Human umbilical cord Wharton's jelly stem cells and its conditioned medium support hematopoietic stem cell expansion ex vivo

Bone marrow mesenchymal stromal cells (BMMSCs) have been used as feeder support for the ex vivo expansion of hematopoietic stem cells (HSCs) but have the limitations of painful harvest, morbidity, and risk of infection to the patient. This prompted us to explore the use of human umbilical cord Wharton's jelly MSCs (hWJSCs) and its conditioned medium (hWJSC-CM) for ex vivo expansion of HSCs in allogeneic and autologous settings because hWJSCs can be harvested in abundance painlessly, are proliferative, hypoimmunogenic, and secrete a variety of unique proteins. In the presence of hWJSCs and hWJSC-CM, HSCs put out pseudopodia-like outgrowths and became highly motile. Time lapse imaging showed that the outgrowths helped them to migrate towards and attach to the upper surfaces of hWJSCs and undergo proliferation. After 9 days of culture in the presence of hWJSCs and hWJSC-CM, MTT, and Trypan blue assays showed significant increases in HSC numbers, and FACS analysis generated significantly greater numbers of CD34(+) cells compared to controls. hWJSC-CM produced the highest number of colonies (CFU assay) and all six classifications of colony morphology typical of hematopoiesis were observed. Proteomic analysis of hWJSC-CM showed significantly greater levels of interleukins (IL-1a, IL-6, IL-7, and IL-8), SCF, HGF, and ICAM-1 compared to controls suggesting that they may be involved in the HSC multiplication. We propose that cord blood banks freeze autologous hWJSCs and umbilical cord blood (UCB) from the same umbilical cord at the same time for the patient for future ex vivo HSC expansion and cell-based therapies.

Statins inhibit the growth of variant human embryonic stem cells and cancer cells in vitro but not normal human embryonic stem cells

BACKGROUND AND PURPOSE

Statins inhibit proliferation of various human cancer cell lines in vitro. As human embryonic stem cells (hESCs) possess neoplastic-like properties we have evaluated the role of various statins on karyotypically normal hESCs (HES3 and BG01), abnormal hESCs (BG01V) and breast adenocarcinoma cells (MCF-7) to evaluate whether the mode of action of the statins was via a stemness pathway.

EXPERIMENTAL APPROACH

All cell lines were treated with simvastatin, pravastatin, lovastatin and mevastatin (1 micromol x L(-1) to 20 micromol x L(-1)) up to 7 days and their effects on cell proliferation, cell cycle, apoptosis and pluripotency studied.

KEY RESULTS

All four statins did not inhibit HES3 and BG01 proliferation, but BG01V and MCF-7 were inhibited by simvastatin, lovastatin and mevastatin. These inhibitory effects were reversed by the endogenous isoprenoids, farnesylpyrophosphate and geranylgeranylpyrophosphate. Terminal deoxynucleotidyl transferase biotin-dUTP nick end labelling and cell cycle assay confirmed apoptosis in BG01V and MCF-7. Stem cell surface markers [stage-specific embryonic antigen-4, tumour rejection antigen-1-81, octamer-4 (OCT-4)] were expressed in HES3 and BG01, but not in BG01V cells, even after prolonged treatment with simvastatin. In BG01V and MCF-7, the pro-apoptotic Bcl-2-associated X protein genes were up-regulated, while the antiapoptotic BCL2 and SURVIVIN genes were down-regulated. Expression of the stemness-related genes namely, the growth differentiation factor-3, NANOG and OCT-4 was decreased in BG01V compared with BG01 and HES3.

CONCLUSIONS AND IMPLICATIONS

Normal hESCs were resistant to prolonged exposure to statins over a range of doses, compared with BG01V and MCF-7, probably because of genetic and behavioural differences. The statins not only have anti-cancer properties but can suppress abnormal hESCs thus promoting growth of normal hESCs in vitro.

Comparative growth behaviour and characterization of stem cells from human Wharton's jelly

Human embryonic stem cells (hESC) face ethical sensitivities and the problem of teratoma formation. Although Wharton's jelly stem cells (WJSC), also of embryonic origin, may not face such ethical concerns, it is not definitely known whether under hESC culture conditions they would be as pluripotent as hESC. WJSC grown on plastic showed two types of morphology (epithelioid and short fibroblastic) in primary culture depending on the culture medium used, and only fibroblastic morphology when passaged. When grown in the presence of hESC medium on mouse feeder cells, they produced atypical colonies containing hESC-like cells with high-nuclear cytoplasmic ratios and prominent nucleoli. They were positive for the hESC markers Tra-1-60, Tra-1-81, SSEA-1, SSEA-4, Oct-4 and alkaline phosphatase, negative for SSEA-3, showed normal karyotypes, developed embryoid body (EB)-like structures, did not produce teratomas in SCID mice and differentiated into neuronal derivatives. They were also positive for the mesenchymal CD markers (CD105, CD90, CD44), negative for CD34 and HLA, and although nine out of 10 embryonic stem cell genomic markers were detectable, these were expressed at low levels. WJSC are thus not as pluripotent as hESC but widely multipotent, and have the advantages of being able to be scaled up easily and not inducing teratomas.

Nine-day-old human embryo cultured in vitro: a clue to the origins of embryonic stem cells

The aims of this study were to investigate whether the human embryo could sustain development beyond the blastocyst stage in vitro and to identify the precise origins of embryonic stem cells (ES cells) from the embryoblast. A frozen-thawed 4-cell embryo was cultured to the post-blastocyst stage. This 9-day-old embryo presented a solid mass of inner cells (resembling a tumour) surrounded by surface trophoblast cells. Clumps of multinucleated syncytiotrophoblast cells were evident at one pole. Most cells resembled those of blastocysts. However, there were groups of comparatively undifferentiated cells within the inner cell mass somewhat resembling ES cells documented previously, that might give a clue as to their origins. The embryo attempted to form an amnion with a cavity, but did not present a bilaminar, discoidal structure as expected in week 2 of development, and hence was abnormal.

