Pharmacology, Toxicology and Environmental Health Commons^™

Tgf-Β Signaling: New Insights Into Aortic Aneurysms, Sean E. Thatcher

Pharmacology and Nutritional Sciences Faculty Publications

No abstract provided.

Thrombospondin 1 Deficiency Ameliorates The Development Of Adriamycin-Induced Proteinuric Kidney Disease, Hasiyeti Maimaitiyiming, Qi Zhou, Shuxia Wang

Pharmacology and Nutritional Sciences Faculty Publications

Accumulating evidence suggests that thrombospondin 1 (TSP1) is an important player in diabetic nephropathy. However, the role of TSP1 in podocyte injury and the development of non-diabetic proteinuric kidney disease is largely unknown. In the current study, by using a well-established podocyte injury model (adriamycin-induced nephropathy mouse model), we examined the contribution of TSP1 to the development of proteinuric kidney disease. We found that TSP1 was up-regulated in the glomeruli, notably in podocytes, in adriamycin injected mice before the onset of proteinuria. ADR treatment also stimulated TSP1 expression in cultured human podocytes in vitro. Moreover, increased TSP1 mediated ADR-induced …

Network-Driven Plasma Proteomics Expose Molecular Changes In The Alzheimer's Brain, Philipp A. Jaeger, Kurt M. Lucin, Markus Britschgi, Badri Vardarajan, Ruo-Pan Huang, Elizabeth D. Kirby, Rachelle Abbey, Bradley F. Boeve, Adam L. Boxer, Lindsay A. Farrer, Nicole Finch, Neill R. Graff-Radford, Elizabeth Head, Matan Hofree, Ruochun Huang, Hudson Johns, Anna Karydas, David S. Knopman, Andrey Loboda, Eliezer Masliah, Ramya Narasimhan, Ronald C. Petersen, Alexei Podtelezhnikov, Suraj Pradhan, Rosa Rademakers, Chung-Huan Sun, Steven G. Younkin, Bruce L. Miller, Trey Ideker, Tony Wyss-Coray

Pharmacology and Nutritional Sciences Faculty Publications

Background: Biological pathways that significantly contribute to sporadic Alzheimer’s disease are largely unknown and cannot be observed directly. Cognitive symptoms appear only decades after the molecular disease onset, further complicating analyses. As a consequence, molecular research is often restricted to late-stage post-mortem studies of brain tissue. However, the disease process is expected to trigger numerous cellular signaling pathways and modulate the local and systemic environment, and resulting changes in secreted signaling molecules carry information about otherwise inaccessible pathological processes.

Results: To access this information we probed relative levels of close to 600 secreted signaling proteins from patients’ blood samples using …

Extracorporeal Membrane Oxygenation (Ecmo) For Severe Toxicological Exposures: Review Of The Toxicology Investigators Consortium (Toxic)., G S. Wang, R Levitan, T J. Wiegand, Jennifer Lowry, R F. Schult, S Yin, Toxicology Investigators Consortium

Manuscripts, Articles, Book Chapters and Other Papers

Although there have been many developments related to specific strategies for treating patients after poisoning exposures, the mainstay of therapy remains symptomatic and supportive care. One of the most aggressive supportive modalities is extracorporeal membrane oxygenation (ECMO). Our goal was to describe the use of ECMO for toxicological exposures reported to the American College of Medical Toxicology (ACMT) Toxicology Investigators Consortium (ToxIC). We performed a retrospective review of the ACMT ToxIC Registry from January 1, 2010 to December 31, 2013. Inclusion criteria included patients aged 0 to 89 years, evaluated between January 2010 through December 2013, and received ECMO for …

