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Biomedical subjects

M Alikani

Publications and source records attributed to M Alikani.

At least 19 recordsLinked to original sources
PubMed2001

Developmental ability of chromosomally abnormal human embryos to develop to the blastocyst stage.

BACKGROUND: A correlation between morphology, developmental competence and chromosome abnormalities is established. However, since absolute correlations are rare, embryo selection remains one of the most arduous tasks in assisted reproduction. This study was undertaken in order to determine which chromosomal abnormalities are compatible with development to the blastocyst stage. METHODS: Embryos diagnosed by preimplantation genetic diagnosis (PGD) as chromosomally abnormal or unsuitable for transfer were cultured to day 5 or 6. Morphology and development were observed daily. After extended culture, embryos were fixed and analysed by two rounds of FISH with the same probes used for PGD. RESULTS: Some types of numerical chromosome abnormalities do not preclude full differentiation in vitro. For instance, extensive mosaicism was detected in blastocysts and trisomic embryos reached the blastocyst stage with a frequency of 37%. Interestingly, only those monosomies compatible with first trimester development (monosomy X and 21) were detected at blastocyst stage. CONCLUSION: Even though there is a strong selection against chromosomally abnormal embryos, extended culture to day 5 or 6 cannot be used as a reliable tool to select against clinically relevant chromosome abnormalities such as trisomies.

Adult↗
PubMed2000

Chromosome abnormalities in 1255 cleavage-stage human embryos.

The relationship was examined between chromosome abnormalities in cleavage stage human embryos and maternal age, embryo morphology and development rate. Embryos that were classified as suboptimal for transfer from patients undergoing IVF treatment were disaggregated, and all or most of their cells were fixed for analysis by fluorescence in-situ hybridization. Chromosomes X, Y, 13, 18 and 21, and in some instances 16 were examined. A total of 731 non-viable embryos was analysed. An increase in chromosome abnormalities with decreasing embryo competence and increasing maternal age was shown. Compared with an earlier study, the major difference was that polyploidy (P<00.01) and aneuploidy were previously more common. After pooling results, it was found that aneuploidy increased with maternal age, from 3.1% in embryos from 20-34 years old patients to 17% in patients 40 years or older. Also, aneuploidy occurred more frequently in embryos with good morphology and development rate than in embryos developing poorly. In contrast, dysmorphic and slowly developing or arrested embryos had significantly more polyploidy and mosaicism than normally developing embryos. Clear associations between maternal age and aneuploidy, and between cleavage anomalies and mosaicism have been established in non-viable embryos. Arrested embryos were mostly polyploid. Moreover, polyploidy was found more frequently in embryos analysed on day 4, suggesting that developmentally compromised embryos became arrested in extended culture. A slightly higher aneuploidy rate in the earlier study may be attributed to differences in hormonal stimulation, which also resulted in different numbers of oocytes recruited and matured.

Journal Article↗
PubMed2000

Cleavage anomalies in early human embryos and survival after prolonged culture in-vitro.

This study examines the relationship between common morphological anomalies of cleaving embryos and their ability to form apparently normal blastocysts in vitro. The impact of cleavage rate, fragmentation, and multinucleation on compaction, cavitation, along with inner cell mass and trophectoderm formation has been assessed. The study population consisted of 102 patients who elected or were selected to have a day 5 embryo transfer. Clinical pregnancy and implantation rates were 66.7 and 49% respectively. Slow and fast cleavage had a significant negative association with normal blastocyst formation. Only 13.8% (67/484) of embryos with <7 cells and 27.5% (25/91) of those with >9 cells on day 3 formed blastocysts with apparently normal morphology, compared to 41.9% (252/602) with 7-9 cells on day 3 (P < 0.001). Fragmentation had a negative impact on normal blastocyst formation. Embryos with >15% fragmentation formed normal blastocysts at a significantly lower rate (46/279; 16.5%) than embryos with 0-15% fragmentation (311/935; 33.3%) (P < 0. 001). Furthermore, the pattern of fragmentation was associated with blastocyst formation. Type IV fragmentation led to a significant reduction in blastocyst formation (25/170 or 14.7%), compared to types I, II and III which performed much better (38.6, 32.9 and 32.4% respectively). Only 15.9% (22/138) of embryos with one or more multinucleate cells on day 2 and/or 3 formed normal blastocysts compared with 31.9% (335/1051) (P < 0.001) of those without multinucleation. Collectively, the data suggest that cleavage anomalies, some of which do not preclude development after short-term culture, may reduce the developmental competence of embryos after prolonged culture.

