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Results 251 - 300 of 2169
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Crawford Laura A - - 2009
The factors necessary for normal pancreatic islet morphogenesis have not been well characterized. Here we report that connective tissue growth factor (CTGF) is involved in the establishment of normal islet endocrine cell ratio and architecture. CTGF is a secreted protein known to modulate several growth factor-signaling pathways including TGF-beta, BMP, ...
Greiner Thomas U - - 2009
BACKGROUND: Pancreatic islets of Langerhans originate from endocrine progenitors within the pancreatic ductal epithelium. Concomitant with differentiation of these progenitors into hormone-producing cells such cells delaminate, aggregate and migrate away from the ductal epithelium. The cellular and molecular mechanisms regulating islet cell delamination and cell migration are poorly understood. Extensive ...
Morgan Noel G - - 2009
This chapter describes a method to measure the viability of isolated intact islets of Langerhans from rat pancreas and considers the use of isolated islets and of pancreatic beta-cell lines to study cell viability following culture. The islet isolation method is based on the use of preparations of collagenase to ...
Shen H-C Jennifer - - 2009
The von Hippel-Lindau (VHL) syndrome is a pleomorphic familial disease characterized by the development of highly vascularized tumors, such as hemangioblastomas of the central nervous system, pheochromocytomas, renal cell carcinomas, cysts and neuroendocrine tumors of the pancreas. Up to 75% of VHL patients are affected by VHL-associated pancreatic lesions; however, ...
Granicka L H - - 2009
Living cells encapsulated in polymeric shells are receiving increasing attention because of their possible biotechnological and biomedical applications. The aim of this work is to evaluate how different polyelectrolyte coatings, characterized by different numbers of polyelectrolyte layers and by different polyelectrolyte conformations, affect the viability of encapsulated biological material. We ...
Bulur Nurdan - - 2009
BACKGROUND/AIMS: The expression of the electrogenic Na+-HCO3--cotransporter NBCe1 was recently documented in rat pancreatic islet B-cells, it being speculated that such a protein participates in the extrusion of bicarbonate generated by the oxidative catabolism of nutrients from insulin-producing cells. Considering the prevalence of a Crabtree effect in tumoral insulin-producing cells, ...
Delisle Juliette Cuvelier - - 2009
BACKGROUND: Pancreatic duodenal homeobox-1 (Pdx-1) or Pdx-1-VP16 gene transfer has been shown to induce in vitro rat liver-stem WB cell conversion into pancreatic endocrine precursor cells. High glucose conditions were necessary for further differentiation into functional insulin-producing cells. Pdx-1 has the ability to permeate different cell types due to an ...
Li Wan-Chun - - 2009
Transdifferentiation is defined as an irreversible switch in postnatal life of one differentiated cell to another. Transdifferentiation from different cellular origins into pancreatic-like beta-cells is of clinical significance since this approach may offer a potential cure for diabetes. In order to achieve this goal, the liver is considered as a ...
Cousin Beatrice - - 2009
BACKGROUND: Normal tissue homeostasis is maintained by dynamic interactions between epithelial cells and their microenvironment. Disrupting this homeostasis can induce aberrant cell proliferation, adhesion, function and migration that might promote malignant behavior. Indeed, aberrant stromal-epithelial interactions contribute to pancreatic ductal adenocarcinoma (PDAC) spread and metastasis, and this raises the possibility ...
Cabrera-Vásquez Siraam - - 2009
BACKGROUND: Pancreatic islets are not fully developed at birth and it is not clear how they are vascularised and innervated. Nerve Growth Factor (NGF) is required to guide sympathetic neurons that innervate peripheral organs and also in cardiovascular system and ovary angiogenesis. Pancreatic beta cells of a transgenic mouse that ...
Muller Dany - - 2009
Studies of gene expression by different islet endocrine cell populations can provide useful information about signal transduction cascades regulating alpha-, beta- and delta-cell function. Experiments on expression of beta-cell gene products are relatively easy to perform in rodent islets as these islets are readily isolated at high purities from the ...
Miller Kevin - - 2009
The islet of Langerhans is a unique micro-organ within the exocrine pancreas, which is composed of insulin-secreting beta-cells, glucagon-secreting alpha-cells, somatostatin-secreting delta-cells, pancreatic polypeptide-secreting PP cells and ghrelin-secreting epsilon-cells. Islets also contain non-endocrine cell types such as endothelial cells. However, the mechanism(s) of islet formation is poorly understood due to ...
