Exercise‐related severe cardiac events Vicent, L.; Ariza‐Solé, A.; González‐Juanatey, J. R. ...
Scandinavian journal of medicine & science in sports,
April 2018, Volume:
28, Issue:
4
Journal Article
Peer reviewed
Physical activity has benefits on health. However, there is a small risk of effort‐related adverse events. The aim of this study is to describe exercise‐related severe cardiovascular events and to ...relate them with the type of sport performed. We performed a ten‐year retrospective study in eight Spanish cardiac intensive care units. Adverse cardiac events were defined as acute myocardial infarction, cardiac arrest or syncope related to physical activity. From 117 patients included, 109 were male (93.2%), and mean age was 51.6 ± 12.3 years; 56 presented acute myocardial infarction without cardiac arrest (47.9%), 55 sudden cardiac death (47.0%) and six syncope (5.1%). The sports with higher number of events were cycling (33%‐28.2%), marathon or similar running competitions (19%‐16.2%), gymnastics (18%‐15.3%) and soccer (17%‐14.5%). Myocardial infarction was observed more frequently in cyclists compared to other sports (69.7% vs 39.3%, P = .001). The most common cause of sudden cardiac death was myocardial infarction in those >35 years (23%‐63.9%) and idiopathic ventricular fibrillation in younger patients (5%‐62.5%). Significant coronary artery disease was present in 85 (79.4%). Only one patient with cardiac arrest presented with a non‐shockable rhythm (asystole). Eleven patients (9.4%) died during hospitalization; in all cases, they had presented cardiac arrest. All discharged patients were alive at the end of follow‐up. Exercise‐related severe cardiac events are mainly seen in men. Coronary heart disease is very frequent; about half present acute myocardial infarction and the other half cardiac arrest. In our cohort, prognosis was good in patients without cardiac arrest.
Based on a theoretical revision of the social vulnerability concept, this article proposes a scheme of vulnerability indicators within the human environment focused on different aetiology risks. An ...adaptation of this generic scheme of vulnerability factors is set for the specific field of aquifer contamination risk, as well as a methodology for its analysis. Finally, model application examples are given for the Sierra de Líbar and Sierra de Mijas carbonate aquifers and the Vélez River detrital aquifer, all of which are located in the south of Spain. Obtained cartography results show a range of utilities for risk mitigation and permit appropriate spatial discrimination for its performance over different scales. The exposure and vulnerability of the groundwater contamination risk concept is evaluated in specific maps, taking into account the resident population as well as their assets.
•36 RT plans for PoCa were assessed by means of TCP, NTCP and second cancer risk.•SBRT techniques exhibited the lowest second cancer risk.•SPCR rates were low and small impact on plan ranking was ...shown.•Best plans were the10MV SBRTs.•High energy IMRT did not appear to increase in excess the second cancer risk.
To perform a systematic and thorough assessment, using the Uncomplicated and Cancer-Free Control Probability (UCFCP) function, of a broad range of photon prostate cancer RT treatments, on the same scenario (a unique pelvic CT set). UCFCP considers, together with the probabilities of local tumour control (TCP) and deterministic (late) sequelae (NTCP), the second primary cancer risk (SPCR) due to photon and neutron peripheral doses.
Thirty-six radiotherapy plans were produced for the same CT. 6, 10, 15 and 18 MV 3DCRT, IMRT and VMAT (77.4 Gy in 43 fractions) and 6 and 10 MV SBRT (36.25 Gy in 5 fractions with flattened and FFF beams) for Elekta, Siemens and Varian Linacs plans were included. DVH and peripheral organ dosimetry were used to compute TCP, NTCP, and SPCR (the competition and LNT models) for further plan ranking.
Biological models (and parameters) used predicted an outcome which is in agreement with epidemiological findings. SBRT plans showed the lowest SPCR and a below average NTCPrectal. High energy plans did not rank worse than the low energy ones. Intensity modulated plans were ranked above the 3D conformal techniques.
According to UCFCP, the best plans were the10 MV SBRTs. SPCR rates were low and did not show a substantial impact on plan ranking. High energy intensity-modulated plans did not increase in excess the average of SPCR. Even more, they ranked among the best, provided that MU were efficiently managed.
Purpose:
The high mass density and low mobilities of charge carriers can cause important recombination in liquid-filled ionization chambers (LICs). Saturation correction methods have been proposed ...for LICs. Correction methods for pulsed irradiation are based on Boag equation. However, Boag equation assumes that the charge ionized by one pulse is fully collected before the arrival of the next pulse. This condition does not hold in many clinical beams where the pulse repetition period may be shorter than the charge collection time, causing overlapping between charge carriers ionized by different pulses, and Boag equation is not applicable there. In this work, the authors present an experimental and numerical characterization of collection efficiencies in LICs beyond the Boag limit, with overlapping between charge carriers ionized by different pulses.
Methods:
The authors have studied recombination in a LIC array for different dose-per-pulse, pulse repetition frequency, and polarization voltage values. Measurements were performed in a Truebeam Linac using FF and FFF modalities. Dose-per-pulse and pulse repetition frequency have been obtained by monitoring the target current with an oscilloscope. Experimental collection efficiencies have been obtained by using a combination of the two-dose-rate method and ratios to the readout of a reference chamber (CC13, IBA). The authors have also used numerical simulation to complement the experimental data.
Results:
The authors have found that overlap significantly increases recombination in LICs, as expected. However, the functional dependence of collection efficiencies on the dose-per-pulse does not change (a linear dependence has been observed in the near-saturation region for different degrees of overlapping, the same dependence observed in the nonoverlapping scenario). On the other hand, the dependence of collection efficiencies on the polarization voltage changes in the overlapping scenario and does not follow that of Boag equation, the reason being that changing the polarization voltage also affects the charge collection time, thus changing the amount of overlapping.