Blastocyst↗
PubMed1999

Human embryo fragmentation in vitro and its implications for pregnancy and implantation.

OBJECTIVE: To evaluate the effects of fragmentation and fragment removal in day 3 human embryos on implantation and pregnancy. DESIGN: Retrospective analysis of ETs homogeneous with respect to embryo fragmentation. SETTING: A program of IVF-ET. PATIENT(S): The study population consisted of 2,410 patients. INTERVENTION(S): The degree and pattern of fragmentation were evaluated on days 2 and 3; microsurgical fragment removal was performed after assisted hatching on day 3. MAIN OUTCOME MEASURE(S): Clinical pregnancy and implantation rates. RESULT(S): The degree and pattern of fragmentation significantly impact pregnancy and implantation. With the application of microsurgical fragment removal before ET, embryos with 6%-35% fragmentation implant with similar frequency. The presence of large fragments (type IV) is detrimental to the developing embryo, whereas localized or small and scattered fragments do not significantly affect implantation. CONCLUSION(S): The potential of fragmented embryos for implantation is determined partly by the distribution of fragments. Adoption of an embryo classification system reflecting types of fragmentation is advisable. The use of microsurgical fragment removal significantly alters the course of development for some embryos and improves their implanting potential.

Adult↗
PubMed1999

Search for a human homologue of the mouse Ped gene.

The Ped gene influences the rate of cleavage division of preimplantation mouse embryos and subsequent embryonic survival. The mouse Ped gene product is a major histocompatibility complex (MHC) class Ib protein called Qa-2. Studies from many human in-vitro fertilization (IVF) clinics suggest that the mouse Ped gene has a human homologue because embryos fertilized at the same time have different cleavage rates, and those embryos that cleave at a faster rate are more likely to result in a viable pregnancy. Candidates for the human homologue of the mouse Ped gene include the MHC class Ib genes HLA-E, HLA-F, and HLA-G. The presence of mRNA for these three genes was tested in 108 spare day 3 human preimplantation embryos from 25 couples by using reverse transcription-polymerase chain reaction (RT-PCR). Of the 86 embryos tested for HLA-E mRNA, 72 were positive (84%), and of the 88 embryos tested for HLA-G mRNA, 39 were positive (44%). None of the 17 embryos tested for HLA-F mRNA were positive (0%). Studies of expression of HLA-G protein were undertaken to ascertain whether HLA-G was attached to the cell membrane via a glycosylphosphatidylinositol (GPI) linkage similar to that found in Qa-2 protein. Treatment of JEG-3 cells, an HLA-G expressing cell line, with phospholipase C did not result in removal of HLA-G showing that HLA-G, unlike Qa-2, is not GPI linked to the cell surface. The pros and cons of HLA-E, HLA-F, and HLA-G as candidates for the human Ped gene are discussed.

Animals↗
PubMed1998

Chromosome abnormalities in embryos obtained after conventional in vitro fertilization and intracytoplasmic sperm injection.

OBJECTIVE: To compare the rate of numerical chromosome abnormalities in embryos derived from bipronucleated zygotes produced by intracytoplasmic sperm injection (ICSI) and conventional IVF. DESIGN: Embryos were classified by maternal age and morphological and developmental characteristics to avoid bias when comparing chromosome abnormalities in ICSI and IVF embryos. SETTING: The Institute for Reproductive Medicine and Science of Saint Barnabas Medical Center, West Orange, New Jersey. PATIENT(S): Seventy-nine couples undergoing IVF and 53 couples undergoing ICSI. INTERVENTION(S): Embryos donated for research were fully biopsied, and their cells were analyzed by fluorescence in situ hybridization with specific probes for chromosomes X, Y, 13, 18, and 21 and some with also a probe for chromosome 16. MAIN OUTCOME MEASURE(S): Embryo chromosome abnormalities. RESULT(S): A total of 245 embryos obtained through conventional IVF and 136 embryos obtained through ICSI were analyzed. There were no statistical differences between the rates of numerical chromosomal abnormalities detected in the IVF (61%) and ICSI (52%) embryos analyzed. Regarding gonosomal aneuploidy, the same rate was found in both ICSI (1%) and IVF groups (2%). CONCLUSION(S): If the parents are chromosomally normal, the results indicate that, at the embryo level and before any embryo selection has occurred in utero, ICSI does not produce more numerical chromosomal abnormalities than conventional IVF.

