospermic cases with sperm count less than 20 million/ml.Group 3: 25 athenozoospermic cases with reduced sperm motility <40%.Group 4: 25 teratozoospermic cases with more than >40% abnormal forms.L. carnitine therapy in the form of Carnivita forte 1gm /tab. b.i.d. for three months were given to groups 2, 3 and 4. All the patients underwent semen analysis before and 90 days after therapy. Group 1 was subjected to two semen analysis 3 months apart as a control. Smears were made on slides, fixed in absolute ethyl alcohol and stained with H&E and methyl green pyronin for light microscopic study. A second semen sample was processed for electron microscopic study.ResultsIn the fertile control group, there have not been any statistically significant differences among the patients at the beginning of the study and after 3 months regarding all the studied parameters. In Oligo group, highly significant decrease in the mean percent of head defects, cytoplasmic droplet and mitochondrial sheath defects were observed after treatment. In both atheno and terato groups, highly significant decrease in the mean percent of head defects, midpiece defects, cytoplasmic droplet and mitochondrial sheath defects were observed after treatment. The mean of DNA content of sperm heads demonstrated highly significant increase in oligo, atheno and terato-zoospermia groups as compared to the same groups before treatment.ConclusionThese results clearly show that L-carnitine treatment has ameliorative impact on the quality of spermatozoa in the infertile men, resulting in a decrease number in morphologically abnormal spermatozoa. These data indicated that this agent affects the quality of spermatozoa in infertile patients who need intra cytoplasmic sperm injection (ICSI) as a method for infertility treatment.     

Semen parameters in 114 fertile men

We studied the quality of semen in 114 fertile men (their wives were in the first trimester of pregnancy), aged 31.9 ± 5.7 yr. The results (mean ± S.D.) were as follows: number of spermatozoa, (72 ± 61.6) · 10⁶/ml; motile spermatozoa, 56.6% ± 13.5; spermatozoal velocity, 34.2 ± 4.3 μm/s; motility index, 19.5 ± 5.6 μm/s; normal forms, 51.7% ± 13. It was found that the percentage of motile spermatozoa and the index of motility decrease progressively, at a rate of about 5–10% per hour. In contrast, in the majority of cases, sperm velocity increases during the first 4 h. Low significant correlation was found between percentage of motility and spermatozoal velocity the first hour after ejaculation. Furthermore, moderate significant correlations were found between number of spermatozoa/ml, percentage of motility and normal forms. Finally, low significant negative correlation was found between number of spermatozoa/ml and spermatozoal velocity.     

Potential adverse effect of semen processing on human sperm deoxyribonucleic acid integrity.

OBJECTIVE: To examine the effect of standard Percoll density-gradient centrifugation on human sperm DNA denaturation. DESIGN: Prospective, observational study. SETTING: University-based infertility clinic. PATIENT(S): Twenty-five nonazoospermic men. INTERVENTION(S): Semen samples (n = 25) were obtained from consecutively seen nonazoospermic men presenting for infertility evaluation. Samples were processed by two-layer and four-layer Percoll density gradients. Sperm motility and sperm chromatin structure (evaluated by flow cytometry analysis of acridine orange-treated spermatozoa) were monitored before and after semen processing. Sperm chromatin integrity was expressed as the percentage of spermatozoa that demonstrated denatured DNA. MAIN OUTCOME MEASURE(S): Sperm motility and DNA integrity. RESULT(S): Mean sperm motility improved significantly after processing with two-layer and four-layer Percoll gradients compared with whole semen (54% and 57% motility versus 44% motility, respectively). In contrast, the percentage of sperm with denatured DNA increased after processing with two-layer and four-layer Percoll gradients compared with whole semen (34% and 32% versus 18%, respectively). CONCLUSION(S): Our data demonstrate that the improvement seen in sperm motility after Percoll processing is not associated with a similar improvement in sperm DNA integrity. These data suggest that we reexamine current sperm processing techniques to minimize sperm DNA damage and the potential transmission of genetic mutations in assisted reproductive cycles.     

Cryopreservation of Low Number of Human Spermatozoa; Which is Better: Vapor Phase or Direct Submerging in Liquid Nitrogen?

