Medical Toxicology Commons^™

The Preliminary Study Of Effects Of Tolfenamic Acid On Cell Proliferation, Cell Apoptosis, And Intracellular Collagen Deposition In Keloid Fibroblasts In Vitro, Dan Yi, Mackenzie S. Newman, Yanfang Chen, Richard Simman

Pharmacology and Toxicology Faculty Publications

Keloid scarring is a fibroproliferative disorder due to the accumulation of collagen type I. Tolfenamic acid (TA), a nonsteroidal anti-inflammatory drug, has been found to potentially affect the synthesis of collagen in rats. In this preliminary study, we aimed to test the effects of TA on cell proliferation, cell apoptosis, and the deposition of intracellular collagen in keloid fibroblasts. Normal fibroblasts (NFs) and keloid fibroblasts (KFs) were obtained from human dermis tissue. Within the dose range 10−3–10−6 M and exposure times 24 h, 48 h, and 72 h, we found that 0.55 × 10−3 M TA at 48 h exposure …

Anti-Cancer Effects Of Glypican-3 On Huh-7 Hepatocellular Carcinoma Cells, Jiyu Wen, Xiaojun Wen, Jinju Wang, Yang Shu, Zhidong Qiu, Zhongkao Liu, Ran Li, Guofang Zeng, Shiting Bao, Huilai Miao, Yanfang Chen, Mingyi Li

Pharmacology and Toxicology Faculty Publications

Aim: Previous studies have suggested Glypican-3 (GPC3) could be a valuable diagnostic marker for hepatocellular carcinoma. This study examined the effects of overexpression of GPC3 on Huh-7 hepatoma cells.

Methods: We constructed a recombinant plasmid vector pcDNA3.1 (+)-GPC3 for GPC3 overexpression studies in Huh-7 cells. RT-PCR and Western blotting were used to confirm GPC3 gene expression. Cell proliferation was evaluated by 5-ethynyl-2-deoxyuridine (EdU) incorporation assay. Cell cycle progression and apoptosis were determined by flow cytometry using propidium iodide (PI) and Annexin V-FITC/PI staining, respectively. Cell migration and invasion were examined by Boyden Transewll and Matrigel assays.

Results: GPC3 overexpression effectively …

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 …

Synthetic Triterpenoids Can Protect Against Toxicity Without Reducing The Efficacy Of Treatment With Carboplatin And Paclitaxel In Experimental Lung Cancer, Karen T. Liby

Dartmouth Scholarship

Synthetic oleanane triterpenoids are multifunctional drugs being developed for the prevention and treatment of a variety of chronic diseases driven by inflammation and oxidative stress. Low nanomolar concentrations of triterpenoids inhibit the induction of inflammatory cytokines, and these drugs are potent activators of the Nrf2 cytoprotective pathway. In contrast, low micromolar concentrations of triterpenoids increased the production of ROS and induced apoptosis in a dose-dependent manner in malignant MCF10 CA1a breast cancer cells. Because cancer cells respond differently to ROS than normal cells, it should be possible to exploit these differences therapeutically. In an experimental model of lung cancer, the …

Strand Exchange Of Telomeric Dna Catalyzed By The Werner Syndrome Protein (Wrn) Is Specifically Stimulated By Trf2, Deanna Edwards, David K. Orren, Amrita Machwe

Toxicology and Cancer Biology Faculty Publications

Werner syndrome (WS), caused by loss of function of the RecQ helicase WRN, is a hereditary disease characterized by premature aging and elevated cancer incidence. WRN has DNA binding, exonuclease, ATPase, helicase and strand annealing activities, suggesting possible roles in recombination-related processes. Evidence indicates that WRN deficiency causes telomeric abnormalities that likely underlie early onset of aging phenotypes in WS. Furthermore, TRF2, a protein essential for telomere protection, interacts with WRN and influences its basic helicase and exonuclease activities. However, these studies provided little insight into WRN's specific function at telomeres. Here, we explored the possibility that WRN and TRF2 …

