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Biomedical subjects

B Urman

Publications and source records attributed to B Urman.

At least 19 recordsLinked to original sources
PubMed2006

Cytogenetic results of amniocentesis materials: incidence of abnormal karyotypes in the Turkish collaborative study.

The experience on prenatal chromosome diagnosis of four Turkish centers participating in a collaborative study on 6041 genetic amniocentesis performed during a 4-8 years period were reviewed. 5887 (97.5%) patients had strong clinical indications for prenatal chromosome studies and 154 (2.5%) were referred because of maternal anxiety and a bad history of previous gestations. The main indication groups were: advanced maternal age (3197 cases), positive serum screening (2011 cases), ultrasound-identified anomaly (492 cases), previous fetus/child with chromosomal aberrations (103 cases), a history of a previous abnormal and/or mentally handicapped child (70 cases) and a parental chromosome rearrangement (14 cases). The average maternal age was 33.9 years and average gestational age was 18 weeks. A total of 179 affected fetuses were detected in this collaborative study (3%) of which 133 were unbalanced (74.3%). Among the 124 (69%) numerical aberrations, 102 (82.3%) were autosomal aneuploidies, 20 (16.1%) were gonosomal aneuploidies and 2 (1.6%) were poliploidies. Among the 55 (31%) structural aberrations, balanced translocation was the most common (63.6%) and 11 cases of inversion, four cases of unbalanced translocation, two cases of marker chromosome and three cases of other abnormalities were found. The overall culture success rate was 99.7%. Pregnancy termination that is permitted by legal authorities was accepted by 94.7% (126/133) with parents at unbalanced cytogenetic result announcement.

Adolescent↗
PubMed2003

An alternative to PVP for slowing sperm prior to ICSI.

BACKGROUND: There is a growing awareness of potential problems in exposing sperm to polyvinylpyrrolidone (PVP) to slow their motility, a procedure commonly used prior to ICSI. The study presented here evaluates an alternative product for slowing sperm motility, which contains hyaluronate, a substance found naturally in the reproductive tract. METHODS: Computerized sperm motility analysis was used to compare the motilities of sperm exposed to either a PVP-containing product (ICSI-100), or a hyaluronate-containing product (SpermCatch), or control sperm resuspended in a sperm maintenance medium. A subjective assessment was made of the ease with which sperm could be isolated and be drawn into, and expelled from, an injection pipette after having their tails nicked. Sperm exposed to either ICSI-100 or SpermCatch were used for ICSI. Fertilization rate, zygote development, grading, and outcome of transfer were recorded for the two treatment groups. RESULTS: The hyaluronate-containing product slowed sperm motility sufficiently for the sperm to be captured in an injection pipette, was easy to draw into and expel from the pipette, prevented sperm sticking to plastic or glassware, and did not affect post-injection zygote development. Clinical pregnancy rates were similar for the two groups. CONCLUSIONS: This product represents an alternative to PVP for slowing sperm motility prior to ICSI.

Cleavage Stage, Ovum↗
PubMed2001

Blastocyst-stage transfer of poor-quality cleavage-stage embryos results in higher implantation rates.

OBJECTIVE: To determine the feasibility and success of blastocyst-stage embryo transfers in patients having only fair and poor quality cleavage-stage embryos on day 3. DESIGN: Prospective case study with historic controls. SETTING: Tertiary care private hospital IVF center. PATIENT(S): A total of 158 day 5 embryo transfer cycles in patients with grade 3 and grade 4 cleavage-stage embryos. Control group consisted of 162 day 3 transfer cycles performed with embryos of similar quality. INTERVENTION(S): In vitro culture of embryos up to the blastocyst stage. MAIN OUTCOME MEASURE(S): The percentage of cycles that culminated in the transfer of at least one blastocyst and implantation and pregnancy rate related to the day of transfer. RESULT(S): In the day 3 transfer group, a mean of 5.2 embryos were replaced per patient. This was significantly more than the mean of 2.4 embryos that could be replaced on day 5 (P <.001). The clinical pregnancy rate per embryo transfer was 27.2% and 33.5% in the two groups, respectively (P >.05). The implantation rate per embryo was significantly higher in the day 5 transfer group (15% vs. 5.9%). The multiple pregnancy and abortion rates were similar between the groups. CONCLUSION(S): Transfer of fair and poor quality embryos at the blastocyst stage is feasible and is associated with higher implantation rates as compared to transfer of similar quality embryos on day 3.

