Digital Commons Network^™

Caffeine And Progression Of Parkinson Disease: A Deleterious Interaction With Creatine., David K. Simon, Cai Wu, Barbara C. Tilley, Anne-Marie Wills, Michael J. Aminoff, Jacquelyn Bainbridge, Robert A. Hauser, Jay S. Schneider, Saloni Sharma, Carlos Singer, Caroline M. Tanner, Daniel Truong, Pei Shieen Wong

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

OBJECTIVE: Increased caffeine intake is associated with a lower risk of Parkinson disease (PD) and is neuroprotective in mouse models of PD. However, in a previous study, an exploratory analysis suggested that, in patients taking creatine, caffeine intake was associated with a faster rate of progression. In the current study, we investigated the association of caffeine with the rate of progression of PD and the interaction of this association with creatine intake.

METHODS: Data were analyzed from a large phase 3 placebo-controlled clinical study of creatine as a potentially disease-modifying agent in PD. Subjects were recruited for this study from …

The Evolution Of Epilepsy Surgery Between 1991 And 2011 In Nine Major Epilepsy Centers Across The United States, Germany, And Australia., Lara Jehi, Daniel Friedman, Chad Carlson, Gregory Cascino, Sandra Dewar, Christian Elger, Jerome Engel, Robert Knowlton, Ruben Kuzniecky, Anne Mcintosh, Terence J O'Brien, Dennis Spencer, Michael R. Sperling, Gregory Worrell, Bill Bingaman, Jorge Gonzalez-Martinez, Werner Doyle, Jacqueline French

Department of Neurology Faculty Papers

OBJECTIVE: Epilepsy surgery is the most effective treatment for select patients with drug-resistant epilepsy. In this article, we aim to provide an accurate understanding of the current epidemiologic characteristics of this intervention, as this knowledge is critical for guiding educational, academic, and resource priorities.

METHODS: We profile the practice of epilepsy surgery between 1991 and 2011 in nine major epilepsy surgery centers in the United States, Germany, and Australia. Clinical, imaging, surgical, and histopathologic data were derived from the surgical databases at various centers.

RESULTS: Although five of the centers performed their highest number of surgeries for mesial temporal sclerosis …

Increased Expression Of Napdh Oxidase 4 In Systemic Sclerosis Dermal Fibroblasts: Regulation By Transforming Growth Factor Β., Sonsoles Piera-Velazquez, Alma Makul, Sergio A. Jimenez

Department of Dermatology and Cutaneous Biology Faculty Papers

OBJECTIVE: Systemic sclerosis (SSc) is characterized by severe and often progressive fibrosis of the skin and multiple internal organs. The mechanisms responsible for these alterations remain obscure, although excessive reactive oxygen species (ROS)-mediated oxidative stress has been implicated. NOX-4 is 1 of 7 isoforms of NADPH oxidase responsible for the generation of ROS. The purpose of this study was to examine NOX-4 expression in skin and cultured dermal fibroblasts from SSc patients and to examine its regulation by transforming growth factor β1 (TGFβ1).

METHODS: NOX-4 was assessed in normal and SSc skin by immunohistologic analysis and in normal and SSc …

Combined Retrograde/Antegrade Approach To Transcatheter Closure Of An Aortic Paravalvular Leak, Abdulla A Damluji, Husnu E Kaynak, Alan W Heldman

The Texas Heart Institute Journal

New interventional techniques have made transcatheter closure of aortic paravalvular leaks a viable therapeutic option to treat the sequelae of these defects, including congestive heart failure and hemolysis. We report the transcatheter closure of an aortic paravalvular leak via a combined retrograde/antegrade approach. This was necessary because of difficulty in crossing the defect with a sheath from the retrograde approach. This technique might be useful in application to other difficult structural heart interventions. To our knowledge, this is the first report of a treated paravalvular leak around a Mitroflow(®) Aortic Pericardial Heart Valve.

Down Syndrome With Complete Atrioventricular Septal Defect, Hypertrophic Cardiomyopathy, And Pulmonary Vein Stenosis, Guruprasad Mahadevaiah, Manoj Gupta, Ravi Ashwath

The Texas Heart Institute Journal

The prevalence of congenital heart disease in infants with Down syndrome is 40%, compared with 0.3% in children who have normal chromosomes. Atrioventricular and ventricular septal defects are often associated with chromosomal aberrations, such as in trisomy 21, whereas hypertrophic cardiomyopathy is chiefly thought to be secondary to specific gene mutations. We found only one reported case of congenital hypertrophic cardiomyopathy and atrioventricular septal defect in an infant with Down syndrome. Here, we report atrioventricular septal defect, hypertrophic cardiomyopathy, and pulmonary vein stenosis in a neonate with Down syndrome-an apparently unique combination. In addition, we discuss the relevant medical literature.

