Spelling suggestions: "subject:"biochemical cancerdiagnostic used"" "subject:"biochemical fasterdiagnostic used""
11 |
Mechanism of neuroprotection in stroke-related modelsUnknown Date (has links)
Stroke is the third leading cause of mortality in the United States, and so far, no clinical interventions have been proved truly effective in stroke treatment. Stroke my result in hypoxia, glutamate release and oxidative stress, etc. The purpose of this dissertation study is to evaluate the neuroprotective effects of four drugs (taurine, G-CSF sulindac and DETC-MeSO) on PC12 cell line or primary cortical neuronal cell culture, and to understand the protective mechanisms underlying in three stroke-related models : hypoxia, excessive glutamtate and oxidative stress. In the first part of this dissertation, we studied the neuroprotection of taurine against oxidative stress induced by H2O2 in PC12 cells. Our results show that extracellular taurine exerts a neuroprotective function by restoring the expression of Bcl-2 and downregulation of the three Endoplasmic Reticulum (ER) stress markers : GRP78, Bim and CHOP/GADD153, suggesting that ER stress can be provoked by oxidative stress and can be suppressed by taurine. In the second part, glutamate excitotoxicity-induced ER stress was studied with dose and time as variables in primary cortical neurons. The results demonstrate that glutamate excitotoxicity leads to the activation of three ER stress pathways (PERK, ATF6 and IRE1) by initiating PERK first, ATF6 second and IRE1 pathway last. The third part of this dissertation studied the robust and beneficial protection of taurine in cortical neurons under hypoxia/reoxygenation or glutamate toxicity condition. We found that taurine suppresses the up-regulation of GRP778, Bim, caspase-12 and GADD153/CHOP induced by excessive glutamate or hypoxia/reoxygenation, suggesting that taurine may exert a protective function against hypoxia/regeneration by reducing the ER stress. / Moreover, taurine can down-regulate the ratio of cleaved ATF6 and full length ATF6, and p-IRE1 expresssion, indicating that taurine inhibits the ER stress induced by hypoxia/reoxygenation or glutamate through suppressing ATF6 and IRE1 pathways. In the fourth part, the synergistic benefits of the combination of taurine and G-CSF, and the neuroprotective effects of G-CSF, sulindac or DETC-MeSO are studied in cortical neurons. Our results show that G-CSF, sulindac or DETC-MeSO can highly increase the neuron visibility by inhibiting ER stress induced by hypoxia/reoxygenation or glutamate toxicity. Furthermore, we proved that G-CSF or sulindac can significantly inhibit the activation of ATF6 or IRE1 pathway stimulated by hypoxia/reoxygenation, and DETC-MeSO can suppress the activation of both PERK and IRE1 pathways in primary neuron cultures. These findings provide promising and rational strategies for stroke therapy. / by Chunliu Pan. / Thesis (Ph.D.)--Florida Atlantic University, 2012. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2012. Mode of access: World Wide Web.
|
12 |
Studies on the mechanism by which sulindac sensitizes cancer cells to oxidative stressUnknown Date (has links)
by Alexander Kreymerman. / Thesis (M.S.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web. / Sulindac is a known NSAID that has also been shown to have anti-cancer activity that is not related to its ability to inhibit COX 1 and 2. During the past 15 years there have been a large number of studies attempting to elucidate its mechanism of action. Our laboratory has shown that sulindac can both protect normal cells and enhance the killing of cancer cells under oxidative stress from H2O2 and TBHP. However, except for mitochondrial dysfunction and ROS production, the mechanism by which sulindac sensitized the cancer cells to oxidative stress remains unknown. Results of this research project suggest that the effect of sulindac and oxidative stress not only involves mitochondrial ROS production, but also aspects of the preconditioning response. In normal cells this leads to survival by a preconditioning pathway, likely involving PKCε. . However, cancer cells react by initiating a pathway leading to apoptosis involving PKCδ.
