The developmental analysis of an embryonic lethal (C6H) in the mouse.
(25/1114)
A development study of the effects of the C6H allele at the albino locus has identified the C6H homozygote as an early postimplantation lethal. Homozygous C6H embryos can first be recognized at 6 1/2-7 days of gestation by abnormalities of the ectoplacental and parietal endodern. At 7 1/2 days, mutant embryos appear severely retarded with obvious abnormalities in all germ layers. All C6H homozygotes are dead and resorbed by 8 days of development. It is proposed that the mutation interferes with the normal differentiation of the parietal endoderm, ectoplacental cone and extra-embryonic ectoderm of the egg cyclinder. (+info)
Histological characteristics of canine deciduoma induced by intrauterine inoculation of E. coli suspension.
(26/1114)
Canine deciduoma could be induced in the diestrous uterus by an intrauterine inoculation of a culture suspension of E. coli originally isolated from naturally occurring canine pyometra. These deciduomas had the same histological findings as those of naturally occurring canine pyometra with so called "Swiss cheese endometrium". This suggests a possibility that the canine pyometra is a kind of naturally occurring decidual reaction (deciduoma) induced by one of several triggers such as bacterial infection. (+info)
"Mesenchymal tumor" or "decidual-like reaction"?
(27/1114)
For more than 40 yr, an unusual urinary bladder lesion has been known to occur in certain strains of mice, but no consensus has been obtained regarding its etiology, pathogenesis, biology, or classification. The lesion was first assumed to be epithelial and non-neoplastic, then it was called a smooth muscle cell tumor or leiomyosarcoma because of ultrastructural characteristics for smooth muscle cells. Later, the nonspecific term "mesenchymal tumor" was introduced due to histomorphologic differences from all smooth muscle tumors known. Recently, a proposal was made to name it "decidual-like reaction" because of the histomorphologic similarity to the rare spontaneous decidual reaction in the uterus of aging mice. Both lesions are characterized by spindle and large pleomorphic epithelioid cells with large bizarre nuclei; these characteristics mimic anaplasia of malignant tumors and led pathologists to assume a neoplastic nature. The decidual hypothesis is supported by the regular presence of nuclear progesterone receptors, the occasional occurrence of eosinophilic cytoplasmic granules, the rare finding of cells morphologically resembling granulated metrial gland cells (all also observed in the uterine decidual reaction), and the reproducibility through long-term feeding of combinations of estrogens and progestogens. It appears that the new decidual hypothesis can explain many detailed facets of the lesion, with the exception of the reported smooth muscle cell characteristics. The controversy of "mesenchymal tumor versus decidual-like reaction" should be resolved soon, not only as a scientific issue, but also because of consequences for risk assessment. (+info)
Human decidual stromal cells express alpha-smooth muscle actin and show ultrastructural similarities with myofibroblasts.
(28/1114)
Previous reports in human and mouse material demonstrated that decidual stromal cells expressed antigens associated with haematopoietic cells, exerted immune functions, and originated from bone marrow. These findings suggested that these cells belonged to the haematopoietic lineage. We purified and expanded in culture precursors of human decidual stromal cells, and found in electron microscopic images that the ultrastructure of these cells was similar to that of myofibroblasts, which are of mesenchymal origin. The relationship between these two types of cell was confirmed by the detection (by flow cytometry) in the decidual precursors of alpha-smooth muscle actin, a contractile microfilament expressed solely by smooth muscle cells, myofibroblasts and related cells. This filament was also detected in decidual stromal cells decidualized in vitro by the effect of progesterone. We also found vimentin in decidual precursors and decidualized cells. This intermediate filament has been previously reported to be expressed by all decidual stromal cells and also by myofibroblasts. Desmin, another intermediate filament expressed by myofibroblasts, was not detected in the decidual precursors; however, this filament was observed in decidualized cells. The expression of alpha-smooth muscle actin by decidual stromal cells was also found by immunostaining in cryostat sections of early decidua. Our results suggest that decidual stromal cells are related to myofibroblasts. (+info)
Increased blood vessel density in decidua parietalis is associated with spontaneous human first trimester abortion.
