Medicine and Health Sciences Commons^™

The Pathways To Mental Health Care Of First-Episode Psychosis Patients: A Systematic Review., Kelly K. Anderson, Rebecca Fuhrer, Ashok K. Malla

Epidemiology and Biostatistics Publications

BACKGROUND: Although there is agreement on the association between delay in treatment of psychosis and outcome, less is known regarding the pathways to care of patients suffering from a first psychotic episode. Pathways are complex, involve a diverse range of contacts, and are likely to influence delay in treatment. We conducted a systematic review on the nature and determinants of the pathway to care of patients experiencing a first psychotic episode.

METHOD: We searched four databases (Medline, HealthStar, EMBASE, PsycINFO) to identify articles published between 1985 and 2009. We manually searched reference lists and relevant journals and used forward citation …

End-Of-Life Care For Hospitalized Patients With Lung Cancer: Utilization Of A Palliative Care Service., Barbara Reville, M.S., Achpn, Marshal N Miller, B.S., Richard W Toner, M.S., Joanne Reifsnyder, Ph.D., Achpn

Department of Family & Community Medicine Faculty Papers

PURPOSE: High symptom burden and hospital mortality among patients with lung cancer argues for early palliative care intervention. Patient characteristics and discharge dispositions in hospitalized patients with lung cancer receiving usual care were compared to those referred to a new palliative care service.

METHODS: A retrospective database review of all lung cancer discharges receiving usual care (UC) and palliative care service (PCS) consultation was conducted. Demographics, length of stay, discharge disposition, and mortality were described and compared. Palliative Performance Scale scores were described according to discharge disposition in the PCS group. Disposition of all patients receiving either chemotherapy or surgery …

Leg Ulcers In Sickle Cell Disease., Caterina P Minniti, James Eckman, Paola Sebastiani, Martin H Steinberg, Samir K. Ballas

Department of Medicine Faculty Papers

Sickle cell disease is a single amino acid molecular disorder of hemoglobin leading to its pathological polymerization, red cell rigidity that causes poor microvascular blood flow, with consequent tissue ischemia and infarction. The manifestations of this disease are protean.Among them, leg ulcers represent a particularly disabling and chronic complication, often associated with a more severe clinical course.Despite the fact that this complication has been recognized since the early times of SCD, there has been little improvement in the efficacy of its management and clinical outcome over the past 100 years. Recently, vasculopathic abnormalities involving abnormal vascular tone and activated, adhesive …

S100a1: A Multifaceted Therapeutic Target In Cardiovascular Disease., David Rohde, Julia Ritterhoff, Mirko Voelkers, Hugo A Katus, Thomas G Parker, Patrick Most

Department of Medicine Faculty Papers

Cardiovascular disease is the leading cause of death worldwide, showing a dramatically growing prevalence. It is still associated with a poor clinical prognosis, indicating insufficient long-term treatment success of currently available therapeutic strategies. Investigations of the pathomechanisms underlying cardiovascular disorders uncovered the Ca(2+) binding protein S100A1 as a critical regulator of both cardiac performance and vascular biology. In cardiomyocytes, S100A1 was found to interact with both the sarcoplasmic reticulum ATPase (SERCA2a) and the ryanodine receptor 2 (RyR2), resulting in substantially improved Ca(2+) handling and contractile performance. Additionally, S100A1 has been described to target the cardiac sarcomere and mitochondria, leading to …

Are Roadside Pedestrian Injury Patterns Predictable In A Densely Populated, Urban Setting?, Niels D. Martin, Daniel J. Grabo, Lili Tang, Jacqueline Sullivan, Kris R. Kaulback, Michael S. Weinstein, Gary A. Lindenbaum, Murray J. Cohen

Department of Surgery Faculty Papers

BACKGROUND: Roadside pedestrian injuries represent a significant portion of trauma team activations, especially at urban trauma centers. Patient demographics and severity of injury vary greatly in this patient population. Herein, we hypothesize that injury patterns may be predictable, especially with respect to age.

MATERIALS AND METHODS: All patients with roadside pedestrian injuries evaluated at our urban, level one trauma center from January 2006 through December 2008 were retrospectively reviewed. Data were collected from the institutional trauma registry. Age was used as an independent variable and compared with injury type, substance abuse, discharge setting, and mortality.