|
13 |
Mechanism and treatment of restrictive cardiomyopathyUnknown Date (has links)
Restrictive cardiomyopathy (RCM) is a cardiac muscle disorder characterized by increased ventricular stiffness and diastolic dysfunction. Patients with RCM often present severe cardiac problems which usually lead to heart failure and sudden death. No effective treatment is available for RCM which makes the finding of novel efficient therapies an urgent necessity. Great progress in molecular biology techniques and advances in transgenic animal development provide great opportunities for the study of RCM and other cardiovascular diseases encountered in clinical patients.... Our laboratory is among the first to generate transgenic mouse models of RCM based on cardiac troponin I (cTnI) missense mutations. In this study, transgenic mice that suffer from RCM have been generated to understand the factors behind the diastolic dysfunction associated with that myocardial disease.... The information obtained from this study allows a better understanding of the role of troponin in RCM and the factors behind the physiopathology of the disease. It will also offer a therapeutic strategy taking into account the physiological characteristic of RCM. / by Pierre-Ives Jean-Charles. / Thesis (Ph.D.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
|
14 |
cTnI N-Terminal deletion: an agent for rescuing restrictive cardiomyopathy, a disease caused by mutations of Cardiac Troponin IUnknown Date (has links)
Restrictive cardiomyopathy (RCM) is represented in part by left ventricular stiffness
and diastolic dysfunction. Missense mutations of the cardiac troponin I (cTnI) gene cause
idiopathic RCM. These mutations are located in the C-terminus of cTnI and affect cardiac
relaxation. Transgenic mouse models presenting the pathology observed in clinical
patients with RCM have been generated previously and express the mutant cTnI in their
hearts. RCM-linked mutations increase cardiac myofilament Ca2+ sensitivity and promote
diastolic dysfunction in the heart. Previous studies using double transgenic mice
(cTnI/R193H/ND) showed that ventricular relaxation is enhanced in the cTnI/R193H
transgenic mice. In this study, another double transgenic mouse model,
(cTnI/R193H/ND/KO), provides an avenue to investigate its rescuing effects on RCMlinked
mutations in the cTnI /R193H/KO mouse. Use of molecular biological techniques,
transgenic animal developments and murine echocardiography in this study has
culminated into a greater understanding of RCM and diastolic dysfunction. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
|
15 |
Non-invasive evaluation of non-alcoholic fatty liver disease using biochemical and genetic markers. / CUHK electronic theses & dissertations collectionJanuary 2013 (has links)
Shen, Jiayun. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 166-199). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
|
16 |
Fluorescent Indicators for Disease BiomarkersLim, Soojin 01 January 2012 (has links)
Xanthene dyes are common fluorophores which have been widely used as molecular probes. The xanthene fluorophores can be used as highly selective optical sensors to detect disease biomarkers. A new fluorogenic dye containing an alpha, beta-unsaturated aldehyde moiety exhibits selective fluorescent signal enhancement in the presence of cysteine or peptides containing N-terminal cysteine residues. The mechanism is based on synergistic covalent and supramolecular interactions. A unique rhodamine boronic acid indicator is used in an optimized data collection protocol for wavelength- and time-dependent selectivity of various saccharides and nucleosides. One indicator is thereby capable of selectively distinguishing structurally related analytes in mixtures. Moreover, the rhodamine-based boronic acid responds linearly to increasing riboside concentrations in urine samples, potentially enabling the screening for inborn purine metabolism disorders.
|
17 |
Utilization of antigen-specific host responses in the evaluation of Mycobacterium tuberculosis infection, development of disease and treatment effectMenezes, Angela Maria 03 1900 (has links)
Thesis (MScMedSc)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Setting
This study was conducted in the Tygerberg district, Cape Town, in the Western Cape, South Africa
Background
The evaluation of early tuberculosis (TB) treatment response is based on month 2 sputum culture status. This method of evaluation has a number of limitations: the test requires relatively advanced laboratory infrastructure and procedures, it takes several weeks to obtain results and is a relatively a poor marker at predicting treatment response. The discovery of potential host markers which reflect the efficacy of early treatment would be of great importance for clinical management of individual patients. The treatment failure would be detectable earlier than at week 8 of treatment. The duration of clinical trials of new anti-tuberculosis drugs may also be substantially reduced by such markers if these would be measurable earlier than at week 8 of therapy.
