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T Calandra

Publications and source records attributed to T Calandra.

At least 19 recordsLinked to original sources
PubMed2006

[Severe sepsis and septic shock].

Severe sepsis and septic shock are frequent pathologies accounting for approximately 11% of all admissions in intensive care units (ICU). In the United States, between 1979 and 2000 the incidence of sepsis increased by 8,7% annually and septic shock) remains the second most frequent cause of death in non-coronary ICU. Although our understanding of the host defense mechanisms against infections and of the pathogenesis of septic shock have progressed during the last decade, these progresses have not yet yielded the anticipated advantages. Recent new therapeutic approaches, especially early-goal directed therapy, activated protein C (drotrecogin alpha activated), moderate doses of corticosteroids and intensive insulin therapy have given encouraging results.

Adrenal Cortex Hormones↗
PubMed2006

Piperacillin-tazobactam monotherapy in high-risk febrile and neutropenic cancer patients.

Combination therapy with a beta-lactam plus an aminoglycoside has been the standard approach for treating febrile neutropenia for many years. More recently, beta-lactam monotherapy has also been shown to be a reliable and safe approach. In the present study, 763 eligible patients with fever and neutropenia received piperacillin-tazobactam monotherapy. On day 3, according to the study protocol, 165 patients with persistent fever who fulfilled the study entry criteria were randomised to receive vancomycin or a placebo. The success rate was 51% in the intention-to-treat analysis and 62% in the per-protocol analysis. The overall mortality rate was 8% (58/763), with only 18 (2.4%) deaths attributed to the initial or subsequent infection. Randomisation had no influence on the study endpoints. The adverse event rate was evaluated only in the patient population not included in the randomised part of the study. Among these patients, adverse events probably or definitely related to piperacillin-tazobactam therapy were uncommon, confirming the favourable safety profile of piperacillin-tazobactam. It was concluded that piperacillin-tazobactam could be considered as monotherapy for patients with high-risk febrile neutropenia.

Adolescent↗
PubMed2005

[Utility of procalcitonin for the diagnosis and the follow-up of infections in febrile neutropenic patients].

Procalcitonin is a marker of severe bacterial infections in non-neutropenic patients. The goal of this review is to assess its utility in the management of neutropenic patients. A delayed treatment of infection in this setting results in severe morbidity and high mortality. As traditional diagnostic tools often fail to exclude infection when fever occurs, all these patients receive empirical antimicrobial therapies during long periods of time. Present knowledge suggests that procalcitonin may contribute to identify patients in whom 1) antibiotics could be stopped in the absence of bacterial infection, 2) investigations and adjustments of the antimicrobial therapy for persistent fever are needed. The use of procalcitonin for the management of febrile neutropenic patients should be studied prospectively.

Anti-Bacterial Agents↗
PubMed2004

Full-course oral levofloxacin for treatment of hospitalized patients with community-acquired pneumonia.

Most guidelines for the management of hospitalized patients with community-acquired pneumonia (CAP) recommend commencing therapy with intravenous antibiotics, primarily because of concern about absorption of oral antibiotics in acutely ill patients. However, patients who respond are rapidly switched to oral therapy, which has been shown to reduce costs and to shorten the length of stay. The aim of the present study was to determine whether a full course of oral antibiotics is as efficacious and as safe as intravenous-to-oral sequential antibiotic therapy for the treatment of hospitalized, non-ICU patients with CAP. In an open-labelled, controlled study, 129 hospitalized patients with CAP were randomly assigned in a 2:1 ratio to receive either a full course of oral levofloxacin (500 mg q12 h) or an intravenous-to-oral sequential therapy consisting of intravenous ceftriaxone (2 g q24 h) with or without clarithromycin (500 mg q12 h) followed by an oral antibiotic (a beta-lactam agent in the majority of patients). The primary study endpoint was the resolution of CAP; secondary endpoints included length of stay and overall mortality. CAP resolved in 72 of 79 (91.1%) patients in the levofloxacin group and in 34 of 37 (91.9%) patients in the intravenous-to-oral sequential therapy group (difference, -0.8%, 95%CI, -11.6-10.0). Median length of stay was 8 days (range, 2-74 days) in the levofloxacin group and 10 days (range, 3-29 days) in the intravenous-to-oral sequential therapy group ( P=0.28). Day 30 mortality rates were 1.3% (1 of 79) and 8.1% (3 of 37), respectively (difference, -6.8%, 95%CI, -16.0-2.3). Full-course oral levofloxacin is as efficacious and as safe as standard intravenous-to-oral sequential antibiotic therapy for the treatment of hospitalized patients with CAP.

