Internists, Oncology Specialist (cancer)
13 years of experience

Accepting new patients
Pottstown Memorial Medical Center
1600 E High St
Pottstown, PA 19464
Locations and availability (3)

Education ?

Medical School Score
Philadelphia College of Osteopathic Medicine (1997)
  • Currently 1 of 4 apples

Awards & Distinctions ?

American Board of Internal Medicine
American Society of Hematology

Affiliations ?

Dr. Stevens is affiliated with 1 hospitals.

Hospital Affilations



  • Pottstown Memorial Medical Center
    1600 E High St, Pottstown, PA 19464
    • Currently 2 of 4 crosses
  • Publications & Research

    Dr. Stevens has contributed to 54 publications.
    Title Using Touch or Imagined Touch to Compensate for Loss of Proprioception: a Case Study.
    Date April 2012
    Journal Neurocase

    Proprioception is the sense of the position of one's own body. Here, we present a case study of an individual with proprioceptive loss in one limb consequent to stroke. The patient indicated that merely touching his impaired arm with his unimpaired arm temporarily restored his proprioception. We examined this claim and the effects of imagined touch by the unimpaired arm. Assessments were made using three-dimensional tracking of reaching trajectories towards targets in conditions of light and darkness. Both actual and imagined touching significantly reduced movement error and jerk, specifically for targets located in regions that both hands would be able to reach.

    Title Nonfatal Bathroom Injuries Among Persons Aged ≥15 Years--united States, 2008.
    Date February 2012
    Journal Journal of Safety Research

    Information about where nonfatal unintentional injuries occur is limited, but bathrooms commonly are believed to be a hazardous location.

    Title Student Nurses' Career Preferences for Working with Older People: a Replicated Longitudinal Survey.
    Date November 2011
    Journal International Journal of Nursing Studies

    The world's populations are ageing and the need for nurses and health care workers from all disciplines to manage this phenomenon is increasing. Yet the literature and previous research undertaken by the author reveal consistently that working with older people is ranked poorly as a perceived career destination of student of nursing.

    Title Timing of Anticipatory Muscle Tensing Control: Responses Before and After Expected Impact.
    Date March 2011
    Journal Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale

    It is widely accepted that human motor control is anticipatory in nature. Previous studies have used electromyography (EMG) to examine muscle responses to falling objects and identified anticipatory muscle tensing (AMT) as a spike in activation that occurs prior to object impact. Some studies have suggested that humans use an internal model of gravity to mediate precisely timed AMT responses. The present study further examines predictive motor control through the analysis of AMT during an object catching task. For some trials, participants watched an object falling toward the hand; for other trials, their eyes were closed. For some trials, the object fell downward and impacted the hand; for other randomly selected trials, the object abruptly stopped 12 cm above the hand, enabling an assessment of the effect of impact anticipation independent of the reflexive tactile response associated with an actual impact. In Experiment 1, AMT did not shift for approximately 113 ms after the abrupt stop of the ball. In Experiment 2, we randomly varied the start height of the object and found well-timed AMT with a 129-ms lag time. A control system based on simple memory for fall time duration cannot explain these findings. We argue that an AMT control system with a lag time of approximately 121 ms could not perform with human levels of accuracy without accounting for the acceleration of downward moving objects.

    Title Mapping Solvation Dynamics at the Function Site of Flavodoxin in Three Redox States.
    Date January 2011
    Journal Journal of the American Chemical Society

    Flavoproteins are unique redox coenzymes, and the dynamic solvation at their function sites is critical to the understanding of their electron-transfer properties. Here, we report our complete characterization of the function-site solvation of holoflavodoxin in three redox states and of the binding-site solvation of apoflavodoxin. Using intrinsic flavin cofactor and tryptophan residue as the local optical probes with two site-specific mutations, we observed distinct ultrafast solvation dynamics at the function site in the three states and at the related recognition site of the cofactor, ranging from a few to hundreds of picoseconds. The initial ultrafast motion in 1-2.6 ps reflects the local water-network relaxation around the shallow, solvent-exposed function site. The second relaxation in 20-40 ps results from the coupled local water-protein fluctuation. The third dynamics in hundreds of picoseconds is from the intrinsic fluctuation of the loose loops flanking the cofactor at the function site. These solvation dynamics with different amplitudes well correlate with the redox states from the oxidized form, to the more rigid semiquinone and to the much looser hydroquinone. This observation of the redox control of local protein conformation plasticity and water network flexibility is significant, and such an intimate relationship is essential to the biological function of interprotein electron transfer.

    Title Coexpression of Potato Type I and Ii Proteinase Inhibitors Gives Cotton Plants Protection Against Insect Damage in the Field.
    Date September 2010
    Journal Proceedings of the National Academy of Sciences of the United States of America

    Potato type I and II serine protease inhibitors are produced by solanaceous plants as a defense mechanism against insects and microbes. Nicotiana alata proteinase inhibitor (NaPI) is a multidomain potato type II inhibitor (pin II) that is produced at high levels in the female reproductive tissues of the ornamental tobacco, Nicotiana alata. The individual inhibitory domains of NaPI target the major classes of digestive enzymes, trypsin and chymotrypsin, in the gut of lepidopteran larval pests. Although consumption of NaPI dramatically reduced the growth and development of a major insect pest, Helicoverpa punctigera, we discovered that surviving larvae had high levels of chymotrypsin activity resistant to inhibition by NaPI. We found a potato type I inhibitor, Solanum tuberosum potato type I inhibitor (StPin1A), was a strong inhibitor of the NaPI-resistant chymotrypsin activity. The combined inhibitory effect of NaPI and StPin1A on H. armigera larval growth in the laboratory was reflected in the increased yield of cotton bolls in field trials of transgenic plants expressing both inhibitors. Better crop protection thus is achieved using combinations of inhibitors in which one class of proteinase inhibitor is used to match the genetic capacity of an insect to adapt to a second class of proteinase inhibitor.

