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G Verheyen

Publications and source records attributed to G Verheyen.

At least 37 records · Page 2Linked to original sources
PubMed1999

Freezing of testicular tissue as a minced suspension preserves sperm quality better than whole-biopsy freezing when glycerol is used as cryoprotectant.

Frozen-thawed testicular spermatozoa have been used successfully for ICSI, especially in cases of obstructive azoospermia with normal spermatogenesis. Fewer attempts, however, have been made to check whether these rather immature spermatozoa, in a different environment with several other cell types present, have cryobiological requirements other than those of ejaculated spermatozoa. This is the reason why the freezing protocols and cryoprotectants (glycerol) used for freezing testicular tissue are based on experience with semen freezing. This study aimed to assess whether cryosurvival and/or motility was influenced by freezing of testicular tissue either as an intact biopsy or as a shredded tissue suspension, when glycerol was used as cryoprotectant. Freezing of testicular tissue as a suspension preserved motility (type B + C) significantly better than freezing of whole biopsies (9.2% vs. 4.0%). Similar observations have been made for vitality (39.3% vs. 25.4%). Centrifugation on 50% Percoll in order to remove the cryoprotectant resulted in a huge loss of spermatozoa (or late spermatids) and should therefore be especially avoided in cases of testicular failure. On the basis of these observations, mincing of the testicular biopsies before freezing may be advocated. Testicular spermatozoa seem to be better preserved when frozen in suspension, at least when slowly permeating glycerol is used as a cryoprotectant.

Biopsy↗
PubMed1999

No differences in outcome after intracytoplasmic sperm injection with fresh or with frozen-thawed epididymal spermatozoa.

This retrospective consecutive case series aimed at comparing the results of intracytoplasmic sperm injection (ICSI) with fresh and with frozen-thawed epididymal spermatozoa obtained after microsurgical epididymal sperm aspiration (MESA) in 162 couples. These couples were suffering from infertility because of congenital bilateral absence of the vas deferens (n = 109), failed microsurgical reversal for vasectomy or postinfectious epididymal obstruction (n = 44), irreparable epididymal obstruction (n = 4), ejaculatory duct obstruction (n = 2) or anejaculation (n = 3). Overall, 176 MESA procedures were performed in the husbands, followed by 275ICSI procedures with either fresh (n = 157) or frozen-thawed (n = 118) epididymal spermatozoa. No significant differences were observed in the parameters of spermatozoa used either freshly or frozen-thawed. In the fresh epididymal sperm group 59.4% of all the injected oocytes fertilized normally as compared to 56.2% of all injected oocytes in the frozen-thawed epididymal sperm group, and embryonic development was comparable between the two groups. A total of 245 transfers were performed: 145 after the use of fresh epididymal spermatozoa and 100 after the use of frozen-thawed spermatozoa. The overall pregnancy rate per ICSI cycle was significantly lower when frozen-thawed epididymal spermatozoa were used (26.3 versus 39.5%). However, no significant differences were found either in clinical and ongoing pregnancy rates or in implantation rates. There were no differences in pregnancy outcome. In patients suspected of having obstructive azoospermia with no work-up or an incomplete one, MESA is the preferred method for sperm recovery because a full scrotal exploration can be performed and, whenever indicated, a vasoepididymostomy may be performed concomitantly. Recovery of epididymal spermatozoa for cryopreservation during a diagnostic procedure is certainly a valid option in these patients since ICSI may be performed later or even in another centre using the frozen-thawed epididymal spermatozoa without jeopardizing the ICSI success rate.

Cryopreservation↗
PubMed1999

Light and electron microscopic analysis of human testicular spermatozoa and spermatids from frozen and thawed testicular biopsies.

The morphological changes caused by freezing and thawing human testicular spermatozoa have been assessed here. Retrieval of testicular biopsies was carried out on six patients with obstructive azoospermia preparatory to intracytoplasmic sperm injection (ICSI). Light microscope analysis was carried out on testicular cells and ultrastructural analysis was carried out on spermatozoa and different spermatid stages before and after the freezing procedure. Upon examination under light microscopy, all germ cells presented increased vacuolization in their cytoplasm and shrinkage or swelling of the nuclei and cytoplasmic membranes. These altered structures were accentuated in the spermatocyte I cell which often presented disrupted membranes. The ultrastructural findings under transmission electron microscopy demonstrated that after freezing and thawing the major types of cryoinjury were the swelling and rupture of inner and outer acrosomal and plasma membranes. The acrosome material often appeared as dispersed material or as condensed spots or was even lost. Such damage was observed mainly at the spermatozoa and late spermatid stages. We conclude that the freezing and thawing of testicular biopsies causes similar morphological damage to testicular spermatozoa and frozen-thawed ejaculated spermatozoa. It is still unclear whether these changes in testicular spermatozoa after freezing and thawing may compromise its use in the ICSI procedure.