Efficacy Of Oral Anticoagulation In Stroke Prevention Among Sinus-Rhythm Patients Who Lack Left Atrial Mechanical Contraction After Cryoablation, José Martínez-Comendador, Javier Gualis, José Miguel Marcos-Vidal, Jonnatan Buber, Carlos Esteban Martín, Jesús Gomez-Plana, Miguel Angel Rodríguez, Ignacio Iglesias-Garriz, David Alonso, Carlos Soria, Eva Higuera Miguélez, Mario Castaño

The Texas Heart Institute Journal

The customary recommendation is that oral anticoagulation be withdrawn a few months after cryoablation for atrial fibrillation, independently of left atrial mechanical contraction in patients in sinus rhythm. Recently, a 5-fold increase in stroke has been described in sinus-rhythm patients who lack atrial mechanical contraction. One aim of this study was to evaluate the efficacy of oral anticoagulation in preventing postoperative stroke in such patients.

This prospective study divided 154 sinus-rhythm patients into 2 groups, depending on the presence (108 patients) or absence (46 patients) of left atrial mechanical contraction at 6 months after surgery, and monitored them annually for …

Evaluation Of Previously Cannulated Radial Arteries As Patent Coronary Artery Bypass Conduits, Timothy Watson, Adele Pope, Niels Van Pelt, Peter N Ruygrok

The Texas Heart Institute Journal

In coronary artery bypass grafting, good-quality conduits are needed to maximize the potential for long-term patency. Revascularization has traditionally been achieved with use of the saphenous vein and the internal thoracic arteries. In recent years, total arterial revascularization with use of the radial arteries has been promoted. Meanwhile, use of the transradial approach for coronary angiography has also increased. The long-term effects of previous cannulation in radial artery bypass grafts are not known. Therefore, we used multidetector computed tomographic angiography to investigate radial-artery graft patency in a small series of patients who had undergone transradial angiography. We found a high …

The Dna Structure And Sequence Preferences Of Wrn Underlie Its Function In Telomeric Recombination Events, Deanna N. Edwards, Amrita Machwe, Li Chen, Vilhelm A. Bohr, David K. Orren

Toxicology and Cancer Biology Faculty Publications

Telomeric abnormalities caused by loss of function of the RecQ helicase WRN are linked to the multiple premature ageing phenotypes that characterize Werner syndrome. Here we examine WRN's role in telomeric maintenance, by comparing its action on a variety of DNA structures without or with telomeric sequences. Our results show that WRN clearly prefers to act on strand invasion intermediates in a manner that favours strand invasion and exchange. Moreover, WRN unwinding of these recombination structures is further enhanced when the invading strand contains at least three G-rich single-stranded telomeric repeats. These selectivities are most pronounced at NaCl concentrations within …

Dual Use Of Va And Non-Va Hospitals By Veterans With Multiple Hospitalizations, Alan N. West, Mary E. Charlton, Mary Vaughan-Sarrazin

Dartmouth Scholarship

Background: Veterans who are hospitalized in both VA and non-VA hospitals within a short timespan may be at risk for fragmented or conflicting care. To determine the characteristics of these “dual users,” we analyzed administrative hospital discharge data for VA-enrolled veterans of any age in seven states, including any VA or non-VA hospitalizations they had in 2004 – 2007. Method: For VA enrollees in Arizona, Iowa, Louisiana, Florida, South Carolina, Pennsylvania, or New York in 2007, we merged 2004 – 2007 discharge data for all VA hospitalizations and all non-VA hospitalizations listed in state health department or hospital association databases. …

Isoform-Specific Dynamic Translocation Of Pkc By Α1-Adrenoceptor Stimulation In Live Cells., Jin O-Uchi, Jaime Sorenson, Bong Sook Jhun, Jyotsna Mishra, Stephen Hurst, Kaleef Williams, Shey-Shing Sheu, Coeli M.B. Lopes