Pharmacogenetic Allele Nomenclature: International Workgroup Recommendations For Test Result Reporting., L V. Kalman, Jag Agúndez, M Lindqvist Appell, J L. Black, G C. Bell, S Boukouvala, C Bruckner, E Bruford, K Caudle, S A. Coulthard, A K. Daly, Al Del Tredici, J T. Den Dunnen, K Drozda, R E. Everts, D Flockhart, R R. Freimuth, Andrea Gaedigk, H Hachad, T Hartshorne, M Ingelman-Sundberg, T E. Klein, V M. Lauschke, D R. Maglott, H L. Mcleod, G A. Mcmillin, U A. Meyer, D J. Müller, D A. Nickerson, W S. Oetting, M Pacanowski, V M. Pratt, M V. Relling, A Roberts, W S. Rubinstein, K Sangkuhl, M Schwab, S A. Scott, S C. Sim, R K. Thirumaran, L H. Toji, R F. Tyndale, Rhn Van Schaik, M Whirl-Carrillo, Ktj Yeo, U M. Zanger

Manuscripts, Articles, Book Chapters and Other Papers

This article provides nomenclature recommendations developed by an international workgroup to increase transparency and standardization of pharmacogenetic (PGx) result reporting. Presently, sequence variants identified by PGx tests are described using different nomenclature systems. In addition, PGx analysis may detect different sets of variants for each gene, which can affect interpretation of results. This practice has caused confusion and may thereby impede the adoption of clinical PGx testing. Standardization is critical to move PGx forward.

Role Of Pharmacogenetics In Improving The Safety Of Psychiatric Care By Predicting The Potential Risks Of Mania In Cyp2d6 Poor Metabolizers Diagnosed With Bipolar Disorder., Santiago Sánchez-Iglesias, Virginia García-Solaesa, Belén García-Berrocal, Almudena Sanchez-Martín, Carolina Lorenzo-Romo, Tomás Martín-Pinto, Andrea Gaedigk, José Manuel González-Buitrago, María Isidoro-García

Manuscripts, Articles, Book Chapters and Other Papers

One of the main concerns in psychiatric care is safety related to drug management. Pharmacogenetics provides an important tool to assess causes that may have contributed the adverse events during psychiatric therapy. This study illustrates the potential of pharmacogenetics to identify those patients for which pharmacogenetic-guided therapy could be appropriate. It aimed to investigate CYP2D6 genotype in our psychiatric population to assess the value of introducing pharmacogenetics as a primary improvement for predicting side effects.A broad series of 224 psychiatric patients comprising psychotic disorders, depressive disturbances, bipolar disorders, and anxiety disorders was included. The patients were genotyped with the AmpliChip …

Chronic Ethanol Exposure Enhances The Aggressiveness Of Breast Cancer: The Role Of P38Γ, Mei Xu, Siying Wang, Zhenhua Ren, Jacqueline A. Frank, Xiuwei H. Yang, Zhuo Zhang, Zun-Ji Ke, Xianglin Shi, Jia Luo

Pharmacology and Nutritional Sciences Faculty Publications

Both epidemiological and experimental studies suggest that ethanol may enhance aggressiveness of breast cancer. We have previously demonstrated that short term exposure to ethanol (12–48 hours) increased migration/invasion in breast cancer cells overexpressing ErbB2, but not in breast cancer cells with low expression of ErbB2, such as MCF7, BT20 and T47D breast cancer cells. In this study, we showed that chronic ethanol exposure transformed breast cancer cells that were not responsive to short term ethanol treatment to a more aggressive phenotype. Chronic ethanol exposure (10 days - 2 months) at 100 (22 mM) or 200 mg/dl (44 mM) caused the …

Cd151-Α3Β1 Integrin Complexes Are Prognostic Markers Of Glioblastoma And Cooperate With Egfr To Drive Tumor Cell Motility And Invasion, Pengcheng Zhou, Sonia Erfani, Zeyi Liu, Changhe Jia, Yecang Chen, Bingwei Xu, Xinyu Deng, Jose E. Alfáro, Li Chen, Dana L. Napier, Michael Lu, Jian-An Huang, Chunming Liu, Olivier Thibault, Rosalind Segal, Binhua P. Zhou, Natasha Kyprianou, Craig Horbinski, Xiuwei H. Yang

Pharmacology and Nutritional Sciences Faculty Publications

Glioblastoma, one of the most aggressive forms of brain cancer, is featured by high tumor cell motility and invasiveness, which not only fuel tumor infiltration, but also enable escape from surgical or other clinical interventions. Thus, better understanding of how these malignant traits are controlled will be key to the discovery of novel biomarkers and therapies against this deadly disease. Tetraspanin CD151 and its associated α3β1 integrin have been implicated in facilitating tumor progression across multiple cancer types. How these adhesion molecules are involved in the progression of glioblastoma, however, remains largely unclear. Here, we examined an in-house tissue microarray-based …

