Biomedical subjects

R Gamzu

Publications and source records attributed to R Gamzu.

At least 37 records · Page 2Linked to original sources

PubMed1999

Pre-freezing sperm preparation does not impair thawed spermatozoa binding to the zona pellucida.

The present study was conducted to assess the fertilizing potential of frozen-thawed spermatozoa, which were cryopreserved after separation on a Percoll gradient, or washed out of seminal plasma. For this purpose, binding to the zona pellucida and other characteristics of the treated sperm cells were compared with those of cryopreserved spermatozoa from the same original sample which were not manipulated before freezing. Semen specimens were obtained from 80 candidates for sperm donation. Percoll-treated sperm samples compared with the sibling, unprocessed controls had significantly higher values of sperm motility characteristics and per cent of cells with normal morphology after freezing and thawing. Sperm binding ability to the zona pellucida was not statistically different (109 +/- 8.1% and 94 +/- 6.7% in unprocessed and Percoll-treated samples respectively). Sperm specimens processed by washing had significantly higher values for motility characteristics than untreated sibling samples, but no differences were found between the treated and untreated samples for morphology and binding to the zona pellucida (hemizona index of 75 +/- 7.0% and 76 +/- 6.7% in unprocessed and washed samples respectively). These findings suggest that, judged by the binding assay, the aforementioned pre-freezing separation processes have no adverse effect upon the fertilizing potential of the thawed sperm cells. These procedures make it possible to optimize the progressive motile sperm cell concentration of the frozen specimen, which facilitates the storage of samples with good quality, even when the features of the original semen are sub-optimal.

Cell Separation↗

PubMed1999

Genetic evaluation of infertile men.

Recently, microdeletions in the azoospermic factor region of the Y chromosome, in addition to chromosomal anomalies, have been detected in men with azoospermia or severe oligozoospermia. In this study we evaluated the molecular and cytogenetic defects of infertile men. The frequency of Y microdeletions among 105 azoospermic, 28 oligozoospermic and 32 fertile men was tested on lymphocyte DNA using a series of 20 sequence-tagged sites. In addition, microdeletions were evaluated on testicular-derived DNA among 26 azoospermic patients who underwent testicular biopsy and in whom no sperm cells could be identified. Karyotype analysis was performed on 72 of the infertile patients. Deletions were detected in 6.7% azoospermic and 3.6% oligozoospermic men. No deletions were identified among the fertile men. Identical results were obtained with DNA derived either from lymphocytes or testicular tissue. The frequency of chromosomal aberrations in the 72 infertile patients tested (62 azoospermic, 10 oligozoospermic) was 16.6%, with a high percentage of gonosome anomalies. Additional andrological parameters (hormone values, cryptorchidism) failed to identify men at risk for having microdeletions before the test. Our findings support the recommendation to perform genetic defect screening among infertile men before their enrollment in an intracytoplasmic injection/in-vitro fertilization programme.

Adult↗

PubMed1998

Expression of mannose-ligand receptors on human spermatozoa: effect of lecithin and association with sperm binding to the zona pellucida.

OBJECTIVE: To evaluate the change in the expression of mannose-ligand receptors and sperm binding capacity after the incubation of sperm cells with lecithin liposomes. DESIGN: A randomized, blinded-controlled experiment. SETTING: Andrology laboratory at the Lis Maternity Hospital. PATIENT(S): Fifteen fertile sperm donors and 10 subfertile men. INTERVENTION(S): Incubation of sperm samples with either control medium or 1 mg/mL of liposomal lecithin for 2 hours. MAIN OUTCOME MEASURE(S): Expression of mannose-ligand receptors as evaluated by mannosylated bovine serum albumin-fluorescein isothiocyanate and sperm binding to the zona pellucida as evaluated by the hemizona assay. RESULT(S): The mean +/- SE percentages of spermatozoa with patterns I, II, and III were 86% +/- 4.8%, 11% +/- 3.4%, and 3% +/- 1.6%, respectively, after treatment with control medium and 71% +/- 5.7%, 22% +/- 3.5%, and 7% +/- 2.5%, respectively, after treatment with lecithin. The same effect of lecithin was observed in the 10 sperm samples from subfertile men. The mean +/- SE numbers of sperm that bound to hemizonae after treatment with control medium or lecithin were 116 +/- 32.4 and 176 +/- 29.6, respectively. Statistically significant correlations were observed between the shift in patterns II and III and the enhancement of sperm binding after lecithin treatment (r = 0.44 and 0.6, respectively). CONCLUSION(S): Lecithin shifts the expression of mannose-ligand receptors to the capacitated and acrosoine-reacted patterns and enhances the binding capacity of the sperm cells.

