Biomedical subjects

K M Wright

Publications and source records attributed to K M Wright.

At least 19 recordsLinked to original sources

PubMed2001

Microstructural effects on microbial survival: phase-separating dextran solutions.

Evolving microstructure in a model dextran solution is shown to exert a major influence on the survival of Escherichia coli K-12 frag 1 and Salmonella typhimurium LT2. The microstructure results from microscopic phase separation, which develops over several hours resulting in hardening of the solution into a glassy state. The microstructure is characterized by an array of physical methods including image analysis, electron spin resonance and bulk rheology, and it is shown that bacterial survival depends on the formation of microscopic. water-rich domains and not primarily on bulk water activity or hardness.

Colony Count, Microbial↗

PubMed2001

Effective particle-mediated vaccination against mouse melanoma by coadministration of plasmid DNA encoding Gp100 and granulocyte-macrophage colony-stimulating factor.

Particle-mediated gene delivery was used to immunize mice against melanoma. Mice were immunized with a plasmid cDNA coding for the human melanoma-associated antigen, gp100. Murine B16 melanoma, stably transfected with human gp100 expression plasmid, was used as a tumor model. Particle-mediated delivery of gp100 plasmid into the skin of naïve mice resulted in significant protection from a subsequent tumor challenge. Co-delivery of murine granulocyte-macrophage colony-stimulating factor (GM-CSF) expression plasmid together with the gp100 plasmid consistently resulted in a greater level of protection from tumor challenge. The inclusion of the GM-CSF plasmid with the gp100 DNA vaccine allowed a reduction in the gp100 plasmid dose required for antitumor efficacy. Protection from tumor challenge was achieved with as little as 62.5 ng of gp100 DNA per vaccination. Tumor protection induced by the gp100 + GM-CSF gene combination was T cell mediated, because it was abrogated in vaccinated mice treated with anti-CD4 and anti-CD8 monoclonal antibodies. In addition, administration of the gp100 + GM-CSF DNA vaccine to mice bearing established 7-day tumors resulted in significant suppression of tumor growth. These results indicate that inclusion of GM-CSF DNA augments the efficacy of particle-mediated vaccination with gp100 DNA, and this form of combined gp100 + GM-CSF DNA vaccine warrants clinical evaluation in melanoma patients.

Animals↗

PubMed2000

Surgery of amphibians.

This article is an introduction to common amphibian surgical techniques. No overwhelming obstacles preclude incorporating amphibian surgeries into the repertoire of veterinary clinicians. With the proper tools and reference materials and a little practice, the skills needed may be readily acquired.

Amphibians↗

PubMed2000

Analysis of the N gene hypersensitive response induced by a fluorescently tagged tobacco mosaic virus.

The hypersensitive response (HR) triggered on Nicotiana edwardsonii by tobacco mosaic virus was studied using a modified viral genome that directed expression of the green fluorescent protein. Inoculated plants were initially incubated at 32 degrees C to inhibit the N gene-mediated HR. Transfer to 20 degrees C initiated the HR, and fluorescent infection foci were monitored for early HR-associated events. Membrane damage, which preceded visible cell collapse by more than 3 h, was accompanied by a transient restriction of the xylem within infection sites. Following cell collapse and the rapid desiccation of tissue undergoing the HR, isolated, infected cells were detected at the margin of necrotic lesions. These virus-infected cells were able to reinitiate infection on transfer to 32 degrees C, however, if maintained at 20 degrees C they eventually died. The results indicate that the tobacco mosaic virus-induced HR is a two-phase process with an early stage culminating in rapid cell collapse and tissue desiccation followed by a more extended period during which the remaining infected cells are eliminated.

Cell Death↗

PubMed1999

Basic husbandry and clinical assessment of the amphibian patient.

The veterinarian presented with an amphibian patient must be prepared to assess both the animal's medical condition and its husbandry record; good health is inextricably linked to proper care and diet. This article provides the clinician with guidelines for maintaining amphibians in captivity, including information on climate control and lighting, housing and cage enrichment, and nutrition. The article also covers questions to ask when taking a history, methods of restraint, and practical advice on the equipment and techniques used to conduct a complete physical examination of the amphibian patient.

Amphibians↗

PubMed1996

Dynamic NMR Q-space studies of microstructure with the multigrade CPMG sequence.