Center for Translational Medicine Faculty Papers

Protein kinase C (PKC) plays key roles in the regulation of signal transduction and cellular function in various cell types. At least ten PKC isoforms have been identified and intracellular localization and trafficking of these individual isoforms are important for regulation of enzyme activity and substrate specificity. PKC can be activated downstream of Gq-protein coupled receptor (GqPCR) signaling and translocate to various cellular compartments including plasma membrane (PM). Recent reports suggested that different types of GqPCRs would activate different PKC isoforms (classic, novel and atypical PKCs) with different trafficking patterns. However, the knowledge of isoform-specific activation of PKC by each …

Risk Factors For Hemorrhoids On Screening Colonoscopy, Anne F. Peery, Robert S. Sandler, Joseph A. Galanko, Robert S. Bresalier, Jane C. Figueiredo, Dennis J. Ahnen, Elizabeth L. L. Barry, John A. Baron

Dartmouth Scholarship

Background: Constipation, a low fiber diet, sedentary lifestyle and gravidity are commonly assumed to increase the risk of hemorrhoids. However, evidence regarding these factors is limited. We examined the association between commonly cited risk factors and the prevalence of hemorrhoids. Methods: We performed a cross sectional study of participants who underwent a colonoscopy in a colorectal adenoma prevention trial and who had a detailed assessment of bowel habits, diet and activity. The presence of hemorrhoids was extracted from the subjects’ colonoscopy reports. We used logistic regression to estimate odds ratios and 95% confidence intervals while adjusting for age and sex. …

Can Big Data Help Us Close An Epilepsy Care Gap?, Christine B. Baca, Gregory L. Barkley

Neurology Articles

No abstract provided.

Leukaemia Cutis After Starting Bendamustine: Cause Or Coincidence?, Sagger Mawri, Shahzaib Nabi, Bassel Jallad, Joseph Won

Internal Medicine Articles

A 55-year-old man with a history of chronic lymphocytic leukaemia presented with diffuse skin lesions that began 1 week after starting a new chemotherapy regimen with bendamustine and rituximab. The lesions appeared as erythematous papules that were neither itchy nor tender, and did not blanch with pressure. Initially, they began on his scalp and flanks and, over the next few days, spread diffusely throughout his body, becoming darker in colour. Skin biopsy showed atypical clonal B-cell proliferation in a perivascular, periadnexal and dermal band-like distribution, which was further characterised by immunohistochemical evaluation. These findings were suggestive of leukaemia cutis and …

Mechanistic Insights Into Glucan Phosphatase Activity Against Polyglucan Substrates, David A. Meekins, Madushi Raththagala, Kyle D. Auger, Benjamin D. Turner, Diana Santelia, Oliver Kötting, Matthew S. Gentry, Craig W. Vander Kooi

Molecular and Cellular Biochemistry Faculty Publications

Glucan phosphatases are central to the regulation of starch and glycogen metabolism. Plants contain two known glucan phosphatases, Starch EXcess4 (SEX4) and Like Sex Four2 (LSF2), which dephosphorylate starch. Starch is water-insoluble and reversible phosphorylation solubilizes its outer surface allowing processive degradation. Vertebrates contain a single known glucan phosphatase, laforin, that dephosphorylates glycogen. In the absence of laforin, water-soluble glycogen becomes insoluble, leading to the neurodegenerative disorder Lafora Disease. Because of their essential role in starch and glycogen metabolism glucan phosphatases are of significant interest, yet a comparative analysis of their activities against diverse glucan substrates has not been established. …

Computerized Adaptive Tests Detect Change Following Orthopaedic Surgery In Youth With Cerebral Palsy., M J Mulcahey, Mary D Slavin, Pengsheng Ni, Lawrence C Vogel, Scott H Kozin, Stephen M Haley, Alan M Jette

Department of Occupational Therapy Faculty Papers

BACKGROUND: The Cerebral Palsy Computerized Adaptive Test (CP-CAT) is a parent-reported outcomes instrument for measuring lower and upper-extremity function, activity, and global health across impairment levels and a broad age range of children with cerebral palsy (CP). This study was performed to examine whether the Lower Extremity/Mobility (LE) CP-CAT detects change in mobility following orthopaedic surgery in children with CP.

