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Biomedical subjects

H Yavetz

Publications and source records attributed to H Yavetz.

At least 19 recordsLinked to original sources
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↗
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

Are Israeli women in a low risk group for developing squamous cell carcinoma of the uterine cervix?

OBJECTIVE: Invasive cervical squamous cell carcinoma is not a common disease among Jewish women. In the present study an attempt was made to find what is the distribution of the known risk factors in this population. METHODS: Three hundred and ninety-one patients with various cervical cytological abnormalities comprised the study group. They were compared to 350 Israeli women with negative cytology. The risk factors were extracted from an anonymous questionnaire. The results were statistically analyzed and compared to the equivalent figures published in the literature pertaining to non-Jewish women. RESULTS: The prevalence of abnormal cytology among the Israeli women was almost the same as that of the non-Jewish group: 24/1000 and 26/1000, respectively. Significant statistical differences were found between the following risk factors: number of sexual partners, age at first intercourse, age at first pregnancy. Women in the study group were younger when they became sexually active and at first pregnancy, they had a larger number of sexual partners, fewer of them were married and fewer of them were observant of Jewish ritual practices. In addition, they had achieved higher academic levels than the women in the control group. CONCLUSIONS: It was found that the distribution of the known risk factors among the study group was practically the same as those in the non-Jewish population. Moreover, it was found that there was an increase of 29.2% (from 17/1000 to 24/1000) in the prevalence of cervical premalignant lesions among the Israeli women. We believe that this population can no longer be considered as being at low risk for this disease.

Adolescent↗
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

Blood luteinizing hormone and prolactin concentrations in response to naltrexone challenge: studies on rats with diabetes induced by different doses of streptozotocin.

Opiate system involvement in diabetes induced by three different doses of streptozotocin (STZ; 40, 50, and 60 mg/kg body weight [BW]) was studied by monitoring luteinizing hormone (LH) and prolactin (PRL) levels as a response to naltrexone (Nalt) administration. After four weeks of diabetes a marked decrease in BW, as well as severe hyperglycemia and increased blood urea nitrogen (BUN) levels were found. The rats, whose diabetes was induced by 50 mg/kg of STZ, exhibited the highest amount of blood glucose (P < 0.05, compared with the 40 mg/kg induced group) and BUN levels (P < 0.004 compared with the other two groups) and BW loss. The normal response to Nalt, which is expressed by elevation of plasma LH and decreased plasma PRL levels was observed only in the low-dose STZ (40 mg/kg BW) diabetes-induced group, while in the other two diabetic groups (50 and 60 mg/kg BW) there was no significant change in plasma LH and PRL as a result of the Nalt challenge. Presensitization of the endogenous opioid receptors by morphine in normoglycemic (control) and "low-dose diabetic" rats (40 mg/kg BW of STZ), presented a clear difference between the two. Morphine pretreatment inhibited LH response to Nalt in the low-dose, STZ-induced diabetic rats, while no effect of morphine pretreatment on LH response to Nalt could be recorded in the normoglycemic group. Thus it can be concluded that in STZ-induced diabetes, plasma glucose and BUN levels do not reflect the neuroendocrine injury observed when monitored by LH and PRL secretion in response to Nalt challenge. Supersensitization of the opioid receptors before the Nalt challenge may increase the ability to reveal neuroendocrine system impairment.

Animals↗
PubMed1994

Outcome of donor versus husband insemination in couples with unexplained infertility treated by in vitro fertilization and embryo transfer.

OBJECTIVE: To examine the IVF-ET outcome of couples with unexplained infertility treated by husband versus donor sperm. DESIGN: A retrospective analysis of the IVF-ET outcome of couples with unexplained infertility treated by either husband or donor sperm and in a subgroup of patients treated simultaneously by husband and donor sperm. SETTING: IVF Unit, Serlin Maternity Hospital, Tel Aviv, Israel. PATIENTS: Couples diagnosed as having unexplained infertility underwent IVF at our Unit; included were 96 couples treated by husband insemination (group A), 27 couples who received donor insemination because of azoospermia (group B), and 8 couples who sought donor insemination after having previously failed IVF (group C). RESULTS: No statistically significant difference was found between groups A and B regarding age of the females, duration of infertility, number of IVF cycles, fertilization rate, number of ETs, and pregnancy rate. Oocytes collected in group C were subdivided further into two groups: 45 were incubated with husband sperm and 46 were incubated with donor sperm. Fertilization rates were 46.6% and 50%, respectively. One pregnancy occurred. CONCLUSION: In couples with unexplained infertility who had undergone IVF-ET with husband insemination, the fertilization and pregnancy rates were similar to those of couples who were treated by donor sperm.