Does sperm morphology play a significant role in increased sex chromosomal disomy? A comparison between patients with teratozoospermia and OAT by FISH

Eight semen samples from men with teratozoospermia (T), along with samples from 3 men with normal fertility and 5 samples from men with oligoasthenoteratozoospermia (OAT) were analyzed for X and Y chromosomal anomalies with the use of fluorescently labeled centromeric probes. This study was undertaken to determine whether patients with abnormal sperm morphology (teratozoospermia) have increased or decreased incidence of a sex chromosomal anomaly. The sex chromosome disomy for the T samples was 0.36% and for the OAT group it was 0.61%, compared with baseline value for the normozoospermia group (0.09%).

Comparative evaluation of fresh and washed human sperm cryopreserved in vapor and liquid phases of liquid nitrogen

Infectious organisms such as hepatitis B were recently shown to survive in liquid nitrogen. To prevent cross-contamination of semen samples via liquid nitrogen, studies were undertaken to evaluate human sperm survival in the vapor phase of liquid nitrogen at -189 degrees C. The study was conducted in 2 separate experiments. In the first experiment, a total of 30 unwashed, fresh semen samples (15 normozoospermic and 15 oligozoospermic) were evaluated for motility, vitality, and morphology after freeze-thaw survival in vaporous (-189 degrees C) and liquid nitrogen (-196 degrees C; control) phases. Similar evaluations were carried out in a second experiment on 27 samples (15 normozoospermic and 12 oligozoospermic) that were previously washed by the swim-up method. Motile sperm recovery rates were significantly different between liquid and vapor phases (unwashed, normozoospermic: 42.76% +/- 3.23% vs 45.52% +/- 4.44%, P < .05; washed, normozoospermic: 34.44% +/- 4.41% vs 37.58% +/- 3.90%, P < .05; unwashed, oligozoospermic: 16.53% +/- 3.34% vs 18.25% +/- 4.36%, P < .05; washed, oligozoospermic: 10.32% +/- 2.54% vs 12.25% +/- 2.81%, P < .05). Recovery rates for motility were much higher for unwashed samples compared with washed semen samples. In all experiments the recovery of normal and live forms showed no significant differences between the vapor and liquid nitrogen storage phases (P > .05). The results demonstrate that both washed and unwashed human sperm survive satisfactorily with good recovery in the vapor of liquid nitrogen and can be recommended for future storage in medically assisted conception programs.

Myocyte transplantation for myocardial repair: a few good cells can mend a broken heart

Cell transplantation is a potential therapeutic approach for patients with chronic myocardial failure. Experimental transplantation of neonatal and fetal cardiac myocytes showed that the grafted cells can functionally integrate with and augment the function of the recipient heart. Clinical application of this approach will be limited by shortage of donors, chronic rejection, and because it is ethically contentious. By contrast skeletal myoblasts (satellite cells) are abundant and can be grafted successfully into the animal's own heart even after genetic manipulation in vitro. Functional integration of myoblasts, however, is hampered by the lack of intercellular gap junction communication and the difference in excitation-contraction coupling between skeletal and cardiac myocytes. In experimental studies several other cell types have been used to augment cardiac function. In this review we discuss the published results of myocyte transplantation with emphasis on potential sources of cells, the ethics of using donor embryonic and fetal cardiomyocytes, genetic transformation of skeletal myoblasts for myocardial repair, and the functional benefits of cell transplantation to the failing heart.

Ultrastructural observations of enzymatically treated human blastocysts: zona-free blastocyst transfer and rescue of blastocysts with hatching difficulties

Enzymatic treatment of the zona pellucida to either soften or remove totally the zona before blastocyst transfer has resulted in high implantation rates. The zona is usually completely dissolved after 1.5 min exposure with 10 IU pronase at 37 degrees C. Since there may be concerns that pronase treatment for periods of 1.5 min or longer may cause adverse effects on the trophectoderm (TE) and inner cell mass (ICM), the changes to human blastocysts exposed to different time intervals of pronase were investigated. Of 18 blastocysts exposed to pronase for 1.5 min, the zona was completely dissolved and no changes were observed by light microscopy (LM) or transmission electron microscopy (TEM), compared with 11 naturally hatched untreated blastocysts (controls). In another five blastocysts exposed to pronase for 2 min, no LM changes were observed but subtle TEM changes such as fewer bundles of tonofibrils attached to desmosomes were observed. When three other blastocysts were exposed to pronase for 5 min, the blastocoele collapsed, and the TE cells started to show blebbing under LM. Under TEM, the cytoplasm of TE cells was extensively vacuolated and many TE cells showed cytoplasmic blebbing towards the blastocoele. However, the epithelium was uninterrupted with intact tight junctions and desmosomes. Of a separate group of 44 blastocysts cultured in vitro, 54.5% had hatching difficulties when monitored from day 5 to day 8 and 80% of these could be rescued by removal of the zona with pronase for 1.5 min prior to extensive degeneration taking place. The results confirm that the optimal time for softening or complete removal of the zona before transfer was around 1.5 min and that enzymatic treatment was a safe, non-invasive procedure to remove the zona of blastocysts. The human embryonic TE is a very hardy, robust epithelium that withstands pronase treatment.

Discrepancy between cytogenetic and FISH results on an amniotic fluid sample of 45,X/46,X,idic(Y)(p11)

The presence of abnormal ultrasound markers showing a thick nuchal fold with short middle phalanx of the fifth finger in an otherwise normal-appearing female fetus led to the sampling of amniotic fluid at 16 weeks gestation. Cytogenetic analysis with routine G-banding showed a 45,X karyotype in all 20 cells analysed from two flasks. However, fluorescent in situ hybridization on uncultured cells showed presence of a Y signal in 9 cells, 11 cells showing a single signal for the X. A cytogenetic analysis of the fetal blood at 23 weeks confirmed the presence of two cell lines, 45,X and 46,X, idic(Y)(p11). The couple opted to have the pregnancy terminated. However, the fetus was not available to carry out confirmatory tests.

