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G Verheyen

Publications and source records attributed to G Verheyen.

At least 19 recordsLinked to original sources
PubMed2006

How successful is repeat testicular sperm extraction in patients with azoospermia?

BACKGROUND: Little is known about the extraction rate in repeated sperm retrieval procedures in azoospermic patients. This study aimed to assess the feasibility of repeated sperm recovery in these patients. METHODS: A total of 1066 azoospermic men had their first sperm recovery between 1 January 1995 and 31 December 2003. A total of 381 men had obstructive azoospermia (OA), 628 nonobstructive azoospermia (NOA) and 57 showed hypospermatogenesis. RESULTS: Overall, sperm could be retrieved in all procedures in the 598 cycles performed in OA men (100%). A total of 117, 57, 24, 11, 7 and 1 men underwent, respectively, two, three, four, five, six and seven sperm retrievals; all were successful. Of the 784 procedures performed on the 628 men with NOA, sperm could be retrieved in 384 procedures (49%). During the first testicular sperm extraction (TESE) procedure, sperm could be extracted in 261 men with NOA (41.6%). A total of 103 men had a second attempt, 34 had a third attempt, 11 had a fourth attempt, 6 had a fifth attempt and 2 had a sixth attempt. In these cycles, sperm could be extracted in, respectively, 77 (74.7%), 28 (82.3%), 11 (100%), 5 (83.3%) and 2 (100%) men. CONCLUSION: Repeated TESE ensures a high sperm recovery rate even in patients with NOA. In NOA patients, studies reporting on TESE may therefore overestimate the retrieval rate by reallocating successful patients. These data also show that when no spermatozoa can be obtained after thawing cryopreserved testicular sperm for ICSI in NOA patients, a repeat TESE procedure can be planned.

Humans↗
PubMed2006

Early pregnancy loss is significantly higher after day 3 single embryo transfer than after day 5 single blastocyst transfer in GnRH antagonist stimulated IVF cycles.

The current study aimed to investigate whether single day-3 embryo transfer (SET) results in higher early pregnancy loss (EPL) than single blastocyst transfer (SBET). A total of 896 patients underwent 1103 IVF cycles with a gonadotrophin-releasing hormone (GnRH) antagonist protocol. In 603 cycles (D3 group) a single embryo on day 3 of the embryo culture was transferred, whereas in the remaining 500 cycles a single blastocyst was transferred on day 5 (D5 group). Multifollicular ovarian stimulation was performed with a GnRH antagonist protocol starting on day 6. SET resulted in 209 pregnancies (34.7%), compared with 221 pregnancies (44.2%) for SBET. Early pregnancy loss rate was significantly higher with SET compared with SBET (26.8% versus 17.2%, P = 0.017) and ongoing implantation rate was also significantly higher with day 5 compared with day-3 embryo transfer (OR:1.68, 95% confidence interval:1.31-2.18). Sub-optimal embryo selection for transfer on day 3, in addition to asynchronization between altered endometrium and early exposure of cleavage-stage embryos, might explain the above difference. Nevertheless, the higher implantation potential of the blastocyst questions the rationale behind performing single embryo transfer on day 3 of embryo culture in women under 36 years old.

Adult↗
PubMed2006

New Belgian embryo transfer policy leads to sharp decrease in multiple pregnancy rate.

Since 1 July 2003, a new transfer policy aiming to reduce multiple pregnancies was brought into law in Belgium. The policy restricts the number of embryos transferred, depending on the patient's age and treatment cycle. This study aimed to evaluate the effect of this policy. Two 15-month periods before and after the start of the new law were compared for the following parameters: positive human chorionic gonadotrophin (HCG), clinical pregnancy rate and multiple pregnancy rate according to the age categories defined by the policy: <36, 36-39 and 40-42 years. HCG rates (34.2 and 32.8%) and clinical pregnancy rates (26.2 and 24.0%) per cycle were similar for the two periods. Overall, the multiple pregnancy rate was reduced from 29.1 to 9.5% (all patients) and from 28.9 to 6.2% in women <36 years. Most twins were observed in the third cycle of patients <36 years and in the first three cycles in women of 36-39 years. It can be concluded that a significant decline (P < 0.001) in multiple pregnancies was mainly observed in patients <36 years of age. Clinical pregnancy rates were not compromised by the new law. Elective single embryo transfer should be considered more seriously for women 36-39 years of age.