Blood Pressure Changes In Relation To Arsenic Exposure In A U.S. Pregnancy Cohort, Shohreh F. Farzan, Yu Chen, Fen Wu, Jieying Jiang, Mengling Liu, Emily Baker, Susan A. Korrick, Margaret R. Karagas

Dartmouth Scholarship

Background:

Inorganic arsenic exposure has been related to the risk of increased blood pressure based largely on cross-sectional studies conducted in highly exposed populations. Pregnancy is a period of particular vulnerability to environmental insults. However, little is known about the cardiovascular impacts of arsenic exposure during pregnancy.

Objectives:

We evaluated the association between prenatal arsenic exposure and maternal blood pressure over the course of pregnancy in a U.S. population.

Methods:

The New Hampshire Birth Cohort Study is an ongoing prospective cohort study in which > 10% of participant household wells exceed the arsenic maximum contaminant level of 10 μg/L established by …

Association Between Arsenic Exposure From Drinking Water And Longitudinal Change In Blood Pressure Among Heals Cohort Participants, Jieying Jiang, Mengling Liu, Faruque Parvez, Binhuan Wang, Fen Wu, Mahbub Eunus, Sripal Bangalore, Jonathan D. Newman, Alauddin Ahmed, Tariqul Islam, Muhammed Rakibuz-Zaman, Rabiul Hasan, Golam Sarwar, Diane Levy, Vesna Slavkovich, Maria Argos, Molly Scannell Bryan, Shohreh F. Farzan, Richard B. Hayes, Joseph H. Graziano, Habibul Ahsan, Yu Chen

Dartmouth Scholarship

Background:

Cross-sectional studies have shown associations between arsenic exposure and prevalence of high blood pressure; however, studies examining the relationship of arsenic exposure with longitudinal changes in blood pressure are lacking.

Method:

We evaluated associations of arsenic exposure in relation to longitudinal change in blood pressure in 10,853 participants in the Health Effects of Arsenic Longitudinal Study (HEALS). Arsenic was measured in well water and in urine samples at baseline and in urine samples every 2 years after baseline. Mixed-effect models were used to estimate the association of baseline well and urinary creatinine-adjusted arsenic with annual change in blood pressure …

Placental Dna Methylation Related To Both Infant Toenail Mercury And Adverse Neurobehavioral Outcomes, Jennifer Zeynab Joukhadar Maccani, Devin C. Koestler, Barry Lester, E Andres Houseman, David A. Armstrong, Karl T. Kelsey, Carmen J. Marsit

Dartmouth Scholarship

Background:

Prenatal mercury (Hg) exposure is associated with adverse child neurobehavioral outcomes. Because Hg can interfere with placental functioning and cross the placenta to target the fetal brain, prenatal Hg exposure can inhibit fetal growth and development directly and indirectly.

Objectives:

We examined potential associations between prenatal Hg exposure assessed through infant toenail Hg, placental DNA methylation changes, and newborn neurobehavioral outcomes.

Methods:

The methylation status of > 485,000 CpG loci was interrogated in 192 placental samples using Illumina’s Infinium HumanMethylation450 BeadArray. Hg concentrations were analyzed in toenail clippings from a subset of 41 infants; neurobehavior was assessed using the NICU …

Cd151-Α3Β1 Integrin Complexes Suppress Ovarian Tumor Growth By Repressing Slug-Mediated Emt And Canonical Wnt Signaling, Lauren A. Baldwin, John T. Hoff, Jason Lefringhouse, Michael Zhang, Changhe Jia, Zeyi Liu, Sonia Erfani, Hongyan Jin, Mei Xu, Qing-Bai She, John R. Van Nagell Jr., Chi Wang, Li Chen, Rina Plattner, David M. Kaetzel, Jia Luo, Michael Lu, Dava West, Chunming Liu, Fred R. Ueland, Ronny Drapkin, Binhua P. Zhou, Xiuwei H. Yang