Abortion, Spontaneous↗
PubMed2001

Maternal methylation imprints on human chromosome 15 are established during or after fertilization.

Prader-Willi syndrome (PWS) is a neurogenetic disorder that results from the lack of transcripts expressed from the paternal copy of the imprinted chromosomal region 15q11-q13 (refs. 1,2). In some patients, this is associated with a deletion of the SNURF-SNRPN exon 1 region inherited from the paternal grandmother and the presence of a maternal imprint on the paternal chromosome. Assuming that imprints are reset in the germ line, we and others have suggested that this region constitutes part of the 15q imprinting center (IC) and is important for the maternal to paternal imprint switch in the male germ line. Here we report that sperm DNA from two males with an IC deletion had a normal paternal methylation pattern along 15q11-q13. Similar findings were made in a mouse model. Our results indicate that the incorrect maternal methylation imprint in IC deletion patients is established de novo after fertilization. Moreover, we found that CpG-rich regions in SNURF-SNRPN and NDN, which in somatic tissues are methylated on the maternal allele, are hypomethylated in unfertilized human oocytes. Our results indicate that the normal maternal methylation imprints in 15q11-q13 also are established during or after fertilization.

Animals↗
PubMed2001

Blastocyst transfer following intracytoplasmic injection of ejaculated, epididymal or testicular spermatozoa.

Recent studies indicate a strong paternal influence on embryo development and progression of the embryo to the blastocyst stage. The aim of this study was to compare, during extended culture, the in-vitro development of embryos resulting from intracytoplasmic sperm injection (ICSI) of ejaculated spermatozoa (group 1, n = 347), epididymal (group 2, n = 22) or testicular (group 3, n = 18) spermatozoa from obstructive azoospermic and testicular spermatozoa from non-obstructive azoospermic (group 4, n = 31) subjects. Fertilization and blastocyst formation rates were significantly lower in group 4 (P < 0.05). The incidence of expanded and hatching blastocysts was significantly lower in group 4 (P < 0.05). Overall in 93.2% ejaculate ICSI cycles, blastocysts were transferred on day 5. This was significantly higher than the 62% day 5 transfers in the non-obstructive azoospermic group (P < 0.05). Implantation rate per embryo was significantly higher in the ejaculate ICSI group compared with the other groups (P < 0.05). Clinical pregnancy per transfer was similar between groups; however, significantly fewer multiple pregnancies were encountered in the non-obstructive azoospermic group (P < 0.01). In conclusion, the source of the spermatozoa, most likely to be indicative of the severity of spermatogenic disorder, affects the rate of blastocyst formation and blastocyst implantation. Spermatozoa from non-obstructive azoospermic subjects, when utilized for ICSI, result in embryos that progress to the blastocyst stage at a lower and slower rate and implant less efficiently.

Adult↗
PubMed2001

The effect of pronuclear morphology on embryo quality parameters and blastocyst transfer outcome.

BACKGROUND: Embryo quality may be accurately assessed as early as the pronuclear zygote phase, as shown in recent studies. However, it is not known whether good quality zygotes are destined to become good quality cleavage stage embryos and blastocysts. METHODS: In this retrospective study, 86 intracytoplasmic sperm injection-embryo transfer cycles were studied where each available embryo was scored from the zygote until the blastocyst stage. Embryonic normality parameters such as pronuclear pattern, early cleavage, cleavage stage embryo grade, the presence of embryos with > or =8 cells on day 3 and blastocyst quality were recorded. Embryo transfer was undertaken at the blastocyst stage and the outcome was studied according to the pronuclear pattern exhibited by the zygotes. RESULTS: Embryos that showed an ideal pronuclear pattern (0 PN pattern) cleaved earlier and faster and resulted in better quality cleavage stage embryos and blastocysts. The incidence of blastocyst formation was 72% in zygotes showing a 0 PN pattern, compared with 12.7% in zygotes with double pronuclear abnormality. Higher implantation and pregnancy rates were obtained when at least one blastocyst derived from a 0 PN pattern zygote was included in the set of embryos to be transferred. CONCLUSIONS: Our results indicate that the pronuclear pattern of the zygote is closely related to blastocyst formation and quality. Blastocysts derived from 0 PN zygotes have a higher potential for implantation.