Adult↗
PubMed2006

Investigation of co-genotoxic effects of radiofrequency electromagnetic fields in vivo.

We investigated the possible combined genotoxic effects of radiofrequency (RF) electromagnetic fields (900 MHz, amplitude modulated at 217 Hz, mobile phone signal) with the drinking water mutagen and carcinogen 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX). Female rats were exposed to RF fields for a period of 2 years for 2 h per day, 5 days per week at average whole-body specific absorption rates of 0.3 or 0.9 W/kg. MX was given in the drinking water at a concentration of 19 microg/ml. Blood samples were taken at 3, 6 and 24 months of exposure and brain and liver samples were taken at the end of the study (24 months). DNA damage was assessed in all samples using the alkaline comet assay, and micronuclei were determined in erythrocytes. We did not find significant genotoxic activity of MX in blood and liver cells. However, MX induced DNA damage in rat brain. Co-exposures to MX and RF radiation did not significantly increase the response of blood, liver and brain cells compared to MX exposure only. In conclusion, this 2-year animal study involving long-term exposures to RF radiation and MX did not provide any evidence for enhanced genotoxicity in rats exposed to RF radiation.

Animals↗
PubMed2005

Study of two markers of apoptosis and meiotic segregation in ejaculated sperm of chromosomal translocation carrier patients.

BACKGROUND: To try to explain the infertility of chromosomal translocation carrier patients, we compared the expression of two markers of apoptosis in the sperm of patients and of fertile donors, and we studied the meiotic segregation in the ejaculated sperm of these translocation carriers. METHODS: Twenty semen samples of translocation carriers, [reciprocal (n=14) and Robertsonian translocations (n=6)], were compared with the semen samples of donors (n=20). Different tests were applied: annexin V binding assay; terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling (TUNEL); and fluorescence in situ hybridization (FISH). RESULTS: The annexin V binding assay in sperm of patients with chromosomal translocation (n=17) showed a significantly increased proportion of sperm with externalized phosphatidylserine (PS) than in the control group (n=20, P<or=0.05). The rates of DNA fragmentation investigated by TUNEL reaction were higher in samples of translocation carriers (n=14) than in donors (n=20, P<0.0001). The measures by FISH technique showed that the proportions of balanced or normal gametes were predominant in the reciprocal translocation group (alternate: n=7; from 33.0 to 58.8%; adjacent I: n=7; from 4.6 to 43.8%) and in the Robertsonian translocation group (normal: n=5; from 76.0 to 88.5%). CONCLUSIONS: Our data show a predominant proportion of balanced gametes in sperm of chromosomal translocation carrier patients. Moreover, PS externalization and DNA fragmentation rates are significantly higher in ejaculated sperm of these patients than in donor sperm. These tests could be used to predict the outcome of ICSI for these patients.

Annexin A5↗
PubMed2005

Flow cytometric characterisation of antigen presenting dendritic cells after in vitro exposure to diesel exhaust particles.

The aim of this study was to obtain more insight into the effect of diesel exhaust particles (DEP) on the maturation of primary human dendritic cells. Monocyte-derived dendritic cells (Mo-DC) derived from seven different donors were exposed to different DEP concentrations (0.2,2,20,200 and 2,000 ng/ml) in the presence or absence of lipopolysaccharide (LPS), and changes in the surface expression of HLA-DR, CD86 and CD83 were examined. Exposure of Mo-DC to DEP alone did not alter expression levels of any of the markers. Treatment with LPS alone increased the expression levels of all three surface markers, although the levels were not significantly different compared to untreated DCs. The LPS-induced marker expression could be further enhanced by co-stimulation of the cells with DEP. Statistical significantly increased levels of CD83 expression were observed after exposure to 0.2 (p=0.018), 20 (p=0.010) and 200 ng/ml (p=0.047) DEP combined with LPS in the group of responders. We conclude that DEP has an adjuvant effect on LPS-induced maturation of Mo-DC.

