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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.
11

Imunochemické stanovení aktivní a neaktivní formy katepsinu B u pacientů s karcinomem močového měchýře / Immunochemical determination of active and inactive form of cathepsin B in patients with bladder cancer

Urban, Tomáš January 2015 (has links)
This thesis is focused on immunochemical determination of concentration of active and inactive form of cathepsin B in patients with bladder cancer in order to compare diagnostic efficiency of methods for their possible use for routine diagnosis. Cathepsin B and procathepsin B were measured in serum and urine in 82 patients with bladder cancer (47 men and 35 women), with the average age of 66.5 year. The control group contain of 72 healthy subjects (31 men and 41 women), with the average age of 58.5 year. The concentration of cathepsin B and procathepsin B in the urine were corrected to creatinine, which was determined by the enzymatic creatinase method. The concentrations of cathepsin B in urine were singnificantly elevated in patients than in control group (median = 3.5 µg/l vs. 0.9 µg/l, P = 0.01), similarly the results of the cathepsin B/creatinine ratio were elevated (median = 0.4 µg/mmol vs. 0.1 µg/mmol, P = 0.01). There were no significant difference in concentration in serum between patients and control group (median = 4.8 µg/l vs. 4.2 µg/l, P = 0.8). The concentration values of procathepsin B were significantly higher in patients compare to control group both in urine (median = 3.9 µg/l vs. 1.4 µg/l, P < 0.0001), in serum (median = 73.3 µg/l vs. 58.7 µg/l, P = 0.0005) and similarly in...
12

BIS-MPA DENDRIMERS AS A PLATFORM FOR MOLECULAR IMAGING APPLICATIONS

Sadowski, Lukas January 2016 (has links)
The objective of this research was to develop and validate new macromolecular imaging agents to detect and characterize malignant tumours. Using well-defined, highly branched macromolecules called dendrimers as the structural scaffold, efficient functionalization of the periphery was demonstrated using “click” chemistry in order to prepare multivalent imaging probes. Furthermore, a transmetalation was demonstrated to displace chelated copper with technetium, enabling “click” reactions to be performed in the presence of the dipicolylamine (DPA), a ligand known to chelate many metals. The dendritic scaffold was functionalized with either hydrophobic or hydrophilic targeting vectors. The hydrophobic ligand, an acyloxymethyl ketone targeting the overexpression of cathepsin B exhibited poor in vitro affinity when coupled to either G1 or G2 dendrimers, despite the use of various linkers. A glu-urea-lys dipeptide, representing a hydrophilic prostate specific membrane antigen targeting vector, demonstrated excellent affinity in vitro. The lead compound, a G2 dendrimer bearing four PSMA targeting vectors attached via an alkyl spacer was further investigated in vitro and in vivo. Unfortunately, poor tumor uptake was observed and the compound was hypothesized to hydrolyze readily (<15min), based on the in vitro plasma stability data. To rectify the aforementioned problem, non neo-pentyl esters were replaced with either carbamate or ether linkages. In vitro plasma stability analysis of the analogous compounds demonstrated increased stability. In particular, the ether analogue was found to be most stable, with minimal degradation observed after 4 hours. / Thesis / Doctor of Philosophy (PhD)
13

Synthesis and Biological Activity of <i>N</i>-Acyl Aziridines

Wells, Greggory M. 04 August 2016 (has links)
No description available.
14

Lokalisation av cathepsin B och cystatin C i gingival vävnad från patienter med kronisk parodontit