Pharmacology and Nutritional Sciences Faculty Publications

Human ovarian cancer is diagnosed in the late, metastatic stages but the underlying mechanisms remain poorly understood. We report a surprising functional link between CD151-α3β1 integrin complexes and the malignancy of serous-type ovarian cancer. Analyses of clinical specimens indicate that CD151 expression is significantly reduced or diminished in 90% of metastatic lesions, while it remains detectable in 58% of primary tumors. These observations suggest a putative tumor-suppressing role of CD151 in ovarian cancer. Indeed, our analyses show that knocking down CD151 or α3 integrin enhances tumor cell proliferation, growth and ascites production in nude mice. These changes are accompanied by …

Neuroinflammation And Neurologic Deficits In Diabetes Linked To Brain Accumulation Of Amylin, Sarah Srodulski, Savita Sharma, Adam B. Bachstetter, Jennifer M. Brelsfoard, Conrado Pascual, Xinmin Simon Xie, Kathryn E. Saatman, Linda J. Van Eldik, Florin Despa

Pharmacology and Nutritional Sciences Faculty Publications

BACKGROUND: We recently found that brain tissue from patients with type-2 diabetes (T2D) and cognitive impairment contains deposits of amylin, an amyloidogenic hormone synthesized and co-secreted with insulin by pancreatic β-cells. Amylin deposition is promoted by chronic hypersecretion of amylin (hyperamylinemia), which is common in humans with obesity or pre-diabetic insulin resistance. Human amylin oligomerizes quickly when oversecreted, which is toxic, induces inflammation in pancreatic islets and contributes to the development of T2D. Here, we tested the hypothesis that accumulation of oligomerized amylin affects brain function.

METHODS: In contrast to amylin from humans, rodent amylin is neither amyloidogenic nor cytotoxic. …

Cc2d1a Regulates Human Intellectual And Social Function As Well As Nf-Κb Signaling Homeostasis., M. Chiara Manzini, Lan Xiong, Ranad Shaheen, Dimira E Tambunan, Stefania Di Costanzo, Vanessa Mitisalis, +15 Additional Authors

Pharmacology and Physiology Faculty Publications

Autism spectrum disorder (ASD) and intellectual disability (ID) are often comorbid, but the extent to which they share common genetic causes remains controversial. Here, we present two autosomal-recessive "founder" mutations in the CC2D1A gene causing fully penetrant cognitive phenotypes, including mild-to-severe ID, ASD, as well as seizures, suggesting shared developmental mechanisms. CC2D1A regulates multiple intracellular signaling pathways, and we found its strongest effect to be on the transcription factor nuclear factor κB (NF-κB). Cc2d1a gain and loss of function both increase activation of NF-κB, revealing a critical role of Cc2d1a in homeostatic control of intracellular signaling. Cc2d1a knockdown in neurons …

Cardioprotection By Controlling Hyperamylinemia In A "Humanized" Diabetic Rat Model, Sanda Despa, Savita Sharma, Todd R. Harris, Hua Dong, Ning Li, Nipavan Chiamvimonvat, Heinrich Taegtmeyer, Kenneth B. Margulies, Bruce D. Hammock, Florin Despa

Pharmacology and Nutritional Sciences Faculty Publications

BACKGROUND: Chronic hypersecretion of the pancreatic hormone amylin is common in humans with obesity or prediabetic insulin resistance and induces amylin aggregation and proteotoxicity in the pancreas. We recently showed that hyperamylinemia also affects the cardiovascular system. Here, we investigated whether amylin aggregates interact directly with cardiac myocytes and whether controlling hyperamylinemia protects the heart.