Administration, Oral↗
PubMed2004

Cost-effectiveness of full-course oral levofloxacin in severe community-acquired pneumonia.

Oral levofloxacin is as efficient as sequential antibiotic treatment in community-acquired pneumonia (CAP). The current authors assessed whether oral levofloxacin treatment of patients with severe CAP, followed-up for 30 days, would save money. Over a 12-month period, 129 hospitalised patients with severe non-intensive care unit CAP were randomly assigned to receive either oral levofloxacin or sequential antibiotic treatment. Direct and indirect costs were compared over a 30-day period from several perspectives. CAP resolved in 71 out of 77 oral levofloxacin (92%) and in 34 out of 37 sequential antibiotic treatment patients (92%). Patients' characteristics, treatment duration, hospital length of stay and mortality were similar in both groups. Drug acquisition costs were 1.7-times smaller in oral levofloxacin patients, who were less often transferred to rehabilitation centres, but they used more physicians' visits during follow-up and their total costs were lower. As only a minority of patients was still active, inability to work and, hence, indirect costs were similar in both groups. In this study, oral levofloxacin for severe non-intensive care unit community-acquired pneumonia was equally effective as sequential antibiotic treatment, but did not lead to major costs savings except for drug acquisition costs. External factors linked with patients' characteristics and/or medical practice are likely to play a role and should be addressed.

Aged↗
PubMed2003

Vancomycin versus placebo for treating persistent fever in patients with neutropenic cancer receiving piperacillin-tazobactam monotherapy.

This prospective, double-blind trial assessed whether the addition of a glycopeptide would be able to reduce the time to defervescence in neutropenic patients with cancer who had persistent fever 48-60 h after the initiation of empirical piperacillin-tazobactam monotherapy. Of 763 eligible patients, 165 with persistent fever were randomized to receive piperacillin-tazobactam therapy plus either vancomycin therapy or placebo. Defervescence was observed in 82 (95%) of 86 patients in the vancomycin group and in 73 (92%) of 79 patients in the placebo group (P=.52). The distributions of the time to defervescence were not statistically significant between the 2 groups (estimated hazard ratio, 1.03; 95% confidence interval, 0.75-1.43; P=.75). The number of additional episodes of gram-positive bacteremia and the percentage of patients for whom amphotericin B was empirically added to their therapy regimen were also similar in both groups. This study failed to demonstrate that the empirical addition of vancomycin therapy to the treatment regimen is of benefit to persistently febrile neutropenic patients with cancer.

Adolescent↗
PubMed2001

Critical role of lipopolysaccharide-binding protein and CD14 in immune responses against gram-negative bacteria.

LPS-binding protein (LBP) and CD14 potentiate cell activation by LPS, contributing to lethal endotoxemia. We analyzed the contribution of LBP/CD14 in models of bacterial infection. Mice pretreated with mAbs neutralizing CD14 or LBP showed a delay in TNF-alpha production and died of overwhelming infection within 24 h, after a challenge with 250 CFU of virulent Klebsiella pneumoniae. Blockade of TNF-alpha also increased lethality, whereas pretreatment with TNF-alpha protected mice, even in the presence of LBP and CD14 blockade. Anti-LBP or anti-CD14 mAbs did not improve or decrease lethality with a higher inoculum (10(5) K. pneumoniae) and did not affect outcome following injections of low or high inocula of Escherichia coli O111. These results point to the essential role of LBP/CD14 in innate immunity against virulent bacteria.

Acute-Phase Proteins↗
PubMed2001

CD14 expression on monocytes and TNF alpha production in patients with septic shock, cardiogenic shock or bacterial pneumonia.

OBJECTIVES: In patients with septic shock, circulating monocytes become refractory to stimulation with microbial products. Whether this hyporesponsive state is induced by infection or is related to shock is unknown. To address this question, we measured TNF alpha production by monocytes or by whole blood obtained from healthy volunteers (controls), from patients with septic shock, from patients with severe infection (bacterial pneumonia) without shock, and from patients with cardiogenic shock without infection. MEASUREMENTS: The numbers of circulating monocytes, of CD14+ monocytes, and the expression of monocyte CD14 and the LPS receptor, were assessed by flow cytometry. Monocytes or whole blood were stimulated with lipopolysaccharide endotoxin (LPS), heat-killed Escherichia coli or Staphylococcus aureus, and TNF alpha production was measured by bioassay. RESULTS: The number of circulating monocytes, of CD14+ monocytes, and the monocyte CD14 expression were significantly lower in patients with septic shock than in controls, in patients with bacterial pneumonia or in those with cardiogenic shock (p < 0.001). Monocytes or whole blood of patients with septic shock exhibited a profound deficiency of TNF alpha production in response to all stimuli (p < 0.05 compared to controls). Whole blood of patients with cardiogenic shock also exhibited this defect (p < 0.05 compared to controls), although to a lesser extent, despite normal monocyte counts and normal CD14 expression. CONCLUSIONS: Unlike patients with bacterial pneumonia, patients with septic or cardiogenic shock display profoundly defective TNF alpha production in response to a broad range of infectious stimuli. Thus, down-regulation of cytokine production appears to occur in patients with systemic, but not localised, albeit severe, infections and also in patients with non-infectious circulatory failure. Whilst depletion of monocytes and reduced monocyte CD14 expression are likely to be critical components of the hyporesponsiveness observed in patients with septic shock, other as yet unidentified factors are at work in this group and in patients with cardiogenic shock.

