Medical Sciences Commons^™

Living In A Material World: How Visual Cues To Material Properties Affect The Way That We Lift Objects And Perceive Their Weight, Gavin Buckingham, Jonathan Cant, Melvyn Goodale

Gavin Buckingham

The visual properties of an object provide many cues as to the tensile strength, compliance, and density of the material from which it is made. However, it is not well understood how these implicit associations affect our perceptions of these properties and how they determine the initial forces that are applied when an object is picked up. Here we examine the effects of these cues on such forces by using the classic "material-weight illusion" (MWI). Grip and load forces were measured in three experiments as participants lifted cubes made from metal, wood, and expanded polystyrene. These cubes were adjusted to …

Pillows For Pain, Michael Lock

Michael Lock

No abstract provided.

Effect Of Short-Term Use Of Testosterone Enanthate On Personality And Mood In Healthy Young Males, Rosanne Coutts, Shane Rogerson, Glen Deakin, Sonya Marshall-Gradisnik, Rudi Meir, Shi Zhou, Robert Weatherby

Sonya Marshall-Gradisnik

Supported by notions that supplementation enhances mental, physical and sexual powers steroid users focus on its ability to influence emotional state, and more profoundly shape identity. The notion of anabolic steroid hormone induced changes in biological drive, causing increased anger and hostility is anecdotal but inconclusive.

PURPOSE:

To quantify the existence of either Personality or Mood effects that may be observed during and following six weeks of the administration of controlled doses of testosterone enanthate.

METHODS: Eighteen males (25±4.0 yrs) were match paired and randomly assigned in a double blind manner to either a testosterone enanthate or placebo group. During …

Effects Of Estrogen On The Mechanical Behavior Of The Human Achilles Tendon In Vivo, Adam Bryant, Ross Clark, Simon Bartold, Aron Murphy, Kim Bennell, Erik Hohmann, Sonya Marshall-Gradisnik, Craig Payne, Kay Crossley

Sonya Marshall-Gradisnik

The purpose of this study was to elucidate the effect of normal fluctuating [nonmonophasic oral contraceptive pill (MOCP) users] and low, consistent (MOCP users) endogenous plasma estrogen levels on the strain behavior of the Achilles tendon in vivo. Twenty women (age 28.0 ± 4.2 yr, height 1.67 ± 0.07 m, mass 61.6 ± 6.8 kg) who had been using the MOCP for at least 12 mo together with 20 matched women who were non-MOCP users (age 31.9±7.3 yr, height 1.63 ± 0.05 m, mass 62.5 ± 5.9 kg) participated in this study. Non-MOCP users were tested at the time of …

Characterization Of The Α1-Adrenoceptor Subtype Mediating Contractions Of The Pig Internal Anal Sphincter, K. Mills, Natasha Hausman, Russ Chess-Williams

Russ Chess-Williams

Background and purpose: The internal anal sphincter has been shown to contract in response to a1-adrenoceptor stimulation and therefore a1-adrenoceptor agonists may be useful in treating faecal incontinence. This study characterizes the a1-adrenoceptor subtype responsible for mediating contraction of the internal anal sphincter of the pig.

Experimental approach: The potency of agonists and the affinities of several receptor subtype selective antagonists were determined on smooth muscle strips for the pig internal anal sphincter. Cumulative concentration–response curves were performed using phenylephrine and noradrenaline.

Key results: The potency of the a1A-adrenoceptor selective agonist A61603 (pEC50¼7.79±0.04) was 158-fold greater than that for noradrenaline …

Contractile Properties Of The Pig Bladder Mucosa In Response To Neurokinin A: A Role For Myofibroblasts?, P Sadananda, Russ Chess-Williams, E Burcher

Russ Chess-Williams

Background and purpose: The bladder urothelium is now known to have active properties. Our aim was to investigate the contractile properties of the urinary mucosa in response to the tachykinin neurokinin A (NKA) and carbachol. Experimental approach: Discrete concentration–response curves for carbachol and NKA were obtained in matched strips of porcine detrusor, mucosa and intact bladder, suspended in organ baths. The effects of inhibitors and tachykinin receptor antagonists were studied on NKA-mediated contractions in mucosal strips. Intact sections of bladder and experimental strips were processed for histology and immunohistochemistry. Key results: All types of strips contracted to both carbachol and …

Multiple Loci Within The Major Histocompatibility Complex Confer Risk Of Psoriasis, Bing-Jian Feng, Liang-Dan Sun, Razieh Soltani-Arabshahi, Anne M. Bowcock, Rajan P. Nair, Philip Stuart, James T. Elder, Steven J. Schrodi, Ann B. Begovich, Goncalo R. Abecasis, Xue-Jun Zhang, Kristina P. Callis Duffin, Gerald G. Krueger, David E. Goldgar

