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Articles 61 - 90 of 125

Full-Text Articles in Biochemical and Biomolecular Engineering

Recombinant Factors For Hemostasis, Jennifer Calcaterra Jul 2010

Recombinant Factors For Hemostasis, Jennifer Calcaterra

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Trauma deaths are a result of hemorrhage in 37% of civilians and 47% military personnel and are the primary cause of death for individuals under 44 years of age. Current techniques used to treat hemorrhage are inadequate for severe bleeding. Preliminary research indicates that fibrin sealants (FS) alone or in combination with a dressing may be more effective; however, it has not been economically feasible for widespread use because of prohibitive costs related to procuring the proteins. To meet future demands for hemostatic therapies, FS will likely include recombinant human fibrinogen (rFI) and recombinant human Factor XIII (rFXIII). The underlying …

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Rapid Diagnosis Of Tuberculosis In A Peripheral Setting, Elsje Pienaar May 2010

Rapid Diagnosis Of Tuberculosis In A Peripheral Setting, Elsje Pienaar

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Tuberculosis is an ancient and worldwide epidemic affecting millions of people in mainly the developing world, killing almost 2 million people in 2008. Current diagnostic techniques are outdated and have proven insufficient to control the disease. Smear microscopy has poor sensitivity and culture is slow to yield results. Modern diagnostic techniques are making great strides in shortening time to result but are restricted by two qualities: 1) prohibitively high costs prevent implementation in resource poor areas, and 2) equipment and technician requirements limit application to centralized laboratories. There exists a divide between new technologies and the people that need them …

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Synthesis Of An Endothelial Cell Mimicking Surface Containing Thrombomodulin And Endothelial Protein C Receptor, Karl E. Kador Apr 2010

Synthesis Of An Endothelial Cell Mimicking Surface Containing Thrombomodulin And Endothelial Protein C Receptor, Karl E. Kador

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Synthetic materials for use in blood contacting applications have been studied for many years with limited success. One of the main areas of need for these materials is the design of synthetic vascular grafts for use in the hundreds of thousands of patients who have coronary artery bypass grafting, many without suitable veins for autologous grafts. The design of these grafts is constrained by two common modes of failure, the formation of intimal hyperplasia (IH) and thrombosis. IH formation has been previously linked to a mismatching of the mechanical properties of the graft and has been overcome by creating grafts …

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Nonequilibrium Thermodynamics Modeling Of Coupled Biochemical Cycles In Living Cells, Yaşar Demirel Jan 2010

Nonequilibrium Thermodynamics Modeling Of Coupled Biochemical Cycles In Living Cells, Yaşar Demirel

Yaşar Demirel Publications

Living cells represent open, nonequilibrium, self organizing, and dissipative systems maintained with the continuous supply of outside and inside material, energy, and information flows. The energy in the form of adenosine triphosphate is utilized in biochemical cycles, transport processes, protein synthesis, reproduction, and performing other biological work. The processes in molecular and cellular biological systems are stochastic in nature with varying spatial and time scales, and bounded with conservation laws, kinetic laws, and thermodynamic constraints, which should be taken into account by any approach for modeling biological systems. In component biology, this review focuses on the modeling of enzyme kinetics …

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Simulation Of Corn Stover And Distillers Grains Gasification With Aspen Plus, Ajay Kumar, Hossein Noureddini, Yaşar Demirel, David Jones, Milford Hanna Jan 2009

Simulation Of Corn Stover And Distillers Grains Gasification With Aspen Plus, Ajay Kumar, Hossein Noureddini, Yaşar Demirel, David Jones, Milford Hanna

Yaşar Demirel Publications

A model was developed to simulate the performance of a lab‐scale gasifier and predict the flowrate and composition of product from given biomass composition and gasifier operating conditions using Aspen Plus software. Mass balance, energy balance, and minimization of Gibbs free energy during the gasification were applied to determine the product gas composition. Carbon conversion efficiency and tar content were provided to the model as inputs as these could not be predicted by the model based on minimization of Gibbs free energy. Experiments for validation of the model were performed on a lab‐scale fluidized bed gasifier using corn stover and …

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Identification And Characterization Of Calcium And Manganese Transporting Atpase (Pmr1) Gene Of Pichia Pastoris, Michael P. Dux, Mehmet Inan Feb 2007