Objectives
1) To evaluate diluted, 7-day whole blood cultures stimulated with live Mycobacterium tuberculosis (M.tb) for the presence of host markers of early TB treatment response
2) To evaluate an overnight, undiluted, M.tb antigen stimulated whole blood culture Quantiferon Gold In Tube (QFT-GIT) supernatants for host markers of early TB treatment response
The study designs were as follows:
In study one, baseline samples and samples from week 1, week 2 and week 4 of treatment from 30 cured TB patients were selected from a larger biomarker study, in which whole blood was stimulated with live M.tb or left unstimulated. Fifty seven host markers were measured in supernatants by multiplex cytokine arrays.
In study two, baseline samples and samples from week 2 and week 8 of treatment from 19 cured TB patients were randomly selected from the placebo group in a micronutrient supplement study. QFT-GIT supernatants from these participants were assessed through multiplex cytokine arrays for levels of fifty seven host markers. All of the participants in both studies were Human Immunodeficiency Virus (HIV) negative.
Changes in marker expression over time and between fast and slow responders to treatment were evaluated. Comparability between the two culture methods was assessed for markers that were evaluated in both studies.
Results
In study one, the majority of host markers showed significant changes over time in the unstimulated supernatants. Only GRO and IL-1beta changed significantly in an antigen-specific manner (background levels subtracted). No significant changes were observed between fast and slow responders.
In study two, the majority of host markers showed significant changes over time in the unstimulated supernatants whereas only MDC and IL-4 changed during the observation period in antigen stimulated levels. Significant differences were observed between fast and slow responders at pre-treatment for IL-13 Ag-Nil and IL-1betaAg-Nil .
Conclusion
This study revealed, antigen-specific responses showed only limited potential for early TB treatment response monitoring, but may have potential in differentiating between treatment outcomes. Future investigations may have to include later time points during treatment as these were not included in the present assessment. The QFT-GIT samples do not appear to be equivalent to live M.tb stimulated 7-day whole blood assays. / AFRIKAANSE OPSOMMING: Instelling
Die studie is uitgevoer in die Tygerbergdistrik, Kaapstad, Wes-Kaap, Suid-Afrika.
Agtergrond
Die evaluering van die respons op vroeë tuberkulose (TB) behandeling word gebaseer op die status van maand 2 sputum kulture. Hierdie evalueringsmetode het ‘n paar beperkinge: die toets benodig relatief gevorderde laboratorium infrastruktuur en prosedures, die toetsuitslae is eers na ‘n paar weke beskikbaar en dit is n relatiewe swak merker om repons op behandeling te voorspel. Die ontdekking van potensiële selfmerkers wat die doeltreffendheid van vroeë behandeling weerspieël sal van groot belang wees vir die kliniese bestuur van individuele pasiënte. Mislukking van die behandeling sal sodoende voor week 8 van behandeling waargeneem kan word. Die tydsduur van kliniese proewe van nuwe anti-tuberkulose medikasie mag ook baie verkort word met sulke merkers as dit voor week 8 van behandeling gemeet kan word.
Doelwitte
1) Om verdunde, 7-dae oue volbloedkulture, met lewende Mikobakterium tuberkulosis (M.tb) gestimuleer, te evalueer vir die teenwoordigheid van vroeë TB behandeling respons selfmerkers.
2) Om die supernatant van oornag, onverdunde, M.tb antigeen gestimuleerde volbloedkulture Quantiferon Gold In Tube (QFT-GIT) vir vroeë behandeling respons selfmerkers te evalueer.
Die studie-ontwerpe was soos volg:
Met studie een is basislynmonsters en monsters verkry na week 1, week 2 en week 4 van behandeling van 30 geneesde TB-pasiënte geselekteer uit ‘n groter biomerkerstudie waarin die volbloed met lewende M.tb gestimuleer is of ongestimuleer gelaat is. Sewe-en-vyftig selfmerkers is in die supernatante gemeet deur middel van multipleks sitokine arrays.