Svensson, Eva-Liisa, Thulin, Regina January 2012 (has links)
Cysteinproteaset cathepsin B har en trolig roll i vävnadsnedbrytningen vid kronisk parodontit då det visats kunna bryta ner extracellulära komponenter. Cystatin C är en fysiologisk inhibitor av cathepsin B och båda har kopplats till parodontal sjukdom. Syftet med studien var att undersöka närvaro av samt lokalisera cathepsin B och cystatin C i gingivala biopsier från patienter med kronisk parodontit. Närvaro och lokalisation av cathepsin Bs och cystatin Cs demonstrerades genom immunohistokemisk metod av kryostatsnittad vävnad. Polyklonal kanin anti-human primär antikropp för både enzym och inhibitor användes. För identifiering av primära antikroppar användes Dako REAL™ EnVision™ Detection System. Granskning skedde i ljusmikroskop. Studien visar på en närvaro av både enzym och inhibitor i epitel och bindväv i parodontalt sjuk vävnad. Cathepsin B lokaliserades i stor utsträckning till bindväven, främst perivaskulärt. I epitelet lokaliserades endast ett fåtal infärgade celler. Cystatin C hade i bindväven en diffus utbredning vilket gjorde lokalisation till specifika cellpopulationer svår. I epitelet sågs en tydlig infärgning kring/i celler med dendritiskt utseende. Dessa celler identifierades som sannolika langerhanska celler. / The cysteine protease cathepsin B has been shown to have a possible role in tissue destruction in chronic periodontitis, as it has been shown to degrade extracellular components. Cystatin C is a physiological inhibitor of cathepsin B and both are associated with periodontal disease. The aim with this study was to investigate the presence and localization of cathepsin B and cystatin C in gingival biopsies from patients with chronic periodontitis. Cathepsin B's and cystatin C’s presence and localization was demonstrated by immunohistochemical method of cryostat sectioned tissue from patients with chronic periodontitis. Polyclonal rabbit anti-human primary antibody for both the enzyme and the inhibitor were used. Identification of the primary antibodies were confirmed with Dako REAL ™ EnVision ™ Detection System. The sectioned tissue was analysed by using light microscopy. Our study indicates a presence of both enzyme and inhibitor in epithelial and connective tissue from patients with periodontal disease. Cathepsin B was localized mainly to the connective tissue, primarily to the perivascular space. In the epithelium only a few stained cells were identified. In the connective tissue, cystatin C had a diffuse distribution. Therefor it was difficult to distinguish the specific cell populations associated with the inhibitor. The epithelium showed a clear staining around/in dendritic cells. These cells were identified as probable Langerhans cells.
15

Untersuchung des Effekts einer Überexpression von Cathepsin B in Zielzellen zytotoxischer Zellen / Analysis of the effect of an overexpression of cathepsin B in target cells of cytotoxic T cells

Kahlmeyer, Andreas Johannes 03 July 2012 (has links)
No description available.
16

Catepsinas B vitelolíticas de Culex quinquefasciatus. / Viteolytic cathepsinas B of Culex quinquefasciatus.

Moura, Alexandre Santos de 21 February 2014 (has links)
Apesar de Culex quinquefasciatus ser um eficiente vetor de doenças tais como a filariose linfática, febre do Nilo Ocidental e outras várias neuroviroses, poucas pesquisas sobre sua fisiologia têm sido conduzidas. Como em todos os animais ovíparos, o desenvolvimento embrionário dos mosquitos depende da degradação dos nutrientes armazenados no ovo, sendo a catepsina B uma protease que tem sido identificada e caracterizada em vários insetos como envolvida nesta função. Neste trabalho identificamos, por espectrometria de massas, duas catepsinas B de Culex quinquefasciatus, parcialmente purificadas por autoproteólise de extrato total de ovos. Segundo a anotação de suas sequências no banco de dados específico para vetores, o VectorBase, elas são enzimas parálogas e suas sequências apresentam 77% de homologia. Denominadas neste trabalho como CatB1 e CatB2, ambas são expressas simultaneamente no corpo gorduroso de todas as fêmeas vitelogênicas de nossa colônia e sua atividade pode ser detectada nos ovários vitelogênicos, sugerindo sua origem materna. A transcrição de ambas as enzimas se inicia após o repasto sanguíneo (ARS), alcançando o pico de expressão às 36 h ARS, de forma bastante semelhante à da vitelogenina. / Despite Culex quinquefasciatus be an efficient vector of diseases such as lymphatic filariasis, West Nile fever and other various neurotrophic viruses, little research on its physiology have been conducted. As in all oviparous animals, embryonic development of mosquitoes depends on the degradation of the nutrients stored in the egg. Cathepsin B is a protease that has been identified and characterized in a number of insects as involved in this function. In this work we have identified, by mass spectrometry, two cathepsins B of Culex quinquefasciatus, partially purified by self-proteolysis of total egg extract. According to the annotation of their sequences in the specific vector database, the VectorBase, they are paralogue enzymes and their sequences have 77% homology. Named in this work as CatB1 and CatB2, both are expressed simultaneously in the fat body of all vitellogenic females of our colony and its activity can be detected in vitellogenic ovaries, suggesting a maternal origin. The transcription of both enzymes starts post blood meal (PBM), reaching their peak of expression at 36 h PBM, quite similar to vitellogenin.
17