Antigens, CD↗
PubMed2004

Should diagnostic testicular sperm retrieval followed by cryopreservation for later ICSI be the procedure of choice for all patients with non-obstructive azoospermia?

BACKGROUND: This was a retrospective study to determine if diagnostic testicular biopsy followed by cryopreservation should be the procedure of choice for all patients with testicular failure. METHODS: The first part of the study analysed 97 ICSI cycles scheduled with frozen-thawed testicular sperm for 69 non-obstructive azoospermia (NOA) patients. The second part focused on a subgroup of 32 patients who underwent 42 ICSI cycles with frozen and 44 cycles with fresh testicular sperm. Sperm characteristics, fertilization, embryo quality, pregnancy and implantation rates were evaluated. RESULTS: Part I: The average time needed to find sperm was 113 min per cycle and 17 min per individual sperm. Fertilization rate, embryo transfer rate, ongoing pregnancy and implantation rates were 58.4%, 83%, 20.8% and 11.3%, respectively. Part II: The search time per sperm was higher (P=0.016) in frozen (18 min) than in fresh suspensions (13 min). A higher embryo transfer rate was observed in fresh cycles than in frozen cycles (93.2% vs 76.2%, P=0.028). Fertilization, ongoing pregnancy and implantation rates were comparable for the two groups. CONCLUSIONS: Even in a programme with low-restrictive criteria for patient allocation and for sperm cryopreservation, diagnostic testicular biopsy followed by cryopreservation can be the procedure of choice for patients with testicular failure.

Adult↗
PubMed2004

Outcome of testicular sperm recovery and ICSI in patients with non-obstructive azoospermia with a history of orchidopexy.

BACKGROUND: Little is known about sperm recovery and ICSI using testicular sperm from men with non-obstructive azoospermia who had a previous orchidopexy. We therefore studied the sperm recovery in this subgroup and evaluated clinical parameters predicting successful sperm retrieval and the outcome of ICSI. METHODS: A total of 79 non-obstructive azoospermic men with a history of orchidopexy underwent a sperm recovery procedure. The predictive value of clinical parameters such as age at sperm retrieval, age at orchidopexy, testicular volume, FSH, FSH/LH ratio, testosterone and androgen sensitivity index (LH x testosterone) for successful testicular sperm retrieval was evaluated using receiver operating characteristics (ROC) curve analysis. A comparison between 64 ICSI cycles performed in these couples and 92 cycles performed in couples in which the men had an unexplained non-obstructive azoospermia was carried out. RESULTS: Testicular spermatozoa were recovered in 41 patients (52%). The mean age at orchidopexy of the patients with a positive sperm recovery was 10.6 years [95% confidence interval (CI) 7.3-13.8] versus 15.5 years (95% CI 11.3-19.8) for those where no spermatozoa were found. The mean testicular volume of the largest testis of patients with spermatozoa found was 10 ml (95% CI 8.3-11.9) versus 8.5 ml (95% CI 5.8-11.1) in patients with no spermatozoa found. The mean FSH and testosterone value for patients with successful and unsuccessful sperm recovery, respectively, was 24.1 IU/l (95% CI 17.9-30.3) and 4.4 ng/ml (95% CI 3.7-5.1) versus 28.8 IU/l (95% CI 19.4-38.2) and 3.4 ng/ml (95% CI 2.2-4.5). All clinical and biological parameters examined failed to predict the outcome of the testicular sperm extraction. No differences were observed between the orchidopexy and unexplained group for the number of oocytes retrieved, fertilization rate, embryo quality, pregnancy rate and implantation rate. CONCLUSIONS: As in the population of men with non-obstructive azoospermia, the sperm recovery rate for patients with a history of orchidopexy is approximately 50% and there are currently no clinical parameters predicting successful sperm retrieval in this subpopulation of patients. The outcome of the ICSI cycles is comparable with that in the population of men with non-obstructive azoospermia.

