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Editorial: Tissue Repair and Regenerative Mechanisms by Stem/Progenitor Cells and Their Secretome
Full text linkTissue Repair and Regenerative Mechanisms by Stem/Progenitor Cells and Their Secretome
Regenerative medicine is a branch of translational research which is energizing and empowering clinical practice. A multitude of novel approaches proposed during the recent years is slowly but dramatically transforming the health care system, harnessing the power of repairing, replacing, restoring, and regenerating human organs and tissues affected by various degenerative disorders and diseases.
During the twentieth century, hundreds of thousands of patients with end-stage diseases have been rescued by solid organ transplants as ultimate treatment option. In the past 3 decades, cell-based therapies have been gaining importance since they can contribute to regeneration of failing organs or damaged tissues by direct replacement of the lost cells or by facilitating the body’s natural regenerative processes by removing roadblocks. A growing armamentarium of therapeutic options, spanning from bioartificial organs and tissues, stem and progenitor cells, biomaterials, cell secretome, and extracellular vesicles have become available as medical treatments substituting the standard pharmaceutics.
Examples of “classical” cellular therapies are peripheral blood stem cell or stromal cell transplantations, and more recently, allogenic hepatocyte or pancreatic islet transplants.
While pancreas transplantation remains the gold standard in diabetes patients where the insulin injection fails to control symptoms, transplantation of islets of Langerhans has been recognized as a successful cell-based treatment in type 1 diabetes. The mechano-enzymatic separation of endocrine tissue from the exocrine pancreatic parenchyma required several decades to become a standardized clinical approach approved by Medical Product Agencies worldwide
Translation of amnion stem cells to the clinic
No full textCellular therapy for liver disease has been available in the clinic for more than 20 years, yet remarkably few patients receive this experimental therapy. Reasons for the small number of transplants performed are partially related to access to useful liver tissue and the difficulty with the isolation of viable cells. Stem cell sources of hepatocytes could theoretically relieve these obstacles to therapy if large numbers of functional hepatocytes could be generated and transplanted without risk of tumorigenicity. To date, there are no reports of stem cell sources with all of these characteristics, despite claims otherwise. Here we report the results of preclinical studies with appropriate animals models of metabolic liver disease and acute liver failure, and their correction by the transplantation of human amnion epithelial stem cells. The encouraging results of the preclinical studies have motivated the movement of isolation and banking of these cells to good manufacturing practice conditions so that the cells can be used in the clinic for transplantation of patients with liver disease
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Isolation of amniotic mesenchymal stem cells
No full textMesenchymal stem cells (MSCs) have the ability to differentiate into osteocytes, chondrocytes, and adipocytes and possess immunomodulatory properties. Amniotic membrane from human term placenta is a potential source of multipotent MSCs that could be useful for regenerative medicine. This unit describes a detailed and simple protocol for the isolation of amniotic mesenchymal cells. We also introduce a simple density separation technique for the purification of this cell type from possible contamination with amniotic epithelial cells
Human placental stem cell transplant lengthens survival and corrects a murine model of a human metabolic liver disease
No full textVariations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Melatonin expresses powerful anti-inflammatory and antioxidant activities resulting in complete improvement of acetic-acid-induced colitis in rats
No full textIntroduction: Increased free-radical production, decreased antioxidant capacity, and excessive inflammation are well-known features in the pathogenesis of inflammatory bowel disease. Melatonin is a powerful antioxidant and a scavenger of hydroxyl radicals. Melatonin has also been shown to have anti-inflammatory activities in tissues. Our study objective is to investigate the effects of melatonin on tissue inflammatory activities using an ulcerative colitis (UC) model induced by acetic acid (AA) in rats. Methods: Wistar rats (n = 32) were divided into four groups. AA-induced colitis was performed in two of the groups, while the other two groups were injected with saline intrarectally. One of the AA-induced colitis groups and one of the control groups were administered 100 mg/kg/day melatonin intraperitoneally, and the pair groups were given saline. After 4 days, colonic changes were evaluated biochemically by measuring proinflammatory cytokines [tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6], myeloperoxidase (MPO), malondialdehyde (MDA), glutathione (GSH), and superoxide dismutase (SOD) levels in tissue homogenates and by histopathological examination. Results: AA caused colonic mucosal injury, whereas melatonin suppressed these changes in the AA-induced colitis group (P < 0.001). AA administration resulted in increased TNF-α, IL-1β, IL-6, MPO, and MDA levels, and decreased GSH and SOD levels, whereas melatonin administration reversed these effects (all P < 0.001). Conclusions: The present study proposes that melatonin has a dual action as an effective anti-inflammatory and an antioxidant, and may be a hopeful therapeutic agent for UC
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