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Biomedical subjects

Ilan Tur-Kaspa

Publications and source records attributed to Ilan Tur-Kaspa.

13 recordsLinked to original sources
PubMed2006

A prospective evaluation of uterine abnormalities by saline infusion sonohysterography in 1,009 women with infertility or abnormal uterine bleeding.

OBJECTIVE: To evaluate the role of saline infusion sonohysterography (SIS) in the investigation of uterine abnormalities and malformations in patients referred for infertility work-up compared with women with abnormal uterine bleeding (AUB). DESIGN: Prospective cohort study. SETTING: Academically oriented private practice. PATIENT(S): One thousand nine consecutive women examined by SIS for infertility work-up (n = 600, infertility group) or AUB investigation (n = 409, AUB group). INTERVENTION(S): SIS. MAIN OUTCOME MEASURE(S): Intracavitary abnormalities and uterine anomalies. RESULT(S): Among the women in the infertility group, 16.2% (n = 97) were found to have intracavitary abnormalities, including polyps (13.0%), submucous fibroids (2.8%), and adhesions (0.3%). Significantly, more patients in the AUB group (39.6%, n = 162) revealed intracavitary abnormalities, including polyps (29.8%), submucous fibroids (9.0%), and adhesions (0.7%). In contrast, significantly more uterine anomalies were found in the infertility group (20%, n = 120) compared with the AUB group (9.5%, n = 39). Arcuate uterus was the most common finding (15% vs. 6.4% of patients, respectively). CONCLUSION(S): An SIS procedure for infertility work-up revealed a substantial percentage of infertile patients with intracavitary abnormalities and uterine anomalies. Because the technique is safe, well tolerated, and feasible in an outpatient setting, SIS should be considered routinely in the early stage of infertility and AUB investigation.

Administration, Intravaginal↗
PubMed2006

Multiple micromanipulations for preimplantation genetic diagnosis do not affect embryo development to the blastocyst stage.

To determine the impact of multiple micromanipulation procedures for preimplantation genetic diagnosis (PGD) on embryo development, a retrospective analysis was performed of 9,925 embryos (862 PGD cycles), which were compared with 28,126 nonbiopsied embryos (2,751 consecutive intracytoplasmic sperm injection [ICSI] cycles) from the same time period. Because fertilization rates, the proportion of embryos with > or = 6 cells on day 3, and blastocyst rates were similar in the PGD and control groups, we conclude that multiple micromanipulations on oocytes and embryos can be performed safely for PGD.

Adult↗
PubMed2006

Müllerian anomalies, hearing loss, and connexin 26 mutations.

In a study of the possible inter-relationship among müllerian anomalies, hearing loss, and connexin 26 mutations, we evaluated all women in whom müllerian anomalies were diagnosed on hysterosalpingography during a 6-year period (n = 24/519). Audiometric testing revealed five (22.7%) with unrecognized sensorineural hearing loss; however, on genetic evaluation, none harbored a connexin 26 mutation.

Connexin 26↗
PubMed2006

Preimplantation HLA typing with aneuploidy testing.

Preimplantation HLA typing has been introduced for the treatment of affected siblings, requiring HLA-identical stem cell transplantation. This was applied either in combination with preimplantation genetic diagnosis (PGD) to ensure that the preselected HLA-matched embryos were also free of the genetic disorder, or without PGD, with the only purpose of selecting and transferring the HLA-matched embryos. Because patients requesting preimplantation HLA typing are usually of advanced reproductive age, aneuploidy testing allows not only the avoidance of the birth of children with chromosomal disorders, but also improvement of the reproductive outcome, which is still not sufficiently high in preimplantation HLA typing at the present time. This study presents the results of the first experience of preimplantation HLA typing combined with aneuploidy testing, demonstrating feasibility and impact of aneuploidy testing on the accuracy and outcome of preimplantation HLA typing. Of a total of 138 cycles performed, 87 were combined with PGD and 52 without testing for the causative gene, of which aneuploidy testing was performed in 27 cycles, allowing the preselection and transfer of only those HLA-matched embryos that were also euploid. Although the euploid HLA-identical embryos were available for transfer in only half of these cycles, pregnancy and birth of unaffected HLA-identical children were observed in approximately half of these cycles, suggesting the potential usefulness of incorporating aneuploidy testing into preimplantation HLA typing.

Adult↗
PubMed2006

Pre-embryonic diagnosis for Sandhoff disease.

