The migration and loss of human primordial germ stem cells from the hind gut epithelium towards the gonadal ridge.

Human primordial germ cells (PGCs) can be recognized in the yolk sac wall, from 3-4 weeks post conception (wpc), in the hind gut epithelium from week 4 and in the gonadal area from early week 5. The objective of this study was to map the migration route of PGCs and elucidate the role of the nervous system in this process. Sixteen human specimens, 5-14 wpc obtained from legal abortions were included.

Primary cilia and aberrant cell signaling in epithelial ovarian cancer.

Background: Ovarian cancer is the fourth leading cause of cancer-related deaths among women in Denmark, largely due to the advanced stage at diagnosis in most patients. Approximately 90% of ovarian cancers originate from the single-layered ovarian surface epithelium (OSE). Defects in the primary cilium, a solitary sensory organelle in most cells types including OSE, were recently implicated in tumorigenesis, mainly due to deregulation of ciliary signaling pathways such as Hedgehog (Hh) signaling.

YKL-40 is differentially expressed in human embryonic stem cells and in cell progeny of the three germ layers.

The secreted glycoprotein YKL-40 participates in cell differentiation, inflammation, and cancer progression. High YKL-40 expression is reported during early human development, but its functions are unknown. Six human embryonic stem cell (hESC) lines were cultured in an atmosphere of low or high oxygen tension, in culture medium with or without basic fibroblast growth factor, and on feeder layers comprising mouse embryonic fibroblasts or human foreskin fibroblasts to evaluate whether hESCs and their progeny produced YKL-40 and to characterize YKL-40 expression during differentiation.

Germ cell numbers in human embryonic and fetal gonads during the first two trimesters of pregnancy: analysis of six published studies.

Background: The number of germ cells in human embryonic and fetal ovaries in relation to age is currently based on volumetric estimations from one study including a total of 12 ovaries. Six recent publications present stereological estimations of the number of germ cells in ovaries and testes for the first two trimesters.

Methods: Germ cell numbers from 103 human first and second trimester gonads aged 37-133 days post-conception (p.

Paternal smoking habits affect the reproductive life span of daughters.

The present study assessed whether the smoking habits of fathers around the time of conception affected the period in which daughters experienced menstrual cycles (i.e., the reproductive life span).

No evidence for the presence of oogonia in the human ovary after their final clearance during the first two years of life.

Background: Conflicting results of studies on mouse and human have either verified or refuted the presence of oogonia/primordial germ cells in the post-natal ovary. The aim of this study was to trace whether oogonia recognized by immunohistochemical methods in the first trimester human ovary were present also in peri- and post-natal ovaries.

Methods: For this study, 82 human ovaries were collected: 25 from embryos from 5 to 10 weeks post conception (wpc), 2 at 18 wpc, 32 from 32 wpc to 2 years and 23 from 2 to 32 years.

Proliferation of germ cells and somatic cells in first trimester human embryonic gonads as indicated by S and S+G2+M phase fractions.

Objectives: The number of germ cells and somatic cells in human embryonic and foetal gonads has previously been estimated by stereological methods, which are time- and labour-consuming with little information concerning cell proliferation. Here, we studied whether flow cytometry could be applied as an easier method, also enabling estimation of the fraction of cells in S or S+G(2)+M (SG(2) M) cell-cycle phases as indicators of cell proliferation.

Methods: Cell suspensions from 35 human embryonic gonads at days 37 to 68 post-conception (pc) were immunomagnetically sorted into C-KIT positive (germ) cells and negative (somatic) cells.

The ovulation pattern during three consecutive menstrual cycles has a significant impact on pregnancy rate and sex of the offspring.

Identification of the ovary at the time of ovulation during three consecutive menstrual cycles results in one of eight ovulation patterns, left-left-right, right-left-right, left-right-right, and right-right-right of right-sided ovulation and right-right-left, left-right-left, right-left-left, and left-left-left of left-sided ovulation. Our data suggest that IVF and IUI treatment in cycles in which development of the preovulatory follicle(s) occurs in the right-sided ovary-and ovulations took place from the left-sided ovary in the preceding two cycles (left-left-right)-is likely to show the best pregnancy potential and high offspring sex ratio.