Adult↗
PubMed1999

Controlled comparison of conventional in-vitro fertilization and intracytoplasmic sperm injection in patients with asthenozoospermia.

A controlled comparison between conventional in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) has been carried out for patients with </=5% rapid progressive (type A) spermatozoa in their fresh semen. Twenty couples were allocated to the study. All semen samples fulfilled the minimum criteria to be allocated to the conventional IVF programme. The two pronuclear (2PN) fertilization rate per retrieved cumulus-oocyte complex was significantly higher after ICSI (63.4%) than after conventional IVF (22.9%), with complete fertilization failure after IVF in 10 out of the 20 cycles. Embryo quality was similar for both treatments. Sixteen patients received only ICSI embryos, two patients only IVF embryos and two patients received IVF and ICSI embryos. The ongoing clinical pregnancy rate was 45%, the implantation rate was 37%. Comparison of the characteristics of patients/cycles with and without 2PN fertilization revealed a higher proportion of progressively motile spermatozoa in the prepared sperm fraction for the group of patients with fertilization after conventional IVF. It can be concluded from this study that absence of or an extremely low proportion of rapid progressive motility in fresh semen indicates a high risk of complete fertilization failure with conventional IVF.

Embryo Implantation↗
PubMed1999

Seven years of intracytoplasmic sperm injection and follow-up of 1987 subsequent children.

Intracytoplasmic sperm injection (ICSI) with ejaculated, epididymal or testicular spermatozoa was first successful in 1992 and has since become the widely accepted treatment for couples with severe male-factor infertility. The outcome of several thousands of ICSI cycles in terms of fertilization, embryo cleavage and implantation is similar to that for conventional in-vitro fertilization in couples with tubal or idiopathic infertility. To evaluate the important issue of safety of the new technique of ICSI, a prospective follow-up study of 1987 children born after ICSI was carried out. The aim was to compile data on karyotypes, congenital malformations, growth parameters and developmental milestones. Parents' agreement to genetic counselling was obtained as well as prenatal diagnosis, followed by a physical examination of the children at 2 months, 1 year and 2 years. Between April 1991 and August 1997, 1699, 91 and 118 children were born after ICSI with ejaculated, epididymal and testicular spermatozoa respectively; 79 children were born from cryopreserved ICSI embryos. In all, 1082 karyotypes were determined by prenatal diagnosis, 18 of which were abnormal and de novo (1.66%) (nine each of autosomal and sex chromosomal aberrations), and 10 karyotypes (0.92%) were inherited structural aberrations. Of these, nine (eight balanced structural aberrations and one unbalanced trisomy 21) were transmitted from the father. Ten pregnancies were terminated after prenatal karyotyping or DNA testing. Forty-six major malformations (2.3%) were observed at birth. Seven malformations, observed by prenatal ultrasound, were terminated. Twenty-one (1.1 %) stillbirths, including four with major malformations, occurred later than 20 weeks of pregnancy. Mean gestational age at birth was 38.7 weeks for singletons, 36.0 weeks for twins and 32.0 weeks for triplets. No specifically higher incidence of malformations was found in any given subgroup.

Chromosome Aberrations↗
PubMed1999

What is reflex sympathetic dystrophy?

In the literature there is no unanimity with respect to the diagnosis of reflex sympathetic dystrophy (RSD). Frequently, the diagnosis is established on mere clinical grounds. In our opinion, however, bone scintigraphy is of major importance for the diagnosis. Using this examination, true RSD can be clearly differentiated from other conditions which are incorrectly diagnosed and treated as RSD. If the bone scan is not suggestive of RSD, the clinical picture, radiological examination and vascular scan may lead to the correct diagnosis. This may be a pseudodystrophy, in which a hypovascularization is found right from the start, while in true RSD there is initially a hypervascularization. Other conditions which may be confused with RSD are causalgia, neurotic compulsive postures, hysterical conversion, malingering and even self-mutilation. In the spontaneous course of RSD three phases can be distinguished. Stage I is the warm or hypertrophic phase, stage II the cold or atrophic phase. Per definition the third phase corresponds to stabilization or, in rare instances, to healing. By means of the vascular scan the correct stage can be determined, and the results of treatment evaluated. Finally it should be noted that in children the condition is completely different from true RSD, as it concerns a pseudodystrophy or disuse-related dystrophy. This condition may also be seen in adults and adolescents, usually females. The bone scan is always negative. In this way bone scintigraphy constitutes the means to answer the question as to what RSD is and what it is not. An algorithm for the differential diagnosis is presented.