Cryopreservation and subsequent survival of semen samples with low numbers of human spermatozoa in assisted reproductive technology (ART) facilities can be challenging. The aim of this study was to compare the quality of warmed human spermatozoa following vitrification using direct submerging (DS) in liquid nitrogen (LN₂) or with LN₂ vapour (V). Normozoospermic ejaculates were prepared by the swim-up technique and the motile sperm fraction was divided into three groups: (i) fresh (control); (ii) DS methods in LN₂ (DS Group); or (iii) cryopreserved in V (Group V). Cryopreservation was performed in a small volume using a Cryotech device. After warming, sperm parameters (motility, viability, acrosome, DNA fragmentation and chromatin integrity) were assessed using cytochemical assays. Progressive motility, viability, chromatin integrity and DNA fragmentation differed significantly after warming when compared with the control. Sperm progressive motility and total motility rates were significantly higher in the DS Group compared to Group V. However, normal morphology, acrosome integrity and DNA damage were not significantly different between two groups. Also, sperm chromatin condensation using chromomycin-A3 (CMA3) and Aniline Blue (AB) staining showed fewer alterations in the DS Group compared to Group V. The rates of spermatozoa with an intact acrosome decreased significantly after thawing from 81.30?±?6.76% to 68.84?±?14.70% in the DS Group and to 60.92?±?8.06% in Group V. Cryopreservation of a small number of spermatozoa with the DS method showed superior outcomes with regard to motility, viability and chromatin configuration.     

A New Method for the Purification of Human Motile Spermatozoa Applying Density-Gradient Centrifugation: Polysucrose Media Compared to Percoll Media

Purpose: A newly developed method for the Isolation of human motile spermatozoa using density-gradient centrifugation was compared with the traditionally used Percoll technique. Method: Sperm samples were divided into two equal aliquots, which were purified with either the traditionally performed Percoll technique or a new alternative based on polysucrose/Optiprep media. For each sample the isolation was performed during the same run of the centrifuge. Results: The average recovery of progressively motile spermatozoa with the polysucrose/Optiprep method was significantly higher (48 ± 7%) than with the Percoll method (38 ± 6%) (n = 18). The average percentage of motile spermatozoa and the motility score were similar in the purified preparations. Conclusions: The new polysucrose/Optiprep-based density-gradient centrifugation technique for the isolation of motile human spermatozoa is as good as the traditionally used Percoll method and may replace it in connection with assisted reproduction techniques.     

Serum anti-Müllerian hormone levels do not predict the efficiency of testicular sperm retrieval in men with non-obstructive azoospermia

Background. We aimed to determine whether serum concentrations of anti-Müllerian hormone (AMH) can be used as a tool for prediction of the efficacy of sperm retrieval.

Methods. This was a prospective cohort observational study. AMH levels were determined in 47 men presenting for infertility evaluation. Group 1 consisted of 24 infertile patients diagnosed with non-obstructive azoospermia. Group 1 was further divided into two subgroups. The patients with spermatozoa in their testicular samples constituted group 1a (n = 13), while the patients with absence of spermatozoa constituted group 1b (n = 11). Twenty-three normozoospermic fertile men constituted group 2. Serum AMH was measured before obtaining testicular specimens.

Results. Testicular spermatozoa were recovered in 13 out of the 24 patients (54%). Demographic characteristics of the three groups were similar. The difference between serum AMH levels among the three groups did not reach statistical significance.

Conclusions. We speculated that although AMH is secreted predominantly into the seminiferous tubules, studying serum samples might be more advantageous than seminal plasma because the presence of seminal proteases could influence AMH levels in the latter. However, our results did not demonstrate differences in serum concentrations of AMH between the studied groups. Studies with extended patient populations focusing on seminal plasma concentrations of AMH are warranted.     

