Search PubMed⌕ Search

Biomedical subjects

H Joris

Publications and source records attributed to H Joris.

At least 37 records · Page 2Linked to original sources
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

Clinical experience with preimplantation genetic diagnosis and intracytoplasmic sperm injection.

Preimplantation genetic diagnosis (PGD) is a novel procedure whose use may be considered to obtain a very early prenatal diagnosis for couples at risk for transmitting genetic diseases. Using the polymerase chain reaction (PCR) or fluorescence in-situ hybridization (FISH) the genotype or the sex of biopsied cleavage-stage embryos obtained after in-vitro fertilization can be determined and selected embryos can then be transferred. In-vitro fertilization with intracytoplasmic sperm injection is the method of choice to obtain embryos to be analysed through PCR to reduce contamination by residual sperm DNA. In our series of 61 PGD cycles for 29 couples at risk over a period of 4 years the ongoing pregnancy rate per cycle was 15%, per transfer 19% and per patient 31%. One of the six morphologically normal children born, who is still alive and doing well, weighed 850 g after birth at 25 weeks following a complicated triplet pregnancy. More experience is needed to correctly evaluate the efficiency and safety of this novel technique as well as to determine its place in the prevention of genetic disease.

Adult↗
PubMed1998

Intracytoplasmic sperm injection: laboratory set-up and injection procedure.

Intracytoplasmic sperm injection (ICSI) as treatment for male-factor infertility has been introduced worldwide in the past few years in many laboratories using assisted reproduction techniques. Some changes in the existing set-up are necessary before implementing this procedure. The equipment can be divided into two groups: that required for preparation of the microtools and that required for the microinjection procedure itself. A pipette puller, grinder and microforge are necessary for preparation of the microtools. The correct settings and use of these instruments are of crucial importance in preparing a good needle, which in turn is crucial to the injection procedure itself. The microscope has to be equipped with a heated stage, correct optics and manipulators and injectors. The correct settings and use of this equipment also influence the injection procedure and may influence the success rate. Retrospective analysis of the evolution of ICSI in our centre clearly shows a marked improvement following the introduction of some modifications into the procedure. These modifications were (i) reducing the concentration of hyaluronidase used for cumulus and corona radiata removal, (ii) selecting a motile spermatozoon that was immobilized prior to the injection and (iii) aspiration of cytoplasm to ensure rupture of the oocyte membrane. The injection procedure itself can also be influenced by oocyte characteristics. It has been reported that the reaction of the oocyte to the penetration by the pipette has an influence on the success rate. The ICSI procedure has about the same success rate as IVF in cases of non-male infertility. However, work can still be done to improve the success rate of this procedure.

Fertilization in Vitro↗
PubMed1998

Pregnancy after preimplantation genetic diagnosis for Charcot-Marie-Tooth disease type 1A.

Charcot-Marie-Tooth (CMT) disease type 1A is an autosomal dominant peripheral neuropathy characterized by slow progressive distal muscle wasting and weakness, and decreased nerve conduction velocities. Most CMT1A cases (>98%) are caused by a duplication of a 1.5 Mb region on the short arm of chromosome 17 containing the PMP22 gene. A couple with a previous history of CMT followed by termination of pregnancy was referred to our centre for preimplantation genetic diagnosis (PGD). The husband carries the CMT1A duplication which can be detected by polymerase chain reaction (PCR) analysis using polymorphic (CA)n markers localized within the duplication. PCR amplification of genomic DNA of the parents-to-be with one of the two primers labelled with fluorescein, followed by automated laser fluorescence (ALF) gel electrophoresis of the amplified fragments allows the distinction between both genotypes. Embryos obtained after intracytoplasmic sperm injection (ICSI) were evaluated for the presence of the normal allele of the father. PCR with single Epstein-Barr virus-transformed lymphoblasts and blastomeres resulted in 91.4 and 93.5% amplification efficiency respectively, whereas none of the blank controls gave a positive signal. Allele drop-out (ADO) was observed in eight out of 32 lymphoblasts (25%) or in five out of 21 blastomeres (23.8%). However, within this set-up ADO will never lead to transfer of an affected embryo. A first ICSI-PGD cycle did not result in embryo transfer for the patient. A second cycle involved 10 mature oocytes of which eight were fertilized, resulting in five embryos for biopsy. Two unaffected embryos were available for transfer and resulted in a singleton pregnancy. The genotype of the fetus has been confirmed healthy by chorionic villus sampling.

Alleles↗
PubMed1998

Fluorescent PCR and automated fragment analysis for the clinical application of preimplantation genetic diagnosis of myotonic dystrophy (Steinert's disease).