Adult↗
PubMed2004

Can biological or clinical parameters predict testicular sperm recovery in 47,XXY Klinefelter's syndrome patients?

BACKGROUND: Contradictory results are available regarding prediction of testicular sperm extraction in 47,XXY patients. This study, therefore, aimed at assessing the availability of testicular sperm and evaluates clinical parameters predicting successful sperm retrieval in azoospermic 47,XXY Klinefelter's syndrome patients. METHODS: Sperm recovery procedures were performed in 50 non-mosaic azoospermic Klinefelter patients. The facial hair pattern and the presence of gynaecomastia in men with successful and unsuccessful sperm recovery were compared using Fisher's exact test. The predictive value of clinical parameters such as age, testicular volume, FSH, FSH:LH ratio, testosterone and androgen sensitivity index (LH x testosterone) for successful testicular sperm retrieval was evaluated using the receiver operating characteristics (ROC) curve analysis. RESULTS: In 24 patients (48%) testicular sperm were recovered. Ninety-four per cent of the men in whom sperm was found had a normal facial hair pattern compared to 93% in whom no sperm was recovered (not significant, NS). Seventeen percent of the men with successful testicular sperm extraction had gynaecomastia compared to 31% of the men with failed testicular sperm extraction (NS). The mean testicular volume of the largest testis in patients with sperm found was 4.2 ml compared to 3.6 ml in patients with no sperm found (NS). The mean FSH and testosterone values in patients with sperm recovered were 31.2 IU/l and 3.1 ng/ml versus 40.4 IU/l (P = 0.04) and 3.2 ng/ml (NS) in patients without sperm recovered. All examined clinical and biological parameters failed to predict the outcome of the testicular sperm extraction using ROC curve analysis. CONCLUSION: As in the general population of men with non-obstructive azoospermia, there are currently no clinical parameters predicting successful sperm retrieval in the subpopulation of patients with non-mosaic Klinefelter syndrome.

Gynecomastia↗
PubMed2002

Serum inhibin B cannot predict testicular sperm retrieval in patients with non-obstructive azoospermia.

BACKGROUND: Serum inhibin B, a direct product of the Sertoli cells, may serve as a marker of spermatogenesis. The present retrospective study aimed at evaluating the predictive value of inhibin B for retrieving testicular sperm in non-obstructive azoospermic men. METHODS: The serum inhibin B concentration before sperm retrieval was reviewed in 185 non-obstructive azoospermic patients. RESULTS: Testicular sperm were successfully recovered in 92 of 185 patients (49.7%). The mean inhibin B concentration in these patients was 37.3 pg/ml. No sperm were found in 93 patients (50.3%), and the mean serum inhibin B concentration was 44.9 pg/ml. The discrimination between successful and unsuccessful sperm retrieval was analysed using the receiver operating characteristics (ROC) curve analysis. The best discriminating inhibin B concentration was 13.7 pg/ml (sensitivity 44.6%, specificity 63.4%) with an area under the ROC curve (AUC) of 0.51. Combining both serum FSH and inhibin B did not improve the predictive value: the AUC of inhibin B in men with a serum FSH concentration <25 and > or = 25 IU/l (being the best threshold value in the population studied) was respectively 0.53 and 0.50. The AUC of the inhibin B:FSH ratios was 0.55. CONCLUSIONS: This analysis shows that inhibin B, either alone or in combination with serum FSH, fails to predict the presence of sperm in men with non-obstructive azoospermia undergoing testicular sperm extraction.

Adult↗
PubMed2002

FISH analysis of chromosome X, Y and 18 abnormalities in testicular sperm from azoospermic patients.