Identification And Characterization Of Calcium And Manganese Transporting Atpase (Pmr1) Gene Of Pichia Pastoris, Michael P. Dux, Mehmet Inan

Papers in Biotechnology

A gene homologous to Saccharomyces cerevisiae PMR1 has been cloned in the methylotrophic yeast Pichia pastoris.The entire P. pastoris PMR1 gene (PpPMR1 ) codes a protein of 924 amino acids. Sequence analysis of the PpPMR1 cDNA and the genomic DNA revealed that there is no intron in the coding region. The putative gene product contains all of the conserved regions observed in P-type ATPases and exhibits 66.2%, 60.3% and 50.6% identity to Pichia angusta (Hansenula polymorpha), Saccharomyces cerevisiae PMR1 and human ATP2C1 gene products, respectively. A pmr1 null mutant strain of P. pastoris exhibited growth defects in media with the …

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Cell Bank Characterization And Fermentation Optimization For Production Of Recombinant Heavy Chain C-Terminal Fragment Of Botulinum Neurotoxin Serotype E (Rbonte(HC): Antigen E) By Pichia Pastoris, Jayanta Sinha, Mehmet Inan, Sarah Fanders, Shinichi Taoka, Mark Gouthro, Todd Swanson, Rick Barent, Ardis Barthuli, Bonnie M. Loveless, Leonard A. Smith, Theresa Smith, Ian Henderson, John Ross, Michael M. Meagher Jan 2007

Cell Bank Characterization And Fermentation Optimization For Production Of Recombinant Heavy Chain C-Terminal Fragment Of Botulinum Neurotoxin Serotype E (Rbonte(HC): Antigen E) By Pichia Pastoris, Jayanta Sinha, Mehmet Inan, Sarah Fanders, Shinichi Taoka, Mark Gouthro, Todd Swanson, Rick Barent, Ardis Barthuli, Bonnie M. Loveless, Leonard A. Smith, Theresa Smith, Ian Henderson, John Ross, Michael M. Meagher

Papers in Biochemical Engineering

A process was developed for production of a candidate vaccine antigen, recombinant C-terminal heavy chain fragment of the botulinum neurotoxin serotype E, rBoNTE(Hc)in Pichia pastoris. P. pastoris strain GS115 was transformed with the rBoNTE(Hc) gene inserted into pHILD4 Escherichia coli—P. pastoris shuttle plasmid. The clone was characterized for genetic stability, copy number, and BoNTE(Hc) sequence. Expression of rBoNTE(Hc) from the Mut+ HIS4 clone was confirmed in the shake-flask, prior to developing a fed-batch fermentation process at 5 and 19 L scale. The fermentation process consists of a glycerol growth phase in …

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Efficient, Thermally Stable, Second Order Nonlinear Optical Response In Organic Hybrid Covalent/Ionic Self-Assembled Films, Kevin E. Van Cott May 2006

Efficient, Thermally Stable, Second Order Nonlinear Optical Response In Organic Hybrid Covalent/Ionic Self-Assembled Films, Kevin E. Van Cott

Papers in Biomolecular Engineering

A covalent/electrostatic layer-by-layer self-assembly method was used to achieve polar ordering of a water soluble, reactive dye in the fabrication of nonlinear optical (NLO) films. We observed a quadratic relationship between the second harmonic intensity I2 and bilayer number for all films made with Procion Brown MX-GRN, demonstrating that the polar ordering of the chromophores is consistent in each successive bilayer. As the ionic strength of the dye deposition solution was increased to 0.5 M NaCl, the of the films increased by approximately 250% to 50 × 10-9 esu, with a corresponding average chromophore tilt angle of 38. This was …

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Use Of A Modified Zirconia Support In The Separation Of Immunoproteins, Anuradha Subramanian, Sabyasachi Sarkar Mar 2006

Use Of A Modified Zirconia Support In The Separation Of Immunoproteins, Anuradha Subramanian, Sabyasachi Sarkar

