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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.
61

Angiotensin Converting Enzyme Inhibitor Cough: A Review of Characteristics, Frequency, Mechanism, and Treatment

Sulzbach, Robert M. January 2008 (has links)
Class of 2008 Abstract / Objectives: : The purpose of this paper is to provide greater understanding of ACE inhibitor cough and appropriate treatment options. Methods: A Medline search of key terms from 1975-2008 was conducted and all types of published material were included in this review. The articles were evaluated for relevance and appropriateness for inclusion in this review. Subjects considered appropriate included ACE inhibitor cough treatment, mechanism of action, incidence and prevalence, genetics, cough characteristics, onset and resolution of cough, and others. Whenever possible, original studies were obtained but several reviews were also used. Results: ACE inhibitor cough is typically a dry, non-productive, persistent but benign cough reportedly occurring in anywhere from 0.5%-50% of patients receiving ACE inhibitors, though most studies indicate less than 20%. The mechanism is not completely understood but seems to be related to a complicated mechanism involving pathways caused by ACE inhibition and including bradykinin, C fibers, and prostaglandins. Several treatment options have been successful in resolving or relieving cough, including NSAIDs, baclofen, cromolyn and others. Results, however, are inconsistent. Anti-tussive agents, switching to a different ACE inhibitor, or lowering the dose of the current ACE inhibitor do not seem to be effective. Conclusions: In spite of its benign nature, ACE inhibitor cough is usually bothersome enough to discontinue the medication and therefore can not be ignored. Several treatments have appeared effective, all of which carry the risk of drug interactions and additional side effects, and alternative therapy such as angiotensin receptor blockers seem to be reasonable in indicated patients.
62

STRUCTURAL & KINETIC STUDIES ON LIGAND SPECIFICITY IN AVIAN, CHIROPTERAN, AND HUMAN CORONAVIRAL 3CL PROTEASES

Brandon J Anson (11525971) 22 November 2021 (has links)
SARS-CoV-2, the coronavirus responsible for the CoVID-19 syndrome, continues to be a major public health crisis worldwide. While the ongoing vaccination development and deployment efforts are a critical first line of defense, small-molecule therapeutics are needed to treat those who are infected and in desperate need of medical attention. Perhaps the most studied coronaviral target is the 3CL protease enzyme responsible for the proteolytic processing of the viral polyproteins pp1a and pp1ab which is essential for viral replication. We evaluated a series of five new compounds with four containing an (acyloxy)-methyl ketone reactive group including clinical candidate Pf-00835231 for their inhibitor potencies against SARS-CoV23CL protease. All five compounds exhibit remarkable potencies with Kivalues in the high picomolar to low nanomolar range against SARS-CoV-2. The X-ray structures of all five compounds were determined in complexes with SARS-CoV-2 3CLpro to between 1.4 Å and 1.6 Å resolution. All five compounds are observed to form a covalent bond with catalytic Cysteine 145 with four compounds forming adducts with the expected tetrahedral geometry. Compound 4 however, which contains an (acyloxy)-methyl ketone warhead, was found to form an adduct with bond geometries similar to an episulfonium cation. Despite possessing similar chemistry and scaffolds, inhibitor binding to the SARS-CoV-2 3CLpro induced a variety of subtle active site conformational differences, particularly in the S2/S4 separating strand and connecting strands.<div><br></div><div>Understanding substrate specificity in coronaviral main protease is essential for designing competitive inhibitors. While first principles are already established, including a Q/X cleavage-site (where X is either Alanine or Serine), differences exist between α, β, γand δ clades that are important for recognition, and ultimately inhibitor design. Covalent complexes of SARS-CoV-2 and avian infectious bronchitis virus (IBV) covalently bound, in trans, to the C-terminus of the same enzyme have been crystallized and modeled at 2.6 and 2.2 Å, respectively. The similarities and differences in their binding are described in chapter 6.<br></div><div><br></div><div>Middle-East Respiratory Syndrome Coronavirus is a re-emergent zoonotic pathogen with a 30% mortality rate in humans. The positive-sense single-stranded RNA genome is translated by the into polyproteins 1a (pp1a) and polyprotein 1ab (pp1ab). Pp1ab contains the constituents of the viral RNA-dependent RNA polymerase complex. These must be cleaved by 3CLpro, which is contained within this pair of polyproteins, before viral replication and transcription may occur. Attempts to drug this cysteine protease have proven difficult since competitive inhibitors activate the Wild-Type protease at low concentrations via a non-competitive binding mechanism. This mechanism is mediated by non-conserved residues in regions that are distal to the catalytic site. During the viral life-cycle these residues modulate recognition This study focuses on determining the identities of these residues and their effects on the dose-response curves of established competitive inhibitors of Coronaviral 3CLpro. It also explores how the residues in these regions synergize to effect intrinsic kinetic parameters of this family of enzymes including turnover (kcat) and dimer dissociation constant (KD). Additionally, a rapid-equilibrium kinetic model was developed to rationalize this unique phenomenon where competitive inhibitors cause significant activation of the enzyme’s activity.<br></div>
63