Blastocyst↗
PubMed2000

Blastocyst quality affects the success of blastocyst-stage embryo transfer.

OBJECTIVE: To determine the relationship between blastocyst quality and the results of embryo transfer at the blastocyst stage. DESIGN: Retrospective case analysis. SETTING: Tertiary care private hospital IVF center. PATIENT(S): A total of 350 blastocyst-stage embryo transfer cycles. INTERVENTION(S): In vitro culture to the blastocyst stage was undertaken in 350 ICSI cycles where four or more cleavage-stage embryos were available on day 3. MAIN OUTCOME MEASURE(S): Relationship between blastocyst quality and implantation and clinical and multiple pregnancy rates. RESULT(S): Transfer of at least one grade 1 or grade 2 blastocyst or one hatching blastocyst was associated with very high implantation and pregnancy rates. However, transfer of grade 3 blastocysts yielded very low implantation and pregnancy rates. CONCLUSION(S): There appears to be a strong correlation between blastocyst quality and success of blastocyst transfer.

Blastocyst↗
PubMed2000

Low-dose aspirin does not increase implantation rates in patients undergoing intracytoplasmic sperm injection: a prospective randomized study.

PURPOSE: The aim was to evaluate the effect of aspirin on pregnancy and implantation rates in an unselected group of patients undergoing intracytoplasmic sperm injection (ICSI). METHODS: Two hundred and seventy-nine patients were randomized to receive 80 mg of aspirin (n = 139) or no treatment (r = 136) starting from the first day of controlled ovarian hyperstimulation. RESULTS: Duration of stimulation, gonadotropin consumption, peak estradiol, number of oocytes retrieved, fertilization rate, cleavage rate, and number of embryos transferred were similar in the two groups. Implantation and clinical pregnancy rates were 15.6% and 39.6% versus 15.1% and 43.4% in aspirin treated and untreated groups, respectively (P > 0.05). CONCLUSIONS: Low-dose aspirin administration does not improve implantation and pregnancy rates in an unselected group of patients undergoing ICSI.

Adult↗
PubMed2000

In-vitro spermatogenesis resumption in men with maturation arrest: relationship with in-vivo blocking stage and serum FSH.

We have shown previously that germ cells recovered from some men with maturation arrest can resume spermatogenesis in vitro and give rise to late elongated spermatids. This study relates the ability of germ cells to differentiate in vitro to the stage at which spermatogenesis is blocked in vivo and to the patient's serum FSH concentration. The presence of germ cells at different stages of spermatogenesis was assessed, before and after culture, by classical cytology, by fluorescence in-situ hybridization and by immunocytochemistry with a germline-specific marker. The proportion of cases of maturation arrest at the primary spermatocyte, secondary spermatocyte and spermatid stage in which in-vitro resumption of meiosis was achieved was 24.3% (9/37), 100% (3/3) and 51.1% (23/45) respectively. Serum FSH concentrations were higher than normal in most cases. However, lower values were measured in patients in whom in-vitro spermatogenesis was achieved compared with those in whom no progression was detected. These data show that, under the conditions of this study, germ cells from men with very high serum FSH concentrations (>20 IU/l) are less likely to resume spermatogenesis in vitro than those coming from men with only moderate increase (10-20 IU/l).

Adult↗
PubMed2000

Progression to the blastocyst stage of embryos derived from testicular round spermatids.