Met studie twee is basislynmonsters en monsters verkry na week 2 en week 8 van behandeling van 19 geneesde TB-pasiënte lukraak uit die plasebo-groep in ‘n mikrovoedingstowwe-aanvullingstudie geselekteer. Vlakke van 57 selfmerkers is in die QFT-GIT supernatante van hierdie deelnemers, deur middel van die multipleks sitokine arrays, bepaal. Al die deelnemers van beide studies was HIV negatief.
Veranderinge in merker-uitdrukking oor tyd, asook tussen vinnige en stadige respons tot behandeling, is ge-evalueer. Die vergelykbaarheid van die twee kultuurmetodes is geassesseer ten opsigte van die ge-evalueerde merkers in albei studies.
Resultate
Met studie een het die meerderheid van die selfmerkers in die ongestimuleerde supernatante kenmerkende verandering oor tyd gewys. Slegs GRO en IL-1beta het aansienlik verander in die antigeenspesifieke wyse (agtergrond vlakke afgetrek). Geen kenmerkende veranderinge was waargeneem tussen die vinnige en stadige respons pasiënte nie.
Met studie twee het die meerderheid van die selfmerkers aansienlike veranderinge oor tyd in die ongestimuleerde supernatante gewys, in vergelyking waar net die MDC en IL-4 veranderinge gedurende die observasie periode in antigeen gestimuleerde vlakke getoon het. Kenmerkende verskille is tussen die vinnige en stadige respons pasiënte in voorbehandeling vir IL-13 Ag-Nil en IL-1betaAg-Nil waargeneem.
Gevolgtrekking
Die studie bewys dat antigeenspesifieke response slegs beperkte potensiaal vir vroeë TB behandeling respons monitering het, maar mag die potensiaall vir onderskeidende behandeling uitkomste hê. Toekomstige ondersoeke sal dalk latere tydpunte gedurende die behandeling moet insluit aangesien dit nie in hierdie evaluasie ingesluit is nie. Die QFT-IT monsters verskyn nie as gelykwaardig met die lewendig M.tb gestimuleerde 7-dae volbloed toetse nie.
|
18 |
Mechanisms of protection against ischemic damage in the heartUnknown Date (has links)
Heart disease including ischemic heart disease is the highest contributor to death and morbidity in the western world. The studies presented were conducted to determine possible pathways of protection of the heart against ischemia/reperfusion. We employed adenovirus mediated over-expression of Methionine sulfoxide reductase A (MsrA) in primary neonatal rat cardiac myocytes to determine the effect of this enzyme in protecting against hypoxia/reoxygenation. Cells transfected with MsrA encoding adenovirus and subjected to hypoxia/reoxygenation exhibited a 45% decrease in apoptosis as compared to controls. Likewise total cell death as determined by levels of Lactate Dehydrogenase (LDH) release was dramatically decreased by MsrA overexpression. The initial hypothesis that led to our testing sulindac was based on the fact that the S epimer of sulindac was a substrate for MsrA and that this compound might function as a catalytic anti-oxidant based on a reaction cycle that involved reductio n to sulindac sulfide followed by oxidation back to sulindac. To test this we examined the protective effect of sulindac in hypoxia re-oxygenation in both cardiac myocytes in culture and using a Langendorff model of myocardial ischemia. Using this model of myocardial ischemia we showed that pre-incubation of hearts with sulindac, or the S and R epimers of sulindac resulted in protection against cell death. We present several lines of evidence that the protective effect of sulindac is not dependent on the Msr enzyme system nor does it involve the well established role of sulindac as a Cyclooxygenase (COX) inhibitor. Numerous signaling pathways have been implicated in myocardial protective mechanisms, many of which require fluctuations in ROS levels as initiators or mediators. / Sulindac shows very good potential as a preconditioning agent that could induce tissue protection against oxidative damage.Blocking of preconditioning pathways by administration of the PKC blocker chelerythine abrogated the ischemic protection afforded by sulindac. Secondly, an end-effector of preconditioning, inducible nitric oxide synthase (iNOS),was found to be induced by greater than 5 fold after 48 h prior feeding sulindac. / by Ian Moench. / Thesis (Ph.D.)--Florida Atlantic University, 2008. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2008. Mode of access: World Wide Web.
