Medical Toxicology Commons^™

Mechanisms Of Chromate-Induced Suppression Of Rad51: A One Environmental Health Approach., Rachel M. Speer

Electronic Theses and Dissertations

Lung cancer is the leading cause of cancer death. Lung cancer is commonly associated with smoking, however, 1 in 5 women and 1 in 12 men who develop lung cancer are never-smokers. Environmental exposures, therefore, account for a significant portion of lung cancer cases. Hexavalent chromium [Cr(VI)] is a global environmental contaminant and known human lung carcinogen. Cr(VI) and other carcinogenic metals induce chromosome instability, an early event in lung cancer. Structural chromosome instability arises in part due to failed DNA repair. Particulate Cr(VI), the most potent form of Cr(VI), induces DNA double strand breaks and inhibits the high-fidelity DNA …

The Effect Of Β-Caryophyllene On Isoproterenol-Induced Myocardial Infarction, Farah M. Jamal Laham

Theses

Cannabinoid type 2 receptors (CB2), a key member of the endocannabinoid system have recently emerged as a crucial therapeutic target for cardiovascular diseases (CVDs). Downregulation of CB2 receptors has been witnessed in various cancers, neurological and cardiovascular disorders. Thus, the activation of CB2 receptors may protect against ISO-induced myocardial infarction (MI) in rats. The present study investigates the cardioprotective effect of a selective cannabinoid type 2 receptor agonist β-caryophyllene (BCP), a dietary phytocannabinoid, and a natural bicyclic sesquiterpene against isoproterenol (ISO)-induced MI in rats. Male albino Wistar rats were pre-and co-treated with β-caryophyllene (50 mg/kg, orally) twice daily for 10 …

Renal Safety And Racial Disparity In Patients On Antiviral Treatment For Chronic Hepatitis B, Matthew Miller, Sindhuri Benjaram, Raya Kutaimy, Paul Naylor, Elizabeth May, Murray Ehrinpreis, Milton Mutchnick

Medical Student Research Symposium

Background:

Many African Americans (AA) are chronically infected with Hepatitis B (HBV). While antiviral therapy is highly effective, clinical trials suggest a treatment-related decline in kidney function is possible. Given that chronic HBV predominately affects Asians worldwide, most studies have contained few AA patients. We evaluated these treatment-related kidney function changes in our predominately AA patient population.

Methods:

From 225 HBV patients, we identified 42 patients who were not co-infected with HIV or HCV, had a recent visit, and at least one earlier visit (before Jan 2017). If on treatment with antivirals it must have been for at least 2 …

A Phantom Of The Past: Withdrawal From Meprobamate Presenting With Focal Seizures., Thomas M. Zink, John E. Erickson

Journal of Maine Medical Center

Introduction: Meprobamate (Miltown, Equinil) is a sedative-hypnotic medication that first gained popularity as an anxiolytic and later as a muscle relaxant. It is a major metabolite of the more commonly used muscle relaxant carisoprodol (Soma). In vitro and electroencephalogram studies demonstrated that meprobamate modulates gama-aminobutyric acid (GABA) receptors, similar to barbiturates. Withdrawal from meprobamate manifests in symptoms ranging from mild anxiety to severe autonomic instability and death. Meprobamate is rarely prescribed, but is still given to a small subset of elderly patients.

Clinical findings: In this case of meprobamate withdrawal, the patient initially displayed altered mental status and recurrent seizures …

The Effects Of Autophagy And Senescence On Sensitivity To Cisplatin In Head And Neck Cancer, Zara H. Siddiqui

Theses and Dissertations

While current treatments in cancer, such as chemotherapy and radiation, can generally be effective in eliminating disease in patients, there also exists the possibility of recurrence of cancer cells over time. In patients diagnosed with locally advanced head and neck carcinoma, about 50-60% develop a loco-regional recurrence within two years, and 20-30% of patients develop metastatic disease at distant sites in the body [5]. On a cellular level, one mechanism for this survival may be that natural mechanisms such as autophagy and senescence play a role in allowing cells to survive after undergoing treatment. One standard of care chemotherapy for …