Adolescent↗
PubMed1998

Is there any need for diagnostic laparoscopy in couples undergoing intracytoplasmic sperm injection for severe male-factor infertility.

PURPOSE: Our purpose was to determine whether there is a need for a preliminary diagnostic laparoscopy in couples undergoing intracytoplasmic sperm injection (ICSI) because of severe male-factor infertility. METHODS: In this retrospective study, the results of diagnostic laparoscopy in 342 women with a normal fertility workup undergoing ICSI were evaluated and sperm parameters were correlated with the findings at laparoscopy. Subgroups of patients were defined according to sperm quality, which was expressed as total normal motile count [TNMC = volume (ml) x concentration (10(6)/ml) x percentage progressive motility/100 x percentage normal morphology/100]. RESULTS: When sperm morphology was evaluated according to Kruger's strict criteria, the probability of finding pathology on laparoscopy in the normal male group (16.7%) was statistically higher than that in the group with severely abnormal sperm (1.8%; P < 0.01). CONCLUSIONS: There is no need to perform a preliminary diagnostic laparoscopy in the female partner if a full workup is normal in couples with severe male-factor infertility willing to undergo ICSI.

Female↗
PubMed1998

Enzymatic digestion of testicular tissue may rescue the intracytoplasmic sperm injection cycle in some patients with non-obstructive azoospermia.

Recovery of testicular spermatozoa from azoospermic patients with testicular failure, followed by intracytoplasmic sperm injection (ICSI) is a recent advance in the treatment of male infertility. In most cases, free spermatozoa are recovered from testicular tissue after mechanical mincing of multiple biopsies. Testicular sperm retrieval, however, remains unsuccessful in 30-50% of male patients suffering from Sertoli cell-only syndrome and maturation arrest. In this study, a strategy was developed in order to maximize the chance of sperm retrieval in difficult cases of testicular failure. The ultimate step was the use of enzymatic procedures (collagenase type IV) to dissociate the testicular tissue completely. Testicular tissue of 41 patients for whom no spermatozoa were found after mechanical mincing of the testicular tissue was investigated. In 14 out of the 41 cases (34%), enough spermatozoa for ICSI were found after fine mincing of multiple biopsies and several hours' search in the cell suspension treated with the erythrocyte-lysing buffer (ELB). In 27 out of the 41 patients, no spermatozoa were found even after the use of ELB. In seven out of these 27 failures (26%), spermatozoa for ICSI were retrieved after enzymatic dissociation of the residual minced tissue pieces, thus making ICSI possible despite failure to find spermatozoa with conventional mincing. From this study, we may conclude that enzymatic digestion of testicular tissue is easy to perform, is not time-consuming and constitutes a successful method in reducing the sperm recovery failures in patients with non-obstructive azoospermia.

Adult↗
PubMed1998

Correlation between motility of testicular spermatozoa, testicular histology and the outcome of intracytoplasmic sperm injection.

The objective of the present study was to analyse the influence of motility on the results of intracytoplasmic sperm injection (ICSI) when testicular spermatozoa are used for microinjection and to correlate this with testicular histology. A total of 197 ICSI treatment cycles (167 couples) was analysed retrospectively in which testicular spermatozoa were used, because of complete azoospermia, for microinjection. Fertilization, embryo cleavage, transfer and pregnancy rates were evaluated and compared in relation to motility of testicular spermatozoa. In 170 cycles, histological diagnoses were compared with findings on motility. Injection of motile testicular spermatozoa (in 159 cycles) provided a higher normal fertilization rate than did injection of non-motile spermatozoa (in 14 cycles; 65 versus 45% respectively). Normal spermatogenesis was diagnosed in a significantly higher proportion and incomplete maturation arrest in a significantly lower proportion in the group of patients in which only motile spermatozoa were used for microinjection (65 and 10%), as compared to the group where exclusively non-motile spermatozoa were used (36 and 36%). Fertilization rate after ICSI was relatively high when non-motile testicular spermatozoa were used for microinjection, but use of motile testicular spermatozoa was associated with a still higher fertilization rate (except when histology of the testicular biopsy showed normal spermatogenesis), and therefore selection of motile testicular spermatozoa is always preferable for ICSI. Normal spermatogenesis predicts a greater probability, and maturation arrest a lower probability of recovering motile testicular spermatozoa.

Cytoplasm↗
PubMed1998

Simple and reliable identification of the human round spermatid by inverted phase-contrast microscopy.