Embryonic stem cell lines from human blastocysts: somatic differentiation in vitro

We describe the derivation of pluripotent embryonic stem (ES) cells from human blastocysts. Two diploid ES cell lines have been cultivated in vitro for extended periods while maintaining expression of markers characteristic of pluripotent primate cells. Human ES cells express the transcription factor Oct-4, essential for development of pluripotential cells in the mouse. When grafted into SCID mice, both lines give rise to teratomas containing derivatives of all three embryonic germ layers. Both cell lines differentiate in vitro into extraembryonic and somatic cell lineages. Neural progenitor cells may be isolated from differentiating ES cell cultures and induced to form mature neurons. Embryonic stem cells provide a model to study early human embryology, an investigational tool for discovery of novel growth factors and medicines, and a potential source of cells for use in transplantation therapy.

Regulation of human and mouse oocyte maturation in vitro with 6-dimethylaminopurine

It has been postulated that premature shortening of the oocyte growth phase due to the recovery of oocytes from small diameter follicles may be responsible for the developmental anomalies associated with in-vitro maturation. 6-Dimethylaminopurine (DMAP) was used to artificially lengthen the pre-maturation period of oocyte growth, in vitro, by inhibiting germinal vesicle breakdown in mouse and human oocytes. DMAP inhibited the meiotic maturation of mouse and human oocytes and the inhibition was fully reversible. The timing of polar body extrusion was accelerated in mouse oocytes following the withdrawal of DMAP; however, the kinetics of nuclear maturation in human oocytes was unaffected by exposure to DMAP. All mouse and human DMAP-treated oocytes that matured to metaphase II expressed histone H1 kinase activity. Fertilization rates in both DMAP-treated and control mouse and human oocytes were comparable, and human embryonic development was similar in control and DMAP-treated oocytes. However, blastocyst development was significantly reduced in DMAP-treated mouse oocytes (P < 0.05). It is concluded that lengthening the prematuration growth phase, by temporarily inhibiting kinase activity with DMAP, does not directly improve oocyte developmental competence but provides a useful tool for further investigating meiotic and developmentally related events in vitro by manipulating meiotic resumption.

Effects of peritoneal macrophages from women with endometriosis on endometrial cellular proliferation in an in vitro coculture model

OBJECTIVE

To study the effects of peritoneal macrophages on endometrial cellular proliferation in an in vitro coculture model and to compare the magnitude of these effects between macrophages from women with endometriosis and normal women.

DESIGN

Controlled study of peritoneal macrophage function.

SETTING

University hospital.

PATIENT(S)

Patients with a normal peritoneal cavity (n = 15) and with pelvic endometriosis (n = 20) undergoing laparoscopy.

INTERVENTION(S)

Peritoneal macrophages were cocultured with endometrial epithelial and stromal cells; endometrial cell cultures without macrophage coculture acted as controls.

MAIN OUTCOME MEASURE(S)

Endometrial cellular proliferation measured by 3H-thymidine incorporation.

RESULT(S)

Endometrial epithelial cells cocultured with peritoneal macrophages from women with endometriosis showed significantly increased proliferation compared with cocultures using macrophages from normal women when assessed at 24 hours (1.56 versus 1.03 times, respectively, over control) and at 72 hours (1.55 versus 1.10 times over control). Endometrial stromal cells cocultured with peritoneal macrophages from women with endometriosis similarly exhibited increased proliferation compared with cocultures using macrophages from normal women when assessed at 24 hours (1.65 versus 1.17 times over control) and at 72 hours (1.65 versus 1.21 times over control).

CONCLUSION(S)

Peritoneal macrophages of patients with endometriosis stimulate cellular proliferation of endometrial epithelial and stromal cells in vitro.

Comparison of human blastulation rates and total cell number in sequential culture media with and without co-culture

Recent interest in delayed embryo transfers necessitated the evaluation of two improved in-vitro systems that could generate viable blastocysts. A total of 178 two-pronucleated embryos (entire cohorts) from 19 patients was cultured in IVF50 medium (100 microl) under oil for 24 h until day 2. Each patient's day 2 embryos were then equally allotted to two in-vitro systems. Embryos in system A were grown until the morning of day 3 on Vero cells covered with IVF50 medium (100 microl) under oil. The medium was then replaced on day 3 with a 1:1 mixture (100 microl) of IVF50:S2 medium and on day 4 with S2 medium only. The same culture protocol was used for system B without Vero cells. Throughout the 5 days all dishes were housed in sealed humidified modular chambers containing a triple gas atmosphere. Separately, 175 spare embryos from 80 patients were grown in system A and B up to days 6 and 7 for total cell number (TCN) analysis. Blastulation rates were not significantly different between system A and B (67.4 versus 68.5%; P > 0.01) although co-cultured embryos cleaved slightly faster by day 4. The overall pregnancy and implantation rates were 52.0% and 32.1% for the 19 patients each of whom received a mixed cohort of three day 5 embryos from both systems. TCN values for the day 6 and 7 blastocysts from both systems were high and increased steadily from days 6-7 and from expanded to hatching stages. There were no significant differences in TCN for day 6 expanded blastocysts between the two systems although day 6 hatching and hatched co-cultured blastocysts had greater values than non-co-cultured blastocysts (246.0 +/- 18.5 and 236.7 +/- 17.8 versus 173.0 +/- 13.5 and 166.5 +/- 16.0; P < 0.01). The results demonstrated that the culture protocol using the sequential IVF50-S2 media combination was a good substitute for Vero cell co-culture for the transfer of viable day 3-6 embryos.

