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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
551

In Acute Ischemic Stroke Patients With Smoking Incidence, Are More Women Than Men More Likely to Be Included or Excluded From Thrombolysis Therapy?

Rotimi, Oluyemi R., Ajani, Iretioluwa F., Penwell, Alexandria, Lari, Shyyon, Walker, Brittany, Nathaniel, Thomas I. 01 January 2020 (has links)
Background: Clinical factors associated with exclusion from recombinant tissue plasminogen activator in both men and women are not completely understood. The aim of this study is to determine whether there is a gender difference in clinical risk factors that excluded ischemic stroke patients with a history of smoking from recombinant tissue plasminogen activator. Methods: Retrospective data from a stroke registry were analyzed, and multivariable linear regression models were used to determine gender differences. Logistic regression models determined exclusion clinical risk factors for thrombolysis in male and female acute ischemic stroke patients with a history of smoking, while sequentially adjusting for sociodemographic, clinical, and stroke-related variables. The Kaplan–Meier survival analysis was used to determine the exclusion probabilities of men and women with a history of smoking within the stroke population. Results: Of the 1,446 acute ischemic stroke patients eligible for recombinant tissue plasminogen activator, 379 patients with a history of smoking were examined, of which 181 received recombinant tissue plasminogen activator while 198 were excluded from receiving recombinant tissue plasminogen activator. Of the 198 patients, 75 females and 123 males were excluded from receiving recombinant tissue plasminogen activator. After multivariable adjustment for age, National Institutes of Health scores, and stroke-related factors, females who present with weakness/paresis on initial examination (OR = 0.117, 95% CI, 0.025–0.548) and men who present with a history of previous transient ischemic attack (OR = 0.169, 95% CI, 0.044–0.655), antiplatelet medication use (OR = 0.456, 95% CI, 0.230–0.906), and weakness/paresis on initial examination (OR = 0.171, 95% CI, 0.056–0.521) were less likely to be excluded from recombinant tissue plasminogen activator (thrombolysis therapy). Conclusions: In an ischemic stroke population with a history of smoking, female smokers are more likely to be excluded from thrombolysis therapy in comparison to men, even after adjustment for confounding variables.
552

Successful Treatment of Autoimmune Neutropenia With Recombinant Human Granulocyte-Colony Stimulating Factor (R-metHuG-CSF)

Krishnan, K., Ross, C. W., Bockenstedt, P. L., Adams, P. T. 01 January 1997 (has links)
Autoimmune neutropenia (AIN) is characterized by antibody mediated peripheral destruction of neutrophils. Since there is no effective treatment, antibiotics have to be used frequently for recurrent infections. Five selected patients with serologically proven AIN were treated with r-metHuG- CSF at 5-8 μg/kg body weight (300-480 μg) daily: the dose and frequency of r-metHuG-CSF was reduced after neutrophil counts above 1.0 x 109/l were obtained. R-metHuG-CSF is effective in AIN and causes a sustained rise in ANC which can he maintained on a low dose administered twice or thrice weekly.
553

Denaturants or Cosolvents Improve the Specificity of PCR Amplification of a G + C-Rich DNA Using Genetically Engineered DNA Polymerases

Varadaraj, Kulandaiappan, Skinner, Dorothy M. 01 January 1994 (has links)
We describe conditions that improve the specificity of amplification of a G + C-rich (57% G + C) DNA by PCR. Under standard conditions a 368-bp segment of the approx. 2.1-kb repeat unit of a satellite DNA that accounts for approx. 3% of the genome of the Bermuda land crab, Gecarcinus lateralis, was not amplified specifically. To establish optimal conditions for amplification of the segment of the G + C-rich satellite, we used two genetically engineered enzymes, AmpliTaq DNA polymerase and AmpliTaq DNA polymerase. Stoffel fragment (SF), and a number of denaturants or co-solvents. In the absence of denaturants or co-solvents, amplified products of both enzymes contained non-specific bands upon gel electrophoresis. Addition of certain denaturants or co-solvents to PCR mixtures resulted in the production of the single specific band of the expected size. Reagents that improved specificity of the amplified product were formamide, glycerol, DMSO, Tween-20 and NP-40; on the other hand, urea, ethanol and 1-methyl-2-pyrrolidone (NMP) inhibited amplification. Of the two enzymes, SF was more specific and efficient. The products of AmpliTaq DNA polymerase included one or more extra bands, even in the presence of denaturants or co-solvents, except for glycerol or DMSO.
554

