| U-M study reveals lack of diversity in embryonic stem cell lines
December 16, 2009 at 5:54 pm
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| Stem-cell activators switch function, repress mature cells
December 16, 2009 at 2:35 pm
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| Lung cancer and melanoma laid bare
December 16, 2009 at 2:35 pm
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| Caltech, UCLA launch Joint Center for Translational Medicine
December 16, 2009 at 2:35 pm
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| Cord Blood America Says 2009 Debt Reduction Tops $10 Million
December 16, 2009 at 10:15 am
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| Boston University School of Medicine's pulmonary center receives $1.4 million grant
December 16, 2009 at 10:15 am
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| A new direction for cardiac regeneration therapy: application of synergistically acting epicardium-derived cells and cardiomyocyte progenitor cells.
December 16, 2009 at 9:54 am
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| | A new direction for cardiac regeneration therapy: application of synergistically acting epicardium-derived cells and cardiomyocyte progenitor cells. Circ Heart Fail. 2009 Nov;2(6):643-53 Authors: Winter EM, van Oorschot AA, Hogers B, van der Graaf LM, Doevendans PA, Poelmann RE, Atsma DE, Gittenberger-de Groot AC, Goumans MJ BACKGROUND: Adult human epicardium-derived cells (EPDCs), transplanted into the infarcted heart, are known to improve cardiac function, mainly through paracrine protection of the surrounding tissue. We hypothesized that this effect might be further improved if these supportive EPDCs were combined with cells that could possibly supply the ischemic heart with new cardiomyocytes. Therefore, we transplanted EPDCs together with cardiomyocyte progenitor cells that can generate mature cardiomyocytes in vitro. METHODS AND RESULTS: EPDCs and cardiomyocyte progenitor cells were isolated from human adult atrial appendages, expanded in culture, and transplanted separately or together into the infarcted mouse myocardium (total cell number, 4x10(5)). Cardiac function was determined 6 weeks later (9.4T MRI). Coculturing increased proliferation rate and production of several growth factors, indicating a mutual effect. Cotransplantation resulted in further improvement of cardiac function compared with single cell-type recipients (P<0.05), which themselves demonstrated better function than vehicle-injected controls (P<0.05). However, in contrast to our hypothesis, no graft-derived cardiomyocytes were observed within the 6-week survival, supporting that not only EPDCs but also cardiomyocyte progenitor cells acted in a paracrine manner. Because injected cell number and degree of engraftment were similar between groups, the additional functional improvement in the cotransplantation group cannot be explained by an increased amount of secreted factors but rather by an altered type of secretion. CONCLUSIONS: EPDCs and cardiomyocyte progenitor cells synergistically improve cardiac function after myocardial infarction, probably instigated by complementary paracrine actions. Our results demonstrate for the first time that synergistically acting cells hold great promise for future clinical regeneration therapy. PMID: 19919990 [PubMed - indexed for MEDLINE] |
| Umbilical cord mesenchymal stem cells (UC-MSC: biology, banking and clinical applications).