Embryos found to be abnormal during preimplantation genetic diagnosis (PGD) are discarded or analysed to confirm the diagnosis. To overcome this limitation, which is unacceptable in some communities and ethnic groups, pre-embryonic genetic diagnosis has been introduced, involving sequential first and second polar body analysis followed by transfer of embryos deriving from the mutation-free oocytes, while removing from culture and freezing the mutant oocytes at the pronuclear stage. The technique is applied here to PGD of Sandhoff disease caused by 16-kb deletion of the hexosaminidase B gene for a couple with a religious objection to discarding embryos irrespective of embryo genotype. Of 16 oocytes tested in a standard IVF protocol for 16-kb deletion, simultaneously with five linked polymorphic markers, eight were predicted mutant and frozen prior to syngamy, with the remaining eight, found to be free of mutation, further cultured and confirmed unaffected using blastomere biopsy. The transfer of two of these embryos resulted in birth of an unaffected child, demonstrating feasibility of pre-embryonic diagnosis to avoid embryo discard.

Adult↗
PubMed2005

Periovulatory increase in temperature difference within the rabbit oviduct.

BACKGROUND: Earlier studies demonstrated a small temperature difference between the sperm storage and fertilization sites within the oviducts of rabbits and pigs. Our aim was to reveal the time dependence of this temperature difference relative to ovulation, and to determine how this difference is generated-by temperature elevation at one of these sites or by temperature decrease at the other site. METHODS: The temperature at the sperm storage site (at the isthmus near the uterotubal junction) and at the fertilization site (the isthmic-ampullary junction) of rabbit oviducts were measured before, during, and after ovulation by two probes, connected to digital thermometers. Rectal temperature was constantly measured and served as a control for body temperature. RESULTS: The temperature difference between the fertilization site and the storage site was 0.8+/-0.2 degrees C before ovulation. This difference increased at ovulation, reaching 1.6+/-0.1 degrees C after ovulation (P<0.03). This increased difference was mainly due to temperature decrease in the sperm storage site. CONCLUSION: The temperature-difference increase within the rabbit oviduct is generated at ovulation by a reduced temperature at the sperm storage site. This temperature gradient may play a role in mammalian reproduction via sperm thermotaxis.

Animals↗
PubMed2005

Preimplantation genetics: Improving access to stem cell therapy.

There has been progress in the application of stem cell transplantation for treatment of an increasing number of severe congenital and acquired bone marrow disorders, currently restricted by the availability of human leukocyte antigen (HLA)-matched related donors. Preimplantation HLA typing has recently been introduced to improve the access to stem cell therapy for inherited bone marrow failures. Preimplantation genetic diagnosis (PGD) provides an option not only for avoiding an affected pregnancy with thalassemia and other inherited disorders but also for preselection of the HLA-compatible donors for affected siblings. Multiple short tandem repeat markers throughout the HLA region are applied for this purpose, allowing 100% accuracy of HLA typing, through picking up possible recombination in the HLA region, as well as the copy number of chromosome 6, which affect accuracy of preimplantation HLA typing. Present experience of preimplantation HLA typing includes preimplantation HLA typing in 180 cycles, 122 of which were done as part of PGD for Fanconi anemia, thalassemia, Wiscott-Aldrich syndrome, hyper-immunoglobulin M syndrome, hypohidrotic ectodermal dysplasia with immune deficiency, and X-linked adrenoleukodystrophy, and 58 for the sole purpose of HLA typing for leukemias and for aplastic and Diamond-Blackfan anemia. The applied method resulted in the accurate preselection and transfer of 100% HLA-matched embryos, yielding already three dozen clinical pregnancies and the birth of two dozen HLA-matched children to the siblings requiring stem cell transplantation. Successful therapy with HLA-matched stem cells, obtained from these PGD children, has been achieved already for Diamond-Blackfan anemia hypohidrotic ectodermal dysplasia with immune deficiency and thalassemia.

Anemia, Diamond-Blackfan↗
PubMed2004

Human sperm chemotaxis: both the oocyte and its surrounding cumulus cells secrete sperm chemoattractants.

BACKGROUND: Human sperm chemotaxis to pre-ovulatory follicular fluid is well established in vitro. However, it is not known whether the female's oocyte-cumulus complex secretes sperm chemoattractants subsequent to ovulation (for enabling sperm chemotaxis within the Fallopian tube) and, if so, which of these cell types--the oocyte or the cumulus oophorus--is the physiological origin of the secreted chemoattractant. METHODS: By employing a directionality-based chemotaxis assay, we examined whether media conditioned with either individual, mature (metaphase II) human oocytes or the surrounding cumulus cells attract human sperm by chemotaxis. RESULTS: We observed sperm chemotaxis to each of these media, suggesting that both the oocyte and the cumulus cells secrete sperm chemoattractants. CONCLUSIONS: These observations suggest that sperm chemoattractants are secreted not only prior to ovulation within the follicle, as earlier studies have demonstrated, but also after oocyte maturation outside the follicle, and that there are two chemoattractant origins: the mature oocyte and the surrounding cumulus cells.

Cells, Cultured↗
PubMed2003

Lack of species-specificity in mammalian sperm chemotaxis.