Myotonic dystrophy (DM), or Steinert's disease, is an autosomal dominant disease characterized by myotonia, muscular weakness and atrophy, as well as lens opacities, cardiomyopathy and mild endocrine changes. The gene for DM located on 19q contains a triplet repeat at the 3' end of the gene. In DM patients, this repeat is found to be expanded. We have previously described a preimplantation genetic diagnosis (PGD) for DM using polymerase chain reaction (PCR) followed by conventional analysis on ethidium bromide-stained gels. The major drawback of this system was that allelic dropout occurred in >20% of the cells, leading to the loss of healthy embryos for transfer. To resolve this problem, we developed a PGD for DM using fluorescent PCR followed by fragment analysis on an automated DNA sequencer and made a comparison between the conventional PCR described earlier and fluorescent PCR, which turned out to be superior in accuracy and efficiency. Three PGD cycles were performed using fluorescent PCR and are described here.

Adult↗
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

Relationship between serum follicle stimulating hormone in the male and standard sperm parameters, and the results of intracytoplasmic sperm injection.

Serum follicle stimulating hormone (FSH) is routinely measured when evaluating the infertile male for intracytoplasmic sperm injection (ICSI). However, among the sperm parameters, only its relationship with sperm concentration is well documented. Few investigations concern the relationship between FSH and sperm motility and morphology, and the results of ICSI. A retrospective study of 316 couples who underwent ICSI was carried out to determine the relationships between serum FSH concentrations in the male and (i) standard sperm parameters_(concentration, motility and morphology) and (ii) fertilization, cleavage, pregnancy and implantation rates after ICSI. There was an inverse correlation with sperm concentration and total motility but no relationship was found with progressive motility and sperm morphology. Neither was any relationship found between serum FSH and fertilization, cleavage, pregnancy and implantation rates, and the results of ICSI. These findings suggest the need to review the routine measurement of serum FSH in the infertile male when ICSI is the planned treatment procedure.

Female↗
PubMed1997

Effects of different hyaluronidase concentrations and mechanical procedures for cumulus cell removal on the outcome of intracytoplasmic sperm injection.

The aim of this study was to compare concentrations of hyaluronidase and mechanical methods used to denude human oocytes from surrounding cumulus and corona cells prior to intracytoplasmic sperm injection (ICSI). Cumulus and corona cells were removed in two pipetting steps: first in a medium containing hyaluronidase, and then in a medium without enzyme. The first step in the procedure was investigated. Different hyaluronidase concentrations (78, 39 or 10 IU/ml) and pipettes of different size (inner diameter 250 or > 1000 microm) were used to remove the cumulus cells. The time required to denude the oocytes was recorded. Metaphase II oocytes were injected, and the survival, fertilization, embryo development and pregnancy rates were evaluated. We found that by using a pipette with an inner diameter of at least 1000 microm we were able to decrease significantly the time an oocyte is exposed to hyaluronidase, even if the concentration of enzyme is very low (10 IU/ml). For the different conditions there was no statistically significant effect on the outcome in terms of survival, normal fertilization [two pronuclear (2PN)], parthenogenetic activation (1PN), abnormal fertilization (3PN), embryo development and pregnancy rates after ICSI. In conclusion, a concentration as low as 10 IU/ml hyaluronidase in combination with a pipette of at least 1000 microm inner diameter can be used successfully to denude oocytes for microinjection.

Cytological Techniques↗
PubMed1997

The role of the number of replaced embryos on intracytoplasmic sperm injection outcome in women over the age of 40.

In order to examine if the transfer of more than three embryos has any beneficial effect on the outcome of intracytoplasmic sperm injection (ICSI) cycles in women aged > 40 years, a retrospective analysis was made of all the ICSI cycles which were performed in this age group from 1 October 1991 to 31 December 1995. A total of 525 cycles was performed in 321 patients. In 413 cycles, at least one normally fertilized embryo was available for transfer. In 271 cycles, one to three embryos were replaced while in the remaining 142 cycles at least four embryos were replaced. There was no difference in implantation rate (number of gestational sacs/number of embryos transferred), after the transfer of one to three embryos (5.2%), compared with the transfer of at least four embryos (5.1%). The pregnancy rate/embryo transfer and the clinical pregnancy rate/embryo transfer were, however, higher when at least four embryos were replaced than was the case with one to three embryos (27.5 versus 11.8%, P < 0.0001 and 20.42 versus 9.96%, P < 0.005, respectively). There were no statistically significant differences in the delivery rates, multiple pregnancy rates or spontaneous abortion rates. The pregnancy rate and the clinical pregnancy rate after ICSI in women > or = 40 years of age are related to the number of embryos replaced.