December 16, 2009 at 9:54 am
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| | Umbilical cord mesenchymal stem cells (UC-MSC: biology, banking and clinical applications). Bull Acad Natl Med. 2009 Mar;193(3):545-7; discussion 547 Authors: Han ZC PMID: 19883009 [PubMed - indexed for MEDLINE] |
| [Gene-stem Cell therapy for ischemic stroke]
December 16, 2009 at 9:54 am
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| | [Gene-stem Cell therapy for ischemic stroke] Brain Nerve. 2009 Sep;61(9):1043-9 Authors: Abe K Besides blood flow restoration, neuroprotection is essential for treating strokes at an acute stage. Both neurotrophic factors (NTFs) and free radical scavengers can act as neuroprotective agents with abilities to inhibit cell death and facilitate cell survival under cerebral ischemia. For example, topical application of glial cell line-derived neurotrophic factor (GDNF) remarkably reduced infarct size and brain edema after middle cerebral artery (MCA) occlusion in rats. Reduction in the infarct size was not found to be related to a change in the cerebral blood flow (CBF), but was accompanied by marked reduction in BrdU-positive cells in the affected area after TdT-mediated dUTP-biotin nick end labeling (TUNEL) for caspses. Thus, GDNF elicited a direct protective effect against ischemic brain damage, but without improving CBF. Sendai virus vectors harboring the GDNF gene led to a remarkable reduction in infract volume without affecting regional CBF but reduced the translocation of apoptosis inducible factor (AIF) from the mitochondria to cytoplasm. Regenerative therapy involving neural stem cells which are intrinsically activated or exogenously transplanted, is an important treatment strategy. To facilitate stem cell migration, an artificial scaffold can be implanted into the injured brain for promoting ischemic brain repair. Addition of NTFs greatly enhanced an intrinsic migration or invasion of stem cells into the scaffold: this strategy could be used in the future for enhancing regenerative potential of brain cells after chronic ischemia-induced brain damage. PMID: 19803403 [PubMed - indexed for MEDLINE] |
| Skeletal muscle stem cells in developmental versus regenerative myogenesis.
December 16, 2009 at 9:54 am
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| | Skeletal muscle stem cells in developmental versus regenerative myogenesis. J Intern Med. 2009 Oct;266(4):372-89 Authors: Tajbakhsh S Tissue and organ regeneration proceed in a coordinated manner to restore proper function after trauma. Vertebrate skeletal muscle has a remarkable ability to regenerate after repeated and complete destruction of the tissue, yet limited information is available on how muscle stem and progenitor cells, and other nonmuscle cells, reestablish homeostasis after the regenerative process. The genetic pathways that regulate the establishment of skeletal muscle in the embryo have been studied extensively, and many of the genes that govern muscle stem cell maintenance and commitment are redeployed during adult homeostasis and regeneration. Therefore, correlates can be made between embryonic muscle development and postnatal regeneration. However, there are some important distinctions between prenatal development and regeneration - in the context of the cells, niche, anatomy and the regulatory genes employed. The similarities and distinctions between these two scenarios are the focus of this review. PMID: 19765181 [PubMed - indexed for MEDLINE] |
| A potentially versatile nucleotide hydrolysis activity of group II chaperonin monomers from Thermoplasma acidophilum.
December 16, 2009 at 9:54 am
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| | A potentially versatile nucleotide hydrolysis activity of group II chaperonin monomers from Thermoplasma acidophilum. Biochemistry. 2009 Oct 13;48(40):9405-15 Authors: Noi K, Hirai H, Hongo K, Mizobata T, Kawata Y Compared to the group I chaperonins such as Escherichia coli GroEL, which facilitate protein folding, many aspects of the functional mechanism of archaeal group II chaperonins are still unclear. Here, we show that monomeric forms of archaeal group II chaperonin alpha and beta from Thermoplasma acidophilum may be purified stably and that these monomers display a strong AMPase activity in the presence of divalent ions, especially Co(2+) ion, in addition to ATPase and ADPase activities. Furthermore, other nucleoside phosphates (guanosine, cytidine, uridine, and inosine phosphates) in addition to adenine nucleotides were hydrolyzed. From analyses of the products of hydrolysis using HPLC, it was revealed that the monomeric chaperonin successively hydrolyzed the phosphoanhydride and phosphoester bonds of ATP in the order of gamma to alpha. This activity was strongly suppressed by point mutation of specific essential aspartic acid residues. Although these archaeal monomeric chaperonins did not alter the refolding of MDH, their novel versatile nucleotide hydrolysis activity might fulfill a new function. Western blot experiments demonstrated that the monomeric chaperonin subunits were also present in lysed cell extracts of T. acidophilum, and partially purified native monomer displayed Co(2+)-dependent AMPase activity. PMID: 19728744 [PubMed - indexed for MEDLINE] |
| Sox2 is dispensable for the reprogramming of melanocytes and melanoma cells into induced pluripotent stem cells.