    Title Ultrafast Proteinquake Dynamics in Cytochrome C.
    Date July 2010
    Journal Journal of the American Chemical Society

    We report here our systematic studies of the heme dynamics and induced protein conformational relaxations in two redox states of ferric and ferrous cytochrome c upon femtosecond excitation. With a wide range of probing wavelengths from the visible to the UV and a site-directed mutation we unambiguously determined that the protein dynamics in the two states are drastically different. For the ferrous state the heme transforms from 6-fold to 5-fold coordination with ultrafast ligand dissociation in less than 100 fs, followed by vibrational cooling within several picoseconds, but then recombining back to its original 6-fold coordination in 7 ps. Such impulsive bond breaking and late rebinding generate proteinquakes and strongly perturb the local heme site and shake global protein conformation, which were found to completely recover in 13 and 42 ps, respectively. For the ferric state the heme however maintains its 6-fold coordination. The dynamics mainly occur at the local site, including ultrafast internal conversion in hundreds of femtoseconds, vibrational cooling on the similar picosecond time scale, and complete ground-state recovery in 10 ps, and no global conformation relaxation was observed.

    Title Biomarkers of Organophosphorus Nerve Agent Exposure: Comparison of Phosphylated Butyrylcholinesterase and Phosphylated Albumin After Oxime Therapy.
    Date April 2010
    Journal Archives of Toxicology

    Organophosphorus nerve agents inhibit the activity of cholinesterases by phosphylation of the active site serine. In addition, sarin, cyclosarin, soman and tabun have been shown to phosphylate a tyrosine residue in albumin. Therapies against nerve agent poisoning include the use of oximes to reactivate inhibited cholinesterases by displacement of the phosphyl moiety and hence detectable levels of adducts with cholinesterases may be reduced. Adducts with tyrosine have been shown to be persistent in the guinea pig in the presence of oxime therapy. Plasma samples obtained from an animal study aimed at improving therapy against nerve agent poisoning were used to compare the suitability of tyrosine and butyrylcholinesterase (BuChE) adducts as biomarkers of nerve agent exposure after treatment with therapeutic oximes. Under the terms of the project licence, these samples could be collected only on death of the animal, which occurred within hours of exposure or when culled at 23 or 24 days. Tyrosine adducts were detected in all samples collected following intra-muscular administration of twice the LD50 dose of the respective nerve agent. Aged BuChE adducts were detected in samples collected within a few hours after administration of soman and tabun, but not after 23 or 24 days. No BuChE adducts were detected in animals exposed to sarin and cyclosarin where samples were collected only after 23 or 24 days.

    Title Ultrafast Dynamics of Resonance Energy Transfer in Myoglobin: Probing Local Conformation Fluctuations.
    Date March 2010
    Journal The Journal of Physical Chemistry. B

    We report here our systematic characterization of resonance energy transfer between intrinsic tryptophan and the prosthetic heme group in myoglobin in order to develop a novel energy-transfer pair as a molecular ruler in heme proteins to study local conformation fluctuations. With site-directed mutagenesis, we designed four tryptophan mutants along the A-helix of myoglobin and each mutant contains only a single tryptophan-heme energy-transfer pair. With femtosecond resolution, we observed, even at separation distances of 15-25 A, ultrafast energy transfer in tens to hundreds of picoseconds. On these time scales, the donor and acceptor cannot be randomized and the orientation factor in Forster energy transfer is highly restricted. Thus, direct measurement of the orientation-factor changes at different mutation sites reveals relative local structure flexibility and conformation fluctuations as particularly demonstrated here for positions of tryptophan 7 and 14. More importantly, the local environment relaxation occurs on the similar time scales of the energy transfer dynamics, resulting in a nonequilibrium dynamic process. With femtosecond- and wavelength-resolved fluorescence dynamics, we are able to determine the time scales of such nonequilibrium energy-transfer dynamics and elucidate the mechanism of the nonexponential energy-transfer dynamics caused by local dynamic heterogeneity and/or local environment relaxation.

    Title Interactions Between Imagined Movement and the Initiation of Voluntary Movement: a Tms Study.
    Date June 2009
    Journal Clinical Neurophysiology : Official Journal of the International Federation of Clinical Neurophysiology

    The purpose was to examine motor imagery-induced enhancement in corticospinal excitability during a reaction time (RT) task.

    Title Fall-related Traumatic Brain Injury Deaths and Hospitalizations Among Older Adults--united States, 2005.
    Date October 2008
    Journal Journal of Safety Research

    PROBLEM: Among older adults, both unintentional falls and traumatic brain injuries (TBI) result in significant morbidity and mortality; however, only limited national data on fall-related TBI are available. METHOD: To examine the relationship between older adult falls and TBI deaths and hospitalizations, CDC analyzed 2005 data from the National Center for Health Statistics' National Vital Statistics System and the Agency for Healthcare Research and Quality's Nationwide Inpatient Sample. RESULTS: In 2005, among adults>or=65 years, there were 7946 fall-related TBI deaths and an estimated 56,423 hospitalizations for nonfatal fall-related TBI in the United States. Fall-related TBI accounted for 50.3% of unintentional fall deaths and 8.0% of nonfatal fall-related hospitalizations. SUMMARY: These findings underscore the need for greater dissemination and implementation of evidence-based fall prevention interventions.