(29/1114)
Spontaneous pregnancy loss affects 15-18% of couples, and a number of potential causes are being discussed. The purpose of the present study was to assess if angiogenic disorders in the decidua of early human pregnancy could be related to spontaneous abortions. First trimester human decidua from elective terminations of normally progressing pregnancies and from missed abortions were investigated immunohistochemically. We quantified vessel density in decidua from normal pregnancies and from abortions by von Willebrand factor (vWF), platelet endothelial cell adhesion molecule (PECAM-1) and CD34 staining. Decidual blood vessel expression of alphavbeta3 integrin was also investigated. Significant increase (P < 0.02) in vessel density was observed in decidua parietalis of abortions, compared to decidua basalis. This increase was detected on slides stained for vWF and CD34, but not for PECAM-1. We observed a 15% increase analysing with vWF and a 77% increase with CD34 staining. alphavbeta3 integrin expression was not significantly different, neither in decidua parietalis from abortion, nor parietalis from normal pregnancies. Our data suggest that the increased vascularization in decidua parietalis from abortions could reflect complex disorders, such as specific cytokine expressions and hypoxia phenomena during the development of the decidua. (+info)
Role of decidual natural killer (NK) cells in patients with missed abortion: differences between cases with normal and abnormal chromosome.
(30/1114)
In order to study the mechanism of abortion, the proportions of NK cells in the peripheral blood and decidual lymphocytes were evaluated in both chromosomally normal and abnormal missed abortions. In normal pregnancy, CD56+16-3- NK cells are a major element of decidual lymphocytes. The percentages of CD56+16-3-NK cells of peripheral lymphocytes in normal pregnancies were not statistically significantly different from those of chromosomally normal and abnormal abortions. In the decidua, the percentages of CD56+16-3- NK cells of decidual lymphocytes showed no statistically significant differences between normal pregnancies and chromosomally abnormal abortions. However, the percentages of CD56+16-3-NK cells of chromosomally normal abortions were lower than those of chromosomally abnormal (P = 0.0025). Moreover, the percentages of CD56+16- NK cells in abortions with normal chromosomes were lower than those in normal pregnancies or abortions with abnormal chromosomes (P = 0.0037, P = 0.0025). However, when the proportion of CD56+ NK cells expressing CD16 was evaluated, there were no statistically significant differences in the percentages of CD56+16+ NK cells in normal pregnancies and missed abortions with normal chromosomes and abnormal chromosomes. We conclude that the expression of decidual CD56+16-3- NK cells in missed abortions with normal chromosomes is different from abortions with abnormal chromosomes and that this phenomenon may depend on an abnormal immune response of the maternal side. (+info)
Transcription factors Ets1, Ets2, and Elf1 exhibit differential localization in human endometrium across the menstrual cycle and alternate isoforms in cultured endometrial cells.
(31/1114)
To better understand the transcriptional regulation of human endometrial remodeling, the localization of three members of the Ets family of transcription factors was examined at different stages of the menstrual cycle. Elf1 was found by immunohistochemistry to be predominantly localized to the glandular epithelium. In contrast, Ets1 and Ets2 were found at lower intensities in both glandular epithelial and stromal cells. Low expression during the menstrual phase of the cycle, and high expression and intensity of staining in decidualized stromal cells of the late secretory phase were common to Ets1, Ets2, and Elf1. These localization patterns were confirmed in cultured human endometrial stromal and epithelial cells by Western blotting, which also demonstrated different isoforms and phosphorylation products of Ets1 and Ets2 in the two cell types. This study has shown for the first time that members of the Ets family of transcription factors, previously found predominantly during development and in hematopoietic cells, are expressed in the human endometrium and display cell and cycle-stage specificity. Expression of Elf1 predominantly in the glandular epithelium may indicate that Elf1 plays a unique role in epithelium-specific gene regulation in the endometrium. (+info)
Progesterone regulation of epidermal growth factor receptor in rat decidua basalis during pregnancy.
(32/1114)
Ovarian steroid hormones and epidermal growth factor (EGF) play important interactive roles in proliferation and decidualization of mesometrial stromal cells during pregnancy. This study determined the ontogeny of EGF receptor (EGF-R) expression in the decidua basalis (DB) throughout pregnancy and its regulation by estrogen and progesterone (P4). DB were isolated from rats between Days 8-21 of pregnancy and prepared for immunohistochemistry or Western analysis. In one study, rats were ovariectomized (Ovx) on Day 8 or 9 and given estradiol-17beta, P4, or both. In another study, the antiprogestin, mifepristone (RU-486), was administered on Day 9. During normal pregnancy, total EGF-R (phosphorylated and unphosphorylated forms) increased from Day 8 to a maximum level on Days 10 and 12. Tyrosine-phosphorylated EGF-R (pEGF-R), the bioactive form, was also highest on Days 10 and 12. Both forms of receptor decreased to almost undetectable levels during DB regression on Days 17-21. Immunohistochemistry of DB from Ovx rats revealed that only P4 was able to maintain normal expression of EGF-R; RU-486 decreased EGF-R expression within 6 h, and by 24 h EGF-R and pEGF-R were 15% of the Day 10 control group levels. These findings show that EGF-R is a P4-dependent protein associated with stromal cell proliferation and decidualization. (+info)