Ultrastructural and histochemical observations of neuroendocrine granules in nonneoplastic ovaries

Argyrophil and argentaffin cells are rarely seen in female genital tract structures. Their presence in normal, apparently healthy ovaries has not been reported until the present observation. Histochemical and ultrastructural studies demonstrated cells within the ovaries of two nonpregnant patients in the reproductive age that belong to the neuroendocrine or amine precursor uptake and decarboxylation (APUD) system. The lack of other discernible pathologic conditions suggests that these cells may be normal cellular constituents within the ovaries and lends support to the belief of a neural crest origin for primary ovarian carcinoid not associated with teratomatous or mucinous elements.     

Preliminary studies on apoptosis in human fetal ovaries

OBJECTIVE: To evaluate if apoptosis occurs in human germ cells between 19 and 33 gestational weeks (GW). DESIGN: Human fetal ovaries were obtained from aborted fetuses aged 19-33 GW. SETTING: Rabin Medical Center, a major tertiary care and referral center. PATIENT(S): Twenty-seven women undergoing pregnancy termination. The abortions were mostly because of fetal anatomical or chromosomal abnormalities. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Microscopy studies, terminal deoxynucleotidyl transferase (TdT) assay (TUNEL), and immunocytochemistry for B-cell lymphoma/leukemia-2 (bcl-2). RESULT(S): TUNEL assay revealed a slight increase in apoptotic oocytes in fetuses from 23 GW, with a peak at 27 GW. Overexpression of bcl-2 was detected in all ovarian components, regardless of fetal age. CONCLUSION(S): There seems to be a slight increase in apoptosis in oocytes from 23 GW with a peak at 27 GW. However, it is very unlikely that these low apoptotic rates could be the cause of the extensive germ cell loss throughout human pregnancy. The overexpression of bcl-2 possibly suggests either that this gene is necessary to overcome extensive apoptotic activity or that it is responsible for the low apoptosis rates. However, these results should be considered with caution, since the ovaries were mostly from abnormal fetuses after feticide.     

The ultrastructure of the interstitial cells in human fetal ovaries.

Steroid-active interstitial cells (stromal lutein cells) in human fetal ovaries of 12, 15 and 22 weeks of gestation were studied by means of electron microscope. The large cells, which are predominantly situated in the vicinity of capillaries, show high structural similarity to Leydig cells (type A) of the fetal testis. Both are characterized by extensively development of smooth endoplasmic reticulum, accumulation of lipids, and numerous mitochondria of the tubular type containing osmiophilic inclusions. Whether the interstitial cell system of the fetal ovary has any specific function in developmental physiology of the genital system cannot be decided on the basis of the present results. Its differentiation may only indicate adequate response of competent mesenchymal cells to gonadotropic stimulation.     

Ultrastructural observations of the human uterine smooth muscle cells during gestation

At term pregnancy, the myometrium consists of bundles of smooth muscle cells bound together by varying amounts of connective tissue. Each bundle contains both dark and light muscle cells. During uterine contractions it is believed that the smooth muscle cells become darker, decrease in volume, and exhibit changes in diameter. This is accompanied by widening of the interspaces and by a decrease in the areas of cellular contact. Between contractions, there are more light cells which become arranged closer to each other and exhibit large areas of interdigitation. The significance of these observations in the mechanism of uterine contraction and retraction is discussed. Cells believed to be modified smooth muscle cells occupy the myoendometrial junction and the decidua basalis. They are irregular in shape, poor in myofilament content, and rich in other cytoplasmic organelles and form a loosely arranged layer of cells between the myometrium and the trophoblast. The possible functional significance of these cells is also discussed.     

Ultrastructural evolution of nucleoli of female rat germ cells.

The nucleoli of oogonia and oocytes of rat ovaries during fetal and neonatal life were studied by light and electron microscopy. An evolution from atypical to typical nucleoli was shown. Nucleoli undergo a gradual increase in size and change from dense fibrillar bodies to complete nucleoli with pars fibrosa, pars granulosa, pars amorpha, and associated chromatin.     

Ultrastructural observations on polyspermic penetration of zona pellucida-free human oocytes inseminated in vitro.

An ultrastructural analysis of polyspermic human ova, obtained by insemination in vitro of zona pellucida-free oocytes, has demonstrated the following: 1. Sperm with an intact or reacted acrosome fuse equally well with the oocyte, and the sperm head is incorporated first. Sperm flagellum entry into the ooplasm is accomplished by sliding, while the sperm plasma membrane is being incorporated into the vitelline membrane. 2. Dismantling of the sperm flagellum within the ooplasm rapidly occurs by dispersion and disintegration successively of the mitochondria, the outer dense fibers of the midpiece, and the fibrous sheath of the principal piece. The axial filament complex persists much longer, and can be demonstrated by electron microscopy for 24 hours or more postinsemination. 3. The mode of assembly of the male pronucleus membrane and the incorporation of maternal chromosomes into the female pronucleus. 4. The vital role of the zona pellucida, which appears to be the essential, if not the unique, site of the block to polyspermy.     