METHODS AND RESULTS: By Western blot, we found abundant amylin aggregates in lysates of cardiac myocytes from obese patients, but not in controls. Aggregated amylin was elevated in failing hearts, suggesting a role in myocyte injury. Using rats overexpressing human amylin in the pancreas (HIP …

The Rak/Frk Tyrosine Kinase Associates With And Internalizes The Epidermal Growth Factor Receptor, Ling Jin, Rolf J. Craven

Pharmacology and Nutritional Sciences Faculty Publications

Src is the founding member of a diverse family of intracellular tyrosine kinases, and Src has a key role in promoting cancer growth, in part, through its association with receptor tyrosine kinases. However, some Src-related proteins have widely divergent physiological roles, and these proteins include the Rak/Frk tyrosine kinase (Frk stands for Fyn-related kinase), which inhibits cancer cell growth and suppresses tumorigenesis. Rak/Frk phosphorylates and stabilizes the Pten tumor suppressor, protecting it from degradation, and Rak/Frk associates with the retinoblastoma (Rb) tumor suppressor. However, the role of Rak/Frk in receptor-mediated signaling is largely unknown. Here, we demonstrate that Rak/Frk associates …

Sensitization Of Human Cancer Cells To Gemcitabine By The Chk1 Inhibitor Mk-8776: Cell Cycle Perturbation And Impact Of Administration Schedule In Vitro And In Vivo, Ryan Montano, Ruth Thompson, Injae Chung, Huagang Hou, Nadeem Khan, Alan Eastman

Dartmouth Scholarship

Chk1 inhibitors have emerged as promising anticancer therapeutic agents particularly when combined with antimetabolites such as gemcitabine, cytarabine or hydroxyurea. Here, we address the importance of appropriate drug scheduling when gemcitabine is combined with the Chk1 inhibitor MK-8776, and the mechanisms involved in the schedule dependence.

Accommodations For Patients With Disabilities In Primary Care: A Mixed Methods Study Of Practice Administrators, Jennifer Renee Pharr

Environmental & Global Health Faculty Research

Structural barriers that limit access to health care services for people with disabilities have been identified through qualitative studies; however, little is known about how patients with disabilities are accommodated in the clinical setting when a structural barrier is encountered. The purpose of this study was to identify how primary care medical practices in the United States accommodated people with disabilities when a barrier to service is encountered. Primary care practice administrators from the medical management organization were identified through the organization’s website. Sixty-three administrators from across the US participated in this study. Practice administrators reported that patients were examined …

Predicting Barriers To Primary Care For Patients With Disabilities: A Mixed Methods Study Of Practice Administrators, Jennifer Renee Pharr, Michelle Chino

Environmental & Global Health Faculty Research

Background. People with disabilities continue to be identified as a group who experience disparate health/health care. They are less likely to engage in some health care services. Structural barriers are often identified as one of the reasons for the underutilization of some health care services by people with disabilities. However, to date no study has been conducted to understand why structural barriers persist twenty years after the Americans with Disabilities Act (ADA) became law.

Objectives. We examined the relationship between primary care practice administrators’ knowledge of the ADA and the number of accessibility barriers that patients with mobility disabilities might …

Health Disparities Experienced By People With Disabilities In The Us: A Behavioral Risk Factor Surveillance System Study, Jennifer Renee Pharr, Timothy J. Bungum

Environmental & Global Health Faculty Research

The Americans with Disabilities Act became law in 1990; since then research has shown that people with disabilities continue to experience barriers to health care. The purpose of this study was to compare utilization of preventive services, chronic disease rates, and engagement in health risk behaviors of participants with differing severities of disabilities to those without disabilities. This study was a secondary analysis of 2010 data collected in the Behavioral Risk Factor Surveillance System national survey in the United States. Rao Chi square test and logistic regression were employed. Participants with disabilities had significantly higher adjusted odds ratios for all …

Cdc42-Dependent Activation Of Nadph Oxidase Is Involved In Ethanol-Induced Neuronal Oxidative Stress, Xin Wang, Zunji Ke, Gang Chen, Mei Xu, Kimberly A. Bower, Jacqueline A. Frank, Zhuo Zhang, Xianglin Shi, Jia Luo

Pharmacology and Nutritional Sciences Faculty Publications

It has been suggested that excessive reactive oxygen species (ROS) and oxidative stress play an important role in ethanol-induced damage to both the developing and mature central nervous system (CNS). The mechanisms underlying ethanol-induced neuronal ROS, however, remain unclear. In this study, we investigated the role of NADPH oxidase (NOX) in ethanol-induced ROS generation. We demonstrated that ethanol activated NOX and inhibition of NOX reduced ethanol-promoted ROS generation. Ethanol significantly increased the expression of p47^phox and p67^phox, the essential subunits for NOX activation in cultured neuronal cells and the cerebral cortex of infant mice. Ethanol caused serine …