Adult↗
PubMed1998

Genetic regulation of egg and embryo survival.

In both mice and humans, 15-50% of embryos die during the preimplantation period from mechanisms that are largely unknown. Two major criteria predict preimplantation embryo quality, the rate of development and the degree of fragmentation. We review evidence that both of these criteria have a genetic basis. Rate of development and subsequent embryo survival are controlled by a gene, Ped, we discovered in the mouse. Although progress is being made in the search for the human homologue of the mouse Ped gene, it has not yet been identified. Fragmentation, observed in both mouse and human embryos, is probably the result of apoptosis. We analysed transcription of two genes that regulate apoptosis, bcl-2 and bax, and found that both are transcribed in mouse and human preimplantation embryos. Overall, the literature reviewed and new data presented in this paper support the concept that there is a genetic basis for preimplantation egg and embryo survival.

Animals↗
PubMed1998

Ooplasmic transfer in mature human oocytes.

Ooplasmic transplantation aimed at restoring normal growth in developmentally compromised oocytes and embryos was evaluated in seven couples (eight cycles) with multiple implantation failures. Two approaches were investigated to transfer ooplasm from donor eggs at metaphase II (MII) stage into patient MII eggs: (i) electrofusion of a ooplasmic donor fragment into each patient egg (three cycles), and (ii) direct injection of a small amount of ooplasm from a donor egg into each patient egg (five cycles). Some donor eggs were used multiple times. Donor eggs were divided into two groups, one being used for ooplasmic extraction and the other one for egg donation. Cleaved embryos resulting from the latter were cryopreserved, where numbers and satisfactory development permitted. A second control group consisted of embryos derived from patient eggs after intracytoplasmic sperm injection without ooplasmic transfer. This was performed when sufficient number of eggs were available (n = 5). Donor eggs (n = 40) were evaluated cytogenetically after micromanipulation in order to confirm the presence of chromosomes. One egg was anuclear and the recipient embryos were not transferred. Normal fertilization was significantly higher after injection of ooplasm (63%) in comparison with fusion (23%). Pronuclear anomalies appeared enhanced after fusion with ooplasts. Embryo morphology was not improved in the three cycles with electrofusion and patients did not become pregnant. An improvement in embryo morphology was noted in two patients after injection of ooplasm and both became pregnant, but one miscarried. A third pregnancy was established in the repeat patient, without obvious embryo improvement. One baby was born and the third pregnancy is ongoing with a normal karyotype. Two other patients with male factor infertility had poor embryos after ooplasmic injection, but the donor embryo controls were also poor. The patients did not become pregnant and had no donor embryos frozen. Ooplasmic transfer at the MII stage may be promising in patients with compromised embryos; however, evaluation of ooplasmic anomalies and optimization of techniques will require further investigation prior to widescale application.

Cell Culture Techniques↗
PubMed1996

A model for the incorporation of intracytoplasmic sperm injection into a private practice in vitro fertilization program.

OBJECTIVE: To describe a method for the training of personnel and the implementation of intracytoplasmic sperm injection (ICSI) into an IVF program. The results of the first 75 cycles are reviewed. DESIGN: Retrospective review of the first 75 consecutive ICSI procedures. SETTING: Private, community-based IVF program. MAIN OUTCOME MEASURES: The fertilization rate, damage rate, ongoing pregnancy rate (PR), and implantation rate were measured. RESULTS: Nine percent of the injected oocytes were damaged. The fertilization rate was 60%, and the cleavage rate was 98%. Fifty-nine percent of the cycles resulted in an ongoing pregnancy, and the implantation rate per embryo was 26%. CONCLUSIONS: A high initial PR can be obtained with ICSI using a systematic training regimen.