Adult↗
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↗
PubMed1994

Human testis cDNAs identified by sera from infertile patients: a molecular biological approach to immunocontraceptive development.

Sera from patients with known or suspected immunological infertility were used to screen a human testis cDNA library. A total of 59 sera detected 38 unique cDNA inserts of which four were testis specific by Northern blot analyses. One of these is a testis-specific isoform of calpastatin. Five additional clones, although not testis specific, were found to be testis abundant. The number and type of clones identified by these human sera suggests a possible aetiology for immunologic infertility. The testis-specific clones will be further characterized to establish their usefulness as contraceptive vaccine candidates.

Antigens↗
PubMed1994

Retrograde ejaculation.

Retrograde ejaculation is an uncommon cause of male infertility. It should be suspected in any case of azoospermia, and might be congenital, acquired or idiopathic in origin. When pharmacological attempts to restore anterograde ejaculation fail, it is suggested that spermatozoa should be recovered from post-ejaculation urine to be applied in one of the modern techniques of assisted reproduction. The successful recovery of viable spermatozoa from the urine is dependent upon careful regulation of pH and osmolarity of the urine at the time of ejaculation. Careful handling of the retrieved spermatozoa enables isolation of sperm cells with good quality for insemination of ovulated oocytes (in vivo) or retrieved oocytes (in vitro).

Ejaculation↗
PubMed1994

Management of bilateral nonpalpable testes: laparoscopic diagnosis and orchidectomy.

Bilateral nonpalpable testes in the adult human are associated with testicular malignancy, infertility and other abnormalities. Investigation for localization of the testes is mandatory, and either orchidopexy or orchidectomy is indicated. Laparoscopy was performed in an azoospermic male with bilateral unpalpable testes. A diagnosis of intra-abdominal testes was made and bilateral orchidectomy was performed. Laparoscopy is recommended for diagnosis and precise localization, as well as for orchidectomy, thus avoiding open abdominal operation in cases of intra-abdominal testes.

Adult↗
PubMed1994

Serum prolactin response to ether stress in diabetic rats: opiate system contribution.

Diabetes in streptozotocin-treated rats is associated with alterations in various neuroendocrine systems, including endogenous opioids. These changes are suggested to be responsible for the significant reduction in serum prolactin (PRL) response to a brief restraint stress in diabetic male rats, as compared with normoglycemic controls. The present study examines serum PRL response to ether exposure in diabetic male rats. The animals' response to ether stress, which is known to be related to the opioid system, was examined twice in each rat: shortly after cannula insertion (Day 1), and seven days later. In order to evaluate the opiate system involvement, the experiment was repeated on Day 1 and 7 after surgery in a group of rats which were pretreated with naltrexone (Nalt), an opioid receptor antagonist. Opioid receptor sensitization was also performed by prior acute morphine administration on Day 7 after cannulation surgery. Following adaptation to the cannulation, no difference in serum PRL response to ether stress was found between diabetic and normoglycemic rats. However, on Day 1 after surgery, a significant difference was found between the diabetic and control groups: the normoglycemic (control) group exposed to ether responded to the surgical stress by augmented serum PRL levels. This response was not recorded in the diabetic rats. Opioid receptor blockade by Nalt administration 30 min before ether exposure eliminated this difference. Opioid receptor sensitization by morphine pretreatment facilitated PRL secretion in normoglycemic rats exposed to either, while no effect could be distinguished in the diabetic group. It is therefore concluded that the streptozotocin-induced diabetic rats do not differ from normoglycemic ones in their ability to respond to acute ether stress by itself. However, enhanced PRL secretion induced by ether exposure under additional surgical stress, or by presensitization of the opioid receptors by morphine, is prevented in diabetic rats, probably due to diminished opioid receptor response.

Animals↗
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↗