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Biomedical subjects

E Salas

Publications and source records attributed to E Salas.

At least 19 recordsLinked to original sources
PubMed2006

Bloodstream cells phenotypically identical to human mesenchymal bone marrow stem cells circulate in large amounts under the influence of acute large skin damage: new evidence for their use in regenerative medicine.

OBJECTIVES: Recent work has shown that human bone marrow contains mesenchymal stem cells (MSCs). However, little is known about their presence in peripheral blood. Since these cells are potentially responsible for tissue repair after injury, their number should be increased during these situations. To demonstrate their number during these situations, we measured MSCs in the peripheral blood of healthy donors and burn patients. MATERIALS AND METHODS: Blood samples were obtained from 15 acute burn patients and 15 healthy donors. We performed flow cytometric analysis, using a large monoclonal antibody panel: CD44, CD45, CD14, DR, CD34, CD19, CD13, CD29, CD105, CD1a, CD90, CD38, CD25. MSC phenotype was considered positive for CD44, CD13, CD29, CD90, and CD105, and negative for the other monoclonals. The testing was performed on day 3 after injury. We correlated the results with the age, sex, and size and type of burns. RESULTS: Cells expressing the MSC phenotype were detected in the peripheral blood of both groups. Noteworthy, compared with samples from healthy donors (0.0078 +/- 0.0044), blood obtained from burn patients showed a higher MSC percentage (0.1643 +/- 0.115; P < .001). The percentage of MSCs correlated with the size and severity of the burn. Increased values were also observed among younger patients. CONCLUSIONS: MSCs have an important role in regenerative processes of human tissues. We found cells phenotypically identical to MSCs circulating in physiological number in normal subjects, but in significantly higher amounts during acute large burns. Therefore, they may represent a previously unrecognized circulatory component to the process of skin regeneration.

Adult↗
PubMed2006

Ischemic preconditioning and kidney transplantation: in vivo nitric oxide monitoring in a rat ischemia-reperfusion experimental model.

Direct nitric oxide measurement in live tissue would help us to understand its role in ischemia-reperfusion injury and its relationship to ischemic preconditioning (IP). We constructed four experimental groups of ischemia-reperfusion in the rat kidney: G1 were controls; G2, 1 hour of renal ischemia; G3 and G4: one or two 15/10 minute cycles, respectively, of IP prior to 1 hour of ischemia. Real-time in vivo nitric oxide measurements were compared with functional parameters of kidney damage at 24 hours. The peaks of nitric oxide production in the IP periods increased less in the rising curve of nitric oxide production during the 1 hour ischemia time. No improvement in the IP groups was observed based on serum creatinine levels at 24 hours.

Animals↗
PubMed2005

Isolation of flavanol-anthocyanin adducts by countercurrent chromatography.

Pigments of the flavanol-anthocyanin (F-A+) type detected earlier in wine are synthesized using a protocol adapted from the synthesis of procyanidin dimers. The F-A+ adduct thus obtained is purified by countercurrent liquid-liquid partition, currently referred to as countercurrent chromatography (CCC). The solvent system consists of tert-butyl methyl ether-n-butanol-acetonitrile-water (2:2:1:5, acidified with 0.1% trifluoroacetyl) with the light organic phase acting as a stationary phase and the aqueous phase as the mobile phase. Four fractions are recovered and analyzed by high-performance liquid chromatography coupled to a diode-array detector and electrospray ionization mass spectrometer. The multilayer CCC method allowed the separation of pigments in three different groups. The first group consists of hydrosoluble pigments present in fraction 1; the second group consists of the F-A+ adducts [catechin-malvidin 3 glucoside (Mv3glc), along with some (catechin)2-Mv3glc]; and the third group is their anthocyanin precursor, Mv3glc.

Anthocyanins↗
PubMed2005

Promoting health care safety through training high reliability teams.