Human sperm penetration of zona-free hamster eggs after storage of the semen for 48 hours at 2 degrees C to 5 degrees C

The motility of human spermatozoa and their ability to penetrate zona-free hamster eggs were examined after dilution of the semen with TES-Tris (TEST) yolk buffer and storage for 48 hours at 2 degrees C to 5 degrees C. Semen samples from 10 fertile donors and 19 infertility patients were studied. More than 65% of the spermatozoa which were initially motile in the TEST yolk buffer remained active after storage. During storage, the mean swimming speed of the sperm declined to approximately 60% of the prestorage value. The percentage of zona-free hamster eggs that were penetrated by spermatozoa from patients and donors increased significantly following 48 hours of storage at 2 degrees C to 5 degrees C. Normal semen and abnormal semen were equally preserved by this storage method. This procedure may be used to ship semen samples by commercial transportation to specialized laboratories for testing. Low temperature storage in the TEST yolk buffer appears to enhance the fertilizing capacity of human spermatozoa in vitro.     

Relationship between the number of veins ligated in a varicocelectomy with testicular volume,hormonal levels and semen parameters outcome

Purpose: Correlate semen analysis, hormones, and testicular volume with the number of veins ligated.Methods: Patients were divided into three groups: Group 1 (≤5 veins), Group 2 (6–10 veins), and Group 3 (> 10 veins). We evaluated testicular volume, hormonal levels, sperm concentration, and motility before and after the surgical procedure.Results: In Group 1, even though there was an improvement in both testicular volume and sperm concentration; testosterone levels and sperm motility did not improve with surgery. In Group 2, no changes were detected in the both testicular volumes, in sperm concentration, motility, and testosterone levels. In Group 3, an improvement was seen in the right testicle volume, testosterone levels, and sperm concentration. Follicle-stimulating hormone levels decreased following the surgical procedure in all groups.Conclusion: Patients with more than 10 ligated veins have better chances to improve sperm concentration. FSH levels decreased in all groups of patients.     

The effects of age on DNA fragmentation,chromatin packaging and conventional semen parameters in spermatozoa of oligoasthenoteratozoospermic patients

Purpose To investigate the effects of male ageing on DNA fragmentation and chromatin packaging in the spermatozoa of oligoasthenoteratozoospermic (OAT) patients. Methods Sixty-one OAT patients and 49 men with proven fertility (controls) were included in the present study. DNA fragmentation was detected by terminal deoxynucleotidyl transferase-mediated dUTP-nick end labelling (TUNEL) assay, while chromatin packaging was assessed by chromomycin A₃ (CMA₃) staining. Results In the patient group, semen volume, percentage of normally shaped spermatozoa and sperm motility decreased significantly (P < 0.05) with age, while sperm concentration and the percentage of TUNEL and CMA₃ positive spermatozoa showed a statistically significant increase with age (P < 0.05). In the control group, conventional semen parameters as well as DNA fragmentation and chromatin packaging did not show a statistically significant change with age (P > 0.05). Conclusion Increased age in OAT patients is associated with an increase in sperm concentration, DNA fragmentation and poor chromatin packaging, as well as a decline in semen volume, sperm morphology and motility.     

Efficacy and safety of papaverine as an in vitro motility enhancer on human spermatozoa

Purpose

The aim of this study was to examine the ability and safety of papaverine supplementation for in vitro sperm motility enhancement. In addition, sperm motility enhancement of papaverine was compared to pentoxifylline and theophylline. The post-thaw spermatozoa were used as an asthenozoospermia model.

Methods

Post thaw sperm suspensions were divided into two groups: papaverine (100 μmol/L) and control, and each was investigated in two subgroups of 30- and 60-min exposure times. Detailed motility parameters were detected using a computerized sperm motility analyzer. Acrosomal status, viability, apoptosis, and DNA fragmentation were evaluated by flow cytometry. Furthermore, the motility-enhancing capacity of papaverine, pentoxifylline, and theophylline was compared.

Results

Cryopreservation impaired sperm parameters dramatically but no significant changes occurred in acrosomal status and apoptosis. Supplementation of papaverine enhanced motility parameters consistently at all exposure intervals, significantly. However, viability was lower at the 60th minute compared to the 30th minute (p=0.019). Papaverine did not alter any acrosomal or apoptotic markers at any time points. All of the compounds compared in this study increased the motility parameters, where theophylline supplementation provided significantly better improvement in total motility compared to papaverine and pentoxifylline.