Hypoxia/Aglycemia-Induced Endothelial Barrier Dysfunction And Tight Junction Protein Downregulation Can Be Ameliorated By Citicoline, Xiaotang Ma, Huiting Zhang, Qunwen Pan, Yuhui Zhao, Ji Chen, Yanfang Chen

Pharmacology and Toxicology Faculty Publications

This study explores the effect of citicoline on the permeability and expression of tight junction proteins (TJPs) in endothelial cells under hypoxia/aglycemia conditions. Hypoxia or oxygen and glucose deprivation (OGD) was utilized to induce endothelial barrier breakdown model on human umbilical vein endothelial cells (HUVECs) and mouse brain microvascular endothelial cells (bEnd.3s). The effect of citicoline on endothelial barrier breakdown models was determined at either low or high concentrations. FITC-Dextran flux was used to examine the endothelial permeability. The expression of TJPs was measured by immunofluorescence, Real-time PCR and Western Blot methods. Results showed that hypoxia or OGD increased the …

Early Chronic Low-Level Lead Exposure Produces Glomerular Hypertrophy In Young C57bl/6j Mice, Christina Sobin, John Basgen

Selected Works Temporary Series

Early chronic lead exposure continues to pose serious health risks for children, particularly those living in lower socioeconomic environments. This study examined effects on developing glomeruli in young C57BL/6J mice exposed to low (30 ppm), higher (330 ppm) or no lead via dams’ drinking water from birth to sacrifice on post-natal day 28. Low-level lead exposed mice [BLL mean (SD); 3.19 (0.70) µg/dL] had an increase in glomerular volume but no change in podocyte number compared to control mice [0.03 (0.01) µg/dL]. Higher-level lead exposed mice [14.68 (2.74) µg/dL] had no change in either glomerular volume or podocyte number. The …

A Characterization Of Gold Nanoparticle Uptake By Mammalian Cells, Thomas Garner

All Dissertations

Over the past decade, there has been an exponential growth in products and applications that utilize nanotechnology, as these materials present exciting opportunities for the development of new products, enhancement of existing products, and the evolution of innovative procedures. However, this recent growth has occurred in the absence of detailed knowledge concerning the interactions of nanoparticles with biological systems. Nanoparticles must usually be bioavailable in order to elicit a biological response, and to reach an active site they must usually cross a membrane. As a result, cell culture studies have proven to be beneficial and are generally one of the …

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, …

Diet And Toenail Arsenic Concentrations In A New Hampshire Population With Arsenic-Containing Water, Kathryn L. Cottingham, Roxanne Karimi, Joann F. Gruber, M Scot Zens, Vicki Sayarath, Carol L. Folt, Tracy Punshon, J. Steven Morris, Margaret R. Karagas

Dartmouth Scholarship

Background: Limited data exist on the contribution of dietary sources of arsenic to an individual's total exposure, particularly in populations with exposure via drinking water. Here, the association between diet and toenail arsenic concentrations (a long-term biomarker of exposure) was evaluated for individuals with measured household tap water arsenic. Foods known to be high in arsenic, including rice and seafood, were of particular interest.

Methods: Associations between toenail arsenic and consumption of 120 individual diet items were quantified using general linear models that also accounted for household tap water arsenic and potentially confounding factors (e.g., age, caloric intake, sex, smoking) …

Mismatch Repair Genes Mlh1 And Mlh3 Modify Cag Instability In Huntington's Disease Mice: Genome-Wide And Candidate Approaches, Ricardo Mouro Pinto, Ella Dragileva, Andrew Kirby, Alejandro Lloret, Edith Lopez, Jason St. Claire, Gagan B. Panigrahi, Caixia Hou, Kim Holloway, Tammy Gillis, Jolene R. Guide, Paula E. Cohen, Guo-Min Li, Christopher E. Pearson, Mark J. Daly, Vanessa C. Wheeler

