Infarcted cardiac microenvironment may hinder cardiac lineage differentiation of human embryonic stem cells.

Microenvironment regulates cell fate and function. In this study, we investigated the effects of the infarcted cardiac microenvironment on cardiac differentiation of human embryonic stem cells (hESCs). hESCs were intramyocardially transplanted into infarcted or uninjured rat hearts. After 4 weeks, mesodermal and cardiac lineage markers were detected by immunofluorescence. Cardiac function was assessed by echocardiography. hESCs were differentiated in vitro under hypoxic (5% O2 ), low-nutrient (5% FBS), or control condition. The numbers of beating clusters, proportions of cardiac troponin T (cTnT)-positive cells, and relative levels of cardiac-specific markers were determined. Results showed that in both uninjured and infarcted hearts, hESCs survived, underwent development, and formed intracardiac grafts, with a higher proportion in the uninjured hearts. However, cells that were double positive for human fetal liver kinase 1 (Flk1), a marker of cardiac progenitors, and human ß-tubulin, a marker for labeling human cells, were found in the uninjured hearts but not in the infarcted hearts. hESC transplantation did not restore the cardiac function of acutely infarcted rats. In vitro, low FBS treatment was associated with fewer beating clusters, a lower proportion of cTnT-positive cells and lower levels of cardiac troponin I (cTnI) and α-myosin heavy chain (α-MHC) expression than those in the control. Conversely, hypoxia treatment was associated with a higher proportion of cTnT-positive cells and higher levels of cTnI expression. In conclusion, transplanted hESCs differentiate toward Flk1-positive cardiac progenitors in the uninjured but not infarcted hearts. The infarcted cardiac microenvironment recapitulated is unsuitable for cardiac differentiation of hESCs, likely due to nutrient deprivation.

Thymopentin enhances the generation of T-cell lineage derived from human embryonic stem cells in vitro.

Thymopentin is a group of biologically active peptide secreted mainly by the epithelial cells of thymic cortex and medulla. Whether it promotes T cells production from human embryonic stem cells(hESCs) in vitro remains an elusive issue. In the present study, we develop a novel strategy that enhances T-cell lineage differentiation of hESCs in collagen matrix culture by sequential cytokine cocktails treatment combined with thymopentin stimulation. We observed that approximately 30.75% cells expressed CD34 on day 14 of the cultures and expressed the surface markers of erythroid, lymphoid and myeloid lineages. The results of colony assays and gene expressions by RT-PCR analysis also demonstrated that hematopoietic progenitor cells (HPCs) derived from hESCs were capable of multi-lineage differentiation. Further study revealed that culturing with thymopentin treatment, the CD34(+)CD45RA(+)CD7(+) cells sorted from HPCs expressed T-cell-related genes, IKAROS, DNTT, TCRγ and TCRß, and T-cell surface markers, CD3, cytoplasmic CD3, CD5, CD27, TCRγδ, CD4 and CD8. The differentiated cells produced the cytokines including IFN-γ, IL-2 and TNF-α in response to stimulation, providing the evidence for T-cell function of these cells. In conclusion, thymopentin enhances T-cell lineage differentiation from hESCs in vitro by mimicking thymus peptide environment in vivo.

Insulin-producing cells derived from human embryonic stem cells: comparison of definitive endoderm- and nestin-positive progenitor-based differentiation strategies.