    Title Self-reported Falls and Fall-related Injuries Among Persons Aged>or=65 Years--united States, 2006.
    Date October 2008
    Journal Journal of Safety Research

    PROBLEM: In 2005, 15,802 persons aged>or=65 years died from fall injuries. How many older adults seek outpatient treatment for minor or moderate fall injuries is unknown. METHOD: To estimate the percentage of older adults who fell during the preceding three months, the Centers for Disease Control and Prevention (CDC) analyzed data from two questions about falls included in the 2006 Behavioral Risk Factor Surveillance System (BRFSS) survey. RESULTS: Approximately 5.8 million (15.9%) persons aged>or=65 years reported falling at least once during the preceding three months, and 1.8 million (31.3%) of those who fell sustained an injury that resulted in a doctor visit or restricted activity for at least one day. DISCUSSION: This report presents the first national estimates of the number and proportion of persons reporting fall-related injuries associated with either doctor visits or restricted activity. SUMMARY: The prevalence of falls reinforces the need for broader use of scientifically proven fall-prevention interventions. IMPACT ON INDUSTRY: Falls and fall-related injuries represent an enormous burden to individuals, society, and to our health care system. Because the U.S. population is aging, this problem will increase unless we take preventive action by broadly implementing evidence-based fall prevention programs. Such programs could appreciably decrease the incidence and health care costs of fall injuries, as well as greatly improve the quality of life for older adults.

    Title Practice Parameter: Assessing Patients in a Neurology Practice for Risk of Falls (an Evidence-based Review): Report of the Quality Standards Subcommittee of the American Academy of Neurology.
    Date March 2008
    Journal Neurology

    OBJECTIVE: To develop a practice parameter for screening methods and assessments of risk for falls pertaining to patients likely to be seen in neurology practices. METHODS: Relevant literature was systematically reviewed and strength of evidence classified based on the American Academy of Neurology's criteria (Level A: established; Level B: probable; Level C: possible). RESULTS: An increased risk of falls is established among persons with diagnoses of stroke, dementia, and disorders of gait and balance (Level A) and probable among patients with Parkinson disease, peripheral neuropathy, lower extremity weakness or sensory loss, and substantial vision loss (Level B). A history of falling in the past year strongly predicts the likelihood of future falls (Level A). Screening measures have been developed to further assess risks of falls, including functional assessments that may be useful (Levels B and C). Several of these assess overlapping neurologic functions--i.e., gait, mobility, and balance--and there is insufficient evidence to assess whether they offer benefit beyond that provided by a standard neurologic examination. CONCLUSIONS: Patients with neurologic or general conditions associated with an increased risk of falling should be asked about recent falls and further examined for the presence of specific neurologic deficits that predict falls, which include gait and balance disorders; deficits of lower extremity strength, sensation, and coordination; and cognitive impairments. If substantial risks of falls are identified, appropriate interventions that are described in other evidence-based guidelines may be considered.

    Title Seasonal Patterns of Fatal and Nonfatal Falls Among Older Adults in the U.s.
    Date January 2008
    Journal Accident; Analysis and Prevention

    INTRODUCTION: While many believe that older adults fall more often during the winter months, research on this is inconclusive. This study used nationally representative data from 2001 to 2002 to examine unintentional fatal fall rates among older men and women by season and climate, and nonfatal fall rates by season. METHODS: We studied fatal and nonfatal unintentional falls among U.S. adults aged > or =65 during December 2001-November 2002 by season. Fatal fall data were obtained from National Center for Health Statistics' annual mortality tapes; nonfatal fall data for injuries treated in emergency departments were obtained from the National Electronic Injury Surveillance System All Injury Program. Fatal falls were also analyzed by climate based on each state's average January 1, 2001 temperature (colder climates < or =32 degrees F (0 degrees C) and warmer climates >32 degrees F (0 degrees C)). RESULTS: From December 2001 through November 2002, neither fatal nor nonfatal fall injury rates showed any seasonal patterns. For fatal falls, the average rate was 9.1 percent higher in colder climates, regardless of season. CONCLUSION: Among older adults, fatal fall rates appear to be influenced more by climate than by season. Additional research is needed to clarify the mechanisms underlying these observations.

    Title Visualization of Complex Automotive Data.
    Date December 2007
    Journal Ieee Computer Graphics and Applications

    Making complicated data easier to understand has always been a challenge. Four types of visualization applications (CAD, generalized, specialized, and custom) have successfully been used by automotive manufacturers such as General Motors to help meet this goal. Here are some ways that common processes can be developed for all types of visualization.

    Title Motor Imagery of Gait: a Quantitative Approach.
    Date October 2007
    Journal Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale

    Motor imagery (MI) is widely used to study cognitive aspects of the neural control of action. Prior studies were mostly centred on hand and arm movements. Recently a few studies have used imagery tasks to explore the neurophysiology of human gait, but it remains unclear how to ascertain whether subjects actually perform imagery of gait as requested. Here we describe a new experimental protocol to quantify imagery of gait, by behaviourally distinguishing it from visual imagery (VI) processes and by showing its temporal correspondence with actual gait. Fourteen young healthy subjects performed two imagery tasks and an actual walking (AW) task. During both imagery tasks subjects were sitting on a chair and faced a computer screen that presented photographs of walking trajectories. During one task (MI), subjects had to imagine walking along the walking trajectory. During the other task (VI), subjects had to imagine seeing a disc moving along the walking trajectory. During the AW task, subjects had to physically walk along the same walking trajectory as presented on the photographs during the imagery tasks. We manipulated movement distance by changing the length of the walking trajectory, and movement difficulty by changing the width of the walking trajectory. Subjects reported onset and offset of both actual and imagined movements with a button press. The time between the two button presses was taken as the imagined or actual movement time (MT). MT increased with increasing path length and decreasing path width in all three tasks. Crucially, the effect of path width on MT was significantly stronger during MI and AW than during VI. The results demonstrate a high temporal correspondence between imagined and AW, suggesting that MI taps into similar cerebral resources as those used during actual gait. These results open the possibility of using this protocol for exploring neurophysiological correlates of gait control in humans.

    Title The Costs of Fatal and Non-fatal Falls Among Older Adults.
    Date August 2007
    Journal Injury Prevention : Journal of the International Society for Child and Adolescent Injury Prevention

    To estimate the incidence and direct medical costs for fatal and non-fatal fall injuries among US adults aged >or=65 years in 2000, for three treatment settings stratified by age, sex, body region, and type of injury.

