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Biomedical subjects

S M Wright

Publications and source records attributed to S M Wright.

At least 37 records · Page 2Linked to original sources
PubMed2001

Self-help countermeasure strategies for populations living within contaminated areas of Belarus, Russia and Ukraine.

Countermeasures have been effectively employed within intensive agricultural systems in areas of the Former Soviet Union (FSU) affected by the Chernobyl accident. However, ingestion doses continue to be elevated in some areas as a result of few foodstuffs which are collected from the wild or produced by the household. Forest fungi and berries, and milk from privately owned cattle are the most notable contributors to 137Cs intakes amongst these foodstuffs. In this paper we consider advice which would help affected populations to both understand the importance of these exposure routes and to reduce their exposure. In addition to the potential radiological benefits, self-help schemes are highly cost-effective and likely to have a positive psychological influence on populations living within contaminated areas of the FSU. Evidence to suggest that the transfer of radiocaesium to cow milk is considerably higher in the FSU than within western Europe and North America is discussed.

Agriculture↗
PubMed2001

A sixteen-channel multiplexing upgrade for single channel receivers.

With the increasing interest in phased arrays in magnetic resonance imaging, imaging system receivers capable of acquiring larger number of parallel signals are needed. Suggested techniques for rapid imaging propose the use of arrays with as many as 128 elements. While simply duplicating the number of receiver chains as needed is a viable technique, it quickly becomes both cumbersome and expensive. Time domain multiplexing offers an alternative solution to this problem. By using RF multiplexing switches, a single receiver can be upgraded to an array receiver capable of multi-channel data acquisition giving users array capability. Additionally, it can be used to dramatically increase acquisition capability of multiple receiver systems. This paper reports results from a multiplexing system upgrade, which converts a single channel standard clinical imaging system to a 16-channel array system. The upgrade includes both the RF multiplexing front-end and an external data acquisition system with image processing capability. Issues concerning the implementation of high channel-count multiplexers are also discussed.

Equipment Design↗
PubMed2001

Multi-channel magnetic resonance spectroscopy through time domain multiplexing.

Time domain multiplexing (TDM) is presented as a viable approach to increasing the sensitivity and efficiency of magnetic resonance spectroscopic (MRS) experiments through multi-channel signal acquisition. By switching very rapidly between coils of a receive phased array, TDM receiver extensions allow the acquisition of multiple, independent spectra through a single channel magnetic resonance console. A TDM receiver extension designed for imaging and spectroscopy is described, and the impact of this hardware extension on the processing and quantitation of MRS data is addressed. The primary complication involves the use of fixed bandwidth RF band-pass filters that can not be adjusted to match the spectral width of the desired MRS experiment.MRS sequences whose bandwidths are narrower than the bandwidth provided by TDM band-pass filters can be acquired through TDM with minimal loss of SNR as long as two constraints are met. The first constraint requires that the entire bandwidth of the band-pass filters be sampled at or more rapidly than the Nyquist rate associated with their bandwidth, to prevent extra noise from aliasing into the final spectrum. The second requirement is that spectral resolution be held constant to that of the desired experiment. Results from a two-channel multiplexed MRS experiment, conducted according to these guidelines, illustrate that TDM can be used to allow acquisition of multi-channel MRS experiments through single channel console systems with a minimal loss in SNR.

Equipment Design↗
PubMed2001

Teaching resource and information management using an innovative case-based conference.

Physicians play a critical role in controlling resource use in medicine. This paper describes an innovative, interdisciplinary conference that teaches housestaff and medical students about resource and information management in the hospital setting. The objectives are to help foster communication between physicians and other members of the health care team, to improve the understanding of hospital reimbursement, and to influence attitudes toward practicing cost effectiveness. The conference structure includes the following components: case presentation by the treating physician and follow-up information provided by the primary care physician, a review of the itemized hospital bill, discussion of coding issues, discussion of hospital reimbursement comparing case data to institutional and state averages, and a summary of key take-home points and lessons.