Antigens, CD↗
PubMed2001

New strategies for clinical trials in patients with sepsis and septic shock.

OBJECTIVE: The difficulty in identifying new treatment modalities that significantly reduce the mortality and morbidity rates associated with sepsis has highlighted the need to reevaluate the approach to clinical trial design. The United Kingdom Medical Research Council convened an International Working Party to address these issues. DATA SOURCES: The subject areas that were to be the focus of discussion were identified by the co-chairs, and group leaders were nominated. Preconference reading material was circulated to group members. STUDY SELECTION AND DATA EXTRACTION: Small-group discussion fed into an iterative process of feedback from plenary sessions, followed by the formulation of recommendations. Finally, each working group prepared a summary of its recommendations and these are reported herein. DATA SYNTHESIS: There were five key recommendations. First, investigators should no longer rely solely on the American College of Chest Physicians/Society of Critical Care Medicine definitions of sepsis or sepsis syndrome as the basis of trial entry. Entry criteria should be based on three principles: a) All patients should have infection; b) there should be evidence of a pathologic process that represents a biologically plausible target for the proposed intervention, for example, an abnormal circulating level of a biological marker pertinent to the study drug; and c) patients should fall into an appropriate category of severity (usually severe sepsis). Second, investigators should use a scoring system for organ dysfunctions that has been validated and that can be incorporated into all sepsis studies; agreement on the use of a single system would simplify comparisons between studies. Third, the primary outcome measure generally should be mortality rates, but under appropriate circumstances major morbidities could be considered as primary end points. Regardless of choice of the duration to primary end point, patients should be followed for > or =90 days. Fourth, sample size needs to be based on a realistic assessment of achievable effect size based on knowledge of the at-risk population. Fifth, subgroups should be few in number and should be defined a priori on the basis of variables present before randomization. CONCLUSIONS: Important changes in several aspects of trial design may improve the quality of clinical studies in sepsis and maximize the chance of identifying effective therapeutic agents.

Clinical Trials as Topic↗
PubMed2001

Macrophage migration inhibitory factor and innate immune responses to bacterial infections.

OBJECTIVES: To review the role of macrophage migration inhibitory factor (MIF) in host responses to infection and to explore the potential of MIF as a novel target for therapeutic intervention in patients with severe sepsis and septic shock. DATA SOURCES: Published articles on the role of MIF in innate immune responses against microbial pathogens. DATA SUMMARY: MIF has emerged recently as an important effector molecule of the innate immune system. MIF is expressed constitutively by monocytes/macrophages, T cells, B cells, endocrine cells, and epithelial cells. Microbial toxins and cytokines are powerful inducers of MIF release by immune cells. MIF expression is up-regulated during the course of inflammatory and infectious diseases and was found to play an important role in the pathogenesis of sepsis and septic shock. CONCLUSION: Given the role of MIF in innate immune responses against microbial pathogens and in the regulation of inflammatory responses, modulation of MIF production or neutralization of its activity may offer new therapeutic options for the management of patients with sepsis.

Animals↗
PubMed2001

Role of plasma, lipopolysaccharide-binding protein, and CD14 in response of mouse peritoneal exudate macrophages to endotoxin.