ACUTE RESPONSE OF NEUROPROTECTIVE ASSOCIATED BIOMARKERS TO VARIOUS COMPOUND RESISTANCE EXERCISES IN WELL-TRAINED MEN

Unknown Date (has links)
This study examined if multi-joint resistance exercises could elicit expression of biomarkers associated with neuroprotection. Thirteen well-trained males performed 4 sets to failure at 80% of a one-repetition maximum (1RM) on the back squat, bench press, and deadlift. The biomarkers measured immediately pre- and post-exercise were brain derived neurotrophic factor (BDNF), insulin-like growth factor 1 (IGF-1), cathepsin B (CatB), and interleukin 6 (IL-6). There was a main time effect (p<0.01) for BDNF with significant increases in the deadlift (p=0.01) and bench press (p=0.01) conditions, but not the squat (p=0.21). There was a main time effect (p<0.01) for IL-6 with a significant increase in the squat (p<0.01). There was no significant increase in CatB or IGF-1 (p>0.05). Additionally, there was no significant relationship between BDNF and IL-6 response. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection
18

Amyloid β-protein, Cystatin C and Cathepsin B as Biomarkers of Alzheimer's Disease

Sundelöf, Johan January 2010 (has links)
It is suggested that Alzheimer’s disease (AD) is caused by an imbalance between production, degradation and clearance of the amyloid-β (Aβ) protein. This imbalance leads to aggregation of Aβ and tau proteins and neurodegeneration in the brain. Today there is increasing evidence that the balance between the protease cathepsin B and the protease inhibitor cystatin C affects the tendency for Aβ to aggregate. The primary aim of this thesis was to investigate Aβ, cystatin C and cathepsin B levels in blood and cerebro-spinal fluid (CSF) in relation to the risk of AD. Studies I &amp; II were based on the re-examinations of participants, at ages 70 and 77, in the Uppsala Longitudinal Study of Adult Men (ULSAM), a community-based prospective study initiated in 1970 (participants then being 50 years of age). In ULSAM, low plasma Aβ1-40 (Study I) and low serum cystatin C levels (Study II) were associated with a higher risk of AD. Studies III &amp; IV were based on a cross-sectional sample of people with AD, mild cognitive impairment and healthy controls, recruited at three Swedish Memory Disorder units: Uppsala University Hospital, Uppsala, Skåne University Hospital, Malmö, and Karolinska University Hospital, Huddinge, Stockholm. In Study III, CSF cystatin C levels were positively correlated with both Aβ1-42 and tau levels. In Study IV, individuals with AD had higher mean plasma cathepsin B levels than healthy controls. In conclusion, low plasma Aβ1-40 and low serum cystatin C levels may precede clinically manifest AD in elderly men, cystatin C levels are positively correlated with Aβ1-42 and tau levels in CSF, and mean plasma cathepsin B levels are higher in people with AD compared to healthy controls. In addition to Aβ1-42 and tau levels in CSF, Aβ1-40, cystatin C and cathepsin B levels in blood may reflect the risk of AD.
19

A study of proteinases of invasive cells using cryoultramicrotomy and immunogold labelling.

