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Biomedical subjects

Eduardo Salas

Publications and source records attributed to Eduardo Salas.

15 recordsLinked to original sources

The nitric oxide donor LA 419 decreases ischemic brain damage.

Stroke represents a major clinical problem with limited available therapeutic treatments. Nitric oxide (NO) and the enzymes that produce it are involved in the pathogenesis of this disease. Here we investigated whether the novel NO donor LA 419 was able to ameliorate the consequences of stroke in an experimental model of global ischemia. We observed a sharp increase in the amounts of inducible NO synthase (iNOS) and nitrotyrosine in the cerebral cortex of experimental rats and a moderate increase of neuronal NO synthase (nNOS), as demonstrated by immunohistochemistry, Western blotting, and enzymatic activity assays. Treatment of these animals with LA 419 completely prevented ischemia-induced upregulation of nitrergic markers. Magnetic resonance imaging of the experimental brains showed a marked decrease in apparent diffusion coefficient (ADC) following ischemia-reperfusion, which was significantly corrected by pre-treatment with LA 419. These results clearly show that LA 419 is an efficient modulator of NO-related pathophysiological events and could eventually be used for the treatment of patients with cerebrovascular pathologies.

Animals↗

Understanding team adaptation: a conceptual analysis and model.

This endeavor provides a multidisciplinary, multilevel, and multiphasic conceptualization of team adaptation with theoretical roots in the cognitive, human factors, and industrial-organizational psychology literature. Team adaptation and the emergent nature of adaptive team performance are defined from a multilevel, theoretical standpoint. An input-throughput-output model is advanced to illustrate a series of phases unfolding over time that constitute the core processes and emergent states underlying adaptive team performance and contributing to team adaptation. The cross-level mixed-determinants model highlights team adaptation in a nomological network of lawful relations. Testable propositions, practical implications, and directions for further research in this area are also advanced.

Adaptation, Psychological↗

Teamwork as an essential component of high-reliability organizations.

Organizations are increasingly becoming dynamic and unstable. This evolution has given rise to greater reliance on teams and increased complexity in terms of team composition, skills required, and degree of risk involved. High-reliability organizations (HROs) are those that exist in such hazardous environments where the consequences of errors are high, but the occurrence of error is extremely low. In this article, we argue that teamwork is an essential component of achieving high reliability particularly in health care organizations. We describe the fundamental characteristics of teams, review strategies in team training, demonstrate the criticality of teamwork in HROs and finally, identify specific challenges the health care community must address to improve teamwork and enhance reliability.

Cooperative Behavior↗

Does crew resource management training work? An update, an extension, and some critical needs.

OBJECTIVE: This review provides the state of crew resource management (CRM) training evaluations since the E. Salas, C. S. Burke, C. A. Bowers, and K. A. Wilson (2001) review and extends it to areas beyond aviation cockpits. Some critical evaluation needs in CRM training are also covered. BACKGROUND: Because of the purported success of CRM training in aviation, other high-consequence domains have begun to implement CRM training for their workforces. However, the true impact of CRM training in aviation and these other domains has yet to be determined. METHOD: Using D. L. Kirkpatrick's (1976) framework for evaluating training (i.e., reactions, learning, behavior, and organizational impact), we reviewed 28 published accounts of CRM training to determine its effectiveness within aviation, medicine, offshore oil production and maintenance, shipping/maritime, and nuclear power domains. RESULTS: Findings indicate that CRM training generally produced positive reactions from trainees; however, the impact of training on learning and behavioral changes suggest mixed results across and within domains. Furthermore, and as was found by Salas, Burke, et al. in 2001, we cannot ascertain whether CRM has had an impact on the organization's bottom line (i.e., safety). CONCLUSION: Based on the results, there are several critical needs that the CRM training community must address before CRM training can have the desired impact on safety: a mandate, access to data, and resources. APPLICATION: As CRM training expands to organizations beyond aviation, it is critical that its impact be understood such that it can be improved and achieve the intended results.

Fatigue↗

Effects on primary haemostasis of an anti-inflammatory agent with 5-lipoxygenase and cyclooxygenase inhibitory activity.

