Medicine and Health Sciences Commons^™

Dissociation Of Automatic And Strategic Lexical-Semantics: Functional Magnetic Resonance Imaging Evidence For Differing Roles Of Multiple Frontotemporal Regions, Brian T. Gold, David A. Balota, Sara J. Jones, David K. Powell, Charles D. Smith, Anders H. Andersen

Neuroscience Faculty Publications

Behavioral research has demonstrated three major components of the lexical-semantic processing system: automatic activation of semantic representations, strategic retrieval of semantic representations, and inhibition of competitors. However, these component processes are inherently conflated in explicit lexical-semantic decision tasks typically used in functional magnetic resonance imaging (fMRI) research. Here, we combine the logic of behavioral priming studies and the neurophysiological phenomenon of fMRI priming to dissociate the neural bases of automatic and strategic lexical-semantic processes across a series of three studies. A single lexical decision task was used in all studies, with stimulus onset asynchrony or linguistic relationship between prime and …

Depression, Sensation Seeking, And Maternal Smoking As Predictors Of Adolescent Cigarette Smoking, Judy Van De Venne, Kay Bradford, Catherine A. Martin, Megan Cox, Hatim A. Omar

Family Sciences Faculty Publications

The purpose of this study was to examine maternal and adolescent depression, maternal and teen sensation seeking, and maternal smoking, and their associations with adolescent smoking. Data were collected from a sample of 47 male and 66 female adolescents (ages 11-18 years) and their mothers from three different health clinics. The findings indicated that maternal sensation seeking was linked indirectly with adolescent smoking through teen sensation seeking, both of which were significantly associated with teen smoking (β = 0.29, p < 0.001 and β = 0.32, p < 0.001, respectively). Teen depression was associated positively with teen smoking (β = 0.24, p < 0.01) when controlling for sensation seeking behaviors. Maternal smoking was also directly linked to adolescent smoking (β = 0.20, p < 0.05). These findings underscore a potentially important role of sensation seeking in the origins of adolescent smoking, and clarify pathways of influence with regard to maternal attitudes and behaviors in subsequent teenage nicotine use.

A Pilot Study: Attention Deficit Hyperactivity Disorder, Sensation Seeking, And Pubertal Changes, Catherine A. Martin, Greg Guenthner, Christopher Bingcang, W. Jackson Smith, Thomas E. Curry, Hatim A. Omar, Mary Kay Rayens, Tom H. Kelly

Pediatrics Faculty Publications

This study was designed to examine the relationship of pubertal changes and sensation seeking (SS) in adolescents with Attention Deficit Hyperactivity Disorder (ADHD). Patients with current or past histories of uncomplicated stimulant medication use for ADHD between the ages of 11 and 15 (13 ± 1.5) were recruited from a Child Psychiatry and a General Pediatric Clinic. SS was measured using the SS Scale for Children. Pubertal development was measured using Tanner staging, free testosterone, and DHEAS. Subjects and their parent were interviewed with the Diagnostic Interview Schedule for Children (DISC). SS total score was correlated with Tanner stage, free …

Molecular Diagnosis Of Burkitt's Lymphoma., Sandeep S. Dave, Kai Fu, George W. Wright, Lloyd T. Lam, Philip Kluin, Evert-Jan Boerma, Timothy Greiner, Dennis D. Weisenburger, Andreas Rosenwald, German Ott, Hans-Konrad Müller-Hermelink, Randy D. Gascoyne, Jan Delabie, Lisa M. Rimsza, Rita M. Braziel, Thomas M. Grogan, Elias Campo, Elaine S. Jaffe, Bhavana J. Dave, Warren Sanger, M Bast, Julie M. Vose, James O. Armitage, Joseph M. Connors, Erlend B. Smeland, Stein Kvaloy, Harald Holte, Richard I. Fisher, Thomas P. Miller, Emilio Montserrat, Wyndham H. Wilson, Manisha Bahl, Hong Zhao, Liming Yang, John Powell, Richard Simon, Wing C. Chan, Louis M. Staudt

Journal Articles: Pathology and Microbiology

BACKGROUND: The distinction between Burkitt's lymphoma and diffuse large-B-cell lymphoma is crucial because these two types of lymphoma require different treatments. We examined whether gene-expression profiling could reliably distinguish Burkitt's lymphoma from diffuse large-B-cell lymphoma.

METHODS: Tumor-biopsy specimens from 303 patients with aggressive lymphomas were profiled for gene expression and were also classified according to morphology, immunohistochemistry, and detection of the t(8;14) c-myc translocation.