BACKGROUND: Sperm extracted from testicular biopsies of azoospermic men can successfully be used for ICSI. The concern exists that testicular sperm from azoospermic men suffering from severe testicular failure may have a higher frequency of aneuploidy, which may lead to an increased risk for chromosomally abnormal offspring. METHODS: Testicular sperm from patients showing spermatogenic failure (n = 17) and from patients with normal spermatogenesis (n = 26) were analysed by fluorescence in-situ hybridization (FISH). Numerical chromosomal abnormalities for chromosomes X, Y and 18 were evaluated by FISH in a total of 1697 testicular sperm derived from 43 azoospermic patients. RESULTS: No difference was observed between the frequency of chromosomal abnormalities in testicular sperm from patients with normal spermatogenesis (5.6%) and from patients with spermatogenic failure (8.2%). However, the frequency of aneuploidy for chromosome 18 was higher in the group of azoospermic patients with spermatogenic failure than in the group with normal spermatogenesis (3.2 versus 1.3%). Within the obstructive group, sex chromosome aneuploidy (4.5%) occurred more frequently than chromosome 18 aneuploidy (1.3%; P < 0.001). Among testicular sperm derived from patients with spermatogenic failure, sex chromosomal aneuploidy (5.8%) was similar to that for chromosome 18 (3.2%). CONCLUSIONS: So far, no difference in the total frequency of chromosomal abnormalities has been observed between patients with normal spermatogenesis and patients with severe testicular failure. However, aneuploidy for chromosome 18 was higher in the group with spermatogenic failure.

Adult↗
PubMed2002

Pseudodystrophy. A conversion disorder mimicking reflex sympathetic dystrophy.

The authors suggest some criteria by which pseudodystrophy and reflex sympathetic dystrophy, although sharing some similar clinical features, can be distinguished as two different conditions, each requiring its own approach and management. The most important distinction is found on bone scintigraphy. In reflex sympathetic dystrophy the bone scan shows a typical increased tracer uptake (at least during stages I and II); in pseudodystrophy there is a normal or decreased tracer uptake in the affected region. Moreover the vascularization is increased in reflex sympathetic dystrophy stage I, whereas in pseudodystrophy hypovascularization is found from the beginning. The clinical features, as well as the results of technical investigations, psychological evaluation and treatment of 4 patients with pseudodystrophy are presented. The importance of distinguishing this condition from reflex sympathetic dystrophy is stressed.

Adolescent↗
PubMed2000

A European multicenter association study of HTR2A receptor polymorphism in bipolar affective disorder.

The available data on the role of 5-HT in a variety of behaviors support the hypothesis that a dysfunction in brain serotoninergic system activity contributes to vulnerability to major depression. The diversity in the electrophysiological actions of 5-HT in the central nervous system can now be categorized according to receptor subtypes and their respective effector mechanisms. In particular, the implication of central postsynaptic 5-HT2A receptor in affective disorders has been supported by findings consistent with the hypothesis of 5-HT2A receptor up-regulation in depression. For these reasons, the 5-HT2A receptor (HTR2A) gene can be considered as a candidate gene in bipolar affective disorder (BPAD). We tested the possible genetic contribution of the polymorphic DNA variation T102C in exon 1 of HTR2A (chromosome 13q14-21) gene in a large European multicentric case-control sample. Allele and genotype frequencies, as well as homo-heterozygote distributions were compared between the two groups of 309 bipolar affective disorder patients and 309 matched controls. No significant differences were observed in the allelic and genotypic (also for homo-heterozygote) distribution between BPAD and controls. These results indicate that, in our sample, the 5-HT2A receptor polymorphism studied is unlikely to play a major role in the genetic susceptibility to BPAD. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:136-140, 2000.

Adult↗
PubMed2000

Linkage of mood disorders with D2, D3 and TH genes: a multicenter study.

BACKGROUND: It has been suggested that the dopaminergic system is involved in the pathophysiology of mood disorders. We conducted a multicenter study of families with mood disorders, to investigate a possible linkage with genes coding for dopamine receptor D2, dopamine receptor D3 and tyrosine hydroxylase (TH). METHODS: Twenty three mood disorder pedigrees collected within the framework of the European Collaborative Project on Affective Disorders were analyzed with parametric and non-parametric linkage methods. Various potential phenotypes were considered, from a narrow (only bipolar as affected) to a broad (bipolar+major depressive+schizoaffective disorders) definition of affection status. RESULTS: Parametric analyses excluded linkage for all the candidate genes, even though small positive LOD (Limit of Detection) scores were observed for TH in three families. Non-parametric analyses yielded negative results for all markers. CONCLUSION: The D2 and D3 dopamine receptors were, therefore, not a major liability factor for mood disorders in our sample, whereas TH may play a role in a subgroup of patients.

