Putative stem cells with an embryonic character isolated from the ovarian surface epithelium of women with no naturally present follicles and oocytes

There have been some proposals that stem cells exist in the ovarian surface epithelium (OSE) of the adult human ovary; however, no direct evidence of such cells has been given until now. The aim of this study was to isolate the putative ovarian stem cells (OSCs) from the OSE layer in women with no naturally present oocytes and follicles--20 postmenopausal women and five women with premature ovarian failure. Small round cells with a bubble-like structure and diameters from 2 to 4 microm were isolated from the material obtained by OSE scraping. They expressed early embryonic developmental markers such as stage-specific embryonic antigen-4 and Oct-4, Nanog, Sox-2, and c-kit transcription markers, and they displayed prominent c-kit immunohistochemical staining. These cells were separated by density gradient centrifugation and grown in vitro, where they proliferated. Some of them grew intensively and reached a diameter of approximately 20 microm after 5-7 days. In the OSE cell culture, oocyte-like cells developed, which reached a diameter of up to 95 microm and expressed Oct-4A, Oct-4B, c-kit, VASA, and ZP2 transcription markers, corresponding to early oocytes. They did not express SCP3 meiotic marker. In conclusion, the discovered cells are proposed to represent the adult OSCs with the expression of embryonic stem cell markers. The expression of germ lineage marker c-kit points toward their primordial germ cell ancestry. A new term "embryonic-like stem cells of the adult" is proposed for embryonic-like stem cells that might persist in various tissues and organs of adults. These findings could be used for further studies aimed at the autologous treatment of ovarian infertility and degenerative diseases.

Study origin of germ cells and formation of new primary follicles in adult human and rat ovaries

The central thesis regarding the human ovaries is that, although primordial germ cells in embryonal ovaries are of extraovarian origin, those generated during the fetal period and in postnatal life are derived from the ovarian surface epithelium (OSE) bipotent cells. With the assistance of immune system-related cells, secondary germ cells and primitive granulosa cells originate from OSE stem cells in the fetal and adult human gonads. Fetal primary follicles are formed during the second trimester of intrauterine life, prior to the end of immune adaptation, possibly to be recognized as self-structures and renewed later. With the onset of menarche, a periodical oocyte and follicular renewal emerges to replace aging primary follicles and ensure that fresh eggs for healthy babies are always available during the prime reproductive period. The periodical follicular renewal ceases between 35 and 40 yr of age, and the remaining primary follicles are utilized during the premenopausal period until exhausted. However, the persisting oocytes accumulate genetic alterations and may become unsuitable for ovulation and fertilization. The human OSE stem cells preserve the character of embryonic stem cells, and they may produce distinct cell types, including new eggs in vitro, particularly when derived from patients with premature ovarian failure or aging and postmenopausal ovaries. Our observations also indicate that there are substantial differences in follicular renewal between adult human and rat ovaries. As part of this chapter, we present in detail protocols utilized to analyze oogenesis in humans and to study interspecies differences when compared to the ovaries of rat females.

Ovarian germ cells

Surface cells in adult ovaries represent germ line-competent embryonic stem cells. They are a novel type of totipotent progenitors for distinct cell types including female germ cells/oocytes, with the potential for use in the autologous treatment of ovarian infertility and stem cell therapy. Ovarian infertility and stem cell therapy are complex scientific, therapeutic, and socioeconomic issues, which are accompanied by legal restrictions in many developed countries. We have described the differentiation of distinct cell types and the production of new eggs in cultures derived from adult human ovaries. The possibility of producing new eggs from ovarian surface epithelium representing totipotent stem cells supports new opportunities for the treatment of premature ovarian failure, whether idiopathic or after cytostatic chemotherapy treatment, as well as infertility associated with aged primary follicles, and infertility after natural menopause. The stem cells derived from adult human ovaries can also be used for stem cell research and to direct autologous stem cell therapy. This chapter describes general considerations regarding the egg origin from somatic progenitor cells, oogenesis and follicle formation in fetal and adult human ovaries (follicular renewal), including the promotional role of the immune system-related cells in vivo, and possible causes of ovarian infertility. It then provides detailed protocols for the separation and cultivation of adult ovarian stem cells.

