Biomedical subjects

Kersti Lundin

Publications and source records attributed to Kersti Lundin.

13 recordsLinked to original sources

PubMed2007

Effect of rescuing donated immature human oocytes derived after FSH/hCG stimulation following in vitro culture with or without Follicular Fluid Meiosis Activating Sterol (FF-MAS)--an embryo chromosomal and morphological analysis.

PURPOSE: Studies in mice and humans have shown that Follicular Fluid - Meiosis Activating Sterol (FF-MAS) induces meiotic maturation of immature oocytes in vitro. A multicenter, prospectively randomised study evaluated chromosomal status of embryos from FSH/hCG primed human immature oocytes, cultured with or without FF-MAS. METHODS: Denuded immature oocytes (n=365) were randomly allocated into inert control, FF-MAS 5 microM or 20 microM. Seventy +/-2 hours after ICSI on matured oocytes, all cleaved embryos were fixed for fluorescence in situ hybridisation analysis. RESULTS: Only 15% of oocytes resulted in cleaved embryos. GV oocytes matured at significantly lower rates (14% and 7%) in the two FF-MAS groups compared to the inert control group (47%). High rates of chromosomal abnormalities were found in all groups. CONCLUSION: Immature oocytes showed poor development with high rates of embryo chromosomal abnormalities. Exposure to FF-MAS in the concentrations, duration and/or formulation used in this study did not improve the results.

Animals↗

PubMed2006

Derivation of a xeno-free human embryonic stem cell line.

Elimination of all animal material during both the derivation and long-term culture of human embryonic stem cells (hESCs) is necessary prior to future application of hESCs in clinical cell therapy. The potential consequences of transplanting xeno-contaminated hESCs into patients, such as an increased risk of graft rejection [Stem Cells 2006; 24:221-229] and the potential transfer of nonhuman pathogens, make existing hESC lines unsuitable for clinical applications. To avoid xeno-contamination during derivation and culture of hESCs, we first developed a xeno-free medium supplemented with human serum, which supports long-term (>50 passages) culture of hESCs in an undifferentiated state. To enable derivation of new xeno-free hESCs, we also established xeno-free human foreskin fibroblast feeders and replaced immunosurgery, which involves the use of guinea pig complement, with a modified animal-product-free derivation procedure. Here, we report the establishment and characterization (>20 passages) of a xeno-free pluripotent diploid normal hESC line, SA611.

Cell Culture Techniques↗

PubMed2006

Interobserver agreement and intraobserver reproducibility of embryo quality assessments.

BACKGROUND: The objective of this investigation was to determine the inter- and intraobserver agreement when assessing embryo quality. METHODS: This investigation included 4002 cleaved embryos from 7535 oocytes retrieved in 688 patients undergoing IVF cycles in a multicentre trial. Embryos were evaluated locally at the inverted microscope at 28, 44 and 68 h (+/-1 h) post-insemination. Digital images of the embryos were assessed centrally by three blinded embryologists. To assess reproducibility, 215 randomly selected cleaved embryos from 33 patients were re-evaluated by the three central embryologists. RESULTS: The interobserver agreement among the central embryologists (using the same method of evaluation; 2D images) was good for classification of top-quality embryos (kappa 0.71-0.73), excellent for classification of normally developed embryos (kappa 0.83-0.86) and good-excellent for classification of transferable embryos (kappa 0.78-0.82). The interobserver agreement between local and consolidated central assessment (different methods of evaluation, inverted microscopy versus 2D images) was good for all three embryo classifications (kappa 0.64-0.79). The intraobserver reproducibility for all three overall embryo classifications was excellent for the consolidated central assessment (kappa 0.80-0.91). CONCLUSION: Embryo quality can be determined with a good degree of interobserver agreement independently of the method of evaluation. Embryologists classify embryos with excellent intraobserver reproducibility.

Embryo Implantation↗

PubMed2006

Chromosomal integrity maintained in five human embryonic stem cell lines after prolonged in vitro culture.