Congresses as Topic↗
PubMed2001

The challenge of problem residents.

Internal medicine residency training is demanding and residents can experience a wide variety of professional and personal difficulties. Residency programs everywhere have had and will continue to have problem residents. Training programs should be equipped to effectively identify and manage residents who experience problems. Previous articles that have been published on the topic of problem residents primarily addressed concerns such as impairment due to depression and substance abuse. The content of this article is derived from a comprehensive review of the literature as well as other data sources such as interviews with program directors and workshops at national professional meetings. This article focuses primarily on four issues related to problem residents: their identification, underlying causes, management, and prevention. The study attempts to be evidence-based, wherever possible, highlighting what is known. Recommendations based on the synthesis of the data are also made. Future ongoing studies of problem residents will improve our understanding of the matters involved, and may ultimately lead to improved outcomes for these trainees.

Clinical Competence↗
PubMed2001

Contribution of a lecturer-practitioner in implementing evidence-based health care.

This article describes and discusses the role of a lecturer-practitioner (LP) in the context of a university and practice development unit within a primary care trust in contributing to evidence-based health care. Evidence-based health care is currently high on the political and professional agendas. Methods employed in practice to create an environment that encourages and supports innovation will be described. Methods used in the educational establishment will also be highlighted from a theoretical and practice perspective. Progress to date and expected future outcomes will be shared. The article concludes that progress is dependent on all those involved, sharing common goals in the implementation of evidence based health care as it will continue to remain high on the agenda in the educational and service sectors. This drive towards clinical effectiveness and evidence based practice puts the LP in an ideal position to reduce the practice-theory gap by the nature of their integrated role.

Community Health Nursing↗
PubMed2001

Racial differences in outcomes of veterans undergoing percutaneous coronary interventions.

BACKGROUND: In the era of stenting relatively little is known about racial differences in the outcomes of percutaneous interventions (PCI). The purpose of this study was to determine whether there were racial differences with respect to short- and long-term outcomes in veterans undergoing PCI. METHODS: We used the national Department of Veterans Affairs (VA) patient treatment file to identify 24,625 African American and white veterans who had PCI in VA medical centers between October 1, 1994, and September 30, 1999. Baseline demographic characteristics were obtained, as was a measure of comorbidity. Short-term outcomes included hospital mortality and same-admission coronary artery bypass surgery, and long-term outcomes were vital status and rehospitalization. Multivariate statistical methods were used to adjust for patient differences when comparing both short- and long-term outcomes for African American and white veterans. RESULTS: African Americans were 11% of veterans, and in comparison with their white counterparts had more hypertension, diabetes, and acute myocardial infarction. African Americans less often underwent stenting (44% vs 49%), although hospital mortality (2.0% vs 1.9%) and same-admission bypass surgery (1.9% vs 2.2%) rates were similar. Two-year survival was 89% in African Americans and 91% in white veterans (P =.0014), and after adjustment for covariates African Americans had slightly higher mortality rates (hazard ratio 1.11, 95% confidence interval 1.05-1.17). At 2 years almost 61% of both African American and white veterans were rehospitalized for any reason. CONCLUSION: Short- and long-term outcomes for African American and white veterans undergoing PCI in VA medical centers were similar, although African Americans underwent stenting less often.

Black or African American↗
PubMed2001

Personal growth in medical faculty: a qualitative study.

