Natural Sciences and Mathematics: Recent submissions
Now showing items 41-60 of 143
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Characterization of Novel Extracellular Matrix (Ecm) Proteins (Mgp and Lumican) and Their Implications in Vascular Development, Angiogenesis, and CancerExtracellular matrix (ECM) constitutes a large component of our tissue structure. Primarily, ECM provides structural and adhesive support to our cells, but it also controls cellular signaling and behavior. Homeostasis of extracellular matrix composition and function is maintained by our body through a balanced synthesis, degradation and remodeling of ECM. However, under pathological conditions and genetic mutations, ECM homeostasis is disrupted due to deregulation in ECM synthesis, assembly, remodeling, and degradation. A number of diseases, including cardiovascular diseases and cancer, are found to occur due to alterations in ECM. Therefore, targeting ECM can be an attractive therapeutic approach to treat these diseases, and it requires our complete understanding of the ECM molecules and the molecular mechanism it employs in controlling cellular functions. To this end, this study is aimed at the characterization of two ECM proteins—Matrix Gla Protein (MGP) and Lumican—for their roles in vascular development, angiogenesis, and cancer. Findings from this study show that MGP is a critical ECM regulator that promotes angiogenic resolution by suppressing endothelial sprouting and stabilizing vascular lumen formation. In addition, MGP also inhibits tumor growth by inhibiting tumor angiogenesis. On the other hand, our findings show Lumican suppresses tumor growth and has anti-angiogenic activity in a context specific manner.
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Cloning and Characterization of Hypothetical Exported Proteins from Community Associated Staphylococcus AureusMethicillin resistant Staphylococcus aureus (MRSA), a major cause of nosocomial infections, has acquired resistance to beta-lactam and other antibiotics. Recently, community associated MRSA (CA-MRSA) has developed independent of hospital associated MRSA (HA-MRSA). One of the major differences between the hospital and community strains is that the former is multi-resistant to antibiotics while the latter is not as resistant but is significantly more invasive. This increased invasiveness and the ability to cause life-threatening infections, even in immunocompetent individuals, makes CA-MRSA critically important as a public health problem. CA-MRSA is known to cause skin and soft tissue infections; bacteria interact with host skin cells and gain access to deeper tissues causing invasive infections. During this process the bacteria may secrete proteins that aid in the interaction with the host by adhering, invading or causing host cell death and lysis. To understand the virulence mechanisms involved in invasion, we investigated genes described as hypothetical proteins in MSSA476. The bioinformatics-selected proteins showed high probability of being secreted and most were unique to CA-MRSA. Our analysis showed 24 such genes. This study shows primer design for 15 of the genes (7 of the 24 had already been cloned in our laboratory). Using gateway cloning, the 15 genes were cloned into BL-21 expression clones. CA-MRSA’s are known for causing invasive skin infections. To further understand the involvement of our proteins of interest in invasion, human keratinocyte cell lines were used in a study of virulence and interaction with skin. To understand the involvement of our hypothetical secreted proteins, we investigated the mRNA expression level, using RT-qPCR and Livak method, of 20 hypothetical exported proteins in presence of human dermal keratinocyte cell line. Our investigation revealed two genes that showed increased mRNA expression in the presence of keratinocytes, which may be due to factors associated with keratinocytes that may have triggered increased mRNA expression. Keratinocytes are capable of forming cell-cell junctions and producing antimicrobial peptides and cytokines in response to microbes. The increased mRNA expression of two genes may be towards binding to junctions for invasion or may be expressed in response to antimicrobial peptides or cytokines.
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Remote Sensing of Tanzanian Volcano Oldoinyo Lengai: Verifying Detection Methods of Flow ActivityEvery day volcanoes erupt with varying magnitudes across the globe, and remote sensing used to keep track of volcanic activity would be a useful application. One promising use of remote sensing to understand volcanoes at a distance is to distinguish gaseous or lava flow activity. Current methods for differentiating volcanic activity with remote sensing have only been applied at Mt. Etna, and research is still needed to verify that the detection of gaseous or lava flow activity is possible at volcanoes with different compositions. The subject of this study, the Oldoinyo Lengai volcano, is a natrocarbonatite stratovolcano with drastically different chemical composition from Mt. Etna. These composition differences allow for the verification of gaseous or lava flow activity remotely over time. Furthermore, looking closely at how volcano composition affects detection will allow us to understand the variables required to detect gaseous or lava flow activity. The results of the research are inconclusive, but provide useful information for this application of remote sensing. For Oldoinyo Lengai, the Landsat TM data were unable to resolve lava flows or degassing activity, due to a combination of the volcano’s small size, the lack of lava flows, and/or pixel saturation. Superior sensors such as hyperspectral sensors are needed to adequately perform the analysis, and would likely result in the capability to differentiate volcanic activity. Further applicability of the study is prudent due to the varying nature of volcanoes and sensors. Gathering additional detailed information should be at the forefront of volcanic monitoring research.
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A study of the unit plan of teaching chemistryNot available.
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A measure of the value of recordings in teaching arithmeticNot available.
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An experiment in directed studyNot available.