Progression to the blastocyst stage of embryos derived from testicular round spermatids in men with non-obstructive azoospermia was studied. A total of 56 men were studied in whom partial spermatogenesis failure had occurred where only very few spermatozoa (fewer than the number of oocytes retrieved) were extracted from multiple testicular biopsy specimens. Oocytes remaining after intracytoplasmic injection of testicular spermatozoa (group 1) were injected with round spermatids (ROSI, group 2). Only embryos derived from group 1 were transferred. Remaining embryos were observed under culture for 8 days and their progression to the blastocyst stage was recorded. Of the 546 oocytes injected with testicular spermatozoa, 404 (73.9%) showed evidence of 2-pronuclear (2PN) fertilization. Injection of testicular round spermatids resulted in 2PN fertilization rate of 50% (P < 0.05). Using a four-point grading system, 53% of the good quality embryos (grade 1 or 2) in group 1 reached the blastocyst stage compared with 25% in group 2 (P < 0.05). The rate of progression to the blastocyst stage of grade 3 and grade 4 embryos was 46 and 8.5% in the two groups respectively (P < 0.05). Using a different three-point grading system for the blastocysts, 75.3% of the blastocysts in group 1 were either grade 1 or grade 2 and 24.7% were grade 3. However, in group 2 all blastocysts were grade 3. All embryos observed in group 1 reached the blastocyst stage by day 5 or 6 compared with 25% of the embryos reaching the blastocyst stage by this time in group 2. While 31.2% of the blastocysts in group 1 showed evidence of spontaneous hatching in vitro, none of the blastocysts in group 2 hatched. In conclusion, progression to the blastocyst stage occurred at a much lower and slower rate in embryos derived from testicular round spermatids. Furthermore, all blastocysts resulting from ROSI were of poor quality and none showed spontaneous hatching. These results may explain the dismal outcome associated with ROSI.

Blastocyst↗
PubMed2000

Outcome of testicular sperm retrieval procedures in non-obstructive azoospermia: percutaneous aspiration versus open biopsy.

The aim of this study was to evaluate whether the extraction of testicular spermatozoa with percutaneous versus open biopsy has an effect on the treatment outcome with intracytoplasmic sperm injection (ICSI) in men with non-obstructive azoospermia. Regardless of testicular size, follicle stimulating hormone concentration, and previous biopsy result, percutaneous testicular sperm aspiration (PTSA) using a 21-gauge butterfly needle was attempted first and if this failed testicular sperm extraction (TESE) was performed. In 63 men spermatozoa were found with PTSA whereas in 228 men TESE had to be undertaken. More men in the PTSA group had previously been diagnosed with hypospermatogenesis (82 versus 50%). Compared with the PTSA group, more men in the TESE group had germ cell aplasia (27 versus 10%) or maturation arrest (22 versus 8%). There was no difference between the groups regarding mean age of men and their partners, duration of stimulation, oestradiol concentration on the day of human chorionic gonadotrophin, number of oocytes retrieved, fertilization rate, and embryo quality between the two groups. The number of embryos transferred (4.38 versus 3.90) was significantly higher in the PTSA group (P < 0.05), reflecting the increased number of embryos available for transfer. Implantation rate per embryo was 20.7% in the PTSA and 13.3% in the TESE group (P < 0.05). Clinical pregnancy rates were 46 and 29% in the PTSA and TESE groups respectively (P < 0.05). Clinical abortion rates were similar (21.2 versus 24%). It is concluded that in men with non-obstructive azoospermia, easier sperm retrieval, which is most likely indicative of a more favourable histopathology, is associated with higher implantation rates per embryo.

Adult↗
PubMed2000

Comparing two embryo transfer catheters. Use of a trial transfer to determine the catheter applied.

