Search results for "differentiation"
showing 10 items of 1605 documents
Heterogeneity of Stem Cells in the Thyroid
2019
Identification of thyroid stem cells in the past few years has made important contributions to our understanding of the cellular and molecular mechanisms that induce tissue regeneration and repair. Embryonic stem (ES) cells and induced-pluripotent stem cells have been used to establish reliable protocols to obtain mature thyrocytes and functional follicles for the treatment of thyroid diseases in mice. In addition, the discovery of resident thyroid progenitor cells, along with other sources of stem cells, has defined in detail the mechanisms responsible for tissue repair upon moderate or severe organ injury.In this chapter, we highlight in detail the current state of research on thyroid ste…
An Automatic Differentiation Based Approach to the Level Set Method
2015
This paper discusses an implementation of the parametric level set method. Adjoint approach is used to perform the sensitivity analysis, but contrary to standard implementations, the state problem is differentiated in its discretized form. The required partial derivatives are computed using tools of automatic differentiation, which avoids the need to derive the adjoint problem from the governing partial differential equation. The augmented Lagrangian approach is used to enforce volume constraints, and a gradient based optimization method is used to solve the subproblems. Applicability of the method is demonstrated by repeating well known compliance minimization studies of a cantilever beam …
Natural nest-sites of Great Tits (Parus major) in a primeval temperate forest (Białowieża National Park, Poland)
2015
Knowledge of the breeding ecology of the Great Tit Parus major is vast, but almost exclusively concerns birds using nest-boxes. Information on birds nesting in natural conditions is scant. Here, we present the results of the first thorough study on natural nest-sites of the Great Tit. The data, including descriptions of nest-cavity location and dimensions, were collected during 39 breeding seasons in the primeval forest of Bialowieza National Park (BNP), Poland. With an excess of available tree-cavities providing a diverse choice of nesting options, Great Tits nested mainly in non-excavated, very deep and spacious cavities with elongated, narrow openings, placed at intermediate heights in l…
The expression level of the orphan nuclear receptor GCNF (germ cell nuclear factor) is critical for neuronal differentiation.
2004
The germ cell nuclear factor (GCNF) is essential for normal embryonic development and gametogenesis. To test the prediction that GCNF is additionally required for neuronal differentiation, we used the mouse embryonal carcinoma cell line PCC7-Mz1, which represents an advantageous model to study neuronal cells from the stage of fate choice until the acquirement of functional competence. We generated stable transfectants that express gcnf sense or antisense RNA under the control of a tetracycline-regulated promoter. After retinoic acid-induced withdrawal from the cell cycle, sense clones developed a neuron network with changed properties, and the time course of neuron maturation was shortened.…
Perlecan is critical for heart stability
2008
Aims Perlecan is a heparansulfate proteoglycan found in basement membranes, cartilage, and several mesenchymal tissues that form during development, tumour growth, and tissue repair. Loss-of-function mutations in the perlecan gene in mice are associated with embryonic lethality caused primarily by cardiac abnormalities probably due to hemopericards. The aim of the present study was to investigate the mechanism underlying the early embryonic lethality and the pathophysiological relevance of perlecan for heart function. Methods and results Perlecan-deficient murine embryonic stem cells were used to investigate the myofibrillar network and the electrophysiological properties of single cardiomy…
Reconstruction of Endometrium from Human Endometrial Side Population Cell Lines
2011
Endometrial regeneration is mediated, at least in part, by the existence of a specialized somatic stem cell (SSC) population recently identified by several groups using the side population (SP) technique. We previously demonstrated that endometrial SP displays genotypic, phenotypic and the functional capability to develop human endometrium after subcutaneous injection in NOD-SCID mice. We have now established seven human endometrial SP (hESP) cell lines (ICE 1-7): four from the epithelial and three from the stromal fraction, respectively. SP cell lines were generated under hypoxic conditions based on their cloning efficiency ability, cultured for 12-15 passages (20 weeks) and cryopreserved.…
Ultramicro-trauma in the endometrial-myometrial junctional zone and pale cell migration in adenomyosis
2015
Objective To determine if ultrastructural tissue trauma occurs in the junctional zone in uteri in adenomyosis. Design A case-control experimental study. Setting Endometriosis research center. Patient(s) Twelve uteri with adenomyosis, and 9 uteri without adenomyosis, were gained during laparoscopy-assisted vaginal hysterectomy. Intervention(s) Transmission electron microscopic study of the junctional zone, as well as immunohistochemical staining for epithelial cadherin, and van Gieson staining and immunofluorescence for CD45 and CD68. Main Outcome Measure(s) Analysis of the electron microscopy photos and the immunoreactive scores of the staining. Result(s) The inner myometrial muscle fibers …
Presence of endothelial progenitor cells, distinct from mature endothelial cells, within human CD146+ blood cells.
2006
SummaryCD146 is an adhesion molecule present on endothelial cells throughout the vascular tree. CD146 is also expressed by circulating endothelial cells (CECs) widely considered to be mature endothelial cells detached from injured vessels. The discovery of circulating endothelial progenitor cells (EPCs) originating from bone marrow prompted us to investigate whether CD146 circulating cells could also contains EPCs. We tested this hypothesis using an approach combining elimination of CECs by an adhesion step, followed by immunomagnetic sorting of remaining CD146+ cells from the non adherent fraction of cord blood mononuclear cells. When cultured under endothelial-promoting conditions, these …
Quantification of vesicles in differentiating human SH-SY5Y neuroblastoma cells by automated image analysis
2005
A new automated image analysis method for quantification of fluorescent dots is presented. This method facilitates counting the number of fluorescent puncta in specific locations of individual cells and also enables estimation of the number of cells by detecting the labeled nuclei. The method is here used for counting the AM1-43 labeled fluorescent puncta in human SH-SY5Y neuroblastoma cells induced to differentiate with all-trans retinoic acid (RA), and further stimulated with high potassium (K+) containing solution. The automated quantification results correlate well with the results obtained manually through visual inspection. The manual method has the disadvantage of being slow, labor-i…
New cell lines of gastric and pancreatic cancer: distinct morphology, growth characteristics, expression of epithelial and immunoregulatory antigens.
1995
Two new cell lines from stomach cancers and one from a pancreatic carcinoma are presented. MZ-GC-1 was established from a hepatic metastasis of a well differentiated gastric adenocarcinoma. MZ-GC-2 was derived from ascites induced by a poorly differentiated gastric adenocarcinoma. MZ-PC-1 originated from the pleural effusion of a moderately well differentiated pancreatic ductal adenocarcinoma. MZ-GC-1 cells were adherent and partially polarized, connected tightly via desmosomes. In contrast MZ-GC-2 cells consisted of slightly adherent or floating subpopulations and displayed no desmosomes. MZ-PC-1 cells were adherent and showed polarized growth, connected by apical junctional complexes. Cel…