RESULTS: A classifier based on gene expression correctly identified all 25 pathologically verified cases of classic Burkitt's lymphoma. Burkitt's lymphoma was readily distinguished from diffuse large-B-cell lymphoma by the high level of expression of c-myc target …

Representation Of Head-Centric Flow In The Human Motion Complex., Jeroen Goossens, Sean P Dukelow, Ravi S Menon, Tutis Vilis, Albert V Van Den Berg

Brain and Mind Institute Researchers' Publications

Recent neuroimaging studies have identified putative homologs of macaque middle temporal area (area MT) and medial superior temporal area (area MST) in humans. Little is known about the integration of visual and nonvisual signals in human motion areas compared with monkeys. Through extra-retinal signals, the brain can factor out the components of visual flow on the retina that are induced by eye-in-head and head-in-space rotations and achieve a representation of flow relative to the head (head-centric flow) or body (body-centric flow). Here, we used functional magnetic resonance imaging to test whether extra-retinal eye-movement signals modulate responses to visual flow in …

Level I Fieldwork Today: A Study Of Contexts And Perceptions., Caryn Johnson, Kristie P. Koenig, Catherine Verrier Piersol, Susan E. Santalucia, Wendy Wachter-Schutz

Department of Occupational Therapy Faculty Papers

The last comprehensive examination of the Level I fieldwork experience was performed 15 years ago (Shalik, 1990) and addressed the different types of settings in which fieldwork occurred; amounts and types of supervision; structure and scheduling of the Level I experiences; and the effects of supervising Level I students on productivity. Although every occupational therapy and occupational therapy assistant student encounters a number of Level I fieldwork opportunities, little is available describing the process and contexts of the Level I fieldwork experience today. This study, which examines 1,002 student reports on Level I fieldwork experiences, finds that Level I fieldwork …

A Role For Cetp Taqib Polymorphism In Determining Susceptibility To Atrial Fibrillation: A Nested Case Control Study, Folkert W. Asselbergs, Jason H. Moore, Maarten P. Van Den Berg, Eric B. Rimm

Dartmouth Scholarship

Studies investigating the genetic and environmental characteristics of atrial fibrillation (AF) may provide new insights in the complex development of AF. We aimed to investigate the association between several environmental factors and loci of candidate genes, which might be related to the presence of AF. A nested case-control study within the PREVEND cohort was conducted. Standard 12 lead electrocardiograms were recorded and AF was defined according to Minnesota codes. For every case, an age and gender matched control was selected from the same population (n = 194). In addition to logistic regression analyses, the multifactor-dimensionality reduction (MDR) method and interaction …

Prenatal Cocaine Exposure Alters Alpha2 Receptor Expression In Adolescent Rats, Rosemarie M. Booze, David R. Wallace, Janelle M. Silvers, Barbara J. Strupp, Diane M. Snow, Charles F. Mactutus

Neuroscience Faculty Publications

BACKGROUND: Prenatal cocaine exposure produces attentional deficits which to persist through early childhood. Given the role of norepinephrine (NE) in attentional processes, we examined the forebrain NE systems from prenatal cocaine exposed rats. Cocaine was administered during pregnancy via the clinically relevant intravenous route of administration. Specifically, we measured alpha2-adrenergic receptor (alpha2-AR) density in adolescent (35-days-old) rats, using [3H]RX821002 (5 nM).

RESULTS: Sex-specific alterations of alpha2-AR were found in the hippocampus and amygdala of the cocaine-exposed animals, as well as an upregulation of alpha2-AR in parietal cortex.

CONCLUSION: These data suggest that prenatal cocaine exposure results in a persistent alteration …

Spontaneous Intracranial Arterial Dissection In The Young: Diagnosis By Ct Angiography, William C. Robertson, Curtis A. Given

Neurology Faculty Publications

BACKGROUND: Spontaneous carotid artery dissections have been rarely reported in children. Diagnosis has traditionally been confirmed by catheter arteriography. More recently diagnosis has been made by magnetic resonance imaging and magnetic resonance angiography; however the sensitivity of these techniques has yet to be determined. The authors are unaware of reports of carotid dissection confirmed by dynamic computed tomography (computerized tomographic arteriography) in the young.

