Controlled growth factor release from synthetic extracellular matrices

Polymeric matrices can be used to grow new tissues and organs(1,2), and the delivery of growth factors from these matrices is one method to regenerate tissues(3,4). A problem with engineering tissues that exist in a mechanically dynamic environment, such as bone, muscle and blood vessels(5,6), is that most drug delivery systems have been designed to operate under static conditions. We thought that polymeric matrices, which release growth factors in response to mechanical signals, might provide a new approach to guide tissue formation in mechanically stressed environments. Critical design features for this type of system include the ability to undergo repeated deformation, and a reversible binding of the protein growth factors to polymeric matrices to allow for responses to repeated stimuli. Here we report a model delivery system that can respond to mechanical signalling and upregulate the release of a growth factor to promote blood vessel formation. This approach may rnd a number of applications, including regeneration and engineering of new tissues and more general drug-delivery applications.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62980/1/408998a0.pd

Differentiation stage alters matrix control of stem cells

Cues from the material to which a cell is adherent (e.g., adhesion ligand presentation, substrate elastic modulus) clearly influence the phenotype of differentiated cells. However, it is currently unclear if stem cells respond similarly to these cues. This study examined how the overall density and nanoscale organization of a model cell adhesion ligand (arginine-glycine-aspartic acid [RGD] containing peptide) presented from hydrogels of varying stiffness regulated the proliferation of a clonally derived stem cell line (D1 cells) and preosteoblasts (MC3T3-E1). While the growth rate of MC3T3-E1 preosteoblasts was responsive to nanoscale RGD ligand organization and substrate stiffness, the D1 stem cells were less sensitive to these cues in their uncommitted state. However, once the D1 cells were differentiated towards the osteoblast lineage, they became more responsive to these signals. These results demonstrate that the cell response to material cues is dependent on the stage of cell commitment or differentiation, and these findings will likely impact the design of biomaterials for tissue regeneration. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2008Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58039/1/31521_ftp.pd

Sustained and controlled release of daunomycin from cross-linked poly(aldehyde guluronate) hydrogels

We have incorporated daunomycin, an antineoplastic agent, into a biodegradable hydrogel through a labile covalent bond. In brief, sodium alginate was chemically broken down to low molecular weight and followed by oxidation to prepare poly(aldehyde guluronate). Adipic dihydrazide was used to incorporate the drug into the polymer backbone and cross-link the polymer to form hydrogels. Daunomycin can be released from the hydrogel after the hydrolysis of the covalent linkage between the drug and the polymer. A wide range of release profiles of daunomycin (e.g., from 2 days to 6 weeks) has been achieved using these materials, and the biological activity of the released daunomycin was maintained. © 2000 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 89: 910–919, 2000Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34502/1/8_ftp.pd

Tellurium substitution effect on superconductivity of the alpha-phase Iron Selenide

We have carried out a systematic study of the PbO-type compound FeSe_{1-x}Te_x (x = 0~1), where Te substitution effect on superconductivity is investigated. It is found that superconducting transition temperature reaches a maximum of Tc=15.2K at about 50% Te substitution. The pressure-enhanced Tc of FeSe0.5Te0.5 is more than 10 times larger than that of FeSe. Interestingly, FeTe is no longer superconducting. A low temperature structural distortion changes FeTe from triclinic symmetry to orthorhombic symmetry. We believe that this structural change breaks the magnetic symmetry and suppresses superconductivity in FeTe.Comment: Some typing errors are corrected; we take out one figures, now the paper has 14 pages, 5 figure

Intra-arterial delivery of triolein emulsion increases vascular permeability in skeletal muscles of rabbits

<p>Abstract</p> <p>Background</p> <p>To test the hypothesis that triolein emulsion will increase vascular permeability of skeletal muscle.</p> <p>Methods</p> <p>Triolein emulsion was infused into the superficial femoral artery in rabbits (triolein group, n = 12). As a control, saline was infused (saline group, n = 18). Pre- and post-contrast T1-weighted MR images were obtained two hours after infusion. The MR images were qualitatively and quantitatively evaluated by assessing the contrast enhancement of the ipsilateral muscles. Histologic examination was performed in all rabbits.</p> <p>Results</p> <p>The ipsilateral muscles of the rabbits in the triolein group showed contrast enhancement, as opposed to in the ipsilateral muscles of the rabbits in the saline group. The contrast enhancement of the lesions was statistically significant (p < 0.001). Histologic findings showed that most examination areas of the triolein and saline groups had a normal appearance.</p> <p>Conclusion</p> <p>Rabbit thigh muscle revealed significantly increased vascular permeability with triolein emulsion; this was clearly demonstrated on the postcontrast MR images.</p

