PubMed Health⌕ Search

Biomedical subjects

E Strehler

Publications and source records attributed to E Strehler.

At least 19 recordsLinked to original sources
PubMed1999

Influence of ovarian stimulation on the detection of human papillomavirus DNA in cervical scrapes obtained from patients undergoing assisted reproductive techniques.

OBJECTIVE: To determine whether gonadotropin stimulation influences the detection of human papillomavirus (HPV) DNA in cervical scrapes. DESIGN: Prospective, controlled study. SETTING: Tertiary care infertility clinic. PATIENT(S): Two hundred ninety-four patients enrolled in an IVF or IUI program. Two thousand two hundred sixty-two women from an ongoing screening study who were of similar age served as a control group. INTERVENTION(S): Cervical scrapes were obtained with a cytobrush before and after ovarian stimulation with gonadotropins. MAIN OUTCOME MEASURE(S): Human papillomavirus status was assessed with a general primer (GP) polymerase chain reaction (PCR) using the GP5+/GP6+ system. In GP-PCR-positive samples, high-risk HPV types were identified with a cocktail of digoxigenin-labeled oligonucleotides. Viral load was evaluated by semiquantitative analysis of the PCR products. RESULT(S): The prevalence of high-risk HPVs was 7.8% before stimulation and 6.8% after stimulation and, thus, was similar to the prevalence in controls (8.4%). Twenty-nine patients were positive for high-risk HPVs: 14 were positive before and after stimulation, 6 were negative before and positive after stimulation, and 9 were positive before and negative after stimulation. Positivity for high-risk HPVs and viral load did not correlate directly with serum estrogen levels. CONCLUSION(S): Ovarian stimulation has no significant effect on the prevalence of HPV DNA in cervical scrapes obtained from patients undergoing assisted reproductive techniques.

Adult↗
PubMed1998

Detrimental effects of polyvinylpyrrolidone on the ultrastructure of spermatozoa (Notulae seminologicae 13).

The effect of in-vitro treatment by polyvinylpyrrolidone (PVP) on the ultrastructure of human spermatozoa has been tested previously with the statistical analysis of B. Baccetti et al. (1995, J. Androl., 16, 356-371). PVP had a primary detrimental action on the plasma membrane, as well as on acrosomal and mitochondrial membranes. Furthermore, membrane damage induces deterioration of the chromatin, axonemal tubules, fibrous sheath, and accessory fibres.

Acrosome↗
PubMed1998

Glass wool filtration leads to a higher percentage of spermatozoa with intact acrosomes: an ultrastructural analysis.

We investigated the possibility of ultrastructural damage to human spermatozoa induced by different sperm preparation techniques. Ejaculates from 20 normozoospermic men were divided into equal aliquots and processed by glass wool filtration, Percoll density gradient centrifugation, and a simple two-step centrifugation procedure which served as a control. The evaluation of 60 spermatozoa from each of 20 test subjects (in all, n = 1200) ensured that a sufficiently large number of spermatozoa were investigated. Ultrastructural damage was assessed by scanning electron microscopy. We investigated the state of the acrosome after sperm preparation and measured the percentage of intact spermatozoal structures compared with that of the control. Compared with Percoll density gradient centrifugation, glass wool filtration yielded a significantly increased proportion of intact acrosomes. However, both preparations gave significantly better results than the control. In conclusion, both glass wool filtration and Percoll centrifugation are efficient techniques for the accumulation of spermatozoa with intact acrosomes. Because of the significantly higher percentage of intact acrosomes, glass wool filtration appears to be the more appropriate method. The significance of the conspicuous bending of sperm tails after Percoll centrifugation is not yet known.

Acrosome↗
PubMed1997

The effect of follicle stimulating hormone therapy on human sperm structure (Notulae seminologicae 11).

