Matching Items (6)

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In situ drug-receptor binding kinetics in single cells: a quantitative label-free study of anti-tumor drug resistance

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Many drugs are effective in the early stage of treatment, but patients develop drug resistance after a certain period of treatment, causing failure of the therapy. An important example is

Many drugs are effective in the early stage of treatment, but patients develop drug resistance after a certain period of treatment, causing failure of the therapy. An important example is Herceptin, a popular monoclonal antibody drug for breast cancer by specifically targeting human epidermal growth factor receptor 2 (Her2). Here we demonstrate a quantitative binding kinetics analysis of drug-target interactions to investigate the molecular scale origin of drug resistance. Using a surface plasmon resonance imaging, we measured the in situ Herceptin-Her2 binding kinetics in single intact cancer cells for the first time, and observed significantly weakened Herceptin-Her2 interactions in Herceptin-resistant cells, compared to those in Herceptin-sensitive cells. We further showed that the steric hindrance of Mucin-4, a membrane protein, was responsible for the altered drug-receptor binding. This effect of a third molecule on drug-receptor interactions cannot be studied using traditional purified protein methods, demonstrating the importance of the present intact cell-based binding kinetics analysis.

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  • 2014-10-14

Parental Approach to Cardiovascular Health Promotion & Prevention in Children

Description

Cardiovascular Disease (CVD) is the leading cause of death in the world today! More specifically, ischemic heart disease, also known as coronary artery disease, tops the world’s most deadly disease

Cardiovascular Disease (CVD) is the leading cause of death in the world today! More specifically, ischemic heart disease, also known as coronary artery disease, tops the world’s most deadly disease and is responsible for nearly 9 million deaths every year (World Health Organization, n.d.). This paper describes a Parental Approach to Cardiovascular Health Promotion and Prevention in children. The risk factors for CVD have been well established in adults and emerging evidence underline the importance of experiences and exposures on the consequent development of CVD. The aim of this project is to highlight the importance of early intervention in childhood by promoting cardiovascular health education and prevention in children. CVD is cause by a culmination of genetic and lifestyle factors and the many risk factors associated with cardiovascular disease is divided into two categories: those which are changeable or modifiable and those that are unchangeable or non-modifiable. The earlier that parents address the modifiable risk factors, the better the child’s outcome of preventing heart disease in adulthood. Therefore, alternative means of a healthy dietary approach such as the 5-2-1-0 program in addition to exercising is extremely crucial. This paper will discuss the different preventative strategies and ways to mitigate symptoms of CVD. Therefore, I have developed a 4-step outline for cardiovascular health education and prevention strategies which parents can use when raising their children.

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  • 2020-05

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Establishing a foundation for investigating the role of nutrition on immunity in wildlife

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This review examines existing research on relationships between two established disciplines, nutrition and immunology, with a specific focus on the complement system in vertebrate organisms and how its functioning is

This review examines existing research on relationships between two established disciplines, nutrition and immunology, with a specific focus on the complement system in vertebrate organisms and how its functioning is affected by nutritional status. The available studies assessed the effects of certain vitamins, lipids, carbohydrates, proteins, and overall body condition, measured as body mass index (BMI), on the three complement activation pathways (classical, lectin, and alternative) and their components (C1q, C1s, C3, C4, C5, C6, C8, C9, and C3 proactivator) in blood plasma. Across studies, an increased abundance and/or activity of complement components in plasma was observed in rodents and humans after intake of vitamin A, vitamin C, lipids, and proteins. Higher relative activity was also observed in bats with high body mass index (BMI), a measure of general body condition. Overall, results indicate that nutritional status has a pronounced effect on the complement system in species studied. However, only few studies have investigated effects of nutrition on complement in non-model organisms, such as wildlife, indicating major gaps in knowledge related to taxa that more likely experience nutrient limitations, e.g. through seasonal variation in resources, droughts, etc. as compared with model organisms used under laboratory settings. Understanding potential relationships between nutrition and immunity in a broader suite of species is crucial, nonetheless, due to the number of emerging wildlife diseases that are spreading at an alarming rate. Therefore, I critiqued the available evidence to help predict how wildlife hosts will resist or tolerate diseases, such as white-nose syndrome, sylvatic plague, and avian influenza, based on the nutritional status of an individual host. I also considered methodological approaches and assessed their potential for use in wildlife. The studies in this review used different methods to measure complement protein activity, such as hemolytic and functional assays. Future studies can also take advantage of newer high-throughput methods, such as proteomics combined with functional assays. This can lead to a more comprehensive understanding of the efficacy of complement proteins to neutralize invading pathogens under different host nutritional states. My investigation into relationships between nutrition and complement will also inform similar investigations to uncover effects of nutrition on other aspects of immunity, such as antimicrobial peptides. Overall, my assessment concludes that complement is a good candidate for investigating the role of nutrition on immunity in wildlife because it is sensitive to changes in some nutritional components, particularly vitamins, lipids, and proteins.

