Abstracts from Medical Technology,
Physical Therapy, and Nursing
Undergraduate Summer Research Symposium August 10, 2005

Ordered alphabetically by student's last name

Anabolic Steroid Use Found among Teenage Physical/Sexual Abuse Victims with Longitudinal Trends

Julie M. Cullen and Thomas L. Hardie 
Department of Nursing

The objective of this study was to look at steroid usage and prevalence, and to examine the relationship between physical/sexual abuse and anabolic steroid use in high school students nationwide. The study design used was secondary analysis of the Center for Disease Controls’ Youth Risk Behavior Surveys (YRBS). These surveys are conducted for high school student’s grades 9 through 12. The data that was analyzed for this investigation came from the CDC’s National Youth Risk Behavior Survey for years 1999, 2001, and 2003. Logistic regression (backward selection) was used to examine steroid use based on differences in gender, history of being forced to have sex, history of being hit or slapped with intent to harm, and year of survey. Steroid use is increasing as time progresses, with a higher overall percentage of male users. However, females have the highest increases in prevalence rates. The young men and women that reported use of anabolic steroids were far more likely to report being forced to have sexual intercourse and/or being hit or slapped by their boyfriend/girlfriend. Although further research is needed, this study revealed extremely important information for clinicians, sport coaches, trainers, and other health care providers to be aware of when working with adolescents. Funded by National Institutes of Health (Delaware INBRE program)

Spontaneous Baroreflex Sensitivity is Not Effected by an Acute Sodium Load

Kathleen M. DiBiase, E.E. Paul, M.M. Wenner,A.V. Prettyman, M.E.Stillabower, M.D, & W.B. Farquhar
Cardiovascular Research Laboratory, University of Delaware, and Christiana Care Health Services, Newark, DE.

Acute changes in blood pressure (BP) are buffered by mechanoreceptors located in the walls of the aorta and carotid bulb.  These receptors are called baroreceptors, and baroreflex sensitivity (BRS) is often quantified as the relationship (i.e. slope) between R-R interval (the inverse of heart rate) and BP.  Bealer (2003) demonstrated that an acute sodium load decreases BRS in male Sprague-Dawley rats.  This may have relevance for the problem of salt sensitive hypertension.  We hypothesized that an acute sodium load would likewise reduce BRS in humans.  We also tested the hypothesis that individuals with low baseline BRS would respond to a sodium load with the greatest increase in blood pressure (BP).  Thirty-two normotensive subjects (age 26±1 years) were infused with a hypertonic saline (3.0%) solution (rate: 0.15mL/kg/min) for 60 minutes. Beat-to-beat BP was measured noninvasively on the finger using a Finapres, R-R interval via an ECG, and blood draws were taken throughout to track changes in serum sodium, osmolality, and hematocrit.  BRS was assessed using the PRVBRS software.  The infusion caused BP to increase 12±1 mmHg.  BRS did not change during the infusion (pre infusion: 18.7±1.4 msec/mmHg, post-infusion: 18.8±1.2 msec/mmHg, p=N.S.).  There were also no significant correlation between baseline BRS and the sodium-induced increase in BP (r=0.03, r2=0.0007, p=0.89).  We conclude that an acute sodium load in humans does not reduce BRS, and baseline BRS does not correlate with the subsequent sodium-induced rise in BP.  Thus, mechanisms other than BRS must mediate sodium-induced BP changes.  Supported by the INBRE Grant. 