Papers in Biotechnology

Zirconia beads (25–38 μm in diameter) were modified with N,N,N′,N′-ethylenediaminetetramethylenephosphonic acid to generate a zirconia based pseudoaffinity support, further referred to as r_PEZ. The influence of pH, salt concentration and temperature on the binding of human immunoglobulin G (hIgG) to r_PEZ was studied. Temperature had no significant impact on the maximum binding capacity (Qmax), and the equilibrium-binding constant (Kd), whereas pH and the salt concentration had a noticeable impact on both Qmax and Kd. The Qmax value of 55 mg hIgG/ml of bead was obtained at a pH of 5.5 and found to decrease with an increase of pH. The …

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A Comparative Study Of Monoclonal Antibodies (Mabs) Purified From Cell Culture Supernatant On Edtpa-Modified Zirconia Beads And Protein A-Hyper D Support, Anuradha Subramanian, Blanca Martinez, Jill Holm, Peter W. Carr, Clayton V. Mcneff Mar 2006

A Comparative Study Of Monoclonal Antibodies (Mabs) Purified From Cell Culture Supernatant On Edtpa-Modified Zirconia Beads And Protein A-Hyper D Support, Anuradha Subramanian, Blanca Martinez, Jill Holm, Peter W. Carr, Clayton V. Mcneff

Papers in Biotechnology

Colloidal zirconia was spray dried to yield zirconia particles, which were further modified with N, N, N0, N0- Ethylenediamine tetra methylenephosphonic acid (EDTPA) to yield a sup-port for use in bioseparations. EDTPA modified zirconia particles will be further referred to as, r_PEZ. Cell culture supernatants rich in monoclonal antibody (Mab) subtypes IgG1, IgG2a, IgG2b, and IgG3 were chromatographed on a r_PEZ column, and on a protein A-hyper D col-umn that was purchased commercially. All Mab subtypes bound to r_PEZ and process yields in the range of 88 to 99% were obtained. The purity of the Mab products were ascertained by …

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Enhancement Of Protein Secretion In Pichia Pastoris By Overexpression Of Protein Disulfide Isomerase, Mehmet İnan, Dinesh Aryasomayajula, Jayanta Sinha, Michael M. Meagher Sep 2005

Enhancement Of Protein Secretion In Pichia Pastoris By Overexpression Of Protein Disulfide Isomerase, Mehmet İnan, Dinesh Aryasomayajula, Jayanta Sinha, Michael M. Meagher

Papers in Biochemical Engineering

A potential vaccine candidate, Necator americanus secretory protein (Na-ASP1), against hookworm infections, has been expressed in Pichia pastoris. Na- ASP1, a 45 kDa protein containing 20 cysteines, was directed outside the cell by fusing the protein to the preprosequence of the α-mating factor of Saccharomyces cerevisiae. Most of the protein produced by single copy clones was secreted outside the cell. However, increasing gene copy number of Na-ASP1 protein in P. pastoris saturated secretory capacity and therefore, decreased the amount of secreted protein in clones harboring multiple copies of Na-ASP1 gene. Overexpression of the …

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Crosslinked Chitosan: Its Physical Properties And The Effects Of Matrix Stiffness On Chondrocyte Cell Morphology And Proliferation, Anuradha Subramanian, Hsin-Yi Lin Aug 2005

Crosslinked Chitosan: Its Physical Properties And The Effects Of Matrix Stiffness On Chondrocyte Cell Morphology And Proliferation, Anuradha Subramanian, Hsin-Yi Lin

Papers in Biotechnology

Chitosan [<(1-4)-2 amino-2-deoxy-d-glucose], the natural polyaminosaccharide derived from N-deacetylation of chitin [<(1-4)-2 acetamide-2-deoxy-d-glucose], has been shown to possess attractive biological and cell interactive properties. Recently chitosan and chitosan analogs have also been shown to support the growth and continued function of chondrocytes. In the present study, chitosan substrates are crosslinked with a func-tional diepoxide (1,4 butanediol diglycidyl ether) to alter its mechanical property, and the viability and proliferation of the canine articular chondrocytes seeded on the crosslinked surface are further assayed. Of interest is the impact of substrate stiffness on the growth and proliferation of articular canine chondrocytes. Cross linked scaffolds were also sub-jected to degradation by chitosanase to examine the impact of cross linking on enzyme- assisted degradation. The hydrophilicity and compression modulus of the crosslinked sur-faces were measured via contact-angle measurements and compression tests, respec-tively. Scanning electron microscopy (SEM) and fluorescent staining were used to ob-serve the proliferation and morphology of chondrocyte cells on noncrosslinked and crosslinked surfaces. The crosslinked chitosan was found to be nontoxic to chondrocytes and more hydrophilic. Its compression modulus and stiffness increased, which may im-prove the scaffold resistance to wear and in vivo shrinkage once implanted. The in-creased stiffness also seemed to serve as an additional mechanical stimulus to promote chondrocyte growth and proliferation. The cell morphology on crosslinked scaffolds seen by SEM and fluorescent stain was the typical chondrocytic rounded shape. The method proposed provides a nontoxic way to increase the mechanical strength of the chitosan scaffolds.

