Current Search: Biochemical markers -- Diagnostic use (x)
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- Title
- Assessment of anatomical structures and hemodynamic function of cTnI[193His] transgenic mice with micro-echocardiography.
- Creator
- Gobara, Nariman., Charles E. Schmidt College of Medicine
- Abstract/Description
-
Transgenic mice were generated to express a restrictive cardiomyopathy (RCM) human cardiac troponin I (cTnI) R192H mutation in the heart. My study's objective was to assess cardiac function during the development of diastolic dysfunction and to gain insight into the pathophysiological impact of the RCM cTnI mutation. Cardiac function was monitored in cTnI193His mice and wild-type littermates for a period of 12 months. It progressed gradually from abnormal relaxation to diastolic dysfunction...
Show moreTransgenic mice were generated to express a restrictive cardiomyopathy (RCM) human cardiac troponin I (cTnI) R192H mutation in the heart. My study's objective was to assess cardiac function during the development of diastolic dysfunction and to gain insight into the pathophysiological impact of the RCM cTnI mutation. Cardiac function was monitored in cTnI193His mice and wild-type littermates for a period of 12 months. It progressed gradually from abnormal relaxation to diastolic dysfunction characterized with micro- echocardiography by a reversed E/A ratio, increased deceleration time, and prolonged isovolumetric relaxation time. The negative impact of cTnI193His on cardiac function was further demonstrated in isolated mouse working heart preparations. Dobutamine stimulation increased heart rate in cTnI193His mice but did not improve CO. The cTnI193His mice had a phenotype similar to that in human RCM patients carrying the cTnI mutation characterized morphologically by enlarged atria and restricted ventricle and functionally by diastolic dysfunction.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/186680
- Subject Headings
- Mice as laboratory animals, Biochemical markers, Diagnostic use, Cardiovascular system, Pathophysiology, Coronary heart disease, Molecular diagnosis
- Format
- Document (PDF)
- Title
- Protective mechanism of Sulindac against animal model of ischemic stroke.
- Creator
- Modi, Jigar P., Charles E. Schmidt College of Medicine, Department of Biological Sciences
- Abstract/Description
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The Effect of Sulindac was studied on an animal model of ischemic stroke. Sulindac, a non steroid anti inflammatory drug (NSAID) could protect cell death due to hypoxia/reoxygenation. This drug was given 2 days before and 24 hrs after ischemia until animals were sacrificed on 3rd or 11th day. Infarct size was measured for these animals. Sulindac induced Hsp 27 in ischemic penumbra and core on Day 3 & 11 with uncoated nylon suture which shows its cell-survival and anti-apoptotic activity. Also...
Show moreThe Effect of Sulindac was studied on an animal model of ischemic stroke. Sulindac, a non steroid anti inflammatory drug (NSAID) could protect cell death due to hypoxia/reoxygenation. This drug was given 2 days before and 24 hrs after ischemia until animals were sacrificed on 3rd or 11th day. Infarct size was measured for these animals. Sulindac induced Hsp 27 in ischemic penumbra and core on Day 3 & 11 with uncoated nylon suture which shows its cell-survival and anti-apoptotic activity. Also, it increased expression of cell survival markers such as Akt, Bcl2 & Grp 78 in ischemic penumbra and core. With silicon suture it reduced expression of Hsp 27 in ischemic penumbra and core, alleviating cell stress and having pro-survival and anti-stress effects. In conclusion sulindac may have excellent potential as neuro protective agent against oxidative stress in cerebral ischemia.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3333056
- Subject Headings
- Apoptosis, Biochemical markers, Diagnostic use, Oxidation reduction reaction, Cerebral ischemia, Prevention
- Format
- Document (PDF)
- Title
- Roles of troponin I in heart development and cardiac function.
- Creator
- Du, Jianfeng., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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Two major troponin I (TnI) genes, fetal TnI (ssTnI) and adult TnI (cTnI), are expressed in the mammalian heart under the control of a developmentally regulated program. In this study, the up-stream domain (~1,800 bp) of mouse fetal TnI gene has been cloned and characterized. There is a high homology of this region among mouse, rat and human. Transfection assays indicated that conserved GA-rich sequences, CREB and a CCAAT box within the first 300 bp upstream of the transcription start site...
Show moreTwo major troponin I (TnI) genes, fetal TnI (ssTnI) and adult TnI (cTnI), are expressed in the mammalian heart under the control of a developmentally regulated program. In this study, the up-stream domain (~1,800 bp) of mouse fetal TnI gene has been cloned and characterized. There is a high homology of this region among mouse, rat and human. Transfection assays indicated that conserved GA-rich sequences, CREB and a CCAAT box within the first 300 bp upstream of the transcription start site were critical for the gene expression. Electrophoretic mobility shift assays (EMSAs) and chromatin immunoprecipitation (ChIP) assays revealed binding proteins to CREB site in nuclear extracts from myocardial cells. Thyroid hormone (T3) caused a significant inhibitory effect on ssTnI expression in myocardial cells. Cardiac troponin I (cTnI) mutations have been linked to the development of restrictive cardiomyopathy (RCM) in human patients. We modeled one mutation in human cTnI Cv terminus, arginine1 92 histidine (R192H) by cardiac specific expression of the mutated protein (cTnI193His in mouse sequence) in transgenic mice. The main functional alteration detected in cTnI193His mice by ultrasound cardiac imaging examinations was impaired cardiac relaxation manifested by a decreased left ventricular end diastolic dimension (LVEDD) and an increased end diastolic dimension in both atria. Echocardiography revealed a series of changes on the transgenic mice including a reversed E-to-A ratio, increased deceleration time, and prolonged isovolumetric relaxation time. At the age of 12 months, cardiac output in cTnI193His mice was significantly declined, and some transgenic mice showed congestive heart failure. The negative impact of cTnI193His on ventricular contraction and relaxation was further demonstrated in isolated mouse working heart preparations., Dobutamine stimulation increased heart rate in cTnI193His mice but did not improve CO.The cTnI193His mice had a phenotype similar to that in human RCM patients carrying the cTnI mutation. The results demonstrate a critical role of the COOH-terminal domain of cTnI in the diastolic function of cardiac muscle. This mouse model provides us with a tool to further investigate the pathophysiology and the development of RCM.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/FAU/186287
- Subject Headings
- Mice as laboratory animals, Biochemical markers, Diagnostic use, Heart, Diseases, Molecular diagnosis, Cardiovascular system, Pathophysiology
- Format
- Document (PDF)
- Title
- Identification of MicroRNA biomarkers for cancer by combining multiple feature selection techniques.
