|  |  |  | | | | | TE-RegenMed-StemCell feed | | | | | | | | | | | | | | | | | | | Evaluation of a lecture recording system in a medical curriculum. Anat Sci Educ. 2010 Oct 15; Authors: Bacro TR, Gebregziabher M, Fitzharris TP Recently, the Medical University of South Carolina adopted a lecture recording system (LRS). A retrospective study of LRS was implemented to document the students' perceptions, pattern of usage, and impact on the students' grades in three basic sciences courses (Cell Biology/Histology, Physiology, and Neurosciences). The number of accesses and length of viewings of the recordings were recorded per week for each student and correlated with the grades in each of the three courses. Attendance records were not available. The results showed considerable variability in the use of the LRS by both faculty and students during the entire semester and across all three courses, including week to week variations. Data indicated that 30% of the students did not use the LRS at all with 41% of the students using it very little (less than 10 times for a total of 131 recordings). Specific patterns of usage were identified for each of the three courses throughout the semester, with an increase in access prior or during examination weeks. However, the statistical analysis showed that there was no correlation between the final grades and the usage of LRS. Finally, a survey of the students' perception showed that 74% agreed/strongly agreed that the recordings were useful with 6% disagreeing/strongly disagreeing and 11% undecided. This study showed that the use of LRS might be a viable alternative for students unable to attend lecture due to circumstances such as illness but that more research is needed to truly understand the best pedagogical use of LRS. Anat Sci Educ. © 2010 American Association of Anatomists. PMID: 20954266 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Enhanced Differentiation of Embryonic and Neural Stem Cells to Neuronal Fates on Laminin Peptides Doped Polypyrrole. Macromol Biosci. 2010 Oct 15; Authors: Zhang L, Stauffer WR, Jane EP, Sammak PJ, Cui XT PPy is a conducting polymer material that has been widely investigated for biomedical applications. hESCs and adult rNSCs were grown on four PPy surfaces doped with PSS or peptide from laminin (p20, p31, and a mixture of p20 and p31) respectively. After 7 d, both PPy/p20 and PPy/p31 promoted neuroectoderm formation from hESCs. After 14 d of culture, surfaces containing p20 showed the highest percentage of neuronal differentiation from hESC, while the PPy/p31 surface showed better cell attachment and spreading. In rNSCs cultures, a higher percentage of neurons were found on the PPy/p20 surface than other surfaces at 7 and 14 d. For differentiated neurons, p20 promoted both the primary and total neurite outgrowth. Longer primary neurites were found on p20-containing surfaces and a longer total neurite length was found on PPy/p20 surface. These results demonstrated that, by doping PPy with different bioactive peptides, differentiation of stem cells seeded at different stages of development is affected. PMID: 20954199 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Test-retest reliability of MRI-based disk position diagnosis of the temporomandibular joint. Clin Oral Investig. 2010 Oct 15; Authors: Nagamatsu-Sakaguchi C, Maekawa K, Ono T, Yanagi Y, Minakuchi H, Miyawaki S, Asaumi J, Takano-Yamamoto T, Clark GT, Kuboki T This study evaluated the test-retest reliability for determining the temporomandibular joint (TMJ) disk position, diagnosed using magnetic resonance imaging (MRI). These assessments were done as a base-line measurement for a prospective cohort study, which examines the risk factors for precipitation and progression of temporomandibular disorders. Fifteen subjects (mean age, 24.2 ± 0.94 years; male/female = 8/7) were recruited from the students of Okayama University Dental School. Sagittal MR TMJ images were taken with a 1.5-T MR scanner (Magneton Vision, Siemens) in close and maximal open positions twice at about 1-week (6-11 days) interval. The images were displayed using 200% magnification on a computer screen with a commercially available image software package (OSIRIS, UIN/HCUG). Three calibrated examiners diagnosed the disk positions using the standardized criteria. The disk position of each joint was classified as normal, anterior disk displacement with or without reduction, and others. The first and second disk position diagnoses were compared, and the test-retest reliability level was calculated using the kappa index. The second disk position diagnosis was consistent with the first in 27 out of 30 joints. The calculated kappa value representing the test-retest reliability level between the first and second disk position diagnosis was 0.812. These results indicated that the test-retest reliability of MRI-based diagnosis of TMJ disk positions at about 1-week interval was substantially high, even though they were not completely consistent. PMID: 20953807 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Human cell-based micro electrode array platform for studying neurotoxicity. Front Neuroengineering. 