Adult↗
PubMed1996

Oolemma characteristics in relation to survival and fertilization patterns of oocytes treated by intracytoplasmic sperm injection.

The aim of this study was to analyse the various reactions displayed by the oolemma to the penetrating pipette during intracytoplasmic sperm injection (ICSI) and correlate them with clinical factors, oocyte survival and fertilization patterns. Three types of oolemma responses were observed: normal breakage, when the injection needle created an invagination that ruptured at the approximate centre of the egg; sudden breakage, when the membrane broke without creating a funnel; and difficult breakage, when the membrane did not break or broke after several penetration attempts. A total of 2928 oocytes were analysed with the following observations: 73.9% (n = 2164) experienced normal breakage, 11.8% (n = 345) sudden breakage, and 14. 3% (n = 419) difficult breakage. The survival rate and number of normally fertilized oocytes were significantly lower and the incidence of digynic oocytes was significantly higher in the sudden breakage group; furthermore, in this group a significantly shorter length of stimulation was observed along with lower serum oestradiol concentrations when compared to oocytes experiencing normal and difficult breakage patterns. These recorded patterns were predictive of the survival and fertilization ability of the injected oocytes, as well as the incidence of digyny. The link between membrane behaviour and various clinical parameters appears to indicate a correlation between the modality of stimulation and oolemma characteristics.

Cell Membrane↗
PubMed1996

Beneficial aspects of co-culture with assisted hatching when applied to multiple-failure in-vitro fertilization patients.

A study was conducted on patients who had attempted and failed previous in-vitro fertilization (IVF) procedures an average of 3.8 times following the application of assisted hatching with conventional culture systems. The aim of this investigation was to determine if addition of co-culture methodologies could reduce embryonic abnormalities and thus improve the prognosis for pregnancy. The study population consisted of 123 patients, subdivided into three patient categories. Previous IVF results from conventional culture were used to evaluate any potential benefits derived from the present co-culture application. Following co-culture, the rate of blastomere development was increased and the rate of fragmentation decreased. An increased rate of blastomere development was most noticeable in the patients aged < or = 39 years with no male factor as well as the intracytoplasmic sperm injection (ICSI) subgroup. Similarly, the rate of fragmentation was significantly reduced in the aforementioned subgroups. The most pronounced impact of co-culture was on pregnancy and implantation rates. The overall clinical and ongoing pregnancy rates were 38% (47/123) and 36% (44/123) respectively. The corresponding implantation rate was 17% (72/ 412) as shown by embryonic cardiac activity. The ongoing pregnancy rates in the < or = 39 years no male factor, > or = 40 years no male factor and ICSI no age limit patient subgroups were 41% (21/51), 30% (8/27) and 33% (15/45) respectively. The results indicate that addition of co-culture to the IVF procedure for poor-prognosis patients may be advisable.

Adult↗
PubMed1996

The presence of multinucleated blastomeres in human embryos is correlated with chromosomal abnormalities.

The purpose of the present study was to determine whether the presence of one or more multinucleated blastomeres during early embryonic development is associated with chromosomal abnormalities in sibling blastomeres of that embryo. Embryos with multinucleated cells (n = 47) detected on day 2 or 3 or development were compared to dividing embryos without multinucleation. Arrested embryos were excluded from this study. Chromosome abnormalities were detected using fluorescent in-situ hybridization (FISH) with X, Y, 18 and 13/21 chromosome-specific probes. Of 47 embryos included in this study, 76.6% were chromosomally abnormal, compared to 50.9% in the control group (P < 0.001). Excluding aneuploidy, which is originated in the gametes and not the embryo, the differences were even higher, with 74.5% of multinucleated embryos being chromosomally abnormal compared to 32.3% of non-multinucleated embryos (P < 0.001). Day of multinucleation appearance, number of nuclei per cell, number of multinucleated cells per embryo and developmental quality of the embryos as well as the type of fertilization (intracytoplasmic sperm injection versus standard insemination) were not found to affect the rate of chromosomal abnormalities in embryos with multinucleated cells. These results suggest that embryos with multinucleated cells may not be suitable for replacement and should be excluded unless no other embryos are available.