The effects of follicle stimulating hormone (FSH) treatment on the quality of human spermatozoa were assessed by examining the ultrastructure and the function of infertile human spermatozoa using a previously-defined formula. Using the spermatozoa as an andrological monitor shows that the therapeutic effect of FSH depends on the type of sperm defect. The response to FSH is, in many cases, positive and can be evaluated by examining the state of the ejaculated spermatozoa. From an initial group of 81 patients, 15 were placebo-treated controls, and 19 were non-responders (mainly with microbially infected semen). Out of 47 responders, after therapy nine achieved improved sperm quality which approached the natural fertility threshold. These responders all had spermatozoa affected by immaturity or apoptosis (n = 27). The 20 microbially-infected responders also had immature spermatozoa and never achieved the quality level of natural fertility. Thus, a natural fertility level was only achieved by nine responders out of 27 (three with immature spermatozoa, and six with apoptotic spermatozoa). Using our method of sperm analysis, these patients' spermatozoa were clearly categorized before treatment as either immature or apoptotic. In consequence, the success of the therapy was predictable. The response of individual organelles to therapy was examined. Certain qualities of the acrosome, the chromatin, the mitochondria, and the axoneme appear to be sensitive to FSH. Most of the previous conflicting results reported in the literature may be due to a lack of relevant discrimination between the different defects present in the spermatozoa of the patients, without assessing the likelihood of their response.

Acrosome↗
PubMed1997

Submicroscopic mathematical evaluation of spermatozoa in assisted reproduction. 3. Partial zona dissection (PZD) (Notulae seminologicae 12).

This paper belongs to a series of application of the Baccetti's et al. (1995) formula to the submicroscopical mathematical examination of the human spermatozoa used for assisted reproduction. The present experiment concerns partial zona dissection, a technique requiring a careful evaluation of sperm quality in order to predict the success of the program. Our results demonstrate that the sperm submicroscopic characters introduced in the formula are clearly correlated with the result of PZD. In fact the two numbers concerning the sperm ultrastructural quality (percentage and total number of spermatozoa free from defects in the ejaculate) obtained in successful and unsuccessful PZD groups, showed a large difference (P < 0.01). The most important characteristics seem to be the quality of the acrosomal complex, the condition of the chromatin and the mitochondrial assembly. All these characteristics are expressed with largely different means in successful and unsuccessful ejaculates (from P < 0.05 to P < 0.01). A comparison with the results previously obtained in ICSI (Strehler et al., 1995) and IVF (Piomboni et al., 1996) shows that sperm quality is significantly more implicated in the success of IVF than of PZD or ICSI.

Female↗
PubMed1996

Submicroscopic mathematical evaluation of spermatozoa in assisted reproduction. 2. In vitro fertilization. (Notulae seminologicae. 7)

This paper belongs to a series of applications of the Baccetti et al. formula (1) to the submicroscopical mathematical examination of human spermatozoa used for assisted reproduction. The present experiment concerns IVF, a technique requiring careful evaluation of sperm quality to predict the success of the program. Our results demonstrate that the sperm submicroscopic characters introduced in the formula are clearly correlated with the result of IVF. In fact the two numbers concerning sperm quality (percentage of spermatozoa free from structural defects and total number in the ejaculate of spermatozoa free from defects) obtained in successful and unsuccessful IVF groups, showed a large difference. The t distribution in both cases reached a significance of 0.005. The synthetic parameters obtained are therefore a good tool in the prediction of sperm power in in vitro insemination techniques. The most important characteristics seem to be the quality of the acrosomal complex, the status of the chromatin, the shape of mitochondria, the axonemal pattern, and the membrane integrity. All these characteristics are expressed with largely different means in successful and unsuccessful ejaculates (t distribution significant at 0.005). All these data confirm that submicroscopic mathematical diagnosis offers a convincing evaluation of sperm structure and function, involving all organelles, including acrosome function and cell motility. It is also demonstrated that sperm quality is a major factor in the success of IVF and that it is clearly revealed by the integrity of the majority of the sperm organelles.

Acrosome↗
PubMed1996

Influence of smoking on fertility in women attending an in vitro fertilization program.