A Clinically Relevant Mouse Model Of Cisplatin-Induced Kidney Injury., Cierra Nichole Sharp

Electronic Theses and Dissertations

Cisplatin is a potent chemotherapeutic used for the treatment of many solid cancers, including testicular, ovarian, and lung cancer. Cisplatin causes many adverse side effects, of which nephrotoxicity leading to acute kidney injury is dose-limiting. Approximately 30% of patients will develop nephrotoxicity with cisplatin, and will either have their next dose of cisplatin lowered, skipped, or be switched to a less nephrotoxic chemotherapeutic altogether. These outcomes are not ideal when trying to treat cancer. Previously, it was believed that patients could recover from cisplatin-induced acute kidney injury with little to no lasting effects, but recent longitudinal studies have shown this …

An Aged Canid With Behavioral Deficits Exhibits Blood And Cerebrospinal Fluid Amyloid Beta Oligomers, Clare Rusbridge, Francisco J. Salguero, Monique Antoinette David, Kiterie M. E. Faller, Jose T. Bras, Rita J. Guerreiro, Angela C. Richard-Londt, Duncan Grainger, Elizabeth Head, Sebastian G. P. Brandner, Brian Summers, John Hardy, Mourad Tayebi

Pharmacology and Nutritional Sciences Faculty Publications

Many of the molecular and pathological features associated with human Alzheimer disease (AD) are mirrored in the naturally occurring age-associated neuropathology in the canine species. In aged dogs with declining learned behavior and memory the severity of cognitive dysfunction parallels the progressive build up and location of Aβ in the brain. The main aim of this work was to study the biological behavior of soluble oligomers isolated from an aged dog with cognitive dysfunction through investigating their interaction with a human cell line and synthetic Aβ peptides. We report that soluble oligomers were specifically detected in the dog's blood and …

Maternal Engineered Nanomaterial Inhalation During Gestation Alters The Fetal Transcriptome, P.A. Stapleton, Q.A. Hathaway, C.E. Nichols, A.B. Abukabda, M.V. Pinti, D.L. Shepherd, C.R. Mcbride, J. Yi, V.C. Castranova, J.M Hollander, Timothy Robert Nurkiewicz

Faculty & Staff Scholarship

Background: The integration of engineered nanomaterials (ENM) is well-established and widespread in clinical, commercial, and domestic applications. Cardiovascular dysfunctions have been reported in adult populations after exposure to a variety of ENM. As the diversity of these exposures continues to increase, the fetal ramifications of maternal exposures have yet to be determined. We, and others, have explored the consequences of ENM inhalation during gestation and identified many cardiovascular and metabolic outcomes in the F1 generation. The purpose of these studies was to identify genetic alterations in the F1 generation of Sprague-Dawley rats that result from maternal ENM inhalation during gestation. …

Characterization Of A Mutant Oncolytic Adenovirus And The Role Of Jnk In Enhancing Virotherapy., Stephen L. Wechman

Electronic Theses and Dissertations

Oncolytic adenoviruses (Ads) have great therapeutic potential for lung cancer treatment. Cancer selective E1b-deleted Ads are safe; however, their clinical cancer therapeutic efficacy remains limited. The limited efficacy of Ad virotherapy is due to many factors including inefficient cancer cell lysis, Ad release and spread. Progress in overcoming these barriers to Ad virotherapy are hampered by limited knowledge of the genes associated with enhanced Ad release and spread and the dearth of understanding of the mechanisms by which E1b-deleted Ads cause cancer cell lysis. The role of c-JNK n- terminal kinase (JNK) phosphorylation in this process remains unknown. …

The Interaction Of Homoserine Lactones And Paraoxonase 2 Modulates Cell Death Signaling And Cell Proliferation., Aaron Mackallan Neely