Comparative evaluation of two density gradient preparations for sperm separation for medically assisted conception

To evaluate and optimize the sperm separation efficiency of a novel silane-coated silica bead (Puresperm), serial studies were carried out to compare the various sperm parameters between: (i) three-layer (90%-70%-40%) Puresperm and three-layer (90%-70%-40%) conventional polyvinylpyrrolidone (PVP)-coated silica bead (Percoll) gradients; (ii) three-layer (90%-70%-40%) and two-layer (90%-45%) Puresperm gradients and separately the same for Percoll; and (iii) large (3.0 ml) and small (0.75 ml) semen loading volumes on three-layer Puresperm gradients. Normozoospermic semen samples were treated and analysed in 12 replicates for each experiment. Manual evaluation of concentration, percentage motility, percentage vitality, percentage normal morphology; computer-assisted semen analysis evaluation of concentration, percentage motility, grade of motility, motion characteristics (curvilinear velocity, linearity, amplitude of lateral head velocity, beat cross frequency, percentage hyperactivation); and yields from the initial semen samples were compared. Percoll was found to be superior to Puresperm in concentration, percentage motility, percentage vitality and yields after three-layer density gradient centrifugation. There were no significant differences in sperm parameters between two- and three-layer Percoll gradients, but three-layer Puresperm gradients behaved significantly better than two-layer gradients. Large semen volume loads on three-layer Puresperm gradients resulted in greater sperm concentrations, percentage motility, percentage vitality and percentage normal morphology, but small semen volume loads produced greater yields of good-quality spermatozoa. In the light of Percoll being withdrawn from the shelf for the use of assisted reproduction because of the presence of PVP, three-layer Puresperm gradients with large semen loading volumes appear to be an attractive alternative for sperm separation in medically assisted conception.

Blastocyst transfer after enzymatic treatment of the zona pellucida: improving in-vitro fertilization and understanding implantation

It has been shown recently that delayed transfers improve implantation rates in assisted reproductive technology programmes. In a prospective study, the pregnancy rates and safety of outcome were evaluated in a group of patients after the transfer of day 5 blastocysts with enzymatic treatment of the zona pellucida. Nineteen women with a mean age of 32.6+/-5.2 years and mean 2.1+/-2.2 repeated attempts had blastocyst transfers with a mean number of 2.5+/-0.7 embryos replaced per patient. The clinical pregnancy rates per cycle/transfer and implantation rate were 53% and 33%, respectively. The multiple pregnancy rate was 40% (two pregnancies were triplets). The pregnancy and implantation rates were very much higher than observed for most assisted reproduction technology centres. The 'in-vitro implantation' rates of zona-free blastocysts on a variety of feeder monolayers was 92%, offering some thoughts as to the role of the zona and interaction of the inner cell mass and trophoectoderm with the endometrium in implantation. Based on the in-vitro studies and the high multiple pregnancy rates, it appears that zona-manipulated blastocysts implant relatively well and there would be a need to reduce the number of transferred embryos to one or two, thus reducing multiple pregnancies and having spare blastocysts available for cryopreservation. The results also suggest that using the embryo culture protocol and method of transfer in the present study offers encouraging improvements to assisted reproduction technology, and enzymatic treatment of the zona may allow better anchorage and dialogue of the embryo with the endometrium, helping us to improve and understand implantation.

The first 2 case reports of frozen embryo donation twin pregnancies in Singapore: hormonal profiles and obstetrical outcome

A 35 year old women with premature ovarian failure and another 30 year old women with gonadal dysgenesis were the recipients of donated supernumerous frozen embryos after successfully prepared with cyclic steroid replacement therapy as described previously. One patient received 4 and the second 2 frozen embryos, transferred transcervically on the 3rd day of progesterone administration. Both patients had viable twin pregnancies. The plasma beta hCG levels for both patients at 2 weeks post replacement (4 weeks gestation) were lower than the median values in our normal, uncomplicated singleton pregnancy for the same gestation. The level after 4 weeks post-replacement (6 weeks gestation) became comparable. Plasma progesterone profiles suggested a level of above 70 ng/ml would be enough to support the twin pregnancies. The first patient developed antepartum haemorrhage of unknown origin at 34 weeks of gestation preceding preterm premature rupture of membranes and subsequently had preterm labour. The second patient developed proteinuric hypertension at 33 weeks of gestation. Both ended in a lower segment cesarean section. Both sets of twins and their mothers were discharged well.

Analysis of cystic hygroma, ascitic, and pleural fluids by conventional lymphocyte culture and fluorescent in situ hybridization

Serous fluids from cystic hygromas, pleural effusions, and ascites are an easily accessible and plentiful source of lymphocytes. The feasibility and reliability of using these as alternative sources to conventional amniotic fluid or fetal blood cultures have been studied here. In some cases of prenatal diagnosis, especially in pregnancies complicated by the presence of cystic hygromas and fetal hydrops, obtaining amniotic fluid or fetal blood can be difficult due to obstruction by the cyst or oligohydramnios. A total of 14 cases with fetal hydrops detected ultrasonigraphically between 15 and 33 weeks of pregnancy over a period of 1 year have been subjected to conventional amniotic fluid or fetal blood karyotyping, along with samples of fluids from cystic hygromas, ascites or pleural effusions as obtained. Pleural fluids (n = 4), cystic hygroma fluids (n = 5), and ascitic fluids (n = 6) were obtained. The culture failure rate was low, 2/14. Karyotypically, two of the fluids, both from cystic hygromas, were 45,X; the rest were normal. A rapid 1-day additional test of fluorescent in situ hybridization (FISH) was carried out on uncultured cells of the alternative fluids using probes for the most commonly occurring aneuploidies, 13, 18, 21, X and Y, with good results.

Fluorescent in-situ hybridization--some of its applications in clinical cytogenetics

Fluorescent in-situ hybridization (FISH) is becoming more and more relevant as an important future tool in prenatal and pre-implantation genetic diagnosis and cancer cytogenetics. This review describes the FISH technique as applied to whole chromosome spreads and interphase cells and discusses its applications in clinical cytogenetics. Information is presented on the various types of probes and the subsequent hybridization and detection procedures. The potential use of this novel FISH technique in the diagnosis of numerical and structural chromosomal aberrations in routine karyotyping for prenatal diagnosis, tumour cytogenetics and pre-implantation genetic diagnosis is outlined.

