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Cell Condensation (cell + condensation)
Selected AbstractsO-10 Endometrial cells in cervical smears: cytological features associated with clinically significant endometrial pathologyCYTOPATHOLOGY, Issue 2007R. N. Tiam Introduction:, To establish the significance of cytological features which could predict clinically significant endometrial pathology, and therefore guide reporting practice in cervical samples. Methods:, A retrospective review of SurePath liquid-based cytology (LBC) cervical samples between 2002 and 2006, obtained at screening and colposcopy. These smears contained normal endometrial cells present at inappropriate times of the menstrual cycle, endometrial cells with atypia (borderline change) and with features suspicious / diagnostic of endometrial carcinoma (glandular neoplasia). False negative and false positive cases detected on subsequent histology were also included. The control group comprised negative samples and a few abnormal smears. All smears were randomly assigned and blinded to menopausal status, age, use of oral contraceptive pill and hormone replacement therapy and presence of intrauterine device. Each smear was reviewed for 16 cytologic criteria and a cytological diagnosis was given for each. Results:, A total of 219 smears were available for review; 137 were negative, out of which 85 contained normal endometrial cells, 41 contained endometrial cells with atypia, 10 contained endometrial cells with features suggestive of adenocarcinoma and 31 contained endometrial cells with features diagnostic of adenocarcinoma. The feature most associated with benign endometrial cells is top hat with central cell condensation. In contrast, the features associated with malignant endometrial cells are smooth nuclear membrane, pale chromatin, small nucleoli and scalloped borders. Discussion:, The criteria identified in this study do not definitively define a neoplastic process, but appear to be helpful in individual cases. This study emphasises that endometrial changes should be always interpreted with the relevant clinical information, which would otherwise lead to overdiagnosis in premenopausal women. [source] Vascular regression is required for mesenchymal condensation and chondrogenesis in the developing limbDEVELOPMENTAL DYNAMICS, Issue 3 2001Melinda Yin Abstract Vascular regression occurs during limb mesenchymal cell condensation and chondrogenesis, but it is unclear whether it is required for these processes or is a secondary phenomenon without major regulatory roles. To address this issue, beads presoaked with the potent angiogenic factor vascular endothelial growth factor (VEGF) were implanted in the vicinity of the prospective digit 2 in early chick embryo wing buds and the effects on angiogenesis and digit development were determined over time. We found that VEGF treatment caused a marked local increase in blood vessel number and density. Strikingly, this was accompanied by inhibition of digit 2 development as revealed by lack of expression of chondrogenic transcription factor Sox9 and absence of Alcian blue staining. Vascular distribution and skeletal development in adjacent areas remained largely unaffected. Inhibition of digit formation and excess vascularization were both reversible upon further embryonic growth and dissipation of VEGF activity. When supernumerary digits were induced at the anterior limb margin by retinoic acid treatment, their development was also preceded by vascular regression; interestingly, cotreatment with VEGF inhibited supernumerary digit development as well. Direct exposure of limb mesenchymal cells in micromass cultures to VEGF caused no obvious effects on condensation and chondrogenesis, indicating that VEGF effects are not due to direct action on skeletal cells. Our results are the first to provide evidence that vascular regression is required for mesenchymal condensation and chondrogenesis. A model of how patterning mechanisms and vascular regression may intersect and orchestrate limb skeletogenesis is proposed. © 2001 Wiley-Liss, Inc. [source] rBMP represses Wnt signaling and influences skeletal progenitor cell fate specification during bone repairJOURNAL OF BONE AND MINERAL RESEARCH, Issue 6 2010Steve Minear Abstract Bone morphogenetic proteins (BMPs) participate in multiple stages of the fetal skeletogenic program from promoting cell condensation to regulating chondrogenesis and bone formation through endochondral ossification. Here, we show that these pleiotropic functions are recapitulated when recombinant BMPs are used to augment skeletal tissue repair. In addition to their well-documented ability to stimulate chondrogenesis in a skeletal injury, we show that recombinant BMPs (rBMPs) simultaneously suppress the differentiation