Adult↗

PubMed1998

Multiple testicular sampling in non-obstructive azoospermia--is it necessary?

Spermatogenesis may be focal in non-obstructive azoospermia. The present study was conducted to determine whether the performance of multiple, rather than a single testicular sample contributes to obtaining spermatozoa in amounts sufficient for fertilization and cryopreservation in non-obstructive, azoospermic patients. Furthermore, the aim was to clarify the significance of location for retrieval from the testis in such cases. Three biopsies were taken from identical locations in 55 testes of 29 men with non-obstructive azoospermia: (i) the rete testis region, ii) the midline, and (iii) the proximal region of the testis. When sperm cells were detected, they were used for intracytoplasmic sperm injection (ICSI), and the remainder were then cryopreserved in as many aliquots as possible (adjusted for ICSI procedure). Spermatozoa were found in 28 testes (50.9%) of 18 men (62.1%). In the testes from which spermatozoa were obtained, they were present in three, two or one locations in 15 (53.6%), five (17.9%) and eight (28.6%) cases respectively. The possibility of finding spermatozoa was not influenced by the location in the testis. Multiple testicular sperm extraction is recommended in cases of non-obstructive azoospermia, since it may enhance diagnostic accuracy of absolute testicular failure and increase the number of sperm cells retrieved.

Adult↗

PubMed1997

Sperm quality in Hodgkin's disease versus non-Hodgkin's lymphoma.

The study was conducted to determine the deleterious effect of lymphoma disease on spermatogenesis and to evaluate the possibility that the disease is mediated primarily by inherent mechanisms in Hodgkin's disease and non-Hodgkin's lymphoma patients. A total of 89 patients with lymphoma disease (Hodgkin's and non-Hodgkin's) were referred for sperm preservation prior to adjuvant treatments. A comparison was made of pre- and post-thaw sperm quality between lymphoma patients and healthy volunteers who applied for sperm donation. This was followed by further assessment of the differences between patients with Hodgkin's disease and non-Hodgkin's lymphoma in terms of sperm variables, clinical parameters and blood hormone concentrations. It was found that patients with lymphoma disease had significantly impaired pre-freeze and post-thaw sperm quality compared with that of healthy volunteers. Patients with non-Hodgkin's lymphoma had spermatozoa of higher quality than patients with Hodgkin's disease. No differences were found in the clinical or hormonal parameters between these two groups. As expected, reduced testicular size and abnormal testicular consistency were correlated with decreased sperm quality. The mere presence of cancer disease has a direct negative effect on spermatogenesis, which is probably not related to incidental side-effects. A variable degree of impairment should be expected with different categories of cancer.

Adolescent↗

PubMed1997

Testicular cancer and spermatogenesis.