A Domain That Assumes a Z-Conformation Includes a Specific Deletion in Some Cloned Variants of a Complex Satellite

Fowler, Richard F., Stringfellow, Leslie A., Skinner, Dorothy M. 15 November 1988 (has links)
Sequence analyses show that deletions of 10 and 12 bp occur at homologous sites in a domain that is rich in alternating purines and pyrimidines (Pu/Py) in B42 and EXT, two cloned variants of a complex satellite DNA. A 3-bp deletion occurs 27 bp upstream from the site of the specific deletions in B42 and RU, a third cloned satellite variant that has not suffered the 10-bp deletion. Under torsional stress, the Pu/Py-rich domain adopts a Z-conformation as shown by (i) inhibition of cutting at a BssHII site that accounts for built2 5 of a 15-bp tract of pure Pu/Py in the domain; (ii) binding of polyclonal and monoclonal anti-Z-DNA antibodies to the domain; and (iii) antibody stabilization and subsequent relaxation of the Z-region.
555

Human Enteropeptidase Light Chain: Bioengineering of Recombinants and Kinetic Investigations of Structure and Function

Smith, Eliot T., Johnson, David A. 01 May 2013 (has links)
The serine protease enteropeptidase exhibits a high level of substrate specificity for the cleavage sequence DDDDK∼ X, making this enzyme a useful tool for the separation of recombinant protein fusion domains. In an effort to improve the utility of enteropeptidase for processing fusion proteins and to better understand its structure and function, two substitution variants of human enteropeptidase, designated R96Q and Y174R, were created and produced as active (>92%) enzymes secreted by Pichia pastoris with yields in excess of 1.7 mg/Liter. The Y174R variant showed improved specificities for substrates containing the sequences DDDDK (kcat/KM=6.83 × 106 M-1 sec-1) and DDDDR (kcat/ KM=1.89 × 107 M-1 sec-1) relative to all other enteropeptidase variants reported to date. BPTI inhibition of Y174R was significantly decreased. Kinetic data demonstrate the important contribution of the positively charged residue 96 to extended substrate specificity in human enteropeptidase. Modeling shows the importance of the charge-charge interactions in the extended substrate binding pocket.
556

Human Enteropeptidase Light Chain: Bioengineering of Recombinants and Kinetic Investigations of Structure and Function

Smith, Eliot T., Johnson, David A. 01 May 2013 (has links)
The serine protease enteropeptidase exhibits a high level of substrate specificity for the cleavage sequence DDDDK∼ X, making this enzyme a useful tool for the separation of recombinant protein fusion domains. In an effort to improve the utility of enteropeptidase for processing fusion proteins and to better understand its structure and function, two substitution variants of human enteropeptidase, designated R96Q and Y174R, were created and produced as active (>92%) enzymes secreted by Pichia pastoris with yields in excess of 1.7 mg/Liter. The Y174R variant showed improved specificities for substrates containing the sequences DDDDK (kcat/KM=6.83 × 106 M-1 sec-1) and DDDDR (kcat/ KM=1.89 × 107 M-1 sec-1) relative to all other enteropeptidase variants reported to date. BPTI inhibition of Y174R was significantly decreased. Kinetic data demonstrate the important contribution of the positively charged residue 96 to extended substrate specificity in human enteropeptidase. Modeling shows the importance of the charge-charge interactions in the extended substrate binding pocket.
557

