|  |  |  | | | | | TE-RegenMed-StemCell feed | | | | | | | | | | | | | | | | | | | Extracellular matrix and heart development. Birth Defects Res A Clin Mol Teratol. 2011 May 25; Authors: Lockhart M, Wirrig E, Phelps A, Wessels A The extracellular matrix (ECM) of the developing heart contains numerous molecules that form a dynamic environment that plays an active and crucial role in the regulation of cellular events. ECM molecules found in the heart include hyaluronan, fibronectin, fibrillin, proteoglycans, and collagens. Tight regulation of the spatiotemporal expression, and the proteolytic processing of ECM components by proteases including members of the ADAMTS family, is essential for normal cardiac development. Perturbation of the expression of genes involved in matrix composition and remodeling can interfere with a myriad of events involved in the formation of the four-chambered heart and result in prenatal lethality or cardiac malformations as seen in humans with congenital heart disease. In this review, we summarize what is known about the specific importance of some of the components of the ECM in relation to the cardiovascular development. Birth Defects Research (Part A), 2011. © 2011 Wiley-Liss, Inc. PMID: 21618406 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Rapamycin and other longevity-promoting compounds enhance the generation of mouse induced pluripotent stem cells. Aging Cell. 2011 May 25; Authors: Chen T, Shen L, Yu J, Wan H, Guo A, Chen J, Long Y, Zhao J, Pei G Reprogramming of somatic cells to a pluripotent state was first accomplished using retroviral vectors for transient expression of pluripotency-associated transcription factors. This seminal work was followed by numerous studies reporting alternative (non-insertional) reprogramming methods, and various conditions to improve the efficiency of reprogramming. These studies have contributed little to an understanding of global mechanisms underlying reprogramming efficiency. Here we report that inhibition of the mTOR (mammalian target of rapamycin) pathway by rapamycin or PP242 enhances the efficiency of reprogramming to induced pluripotent stem cells (iPSCs). Inhibition of the insulin/IGF-1 signaling pathway, which like mTOR is involved in control of longevity, also enhances reprogramming efficiency. In addition the small molecules used to inhibit these pathways also significantly improved longevity in Drosophila melanogaster. We further tested the potential effects of six other longevity-promoting compounds on iPSC induction, including two sirtuin activators (resveratrol and fisetin), an autophagy inducer (spermidine), a PI3K (phosphoinositide 3-kinase) inhibitor (LY294002), an antioxidant (curcumin) and an AMPK (activating adenosine monophosphate-activated protein kinase) activator (metformin). With the exception of metformin, all of these chemicals promoted somatic cell reprogramming, though to different extents. Our results show that the controllers of somatic cell reprogramming and organismal lifespan share some common regulatory pathways, which suggests a new approach for studying aging and longevity on the basis of the regulation of cellular reprogramming. PMID: 21615676 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Transformation-related protein 53 expression in the early mouse embryo compromises preimplantation embryonic development by preventing the formation of a proliferating inner cell mass. Biol Reprod. 2010 Dec;83(6):958-64 Authors: Ganeshan L, Li A, O'Neill C The developmental viability of the preimplantation embryo requires the successful formation of a cluster of pluripotent stem cells called the inner cell mass. Development is variably compromised by a range of exogenous stressors (including their production by assisted reproductive technologies). Inbred C57BL/6 strain embryos are particularly susceptible to the stresses associated with embryo culture, whereas hybrid embryos are more resistant, and this is accounted for in part by the overexpression of transformation-related protein 53 in cultured inbred embryos compared with similarly treated hybrid embryos or embryos not subjected to culture. We show here that this loss of viability is a consequence of the Trp53-dependent reduction in the capacity of blastocysts to form a proliferating inner cell mass. Formation of the trophectodermal line was not adversely affected by these stresses. PMID: 20739669 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Regenerative medicine spoilt for choice. Curr Biol. 2011 Apr 12;21(7):R235-7 Authors: Gross M PMID: 21618731 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | The Nell-1 growth factor stimulates bone formation by purified human perivascular cells. Tissue Eng Part A. 2011 May 26; Authors: Zhang X, Peault B, Chen W, Li W, Corselli M, James AW, Lee M, Siu RK, Pang S, Zheng Z, Shen J, Kwak J, Zara J, Chen F, Zhang H, Yin W, James AW, Wu B, Ting K, Soo C The search for novel sources of stem cells other than bone marrow mesenchymal stem cells (BMSCs) for bone regeneration and repair has been a critical endeavor. We previously established an effective protocol to homogeneously purify human pericytes from multiple fetal and