OBJECTIVE: To investigate the influence of cigarette smoking of women on the fertilization and pregnancy rates obtained by IVF treatment. PATIENTS: One hundred ninety-seven infertile, otherwise healthy women who entered an IVF program for the first time. SETTING: Fertility unit at the Women's University hospital of the University of Ulm, Ulm, Germany. INTERVENTIONS: The study population consisted of 197 women (23 to 39 years old) who were divided into the following groups: nonsmokers (n = 68), passive smokers (n = 26), and active smokers (n = 103) according to the cotinine concentration measured in follicular fluid. The reason for infertility was strictly a tubal factor with apparently normal ovulatory cycles. To guarantee an objective recording of tobacco smoke exposure, the smoking habit was not determined by questionnaires, but by cotinine, the principal metabolite of nicotine. RESULTS: There were no significant differences in fertilization and pregnancy rates between the different groups. The E2 serum levels were decreased significantly in women who smoked when compared with the results obtained from nonsmokers and passive smokers. Overall, a strong negative correlation of the cotinine and E2 levels was observed (r = -0.65). CONCLUSION: The results suggest that there is no clinically detectable impairment of fertilization potential due to female smoking and that there is a greater influence on the outcome of IVF by other factors.

Adult↗
PubMed1995

Predicting the success of in vitro fertilization: conventional semen analysis compared to the hamster ova penetration test.

In vitro fertilization has been advocated as a possible treatment for male factor infertility. Using data collected on 154 men, conventional semen analysis and the hamster ova penetration test are compared with respect to their power in predicting the success of assisted conception. As performing the hamster test is more expensive than the semen analysis, we also investigate a combined strategy. It performs better than the discrimination based solely on the semen parameters, but does not lead to an improvement over the overall discriminatory power obtained from the hamster test alone.

Adult↗
PubMed1995

[Idiopathic habitual abortion: experiences with active immunotherapy].

The effect of lymphocyte transfusions on the stabilisation and successful outcome of pregnancy was investigated in 30 women with recurrent abortions presumably caused by immunologic factors. Lymphocyte concentrates were obtained from stored whole blood of the husbands and transferred by intravenous injection. Exclusion criteria for this study were the presence of antipaternal lymphocytotoxic antibodies in the patient's serum (cross match) or an advanced pregnancy (> 12 weeks). After transfusion of paternal lymphocytes 19 (63%) women had uncomplicated and successful pregnancies whereas 11 (37%) suffered again from early pregnancy loss. Two out of these 11 patients aborted twice. The probability of a successful treatment decreased as soon as lymphocytotoxic antibodies appeared in the patient's serum (p < or = 0.021). Women with a lower number of abortions before treatment carried their pregnancies to full term more frequently (p < or = 0.03). The number of transfusions, the period between start of treatment and conception as well as the distribution of age within the two groups had no significant effect on the outcome of therapy. A lack of lymphocytotoxic antibodies or their late appearance during treatment give a positive prognosis for the progress of pregnancy. Compared with a fertile control group, couples with habitual abortions showed no significantly increased HLA sharing. Immunisation with paternal lymphocytes in cases of presumably habitual abortions due to immunologic factors appears as an effective therapy with only few side effects. Large, randomised, double-blind, and placebo-controlled trials are needed before drawing conclusions.

Abortion, Habitual↗
PubMed1995

[Cytogenetic abnormalities in sperm: a risk factor for application of medical reproduction techniques?].

Microinsemination techniques are increasingly applied to achieve fertilisation of the oocyte in cases of male fertility disorders. Thus, spermatozoa can directly interact with the oolemma or the ooplasm, thereby obviating the need for penetration through cumulus oophorus and zona pellucida. However, problems associated with this particular feature arise in view of the following considerations: 1. The gametes from subfertile males are suspected to carry more cytogenetic anomalies in addition to an impaired sperm quality when compared to fertile men. 2. Cumulus and zona play an important role in the selection of morphologically abnormal and dysfunctional spermatozoa. 3. Consequently, bypassing natural sperm selection processes would lead to more abnormal embryos, abortions, and births of diseased or handicapped children. Spermatozoa can be analysed cytogenetically after fusion with zona-free hamster eggs or by fluorescence in situ hybridization (FISH). Both techniques did not confirm increased aberrations in gametes from subfertile men with a normal somatic karyotype. However, a definite conclusion cannot be drawn because of the limited data and restrictions concerning their interpretation. This also holds true for the evaluation of correlations indicating no significant relationship between the chromosomal constitution and sperm motility or morphology, respectively. Currently, the risk of malformation after microinsemination does not appear to be increased when compared to conventional IVF but the results do not yet allow a reliable statistical evaluation. In contrast, decreased morphological quality, impaired implantation, and early abortions have been reported for embryos produced by assisted fertilisation. This suggests that an effective natural selection of abnormal embryos will prevent a significant increase in malformations in the following generation.(ABSTRACT TRUNCATED AT 250 WORDS)

Chromosome Aberrations↗
PubMed1995

[Smoking--a possible cause for failure in IVF/ET treatment?].