Assessment of Field-Grown Cellulase-Expressing Corn

Garda, Martina, Devaiah, Shivakumar P., Vicuna Requesens, Deborah, Chang, Yeun Kyung, Dabul, Audrei, Hanson, Christy, Hood, Kendall R., Hood, Elizabeth E. 18 April 2015 (has links)
Transgenic plants in the US and abroad generated using genetic engineering technology are regulated with respect to release into the environment and inclusion into diets of humans and animals. For crops incorporating pharmaceuticals or industrial enzymes regulations are even more stringent. Notifications are not allowed for movement and release, therefore a permit is required. However, growing under permit is cumbersome and more expensive than open, non- regulated growth. Thus, when the genetically engineered pharmaceutical or industrial crop is ready for scale-up, achieving non-regulated status is critical. Regulatory compliance in the US comprises petitioning the appropriate agencies for permission for environmental release and feeding trials. For release without yearly permits, a petition for allowing non-regulated status can be filed with the United States Department of Agriculture with consultations that include the Food and Drug Administration and possibly the Environmental Protection Agency, the latter if the plant includes an incorporated pesticide. The data package should ensure that the plants are substantially equivalent in every parameter except for the engineered trait. We undertook a preliminary study on transgenic maize field-grown hybrids that express one of two cellulase genes, an exo-cellulase or an endo-cellulase. We performed field observations of whole plants and numerous in vitro analyses of grain. Although some minor differences were observed when comparing genetically engineered hybrid plants to control wild type hybrids, no significant differences were seen.
558

Production, Safety and Antitumor Efficacy of Recombinant Oncofetal Antigen/Immature Laminin Receptor Protein

Barsoum, Adel L., Liu, Bainan, Rohrer, James W., Coggin, Joseph H., Tucker, J. Allan, Pannell, Lewis K., Schwarzenberger, Paul O. 01 June 2009 (has links)
We describe here for the first time an efficient high yield production method for clinical grade recombinant human Oncofetal Antigen/immature laminin receptor protein (OFA/iLRP). We also demonstrate significant antitumor activity for this protein when administered in liposomal delivery form in a murine model of syngeneic fibrosarcoma. OFA/iLRP is a therapeutically very promising universal tumor antigen that is expressed in all mammalian solid tumors tested so far. We have cloned the human OFA/iLRP cDNA in a bacterial expression plasmid which incorporates a 6x HIS-tag. Large scale cultures of the plasmid transformed Escherichia coli were performed and the crude HIS-tagged OFA/iLRP was isolated as inclusion bodies and solubilized in guanidine chloride. The protein was then purified by successive passage through three column chromatography steps of immobilized metal affinity, anion exchange, and gel filtration. The resulting protein was 94% pure and practically devoid of endotoxin and host cell protein. The purified OFA/iLRP was tested in mice for safety and efficacy in tumor rejection with satisfactory results. This protein will be used for loading onto autologous dendritic cells in an FDA approved phase I/II human cancer vaccine trial in OFA/iLRP-positive breast cancer patients.
559

Molecular Characterization of Mitofilin, a Novel, Mitochondrial, Coiled Coil Protein, and the Relationship Between Organism Complexity and Coiled Coil Protein-Mediated Structure: A Dissertation