Human embryonic stem cells (hESCs) are pluripotent and capable of undergoing multilineage differentiation into highly specialized cells including pancreatic islet cells. Thus, they represent a novel alternative source for targeted therapies and regenerative medicine for diabetes. Significant progress has been made in differentiating hESCs toward pancreatic lineages. One approach is based on the similarities of pancreatic ß cell and neuroepithelial development. Nestin-positive cells are selected as pancreatic ß cell precursors and further differentiated to secrete insulin. The other approach is based on our knowledge of developmental biology in which the differentiation protocol sequentially reproduces the individual steps that are known in normal ß cell ontogenesis during fetal pancreatic development. In the present study, the hESC cell line PKU1.1 was induced to differentiate into insulin-producing cells (IPCs) using both protocols. The differentiation process was dynamically investigated and the similarities and differences between both strategies were explored. Our results show that IPCs can be successfully induced with both differentiation strategies. The resulting IPCs from both protocols shared many similar features with pancreatic islet cells, but not mature, functional ß cells. However, these differently-derived IPC cell types displayed specific morphologies and different expression levels of pancreatic islet development-related markers. These data not only broaden our outlook on hESC differentiation into IPCs, but also extend the full potential of these processes for regenerative medicine in diabetes.

Clinical, cytogenetic, and molecular analysis with 46,XX male sex reversal syndrome: case reports.

PURPOSE: To investigate the clinical characteristics of different categories of sex-reversed 46,XX individuals and their relationships with chromosomal karyotype and the SRY gene. METHODS: Chromosome karyotyping for peripheral blood culture and multi-PCR and FISH were performed. RESULTS: Endocrinological data showed that their endocrine hormone levels were similar to that observed for Klinefelter syndrome, with higher FSH and LH levels and lower T levels. Chromosome karyotyping for peripheral blood culture revealed 46, XX complement for 11 males. Molecular studies showed that there were locus deletions at SY84, SY86, SY127, SY134, SY254 and SY255 in AZF on chromosome Y in 9 cases, with the SRY gene present at the terminus of the X chromosome short arm. In one case, besides 6 locus deletions in AZF, there was also SRY gene deletion. In another case, there were locus deletions only at SY254 and SY255, with SY84, SY86, SY127 SY134 loci and SRY present. CONCLUSIONS: The majority (10/11) of 46,XX males were SRY positive, with the SRY gene translocated into the terminus of the X chromosome short arm. These patients were caused mainly by an X/Y chromosomal inter-change during paternal meiosis, leading to the differentiation of primary gonads into testes. Only a single patient (1/11) was SRY-negative, in which there might be some unknown downstream genes involved in sex determination.

Dynamic expression of microRNAs during the differentiation of human embryonic stem cells into insulin-producing cells.

Human embryonic stem (hES) cells with the capacity of self-renewal and multilineage differentiation are promising sources for generation of pancreatic islet cells for cell replacement therapy in diabetes. Here we induced hES cells into insulin-producing cells (IPCs) in a stepwise process which recapitulated islet organogenesis by directing cells through the stages resembling definitive endoderm, gut-tube endoderm, pancreatic precursor and cells that expressed pancreatic endocrine hormones. The dynamic expression of microRNAs (miRNAs) during the differentiation was analyzed and was compared with that in the development of human pancreatic islets. We found that the dynamic expression patterns of miR-375 and miR-7 were similar to those seen in the development of human fetal pancreas, whereas the dynamic expression of miR-146a and miR-34a showed specific patterns during the differentiation. Furthermore, the expression of Hnf1ß and Pax6, the predicted target genes of miR-375 and miR-7, was reciprocal to that of miR-375 and miR-7. Over-expression of miR-375 down-regulated the expression of gut-endoderm/pancreatic progenitor specific markers Hnf1ß and Sox9. Therefore, the miRNAs may directly or indirectly regulate the expression of pancreatic islet organogenesis-specific transcription factors to control the differentiation and maturation of pancreatic islet cells.

Mesoderm is committed to hemato-endothelial and cardiac lineages in human embryoid bodies by sequential exposure to cytokines.