The aim of this study was to investigate the relation between cigarette smoking of women and the fertilisation and pregnancy rates obtained by in-vitro fertilisation treatment. To guarantee an objective recording of tobacco smoke exposure, the smoking habit was not determined by questionnaires, but by cotinine, the principal metabolite of nicotine. The study population consisted of 197 women (23-39 years old) who were divided into the groups 'non-smokers' (n = 68), 'passive smokers' (n = 26) and 'active smokers' (n = 103) according to the cotinine concentration measured in follicular fluid. The reason for infertility was strictly a tubal factor with apparently normal ovulatory cycles. There were no significant differences in fertilisation and pregnancy rates between the different groups (p > 0.05). The E2 serum levels were significantly decreased in women who smoked, compared with the results obtained from non-smokers and passive smokers (p < 0.025). Overall, a strong negative correlation of the cotinine- and E2 levels was observed (r = -0.65). The results suggest that there is no clinically detectable impairment of fertilisation potential due to female smoking and that there is a greater influence on the outcome of in-vitro fertilisation by other factors.

Adult↗
PubMed1995

Submicroscopic mathematical evaluation of spermatozoa in assisted reproduction. I. Intracytoplasmic sperm injection. (Notulae seminologicae 6).

After a large introduction concerning the influence of sperm quality in the success of in vitro fertilization, the debated problem of the importance of the sperm quality in intracytoplasmic sperm injection is investigated. The spermatozoa are studied by electron microscopy, and the results evaluated by the formula of Baccetti et al. (1995). The quality of spermatozoa has been correlated with the success of ICSI. The first conclusion has been that ejaculates which produced embryos contained higher percentages and overall higher total number of 'healthy' spermatozoa than those which obtained fertilizations arrested at the two pronuclei stage, or showed no fecundation at all. A second conclusion was that the quality of sperm organelles is mainly involved in the oocyte activation, but after the 2 pronuclei stage, segmentation usually proceeds with few influences from sperm quality. The highest involvement of spermatozoa is therefore the initiation of oocyte activation. A third conclusion confirmed the need of ultrastructural evaluation of sperm cell organization, deeply investigating the inner organelles. Moreover, we observed that the head organelles are more involved that the tail ones. Three acrosomal characteristics are concerned: the shape, the dimensions and the content. All of them are significantly better in the oocyte activating than in non activating spermatozoa. Also the nuclear shape and the status of the chromatin (frequently strictly interdependent) are significantly concerned with the oocyte activation and with the embryo segmentation. In the tail, the mitochondrial shape is significantly different in activating and not activating spermatozoa, and also in those producing embryo segmentation. Moreover, the absence of dynein arms seems to be determinant in impeding the oocyte activation.

Fertilization in Vitro↗
PubMed1995

[Electron microscopic analysis of possible ultrastructural damage to spermatozoa after preparation by various methods].

We investigated the possibility of ultrastructural damage to human spermatozoa induced by different sperm preparation techniques. Ejaculates from 20 normozoospermic men were divided into equal aliquots and processed by glass wool filtration, Percoll density gradient centrifugation, and a simple two step centrifugation procedure which served as a control. Ultrastructural damage was assessed by scanning electron microscopy. Compared with Percoll density gradient centrifugation, glass wool filtration yielded a significantly increased proportion of intact acrosomes (p < 0.05). However, both preparations gave significantly better results than control (p < 0.001 and p < 0.01 for glass wool filtration and Percoll centrifugation, respectively). The conspicuous bending of sperm tails after Percoll centrifugation has a yet unknown importance. In conclusion, both glass wool filtration and Percoll centrifugation are efficient techniques for the accumulation of spermatozoa with intact acrosomes. Because of the higher sperm recovery rate, glass wool filtration appears to be the more appropriate method.