adult tissues including adipose, bone marrow, skeletal muscle and pancreas, and identified pericytes as a primitive origin of human mesenchymal stem cells (MSCs). In the present study, we further characterized the osteogenic potential of purified human pericytes combined with a novel osteoinductive growth factor, Nell-1. Purified pericytes grown on either standard culture ware or human cortical bone chip (hCBC) scaffolds exhibited robust osteogenic differentiation in vitro. Using a nude mouse muscle pouch model, pericytes formed significant new bone in vivo as compared to scaffold alone (hCBC). Moreover, Nell-1 significantly increased pericyte osteogenic differentiation, both in vitro and in vivo. Interestingly Nell-1 significantly induced pericyte proliferation and was observed to have pro-angiogenic effects, both in vitro and in vivo. These studies suggest that pericytes are a potential new cell source for future efforts in skeletal regenerative medicine, and that Nell-1 is a candidate growth factor able to induce pericyte osteogenic differentiation. PMID: 21615216 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Induction of human neuronal cells by defined transcription factors. Nature. 2011 May 26; Authors: Pang ZP, Yang N, Vierbuchen T, Ostermeier A, Fuentes DR, Yang TQ, Citri A, Sebastiano V, Marro S, Südhof TC, Wernig M Somatic cell nuclear transfer, cell fusion, or expression of lineage-specific factors have been shown to induce cell-fate changes in diverse somatic cell types. We recently observed that forced expression of a combination of three transcription factors, Brn2 (also known as Pou3f2), Ascl1 and Myt1l, can efficiently convert mouse fibroblasts into functional induced neuronal (iN) cells. Here we show that the same three factors can generate functional neurons from human pluripotent stem cells as early as 6 days after transgene activation. When combined with the basic helix-loop-helix transcription factor NeuroD1, these factors could also convert fetal and postnatal human fibroblasts into iN cells showing typical neuronal morphologies and expressing multiple neuronal markers, even after downregulation of the exogenous transcription factors. Importantly, the vast majority of human iN cells were able to generate action potentials and many matured to receive synaptic contacts when co-cultured with primary mouse cortical neurons. Our data demonstrate that non-neural human somatic cells, as well as pluripotent stem cells, can be converted directly into neurons by lineage-determining transcription factors. These methods may facilitate robust generation of patient-specific human neurons for in vitro disease modelling or future applications in regenerative medicine. PMID: 21617644 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Long-Term Stability of Adipose Tissue Generated from a Vascularized Pedicled Fat Flap inside a Chamber. Plast Reconstr Surg. 2011 Jun;127(6):2283-92 Authors: Doldere JH, Thompson EW, Slavin J, Trost N, Cooper-White JJ, Cao Y, O'connor AJ, Penington A, Morrison WA, Abberton KM : Numerous studies demonstrate the generation and short-term survival of adipose tissue; however, long-term persistence remains elusive. This study evaluates long-term survival and transferability of de novo adipose constructs based on a ligated vascular pedicle and tissue engineering chamber combination. PMID: 21617462 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Micropatterned methacrylate polymers direct spiral ganglion neurite and Schwann cell growth. Hear Res. 2011 May 18; Authors: Clarke JC, Tuft BW, Clinger JD, Levine R, Figueroa LS, Allan Guymon C, Hansen MR Significant advances in the functional outcomes achieved with cochlear implantation will likely require tissue-engineering approaches to improve the neural prosthesis interface. One strategy is to direct spiral ganglion neuron (SGN) axon growth in a highly organized fashion to approximate or contact stimulating electrodes. Here we assessed the ability of micropatterns induced by photopolymerization in methacrylate (MA) polymer systems to direct cultured neonatal rat SGN neurite growth and alignment of SG Schwann cells (SGSCs). SGN survival and neurite length were comparable among various polymer compositions. Remarkably, there was no significant difference in SGN survival or neurite length between laminin and non-laminin coated MA polymer substrates, suggesting high biocompatibility with SG tissue. Micropatterning with photopolymerization generated microchannels with a ridge periodicity of 50 μm and channel depths of 0.6-1.0 μm. SGN neurites grew within the grooves of the microchannels. These topographies strongly induced alignment of dissociated SGN neurites and SGSCs to parallel the pattern. By contrast, fibroblasts failed to align with the micropattern suggesting cell specific responses to topographical cues. SGN neurites extending from explants turned to parallel the pattern as they encountered the microchannels. The extent of turning was significantly correlated with angle at which the neurite initially encountered the pattern. These results indicate that SGN neurites respond to microtopographical features and that these features can be