Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2019 ( 14 )

2018 ( 21 )

2017 ( 19 )

2016 ( 11 )

Custom range...

Search Results: 1 - 10 of 10087 matches for " Marc Leone "
All listed articles are free for downloading (OA Articles)
Page 1 /10087
Display every page Item
Terlipressin or Europressin?
Marc Leone
Critical Care , 2009, DOI: 10.1186/cc8035
Abstract: In the previous issue of Critical Care, a European group made a new contribution to the terlipressin literature [1]. For the first time, terlipressin, vasopressin, and norepinephrine were compared among patients with septic shock. Because vasopressin is not available in most European countries, terlipressin, a vasopressin analog, was used in patients with norepinephrine-resistant septic shock. Terlipressin is initially indicated in patients with hepatorenal syndrome and bleeding esophageal varices. In 2001, a German group showed its efficacy in endotoxemic sheep [2]. In 2002, a British group treated eight patients with norepinephrine-resistant septic shock by repeated bolus administration of terlipressin [3]. In 2004, studies from France, Spain, and Italy confirmed the feasibility of terlipressin in septic shock [4-6].Vasopressin and its analogs act on three subtypes of receptors: V1, V2, and V3 [7]. V1 receptors are found on various cells, including vascular smooth muscle cells, causing vasoconstriction. V2 receptors are expressed by kidney-collecting duct cells and mediate water retention. V3 receptors are found on cells within the central nervous system and modulate corticotrophin secretion. In septic shock, treatment is aimed to stimulate V1 receptors, and the vascular selectivity (V1/V2) of terlipressin is 2.2/1.0 compared with 1.0/1.0 for vasopressin [8].Initially, terlipressin was used as a substitute for vasopressin. The difference is their pharmacokinetics [7]. The half-life of terlipressin is 6 hours compared with 20 minutes for vasopressin. Because of the prolonged half-life of terlipressin, patients with septic shock received repeated boluses (1 mg) of the drug [3,4]. After intravenous injection, terlipressin works as a prodrug that slowly metabolizes to lysinevasopressin and in this way provides prolonged biological effect. Nevertheless, a recent paper shows that terlipressin is not only a prodrug of vasopressin but also a strong vasoconstrictor per se
Rescue therapy in septic shock – is terlipressin the last frontier?
Marc Leone, Claude Martin
Critical Care , 2006, DOI: 10.1186/cc4863
Abstract: In the previous issue of Critical Care, Rodriguez-Nunez and coworkers [1] report their experience with terlipressin in 16 children with refractory septic shock. Over the past few years there has been much interest in the use of terlipressin in such settings, both in adults [2-6] and children [7-10].Septic shock is a form of distributive shock characterized by arteriolar and venous vasodilatation. The objectives of treatment are twofold [11]: to maintain oxygen delivery above a critical threshold and to increase mean arterial pressure (MAP) to a level that allows distribution of cardiac index (CI) sufficient for adequate organ perfusion. Among the catecholamines, noradrenaline (norepinephrine) and dopamine are often favoured. However, vascular responsiveness to catecholamines diminishes over time, and patients may die in states of intractable shock [12]. The vascular hyporeactivity to catecholamines is caused, among other mechanisms, by excessive nitric oxide formation associated with an activation of ATP-sensitive potassium channels and reduction in calcium entry through voltage-gated calcium channels [13]. Thus, the search for alternative vasopressors is of high priority.Vasopressin mediates vasoconstriction via V1 receptors and increases intracellular calcium concentration. This action is not impaired during sepsis, and vasopressin has been shown to be effective in reversing catecholamine-resistant hypotension in patients with septic shock [14]. Vasopressin is not available in all countries, and some hospital pharmacies dispense lysine vasopressin, or terlipressin (Glypressine?; Ferring Company, Berlin, Germany), which is the form of vasopressin that is present in pig.The first clinical trial evaluating the efficacy of terlipressin in septic shock was performed in a small case series of eight patients [2]. Terlipressin was administered as a single bolus of 1 mg (the dosage used in gastroenterological indications) in patients with septic shock refractory to catecho
Passive Smoking and Infectious Disease: A Serious Hazard for Cardiovascular System  [PDF]
Aurelio Leone
International Journal of Clinical Medicine (IJCM) , 2011, DOI: 10.4236/ijcm.2011.25090
Abstract: Exposure to passive smoking is usually associated with heavy changes in both function and structure of the cardiovascular system at different levels: coronary circulation, heart metabolism, myocardial muscle. These changes may be transient but may have characteristics of irreversibility. Major determinant of cardiovascular alterations is hypoxia due to tobacco products of the environment although a large number of alterations affect immune t-cells and antibody response. All infectious diseases which involve cardiovascular system, including some tropical patterns, particularly Chagas disease, are adversely influenced as a consequence of a continuous although irregular exposure to passive smoking, which worsens the degree of cardiac muscle alterations at different levels like myocardium, coronary arteries and both these structures. Therefore, exposure to passive smoking must be avoided for those individuals suffering from infectious diseases of the heart whatever factor can be responsible.