Electronic Theses and Dissertations

Pseudomonas aeruginosa produces N-(3-oxododecanoyl)-homoserine lactone (C12) as a quorum-sensing molecule that functions to facilitate bacteria-bacteria communication. C12 has also been reported to affect many aspects of human host cell physiology, including evoking cell death in various types of cells. However, the signaling pathway(s) leading to C12-triggerred cell death remains unclear. To clarify cell death signaling induced by C12, we examined mouse embryonic fibroblasts (MEFs) deficient in one or more caspases. Our data indicate that, unlike most apoptotic inducers, C12 evokes a novel form of apoptosis in cells, probably through the direct induction of mitochondrial membrane permeabilization. Importantly, C12 induces apoptosis …

The Role Of Nicotine, A7 Nicotinic Acetylcholine Receptors And Extracellular Matrix Remodeling In Pulmonary Fibrosis., Glenn Ward Vicary

Electronic Theses and Dissertations

The median survival for idiopathic pulmonary fibrosis (IPF) patients from diagnosis is a dismal 3 years. This condition is characterized by pulmonary fibroproliferation and excess production and disordered deposition of extracellular matrix (ECM) proteins resulting in obliteration of the original tissue architecture, loss of lung function and eventual death due to respiratory failure. The main hindrance to the development of effective treatments against pulmonary fibrosis is the late detection of its progression and is often of unknown cause. Tobacco smoke represents the most important environmental factor linked to the development of pulmonary fibrosis, with over 60% of IPF patients current …

Effect Of Genipin On Cisplatin- Induced Nephrotoxicity, Eglal Orner Mahgoub

Theses

Cisplatin (CSP) is a potent and widely used chemotherapeutic agent. However, clinical efficacy of CSP is compromised due to the elicitation of nephrotoxicity and ototoxicity. In this study, I have investigated the nephroprotective effects of a phytochemical – genipin (GP) isolated from gardenia flower (Gardenia jasminoides), on a murine model of cisplatin-induced nephropathy. CSP-induced renal tissue injury was characterized by elevated levels of serum blood urea nitrogen (BUN), creatinine (Cr) and cystatin-C. In addition, levels of kidney injury molecule-1 (KIM-1) were increased in the renal tissues of CSP administered animals. CSP also induced renal oxidative stress, evidenced by increased NADPH …

Developing A More Clinically-Relevant Mouse Model Of Cisplatin-Induced Nephrotoxicity., Cierra N. Sharp

Electronic Theses and Dissertations

Cisplatin is a nephrotoxic chemotherapeutic that causes acute kidney injury (AKI) in 30% of patients. Although recovery can occur after one episode of cisplatin-induced AKI, studies have indicated multiple episodes may lead to the development of chronic kidney disease (CKD), an irreversible disease with no current treatments. The standard mouse model of cisplatin-induced AKI consists of one, high dose of cisplatin (> 20 mg/kg) that is lethal to the animal three days later. This model doesn’t accurately reflect the repeated dosing regimen patients receive, and doesn’t allow for long-term outcome studies of pathologies associated with CKD. We have developed a …

Role Of Phosphodiesterase-4 In Alcohol-Induced Organ Injury., Diana Veronica Avila

Electronic Theses and Dissertations

Alcoholic liver disease (ALD) remains a leading cause of death from liver disease in the U.S., and there is still no FDA-approved therapy. Alcohol metabolism leads to generation of free radicals and oxidative stress with a resultant formation of lipid peroxidation products, which, in turn, contribute to the development of ALD. Alcohol induced hepatic steatosis is the earliest and most frequent manifestation of ALD and a significant risk factor for progressive liver disease. Cyclic adenosine monophosphate (cAMP) signaling has been shown to significantly regulate lipid metabolism. Moreover, agents that increase cAMP have been shown to effectively mitigate oxidative stress both …

Acrolein Is A Critical Mediator Of Alcohol-Induced Liver And Intestinal Injury In Alcoholic Liver Disease., Wei-Yang (Jeremy) Chen

Electronic Theses and Dissertations

Alcohol consumption can cause alcoholic liver disease (ALD), which remains a major cause of morbidity and mortality in the United States. Chronic alcohol consumption causes a pro-oxidant environment in the liver and increases hepatic lipid peroxidation. Acrolein is the most reactive and toxic aldehyde generated through lipid peroxidation. Acrolein forms protein adducts and triggers endoplasmic reticulum (ER) stress and hepatocyte apoptosis, which are recognized etiologic factors in ALD. Several studies have established the critical role of the gut-liver axis in ALD pathogenesis, wherein alcohol-induced gut barrier dysfunction contributes to liver injury. This study investigates, in vitro and in vivo, the …