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Purification And Scale-Up Of A Recombinant Heavy Chain Fragment C Of Botulinum Neurotoxin Serotype E In Pichia Pastoris Gs115, Michael P. Dux, Rick Barent, Jayanta Sinha, Mark Gouthro, Todd Swanson, Ardis Barthuli, Mehmet İnan, John T. Ross, Leonard A. Smith, Theresa J. Smith, Robert Webb, Bonnie Loveless, Ian Henderson, Michael M. Meagher Aug 2005

Purification And Scale-Up Of A Recombinant Heavy Chain Fragment C Of Botulinum Neurotoxin Serotype E In Pichia Pastoris Gs115, Michael P. Dux, Rick Barent, Jayanta Sinha, Mark Gouthro, Todd Swanson, Ardis Barthuli, Mehmet İnan, John T. Ross, Leonard A. Smith, Theresa J. Smith, Robert Webb, Bonnie Loveless, Ian Henderson, Michael M. Meagher

Papers in Biochemical Engineering

A recombinant C-terminus heavy chain fragment from Botulinum neurotoxin serotype E (BoNT/E) is proposed as a vaccine against the serotype E neurotoxin. This fragment, rBoNTE(Hc), was produced intracellular in Pichia pastoris GS115 by a three-step fermentation process, i.e., glycerol batch phase and a glycerol fed-batch phase to achieve high cell densities, followed by a methanol fed-batch induction phase. The rBoNTE(Hc) protein was purified from the soluble fraction of cell lysates using three ion-exchange chromatography steps (SP Sepharose Fast Flow, Q Sepharose Fast Flow, Sp Sepharose High Performance) and polished with a hydrophobic charge induction chromatography step (MEP HyperCel). Method development …

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The Phosphoglycolate Phosphatase Gene And The Mutation In The Phosphoglycolate Phosphatase-Deficient Mutant (Pgp1-1) Of Chlamydomonas Reinhardtii, Kensaku Suzuki, Hidenobu Uchida, Tarlan G. Mamedov Jul 2005

The Phosphoglycolate Phosphatase Gene And The Mutation In The Phosphoglycolate Phosphatase-Deficient Mutant (Pgp1-1) Of Chlamydomonas Reinhardtii, Kensaku Suzuki, Hidenobu Uchida, Tarlan G. Mamedov

Papers in Biochemical Engineering

The sequences of the phosphoglycolate phosphatase (PGPase) gene Pgp1 and the 5′-upstream region from Chlamydomonas reinhardtii wildtype 2137 and the pgp1-1 mutant N142 that lacks the activity of PGPase (PGP1) were determined. The comparison revealed the alteration of a G to A at position 98 relative to the start codon. This destroyed the “GT” splice donor site at the beginning of the first intron of this gene, resulting in an extension of the first exon to 49 translatable codons followed by a stop codon, containing the codons corresponding to whole transit peptide for the chloroplast stroma and the first four …

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Uv-Vis -Infrared Optical And Afm Study Of Spin-Cast Chitosan Films, W H. Nosal, D. W. Thompson, Sabyasachi Sarkar, Anuradha Subramanian, John A. Woollam, L Yan Jun 2005

Uv-Vis -Infrared Optical And Afm Study Of Spin-Cast Chitosan Films, W H. Nosal, D. W. Thompson, Sabyasachi Sarkar, Anuradha Subramanian, John A. Woollam, L Yan