Steven J Schrodi

Psoriasis is a common inflammatory skin disease characterized by thickened scaly red plaques. Previously we have performed a genome-wide association study (GWAS) on psoriasis with 1,359 cases and 1,400 controls, which were genotyped for 447,249 SNPs. The most significant finding was for SNP rs12191877, which is in tight linkage disequilibrium with HLA-Cw*0602, the consensus risk allele for psoriasis. However, it is not known whether there are other psoriasis loci within the MHC in addition to HLA-C. In the present study, we searched for additional susceptibility loci within the human leukocyte antigen (HLA) region through in-depth analyses of the GWAS data; …

Cognition As An Outcome Measure In Schizophrenia, Amresh Srivastava

Amresh Srivastava

No abstract provided.

Atypical Antipsychotics And Cognitive Enhancement In Schizophrenia: The Current Status, Amresh Srivastava

Amresh Srivastava

No abstract provided.

Switching And Selecting Atypical Antipsychotic Drugs: Quetiapine, Amresh Srivastava

Amresh Srivastava

No abstract provided.

Physical Activity And Neurocognitive Function Across The Lifespan, Jason Themanson, Charles Hillman, Sarah Buck

Jason R. Themanson, Ph.D

No abstract provided.

Regression When The Predictors Are Images, Philip T. Reiss

Philip T. Reiss

No abstract provided.

Acute Aerobic Exercise Effects On Event-Related Brain Potentials, Jason Themanson, Charles Hillman, Matthew Pontifex

Jason R. Themanson, Ph.D

No abstract provided.

A Fully Automated Non-External Marker 4d-Ct Sorting Algorithm Using A Serial Cine Scanning Protocol, Greg Carnes, Stewart Gaede, Edward Yu, Jake Van Dyk, Jerry Battista, Ting-Yim Lee

Edward Yu

Current 4D-CT methods require external marker data to retrospectively sort image data and generate CT volumes. In this work we develop an automated 4D-CT sorting algorithm that performs without the aid of data collected from an external respiratory surrogate. The sorting algorithm requires an overlapping cine scan protocol. The overlapping protocol provides a spatial link between couch positions. Beginning with a starting scan position, images from the adjacent scan position (which spatial match the starting scan position) are selected by maximizing the normalized cross correlation (NCC) of the images at the overlapping slice position. The process was continued by 'daisy …

Rightward Biases During Bimanual Reaching, Gavin Buckingham, David Carey

Gavin Buckingham

Two experiments were carried out to investigate whether attention is biased toward the right hand of right handers during bimanual coordination (Peters 1981). A novel discontinuous double-step reaching task was developed, where right-handed participants executed a bimanual reach followed by a left or right hand unimanual reach. Asymmetries in the downtime between the bimanual and unimanual reach portions (the refractory period) were used to infer the direction of attention. A shorter right hand refractory period was found in the first experiment, indicating a rightward bias in attention. In a second experiment, shifting the focus of attention during the bimanual portion …

Nontraditional Epilepsy Treatment Approaches, Michael A. Rogawski, Gregory L. Holmes

Michael A. Rogawski

Overview of articles published in a special issue of Neurotherapeutics (April 2009) on nontraditional (non-drug) epilepsy treatment approaches. From the Fourth Workshop on New Horizons in the Development of Antiepileptic Drugs: Nontraditional Approaches to Treat Epilepsy, which was held at the Clontarf Castle, Dublin, March 5-7, 2008.

Convection-Enhanced Delivery In The Treatment Of Epilepsy, Michael A. Rogawski

Michael A. Rogawski

Convection-enhanced delivery (CED) is a novel drug-delivery technique that uses positive hydrostatic pressure to deliver a fluid containing a therapeutic substance by bulk flow directly into the interstitial space within a localized region of the brain parenchyma. CED circumvents the blood-brain barrier and provides a wider, more homogenous distribution than bolus deposition (focal injection) or other diffusion-based delivery approaches. A potential use of CED is for the local delivery of antiseizure agents, which would provide an epilepsy treatment approach that avoids the systemic toxicities of orally administered anti-epileptic drugs and bystander effects on nonepileptic brain regions. Recent studies have demonstrated …

Gender Differences In Presenting And Prodromal Stroke Symptoms, Eileen Stuart-Shor, Gregory A. Wellenius, Donna Dello Iacono, Murray A. Mittleman

Eileen Stuart-Shor

BACKGROUND AND PURPOSE: Prompt recognition of stroke symptoms is critical to timely treatment and women have increased delay to treatment. Women may be more likely to present with atypical symptoms, but this hypothesis has not been extensively evaluated.