BACKGROUND: A physician's effectiveness depends on good communication, and cognitive and technical skills used with wisdom, compassion, and integrity. Attaining the last attributes requires growth in awareness and management of one's feelings, attitudes, beliefs, and life experiences. Yet, little empiric research has been done on physicians' personal growth. OBJECTIVE: To use qualitative methods to understand personal growth in a selected group of medical faculty. DESIGN: Case study, using open-ended survey methods to elicit written descriptions of respondents' personal growth experiences. SETTING: United States and Great Britain. PARTICIPANTS: Facilitators, facilitators-in-training, and members of a personal growth interest group of the American Academy on Physician and Patient, chosen because of their interest, knowledge, and experience in the topic area and their accessibility. MEASUREMENTS: Qualitative analysis of submitted stories included initially identifying and sorting themes, placing themes into categories, applying the categories to the database for verification, and verifying findings by independent reviewers. RESULTS: Of 64 subjects, 32 returned questionnaires containing 42 stories. Respondents and nonrespondents were not significantly different in age, sex, or specialty. The analysis revealed 3 major processes that promoted personal growth: powerful experiences, helping relationships, and introspection. Usually personal growth stories began with a powerful experience or a helping relationship (or both), proceeded to introspection, and ended in a personal growth outcome. Personal growth outcomes included changes in values, goals, or direction; healthier behaviors; improved connectedness with others; improved sense of self; and increased productivity, energy, or creativity. CONCLUSIONS: Powerful experiences, helping relationships, and introspection preceded important personal growth. These findings are consistent with theoretic and empiric adult learning literature and could have implications for medical education and practice. They need to be confirmed in other physician populations.

Adult↗
PubMed2001

Which values do attending physicians try to pass on to house officers?

CONTEXT: Professional development in medicine includes the acquisition of values and attitudes which are fundamental to the role of the physician. Little is known about which values and attitudes attending physicians emphasize in their teaching of medical trainees to help them develop professionally. OBJECTIVE: To determine the values and attitudes which attending physicians try to pass on to residents in order to encourage their professional development. DESIGN: Cross-sectional study using a mailed survey. SETTING: Four university-affiliated teaching hospitals. SUBJECTS: Attending physicians with residency-level teaching responsibilities. MEASUREMENTS: The self-reported single value or attitude that attending physicians try to pass on to house officers. RESULTS: Of the 341 attending physicians who returned a completed questionnaire, 265 (78%) shared the single value or attitude they try to pass on to residents. The four main categories into which more than 95% of responses could be categorized were: (i) caring, (ii) respect, (iii) communication and (iv) integrity. There were no statistically significant differences between the responses given by attending physicians who had been named as excellent role models and their colleagues who had not been so named. CONCLUSIONS: Attending physicians attempt to pass on values and attitudes they consider important for the professional development of medical trainees. Future research might focus on optimal ways to teach these qualities to medical learners.

Attitude of Health Personnel↗
PubMed2000

National survey of internal medicine residency program directors regarding problem residents.

CONTEXT: Internal medicine residency training is demanding and residents can experience a wide variety of professional and personal difficulties. A problem resident is defined by the American Board of Internal Medicine as "a trainee who demonstrates a significant enough problem that requires intervention by someone of authority." Data are sparse regarding identification and management of such residents. OBJECTIVE: To gain more understanding of the prevalence, identification, management, and prevention of problem residents within US internal medicine residency programs. DESIGN, SETTING, AND PARTICIPANTS: Mailed survey of all 404 internal medicine residency program directors in the United States in October 1999, of whom 298 (74%) responded. MAIN OUTCOME MEASURES: Prevalence of problem residents; type of problems encountered; factors associated with identification and management of problem residents. RESULTS: The mean point prevalence of problem residents during academic year 1998-1999 was 6.9% (SD, 5.7%; range, 0%-39%), and 94% of programs had problem residents. The most frequently reported difficulties of problem residents were insufficient medical knowledge (48%), poor clinical judgment (44%), and inefficient use of time (44%). Stressors and depression were the most frequently identified underlying problems (42% and 24%, respectively). The most frequent processes by which problem residents were discovered included direct observation (82%) and critical incidents (59%). Chief residents and attending physicians most frequently identified problem residents (84% and 76%, respectively); problem residents rarely identified themselves (2%). Many program directors believed that residents who are from an underrepresented minority, are international medical graduates, or are older than 35 years are at increased risk of being identified as a problem resident (P<.05). Program directors believed that frequent feedback sessions (65%) and an assigned mentor for structured supervision (53%) were the most helpful interventions. CONCLUSION: Nearly all internal medicine residency programs in this sample had problem residents, whose presenting characteristics and underlying issues were diverse and complex. JAMA. 2000;284:1099-1104

Administrative Personnel↗
PubMed2000

Capturing zebras: what to do with a reportable case.