A new approach to q-space studies of microstructure is proposed, which exploits the combined information contained in the water proton transverse relaxation time distribution and the frequency dependence of the apparent water diffusivity in heterogeneous systems. Using an automated two-dimensional multigrade CPMG sequence, both the pulse spacing and the amplitude of the applied field gradient are varied systematically and used to measure the frequency and wave vector dependence of the multiple exponential echo decay constants and amplitudes. Undesirable crossterms in the applied and background field gradients are eliminated by a simple procedure involving a sign reversal in the applied gradient. Nonlinear, local susceptibility-induced field gradients are shown to lead to enhanced, frequency-dependent apparent water diffusivities that are sensitive to the local microstructure.

Algorithms↗

PubMed1996

A new concept for implementation of a required general surgery clerkship.

BACKGROUND: Two years ago our institution abbreviated the junior internal medicine and general surgery clerkships to accommodate a 4-week family practice clerkship and a 4-week elective clerkship. As a consequence, 1-month mandatory internal medicine and general surgery clerkships were placed in the senior year. METHODS: The surgical disorders most commonly encountered by the generalist are discussed. The senior students spend 4 weeks with a community-based surgeon. All lectures are presented by full-time faculty and adhere to the student manual, which is designed to coincide with examination material. Three histories and physicals are reviewed by the course director to determine utilization of critical thinking skills. The development of healthy interpersonal and professional relationships is addressed by a 2-hour module on the essentials of integrity, compassion, humility, and self-knowledge. A faculty development seminar provides an awareness of course objectives and logistics. Student grades are determined by the preceptor's evaluation (50%), an in-house written examination (50%), and submission of adequate history and physicals. RESULTS: Subjective reviews by students (n = 115) reveal that although only 27% of the students care to pursue a surgical practice, 85% feel that their time was effectively spent and 83% feel that the clerkship should be offered to future fourth year medical students. Seventy percent of submitted history and physicals (n = 420) exhibit appropriate critical thinking skills. CONCLUSIONS: We are currently in the midst of our third year of implementation. The students are receiving insight into a surgical approach to common disease processes. History and physical examination skills and healthy interpersonal relationships are reinforced. Although change is often difficult to accomplish and accept, the positive response to the newly formatted senior curriculum has exceeded expectations.

Clinical Clerkship↗

PubMed1996

Combined relaxation and diffusion studies of porous media using the multigrade CPMG sequence.

A new approach to q-space NMR studies of microstructure is proposed that exploits the combined information contained in the water proton transverse relaxation time distribution and the frequency dependence of the apparent water diffusivity. A simple protocol is used to eliminate undesirable crossterms in background susceptibility gradients. Local, microscopic nonlinearity in the applied field gradients is shown to lead to enhancement of the apparent water diffusivity in small pores at high frequencies. The relationships between NMR relaxation studies of pore emptying with sorption isotherms, electrical conductivity, and microbiological survival are indicated.

Glass↗

PubMed1996

Post-traumatic stress disorder symptoms among Gulf War veterans.

This study assessed the prevalence of risk for development of post-traumatic stress disorder (PTSD) symptoms among active duty and reserve veterans from Pennsylvania and Hawaii who either deployed (N = 1,524) or did not deploy (N = 2,727) to the Persian Gulf as a result of Operation Desert Storm. All participants anonymously completed a survey questionnaire that included the Impact of Event Scale and the Brief Symptom Inventory. Results indicate the likelihood of PTSD symptoms in approximately 8.0% of active duty veterans and 9.3% of reserve veterans who deployed to the Persian Gulf. PTSD risk comparisons are made with other active duty Army veterans assessed 1 year earlier. Sources of trauma are presented and implications for future military deployments on potential risks for developing PTSD are discussed.

Adult↗

PubMed1996

Psychological health of Gulf War-era military personnel.

This study assessed the effects of the Persian Gulf War on the psychological health and adjustment of military personnel in Hawaii and Pennsylvania who either deployed (N = 1,524) or did not deploy (N = 2,727) to the Persian Gulf during Operations Desert Shield/Desert Storm. All participants anonymously completed a questionnaire providing information on demographics, psychological and psychosocial health, deployment stressors, current life problems, current distress, and causal attributions of present problems. Results indicate that deployed veterans experienced significant levels of stress in-theater and continue to report significant stress in their lives today. Although considerable stress is experienced, the majority of veterans are handling it unremarkably. Implications for future deployments and the need for military-normed assessment instruments are discussed.

Adult↗

PubMed1995

Gruesomeness, emotional attachment, and personal threat: dimensions of the anticipated stress of body recovery.

Previous research has shown that exposure to grotesque death has been associated with posttraumatic stress disorder and higher levels of stress have been associated with mortuary workers who anticipated handling remains than those who did not. Additional research is presented here to further clarify the nature of the anticipated stress of handling the dead. Anticipated stress of handling human remains was rated for 13 different situations by 479 persons (384 men and 95 women) without such experience, but whose job was likely to require it. Factor analysis of their ratings revealed three psychological dimensions: the gruesomeness of the remains, an emotional link between the viewer and the remains, and personal threats to the remains handler. Suggestions for preventive measures, training, and interventions for those who may handle remains are made.