Papers in Biotechnology

Optical properties OS spin-cast chitosan films have been determined in the infrared, visible, and ultraviolet region or the spectrum ~tsing spectroscopic ellipsometry. Optical constants for the Vvis-near IR spectra from 130 to 1700 nm were determined using Cauchy dispersion forms com-bined with Lorentzian oscillator models in the absorptive shorler wavelength regions. Infrared ndex of refraction and extinction coefficients from 750 to 4000cm-' were determined using ellip-sometric data fits to dispersion models based on harmonic oscillators. This modeling determined that optical onisotropy was present and measurable over all wavelength regions of ellipsomctric data. To obtain information on the micro- and nano-scale …

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Chromatographic Purification Of Mabs With Non-Affinity Supports, Anuradha Subramanian Jun 2005

Chromatographic Purification Of Mabs With Non-Affinity Supports, Anuradha Subramanian

Papers in Biotechnology

The introduction of new protein-based therapeutics such as monoclonal antibodies (MAbs), MAb-based vaccines, growth factors and plasma proteins implies the need to study, characterize, and purify. The separation step is likely to be a bottleneck and cost-effective technology will be needed to rectify it. The currently prevalent matrices for chromatographic separation of immunoglobulins (Igs) are based on Protein A or its recombinant versions (Protein G). They display excellent selectivity and specificity, but are expensive. A Protein A matrix costs $8,000 to 12,000 per L-resin. The typical production column volume is 100 L. The million-dollar matrix is far more expensive than …

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Modeling Of Immunoglobulin Uptake By N,N,N′,N′-Ethylenediaminetetramethylenephosphonic Acid-Modified Zirconia Particles Under Static And Dynamic Conditions, Sabyasachi Sarkar, Anuradha Subramanian May 2005

Modeling Of Immunoglobulin Uptake By N,N,N′,N′-Ethylenediaminetetramethylenephosphonic Acid-Modified Zirconia Particles Under Static And Dynamic Conditions, Sabyasachi Sarkar, Anuradha Subramanian

Papers in Biotechnology

A matrix developed from N,N,N′,N′-ethylenediaminetetramethylenephosphonic acid-modified zirconia beads (further referred to as r_PEZ); 25–38 μm in diameter and with a pore size of 22 ± 3 nm, was utilized for the separation of immunoglobulins (Igs). r_PEZ has been shown to bind to various Igs originating from a wide variety of species. To understand the mechanisms controlling the uptake of Igs by r_PEZ, static protein uptake experiments were carried out. The protein uptake profiles were further modeled with a kinetic rate constant model. Individual studies were undertaken for human immunoglobulin A, G and M (HIgA, HIgG and HIgM). The kinetic rate …

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The Use Of Confocal Laser Scanning Microscopy To Study The Transport Of Biomacromolecules In A Macroporous Support, Anuradha Subramanian, Jennifer Hommerding Apr 2005

The Use Of Confocal Laser Scanning Microscopy To Study The Transport Of Biomacromolecules In A Macroporous Support, Anuradha Subramanian, Jennifer Hommerding

Papers in Biotechnology

Large-pore materials or supports resembling polymer conduits are used as packing material in chromatographic operations. Our ongoing research has shown that, when modified with peptides or ligands, chitosan beads that are 800 m in diameter and have 3.5% solids can be used as matrices in bioseparations. The goal of the present study is to evaluate the transport properties of biomolecules in the modified chitosan beaded matrices. Batch uptake experiments with fluorescently tagged pure human IgG, human IgA and human IgM were conducted to visualize the distribution of binding sites throughout the bead as well as to evaluate restrictions to diffusion, …

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Identification Of The Mass Transfer Mechanisms Involved In The Transport Of Human Immunoglobulin - G In N,N,N',N' -Ethylnediaminetetramenthylenephosphonic Acid Modified Zirconia, Sabyasachi Sarkar, Perer W. Carr, Anuradha Subramanian Apr 2005

Identification Of The Mass Transfer Mechanisms Involved In The Transport Of Human Immunoglobulin - G In N,N,N',N' -Ethylnediaminetetramenthylenephosphonic Acid Modified Zirconia, Sabyasachi Sarkar, Perer W. Carr, Anuradha Subramanian