AFM studies of the Metallicity of Single-walled Carbon Nanotubes and Corrosion Inhibitor Adsorption

Xiong, Yao 03 October 2011 (has links)
No description available.
64

A quantitative assessment of the anti-nutritional properties of Canadian pulses

Shi, Lan 22 December 2015 (has links)
This study has assessed the effects of pulse type and processing (soaking and cooking) on antinutritional factors (α-amylase inhibitor, trypsin inhibitor, chymotrypsin inhibitor, lectins, phytic acid and oxalates) in a wide range of Canadian pulses, using soybean as a control. The contents of these antinutrients in Canadian pulses varied widely, but the levels were generally lower than those found in soybean. Analysis of variance indicated that both pulse type and processing had significant effects (P < 0.0001) on the investigated seeds. Soaking markedly decreased the contents of α-amylase inhibitor, trypsin inhibitor, chymotrypsin inhibitor, lectins and oxalates, but had no impact on phytic acid. Cooking of presoaked seeds appeared to be more effective; all proteinaceous antinutrients (α-amylase inhibitor, trypsin inhibitor, chymotrypsin inhibitor and lectins) were decreased by 80 – 100%, and significant reductions in phytic acid content (11 – 39%) were observed for all pulses, except common beans and soybean. / February 2016
65

Interakce vybraných protinádorových látek ze skupiny inhibitorů MAPK/ERK signalizační kaskády s ABC lékovými transportéry / Interactions of selected anticancer drugs of the MAPK/ERK signaling pathway inhibitors group with the ABC drug transporters

Slatinský, Lukáš January 2018 (has links)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Lukáš Slatinský Supervisor: Assoc. prof. PharmDr. Martina Čečková, Ph.D. Title of diploma thesis: Interactions of selected anticancer drugs of the MAPK/ERK signaling pathway inhibitors group with the ABC drug transporters ABCB1 (Pgp, P-glycoprotein) and ABCG2 (BCRP, breast cancer resistance protein) are members of a transmembrane efflux ATP dependent transporter family, so called ATP-binding cassettes (ABC). Physiologicaly they are expressed in the cellular membrane and protect body tissues against potentially toxic xenobiotics including drugs. They represent also one of the tumor defense mechanisms when being able to efflux a wide variety of cytotoxic drugs out of the cancer cells leading to treatment failure. BRAF protein plays an important regulatory and signal role in MAPK/ERK pathway affecting cell division, differentiation and secretion. Mutations of BRAF lead to overactivity in MAPK/ERK pathway in many cancer cells and can be therefore targeted by anticancer therapy. Cobimetinib and dabrafenib are relatively new anticancer therapeutics inhibiting the signal pathway mentioned above and they are used in treatment of melanoma carrying the BRAF mutation. The aims of this project were to...
66

Anticoagulation Review: A Primer for the Home Health Care Provider

Stewart, David W., Gentry, Chad, Freshour, Jessica 01 April 2012 (has links)
Anticoagulants, also known as antithrombotics, are among the most commonly prescribed medications in the United States. Understanding how these medications work, the propensity for interactions with other drugs, dietary factors, and disease states is important for clinicians assessing and providing care to patients in all environments. In this review, we seek to provide essential information for the home health care provider for evaluating patients receiving anticoagulants commonly prescribed in the home health care setting. The low-molecular-weight heparins and vitamin K antagonists are the most commonly used agents for outpatient anticoagulation. New agents, such as the direct factor Xa inhibitors and direct thrombin inhibitors have recently been approved with additional new agents in the approval process and development pipeline. We seek to review the most pertinent information for each of these classes of medications providing information on pharmacology, interactions with other drugs, diet, and diseases and important clinical information.
67