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  • 2020-05

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Plasmonic imaging of protein interactions with single bacterial cells

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Quantifying the interactions of bacteria with external ligands is fundamental to the understanding of pathogenesis, antibiotic resistance, immune evasion, and mechanism of antimicrobial action. Due to inherent cell-to-cell heterogeneity in

Quantifying the interactions of bacteria with external ligands is fundamental to the understanding of pathogenesis, antibiotic resistance, immune evasion, and mechanism of antimicrobial action. Due to inherent cell-to-cell heterogeneity in a microbial population, each bacterium interacts differently with its environment. This large variability is washed out in bulk assays, and there is a need of techniques that can quantify interactions of bacteria with ligands at the single bacterium level. In this work, we present a label-free and real-time plasmonic imaging technique to measure the binding kinetics of ligand interactions with single bacteria, and perform statistical analysis of the heterogeneity. Using the technique, we have studied interactions of antibodies with single Escherichia coli O157:H7 cells and demonstrated a capability of determining the binding kinetic constants of single live bacteria with ligands, and quantify heterogeneity in a microbial population.

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  • 2015-01-15

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Exploring the nature of protein-peptide interactions on surfaces

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Protein-surface interactions, no matter structured or unstructured, are important in both biological and man-made systems. Unstructured interactions are more difficult to study with conventional techniques due to the lack of

Protein-surface interactions, no matter structured or unstructured, are important in both biological and man-made systems. Unstructured interactions are more difficult to study with conventional techniques due to the lack of a specific binding structure. In this dissertation, a novel approach is employed to study the unstructured interactions between proteins and heterogonous surfaces, by looking at a large number of different binding partners at surfaces and using the binding information to understand the chemistry of binding. In this regard, surface-bound peptide arrays are used as a model for the study. Specifically, in Chapter 2, the effects of charge, hydrophobicity and length of surface-bound peptides on binding affinity for specific globular proteins (&beta-galactosidase and &alpha1-antitrypsin) and relative binding of different proteins were examined with LC Sciences peptide array platform. While the general charge and hydrophobicity of the peptides are certainly important, more surprising is that &beta-galactosidase affinity for the surface does not simply increase with the length of the peptide. Another interesting observation that leads to the next part of the study is that even very short surface-bound peptides can have both strong and selective interactions with proteins. Hence, in Chapter 3, selected tetrapeptide sequences with known binding characteristics to &beta-galactosidase are used as building blocks to create longer sequences to see if the binding function can be added together. The conclusion is that while adding two component sequences together can either greatly increase or decrease overall binding and specificity, the contribution to the binding affinity and specificity of the individual binding components is strongly dependent on their position in the peptide. Finally, in Chapter 4, another array platform is utilized to overcome the limitations associated with LC Sciences. It is found that effects of peptide sequence properties on IgG binding with HealthTell array are quiet similar to what was observed with &beta-galactosidase on LC Science array surface. In summary, the approach presented in this dissertation can provide binding information for both structured and unstructured interactions taking place at complex surfaces and has the potential to help develop surfaces covered with specific short peptide sequences with relatively specific protein interaction profiles.

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Date Created
  • 2014