3D Visualization of Volumetric Data

Allen Huang and Karl V. Steiner, 
Delaware Biotechnology Institute
People in many fields are beginning to use virtual reality to train personnel.  Examples are flight simulators and driving simulators.  Industries are now attempting to apply virtual reality to medicine.  Using the software, Amira, volumetric data such as computerized axial tomography (CAT) scans can be transformed into three-dimensional objects. The lungs and heart in the CAT scan data set for the torso, generated by the Christiana Care Health System’s Radiology system, was generated into three-dimensional objects to get familiar with the Amira program.  A mouse data was then obtained from the Department of Biology Micro CT scanner to test if mouse data can be transformed into three-dimensional objects.  The front of the mouse was successfully converted into a three-dimensional object.  From the results, it can be shown that virtual reality and biomedical imaging can be used for medical and scientific purposes.  The three-dimensional objects generated can be used in the future as input data for the creation of virtual surgery or virtual dissection.This research is supported by NIH grant 2 P20 RR016472-04 from the NCRR.

Effects of the Monomeric Disintegrin, Eristostatin, on Melanoma Intracellular Protein Phosphorylation

Brett Hensley, Carrie Paquette-Straub,  and Mary Ann McLane
Department of Medical Technology

Disintegrins, low molecular weight proteins isolated from snake venom, can interact with many cell types and adhesion molecules.  One disintegrin, eristostatin, has the ability to inhibit platelet aggregation and human and murine melanoma cell metastasis.  No mechanism elucidating eristostatin’s mode of inhibition has been discovered thus far.  In this study we evaluated the effect of eristostatin on tyrosine phosphorylation of intracellular proteins within five human melanoma cell lines: C8161, M24met, 1205 LU, MV3, and WM164. We determined that eristostatin significantly changed the protein phosphorylation within all five cell lines. The 1205 LU cell line showed a significant increase in protein phosphorylation from 100-140 kDa, 60-75 kDa, and 37-45 kDa when treated with eristostatin compared to cells treated with water.  M24met cells showed a similar increase in protein phosphorylation at 95-100 kDa and 40-45 kDa when treated with eristostatin.  A decrease in protein phosphorylation was found at 40-45 kDa for eristostatin-treated C8161 cells and at 95-100 kDa and 135-140 kDa for eristostatin-treated MV3 cells.  Eristostatin-treated WM164 cells showed a small decrease in protein phosphorylation at 55-60 kDa and 135-140 kDa as well as a small increase at 65-70 kDa and 125-130 kDa.  By identifying the molecular weight of each tyrosine phosphorylated protein, we hope to identify the specific protein or proteins within the cell and determine their effect on melanoma cell metastasis. Funding provided by the University of Delaware, Science and Engineering Scholarship.

An Intervention Study: A Clinical Comparison of the Rectal Trumpet and Fecal Collector
in Acutely Ill Patients with Fecal Incontinence

Elizabeth Leary and Linda Bucher
Department of Nursing

Diarrhea is a major common health problem that may have serious complications.  Frequently the acutely ill hospitalized patient may develop incontinence due to many factors, including immobility, medication or tube feedings.  If incontinence is uncontrolled, dermatitis of the perineal area may occur within minutes of contact with the  corrosive watery stool.  Furthermore, incontinence may lead to complications such as breakdown in skin integrity, pressure ulcers, infection and sepsis.  These problems not only impact the patients’ overall health negatively, but also the hospital, due to increased length of stay and cost.  There are numerous devices on the market to control incontinence including diapers, fecal incontinence pouches, anal plugs, and rectal catheters.  However, these devices have limitations that can impact the health and comfort of the patient and may be difficult for staff to use and maintain.  Nasopharyngeal airways, also known as nasal trumpets, are commonly used in patients to maintain a patent nasal airway or when an oropharyngeal airway is contraindicated.  The device is also known to protect the nasal mucosa of patients requiring frequent nasal suctioning.  Recent studies have shown the device to have promise controlling fecal incontinence while attached to a collection unit.  The purpose of this study is to compare the rectal trumpet system and the fecal collector, the standard of care at the institution under study.  The primary objective is to determine the effectiveness of the devices in maintaining skin integrity in patients with fecal incontinence.  The secondary objectives include comparing the ease of use, cost effectiveness and level of patient comfort while the device is in place. This project was funded in part by the Southeastern Pennyslvania Chapter of the American Assosiation of Critical Care Nurses and The Wound Ostomy Continence Nursing Foundation.  