RESULTS: There were 226 roadside …

The Mir-15/107 Group Of Microrna Genes: Evolutionary Biology, Cellular Functions, And Roles In Human Diseases, John R. Finnerty, Wang-Xia Wang, Sébastien S. Hébert, Bernard R. Wilfred, Guogen Mao, Peter T. Nelson

Pathology and Laboratory Medicine Faculty Publications

The miR-15/107 group of microRNA (miRNA) gene is increasingly appreciated to serve key functions in humans. These miRNAs regulate gene expression involved in cell division, metabolism, stress response, and angiogenesis in vertebrate species. The miR-15/107 group has also been implicated in human cancers, cardiovascular disease and neurodegenerative disease, including Alzheimer's disease. Here we provide an overview of the following: (1) the evolution of miR-15/107 group member genes; (2) the expression levels of miRNAs in mammalian tissues; (3) evidence for overlapping gene-regulatory functions by different miRNAs; (4) the normal biochemical pathways regulated by miR-15/107 group miRNAs; and (5) the roles played …

Microrna-21 Dysregulates The Expression Of Mef2c In Neurons In Monkey And Human Siv/Hiv Neurological Disease., Sowmya V. Yelamanchili, A Datta Chaudhuri, L N. Chen, Huangui Xiong, Howard S. Fox

Journal Articles: Pharmacology & Experimental Neuroscience

MicroRNAs (miRNAs) play important roles in regulating a plethora of physiological and pathophysiogical processes including neurodegeneration. In both HIV associated dementia in humans and its monkey model SIV encephalitis we find miR-21, a miRNA largely known for its link to oncogenesis, to be significantly upregulated in the brain. In situ hybridization of the diseased brain sections revealed induction of miR-21 in neurons. MiR-21 can be induced in neurons by prolonged N-methyl-D-aspartic acid receptor stimulation, an excitotoxic process active in HIV and other neurodegenerative diseases. Introduction of miR-21 into human neurons leads to pathological functional defects. Furthermore, we show that miR-21 …

Hepatitis C Virus Core-Derived Peptides Inhibit Genotype 1b Viral Genome Replication Via Interaction With Ddx3x, Chaomin Sun, Cara T. Pager, Guangxiang Luo, Peter Sarnow, Jamie H. D. Cate

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The protein DDX3X is a DEAD-box RNA helicase that is essential for the hepatitis C virus (HCV) life cycle. The HCV core protein has been shown to bind to DDX3X both in vitro and in vivo. However, the specific interactions between these two proteins and the functional importance of these interactions for the HCV viral life cycle remain unclear. We show that amino acids 16-36 near the N-terminus of the HCV core protein interact specifically with DDX3X both in vitro and in vivo. Replication of HCV replicon NNeo/C-5B RNA (genotype 1b) is significantly suppressed in HuH-7-derived cells expressing green fluorescent …

Cardiovascular Risk Associated With Interactions Among Polymorphisms In Genes From The Renin-Angiotensin, Bradykinin, And Fibrinolytic Systems, John P. Bentley, Folkert W. Asselbergs, Christopher S. Coffey, Patricia R. Hebert, Jason H. Moore, Hans L. Hillege, Wiek H. Van Gilst

Dartmouth Scholarship

Background: Vascular fibrinolytic balance is maintained primarily by interplay of tissue plasminogen activator (t-PA) and plasminogen activator inhibitor type 1 (PAI-1). Previous research has shown that polymorphisms in genes from the renin- angiotensin (RA), bradykinin, and fibrinolytic systems affect plasma concentrations of both t-PA and PAI-1 through a set of gene-gene interactions. In the present study, we extend this finding by exploring the effects of polymorphisms in genes from these systems on incident cardiovascular disease, explicitly examining two-way interactions in a large population- based study.

Methodology/Principal Findings: Data from the population-based PREVEND study in Groningen, The Netherlands (n = 8,138) …

Research Priorities In Hypertrophic Cardiomyopathy: Report Of A Working Group Of The National Heart, Lung, And Blood Institute., Thomas Force, Robert O Bonow, Steven R Houser, R John Solaro, Ray E Hershberger, Bishow Adhikari, Mark E Anderson, Robin Boineau, Barry J Byrne, Thomas P Cappola, Raghu Kalluri, Martin M Lewinter, Martin S Maron, Jeffery D Molkentin, Steve R Ommen, Michael Regnier, W H Wilson Tang, Rong Tian, Marvin A Konstam, Barry J Maron, Christine E Seidman