Conclusion

Our results suggest that in vitro papaverine treatment for 30 min adequately improves motility of post-thaw sperm, without leading to acrosome reaction, DNA damage, and viability loss. Theophylline’s potency on increasing the ratio of total motile spermatozoa was found significantly superior than the two tested compounds. Prospective clinical studies with embryo production, pregnancy, and live birth data should be undertaken.

     

Optimal Utilization of Cryopreserved Human Semen for Assisted Reproduction: Recovery and Maintenance of Sperm Motility and Viability

Purpose: Our purpose was to evaluate sperm motility and viability and the maintenance of these parameters in already cryopreserved semen samples following repeated freezing/thawing cycles. Methods: Human spermatozoa were subjected to five cycles of cryopreservation/thawing. Recovery of sperm motility and viability and the proportion of viable nonmotile sperm were determined up to 6 hr after thaw. Results: Sperm motilities (prefreeze motility, 70.1%; n = 9 samples) after each of five freeze/thaw cycles were 24.4, 8.0, 3.5, 1.5, and 1.8%. The recovery of sperm viability was higher than that of motility after each cycle: 39.1, 25.3, 22.6, 17.8, and 16.5%. Recoveries of motility and viability were improved if the thawed samples were left in the original cryopreservation medium prior to refreezing vs. if a washing/resuspension step was included. The recovery of sperm motility in the first thawing cycle was indicative of the expected motile sperm recovery in the second thawing cycle. Conclusions: Cryopreserved semen that is intended to be reused in future assisted reproduction treatments should be thawed only once and aliquoted in the original freezing medium before refreezing. The recovery of sperm motility and viability in the second thawing cycle, thus the applicability of the sample in conventional in vitro fertilization or intracytoplasmic sperm injection may be anticipated in >90% of the samples. In view of intracytoplasmic sperm injection it is important that sperm viability is maintained better than motility; after the first, second, and third thawing cycles the ratios of motile:nonmotile viable sperm were 1:1, 1:4, and 1:7, respectively.     

Correlations between two markers of sperm DNA integrity, DNA denaturation and DNA fragmentation, in fertile and infertile men

OBJECTIVE: To evaluate two different assays of human sperm DNA integrity, DNA denaturation (DD) and DNA fragmentation (DF), and to correlate these with standard semen parameters. DESIGN: Prospective, observational study. SETTING: University infertility clinic.Patient(s): Forty consecutive semen samples from 33 nonazoospermic men presenting for infertility evaluation and 7 fertile men presenting for vasectomy. Intervention(s): Assessment of sperm concentration, motility, morphology, DD and DF. MAIN OUTCOME MEASURE(S): Sperm DD and DF in fertile and infertile men. RESULT(S): The mean (+/-SE) rates of DD and DF were significantly higher in infertile subjects compared to fertile controls, respectively: 25.4 +/- 3.0 vs. 10.2 +/- 2.3 (P=.028) and 27.6 +/- 2.5 vs. 13.3 +/- 2.5% (P=.016). DF and DD correlated strongly (r = 0.71, P<.0001). Also, DD and DF correlated negatively with standard semen parameters (concentration, motility, and morphology), the strongest correlation being with sperm motility. CONCLUSION(S): The strong correlation between sperm DD and DF, and the higher levels of sperm DNA damage in infertile compared with fertile men, indicate that male infertility is associated with poor sperm DNA integrity. Although infertile men may father children with assisted conception, fertilization with DNA-damaged spermatozoa may increase the risk of genetic disease in the offspring.     

Doppler study and evidences of perfusion changes in the ophthalmic artery of pregnant smokers

Abstract

Objectives: To compare the ophthalmic artery (OA) perfusion of pregnant smokers and nonsmokers by Doppler indexes. Correlate these with the interval of last cigarette, cigarettes per day, years smoking and carbon monoxide expired (COex).