OBJECTIVE: To analyze the performance of two different embryo transfer catheters (Wallace and Frydman) in an in vitro fertilization (IVF)-intracytoplasmic sperm injection (ICSI) program. STUDY DESIGN: Four hundred twenty-eight IVF or ICSI embryo transfer cycles were analyzed. A trial transfer was performed before the initiation of controlled ovarian hyperstimulation to determine the choice of embryo transfer catheter, Wallace or Frydman. Actual transfer was undertaken with the catheter chosen from the trial transfer. RESULTS: During actual embryo transfer, 214 (93.5%) of the intended 229 Wallace transfers were successful, and in 15 transfers the Frydman catheter was used. Of the intended 199 Frydman transfers, all were successful. Clinical pregnancy rate, implantation rate per embryo and ectopic pregnancy rate per transfer for the Wallace catheter were 41.6%, 16% and 0.9%, respectively. Respective rates for the Frydman catheter were 36.0%, 14.4% and 0.9% (P > .05 for all variables). Trial catheterization prevented most of the unanticipated procedural difficulties during the actual transfer. CONCLUSION: Both Wallace and Frydman catheters performed similarly, although there was a slight but nonsignificant increase in clinical pregnancy rates with the Wallace catheter.

Adult↗
PubMed1999

Elevated serum progesterone level on the day of human chorionic gonadotropin administration does not adversely affect implantation rates after intracytoplasmic sperm injection and embryo transfer.

OBJECTIVE: To evaluate the association between serum P levels on the day of hCG administration and the outcome of intracytoplasmic sperm injection (ICSI). DESIGN: Retrospective case study. SETTING: Assisted reproduction unit of a tertiary care private hospital. PATIENT(S): Nine hundred eleven ICSI cycles that proceeded to ET were studied. INTERVENTION(S): The decision to administer hCG was based on serum E2 levels and follicle size. Serum P was measured from frozen sera obtained on the day of hCG administration. Cycles were stratified according to serum P levels of <0.9 ng/mL (n = 298) or > or =0.9 ng/mL (n = 613). This cutoff level was selected because it yielded the highest sensitivity and specificity according to a receiver operator characteristic curve. MAIN OUTCOME MEASURE(S): Implantation and clinical pregnancy rates. RESULT(S): In cycles with high serum P levels, more oocytes were retrieved and more embryos were available for transfer. Clinical pregnancy rates per ET in the low and high P groups were 36.9% and 45.4%, respectively (P<.05). The implantation rate per embryo was similar in the two groups (14.9% and 16.4%, respectively, in cycles with P levels <0.9 vs > or =0.9 ng/mL). Abortion rates were 22.7 and 25.8%, respectively (P>.05). CONCLUSION(S): Our data showed no adverse effect of high serum P levels on the day of hCG administration on implantation rates after ICSI and ET.

Adult↗
PubMed1999

In-vitro culture of spermatozoa induces motility and increases implantation and pregnancy rates after testicular sperm extraction and intracytoplasmic sperm injection.

The aim of this study was to determine the effect of 24-h in-vitro culture of testicular spermatozoa in recombinant follicle stimulating hormone (recFSH) supplemented medium versus simple medium on sperm motility, and to analyse the outcome of intracytoplasmic sperm injection (ICSI) of such spermatozoa. A total of 143 positive testicular sperm extraction procedures in men with non-obstructive azoospermia was evaluated prospectively. Extracted testicular tissue samples were randomized to be cultured in vitro for 24 h in simple medium or recFSH supplemented media. ICSI was performed with spermatozoa cultured in recFSH (n = 73) or in simple medium (n = 70). Sperm motility following in-vitro culture, embryo quality after ICSI, and implantation and pregnancy rates were assessed. Of the 898 MII oocytes available in the recFSH group, 646 (71.9%) were injected with spermatozoa showing either twitching or progressive motility. However, only 29.1% of the oocytes in the simple medium group (245/841) were injected with motile spermatozoa (P < 0.05). Fertilization rate (68.8 versus 42.1%), implantation rate per embryo (20.1 versus 13.2%), and clinical pregnancy rate (47. 9 versus 30%) were significantly increased in the recFSH group compared with the simple medium group respectively (P < 0.05). In conclusion, in-vitro culture with recFSH appears to increase the motility of testicular spermatozoa, thus increasing the success of ICSI.

Cells, Cultured↗
PubMed1998

Performing testicular or epididymal sperm retrieval prior to the injection of hCG.