Determination of derivatized amino acids in human embryo culture media by gas chromatography

An adequate analytical method for determination of amino acids can provide a better insight in the metabolism of in vitro human embryo cultures, increasing the success rate of embryo implantation. Since individual amino acid amounts per embryo occur in the nanogram range, GC was the technique of choice, due to its inherent sensitivity and high sample throughput. Amino acids were analyzed as alkyl formate derivatives. The limits of detection (LOD) of all amino acids involved were in the sub-nmol range. The high risk of sample contamination proved to be the major analytical issue, but it could be overcome. For an extended method sensitivity, a simple preconcentration step could also be used.

Outcome of frozen-thawed blastocysts derived from gonadotropin releasing hormone agonist or antagonist cycles

PURPOSE

The aim of this retrospective study was to compare the outcome of frozen-thawed blastocysts derived from the cycles using controlled ovarian stimulation with GnRH agonists vs. GnRH antagonists.

METHODS

Survival, pregnancy and cumulative live birth rates in 231 freeze-thaw cycles derived from the GnRH agonist cycles (GnRH agonist group), and in 175 freeze-thaw cycles derived from the GnRH antagonist cycles (GnRH antagonist group) were compared.

RESULTS

In the GnRH agonist group significantly higher proportion of blastocysts survived the thawing procedure than in the GnRH antagonist group (86.1% versus 78.5%; p < 0.01). The differences in cumulative live birth rates did not differ significantly between the groups: in the GnRH agonist group the cumulative live birth rate was 16.5%, and in the GnRH antagonist group it was 14.2%.

CONCLUSIONS

Frozen-thawed blastocysts derived from the GnRH agonist cycles have better survival rates and similar cumulative live birth rates than those derived from the GnRH antagonist cycles.

Potential new strategies for the treatment of ovarian infertility and degenerative diseases with autologous ovarian stem cells

The 50-year-old and currently prevailing view that all oocytes in adult human ovaries persist from the fetal period of life is controversial as it clashes with Darwinian evolutionary theory. Studies of oogenesis and follicular renewal in adult human ovaries, and of the role of hormonal signals and third-party cells (tissue macrophages and T cells), could all be helpful in providing better understanding of the causes of ovarian infertility, its prevention and potential therapy. In addition, the authors recently reported differentiation of distinct cell types and the production of new eggs in cultures derived from premenopausal and postmenopausal human ovaries. It is possible that fertilisation of such eggs will open up new opportunities for providing genetically related children to infertile women for whom conventional in vitro fertilisation has failed. As ovarian stem cells appear to represent a new type of totipotent adult stem cell, they could also be utilised for autologous stem cell therapy of degenerative diseases, without any involvement of allogeneic embryonic stem cells and somatic cell nuclear transfer.

Increased ammonium in culture medium reduces the development of human embryos to the blastocyst stage

The objective of this prospective study was to evaluate the effect of ammonium accumulated in sequential media and determined by enzymatic spectrophotometric method on the blastocyst development in 281 human embryos from 100 stimulated and natural in vitro fertilization (IVF) cycles. Ammonium concentration was increased in 62% of cycles and was correlated negatively with the blastocyst development after classical IVF, but not after intracytoplasmic sperm injection (ICSI).

Intracytoplasmic sperm injection as a complement to gonadotrophin treatment in infertile men with hypogonadotrophic hypogonadism

In this study we sought to determine whether intracytoplasmic sperm injection (ICSI) could improve the efficacy of treatment with gonadotrophins in gonadotrophin-deficient men in terms of pregnancy. A series of six adult men (aged 26-47 years) with hypogonadotrophic hypogonadism (HH) is reported: four men with prepubertal isolated idiopathic HH (IIHH) and two adult-onset HH, as part of hypopituitarism secondary to surgical treatment of a pituitary tumour. All were azoospermic. To restore spermatogenesis, all received hormonal treatment with intramuscular human menopausal gonadotrophins (HMG) and human chorionic gonadotrophin (HCG) for 2 to 23 months. High basal serum inhibin B was predictive of rapid and complete recovery of spermatogenesis. In the two adult-onset HH, a natural pregnancy was achieved within 3 months. The four men with IIHH underwent ICSI because of poor sperm quality. ICSI using fresh or frozen-thawed ejaculated spermatozoa was performed after 6-23 months of gonadotrophin treatment. ICSI provided good clinical results in terms of fertilization and embryo quality, and resulted in three pregnancies that ended in three term deliveries. In men with oligozoospermia related to prepubertal IIHH, ICSI shortens the hormonal treatment and enhances the chances of pregnancy.