CASE PRESENTATION: We recently evaluated a fourteen year-old male following the development of transient neurologic symptoms. There was no antecedent illness or trauma. Dynamic computed tomography revealed an intracranial dissection involving the supraclinoid segment of the …

Na+/K+ -Atpase Regulates Tight Junction Formation And Function During Mouse Preimplantation Development., Michelle I Violette, Pavneesh Madan, Andrew J Watson

Obstetrics & Gynaecology Publications

Research applied to the early embryo is required to effectively treat human infertility and to understand the primary mechanisms controlling development to the blastocyst stage. The present study investigated whether the Na(+)/K(+)-ATPase regulates tight junction formation and function during blastocyst formation. To investigate this hypothesis, three experimental series were conducted. The first experiments defined the optimal dose and treatment time intervals for ouabain (a potent and specific inhibitor of the Na(+)/K(+)-ATPase) treatment. The results demonstrated that mouse embryos maintained a normal development to the blastocyst stage following a 6-h ouabain treatment. The second experiments investigated the effects of ouabain treatment …

Cutaneous And Presumed Visceral Leishmaniasis In A Soldier Deployed To Afghanistan, James P. Woodrow, Joshua D. Hartzell, Jim Czarnik, David Brett-Major, Glenn Wortmann

Journal Articles: Epidemiology

Leishmaniasis has been frequently diagnosed in US military personnel returning from duty in Southwest Asia. The majority of cases have demonstrated cutaneous disease, although a few cases of visceral disease have been documented. We present the case of an immunocompetent, HIV-negative, US Army soldier who suffered both visceral and cutaneous manifestations of leishmaniasis after returning from deployment in Afghanistan. Overlap of cutaneous and visceral involvement is rare and has not been reported in our cohort. Latent Plasmodium vivax infection may have been an exacerbating cofactor. We discuss this case and present a review of the literature.

Embryonic Stem Cell-Derived Hematopoietic Stem Cells, Yuan Wang, Frank Yates, Olaia Naveiras, Patricia Ernst, George Q. Daley

Dartmouth Scholarship

Despite two decades of studies documenting the in vitro blood-forming potential of murine embryonic stem cells (ESCs), achieving stable long-term blood engraftment of ESC-derived hematopoietic stem cells in irradiated mice has proven difficult. We have exploited the Cdx-Hox pathway, a genetic program important for blood development, to enhance the differentiation of ESCs along the hematopoietic lineage. Using an embryonic stem cell line engineered with tetracycline-inducible Cdx4 , we demonstrate that ectopic Cdx4 expression promotes hematopoietic mesoderm specification, increases hematopoietic progenitor formation, and, together with HoxB4, enhances multilineage hematopoietic engraftment of lethally irradiated adult mice. Clonal analysis of retroviral integration sites …

Resident Efficiency In A Pediatric Emergency Department., M Denise Dowd, Celeste Tarantino, Theodore M. Barnett, Laura Fitzmaurice, Jane F. Knapp

Manuscripts, Articles, Book Chapters and Other Papers

OBJECTIVES: To measure the hourly rate of patients evaluated and treated by resident physicians in an academic pediatric emergency department (PED) and examine differences in the rate by subspecialty and year of training.

METHODS: For all residents rotating in an academic, urban children's hospital PED, the rate of patients seen per hour over the course of their rotation was calculated using an electronic tracking system, EmSTAT, for calendar year 2000. Rates are reported as the mean number of patients seen per resident hour worked. Mean differences are reported for resident subspecialties (emergency medicine, pediatrics, and family practice) and postgraduate year …

A Drosophila Deg/Enac Channel Subunit Is Required For Male Response To Female Pheromones, Heping Lin, Kevin J. Mann, Elena Starostina, Ronald D. Kinser, Claudio W. Pikielny

Dartmouth Scholarship

Odorants and pheromones as well as sweet- and bitter-tasting small molecules are perceived through activation of G protein-coupled chemosensory receptors. In contrast, gustatory detection of salty and sour tastes may involve direct gating of sodium channels of the DEG/ENaC family by sodium and hydrogen ions, respectively. We have found that ppk25, a Drosophila melanogaster gene encoding a DEG/ENaC channel subunit, is expressed at highest levels in the male appendages responsible for gustatory and olfactory detection of female pheromones: the legs, wings, and antennae. Mutations in the ppk25 gene reduce or even abolish male courtship response to females in the dark, …

Does The Choice Of Bottle Nipple Affect The Oral Feeding Performance Of Very-Low-Birthweight (Vlbw) Infants?, C E. Scheel, Richard J. Schanler, Chantal Lau

