Chemical and Pharmacologic Phenomena Commons^™

The Neurochemistry Of Group Singing: Bonding And Oxytocin, Jason Keeler

Masters Theses

The purpose of this study was to examine the neurochemical correlates of group vocal improvisation and to determine the feasibility of the research methods. One group of four participants sang together in two conditions: pre-composed and improvised. Concentrations of plasma oxytocin and adrenocorticotropic hormone (ACTH) were measured before and after each singing condition to assess levels of hormones associated with social affiliation, engagement and arousal. Successful implementation of the methodology, including recruitment, data collection, and sample analysis, served as the primary outcome of this study. ACTH concentrations decreased in both conditions, and significantly so in the pre-composed singing condition. Mean …

Steroid Receptor Isoform Expression In Drosophila Nociceptor Neurons Is Required For Normal Dendritic Arbor And Sensitivity, Aidan L. Mcparland, Taylor L. Follansbee, Gwendolyn D. Vesenka, Alexandra E. Panaitiu, Geoffrey K. Ganter

Biology Student Publications

Steroid hormones organize many aspects of development, including that of the nervous system. Steroids also play neuromodulatory and other activational roles, including regulation of sensitivity to painful stimuli in mammals. In Drosophila, ecdysteroids are the only steroid hormones, and therefore the fly represents a simplified model system in which to explore mechanisms of steroid neuromodulation of nociception. In this report, we present evidence that ecdysteroids, acting through two isoforms of their nuclear ecdysone receptor (EcR), modulate sensitivity to noxious thermal and mechanical stimuli in the fly larva. We show that EcRA and EcRB1 are expressed by third instar larvae in …

Using Water–Solvent Systems To Estimate In Vivo Blood–Tissue Partition Coefficients, Andrew Lang, Caitlin E. Derricott

College of Science and Engineering Faculty Research and Scholarship

Background: Blood–tissue partition coefficients indicate how a chemical will distribute throughout the body and are an important part of any pharmacokinetic study. They can be used to assess potential toxicological effects from exposure to chemicals and the efficacy of potential novel drugs designed to target certain organs or the central nervous system. In vivo measurement of blood–tissue partition coefficients is often complicated, time-consuming, and relatively expensive, so developing in vitro systems that approximate in vivo ones is desirable. We have determined such systems for tissues such as brain, muscle, liver, lung, kidney, heart, skin, and fat. Results: Several good (p < 0.05) blood–tissue partition coefficient models were developed using a single water– solvent system. These include blood–brain, blood–lung, blood–heart, blood–fat, blood–skin, water–skin, and skin permeation. Many of these partition coefficients have multiple water–solvent systems that can be used as models. Several solvents—methylcyclohexane, 1,9-decadiene, and 2,2,2-trifluoroethanol—were common to multiple models and thus a single measurement can be used to estimate multiple blood–tissue partition coefficients. A few blood–tissue systems require a combination of two water–solvent partition coefficient measurements to model well (p < 0.01), namely: blood–muscle: chloroform and dibutyl ether, blood–liver: N-methyl-2-piperidone and ethanol/water (60:40) volume, and blood–kidney: DMSO and ethanol/water (20:80) volume. Conclusion: In vivo blood–tissue partition coefficients can be easily estimated through water–solvent partition coefficient measurements.

Dietary Intake And Bio-Activation Of Nitrite And Nitrate In Newborn Infants, Jesica Ann Jones

Loma Linda University Electronic Theses, Dissertations & Projects

Nitrate and nitrite are commonly thought of as inert end products of nitric oxide (NO) oxidation, possibly carcinogenic food additives, or well-water contaminants. However, recent studies have shown that nitrate and nitrite play an important role in cardiovascular and gastrointestinal homeostasis through conversion back into NO via a physiological system involving enterosalivary recirculation, bacterial nitrate reductases, and enzyme-catalyzed or acidic reduction of nitrite to NO. The diet is a key source of nitrate in adults; however, infants ingest significantly less nitrate due to low concentrations in breast milk. In the mouth, bacteria convert nitrate to nitrite, which has gastro-protective effects. …

Synthesis And Flammability Testing Of Epoxy Functionalized Phosphorous-Based Flame Retardants, Vladimir Benin, Xuemei Cui, Alexander Morgan, Karl Seiwert

Chemistry Faculty Publications

Several potential new phosphorus-containing flame retardant molecules were evaluated for heat release reduction potential by incorporation of the molecules into a polyurethane, generated from methylene diphenyl diisocyanate and 1,3-propane diol. The heat release reduction potential of these substances was evaluated using the pyrolysis combustion flow calorimeter (PCFC). The polyurethanes were prepared in the presence of the potential flame retardants via solvent mixing and copolymerization methods to qualitatively evaluate their potential reactivity into the polyurethane prior to heat release testing. The functionality of the flame retardants was epoxide based that would potentially react with the diol during polyurethane synthesis. Flammability testing …