Many organizations have been using teams as a means of achieving organizational outcomes (such as productivity and safety). Research has indicated that teams, especially those operating in complex environments, are not always effective. There is a subset of organizations in which teams operate that are able to balance effectiveness and safety despite the complexities of the environment (for example, aviation, nuclear power). These high reliability organizations (HROs) have begun to be examined as a model for those in other complex domains, such as health care, that strive to reach a status of high reliability. In this paper we analyse the components leading to the effectiveness of HROs by examining the teams that comprise them. We use a systems perspective to uncover the behavioral markers by which high reliability teams (HRTs) are able to uphold the values of their parent organizations, thereby promoting safety. Using these markers, we offer guidelines and developmental strategies that will help the healthcare community to shift more quickly to high reliability status by not focusing solely on the organizational level.

Delivery of Health Care↗
PubMed2004

Effects of a novel platelet nitric oxide donor (LA816), aspirin, clopidogrel, and combined therapy in inhibiting flow- and lesion-dependent thrombosis in the porcine ex vivo model.

BACKGROUND: Acetylsalicylic acid (ASA), or aspirin, plus clopidogrel is becoming the standard antithrombotic treatment in people with coronary disease. Novel approaches such as the use of platelet-selective nitric oxide (NO) donors may provide additional protection against thrombosis. We evaluated the antithrombotic properties of a novel platelet-selective NO donor (LA816) administered alone and in combination with ASA, clopidogrel, or ASA+clopidogrel. METHODS AND RESULTS: Thrombogenicity was measured in the porcine experimental model and assessed as platelet-thrombus formation in the ex vivo Badimon perfusion chamber. Pigs were randomly divided into 4 groups: (1) placebo control, (2) clopidogrel, (3) ASA, and (4) ASA+clopidogrel (ASA and clopidogrel were given orally, 10 mg x kg(-1) x d(-1) for 3 d). The animals were anesthetized, heparinized, and catheterized, and the Badimon perfusion chamber was placed in an extracorporeal shunt. After baseline perfusions, all animal groups received the intravenous infusion of LA816 for 2 hours. Platelet aggregation, blood pressure, and heart rate also were evaluated during the experiments. LA816, clopidogrel, and ASA+clopidogrel produced a reduction of approximately 45% on thrombus mass versus placebo control perfusions (P<0.05). Combined treatment of oral ASA+clopidogrel and intravenous LA816 produced a significant further reduction of 25% in platelet deposition (70% from placebo controls; P<0.0001). LA816 intravenous treatment did not modify blood pressure or heart rate. CONCLUSIONS: Acute NO donation with LA816, without modifying hemodynamic parameters, provides the same inhibitory effect as that obtained with chronic treatment with clopidogrel+ASA. Moreover, LA816 provides platelet inhibitory effects in addition to those of the combined blockade of cyclooxygenase and P2y(12) receptor.

Adenosine Diphosphate↗
PubMed2004

How to turn a team of experts into an expert medical team: guidance from the aviation and military communities.

There is no question that interdisciplinary teams are becoming ubiquitous in healthcare. It is also true that experts do not necessarily combine to make an expert team. However when teams work well they can serve as adaptive systems that allow organisations to mitigate errors within complex domains, thereby increasing safety. The medical community has begun to recognise the importance of teams and as such has begun to implement team training interventions. Over the past 20 years the military and aviation communities have made a large investment in understanding teams and their requisite training requirements. There are many lessons that can be learned from these communities to accelerate the impact of team training within the medical community. Therefore, the purpose of the current paper is to begin to translate some of the lessons learned from the military and aviation communities into practical guidance that can be used by the medical community.

Aviation↗
PubMed2002

Quantitative ultrasound calcaneus measurements: normative data and precision in the spanish population.

Quantitative ultrasound (QUS) assessment at the calcaneus has been found to be a safe and reliable method for evaluating skeletal status. In this study we have determined the normative QUS data in the Spanish population for the Sahara Clinical Sonometer (Hologic). Broadband ultrasound attenuation (BUA), speed of sound (SOS), quantitative ultrasound index (QUI) and estimated bone mineral density (BMD) were determined. We also studied the precision in vivo and in vitro. The short-term in vivo precision (CV) was 4.88% for BUA, 0.36% for SOS, 3.45% for QUI and 4.15% for BMD, while in vitro precision was 0.40% for SOS and 2.67% for BUA. Our results are comparable to reference population data previously published in other countries and may serve as reference normative data for both genders in Spain.