METHODS: We examined gender differences in the prevalence of presenting and prodromal stroke symptoms among 1107 consecutive patients hospitalized with neurologist-confirmed acute ischemic stroke. Patient demographics, clinical variables, and stroke symptoms were abstracted from medical records by trained abstractors using standardized forms. Estimates were age-standardized to the age distribution of men and women combined. Presenting symptoms occurred within 24 hours of incident …

Smoothing Parameter Selection For A Class Of Semiparametric Linear Models, Philip T. Reiss, R. Todd Ogden

Philip T. Reiss

Spline-based approaches to nonparametric and semiparametric regression, as well as to regression of scalar outcomes on functional predictors, entail choosing a parameter controlling the extent to which roughness of the fitted function is penalized. In this paper we demonstrate that the equations determining two popular methods for smoothing parameter selection, generalized cross-validation and restricted maximum likelihood, share a similar form that allows us to prove several results common to both, and to derive a condition under which they yield identical values. These ideas are illustrated by application of functional principal component regression, a method for regressing scalars on functions, to …

Chapter 20:The Impact Of Probiotics On Maternal And Child Health: Clinical Evidence., Kingsley Anukam, Gregor Reid

Kingsley C Anukam

Key Points • Alleviating the problems of maternal and child health in countries with large malnourished and/or HIV-infected populations, will require multidimensional approaches including holistic and pharmaceutical interventions. • Urogenital infections have a major role in preterm labor and the well-being of newborns. • Probiotics show potential in reducing the risk of recurrence of urinary tract infection (UTI). • There is some evidence to suggest that probiotics can have a role to play in bacterial vaginosis (BV) and maternal health. • The role of probiotics in a number of newborn, and childhood diseases is reviewed in this chapter.

Responding, Rather Than Reacting To, Race In Biomedical Research: A Response To Professors Caulfield And Mwaria, Michael J. Malinowski

Michael J. Malinowski

This Commentary is part of a colloquy on race-based genetics research.

Effects Of Rsa Feedback On Post-Traumatic Stress Disorder Symptomatology, Phillip Fourie

Phillip Fourie

Post-traumatic Stress Disorder (PTSD) is one of the Anxiety Disorders, with particularly debilitating effects due to flashbacks and hypervigilance in daily life. Treatments commonly focus upon either pharmacological or psychotherapeutic modalities, but there is often a need to merge both of these approaches so as to deal effectively with the somatic as well as the psychological symptoms of PTSD in particular clients. This case study reports the application of a combined approach, using both client-centered counselling plus biofeedback of respiratory sinus arrhythmia to train the client to control his exaggerated sympathetic nervous system responses. Results indicated that both physiological and …

Antioxidant Enzyme Gene Transfer For Ischemic Diseases, Jian Wu

jian duan wu

1. Adv Drug Deliv Rev. 2009 Apr 28;61(4):351-63. Epub 2009 Feb 20. Antioxidant enzyme gene transfer for ischemic diseases. Wu J, Hecker JG, Chiamvimonvat N. Department of Internal Medicine, Transplant Research Program, University of California, Davis Medical Center, Sacramento, CA 95817, USA. jdwu@ucdavis.edu The balance of redox is pivotal for normal function and integrity of tissues. Ischemic insults occur as results of a variety of conditions, leading to an accumulation of reactive oxygen species (ROS) and an imbalanced redox status in the tissues. The oxidant stress may activate signaling mechanisms provoking more toxic events, and eventually cause tissue damage. Therefore, …

The Use Of Ct Density Changes At Internal Tissue Interfaces To Correlate Internal Organ Motion With An External Surrogate, Stewart Gaede, Gregory Carnes, Edward Yu, Jake Van Dyk, Jerry Battista, Ting-Yim Lee

Edward Yu

The purpose of this paper is to describe a non-invasive method to monitor the motion of internal organs affected by respiration without using external markers or spirometry, to test the correlation with external markers, and to calculate any time shift between the datasets. Ten lung cancer patients were CT scanned with a GE LightSpeed Plus 4-Slice CT scanner operating in a ciné mode. We retrospectively reconstructed the raw CT data to obtain consecutive 0.5 s reconstructions at 0.1 s intervals to increase image sampling. We defined regions of interest containing tissue interfaces, including tumour/lung interfaces that move due to breathing …

A Dissociation Between Perception And Action In The Material‐Weight Illusion, Gavin Buckingham, Jonathan Cant, Kai-Ling Kao, Melvyn Goodale

Gavin Buckingham

We examined what forces are applied to objects that elicit this illusion when they are lifted.We predicted that:

(1) Forces on early trials will scale to each participant’s expectations of how much a particular block will weigh ‐ excessive force will be applied to the metal block and insufficient force applied to the polystyrene block.