We had attempted to publish a report of an unusual manifestation of an uncommon disease discovered at autopsy. The case report was not accepted for publication because we had failed to order a highly specific test that would have unequivocally confirmed the diagnosis we entertained and subsequently wrote about. After much deliberation about this case and an extensive review of the literature, we now believe that there is a preferred approach to dealing with a reportable case. Because physicians seldom encounter cases that are reportable, we felt that sharing the important lessons we learned from our missed opportunity might prove helpful and encourage those who are considering preparing a case report for publication.

Humans↗
PubMed2000

SMASH imaging with an eight element multiplexed RF coil array.

SMASH (SiMultaneous Acquisition of Spatial Harmonics) is a technique which can be used to acquire multiple lines of k-space in parallel, by using spatial information from a radiofrequency coil array to perform some of the encoding normally produced by gradients. Using SMASH, imaging speed can be increased up to a maximum acceleration factor equal to the number of coil array elements. This work is a feasibility study which examines the use of SMASH with specialized coil array and data reception hardware to achieve previously unattainable accelerations. An eight element linear SMASH array was designed to operate in conjunction with a time domain multiplexing system to examine the effectiveness of SMASH imaging with as much as eightfold acceleration factors. Time domain multiplexing allowed the multiple independent array elements to be sampled through a standard single-channel receiver. SMASH-reconstructed images using this system were compared with reference images, and signal to noise ratio and reconstruction artifact power were measured as a function of acceleration factor. Results of the imaging experiments showed an almost constant SNR for SMASH acceleration factors of up to eight. Artifact power remained low within this range of acceleration factors. This study demonstrates that efficient SMASH imaging at high acceleration factors is feasible using appropriate hardware, and that time domain multiplexing is a convenient strategy to provide the multiple channels required for rapid imaging with large arrays.

Biophysical Phenomena↗
PubMed2000

When should learning about hospitalized patients end? Providing housestaff with post-discharge follow-up information.

PURPOSE: As hospital stays grow shorter, many patients are discharged to follow up with their primary care physicians before their diagnoses and responses to treatment are clear. The authors studied the value and feasibility of providing housestaff with follow-up information about their former inpatients. METHOD: Patients included in the study (1) had been admitted to the housestaff service during the study period (January to March 1997), (2) had received follow-up care from a primary care physician in the Johns Hopkins Bayview Physicians' Professional Association, and (3) had been hospitalized for at least three days. The primary care physician completed a single-page follow-up form four to six weeks after the patient's discharge from the hospital; that form was given to the house officers who had cared for that patient. RESULTS: Responses to a preintervention questionnaire completed by 28 of 39 house officers (72%) showed that 92% felt it to be important or extremely important to get follow-up information about inpatients; 86% indicated that they rarely or never receive such information. During the study period, house officers were sent follow-up information for 65 of 76 eligible patients (85%). In their responses to a post-intervention questionnaire (response rate 73%), the house officers most valued learning about the accuracy of the discharge diagnosis, the results of additional diagnostic tests, and information about the patient's quality of life since discharge. Housestaff's satisfaction with the follow-up information received about inpatients improved (p = .001). CONCLUSIONS: Providing follow-up information was a feasible intervention that was valued by housestaff.

Adult↗
PubMed2000

Simultaneous optical and nuclear magnetic resonance spectroscopy for monitoring cardiac energetics in vivo.