Carfilzomib demonstrates broad anti-tumor activity in pre-clinical non-small cell and small cell lung cancer models

Baker, Amanda F., Hanke, Neale T., Sands, Barbara J., Carbajal, Liliana, Anderl, Janet L., Garland, Linda L. January 2014 (has links)
BACKGROUND: Carfilzomib (CFZ) is a proteasome inhibitor that selectively and irreversibly binds to its target and has been approved in the US for treatment of relapsed and refractory multiple myeloma. Phase 1B studies of CFZ reported signals of clinical activity in solid tumors, including small cell lung cancer (SCLC). The aim of this study was to investigate the activity of CFZ in lung cancer models. METHODS: A diverse panel of human lung cancer cell lines and a SHP77 small cell lung cancer xenograft model were used to investigate the anti-tumor activity of CFZ. RESULTS: CFZ treatment inhibited both the constitutive proteasome and the immunoproteasome in lung cancer cell lines. CFZ had marked anti-proliferative activity in A549, H1993, H520, H460, and H1299 non-small cell lung cancer (NSCLC) cell lines, with IC₅₀ values after 96 hour exposure from <1.0 nM to 36 nM. CFZ had more variable effects in the SHP77 and DMS114 SCLC cell lines, with IC₅₀ values at 96 hours from <1 nM to 203 nM. Western blot analysis of CFZ-treated H1993 and SHP77 cells showed cleavage of poly ADP ribose polymerase (PARP) and caspase-3, indicative of apoptosis, and induction of microtubule-associated protein-1 light chain-3B (LC3B), indicative of autophagy. In SHP77 flank xenograft tumors, CFZ monotherapy inhibited tumor growth and prolonged survival, while no additive or synergistic anti-tumor efficacy was observed for CFZ + cisplatin (CDDP). CONCLUSIONS: CFZ demonstrated anti-proliferative activity in lung cancer cell lines in vitro and resulted in a significant survival advantage in mice with SHP77 SCLC xenografts, supporting further pre-clinical and clinical investigations of CFZ in NSCLC and SCLC.
68

Neuroprotection gene therapy in retinal degeneration

Shan, Haidong January 2013 (has links)
Retinal degenerative disease, which includes age-related macular degeneration and retinitis pigmentosa, is the main cause of blindness in developed countries. Degeneration of the retinal pigment epithelium (RPE) and photoreceptor cells through apoptosis is believed to be the main mechanism of cell death. X-linked inhibitor of apoptosis (XIAP) is an endogenous anti-apoptotic protein that mediates its effects through the inhibition of caspases - the proteins regulating the final stages of apoptosis. The neuroprotection of XIAP has been demonstrated in various neurodegenerative models. Retinal gene therapy based on adeno-associated virus (AAV) has recently been proven safe and effective in clinical trials of Leber's congenital amaurosis. However, studies are very limited so far about AAV-mediated XIAP effect on degeneration of the RPE and photoreceptor cells. In this thesis, a comprehensive study of AAV-mediated XIAP was performed in the RPE and photoreceptor degenerative models. First, an oxidative stress model was investigated using H2O2 in a human RPE cell line. Second, AAV2-mediated XIAP conferred marked protection on the RPE cells against H2O2 induced apoptosis. Third, an in vivo analysis using confocal scanning laser ophthalmoscope was applied to the NaIO3 induced retinopathy in two transgenic mice (NRL-GFP and B6TGOPN1LW-EGFP). However, subretinal injection of AAV2-XIAP did not rescue photoreceptor cells in the NaIO3-treated animals. Finally, AAV8-XIAP was tested in a rhodopsin mutant mouse line with retinal degeneration (the Rho-/- B6TGOPN1LW-EGFP mouse) but did not reveal any protection on cone photoreceptors. Overall the work in this thesis indicates a limited protection of AAV-mediated XIAP on the RPE and photoreceptor cells in the degenerative models used. XIAP based gene therapy may be helpful for RPE preservation in atrophic AMD, but it needs further research.
69

The role of matrix metalloproteinase-2 and its inhibitors in keratoconus

Parkin, Ben January 2001 (has links)
No description available.
70

Reversible Photoregulation of Binding of the Serine Protease α-Chymotrypsin to a Functional Surface