Attraction of spermatozoa by way of chemotaxis to substances secreted from the egg or its surrounding cells has been demonstrated in marine species, amphibians, and mammals. This process is species- or family-specific in marine invertebrates: a chemoattractant for one marine species is usually not recognized by another species or by a member of another family. It is not known whether this selectivity is also the rule in other phyla. Furthermore, it is not at all obvious that such selectivity would be advantageous to species with internal fertilization. Here, using a directionality-based assay for chemotaxis, we studied in vitro the chemotactic response of human and rabbit spermatozoa to human, rabbit, and bovine egg-related factors. We found that spermatozoa from each of the two sources responded similarly well to egg-related factors obtained from any of the three species examined. These results indicate lack of chemotaxis-related, species specificity between these species, suggesting that their sperm chemoattractants are common or very similar. The findings further suggest that mammals do not rely on species specificity of sperm chemotaxis for avoidance of interspecies fertilization.

Animals↗
PubMed2003

Perioperative factors for predicting successful hysteroscopic endometrial ablation.

OBJECTIVE: To investigate factors affecting the success of hysteroscopic endometrial ablation in order to improve patient counseling. STUDY DESIGN: Preoperative patient characteristics (age, parity, uterine length, and presence and location of myomas) and intraoperative factors (intracavitary findings, ablation or resection, and operator) were analyzed. Forty-three women with a uterine size of < or = 10 weeks underwent hysteroscopic endometrial ablation or resection and had a median follow-up of 20 months. All were treated with depot triptorelin, 3.75 mg, 1 month prior to the procedure. Alleviation of menorrhagia and amenorrhea was classified as treatment success. Comparative analyses were made between patients with failed vs. successful procedures and with reduced bleeding vs. those with amenorrhea following surgery. RESULTS: Thirty-seven women (86%) reported a decrease in menstrual flow or amenorrhea. In 6 patients (14%), bleeding persisted or became more severe. There were no statistically significant differences between women who had successful vs. failed procedures with regard to all preoperative and intraoperative parameters analyzed. Patients with amenorrhea were significantly older as compared to women with reduced bleeding (47.5 +/- SD 5.0) vs. 44.0 +/- SD 4.1 years, P = .03. CONCLUSION: Most women with uterine size of < or = 10 weeks may expect alleviation of menorrhagia or amenorrhea after surgery. Apart from age, all other preoparative and intraoperative factors examined had no predictive value for a successful procedure. These data are valuable for proper patient counseling before hysteroscopic endometrial ablation.

Adult↗
PubMed2002

Hereditary thrombophilias are not associated with a decreased live birth rate in women with recurrent miscarriage.

OBJECTIVE: To assesses the live birth rate without treatment in women with hereditary thrombophilia who have recurrent miscarriage and women without thrombophilia who have recurrent miscarriage. DESIGN: Prospective observational study. SETTING: Tertiary referral unit in university hospital. PATIENT(S): One hundred twenty women with thrombophilia and 65 women without thrombophilia. MAIN OUTCOME MEASURE(S): Number of live births or repeated miscarriages. RESULTS: Of the 185 patients, 44 with thrombophilia and 26 without thrombophilia have conceived. Nineteen of the 44 pregnancies (43.2%) in thrombophilia patients have terminated in live births, compared with 8 of 26 pregnancies (30.8%) in patients without thrombophilia. This difference is not statistically significant. CONCLUSIONS: Hereditary thrombophilia did not seem to affect the live birth rate in women with recurrent miscarriage.

Abortion, Habitual↗
PubMed2002

Guanylate cyclase activity and sperm function.

In species with external fertilization, the guanylate cyclase family is responsible for the long-distance interaction between gametes, as its activation allows sperm chemotaxis toward egg-derived substances, gamete encounter, and fertilization. In species with internal fertilization, guanylate cyclase-activating substances, which are secreted by several tissues in the genital tracts of both sexes, deeply affect sperm motility, capacitation, and acrosomal reactivity, stimulating sperm metabolism and promoting the ability of the sperm to approach the oocyte, interact with it, and finally fertilize it. A complex system of intracellular pathways is activated by guanylate cyclase agonists in spermatozoa. Sperm motility appears to be affected mainly through an increase in intracellular cAMP, whereas the acrosome reaction depends more directly on cyclic GMP synthesis. Both cyclic nucleotides activate specific kinases and ion signals. A complex cross-talk between cAMP- and cyclic GMP-generating systems occurs, resulting in an upward shift in sperm function. Excessive amounts of certain guanylate cyclase activators might exert opposite, antireproductive effects, increasing the oxidative stress on sperm membranes. In view of the marked influence exerted by guanylate cyclase-activating substances on sperm function, it seems likely that guanylate cyclase activation or inhibition may represent a new approach for the diagnosis and treatment of male and/or female infertility.

Animals↗