The importance of neuronal growth factors in the ovary.

The neurotrophin family consists of nerve growth factor (NGF), neurotrophin 3 (NT3) and neurotrophin 4/5 (NT4/5), in addition to brain-derived neurotrophic factor (BDNF) and the neuronal growth factors, glial cell line-derived neurotrophic factor (GDNF) and vasointestinal peptide (VIP). Although there are a few literature reviews, mainly of animal studies, on the importance of neurotrophins in the ovary, we aimed to provide a complete review of neurotrophins as well as neuronal growth factors and their important roles in normal and pathological processes in the ovary. Follicular assembly is probably stimulated by complementary effects of NGF, NT4/5 and BDNF and their receptors. The neurotrophins, GDNF and VIP and their receptors have all been identified in preantral and antral follicles of mammalian species, including humans. Transgenic mice with mutations in the genes encoding for Ngf, Nt4/5 and Bdnf and their tropomyosin-related kinase ß receptor showed a reduction in preantral follicles and an abnormal ovarian morphology, whereas NGF, NT3, GDNF and VIP increased the in vitro activation of primordial follicles in rats and goats. Additionally, NGF, NT3 and GDNF promoted follicular cell proliferation; NGF, BDNF and VIP were shown to be involved in ovulation; VIP inhibited follicular apoptosis; NT4/5, BDNF and GDNF promoted oocyte maturation and NGF, NT3 and VIP stimulated steroidogenesis. NGF may also exert a stimulatory effect in ovarian cancer and polycystic ovarian syndrome (PCOS). Low levels of NGF and BDNF in follicular fluid may be associated with diminished ovarian reserve and high levels with endometriosis. More knowledge of the roles of neuronal growth factors in the ovary has important implications for the development of new therapeutic drugs (such as anti-NGF agents) for ovarian cancer and PCOS as well as various infertility problems, warranting further research.

Cryopreservation of in vitro matured oocytes in addition to ovarian tissue freezing for fertility preservation in paediatric female cancer patients before and after cancer therapy.