Ongoing normal pregnancy after transfer of zona-free blastocysts: implications for embryo transfer in the human

Recent reports suggest that transfer of day 5 blastocysts improves implantation rates in in-vitro fertilization programmes. This paper reports a successful ongoing pregnancy after the transfer of zona-free day 6 expanded and hatching blastocysts. The patient was 37 years old and had undergone six stimulated and two thaw cycles previously, all of which had failed. Stimulation was by down-regulation and oocytes recovered transvaginally by ultrasound guidance. Two pronuclear embryos were co-cultured on Vero cells to day 6. The zonae of two hatching and two fully expanded blastocysts were removed using 0.5% pronase, and the zona-free blastocysts were then transferred. Pregnancy was confirmed on day 18 with a positive human chorionic gonadotrophin (HCG) and ultrasound at 6 weeks showed a single healthy fetal heart inside a clear sac. At 14 weeks a triple test (oestriol, J-HCG and alpha-fetoprotein) was normal and at 22 weeks a detailed ultrasound scan showed no congenital anomalies. This is the first report in the human of a normal ongoing pregnancy after the transfer of zona-free day 6 embryos.

Intracytoplasmic injection of human sperm into the hamster oocyte (hamster ICSI assay) as a test for fertilizing capacity of the severe male-factor sperm

OBJECTIVE

Our objective was to investigate the fertilizing ability of human sperm from severe male-factor patients, by microinjection of single sperm into the hamster oocyte.

DESIGN

Semen samples of severe male factor either with a 0% penetration rate in the zona-free hamster test or with a very low number of motile sperm for which performing the standard penetration test was impossible were used. For the control study, oligozoospermic semen samples with at least 10% penetration rate in zona free hamster test were used.

SETTING

All materials were collected from the National University Hospital, Singapore.

METHODS

There were 10 patients in both the experimental and the control groups. Intracytoplasmic sperm injection (ICSI) was carried out. The main outcome measures were sperm head decondensation and pronuclear formation.

RESULTS

Twenty-one percent of the injected sperm could decondense and undergo male pronuclear formation. This rate was not significantly different from that in the control study group (28%; P = 0.13). A small proportion of the oocytes was damaged during the procedure (9.2 and 8.75% in experimental and control groups, respectively).

CONCLUSIONS

Hamster-ICSI assay may be of benefit in predicting the sperm's ability for further development before allowing the patient to undergo the clinical program.

Evaluation of motility, freezing ability and embryonic development of murine epididymal sperm after coculture with epididymal epithelium

Murine sperm from the caput, corpus and cauda epididymis were cocultured with epididymal epithelial cells of their own region or more distal regions, in the presence and absence of androgens (testosterone and dihydrotestosterone). Epithelial cell cultures were used 3 or 10 days after preparation in a complex tissue culture medium (Chang's) as plated tubules. The coculture studies involving spermatozoa and oocytes with epithelial cells were carried out in T6 medium. Motility of caput spermatozoa was maintained for 24 h in the presence of day 3 corpus and cauda epithelial cells and hormones but not under other conditions. Likewise, the motility of corpus spermatozoa was maintained for 24 h in the presence of day 3 cauda epithelial cells and hormones but not other conditions. Fertilization of zona-intact oocytes by epididymal spermatozoa was not affected by their coculture for 24 h with epithelial cells but fertilization rates for zone-free oocytes were increased for caput spermatozoa cocultured with more distal epithelial cells. Fertilization rates for both zona-intact and zone-free oocytes were increased for corpus spermatozoa cocultured with more distal cauda epithelial cells. The developmental capacity of embryos derived from caput spermatozoa was not significantly increased by coculture with epithelial cells but those derived from corpus spermatozoa cocultured with cauda epithelial cells were significantly increased. We conclude that the presence of more distal epithelial cells of the mouse epididymis maintains motility in culture, increases the ability of caput and corpus spermatozoa to fertilize zona-free oocytes and increases the developmental capacity of embryos formed from corpus spermatozoa. These observations demonstrate the function of epididymal regions in the maturation of murine spermatozoa for fertilization and embryo development.

Fertilization, embryonic development and implantation of mouse oocytes with one or two laser-drilled holes in the zona, and inseminated at different sperm concentrations

The zonae pellucidae of mouse oocytes were photo-ablated by an ultraviolet laser (337.1 nm) to create one or two 10 microm holes. The pulse energy used was approximately 3 microJ/s, with a frequency of 10 pulse/s. These laser zona-drilled (LZD) oocytes with one hole (LZD1) or two holes (LZD2) and the zona-intact controls were inseminated with spermatozoa at standard concentrations of 5x10(4), 5x10(5), 1x10(6) and 2x10(6)/ml. Fertilization was significantly improved at all sperm concentrations in LZD1 and LZD2 oocytes as compared to the controls. However, there was no significant difference in fertilization rates between LZD1 and LZD2. LZD2 produced significantly higher numbers of blastocysts at day 5. Hatching was significantly enhanced in the presence of either one or two holes in the zona. Polyploidy was generally absent, except in LZD2 oocytes (1%) inseminated at higher sperm concentrations. Differential cell counts of expanded LZD blastocysts were similar to those of the controls. Significantly fewer LZD2 blastocysts implanted and produced viable fetuses than LZD1 and control blastocysts. Morphological abnormalities of the fetuses were absent in all three groups. Laser zona-drilling using the ultraviolet laser was shown to be fast, efficient and safe.

Update on micromanipulation techniques for assisted conception

This article reviews the progress in the field of micromanipulation in the past year. The major event has been the wide application of intracytoplasmic sperm injection. Other advances include haploid spermatid injection and the development of successful mouse models for intracytoplasmic sperm injection. There is now increasing awareness of the genetic basis of male infertility and its possible impact on how we offer treatment.