Based on the results of animal studies, round spermatid injection (ROSI) has been introduced into the clinical practice of several in-vitro fertilization (IVF) centres. The efficiency of this procedure in terms of fertilization rates and pregnancy rates, however, remains very poor. An essential aspect which does not receive enough attention is the correct identification of this type of round cell within a heterogeneous population of testicular cells. A Nikon inverted microscope equipped with phase-contrast optics (DLL) provided a clear image which allowed reliable recognition of round spermatids in cell suspensions smeared at the glass bottom of the dish. Fluorescent in-situ hybridization confirmed the haploid status of the selected cells. However, exploration of several biopsies from patients with non-obstructive azoospermia showing no spermatozoa after extensive search did not reveal any round spermatids. This observation questions whether enough effort is spent on searching for mature spermatozoa or late spermatids. Experimental investigations should precede the introduction of ROSI into the clinical practice of any IVF centre.

Cell Size↗
PubMed1998

Results of intracytoplasmic sperm injection with ejaculated, fresh and frozen-thawed epididymal and testicular spermatozoa.

Over the past 5 years, intracytoplasmic sperm injection (ICSI) has been developed to alleviate severe long-standing andrological infertility in couples who could not be helped by standard in-vitro fertilization (IVF), or who could not undergo IVF because too few motile and morphologically normal spermatozoa were present in the ejaculate. ICSI can also be carried out with fresh and frozen-thawed epididymal spermatozoa from patients with obstructive azoospermia and with testicular spermatozoa from most patients with obstructive azoospermia and from some patients with non-obstructive azoospermia. This review reports the results of 5 years of ICSI practice (1991-1995) at the Brussels Free University Centre for Reproductive Medicine, including selection of patients, oocyte and spermatozoa for ICSI, ICSI procedures and its assessment. ICSI was performed in 97% of the 4688 planned treatment cycles. Ejaculated spermatozoa were used in 88% of the cycles, epididymal spermatozoa in 5% of the cycles and testicular spermatozoa in 7% of the cycles. ICSI was performed on 48393 metaphase II oocytes. Of these, 89.5% were morphologically intact, and 70.9% of the intact oocytes were normally fertilized; 64.9% of the two-pronuclear oocytes developed after a further 24 h of in-vitro culture into cleaved embryos, which were transferred or cryopreserved for subsequent use. After transfer of fresh embryos, the percentage of cycles with positive serum human chorionic gonadotrophin was 36.2% per transfer and the percentage of deliveries was 27.0% per transfer. The performance of ICSI with regard to damage, pronuclear status, embryo development and transfer was analysed separately for the four different types of spermatozoa used: fresh ejaculated, epididymal and testicular as well as frozen-thawed epididymal spermatozoa.

Cryopreservation↗
PubMed1998

Special applications of intracytoplasmic sperm injection: the influence of sperm count, motility, morphology, source and sperm antibody on the outcome of ICSI.

The relationship between the three basic parameters of ejaculated spermatozoa, i.e. concentration, motility and morphology, and the results of intracytoplasmic sperm injection (ICSI) were investigated in 838 microinjection cycles. A further 123 ICSI treatment cycles in which testicular spermatozoa were used for microinjection were also evaluated. The influence of anti-sperm antibodies (ASA) on the outcome of ICSI was investigated by analysing 55 cycles where the proportion of ASA-bound spermatozoa was > or =80%. After microinjection, oocyte intactness, fertilization, embryo cleavage, transfer and pregnancy rates were recorded and compared. The results showed that neither the type nor the extent of sperm impairment had an important influence on the outcome of ICSI when ejaculated spermatozoa were used. Only two very rare conditions had a strongly negative influence on the result of ICSI, i.e. where immotile (presumably dead) spermatozoa or where round-headed spermatozoa were injected into the oocyte. Neither the proportion of ASA-bound spermatozoa, the type of dominantly present ASA, nor the location of ASA on the spermatozoa had an important influence on fertilization, embryo development or pregnancy rates after ICSI. In most of the cycles combined with testicular biopsy (79%), there were enough motile spermatozoa present in the wet preparation for injection of all the oocytes. Injection of motile testicular spermatozoa led to a higher normal fertilization rate than did injection of non-motile spermatozoa (65 versus 21%). It can be concluded that injection of motile (living) spermatozoa into oocytes is the most important factor in determining good results with ICSI and that other sperm parameters do not have a strong influence on the outcome of ICSI.

Antibodies↗
PubMed1997

No association between bipolar affective disorder and a serotonin receptor (5-HT2A) polymorphism.