We retrospectively analysed the characteristics of 54 men with testicular cancer. The group comprised 32 men with pure seminoma and 22 with non-seminoma germ cell tumours (NSGCT). This group was further compared to 190 healthy sperm donor candidates. Sperm quality was found to be higher in the seminoma versus the NSGCT patients in: sperm concentration [50 (0-230) versus 17 (0-288) x 10(6)/ml, P < 0.001], total motile sperm counts (TMC) [57 (0-508) versus 12 (0-854) x 10(6)/ejaculate, P = 0.002], post-thaw forward motile concentration [3 (0-28) versus 1.7 (0-17) x 10(6)/ml, P = 0.003] and motility percentage [20 (0-57) versus 12.5 (0-42) %, P = 0.002]. Serum hormone concentrations did not differ between these two sub-groups, although the follicle stimulating hormone concentrations were higher than normal in both (14.6 +/- 2.5 versus 10.4 +/- 1.4 mIU/ml, P > 0.05). As is well documented, cancer patients were found to have lower sperm quality compared to healthy candidates. The existence of these differences, and the fact that testicular cancer affects spermatogenesis, indicated that the mechanisms involved in the deterioration of sperm quality can, at least partially, be attributed to the type and origin of the malignant cancer. The higher sperm counts in the seminoma group may be related to the fact that the resemblance of the seminoma cells to normal germ cells is greater than that of the NSGCT cells, and therefore they retain a better capacity to function. Due to modern assisted reproductive technologies and micromanipulation achievements, the lower yield of spermatozoa in severe cases is no longer a major obstacle to offering cryopreservation to these patients.

Cryopreservation↗

PubMed1997

Reduction of sperm cholesterol:phospholipid ratio is a possible mechanism for enhancement of human sperm binding to the zona pellucida following incubation with phosphatidylcholine liposomes.

TEST (TES (N-tris[hydroxymethyl]methyl-2-aminoethanesulfonic acid) and Tris) yolk buffer (TYB) has recently been shown to improve the binding capacity of spermatozoa to zona pellucidae. The present study had two objectives: 1) to elucidate which component(s) of TYB dominates this effect and 2) to define the responsible mechanism. Sperm samples obtained from subfertile men were incubated for 2 h in either TYB or media containing egg yolk lipoproteins or phospholipids. After incubation, sperm binding was tested by the hemizona assay. Yolk lipoprotein-treated spermatozoa bound hemizonae with efficiency equal to that of the spermatozoa incubated in control medium. Conversely, incubation of spermatozoa in media containing either TYB, yolk-phospholipids, or pure phosphatidylcholine (PC) resulted in a 2- to 3-fold increased binding capacity (p < 0.01). A close correlation was found between the effect of yolk-phospholipids and TYB on the binding capacity of the same sperm samples, compared to spermatozoa incubated in control medium. Incubation of spermatozoa in yolk phospholipid medium caused a dose-dependent increase of sperm binding capacity (p < 0.05). Treatment of sperm samples with 1 mg/ml or more of purified PC preparation also resulted in a reduction of the sperm cholesterol:phospholipid molar ratio. Significant correlations between the effects of the treatments on sperm cholesterol: phospholipid molar ratio and sperm binding were obtained with yolk-phospholipids (r = -0.55) or 1 mg/ml purified PC (r = -0.61). We conclude that 1) the enhanced binding capacity of human spermatozoa following TYB treatment is probably due to yolk-phospholipids, mainly egg yolk PC; and 2) it appears that the enhanced binding capacity of human spermatozoa following treatment with egg yolk-containing media may be a result of the reduction of the cholesterol:phospholipid molar ratio in the sperm cells.

Acrosome↗

PubMed1995

The use of hemizona assay in the evaluation of the optimal sperm preparation technique.

The objective of the study was to evaluate the benefit of different sperm preparation methods by using the hemizona assay. A total of 58 men admitted to the male infertility clinic for evaluation were tested by routine semen analysis and hemizona assay. Five different techniques (swim-up, TEST-yolk buffer, Percoll, pentoxifylline and progesterone) were used for preparation of sperm suspensions. The effect of these treatments on the sperm-binding capacity using the hemizona assay was assessed. The routine swim-up preparation was used as the reference method. Of the four preparation methods, only the TEST-yolk buffer and pentoxifylline exhibited an overall statistically significant improvement in sperm-binding capacity in comparison with the swim-up preparation method (P = 0.01 and 0.001 respectively). Following preparation with Percoll and progesterone there was no change in the mean value of binding capacity, compared with swim-up. However, examination of the effect of the four treatments on each specimen individually yielded a diversity in the response, e.g. having the capability to enhance, damage or be ineffective in sperm binding capacity. The results support the conclusion that in-vitro sperm preparation methods can affect sperm binding to the zona pellucida. Since there is a diversity in the response of sperm samples to different treatments, the hemizona assay can be used in selecting the optimal sperm preparation method prior to its use for assisted reproductive techniques. This is advocated mainly for the 'male factor' group.