Human embryonic stem (hES) cells can differentiate into cells of the three germ layers in vitro and serve as a powerful resource to study mechanisms involved in cell fate decisions. However, it is difficult to promote the directed and efficient differentiation of hES cells toward a specific lineage. Here we establish a stepwise strategy for generating hemato-endothelial and cardiac precursors from hES cells in single culture conditions. The efficiency of committing hES cells to three cell lineages was significantly higher with our approach than with exposure to single or multiple cytokines. Efficiency was determined using quantitative analysis by gene expression, flow cytometry, and colony assays. Several cytokines were sufficient to drive the efficient differentiation of hES cells into specific lineages. Each of these factors appeared to regulate specific steps of differentiation: BMP4 promoted the efficient formation of mesoderm; bFGF induced the differentiation of these mesodermal precursors to the hemangioblast fate; VEGF and TPO were required for the production of committed hematopoietic progenitors. This stepwise control of differentiation in vitro leads to a high frequency of hemato-endothelial and cardiac precursors derived from hES cells and offers a unique model for studying the molecular and cellular events that regulate hematopoiesis and cardiogenesis.

Ghrelin induces cardiac lineage differentiation of human embryonic stem cells through ERK1/2 pathway.

BACKGROUND: Ghrelin, an endogenous ligand for growth hormone secretagogue receptor (GHS-R), shows cardioprotective activity and regulates the differentiation of several mesoderm-derived cells, including myocytes, adipocytes and osteoblasts. The effect of ghrelin on cardiogenesis and its underlying mechanism, however, have not been studied in detail. METHODS: The effects of ghrelin on cardiomyocyte differentiation were tested both in human embryonic stem cells (hESCs) cultured in embryoid body (EB)-based differentiation protocol, and in hESCs transplanted into rat hearts. The signaling mechanisms of ghrelin were further investigated under the EB-based culture condition. RESULTS: The generation of beating EBs and the expression of cardiac-specific markers including cardiac troponin I (cTnI) and α-myosin heavy chain (α-MHC) were 2 to 3-fold upregulated by ghrelin. Although GHS-R1α protein was expressed in differentiated EBs, the effects of exogenous ghrelin were unchanged by D-[lys(3)]-GHRP-6, a specific GHS-R1α antagonist. Moreover, des-acyl ghrelin, which does not bind to GHS-R1α, displayed similar effects with ghrelin. Importantly, activation of ERK1/2, but not Akt, was induced by ghrelin in the newly-formed EBs, and the ghrelin-induced effects of cardiomyocyte differentiation were abolished by adding specific ERK1/2 inhibitor PD98059, but not specific PI3K inhibitor Wortmannin. In addition, ghrelin promoted the differentiation of grafted hESCs into Sox9- and Flk1-positive mesodermal/cardiac progenitor cells in rat hearts. CONCLUSIONS: These results suggest that ghrelin induces cardiomyocyte differentiation from hESCs via the activation of the ERK1/2 signaling pathway. Our study, therefore, indicates that using ghrelin may be an effective strategy to promote the differentiation of hESCs into cardiomyocytes.

[Comparison of GnRH antagonist fixed protocol and GnRH agonists long protocol in infertile patients with normal ovarian reserve function in their first in vitro fertilization-embryo transfer cycle].