Seminal elastase-inhibitor complex, a marker of genital tract inflammation, and negative IVF outcome measures: role for a silent inflammation?

There is no consensus on whether and how male genital tract inflammation affects sperm fertilizing potential. The aims of this prospective study were to evaluate the elastase-inhibitor complex in seminal plasma (s-EI) level, a marker of male genital tract inflammation, in men undergoing in vitro fertilization (IVF) having no clinical signs of inflammation, and its association with semen characteristics, and the predictive role of s-EI for the outcome of IVF in terms of fertilization, embryo development to the blastocyst stage and pregnancy. The study involved 104 male partners of infertile couples with normal spermiogram undergoing IVF. On the day of oocyte retrieval, spermiogram and s-EI assessment using homogeneous immunoassay were performed. The outcome of IVF according to the s-EI level was assessed in 85 cycles with two or more oocytes. In 67 cycles embryos were cultured to the blastocyst stage. Spearman's and Pearson's correlation tests, chi-square test, and multiple linear and logistic regression analyses were used for statistical evaluation. Increased s-EI level (> or =250 microg/L) was detected in semen of 32% of men, and in 24% of men without leucocytospermia. We found an association between the s-EI level and semen leucocytes (r = 0.49, p = 0.004) but not with classical sperm characteristics. No correlation between the s-EI level and fertilization was observed. Increased s-EI levels were associated with a poorer blastocyst development rate (p = 0.03) and a higher number of arrested embryos (p = 0.04). Extended embryo culture to the blastocyst stage shows a negative effect of clinically silent male genital tract inflammation on embryo developmental potential.

Recombinant FSH vs. urinary FSH for ovarian stimulation in in vitro fertilization

OBJECTIVE

To compare ovarian stimulation with recombinant FSH (rFSH) vs. urinary FSH (uFSH) in terms of hormonal events within ovarian follicles and the outcome of in vitro fertilization.

STUDY DESIGN

A prospective randomized comparative study of rFSH (n = 70) vs. uFSH (n = 61) ovarian stimulation. Hormone determinations were serum estradiol (E2) on the day of human chorionic gonadotropin (hCG) administration, and E2, androstenedione (A) and testosterone (T) at the time of follicular aspiration in the follicular fluid and serum.

RESULTS

The total dose of gonadotropins required and the length of ovarian stimulation were the same in the 2 groups. In follicular fluid the E2 and the A levels were significantly higher in the rFSH group (3,065 +/- 1,646 vs. 2,368 +/- 1,240 nmol/L, P = .004, and 103.7 +/- 51.6 vs. 89.0 +/- 42.3 nmol/L, P = .042, respectively), whereas A:E2 and T:E2 ratios were significantly lower (39.6 +/- 22.5 vs. 52.3 +/- 59.6, P = .042, and 9.1 +/- 4.7 vs. 17.6 +/- 26.9, P = .006, respectively). Serum hormonal levels, number of oocytes retrieved and pregnancy rates did not differ significantly between the groups.

CONCLUSION

rFSH provides results similar to those of uFSH. rFSH enhances steroidogenesis and provokes different androgen/estrogen ratios than does uFSH without influencing the outcome of in vitro fertilization.

Successful freezing and thawing of blastocysts cultured in sequential media using a modified method

OBJECTIVE

To evaluate the clinical role of blastocyst freezing and thawing after prolonged culturing in sequential media.

DESIGN

Retrospective analysis of 293 blastocyst freeze-thawing cycles.

SETTING

University hospital infertility unit.

PATIENT(S)

Nonselected couples undergoing IVF.

INTERVENTION(S)

Blastocysts were frozen and thawed by a modified method.

MAIN OUTCOME MEASURES

Blastocyst recovery after freeze-thawing and pregnancy rates after the transfer. Evaluation of the effect of the number of transferred blastocysts, the method of IVF, and of the woman's age on the results achieved by frozen-thawed blastocysts.