Cell Separation↗

PubMed1995

Female age does not affect the capacity of human zona pellucida to bind spermatozoa.

The purpose of this study was to evaluate the effect of female age on the capacity of the zona pellucida to bind spermatozoa. A total of 1008 unfertilized oocytes obtained from 210 women (aged 21-43 years) participating in the in-vitro fertilization programme were tested using a hemizona assay. Spermatozoa taken from a cryopreserved pool of fertile donor specimens served as a control in the hemizona assay, and were used to assess the ability of the zona pellucida to bind spermatozoa. The mean +/- SD number of spermatozoa attached to the hemizona was 107 +/- 42. The binding capacity of different oocytes from the same cohort varied substantially (coefficient of variation = 28%). Age was not found to be correlated with the number of spermatozoa bound to the zona pellucida (r = -0.02; P > 0.1). It was concluded that female age has no role in the ability of the human zona pellucida to bind spermatozoa.

Adult↗

PubMed1995

Pentoxifylline improves sperm binding to the zona pellucida in the hemizona assay.

OBJECTIVE: To evaluate the effect of pentoxifylline on sperm binding capacity to zona pellucida (ZP) using the hemizona assay (HZA). DESIGN: The fertility potential of 82 men was evaluated by routine semen analysis. Each ejaculate was incubated with or without pentoxifylline (3 mM) in Ham's F-10 medium (Flow Laboratories, Irvine, Scotland) before the HZA. The effect of the pentoxifylline treatment on sperm-binding capacity to ZP was assessed by the hemizona index. RESULTS: The mean hemizona indexes with medium or pentoxifylline treatment were 23% +/- 2.1% (mean +/- SE) and 41% +/- 3.4%, respectively. Taking into consideration a significant change of the hemizona index on rising above the intra-assay coefficient of variation (+/- 8%) after pentoxifylline treatment, 73.1% of specimens improved, 19.5% deteriorated, and 7.4% remained unchanged. Using a threshold hemizona index of 23% as a discriminator between fertile and infertile specimens, 43.5% of the "pentoxifylline-improved" samples ascended to the fertile zone (> 23%). No correlations were found between sperm variables in the raw semen and the effect of pentoxifylline on sperm binding capacity. CONCLUSION: Pentoxifylline may improve the binding capacity of human spermatozoa. However, this effect is confined to a selected group of patients and cannot be predicted by the basic sperm variables. Thus, to avoid uncertain or damaging effects of pentoxifylline while preparing sperm suspension for assisted reproductive techniques, it is recommended that its effect be tested by the HZA system before its use.

Female↗

PubMed1994

The hemizona assay is of good prognostic value for the ability of sperm to fertilize oocytes in vitro.

OBJECTIVES: To assess the prognostic value of hemizona assay (HZA) in predicting the success of IVF. DESIGN: Samples from 133 patients, who were referred for semen evaluation, were tested by HZA. Thirty samples were tested twice to assess interassay variation. Seventy couples were also referred for IVF. Results of HZA were compared with standard parameters of sperm quality, fertilization rates, and pregnancies. RESULTS: The intra-assay and interassay coefficient of variation were 8% and 14%, respectively. Hemizona assay results had the highest correlation with sperm morphology (r = 0.60). Of all parameters evaluated, fertilization rates were best predicted by hemizona index (HZI) (r = 0.75). The assay was found to have high sensitivity and specificity rates, at a threshold HZI of 23%. CONCLUSIONS: The HZA is a valuable prognostic test for IVF. With a threshold HZI of 23%, it has a good predictive value for fertilization rates in IVF, and may thus be used for patient preselection before IVF.

Female↗

PubMed1994

The effect of egg yolk on the binding capacity of human spermatozoa to zona pellucida.