Toxicology and Cancer Biology Faculty Publications

The Huntington's disease gene (HTT) CAG repeat mutation undergoes somatic expansion that correlates with pathogenesis. Modifiers of somatic expansion may therefore provide routes for therapies targeting the underlying mutation, an approach that is likely applicable to other trinucleotide repeat diseases. Huntington's disease Hdh(Q111) mice exhibit higher levels of somatic HTT CAG expansion on a C57BL/6 genetic background (B6.Hdh(Q111) ) than on a 129 background (129.Hdh(Q111) ). Linkage mapping in (B6x129).Hdh(Q111) F2 intercross animals identified a single quantitative trait locus underlying the strain-specific difference in expansion in the striatum, implicating mismatch repair (MMR) gene Mlh1 as the most likely candidate modifier. …

Cutaneous Manifestations Of Giant Cell Arteritis, Christina E. Borchers, Ronald E. Warwar

Pharmacology and Toxicology Faculty Publications

A 68 year old woman with advanced giant cell arteritis presented with progressive tongue, lip, and scalp necrosis. She was initially misdiagnosed and treated for oral thrush by her primary care physician and emergency department personnel. She was ultimately correctly diagnosed with giant cell arteritis after she developed a left central retinal artery occlusion, ischemic optic neuropathy, and third cranial nerve palsy. She was treated with corticosteroids and the vasculitis was arrested. She was left with permanent defects in her tongue and lip as well as blindness in the left eye.

Proteomic Analysis Of Mismatch Repair-Mediated Alkylating Agent-Induced Dna Damage Response, Xi Chen, Yong Zhao, Guo-Min Li, Lin Guo

Toxicology and Cancer Biology Faculty Publications

BACKGROUND: Mediating DNA damage-induced apoptosis is an important genome-maintenance function of the mismatch repair (MMR) system. Defects in MMR not only cause carcinogenesis, but also render cancer cells highly resistant to chemotherapeutics, including alkylating agents. To understand the mechanisms of MMR-mediated apoptosis and MMR-deficiency-caused drug resistance, we analyze a model alkylating agent (N-methyl-N’-nitro-N-nitrosoguanidine, MNNG)-induced changes in protein phosphorylation and abundance in two cell lines, the MMR-proficient TK6 and its derivative MMR-deficient MT1.

RESULTS: Under an experimental condition that MNNG-induced apoptosis was only observed in MutSα-proficient (TK6), but not in MutSα-deficient (MT1) cells, quantitative analysis …

Mothers’S Education And Working Status; Do They Contribute To Corrosive Poisoning Among Paediatric Patients Of Karachi, Pakistan?, Emaduddin Siddiqui, Kiran Ejaz, Sayyeda Ghazala Irfan Kazi, Saif Siddiqui, Syed Jamal Raza

Department of Emergency Medicine

Objectives: To determine the causative factors behind corrosive poisoning in children like effect of working mothers, their educational status, financial background, family size and number of siblings.

Methods: The multi-centre, prospective, case series of all paediatric patients presenting to the Emergency Department of the National Institute of Child Health and the Aga Khan University Hospital, Karachi from August 2008 to July 2009 is presented. It comprised all paediatric patients with a history of corrosive poisoning at the two hospitals. SPSS 20 was used for statistical analysis.

Results: Out of 105 cases, 56(53%) related to the private-sector Aga Khan University Hospital, …

Metal-Based Nanoparticle Interactions With The Nervous System: The Challenge Of Brain Entry And The Risk Of Retention In The Organism, Robert A. Yokel, Eric A. Grulke, Robert C. Macphail

Pharmaceutical Sciences Faculty Publications

This review of metal-based nanoparticles focuses on factors influencing their distribution into the nervous system, evidence they enter brain parenchyma, and nervous system responses. Gold is emphasized as a model metal-based nanoparticle and for risk assessment in the companion review. The anatomy and physiology of the nervous system, basics of colloid chemistry, and environmental factors that influence what cells see are reviewed to provide background on the biological, physical–chemical, and internal milieu factors that influence nervous system nanoparticle uptake. The results of literature searches reveal little nanoparticle research included the nervous system, which about equally involved in vitro and in …