Sex-Related Differences in Gene Expression Following Coxiella burnetii Infection in Mice: Potential Role of Circadian Rhythm
Julien Textoris,Leang Heng Ban,Christian Capo,Didier Raoult,Marc Leone,Jean-Louis Mege
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0012190
Abstract: Q fever, a zoonosis due to Coxiella burnetii infection, exhibits sexual dimorphism; men are affected more frequently and severely than women for a given exposure. Here we explore whether the severity of C. burnetii infection in mice is related to differences in male and female gene expression profiles.
High central venous oxygen saturation in the latter stages of septic shock is associated with increased mortality
Julien Textoris, Louis Fouché, Sandrine Wiramus, Fran?ois Antonini, Sowita Tho, Claude Martin, Marc Leone
Critical Care , 2011, DOI: 10.1186/cc10325
Abstract: We retrospectively analyzed data from all admissions to our ICU between January 2008 and December 2009. All septic shock patients in whom the ScvO2 was measured were included. The measures of ScvO2max within the first 72 hours after the onset of shock were collected.A total of 1,976 patients were screened and 152 (7.7%) patients met the inclusion criteria. The level of ScvO2max was 85% (78 to 89) in the non-survivors, compared with 79% (72 to 87) in the survivors (P = 0.009).Our findings raise concerns about high levels of ScvO2 in patients with septic shock. This may reflect the severity of the shock with an impaired oxygen use. Future strategies may target an optimization of tissue perfusion in this specific subgroup of patients.Shock is characterized by either an inadequacy between tissue requirements in oxygen and oxygen delivery or the inadequate use of oxygen. The hemodynamic management of patients in shock aims at improving tissue oxygenation. Central venous blood saturation in oxygen (ScvO2) is a useful tool reflecting the global transport and metabolism of oxygen. International guidelines suggest the need to optimize ScvO2 in the early phase of management of severe sepsis and septic shock [1].Low levels reflect (i) an inadequate cardiac output with an excessive extraction of oxygen [2], (ii) a low hemoglobin concentration, and/or (iii) a low level of arterial oxygen pressure (PaO2). In contrast, high levels of ScvO2 means either (i) a very high oxygen delivery in excess of tissue requirements and/or (ii) decreased cellular consumption of oxygen (mitochondrial dysfunction) and/or (iii) more rarely, a large arterio-venous shunt. In its most simple form, the oxyhemoglobin dissociation curve describes the relation between the partial pressure of oxygen (x axis) and the oxygen saturation (y axis). Many factors influence the affinity of this binding, altering the curve shape. For example, acidosis and body hyperthermia induce a right shift of the curve. This shif
Impact of intensive care on renal function before graft harvest: results of a monocentric study
Valéry Blasco, Marc Leone, Julien Bouvenot, Alain Geissler, Jacques Albanèse, Claude Martin
Critical Care , 2007, DOI: 10.1186/cc6120
Abstract: Between 1 January 1999 and 31 December 2005, we performed an observational study on 143 brain-dead donors. ICU chronology, hemodynamic, hematosis, and treatment data were collected for each patient from ICU admission to kidney removal.Twenty-two percent of the 143 patients had a serum creatinine level above 120 μmol/L before graft harvest. The independent factors revealed by multivariate analysis were the administration of epinephrine (odds ratio [OR]: 4.36, 95% confidence interval [CI]: 1.33 to 14.32; p = 0.015), oliguria (OR: 3.73, 95% CI: 1.22 to 11.36; p = 0.021), acidosis (OR: 3.26, 95% CI: 1.07 to 9.95; p = 0.038), the occurrence of disseminated intravascular coagulation (OR: 3.97, 95% CI: 1.05 to 15.02; p = 0.042), female gender (OR: 0.13, 95% CI: 0.03 to 0.50; p = 0.003), and the administration of desmopressin (OR: 0.12, 95% CI: 0.03 to 0.44; p = 0.002). The incidence of elevated serum creatinine level above 20% between admission and graft harvest was 41%. The independent risk factors were the duration of brain death greater than 24 hours (OR: 2.64, 95% CI: 1.25 to 5.59; p = 0.011) and the volume of mannitol (OR: 2.08, 95% CI: 1.03 to 4.21; p = 0.041).This study shows that the resuscitation of brain-dead donors impacts on their renal function. The uses of epinephrine and mannitol are associated with impairment of kidney function. It seems that graft harvest should be performed less than 24 hours after brain death diagnosis.The success of organ transplantation depends on the quality of the resuscitation of donors [1]. However, its renal impact has not been subject to much evaluation up to the present. To the best of our knowledge, no studies have evaluated the impact of the resuscitation on the preharvesting renal function of potential brain-dead donors. The risk factors for renal function impairment in such patients are important since this can affect the future renal graft. Consequently, the primary objective of the present study was to assess the risk fact