There have been recent reports of human embryonic stem cell (hESC) lines developing chromosomal aberrations after long-term culture, indicating an unstable genomic status due to the in vitro milieu. This raises concern, since it would limit their use in therapeutics. In this study the chromosomal status of five well-characterized hESC lines, SA002, SA002.5, AS034.1.1, SA121 and SA461, was monitored during long-term in vitro culture. The criteria of defined hESCs were met by all of the five hESC lines (four diploid and one trisomic for chromosome 13). The genomes were screened for chromosomal aberrations and rearrangements using comparative genomic hybridization (CGH), interphase fluorescence in situ hybridization (FISH) and traditional karyotyping on several occasions while in culture. The genomic integrity was shown to be maintained after repeated freeze-thaw procedures and continuous culture in vitro for up to 22 months (148 passages). We discuss the most common de novo chromosomal aberrations reported in hESCs, as well as their possible origin.

Cell Culture Techniques↗

PubMed2006

The interface between assisted reproductive technologies and genetics: technical, social, ethical and legal issues.

The interface between assisted reproductive technologies (ART) and genetics comprises several sensitive and important issues that affect infertile couples, families with severe genetic diseases, potential children, professionals in ART and genetics, health care, researchers and the society in general. Genetic causes have a considerable involvement in infertility. Genetic conditions may also be transmitted to the offspring and hence create transgenerational infertility or other serious health problems. Several studies also suggest a slightly elevated risk of birth defects in children born following ART. Preimplantation genetic diagnosis (PGD) has become widely practiced throughout the world for various medical indications, but its limits are being debated. The attitudes towards ART and PGD vary substantially within Europe. The purpose of the present paper was to outline a framework for development of guidelines to be issued jointly by European Society of Human Genetics and European Society of Human Reproduction and Embryology for the interface between genetics and ART. Technical, social, ethical and legal issues of ART and genetics will be reviewed.

Ethics, Medical↗

PubMed2006

Choosing fertilization method by analyzing sperm morphology or by performing swim-up preparation.

BACKGROUND: Evaluation of sperm morphology has been used as a screening method for choosing between intracytoplasmic sperm injection (ICSI) and conventional in vitro fertilization (IVF). However, sperm morphology analysis is a time-consuming and often subjective scoring method, and may lead to an unnecessarily large proportion of invasive and costly ICSI treatments. The aim of this study was to evaluate if the yield after swim-up preparation could be of advantage over sperm morphology evaluation for choosing fertilization method. MATERIAL AND METHODS: In the first part of the study 53 split cycles with less than 5% normal forms in the ejaculate were retrospectively evaluated. Part 2 is a prospective evaluation including 357 cycles where the number of sperm available after a standardized swim-up procedure was used for choosing fertilization method. In all cycles where < or = 1 million sperm were obtained after swim-up, conventional IVF was performed. RESULTS: In the first part no statistically significant difference in fertilization rates was found for IVF and ICSI respectively (59.2% versus 64.7%). Four IVF cycles ended up in total fertilization failure (TFF) while in no ICSI cycle was TFF obtained. In the second part 8.9% TFF was obtained in the poor sperm morphology group compared to 1.3% in the good morphology group. These TFF corresponded to 1% of all our treatment cycles. CONCLUSION: The present strategy reduced ICSI treatments by 10%, thereby reducing the cost and workload. It can be discussed if an increase of TFF in absolute number of eight is balanced by a reduced workload of 100 ICSI treatments.

Adult↗

PubMed2004

Chromosomal abnormality rate in human pre-embryos derived from in vitro fertilization cycles cultured in the presence of Follicular-Fluid Meiosis Activating Sterol (FF-MAS).

BACKGROUND: The objective of the study was to investigate the effect of Follicular-Fluid Meiosis Activating Sterol (FF-MAS) when added to the culture media on the incidence of chromosomal abnormalities and pre-embryo development in human pre-embryos. METHODS: 243 women undergoing IVF/ICSI treatment donated 353 oocytes in a multicentre, prospective, randomized, double blind, four-arm, controlled trial performed at Danish and Swedish public and private IVF centers. Metaphase II oocytes were randomly assigned to: FF-MAS 5 microM, FF-MAS 20 microM, ethanol 0.2% (vehicle control) or water for injection (inert control). The exposure regimen of FF-MAS to the human oocytes was 4 h prior to fertilization by ICSI and 20 h exposure post ICSI. The primary endpoint was the incidence of numerical chromosomal abnormalities. Secondary endpoints were cleavage rate and pre-embryo quality. RESULT: On the pre-embryo level, no significant differences in chromosomal abnormality rate were observed among the four groups. However, the percentage of uniformly normal pre-embryos was significantly lower in the pooled FF-MAS group (5 microM: 12% and 20 microM: 17%) than in the pooled control group (inert control 32% and vehicle control 42%). A high level of mosaicism (41-60%) was found in all groups. At the blastomere level, the percentage of blastomeres categorized as normal was significantly lower in the FF-MAS 5 microM group (41%) and the FF-MAS 20 microM (29%) group versus the inert (52%) and the vehicle (61%) groups. Significantly reduced cleavage and good quality pre-embryo rates were found in both FF-MAS groups. CONCLUSION: FF-MAS increased the rate of aneuploidy and had detrimental effects on cleavage and pre-embryo development, when exposed both before and after fertilization.