Amikacin Concentrations Predictive Of Ototoxicity In Multidrug-Resistant Tuberculosis Patients, Chawangwa Modongo, Jotam G. Pasipanodya, Nicola M. Zetola, Scott M. Williams

Dartmouth Scholarship

Aminoglycosides, such as amikacin, are used to treat multidrug-resistant tuberculosis. However, ototoxicity is a common problem and is monitored using peak and trough amikacin concentrations based on World Health Organization recommendations. Our objective was to identify clinical factors predictive of ototoxicity using an agnostic machine learning method. We used classification and regression tree (CART) analyses to identify clinical factors, including amikacin concentration t

hresholds that pre- dicted audiometry-confirmed ototoxicity among 28 multidrug-resistant pulmonary tuberculosis patients in Botswana. Amika- cin concentrations were measured for all patients. The quantitative relationship between predictive factors and the probability of ototoxicity were then identified using …

Acclimatization To High-Altitude, Long-Term Hypoxia Alters Bk Channel Structure And Function, Xiaoxiao Tao

Loma Linda University Electronic Theses, Dissertations & Projects

We examined the major possible mechanisms for the left shift of the BK channel I-V relationship in native basilar artery myocytes from the two LTH groups. These mechanisms included: differential expression of the accessary BK -1 subunit; differential phosphorylation of the BK subunit; and splice variation of the BK subunit. Using molecular cloning, heterologous expression, and patch-clamp electrophysiology techniques, we elucidated a mechanism that, at least in part, contributes to the differences we observed between channels from native normoxic and LTH myocytes.

Statins And Kidney Failure, Rebekah Pemberton

Senior Honors Theses

Use of the HMG-CoA Reductase Inhibitors, also known as statins, in patients with renal dysfunction is laden with controversy. Studies on statin use in renal patients have given varying reports. Some research has indicated that these medications may exacerbate existing renal dysfunction and induce further progression of renal disease. Furthermore, some researchers have suggested statins may actually cause some cases of renal dysfunction through the effects of rhabdomyolysis, acute interstitial nephritis, or necrotizing immune-mediated myopathy, while other researchers have asserted that the statins can have nephroprotective effects. The use of statins is believed to be ineffective in patients who are …

Cancer Stem Cells In The Screening Of Anticancer Drugs For Central Nervous System Tumors, Sarah Elizabeth Daron-Mathis

Theses, Dissertations and Capstones

There is a growing need (in the medical field) to design personalized therapy for cancer patients. Decades of cancer research have found no silver bullet that can cure all or even most patients. This study evaluated four patients affected by central nervous system (CNS) tumors (Ependymoma and Glioblastoma), and found that tumors with the same histology had unique responses to treatment. Each sample presented different levels of heterogeneity in expressed biomarkers and responded to drugs at varying levels.

Oncologists conventionally treat cancer patients with drugs tested in large clinical trials. However, often patients do not experience positive outcomes following treatments …

Drug Interactions With Glutaredoxin Orthologues, Kahlilah R. Napper, Thomas C. Leeper, Ram Khattri, Daniel Morris, Caroline Davis

Williams Honors College, Honors Research Projects

Glutaredoxin, an enzymatic protein, is an important component of cell viability and function. It catalyzes reactions involved in DNA synthesis and innate immunity [1,4]. Glutaredoxin is also essential in antibiotic resistance in pathogenic bacterial species. Pseudomonas aeruginosa in particular is responsible for infecting the lung tissue of its human hosts, resulting in the development of pneumonia and cystic fibrosis [3]. Because glutaredoxin is pertinent in cell proliferation of eukaryotic and bacterial cells alike, medicinal fragments that take advantage of the subtle differences in protein structure of the orthologous proteins can be synthesized and enhanced to bind bacterial glutaredoxins, without inhibiting …

Investigating The Effect Of Arsenic On Chromium(Vi)-Induced Genotoxicity In Human Lung Fibroblasts, Jason Stewart Ms

All Student Scholarship

Hexavalent chromium (Cr(VI)) compounds are well-established human lung carcinogens. Arsenic (As) is a well documented human carcinogen with long term exposure to AS in drinking water being linked to lung, kidney and liver cancer, among others. Co-exposure studies are now becoming more common as humans are not exposed to just one toxicant at a time. This is the first study to investigate the effects of co-exposure with arsenic and soluble or particulate Cr(Vi) compounds in human lung fibroblasts.