STUDY QUESTION: Is a protocol that combines in vitro maturation of germinal vesicle-stage oocytes and their vitrification with freezing of cortical ovarian tissue feasible for use in fertility preservation for both chemotherapy-naive paediatric patients as well as patients after initiation of cancer therapy? SUMMARY ANSWER: Follicle-containing ovarian tissue as well as oocytes that can undergo maturation in vitro can be obtained from paediatric patients (including prepubertal girls) both before and after cancer therapy. WHAT IS KNOWN ALREADY: Anticancer therapy reduces the number of follicles/oocytes but this effect is less severe in young patients, particularly the paediatric age group. Autotransplantation of ovarian tissue has yielded to date 60 live births, including one from tissue that was cryostored in adolescence. However, it is assumed that autografting cryopreserved-thawed ovarian cortical tissue poses a risk of reseeding the malignancy. Immature oocytes can be collected from very young girls without hormonal stimulation and then matured in vitro and vitrified. We have previously shown that there is no difference in the number of ovarian cortical follicles between paediatric patients before and after chemotherapy. STUDY DESIGN, SIZE, DURATION: A prospective study was conducted in a cohort of 42 paediatric females with cancer (before and after therapy initiation) who underwent fertility preservation procedures in 2007-2014 at a single tertiary medical centre. PARTICIPANTS/MATERIALS, SETTING, METHODS: The study group included girls and adolescent females with cancer: 22 before and 20 after chemotherapy. Following partial or complete oophorectomy, immature oocytes were either aspirated manually ex vivo from visible small antral follicles or filtered from spent media. Oocytes were incubated in oocyte maturation medium, and those that matured at 24 or 48 h were vitrified. Ovarian cortical tissue was cut and prepared for slow-gradual cryopreservation. Anti-Mullerian hormone (AMH) levels were measured in serum before and after oophorectomy. MAIN RESULTS AND ROLE OF CHANCE: Ovarian tissue was successfully collected from 78.7% of the 42 patients. Oocytes were obtained from 20 patients before chemotherapy and 13 after chemotherapy. The youngest patients from whom oocytes were retrieved were aged 2 years (two atretic follicles) and 3 years. Of the 395 oocytes collected, ∼30% were atretic (29.6% in the pre-chemotherapy group, 37% in the post-chemotherapy group). One hundred twenty-one oocytes (31%) were matured in vitro and vitrified: 67.8% from patients before chemotherapy, the rest after chemotherapy. Mature oocytes suitable for vitrification were obtained from 16/20 patients before chemotherapy and from 12/13 patients after chemotherapy (maturation rate, 32 and 26.4%, respectively). There were significant correlations of the number of vitrified oocytes with patient age (more matured oocytes with older age) (P = 0.001) and with pre-oophorectomy AMH levels (P = 0.038 pre-chemotherapy group, P = 0.029 post-chemotherapy group). Oocytes suitable for vitrification were obtained both by manual aspiration of antral follicles (45%) and from rinse solutions after dissection. There were significantly more matured oocytes in the pre-chemotherapy group from aspiration than in the post-chemotherapy group after both aspiration (P < 0.033) and retrieval from rinsing fluids (P < 0.044). The number of pre-antral follicles per histological section did not differ in the pre- versus post-chemotherapy. AMH levels dropped by approximately 50% after ovarian removal in both groups, with a significant correlation between pre- and post-oophorectomy levels (P = 0.002 pre-chemotherapy group, P = 0.001 post-chemotherapy group). LIMITATIONS, REASONS FOR CAUTION: There were no patients between 5 years and 10 years old in the post-chemotherapy group, which might have affected some results and correlations. Oocytes from patients soon after chemotherapy might be damaged, and caution is advised when using them for fertility-restoration purposes. The viability, development capability and fertilization potential of oocytes from paediatric patients, especially prepubertal and after chemotherapy, are unknown, in particular oocytes recovered from the media after the tissue dissection step. WIDER IMPLICATIONS OF THE FINDINGS: Although more oocytes were collected and matured from chemotherapy-naïve paediatric patients, ovarian tissue and immature oocytes were also retrieved from young girls in whom cancer therapy has already been initiated. Our centre has established a protocol for potential maximal fertility preservation in paediatric female patients with cancer. Vitrified-in vitro-matured oocytes may serve as an important gamete source in paediatric female patients with cancer because the risk of reseeding the disease is avoided. Further studies are needed on the fertility-restoring potential of oocytes from paediatric and prepubertal patients, especially after exposure to chemotherapy. STUDY FUNDING/COMPETING INTERESTS: The study was conducted as part of the routine procedures for fertility preservation at our IVF unit. No funding outside of the IVF laboratory was received. Funding for the AMH measurements was obtained by a research grant from the Israel Science Foundation (to B.-A.I., ISF 13-1873). None of the authors have competing interests. TRIAL REGISTRATION NUMBER: N/A.

Optimizing the process of fertility preservation in pediatric female cancer patients - a multidisciplinary program.

BACKGROUND: Current evidence indicates sub-optimal incidence of fertility preservation (FP) in eligible patients. We present herein our designated multidisciplinary program for FP in pediatric and adolescent population and present our data on FP in female patients. METHODS: Pediatric patients (age 0-18) who were candidate for highly gonadotoxic treatments were referred to FP program for a multidisciplinary discussion and gonadal risk-assessment followed by either oocyte cryopreservation or ovarian cryopreservation (OCP) for female patients, and sperm banking for male patients. The OCP protocol consists of aspiration of oocytes from small antral follicles and in-vitro maturation followed by cryopreservation, as well as ovarian tissue cryopreservation. RESULTS: The establishment of a designated FP program resulted in a significant increase in referral and subsequent FP procedures of all eligible patients. Sixty-two female patients were referred for FP discussion during a period of 36 months; 41 underwent OCP; 11 underwent oocyte cryopreservation and six were declined due to parental decision. The median age was 13.2y (range 18 months-18y). Thirty-two (51.6 %) were chemotherapy-naïve. Seventeen patients (27 %) had sarcoma, 16 patients (26 %) had acute leukemia. The mean number of mature oocytes that were eventually vitrified was significantly higher in chemotherapy-naïve patients compared with chemotherapy-exposed patients (mean 12 oocytes (1-42) versus 2 (0-7)). CONCLUSION: Multidisciplinary programs that encompass experts of all relevant fields, skilled laboratory resources and a facilitated path appear to maximize the yield. We observed a considerable higher referral rates following launching a designated program and earlier OCP in chemo-naïve patients that culminated in a better fertility preservation procedure.