PURPOSE: Our purpose was to determine the feasibility and efficacy of performing testicular or epididymal sperm retrieval prior to the injection of human chorionic gonadotropin (hCG). METHODS: This report deals with 87 sperm-positive percutaneous epididymal sperm aspiration (PESA), percutaneous testicular sperm aspiration (PTSA), or testicular sperm extraction (TESE) cycles. All sperm retrieval procedures were performed prior to administration of hCG to the women. Retrieved spermatozoa were cultured in vitro in simple medium for approximately 40 hr prior to intracytoplasmic sperm injection. RESULTS: In all but one cycle in which TESE was performed for nonobstructive azoospermia, motile sperm were available for ICSI. The overall fertilization rate was 53%. Pregnancy rate per transfer and implantation rate per embryo were 41.2 and 15.7%, respectively. CONCLUSIONS: Satisfactory fertilization and pregnancy rates can be achieved when PESA, PTSA, or TESE is performed prior to the injection of hCG followed by in vitro culture of spermatozoa approximately 40 hr before ICSI. Scheduling of testicular or epididymal sperm retrieval cases in this way appears to ease the workload on laboratory and operating room personnel. Furthermore, withholding hCG when sperm is absent may obviate the unnecessary risk of ovarian hyperstimulation when spermatozoa cannot be retrieved.

Biopsy↗
PubMed1998

Methylation levels at selected CpG sites in the factor VIII and FGFR3 genes, in mature female and male germ cells: implications for male-driven evolution.

Transitional mutations at CpG dinucleotides account for approximately a third of all point mutations. These mutations probably arise through spontaneous deamination of 5-methylcytosine. Studies of CpG mutation rates in disease-linked genes, such as factor VIII and FGFR3, have indicated that they more frequently originate in male than in female germ cells. It has been speculated that these sex-biased mutation rates might be a consequence of sex-specific methylation differences between the female and the male germ lines. Using the bisulfite-based genomic-sequencing method, we investigated the methylation status of the human factor VIII and FGFR3 genes in mature male and female germ cells. With the exception of a single CpG, both genes were found to be equally and highly methylated in oocytes and spermatocytes. Whereas these observations strongly support the notion that DNA methylation is the major determining factor for recurrent CpG germ-line mutations in patients with hemophilia and achondroplasia, the higher mutation rate in the male germ line is apparently not a simple reflection of sex-specific methylation differences.

Achondroplasia↗
PubMed1998

Oocyte morphology does not affect fertilization rate, embryo quality and implantation rate after intracytoplasmic sperm injection.

In this study, we compared the fertilization rate and embryo quality after intracytoplasmic sperm injection (ICSI) as they relate to oocyte morphology. A total of 654 ICSI cycles yielding 5903 metaphase II oocytes were observed. The oocytes retrieved in these cycles were divided into (i) normal oocytes, (ii) oocytes with extracytoplasmic abnormalities (dark zona pellucida and large perivitelline space), (iii) oocytes with cytoplasmic abnormalities (dark cytoplasm, granular cytoplasm, and refractile body), (iv) oocytes with shape abnormalities, and (v) oocytes with more than one abnormality (double and triple abnormalities). Intracytoplasmic vacuoles and aggregates of smooth endoplasmic reticulum were not recorded separately. The fertilization rate and quality of morphologically graded embryos did not differ between the groups. There were 77 cycles where all transferred embryos were derived from abnormal oocytes, and 164 cycles where all embryos were derived from normal oocytes. These cycles were studied further. The two groups were comparable regarding mean female age, duration of infertility, duration of ovarian stimulation, number of ampoules of gonadotrophin injected, and number of oocytes retrieved. Two clinical pregnancy rates (44.4 versus 42.1%) and implantation rates per embryo (10.3 versus 13.2%) were similar. In conclusion, in couples undergoing ICSI, abnormal oocyte morphology is not associated with a decreased fertilization rate or unfavourable embryo quality. Furthermore, embryos derived from abnormal oocytes yield similar clinical pregnancy and implantation rates when transferred compared with embryos derived from normal oocytes.

Cell Size↗