    Title Recent Trends in Mortality from Unintentional Injury in the United States.
    Date October 2006
    Journal Journal of Safety Research

    INTRODUCTION: Recent observations suggest that the unintentional injury mortality rate may be increasing in the United States for the first time since 1979. METHOD: This study examined trends in unintentional injury mortality by sex, race, mechanism, and age group to better understand these increases. RESULTS: From 1992 to 2002, mortality increased 11.0% (6.5% for males, 18.5% for females). The mortality rate increased 16.5% among whites, but declined among African Americans and other races. Rates among whites exceeded rates among African Americans for the first time since 1998. Fall rates increased 39.5% from 1992 to 2002, and poisoning rates increased 121.5%. Motor-vehicle rates did not increase overall. Rates in age groups from 40-64 years of age increased for falls, poisoning, and motor-vehicle crashes. Only fall rates increased for the 65+ age group. CONCLUSIONS: These results raise the issue of whether these increases have one or more risk factors in common, such as recent increases in the use of alcohol and prescription drugs.

    Title A Self-assessment Tool Was Reliable in Identifying Hazards in the Homes of Elders.
    Date January 2006
    Journal Journal of Clinical Epidemiology

    BACKGROUND AND OBJECTIVES: Falls are a leading cause of fatal and nonfatal injuries, particularly among the elderly. A reliable instrument for self-assessment of home falls hazards would facilitate screening for falls risk. This study examined the reliability of self-assessment of home falls hazards by elderly women. METHODS AND SETTING: Participants were 52 elderly women, aged 67 to 97. All evaluations were performed in the participants' homes. Home falls hazards were evaluated independently by study participants and by trained observers. RESULTS: Kappa statistics indicated good to excellent agreement for most of the environmental factors. However, observers were significantly more likely than the study participants to report certain tripping hazards, particularly objects in walkways. CONCLUSION: This home checklist is an important step towards a reliable self-report instrument for measuring home falls hazards. Self-assessment appears to be a reliable method for assessing many putative hazards of falling in the home. However, our findings raise questions regarding the reliable assessment of tripping hazards.

    Title A Comparison of the Case-control and Case-crossover Designs for Estimating Medical Costs of Nonfatal Fall-related Injuries Among Older Americans.
    Date November 2005
    Journal Medical Care

    Although the case-crossover design has been used widely in epidemiological and cost-offset studies as an alternative to the case-control design, it is rarely applied to cost-of-illness studies. In this study, costs for a series of hospitalized and nonhospitalized fall-related injuries were computed using the 2 approaches to allow for a direct comparison of the results.

    Title Beneficial Effects of Postural Intervention on Prehensile Action for an Individual with Ataxia Resulting from Brainstem Stroke.
    Date August 2005
    Journal Neurorehabilitation

    This paper examined the effectiveness of postural training on upper extremity performance in an ataxic individual. The ataxia resulted from a brain stem stroke.

    Title The Movement-specific Effect of Motor Imagery on the Premotor Time.
    Date August 2005
    Journal Motor Control

    The purpose of this study was to investigate the effect of motor imagery on the premotor time (PMT). Twelve healthy adults performed reaction time movements in response to external visual signals at rest, when holding an object (muscle activation), or performing different background imagined movements (motor imagery). When compared to rest, muscle activation reduced the PMT; imagined finger extension of the right hand and imagined finger flexion of the left hand elongated the PMT; imagined finger flexion of the right hand had no effect on the PMT. This movement-specific effect is interpreted as the sum of the excitatory effect caused by enhanced corticospinal excitability specifically for the primary mover of the imagined movement and an overall inhibition associated with increased task complexity during motor imagery. Our results clearly demonstrate that motor imagery has movement-specific effects on the PMT.

    Title The Effect of Motor Imagery on Spinal Segmental Excitability.
    Date May 2005
    Journal The Journal of Neuroscience : the Official Journal of the Society for Neuroscience

    The purpose of this study was to investigate the effect of motor imagery on spinal segmental excitability by recording the reflex responses to externally applied stretch of the extrinsic finger flexors and extensors during the performance of an imaginary task. Nine young healthy subjects performed a series of imagined flexion-extension movements of the fingers. Muscle stretch was imposed concurrently by applying rotations of the metacarpophalangeal joints at 100, 300, or 500 degrees /sec. Three of the nine tested subjects also generated 0.2 Newton meter voluntary flexion torque in preloading tasks before stretch. At 300 degrees /sec stretch, electromyogram (EMG) and torque reflex responses, which were observed in the finger flexors in four of nine subjects during motor imagery, were activated at a short latency (38.6 +/- 10.6 msec). This latency was similar to that recorded during a stretch of preactivated flexor muscles (34.4 +/- 3.6 msec), in which motoneurons are already suprathreshold and in which monosynaptic effects of muscle afferents are likely to be discernable. In a similar manner, for stretches imposed at 500 degrees /sec, responses to stretch of the flexors were observed in all five tested subjects in imaginary flexion tasks at very short latencies (26.4 +/- 3.7 msec), again similar to those induced by tendon taps (22.8 +/- 1.2 msec). No EMG response was observed at rest during stretches. These observations support the view that effects must have been mediated by imagery-related subthreshold activation of spinal motoneurons and/or interneurons, rather than by long-latency transcortical reflex responses. We conclude that motor imagery has a potent effect on the excitability of spinal reflex pathways.

    Title Recreational Injuries Among Older Americans, 2001.
    Date September 2004
    Journal Injury Prevention : Journal of the International Society for Child and Adolescent Injury Prevention

    To describe the epidemiology of non-fatal recreational injuries among older adults treated in United States emergency departments including national estimates of the number of injuries, types of recreational activities, and diagnoses.