Matrix Metalloproteinases 2 and 9 Expression in Melanoma

Dara Missan and Mary E. Miele
Department of Medical Technology

Metastasis is the spread of cancer cells from a primary site to discontinuous sites of the body. The balance of specific genes’ expression within cells impacts the ability of cells to metastasize.  In our laboratory we employ malignant melanoma cells as a model system to study metastasis.  Both increased expression of oncogenes and decreased expression of tumor and/or metastasis suppressor gene can result in melanoma progression. Travel through the extracellular matrix is one of the hallmarks of a successful metastatic cell. The balance of oncogenic proteins such as matrix metalloproteinases (MMPs) 2 and 9, are important in normal cell homeostasis, but may be dysregulated in cancer cells. Other researchers have shown that metastatic ability is associated with increased expression of MMPs. In this project, levels of MMPs 2 and 9 have been examined by reverse transcriptase polymerase chain reaction (RT-PCR); and enzymatic activity by zymography.  Supported by HHMI.

The Effects of Static Stretching on Muscle Contractility and Explosive Force Production

Ryan Robinson2, Cy Wilkins1, Adam Marmon, 1 & Christopher Knight1
1Department of Health, Nutrition & Exercise Sciences, 2Department of Biological Sciences

Static stretching (SS) is common part of exercise or sport preparation.  SS is believed to improve performance (Worrell, 1994) and decrease the risk of musculoskeletal injury (Hartig and Henderson, 1999).  Research indicates that SS causes a decrease in muscle contractility and maximal voluntary force production (Avela, 2004), and perhaps reduced rates of force production.  The aims of this experiment were 1) demonstrate the efficacy of a new custom plantarflexion device and 2) to determine the effects of SS on measures of explosive force production (EFP) including maximal strength and countermovement jump (CMJ) height.  Participants were ten healthy females (18-30 years) who abstained from any lower extremity exercise or stretching 48 hours prior to testing.  Subjects completed three countermovement jumps (CMJ) with 60 seconds of rest between trials.  Subjects then performed five maximal rate of torque development (RTD) trials.  Subjects were instructed to produce their maximal plantarflexion torque as rapidly as possible.  After 10-minutes of rest to remove the effects of post activation potentiation, subjects received three supermaximal electrical stimuli to provide measures of muscle contractility.  Next, subjects underwent a bout of three 45s stretches of the triceps surae.   While seated in the plantarflexion device, an experimenter rotated a bar that dorsiflexed the subject’s ankle to their reported limits of tolerance.  Immediately following stretching, muscle contractility, RTD and CMJ performance were again measured.  The stretching protocol effectively alters muscle contractility with a 24% decrease in peak twitch torque and an 8% reduction in CMJ height.  Funding provided by the Science & Engineering Scholars Program.


Characteristics of Individuals who Undergo Bariatric Surgery: A Review of the Database

Erin Schonewolf and Dr. Erlinda Wheeler
Nursing Department

Over the years, obesity has become a major health problem in the United States.  As more and more people suffer from obesity there is a rising interest in bariatric surgery as a means of weight loss.  Many people who receive the procedure believe it to be a quick fix and do not make the lifestyle changes necessary for the surgery to be successful in achieving weight loss goals.  The purpose of this study is to identify the characteristics of obese individuals who undergo bariatric surgery.  The ultimate goal is to determine the variables that predict non-adherence to follow up care.  The APEX database program at Christiana Care Preventive Medicine & Rehabilitation Institute was utilized to gather the characteristics of the clients involved in their obesity program.  Patient charts were reviewed for any missing data and then entered into the database.  Some of these characteristics include Body Mass Index (BMI) levels, marital status, level of education, employment status, type of surgery, age, and gender.  Results show that the average age is 44 years with a mean BMI level of 49.75 before surgery.  The majority of patients are female, high school graduates, married, have full time jobs, and opt to have the gastric bypass rather than the lap band procedure.  These characteristics are an important foundation to the larger study and can be further analyzed and used, along with other variables, to determine the predictors of noncompliance.    This project was supported by the NIH NCRR INBRE grant to Delaware, grant number 2P20RR016472-04.