Adolescent↗
PubMed2001

To transfer or not to transfer? Investigating the combined effects of trainee characteristics, team leader support, and team climate.

Eighty pilots participated in a study of variables influencing the transfer process. Posttraining performance was assessed in a flight simulation under 1 of 2 conditions. Those in the maximum performance condition were made aware of the skill to be assessed and the fact that their teammates were confederates, whereas those in the typical performance condition were not. The results indicated that (a) simulator ratings correlated with a measure of transfer to the cockpit for those in the typical condition only; (b) team leader support, manipulated in a pretask brief, moderated the disparity between maximum and typical performance; (c) team climate mediated the impact of support on performance in the typical condition; (d) those with a stronger predisposition toward the trained skill viewed their climate as more supportive; and (e) perceptions of team climate were better predictors of performance for those with a more external locus of control.

Adult↗
PubMed2001

The science of training: a decade of progress.

This chapter reviews the training research literature reported over the past decade. We describe the progress in five areas of research including training theory, training needs analysis, antecedent training conditions, training methods and strategies, and posttraining conditions. Our review suggests that advancements have been made that help us understand better the design and delivery of training in organizations, with respect to theory development as well as the quality and quantity of empirical research. We have new tools for analyzing requisite knowledge and skills, and for evaluating training. We know more about factors that influence training effectiveness and transfer of training. Finally, we challenge researchers to find better ways to translate the results of training research into practice.

Cognition↗
PubMed2001

Team training in the skies: does crew resource management (CRM) training work?

The aviation community has invested great amounts of money and effort into crew resource management (CRM) training. Using D. L. Kirkpatrick's (1976) framework for evaluating training, we reviewed 58 published accounts of CRM training to determine its effectiveness within aviation. Results indicated that CRM training generally produced positive reactions, enhanced learning, and promoted desired behavioral changes. However, we cannot ascertain whether CRM has an effect on an organization's bottom line (i.e., safety). We discuss the state of the literature with regard to evaluation of CRM training programs and, as a result, call for the need to conduct systematic, multilevel evaluation efforts that will show the true effectiveness of CRM training. As many evaluations do not collect data across levels (as suggested by D. L. Kirkpatrick, 1976, and by G. M. Alliger, S. I. Tannenbaum, W. Bennett, Jr., & H. Traver, 1997), the impact of CRM cannot be truly determined; thus more and better evaluations are needed and should be demanded.

Aircraft↗
PubMed2001

What determines whether observers recognize targeted behaviors in modeling displays?

Observational learning is based on a critical assumption that trainees can and do recognize critical modeled behaviors. This assumption has been virtually untested in applied settings. We studied the effects of work experience and instructions on the ability of 59 observers to recognize target behaviors in an observational learning paradigm similar to existing ones. Additionally, we investigated the effects of two key factors that were hypothesized to affect the recognition process in observational learning. The results indicated that only observers who had a minimum of work experience (i.e., intermediate and experienced observers in the study) were able to consistently recognize targeted behaviors. Additionally, recognition was influenced by the level of detail of instructions given to the participants. Finally, characteristics of the modeled behaviors greatly affected recognition: Overall, examples of negative behaviors were better recognized than were positive examples. Behaviors whose consequence was shown were also better recognized than those that were neither reinforced nor punished in the video. The results are discussed in terms of their implications for the design of observational learning as a training strategy in complex and applied social learning situations. The applications of this work include the design of training, and the training of evaluators and observers.

Aviation↗
PubMed2001

Does stress training generalize to novel settings?

Many high-stress task environments are complex and dynamic, and it is often difficult during training to anticipate the exact conditions that may be encountered in these settings. We conducted an empirical study to examine whether the positive effects of stress training that addressed one specific type of stressor and task would remain when trainees performed under a novel stressor or performed a novel task. Participants performed a laboratory task under stress conditions. Measures of task performance and self-reported stress were obtained at three performance trials: (a) prior to stress training, (b) after a stress training intervention targeted to that specific task environment, and (c) under novel stressor/task conditions. Results indicated that the beneficial effects of stress training were retained when participants performed under a novel stressor and performed a novel task. We discuss the implications of this study with regard to their application in the design of stress training and the transfer of learning to complex, dynamic task environments.