OBJECTIVE: To compare the clinical outcomes of gonadotropin-releasing hormone (GnRH) antagonist (GnRH-ant) fixed protocol with GnRH agonist (GnRH-a) long protocol in infertile patients with normal ovarian reserve function in their first in vitro fertilization-embryo transfer (IVF-ET) cycle, and to explore the feasibility and advantage of GnRH antagonist protocol performed in normal responders. METHODS: From January 2011 to June 2011, 771 infertile women with normal ovarian reserve function underwent their first IVF or intracytoplasmic sperm injection (ICSI) cycles in Peking University Third Hospital, which were divided into 245 cycles in GnRH-ant fixed protocol group (GnRH-ant group) and 526 cycles in GnRH-a long protocol group (GnRH-a group). The data of general demographic, treatment and clinical outcome were compared between two groups. RESULTS: Age, infertile duration, body mass index (BMI), baseline serum follicle-stimulating hormone (FSH) and estradiol levels between two groups did not reached statistical difference (P > 0.05). The level of estradiol was (12 289 ± 6856) pmol/L in GnRH-ant group and (14 934 ± 8007) pmol/L in GnRH-a group at day of hCG injection. The mean length of stimulation was (10.3 ± 1.2) days in GnRH-ant group and (12.8 ± 1.6) days in GnRH-a group. The dose of gonadotropin was (2013 ± 607) U in GnRH-ant group and (2646 ± 913) U in GnRH-a group. The number of ovum was 15 ± 7 in GnRH-ant group and 17 ± 8 in GnRh-a group. Those clinical parameter all reached statistical difference (P < 0.05). The number of embryo was 7 ± 4 in GnRH-ant group and 8 ± 5 in GnRH-a group, the rate of clinical pregnancy was 40.9% (94/230) in GnRH-ant group and 45.6% (216/474) in GnRH-a group, the rate of implantation was 26.1% (128/490) in GnRH-ant group and 30.9% (307/994) in GnRH-a group, the rate of continuing pregnancy was 38.7% (89/230) in GnRH-ant group and 42.6% (202/474)in GnRH-a group, those parameter did not reach statistical difference (P > 0.05). The rate of moderate or severe ovarian hyperstimulation syndrome was 2.4% (6/245) in GnRH-ant group and 4.2% (22/526) in GnRH-a group, which did not show significant difference (P > 0.05). CONCLUSION: In the first IVF or ICSI cycle of the patients with normal ovarian reserve function, the fixed GnRH-ant protocol could get the same satisfied clinical outcome, and it is more economic, convenient and safer compared with low dose depot GnRH-a long protocol.

Ghrelin promotes the differentiation of human embryonic stem cells in infarcted cardiac microenvironment.

Ghrelin is broadly expressed in myocardial tissues, where it exerts different functions. It also has been found to have a wide variety of biological functions on cell differentiation and tissue development. The aim of this study was to investigate the effect of ghrelin on human embryonic stem cell (hESC) differentiation in infarcted cardiac microenvironment. The hESCs grown on feeder layers expressed several pluripotential markers including alkaline phosphatase (AKP). Four weeks after transplantation into rat infarcted hearts, the hESCs and their progeny cells survived and formed intracardiac grafts were 54.7% and 19.6% respectively in ghrelin- and phosphate-buffered saline (PBS)-treated groups. Double immunostaining with anti-human Sox9 and anti-HNA or anti-human fetal liver kinase-1 (Flk1) and anti ß-tubulin showed that the human grafts were in development. However, double positive stains were only found in the ghrelin-treated group. In addition, the hESC injection protocol was insufficient to restore heart function of the acute myocardial infarction model. Our study, therefore, provides a new insight of ghrelin on promoting hESC survival and differentiation in rat infarcted cardiac microenvironment. This may give a clue for therapy for myocardial infarction by hESCs or progeny cells.

Ghrelin promotes differentiation of human embryonic stem cells into cardiomyocytes.

AIM: Ghrelin is involved in regulating the differentiation of mesoderm-derived precursor cells. The aim of this study was to investigate whether ghrelin modulated the differentiation of human embryonic stem (hES) cells into cardiomyocytes and, if so, whether the effect was mediated by growth hormone secretagogue receptor 1α (GHS-R1α). METHODS: Cardiomyocyte differentiation from hES cells was performed according to an embryoid body (EB)-based protocol. The cumulative percentage of beating EBs was calculated. The expression of cardiac-specific markers including cardiac troponin I (cTnI) and α-myosin heavy chain (α-MHC) was detected using RT-PCR, real-time PCR and Western blot. The dispersed beating EBs were examined using immunofluorescent staining. RESULTS: The percentage of beating EBs and the expression of cTnI were significantly increased after ghrelin (0.1 and 1 nmol/L) added into the differentiation medium. From 6 to 18 d of differentiation, the increased expression of cTnI and α-MHC by ghrelin (1 nmol/L) was time-dependent, and in line with the alteration of the percentages of beating EBs. Furthermore, the dispersed beating EBs were double-positively immunostained with antibodies against cTnI and α-actinin. However, blockage of GHS-R1α with its specific antagonist D-[lys(3)]-GHRP-6 (1 µmol/L) did not alter the effects of ghrelin on cardiomyocyte differentiation. CONCLUSION: Our data show that ghrelin enhances the generation of cardiomyocytes from hES cells, which is not mediated via GHS-R1α.