Papers in Biotechnology

Zirconia particles modified with N,N,N′,N′-ethylenediaminetetramethylenephosphonic acid (EDTPA), further referred to as r_PEZ, were studied as a support material for use in chromatography. Our previous studies have demonstrated the utility of r_PEZ in the separation of immunoglobulins from biological fluids. In the present study we sought to understand the underlying factors and identify the rate-limiting mechanisms that govern the transport of biomolecules in r_PEZ. Pulse injection techniques were used to elucidate the individual mass transfer parameters. Elution profiles obtained under retained and unretained conditions were approximated by the Gaussian equation and the corresponding HETP contributions were estimated. The dependence of …

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Identification And Expression Analysis Of Two Inorganic C-And N-Responsive Genes Encoding Novel And Distinct Molecular Forms Of Eukaryotic Phosphoenolpyruvate Carboxylase In The Green Microalga Chlamydomonas Reinhardtii, Tarlan G. Mamedov, Eric R. Moellering, Raymond Chollet Mar 2005

Identification And Expression Analysis Of Two Inorganic C-And N-Responsive Genes Encoding Novel And Distinct Molecular Forms Of Eukaryotic Phosphoenolpyruvate Carboxylase In The Green Microalga Chlamydomonas Reinhardtii, Tarlan G. Mamedov, Eric R. Moellering, Raymond Chollet

Papers in Biochemical Engineering

Phosphoenolpyruvate carboxylase (PEPC [Ppc]) has been previously purified and characterized in biochemical and immunological terms from two green microalgae, Chlamydomonas reinhardtii and Selenastrum minutum. The findings indicate that these algae possess at least two distinct PEPC enzyme-forms, homotetrameric Class1 and heteromeric Class-2 that differ significantly from each other and their plant and prokaryotic counterparts. Surprisingly, however, green-algal PEPC has been unexplored to date in molecular terms. This study reports the molecular cloning of the two Ppc genes in C. reinhardtii (CrPpc1, CrPpc2), each of which is transcribed in vivo and encodes a fully active, recombinant PEPC that lacks the regulatory, …

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Crystallization And Preliminary X-Ray Analysis Of Na-Asp-1, A Multi-Domain Pathogenesis-Related-1 Protein From The Human Hookworm Parasite Necator Americanus, Mehmet İnan, Oluwatoyin A. Asojo, Alex Lucas, Rick Barent, Jicai Huang, Brad Plantz, Amber Swanson, Mark Gouthro, Michael M. Meagher, Peter J. Hotez Mar 2005

Crystallization And Preliminary X-Ray Analysis Of Na-Asp-1, A Multi-Domain Pathogenesis-Related-1 Protein From The Human Hookworm Parasite Necator Americanus, Mehmet İnan, Oluwatoyin A. Asojo, Alex Lucas, Rick Barent, Jicai Huang, Brad Plantz, Amber Swanson, Mark Gouthro, Michael M. Meagher, Peter J. Hotez

Papers in Biochemical Engineering

Human hookworm infection is a major cause of anemia and malnutrition in the developing world. In an effort to control hookworm infection, the Human Hookworm Vaccine Initiative has identified candidate vaccine antigens from the infective larval stage (L3) of the parasite, including a family of pathogenesis related- 1 (PR-1) proteins known as the ancylostoma-secreted proteins (ASPs). The functions of the ASPs are unknown. In addition, it is unclear why some ASPs have one while others have multiple PR-1 domains. There are no known structures of a multi-domain ASP and in an effort to remedy this situation, recombinant Na …

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Secretion Of Recombinant Human Fibrinogen By The Murine Mammary Gland, William H. Velander Jan 2005

Secretion Of Recombinant Human Fibrinogen By The Murine Mammary Gland, William H. Velander

Papers in Biotechnology

Transgenic animals secreting individual chains and assembled fibrinogen were produced to evaluate the capacity of the mammary gland for maximizing assembly, glycosylation and secretion of recombinant human fibrinogen (rhfib). Transgenes were constructed from the 4.1 kbp murine Whey Acidic Protein promoter (mWAP) and the three cDNAs coding for the Aα,Bβ and γ fibrinogen chains. Transgenic mice secreted fully assembled fibrinogen into milk at concentrations between 10 and 200 μg/ml, with total secretion of subunits approaching 700 μ g/ml in milk. Partially purified fibrinogen was shown to form a visible and stable clot after treatment with human thrombin and factor XIII. …