of skeletal progenitor cells in the endosteum and bone marrow cavity to an osteoblast lineage. Both the prochondrogenic and antiosteogenic effects are achieved because rBMP inhibits endogenous ,-catenin-dependent Wnt signaling. In the injured periosteum, this repression of Wnt activity results in sox9 upregulation; consequently, cells in the injured periosteum adopt a chondrogenic fate. In the injured endosteum, rBMP also inhibits Wnt signaling, which results in the runx2 and collagen type I downregulation; consequently, cells in this region fail to differentiate into osteoblasts. In muscle surrounding the skeletal injury site, rBMP treatment induces Smad phosphorylation followed by exuberant cell proliferation, an increase in alkaline phosphatase activity, and chondrogenic differentiation. Thus different populations of adult skeletal progenitor cells interpret the same rBMP stimulus in unique ways, and these responses mirror the pleiotropic effects of BMPs during fetal skeletogenesis. These mechanistic insights may be particularly useful for optimizing the reparative potential of rBMPs while simultaneously minimizing their adverse outcomes. © 2010 American Society for Bone and Mineral Research [source] Bone morphogenetic protein-2 modulation of chondrogenic differentiation in vitro involves gap junction-mediated intercellular communicationJOURNAL OF CELLULAR PHYSIOLOGY, Issue 2 2002Wei Zhang Undifferentiated mesenchymal cells in the limb bud integrate a complex array of local and systemic signals during the process of cell condensation and chondrogenic differentiation. To address the relationship between bone morphogenetic protein (BMP) signaling and gap junction-mediated intercellular communication, we examined the effects of BMP-2 and a gap junction blocker 18 alpha glycyrrhetinic acid (18,-GCA) on mesenchymal cell condensation and chondrogenic differentiation in an in vitro chondrogenic model. We find that connexin43 protein expression significantly correlates with early mesenchymal cellular condensation and chondrogenesis in high-density limb bud cell culture. The level of connexin43 mRNA is maximally upregulated 48 h after treatment with recombinant human BMP-2 with corresponding changes in protein expression. Inhibition of gap junction-mediated intercellular communication with 2.5 ,M 18,-GCA decreases chondrogenic differentiation by 50% at 96 h without effects on housekeeping genes. Exposure to 18,-GCA for only the first 24,48 h after plating does not affect condensation or later chondrogenic differentiation suggesting that gap junction-mediated intercellular communication is not critical for the initial phase of condensation but is important for the onset of differentiation. 18,-GCA can also block the chondrogenic effects of BMP-2 without effects on cell number or connexin43 expression. These observations demonstrate 18,-GCA-sensitive regulation of intercellular communication in limb mesenchymal cells undergoing chondrogenic differentiation and suggest that BMP-2 induced chondrogenic differentiation may be mediated in part through the modulation of connexin43 expression and gap junction-mediated intercellular communication. J. Cell. Physiol. 193: 233,243, 2002. © 2002 Wiley-Liss, Inc. [source] Immunocytochemical Detection of Synaptophysin in Enteric Neurones during Prenatal Development in the Rat StomachANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 3 2004M. Asar Summary In this study, the localization and appearance of synaptophysin-immunoreactive (IR) nerve cells and their relationships with the developing gastric layers were studied by immunocytochemistry and light microscopy in the embryonic rat stomach. The stomachs of Wistar rat embryos aged 13,21 days were used. The first neuronal bodies and their processes containing synaptophysin-immunoreactivity were observed on embryonic day 13. In contrast, synaptophysin-IR nerve terminals were first observed between mesenchymal cells on embryonic day 14. These results indicate that synaptophysin is expressed in growing neurits and neuronal cell bodies before these neurones have established synaptic connections. The occurrences of mesenchymal cell condensation near synaptophysin-IR neuroblasts on embryonic day 15 reflect an active nerve element-specific mesenchymal cell induction resulting in the morphogenesis of muscle cells. Similarly, the appearance of glandular structures after synaptophysin-IR neuroblasts, on embryonic day 18, suggests that the epithelial differentiation may be closely related to the neuronal maturation as well as other factors. Finally, synaptophysin is functionally important in neuronal development and maturation, together with the establishment of neuroneuronal and neuromuscular contacts and in epithelial differentiation. [source] | |||||||||||||