Adult↗

PubMed2004

A randomized, double-blind, controlled trial of the effect of adding follicular fluid meiosis activating sterol in an ethanol formulation to donated human cumulus-enclosed oocytes before fertilization.

OBJECTIVE: To evaluate the effect of follicular fluid meiosis activating sterol (FF-MAS) in a 0.2% ethanol formulation on chromosomal status and development of preembryos. DESIGN: Multicenter, prospective, randomized, double-blind, five parallel group, controlled trial. SETTING: Public and private IVF-clinics in Denmark and Sweden. PATIENT(S): Two hundred ten women undergoing IVF treatment donated 310 oocytes. INTERVENTIONS(S): FSH/hCG primed cumulus-enclosed oocytes randomized to 4 hours exposure of medium with 0.1, 1, or 10 microM FF-MAS dissolved in 0.2% ethanol, medium with ethanol 0.2%, or medium with water for injection (control) before insemination. MAIN OUTCOME MEASURE(S): Primary: incidence of human preembryos with chromosomal abnormalities. Secondary: fertilization rate, cleavage rate, and preembryo quality after 68 hours of culture. RESULT(S): At the preembryo level, no significant differences in chromosomal abnormality rate were found among any of the groups. At the blastomere level, a significant increased abnormality rate was observed in the ethanol group and the combined FF-MAS groups compared with the control group. No significant differences in fertilization rate, cleavage rate, or preembryo quality were observed among any of the groups and the control group except for a significant reduction in the number of embryos with >or=2 cells at 26 hours in the ethanol group. CONCLUSION(S): No negative effect of FF-MAS was observed. However, addition of ethanol 0.2% to standard IVF-medium with or without FF-MAS for culturing cumulus-enclosed oocytes for 4 hours before insemination increased the chromosomal abnormality rate at the blastomere level. Further studies of FF-MAS in a nonethanol formulation are under way.

Adult↗

PubMed2003

There is a cutoff limit in diameter between a blastomere and a small anucleate fragment.

PURPOSE: To document the DNA content of blastomeres/fragments from early human preembryos and to determine if there is a "cutoff" diameter at which a cell should be considered an anucleate fragment rather than a blastomere. METHODS: Surplus embryos from in vitro fertilization were used. Individual cells were measured, fixated, and stained for DNA. RESULTS: In day 2 preembryos, only 2% of cells with a diameter <45 microm contained DNA, compared with 67% of those > or =45 microm. In day 3 preembryos, 3% of cells <40 microm contained DNA, compared with 66% of those > or =40 microm. CONCLUSIONS: It is suggested that cells <45 microm in day 2 preembryos, and <40 microm in day 3 preembryos should be classified as fragments, and cells larger than this, as blastomeres. This may influence the embryo scoring system for in vitro fertilization. We therefore recommend that cells within this critical range should be measured when scoring preembryos for embryo transfer.

Blastocyst↗

PubMed2003

Fallopian tube sperm perfusion: the impact of sperm count and morphology on pregnancy rates.