Intracytoplasmic sperm injection of mouse oocytes with 5 mM Ca2+ at different intervals

The objective of this investigation was to determine whether intracytoplasmic sperm injection (ICSI) can be performed in the mouse. Metaphase II oocytes were obtained from F1 hybrid mice (C57BL x CBA) by i.p. injections of 10 IU pregnant mare's serum gonadotrophin (PMSG) and human chorionic gonadotrophin (HCG) administered 48 h apart. Oocytes with cumulus oophorus were retrieved 13-14 h post HCG. Cumulus was dispersed with 0.1% hyaluronidase. Mouse spermatozoa were obtained from the cauda epididymides of males of the same strain. The spermatozoa were processed by the standard swim-up procedure. The harvested spermatozoa were then incubated for 1.5 h to allow capacitation. Healthy oocytes were injected with 3-4 pl 5 mM Ca2+, followed by one live morphologically normal spermatozoon into the cytoplasm at intervals of 0, 0.5, 1, 2 and 3 h. The proportion of 2-cell embryos that developed from oocytes injected with Ca2+ and spermatozoa ranged between 29.5 and 36.5% in all groups, with no statistical difference between treatments. Chromosomal analysis showed that two-thirds of the ICSI-derived 2-cell embryos were diploid. The proportion of parthenogenetically activated embryos in the ICSI groups was similar to that in the control group (8-10%) which was injected with Ca2+ and polyvinyl pyrrolidone only. The proportion of blastocysts that developed in culture from the ICSI-derived 2-cell embryos was of the order of 36-42%. Some blastocysts were used for cell number counts. There was a significant increase in total and inner cell mass counts of blastocysts in which the spermatozoon was injected at 2 and 3 h following Ca2+.(ABSTRACT TRUNCATED AT 250 WORDS)

Isolation and culture of inner cell mass cells from human blastocysts

Totipotent non-committed inner cell mass (ICM) cells from human blastocyts, if demonstrated to be capable of proliferating in vitro without differentiation, will have several beneficial uses, not only in the treatment of neurodegenerative and genetic disorders, but also as a model in studying the events involved in embryogenesis and genomic manipulation. Nine patients admitted to an in-vitro fertilization programme donated 21 spare embryos for this study. All 21 embryos were grown from the 2-pronuclear until blastocyst stages on a human tubal epithelial monolayer in commercial Earle's medium (Medicult, Denmark) supplemented with 10% human serum. The medium was changed after blastocyst formation to Chang's medium supplemented with 1000 units/ml of human leukaemia inhibitory factor (HLIF) and the embryos left undisturbed for 72 h to allow the hatched ICM and trophoblast to attach to the feeder monolayer. Nineteen of the 21 embryos from nine patients produced healthy ICM lumps which could be separated and grown in vitro. Two of the lumps differentiated into fibroblasts while the remaining 17 (eight patients) produced cells with typical stem cell-like morphology, were alkaline phosphatase positive and could be maintained for two passages. It was possible to retain the stem cell-like morphology, alkaline phosphatase positiveness and normal karyotype through the two passages in all of them using repeated doses of HLIF every 48 to 72 h. This is the first report on the successful isolation of human ICM cells and their continued culture for at least two passages in vitro.

Evaluation of inhalational anaesthetics on murine in vitro fertilization

Chronic exposure to inhalational anaesthetics has been implicated in producing adverse reproductive effects in exposed personnel. A longer duration of general anaesthesia during laparoscopic oocyte retrieval for human in vitro fertilization programmes was associated with a decrease in fertilization and cleavage rates. In this study, a mouse model was used to evaluate the effects of clinical concentrations of nitrous oxide, isoflurane and halothane on in vitro fertilization. Mouse oocytes were exposed to 3 inhalational anaesthetic mixtures, oxygen/nitrous oxide, oxygen/nitrous/isoflurane 0.5% or oxygen/nitrous oxide/halothane 0.5% just prior to insemination and their subsequent development was assessed. The fertilization (2-cell) rate and early embryonic growth rate, i.e., 4-cell and morula rates were not statistically different from those of controls which were exposed to air. This study showed that short exposures to clinical concentrations of nitrous oxide, isoflurane and halothane had no deleterious effect on in vitro fertilization and early embryonic growth up to the morula stage in the mouse. Their effects on subsequent implantation and foetal teratogenecity are unknown.

An interesting case of intersex: case report

Intersex is a rare problem. Ambiguous genitalia, a frequent presentation of intersex, is seldom due to true hermaphroditism. This case report describes the findings in such a rare case.

Human embryonic behavior in a sequential human oviduct-endometrial coculture system

Embryonic behavior to blastocyst, hatching, and hatched stages were evaluated in 77, four-cell human embryos that were first grown in oviductal cell coculture and then equally allotted at the eight-cell stage to two coculture systems in a serum-free medium (34 continued on oviductal monolayers, 32 on endometrium monolayers). Sixty-three percent and 40% of embryos expanded and hatched in the sequential oviductal-endometrial coculture system when compared with 41% and 9% in the oviductal system alone, respectively. The sequential coculture system appears to be an improved system over the single human oviductal coculture system.

Differential regulation of cholesterol side-chain cleavage (P450scc) and aromatase (P450arom) enzyme mRNA expression by gonadotrophins and cyclic AMP in human granulosa cells

The co-ordinated biosynthesis of progesterone and oestradiol in the human ovary is critical for reproductive cyclicity and eventual pregnancy. The crucial regulatory enzymes for progesterone and oestradiol biosynthesis in granulosa cells are the cholesterol side-chain cleavage (P450scc) and aromatase (P450arom) enzymes respectively. We utilized the cDNA sequences encoding P450arom and P450scc to examine the roles of FSH and LH, and their intracellular second messenger, cyclic AMP (cAMP), in regulating steroidogenic gene expression. Mature granulosa cells (aspirated before the onset of the endogenous LH surge) and granulosa lutein cells (obtained after an ovulatory dose of human chorionic gonadotrophin) were cultured for 4 days with FSH, LH or dibutyryl cAMP (dbcAMP). After the period of culture, total RNA was extracted from granulosa cells and Northern analyses were performed utilizing 32P-labelled cDNAs encoding P450arom and P450scc. Spent culture media were analysed for steroid and cAMP content. Both FSH and LH strongly stimulated P450arom mRNA expression and oestradiol production in mature granulosa cells. On the other hand, P450scc mRNA expression and progesterone biosynthesis were weakly induced by FSH; maximal synthesis occurred only in the presence of LH. With both gonadotrophins at equivalent concentrations, LH generated a 30-fold higher level of cAMP than FSH. Furthermore, the differential effects of FSH and LH on P450 mRNA expression were reproduced by the presence of low and high concentrations of dbcAMP respectively. LH (and high levels of dbcAMP) increased P450arom mRNA expression in mature granulosa cells but inhibited its accumulation in granulosa lutein cells. In contrast, it stimulated P450scc mRNA expression and progesterone synthesis in both mature granulosa and granulosa lutein cells. Therefore, FSH/low cAMP levels stimulated P450arom gene expression and oestradiol production, while LH/high cAMP levels maximally induced P450scc gene expression and function, in a development-related manner consistent with steroid production in vivo. These findings support the hypothesis that one set of genes (like P450arom) in human granulosa cells is regulated by FSH/low cAMP levels and another (like P450scc) by LH/high cAMP levels.