Method: Transversal study involving 70 pregnant smokers divided into 33 pregnant who smoked until 2?h: A group (AG) and B group (BG): 37, who smoked between 2 and 24?h before test. Control group (CG) was composed of 51 pregnant nonsmokers. Doppler indexes were assessed: PSV (Peak Systolic Velocity), EDV (End Diastolic Velocity), PI (Pulsatility Index), RI (Resistance Index) and PR (Peak Ratio). Groups were compared using ANOVA, Kruskal–Wallis test, Student’s t test, Mann–Whitney and Pearson’s correlation coefficient, whereas p?<?0.05.

Results: RI and PI were higher (p?<?0.01) and PSV and EDV were lower (p?<?0.05) in B group compared to other groups. A group presented higher PR (p?<?0.01) compared to control. AG presented years of smoking, cigarettes per day, COex greater than BG and lower interval of last cigarette than BG.

Conclusions: The OA in pregnant smokers shows a biphasic pattern of perfusion correlated with the time of consumption of the last cigarette. There are signs of vasoconstriction and hypoperfusion to tobacco exposure between 2 and 24 and hyperperfusion in A Group compared to B Group.     

Coculture of human spermatozoa with reproductive tract cell monolayers can enhance sperm functions better than coculture with vero cell monolayers

Purpose: In order to develop a better system for support of human sperm function in vitro, we conducted studies to evaluate whether reproductive tract cells are better than non-reproductive tract cells as an adjunt in that regard. Methods: Human spermatozoa were cocultured with Vero cells, with human oviduct cells and endometrial cells, and without cells (control) for either 1, 4, or 24 hr. Sperm motility was then analyzed with a computer-aided sperm analyzer (CASA-Hamiliton Thron, HTM IVOS Motility Analyzer). Aliquots of spermatozoa incubated for 24 hr were also stained with Hoechst 33258 and FITC-PNA to evaluate the status of acrosome in live cells. Results: Significant differences (P<0.05) between the oviduct cell and the control groups after 24 hr were evident in the curvilinear velocity (VCL) (81.4±13.4 vs 60.0±14.1 µm/sec) and amplitude of lateral head displacement (ALH) (5.2±0.6 vs 4.1±0.5 µm). The incidence of acrosome reaction of live sperm was significantly higher in the endometrial cell group than in the controls (25.4±9.9 vs 6.6±2.4%;P<0.001). Conclusions: Coculture with human reproductive tract cells seems to improve some functional parameters of human spermatozoa. Coincubation with such cell lines, especially oviduct cells, might be a feasible approach to optimization of human spermatozoa for assisted fertilization using subfertile or frozen-thawed samples. We think coincubating human spermatozoa with a human reproductive tract cell line, especially oviduct cells, might be a feasible approach in preparing human spermatozoa for assisted fertilization in subfertile and frozen-thawed semen samples.     

New insights into possible factors contributing to male subfertility

Male subfertility contributes significantly to fertility problems in couples. Although semen analysis may identify abnormalities in sperm numbers, morphology and/or motility that might contribute to subfertility, in other instances the semen parameters may appear to be normal, but the spermatozoa might be dysfunctional. A number of endogenous and exogenous factors have now been identified that can significantly affect sperm function in vitro and it is possible that they may have similar effects in vivo . Some endogenous factors maintain the spermatozoa in a non-fertilizing state, to avoid them 'burning out' and losing fertility before they reach an oocyte, while others stimulate spermatozoa to become fertile and then hold them in a state of readiness to fertilize. Exogenous environmental molecules, referred to as xenobiotics, have been shown to continuously stimulate spermatozoa so that they become fertile quickly, but then 'burn out'. Defects relating to the endogenous molecules could result in spermatozoa either never becoming fertile or becoming fertile too quickly and so losing fertilizing potential. By understanding the mechanisms involved in promoting sperm fertilizing ability, it may be possible to develop new therapeutic treatments to overcome such defects. (Reprod Med Biol 2005; 4 : 45–53)     

Relationship Between Standard Semen Parameters,Calcium, Cholesterol Contents,and Mitochondrial Activity in Ejaculated Spermatozoa From Fertile and Infertile Males