Early embryonic sensitivity to cyclophosphamide in cardiac differentiation from human embryonic stem cells.

hESCs (human embryonic stem cells) can differentiate into tissue derivatives of all three germ layers in vitro and mimic the development of the embryo in vivo. In this study, we have investigated the potential of an hESC-based assay for the detection of toxicity to cardiac differentiation in embryonic development. First of all, we developed the protocol of cardiac induction from hESCs according to our previous work and distinguished cardiac precursor cells and late mature cardiomyocytes from differentiated cells, demonstrated by the Q-PCR (quantitative real-time PCR), immunocytochemistry and flow cytometry analysis. In order to test whether CPA (cyclophosphamide) induces developmental and cellular toxicity in the human embryo, we exposed the differentiating cells from hESCs to CPA (a well-known proteratogen) at different stages. We have found that a high concentration of CPA could inhibit cardiac differentiation of hESCs. Two separate exposure intervals were used to determine the effects of CPA on cardiac precursor cells and late mature cardiomyocytes respectively. The cardiac precursor cells were sensitive to CPA in non-cytotoxic concentrations for the expression of the cardiac-specific mRNA markers Nkx2.5 (NK2 transcription factor related, locus 5), GATA-4 (GATA binding protein 4 transcription factor) and TNNT2 (troponin T type 2). Non-cytotoxic CPA concentrations did not affect the mRNA markers' expression in late mature cardiomyocytes, indicating that cardiac precursors were more sensitive to CPA than late cardiomyocytes in cardiogenesis. We set up the in vitro developmental toxicity test model so as to reduce the number of test animals and expenses without compromising the safety of consumers and patients. Furthermore, such in vitro methods may be possibly suited to test a large number of chemicals than the classical employed in vivo tests.

Inhibition of Sirt1 promotes neural progenitors toward motoneuron differentiation from human embryonic stem cells.

Several protocols direct human embryonic stem cells (hESCs) toward differentiation into functional motoneurons, but the efficiency of motoneuron generation varies based on the human ESC line used. We aimed to develop a novel protocol to increase the formation of motoneurons from human ESCs. In this study, we tested a nuclear histone deacetylase protein, Sirt1, to promote neural precursor cell (NPC) development during differentiation of human ESCs into motoneurons. A specific inhibitor of Sirt1, nicotinamide, dramatically increased motoneuron formation. We found that about 60% of the cells from the total NPCs expressed HB9 and ßIII-tubulin, commonly used motoneuronal markers found in neurons derived from ESCs following nicotinamide treatment. Motoneurons derived from ESC expressed choline acetyltransferase (ChAT), a positive marker of mature motoneuron. Moreover, we also examined the transcript levels of Mash1, Ngn2, and HB9 mRNA in the differentiated NPCs treated with the Sirt1 activator resveratrol (50 µM) or inhibitor nicotinamide (100 µM). The levels of Mash1, Ngn2, and HB9 mRNA were significantly increased after nicotinamide treatment compared with control groups, which used the traditional protocol. These results suggested that increasing Mash1 and Ngn2 levels by inhibiting Sirt1 could elevate HB9 expression, which promotes motoneuron differentiation. This study provides an alternative method for the production of transplantable motoneurons, a key requirement in the development of hESC-based cell therapy in motoneuron disease.

Enhancement of cardiomyocyte differentiation from human embryonic stem cells.