Protection Of Dietary Polyphenols Against Oral Cancer, Yijian Ding, Hua Yao, Yanan Yao, Leonard Yenwong Fai, Zhuo Zhang

Toxicology and Cancer Biology Faculty Publications

Oral cancer represents a health burden worldwide with approximate 275,000 new cases diagnosed annually. Its poor prognosis is due to local tumor invasion and frequent lymph node metastasis. Better understanding and development of novel treatments and chemo-preventive approaches for the preventive and therapeutic intervention of this type of cancer are necessary. Recent development of dietary polyphenols as cancer preventives and therapeutic agents is of great interest due to their antioxidant and anti-carcinogenic activities. Polyphenols may inhibit carcinogenesis in the stage of initiation, promotion, or progression. In particular, dietary polyphenols decrease incidence of carcinomas and exert protection against oral cancer by …

Dynamic Functions Of Rhoa In Tumor Cell Migration And Invasion, Kathleen L. O'Connor, Min Chen

Markey Cancer Center Faculty Publications

RhoA is one of the more extensively studied members of the Rho family of small GTPase where it is most readily recognized for its contributions to actin-myosin contractility and stress fiber formation. Accordingly, RhoA function during cell migration has been relegated to the rear of the cell where it mediates retraction of the trailing edge. However, RhoA can also mediate membrane ruffling, lamellae formation and membrane blebbing, thus suggesting an active role in membrane protrusions at the leading edge. With the advent of fluorescence resonance energy transfer (FRET)-based Rho activity reporters, RhoA has been shown to be active at the …

Uv Radiation And The Skin, John A. D'Orazio, Stuart G. Jarrett, Alexandra Amaro-Ortiz, Timothy Scott

Toxicology and Cancer Biology Faculty Publications

UV radiation (UV) is classified as a "complete carcinogen" because it is both a mutagen and a non-specific damaging agent and has properties of both a tumor initiator and a tumor promoter. In environmental abundance, UV is the most important modifiable risk factor for skin cancer and many other environmentally-influenced skin disorders. However, UV also benefits human health by mediating natural synthesis of vitamin D and endorphins in the skin, therefore UV has complex and mixed effects on human health. Nonetheless, excessive exposure to UV carries profound health risks, including atrophy, pigmentary changes, wrinkling and malignancy. UV is epidemiologically and …

Diabetic Db/Db Mice Exhibit Central Nervous System And Peripheral Molecular Alterations As Seen In Neurological Disorders., A. Ernst, Ajaykumar Narayan Sharma, Khalid M. Elased, P. C. Guest, H. Rahmoune, S. Bahn

Pharmacology and Toxicology Faculty Publications

The db/db mouse is a widely used preclinical model in diabetes research. Recent studies have shown that these mice also display aspects of psychosis and depression-like behaviors as seen in some psychiatric disorders. Here, we have performed multiplex immunoassay and liquid chromatography mass spectrometry profiling of the plasma and brain samples from db/db and control mice to identify altered pathways, which could be related to these behavioral abnormalities. This is the first study to carry out profiling of the brain proteome in this model. Plasma from the db/db mice had increased levels of leptin and insulin, decreased levels of peptide …

Assessment Of 17beta-Estradiol Removal From Wastewater Via Abiotic And Biotic Routes And Potential Effects On Food Chain Pathways, Lance Beecher

All Dissertations

Estrone, 17beta-estradiol (E2), and estriol are three of the most relevant natural hormones and are often found to contaminate the environment. When emanating from endogenous sources, these three compounds are not toxic or of concern; however, when estrogens are released into the environment from wastewater effluent they become a concern. The overall goal of the project was to evaluate abiotic and biotic techniques for removal of E2 and to quantify survival and reproduction impacts on an algal species and on an invertebrate species. We accomplished this goal by: 1) quantifying E2 sorption rates to crushed brick, an industrial mineral aggregate …