Clinical review: Vasopressin and terlipressin in septic shock patients
Anne Delmas, Marc Leone, Sébastien Rousseau, Jacques Albanèse, Claude Martin
Critical Care , 2004, DOI: 10.1186/cc2945
Abstract: The neurohypophysis contains vasopressin and oxytocin, which have very similar structures. In humans vasopressin is present in the form of an octapeptide called arginine vasopressin (AVP). The nomenclature of neurohypophysic hormones can be confusing. The name 'vasopressin' made it possible to refer to a hormone that is capable of both increasing arterial pressure in animals and triggering capillary vasoconstriction in humans. Such effects are only observed at high doses. At a low doses it inhibits urine output with no effect on the circulation, earning it the name 'antidiuretic hormone'.The antidiuretic functions of vasopressin have been exploited clinically for many years for the treatment of diabetes insipidus. Its vasopressor properties are currently arousing interest and have been the subject of numerous studies [1-14]. These studies have suggested that vasopressin may have applications in several models of shock, particularly septic shock [1,3,6,8,9,15-19,21-26]. Septic shock is defined as circulatory failure and organ hypoperfusion resulting in systemic infection [27]. Despite improved knowledge of its pathophysiology and considerable advances in its treatment, mortality from septic shock exceeds 50% [28]. Most deaths are linked to refractory arterial hypotension and/or organ failure despite antibiotic therapy, fluid expansion, and vasopressor and positive inotropic treatment [29].This general review analyzes data from the literature on the cardiovascular effects of vasopressin in septic shock so to define the position of this hormone for treatment of a pathological entity that remains one of the most preoccupying in the intensive care unit.The vasopressor effect of an extract from the pituitary gland was first observed in 1895 [30], but the antidiuretic effect was not exploited in the treatment of diabetes insipidus until 1913 [31,32]. The neurohypophysic extracts administered to patients at that time reduced diuresis, increased urine density and intensified
Aerodynamic Brake for Formula Cars  [PDF]
Roberto Capata, Leone Martellucci
World Journal of Mechanics (WJM) , 2015, DOI: 10.4236/wjm.2015.510018
Abstract: In the last years, in formula racing cars championships, the aerodynamic had reached an ever more important stance as a performance parameter. In the last four seasons, Red Bull Racing Technical Officer had designed their Formula 1 car with the specific aim to generate the optimal downforce, in relation to the car instantaneous setup. However, this extreme research of higher downforce brings some negative effects when a car is within the wake of another car; indeed, it is well known that under these condition the aerodynamic is disturbed, and it makes difficult to overtake the leading car. To partially remedy this problem, Formula 1 regulations introduced the Drag Reduction System (DRS) in 2011, which was an adjustable flap located on the rear wing; if it is flattened, allowing to reduce the downforce, increasing significantly the velocity and, therefore, the chances to overtake the leading car. Vice versa, when the flap is closed, it ensures a higher grip, which is very useful especially in medium-slow speed turns. Keeping the focus on the rear wing, but by shifting attention from the increased top speed to increase the grip in the middle and slow speed curves, we decided to study a similar device to the DRS, but with the opposite effect. The aim is to design an aerodynamic brake integrated with the rear wing. In particular, the project idea was to sculpt, on the upper surface of the wing (pressure side), a series of \"C\" shaped cavity, normally covered by adequate sliding panels. These cavities, when they are discovered, at the beginning of the braking phase, produce a turbulence and additional increase downforce, lightening the load on the braking system and allowing the pilot to substantially reduce slippage and to delay the braking. Since it seems that the regulations adopted by the FIA Formula 1 Championship do not allow such a device, it has been decided to apply the concept on a Formula 4 vehicle. This paper describes the design and analyzes the effects of these details on a standard wing cavity, using a commercial CFD software.