The Role Of Pxr And Ikkβ Signaling In Cardiometabolic Disease, Robert N. Helsley

Theses and Dissertations--Pharmacology and Nutritional Sciences

Cardiovascular disease (CVD) is the leading cause of death worldwide and is partially attributed to perturbations in lipid metabolism. Xenobiotics, such as pharmaceutical drugs and environmental chemicals, have been associated with increased risk of CVD in multiple large-scale human population studies, but the underlying mechanisms remain poorly defined. We and others have identified several xenobiotics as potent agonists for the pregnane X receptor (PXR), a nuclear receptor that can be activated by numerous drugs as well as environmental and dietary chemicals. However, the role of PXR in mediating the pathophysiological effects of xenobiotic exposure in humans and animals remains elusive. …

Therapeutic Efficacy Of Cerium Oxide Nanoparticles Against Sepsis Induced Multi-Organ Dysfunction Syndrome In Sprague Dawley Rats, Nandini Durga Prasanna Kumar Manne

Theses, Dissertations and Capstones

Sepsis is a generalized term that signifies the presence of a pathogen in the blood stream to which the body responds by eliciting a systemic inflammatory response. Although sepsis is the leading cause of death in non-coronary intensive care units in United States, there are currently no FDA approved therapeutic drugs to treat this disorder. Cerium oxide nanoparticles (CeO₂) have been shown to exhibit anti-oxidant, anti-inflammatory, and anti-bacterial properties both in vitro and in vivo. Whether CeO₂ nanoparticles can be used for the treatment of sepsis is currently unclear.

To investigate whether CeO₂ nanoparticles can …

An Analysis Of Fatty Acid Metabolism’S Role In The Development Of Acute Functional Tolerance To Ethanol In Caenorhabditis Elegans, Richard Raabe

Theses and Dissertations

An individual’s naïve level of response (LR) to ethanol is predictive of their lifetime likelihood to abuse alcohol. LR is heavily genetically influenced, suggesting that the genes responsible for LR may also be central to the development of abuse disorders. Our laboratory uses the model organism C. elegans to investigate the genetic influences on responses to acute ethanol exposure. We recently found that changes in TAG levels can alter LR. From this result we investigated the role of long-chain polyunsaturated fatty acids (LC-PUFAs) as well enzymes involved in lipid modifications of proteins. We found that LC-PUFAs are necessary for acute …

Surface-Enhanced Raman Spectroscopy (Sers) Tracking Of Chelerythrine, A Na+ K+ Pump Inhibitor, Into Cytosol And Plasma Membrane Fractions Of Human Lens Epithelial Cell Cultures, Kevin M. Dorney, Ioana E.P. Sizemore, Tariq Alqahtani, Norma C. Adragna, Peter K. Lauf

Pharmacology and Toxicology Faculty Publications

Background/aims: The quaternary benzo-phenanthridine alkaloid (QBA) chelerythrine (CET) is a pro-apoptotic drug and Na(+)/K(+) pump (NKP) inhibitor in human lens epithelial cells (HLECs). In order to obtain further insight into the mechanism of NKP inhibition by CET, its sub-cellular distribution was quantified in cytosolic and membrane fractions of HLEC cultures by surface-enhanced Raman spectroscopy (SERS). Methods: Silver nanoparticles (AgNPs) prepared by the Creighton method were concentrated, and size-selected using a one-step tangential flow filtration approach. HLECs cultures were exposed to 50 μM CET in 300 mOsM phosphate-buffered NaCl for 30 min. A variety of cytosolic extracts, crude and purified membranes, …

Sea Water Acidification Affects Osmotic Swelling, Regulatory Volume Decrease And Discharge In Nematocytes Of The Jellyfish Pelagia Noctiluca, Rossana Morabito, Angela Marino, Peter K. Lauf, Norma C. Adragna, Giuseppa La Spada