- Creator
- Kotlarchyk, Alex J., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
MicroRNAs (miRNAs) may serve as diagnostic and predictive biomarkers for cancer. The aim of this study was to identify novel cancer biomarkers from miRNA datasets, in addition to those already known. Three published miRNA cancer datasets (liver, breast, and brain) were evaluated, and the performance of the entire feature set was compared to the performance of individual feature filters, an ensemble of those filters, and a support vector machine (SVM) wrapper. In addition to confirming many...
Show moreMicroRNAs (miRNAs) may serve as diagnostic and predictive biomarkers for cancer. The aim of this study was to identify novel cancer biomarkers from miRNA datasets, in addition to those already known. Three published miRNA cancer datasets (liver, breast, and brain) were evaluated, and the performance of the entire feature set was compared to the performance of individual feature filters, an ensemble of those filters, and a support vector machine (SVM) wrapper. In addition to confirming many known biomarkers, the main contribution of this study is that seven miRNAs have been newly identified by our ensemble methodology as possible important biomarkers for hepatocellular carcinoma or breast cancer, pending wet lab confirmation. These biomarkers were identified from miRNA expression datasets by combining multiple feature selection techniques (i.e., creating an ensemble) or by the SVM-wrapper, and then classified by different learners. Generally speaking, creating a subset of features by selecting only the highest ranking features (miRNAs) improved upon results generated when using all the miRNAs, and the ensemble and SVM-wrapper approaches outperformed individual feature selection methods. Finally, an algorithm to determine the number of top-ranked features to include in the creation of feature subsets was developed. This algorithm takes into account the performance improvement gained by adding additional features compared to the cost of adding those features.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3332260
- Subject Headings
- Gene silencing, Biochemical markers, Cancer, Diagnosis, Data processing, Cancer, Diagnosis, Research, Gene expression, Tumor markers, Diagnostic use
- Format
- Document (PDF)
- Title
- cTnI N-Terminal deletion: an agent for rescuing restrictive cardiomyopathy, a disease caused by mutations of Cardiac Troponin I.
- Creator
- Getfield, Cecile A., Huang, Xupei, Florida Atlantic University, Charles E. Schmidt College of Medicine, Department of Biomedical Science
- Abstract/Description
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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+...
Show moreRestrictive 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.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004196, http://purl.flvc.org/fau/fd/FA00004196
- Subject Headings
- Biochemical markers -- Diagnostic use, Cardiovascular system -- Pathophysiology, Coronary heart disease -- Molecular diagnosis, Mice as laboratory animals, Molecular biology
- Format
- Document (PDF)
- Title
- Studies on the mechanism by which sulindac sensitizes cancer cells to oxidative stress.
- Creator
- Kreymerman, Alexander, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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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...
Show moreSulindac 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 PKCĪµ. . However, cancer cells react by initiating a pathway leading to apoptosis involving PKCĪ“.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3183124
- Subject Headings
- Proteins, Chemical modification, Cellular signal transduction, Biochemical markers, Diagnostic use, Drug resistance in cancer cells, Oxidation-reduction reaction
- Format
- Document (PDF)
- Title
- Mechanism and treatment of restrictive cardiomyopathy.
- Creator
- Jean-Charles, Pierre-Yves, Charles E. Schmidt College of Medicine, Department of Biomedical Science
- Abstract/Description
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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...
Show moreRestrictive 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.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3358554
- Subject Headings
- Biochemical markers -- Diagnostic use, Cardiovascular system -- Pathophysiology, Coronary heart disease -- Molecular diagnosis, Mice as laboratory animals, Molecular biology
- Format
- Document (PDF)
- Title
- Mechanism of neuroprotection in stroke-related models.
- Creator
- Pan, Chunliu., Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
- Abstract/Description
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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...
Show moreStroke 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.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3352284
- Subject Headings
- Sulindac, Physiological effect, Taurine, Physiological effect, Cerebral ischemia, Prevention, Biochemical markers, Diagnostic use, Apoptosis, Oxidation reduction reaction
- Format
- Document (PDF)
- Title
- Mechanisms of protection against ischemic damage in the heart.
- Creator
- Moench, Ian, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
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...
Show moreHeart 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.
Show less - Date Issued
- 2008
- PURL
- http://purl.flvc.org/FAU/186291
- Subject Headings
- Biochemical markers, Diagnostic use, Cardiovascular system, Diseases, Diagnosis, Heart, Diseases, Molecular aspects, Medical care, Quality control, Coronary heart disease, Prevention, Apoptosis, Myocardial infarction, Prevention
- Format
- Document (PDF)