Center for Translational Medicine Faculty Papers

Hypertrophic cardiomyopathy (HCM) is a myocardial disorder characterized by left ventricular (LV) hypertrophy without dilatation and without apparent cause (ie, it occurs in the absence of severe hypertension, aortic stenosis, or other cardiac or systemic diseases that might cause LV hypertrophy). Numerous excellent reviews and consensus documents provide a wealth of additional background.1–8 HCM is the leading cause of sudden death in young people and leads to significant disability in survivors. It is caused by mutations in genes that encode components of the sarcomere. Cardiomyocyte and cardiac hypertrophy, myocyte disarray, interstitial and replacement fibrosis, and dysplastic intramyocardial arterioles characterize the …

Development Of A Macromolecular Prodrug For The Treatment Of Inflammatory Arthritis: Mechanisms Involved In Arthrotropism And Sustained Therapeutic Efficacy., Ling-Dong Quan, P. Edward Purdue, Xin-Ming Liu, Michael D. Boska, Subodh M. Lele, Geoffrey M. Thiele, Ted R. Mikuls, Huanyu Dou, Steven R. Goldring, Dong Wang

Journal Articles: Radiology

INTRODUCTION: The purpose of the present manuscript is to test the hypothesis that arthrotropic localization and synovial cell internalization account for the unique capacity of N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-dexamethasone conjugate (P-Dex, a macromolecular prodrug of dexamethasone) to induce sustained amelioration of joint inflammation and inhibition of tissue damage in an animal model of inflammatory arthritis.

METHODS: Rats with adjuvant-induced arthritis (AA) were treated with P-Dex, free dexamethasone, saline or HPMA homopolymer. To define the biodistribution of P-Dex, conjugates with different imaging labels were given to AA rats and analyzed. Isolated joint tissues were evaluated by fluorescence-activated cell sorting (FACS) and immunohistochemical …

The Importance Of Examining Movements Within The Us Health Caresystem: Sequential Logit Modeling, Chioun Lee, Stephanie L L. Ayers, Jennie Jacobs Kronenfeld, Jemima A. Frimpong, Patrick A. Rivers, Sam S. Kim

Dartmouth Scholarship

Utilization of specialty care may not be a discrete, isolated behavior but rather, a behavior of sequential movements within the health care system. Although patients may often visit their primary care physician and receive a referral before utilizing specialty care, prior studies have underestimated the importance of accounting for these sequential movements. The sample included 6,772 adults aged 18 years and older who participated in the 2001 Survey on Disparities in Quality of Care, sponsored by the Commonwealth Fund. A sequential logit model was used to account for movement in all stages of utilization: use of any health services (i.e., …

Deficient Liver Biosynthesis Of Docosahexaenoic Acid Correlates With Cognitive Impairment In Alzheimer's Disease, Giuseppe Astarita, Kwang-Mook Jung, Nicole C. Berchtold, Vinh Q. Nguyen, Daniel L. Gillen, Elizabeth Head, Carl W. Cotman, Daniele Piomelli

Sanders-Brown Center on Aging Faculty Publications

Reduced brain levels of docosahexaenoic acid (C22:6n-3), a neurotrophic and neuroprotective fatty acid, may contribute to cognitive decline in Alzheimer's disease. Here, we investigated whether the liver enzyme system that provides docosahexaenoic acid to the brain is dysfunctional in this disease. Docosahexaenoic acid levels were reduced in temporal cortex, mid-frontal cortex and cerebellum of subjects with Alzheimer's disease, compared to control subjects (P = 0.007). Mini Mental State Examination (MMSE) scores positively correlated with docosahexaenoic/α-linolenic ratios in temporal cortex (P = 0.005) and mid-frontal cortex (P = 0.018), but not cerebellum. Similarly, liver docosahexaenoic acid content was lower in Alzheimer's …

Maintenance Of Activity And Eating Change After A Clinical Trial Of Tailored Newsletters With Older Rural Women., Susan Noble Walker, Carol H. Pullen, Patricia A. Hageman, Linda S. Boeckner, Melody A. Hertzog, Maureen K. Oberdorfer, Matthew J. Rutledge

Journal Articles: College of Nursing

BACKGROUND: In the Wellness for Women Project, a randomized-by-site 1-year controlled clinical trial, the efficacy of generic newsletters and newsletters tailored on Health Promotion Model behavior-specific cognitions, eating behavior, and activity behavior were compared among 225 women aged 50 to 69 years.