Adolescent↗

PubMed1995

Quality of life and functional status among homeless men attending a day shelter in Louisville, Kentucky.

The homeless present important social and medical problems in most parts of the United States, including urban areas of Kentucky. While some studies have examined the health status of the homeless, very little is known about their quality of life or functional status. In the present study, 188 homeless men attending St. John's Day Shelter in Louisville completed an interviewer-assisted instrument that assessed self-perceived quality of life using the Perceived Quality of Life (PQOL) scale and self-perceived functional status using the Dartmouth COOP charts. The instrument also included questions on demographics and health risk behaviors of the homeless men. The results show that the typical homeless male attending St. John's is an unmarried, white, middle-aged high school graduate who is unemployed. In terms of quality of life, these men indicate general satisfaction with their physical and cognitive abilities, but significantly lower satisfaction with the social aspects of their lives. With regard to functional status, the homeless men report that they function best in terms of physical fitness and ability to perform daily activities. They report lower assessments of overall health, feelings, quality of life, and social support. These results suggest that poor social role functioning among homeless men is a major contributor to their poor quality of life. Thus, improving their health and quality of life may require an emphasis on social services in addition to routine medical care.

Activities of Daily Living↗

PubMed1995

Physical health symptomatology of Gulf War-era service personnel from the states of Pennsylvania and Hawaii.

We present data on physical health and possible "Gulf War syndrome" from a Congressionally mandated study of over 4,000 active duty and reserve service members from the states of Hawaii and Pennsylvania who served during Operation Desert Storm. We found that deployed veterans report significantly more physical health symptoms than non-deployed veterans that cannot be explained by reasons other than deployment alone. We also identified a subgroup of 178 deployed veterans at risk for possible Gulf War syndrome. We recommend that services collect baseline information from units likely to deploy in the future and update that information regularly.

Adult↗

PubMed1994

A new model for bacterial growth in heterogeneous systems.

A general theory of spatially dependent bacterial growth in heterogeneous systems is developed by combining a structured-cell kinetic model of bacterial metabolism with reaction-diffusion equations describing the transport of nutrients in the growth medium. Rate constants in the theory are determined for Listeria monocytogenes by fitting the viable count batch growth data acquired in homogeneous, shake-flask cultures. The rate constants are then used to calculate the form of bacterial growth when it occurs as localized microcolonies in structured systems. The same theory is used to analyse the effects of transient variations in environmental variables.

Bacteriological Techniques↗

PubMed1994

An MRI study of drying in granular beds of nonporous particles.

MRI is used to study the role of capillary and gravitational forces in controlling mass transport of water during isothermal drying of granular beds of nonporous particles. A new model is presented that shows how capillary and gravitational forces relate to Fickian diffusion driven by a chemical potential gradient. In granular beds, where capillary and gravitational forces dominate, the image profiles give direct information on the dependence of the degree of saturation on capillary suction pressure. The effects of changing particle size and surface tension on the profiles is investigated quantitatively, and it is shown that high capillary pressures create anomalies in the drying profiles.

Algorithms↗

PubMed1993

Handling bodies after violent death: strategies for coping.

Interviews with and observations of experienced and inexperienced personnel were conducted to determine their coping strategies before, during, and after their work with the bodies of people who had died violently. Avoidance, denial, and social support from the work group and spouse appeared to facilitate coping. The implications of these findings for therapeutic intervention are discussed.

Accidents, Aviation↗

PubMed1993

Anticipation of handling the dead: effects of gender and experience.

In addition to the direct psychological effects of disaster stressors, anticipation of stress can itself be debilitating. We examined the relationship between the anticipated stress of handling the dead and gender and experience. Experienced persons had lower anticipated stress than inexperienced persons. Inexperienced, females had higher anticipated stress than inexperienced males; experienced males and females did not differ. Results provide support for an 'inoculation' theory of stress buffering in disaster workers.

Adaptation, Psychological↗

PubMed1992

Psychological responses of rescue workers: fire fighters and trauma.

The psychological responses of two groups of fire fighters were examined following the performance of rescue work. Four types of responses were reported: identification with the victims, feelings of helplessness and guilt, fear of the unknown, and physiological reactions. Stress was found to be mediated by availability of social support, type of leadership, level of training, and use of rituals. Implications of these findings for preventive intervention measures are discussed.

Accidents, Aviation↗