METHODS: This multicenter, longitudinal study involved administration of the LE CP-CAT, the Pediatric Outcomes Data Collection Instrument (PODCI) Transfer/Mobility and Sports/Physical Functioning domains, and the Timed "Up & Go" test (TUG) before and after elective orthopaedic surgery in a convenience …

The Fate Of Spacers In The Treatment Of Periprosthetic Joint Infection., Miguel M Gomez, Timothy L Tan, Jorge Manrique, Gregory K Deirmengian, Javad Parvizi Md

Rothman Institute Papers

BACKGROUND: Two-stage exchange arthroplasty remains the preferred method to treat periprosthetic joint infection. The aim of this study was to investigate the clinical course of periprosthetic joint infection following resection arthroplasty and insertion of a spacer.

METHODS: Our institutional database was used to identify 504 cases of periprosthetic joint infection (326 knees and 178 hips) treated with resection arthroplasty and spacer insertion as part of a two-stage exchange arthroplasty. A review of the patient charts was performed to extract information relevant to the objectives of this study that included the details of the clinical course following resection arthroplasty.

RESULTS: The …

Thromboembolism After Intramedullary Nailing For Metastatic Bone Lesions., Brandon Shallop, Alexandria Starks, Simon Greenbaum, David S Geller, Alan Lee, John Ready, Geno J Merli, Mitchell Maltenfort, Phd, John A Abraham

Rothman Institute Papers

BACKGROUND: The risk of venous thromboembolism (VTE) in patients undergoing intramedullary nailing for skeletal metastatic disease is currently undefined. The purpose of our study was to determine the risk of thromboembolic events, to define the risk factors for VTE, and to define the rate of wound complications in this population.

METHODS: A retrospective review of surgical databases at three National Cancer Institute (NCI)-designated cancer centers identified 287 patients with a total of 336 impending or pathologic long-bone fractures that were stabilized with intramedullary nailing between February 2001 and April 2013. Statistical analysis was performed utilizing multivariable logistic regression and Fisher …

Role And Regulation Of Coordinately Expressed De Novo Purine Biosynthetic Enzymes Ppat And Paics In Lung Cancer, Moloy T. Goswami, Guoan Chen, Balabhadrapatruni Chakravarthi, Satya Pathi, Sharath Anand, Shannon Carskadon, Thomas Giordano, Arul Chinnaiyan, Dafydd Thomas, Nallasivam Palanisamy, David Beer, Sooryanarayana Varambally

Urology Articles

Cancer cells exhibit altered metabolism including aerobic glycolysis that channels several glycolytic intermediates into de novo purine biosynthetic pathway. We discovered increased expression of phosphoribosyl amidotransferase (PPAT) and phosphoribosylaminoimidazole carboxylase, phosphoribosylaminoimidazole succinocarboxamide synthetase (PAICS) enzymes of de novo purine biosynthetic pathway in lung adenocarcinomas. Transcript analyses from next-generation RNA sequencing and gene expression profiling studies suggested that PPAT and PAICS can serve as prognostic biomarkers for aggressive lung adenocarcinoma. Immunohistochemical analysis of PAICS performed on tissue microarrays showed increased expression with disease progression and was significantly associated with poor prognosis. Through gene knockdown and over-expression studies we demonstrate that altering …

Gm1 Ganglioside In Parkinson's Disease: Pilot Study Of Effects On Dopamine Transporter Binding., Jay S. Schneider, Franca Cambi, Stephen M. Gollomp, Hiroto Kuwabara, James R. Brašić, Benjamin E. Leiby, Stephanie Sendek, Dean F. Wong

Department of Pharmacology and Experimental Therapeutics Faculty Papers

OBJECTIVE: GM1 ganglioside has been suggested as a treatment for Parkinson's disease (PD), potentially having symptomatic and disease modifying effects. The current pilot imaging study was performed to examine effects of GM1 on dopamine transporter binding, as a surrogate measure of disease progression, studied longitudinally.

METHODS: Positron emission tomography (PET) imaging data were obtained from a subset of subjects enrolled in a delayed start clinical trial of GM1 in PD [1]: 15 Early-start (ES) subjects, 14 Delayed-start (DS) subjects, and 11 Comparison (standard-of-care) subjects. Treatment subjects were studied over a 2.5 year period while Comparison subjects were studied over 2 …

A Comparison Of A Multistate Inpatient Ehr Database To The Hcup Nationwide Inpatient Sample., Jonathan P Deshazo, Mark A Hoffman

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND: The growing availability of electronic health records (EHRs) in the US could provide researchers with a more detailed and clinically relevant alternative to using claims-based data.