Elliott, Edith. January 1993 (has links)
This study forms part of an investigation into the possible relevance of the lysosomal proteinases, cathepsins B, H, Land D, in cancer cell invasion. In this study, the main technique adopted was the Tokuyasu "cryo" method, in which the tissues were fixed, frozen and sectioned and labelled using the relevant antibodies, which were detected with protein A gold probes. In order to implement the Tokuyasu technique, it was necessary to rebuild a knife maker, for the production of adequately sharp glass knives, and to modify a sputter-coater into a glow-discharger, for rendering carbon-coated grids hydrophilic, to promote adhesion of hydrated sections. This study was directed towards human tissues and peptide antibodies were investigated as a means of avoiding isolation of proteins from scarce human tissue, and as a means of obtaining antibodies that will target specific regions of proteins of interest. Peptide antibodies were also considered promising for studies of proteinase trafficking and as immunoinhibiting agents, potentially useful in cancer therapy. Various prediction programmes were investigated for their effectiveness in predicting whether a given peptide sequence will elicit antibodies that will react with the native protein. Successful prediction would increase the success rate of peptide antibody production and thus lower the cost. Leucocytes were studied as a model of an invasive cell, since they are more readily available than tumour cells and serve the purpose during the development of methods. In the course of these studies, an optimal protocol for the fixation of PMNs was developed, involving lateral fixation of cut sections, that should be useful for future studies on these cells. Elastase and cathepsins D and G were found on the surface of activated PMNs and could thus play a role in the invasive properties of these cells. Studies on MCF-10A "normal" breast epithelial cells and their ras-transformed Neo-T counterparts revealed that upon transformation, lysosomes shift from a perinuclear position, to a more peripheral position. None of the cathepsins studied was found on the cell surface of either the normal or ras-transfected cells, suggesting that surface distribution of these enzymes may not be a requirement for invasiveness. These studies suggest that immunocytochemical investigation of cells, in the process of invading through a barrier membrane, might be profitable in elucidating the role of proteinases in invasive cancer. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1993.
20

The Design, Synthesis and Biological Assay of Cysteine Protease Specific Inhibitors