Conclusions:
These results have important consequences for saturation correction methods for LICs. On one hand, the two-dose-rate method, which relies on the functional dependence of the collection efficiencies on dose-per-pulse, can also be used in the overlapping situation, provided that the two measurements needed to feed the method are performed at the same pulse repetition frequency (monitor unit rate). This result opens the door to computing collection efficiencies in LICs in many clinical setups where charge overlap in the LIC exists. On the other hand, correction methods based on the voltage-dependence of Boag equation like the three-voltage method or the modified two-voltage method will not work in the overlapping scenario due to the different functional dependence of collection efficiencies on the polarization voltage.
Cold storage of organs in preservation solutions, such as Institute George Lopez 1 (IGL-1) or histidine-tryptophan-ketoglutarate (HTK), is a mandatory step for organ transplantation. This ...preservation leads to an ischemic injury that affects the outcome of the organ. This article studies the liver graft eluate after organ recovery using IGL-1 or HTK solutions. We explore the influence of the volume used for washing out the liver and the consequences in the graft preservation when both solutions are used. Livers were washed out with different volumes of HTK and IGL-1 according to manufacturers' instructions and then preserved in both solutions for 24 hours at 4°C. Tissue and eluates were collected for subsequent analyses. We measured transaminases (aspartate aminotransferase and alanine aminotransferase), histology by hematoxylin/eosin staining, and red blood cell and hemoglobin counts, respectively. After washing out and cold storage, the IGL-1 processed livers showed better preservation than those with HTK solution; however, in this latter case, an important accumulation of erythrocytes was found when compared to IGL-1. These data were consistent with the higher hemoglobin and red blood cell counts observed for IGL-1 eluates after 24 hours. The volume used for washing out the organ depends on the composition and properties of the organ preservation solutions (ie, IGL-1 and HTK); this is an important factor for the graft cold preservation. The total volume used for washing out the graft should be considered because it has a direct impact on the total cost for clinical transplantations.
Abstract Background Sirtuin 1 (SIRT1) is a nicotinamide adenine dinucleotide +–dependent histone deacetylase that regulates various pathways involved in ischemia-reperfusion injury (IRI). Moreover, ...high-mobility group box 1 protein (HMGB1) has also been involved in inflammatory processes during IRI. However, the roles of both SIRT1 and HMGB1 in liver preservation is poorly understood. In this communication, we evaluated the potential relationship between SIRT1 and HMGB1 in steatotic and non-steatotic liver grafts preserved in Institute Georges Lopez solution (IGL-1) preservation solution enriched or not enriched with trimetazidine (TMZ). Methods Steatotic and non-steatotic livers were preserved in IGL-1 preservation solution (24 hours, 4°C), enriched or not enriched with TMZ (10 μmol/L), and then submitted to ex vivo reperfusion (2 hours; 37°C). Liver injury (AST/ALT) and function (bile output, vascular resistance) were evaluated. SIRT1, HMGB1, autophagy parameters (beclin-1, LC3B), PPAR-γ, and heat-shock protein (HO-1, HSP70) expression were determined by means of Western blot. Also, we assessed oxidative stress, mitochondrial damage (glutamate dehydrogenase), and TNF-α levels. Results Elevated SIRT1 and enhanced autophagy were found after reperfusion in steatotic livers preserved in IGL-1+TMZ when compared with IGL-1. However, these changes were not seen in the case of non-steatotic livers. Also, HO-1 increases in the IGL-1 + TMZ group were evident only in the case of steatotic livers, whereas HSP70 and PPAR-γ protein expression were enhanced only in non-steatotic livers. All reported changes were consistent with decreased liver injury diminution, ameliorated hepatic function, and decreased TNF-α and HMGB levels. In addition, the oxidative stress and mitochondrial damage were efficiently prevented by the IGL-1 + TMZ use. Conclusions SIRT1 is associated with HMGB1 decreases and increased autophagy in steatotic livers, contributing to increased tolerance to cold IRI.
Protection of Reduced‐Size Liver for Transplantation Franco‐Gou, R.; Peralta, C.; Massip‐Salcedo, M. ...
American journal of transplantation,
September 2004, 2004-Sep, 2004-09-00, 20040901, Volume:
4, Issue:
9
Journal Article
Peer reviewed
Open access
The shortage of available organs for liver transplantation has motivated the development of new surgical techniques such as reduced‐size liver transplantation. Ischemia‐reperfusion (I/R) associated ...with liver transplantation impairs liver regeneration. Ischemic preconditioning is effective against I/R injury in clinical practice of liver tumour resections. The present study evaluated the effect of ischemic preconditioning on reduced‐size liver for transplantation and attempted to identify the underlying protective mechanisms. Hepatic injury and regeneration (transaminases, proliferating cell nuclear antigen PCNA labeling index, and hepatocyte growth factor HGF) were assessed after reduced‐size orthotopic liver transplantation (ROLT). Energy metabolism, oxidative stress, tumor necrosis factor‐α (TNF) and interleukin‐6 (IL‐6) were examined as possible mechanisms involved in liver regeneration. Ischemic preconditioning reduced transaminase levels and increased HGF levels and the percentage of PCNA‐positive hepatocytes after ROLT. This was associated with a decrease in oxidative stress following ROLT, whereas energy metabolism and hepatic IL‐6 and TNF release were unchanged. The benefits of ischemic preconditioning on hepatic injury and liver regeneration could be mediated, at least partially by nitric oxide. These results suggest a new potential application of ischemic preconditioning in reduced‐size liver transplantation.
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