RESULT(S)

Frozen-thawed blastocysts provided a 29.5% clinical pregnancy rate per transfer. After the transfer of three blastocysts the pregnancy rate was 42.0%, and after the transfer of one or two blastocysts it was approximately the same (25.0% and 28.0%, respectively). The method of IVF did not affect pregnancy rates, but the increasing age of the woman did. Pregnancies were characterized by a low abortion rate (8.0%) regardless of the age of the woman.

CONCLUSION(S)

A modified method for blastocyst freeze-thawing provides good clinical results. It offers the possibility for a single-thawed blastocyst transfer and represents a good alternative for older women because of its lower risk of spontaneous abortion.

Blastocyst formation--good indicator of clinical results after ICSI with testicular spermatozoa

BACKGROUND

The aim of this study was to evaluate the role of blastocyst culture in patients with azoospermia.

METHODS

In 98 cycles embryos were cultured for 2 days and in 128 cycles for 5 days to reach the blastocyst stage; a maximum of two of the most developed embryos were transferred in each group.

RESULTS

There was a negative correlation between a high (>/=20 IU/l) male serum FSH and embryo development, manifested as embryos not reaching the morula stage on day 5 (r = 0.387; P < 0.05). After prolonged culture, 23% of embryos reached the blastocyst stage. The pregnancy rates per transfer, and the abortion rates were approximately the same in the day 2 group and the day 5 group (20 versus 20% and 19 versus 18% respectively). After blastocyst transfer, a high clinical pregnancy rate (55%) and a low abortion rate (6%) were achieved, whereas the transfer of arrested embryos provided a low pregnancy rate (2%) and a high abortion rate (100%). If only blastocysts had been transferred on day 5, the clinical pregnancy rate per started cycle would have been approximately the same in both groups (13 versus 16%).

CONCLUSIONS

Blastocyst formation is a good indicator of clinical results after ICSI with testicular sperm.

Sperm single-stranded DNA, detected by acridine orange staining, reduces fertilization and quality of ICSI-derived embryos

PURPOSE

The aim of this study was to evaluate the effect of sperm single-stranded DNA, detected by acridine orange (AO), and classical sperm parameters on embryonic quality after ICSI.

METHODS

Before ICSI, the spermatozoa of 183 infertile patients with oligo-, astheno-, teratozoospermia (n = 147), or more than one previous unsuccessful conventional IVF attempt (n = 36) were stained by AO to assess the presence of single-stranded DNA. Two days after ICSI, the embryos of 135 patients were scored for morphology, fragmentation included. Embryos of 48 couples were cultured for 4 days to develop to the morula or blastocyst stage. At most 2 embryos were transferred on Day 2 or 4.

RESULTS

When the level of spermatozoa with single-stranded DNA was increased, there was a significantly lower fertilization rate after ICSI. Besides, increased sperm single-stranded DNA resulted in a higher proportion of heavily fragmented embryos on Day 2 (P < 0.05). In patients with an increased level of spermatozoa with single-stranded DNA, a significantly higher number of embryos were arrested in spite of prolonged culturing (P < 0.05). Classical sperm parameters did not affect the quality and developmental potential of ICSI-derived embryos. No correlation was found between the level of spermatozoa with single-stranded DNA, pregnancy rate, and live-birth rate achieved by ICSI, except in patients with 0% of spermatozoa with single-stranded DNA, in whom the pregnancy rate was significantly higher.

CONCLUSIONS

Sperm single-stranded DNA provides additional data on sperm functional capacity in terms of fertilization and embryonic quality after ICSI.

Intra- and inter-individual variability in human sperm concentration, motility and vitality assessment during a workshop involving ten laboratories

The aim of the present study was to assess variability in the evaluation of human sperm concentration, motility and vitality. Technicians and biologists from 10 teams involved in multicentre studies on semen quality attended the same laboratory, each team using its own methods and equipment to analyse the same semen samples. Inter-individual variability was assessed from 17 fresh semen samples of varying quality. Intra-individual variability was assessed from pools of frozen samples for sperm concentration and motility and stained smears for vitality with three blind evaluations by sample and smear. The mean inter-individual coefficients of variation were 22.9, 21.8 and 17.5% for sperm concentration, motility and vitality respectively. There was no statistical difference among participants for sperm concentration assessment, but significant differences for both motility and vitality (both P: < 0.05). The mean intra-individual coefficients of variation were 15.8, 26.2 and 13.1% for sperm concentration, motility and vitality respectively, with marked differences between expert and novice participants: concentration 9.8% versus 28.0%; motility 22.8% versus 33.0%; and vitality 10.0% versus 19.3%. The present data confirm the need for external quality control schemes for diagnostic purposes, and indicate their utmost importance in multicentre studies on semen quality.