OBJECTIVE: Licofelone ([2,2-dimethyl-6-(4-chlorophenyl)-7-phenyl-2,3-dihydro-1H-pyrrolizine-5-yl]-acetic acid) has been demonstrated to inhibit cyclooxygenase (COX)-1, COX-2, and 5-lipoxygenase. The aim of this study was to investigate the in-vitro effects of licofelone on platelet function. Effects observed were compared with those produced by the classic COX-1 inhibitor aspirin (ASA). METHODS: Platelet aggregation was assessed by a turbidimetric method. Platelet haemostatic performance was studied with the platelet function analyser (PFA-100), using collagen epinephrine and collagen ADP cartridges. Interaction of platelets with thrombogenic surfaces was analysed by perfusion experiments performed under flow conditions using both parallel and annular chambers. RESULTS: Licofelone prolonged the lag time of platelet aggregation induced by arachidonic acid and reduced maximal platelet aggregation induced by ADP or collagen. Studies using PFA-100 demonstrated that licofelone (0.1, 1 and 10 muM) significantly prolonged closure times (P < 0.05) with both types of cartridges. In studies with the parallel chamber exposing purified collagen, both licofelone and ASA significantly reduced (P < 0.05) overall platelet interaction with the thrombogenic surface. In studies performed in annular chamber exposing a highly thrombogenic vessel surface, licofelone reduced height and area of the platelet masses deposited (7.0 +/- 0.5 mum; P < 0.005 and 80.2 +/- 17.3 mum; P < 0.05 vs. control 10.6 +/- 0.9 mum and 194.8 +/- 44.7 mum, respectively). ASA also impaired thrombus formation but differences did not reach the levels of statistical significance. CONCLUSIONS: Under our experimental in-vitro conditions, licofelone interfered with platelet function as demonstrated by a diminished platelet aggregation, being more powerful than ASA and reducing the interaction of platelets with thrombogenic surfaces.

Acetates↗

The role of teamwork in the professional education of physicians: current status and assessment recommendations.

BACKGROUND: The Institute of Medicine (IOM) has recommended that organizations establish interdisciplinary team training programs that incorporate proven methods for team management. Teamwork can be assessed during physician medical education, board certification, licensure, and continuing practice. Team members must possess specific knowledge, skills, and attitudes (KSAs), such as the ability to exchange information, which enable individual team members to coordinate. ASSESSING PHYSICIAN TEAMWORK: KSAs might be elicited and assessed across a physician's career, starting in medical school and continuing through licensure and board certification. Professional bodies should be responsible for the development of specific team knowledge and skill competencies and for promoting specific team attitude competencies. Tools are available to assess medical student, resident, and physician competence in these critical team KSAs. CHALLENGES AND COMPLEXITIES IN TEAM PERFORMANCE MEASUREMENT: For teamwork skills to be assessed and have credibility, team performance measures must be grounded in team theory, account for individual and team-level performance, capture team process and outcomes, adhere to standards for reliability and validity, and address real or perceived barriers to measurement.

Education, Medical↗

Using simulation-based training to improve patient safety: what does it take?

BACKGROUND: Through simulations health care workers can learn by practicing skills taught and experiencing mistakes before interacting with an actual patient. A number of areas within the health care industry are currently using simulation-based training to help individuals and teams improve patient safety. WHAT IS SIMULATION-BASED TRAINING? The key components of simulation-based training are as follows: performance history/skill inventory, tasks/competencies, training objectives, events/exercises, measures/metrics, performance diagnosis, and feedback and debrief. WHAT DOES IT TAKE FOR SIMULATION-BASED TRAINING TO BE EFFECTIVE? To be effective, simulation-based training must be implemented appropriately. The guidelines are as follows: understand the training needs and requirements; instructional features, such as performance measurement and feedback, must be embedded within the simulation; craft scenarios based on guidance from the learning outcomes; create opportunities for assessing and diagnosing individual and/or team performance within the simulation; guide the learning; focus on cognitive/psychological simulation fidelity; form a mutual partnership between subject matter experts and learning experts; and ensure that the training program worked. CONCLUSION: The health care community can gain significantly from using simulation-based training to reduce errors and improve patient safety when it is designed and delivered appropriately.

Guidelines as Topic↗

Glutathione peroxidase activity in cell cultures from different regions of human epididymis.