Energy Cost and Gait Patterns Associated with Walking Speed

Christopher J. Wagner, S. Farquhar2, William Farquhar2, Darcy S. Reisman1, and Katherine S. Rudolph1
1Department of Physical Therapy and the 2Department of Health, Nutrition, and Exercise Sciences

Healthy individuals walk at a self-selected free speed that expends the least amount of energy and walking at slower speeds increases energy cost.  People with hemiparesis after stroke tend to walk slowly with asymmetrical gait patterns.  It is unknown if the slow speed used by people with hemiparesis is the most energy efficient for them or if increasing their walking speed might improve energy efficiency.   The purpose of this study is to determine the level of energy expenditure in people with hemiparesis when they walk at speeds slower than free walking speed.  We believe that faster walking will decrease the amount of energy used and elicit a more symmetrical gait pattern in people with hemiparesis.  Data are presented from one 20 year old healthy adult male who walked on a treadmill in the UD Physical Therapy Motion Analysis Laboratory.  A 6 camera motion analysis system (Vicon370, Lake Forest, CA) captured joint motion data at free speed, and 15% - 60% slower speeds.  Video data was used to calculate joint angles (Visual 3D, C-Motion, Rockville, MD).  Maximal oxygen consumption (VO2 max) was determined by analyzing the expired gas (TrueOne 2400, ParvoMedics, Sandy, UT) during walking at similar speeds in the Human Performance Laboratory of the Department of Health, Nutrition, and Exercise Sciences. These methods will be used to study the impact of velocity on walking patterns and energy cost of people with hemiparesis and develop better rehabilitation programs for the stroke population. This project is funded by the Science and Engineering Scholars Program and the National Institutes of Health R21 HD047468-01.

Peak Rates of Torque Development and Muscle Activation during Rapid Plantarflexion Torque Production

Cy Wilkins1, Ryan Robinson2 Adam Marmon, 1 & Christopher Knight1
1Department of Health, Nutrition & Exercise Sciences, 2Department of Biological Sciences

During rapid movements such as throwing or kicking, co-contraction of the antagonist musculature is necessary for joint stability. Intuitively, excessive antagonist joint torque may decrease the peak rates of torque development (RTD) and therefore movement velocity.  A second determinant of RTD is the amplitude of initial muscular activation in agonist musculature (onset EMG).   The first aim of this experiment was to determine whether greater peak RTD could be achieved with slightly submaximal effort that may reduce co-contraction.  The second aim was to obtain recordings of muscular activity patterns during contractions resulting in a range of different peak RTD scores.  In two experimental conditions, different instructions regarding effort were intended to modify the muscular activation patterns during the performance of peak RTD trials. It was hypothesized that less co-contraction and greater onset EMG would be associated with greater peak rates of torque development. Subjects were instructed to a) produce plantarflexion force as hard and fast as possible and to hold their peak force for two seconds or b) to produce plantarflexion torque above a 50% maximal value as fast as possible with immediate subsequent relaxation.  Condition b produced quick force impulses to approximately 75% MVC.  Subjects were provided feedback of their force in real time on a computer monitor.  Surface electromyography was taken from soleus, medial and lateral heads of the gastrocnemius, and tibialis anterior.  This experiment provides the basis for subsequent research on the recovery of peak RTD in older adults.   Funded by the College of Health Sciences.

Links: Summer 2005 Undergraduate Research Symposium, Symposium Abstracts from other Colleges and Departments,
Undergraduate Research Summer Enrichment ProgramUnversity of Delaware Undergraduate Research Program, Howard Hughes Undergraduate Program.
Created  4 August 2005. Last up dated 16 August 2005 by Hal White
Copyright 2005, University of Delaware