Pearson, David Scott January 2007 (has links)
This thesis presents the first example of reversible photoregulation of the binding of a protease, α-chymotrypsin, to a surface. A modular approach is used involving the azobenzene photoswitch group, a surface linker and an enzyme binding group. This approach is designed to be easily extended to the photoregulation of binding of other proteases to surfaces by use of enzyme binding groups selective to these proteases. Chapter one gives a brief outline of some of the important areas involved in to this work, including molecular switches, proteases and surface modification. Chapter two describes the synthesis of azobenzene-containing boronate esters designed as photoswitch inhibitors of α-chymotrypsin. Boronate esters were prepared containing the aminophenylboronate group or the peptidomimetic borophenylalanine group for enzyme binding and a range of substituents designed for enzyme affinity and/or surface attachment. Syntheses primarily involved peptide coupling reactions and azobenzene formation by condensation of nitrosobenzenes and anilines. Coupling reactions were successfully carried out using EDCI or isobutyl chlorofomate in several cases where other reagents gave unacceptable decomposition. Chapter three describes the syntheses and HPLC stability studies of derivatives of a noncovalent α-chymotrypsin inhibitor. Several dipeptide-based compounds containing either an amide group for surface attachment or an azobenzene group for photoswitching were prepared, primarily using peptide coupling reactions. Each compound was incubated with α-chymotrypsin to assess its stability, and all were found by HPLC monitoring to be stable to α-chymotrypsin catalysed hydrolysis. Chapter four describes syntheses of azobenzene-containing trifluoromethylketones and α-ketoesters designed as photoswitch inhibitors of α-chymotrypsin. Trifluoromethylketones/α-ketoesters containing amine groups for surface attachment were prepared, primarily using peptide coupling reactions, but could not be isolated due to the incompatibility of the electrophilic ketone and primary amine groups. Trifluoromethylketones/α-ketoesters containing terminal alkynes for surface attachment were prepared either by the attachment of an alkyne substituent group to a symmetrical azobenzene core or by Pd-catalysed reaction of a protected alkyne with an azobenzene having a halide substitutent. Chapter five describes syntheses of sulfur-containing surface linkers for use in surface attachment of the photoswitch inhibitors described in chapters 2-4. A range of compounds containing disulfide or protected thiol groups for surface attachment and azide or carboxylic acid groups for inhibitor attachment were prepared. Syntheses primarily involved coupling of functionalised alcohols/amides to carboxylic acid-containing disulfides/thioacetates. Selected linkers were attached to azobenzenes by amide coupling or azide-alkyne cycloaddition for surface attachment, photoswitching and/or enzyme assay. Azide-alkyne cycloaddition yields were initially poor, but were improved by use of stoichiometric amounts of copper catalyst. Chapter six describes UV/vis photoisomerisation studies and enzyme assays carried out to assess enzyme photoswitching of the compounds described in chapters 2-5. The trifluoromethylketones and α-ketoesters described in chapter 4 gave the best results, with moderate inhibition of α-chymotrypsin (µM affinity constants) and up to 5.3 fold changes in inhibition on UV/vis irradiation. Many of the boronate esters described in chapter 2 were found to inhibit α-chymotrypsin, but were somewhat unstable to irradiation. The dipeptide-based compounds described in chapter 3 were inactive against α-chymotrypsin. Good photoisomerisation was obtained for an azobenzene containing a symmetrical disulfide surface linker and poor photoisomerisation was obtained for an azobenzene containing a lipoic acid surface linker. Chapter seven describes surface attachment of selected photoswitch inhibitors and studies of photoregulated enzyme binding to the resultant functional surfaces. Self assembled monolayers (SAMs) of disulfides were formed on gold surfaces and characterised by electrochemistry and contact angle measurements. Binding of α-chymotrypsin to SAMs containing a photoswitch inhibitor was detected by quartz crystal microbalance (QCM), but was found to be largely irreversible. An alkyne-containing photoswitch inhibitor was attached to a surface plasmon resonance (SPR) chip in a two step procedure involving generation of an azide modified surface followed by azide-alkyne cycloaddition. Binding of α-chymotrypsin to the resultant modified surface was detected by SPR and successfully regulated by UV/vis irradiation. Chapter eight provides conclusions for the work described in this thesis and suggests future directions. Chapter nine gives experimental details for the work described in this thesis.

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