Keratinocyte growth factor and its receptor in human ovaries from fetuses, girls and women.

Keratinocyte growth factor (KGF) promotes growth of rat pre-antral follicles. There is limited information regarding its presence or that of its unique receptor (KGFR) in human ovaries, specifically in pre-antral follicles. The aim of the study was to investigate the expression of KGF and KGFR in ovarian samples from human fetuses and girls/women. The samples were prepared for immunohistochemical study of the KGF protein and for in situ hybridization to localize mRNA transcripts of KGFR. Total RNA was extracted from frozen ovarian samples, and the expression of KGF mRNA transcripts was investigated by reverse transcriptase polymerase chain reaction. In both fetuses and girls/women, the protein for KGF was detected from primordial stages in oocytes, granulosa cells (GCs) and stroma cells. Its mRNA transcripts were also detected in all extracts. The mRNA transcripts for KGFR were detected mainly in stroma cells in ovarian samples from both sources; in 10% of the samples, follicular staining was noted also in oocytes and GCs. Further studies adding KGF to the culture medium are needed to elucidate its putative role in human primordial follicle activation.

Platelet-derived growth factors (PDGF-A and -B) and their receptors in human fetal and adult ovaries.

There is no information regarding the presence of platelet-derived growth factors (PDGFs) and their receptors in human ovaries. The expression of PDGF-A, -B and their two receptors, PDGFR-alpha and -beta, was investigated in ovarian samples from women/girls and from human fetuses, at the protein and mRNA levels. The samples were prepared for immunohistochemical staining for PDGF-A and -B and their two receptors and in situ hybridization for the detection of the mRNA transcripts of the receptors. Total RNA was extracted from frozen ovarian samples, and the expression of PDGF-A and -B was investigated by reverse transcription-polymerase chain reaction. The proteins for PDGF-A and -B were detected in oocytes, and in granulosa cells (GC) of 50% of the follicles from women/girls. The proteins and mRNA transcripts for the two receptors were detected in oocytes (mRNA for PDGFR-beta only in 25% of the oocytes). PDGFR-alpha mRNA was expressed in GC of a minority of the samples from women/girls, whereas PDGFR-beta protein and mRNA were identified in over 50% of the GC from this source. PDGF-A and -B transcripts were identified in all the extracts. The presence of the receptors in GC suggests that PDGFs might be involved in the activation of primordial follicles.

Morphological study of fully and partially isolated early human follicles.

OBJECTIVE: To compare the development of fully and partially isolated human follicles by using various culture systems. DESIGN: Human ovarian material was incubated with collagenase and deoxyribonuclease. Fully and partially isolated follicles (30-50 microm) were dissected and studied under light and electron microscopy. The follicles were then cultured on and within various matrices. Fully isolated follicles were also cocultured with stromal cells. SETTING: Rabin Medical Center, a major care and referral center. PATIENT(S): Women undergoing laparoscopy. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Microscopy studies, follicular measurements. RESULT(S): Electron microscopy studies revealed an excess of lipid droplets in the granulosa cells of freshly isolated follicles. An increase in follicular size and granulosa cell number was observed only in the fully isolated follicles cultured within collagen gels for 24 hours. Most of the partially isolated follicles detached from the collagen gels. When cultured on collagen, extracellular matrix, and poly-L-lysine, both the fully and the partially isolated follicles deteriorated within the first 24 hours; coculture with stromal cells had no beneficial effect. CONCLUSION(S): The excess in lipid droplets in granulosa cells of isolated follicles might suggest that the isolation process does not yield completely healthy follicles. However, despite this finding, our studies show that fully isolated follicles, but not partially isolated follicles, can grow within, but not on, a culture matrix.