Bipolar Disorder↗
PubMed2000

Allelic distribution of CTG18.1 in Caucasian populations: association studies in bipolar disorder, schizophrenia, and ataxia.

CTG18.1 is a highly polymorphic and unstable CTG repeat within an intron of the SEF2-1 gene. We tested the CTG18.1 repeat length in affective disorder, schizophrenia, and nonspecific ataxia; these diseases all have shown clinical evidence for anticipation. There was no difference in the allele frequencies comparing the controls and disease groups. The most common allele contains 11 CAGs (35%) followed by alleles with 14-17 CAGs (35%). There was no difference in the distribution of the alleles in the cases vs controls for ataxia (P = 0.11), affective disorders (P = 0.21), or schizophrenia (P = 0.26). The frequency of unstable CTG18.1 alleles was approximately 3% in a population of N. European descent and is not related to the phenotypes tested.

Alleles↗
PubMed2000

Correlation between semen parameters and sperm aneuploidy rates investigated by fluorescence in-situ hybridization in infertile men.

Spermatozoa from 32 infertile patients and 13 controls with normal semen parameters were analysed using dual and triple colour fluorescence in-situ hybridization (FISH) techniques, in order to investigate the rates of aneuploidy for chromosomes 13, 18, 21, X and Y. The patients were divided into three groups according to their karyotypes or the karyotypes of their offspring: 15 were infertile men with abnormal semen parameters and normal karyotypes (group 1), 13 were infertile men with abnormal karyotypes and normal or abnormal semen (group 2) and four were infertile men with abnormal semen and normal karyotypes but whose wives conceived a child (or a fetus) with a numerical chromosomal abnormality through an intracytoplasmic sperm injection cycle (group 3). Patients with abnormal semen parameters showed a significantly higher aneuploidy rate for the investigated chromosomes in their spermatozoa compared to controls (P < 0.005). Our data suggest the presence of a correlation between poor semen parameters and an increase in aneuploidy rate of chromosomes 13, 18, 21, X and Y in spermatozoa (r = -0.81071, P < 0.002); therefore the risk of a chromosomal aneuploidy in spermatozoa seems to be inversely correlated to sperm concentration and total progressive motility. Patients with abnormal karyotypes showed a higher incidence of diploidy and chromosomal aneuploidies compared to controls (P < 0.002). This strongly suggests the presence of an interchromosomal effect of the cytogenetic rearrangement. Men who fathered a child with an abnormal karyotype through intracytoplasmic sperm injection did not present a higher aneuploidy rate for the investigated chromosomes in spermatozoa compared to patients with infertility due to a similar male factor but showed higher incidence of chromosomal aneuploidy compared to normal controls.

Adult↗
PubMed1999

Report of the chromosome 18 workshop.

At the first chromosome 18 workshop held at the 1997 World Congress on Psychiatric Genetics (WCPG) in Santa Fe, NM, several studies were presented that suggested the presence of a bipolar disorder (BP) as well as a schizophrenia (SZ) susceptibility locus on chromosome 18. Although the fact that several independent studies all pointed to a susceptibility locus (or loci) on chromosome 18, the observation that these studies identified nonoverlapping candidate regions was disappointing at least from the viewpoint of molecular genetics aiming at cloning the respective gene(s). Together, the data suggested four possible regions of considerable size that contained a susceptibility gene. At the 1998 WCPG chromosome 18 workshop in Bonn, Germany, less data were submitted and with the exception of a few studies, most data were nonsupportive or negative. Although some refinements were made to the previous candidate loci, overall the picture has not changed in that we are still confronted with the same four potential loci on chromosome 18 for BP and/or SZ, i.e., 18p11.2 and 18q12.1-q12.3 for BP and SZ, and 18q21-q22 and 18q23-qter for BP. So far, no other psychiatric phenotypes show evidence for a susceptibility locus on chromosome 18.

Bipolar Disorder↗