Early sperm-egg interaction after sperm microinjection

The early events of sperm-egg interaction occurring 1-3 h after multiple sperm injection into the perivitelline space (PVS) and after direct injection into the ooplasm of human oocytes are reported. The sperm acrosome reaction occurred in the PVS but was not detected within the ooplasm. Sperm in the PVS were incorporated into the ooplasm in the usual manner described in vitro, after completion of the acrosome reaction, and a block to polyspermy was evident at the oolemma. However, sperm incorporation into the ooplasm was not clearly defined and requires further investigation. Sperm were also incorporated into oolemma-bound vacuoles within the ooplasm and breaches in the ooplasm were seen after intracytoplasmic injection. Both normal and abnormal sperm were found in the PVS and ooplasm, even though sperm from donors with normal semen parameters were used. The effect of freezing in liquid nitrogen on demembranation of sperm for microinjection is also reported.

Mitogenic and cytogenetic evaluation of transforming growth factor-beta on murine preimplantation embryonic development in vitro

Slow cleavage rate has been a major contributory factor influencing embryo morphology in in vitro fertilization (IVF) programs. The role of transforming growth factor-beta (TGF beta 1) in improving this characteristic was evaluated using the murine model. Replicate batches of eight-cell compacting embryos from superovulated mice were divided into three groups. Group A were treated with 0.3 ng/ml TGF beta 1 at the initial compacting stage, followed by a second treatment of 0.1 ng/mL 22 h later at the cavitating stage; group B received 0.3 ng/ml TGF beta 1 at the cavitating stage; group C were controls. The percentages of treated embryos reaching fixed embryonic stages, total cell number (TCN), mitotic index, and incidence of chromosome anomalies were monitored. The percentage of embryos reaching the cavitating, expanded, hatching, and hatched stages in both treatment groups were not significantly different from control (96.6% +/- 4.2% to 37.7% +/- 12.7% vs. 95.3% +/- 7.3% to 47.0% +/- 3.5%; P > 0.05). Values between the two treatment groups were also not significantly different. Embryos in groups A and B produced significantly greater TCN at expanded blastocyst and hatching stages compared to controls (Group A: 107.0 +/- 18.9 vs. 89.9 +/- 17.4, P < 0.05 and 125.5 +/- 16.4 vs. 113.9 +/- 12.1, P < 0.05; Group B: 107.9 +/- 14.0 vs. 89.9 +/- 17.4, P < 0.05 and 124.9 +/- 17.4 vs. 113.9 +/- 12.1, P < 0.05). Values, however, were not significantly different between treatment groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Human sperm function after coculture with human fallopian tubal epithelial cell monolayers: in vitro model for studying cell interactions in early human conception

It has been difficult to study the behavior of sperm in the tubal environment in vivo. Human tubal epithelial cells were therefore cultured in vitro to simulate tubal conditions and human sperm function was assessed in the presence of such cells in vitro. Ampullary epithelial cell lines were established from fallopian tubes collected from premenopausal women undergoing hysterectomy. Approximately 1 x 10(5) cells/mL from monolayers of the third passage were seeded with 1 mL of culture medium into each well of 4-well plastic dishes. Sperm from 10 ejaculates of 10 different oligoasthenozoospermic men 30-41 years of age were recovered by the swim-up method and 200,000 sperm from each ejaculate were added into each well at the time of cell seeding. Control wells were treated the same but without cells. All dishes were incubated at 37 degrees C in 5% CO2, and sperm motility, acrosome reaction, and sperm-cell binding assessed at 1, 5, and 24 h. Curvilinear velocity and mean amplitude of lateral head displacement were significantly different in ampullary cultures as compared with controls for all three time periods: 1 h (67 +/- 5.2 vs 58 +/- 4.9 microns/s, p < 0.05; 4.48 +/- 0.4 vs 3.29 +/- 0.3 microns; p < 0.05), 5 h (75 +/- 5.8 vs 64 +/- 5.0 microns/s, p < 0.05; 4.92 +/- 0.5 vs 3.68 +/- 0.3 microns, p < 0.05), and 24 h (70 +/- 4.8 vs 59 +/- 4.2 microns/s, p < 0.05; 4.36 +/- 0.4 vs 3.11 +/- 0.3 microns, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative evaluation of three sperm-washing methods to improve sperm concentration and motility in frozen-thawed oligozoospermic and normozoospermic samples

Three sperm-washing methods (direct layering without centrifugation, DL; ficoll entrapment, F; and percoll gradient, P) were evaluated for sperm recovery and motility using computer-automated semen analysis on frozen-thawed samples from normozoospermic and oligozoospermic men. The motile sperm recovery after freeze-thawing was significantly greater for normozoospermic compared with oligozoospermic samples (43 +/- 5.08% vs 15.76 +/- 3.53%; p < 0.001). The P-separated prelayer gave significantly higher recovery of motile sperm than the DL and F methods for both oligozoospermic (0.51 +/- 0.14 vs 0.19 +/- 0.05; p < 0.05) and normozoospermic samples (9.74 +/- 3.11 to 43 +/- 6.01 vs 0.88 +/- 0.23 to 15.30 +/- 3.12; p < 0.001). The P-separated postlayer had higher curvilinear velocities than the DL, F, and prelayered P methods for oligozoospermic samples only (71 +/- 5.13 microns/s vs 53 +/- 3.67 to 59 +/- 2.72 microns/s; p < 0.05). Mean amplitude of lateral head displacement values were significantly different for postlayered P-treated sperm compared with DL, F, and prelayered P-treated sperm for normozoospermic samples only (4.25 +/- 0.16 to 4.67 +/- 0.32 vs 3.01 +/- 0.14 to 3.67 +/- 0.19; p < 0.05). Percoll separation without layering may be the best washing method for both normozoospermic and oligozoospermic frozen-thawed sperm, and the treatment of such recovered sperm with a motility-enhancing agent such as pentoxyfylline may yield optimum fertilization rates.