METHODS: In this study we compared a very large EHR database (Health Facts©) to a well-established population estimate (Nationwide Inpatient Sample). Weighted comparisons were made using t-value and relative difference over diagnoses and procedures for the year 2010.

RESULTS: The two databases have a similar distribution pattern across all data elements, with 24 of 50 data elements being statistically similar between the two data sources. In general, differences that were found are consistent …

Development And Validation Of An Epitope Prediction Tool For Swine (Pigmatrix) Based On The Pocket Profile Method, Andres H. Gutiérrez, William D. Martin, Chris Bailey-Kellogg, Frances Terry, Leonard Moise, Anee S. De Groot

Dartmouth Scholarship

Background: T cell epitope prediction tools and associated vaccine design algorithms have accelerated the development of vaccines for humans. Predictive tools for swine and other food animals are not as well developed, primarily because the data required to develop the tools are lacking. Here, we overcome a lack of T cell epitope data to construct swine epitope predictors by systematically leveraging available human information. Applying the “pocket profile method ”, we use sequence and structural similarities in the binding pockets of human and swine major histocompatibility complex proteins to infer Swine Leukocyte Antigen (SLA) peptide binding preferences. We developed epitope-prediction …

Surgical Clipping Versus Endovascular Intervention For The Treatment Of Subarachnoid Hemorrhage Patients In New York State, Kimon Bekelis, Symeon Missios, Shannon Coy, Redi Rahmani, Robert J. Singer, Todd A. Mackenzie

Dartmouth Scholarship

Object:

Randomized trials have demonstrated a survival benefit for endovascular treatment of ruptured cerebral aneurysms. We investigated the association of surgical clipping and endovascular coiling with outcomes in subarachnoid hemorrhage (SAH) patients in a real-world regional cohort. Methods: We performed a cohort study involving patients with ruptured cerebral aneurysms, who underwent surgical clipping, or endovascular coiling from 2009–2013 and were registered in the Statewide Planning and Research Cooperative System (SPARCS) database. An instrumental variable analysis was used to investigate the association of treatment technique with outcomes. Results: Of the 4,098 patients undergoing treatment, 2,585 (63.1%) underwent coiling, and 1,513 (36.9%) …

Targeting Ezh2 Regulates Tumor Growth And Apoptosis Through Modulating Mitochondria Dependent Cell-Death Pathway In Hnscc, Xuan Zhou, Yu Ren, Lingping Kong, Guoshuai Cai, Shanshan Sun, Wangzhao Song, Yu Wang, Rui Jin, Lisha Qi, Mei Mei

Dartmouth Scholarship

EZH2 is a negative prognostic factor and is overexpressed or activated in most human cancers including head and neck squamous cell carcinoma (HNSCC). Analysis of The Cancer Genome Atlas (TCGA) HNSCC data indicated that EZH2 over-expression was associated with high tumor grade and conferred poor prognosis. EZH2 inhibition triggered cell apoptosis, cell cycle arrest and decreased cell growth in vitro. MICU1 (mitochondrial calcium uptake1) was shown to be down regulated when EZH2 expression was inhibited in HNSCC. When the EZH2 and MICU1 were inhibited, HNSCC cells became susceptible to cell cycle arrest and apoptosis. Mitochondrial membrane potential and cytosolic Ca2+ …

Autophagy Is Induced Upon Platelet Activation And Is Essential For Hemostasis And Thrombosis, Madhu M. Ouseph, Yunjie Huang, Meenakshi Banerjee, Smita Joshi, Laura Macdonald, Yu Zhong, Huijuan Liu, Xianting Li, Binggang Xiang, Guoying Zhang, Masaaki Komatsu, Zhenyu Yue, Zhenyu Li, Brian Storrie, Sidney W. Whiteheart, Qing Jun Wang

Molecular and Cellular Biochemistry Faculty Publications

Autophagy is important for maintaining cellular homeostasis, and thus its deficiency is implicated in a broad spectrum of human diseases. Its role in platelet function has only recently been examined. Our biochemical and imaging studies demonstrate that the core autophagy machinery exists in platelets, and that autophagy is constitutively active in resting platelets. Moreover, autophagy is induced upon platelet activation, as indicated by agonist-induced loss of the autophagy marker LC3II. Additional experiments, using inhibitors of platelet activation, proteases, and lysosomal acidification, as well as platelets from knockout mouse strains, show that agonist-induced LC3II loss is a consequence of platelet signaling …