Savinov Alexei Y - - 2009
The pathogenesis of type 1 diabetes begins with the activation of autoimmune T killer cells and is followed by their homing into the pancreatic islets. After penetrating the pancreatic islets, T cells directly contact and destroy insulin-producing beta cells. This review provides an overview of the dynamic interactions which link ...
Yu, Jun
Abstract Background LIM-only 4 (LMO4), a member of the LIM-only (LMO) subfamily of LIM domain-containing transcription factors, was initially reported to have an oncogenic role in breast cancer. We hypothesized that LMO4 may be related to pancreatic carcinogenesis as it is in breast carcinogenesis. If so, this could result in ...
Seeberger Karen L - - 2009
Pancreatic mesenchymal stem cells (MSCs) may be derived from human beta-cells undergoing reversible epithelial-mesenchymal transition (EMT), suggesting that they could be a potential source of new beta-cells. In this study we sought to determine the origin of pancreatic MSCs in the nonendocrine pancreas. Double immunofluorescent (IF) staining and flow cytometry ...
Silva A I - - 2009
A system for vascular hollow fiber bio-artificial pancreas development, optimization and in vitro testing was implemented and operated in a simple and fully described manner, allowing other researchers to test a variety of experimental conditions (different biomaterials, biologic tissue, addition of proteins or other adjuvants). In this work, a polysulfone ...
Zhang S - - 2008
AIM: To investigate the influence of trichostatin A (TSA) on inhibition of cell proliferation and induction of apoptosis in human pancreatic cancer cells. METHODS: MTT-based cytotoxicity assay was used to evaluate the cell viability after treatment with TSA. Cell cycle distribution and apoptosis were examined by means of flow cytometry. ...
Jiang Zhi - - 2008
Both endocrine and exocrine pancreatic cells arise from pancreatic-duodenal homeobox 1 (pdx1)-positive progenitors. The molecular mechanisms controlling cell fate determination and subsequent proliferation, however, are poorly understood. Unlike endocrine cells, less is known about exocrine cell specification. We report here the identification and characterization of a novel exocrine cell determinant ...
Schrader Henning - - 2009
BACKGROUND & AIMS: Chronic pancreatitis (CP) often leads to the development of diabetes. To understand better this pathogenic mechanism, we investigated whether islet cell area and pancreatic volume are reduced in CP patients, islet cell turnover increases in CP patients, and islet cells are less vulnerable to apoptosis than acinar ...
Liu Zhiyong - - 2009
gammadelta-T cells can recognize and kill malignant cells, particularly those of epithelial origin, through mechanisms which do not require the recognition of tumor-specific antigens (innate immune response). This natural ability of gammadelta-T cells to kill tumor cells in a tumor antigen-independent manner provides a strong rationale for developing clinical trials ...
Hinault C - - 2008
One of the major challenges for developmental biologists and investigators in the field of diabetes over the last few decades has been to dissect the origin of pancreatic endocrine cells and to accurately understand the mechanisms that regulate islet cell regeneration. While significant advances have been made recently, there continues ...
Miyatsuka Takeshi - - 2008
Islet cell implantation and pancreas transplantation have been used as treatments for diabetes but are limited by the shortage of donors and the requirement for lifelong immunosuppression. As an alternative, the generation of surrogate insulin-producing cells has been an area of interest for many researchers. Understanding how pancreatic beta-cells are ...
Lucini C - - 2008
Glial cell line-derived neurotrophic factor (GDNF) acts through RET receptor tyrosine kinase and its co-receptor GFRalpha1. In an effort to better understand the possible biological contribution of the GDNF and GFRalpha1/RET complex in pancreatic development, in this study we report the cellular localization of these proteins in the pancreas of ...
Eberhard D D Centre for Regenerative Medicine, Department of Biology & Biochemistry, University of Bath, Bath, - - 2008
We describe an explant culture system to study the formation of pancreatic-type endocrine cells by the biliary tract. In this model, beta-cells and other endocrine cells appear in the biliary duct epithelium and their number increases. Evidence for an origin from the duct epithelium is threefold. Firstly, differentiating cells transiently ...
Gittes George K - - 2009
Pancreatic development represents a fascinating process in which two morphologically distinct tissue types must derive from one simple epithelium. These two tissue types, exocrine (including acinar cells, centro-acinar cells, and ducts) and endocrine cells serve disparate functions, and have entirely different morphology. In addition, the endocrine tissue must become disconnected ...