Cryopreservation of ovarian tissue for a decade in Denmark: a view of the technique.

This paper presents the Danish 10-year experience (1999-2009) with cryopreservation (n=386) and autotransplantation of ovarian tissue (n=18). Before applying the technique to humans, the method was thoroughly tested and validated. The cryoprotectant solution was chosen after histological evaluation of mouse and human ovarian tissue after freezing with four different combinations of cryoprotectants.

Isolation of pre-antral follicles from human ovarian medulla tissue.

Background: Cryopreservation of ovarian tissue for fertility preservation is based on the ovarian cortex that contains the vast majority of the follicular reserve, while the remaining tissue, the medulla is discarded. The present study describes the development of a gentle method for isolating pre-antral follicles from human ovarian medulla and evaluating its follicular content.

Methods: Medulla was collected from 40 girls/women aged 3-35 years undergoing cryopreservation of the ovarian cortex.

In human granulosa cells from small antral follicles, androgen receptor mRNA and androgen levels in follicular fluid correlate with FSH receptor mRNA.

Human small antral follicles (diameter 3-9 mm) were obtained from ovaries surgically removed for fertility preservation. From the individual aspirated follicles, granulosa cells and the corresponding follicular fluid were isolated in 64 follicles, of which 55 were available for mRNA analysis (24 women). Expressions of androgen receptor (AR) mRNA levels in granulosa cells, and of androstenedione and testosterone in follicular fluid, were correlated to the expression of the FSH receptor (FSHR), LH receptor (LHR), CYP19 and anti-Müllerian Hormone-receptor II (AMHRII) mRNA in the granulosa cells and to the follicular fluid concentrations of AMH, inhibin-B, progesterone and estradiol.

Cigarette smoking during early pregnancy reduces the number of embryonic germ and somatic cells.

Background: Cigarette smoking during pregnancy is associated with negative reproductive consequences for male fetuses in adult life such as reduced testicular volume and sperm concentration. The present study evaluates the number of germ and somatic cells present in human embryonic first-trimester gonads in relation to maternal smoking.

Methods: The study includes 24 human first-trimester testes, aged 37-68 days post-conception, obtained from women undergoing legal termination of pregnancy.

Human primordial germ cells migrate along nerve fibers and Schwann cells from the dorsal hind gut mesentery to the gonadal ridge.

The aim of this study was to investigate the spatiotemporal development of autonomic nerve fibers and primordial germ cells (PGCs) along their migratory route from the dorsal mesentery to the gonadal ridges in human embryos using immunohistochemical markers and electron microscopy. Autonomic nerve fibers in the dorsal mesentery, the pre-aortic and para-aortic plexuses and in the gonadal ridge were stained for beta III tubulin, neuron specific enolase and the glia fibrillary acidic protein. Electron microscopy demonstrated the presence of neurofilaments and neurotubules in these nerve fibers and their intimate contact with PGCs.

Concentrations of AMH and inhibin-B in relation to follicular diameter in normal human small antral follicles.

Background: The aim of the present study was to determine the intrafollicular concentrations of anti-Müllerian hormone (AMH), inhibin-B and steroids in normal human small antral follicles and to relate them to follicular size.

Methods: A group of 103 women having one ovary removed for fertility preservation by cryopreservation prior to gonadotoxic treatment served as a source of a total of 272 human small antral follicles. Prior to cryopreservation of the ovarian cortex, fluid from small antral follicles were collected.

The number of oogonia and somatic cells in the human female embryo and fetus in relation to whether or not exposed to maternal cigarette smoking.

Background: Prenatal exposure to maternal cigarette smoking or compounds of cigarette smoke is associated with serious reproductive hazards such as apoptotic death of oogonia in murine offspring and decreased fecundability in human offspring. The present study addresses potential effects of in utero exposure to cigarette smoking.