OBJECTIVES: The purpose of this study was to compare the maintenance of change in healthy eating and physical activity over the 12 months following the tailored versus generic mailed newsletter intervention.

METHODS: Outcomes at 18 and 24 months included behavioral markers and biomarkers of physical activity and eating. Data were analyzed using the multivariate approach to repeated measures …

Public Health Systems And Services Research: Bridging The Practice-Research Gap., F. Douglas Scutchfield, Cynthia D. Lamberth

Preventive Medicine and Environmental Health Faculty Publications

Public health practitioners understand the principles of evidence-based practice

and the science that should drive their efforts to improve the community’s

health through the implementation of science-driven public health programs.

However, the translation of research to practice still has numerous barriers.

This commentary provides suggestions to strengthen the link between research

and practice.

Hiv-1 Reactivation Induced By The Periodontal Pathogens Fusobacterium Nucleatum And Porphyromonas Gingivalis Involves Toll-Like Receptor 2 And 9 Activation In Monocytes/Macrophages, Octavio A. Gonzalez, Mengtao Li, Jeffrey L. Ebersole, Chifu B. Huang

Center for Oral Health Research Faculty Publications

Although oral coinfections (e.g., periodontal disease) are highly prevalent in human immunodeficiency virus type 1-positive (HIV-1⁺) patients and appear to positively correlate with viral load levels, the potential for oral bacteria to induce HIV-1 reactivation in latently infected cells has received little attention. We showed that HIV-1 long terminal repeat (LTR) promoter activation can be induced by periodontopathogens in monocytes/macrophages; nevertheless, the mechanisms involved in this response remain undetermined. Since Toll-like receptor 2 (TLR2), TLR4, and TLR9 activation have been involved in HIV-1 recrudescence, we sought to determine the role of these TLRs in HIV-1 reactivation induced by …

Identification Of Thioaptamer Ligand Against E-Selectin: Potential Application For Inflamed Vasculature Targeting., Aman P Mann, Anoma Somasunderam, René Nieves-Alicea, Xin Li, Austin Hu, Anil K Sood, Mauro Ferrari, David G Gorenstein, Takemi Tanaka

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Active targeting of a drug carrier to a specific target site is crucial to provide a safe and efficient delivery of therapeutics and imaging contrast agents. E-selectin expression is induced on the endothelial cell surface of vessels in response to inflammatory stimuli but is absent in the normal vessels. Thus, E-selectin is an attractive molecular target, and high affinity ligands for E-selectin could be powerful tools for the delivery of therapeutics and/or imaging agents to inflamed vessels. In this study, we identified a thiophosphate modified aptamer (thioaptamer, TA) against E-selectin (ESTA-1) by employing a two-step selection strategy: a recombinant protein-based …

A Role For The Histone Deacetylase Hdac4 In The Life-Cycle Of Hiv-1-Based Vectors., Johanna A Smith, Jennifer Yeung, Gary D Kao, René Daniel

Department of Medicine Faculty Papers

HIV-1 integration is mediated by the HIV-1 integrase protein, which joins 3'-ends of viral DNA to host cell DNA. To complete the integration process, HIV-1 DNA has to be joined to host cell DNA also at the 5'-ends. This process is called post-integration repair (PIR). Integration and PIR involve a number of cellular co-factors. These proteins exhibit different degrees of involvement in integration and/or PIR. Some are required for efficient integration or PIR. On the other hand, some reduce the efficiency of integration. Finally, some are involved in integration site selection. We have studied the role of the histone deacetylase …

Quantitative Imaging Reveals Heterogeneous Growth Dynamics And Treatment-Dependent Residual Tumor Distributions In A Three-Dimensional Ovarian Cancer Model, Jonathan P. Celli, Imran Rizvi, Conor L. Evans, Adnan O. Abu-Yousif, Tayyaba Hasan

Dartmouth Scholarship

Three-dimensional tumor models have emerged as valuable in vitro research tools, though the power of such systems as quantitative reporters of tumor growth and treatment response has not been adequately explored. We introduce an approach combining a 3-D model of disseminated ovarian cancer with high-throughput processing of image data for quantification of growth characteristics and cytotoxic response. We developed custom MATLAB routines to analyze longitudinally acquired dark-field microscopy images containing thousands of 3-D nodules. These data reveal a reproducible bimodal log-normal size distribution. Growth behavior is driven by migration and assembly, causing an exponential decay in spatial density concomitant with …

