Vermilion-Stained Offerings

This thesis is a collection of short stories

Sphingosine-1-Phosphate and Fingolimod (FTY720) Regulate ICl,swell In HL-1 Cardiac Myocytes via Intracellular Binding And Mitochondrial ROS Production

Swelling-activated Cl− current (ICl,swell) is an outwardly-rectifying current that plays an important role in cardiac electrical activity, cellular volume regulation, apoptosis, and acts as a potential effector of mechanoelectrical feedback. Persistent activation of ICl,swell has been observed in models of cardiovascular disease. We previously suggested sphingosine-1-phosphate (S1P) activates volume-sensitive Cl- current (ICl,swell) by ROS-dependent signaling. S1P and its analog, FTY720 (fingolimod), primarily act via G-protein coupled receptors (S1PR; S1PR1-3 in heart), but several intracellular S1P ligands are known. We investigated how these agents regulate ICl,swell. ICl,swell was elicited by bath S1P (500 nM), FTY720 (S1PR1,3 agonist; 10 μM), and SEW2871 (S1PR1 agonist; 10 μM) and was fully inhibited by DCPIB, a specific blocker. These data suggested role of S1PR in activation of ICl,swell. Surprisingly, neither CAY10444 (S1PR3 antagonist; 10 μM) nor VPC23019 (S1PR1,3 antagonist; 13 μM) blocked FTY720-induced ICl,swell. Also, gallein a pan Gbeta-gamma inhibitor, failed to block the S1P-induced current. Moreover, 100 nM FTY720 applied via the pipette evoked a larger, faster activating current than 10 μM bath FTY720. Similarly, 500 nM S1P gave larger, faster activating ICl,swell when added to the pipette than when added in the bath. In contrast to FTY720, bath S1P-induced ICl,swell was blocked by CAY10444, but a 3-fold higher concentration failed to eliminate the response to pipette S1P, and VPC23019 failed to suppress bath and pipette S1P-induced currents. Taken together, inconsistencies in the responses to S1PR agents and the greater sensitivity to pipette than bath S1P and FTY720 support the notion that intracellular ligands rather than sarcolemmal S1PR activated ICl,swell. Next we tested if S1P and FTY720, like osmotic swelling, require both NADPH oxidase and mitochondrial ROS production to evoke ICl,swell. S1P- and FTY720-induced ICl,swell were blocked by rotenone but were insensitive to gp91ds-tat, suggesting only mitochondrial ROS production was needed. One possibility is that S1P and FTY720 elicit ICl,swell by binding to mitochondrial prohibitin-2, an S1P ligand whose knockdown augments mitochondrial ROS productions. These data suggest ICl,swell may be activated by S1P accumulation in ischemia-reperfusion and CHF. Understanding S1P-signaling that elicits ICl,swell may provide insight into electrophysiological mechanisms of cardiac pathology and help identify novel targets for therapy

Providing a Health and Wellness Resource Guide to Senior Patients in Western Connecticut

Senior patients (\u3e60 years) have a higher prevalence of chronic diseases, physical disabilities, mental illnesses, and other co-morbidities, when compared with younger patient populations. In the Primary Care setting, prevention and control of health problems of elderly patients necessitates a multifaceted approach incorporating active collaboration of health, social welfare, rural and urban development, and legal sectors. Through research and community outreach, I found that identifying available senior resources was an important need in the Western Connecticut community. My interviews and research guided the creation of an informational handout on the available resources for senior patients. Resources incorporate many aspects of health, including fitness and wellness, housing, socialization and recreation, medical needs, medical equipment and technology, support groups, and transportation. This handout was given to all patients ages 60 and older.https://scholarworks.uvm.edu/fmclerk/1405/thumbnail.jp