Faculty, Staff and Students Publications

BACKGROUND: There is a continuous debate regarding the best bottle nipple to be used to enhance the bottle-feeding performance of a preterm infant. Aim: To verify that feeding performance can be improved by using the bottle nipple with the physical characteristics that enhance infants' sucking skills. METHODS: Ten "healthy" VLBW infants (941+/-273 g) were recruited. Feeding performance was monitored at two time periods, when taking 1-2 and 6-8 oral feedings/d. At each time and within 24 h, performance was monitored using three different bottle nipples offered in a randomized order. Rate of milk transfer (ml/min) was the primary outcome measure. …

The Neural Mechanisms Of Speech Comprehension: Fmri Studies Of Semantic Ambiguity, Jennifer M Rodd, Matthew H Davis, Ingrid Johnsrude

Brain and Mind Institute Researchers' Publications

A number of regions of the temporal and frontal lobes are known to be important for spoken language comprehension, yet we do not have a clear understanding of their functional role(s). In particular, there is considerable disagreement about which brain regions are involved in the semantic aspects of comprehension. Two functional magnetic resonance studies use the phenomenon of semantic ambiguity to identify regions within the fronto-temporal language network that subserve the semantic aspects of spoken language comprehension. Volunteers heard sentences containing ambiguous words (e.g. 'the shell was fired towards the tank') and well-matched low-ambiguity sentences (e.g. 'her secrets were written …

A Model Program For Youth Suicide Prevention, Hatim A. Omar

Pediatrics Faculty Publications

Youth suicide continues to be one of the leading causes of death in the United States. Nation wide it is the third leading cause of death in the 10-24 year old age group. The rate of suicide varies somewhat from state to state. In the state of Kentucky, youth suicide is the second leading cause of death. This article describes a grass root, community-based program for youth suicide prevention and its impact on the community. The Stop Youth Suicide Campaign was launched in October 2000 and included more than 30 local agencies. This program worked. through public education, education of …

Stress Levels, Psychological Symptoms, And C-Reactive Protein Levels In Covid-19: A Cross-Sectional Study, Jian Zhang, Wei Li, Hideo Hoshi, Stephen L Mills, Stephen C Massey

Faculty, Staff and Student Publications

The correlation between cholinergic sensitivity and the level of stratification for ganglion cells was examined in the rabbit retina. As examples, we have used ON or OFF alpha ganglion cells and ON/OFF directionally selective (DS) ganglion cells. Nicotine, a cholinergic agonist, depolarized ON/OFF DS ganglion cells and greatly enhanced their firing rates but it had modest excitatory effects on ON or OFF alpha ganglion cells. As previously reported, we conclude that DS ganglion cells are the most sensitive to cholinergic drugs. Confocal imaging showed that ON/OFF DS ganglion cells ramify precisely at the level of the cholinergic amacrine cell dendrites, …

Urotensin Ii Modulates Rapid Eye Movement Sleep Through Activation Of Brainstem Cholinergic Neurons, Salvador Huitron-Resendiz, Morten P. Kristensen, Stephen L. Grupke, Christopher Tyler, Olivier Civelli, Christopher S. Leonard, Luis De Lecea

NYMC Faculty Publications

Urotensin II (UII) is a cyclic neuropeptide with strong vasoconstrictive activity in the peripheral vasculature. UII receptor mRNA is also expressed in the CNS, in particular in cholinergic neurons located in the mesopontine tegmental area, including the pedunculopontine tegmental (PPT) and lateral dorsal tegmental nuclei. This distribution suggests that the UII system is involved in functions regulated by acetylcholine, such as the sleep-wake cycle. Here, we tested the hypothesis that UII influences cholinergic PPT neuron activity and alters rapid eye movement (REM) sleep patterns in rats. Local administration of UII into the PPT nucleus increases REM sleep without inducing changes …

Manganese Distribution Across The Blood-Brain Barrier. Iv. Evidence For Brain Influx Through Store-Operated Calcium Channels, Janelle S. Crossgrove, Robert A. Yokel

Pharmaceutical Sciences Faculty Publications

Manganese (Mn) is a required co-factor for many ubiquitous enzymes; however, chronic Mn overexposure can cause manganism, a parkinsonian-like syndrome. Previous studies showed Mn influx into brain is carrier-mediated, though the putative carrier(s) were not established. Studies conducted with cultured bovine brain microvascular endothelial cells (bBMECs), which comprise the blood–brain barrier, revealed ⁵⁴Mn (II) uptake positively correlated with pH, was temperature-dependent, and was sodium- and energy-independent. Brain ⁵⁴Mn uptake correlated inversely with calcium (Ca) concentration, but ⁴⁵Ca uptake was unaltered by high Mn concentration. Lanthanum (La), a non-selective inhibitor of several Ca channel types, as well as …