AIM: To study the secretory activity and androgen regulation of glutathione peroxidase (GPx) in epithelial cell cultures from human epididymis. METHODS: Tissue was obtained from patients undergoing therapeutic orchidectomy for prostatic cancer. Epithelial cell cultures were obtained from the caput, corpus and cauda epididymides. Enzymatic activity was measured in conditioned media by colorimetric methods in absence or presence of 1, 10 or 100 nmol/L testosterone. The effect of 1 micromol/L flutamide was also evaluated. RESULTS: GPx activity was higher in cultures from corpus and cauda than caput epididymidis. The presence of different concentrations of testosterone increase enzyme activity in cell cultures from all epididymal regions. Addition of flutamide reverses the androgen dependent increase of GPx activity. CONCLUSION: GPx activity is secreted from human epididymal cells in a region dependent manner and is regulated by androgens.

Aged↗

Inhibition of thrombosis by a novel platelet selective S-nitrosothiol compound without hemodynamic side effects.

UNLABELLED: Platelet and endothelial production of bioactive nitric oxide (NO) is known to be impaired in acute coronary syndromes, thus compounds that release NO are useful candidates to restore NO-vascular functions. OBJECTIVE: We have studied whether donation of NO with a novel platelet-selective S-nitrosothiol compound (LA810) at a systemic level can inhibit thrombosis elicited by damaged vessel wall (eroded and disrupted vessel wall) at hemodynamic conditions typical of patent and stenotic coronary arteries. METHODS: Thrombogenicity was measured in the porcine experimental model and assessed as platelet-thrombus formation in the ex vivo Badimon perfusion chamber. After baseline perfusions, female pigs (Large WhitexLandrace) were given intravenous infusion of LA810 or GSNO standard S-nitrosothiol during 2 h. Changes in blood pressure, heart rate and in vitro platelet aggregation were measured. RESULTS: LA810 significantly decreased thrombus formation at any degree of vascular damage and shear rate (p<0.001) without hypotensive side-effects or heart rate variations. In contrast, inhibition of thrombus formation by GSNO required high doses associated to hypotensive episodes. Platelet aggregation induced by collagen was inhibited after nitrosothiol infusion in whole blood (LA810) and platelet rich plasma (LA810 and GSNO). In addition, there was a drug-dependent rise in platelet guanosine 3',5'-cyclic monophosphate (cGMP) levels. CONCLUSIONS: This new anti-ischemic NO-donor (NOd) LA810 that inhibits platelet function without hypotensive side-effects seems a highly efficacious strategy to reduce acute thrombosis triggered by coronary artery disease.

Animals↗

Nitric oxide synthase and NADPH-diaphorase after acute hypobaric hypoxia in the rat caudate putamen.

Changes in the production system of nitric oxide (NO), a multifunctional biological messenger known to participate in blood-flow regulation, neuromodulation, and neuroprotection or neurotoxicity, were investigated in the caudate putamen of adult rats submitted to hypobaric hypoxia. Employing immunohistochemistry, Western blotting, enzymatic assay, and NADPH-diaphorase staining, we demonstrate that neuronal nitric oxide synthase (nNOS) expression and constitutive nitric oxide synthase (cNOS) activity were transiently activated by 7 h of exposure to a simulated altitude of 8325 m (27,000 ft). In addition, endothelial nitric oxide synthase (eNOS) immunoreactivity and blood vessel NADPH-diaphorase staining peaked immediately after the hypoxic stimulus, whereas inducible nitric oxide synthase (iNOS) expression and activity remained unaltered. Nitrotyrosine formation, a marker of protein nitration, was evaluated by immunohistochemistry and Western blotting, and was found to increase parallel to nitric oxide synthesis. We conclude that the nitric oxide system undergoes significant transient alterations in the caudate putamen of adult rats submitted to acute hypobaric hypoxia.

Altitude↗

Hypobaric hypoxia modifies constitutive nitric oxide synthase activity and protein nitration in the rat cerebellum.