Veenstra Jan A - - 2008
Regulatory peptides were immunolocalized in the midgut of the fruit fly Drosophila melanogaster. Endocrine cells were found to produce six different peptides: allatostatins A, B and C, neuropeptide F, diuretic hormone 31, and the tachykinins. Small neuropeptide-F (sNPF) was found in neurons in the hypocerebral ganglion innervating the anterior midgut, ...
Yang F - - 2009
AIM AND METHODS: Recurrent pancreatitis is a common complication of severe hypertriglyceridaemia (HTG) often seen in patients carrying various gene mutations in lipoprotein lipase (LPL). This study investigates a possible pathogenic mechanism of cell damage in isolated mouse pancreatic acinar cells and of pancreatitis in LPL-deficient and in wild type ...
Hamada Shin - - 2009
We previously reported that bone morphogenetic protein (BMP)-4 induces epithelial-mesenchymal transition in a pancreatic cancer cell line. To further investigate the detailed molecular mechanism of BMP action in pancreatic cancer, we carried out comprehensive microarray analysis in Panc-1 cells. The microarray analysis elucidated novel BMP target genes, and among them, ...
Wang Y - - 2009
BACKGROUND AND AIMS: Recurrent pancreatitis is a common complication of severe hypertriglyceridaemia in patients with various gene mutations in lipoprotein lipase (LPL) or apolipoprotein CII. However, the exact pathogenetic mechanism has not yet been defined. METHODS: Susceptibility to pancreatitis in LPL-deficient mice was compared with that of wild-type mice after ...
Islam Diana - - 2009
Both Epac and PKA are effectors of the second messenger cAMP. Utilizing an exchange protein directly activated by cAMP (Epac) pathway-specific cAMP analog (ESCA), we previously reported that Epac signaling regulates proglucagon gene (gcg) expression in the glucagon-like peptide-1 (GLP-1)-producing intestinal endocrine L-cell lines GLUTag and STC-1. We now show ...
Lavine Jeremy A - - 2008
Type 1 and type 2 diabetes result from a deficit in insulin production and beta-cell mass. Methods to expand beta-cell mass are under intensive investigation for the treatment of type 1 and type 2 diabetes. We tested the hypothesis that cholecystokinin (CCK) can promote beta-cell proliferation. We treated isolated mouse ...
Bonal Claire - - 2009
The pancreatic mass is determined by the coordinated expansion and differentiation of progenitor cells and is maintained via tight control of cell replacement rates. The basic helix-loop-helix transcription factor c-Myc is one of the main regulators of these processes in many organs. We studied the requirement of c-Myc in controlling ...
Liang Tao - - 2008
BACKGROUND: The pathogenesis of acute pancreatitis is complex and largely unclear. The aim of this study was to explore the relationship between modes of cell death in pancreatic acinar cells, the release of cell contents and the inflammatory response of macrophages. METHODS: Our experiment included four groups: group A (the ...
Misfeldt, Amanda Ackermann
MOLECULAR PHYSIOLOGY AND BIOPHYSICS THE ROLE OF FOXM1 IN PANCREATIC BETA CELL MASS REGENERATION AND EXPANSION AMANDA ACKERMANN MISFELDT Dissertation under the direction of Maureen Gannon, Ph.D. The size of an organisms â cell population, or â cell mass, and its functional capacity are important determinants of glucose homeostasis. In ...
Nunes Paula - - 2008
Vasopressin (VP)-induced exocytosis was dissected in native and aquaporin-2 (AQP2)-expressing renal LLC-PK(1) cells by a fluorimetric exocytosis assay based on soluble secreted yellow fluorescent protein (ssYFP). YFP was targeted to the secretory pathway by addition of an 18-amino acid signal peptide from hen egg white lysozyme. Immunofluorescence labeling, together with ...
Mendes Rosa Maria Marcos - - 2009
The main purpose of this study was to evaluate the regional distribution pattern and relative frequency of some endocrine cells in the three portions of the gastrointestinal tract (GIT)--the proventriculus, gizzard and duodenum- of the rufous-collared sparrow (Zonotrichia capensis subtorquata), by immunohistochemical methods using six types of polyclonal antisera, specific ...
Ichii Hirohito H Cell Transplant Center, Diabetes Research Institute, University of Miami Leonard M. Miller School of Medicine, Miami, FL 33136, USA. - - 2008
Substantial amounts of nonendocrine cells are implanted as part of human islet grafts, and a possible influence of nonendocrine cells on clinical islet transplantation outcome has been postulated. There are currently no product release criteria specific for nonendocrine cells due to lack of available methods. The aims of this study ...