The effect of coculture on human zygote development

It is well over a decade since the birth of the first test-tube baby and still the in-vitro conditions for early embryonic development remain suboptimal. The ideal culture medium to increase longevity and improve viability of human embryos is not available. Since the metabolic requirements of the human embryo changes from one cleavage stage to another, the development of a single culture medium for all stages could not be expected. The use of helper cells (coculture) in vitro offers much promise as there are numerous documentations in both man and animals describing their ability to increase blastulation rates and improve embryo viability. This paper reviews the effect of coculture on human zygote development. The selection and establishment of cell-lines, biologic actions of coculture of gametes and zygotes, the outcome, and future prospects are discussed.

Fetal blood sampling and its complications related to the indications for fetal blood sampling

A prospective study on fetal blood sampling (FBS) was conducted in the Fetomaternal Medicine Division of the Department of Obstetrics and Gynaecology at the National University Hospital, Singapore. FBS was performed on 159 occasions in 156 women between January, 1988 and December, 1991. The aim of this study was to identify the factors that were associated with an adverse outcome following the procedure. Twenty four abnormal pregnancies were terminated; of the remaining 132 desired pregnancies the overall pregnancy loss was 44 (33.3%), which included those within 2 weeks and those after 2 weeks of the procedure and neonatal deaths. Fetal loss occurring within 2 weeks of the procedure is considered a procedure-related loss which occurred in 19 (14.3%) of the 132 pregnancies. When the fetal loss occurred within 2 weeks of the procedure 89% had a major abnormality on ultrasonographic scanning. The conclusion from our study is that the risks of FBS were increased in abnormal pregnancies, most likely due to the underlying pathology.

Outcome of 143 pregnancies conceived by assisted reproductive techniques

One hundred and forty-three pregnancies conceived by assisted reproductive techniques (ART) from October 1985 to June 1989 in the National University Hospital, Singapore, resulted in 66 deliveries and 89 babies. There were 27 (18.7%) biochemical pregnancies, 44 (30.7%) clinical miscarriages and 6 (4.2%) ectopic pregnancies when total pregnancies were considered. Of those who continued pregnancy to second trimester multiple births occurred in 20 (13.3%) patients. A high incidence of vaginal bleeding and hypertension in pregnancy was noted in 32 (48.5%) patients and 18 (27.3%) patients, respectively. Caesarean section was the method of delivery in 48.5% of patients. Twenty-six (29.2%) babies required admission to the neonatal intensive care unit. All babies except one set of twins delivered at 24 weeks of amenorrhoea survived. Fetal abnormality was noted in 2 cases.

The evaluation of various culture media in combination with dimethylsulfoxide for ultrarapid freezing of murine embryos

Bicarbonate-buffered HTF medium, Medicult, and T6 are as effective as PB1 medium when used in combination with DMSO in ultrarapid freezing of two-cell mouse embryos. However, the use of phosphate-buffered T6 results in reduced in vitro development and inner cell mass size as compared with bicarbonate- and Hepes-buffered T6 when used with 3.5 M of DMSO. Hence, the use of this media for ultrarapid freezing should be avoided when this concentration of DMSO is used.

Embryonic behavior of two-cell mouse embryos frozen by the one- and two-step ultrarapid techniques

PURPOSE

A modified two-step ultrarapid freezing technique was compared to the one-step ultrarapid freezing technique. Two-cell mouse embryos were frozen-thawed using the two freezing protocols, and postthaw cryoprotectant removal was carried out in either a single- or a multiple-step procedure.

RESULTS

Statistically similar cryosurvival (96.95-100%) and blastocyst formation rates (87.95-91.47%) were obtained with both freezing groups. In addition, the method of cryoprotectant removal did not have any significant effect on the survival and development of the frozen-thawed embryos in both groups. Blastocysts formed following single-step cryoprotectant removal had significantly lower inner cell mass counts in the one-step than in the two-step group (26.14 and 27.59, respectively; P < 0.05). Embryo transfer studies showed that the implantation and fetal formation rates of embryos frozen by the two-step technique (61.67 and 60.0%, respectively) were similar to those of embryos frozen by the one-step technique (74.12 and 71.76%, respectively).

CONCLUSION

These results demonstrate that the ultrarapid two-step technique is as effective in cryopreserving two-cell mouse embryos as the ultrarapid one-step technique.

In vitro decondensation of mammalian sperm and subsequent formation of pronuclei-like structures for micromanipulation

In this study, we describe an efficient protocol for the formation of in vitro developed pronuclei for micromanipulation techniques. Our approach involved incubation of demembranated or permeabilized mammalian sperm in a phosphate buffer supplemented with heparin and beta-mercaptoethanol. Under the prevailing conditions, we achieved a uniform and reliable synchronous decondensation of sperm nuclear DNA. This initial decondensation facilitated the removal of mammalian protamines upon subsequent incubation in an amphibian egg extract. The interchange of protamines for histones to stabilize the DNA structure is recognized as a prerequisite for pronuclear formation. Furthermore, immunocytochemical studies have revealed that pronuclear development is accompanied by the formation of a nuclear lamina with corresponding DNA synthesis. The method described gave a high yield of nuclei during pronuclear formation. Ultimately, our aim is to transfer the in vitro-developed pronuclei into mammalian oocytes by micromanipulation. This novel procedure may prove useful in alleviating severe male factor problems especially in oligozoospermic cases in our in vitro fertilization center.