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Secretion Of Recombinant Human Fibrinogen By The Murine Mammary Gland, William H. Velander Jan 2005

Secretion Of Recombinant Human Fibrinogen By The Murine Mammary Gland, William H. Velander

Papers in Biotechnology

Transgenic animals secreting individual chains and assembled fibrinogen were produced to evaluate the capacity of the mammary gland for maximizing assembly, glycosylation and secretion of recombinant human fibrinogen (rhfib). Transgenes were constructed from the 4.1 kbp murine Whey Acidic Protein promoter (mWAP) and the three cDNAs coding for the Aα,Bβ and γ fibrinogen chains. Transgenic mice secreted fully assembled fibrinogen into milk at concentrations between 10 and 200 μg/ml, with total secretion of subunits approaching 700 μ g/ml in milk. Partially purified fibrinogen was shown to form a visible and stable clot after treatment with human thrombin and factor XIII. …

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Preparation And Evaluation Of The Electrospun Chitosan/Peo Fibers For Potential Applications In Cartilage Tissue Engineering, Anuradha Subramanian, David Vu, Gustavo F. Larsen, Hsin Yii Lin Jan 2005

Preparation And Evaluation Of The Electrospun Chitosan/Peo Fibers For Potential Applications In Cartilage Tissue Engineering, Anuradha Subramanian, David Vu, Gustavo F. Larsen, Hsin Yii Lin

Papers in Biotechnology

Fibrous materials have morphological similarities to natural cartilage extracellular matrix and have been considered as candidate for bone tissue engineering scaffolds. In this study, we have evaluated a novel electrospun chitosan mat composed of oriented sub-micron fibers for its tensile property and biocompatibility with chondrocytes (cell attachment, proliferation and viability). Scanning electronic microscope images showed the fibers in the electrospun chitosan mats were indeed aligned and there was a slight cross-linking between the parent fibers. The electrospun mats have significantly higher elastic modulus (2.25 MPa) than the cast films (1.19 MPa). Viability of cells on the electrospun mat was 69% …

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Ranque–Hilsch Vortex Tube Thermocycler For Fast Dna Amplification And Real-Time Optical Detection, Ryan J. Ebmeier, Scott E. Whitney, Amitabha Sarkar, Michael Nelson, Nisha Padhye, George Gogos, Hendrik J. Viljoen Dec 2004

Ranque–Hilsch Vortex Tube Thermocycler For Fast Dna Amplification And Real-Time Optical Detection, Ryan J. Ebmeier, Scott E. Whitney, Amitabha Sarkar, Michael Nelson, Nisha Padhye, George Gogos, Hendrik J. Viljoen

Papers in Biochemical Engineering

An innovative polymerase chain reaction (PCR) thermocycler capable of performing real-time optical detection is described below. This device utilizes the Ranque–Hilsch vortex tube in a system to efficiently and rapidly cycle three 20 mL samples between the denaturation, annealing, and elon-gation temperatures. The reaction progress is displayed real-time by measuring the size of a fluo-rescent signal emitted by SYBR green/double-stranded DNA complexes. This device can produce significant reaction yields with very small amounts of initial DNA, for example, it can amplify 0.25 fg (,5 copies) of a 96 bp bacteriophage l-DNA fragment 2.731011-fold by performing 45 cycles in less than …

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Causes Of Proteolytic Degradation Of Secreted Recombinant Proteins Produced In Methylotrophic Yeast Pichia Pastoris: Case Study With Recombinant Ovine Interferon-T, Jayanta Sinha, Bradley A. Plantz, Mehmet Inan, Michael Meagher Dec 2004

Causes Of Proteolytic Degradation Of Secreted Recombinant Proteins Produced In Methylotrophic Yeast Pichia Pastoris: Case Study With Recombinant Ovine Interferon-T, Jayanta Sinha, Bradley A. Plantz, Mehmet Inan, Michael Meagher