Ischemic hypoxia provokes alterations in the production system of nitric oxide in the cerebellum. We hypothesize that the nitric oxide system may undergo modifications due to hypobaric hypoxia and that may play a role in high altitude pathophysiology. Therefore, changes in the nitric oxide system of the cerebellum of rats submitted to acute hypobaric hypoxia were investigated. Adult rats were exposed for 7 h to a simulated altitude of 8235 m (27000 ft.) and then killed after 0 h or 1, 3, 5 and 10 days of reoxygenation. Nitric oxide synthase calcium-dependent and -independent activity, immunoblotting and immunohistochemistry of neuronal, endothelial, and inducible nitric oxide synthase, and nitrotyrosine were evaluated. Immunoreactivity for neuronal nitric oxide synthase slightly increased in the baskets of the Purkinje cell layer and in the granule cells, after 0 h of reoxygenation, although no changes in neuronal nitric oxide synthase immunoblotting densitometry were detected. Calcium-dependent activity significantly rose after 0 h of reoxygenation, reaching control levels in the following points, and being coincident with a peak of eNOS expression. Nitrotyrosine formation showed significant increments after 0 h and 1 day of reoxygenation. Nitrotyrosine immunoreactivity showed an intracellular location change in the neurons of the cerebellar nuclei and in addition, an appearance of nitration in the soma of the Purkinje cells was detected. No changes in inducible nitric oxide synthase activity, immunoblotting or immunohistochemistry were detected. We conclude that at least part of the nitric oxide system is involved in cerebellum responses to hypobaric hypoxia.

Altitude↗

TPL-KATS-card sort: a tool for assessing structural knowledge.

The study of how individuals organize knowledge has been a popular endeavor for several decades. As a result, techniques have been developed to assess how individuals represent and organize knowledge internally. Although several conceptual knowledge elicitation methods have been developed and used to assess the organization of knowledge, their use is often labor intensive and time consuming. Presented here is a software tool that was developed to reduce the problems associated with manually administering the conceptual knowledge elicitation technique, or card sorting. The TPL-KATS-card sort software not only simplifies the administration of the task, but also adds features to the card-sorting task such as media insertion, time stamping, and instructorless administration. In the present article, an introduction to the card-sorting technique is provided, the new software tool is described, and the advantages of the software are detailed.

Concept Formation↗

Effects of Training Goals and Goal Orientation Traits on Multidimensional Training Outcomes and Performance Adaptability.

This research examined the effects of mastery vs. performance training goals and learning and performance goal orientation traits on multidimensional outcomes of training. Training outcomes included declarative knowledge, knowledge structure coherence, training performance, and self-efficacy. We also examined the unique impact of the training outcomes on performance adaptability by predicting generalization to a more difficult and complex version of the task. The experiment involved 60 trainees learning a complex computer simulation over 2 days. The research model posited independent effects for training goals relative to goal orientation traits and independent contributions of training outcomes to the performance adaptability of trainees. The findings were consistent with the proposed model. In particular, self-efficacy and knowledge structure coherence made unique contributions to the prediction of performance adaptability after controlling for prior training performance and declarative knowledge. Implications and extensions are discussed. Copyright 2001 Academic Press.

Journal Article↗

Successful treatment of shoulder pain syndrome due to supraspinatus tendinitis with transdermal nitroglycerin. A double blind study.

We have conducted a prospective double blind randomized and placebo controlled clinical study in 20 patients with shoulder pain syndrome caused by supraspinatus tendinitis to determine whether transdermal nitroglycerin (NTG) has analgesic action in this condition. In a randomized manner we used a 5-mg NTG (Nitroplast) patch per day over 3 days or similar placebo patches applied in the most painful area. Patients were evaluated before treatment was initiated and after 24 and 48 h. The assessment was made blindly by the same clinical investigator. The follow-up showed a significant decrease in intensity of pain at 24 h (7.05 +/- 0.4 to 4.5 +/- 0.5) and 48 h (2 +/- 0.3) in the NTG group (P < 0.003). No changes were observed in the placebo group. The mean pain duration, activity of the extremity and hours of sleep also improved in the NTG group, with no significant modification in the placebo group. Two patients experienced headache as a side effect 24 h after treatment was started. Patients in the NTG group remained free of symptoms when they were assessed 15 days later. We conclude that NTG is useful in the treatment of shoulder pain syndrome caused by supraspinatus tendinitis and that this treatment could be a useful approach to the management of this common disturbance and probably also in other tendon musculoskeletal disorders.

Administration, Cutaneous↗