Mehrtens (nee Nikkel), Janna Marie January 2007 (has links)
This thesis investigates the design, synthesis and biological assay of cysteine protease inhibitors within the papain superfamily of cysteine proteases. This is achieved by examining the effect of inhibitor design, especially warheads, on IC₅₀ values and structureactivity relationships between cysteine protease inhibitors of the papain superfamily. The representative proteases used are m-calpain, μ-calpain, cathepsin B and papain. Chapter One is an introductory chapter; Chapters Two-Four describe the design and synthesis of cysteine protease inhibitors; Chapter Five discusses assay protocol; and Chapter Six contains the assay results and structure-activity relationships of the synthesised inhibitors. Chapter One introduces cysteine proteases of the papain family and examines the structure, physiology and role in disease of papain, cathepsin B, m-calpain and μ-calpain. The close structural homology that exists between these members of the papain superfamily is identified, as well characteristics unique to each protease. Covalent reversible, covalent irreversible and non-covalent warheads are defined. The generic inhibitor scaffold of address region, recognition and warhead, upon which the inhibitors synthesised in this thesis are based, is also introduced. Chapter Two introduces reversible cysteine protease inhibitors found in the literature and that little is known about the effect of inhibitor warhead on selectivity within the papain superfamily. Oxidation of the dipeptidyl alcohols 2.6, 2.26, 2.29, 2.30, 2.35 and 2.36 utilising the sulfur trioxide-pyridine complex gave the aldehydes 2.3, 2.27, 2.19, 2.2, 2.21 and 2.22. Semicarbazones 2.37-2.40 were synthesised by a condensation reaction between the alcohol 2.3 and four available semicarbazides. The amidoximes 2.48 and 2.49 separately underwent thermal intramolecular cyclodehydration to give the 3-methyl-1,2,4- oxadiazoles 2.41 and 2.50. The aldehydes 2.3 and 2.27 were reacted with potassium cyanide to give the cyanohydrins 2.51 and 2.52. The cyanohydrins 2.51 and 2.52 were separately reacted to give 1) the α-ketotetrazoles 2.43 and 2.55; 2) the α-ketooxazolines 2.42 and 2.58; 3) the esterified cyanohydrins 2.60 and 2.61. A two step SN2 displacement reaction of the alcohol 2.6 to give the azide 2.62, an example of a non-covalent cysteine protease inhibitor. Chapter Three introduces inhibitors with irreversible warheads. The well-known examples of epoxysuccinic acids 3.1 and 3.5 are discussed in detail, highlighting the lack of irreversible cysteine protease specific inhibitors. The aldehydes 2.3 and 2.27 were reacted under Wittig conditions to give the α,β-unsaturated carbonyls 3.14-3.18. Horner- Emmons-Wadsworth methodology was utilised for the synthesis of the vinyl sulfones 3.20- 3.23. The dipeptidyl acids 2.24 and 2.28 were separately reacted with diazomethane to give the diazoketones 3.25 and 3.26. The diazoketones 3.25 and 3.26 were separately reacted with hydrogen bromide in acetic acid (33%) to give the α-bromomethyl ketones 3.27 and 3.28, which were subsequently reduced to give the α-bromomethyl alcohols 3.29-3.32. Under basic conditions the α-bromomethyl alcohols 3.29-3.32 ring-closed to form the peptidyl epoxides 3.33-3.36. Chapter Four introduces the disadvantages of peptide-based inhibitors. A discussion is given on the benefits of constraining inhibitors into the extended bioactive conformation known as a β-strand. Ring closing metathesis is utilised in the synthesis of the macrocyclic aldehyde 4.4, macrocyclic semicarbazone 4.15, the macrocyclic cyanohydrin 4.16, the macrocyclic α-ketotetrazole 4.18 and the macrocyclic azide 4.19. Chapter Five introduces enzyme inhibition studies. The BODIPY-casein fluorogenic assay used for establishing inhibitor potency against m-calpain and μ-calpain is validated. Assay protocols are also established and validated for cathepsin B, papain, pepsin and α- chymotrypsin. A discussion of the effect of solvent on enzyme activity is also included as part of this study. Chapter Six presents the assay results for all the inhibitors synthesised throughout this thesis and an extensive structure-activity relationship study between inhibitors is included. The alcohols 2.26 and 2.30 are unprecedented examples of non-covalent, potent, cathepsin B inhibitors (IC₅₀ = 0.075 μM selectivity 80-fold and 1.1 μM, selectivity 18-fold). The macrocyclic semicarbazone 4.15 is an unprecedented example of a potent macrocyclic cysteine protease inhibitor (m-calpain: IC₅₀ = 0.16 μM, selectivity 8-fold). The cyanohydrin 2.51 contains an unprecedented cysteine protease warhead and is a potent and selective inhibitor of papain (IC₅₀ = 0.030 μM, selectivity 3-fold). The O-protected cyanohydrin 2.61 is a potent and selective inhibitor of pepsin (IC₅₀ = 1.6 μM, selectivity 1.5-fold). The top ten warheads for potent, selective cathepsin B inhibition are: carboxylic acid, methyl ester, diazoketone, esterified cyanohydrin, α-bromomethyl ketone, α,β- unsaturated aldehyde, vinyl sulfones, α-bromomethyl-C₃-S,R-alcohol, alcohol and α,β- unsaturated ethyl ester. The selectivity of these warheads was between 5- and 130-fold for cathepsin B. The best inhibitors for cathepsin B were the α-bromomethyl ketone 3.26 (IC₅₀ = 0.075 μM, selectivity 16-fold), the α,β-unsaturated aldehyde 3.18 (IC₅₀ = 0.13 μM, selectivity 13-fold) and the esterified cyanohydrin 3.59 (IC₅₀ = 0.35 μM, selectivity 22- fold). Chapter Seven outlines the experimental details and synthesis of the compounds prepared in this thesis.

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