Blastomeres↗
PubMed1995

Intracytoplasmic sperm injection: a novel treatment for all forms of male factor infertility.

OBJECTIVE: To demonstrate the effectiveness of intracytoplasmic sperm injection to treat male factor infertility and to report on the achievement of fertilization and pregnancy compared with standard in vitro insemination. DESIGN: Controlled clinical study. SETTING: Couples suffering from male factor infertility treated in an academic research environment. PATIENTS: Two hundred twenty-seven couples in whom the male partners were presumed to be the cause of repeated failed attempts at IVF or whose semen parameters were unacceptable for conventional IVF. INTERVENTIONS: Oocytes for this study were harvested after superovulation with GnRH agonist and gonadotropins. After removing the cumulus cells, a single spermatozoon was injected directly into the cytoplasm of metaphase II oocytes, and the outcome was analyzed in terms of semen parameters and origin of semen sample. MAIN OUTCOME MEASURES: Fertilization and pregnancy rates (PRs) in relation to sperm parameters and origin of semen sample. RESULTS: Two hundred twenty-seven couples were treated by intracytoplasmic sperm injection resulting in an ongoing pregnancy rate of 37.0% per retrieval (84/227). There were 47 singleton pregnancies (5 of which were vanishing twin pregnancies), 30 twin gestations, 6 triplet pregnancies, and 1 quadruplet pregnancy. The concentration of the total motile spermatozoa present in the ejaculate as well as the origin of the samples influenced the fertilization rate but not the pregnancy outcome. CONCLUSIONS: Intracytoplasmic sperm injection can be used successfully to treat couples who have failed IVF or who have too few spermatozoa for conventional methods of in vitro insemination. Sperm parameters do not clearly affect the outcome of this technique.

Adult↗
PubMed1995

Cystic fibrosis gene mutations do not affect sperm function during in vitro fertilization with micromanipulation for men with bilateral congenital absence of vas deferens.

OBJECTIVE: To assess the effects of cystic fibrosis transmembrane-conductance regulator (CFTR) gene mutations on sperm function and fertility in men with bilateral congenital absence of the vas deferens. DESIGN: Prospective. SETTING: Division of urologic microsurgery and associated hospital-based IVF unit. MAIN OUTCOME MEASURES: Fertilization and pregnancy rates. PATIENTS: Men referred to our fertility unit for treatment of bilateral congenital absence of the vas deferens, using sperm surgically retrieved from the epididymis with IVF and micromanipulation. RESULTS: Of 45 men with bilateral congenital absence of the vas, 54% (19/35) tested were found to be carriers of CFTR gene mutations, with one compound heterozygote. Epididymal sperm from men affected with CFTR mutations fertilized 19% (29/152) of oocytes, whereas men without mutations fertilized 22% (44/204) of oocytes. Pregnancy rates (PRs) were 36% (5/14) for cycles involving men with CFTR mutations and 33% (5/15) for other patients with congenital absence of the vas deferens but without detectable CFTR mutations. CONCLUSIONS: The presence of detectable CFTR mutations does not affect fertilization rates or PRs for men with bilateral congenital absence of the vas deferens when IVF and micromanipulation are applied.

Cystic Fibrosis↗
PubMed1995

Micropuncture retrieval of epididymal sperm with in vitro fertilization: importance of in vitro micromanipulation techniques.