December 16, 2009 at 9:54 am
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| | Sox2 is dispensable for the reprogramming of melanocytes and melanoma cells into induced pluripotent stem cells. J Cell Sci. 2009 Oct 1;122(Pt 19):3502-10 Authors: Utikal J, Maherali N, Kulalert W, Hochedlinger K Induced pluripotent stem cells (iPSCs) have been derived at low frequencies from different cell types through ectopic expression of the transcription factors Oct4 and Sox2, combined with either Klf4 and c-Myc or Lin28 and Nanog. In order to generate iPSCs more effectively, it will be crucial to identify somatic cells that are easily accessible and possibly require fewer factors for conversion into iPSCs. Here, we show that both human and mouse melanocytes give rise to iPSCs at higher efficiencies than fibroblasts. Moreover, we demonstrate that a mouse malignant melanoma cell line, which has previously been reprogrammed into embryonic stem cells by nuclear transfer, remains equally amenable to reprogramming into iPSCs by these transcription factors. In contrast to skin fibroblasts, melanocytes and melanoma cells did not require ectopic Sox2 expression for conversion into iPSCs. iPSC lines from melanocytic cells expressed pluripotency markers, formed teratomas and contributed to viable chimeric mice with germ line transmission. Our results identify skin melanocytes as an alternative source for deriving patient-specific iPSCs at increased efficiency and with fewer genetic elements. In addition, our results suggest that cancer cells remain susceptible to transcription factor-mediated reprogramming, which should facilitate the study of epigenetic changes in human cancer. PMID: 19723802 [PubMed - indexed for MEDLINE] |
| Collection and culture of alveolar bone marrow multipotent mesenchymal stromal cells from older individuals.
December 16, 2009 at 9:54 am
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| | Collection and culture of alveolar bone marrow multipotent mesenchymal stromal cells from older individuals. J Cell Biochem. 2009 Aug 15;107(6):1198-204 Authors: Han J, Okada H, Takai H, Nakayama Y, Maeda T, Ogata Y In this work, we examined the culture condition of alveolar bone marrow multipotent mesenchymal stromal cells (ABMMSCs), aiming to apply regenerative therapy to older periodontitis patients. To better understand the character of cultured cells from alveolar bone marrow, the expression profiles of well-known genes and their responses to the induction of osteogenic, chondrogenic, or adipogenic differentiation were examined. Using alpha MEM-based culture, ABMMSCs could be obtained from older individuals than in previous reports. Interestingly, ABMMSCs expressing Klf4 were able to differentiate into osteoblasts. The prediction of differentiation potential by Klf4 could be a useful guide for further improvement of the culture conditions required to culture ABMMSCs derived from older individuals. PMID: 19507174 [PubMed - indexed for MEDLINE] |
| Effects of stress shielding and subsequent restressing on mechanical properties of regenerated and residual tissues in rabbit patellar tendon after resection of its central one-third.