2010;3: Authors: Ylä-Outinen L, Heikkilä J, Skottman H, Suuronen R, Aänismaa R, Narkilahti S At present, most of the neurotoxicological analyses are based on in vitro and in vivo models utilizing animal cells or animal models. In addition, the used in vitro models are mostly based on molecular biological end-point analyses. Thus, for neurotoxicological screening, human cell-based analysis platforms in which the functional neuronal networks responses for various neurotoxicants can be also detected real-time are highly needed. Microelectrode array (MEA) is a method which enables the measurement of functional activity of neuronal cell networks in vitro for long periods of time. Here, we utilize MEA to study the neurotoxicity of methyl mercury chloride (MeHgCl, concentrations 0.5-500 nM) to human embryonic stem cell (hESC)-derived neuronal cell networks exhibiting spontaneous electrical activity. The neuronal cell cultures were matured on MEAs into networks expressing spontaneous spike train-like activity before exposing the cells to MeHgCl for 72 h. MEA measurements were performed acutely and 24, 48, and 72 h after the onset of the exposure. Finally, exposed cells were analyzed with traditional molecular biological methods for cell proliferation, cell survival, and gene and protein expression. Our results show that 500 nM MeHgCl decreases the electrical signaling and alters the pharmacologic response of hESC-derived neuronal networks in delayed manner whereas effects can not be detected with qRT-PCR, immunostainings, or proliferation measurements. Thus, we conclude that human cell-based MEA platform is a sensitive online method for neurotoxicological screening. PMID: 20953240 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Fezf2 directs the differentiation of corticofugal neurons from striatal progenitors in vivo. Nat Neurosci. 2010 Oct 17; Authors: Rouaux C, Arlotta P In the developing cerebral cortex, cell-extrinsic and cell-intrinsic signals govern the establishment of neuron subtype-specific identity. Here we show that, within the niche of the striatum, the expression of a single transcription factor, Fezf2, is sufficient to generate corticofugal neurons from progenitors fated to become medium spiny neurons. This demonstrates that a specific population of cortical projection neurons can be directed to differentiate outside of the cortex by cell-autonomous signaling. PMID: 20953195 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | AFM Studies of Cellular Mechanics during Osteogenic Differentiation of Human Amniotic Fluid-derived Stem Cells. Anal Sci. 2010;26(10):1033-7 Authors: Chen Q, Xiao P, Chen JN, Cai JY, Cai XF, Ding H, Pan YL Amniotic fluid-derived stem cells (AFSCs) are becoming an important source of cells for regenerative medicine given with apparent advantages of accessibility, renewal capacity and multipotentiality. In this study, the mechanical properties of human amniotic fluid-derived stem cells (hAFSCs), such as the average Young's modulus, were determined by atomic force microscopy (3.97 ± 0.53 kPa for hAFSCs vs. 1.52 ± 0.63 kPa for fully differentiated osteoblasts). These differences in cell elasticity result primarily from differential actin cytoskeleton organization in these two cell types. Furthermore, ultrastructures, nanostructural details on the surface of cell, were visualized by atomic force microscopy (AFM). It was clearly shown that surface of osteoblasts were covered by mineralized particles, and the histogram of particles size showed that most of the particles on the surface of osteoblasts distributed from 200 to 400 nm in diameter, while the diameter of hAFSCs particles ranged from 100 to 200 nm. In contrast, there were some dips on the surface of hAFSCs, and particles were smaller than that of osteoblasts. Additionally, as osteogenic differentiation of hAFSCs progressed, more and more stress fibers were replaced by a thinner actin network which is characteristic of mature osteoblasts. These results can improve our understanding of the mechanical properties of hAFSCs during osteogenic differentiation. AFM can be used as a powerful tool for detecting ultrastructures and mechanical properties. PMID: 20953044 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Speed- and cane-related alterations in gait parameters in individuals with multiple sclerosis. Gait Posture. 