OBJECTIVES: To evaluate the importance of in vitro micromanipulation techniques, specifically intracytoplasmic sperm injection (ICSI), for the fertility treatment of men with congenital absence of the vas deferens (CAV) or other unreconstructable male reproductive tract obstruction. METHODS: Results using ICSI during in vitro fertilization (IVF) were compared to previously published results of IVF alone and IVF with other micromanipulation techniques at the same infertility center. Main outcome parameters evaluated were: fertilization rate per oocyte, clinical pregnancy rate, and ongoing pregnancies and deliveries. RESULTS: IVF with ICSI yielded a fertilization rate per oocyte of 140 of 312 (45%) and a clinical pregnancy rate of 14 of 27 (52%) per cycle of sperm and egg retrieval. Ongoing pregnancies or deliveries have occurred for 13 of 27 (48%) cycles with ICSI. These results were better than our previously published results of IVF alone or in conjunction with the micromanipulation techniques of subzonal insertion (SuZI) or partial zona dissection (PZD) that yielded a 119 of 631 (19%; P < 0.0001) fertilization rate, clinical pregnancy rate of 14 of 51 (27%; P < 0.001) and ongoing pregnancy or delivery for 12 of 51 cycles (24%; P < 0.001). CONCLUSIONS: Epididymal sperm retrieval should be performed only when micromanipulation is available in conjunction with IVF to maximize chances of fertilization and subsequent pregnancies. The use of ICSI for epididymal sperm appears to maximize chances of pregnancy for couples with surgically unreconstructable obstructive male infertility.

Cytoplasm↗
PubMed1995

Intracytoplasmic sperm injection in dysmorphic human oocytes.

Fertilisation and development of dysmorphic human oocytes recovered from hyperstimulated ovaries have been evaluated following intracytoplasmic sperm injection (ICSI) for treatment of male infertility. A total of 2968 oocytes at metaphase II of meiosis were injected, of which 806 (27.2%) were dysmorphic at the light microscopic level. Cytoplasmic abnormalities included granularity, areas of necrosis, organelle clustering, vacuoles, and accumulating saccules of smooth endoplasmic reticulum. Anomalies of the first polar body and zona pellucida, as well as non-spherical shapes of oocytes, were also noted. Contrary to previous findings linking some dysmorphisms to non-assisted fertilisation failure, in this study no single abnormality led to a reduction in the fertilisation rate, nor was fertilisation compromised in oocytes with multiple abnormalities. The incidence of normal fertilisation (two pronuclei and two polar bodies) was 69% in both the dysmorphic and non-dysmorphic oocytes. While overall pregnancy and implantation results were not altered in the group of patients (n = 242) in whom at least one dysmorphic oocyte was injected, exclusive replacement of embryos which originated from dysmorphic oocytes led to a higher incidence of early pregnancy loss. It is concluded that aberrations in the morphology of human oocytes--most probably a product of controlled ovarian stimulation--are of little or no consequence to fertilisation or early cleavage after ICSI. It is possible, however, that these embryos have a reduced potential for implantation and further development.

Embryo Implantation↗
PubMed1995

Development and implementation of intracytoplasmic sperm injection (ICSI).

The purpose of this paper is to elucidate the experimental steps that led to the development of intracytoplasmic sperm injection (ICSI) and its application in the human. ICSI has become the most successful micromanipulation procedure for treating male infertility. A total of 355 in vitro fertilization (IVF) cycles utilizing ICSI are described; 180 couples were previously treated in 509 IVF cycles but achieved no fertilization and 175 couples could not be treated by IVF because of extremely poor semen parameters. Of the 3063 metaphase II (M II) oocytes retrieved, 2970 were injected with a survival rate of 93.6%, yielding 1917 bipronuclear zygotes (64.5%). In 148 patients, a foetal heart was evidenced by ultrasound; 11 of these patients miscarried between 7 and 13 weeks of gestation. The ongoing pregnancy rate was 38.6% (137/355) per retrieval and 40.5% (137/338) per embryo replacement. At the time of writing, there were 22 deliveries and one therapeutic abortion for a trisomy 21 chromosomal abnormality. In addition, 66 singleton, 37 twin, 10 triplet and 1 quadruplet pregnancies were ongoing. The concentration of motile spermatozoa in the ejaculate only slightly influenced the fertilization rate (P < 0.001) and the pregnancy outcome (P < 0.01). A preliminary injection procedure utilizing intracytoplasmic injection of isolated sperm heads was performed in 35 M II human oocytes with resultant fertilization and cleavage rates of 74% and 73% respectively. Skills in ICSI were acquired by injecting hamster and unfertilized human oocytes with human sperm. ICSI can be used to successfully treat couples who have failed IVF or who have too few spermatozoa for conventional in vitro insemination.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