The antecedents of cross-functional coordination and their implications for marketing adaptiveness

As the gap between accelerating rate of change and organizational capability in responding to it widens, managers face increasing challenges to coordinate and align diverse intra-firm functions. Although coordination across functions in an organization is necessary for integrating complex resources such as responding to uncertainty in business environments, little is known about the internal conditions of a firm in which cross-functional coordination influences marketing adaptiveness. Marketing adaptiveness recognizes the potential conflicting goals of intra-firm functions, and the need to identify disparate but interdependent organizational resources to fit the external environment. In order to account for the potential interactions of multiple conditions in cross-functional coordination, we use fuzzy-set qualitative comparative analysis to analyze survey data of 274 managers in Egyptian firms operating in uncertain environments based on the motivation-ability-opportunity framework and configuration theory. The findings show that the causal pathways leading to cross-functional coordination and marketing adaptiveness can be enhanced by resource dependency, cross-functional teams, multifunctional training, and management support. In particular, management support is a crucial condition for coordination in support of cross-functional teams and multifunctional training. While resource dependency is an important internal factor for coordination, a high resource dependency can result in a negative effect on marketing adaptiveness

Epstein-Barr virus-associated primary nodal T/NK-cell lymphoma shows a distinct molecular signature and copy number changes

The molecular biology of primary nodal T- and NK-cell lymphoma and its relationship with extranodal NK/T-cell lymphoma, nasal type is poorly understood. In this study, we assessed the relationship between nodal and extranodal Epstein-Barr virus-positive T/NK-cell lymphomas using gene expression profiling and copy number aberration analyses. We performed gene expression profiling and copy number aberration analysis on 66 cases of Epstein-Barr virus-associated T/NK-cell lymphoma from nodal and extranodal sites, and correlated the molecular signatures with clinicopathological features. Three distinct molecular clusters were identified with one enriched for nodal presentation and loss of 14q11.2 (TCRA loci). T/NK-cell lymphomas with a nodal presentation (nodal-group) were significantly associated with older age, lack of nasal involvement, and T-cell lineage compared to those with an extranodal presentation (extranodal-group). On multivariate analysis, nodal presentation was an independent factor associated with short survival. Comparing the molecular signatures of the nodal and extranodal groups it was seen that the former was characterized by upregulation of PD-L1 and T-cell-related genes, including CD2 and CD8, and downregulation of CD56, consistent with the CD8+/CD56-immunophenotype. PD-L1 and CD2 protein expression levels were validated using multiplexed immunofluorescence. Interestingly, nodal group lymphomas were associated with 14q11.2 loss which correlated with loss of TCR loci and T-cell origin. Overall, our results suggest that T/NK-cell lymphoma with nodal presentation is distinct and deserves to be classified separately from T/NK-cell lymphoma with extranodal presentation. Upregulation of PD-L1 indicates that it may be possible to use anti-PD1 immunotherapy in this distinctive entity. In addition, loss of 14q11.2 may be a potentially useful diagnostic marker of T-cell lineage

Anaesthesiology & Critical Care Postgraduate Training in Malaysia : training curriculum

This document is the National Postgraduate Medical Curriculum (NPMC) for Anaesthesiology and Critical Care, and is part of the NPMC Project which is intended to cover the development of curricula for all clinical medical specialists in Malaysia. It is to ensure that the training is consistent and competency based, and meets the standards required by the respective national bodies and the National Specialist Register (NSR)

Simulation and characterization of the process and circuit of the MOSFET device with ISRC structure

The main objectives of this project are examining and elucidating unique features of Ultra thin film MOSFET by TCAD tools and providing useful understanding and data that could be used in MOS device and circuit design and optimization for high performance, low voltage/power ICes.RG 6/9