    Title The Formation of Cluster Elliptical Galaxies As Revealed by Extensive Star Formation.
    Date October 2003
    Journal Nature

    The most massive galaxies in the present-day Universe are found to lie in the centres of rich clusters. They have old, coeval stellar populations suggesting that the bulk of their stars must have formed at early epochs in spectacular starbursts, which should be luminous phenomena when observed at submillimetre wavelengths. The most popular model of galaxy formation predicts that these galaxies form in proto-clusters at high-density peaks in the early Universe. Such peaks are indicated by massive high-redshift radio galaxies. Here we report deep submillimetre mapping of seven high-redshift radio galaxies and their environments. These data confirm not only the presence of spatially extended regions of massive star-formation activity in the radio galaxies themselves, but also in companion objects previously undetected at any wavelength. The prevalence, orientation, and inferred masses of these submillimetre companion galaxies suggest that we are witnessing the synchronous formation of the most luminous elliptical galaxies found today at the centres of rich clusters of galaxies.

    Title Using Motor Imagery in the Rehabilitation of Hemiparesis.
    Date August 2003
    Journal Archives of Physical Medicine and Rehabilitation

    To examine the effectiveness of using motor imagery training in the rehabilitation of hemiparesis.

    Title The Public Health Perspective in Health Promotion and Disability Prevention for Older Adults: the Role of the Centers for Disease Control and Prevention.
    Date July 2002
    Journal The Journal of Rural Health : Official Journal of the American Rural Health Association and the National Rural Health Care Association

    As the United States federal public health agency, the role of the Centers for Disease Control and Prevention (CDC) in health promotion and disability prevention with older adults encompasses research, surveillance and program activities in aging. This article characterizes the objectives and context of prevention in later life and summarizes CDCs functions, collaborative partnerships with public health agencies and other organizations, and range of activities in older adult health. As a major focus of these efforts, chronic disease risk reduction is examined through CDC's efforts in the area of physical activity; a longitudinal investigation of osteoarthritis in an older biracial rural population; and chronic illness self-management programs as a prototype for secondary prevention. Other CDC activities highlighted include addressing the burden of vaccine-preventable diseases through CDC-funded programs to improve immunization coverage in older adults, and falls prevention interventions and resources. Future directions in aging at CDC are also outlined.

    Title Submillimeter Evidence for the Coeval Growth of Massive Black Holes and Galaxy Bulges.
    Date February 2002
    Journal Science (new York, N.y.)

    The correlation, found in nearby galaxies, between black hole mass and stellar bulge mass implies that the formation of these two components must be related. Here we report submillimeter photometry of eight x-ray-absorbed active galactic nuclei that have luminosities and redshifts characteristic of the sources that produce the bulk of the accretion luminosity in the universe. The four sources with the highest redshifts are detected at 850 micrometers, with flux densities between 5.9 and 10.1 millijanskies, and hence are ultraluminous infrared galaxies. If the emission is from dust heated by starbursts, then the majority of stars in spheroids were formed at the same time as their central black holes built up most of their mass by accretion. This would account for the observed demography of massive black holes in the local universe. The skewed rate of submillimeter detection with redshift is consistent with a high redshift epoch of star formation in radio-quiet active galactic nuclei, similar to that seen in radio galaxies.

    Title Sceptical Medicine.
    Date June 1999
    Journal The Medical Journal of Australia
    Title Corneal Findings in Hemochromatosis.
    Date November 1998
    Journal Archives of Ophthalmology
    Title Client Perceptions of a Rural-based Cardiac Rehabilitation Program: a Grounded Theory Approach.
    Date August 1998
    Journal The Australian Journal of Rural Health

    A grounded theory approach was used in an attempt to generate theory about client perceptions and experiences of a cardiac rehabilitation program conducted in a rural community. A series of interviews was conducted with a selection of people who had experienced a life-threatening cardiac event. The cohort was divided into two groups: those who attended a cardiac rehabilitation program and those who did not. The findings, though not generalisable, allowed the generation of a number of theories (which may come to be the genesis of future research) regarding the differences in the physiological, psychological, sociological and vocational well-being between the groups. The findings also suggested that location of the program, the times it was conducted, and the communication skills of significant healthcare workers who recruited participants were important factors affecting attendance.

    Title An Evaluation of the Accuracy and Efficiency of a School Screening Model That Uses a Questionnaire.
    Date December 1997
    Journal International Journal of Nursing Practice

    The role of the school nurse is changing to meet the increasing needs for health promotion and health education. However, the evolution is being hampered by the inefficient work practices involved in undertaking some of the more traditional tasks such as school screening. A survey questionnaire model of screening was developed and trialed with a sample of students and parents and then compared with the results of the more traditional one to one screening programme. The questionnaire survey model was evaluated for accuracy and efficiency against the traditional screening model. The questionnaire method exhibited a relatively low error rate and required one third of the time to complete when compared with the traditional screening programme. The implications of these findings as well as the advantages and limitations of each model are examined in the discussion.

    Title The Short-term Natural History of Irritable Bowel Syndrome: a Time-series Analysis.
    Date June 1997
    Journal Behaviour Research and Therapy

    Although researchers have studied irritable bowel syndrome (IBS), including its physiological and psychological characteristics and treatments' effectiveness, basic descriptive information about IBS has been limited to lists of symptoms and explanations of what IBS is not. The purpose of the present study is to describe how core IBS symptoms vary over time. Twenty-five subjects (17 females, 8 males), who were not receiving treatment for IBS, rated the severity of their IBS symptoms daily for 8 weeks. Four symptoms' (abdominal pain, abdominal tenderness, constipation and diarrhea) ratings were slimmed to create a primary IBS symptom score. The data were detrended, then a time-series analysis was performed. Many subjects' IBS severity was predictable over more than one day, and symptoms tended to occur in clusters rather than randomly. Anxiety and depression were slightly to moderately correlated with IBS variables, but virtually all of these correlations were nonsignificant.