Specific Thiazolidinediones Inhibit Ovarian Cancer Cell Line Proliferation And Cause Cell Cycle Arrest In A Pparγ Independent Manner, Linah Al-Alem, R. Chase Southard, Michael W. Kilgore, Thomas E. Curry

Pharmacology and Nutritional Sciences Faculty Publications

BACKGROUND: Peroxisome Proliferator Activated Receptor gamma (PPARγ) agonists, such as the thiazolinediones (TZDs), have been studied for their potential use as cancer therapeutic agents. We investigated the effect of four TZDs--Rosiglitazone (Rosi), Ciglitazone (CGZ), Troglitazone (TGZ), and Pioglitazone (Pio)--on ovarian cancer cell proliferation, PPARγ expression and PPAR luciferase reporter activity. We explored whether TZDs act in a PPARγ dependent or independent manner by utilizing molecular approaches to inhibit or overexpress PPARγ activity.

PRINCIPAL FINDINGS: Treatment with CGZ or TGZ for 24 hours decreased proliferation in three ovarian cancer cell lines, Ovcar3, CaOv3, and Skov3, whereas Rosi and Pio had no …

The Future (Or Lack Of Future) Of Personalized Prescription In Psychiatry, Jose De Leon

Psychiatry Faculty Publications

Rapid technological advances in genetics have created conceptual chaos regarding the genetics of drug response. Terms for differing concepts are used interchangeably: pharmacogenetics with pharmacogenomics, personalized medicine with personalized prescription. Biomarker has many definitions. The author prefers the concept of personalized prescription and uses it with implications beyond pharmacogenetics by considering all scientific information valid for prescribing medication. Genetics may not be crucial for all drugs. In this comprehensive view, clinicians must consider genetic, environmental and personal variables when prescribing medication and incorporate some basic pharmacological principles: (1) safety and efficacy, (2) pharmacokinetics and pharmacodynamics, (3) therapeutic window and prescriber's …

Down-Regulation Of Ppargamma1 Suppresses Cell Growth And Induces Apoptosis In Mcf-7 Breast Cancer Cells, Yekaterina Y. Zaytseva, Xin Wang, R. Chase Southard, Natalie K. Wallis, Michael W. Kilgore

Pharmacology and Nutritional Sciences Faculty Publications

BACKGROUND: Peroxisome proliferator-activated receptor gamma (PPARgamma) is a member of the nuclear hormone receptor superfamily and is highly expressed in many human tumors including breast cancer. PPARgamma has been identified as a potential target for breast cancer therapy based on the fact that its activation by synthetic ligands affects the differentiation, proliferation, and apoptosis of cancer cells. However, the controversial nature of current studies and disappointing results from clinical trials raise questions about the contribution of PPARgamma signaling in breast cancer development in the absence of stimulation by exogenous ligands. Recent reports from both in vitro and in vivo studies …

Borderline Personality Disorder: An Overview Of History, Diagnosis And Treatment In Adolescents, Linah Al-Alem, Hatim A. Omar

Pharmacology and Nutritional Sciences Faculty Publications

Borderline personality disorder (BPD) is a cluster B personality disorder. It is characterized by erratic behaviors, emotional instability and one of its hallmarks is self injurious behavior, which starts in adolescence. Patients with BPD are difficult to treat, most have a history of child sexual abuse, about a quarter present with sexual abuse from a caretaker. Although personality disorders are diagnosed only in adults, BPD manifests itself in adolescence in the form of uncontrollable anger, self mutilations, dissociation and other such behaviors. Hence, there is a growing number of scientists discussing the possibility of diagnosing BPD in adolescents. Here, we …

Pgrmc1: A New Biomarker For The Estrogen Receptor In Breast Cancer, Rolf J. Craven