2010 Oct 15; Authors: Gianfrancesco MA, Triche EW, Fawcett JA, Labas MP, Patterson TS, Lo AC Previous literature reporting gait parameters in the MS population has largely focused on preferred walking speed without the use of an assistive device. However, these data may not fully represent daily activity, as individuals with MS vary their speed or use a cane when walking. In this exploratory study, 11 MS participants and 13 controls walked at both maximal and preferred speed for a distance of 25-feet. Participants with MS that used a cane daily (n=6) were asked to complete additional trials with their cane. When walking unassisted at both speeds, MS participants displayed significantly reduced velocity, cadence, stride length, step length ratio, single support and swing time, as well as increased double support and stance time compared to controls. Cane use resulted in significantly higher velocities when walking at maximal speeds, and showed significantly improved variability, gait asymmetry, and bilateral coordination at preferred walking speed. In conclusion, the use of a cane may significantly improve gait for individuals with MS. Furthermore, gait parameters should be measured at both maximal and preferred speeds, with and without a cane, as its use may mask underlying gait impairment. PMID: 20952198 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Photosensitive materials and potential of photocurrent mediated tissue regeneration. J Photochem Photobiol B. 2010 Sep 29; Authors: Jin G, Prabhakaran MP, Liao S, Ramakrishna S Photocurrent therapy with participation of light and electrical stimulations could be an innovative and promising approach in regenerative medicine, especially for skin and nerve regeneration. Photocurrent is generated when light irradiates on a photosensitive device, and with more and more types of photosensitive materials being synthesized, photocurrent could be applied for enhanced regeneration of tissue. Photosensitive scaffolds such as composite poly (3-hexylthiophene)/polycaprolactone (P3HT/PCL) nanofibers are fabricated by electrospinning process in our lab for skin regeneration in presence of applied photocurrent. This review article discuss on the various in vitro, in vivo and clinical studies that utilized the principle of 'electrotherapy' and 'phototherapy' for regenerative medicine and evaluates the potential application of photocurrent in regenerative medicine. We conclude that photocurrent therapy will play an important role in regenerative medicine. PMID: 20951603 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | A Combined Gene and Cell Therapy Approach for Restoration of Conduction. Heart Rhythm. 2010 Oct 13; Authors: Hofshi A, Itzhaki I, Gepstein A, Arbel G, Gross GJ, Gepstein L OBJECTIVE: To test the feasibility of a novel strategy for conduction repair utilizing genetically-engineered cells designed to form biological "conducting-cables". METHODS: An in-vitro model of conduction block was established using spatially-separated, spontaneously-contracting, non-synchronized, human embryonic stem cell-derived cardiomyocyte-clusters. Immunostaining, dye-transfer, intracellular recordings, and multielectrode array (MEA) studies were performed to evaluate the ability of genetically-engineered HEK293 cells, expressing the SCN5A-encoded Na(+) channel, to couple with cultured cardiomyocytes and to synchronize their electrical activity. RESULTS: Connexin-43 immunostaining and Calcein dye-transfer experiments confirmed the formation of functional gap junctions between the engineered cells and neighboring cardiomyocytes. MEA and intracellular recordings were performed to assess the ability of the engineered cells to restore conduction in the co-cultures. Synchronization was defined by establishment of fixed local activation time differences between the cardiomyocyte-clusters and convergence of their activation cycle-lengths. Non-transfected control cells were able to induce synchronization between cardiomyocyte-clusters separated by distances up to 300μm (n=21). In contrast, the Na(+) channel-expressing cells synchronized contractions between clusters separated by up to 1050μm, the longest distance studied (n=23). Finally, engineered cells expressing the voltage-sensitive K(v)1.3 potassium channel prevented synchronization at any distance. CONCLUSIONS: Genetically-engineered cells, transfected to express Na(+) channels, can form biological "conducting-cables" bridging and coupling spatially-separated cardiomyocytes. This novel cell therapy approach might be useful for the development of therapeutic strategies for both brady- and tachy-arrhythmias. PMID: 20951232 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | HIF-2α as a possible therapeutic target of osteoarthritis. Osteoarthritis Cartilage. 