Several approaches have been used to encourage the differentiation of cardiomyocytes from human embryonic stem cells. However, the differentiation efficiency is low, and appropriate culture protocols are needed to produce adequate numbers of cardiomyocytes for therapeutic cell transplantation. This study investigated the effects of serum on cardiomyocyte differentiation in suspension culture medium during embryoid body (EB) formation by human embryonic stem cells. The addition of ascorbic acid, dimethylsulfoxide and 5-aza-2'-deoxycytidine during days 5-7 at the EB-forming stage resulted in an increase in the numbers of rhythmically contracting clusters of derived cardiomyocytes. Treatment with 0.1 mmol L(-1) ascorbic acid alone, or more notably in combination with 10 micromol L(-1) 5-aza-2'-deoxycytidine, induced the formation of beating cells within EBs. Most of the beating clusters had spontaneous contraction rates similar to those found in human adults, and their contractile activity lasted for up to 194 days.

The reversal of hyperglycaemia in diabetic mice using PLGA scaffolds seeded with islet-like cells derived from human embryonic stem cells.

Islet-like cells derived from embryonic stem (ES) cells may be a promising therapeutic option for future diabetes treatment. Here, we demonstrated a five-stage protocol with adding exendin-4 instead of nicotinamide finally could generate islet-like cells from human embryonic stem (ES) cells. Immunofluorescence analysis revealed a high percentage of c-peptide positive cells in the derivation. However, in addition to insulin/c-peptide, most cells also coexpressed PDX-1 (pancreas duodenum homeobox-1), glucagon, somatostatin or pancreatic polypeptide. Insulin and other pancreatic beta-cell-specific genes were all present in the differentiated cells. Insulin secretion could be detected and increased significantly by adding KCL in high glucose concentration in vitro. Furthermore, subcutaneous transplantation of scaffolds seeded with the islet-like cells or cell transplantation under kidney capsules for further differentiation in vivo could improve 6h fasted blood glucose levels and diabetic phenotypes in streptozotocin-induced diabetic SCID mice. More interestingly, blood vessels of host origin, characterized by mouse CD31 immunostaining, invaded the cell-scaffold complexes. This work reveals a five-stage protocol with adding exendin-4 may be an effective protocol on the differentiation of human ES cells into islet-like cells, and suggests scaffolds can serve as vehicles for islet-like cell transplantation.

Chemically defined sequential culture media for TH+ cell derivation from human embryonic stem cells.

During the past few years several differentiation protocols to derive midbrain dopamine (DA) neurons from human embryonic stem (hES) cells have been developed, but the production of sufficient amounts of the 'right' therapeutic DA cells has not yet been accomplished. The aim of this study was to efficiently generate tyrosine hydroxylase (TH)-positive cells in vitro from our hES cells using a chemically defined culture system. At the end of differentiation, the vast majority of cells (>90%) were positive for both TH and beta-tubulin isotype III (TuJ1). Other markers of dopaminergic cells, like dopamine transporter (DAT) and Nurr1 were also detected by immunofluorescence or RT-PCR. The functions of these cells were confirmed by measurements of DA release in vitro and by transplantation of derived cells into Parkinson's disease (PD) rats in vivo. We found these cells were able to release DA when depolarized by high K(+). Moreover, 4 weeks after transplantation, the hES-derived cells could survive and reduce the apomorphine-induced rotation behaviour of the rats. In conclusion, the experimental system presented here provided a reliable protocol to produce a large number of hES-derived TH(+) cells which may be used in cell therapy for PD in future.

Viability of frozen-thawed human embryos with one-two blastomeres lysis.

OBJECTIVE: To assess the impact of one-two blastomeres lysis on the viability of thawed day 3 human embryos. METHODS: A retrospective analysis was performed on 248 frozen-thawed embryo replacement cycles in which all embryos were frozen at day 3 at the seven-eight cell stage with

Ovarian suppression treatment prior to in-vitro fertilization and embryo transfer in Chinese women with stage III or IV endometriosis.