The Role Of Perlecan And Endorepellin In The Control Of Tumor Angiogenesis And Endothelial Cell Autophagy., Stephen Douglass, Atul Goyal, Renato V. Iozzo

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

During tumor growth and angiogenesis there is a dynamic remodeling of tissue architecture often accompanied by the release of extracellular matrix constituents full of biological activity. One of the key constituents of the tumor microenvironment is the large heparan sulfate proteoglycan perlecan. This proteoglycan, strategically located at cell surfaces and within basement membranes, is a well-defined pro-angiogenic molecule when intact. However, when partially processed by proteases released during cancer remodeling and invasion, the C-terminal fragment of perlecan, known as endorepellin, has opposite effects than its parent molecule. Endorepellin is a potent inhibitor of angiogenesis by exerting a dual receptor antagonism …

How Clinicians Feel About Working With Spouses Of The Chronically Ill, Douglas Ingram

NYMC Faculty Publications

Clinicians who provide psychotherapy to spouses or partners of the chronically ill were solicited through listserves of psychodynamic and other organizations. The current report excluded those therapists working with spouses of dementia patients. Interviews were conducted with clinicians who responded. The interviews highlight the challenges commonly encountered by psychotherapeutic work with this cohort of therapy patients. A comparison is drawn that shows both overlap and distinctions between the experiences of those therapists engaging with spouses of chronically ill patients without a dementing process and those working with spouses of chronically ill patients who do suffer from a dementing process.

Delivery Of Nucleic Acids And Nanomaterials By Cell-Penetrating Peptides: Opportunities And Challenges, Yue-Wern Huang, Han-Jung Lee, Larry Tolliver, Robert Aronstam

Biological Sciences Faculty Research & Creative Works

Many viral and nonviral systems have been developed to aid delivery of biologically active molecules into cells. Among these, cell-penetrating peptides (CPPs) have received increasing attention in the past two decades for biomedical applications. In this review, we focus on opportunities and challenges associated with CPP delivery of nucleic acids and nanomaterials. We first describe the nature of versatile CPPs and their interactions with various types of cargoes. We then discuss in vivo and in vitro delivery of nucleic acids and nanomaterials by CPPs. Studies on the mechanisms of cellular entry and limitations in the methods used are detailed.

Building Trust: A Critical Component Of Global Health., Obidimma C Ezezika

Health Studies Publications

Trust is a concept that we often take for granted. But as much as it serves as glue for human relationships, trust lies, albeit subtly or sometimes hidden, at the crux of all global health interventions and is critical to their success or failure. The recent Ebola pandemic in West Africa shows how distrust among the community, public health officials and government institutions can lead to a massive failure in the delivery of health care and response to a disease outbreak. Media articles and commentaries attributed the slow response to the Ebola crisis to a lack of trust on many …

Finding The Engram., Sheena A Josselyn, Stefan Köhler, Paul W Frankland

Brain and Mind Institute Researchers' Publications

Many attempts have been made to localize the physical trace of a memory, or engram, in the brain. However, until recently, engrams have remained largely elusive. In this Review, we develop four defining criteria that enable us to critically assess the recent progress that has been made towards finding the engram. Recent 'capture' studies use novel approaches to tag populations of neurons that are active during memory encoding, thereby allowing these engram-associated neurons to be manipulated at later times. We propose that findings from these capture studies represent considerable progress in allowing us to observe, erase and express the engram.

Positional Differences In Reactive Hyperemia Provide Insight Into Initial Phase Of Exercise Hyperemia., Jeffrey L Jasperse, J Kevin Shoemaker, Eric J Gray, Philip S Clifford

Kinesiology Publications

Studies have reported a greater blood flow response to muscle contractions when the limb is below the heart compared with above the heart, and these results have been interpreted as evidence for a skeletal muscle pump contribution to exercise hyperemia. If limb position affects the blood flow response to other vascular challenges such as reactive hyperemia, this interpretation may not be correct. We hypothesized that the magnitude of reactive hyperemia would be greater with the limb below the heart. Brachial artery blood flow (Doppler ultrasound) and blood pressure (finger-cuff plethysmography) were measured in 10 healthy volunteers. Subjects lay supine with …