    Title Chronic Medical Conditions and Risk of Fall Injury Events at Home in Older Adults.
    Date June 1997
    Journal Journal of the American Geriatrics Society

    OBJECTIVE: To evaluate the association between selected chronic medical conditions (CMCs) and fall injury events at home among community-dwelling older persons. DESIGN: Population-based case-control study. SETTING: The general community. PARTICIPANTS: Persons aged 65 and older living at home, excluding those using a wheelchair; 467 cases and 691 control subjects were studied. MEASUREMENTS: The main independent variables were self-reported histories of 10 CMCs: diabetes, high blood pressure, anemia, heart attack, Parkinson's disease, stroke, emphysema, cancer (other than skin), cataracts, and glaucoma. RESULTS: The final multivariate model included variables for age, sex, body mass, dependency in activities of daily living, current exercise (three or more times per week), mental status scores, and three CMCs. Persons with a history of stroke or anemia had an increased risk of a fall injury event: for stroke the adjusted odds ratio (aOR) equalled 1.7 (95% confidence interval (CI), 1.0-3.0); for anemia the aOR equalled 1.5 (95% CI, 1.0-2.2). Those with a history of high blood pressure had decreased risk (aOR = .7, 95% CI 0.5-0.9). CONCLUSIONS: Persons 65 and older with a self-reported history of anemia or stroke are at increased risk of a fall injury event in the home, whereas those with a self-reported history of high blood pressure are at decreased risk.

    Title Cross-resistance Phenotypes of Fluconazole-resistant Candida Species: Results with 655 Clinical Isolates with Different Methods.
    Date June 1997
    Journal Diagnostic Microbiology and Infectious Disease

    Candida species test results with two broth macrodilution antifungal susceptibility methods were compared using 655 clinical isolates, and the frequency of fluconazole resistance and phenotypes of azole cross resistance are detailed. A method with an 80% inhibition endpoint (as compared to clear tube endpoint) suggested greater fluconazole susceptibility to C. albicans but had a less pronounced effect on C. glabrata, and seemed to have a negligible influence on results with C. parapsilosis and C. tropicalis. The latter were grouped as susceptible and resistant (based on achievable blood levels), respectively, by both methods. Cross resistance was method dependent and more pronounced with itraconazole than ketoconazole. In vivo correlations are needed to validate the groupings proposed by any in vitro method.

    Title Physical Activity, Functional Limitations, and the Risk of Fall-related Fractures in Community-dwelling Elderly.
    Date April 1997
    Journal Annals of Epidemiology

    This case-control study examines the association of vigorous and mild physical activity with fall-related fractures in a community-dwelling population age 65 and older in South Florida. Vigorous physical activity was defined as exercising, doing heavy housecleaning, or other hard labor three or more times per week in the month prior to the index date; mild physical activity was defined as the number of hours per day subjects reported spending on their feet. A case was any subject who sustained a fall-related fracture (ICD-9CM-800 through ICD-9CM-829) over a 21-month period (n = 471). Controls were at 10% random sample selected from the Health Care Financing Administration Medicare files (n = 712). The presence of any limitation in activities of daily living (ADL) significantly modified the effect of vigorous physical activity. Physically active subjects with no limitations (ADL = 0) were less likely to sustain a fall-related fracture than were inactive subjects with an adjusted odds ratio (aOR) of 0.6, (0.5-0.8 95% CI), and active subjects with any limitation (ADL > or = 1) had an aOR of 3.2 (1.1-9.8 95% CI). Limiting this analysis to 159 hip fracture cases produced similar results. Mild physical activity was not associated with fracture. These results suggest that vigorous physical activity is associated with a lower fracture risk among elderly persons who have no limitation in ADL and with a higher risk among those with any limitations.

    Title Risk Factors for Injuries from In-line Skating and the Effectiveness of Safety Gear.
    Date December 1996
    Journal The New England Journal of Medicine

    BACKGROUND: Of the estimated 22.5 million people participating in in-line skating in the United States in 1995, about 100,000 were sufficiently injured so as to require emergency department care. We investigated the effectiveness of wrist guards, elbow pads, knee pads, and helmets in preventing skating injuries. METHODS: We used data from the 91 hospital emergency departments participating in the National Electronic Injury Surveillance System, a national probability sample of randomly selected hospitals with 24-hour emergency departments. Injured in-line skaters who sought medical attention between December 1992 and July 1993 were interviewed by telephone. We conducted a case-control study of skaters who injured their wrists, elbows, knees, or heads as compared with skaters with injuries to other parts of their bodies. RESULTS: Of 206 eligible injured subjects, 161 (78 percent) were interviewed. Wrist injuries were the most common (32 percent); 25 percent of all injuries were wrist fractures. Seven percent of injured skaters wore all the types of safety gear; 46 percent wore none. Forty-five percent wore knee pads, 33 percent wrist guards, 28 percent elbow pads, and 20 percent helmets. The odds ratio for wrist injury, adjusted for age and sex, for those who did not wear wrist guards, as compared with those who did, was 10.4 (95 percent confidence interval, 2.9 to 36.9). The odds ratio for elbow injury, adjusted for the number of lessons skaters had had and whether or not they performed trick skating, was 9.5 (95 percent confidence interval, 2.6 to 34.4) for those who did not wear elbow pads. Non-use of knee pads was associated with a nonsignificant increase in the risk of knee injury (crude odds ratio, 2.2; 95 percent confidence interval, 0.7 to 7.2). The effectiveness of helmets could not be assessed. CONCLUSIONS: Wrist guards and elbow pads are effective in protecting in-line skaters against injuries.

    Title A Standardized Instrument to Assess Hazards for Falls in the Home of Older Persons.
    Date March 1996
    Journal Accident; Analysis and Prevention

    Hazards in the home are implicated in up to half of all falls among older persons. Yet, the instruments used to identify these hazards usually have been unstandardized, have lacked specific definitions of hazards, and have not been evaluated. Therefore, in 1988, as part of the Study to Assess Falls among the Elderly, in Miami Beach, Florida, the authors evaluated the reliability of a standardized instrument used for assessing the training of evaluators and assessing home environments. Based on up to 176 observations for each potential hazard, the interviewers' assessment of hazards such as throw rugs, tripping hazards, light switch hazards, and hazardous bath surfaces had good overall reliability (kappa = 0.65-0.92). Their assessment of grab-bars and hazardous furniture was unreliable (kappa = 0.18-0.35). Variations in the reliability reflect the difficulty in creating definitions that are simple to be understood and used, yet detailed enough to produce sensitive and specific survey items. Investigators studying falls among older persons should use standardized definitions to train evaluators and assess environmental hazards.