used to direct neurite growth in a highly organized fashion. PMID: 21616131 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Conference discussion: Engineering bioartificial tracheal tissue using hybrid fibroblast-mesenchymal stem cell cultures in collagen hydrogels. Interact Cardiovasc Thorac Surg. 2011 Feb;12(2):161 Authors: Schmid R, Naito H, Cerfolio R, Choong C PMID: 21322163 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Skeletal tissue regeneration - current approaches, challenges and novel reconstructive strategies for an aging population. Tissue Eng Part B Rev. 2011 May 27; Authors: Smith JO, Aarvold A, Tayton ER, Dunlop DG, Oreffo RO Loss of skeletal tissue as a consequence of trauma, injury or disease is a significant cause of morbidity with often wide-ranging socio-economic impacts. Current approaches to replace or restore significant quantities of lost bone come with substantial limitations and inherent disadvantages that may in themselves cause further disability. In addition, the spontaneous repair capacity of articular cartilage is limited, thus investigation into new cartilage replacement and regeneration techniques are warranted. Along with the challenges of an increasingly aging demographic, changing clinical scenarios and rising functional expectations provide the imperative for new, more reliable skeletal regeneration strategies. The science of tissue engineering has expanded dramatically in recent years, notably in orthopedic applications, and it is clear that new approaches for de novo skeletal tissue formation offer exciting opportunities to improve the quality of life for many, particularly in the face of increasing patient expectations. However, significant scientific, financial, industrial and regulatory challenges must be overcome before the successful development of an emergent tissue engineering strategy can be realized. We outline current practice for replacement of lost skeletal tissue and the innovative approaches in tissue regeneration that have so far been translated to clinical use, along with a discussion of the significant hurdles that are presented in the process of translating research strategies to the clinic. PMID: 21615329 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | In Vitro Mineralization of Human Mesenchymal Stem Cells on Three-Dimensional Type I Collagen versus PLGA Scaffolds: A Comparative Analysis. Plast Reconstr Surg. 2011 Jun;127(6):2301-11 Authors: Kruger EA, Im DD, Bischoff DS, Pereira CT, Huang W, Rudkin GH, Yamaguchi DT, Miller TA : Development of a tissue engineered bone graft requires efficient bioactivity screening of biomaterials in clinically relevant three-dimensional systems. The authors analyzed the relative osteogenic potential of two three-dimensional biomaterials-type I collagen and poly(L-lactide-co-glycolide) (PLGA)- to support in vitro mineralization of human mesenchymal stem cells. PMID: 21617464 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Initial fiber alignment pattern alters extracellular matrix synthesis in fibroblast-populated fibrin gel cruciforms and correlates with predicted tension. Ann Biomed Eng. 2011 Feb;39(2):714-29 Authors: Sander EA, Barocas VH, Tranquillo RT Human dermal fibroblasts entrapped in fibrin gels cast in cross-shaped (cruciform) geometries with 1:1 and 1:0.5 ratios of arm widths were studied to assess whether tension and alignment of the cells and fibrils affected ECM deposition. The cruciforms of contrasting geometry (symmetric vs. asymmetric), which developed different fiber alignment patterns, were harvested at 2, 5, and 10 weeks of culture. Cruciforms were subjected to planar biaxial testing, polarimetric imaging, DNA and biochemical analyses, histological staining, and SEM imaging. As the cruciforms compacted and developed fiber alignment, fibrin was degraded, and elastin and collagen were produced in a geometry-dependent manner. Using a continuum mechanical model that accounts for direction-dependent stress due to cell traction forces and cell contact guidance with aligned fibers that occurs in the cruciforms, the mechanical stress environment was concluded to influence collagen deposition, with deposition being the greatest in the narrow arms of the asymmetric cruciform where stress was predicted to be the largest. PMID: 21046467 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Preparing dental students for careers as independent dental professionals: clinical audit and community-based clinical teaching. Br Dent J. 2011 May 28;210(10):475-8 Authors: Lynch CD, Llewelyn J, Ash PJ, Chadwick BL Community-based clinical teaching programmes are now an established feature of most UK dental school training programmes. Appropriately implemented, they enhance the educational achievements and competences achieved by dental students within the earlier part of their developing careers, while helping students to traverse the often-difficult transition between dental school and vocational/foundation training and independent practice. Dental school programmes have often been criticised for 'lagging behind' developments in general dental practice - an important example being the so-called 'business of