Gene Expression Profiles Characterize Inflammation Stages in the Acute Lung Injury in Mice
Isabelle Lesur,Julien Textoris,Béatrice Loriod,Cécile Courbon,Stéphane Garcia,Marc Leone,Catherine Nguyen
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0011485
Abstract: Acute Lung Injury (ALI) carries about 50 percent mortality and is frequently associated with an infection (sepsis). Life-support treatment with mechanical ventilation rescues many patients, although superimposed infection or multiple organ failure can result in death. The outcome of a patient developing sepsis depends on two factors: the infection and the pre-existing inflammation. In this study, we described each stage of the inflammation process using a transcriptional approach and an animal model. Female C57BL6/J mice received an intravenous oleic acid injection to induce an acute lung injury (ALI). Lung expression patterns were analyzed using a 9900 cDNA mouse microarray (MUSV29K). Our gene-expression analysis revealed marked changes in the immune and inflammatory response metabolic pathways, notably lipid metabolism and transcription. The early stage (1 hour–1.5 hours) is characterized by a pro-inflammatory immune response. Later (3 hours–4 hours), the immune cells migrate into inflamed tissues through interaction with vascular endothelial cells. Finally, at late stages of lung inflammation (18 hours–24 hours), metabolism is deeply disturbed. Highly expressed pro-inflammatory cytokines activate transcription of many genes and lipid metabolism. In this study, we described a global overview of critical events occurring during lung inflammation which is essential to understand infectious pathologies such as sepsis where inflammation and infection are intertwined. Based on these data, it becomes possible to isolate the impact of a pathogen at the transcriptional level from the global gene expression modifications resulting from the infection associated with the inflammation.
Does Smoking Act as a Friend or Enemy of Blood Pressure? Let Release Pandora's Box
Aurelio Leone
Cardiology Research and Practice , 2011, DOI: 10.4061/2011/264894
Abstract: In spite of the great number of observations which show the certainty of cardiovascular damage from smoking, the opinions on that are not yet unanimous. There is a discrepancy that could be attributed to the lack of reproducible data particularly in some epidemiological studies. On the contrary, experimental findings conducted on both animals and humans give evidence of exactly reproducible results of cardiovascular alterations and among these the course of Blood Pressure (BP). Findings identify an increase in BP of active smokers or non-smokers exposed to passive smoking, while a lot of others refer a lowering of BP due to smoking. This discrepancy could be explained as follows. Initially, a vasoconstriction mediated by nicotine causes acute but transient increase in systolic BP. This phase is followed by a decrease in BP as a consequence of depressant effects played chronically by nicotine itself. Simultaneously, carbon monoxide is acting directly on the arterial wall causing, in the long run, structurally irreversible alterations. At this time, there is a change in BP that increases again, and often constantly, its levels following chronic exposure. Changes in response to antihypertensive drugs have been observed in hypertensive smokers since smoking influences metabolic steps of the drugs.
Page 1 /10087
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.