|
19 |
Chemokines and 8-isoprostane levels in exhaled breath condensate from adult patients with asthma and chronic obstructive pulmonary disease. / Chemokines & 8-isoprostane levels in exhaled breath condensate from adult patients with asthma and chronic obstructive pulmonary diseaseJanuary 2005 (has links)
Lau Yin Kei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 58-79). / Abstracts in English and Chinese. / Acknowledgement --- p.I / Abstract --- p.IV / Abstract in Chinese --- p.VI / Abbreviations --- p.VIII / Introduction --- p.1 / Chapter 1.1 --- Prevalence of COPD and asthma in Hong Kong --- p.1 / Chapter 1.2 --- Players in pathogenesis of COPD --- p.2 / Chapter 1.3 --- Players in pathogenesis of asthma --- p.4 / Chapter 1.4 --- The use of exhaled breath condensate in previous studies --- p.6 / Chapter 1. 5 --- Brief overview of chemokines --- p.8 / Chapter 1.6 --- Objective of this study --- p.12 / Materials and methods --- p.14 / Chapter 2.1 --- Study population --- p.14 / Chapter 2.1.1 --- Patients with COPD and control subjects --- p.14 / Chapter 2.1.2 --- Patients with asthma and control subjects --- p.15 / Chapter 2.2 --- Lung function --- p.15 / Chapter 2.3 --- Dyspnoea score measurement of patients with COPD --- p.16 / Chapter 2.4 --- Classification of patients and asthma severity --- p.16 / Chapter 2.5 --- Skin prick test and blood tests --- p.16 / Chapter 2.6 --- Collection of exhaled breath condensate --- p.17 / Chapter 2.7 --- Measurement of constituent in EBC --- p.17 / Chapter 2.7.1 --- "Measurement of 8-isoprostane, MCP-1 and GROα in patients with COPD and the corresponding control subjects" --- p.17 / Chapter 2.7.2 --- Measurement of eotaxin and MDC of patients with asthma and the corresponding control subjects --- p.18 / Chapter 2.8 --- Reproducibility of exhaled breath constituent --- p.18 / Chapter 2.8.1 --- "Assessment of reproducibility of the exhaled MCP-1, GROα and8- isoprostane measurements" --- p.19 / Chapter 2.8.2 --- Assessment of reproducibility of the exhaled eotaxin and MDC measurement --- p.19 / Chapter 2.9 --- Statistical analysis --- p.19 / Results --- p.21 / Chapter 3.1 --- Patients with COPD and corresponding control subjects --- p.21 / Chapter 3.2 --- Patients with asthma and corresponding control subjects --- p.28 / Discussion --- p.36 / Chapter 4.1 --- "Exhaled 8-isoprostane, GRO-α and MCP-1 of patients with COPD and corresponding control subjects" --- p.36 / Chapter 4.2 --- Exhaled eotaxin and MDC from patients with asthma and corresponding control subjects --- p.43 / Chapter 4.3 --- Technical aspects of EBC assessment --- p.49 / Future prospect --- p.54 / Conclusion --- p.56 / References --- p.58 / Tables and Figures / Table 1. Demographics of the COPD and control subjects --- p.22 / Figure 1. The level of 8-isoprostane in the exhaled breath condensate of COPD and control subjects --- p.23 / Figure 2. The level of GROa in the exhaled breath condensate of COPD and control subjects --- p.25 / "Figure 3 Bland and Altman's Plot of the repeatability of 8-isoprostane, GROa and MCP-1 in the exhaled breath condensate of normal controls" --- p.27 / Table2. Clinical and physiological details of the subjects --- p.29 / Figure 4. Level of eotaxin in exhaled breath condensate of asthma and control subjects --- p.30 / Figure 5 Level of MDC in exhaled breath condensate of asthma and control subjects --- p.31 / Table 3. Levels of eotaxin and MDC in exhaled breath condensate of asthma subjects on different dose of inhaled corticosteroids --- p.33 / Figure 6. Relationship between exhaled breath condensate level of MDC and total serum IgE level --- p.35
|
Page generated in 0.1226 seconds