Pharmacology and Nutritional Sciences Faculty Publications

Estrogen receptor (ER) status is a critical biomarker in breast cancer, in large part because the ER is the target of tamoxifen and similar drugs. In the previous issue of Breast Cancer Research, Neubauer and colleagues used a proteomic approach to identify proteins that are differentially regulated by ER in breast tumors. The authors showed that ER-negative tumors have elevated levels of PGRMC1 (progesterone receptor membrane component-1), a hormone receptor component and binding partner for P450 proteins. In contrast, PGRMC1 was phosphorylated in ER-positive tumors. The staining patterns of ER and PGRMC1 were mutually exclusive in breast tumor sections, and …

Differential Dynamic Properties Of Scleroderma Fibroblasts In Response To Perturbation Of Environmental Stimuli, Momiao Xiong, Frank C. Arnett, Xinjian Guo, Hao Xiong, Xiaodong Zhou

Faculty, Staff and Student Publications

Diseases are believed to arise from dysregulation of biological systems (pathways) perturbed by environmental triggers. Biological systems as a whole are not just the sum of their components, rather ever-changing, complex and dynamic systems over time in response to internal and external perturbation. In the past, biologists have mainly focused on studying either functions of isolated genes or steady-states of small biological pathways. However, it is systems dynamics that play an essential role in giving rise to cellular function/dysfunction which cause diseases, such as growth, differentiation, division and apoptosis. Biological phenomena of the entire organism are not only determined by …

Expansion Of The Calcium Hypothesis Of Brain Aging And Alzheimer's Disease: Minding The Store, Olivier Thibault, John C. Gant, Philip W. Landfield

Pharmacology and Nutritional Sciences Faculty Publications

Evidence accumulated over more than two decades has implicated Ca2+ dysregulation in brain aging and Alzheimer's disease (AD), giving rise to the Ca2+ hypothesis of brain aging and dementia. Electrophysiological, imaging, and behavioral studies in hippocampal or cortical neurons of rodents and rabbits have revealed aging-related increases in the slow afterhyperpolarization, Ca2+ spikes and currents, Ca2+transients, and L-type voltage-gated Ca2+ channel (L-VGCC) activity. Several of these changes have been associated with age-related deficits in learning or memory. Consequently, one version of the Ca2+ hypothesis has been that increased L-VGCC activity drives many of the other Ca2+-related biomarkers of hippocampal aging. …

Arsenic Exposure Is Associated With Decreased Dna Repair In Vitro And In Individuals Exposed To Drinking Water Arsenic, Angeline S. Andrew, Jefferey L. Burgess, Maria M. Meza, Eugene Demidenko, Mary G. Waugh, Joshua W. Hamilton, Margaret R. Karagas

Dartmouth Scholarship

The mechanism(s) by which arsenic exposure contributes to human cancer risk is unknown; however, several indirect cocarcinogenesis mechanisms have been proposed. Many studies support the role of As in altering one or more DNA repair processes. In the present study we used individual-level exposure data and biologic samples to investigate the effects of As exposure on nucleotide excision repair in two study populations, focusing on the excision repair cross-complement 1 (ERCC1) component. We measured drinking water, urinary, or toenail As levels and obtained cryopreserved lymphocytes of a subset of individuals enrolled in epidemiologic studies in New Hampshire (USA) and Sonora …

The Speciation Of Metals In Mammals Influences Their Toxicokinetics And Toxicodynamics And Therefore Human Health Risk Assessment, Robert A. Yokel, Stephen M. Lasley, David C. Dorman

Pharmaceutical Sciences Faculty Publications

Chemical form (i.e., species) can influence metal toxicokinetics and toxicodynamics and should be considered to improve human health risk assessment. Factors that influence metal speciation (and examples) include: (1) carrier-mediated processes for specific metal species (arsenic, chromium, lead and manganese), (2) valence state (arsenic, chromium, manganese and mercury), (3) particle size (lead and manganese), (4) the nature of metal binding ligands (aluminum, arsenic, chromium, lead, and manganese), (5) whether the metal is an organic versus inorganic species (arsenic, lead, and mercury), and (6) biotransformation of metal species (aluminum, arsenic, chromium, lead, manganese and mercury). The influence of speciation on metal …