Semen granulocyte elastase: its relevance for the diagnosis and prognosis of silent genital tract inflammation

Elastase-inhibitor complex was assessed by immunoassay in the seminal plasma of 312 men attending the outpatient infertility clinic. Using receiver operating characteristic (ROC) curve analysis, elastase at the cut-off value of > or =290 ng/ml was shown to be efficient (sensitivity 79.5%, specificity 74.4%) in the detection of genital tract inflammation as defined by leukocytospermia (>1x10(6) leukocytes/ml). The prevalence of increased elastase in 292 infertile men was significantly higher (34%) as compared with that (5%) observed in 20 fertile men (P: = 0.02). Moreover, high elastase concentration (> or =290 ng/ml) was observed in 66 of the 264 men (25%) without leukocytospermia. A significant positive correlation was found between elastase concentration and patient age (r = 0.202, P: < 0.0001) and the number of leukocytes (r = 0.330, P: < 0.0001). A negative correlation was found between elastase concentration and semen volume (r = -0.146, P: = 0.01) and the percentage of spermatozoa with single-stranded DNA (r = -0.194, P: = 0.024), but there was no correlation between elastase and sperm reactive oxygen species production. A higher seminal elastase concentration was significantly associated with tubal damage in female partners (P: < 0.001). After norfloxacine antibiotic therapy, decrease in elastase concentration was observed in 15 (25%) of the 60 treated patients. Tubal damage in the partner negatively affected the response to antibiotic therapy. In conclusion, granulocyte elastase is a reliable screening test for silent genital tract inflammation of the couple. The elastase-inhibitor complex may have a protective effect in reducing sperm DNA denaturation.

Fuzzy logic alternative for analysis in the biomedical sciences

Fuzzy logic brings new possibilities into control, modeling, data analysis, diagnostics, decision making, and other working fields in biomedical sciences. This paper presents how fuzzy logic can be used as an alternative or supplement to statistics in biomedical analysis. It shows an adaptive neuro-fuzzy inference computing in comparison with linear and curvilinear regression. The main goal of this presentation is to involve fuzzy logic in biomedical research. Thus, we carried out a mathematical treatment of the clinical sample, semen of infertile man, with the independent variable Concentration of spermatozoa and the dependent variable Number of spermatozoa by 230 observations.

Semen quality changes among 2343 healthy Slovenian men included in an IVF-ET programme from 1983 to 1996

To determine whether semen quality in Slovenians has changed over 14 years (1983-96), we analysed retrospectively the semen of 2343 healthy men with a normal spermiogram, who were partners of women with tubal infertility included in the IVF-ET programme. Age at semen collection, duration of sexual abstinence, semen volume, sperm concentration, total sperm count, percentage of spermatozoa with progressive motility, and normal morphology were determined. Multiple regression analysis was used to assess the changes in sperm characteristics according to the year of semen collection, year of the man's birth and the duration of sexual abstinence. Semen volume, sperm concentration, sperm count and total sperm motility did not change between 1983 and 1996, whereas between 1988 and 1996 rapid progressive sperm motility decreased by 0.95% per year (p < 0.0001). Semen volume, sperm concentration, and sperm count increased with duration of sexual abstinence. After adjustment for the year of semen collection and duration of sexual abstinence, multiple regression analysis showed that sperm concentration decreased by 0.67% per each successive year of birth (p = 0.03). Thus the sperm concentration decreased from 87.6 x 10(6)/mL in men born in the 1940s to 77.3 x 10(6)/mL in those born between 1956 and 1960. After 1960, sperm concentration was found to increase. In 2343 healthy men, no decline in semen quality, except in rapid progressive motility, was observed in the study period. Lower sperm concentration was found among men born between 1950 and 1960. This could be related to worse socio-economic status, stress or negative environmental factors in this time period.