Acrosome↗
PubMed1994

In vitro kallikrein treatment of human spermatozoa: stimulation of sperm penetration into zona-free hamster eggs depends on the quality of initial semen parameters but not on constituents of the kallikrein-kinin system in seminal plasma.

We investigated the effect of an in vitro kallikrein treatment of human spermatozoa on their ability to penetrate zona-free hamster eggs. Sixty-four infertility patients were classified into four groups (normo-, oligo-, astheno-, and oligoasthenozoospermia) in order to find out which men would benefit most from this procedure. An aliquot of each ejaculate was diluted with Ham's F-10 medium supplemented with human serum albumin and kept at 22C for 1 hour. Another aliquot was incubated with kallikrein (5 KU/ml.) for one hour at 22C. These sperm suspensions were then washed twice, subjected to a swim-up preparation, and subsequently incubated at 37C for 2 hours. The mean penetration rates of kallikrein-treated samples were significantly higher than those of the corresponding control assays in all but the oligoasthenozoospermia group. Our results suggest a direct proteolytic action of kallikrein because the stimulation of penetration into hamster eggs was not correlated with the amount of constituents of the kallikrein-kinin system (kinins, kininogen, kininase) in seminal plasma.

Animals↗
PubMed1994

[Do preparation techniques induce ultrastructural sperm damage? An electron microscopic study].

We investigated the possibility of ultrastructural damage to human spermatozoa induced by different sperm preparation techniques. Ejaculates from 20 normozoospermic men were divided into equal aliquots and processed by glass wool filtration, Percoll density gradient centrifugation, and a simple two-step centrifugation procedure which served as a control. Ultrastructural damage was assessed by scanning electron microscopy. Compared with Percoll density gradient centrifugation, glass wool filtration yielded a significantly increased proportion of intact acrosomes (p < 0.05). However, both preparations gave significantly better results than control (p < 0.001 and p < 0.01 for glass wool filtration and Percoll centrifugation, respectively). The significance of the conspicuous bending of sperm tails after Percoll centrifugation is not yet known. In conclusion, both glass wool filtration and Percoll centrifugation are efficient techniques for the accumulation of spermatozoa with intact acrosomes. Because of the higher sperm recovery rate, glass wool filtration appears to be the more appropriate method.

Acrosome↗
PubMed1993

[Correlation between cytogenetic anomalies of human spermatozoa and sperm morphology as well as age of patients studied].

Sperm chromosomes from 15 fertile men were analyzed after fusion of their spermatozoa with zona-free hamster eggs. The total proportion of abnormal metaphases as well as the proportions of aneuploidy and structural aberrations were calculated for every man and examined for linear correlations with sperm morphology and the age of the persons studied. A positive correlation between the cytogenetic parameters and the percentage of abnormal sperm morphology was not evident, suggesting that assessment of sperm morphology cannot be used as an indicator of chromosomal damage in human spermatozoa. In contrast, there was a more distinct positive correlation between the age of donors and the three cytogenetic parameters studied. Analogous calculations for two other study groups (group S: male subfertility; group HA: habitual abortions of the wives with unknown etiology) provided less clear results that may be attributed to the lower number of patients or to the existence of special indications as mentioned above.

Abortion, Habitual↗
PubMed1992

Cytogenetics of human spermatozoa: correlations with sperm morphology and age of fertile men.

Sperm chromosomes from 15 fertile men were analyzed after fusion of their spermatozoa with zona-free hamster eggs. The total proportion of abnormal metaphases as well as the proportions of aneuploidy and structural aberrations were calculated for every man and examined for linear correlations with [1] sperm morphology and [2] the age of the persons studied. A positive correlation between the cytogenetic parameters and the percentage of abnormal sperm morphology was not evident, suggesting that assessment of sperm morphology cannot be used as an indicator of chromosomal damage in human spermatozoa. In contrast, there was a more distinct positive correlation between the age of donors and the three cytogenetic parameters studied.

Adult↗