Mechanical isolation and in vitro growth of preantral and small antral human follicles.

OBJECTIVE: To develop a procedure for isolating small human follicles and to determine their growth requirements. DESIGN: Preantral and early antral follicles were isolated manually, allocated randomly to experimental groups, and cultured for a few weeks. SETTING: Patients giving informed consent in hospitals. PATIENT(S): Women undergoing laparotomy or oophorectomy. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Follicular size, E2, histology. RESULT(S): Human FSH (at a dose of 1.5 U/mL) induced antral growth of follicles, and the addition of human LH (2.5 ng/mL) to human FSH stimulated growth and antral development. Histologic studies showed that most of the early antral follicles did not contain an oocyte and already had begun to undergo atresia before culturing. Levels of E2 increased in the incubation medium as the follicles increased in size, but those levels were significantly greater when the follicles contained oocytes. CONCLUSION(S): It is possible to grow small human follicles after they have been isolated manually. To develop successfully, they require a low concentration of human LH in addition to human FSH. The rate of atresia between the preantral and early antral stages in vivo is very high; therefore, it is worthwhile to develop techniques for isolating and culturing the follicles before the antral stages.

IgG exchange as a means of partial correction of anomalies in rat embryos in vitro, induced by sera from women with recurrent abortion.

Many recurrent abortions have an unknown aetiology. A significant proportion of sera from women with spontaneous abortions induced 50% or more anomalies ('high risk' sera) in cultures of 10.5-day-old rat embryos. Because it is assumed that the teratogenic factor(s) in recurrent abortion is often an immunoglobulin G (IgG) antibody, it was attempted to reduce the rate of anomalies induced by high risk sera by removing the IgG fractions and adding IgG fractions from control sera (sera from women in a normal second trimester of pregnancy and after delivery). Concomitantly, an attempt was made to induce anomalies in embryos cultured in control sera by adding IgG fractions from high risk sera. It was found that among the high risk sera there were three groups, according to the response to the IgG exchange: (1) a group in which IgG exchange 'corrected' the anomalies in high risk sera, whereas it induced anomalies in control sera; (2) a group in which anomalies were found both in embryos cultured in high risk sera and those cultured in control sera; (3) a group in which the IgG exchange did not affect the results in the 'experimental' or 'control' embryos. Examination by transmission electron microscopy, of yolk sacs cultured in sera with IgG from women belonging to the third group did not reveal ultrastructural changes. In conclusion, in some high risk sera the teratogenic factor appears to be an IgG only; in others, teratogenicity is brought about not only by an IgG, but also by additional teratogenic factor(s); in the last group, the teratogenic factor(s) does not appear to be an IgG at all.

Effects on rat embryos of culture in serum of women with gestational diabetes.