Glutamate Receptors In Perirhinal Cortex Mediate Encoding, Retrieval, And Consolidation Of Object Recognition Memory., Boyer D Winters, Timothy J Bussey

Brain and Mind Institute Researchers' Publications

Object recognition is consistently impaired in human amnesia and animal models thereof. Results from subjects with permanent brain damage have revealed the importance of the perirhinal cortex to object recognition memory. Here, we report evidence from rats for interdependent but distinct stages in object recognition memory (encoding, retrieval, and consolidation), which require glutamate receptor activity within perirhinal cortex. Transient blockade of AMPA receptor-mediated synaptic transmission within perirhinal cortex disrupted encoding for short- and long-term memory as well as retrieval and consolidation. In contrast, transient NMDA receptor blockade during encoding affected only long-term object recognition memory; NMDA receptor activity was also …

The Cns Role Of Toll-Like Receptor 4 In Innate Neuroimmunity And Painful Neuropathy, Flobert Y. Tanga, Nancy Nutile-Mcmenemy, Joyce A. Deleo

Dartmouth Scholarship

Neuropathic pain remains a prevalent and persistent clinical problem because of our incomplete understanding of its pathogenesis. This study demonstrates for the first time, to our knowledge, a critical role for CNS innate immunity by means of microglial Toll-like receptor 4 (TLR4) in the induction phase of behavioral hypersensitivity in a mouse and rat model of neuropathy. We hypothesized that after L5 nerve transection, CNS neuroimmune activation and subsequent cytokine expression are triggered by the stimulation of microglial membrane-bound TLR4. To test this hypothesis, experiments were undertaken to assess tactile and thermal hypersensitivity in genetically altered (i.e., TLR4 knockout and …

Learning To Like: A Role For Human Orbitofrontal Cortex In Conditioned Reward, Sylvia M L Cox, Alexandre Andrade, Ingrid Johnsrude

Brain and Mind Institute Researchers' Publications

A great deal of human behavior and motivation is based on the intrinsic emotional significance of rewarding or aversive events, as well as on the associations formed between such emotional events and concurrent environmental stimuli. Recent functional neuroimaging studies have implicated the ventral striatum, orbitofrontal cortex (OFC), and amygdala in the representation of reward values and/or in the anticipation of rewarding events. Here, we use functional magnetic resonance imaging to compare brain activation during the presentation of reward with that during presentation of (conditioned) stimuli that have been paired previously with reward. Specifically, we aimed to investigate conditioned reward in …

Clinical Characteristics Of Individuals Using An Online Alcohol Evaluation Program., Daniel Z Lieberman

Psychiatry and Behavioral Sciences Faculty Publications

Access to treatment for substance abuse disorders is limited, and practical strategies are needed to expand opportunities for individuals to receive effective interventions. Automated or semi-automated treatments have shown promise in other disorders. Identifying the characteristics of patients who will be able to benefit from this unconventional approach will increase the likelihood of success. The current study examined 1,297 individuals using an online alcohol evaluation program. Subjects had high scores on the Alcohol Use Disorders Identification Test (AUDIT) and a substantial amount of ambivalence about the possible harm that their drinking caused, but they also had very low levels of …

The Meaning Of Computers To A Group Of Men Who Are Homeless., Kathleen Swenson Miller, Stacey Bunch-Harrison, Brett Brumbaugh, Rekha Sankaran Kutty, Kathleen Fitzgerald

Department of Occupational Therapy Faculty Papers

The purpose of this pilot study was to explore the experience with computers and the meaning of computers to a group of homeless men living in a long-term shelter. This descriptive exploratory study used semistructured interviews with seven men who had been given access to computers and had participated in individually tailored occupation based interventions through a Work Readiness Program. Three themes emerged from analyzing the interviews: access to computers, computers as a bridge to life-skill development, and changed self-perceptions as a result of connecting to technology. Because they lacked computer knowledge and feared failure, the majority of study participants …

Role For Akt3/Protein Kinase Bγ In Attainment Of Normal Brain Size, Rachel M. Easton, Han Cho, Kristin Roovers, Diana W. Shineman