    Title Dependence in Activities of Daily Living As a Risk Factor for Fall Injury Events Among Older People Living in the Community.
    Date April 1995
    Journal Journal of the American Geriatrics Society
    Title Adaptive Control with Feedback of Suramin Using Intermittent Infusions.
    Date August 1994
    Journal Journal of Clinical Oncology : Official Journal of the American Society of Clinical Oncology
    Title Working with the Elderly: Do Student Nurses Care for It?
    Date April 1993
    Journal The Australian Journal of Advanced Nursing : a Quarterly Publication of the Royal Australian Nursing Federation

    This study investigates neophyte student nurses' attitudes to working with the elderly through placing them in relation to attitudes to other nursing career options and by exploring student nurses' reasons for such attitudes. The results are based on a questionnaire answered by 610 students from five NSW teaching institutions. The results indicate that nurses rate working with the elderly very poorly, and that this negativity is based on unfavourable stereotypes of aged persons and their care. These findings are placed in the context of projected demographic changes and the pressures these will place on the health care system and its need for nurses qualified in this area of work.

    Title Alcohol As a Risk Factor for Fall Injury Events Among Elderly Persons Living in the Community.
    Date July 1992
    Journal Journal of the American Geriatrics Society

    OBJECTIVE: To determine if alcohol use is a risk factor for fall injury events among community-dwelling older persons. DESIGN: Case-control study. SETTING: South Miami Beach, Florida. PARTICIPANTS: 320 persons 65 or older who sought treatment at six area hospitals for injuries resulting from falls; 609 controls, matched for sex and age, selected randomly from Health Care Financing Administration (Medicare) files. MAIN INDEPENDENT VARIABLES: Self-reported current alcohol use. RESULTS: No association was found between fall injury events and average weekly alcohol use. CONCLUSIONS: Further efforts at reducing injuries to older persons from falls should concentrate on other modifiable risk factors, including adequate treatment of underlying medical conditions, reducing inappropriate psychotropic medication use, and installing safety devices in the home.

    Title [prevalence of Smoking Among Women in Reproductive Age in Puerto Rico].
    Date June 1992
    Journal Boletín De La Oficina Sanitaria Panamericana. Pan American Sanitary Bureau

    The prevalence of smoking in Puerto Rican women was estimated on the basis of data from 3,157 women 15 to 49 years of age who had been surveyed in the 1982 Evaluation of Fertility and Family Planning in Puerto Rico. The weighted prevalence was 15.5%, with a 95% confidence interval of 13.8 to 17.1. The prevalence varied by age group, education, marital status, place of residence at age 15, and consumption of alcohol. The prevalence of smoking increased in successive birth cohorts while the mean age at initiation of the habit tended to decline. The data suggest that in Puerto Rico smoking is on the rise among younger women.

    Title Histologic Types of Benign Breast Disease and the Risk for Breast Cancer. The Cancer and Steroid Hormone Study Group.
    Date April 1992
    Journal Cancer

    Specific histologic types of benign breast disease (BBD) may increase breast cancer risk. The authors analyzed data from a population-based, case-control study of women aged 20 to 54 with newly diagnosed breast cancer and control subjects randomly selected from the general population. A panel of pathologists classified the histologic findings of biopsy slides for 433 women with breast cancer and 261 control subjects, all of whom had a history of biopsy for BBD, as to the presence of epithelial hyperplasia, atypia, and other histologic features. When compared with women who had never had a breast biopsy, women with BBD without hyperplasia had an odds ratio of 1.5 (95% confidence limits [CL] 1.3 to 1.9), women with hyperplasia without atypia had an odds ratio of 1.8 (CL = 1.3, 2.4), and women with hyperplasia and atypia had an odds ratio of 2.6 (CL = 1.6, 4.1). Fibroadenoma was an independent risk factor for breast cancer (odds ratio = 1.7; CL = 1.1, 2.5). These findings suggest that women with BBD with epithelial hyperplasia either with or without atypia and women with fibroadenoma should be monitored carefully because of their elevated risk for breast cancer.

    Title Race and Weight Change in Us Women: the Roles of Socioeconomic and Marital Status.
    Date March 1991
    Journal American Journal of Public Health

    BACKGROUND. The prevalence of overweight among Black women in the US is higher than among White women, but the causes are unknown. METHODS. We examined the weight change for 514 Black and 2,770 White women who entered the first Health and Nutrtion Examination Survey (1971-75) at ages 25-44 years and were weighed again a decade later. We used multivariate analyses to estimate the weight-change effectgs associated with race, family income, education, and marital change. RESULTS. After multiple adjustments, Black race, education below college level, and becoming married during the follow-up interval were each independently associated with an increased mean weight change. Using multivariate logistic analyses, Black race was not independently associated with an increased risk of major weight gain (change greater than or equal to +13 kg), but it was associated with a reduced likelihood of major weight loss (change less than or equal to -7 kg) (odds ratio - 0.64 [95% CI -0.41, 0.97])]. Very low family income was independently associated with the likelihood of both major weight gain (OR - 1.71 [95% CI - 1.15, 2.55]) and major weight loss (OR - 1.86 [95% CI - 1.18, 2.95]). CONCLUSIONS. Amont US women, Black race is independently associated with a reduced likelihood of major weight loss, but not with major weight gain. Women at greatest risk of weight gain are those with education below college level, those entering marriage, and those with very low family income.