Serum from diabetic patients, as well as having high levels of glucose and ketone bodies, is known to have embryotoxic and teratogenic effects that play an important role in diabetes-induced teratology. We studied the effect of serum from women with gestational diabetes, who are not known to have a high incidence of malformations in their offspring, on the in vitro development of 10.5-day-old rat embryos. Results from these studies were then compared with those using serum from pregnant women with Type I diabetes, serum from pregnant women without diabetes, and normal rat serum. Serum from pregnant women with Type I diabetes caused abnormalities in 71% of the embryos in comparison with an incidence of 53.3% in embryos cultured in serum from women with gestational diabetes. Embryos cultured in serum from women without diabetes or in rat serum had a 9 and 4.2% incidence of defects, respectively. Diabetic serum also decreased the size of the embryos, the number of somites, yolk sac diameter, and the amount of protein in the embryos and their yolk sacs. This damage was more significant when embryos were cultured in Type I diabetic serum than in serum from patients with gestational diabetes. The levels of serum glucose, glycosylated haemoglobin, fructosamine, beta-hydroxybutyrate (beta-HOB) and acetoacetate were also higher in Type I diabetic serum than in serum from gestational diabetes. Significant ultrastructural damage was observed in the yolk sacs of embryos cultured in diabetic serum, with a reduction in the endocytic index. The fact that serum from women with gestational diabetes is teratogenic to early somite rat embryos supports the hypothesis that metabolic factors are responsible for diabetes-induced teratogenicity and that to prevent these defects it is essential to stabilize the diabetic state of the mother before, and during, early gestation.

The role of intravenous albumin in the prevention of severe ovarian hyperstimulation syndrome. A pilot experimental study.

OBJECTIVE: To evaluate the role of intravenous albumin in the prevention of severe ovarian hyperstimulation syndrome (OHSS). DESIGN: A pilot experimental study. MATERIAL AND METHODS: Ovarian hyperstimulation was induced in 5 rabbits using human menopausal gonadotropin/human chorionic gonadotropin, after pretreatment without (control group) or with bovine serum albumin (BSA group). RESULTS: Despite an increase in serum protein levels, the BSA group showed comparable delta increase in body weight and degree of ascites formation. CONCLUSIONS: Intravenous albumin did not prevent severe OHSS in a rabbit model despite the observed increase in serum oncotic pressure.

In vitro maturation of human primordial ovarian follicles: clinical significance, progress in mammals, and methods for growth evaluation.

As cancer treatment improves, more young women of reproductive age are surviving, but they suffer from infertility as a consequence of the radiation and chemotherapy. Human ovarian tissue containing immature primordial follicles has been successfully cryopreserved. The ultimate aim of this technique is to induce ovarian function by re-plantation of ovarian tissue or, further into the future, by in vitro maturation (IVM) of the oocytes derived from the cryopreserved-thawed ovarian tissue, followed by routine in vitro fertilization. IVM of primordial follicles from young cancer survivors would avoid the risk of cancer re-transmission by the ovarian grafts. The present review discusses the current achievements in IVM of female germ cells and primordial ovarian follicles and the attempts to improve their development by adding various factors to the culture medium. The established methods for the evaluation of survival and growth in culture are also discussed: follicular counts, immunocytochemical methods, transmission electron microscopy, fluorescent viability markers and endocrine assays. Although the development of IVM systems is still in its infancy, researchers need to pursue their approach step-by-step, especially with regard to factors that might be involved in the activation of the ovarian follicles or female germ cells. The final measure of success will be the ability of the in vitro matured oocytes to fertilize and produce healthy offsprings. The availability of such treatment will probably lead to its demand not only by cancer patients but by other women as well.

Tyrosine kinase B receptor and its activated neurotrophins in ovaries from human fetuses and adults.

The signals initiating the growth of primordial follicles are unknown. Growth factors such as neurotrophin 4/5 (NT-4/5) and brain-derived neurotrophic factor (BDNF) may play a role in this process. To investigate the expression of NT-4/5 and BDNF and their receptor tyrosine kinase B (TrkB) in the early developing follicles, we fixed and froze 12 ovarian samples from adolescents/adults and 31 ovaries from human fetuses. The fixed samples were prepared for immunohistochemical staining for NT-4/5, BDNF and the TrkB receptor. Total RNA was extracted from the frozen ovarian samples, and the expression of NT-4/5, BDNF and the TrkB receptor (full length and two truncated isoforms) was investigated by RT-PCR. Products were resolved by 1% agarose gel electrophoresis and image analysis. Immunohistochemical staining revealed the expression of NT-4/5 and BDNF mainly in oocytes and, in a minority of samples, also in the granulosa cells (GCs); TrkB receptor was identified in oocytes and GCs. Transcripts of NT-4/5, BDNF and all forms of TrkB receptor were identified in the samples. To elucidate whether indeed NT-4/5 and BDNF are involved in growth initiation of human primordial follicles, they should be added to the culture medium.