The serotonergic system is implicated in the pathogenesis of affective disorders. In particular, the role of the postsynaptic 5-hydroxytryptamine (serotonin) type 2 receptor (5-HT2) has been documented by several studies. The 5-HT2A receptor gene located on chromosome 13 (13q14-21) can be considered a candidate gene for bipolar affective disorder (BPAD). We tested association between a 5-HT2A receptor DNA variant and BPAD using a case-control design. Eighty-three BPAD patients and 129 unrelated normal controls, carefully matched for sex and geographical origin, were studied. Allele and genotype frequencies as well as homo-heterozygote distribution at the 5-HT2A receptor polymorphism were compared between the two groups. No significant allelic or genotypic associations were observed. There was no significant difference for homo-heterozygote distribution between the two groups. These preliminary results may indicate that in our sample the 5-HT2 receptor polymorphism studied is unlikely to play a role in the genetic susceptibility to BPAD.

Adult↗
PubMed1997

An improved treatment procedure for testicular biopsy specimens offers more efficient sperm recovery: case series.

OBJECTIVE: To report an improved sperm recovery procedure from testicular biopsy specimens for intracytoplasmic sperm injection (ICSI). DESIGN: Case series and controlled study. SETTING: Procedures were performed in a tertiary IVF center. PATIENT(S): Nonobstructive azoospermic cases (15 patients) and obstructive azoospermic cases (5 patients). INTERVENTION(S): Intracytoplasmic sperm injection was carried out using testicular sperm isolated from a testicular biopsy specimen either with or without erythrocyte lysing buffer treatment. MAIN OUTCOME MEASURE(S): The time required to collect spermatozoa and the intactness and fertilization and developmental rates of oocytes. RESULT(S): In 7 of the 15 nonobstructive cases, it was possible to perform ICSI when, after shredding of the testicular tissue, no (or virtually no) sperm were present. There was no difference in the fertilization rates (83% and 68%) and developmental rates (87% and 89%) of the 54 sibling oocytes from another 5 patients in whom ICSI was carried out with sperm either treated or not treated with erythrocyte lysing buffer. CONCLUSION(S): Erythrocyte lysing buffer treatment of testicular biopsy specimens enhances the efficiency of sperm collection in those cycles in which spermatozoa are present and does not affect fertilization and embryo development.

Ammonium Chloride↗
PubMed1997

Quality of frozen-thawed testicular sperm and its preclinical use for intracytoplasmic sperm injection into in vitro-matured germinal-vesicle stage oocytes.

OBJECTIVE: To study the effects of cryopreservation on the quality of human testicular spermatozoa and the efficiency of intracytoplasmic sperm injection (ICSI) with frozen-thawed testicular sperm into metaphase II oocytes in vitro-matured from the germinal-vesicle stage oocyte. DESIGN: Preclinical freezing study on supernumarary testicular spermatozoa after ICSI. SETTING: Tertiary IVF center coupled with an institutional research environment. PATIENT(S): Twenty-nine patients undergoing excisional testicular biopsy for ICSI. INTERVENTION(S): Isolated testicular spermatozoa were cryopreserved and thawed; frozen-thawed motile testicular spermatozoa were microinjected. MAIN OUTCOME MEASURE(S): Prefreezing and post-thawing motility and viability, survival rate, fertilization rate, cleavage rate, and embryo quality after ICSI. RESULT(S): Mean percentage motility decreased from 21% before freezing to 6% after thawing. Vitality was impaired to a similar extent, decreasing from 68% to 22% (32% recovery rate). Injection of frozen-thawed testicular spermatozoa into in vitro-matured oocytes resulted in a fertilization rate of 50.9%. Cleavage rate was severely impaired. Half of the fertilized oocytes became arrested in the one-cell stage. CONCLUSION(S): Despite the low quality of the fresh testicular spermatozoa, a high percentage of prepared testicular sperm fractions showed survival and motility after the freezing and thawing process. Injection of frozen-thawed testicular sperm into matured oocytes resulted in fertilization rates comparable with these with fresh testicular sperm, but cleavage rates were severely impaired, which might be due to source of oocytes used for ICSI.

Adult↗
PubMed1997

A chromosome 18 genetic linkage study in three large Belgian pedigrees with bipolar disorder.

The contribution of genetic factors to the susceptibility for affective disorders has been firmly established. Recent reports found evidence for a susceptibility locus for affective disorders in 2 regions on chromosome 18. We describe 3 large Belgian pedigrees with multiple patients with affective disorders. Both chromosome 18 regions were investigated in the 3 families, using parametric and nonparametric segregation methods. In the pericentromeric region, all evidence was against a disease gene in our families. Also the data obtained for the distal part of 18q, argue against a genetic susceptibility factor in our sample.

Belgium↗