OBJECTIVE: To evaluate the efficacy of a 2-month treatment with a gonadotropin-releasing hormone (GnRH) agonist prior to in-vitro fertilization in Chinese women with moderate or severe endometriosis. METHODS: A study of 162 women surgically diagnosed as having moderate or severe endometriosis. Pituitary down-regulation was achieved with injections of a GnRH agonist prior to the IVF procedures either for 7 to 10 days in the mid-luteal phase (group 1 [standard protocol], 97 cycles in total), or for 2 months (group 2, 55 cycles), or 3 months (group 3, 75 cycles). RESULTS: Women pretreated with a GnRH agonist for 2 or 3 months required significantly higher doses of gonadotropin for ovarian stimulation (P<0.001), and for a longer time, than those treated with the standard long protocol (P<0.05). The number of oocytes and good embryos was lower in group 3 than in groups 1 or 2 (P<0.05). The implantation rate was significantly higher in group 2 than in group 1 (P<0.02). CONCLUSION: A 2-month treatment with a GnRH agonist prior to IVF produced a trend toward an increase in the implantation rate in a group of Chinese women with stages III and IV endometriosis.

A normal birth following preimplantation genetic diagnosis by FISH determination in the carriers of der(15)t(Y;15)(Yq12;15p11) translocations: two case reports.

PURPOSE: To investigate the clinical application of fluorescence in situ hybridization (FISH) for assessing chromosome disorders of embryos in preimplantation diagnosis of carriers with der(15)t(Y;15)(q12;p11) translocations. METHODS: Multicolor FISH was performed using directly-labelled DNA probes, chromosome X with one (DXZ1, Xp11.1-q11.1), but Y with two (DYZ3, Yp11.1-q11.1 and DYZ1, Yq12). Normal embryos were transferred on day 6 at blastocyst stage. RESULTS: Couple A: Three of 6 biopsied embryos were normal. Two normal blastocysts were transferred, but no pregnancy was achieved. Couple B: Three of 6 biopsied embryos were normal. Two normal blastocysts were transferred. A normal male infant weighing 3,230 g was born by cesarean section on the 39th week of gestation. All of the remaining nonreplaced embryos showed mosaic or der(15). CONCLUSION: Embryos from carries of der(15)t(Y;15)(q12;p11) translocation showed a high frequency of chromosome abnormalities. PGD is a valuable screen tool for those couples to treat their infertility and break the transmission of der(15) chromosome for their offspring.

Mechanism of emergency contraception with gestrinone: a preliminary investigation.

BACKGROUND: A previous investigation showed that among 120 healthy women treated with a single oral dose of gestrinone for emergency contraception (EC), there was only one pregnancy. The effect of a single oral dose of gestrinone given for EC on ovarian function and endometrial development was studied. STUDY DESIGN: Healthy fertile women were randomly assigned to Group A (n=8) or Group B (n=7). Gestrinone 5 mg was orally administered to each woman before (Group A) or after (Group B) ovulation. The day of ovulation was determined by transvaginal ultrasound and by urinary luteinizing hormone (LH) measured by enzyme immunoassay (One Step LH Ovulation Test). An endometrial biopsy was performed during implantation. Endometrial maturation and expression of markers of endometrial receptivity were analyzed. The tested markers were integrins alpha(1)beta(1), alpha(4)beta(1) and beta(3). Serum estradiol (E(2)) and progesterone (P) levels in serum were determined by radioimmunoassay, and estradiol receptors and progesterone receptors (PRs) in the endometrium were assessed by immunohistochemistry. RESULTS: Gestrinone administered during the periovulatory period did not affect follicular development, ovulation, menstrual cycle length and E(2) and P levels but decreased the expression of PR in the endometrium. Integrin alpha(4)beta(1) tended to increase after treatment with gestrinone without reaching statistical significance. CONCLUSION: The mode of action of gestrinone used for EC is probably inhibition of implantation by acting on the endometrium rather than inhibition of ovulation.