Presence of NGF and its receptors in ovaries from human fetuses and adults.

The ability to mature human primordial follicles in vitro would assist fertility restoration. However, the signals initiating growth of primordial follicles are unknown. Growth factors such as nerve growth factor (NGF) may play a role in this process. To investigate the expression of NGF and its receptors, p75 and TrkA, in early developing follicles (mostly primordial, primary and secondary follicles), ten ovarian samples from adolescents/adults aged 13-39 and 33 ovaries from human fetuses aged 19-33 gestational weeks (GW) were obtained and immediately fixed or frozen. The fixed samples were prepared for a study of immunocytochemical staining of NGF and its two receptors. Total RNA was extracted from the frozen ovarian samples, and the expression of NGF, TrkA and p75 was investigated by RT-PCR. Products were resolved by 1% agarose gel electrophoresis and image analysis. Immunocytochemical staining revealed the expression of NGF in granulosa cells (GC) and oocytes; TrkA was mainly in oocytes and in GC in minority of the samples; and p75 was in some of the stroma cells from fetuses aged less than 22 GW. Transcripts of NGF and TrkA were identified by RT-PCR in all samples, while those for p75 were detected only in ovarian samples from fetuses aged less than 22 GW. To elucidate if NGF is indeed involved in growth initiation of human primordial follicles, it should be added to their culture medium. The immunocytochemical detection of p75 in some of the stroma cells and transcripts in ovarian samples of fetuses less than 22 GW may suggest its role in follicular assembly.

Teratogenic IgG from sera of women with spontaneous abortions seem to induce anomalies and yolk sac damage in rat embryos. A possible method to detect abortions of immunologic origin.

PROBLEM: Spontaneous abortions due to immunological rejection of the embryo may be avoided by immunotherapy with paternal allogeneic leukocytes but there is no appropriate method to detect and differentiate this group of aborters from other groups. METHODS: In previous studies we have demonstrated that in about two-thirds of sera from women with spontaneous abortions the IgG antibodies are responsible (alone or in combination with other factors) for the embryotoxic effects of these sera on cultured rat embryos. We presently cultured 10.5-day-old rat embryos on highly teratogenic serum ("high risk" serum that induced anomalies in more than 50% of the embryos) from women with spontaneous abortions, where the IgG fraction was exchanged with IgG from control sera and vice-versa. We studied by Transmission Electron Microscopy (TEM) the extent of yolk sac damage in comparison to the rate of embryonic anomalies. RESULTS: In cases where IgG antibodies were teratogenic, embryos cultured in control sera with IgG from "high risk" sera exhibited ultrastructural yolk sac damage as well as embryonic anomalies, and the yolk sacs cultured in "high risk" sera with control IgG were normal. In cases in which the IgG exchange did not change the rate of anomalies, as IgG was not teratogenic, yolk sacs from embryos cultured in "high risk" sera remained damaged, while yolk sacs from embryos cultured in control sera after IgG exchange stayed normal. Although no significant difference in total IgG levels was found between the groups, a higher IgG1 level in sera from women with teratogenic IgG was observed in comparison to control women's sera. The obstetrical history of the women with two or more abortions who took part in our study showed that there were more cases of unknown etiology of the abortion in the women from the "high risk" group. CONCLUSIONS: The serum and the IgG fraction from women with habitual abortions can be tested in whole embryo culture to evaluate the embryonic and yolk sac damage. On this basis it may be possible to detect the women in whom the habitual abortions result from immunological rejection.

The effects of sera from women with spontaneous abortions on the in vitro development of early somite stage rat embryos.