There are a number of applications in which it is useful to simultaneously collect data from what are traditionally separate instrumentation modalities. In particular, in vivo physiological investigations in which data from parallel experiments must be correlated would benefit from simultaneous data collection through 1) elimination of subject variability, 2) elimination of treatment variability, and 3) a reduction in the number of animal preparations required. Here we describe the simultaneous collection of fluo-3 optical fluorescence and 31P nuclear magnetic resonance (NMR) spectra to measure intracellular calcium levels and high-energy phosphate metabolism, respectively, in vivo. This work is part of ongoing research into the profound anoxia tolerance exhibited by the hearts of certain turtle species. An NMR compatible optical fluorescence spectrometer was constructed and tested. In the 31-cm bore of a 2 T superconducting magnet, NMR and optical spectra were collected every 10-15 min from the in situ, in vivo hearts of anesthetized turtle subjects prior to and during one to three hours of anoxia. It was found that while PCr stores became significantly depleted during anoxia, beta-adenosine triphosphate (ATP) levels remained within 20% of control values, and intracellular diastolic calcium levels did not vary by more than 10%. The ability to make simultaneous phosphorus and calcium measurements on a single subject is important to understanding the exact relationship between phosphorus energy state and maintenance of calcium homeostasis.

Adenosine Triphosphate↗
PubMed2000

Altered airway surfactant phospholipid composition and reduced lung function in asthma.

Pulmonary surfactant in bronchoalveolar lavage fluid (BALF) and induced sputum from adults with stable asthma (n = 36) and healthy controls (n = 12) was analyzed for phospholipid and protein compositions and function. Asthmatic subjects were graded as mild, moderate, or severe. Phospholipid compositions of BALF and sputum from control subjects were similar and characteristic of surfactant. For asthmatic subjects, the proportion of dipalmitoyl phosphatidylcholine (16:0/16:0PC), the major phospholipid in surfactant, decreased in sputum (P < 0.05) but not in BALF. In BALF, mole percent 16:0/16:0PC correlated with surfactant function measured in a capillary surfactometer, and sputum mole percent 16:0/16:0PC correlated with lung function (forced expiratory volume in 1 s). Neither surfactant protein A nor total protein concentration in either BALF or sputum was altered in asthma. These results suggest altered phospholipid composition and function of airway (sputum) but not alveolar (BALF) surfactant in stable asthma. Such underlying surfactant dysfunction may predispose asthmatic subjects to further surfactant inhibition by proteins or aeroallergens in acute asthma episodes and contribute to airway closure in asthma. Consequently, administration of an appropriate therapeutic surfactant could provide clinical benefit in asthma.

Adolescent↗
PubMed2000

Exogenous surfactant supplementation in infants with respiratory syncytial virus bronchiolitis.

Infants with respiratory syncytial virus (RSV) bronchiolitis are deficient in surfactant, both in quantity and ability to reduce surface tension. New evidence suggests surfactant has a role in maintaining the patency of conducting airways, which has implications for RSV bronchiolitis. A randomized, controlled pilot study was undertaken to assess the effects of exogenous surfactant supplementation to RSV-positive infants on pulmonary mechanics, indices of gas exchange, and the phospholipid composition of bronchoalveolar lavage fluid (BALF). Nineteen ventilated infants (median corrected age 4 wk) received either two doses of surfactant (Survanta, 100 mg/kg) within 24 and 48 h of mechanical ventilation (n = 9), or air placebo (n = 10). Static lung compliance and resistance of infants in the placebo but not in the surfactant-treated group became progressively worse over the first 30 h following enrollment. Although no significant acute changes in gas exchange parameters were seen following surfactant, infants in the surfactant group showed a more rapid improvement in oxygenation and ventilation indices over the first 60 h of ventilation. Surfactant status was assessed from the concentration ratio in BALF of the disaturated phospholipid species dipalmitoylphosphatidylcholine to that of the monounsaturated species palmitoyloleoylphosphatidylcholine. This ratio correlated with both lung compliance (positively) and resistance (negatively), and over time increased in the treated group and declined in placebo infants. The data from this pilot study suggest that functional surfactant has a role in maintaining small airway patency as well as lung compliance in infants infected with RSV and an outcome study is now warranted.

Bronchiolitis, Viral↗