The Intellectual And Moral Integrity Of Bioethics: Response To Commentaries On "A Case Study In Unethical Transgressive Bioethics: 'Letter Of Concern From Bioethicists' About The Prenatal Administration Of Dexamethasone"., Laurence B Mccullough, Frank A Chervenak, Robert L Brent, Benjamin Hippen

Department of Pediatrics Faculty Papers

In our target article we showed that the Letter of Concern (LoC) fails to meet accepted standards for presenting empirical data for the purpose of supplementing a normative claim and for argument-based normative ethics. The LoC fails to meet the standards of evidence-based reasoning by making false claims, failing to reference data that undermine its key premises, and misrepresenting and misinterpreting the scientific publications it selectively references. The LoC fails to meet the standards of argument-based reasoning by treating as settled matters what are, instead, ongoing controversies, offering “mere opinion” as a substitute for argument, and making contradictory claims. The …

Noninvasive Fluorescence Monitoring Of Protoporphyrin Ix Production And Clinical Outcomes In Actinic Keratoses Following Short-Contact Application Of 5-Aminolevulinate, Christine B. Warren, Sara Lohser, Lauren C. Wene, Brian W. Pogue, Philip Bailin, Edward Maytin

Dartmouth Scholarship

Topical 5-aminolevulinic acid (ALA) is widely used in photodynamic therapy (PDT) of actinic keratoses (AK), a type of premalignant skin lesion. However, the optimal time between ALA application and exposure to light has not been carefully investigated. Our objective is to study the kinetics of protoporphyrin IX (P_pIX) accumulation in AK after short contact ALA and relate this to erythemal responses. Using a noninvasive dosimeter, P_pIX fluorescence measurements (5 replicates) were taken at 20-min intervals for 2 h following ALA application, in 63 AK in 20 patients. Data were analyzed for maximal fluorescent signal obtained, kinetic …

Identifying Strategies Early Intervention Occupational Therapists Use To Teach Caregivers., Jessica L. Colyvas, L Brook Sawyer, Philippa H. Campbell

Department of Occupational Therapy Faculty Papers

This study investigated early intervention occupational therapists' use of strategies to teach caregivers. A sample of 40 videotapes made by early intervention occupational therapists was randomly selected from an archival videotape data set of provider home visits. The sample included 20 videotapes illustrating traditional services and 20 videotapes illustrating therapists providing participation-based services. Videotapes were rated using the Teaching Caregivers Scale, which rates three variables on 30-s intervals: (1) routine, (2) provider role, and (3) strategies used to teach caregivers during early intervention home visits. Regardless of the model of service, explicit teaching strategies were rarely used during home visits.

Granuloma Annulare: Not As Simple As It Seems., Lawrence Charles Parish, Joseph A. Witkowski

Department of Dermatology and Cutaneous Biology Faculty Papers

No abstract provided.

A Case Study In Unethical Transgressive Bioethics: "Letter Of Concern From Bioethicists" About The Prenatal Administration Of Dexamethasone., Laurence B Mccullough, Frank A Chervenak, Robert L Brent, Benjamin Hippen

Department of Pediatrics Faculty Papers

On February 3, 2010, a "Letter of Concern from Bioethicists," organized by fetaldex.org, was sent to report suspected violations of the ethics of human subjects research in the off-label use of dexamethasone during pregnancy by Dr. Maria New. Copies of this letter were submitted to the FDA Office of Pediatric Therapeutics, the Department of Health and Human Services (DHHS) Office for Human Research Protections, and three universities where Dr. New has held or holds appointments. We provide a critical appraisal of the Letter of Concern and show that it makes false claims, misrepresents scientific publications and websites, fails to meet …

Comparing Implementations Of Magnetic-Resonance-Guided Fluorescence Molecular Tomography For Diagnostic Classification Of Brain Tumors, Scott C. Davis, Kimberley S. Samkoe, Julia A. O’Hara, Summer L. Gibbs-Strauss, Keith D. Paulsen, Brian W. Pogue