ADENOSINE DIMETHYLTRANSFERASE KsgA: BIOCHEMICAL CHARACTERIZATION OF THE PROTEIN AND ITS INTERACTION WITH THE 30S SUBUNIT

Ribosomes form the core of the protein biosynthesis machinery and are essential to life. Ribosome biogenesis is a complex cellular process involving transcription of rRNA, pre-rRNA processing, rRNA modification and simultaneous assembly of ribosomal proteins. RNA nucleotide modification is observed in all domains of life. While there is enormous conservation of ribosome structure, very few post-transcriptional rRNA modifications have been conserved throughout evolution. A notable example of such rare conservation is the dimethylation of two adjacent adenosines in the 3’-terminal helix, a highly conserved region of the small subunit rRNA. Enzymes that carry out these dimethylations are equally conserved and are collectively known as the KsgA/Dim1 family of methyltransferases. The first member of the family, KsgA, was identified in E. coli as the determinant for resistance to the aminoglycoside antibiotic Kasugamycin. Orthologs have since been described in organisms of wide spread evolutionary origins as well as in eukaryotic cellular organelles, thus underscoring the unprecedented conservation of this family of enzymes and the resultant rRNA modification. The higher evolutionary orthologs of KsgA have adopted secondary roles in ribosome biogenesis in addition to their dimethyltransferase role. The eukaryotic ortholog, Dim1, is essential for proper processing of the primary rRNA transcript. Recently, KsgA has been speculated to function as a late stage ribosome biogenesis factor and a ΔksgA genotype in E. coli has been linked to cold sensitivity and altered ribosomal profiles. This report focuses on the biochemical characterization of KsgA and its interaction with the 30S subunit. We have established the salt conditions required for optimal KsgA methyltransferase activity while confirming that KsgA recognizes a translationally inactive conformation of 30S subunit in vitro. Our study of the functional conservation of KsgA/Dim1 enzymes in the bacterial system revealed that KsgA and the evolutionarily higher orthologs could recognize a common ribosomal substrate. This indicates that the recognition elements of both, the protein and the small subunit, have remained largely unchanged during the course of evolution. Finally, based on our site directed mutagenesis and biochemical studies, we report that KsgA binds to structural components of 16S rRNA other than the helix containing the target nucleosides

Synthesis and Characterization of Polyionic Hydrogels

In this study we describe novel polyionic dendrimer – PEG hydrogels for drug delivery. Hydrogels have a crosslinked insoluble network of polymer chains, which have found many applications including drug delivery and tissue regeneration. Dendrimers provide an ideal platform for drug delivery as they possess a well-defined highly branched nanoscale architecture with many reactive surface groups. Their highly clustered surface groups allow for targeted drug delivery and high drug payload to enhance therapeutic effectiveness. This study presented a new type of polyionic hydrogels based on dendrimers with potential applications in drug delivery and tissue engineering. Polyethylene glycol (PEG) with various chain lengths [1500, 6000 , 12000 Da] was first conjugated to the Starburst™ G3.0 PAMAM dendrimer to form stealth dendrimers through one ending site of PEG using p-nitro phenyl chloroformate and Triethylamine. The free hydroxyl group of PEG was further converted to an acrylate group using acrolyl chloride and Triethylamine. The conjugation was characterized with 1H-NMR. The Ninhydrin assay was used to estimate the loading degree of PEG on the dendrimer surface. The molecular weight and loading degree of PEG was varied. Hydrogel formation was realized by subjecting dendrimer-PEG acrylate to UV exposure for a brief period of time at the presence of Eosin Y, Triethanolamine [TEOA] and 1 vinyl 2 Pyrrolidinone [NVP] photo initiator system. Viscosity increase was observed after hydrogel formation. PEGylated G3.0 PAMAM dendrimer served as cross-linking agent to form hydrogels because of its multiple functionalities. PEGylated half generation dendrimer G3.5 was subjected to hydrogel formation and its swelling behavior was studied. Better hydrogel formation was observed with increased PEG arm length. The surface charges conferred by terminal groups on the dendrimer surface made the hydrogel polyionic with controllable charge density. This new type of hydrogel has many favorable biological properties such as non toxicity and non immunogenecity and multifunctional ties for a variety of in vivo applications. Current studies have demonstrated feasibility of chemistry and hydrogel formation. The swelling studies demonstrated pH sensitive behavior. Degradation of hydrogel was observed, for low PEGylated dendrimer degradation also demonstrated pH sensitivity. Controlled drug delivery and release were also investigated. Hydrophobic drug Cyclosprine A was used, we envision that hydrophobic dendrimer core will used for drug encapsulation and delivery, and later release in controlled fashion. The polymer and hydrogels were evaluated for in vitro cytotoxicity and cell internalization

Mars Propellant Liquefaction and Storage Performance Modeling using Thermal Desktop with an Integrated Cryocooler Model

NASAs current Mars architectures are assuming the production and storage of 23 tons of liquid oxygen on the surface of Mars over a duration of 500+ days. In order to do this in a mass efficient manner, an energy efficient refrigeration system will be required. Based on previous analysis NASA has decided to do all liquefaction in the propulsion vehicle storage tanks. In order to allow for transient Martian environmental effects, a propellant liquefaction and storage system for a Mars Ascent Vehicle (MAV) was modeled using Thermal Desktop. The model consisted of a propellant tank containing a broad area cooling loop heat exchanger integrated with a reverse turbo Brayton cryocooler. Cryocooler sizing and performance modeling was conducted using MAV diurnal heat loads and radiator rejection temperatures predicted from a previous thermal model of the MAV. A system was also sized and modeled using an alternative heat rejection system that relies on a forced convection heat exchanger. Cryocooler mass, input power, and heat rejection for both systems were estimated and compared against sizing based on non-transient sizing estimates