Odgren, Paul R. 01 November 1995 (has links)
In the course of experiments designed to identify and characterize structural proteins of the nuclear matrix, one antibody was generated which recognized an extraction-resistant cytoplasmic protein. This antibody was used as the starting point in the cloning and molecular characterization of a novel protein of the inter-membrane space of the mitochondrion which has been named mitofilin. Mitofilin is expressed in all human cell types, and murine homologues also exist. Mitofilin associates only with mitochondria and not with other membrane-bounded organelles such as Golgi or endoplasmic reticulum. This observation has been confirmed both by biochemical fractionation and multi-label fluorescence microscopy. Recombinant mitofilin, purified to homogeneity by affinity chromatography and preparative electrophoresis, was used to raise second-generation antibodies. Results of Western blot and immunofluorescence microscopy experiments, identical to those obtained using the original monoclonal antibody, verify the cloning and biochemical characterization. The mitofilin polypeptide contains several regions which are predicted to interact by forming coiled coils; a mitochondrial targeting signal; and a hydrophobic, membrane-spanning domain. During the course of this work, a sequence match was found with a cDNA reported by Icho, et al (1994) for a mRNA preferentially expressed in heart muscle, which they have called HMP. Evidence is presented which contradicts those authors' contention that HMP is a kinesin-like motor protein. In the course of these investigations, methods were developed to detect and quantitate the expression of solubilization-resistant proteins of the nuclear matrix and the nuclear matrix-intermediate filament scaffold. This was accomplished by combining SDS-PAGE, high sensitivity chemiluminescent Western blots, and scanning densitometry. Sensitivity in the picogram range was obtained, and reproducibility was assessed. For semi-quantitative measurements of protein expression in tissue samples, cell number was normalized by measurement of lamin B, the major protein of the nuclear envelope. Results of screening several cell and tissue types for the expression of mitofilin and for the nuclear matrix proteins NuMA, the nucleoporin tpr, and lamin B are presented. These preliminary data suggest a potential connection of over-expression of NuMA, tpr, and mitofilin with ovarian carcinoma. In addition, quantitative analysis of mitofilin expression in a variety of human cell types was done using purified recombinant protein antigen as the standard. The presence of coiled coil domains in these and other proteins associated with cellular sub-structures gave rise to the third area of investigation described here. Experimental observations of the nuclear matrix-intermediate filament scaffold (NMIF), a tissue-wide structure greatly enriched in coiled coil proteins, led to the following hypothesis: that the differentiated cell and tissue architecture which characterizes Metazoa has evolved through the propagation and selective expression of genes encoding a wide variety of coiled coil proteins, and the integration of the gene products into a tissue-wide matrix based on coiled coil interactions. This hypothesis was explored by computer searches of sequence data files. The GenBank phylogenetic sequence files were examined with a heptad repeat analysis program to assess the occurrence of coiled coil proteins. how heptad repeat domains are organized within these proteins, and what structural/functional categories they comprised. Of 102,007 proteins analyzed, 5.95% (6074) contained coiled coil domains: 1.26% (1289) contained "extended" (> 75 amino acid) domains. While the frequency of proteins containing coiled coils was surprisingly constant among all biota, extended coiled coil proteins were 4-fold more frequent in the animal kingdom, and may reflect early events in the divergence of plants and animals. Structure/function categories of extended coils also revealed phylogenetic differences. In pathogens and parasites, many extended coiled coil proteins are external and bind host proteins. In animals, the majority of extended coiled coil proteins were identified as constituents of two categories: 1) myosins and motors, or 2) components of the NMIF. This scaffold, produced by sequential extraction of epithelial monolayers in situ, contains only 1-2% of the cell mass while accurately retaining morphological features of living epithelium. The NMIF incorporates many proteins with extensive, interrupted coiled coil forming domains. The increased occurrence of this type of protein in Metazoa compared to plants or protists supports the hypothesis that a tissue-wide matrix of coiled coil interactions underlies metazoan differentiated cell and tissue structure.
560

Development of an elastic sealant for surgical applications

Dehghani, Bijan 08 April 2016 (has links)
The need to close wounds and prevent air/liquid leakage is commonly faced in surgical operations. It is a necessary step required for proper post-operative tissue function and healing. In the past, sutures and staples have been used to carry out this function; however, these different methods each come with limitations based on material and application. Recent studies have shown sealant glues to be a new method with much promise in connecting tissues. Several commercially available products have shown biocompatibility, along with ease of application and strong adherence; however, these come with their own set of limitations. In this project I present a novel tissue adhering substance made from human protein elastin. This protein sealant will allow us to address several issues in tissue-engineered materials such as biocompatibility, cytotoxicity, adhesion strength, binding in wet environment and elasticity. Using recombinant technology, we have been able to purify this protein monomer and form glue-like hydrogels using a cross-linker and UV light activator. This sealant was tested in in vitro models and porcine ex vivo lung model. The results indicate an increased adherence to the tissue as well as a high elasticity allowing the sealant to move more naturally with the tissue. Further testing in large animal in vivo studies will be performed to show safety and efficacy before being implemented into clinical practice.

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