(2) Forces on later trials will scale to the real weight of each block ‐ identical levels of force applied to all the blocks.

(3) MWI will persist throughout ‐ polystyrene block will feel the heaviest, metal block will feel the lightest.

Reduction Of Prelimbic Inhibitory Gating Of Auditory Evoked Potentials After Fear Conditioning, Howard Cromwell

Howard Casey Cromwell

Inhibitory gating (IG) is a basic central nervous system process for filtering repetitive sensory information. Although IG deficits coincide with cognitive and emotional dysfunction in a variety of neuropsychiatric disorders, limited research has been completed on the basic, functional nature of IG. Persistent IG occurs in rat prelimbic medial prefrontal cortex (mPFC), a crucial site for modulating emotional learning. To investigate the interaction of affect and IG, we recorded local field potentials (LFP) directly from prelimbic mPFC and examined the influence of tone-shock fear conditioning (FC) on IG. Behavioral reactions during IG were observed before and after FC, and increase …

Topiramate Reduces Excitability In The Basolateral Amygdala By Selectively Inhibiting Gluk1 (Glur5) Kainate Receptors On Interneurons And Positively Modulating Gaba-A Receptors On Principal Neurons, Maria Braga, Vassiliki Aroniadou-Anderjaska, He Li, Michael Rogawski

Michael A. Rogawski

Topiramate [2,3:4,5-bis-O-(1-methylethylidene)-beta-D-fructopyranose sulfamate] is a structurally novel antiepileptic drug that has broad efficacy in epilepsy, but the mechanisms underlying its therapeutic activity are not fully understood. We have found that topiramate selectively inhibits GluK1 (GluR5) kainate receptor-mediated excitatory postsynaptic responses in rat basolateral amygdala (BLA) principal neurons and protects against seizures induced by the GluK1 kainate receptor agonist (R,S)-2-amino-3-(3-hydroxy-5-tert-butylisoxazol-4-yl)propanoic acid (ATPA). Here, we demonstrate that topiramate also modulates inhibitory function in the BLA. Using whole-cell recordings in rat amygdala slices, we found that 0.3 to 10 microM topiramate 1) inhibited ATPA-evoked postsynaptic currents recorded from BLA interneurons; 2) suppressed ATPA-induced …

Post-Operative Extended Volume External Beam Radiation Therapy In High Risk Esophageal Cancer Patients: A Prospective Experience, E. Yu, P. Tai, J. Younus, R. Malthaner, P. Truong, L. Stitt, G. Rodrigues, R. Ash, R. Dar, B. Yaremko, A. Tomiak, B. Dingle, M. Sanatani, M. Vincent, W. Kocha, D. Fortin, R. Inculet

Edward Yu

Background and purpose: Extended volume external beam radiation therapy (RT) following esophagectomy is controversial. This prospective study evaluates the feasibility of extended volume RT treatment in high-risk esophagectomy patients with cervical anastomosis receiving post–operative combined chemo-radiation therapy. Patients and methods: From 2001-2006, 15 patients with resected esophageal cancer were prospectively accrued to this pilot study, to evaluate the adverse effects of extended volume RT. Eligibility criteria were pathologically proven esophageal malignancy, T3-4, N0-1, disease amenable to surgical resection and esophagectomy with or without resection margin involvement. Patients with distant metastases (M1) and patients treated with previous RT were excluded. All …

Grasping And Lifting Different Materials, Gavin Buckingham, Jonathan Cant, Melvyn Goodale

Gavin Buckingham

The material from which an object is made can determine how heavy it feels (Seashore, 1899). Interestingly, a metal block that has been adjusted to have the same size and mass as a polystyrene block will feel lighter than the polystyrene block. We recently showed that participants experiencing this material-weight illusion’ (MWI) do not apply forces that match their perceptual experience of heaviness ‐ just like in the size‐weight illusion ( Flanagan & Beltzner, 2000).

Our previous study showed that forces on early trials were scaled to each participant’s expectations of how much a particular block should weigh ‐ excessive …

Nerve, Muscle, Blood, Toil, Tears, And Sweat: England’S Pioneering Biophysicist, Soldier, And Statesman, Arshad M. Khan

Arshad M. Khan, Ph.D.

No abstract provided.