1,721,065 research outputs found
Dossiê Antonio Tabucchi. A vida não basta
No full text(2013. Coord. Dossiê). Antonio Tabucchi. A vida não basta, Estudos Italianos em Portugal (n. s.), 8, 141-167.
ISSN 0807 858
Improving neurologic iutcome in cardiac surgery patients with a goal-oriented therapy protocol based on cerebral regional oxygen saturation
No full textIMPROVING NEUROLOGIC OUTCOME IN CARDIAC SURGERY PATIENTS
WITH A GOAL-ORIENTED THERAPY PROTOCOL BASED ON CEREBRAL
REGIONAL OXYGEN SATURATION
F. Franchi, B. Biagioli, A. Tabucchi, S. Scolletta
University of Siena, Siena, Italy
INTRODUCTION. NIRS (near infrared spectroscopy) is a neuro-monitoring tool that
provides cerebral regional oxygen saturation (rSO2).
OBJECTIVES. We hypothesized that a goal-directed therapy (GDT) protocol based on
rSO2 values would be associated with reduced incidence of postoperative neurologic
complications (PNC) in high-risk cardiac surgery (CS) patients.
METHODS. 85 high-risk CS patients (mean age 71 ± 9) were monitored during CS with
NIRS (cNIRS group). Intraoperative interventions were based on a GDT protocol aimed at
improving cerebral rSO2 and blood flow (i.e., increasing arterial oxygen content with red blood cell transfusions and FiO2; increasing systemic blood flow and cerebral perfusion
pressure with fluids, inotropic, and vasoactive drugs and increasing pump-flow during
cardiopulmonary bypass). cNIRS group was compared with 100 patients (mean age 73 ± 6)
(not monitored with cerebral NIRS, N-cNIRS group) who were selected from a historical
database using a propensity-matching analysis. Neuron-specific enolase (NSE) and S-100B
protein were collected at different times in the cNIRS group.
RESULTS. PNC resulted 21 % in the cNIRS group and 35 % in N-cNIRS group
(p\0.05). N-cNIRS group showed longer times of mechanical ventilation (MV)
(150.3 ± 274.9 vs 29.9 ± 65 h, p = 0.02) and ICU stay (13.3 ± 14.7 vs 3.4 ± 3.9 days,
p = 0.01) than cNIRS group. In the cNIRS group, preoperative rSO2 values were signifi-
cantly lower in the patients who exhibited PNC than those who had good neurologic
outcome (59.6 ± 7.6 vs 63.4 ± 7.8 %, p = 0.04). An inverse correlation was found
between the lowest values of intraoperative cerebral rSO2 and the length of MV (r = -0.31,
p = 0.04) and ICU stay (r = -0.43, p = 0.003). Only the peak of NSE, measured 6 h after
CS, showed significant difference between patients who developed PNC and those who did
not (p = 0.02).
CONCLUSIONS. In our cohort of CS patients, NSE and S-100B protein were poor pre-
dictors of PNC. Conversely, the lower the preoperative cerebral rSO2, the poorer the
neurologic outcome. A GDT protocol based on NIRS values, aimed at improving cerebral
rSO2 and blood flow, might reduce PNC in high-risk CS patients.
REFERENCE(S). Murkin JM, Adams SJ, Novick RJ, et al. Monitoring brain oxygen
saturation during coronary bypass surgery: a randomized, prospective study. Anesth Analg.
2007;104(1):51-8
Relationship between hemodynamic parameters and myocardial energy and antioxidant status in heart transplantation
No full textThe relationships between high-energy phosphate levels, oxidative insult and mechanical function represent a key point in heart transplantation and related post-ischemic functional recovery. We evaluated myocardial purine compounds and glutathione antioxidant defence mechanism during 19 heart transplant operations. Heart biopsies were taken before harvesting on beating heart (t1), at the end of cold static preservation (t2) and 30 min after implantation and reperfusion (t3); perchloric extracts of the tissue were analyzed by capillary electrophoresis (CE). Correlation analyses were performed with hemodynamic parameters evaluated 90 min after aortic declamping (T90), 6 h following admission in intensive care unit (T6A) and 1 d post-operation (D1). We evidenced that AMP levels measured at T1 negatively correlate with both cardiac index (CI) and oxygen delivery index (DO2I) evaluated at T6A, respectively. The same behavior was evident plotting IMP levels measured at T3 with CI and DO2I evaluated at D1. After t2 the nucleotide/(nucleoside + base) ratio was in positive correlation with hemodynamic parameters at T6A. Energy charge and GSH/GSSG ratio measured before harvesting were in positive correlation with DO2I evaluated at T90. The present research shows that despite the complexity of the high-energy phosphate metabolism and that of the events associated to a clinical heart transplantation, there are some parameters that, besides reflecting the degree of myocardial preservation, also represents predictive parameters for the following organ functional recovery. It also suggests that heart preservation strategies should carefully take into account the sub-optimal nature of the donor heart at the time of procurement, through a broad spectrum of purine compound and glutathione antioxidant system measurements. (C) 2003 Editions scientitiques et medicales Elsevier SAS. All rights reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Preservation of myocardial energy status by bovine hemoglobin solutions during ischemia.
No full textCompared to murine and human hemoglobin, bovine hemoglobin has a less exothermic oxygen binding and delivers oxygen even at low temperatures. This property could improve oxygen availability for myocytes during hypothermic arrest of hearts. The aim of this study was to evaluate the advantage of using cardioplegic solutions enriched with bovine hemoglobin when storing rat hearts. Hearts excised from rats after perfusion with different cardioplegic solutions (Celsior, Celsior plus 4% human hemoglobin, Celsior plus 4% and 8% bovine hemoglobin) were compared. Biopsies were obtained from the beating hearts before cardioplegic infusion and during a 48 h period of cold storage. Adenosine triphosphate, its catabolites and markers of oxidative stress were measured as indices of preservation. The results show that bovine hemoglobin-enriched solutions highly improve adenosine triphosphate content, decreasing its catabolites; no significant changes in antioxidant status were evident. The statistically significant difference was evident up to 6 h of storage. Doubling the concentration of bovine hemoglobin produces only slight improvement. Alternative hemoglobins with different properties may improve and prolong heart storage. As bovine hemoglobin delivers oxygen even at low temperatures, it improves energy content and anabolic reactions, without decreasing oxidative stress
- …