Dartmouth Scholarship

Studies of Drosophila and mammals have revealed the importance of insulin signaling through phosphatidylinositol 3-kinase and the serine/threonine kinase Akt/protein kinase B for the regulation of cell, organ, and organismal growth. In mammals, three highly conserved proteins, Akt1, Akt2, and Akt3, comprise the Akt family, of which the first two are required for normal growth and metabolism, respectively. Here we address the function of Akt3. Like Akt1, Akt3 is not required for the maintenance of normal carbohydrate metabolism but is essential for the attainment of normal organ size. However, in contrast to Akt1^−/− mice, which display a …

Quantitative 1h Magnetic Resonance Spectroscopic Imaging Determines Therapeutic Immunization Efficacy In An Animal Model Of Parkinson's Disease., Michael D. Boska, Travis B. Lewis, Christopher J. Destache, Eric J. Benner, Jay A. Nelson, Mariano Uberti, R. Lee Mosley, Howard Gendelman

Journal Articles: Radiology

Nigrostriatal degeneration, the pathological hallmark of Parkinson's disease (PD), is mirrored by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) intoxication. MPTP-treated animals show the common behavioral, motor, and pathological features of human disease. We demonstrated previously that adoptive transfer of Copaxone (Cop-1) immune cells protected the nigrostriatal dopaminergic pathway in MPTP-intoxicated mice. Herein, we evaluated this protection by quantitative proton magnetic resonance spectroscopic imaging (1H MRSI). 1H MRSI performed in MPTP-treated mice demonstrated that N-acetyl aspartate (NAA) was significantly diminished in the substantia nigra pars compacta (SNpc) and striatum, regions most affected in human disease. When the same regions were coregistered with immunohistochemical stains for …

Transient Inactivation Of Perirhinal Cortex Disrupts Encoding, Retrieval, And Consolidation Of Object Recognition Memory., Boyer D Winters, Timothy J Bussey

Brain and Mind Institute Researchers' Publications

Damage to perirhinal cortex (PRh) impairs object recognition memory in humans, monkeys, and rats when tested in tasks such as delayed nonmatching to sample, visual paired comparison, and its rodent analog, the spontaneous object recognition task. In the present study, we have capitalized on the discrete one-trial nature of the spontaneous object recognition task to investigate the role of PRh in several distinct stages of object recognition memory. In a series of experiments, transient inactivation of PRh was accomplished with bilateral infusions of lidocaine directly into PRh immediately before the sample phase (encoding), immediately before the choice phase (retrieval), or …

A Pilot Randomized, Controlled Trial Of An In-Home Drinking Water Intervention Among Hiv + Persons, John M. Colford, Sona R. Saha, Timothy J. Wade, Catherine C. Wright, Mai Vu, Sandra Charles, Peter Jensen, Alan Hubbard, Deborah A. Levy, Joseph N. S. Eisenberg

Journal Articles: Epidemiology

Although immunocompromised persons may be at increased risk for gastrointestinal illnesses, no trials investigating drinking water treatment and gastrointestinal illness in such patients have been published. Earlier results from San Francisco suggested an association (OR 6.76) between tap water and cryptosporidiosis among HIV + persons. The authors conducted a randomized, triple-blinded intervention trial of home water treatment in San Francisco, California, from April 2000 to May 2001. Fifty HIV-positive patients were randomized to externally identical active (N = 24) or sham (N = 26) treatment devices. The active device contained a filter and UV light; the sham provided no treatment. …

A Randomized, Controlled Trial Of In-Home Drinking Water Intervention To Reduce Gastrointestinal Illness, John M. Colford, Timothy J. Wade, Sukhminder K. Sandhu, Catherine C. Wright, Sherline Lee, Susan Shaw, Kim Fox, Susan Burns, Anne Benker, M. Alan Brookhart, Mark Van Der Laan, Deborah A. Levy

Journal Articles: Epidemiology

Trials have provided conflicting estimates of the risk of gastrointestinal illness attributable to tap water. To estimate this risk in an Iowa community with a well-run water utility with microbiologically challenged source water, the authors of this 2000-2002 study randomly assigned blinded volunteers to use externally identical devices (active device: 227 households with 646 persons; sham device: 229 households with 650 persons) for 6 months (cycle A). Each group then switched to the opposite device for 6 months (cycle B). The active device contained a 1-microm absolute ceramic filter and used ultraviolet light. Episodes of "highly credible gastrointestinal illness," a …