OBJECTIVE: To evaluate the effects of Tes and Tris (TEST)-yolk buffer (TYB) incubation on sperm function. DESIGN: Sperm samples obtained from 61 patients attending the infertility clinic were incubated in TYB and control medium. Binding to the zona pellucida (ZP), evaluated by the hemizona assay, membrane functional integrity evaluated by the hypoosmotic swelling test, and acrosome reaction and penetration through cervical mucus were assessed to ascertain the effect of TYB treatment. RESULTS: The only substantial effect of TYB treatment was enhanced sperm binding to the ZP. The mean number of sperm cells attached to the hemizonae with TYB or medium treatment, was 42 +/- 6.1 (+/- SE) and 31 +/- 5.8, respectively (n = 61). However, this improvement was most obvious in 12 patients whose sperm samples exhibited a marked increase in sperm binding capacity following TYB treatment compared to medium without TYB, 71 +/- 5.6 and 12 +/- 2.7, respectively. In the other sperm samples (n = 49), sperm binding capacity was similar following TYB and medium treatment (both 35 +/- 6.0). CONCLUSIONS: A 2-hour incubation of sperm samples with TYB-containing medium (at room temperature) enhances the binding capacity of human spermatozoa in approximately 20% of patients considered to have male factor infertility. The basis of this selective effect has yet to be studied further.

Egg Yolk↗

PubMed1993

[Hemizona assay for evaluating fertilizing capacity of human spermatozoa].

The hemizona assay (HZA), which tests the binding capacity of human spermatozoa to the zona pellucida, is described. This assay has very high sensitivity (86-100%) in predicting fertilizing capacity in the in vitro fertilization (IVF) system. It is recommended that it be carried out on semen samples before entering the IVF program. In addition, it can also help evaluate unexplained infertility and assess the quality of ova. The necessity for a control fertilized sample in each HZA might complicate the assay. To simplify the test, the use of sperm from the sperm bank was investigated. It was shown that fresh and frozen-thawed sperm have the same capacity to bind to the hemizonae. Thus, frozen donor semen preserved in the sperm bank can be used for controlling the HZA.

Cryopreservation↗

PubMed1992

Fresh and frozen-thawed human sperm bind in a similar pattern to the zona pellucida in the hemizona assay.

This study evaluated the impact of sperm cryopreservation on sperm quality. The HZA was used to test the binding capacity of fresh as opposed to frozen-thawed sperm from 12 donors. Fresh and frozen-thawed sperm motility was 47% +/- 1.5% and 24% +/- 3.8% (mean +/- SE), respectively. However, the number of sperm cells attached to the hemizonae was 75 +/- 12.0 and 74 +/- 11.9, respectively. We conclude that cryopreservation results in a reduced number of motile sperm cells but does not adversely affect the ability of rescued sperm cells to bind to the ZP. The study also supports the use of frozen-thawed rather than fresh donor sperm for control in the HZA procedure.

Cryopreservation↗

PubMedDate not supplied

Probability of sperm detection in nonobstructive azoospermic men undergoing testicular sperm extraction procedures unrelated to clinical parameters.

The study was conducted to evaluate the significance of preoperative clinical parameters for detection of mature testicular sperm cells in nonobstructive azoospermic men. Sixty-five consecutive men with nonobstructive azoospermia underwent testicular sperm extraction procedures. Testicular samples were analyzed histologically with patterns classified as mature spermatogenesis (normal or partial), arrest of spermatogenesis, and Sertoli cell only. Testicular sperm cells were isolated for use in an IVF/ICSI program. Histologic patterns and detection rate of sperm cells were correlated to clinical characteristics. Mature sperm cells were found in all levels of serum FSH. The men were divided into 3 groups based on their clinical characteristics (serum FSH level and testicular size). The distribution of the different testicular histologic patterns, as well as detection rate of sperm cells, was similar in all groups. No correlation was found between serum levels of FSH, LH, prolactin, or testosterone and sperm presence. None of these parameters, nor the testicular size and consistency, can serve as predictive variables of the histological pattern or the presence of mature sperm cells in the testicular biopsies in cases of nonobstructive azoospermia. Until an effective predictive tool is available, a trial of sperm retrieval is recommended for all azoospermic men independent of their clinical characteristics.