2010 Oct 12; Authors: Saito T, Kawaguchi H OBJECTIVE: Endochondral ossification, a conversion process from nonvascularized and hypoxic cartilage to highly vascularized bone, plays a crucial role in osteoarthritis (OA) development as well as in physiological skeletal growth. We have shown that hypoxia-inducible factor-2α (HIF-2α, encoded by EPAS1) is an extensive regulator of the endochondal ossification process. Here we review the possible signaling network regulating OA development on the axis of HIF-2α. METHODS: Peer reviewed publications published prior to August 2010 were searched in the Pubmed database. Articles that were relevant to HIF and molecular mechanisms of the endochondral ossification and OA were selected. RESULTS: As a trigger of OA, mechanical stress may induce the upstream NF-κB signal and HIF-2α expression in joint cartilage of mice and humans, which causes transactivation of endochondral ossification-related molecules with the most potent β-subunit partner aryl hydrocarbon nuclear translocator-like (ARNTL). In contrast to HIF-2α, HIF-1α functions to maintain cartilage via a distinct mechanism, so that the shifting of the HIFs might possibly be involved in an OA pathogenesis. CONCLUSION: Signals on the HIF-2α axis from NF-κB signaling to the endochondral ossification-related molecules, possibly in combination with HIF-2α and ARNTL, may represent a rational therapeutic target for OA with minimal effects on physiological skeletal homeostasis. PMID: 20950696 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Toward modeling the bone marrow niche using scaffold-based 3D culture systems. Biomaterials. 2010 Oct 15; Authors: Di Maggio N, Piccinini E, Jaworski M, Trumpp A, Wendt DJ, Martin I In the bone marrow, specialized microenvironments, called niches, regulate hematopoietic stem cell (HSC) maintenance and function through a complex crosstalk between different cell types. Although in vivo studies have been instrumental to elucidate some of the mechanisms by which niches exert their function, the establishment of an in vitro model that recapitulates the fundamental interactions of the niche components in a controlled setting would be of great benefit. We have previously shown that freshly harvested bone marrow- or adipose tissue-derived cells can be cultured under perfusion within porous scaffolds, allowing the formation of an organized 3D stromal tissue, composed by mesenchymal and endothelial progenitors and able to support hematopoiesis. Here we describe 3D scaffold-based perfusion systems as potential models to reconstruct ex vivo the bone marrow stem cell niche. We discuss how several culture parameters, including scaffold properties, cellular makeup and molecular signals, can be varied and controlled to investigate the role of specific cues in affecting HSC fate. We then provide a perspective of how the system could be exploited to improve stem cell-based therapies and how the model can be extended toward the engineering of other specialized stromal niches. PMID: 20952054 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | In Vivo Cell Tracking of Canine Allogenic Mesenchymal Stem Cells Administration via Renal Arterial Catheterization and Physiopathological Effects on the Kidney in Two Healthy Dogs. J Vet Med Sci. 2010 Oct 12; Authors: Yoo JH, Park C, Jung DI, Lim CY, Kang BT, Kim JH, Park JW, Kim JH, Park HM Stem cell therapy is being special premise for various renal diseases. However, there is limited literature on localization and pathologic and functional effects of allogenic mesenchymal stem cells (MSCs) in healthy dogs. Two healthy dogs were included in this study. Canine MSCs (cMSCs) were cultured from canine bone marrow and incubated with superparamagnetic iron oxide (SPIO) for in vivo cell tracking via MR imaging. The dogs were given the MSC (3×10(6) cells) into a renal artery via femoral artery catheterization. Follow-up serial renal assessments included ultrasonography and MRI, serum chemistry, urine analysis, and renal clearance tests. The dogs were euthanized at day 8 and 35 respectively for histopathologic evaluation of kidney. Strong hypointensity in MRI was detected in the treated renal cortex the day after cMSCs infusion. However they disappeared from MR image by the 8th day. Of the serum chemistry tests, serum hepatic enzymes (ALT, AST) were significantly elevated for one week after cMSCs treatment. Histopathological findings also revealed infiltration of SPIO-containing cells into the parenchyma of kidney. On 35th day, histopathology, glomerular atrophy, tubular necrosis, and mineralization were found in the subcapsular cortex, with fibrosis of the interstitial tissues. In vivo MRI studies of stem cells were useful in determining the sequential location of stem cells in the renal parenchyma of healthy dogs. Allogenic stem cells administered via renal artery caused inflammation, tubular necrosis, mineralization, and fibrosis without functional complications. PMID: 20953134 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Stem cell therapy for cardiovascular regeneration: The beginning or the end of all hearts' hopes. Pharmacol Ther. 2010 Oct 12; Authors: Madeddu P PMID: 20950648 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | Directors of the California stem cell agency will give away more than $80 million this week and wrestle with the question of what to do with their remaining $1.6 billion and how fast to spend it.
The $1.6 billion is a new figure for the public. Previously it was assumed the agency had $2 billion left, having committed $1 billion in awards. However, $2 billion figure did not include operational | | | | | | | | | |  | |  | |  |
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