December 16, 2009 at 9:54 am
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| | Effects of stress shielding and subsequent restressing on mechanical properties of regenerated and residual tissues in rabbit patellar tendon after resection of its central one-third. J Biomech. 2009 Aug 7;42(11):1592-7 Authors: Maeda E, Asanuma H, Noguchi H, Tohyama H, Yasuda K, Hayashi K Central third of patellar tendon (PT) is used as an autograft for anterior cruciate ligament (ACL) reconstruction. Previous studies investigated temporal changes in material properties of healing tissues in PT after resection of the central third. However, no study has been performed on effects of stress shielding (SS) and restressing (RS) on the properties of healing tissues. The present study hypothesised that SS adversely affects the mechanical integrity of healing tissues, which is recovered by subsequent RS. An entire rectangular defect was created in the central third of rabbit PT. Operated PTs were subjected to either SS or no stress shielding (NSS). A subgroup of stress-shielded PTs was followed by the resumption of normal loading, namely RS. Tensile properties of tissues regenerated in the defect and residual tendons were evaluated. Regenerated tissues of SS for 3 weeks resulted in significantly lower strength than NSS, which was recovered to NSS level by 3 weeks of RS. Strength of residual tissues in RS reversed SS effects, leading to the strength at NSS level after 12 weeks. However, tangent modulus of residual tissues in RS was still significantly lower than that of NSS at 12 weeks. Therefore, SS induces detrimental effects on the mechanical integrity of healing PTs, and the response to RS was different between regenerate and residual tissues, the latter of which took longer period to reach NSS level. PMID: 19486982 [PubMed - indexed for MEDLINE] |
| Tissue engineering therapies for the vocal fold lamina propria.
December 16, 2009 at 9:54 am
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| | Tissue engineering therapies for the vocal fold lamina propria. Tissue Eng Part B Rev. 2009 Sep;15(3):249-62 Authors: Kutty JK, Webb K The vocal folds are laryngeal connective tissues with complex matrix composition/organization that provide the viscoelastic mechanical properties required for voice production. Vocal fold injury results in alterations in tissue structure and corresponding changes in tissue biomechanics that reduce vocal quality. Recent work has begun to elucidate the biochemical changes underlying injury-induced pathology and to apply tissue engineering principles to the prevention and reversal of vocal fold scarring. Based on the extensive history of injectable biomaterials in laryngeal surgery, a major focus of regenerative therapies has been the development of novel scaffolds with controlled in vivo residence time and viscoelastic properties approximating the native tissue. Additional strategies have included cell transplantation and delivery of the antifibrotic cytokine hepatocyte growth factor, as well as investigation of the effects of the unique vocal fold vibratory microenvironment using in vitro dynamic culture systems. Recent achievements of significant reductions in fibrosis and improved recovery of native tissue viscoelasticity and vibratory/functional performance in animal models are rapidly moving vocal fold tissue engineering toward clinical application. PMID: 19338432 [PubMed - indexed for MEDLINE] |
| Technologies for enhancing tissue engineering: materials and environments for guiding stem cell function. Preface.
December 16, 2009 at 9:54 am
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| | Technologies for enhancing tissue engineering: materials and environments for guiding stem cell function. Preface. Tissue Eng Part A. 2009 Feb;15(2):203-4 Authors: Alsberg E, Rowley JA PMID: 19193128 [PubMed - indexed for MEDLINE] |
| Quantification of DNA in biologic scaffold materials.
December 16, 2009 at 9:54 am
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| | Quantification of DNA in biologic scaffold materials. J Surg Res. 2009 Mar;152(1):135-9 Authors: Gilbert TW, Freund JM, Badylak SF Biological scaffold materials composed of extracellular matrix (ECM) are routinely used for a variety of clinical applications ranging from the treatment of chronic skin ulcers to hernia repair and orthopaedic soft tissue reconstruction. The tissues and species from which the ECM is harvested vary widely as do the methods used to remove the cellular component of the source tissues. The efficacy of decellularization procedures can be quantified by examination of the DNA that remains in the ECM. The objective of the present study was to determine the DNA content and fragment length in both laboratory produced and commercially available ECM scaffold materials. Results showed that the majority of DNA is removed from ECM devices but that small amounts remained in most tested materials. PMID: 18619621 [PubMed - indexed for MEDLINE] |
| "tissue engineering"; +79 new citations
December 16, 2009 at 8:08 am
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| 79 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results: "tissue engineering" These pubmed results were generated on 2009/12/16 PubMed, a service of the National Library of Medicine, includes over 15 million citations for biomedical articles back to the 1950's. These citations are from MEDLINE and additional life science journals. PubMed includes links to many sites providing full text articles and other related resources. | | | 
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