Adult↗

PubMedDate not supplied

The expression of mannose-ligand receptor is correlated with sperm morphology.

The objective of the present study was to evaluate the association between the expression of sperm mannose-ligand receptors and sperm morphology. Sperm samples were obtained from 45 men, 30 fertile sperm donors and 15 infertile men. Sperm concentration, motility and morphology were evaluated and then incubated with control medium (Ham's F-10 + 1% HSA) for 4 h. Expression of mannose-ligand receptors was evaluated by mannosylated-BSA-FITC (subdivided into 3 patterns: I, for uncapacitated sperm; II, for capacitated; and III, for acrosome-reacted sperm). The mean (+/- SE) frequencies of sperm cells of the total sperm population that expressed patterns I, II, and III were 88 +/- 2.1%, 7 +/- 1.6%, and 5 +/- 0.8%, respectively, for fertile men, and 90 +/- 2.1%, 7 +/- 1.3%, and 3 +/- 0.5%, respectively, for infertile men. The rate of pattern III expression of mannose-ligand receptors was significantly higher in the fertile group compared to the infertile patients (p <.01). A poor but significant correlation was observed between the rate of pattern III and the percentage of normal-forms sperm cell in the ejaculate (r =.35, p =.018). Fertile sperm samples express more advanced patterns of mannose-ligand receptors compared to infertile men. This phenomenon is related to the morphology of human sperm cell in the ejaculate more than to any other basic sperm characteristics.

Humans↗

PubMedDate not supplied

Improvement in the cervical mucus penetration test by using standard sperm control.

The objective of the present experiments was to establish an acceptable standard for the cervical mucus penetration test (CMPT) by determining the minimal progressive motile spermatozoa concentration (PMSC) that will yield the highest score for proven fertile donor sperm specimens. For this purpose, fresh and frozen-thawed samples were used. Semen was obtained from 29 fertile donors and different PMSC (8, 10, and 14 x 10(6)/mL) were prepared for each sample. The same mucus specimen was used for testing each sperm sample in the three different dilutions. No difference in the scoring of the CMPT between the fresh vs. frozen-thawed groups was found. When PMSC of 14 x 10(6)/mL was used, almost all specimens scored the highest rank. The present study revealed that only semen samples with a minimal PMSC of 14 x 10(6)/mL cells can be used in the CMPT. The information that the freeze-thaw process does not affect the CMPT results supports the concept of cryopreservation of pooled fertile donor specimens in aliquots with adequate concentration of progressive motile spermatozoa for later use as a CMPT control.

Cervix Mucus↗

PubMedDate not supplied

Sperm binding and ultrasound changes after operative repair of varicocele: correlation with fecundity.

The study was conducted to evaluate the changes in sperm binding capacity and ultrasound measurements of the internal spermatic vein, after operative repair of a varicocele. In order to clarify the effect of a varicocele on fertility, these changes were correlated to pregnancy achievement. Twelve infertile males with subnormal semen parameters and varicocele, underwent operative repair. Pre- and post-operatively, all had semen analysis, hemizona assay and ultrasound of the internal spermatic veins. The patients were divided into three subgroups according to pregnancy outcome, and the changes in the different evaluation tests after the operation were compared. Sperm concentration and motility improved post-operatively in all three subgroups, whereas the hemizona index and ultrasonographic measurements improved significantly only in the subgroup that achieved early pregnancies (the mean post-operative percentage of normal morphology was significantly higher), compared to the subgroup without pregnancies. Unlike sperm parameters which improve after operative repair of the varicocele, but have no correlation to conception, sperm binding and ultrasound measurements of the internal spermatic veins improve significantly in cases that achieve early pregnancies. The use of these tests, as well as measuring the percentage of normal morphology, are recommended in all cases of infertility-related varicocele.

Female↗