Incidence, predictors, healthcare utilization, and cost associated with antipsychotic polypharmacy in the Texas Medicaid population

textAntipsychotic medications are effective in the treatment of psychotic disorders. Monotherapy (MT) with antipsychotics is consistently recommended as the treatment of choice by several guidelines yet antipsychotic polypharmacy (APP) is widespread in clinical practice. The objectives of this study were to evaluate the incidence of APP, identify predictors of APP, and compare adherence, health resource utilization, and costs between patients on MT and APP using prescription and medication claims from Texas Medicaid (2006 to 2011). Patients newly initiated on antipsychotics were followed for 12 months and categorized into the APP (exposure to two or more antipsychotics for a defined time interval) and MT (no evidence of APP during the study period) groups. This sample of patients was used to evaluate incidence and predictors of APP and compare medication adherence and persistence between the MT and APP groups using multiple, logistic, and Cox proportional hazards regressions. Patients in the MT and APP groups were then matched based on their duration of exposure to antipsychotics and all-cause healthcare utilization and costs were compared using logistic and generalized linear models regression (negative binomial, Poisson, and gamma). Regression analyses for patients matched on duration of antipsychotic exposure accounted for the correlation between matched pairs. The incidence of APP was 5.4%. Several demographic, clinical, physician, and prior utilization characteristics were associated with APP. Medication adherence and persistence were better in the APP group. Length of hospital stay and medical, drug, and total costs were higher for the APP group. Sensitivity analyses were conducted for psychiatric-related costs and varied overlap and gap periods. The results for most of the sensitivity analyses were similar to the base case. Patients prescribed APP had higher medical, drug and total costs and also higher healthcare utilization i.e. increased drug costs were not offset by decreased medical costs. Long-term APP raises concern as state Medicaid agencies are allocating their limited resources to this expensive treatment which has very scarce data supporting its use. More effectiveness research on APP is needed to help provide prescription guidance to clinicians for patients who do not respond well to treatment with a single antipsychotic.Pharmac

Barriers Encountered by Syringe Exchange Clients in Vermont

Introduction and Aims. Vermont CARES is a nonprofit HIV prevention and advocacy organization which provides a needle exchange program for intravenous drug users. Services are focused on education, prevention, testing, and harm reduction. The Syringe Support Program (SSP) offers clients clean syringes to reduce intravenous transmission of disease. Although SSP are proven avenues for harm reduction, barriers prevent users from utilizing services. Clients are limited by social, economic, and personal obstacles de- scribed in similar populations across the country. This project seeks to identify the barriers Vermont CARES clients face in accessing the SSP, determine needs, and evaluate interest in additional services. Methods. Our team and Vermont CARES staff held a focus group with St. Johnsbury clients to discuss services and barriers. A 39 question paper survey was distributed to three Vermont CARES sites during October, 2017 by Vermont CARES. Participation was voluntary and uncompensated. Sixty-three clients completed the survey. Results and Discussion. Of the 63 respondents, 61.9% stated that lack of ade- quate income contributed most to their inability to meet basic needs. These same clients faced the most barriers to access with economic hardship precipitated by sub- stance abuse, disability, and family commitments. In assessing additional services, clients sought food pantries, hygiene kits, and dental clinics. 56.4% of respondents would use safe injection facilities if provided. Those without income to meet basic needs expressed most interest in safe injection facilities (p=0.022). With barriers recognized, our future aim is to track efficacy of new services in impacting care and quality of life.https://scholarworks.uvm.edu/comphp_gallery/1268/thumbnail.jp

A comparative quantitative & qualitative assessment in orthodontic treatment of white spot lesion treated with 3 different commercially available materials - In vitro study

To comparatively evaluate the esthetic improvement of white-spot lesions (WSLs) treated by: BiominF, CPP-ACP paste with fluoride & ICON resin infiltration, using Spectrophotometer & Diagnodent. The study was done using 72 sound permanent extracted premolars, divided into four groups (18 teeth per group). After taking the ethical approval the study was commenced. WSLs were created on human premolars and randomly assigned to four groups: Group A: Artificial Saliva, Group B: CPP-ACP with fluoride, Group C: BiominF, Group D: Resin infiltration (Icon). The color change (?E) of each specimen was measured with a Spectrophotometer (VITA Easy Shade Compact), and fluorescence loss (?Q) was measured by a laser fluorescence device (DIAGNOdent, Kavo, Biberach, Germany), at different time points after treatment: baseline (0 weeks), 2 weeks, 4 weeks, and 6 weeks. The ?E and ?Q baseline values for the four groups before the treatments did not differ significantly. Icon treatment improved the WSL color significantly and gave the lowest ?E (5.12± 3.92) & ?Q (1.64 ±0.72) compared with other treatments at end of 6 weeks (P< .01). In the BiominF and CPP-ACP with fluoride treatment groups, ?Q & ?E showed significant recovery compared with the baseline values (P< .05). Within the limitations of the study, it can be concluded that all the three remineralizing agents used in the study could effectively remineralize artificial enamel caries and showed improvement in color change and fluoresence as compared to the baseline. Therefore they can be effectively used for the treatment of the white spot lesions