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Articles 1 - 6 of 6

Full-Text Articles in Biomedical Engineering and Bioengineering

The Stromal Cell-Derived Factor-1alpha/Cxcr4 Ligand-Receptor Axis Is Critical For Progenitor Survival And Migration In The Pancreas., Ayse G. Kayali, Kurt Van Gunst, Iain L. Campbell, Aleksandr Stotland, Marcie Kritzik, Guoxun Liu, Malin Flodström-Tullberg, You-Qing Zhang, Nora Sarvetnick Nov 2003

The Stromal Cell-Derived Factor-1alpha/Cxcr4 Ligand-Receptor Axis Is Critical For Progenitor Survival And Migration In The Pancreas., Ayse G. Kayali, Kurt Van Gunst, Iain L. Campbell, Aleksandr Stotland, Marcie Kritzik, Guoxun Liu, Malin Flodström-Tullberg, You-Qing Zhang, Nora Sarvetnick

Journal Articles: Regenerative Medicine

The SDF-1alpha/CXCR4 ligand/chemokine receptor pair is required for appropriate patterning during ontogeny and stimulates the growth and differentiation of critical cell types. Here, we demonstrate SDF-1alpha and CXCR4 expression in fetal pancreas. We have found that SDF-1alpha and its receptor CXCR4 are expressed in islets, also CXCR4 is expressed in and around the proliferating duct epithelium of the regenerating pancreas of the interferon (IFN) gamma-nonobese diabetic mouse. We show that SDF-1alpha stimulates the phosphorylation of Akt, mitogen-activated protein kinase, and Src in pancreatic duct cells. Furthermore, migration assays indicate a stimulatory effect of SDF-1alpha on ductal cell migration ...


Tongue Movements In Feeding And Speech, Karen M. Hiiemae, Jeffrey B. Palmer Nov 2003

Tongue Movements In Feeding And Speech, Karen M. Hiiemae, Jeffrey B. Palmer

Biomedical and Chemical Engineering

The position of the tongue relative to the upper and lower jaws is regulated in part by the position of the hyoid bone, which, with the anterior and posterior suprahyoid muscles, controls the angulation and length of the floor of the mouth on which the tongue body 'rides'. The instantaneous shape of the tongue is controlled by the 'extrinsic muscles ' acting in concert with the 'intrinsic ' muscles. Recent anatomical research in non-human mammals has shown that the intrinsic muscles can best be regarded as a 'laminated segmental system ' with tightly packed layers of the 'transverse', 'longitudinal', and 'vertical' muscle fibers ...


Atp-Independent Contractile Proteins From Plants, Michael Knoblauch, Gundula Noll, Torsten Müller, Dirk Prüfer, Ingrid Schneider-Hüther, Dörte Scharner, Aart Van Bel, Winfried Peters Aug 2003

Atp-Independent Contractile Proteins From Plants, Michael Knoblauch, Gundula Noll, Torsten Müller, Dirk Prüfer, Ingrid Schneider-Hüther, Dörte Scharner, Aart Van Bel, Winfried Peters

Winfried S. Peters

This paper has no abstract; this is the first paragraph. Emerging technologies are creating increasing interest in smart materials that may serve as actuators in micro- and nanodevices. Mechanically active polymers currently studied include a variety of materials. ATP-driven motor proteins, the actuators of living cells, possess promising characteristics, but their dependence on strictly defined chemical environments can be disadvantagous. Natural proteins that deform reversibly by entropic mechanisms might serve as models for artificial contractile polypeptides with useful functionality, but they are rare. Protein bodies from sieve elements of higher plants provide a novel example. sieve elements form microfluidics systems ...


Cloning, Expression, And Characterization Of Gfp:Xkcm1 Deletion Constructs, Patrick Thorsen Apr 2003

Cloning, Expression, And Characterization Of Gfp:Xkcm1 Deletion Constructs, Patrick Thorsen

Life and Environmental Sciences Undergraduate Theses

Kinesins are a type of motor protein that use the energy of ATP hydrolysis to move along microtubules. Kinesin Catastrophe Modulator One (XKCM1) of Xenopus laevis was recently identified as a kinesin that is essential for the establishment and maintenance of mitotic spindles by affecting the microtubule dynamics in Xenopus egg extracts. In the present research, three different deletion constructs of XKCM1 fused with Green Flourescent Protein (GFP) were cloned, expressed, and characterized in order to determine which part of the XKCM1 structure was necessary for proper destabilization of microtubules. These deletion constructs have previously been studied z'n vivo ...


Crystal Structure And Evolution Of A Prokaryotic Glucoamylase, Alexander E. Aleshin, Ping-Hua Feng, Richard B. Honzatko, Peter J. Reilly Mar 2003

Crystal Structure And Evolution Of A Prokaryotic Glucoamylase, Alexander E. Aleshin, Ping-Hua Feng, Richard B. Honzatko, Peter J. Reilly

Chemical and Biological Engineering Publications

The first crystal structures of a two-domain, prokaryotic glucoamylase were determined to high resolution from the clostridial species Thermoanaerobacterium thermosaccharolyticum with and without acarbose. The N-terminal domain has 18 antiparallel strands arranged in β-sheets of a super-β-sandwich. The C-terminal domain is an (α/α)6 barrel, lacking the peripheral subdomain of eukaryotic glucoamylases. Interdomain contacts are common to all prokaryotic Family GH15 proteins. Domains similar to those of prokaryotic glucoamylases in maltose phosphorylases (Family GH65) and glycoaminoglycan lyases (Family PL8) suggest evolution from a common ancestor. Eukaryotic glucoamylases may have evolved from prokaryotic glucoamylases by the substitution of the N-terminal ...


Starch‐Binding Domain Shuffling In Aspergillus Niger Glucoamylase, Catherine A.G. Cornett, Tsuei-Yun Fang, Peter J. Reilly, Clark Ford Jan 2003

Starch‐Binding Domain Shuffling In Aspergillus Niger Glucoamylase, Catherine A.G. Cornett, Tsuei-Yun Fang, Peter J. Reilly, Clark Ford

Chemical and Biological Engineering Publications

Aspergillus niger glucoamylase (GA) consists mainly of two forms, GAI [from the N‐terminus, catalytic domain + linker + starch‐binding domain (SBD)] and GAII (catalytic domain + linker). These domains were shuffled to make RGAI (SBD + linker + catalytic domain), RGAIΔL (SBD + catalytic domain) and RGAII (linker + catalytic domain), with domains defined by function rather than by tertiary structure. In addition, Paenibacillus macerans cyclomaltodextrin glucanotransferase SBD replaced the closely related A.niger GA SBD to give GAE. Soluble starch hydrolysis rates decreased as RGAII ≈ GAII ≈ GAI > RGAIΔL ≈ RGAI ≈ GAE. Insoluble starch hydrolysis rates were GAI > RGAIΔL > RGAI >> GAE ≈ RGAII > GAII, while insoluble starch ...