dentistry', including clinical audit. As readers will be aware, clinical audit is an essential component of UK dental practice, with the aims of improving the quality of clinical care and optimising patient safety. The aim of this paper is to highlight how training in clinical audit has been successfully embedded in the community-based clinical teaching programme at Cardiff. PMID: 21617672 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Cytoprotective response induced by electromagnetic stimulation on SH-SY5Y human neuroblastoma cell line. Tissue Eng Part A. 2011 May 26; Authors: Osera C, Fassina L, Amadio M, Venturini L, Buoso E, Magenes G, Govoni S, Ricevuti G, Pascale A It is well known that physiological functions and pathological conditions of cells and tissues can be influenced not only by chemical molecules, but also by physical stimuli such as electromagnetic waves. In particular, epidemiological studies suggest possible associations between exposure to electromagnetic fields and an increased risk of tumors and neurodegenerative disorders, such as Alzheimer's disease. However, depending on the dose and on the length of treatment, the electromagnetic stimuli can be harmful or induce a cytoprotective cellular response, suggesting a possible application in medical therapy. In this study, under a Tissue Engineering viewpoint, we investigated the effects of an electromagnetic wave (magnetic field intensity, 2 mT; frequency, 75 Hz) on a neuronal cellular model characterized by the overexpression of the amyloid precursor protein (APP). After a prolonged electromagnetic treatment, lower mitochondrial activity and proliferation rate, resulting in a higher cellular quiescence, were observed. Focusing on the stress and oxidative pathways, we detected an overall increase of two fundamental proteins, the chaperone heat shock protein HSP70 and the free radical scavenger SOD-1 enzyme. Interestingly, we found that the electromagnetic stimulation promotes the non-amyloidogenic processing of APP through an increased expression of the α-secretase ADAM10 and an enhanced release of the soluble neurotrophic factor sAPPα (a product of the ADAM10-mediated cleavage of APP). In conclusion, these findings suggest that the electromagnetic stimulus, if properly administered in terms of dose and timing, is able to induce a cytoprotective response in the cell. Moreover, these results suggest a possible use of this particular physical stimulation to improve the functional capability of the cells to face noxae. PMID: 21615217 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Engineered human tumor xenografts with functional human vascular networks. Microvasc Res. 2011 Jan;81(1):18-25 Authors: Alonso-Camino V, Santos-Valle P, Ispizua MC, Sanz L, Alvarez-Vallina L Animal models of human tumor angiogenesis would have multiple applications. However, they are extremely difficult to standardize. In this work, we tried to generate human tumor xenografts containing a human vascular bed in immunodeficient mice by subcutaneous co-implantation of matrigel-embedded human endothelial cells (EC), human mesenchymal stem cells (MSC) as a source of mural cells and HT1080 human fibrosarcoma cells. Unfortunately, in this context human EC were rapidly substituted by their murine counterparts, and by day 16 post-implantation human CD34 positive cells were hardly detectable in intratumoral vessels. In an attempt to inhibit host EC colonization of human xenografts and promote human EC grafting, we investigated the effect of radiation prior to implantation on the vascularization and growth of tumor xenografts. Nude mice underwent either localized (implantation area) or sublethal whole-body exposure to radiation. Localized radiation inhibited both human and murine neovascularization, and even the tumor growth rate was remarkably decreased when compared to control unirradiated mice and sublethally whole-body irradiated mice. Interestingly, numerous human vessels were detectable in sublethally irradiated mice at day 30, with murine EC only over passing human EC when spontaneous hematopoietic reconstitution has taken place. This observation strongly suggests the implication of bone marrow-derived murine endothelial precursors in tumor neovascularization. In summary, we have established a model of human tumor neovascularization that is amenable to both the study of molecular aspects in the angiogenic process and the evaluation of potential new antiangiogenic drugs. PMID: 20934439 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Elastomeric electrospun scaffolds of poly(L: -lactide-co-trimethylene carbonate) for myocardial tissue engineering. J Mater Sci Mater Med. 2011 May 27; Authors: Mukherjee S, Gualandi C, Focarete ML, Ravichandran R, Venugopal JR, Raghunath M, Ramakrishna S In myocardial tissue engineering the use of synthetically bioengineered flexible patches implanted in the infarcted area is considered one of the promising strategy for cardiac repair. In this work the potentialities of a biomimetic electrospun scaffold made of a commercial copolymer of (L: )-lactic acid with trimethylene carbonate (P(L: )LA-co-TMC) are investigated in comparison to electrospun poly(L: )lactic acid. The P(L: )LA-co-TMC scaffold used in this work is a glassy rigid material at room temperature while it is a rubbery soft material at 37°C. Mechanical characterization results (tensile stress-strain and creep-recovery measurements) show that at 37°C electrospun P(L: )LA-co-TMC displays an elastic modulus of around 20 MPa and the ability to completely recover up to 10% of deformation. Cell culture experiments show that P(L: )LA-co-TMC scaffold promotes cardiomyocyte proliferation and efficiently preserve cell morphology, without hampering expression of sarcomeric alpha actinin marker, thus demonstrating its potentialities as synthetic biomaterial for myocardial tissue engineering. PMID: 21617996 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | [In vitro production of human dermal equivalent]. Med Pregl. 2010 Jul-Aug;63(7-8):459-64 Authors: Milosavljević Z, Ljujić B Human dermal tissue is composed of loose and dense connective tissue. Main cell populations are fibroblasts and the dominant fibers are built from collagen type I. The aim of our study was to determine the precise method and time frame for the in vitro production of human dermal equivalent and to investigate the effects of ratio of structural elements and vitamin C on characteristics of the engineered tissue. PMID: 21446130 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | In vivo efficacy of bone marrow stromal cells coated with beta-tricalcium phosphate for the reconstruction of orbital defects in canines. Invest Ophthalmol Vis Sci. 2011 Mar;52(3):1735-41 Authors: Zhou H, Xiao C, Wang Y, Bi X, Ge S, Fan X To repair the segmental orbital rim defects of dogs with three-dimensional (3D) tissue-engineered constructs derived from culturing autogenous bone marrow stromal cells (BMSCs) on β-tricalcium phosphate (β-TCP) scaffolds. PMID: 21087968 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Bio-electrosprays: from bio-analytics to a generic tool for the health sciences. Analyst. 2011 Mar 7;136(5):878-90 Authors: Jayasinghe SN Electrosprays or electrospraying is a process by which an aerosol is generated between two charged electrodes. This aerosol generation methodology has been known for well over a century, and has undergone exploration in aerosol and materials sciences, to many other areas of research and development. In one such exploration, electrosprays were partnered with mass spectrometry for the accurate characterisation of molecules. This technology now widely referred to as electrospray ionisation mass spectrometry (ESI MS) significantly contributes to molecular analysis and cancer biology to name a few. In fact these findings were recognised by the Chemistry Nobel Committee in 2002, and have catapulted electrosprays to many areas of research and development. In this review, the author wishes to introduce and discuss another such recent discovery, where electrosprays have been investigated for directly handling living cells and whole organisms. Over the past few years these electrosprays now referred to as "bio-electrosprays" have undergone rigorous developmental studies both in terms of understanding all the associate physical, chemical and biological sciences for completely assessing their effects, if any on the direct handling of living biological materials. Therefore, the review will bring together all the work that has contributed to fully understanding that bio-electrosprays are an inert technology for directly handling living biological materials, while elucidating some unique features they possess over competing technologies. Hence, demonstrating this approach as a flexible methodology for a wide range of applications spanning bio-analytics, diagnostics to the possible creation of synthetic tissues, for repairing and replacing damaged/ageing tissues, to the targeted and controlled delivery of personalised medicine through experimental and/or medical cells and/or genes. Therefore, elucidating the far reaching ramifications bio-electrosprays have to our health sciences and well-being. PMID: 21271004 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Isolating and defining cells to engineer human blood vessels. Cell Prolif. 2011 Apr;44 Suppl 1:15-21 Authors: Critser PJ, Voytik-Harbin SL, Yoder MC A great deal of attention has been recently focused on understanding the role that bone marrow-derived putative endothelial progenitor cells (EPC) may play in the process of neoangiogenesis. However, recent data indicate that many of the putative EPC populations are comprised of various haematopoietic cell subsets with proangiogenic activity, but these marrow-derived putative EPC fail to display vasculogenic activity. Rather, this property is reserved for a rare population of circulating viable endothelial cells with colony-forming cell (ECFC) ability. Indeed, human ECFC possess clonal proliferative potential, display endothelial and not haematopoietic cell surface antigens, and display in vivo vasculogenic activity when suspended in an extracellular matrix and implanted into immunodeficient mice. Furthermore, human vessels derived became integrated into the murine circulatory system and eventually were remodelled into arterial