Pharmacology and Toxicology Faculty Publications

Ion transporters are the molecular basis for ion homeostasis of the cell and the whole organism. The anion exchanger pendrin is only one of a number of examples where a complete or partial loss of function and/or deregulation of expression of ion transporters may lead or contribute to pathological conditions in humans. A complete understanding of the function of ion transporters in health and disease may pave the way for the identification of new and focused therapeutic approaches. Exchange of knowledge and connectivity between the experts in the feld of transport physiology is essential in facing these challenging tasks. The …

Is Rimonabant A Safe And Effective Treatment For Patients With Alcohol Dependence?, Samantha L. Hughes

PCOM Physician Assistant Studies Student Scholarship

OBJECTIVE: The objective of this selective EBM review is to determine whether or not Rimonabant is a safe and effective treatment for patients with alcohol dependence.

STUDY DESIGN: Systematic review of three English language randomized control trials published in 2005, 2008 and 2010.

DATA SOURCES: Three double-blind, placebo controlled randomized trials comparing Rimonabant or Naltrexone to placebo were found using PubMed, OVID, Medline and Cochrane.

OUTCOMES MEASURED: Outcomes measured include event rate of heavy drinking days using the timeline follow back method, which facilitates self-reporting of drinking habits by utilizing calendars and personal recall. Other outcomes measured include …

Nevirapine Hepatotoxicity: Case Report And Discussion, Matt Baichi

The Medicine Forum

Nevirapine (viramune) is a nonnucleoside reverse transcriptase inhibitor commonly used in combination with other antiretroviral medicines in the treatment of HIV/AIDS. The safety profile of nevirapine, as determined by review of prospective clinical trials, reports rash with an incidence of 16% as the most common side effect. Clinical hepatitis is reported to occur with an incidence of 1%. A review of the literature shows many case reports of nevirapine-induced hepatotoxicity in patients receiving both treatment and prophylaxis for HIV. The purpose of this case report is to stress the importance of early recognition and withdrawal of the offending drug.

The Use Of Cerium Oxide And Curcumin Nanoparticles As Therapeutic Agents For The Treatment Of Ventricular Hypertrophy Following Pulmonary Arterial Hypertension, Madhukar Babu Kolli

Theses, Dissertations and Capstones

Pulmonary arterial hypertension (PAH) is a progressive and fatal disease characterized by inflammation, increased pulmonary vascular resistance, right ventricular failure and premature death. Monocrotaline (MCT) has been used to induce PAH in laboratory rats. Previous in vitro and in vivo work suggested that cerium oxide (CeO2)-and curcumin nanoparticles exhibit anti-inflammatory activity; however, it is unknown if these materials are effective for the treatment of PAH induced cardiac hypertrophy. To determine the efficacy of CeO2 nanoparticle treatment in preventing MCT-induced RV hypertrophy, male Sprague Dawley rats were divided into one of three groups (control, MCT, or MCT + CeO2 nanoparticle, n=6/group). …

The Aryl Hydrocarbon Receptor Binds To E2f1 And Inhibits E2f1-Induced Apoptosis., Jennifer L Marlowe, Yunxia Fan, Xiaoqing Chang, Li Peng, Erik S Knudsen, Ying Xia, Alvaro Puga

Kimmel Cancer Center Faculty Papers

Cellular stress by DNA damage induces checkpoint kinase-2 (CHK2)-mediated phosphorylation and stabilization of the E2F1 transcription factor, leading to induction of apoptosis by activation of a subset of proapoptotic E2F1 target genes, including Apaf1 and p73. This report characterizes an interaction between the aryl hydrocarbon (Ah) receptor (AHR), a ligand-activated transcription factor, and E2F1 that results in the attenuation of E2F1-mediated apoptosis. In Ahr(-/-) fibroblasts stably transfected with a doxycycline-regulated AHR expression vector, inhibition of AHR expression causes a significant elevation of oxidative stress, gammaH2A.X histone phosphorylation, and E2F1-dependent apoptosis, which can be blocked by small interfering RNA-mediated knockdown of …