Adolescent↗
PubMed2000

Influence of residual stenosis in determining restenosis after cutting balloon angioplasty.

The cutting balloon is a new device for coronary angioplasty, which, by the combination of incision and dilatation of the plaque, is believed to minimize arterial wall trauma, the neoproliferative response, and subsequent restenosis. In this study, we sought to determine predictors of the restenosis using this technique. Seventy-seven patients underwent successful coronary angioplasty with cutting balloon alone. In 67 of these patients (87%), we performed a control angiogram at 6-month follow-up. Pre-, post-, and late angiographic results were evaluated by quantitative coronary analysis. Clinical and angiographic variables were correlated with restenosis as a binary variable and a continuous variable (late loss and late minimum luminal diameter). Univariate analysis showed that the immediate postprocedure minimum luminal diameter (MLD) was smaller in the restenotic group (defined as MLD > 50% by quantitative coronary angiography) than in the nonrestenotic group (1.90 +/- 0.47 mm vs. 2.19 +/- 0.56 mm, P < 0.05). In addition, the immediate percentage of stenosis was higher in the restenotic group than in the nonrestenotic group (37% +/- 10% vs. 27% +/- 11%, P < 0. 003). Multivariate analysis identified the immediate postcutting balloon percentage of stenosis as an independent determinant of binary restenosis (P < 0.008). When restenosis was defined as a continuous variable, the immediate postprocedure MLD was an independent predictor of late loss (P < 0.02) and of late MLD (P < 0. 0002). No clinical, preprocedure angiographic, or technical variables tested were associated with restenosis. The degree of postprocedural residual stenosis after cutting balloon angioplasty is predictive of late restenosis.

Adult↗
PubMed2000

The influence of shared mental models on team process and performance.

The influence of teammates' shared mental models on team processes and performance was tested using 56 undergraduate dyads who "flew" a series of missions on a personal-computer-based flight-combat simulation. The authors both conceptually and empirically distinguished between teammates' task- and team-based mental models and indexed their convergence or "sharedness" using individually completed paired-comparisons matrices analyzed using a network-based algorithm. The results illustrated that both shared-team- and task-based mental models related positively to subsequent team process and performance. Furthermore, team processes fully mediated the relationship between mental model convergence and team effectiveness. Results are discussed in terms of the role of shared cognitions in team effectiveness and the applicability of different interventions designed to achieve such convergence.

Achievement↗
PubMed2000

Sustained response to combination therapy in a patient with chronic hepatitis C and thrombocytopenia secondary to alpha-interferon.

Recent data suggest that hepatitis C viral (HCV) infection may induce a significant autoimmune reaction to platelets, but the mechanism is unknown. Many patients with chronic hepatitis C, in fact, have high levels of platelet-associated immunoglobulin G (PAIgG) and HCV-RNA is present in the platelets of 100% of those patients with thrombocytopenia and high PAIgG levels. Hepatitis C virus infection has been associated with the development of thrombocytopenic purpura, sometimes triggered during interferon (IFN) therapy. In such cases, the treatment of the underlying disease is a difficult problem to solve. We report the case of a patient with chronic hepatitis C, who developed life-threatening thrombocytopenic purpura after a prolonged course of IFN-alpha2b over a 4-year period. Treatment with anti-immunoglobulin gammaglobulin (Polyglobin; Química Farmaceutica Bayer, Barcelona, Spain) had a transient effect on the platelet count, but prolonged therapy with prednisone was necessary for definitive relief of the haematological complication. Two years later, the patient was treated with combined therapy, including ribavirin (1200 mg/day) and IFN-alpha2b (5 mU, t.i.w.) for 12 months. This therapy induced a sustained response, both biochemical and virological, without haematological complications. This observation suggests that ribavirin may be of benefit in the treatment of immune-mediated thrombocytopenia in patients with chronic hepatitis C, preventing the harmful effect of IFN-alpha but also allowing both drugs to be combined so as to increase the probability of sustained remission of the liver disease.

Antiviral Agents↗