Dartmouth Scholarship

Fluorescence molecular tomography (FMT) systems coupled to conventional imaging modalities such as magnetic resonance imaging (MRI) and computed tomography provide unique opportunities to combine data sets and improve image quality and content. Yet, the ideal approach to combine these complementary data is still not obvious. This preclinical study compares several methods for incorporating MRI spatial prior information into FMT imaging algorithms in the context of in vivo tissue diagnosis. Populations of mice inoculated with brain tumors that expressed either high or low levels of epidermal growth factor receptor (EGFR) were imaged using an EGF-bound near-infrared dye and a spectrometer-based MRI-FMT …

One Year Survival With Poorly Differentiated Metastatic Pancreatic Carcinoma Following Chemoembolization With Gemcitabine And Cisplatin., Daniel B Brown, Carin F Gonsalves, Charles J Yeo, Agnes K Witkiewicz, Brian I Carr

Department of Radiology Faculty Papers

While hepatic arterial chemoembolization is efficacious for a number of malignancies, there is scant data regarding treatment of pancreatic adenocarcinoma. We report a complete radiographic response at one year from diagnosis of metastatic pancreatic carcinoma. Gemcitabine/cisplatin based chemoembolization may be of potential benefit for patients with liver-dominant metastases from pancreatic carcinoma. Given the typical survival of 6 months or less in this patient group with standard therapies, further research is warranted.

Efficacy Of Morning-Only Compared With Split-Dose Polyethylene Glycol Electrolyte Solution For Afternoon Colonoscopy: A Randomized Controlled Single-Blind Study., Rebecca Matro, Md, Anastasia Shnitser, Md, Maya Spodik, Md, Constantine Daskalakis, Sc.D, Leo Katz, Md, Alexandra Murtha, Ba, David Kastenberg, Md

Division of Internal Medicine Faculty Papers & Presentations

OBJECTIVES: Administering a purgative close to the time of colonoscopy is optimal for cleansing. The aim of this study was to compare the efficacy and tolerability of morning-only (AM-only) polyethylene glycol electrolyte solution (PEG-ELS) to split-dose (PM/AM) PEG-ELS for afternoon colonoscopy.

METHODS: This was a single-center, prospective, randomized, investigator-blinded, non-inferiority study comparing AM-only to PM/AM PEG-ELS for afternoon outpatient colonoscopy. The primary end point was whole colon prep adequacy. Tolerance and polyp detection were secondary outcomes.

RESULTS: Overall, 125 patients were randomized and 9 withdrew without taking any prep. Of 116 analyzed, 62 received AM-only prep and 54 received PM/AM …

Ranolazine Is Effective For Acute Or Chronic Ischemic Dysfunction With Heart Failure, Sudip Nanda Md, Facp, Matthew W. Martinez Md, Tanujit Dey Phd

Department of Medicine

No abstract provided.

Identification Of Methylated Genes Associated With Aggressive Bladder Cancer, Carmen J. Marsit, E. Andres Houseman, Brock C. Christensen, Luc Gagne, Margaret R. Wrensch, Heather H. Nelson, Joseph Weimels, Shichun Zheng, John K. Wiencke, Angeline S. Andrew, Alan R. Schned, Margaret R. Karagas, Karl T. Kelsey

Dartmouth Scholarship

Approximately 500,000 individuals diagnosed with bladder cancer in the U.S. require routine cystoscopic follow-up to monitor for disease recurrences or progression, resulting in over $ 2 billion in annual expenditures. Identification of new diagnostic and monitoring strategies are clearly needed, and markers related to DNA methylation alterations hold great promise due to their stability, objective measurement, and known associations with the disease and with its clinical features. To identify novel epigenetic markers of aggressive bladder cancer, we utilized a high-throughput DNA methylation bead-array in two distinct population-based series of incident bladder cancer (n = 73 and n = 264, respectively). …

Mechanisms Of Oxidant Generation By Catalase, Diane E. Heck, Michael Shakarjian, Hong-Duck Kim, Jeffrey Laskin, Anna M. Vetrano

NYMC Faculty Publications

The enzyme catalase converts solar radiation into reactive oxidant species (ROS). In this study, we report that several bacterial catalases (hydroperoxidases, HP), including Escherichia coli HP-I and HP-II also generate reactive oxidants in response to ultraviolet B light (UVB). HP-I and HP-II are identical except for the presence of NADPH. We found that only one of the catalases, HPI, produces oxidants in response to UVB light, indicating a potential role for the nucleotide in ROS production. This prompts us to speculate that NADPH may act as a cofactor regulating ROS generation by mammalian catalases. Structural analysis of the NADPH domains …