    Title The Incidence of Fall Injury Events Among the Elderly in a Defined Population.
    Date June 1990
    Journal American Journal of Epidemiology

    Falls are a leading cause of death from injury among older persons in the United States, and about one in three older persons falls each year. Yet, reliable estimates of the incidence of fall injury events in a population-based setting are not readily available. Therefore, the authors analyzed population-based surveillance data, between July 1985 and June 1987, from the Study to Assess Falls Among the Elderly, Miami Beach, Florida. The rate of fall injury events coming to acute medical attention increased exponentially with age for both elderly men and women (predominantly white), reaching a high for those aged 85 years or more of 138.5 per 1,000 for males and 158.8 per 1,000 for females. Compared with males, females had a higher incidence of fractures other than skull. Males were nearly twice as likely to die, however, following a fall injury event than were females. Of those fall injury events identified through the surveillance system, about 42% resulted in hospital admission. The mean length of hospital stay was 11.6 days overall and was 15.5 days for hip fracture, 9.8 days for skull fracture/intracranial injury, 11.2 days for all other fractures, and 9.1 days for all other injuries. About 50% of fall injury events that occurred at home and required hospital admission resulted in a person being discharged to a nursing home.

    Title Alcohol Treatment Outcome Evaluation Methodology: State of the Art 1980-1984.
    Date September 1987
    Journal Addictive Behaviors

    The methodology of alcohol treatment outcome studies published during two sequential intervals from 1976 through mid-1984 is critically reviewed. Although considerable methodological improvements have occurred over time, major methodological deficiencies continue to characterize much of the literature, with inadequate reporting of subjects' pretreatment characteristics (e.g., severity of dependence) being the most striking problem. Pervasive differences across studies regarding the types of data gathered and the ways in which findings are reported seriously impede attempts to compare studies and weaken the types of conclusions that can be drawn about treatment efficacy in general. It is suggested that journal editors establish standards of reporting for follow-up studies.

    Title Viral Hepatitis As a Major Cause of Maternal Mortality in Addis Ababa, Ethiopia.
    Date June 1987
    Journal International Journal of Gynaecology and Obstetrics: the Official Organ of the International Federation of Gynaecology and Obstetrics

    Causes of maternal mortality were investigated in Addis Ababa, Ethiopia, from September 1981 to September 1983. Viral hepatitis ranked third among the leading causes of maternal mortality behind septic abortion and puerperal sepsis. There were 26 deaths from viral hepatitis during the 2-year study period for a hospital maternal mortality rate of 91.0 per 100,000 live births. Although 30% of women who died of all maternal causes received antenatal care in Addis Ababa, only 13% of women who died from viral hepatitis in our hospital study received antenatal care. Low socio-economic status (SES) has been shown to be associated with low antenatal care utilization and with an increased risk of protein malnutrition. Malnutrition is considered a predisposing factor for liver damage. Suggestions for reducing hepatitis transmission and maternal mortality through education, better hygiene, and improved sanitation are discussed.

    Title Cancer Incidence Rates Among Blacks in Urban and Rural Georgia, 1978-82.
    Date June 1985
    Journal American Journal of Public Health

    The records of the Atlanta Cancer Surveillance Center were reviewed for all incident cases of cancer diagnosed among Black residents of the catchment areas during calendar years 1978 through 1982. The resultant age-adjusted overall cancer incidence rates for urban Blacks were greater than those for rural Blacks. The largest urban excess was found for cancers of the buccal cavity and pharynx. Urban residence also was associated with lung and prostate cancers among males, and pancreatic cancers among females.

    Title Letter to a Young Colleague.
    Date August 1977
    Journal Australian Family Physician
    Title Hospital Care from General Practitioners.
    Date June 1973
    Journal The Medical Journal of Australia
    Title Calvacin: A New Antitumor Agent.
    Journal Science (new York, N.y.)
    Title A Randomized Trial of a Multifaceted Intervention to Reduce Falls Among Community-dwelling Adults.
    Journal Health Education & Behavior : the Official Publication of the Society for Public Health Education

    Using a randomized controlled trial, we tested the efficacy of a fall prevention intervention to reduce falls among adults in a community-based health promotion program. Adults aged 65 and older within two counties were recruited (control n = 257; intervention n = 286). After 12 months, there was a significant decrease in the number of falls in both groups (odds ratio = 0.45, p < .04), but the time by group membership interaction was not significant (χ(2) = 0.15, p < .69). Multivariate analysis did not find significant differences between the control and intervention groups for physical function as measured by a balance test or a sitting/standing test. Further research is needed on effective methods to deliver multifaceted fall interventions to older adults who are already being served by community health promotion programs.

    Title Ultrafast Dynamics of Nonequilibrium Resonance Energy Transfer and Probing Globular Protein Flexibility of Myoglobin.
    Journal The Journal of Physical Chemistry. A

    Protein structural plasticity is critical to many biological activities and accurate determination of its temporal and spatial fluctuations is challenging and difficult. Here, we report our extensive characterization of global flexibility of a globular heme protein of myoglobin using resonance energy transfer as a molecular ruler. With site-directed mutagenesis, we use a tryptophan scan to examine local structural fluctuations from B to H helices utilizing 10 tryptophan-heme energy transfer pairs with femtosecond resolution. We observed ultrafast resonance energy transfer dynamics by following a nearly single exponential behavior in 10-100 ps, strongly indicating that the globular structure of myoglobin is relatively rigid, with no observable static or slow dynamic conformational heterogeneity. The observation is against our molecular dynamics simulations, which show large local fluctuations and give multiple exponential energy transfer behaviors, suggesting too flexible of the global structure and thus raising a serious issue of the force fields used in simulations. Finally, these ultrafast energy transfer dynamics all occur on the similar time scales of local environmental relaxations (solvation), leading to nonexponential processes caused by energy relaxations, not structural fluctuations. Our analyses of such processes reveal an intrinsic compressed- and/or stretched-exponential behaviors and elucidate the nature of inherent nonequilibrium of ultrafast resonance energy transfer in proteins. This new concept of compressed nonequilibrium transfer dynamics should be applied to all protein studies by time-resolved Förster resonance energy transfer (FRET).

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