BACKGROUND AND OBJECTIVE: To evaluate the effect of changed criteria for sperm count and morphology when performing fallopian tube sperm perfusion (FSP) in unexplained infertility. PATIENTS AND METHODS: We report on a longitudinal study in which two periods of insemination cycles are compared. One hundred and eighty-three couples who started 361 stimulation cycles intended for FSP were included in the first period and 190 couples starting 303 cycles in the second period. The sperm requirement in the first study period was at least 7 million sperm in the prepared test sample. The FSP cycle included downregulation, controlled ovarian hyperstimulation (COH), ovulation induction and intrauterine and intrafallopian tube insemination using a sperm suspension of 3 mL volume. To avoid high-order multiple pregnancies, cycles at risk were converted to in vitro fertilization (IVF). Based on the results from the first period, sperm requirements were lowered to a sperm count of 3 million and at least 5% normal morphology according to strict criteria. RESULTS: FSP was performed in 51% and 60% of started cycles during the two periods with similar pregnancy (24% and 23%) and birth (15% and 19%) rates. Neither sperm count nor morphology above the requirements affected pregnancy rates. IVF-converted, completed cycles reached equal pregnancy (41%) and delivery (32%) rates in both periods. Multiple pregnancy rates were higher after IVF (38%) than after FSP (24%). CONCLUSION: The lowered requirements for sperm count and morphology have not impaired pregnancy results after FSP. Patients who either completed an FSP cycle or had their cycle converted to IVF were all at high risk of multiple pregnancy.

Fallopian Tubes↗

PubMed2003

A morphological and chromosomal study of blastocysts developing from morphologically suboptimal human pre-embryos compared with control blastocysts.

BACKGROUND: IVF laboratories performing embryo transfer at day 2 or 3 after fertilization are currently discarding pre-embryos considered suboptimal using morphological criteria. The objective of this study was to investigate whether blastocysts, cultured from such pre-embryos (surplus), were chromosomally and morphologically normal. As a control group we used morphologically good quality embryos (GQE), cultured to the blastocyst stage. METHODS: Human pre-embryos considered suboptimal were cultured to the blastocyst stage. As a control group, frozen-thawed pre-embryos of good quality were cultured under identical conditions. The chromosomal status of the blastocysts obtained was studied by multi-colour fluorescence in-situ hybridization for chromosomes 13, 16, 18, 21, 22, X and Y. RESULTS: There is, on average, a significantly higher degree of chromosomal aberrations in blastocysts derived from surplus pre-embryos compared to blastocysts derived from GQE, and the chromosomal aberrations are generally found in a higher number of blastomeres per blastocyst. In addition, blastocysts from surplus pre-embryos had significantly poorer morphology compared to GQE. Improvement in morphology and/or developmental rate in surplus pre-embryos between day 2 and day 3 did not predict a morphologically/chromosomally normal blastocyst. However, this study shows that close to half of the surplus pre-embryos that reach the blastocyst stage can be considered chromosomally normal when assessed for these seven chromosomes. Furthermore, we found that chromosomal aberrations were more concentrated in a particular cell population within blastocysts derived from GQE, compared with surplus blastocysts. CONCLUSIONS: The study suggests that even if the IVF laboratory is on average making the correct decision about the potential of a pre-embryo, surplus pre-embryos that might become chromosomally normal blastocysts are still being discarded.

Adult↗

PubMed2002

Cumulative probability of live birth after three in vitro fertilization/intracytoplasmic sperm injection cycles.

OBJECTIVE: To assess the probability of live birth after three available in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles. DESIGN: Retrospective, observational study. SETTING: University hospital. PATIENT(S): Nine hundred seventy-four couples who started their first conventional IVF or ICSI cycle between January 1996 and December 1997. A total of 1985 stimulated cycles were initiated. INTERVENTION(S): Analysis of the cumulative live birth rate using the life-table approach with and without taking dropouts into account. MAIN OUTCOME MEASURE(S): Cumulative live birth rate. RESULT(S): The overall cumulative live birth rate after three completed stimulated cycles (including freezing/thawing cycles) was 65.5% with an "optimistic" approach. For the "realistic" and "pessimistic" approaches the corresponding figures were 63.1% and 55.5%, respectively. Unexpectedly, 65% of couples not achieving a live birth interrupted the full treatment program of three cycles. CONCLUSION(S): The cumulative live birth rate gives the couple a more accurate prognosis of achieving a live birth after IVF/ICSI than the statistics usually provided. With the "realistic" estimation, 63% of the couples achieved childbirth after three available conventional IVF or ICSI cycles. Further studies are required to investigate the high drop-out rate.

Adult↗

PubMed2002

A human oocyte with two sets of MII/PB-structures.

This paper reports a case where a normal-sized human oocyte has been documented having two polar bodies and two metaphase spindles. This finding suggests that the chromosomal content in oocytes of normal size may occasionally be duplicated and offers an additional explanation for the origin of triploid zygotes in humans. We speculate that this duplication may be caused by oocyte fusion at an early stage.

Adult↗