Parameters affecting successful transplantation of frozen-thawed human fetal ovaries into immunodeficient mice

OBJECTIVE: To compare the development and survival of human fetal follicles frozen-thawed with dimethylsulfoxide (DMSO) and propandiol (PROH) in immunodeficient mice, to study the effects of host treatment with FSH, and to compare kidney and subcutaneous transplantation. DESIGN: Controlled histologic study. SETTING: Major tertiary care and referral academic center.Twenty-one women undergoing second-trimester pregnancy termination.Microscopic morphometric analysis and immunocytochemistry for proliferating-cell nuclear antigen in human fetal ovaries grafted into immunodeficient mice. RESULTS: Renal grafts that were frozen-thawed with DMSO rather than PROH survived better in the hosts (79.6% compared with 58.8%), but significantly more follicles were identified in grafts frozen-thawed with PROH (P<.001). Follicular development was observed only in FSH-treated hosts, and follicular survival and development was better in the kidney than the subcutaneous site.CONCLUSION(S): This is the first report showing development of human fetal follicles in immunodeficient mice. Freezing-thawing with PROH seems to support development and survival better than with DMSO. The kidney is a better transplantation site than the subcutaneous site, probably because of its superior vascularization. Administration of FSH to the host is essential for follicular development. Follicular development and growth was better in ovarian grafts from older fetuses, as they contained more formed follicles.     

Putative mesenchymal stem cells isolated from adult human ovaries

Purpose

The purpose of this study was to show that healthy adult human ovaries can be a source of cells showing typical MSCs characteristics under in vitro conditions.

Methods and results

The cells, which were isolated from ovarian cortex tissue and named putative ovarian mesenchymal stem cells (PO-MSCs), were compared to bone marrow-derived MSCs (BM-MSCs) and to adult human dermal fibroblasts (HDFs). The results of a gene expression analysis using the Human Mesenchymal Stem Cell RT² Profiler™ PCR Array revealed that PO-MSCs were different than fibroblasts. They expressed most of the analyzed genes as BM-MSCs, although some genes were differentially expressed. However, the heterogeneity of PO-MSCs samples was revealed. The PO-MSCs expressed the characteristic genes related to MSCs, such as CD105, CD44, CD90, M-CAM, CD73 and VCAM1. In addition, the expression of markers CD44, CD90, M-CAM and STRO-1 was confirmed in PO-MSCs using immunocytochemistry. The PO-MSCs showed multipotent character, since they were able to differentiate into the cells of adipogenic, osteogenic, neural and pancreatic lineage.

Conclusions

Healthy adult human ovaries can harbour an interesting population of cells showing typical MSCs characteristics under in vitro conditions and for this reason we named these cells putative MSCs. These cells express genes encoding main MSCs markers and have an interesting differential potential. Based on these results, we propose PO-MSCs as a novel type of MSCs which share some similarities with BM-MSCs. Nevertheless they show distinct and specific characteristics and are not fibroblasts.

Electronic supplementary material

The online version of this article (doi:10.1007/s10815-014-0254-8) contains supplementary material, which is available to authorized users.     

Angiotensin II receptors on human fetal adrenal cells.

OBJECTIVE: Our objective was to determine if angiotensin II receptors are present on adrenal cells isolated from the human fetal zone and neocortex and to investigate if angiotensin II affects steroid production by these cells. STUDY DESIGN: Primary cultures of both fetal zone and neocortex cells were prepared from fetal adrenal glands. Experiments were conducted to examine the binding of radiolabeled angiotensin II, angiotensin II activation of phospholipase C, and angiotensin II effects on steroidogenesis. RESULTS: The majority of angiotensin II binding sites were of the type 1 subtype, as determined by displacement of radiolabeled angiotensin with specific receptor antagonists. Angiotensin II caused an increase in tritiated inositol phosphate accumulation in both neocortex and fetal zone cells. This increase could be blocked by type 1 angiotensin II receptor antagonists. Angiotensin II stimulated the production of cortisol, dehydroepiandrosterone, and dehydroepiandrosterone sulfate production during treatment for 2 days. The stimulation by angiotensin II, however, was substantially less than that seen in response to corticotropin treatment. CONCLUSIONS: The human fetal adrenal gland contains type 1 angiotensin II receptors early in gestation. The number of these receptors, albeit low, is sufficient to activate inositol phosphate production and steroidogenesis.