Adult↗
PubMed1997

Percoll gradient centrifugation can be omitted in sperm preparation for intracytoplasmic sperm injection.

Prior to intracytoplasmic sperm injection (ICSI), seminal fluid is currently washed out from the ejaculated semen and further sperm selection is carried out by a discontinuous Percoll gradient. Possible deleterious effects from the sperm-separating substance Percoll on sperm function or embryo cleavage after in-vitro fertilization (IVF) have, to our knowledge, not yet been reported and the use of Percoll has been widely accepted in IVF. In this study, we examined whether the omission of the Percoll step in the sperm preparation has any influence on the outcome of the ICSI procedure. Two methods of sperm preparation for ICSI were compared in a controlled study on sibling oocytes: washing the semen sample once, followed by a Percoll gradient centrifugation versus washing the sperm sample twice without a Percoll gradient centrifugation. The mean fertilization rates were similar for the two sperm preparation methods: 78.2 +/- 21.4 and 75.0 +/- 24.1% respectively of the intact oocytes displaying two pronuclei. Cleavage rates did not differ statistically between the two groups. Whereas in both groups similar percentages of excellent, good and poor quality embryos were obtained, the percentage of fair quality embryos was significantly higher in the group without Percoll (16.3 +/- 20.1 versus 9.1 +/- 15.7%). However, no statistical differences were observed in either the percentage of transferable embryos or in the percentage of embryos actually transferred or frozen in the two groups. In conclusion, spermatozoa from ejaculates that are washed out from the seminal fluid without any further selection can be used for ICSI without any adverse effect on fertilization and embryo cleavage.

Cell Separation↗
PubMed1997

Clinical application of preimplantation diagnosis for myotonic dystrophy.

Myotonic dystrophy (DM) or Steinert's disease is a progressive autosomal dominant disease characterized by increasing muscle weakness, myotonia, cataracts, and endocrine abnormalities such as diabetes and testicular atrophy. The gene for DM was cloned in 1992 and the mutation was shown to be an expanded trinucleotide (CTG) repeat. A polymerase chain reaction (PCR)-based assay was described soon after that would allow (prenatal) diagnosis of the disease. Based on these PCR assays, we have developed a method for carrying out single-cell PCR for DM. In preimplantation diagnosis, embryos obtained in vitro are checked for the presence or absence of a disease, after which only embryos shown to be free of the disease under consideration are returned to the mother. A single-cell assay was developed for preimplantation diagnosis in couples where one of the parents is afflicted with DM. Twenty intracytoplasmic sperm injection (ICSI) cycles were carried out in eight patients and between one and four embryos were replaced in 17 out of 20 cycles. Two of the patients became pregnant and have had prenatal diagnosis which has confirmed that they are unaffected.

Adult↗
PubMed1997

Surgical sperm retrieval for intracytoplasmic sperm injection.

The introduction of intracytoplasmic sperm injection (ICSI) provides new hope for many couples suffering from the most untreatable forms of male infertility as ICSI can also be successfully performed using epididymal or testicular spermatozoa. Testicular spermatozoa may be recovered from testicular tissue in every patient with excretory azoospermia, but also in about half of patients with secretory azoospermia. The strongest parameter to predict successful testicular sperm recovery is histopathological examination of a testicular biopsy, especially in patients with some form of germ-cell aplasia. Even in our series of Klinefelter patients, testicular sperm were recovered in eight out of 15 patients and after seven ICSI cycles combined with preimplantation diagnosis, two singletons were born. Less invasive techniques such as percutaneous fine-needle aspiration have been introduced and may yield comparable success rates in patients with normal testicular function. The high fertilization rates after testicular sperm recovery and ICSI and the favourable implantation rates may therefore render microsurgical epididymal sperm aspiration (MESA) obsolete in the future for patients with normal spermatogenesis. Besides, the use of cryopreserved testicular spermatozoa may become an alternative to repeated surgery for obtaining testicular tissue for subsequent ICSI treatment cycles.

Epididymis↗
PubMed1996

Review: preimplantation diagnosis of inherited disease.

Preimplantation diagnosis of inherited diseases has become possible with the techniques of in vitro fertilization, blastomere biopsy of the 6- to 10-cell embryo and DNA analysis of the single blastomeres. Disease-free embryos are selected for transfer to the uterus, thereby avoiding the need for termination of a fetus diagnosed as affected in prenatal diagnosis in the first or early-second trimester of pregnancy. The genetic indications for preimplantation diagnosis are theoretically the same as for prenatal diagnosis, but the defects must be detectable by the polymerase chain reaction. For X-linked recessive diseases, fluorescence in situ hybridization can be used as an alternative for the selection of female embryos. So far almost 40 healthy children have been born worldwide after preimplantation diagnosis for genetic disease. The possibilities and limitations of preimplantation diagnosis, especially in prevention of inherited disease, are discussed in this review.