Purpose: To correlate levels of cholesterol (CH), calcium (Ca²⁺), and mitochondrial activity (MA) with the standard semen parameters and to compare them between fertile and infertile men.Methods: We studied 151 semen samples from infertile (n=60) or fertile (n=91) males. Basic sperm parameters were analyzed. Ca²⁺ and CH concentrations on seminal plasma were determined by enzymoimmunoanalysis. Intracellular Ca²⁺ and CH concentrations in the sperm plasma membrane and mitochondrial activity by fluorometry.Results: There was a significant positive correlation between sperm membrane CH and sperm morphology. Intracellular Ca²⁺ was lower in infertile patients compared to fertile. No differences were found regarding Ca²⁺ and CH concentrations in seminal plasma. MA is directly and strongly related with sperm motility.Conclusions: Intracellular concentrations of Ca²⁺ and the proportion of CH in the sperm membrane are two important markers of the sperm quality due to its direct relationship with sperm morphology and fertility potential.     

Isolation of motile spermatozoa from semen samples using microfluidics

A microfluidic device was designed with two parallel laminar flow channels where non-motile spermatozoa and debris would flow along their initial streamlines and exit one outlet, whereas motile spermatozoa had an opportunity to swim into a parallel stream and exit a separate outlet. Motile sperm samples were prepared with density gradient separation (n = 5). Sperm motility was assessed the following day after exposing aliquots to polydimethylsiloxane (PDMS) used to construct the device. There was no difference in sperm motility when compared with unexposed aliquots (P > 0.05). Unprocessed semen samples (n = 10) were placed in wider channels and sperm motility and strict morphology were assessed from sorted outlets. Sperm motility increased from 44 +/- 4.5% to 98 +/- 0.4% (P < 0.05) and morphology increased from 10 +/- 1.05% to 22 +/- 3.3% (P < 0.05) following processing. Finally, density gradient prepared samples (n = 6) containing 5 x 10(6) motile spermatozoa/ml and 50 x 10(6) round immature germ cells/ml were sorted and assessed in a similar fashion. The ratio of motile spermatozoa to round immature germ cells in the wide inlet (1:10) was significantly improved in the thin outlet (33:1) (P < 0.05). This microfluidic device provides a novel method for isolating motile, morphologically normal spermatozoa from semen samples without centrifugation. This technology may prove useful in isolating motile spermatozoa from oligozoospermic samples, even with high amounts of non-motile gamete and/or non-gamete cell contamination. A movie sequence showing streaming and sorting of spermatozoa may be purchased for viewing on the internet at www.rbmonline.com/Article/847 (free to web subscribers).     

Andrology: The Effect of Human Fallopian Tube Epithelium on Human Sperm Velocity Motility and Binding

Purpose: A prospective, controlled in vitro study was conducted to evaluate the effects of human fallopian tube epithelium on the motility, velocity, and binding of humanspermatozoa. Methods: Eleven fallopian tubes from six women undergoinghysterectomy and semen samples from 14 male partnersof women undergoing in vitro fertilization were collected.Human spermatozoa were cultured with monolayer of humanfallopian tube epithelial cells. The motility and velocity wereanalyzed subsequently at 0, 2, 6, 24, and 48 hr of incubation.The sperm binding capacity was analyzed after 48 hr in thehemizona assay (HZA). Results: The presence of the human fallopian tube epithelialcells did not have any beneficial effects on sperm motilityand velocity. On the other hand, significant promoting effectwas observed in the ability of the sperm to bind to thezona pellucida. Conclusions: The interaction of human spermatozoa withfallopian tube epithelial cells significantly increases spermbinding in the HZA.     

甘油冷冻保护剂及冷冻降温速度对人精子功能及染色体的影响

为研究冷冻对人精子生育力及染色体的影响。本实验选用健康、已生育、２５～３５岁男性供精者的精液,以７．５％的甘油作冷冻保护剂,通过冷冻前后精液常规分析、穿卵试验、染色体核型分析,发现在冷冻－复苏后,精子活动率、穿卵率均有一定程度下降,精子染色体数目和结构异常的发生频率冻贮前后无显著差异。但在活力好、具有生育能力的精子中,携Ｘ－染色体的精子与携Ｙ－染色体的精子所占比例发生了显著改变,由冻前的Ｘ：Ｙ＝５０： ５０变成冻后的 ６０．８５： ３９．１５。