PROBLEM: Spontaneous abortions occur in 40 to 50% of pregnancies, but the causes for some abortions, especially those that are recurrent (spontaneous), are still unknown. METHOD: Following previous studies that demonstrated embryotoxic effects of sera from women with spontaneous abortions in preimplantation mouse embryos, we cultured 10.5-day-old rat embryos in sera from women after spontaneous abortions to look for specific teratogenic effects. RESULTS: About 50% of the embryos cultured in sera from women after spontaneous abortions were malformed, as compared to 19.1 and 27.1% malformations in embryos cultured in sera from women after a normal delivery and during a normal second trimester of pregnancy, respectively. We divided the sera from women who had spontaneous abortions into high-risk, and low-risk sera. In the high-risk sera from one abortion, we found 74.2% malformed embryos and in the high-risk group from two or more abortions this rate was 81.0%. This is compared to a rate of 17.1 and 10.3% in the low-risk sera, respectively. We have also found lower DNA and protein synthesis in the embryos cultured in high-risk sera compared to those cultured in low-risk and control sera. Transmission electron microscopy examination of yolk sacs cultured in high risk sera showed ultrastructural damage as represented by a lower number of microvilli and a higher number of inclusions in the entodermal cells when compared to controls. Amino acid chromatography of the serum and the concentrations of folic acid and zinc were similar in control and high-risk sera. CONCLUSION: It seems that the majority of sera from women with unexplained spontaneous abortions are teratogenic to rat embryos in culture. In about two-thirds of these sera the teratogenic factor(s) seem to be present in the IgG fraction.

Extracellular matrix improves survival of both stored and fresh human primordial and primary ovarian follicles in long-term culture.

Ovarian cortical tissue was obtained during gynaecological operations by biopsy or after oophorectomy from 20 women aged 25-42 years. It was placed in organ culture, either fresh or following thawing after cryopreservation, for 1-4 months. The tissue was cut in slices 0.1-0.3 mm in diameter and transferred to 12 mm inserts in 24-well culture plates. These slices were cultured for 4-21 days in either alpha minimum essential medium (alpha-MEM) or Earle's balanced salt solution with added pyruvate. Both media were supplemented with 10% human serum, insulin, gonadotrophins and antibiotics. Half of the inserts were precoated with extracellular matrix (Matrigel). Histological samples revealed that there were viable, non-atretic, primordial, primary and secondary follicles in all the cultures. Mitoses were seen in the granulosa cells of the secondary follicles. Although the proportion of atretic follicles increased during culture, non-atretic follicles were still present after 21 days. After 4-11 days the proportion of viable follicles was significantly higher when cultured in Earle's solution supplemented with pyruvate, than when cultured in MEM (77 versus 38%, P < 0.001). In cultures with extracellular matrix the proportion of viable follicles was significantly higher after 10-15 days than it was without matrix (85 versus 19%, P < 0.001). Culture after thawing frozen ovarian tissue did not affect the density or the proportion of the viable follicles. Two-thirds of follicles in cryopreserved tissue were viable after 10-15 days in culture. The results indicate that it is possible to culture human primary and primordial follicles in vitro, and follicles in cryopreserved tissue are viable.

Turner's syndrome and fertility: current status and possible putative prospects.

Women with Turner's syndrome should be carefully followed throughout life. Growth hormone therapy should be started at age 2-5 years. Hormone replacement therapy for the development of normal female sexual characteristics should be started at age 12-15 years and continued for the long term to prevent coronary artery disease and osteoporosis. Most women with Turner's syndrome have ovarian dysgenesis; therefore, they are usually infertile, and in very rare cases have spontaneous menses followed by early menopause. Only 2% of the women have natural pregnancies, with high rates of miscarriages, stillbirths and malformed babies. Their pregnancy rate in oocyte donation programmes is 24-47%, but even these pregnancies have a high rate of miscarriage, probably due to uterine factors. A possible future prospect is cryopreservation of ovarian tissue containing immature follicles before the onset of early menopause, but methods of replantation and in-vitro maturation still need to be developed. Should these autologous oocytes indeed be used in the future, affected women would need to undergo genetic counselling before conception, followed by prenatal assessment.