Alleles↗
PubMed1996

Cytogenetics of infertile men.

Chromosomally derived sterility has long been recognized. A review of the literature of somatic chromosome investigations in infertile males has shown that 13.7% of azoospermic males and 4.6% of oligozoospermic males have an abnormal karyotype. In the first group, sex chromosome abnormalities predominate (mainly 47,XXY), whereas in the latter, autosome anomalies (i.e. Robertsonian and reciprocal translocations) are the most frequent. A similar review on meiotic studies revealed that meiotic chromosome anomalies can explain male infertility in 4.3-40.4% of patients. Recently, fluorescent in-situ hybridization studies on spermatozoa from infertile men were published; it was suggested that both X-Y pairing and pairing of the autosomes were impaired, resulting in spermatogenic disruption. We investigated cytogenetically 694 infertile men with abnormal sperm parameters. More patients are needed for this research to investigate the relationship, if any, between the type of chromosome abnormality and its influence on the number, morphology and motility of spermatozoa. To be able to provide proper counselling for those couples whose male infertility can now be treated by intracytoplasmic sperm injection, it is suggested that clinical investigations should include mitotic and meiotic studies, an analysis of the chromosome content of individual spermatozoa and a DNA analysis of blood and spermatozoa to detect partially deleted Y chromosome material.

Chromosome Aberrations↗
PubMed1996

Adaptation of the primer extension preamplification (PEP) reaction for preimplantation diagnosis: single blastomere analysis using short PEP protocols.

Primer extension preamplification (PEP) was first described as a method for whole genome amplification, starting from a single cell, originally a spermatozoon, in order to perform genetic recombination studies. Its usefulness for preimplantation diagnosis was shown soon after; the only drawback was the length of the procedure (> 14 h). We have developed a shorter PEP protocol for single human blastomeres, enabling us to examine several genetic loci of interest in human genetic diseases with a good amplification efficiency.

Blastomeres↗
PubMed1996

Preimplantation diagnosis for X and Y normality in embryos from three Klinefelter patients.

In some 47,XXY Klinefelter patients without evidence of mosaicism, testicular spermatozoa can be successfully recovered and used for intracytoplasmic sperm injection (ICSI). To ensure the replacement of embryos with a normal X and Y chromosome pattern, preimplantation diagnosis can be performed. This paper reports on three 47,XXY Klinefelter patients from whom it was possible to retrieve testicular spermatozoa in order to perform ICSI. From their healthy wives a total of 27 oocyte-cumulus complexes were retrieved from which 22 metaphase-II oocytes were obtained and injected; 19 of these were intact after injection. Two distinct pronuclei were observed in eight oocytes (42.1%) 18 h after injection. On day 3 of development, five embryos (62.5%) had reached at least the 6-cell stage and were of sufficient quality to undergo biopsy and subsequent preimplantation diagnosis for sex chromosome analysis by fluorescent in-situ hybridization. The four embryos diagnosed as normal were transferred to three respective patients, resulting in one biochemical pregnancy. The remaining cells of the fifth embryo were analysed afterwards, revealing a normal X and Y chromosome constitution. So far, in the five embryos diagnosed, a normal sex chromosome pattern has been observed.

Embryo, Mammalian↗
PubMed1995

Intracytoplasmic sperm injection (ICSI): the Brussels experience.

The present report covers the results of a 26-month period in which 1275 consecutive treatment cycles by intracytoplasmic sperm injection (ICSI) were performed in 919 couples. These couples were afflicted with male factor infertility and had had at least one previous failed conventional in vitro fertilization (IVF) treatment cycle. In other couples, the husband had semen parameters incompatible with conventional IVF or suffered from excretory azoospermia which required microsurgical epididymal sperm aspiration or testicular sperm retrieval. Overall, the 2 pronuclear (PN) fertilization rate was 47.7% per retrieved oocyte-cumulus complex and 66.4% per successfully injected metaphase II oocyte. Embryo transfer was performed in 90.8% of started cycles and 362 clinical pregnancies were recorded, giving a clinical pregnancy rate of 28.4% per started cycle or 31.3% per transfer. In addition, updated results on the outcome of pregnancies after microassisted fertilization are presented. As of 30 August 1994, 416 children have been born. Although 16 major congenital malformations have been observed (3.9%), there appears to be no reason for serious concern as regards the occurrence of major congenital anomalies after ICSI.

Belgium↗