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.

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).

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.

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.

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.

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.

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.

Morphometric characteristics of the primordial to primary follicle transition in the human ovary in relation to age.

Background: The growth pattern of the smallest ovarian follicles in humans is still incompletely documented. Using follicle hemispheres in thick histological sections, morphometric changes of primordial to primary follicles and possible age-related effects were evaluated.

Methods: In ovarian sections from 25 females aged 4-39 years a total of 1122 primordial, transitory or primary follicles were assessed for the diameters of follicles, oocytes and oocyte nuclei and for number of granulosa cells (GCs).

Expression and localization of the progesterone receptor in mouse and human reproductive organs.

The effects of gonadotropins on progesterone receptor (PR) expression and localization in the mouse oviduct, uterus, and ovary was examined. In the oviduct ciliated epithelial cells of adult mice and human revealed a unique PR localization to the lower half of the motile cilia whereas the nuclei were unstained or faintly stained. Pubertal female mice were further studied by confocal laser scanning microscopy and western blotting before and after injection with FSH and LH followed by human chorionic gonadotropin (hCG) injection after a 48-h period.

Estradiol and regulation of anti-Müllerian hormone, inhibin-A, and inhibin-B secretion: analysis of small antral and preovulatory human follicles' fluid.

Context: In ovaries surgically removed for fertility preservation, hormone concentrations in fluid from small antral follicles were determined. Levels were compared with those found in preovulatory follicular fluid.

Objective: The objective of this study is to measure intrafollicular concentrations of anti-Müllerian hormone (AMH), inhibin-A, inhibin-B, estradiol, and progesterone.

Ovulation jumping from the left to the right ovary in two successive cycles may increase the chances of pregnancy during intrauterine insemination and/or in vitro fertilization natural cycles.

Identification of the ovary from which ovulation takes place in two consecutive menstrual cycles results in one of four ovulation patterns, contralateral and ipsilateral ovulations on the right or on the left ovary. Our data suggest that IVF and IUI treatment in cycles in which development of the dominant follicle occurs in the right-sided ovary--and ovulation took place from the left-sided ovary in the preceding cycle (contralateral right-sided ovulation)--is likely to show the best pregnancy outcome.

Eggs forever?

A group of scientists from Harvard Medical School (Johnson et al., 2004) claims to have "established the existence of proliferative germ cells that sustain oocyte and follicle production in the postnatal mammalian ovary," expressing no doubts about their methods, results and conclusion. Johnson et al.

Expression of IGF-II mRNA-binding proteins (IMPs) in gonads and testicular cancer.

Insulin-like growth factor-II mRNA-binding proteins 1, 2 and 3 (IMP1, IMP2 and IMP3) belong to a family of RNA-binding proteins implicated in mRNA localization, turnover and translational control. We examined their expression pattern during development of murine and human testis and ovaries. In the mouse, IMPs were expressed in male and female gonadal cells at embryonic day 12.

Localization of transient receptor potential ion channels in primary and motile cilia of the female murine reproductive organs.

We have examined the subcellular localization of transient receptor potential (TRP) ion channels and the potential sensory role of cilia in murine female reproductive organs using confocal laser scanning microscopy analysis on ovary and oviduct tissue sections as well as on primary cultures of follicular granulosa cells. We show that the Ca2+ permeable cation channel, polycystin-2, as well as polycystin-1, a receptor that forms a functional protein complex with polycystin 2, distinctively localize to primary cilia emerging from granulosa cells of antral follicles in vivo and in vitro. Both polycystins are localized to motile oviduct cilia and this localization is greatly increased upon ovulatory gonadotropic stimulation.

Stem cell factor and c-Kit in human primordial germ cells and fetal ovaries.

The distribution of the tyrosine kinase receptor c-Kit and its ligand stem cell factor (SCF) was evaluated by immunohistochemistry in primordial germ cells (PGCs) and human embryonic gonads during weeks 5-8 of prenatal life, and fetal ovaries during weeks 9-36 of prenatal life. Distinct c-Kit and SCF staining was present in primordial germ cells in the wall of the hindgut and in the dorsal mesentery, particularly on level with the 10th thoracic columnar segment. Several PGCs were in close contact with c-Kit-negative but SCF-positive autonomic nerve fibers of the dorsal mesentery.