Methods: Twenty-nine human first-trimester ovaries from legal abortions [aged 38-64 days post-conception (p.

Anti-Müllerian hormone in pregnant women in relation to other hormones, fetal sex and in circulation of second trimester fetuses.

The aim of this study was to investigate the regulation of anti-Müllerian hormone (AMH) blood concentrations in mother and fetus during pregnancy. Serum concentrations of AMH, gonadotrophins, oestradiol and progesterone were measured in pregnant women in the first trimester and AMH concentrations in second-trimester fetuses, and these were compared in relation to the sex of the fetus. A total of 153 women undergoing elective termination of a first-trimester pregnancy and seven second-trimester pregnant women undergoing cordocentesis were included.

Age determination enhanced by embryonic foot bud and foot plate measurements in relation to Carnegie stages, and the influence of maternal cigarette smoking.

Background: Reliable age determination of first-trimester human embryos and fetuses is an important parameter for clinical use and basic science. Age determination by ultrasound or morphometric parameters of embryos 4-6 weeks post conception (p.c.

Two successful pregnancies following autotransplantation of frozen/thawed ovarian tissue.

Background: Cryopreservation of the ovarian cortex with subsequent autotransplantation has, on an experimental basis, been performed to preserve fertility in women being treated for a malignant disease. The present study reports ovarian activity and pregnancies following autotransplantation of frozen/thawed ovarian tissue.

Methods: One complete ovary was cryopreserved from each of six patients who were 26-35 years old prior to treatment.

Concentration of anti-Müllerian hormone and inhibin-B in relation to steroids and age in follicular fluid from small antral human follicles.

Context: Ovaries surgically removed for fertility preservation served as a source of follicle fluid from human small antral follicles.

Objective: The objective of the study was to measure intrafollicular concentrations of anti-Müllerian Hormone (AMH), inhibin-B, progesterone, androstenedione, testosterone, estradiol, and IGF binding protein-4.

Setting: The study was conducted at a university hospital.

Human embryonic stem cells in culture possess primary cilia with hedgehog signaling machinery.

Human embryonic stem cells (hESCs) are potential therapeutic tools and models of human development. With a growing interest in primary cilia in signal transduction pathways that are crucial for embryological development and tissue differentiation and interest in mechanisms regulating human hESC differentiation, demonstrating the existence of primary cilia and the localization of signaling components in undifferentiated hESCs establishes a mechanistic basis for the regulation of hESC differentiation. Using electron microscopy (EM), immunofluorescence, and confocal microscopies, we show that primary cilia are present in three undifferentiated hESC lines.

Human immature oocytes grow during culture for IVM.

Background: Oocyte competence for maturation and embryogenesis is associated with diameter in many mammals. We aimed to test whether this relationship exists in humans and to quantify its impact upon in vitro maturation (IVM).

Methods: We used computer-assisted image analysis daily to measure average diameter, zona thickness and other parameters in oocytes.

Evaluation in mammalian oocytes of gene transcripts linked to epigenetic reprogramming.

The mature mammalian metaphase II (MII) oocyte has a unique ability to reprogram sperm chromatin and support early embryonic development. This feature even extends to the epigenetic reprogramming of a terminally differentiated cell nucleus as observed in connection with somatic cell nuclear transfer. Epigenetic nuclear reprogramming is highly linked to chromatin structure and includes covalent modifications of DNA and core histone proteins as well as reorganization of higher-order chromatin structure.

Regional differences in expression of specific markers for human embryonic stem cells.

Characterization of human embryonic stem cell (hESC) lines derived from the inner cell masses of blastocysts generally includes expression analysis of markers such as OCT4, NANOG, SSEA3, SSEA4, TRA-1-60 and TRA-1-81. Expression is usually detected by immunocytochemical staining of entire colonies of hESC, using one colony for each individual marker. Four newly established hESC lines showed the expected expression pattern and were capable of differentiating into the three germ layers in vitro.