Nyaga Simon G - - 2008
Elevated levels of oxidatively induced DNA lesions have been reported in malignant pancreatic tissues relative to normal pancreatic tissues. However, the ability of the pancreatic cancer cells to remove these lesions has not previously been addressed. This study analyzed the effectiveness of the pancreatic cancer cell line, BxPC-3 to repair ...
Fontanière Sandra - - 2008
Mutations of the multiple endocrine neoplasia type 1 (MEN1) gene predispose patients to MEN1 that affects mainly endocrine tissues, suggesting important physiological functions of the gene in adult endocrine cells. Homozygous disruption of Men1 in mice causes embryonic lethality, whereas the eventual involvement of the gene in embryonic development of ...
Xu J - - 2008
Pyruvate carboxylase (PC) or pyruvate dehydrogenase (PDH) is required to transfer carbons from pyruvate into the Krebs cycle. PC activity is preserved in the islets of obese animals, but it is reduced in the islets of animal models of type 2 diabetes, suggesting that PC is important in beta cell ...
Ronnebaum Sarah M - - 2008
We have previously demonstrated a role for pyruvate cycling in glucose-stimulated insulin secretion (GSIS). Some of the possible pyruvate cycling pathways are completed by conversion of malate to pyruvate by malic enzyme. Using INS-1-derived 832/13 cells, it has recently been shown by other laboratories that NADP-dependent cytosolic malic enzyme (MEc), ...
Nakhai Hassan - - 2008
Recent studies have shown that Wnt/beta-catenin signaling is essential for development of the exocrine pancreas, but the role of beta-catenin-dependent target genes such as Myc during pancreatic development is not well known. Here, we show that tissue-specific deletion of Myc causes a slightly accelerated differentiation of pancreatic epithelial cells into ...
Chan Christina - - 2008
In current literature there is evidence that psychological factors can affect the incidence and progression of some cancers. Data obtained from animal models support the hypothesis that stress can be a cofactor. The underlying mechanisms for the association between psychological factors and pancreatic cancer are very poorly understood. In this ...
Fernandes Tiago G - - 2008
We have developed an immunofluorescence-based assay for high-throughput analysis of target proteins on a three-dimensional cellular microarray platform. This process integrates the use of three-dimensional cellular microarrays, which should better mimic the cellular microenvironment, with sensitive immunofluorescence detection and provides quantitative information on cell function. To demonstrate this assay platform, ...
Rapoport Daniel H - - 2009
Glandular stem cells (GSCs) can be obtained from exocrine glands such as pancreas or salivary glands using well-established cell culturing methods. The resulting cell populations are characterized by a high proliferative capacity and an unusually high plasticity. Cells from pancreas have been demonstrated to differentiate into a multitude of cell ...
Park Hyung Seo - - 2008
Calcium release through inositol (1,4,5)-trisphosphate receptors (InsP(3)R) is the primary signal driving digestive enzyme and fluid secretion from pancreatic acinar cells. The type 2 (InsP(3)R2) and type 3 (InsP(3)R3) InsP(3)R are the predominant isoforms expressed in acinar cells and are required for proper exocrine gland function. Both InsP(3)R2 and InsP(3)R3 ...
Wang Chun-You - - 2008
Pancreatic progenitor cells represent both a potential source of transplantable islets for the treatment of diabetes and a valuable instrument for the investigation of the tumorigenesis of pancreatic carcinoma. It has been reported that pancreatic ductal cells of adults have the characteristics of pancreatic progenitors, but whether these cells can ...
Miyagi Taeko - - 2008
Mammalian sialidases, glycosidases responsible for the removal of sialic acids from glycoproteins and glycolipids, has been implicated to participate in many biological processes as well as in lysosomal catabolism. Among those forms identified to date, plasma membrane-associated sialidase, Neu3, is a key enzyme in degradation of gangliosides, for which it ...
Tahara Junko - - 2008
OBJECTIVES: We have previously reported that pancreatic stellate cells (PSCs) have a phagocytic function. The aim of the present study was to investigate whether engulfment of necrotic acinar cells affects pancreatic fibrogenesis. METHODS: Rat pancreatic acinar cells were incubated for 48 hours to induce necrosis, and PSCs were allowed to ...
Termsuknirandorn Saewadee - - 2008
OBJECTIVE: To test the hypothesis that hypofunction/recovered occlusal function has no effect on the changes in insulin-like growth factor-1 (IGF-1) and IGF-1 receptor expressions and cell proliferation of periodontal ligament (PDL) cells. MATERIALS AND METHODS: To produce occlusal hypofunction, the appliances were attached to the rats' maxillary and mandibular incisors. ...
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