and venous vessels. Identification of this population now permits determination of optimal type I collagen matrix microenvironment into which the cells should be embedded and delivered to accelerate and even pattern number and size of blood vessels formed, in vivo. Indeed, altering physical properties of ECFC-collagen matrix implants changed numerous parameters of human blood vessel formation, in host mice. These recent discoveries may permit a strategy for patterning vascular beds for eventual tissue and organ regeneration. PMID: 21481038 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Evaluation of a community-based clinical teaching programme by current and former student dental therapists and dental hygienists: a pilot investigation. Br Dent J. 2011 May 28;210(10):481-5 Authors: Lynch CD, Ash PJ, Chadwick BL Aim There has been considerable expansion in the involvement of community-based clinical teaching programmes (sometimes termed 'outreach teaching') in UK and other international dental schools. While there has been much interest in the role of this educational methodology in the professional and educational development of student dentists, there has been little, if no, consideration of this form of teaching in relation to dental care professional (DCP) students. The aim of this pilot investigation was to report the feedback and evaluation of current and former student dental therapists and dental hygienists on their experience on the St David's community-based clinical teaching programme at Cardiff.Methods In Autumn 2009, a questionnaire was distributed by hand to the current second year student dental therapist and dental hygiene class at Cardiff (n = 18) and by post to the dental therapist and dental hygiene classes of 2004 (n = 16) and 2007 (n = 17). The questionnaire included both 'open' and 'closed' questions.Results Thirty responses were returned (response rate = 59%; 2004 (n = 5, 31%), 2007 (n = 9, 53%), current class (n = 16, 89%)). Seventy percent of respondents (n = 21) reported that they found the community-based clinical teaching programme to be a pleasant working environment and close to subsequent independent practice. Seventy-seven percent (n = 23) reported that their confidence performing nonsurgical periodontal treatment had increased while at the programme. One respondent commented that the programme was '...an invaluable and insightful introduction to what it would be like working in practice. Without being given the experience, it would have been a big shock to the system when I started working in practice...'Conclusion This pilot investigation has revealed that current and former dental therapist and dental hygiene students are enthusiastic in their support for the inclusion of community-based clinical teaching programmes in their educational and professional development. Most former and current dental therapist and dental hygiene students noted the positive effects of this form of training on their subsequent clinical careers. PMID: 21617673 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | The therapeutic efficacy of human adipose tissue-derived mesenchymal stem cells on experimental autoimmune hearing loss in mice. Immunology. 2011 May;133(1):133-40 Authors: Zhou Y, Yuan J, Zhou B, Lee AJ, Lee AJ, Ghawji M, Yoo TJ Autoimmune inner ear disease is characterized by progressive, bilateral although asymmetric, sensorineural hearing loss. Patients with autoimmune inner ear disease had higher frequencies of interferon-γ-producing T cells than did control subjects tested. Human adipose-derived mesenchymal stem cells (hASCs) were recently found to suppress effector T cells and inflammatory responses and therefore have beneficial effects in various autoimmune diseases. The aim of this study was to examine the immunosuppressive activity of hASCs on autoreactive T cells from the experimental autoimmune hearing loss (EAHL) murine model. Female BALB/c mice underwent β-tubulin immunization to develop EAHL; mice with EAHL were given hASCs or PBS intraperitoneally once a week for 6 consecutive weeks. Auditory brainstem responses were examined over time. The T helper type 1 (Th1)/Th17-mediated autoreactive responses were examined by determining the proliferative response and cytokine profile of splenocytes stimulated with β-tubulin. The frequency of regulatory T (Treg) cells and their suppressive capacity on autoreactive T cells were also determined. Systemic infusion of hASCs significantly improved hearing function and protected hair cells in established EAHL. The hASCs decreased the proliferation of antigen-specific Th1/Th17 cells and induced the production of anti-inflammatory cytokine interleukin-10 in splenocytes. They also induced the generation of antigen-specific CD4(+) CD25(+) Foxp3(+) Treg cells with the capacity to suppress autoantigen-specific T-cell responses. The experiment demonstrated that hASCs are one of the important regulators of immune tolerance with the capacity to suppress effector T cells and to induce the generation of antigen-specific Treg cells. PMID: 21366561 [PubMed - indexed for MEDLINE] | | | | | | | | | |  | |  | |  |
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