Role of reactive oxygen species in diabetes-induced embryotoxicity: studies on pre-implantation mouse embryos cultured in serum from diabetic pregnant women.

Sera from diabetic patients or sera with high levels of diabetic metabolic products, were found to affect mouse and rat blastocysts. In the present study we examined the earliest developmental stages at which human diabetic serum will be lethal to mouse pre-implantation embryos, and whether reactive oxygen species (ROS) are involved in these diabetes-induced injuries. We cultured 2-4 cell-stage embryos and blastocysts in a medium containing 30 or 50% serum obtained from pregnant women with diabetes Type I, Type II and gestational diabetes (GDM) for 72 h. The development of the 2-4 cell-stage embryos was delayed when cultured in 30% diabetic serum, but the viability was impaired to a lesser extent. Viability was reduced in blastocysts cultured in 50% diabetic serum, but the development of the living embryos was not delayed. Cyclic voltametry measures the oxidation potential of the tissue and the concentration of antioxidants, thus reflecting the total antioxidative activity of the embryos. Pre-implantation embryos cultured in diabetic serum had a lower concentration of antioxidants than embryos cultured in non-diabetic serum. It seems, therefore, that diabetic metabolic factors may induce embryotoxicity in pre-implantation embryos through derangement of the antioxidant defense mechanism. A similar mechanism is suggested for the diabetes-induced teratogenicity in post-implantation embryos.

Preservation of fertility in women undergoing chemotherapy: current approach and future prospects.

PURPOSE: Anticancer treatment causes ovarian failure. METHODS: Some hormones may have a protective effect on the ovary. Cryopreservation (freezing) of oocytes has had very limited success, and therefore, currently its use before chemotherapy is not a feasible option. However, cryopreservation of embryos is possible. Another solution is oocyte donation followed by in vitro fertilization (IVF). RESULTS: Ovarian cortical slices containing primordial follicles have been cryopreserved successfully. To restore fertility, cryopreserved-thawed tissue taken from cancer patients before therapy could be replanted after recovery. The possible risk of malignancy restoration could be eliminated by obtaining unilaminar follicles from cryopreserved-thawed tissue and growing them in vitro, followed by routine IVF. CONCLUSIONS: Although women who undergo chemotherapy face limited options for fertility preservation, intensive studies in cryopreservation and in vitro maturation of follicles harbor hope for brighter prospects in the future.

Controlled ovarian hyperstimulation: a state of neutrophil activation.

PROBLEM: To investigate if controlled ovarian hyperstimulation (COH) affects the expression of neutrophil adhesion molecules and if a correlation exists between neutrophil activation and serum sex-steroid levels. METHOD OF STUDY: The pilot study was carried out in the in vitro fertilization (IVF) unit of our department, and required no modification of our routine IVF protocol. Four patients arriving for baseline hormonal profile on day 1 of the menstrual cycle before initiation of COH (control group) and 11 patients admitted for oocyte recovery (study group) were included. Venous blood was obtained from all patients and examined for hormonal profile and neutrophil activation. The latter was performed by staining for the surface adhesion molecules beta2 integrin and L-selectin. Positive cell count and mean fluorescence intensity were determined by flow cytometry. RESULTS: While neutrophil L-selectin was significantly lower in the study group than in the control group, neutrophil beta2 integrin was nonsignificantly higher. Though no significant correlations were found between neutrophil adhesion molecules and patient age, serum estradiol level, and human chorionic gonadotropin level; neutrophil L-selectin was negatively correlated with serum progesterone levels. CONCLUSIONS: COH leads to neutrophil activation, which correlates with the degree of luteinization. Further studies are required to elucidate the relationship between the immune system and COH. These may lead to new strategies for promoting fertility and preventing complications of COH.