Papers in Biotechnology

It was observed that during fermentative production of recombinant ovine interferon-H (r-oIFN-H ) in Pichia pastoris, a secreted recombinant protein, the protein was degraded increasingly after 48 h of induction and the rate of degradation increased towards the end of fermentation at 72 h, when the fermentation was stopped. Proteases, whose primary source was the vacuoles, was found in in-creasing levels in the cytoplasm and in the fermentation broth after 48 h of induction and reached maximal values when the batch was completed at 72 h. Protease levels at various cell fractions as well as in the culture supernatant …

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Exergy Use In Bioenergetics, Yaşar Demirel Nov 2004

Exergy Use In Bioenergetics, Yaşar Demirel

Papers in Analytical Chemistry

Every developed and adapted biological system extracts useful energy from outside, converts, stores it, and uses for muscular contraction, substrate transport, protein synthesis, and other energy utilizing processes. This energy management in a living cell is called the bioenergetics, and the useful energy is the exergy, which is destroyed in every irreversible process because of the entropy production. The converted exergy is the adenosine triphosphate (ATP) produced through the oxidative phosphorylation coupled to respiration in which the exergy originates from oxidation of reducing equivalents of nutrients. A living cell uses the ATP for all the energy demanding activities; it has …

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Production And Purification Of A Chimeric Monoclonal Antibody Against Botulinum Neurotoxin Serotype A , Mark C. Mowry, Michael Meagher Lead Investigator, Leonard Smith, Anuradha Subramanian Oct 2004

Production And Purification Of A Chimeric Monoclonal Antibody Against Botulinum Neurotoxin Serotype A , Mark C. Mowry, Michael Meagher Lead Investigator, Leonard Smith, Anuradha Subramanian

Papers in Biotechnology

Production of recombinant antibodies against botulinum neurotoxin is necessary for the development of a post-exposure treatment. CHO-DG44 cells were transfected with a plasmid encoding the light and heavy chains of a chimeric monoclonal antibody (S25) against botulism neurotoxin serotype A. Stable cell lines were obtained by dilution cloning and clones were shown to produce nearly equivalent levels of light and heavy chain antibody by an enzyme-linked immunosorbent assay (ELISA). In suspension culture, cells produced 35 μg/ml of chimeric antibody after 6 days, corresponding to a specific antibody productivity of 3.1 pg/cell/day. A method for the harvest and recovery of an …

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Haemophilic Factors Produced By Transgenic Livestock: Abundance That Can Enable Alternative Therapies Worldwide, Kevin E. Van Cott, Paul E. Monahan, Timothy C. Nichols, William H. Velander Oct 2004

Haemophilic Factors Produced By Transgenic Livestock: Abundance That Can Enable Alternative Therapies Worldwide, Kevin E. Van Cott, Paul E. Monahan, Timothy C. Nichols, William H. Velander

Papers in Biotechnology

Haemophilia replacement factors, both plasma-derived and recombinant, are in relatively short supply and are high-cost products. This has stymied the study and development of alternative methods of administration of haemophilia therapy even in the most economically advanced countries, owing to the large amounts of material needed because bioabsorption and bioavailability of haemophilic factors can be less than 10% when using non-intravenous routes of delivery. There is therefore a need to increase access to therapy worldwide by decreasing the cost and increasing the abundance so that therapy can be achieved through simplified, alternative delivery methods. Transgenic livestock have been used to …

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Optimization Of Cell Density And Dilution Rate In Pichia Pastoris Continuous Fermentations For Production Of Recombinant Proteins, Wenhui Zhang, Chih-Ping Liu, Mehmet Inan, Michael M. Meagher Jun 2004

Optimization Of Cell Density And Dilution Rate In Pichia Pastoris Continuous Fermentations For Production Of Recombinant Proteins, Wenhui Zhang, Chih-Ping Liu, Mehmet Inan, Michael M. Meagher

Papers in Biomolecular Engineering

This paper provides an approach for optimizing the cell density (Xc) and dilution rate (D) in a chemostat for a Pichia pastoris continuous fermentation for the extracellular production of a recombinant protein, interferon τ (INF-τ). The objective was to maximize the volumetric productivity (Q, mg INF-τ I-1 h-1), which was accomplished using response surface methodology (RSM) to model the response of Q as a function of Xc and D within the ranges 150 ≤ Xc ≤ 450 g cells (wet weight) l-1 and 0.1 μm ≤ D …

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