Plasma lipopolysaccharide (LPS)-binding protein (LBP) and membrane CD14 function to enhance the responses of monocytes to low concentrations of endotoxin. Surprisingly, recent reports have suggested that LBP or CD14 may be dispensable for macrophage responses to low concentrations of LPS or may even exert an inhibitory effect in the case of LBP. We therefore investigated whether LBP and CD14 participated in the response of mouse peritoneal exudate macrophages (PEM) to LPS stimulation. In the presence of a low amount of plasma (<1%) or of recombinant mouse or human LBP, PEM were found to respond to low concentrations of LPS (<5 to 10 ng/ml) in an LBP- and CD14-dependent manner. However, tumor necrosis factor production (not interleukin-6 production) by LPS-stimulated PEM was reduced when cells were stimulated in the presence of higher concentrations of plasma or serum (5 or 10%). Yet, the inhibitory effect of plasma or serum was not mediated by LBP. Taken together with previous results obtained with LBP and CD14 knockout mice in models of experimental endotoxemia, the present data confirm a critical part for LBP and CD14 in innate immune responses of both blood monocytes and tissue macrophages to endotoxins.

Acute-Phase Proteins↗
PubMed2001

Pathogenesis of septic shock: implications for prevention and treatment.

The innate immune system is in the vanguard of host defenses against infection. Recognition of invasive microbial pathogens is mediated by pattern recognition receptors on the surface of immune cells that recognize pathogen-associated molecular motifs. Considerable progress has been made in recent years in understanding how bacterial products initiate sepsis. In gram-negative sepsis, the LPS-binding protein (LBP), CD14 and the recently identified Toll-like receptor 4 (TLR4) are key molecules for the recognition of endotoxin (lipopolysaccharide, LPS) by cells of the myelomonocytic lineage. In gram-positive sepsis, components of the bacterial cell wall (peptidoglycan, PGN; lipoteichoic acids, LTA) have been shown to activate myeloid cells through an interaction with a receptor complex composed of CD14, TLR2 and perhaps also TLR6 (PGN) or CD14 and TLR4 (LTA). By contrast, gram-positive exotoxins act as superantigens and directly stimulate T lymphocytes by cross-linking the MHC class II of antigen presenting cells to specific chains of the T cell receptor. Immune cells activated by microbial pathogens release numerous effector molecules, which orchestrate the innate and adaptive host defenses. Furthermore, bacteria and microbial toxins directly activate the complement and coagulation systems, which play an important part in the host defensive response. Severe sepsis and septic shock can be viewed as clinical manifestations of a failing innate immune response that ultimately results in an overstimulation of the physiological host response. The pathogenesis of sepsis is far more complex that was initially anticipated. However, combined research efforts of basic scientists and clinical investigators continue to provide critical information for the identification of novel therapeutic targets. The exciting results obtained recently with treatment strategies designed to correct coagulation abnormalities occurring during sepsis are an example of how research may ultimately translate into improved patient care.

Drosophila Proteins↗
PubMed2001

Macrophage migration inhibitory factor (MIF) modulates innate immune responses induced by endotoxin and Gram-negative bacteria.

Discovered in the early 1960s as a T-cell cytokine, MIF has emerged to be an important mediator of the innate immune system. MIF was identified recently to be released by a vast array of cells, including monocytes/macrophages, T-cells, B-cells, endocrine cells and epithelial cells in response to infection and stress. Bacteria, microbial toxins and cytokines have been shown to be powerful inducers of MIF secretion by macrophages. MIF stimulates the expression of pro-inflammatory mediators by immune cells and functions to counterbalance the anti-inflammatory and immunosuppressive effects of glucocorticoids. Like TNF and IL-1, MIF plays an important role in host responses to infection. Recombinant MIF was found to exacerbate lethal endotoxemia or bacterial sepsis when co-injected with LPS or Escherichia coli in mice. Conversely, MIF knockout mice or mice treated with anti-MIF antibodies were protected from shock induced by LPS, staphylococcal exotoxins or bacterial peritonitis, even when anti-MIF therapy was started after the onset of infection. Given the central role played by MIF in innate immune responses against microbial pathogens and in the regulation of inflammatory responses, pharmacological modulation of MIF production or neutralization of MIF activity could have broad clinical applications and may offer new treatment options for the management of patients with severe sepsis or septic shock.

Animals↗
PubMed2000

Intracellular action of the cytokine MIF to modulate AP-1 activity and the cell cycle through Jab1.

Cytokines are multifunctional mediators that classically modulate immune activity by receptor-mediated pathways. Macrophage migration inhibitory factor (MIF) is a cytokine that has a critical role in several inflammatory conditions but that also has endocrine and enzymatic functions. The molecular targets of MIF action have so far remained unclear. Here we show that MIF specifically interacts with an intracellular protein, Jab1, which is a coactivator of AP-1 transcription that also promotes degradation of the cyclin-dependent kinase inhibitor p27Kip1 (ref. 10). MIF colocalizes with Jab1 in the cytosol, and both endogenous and exogenously added MIF following endocytosis bind Jab1. MIF inhibits Jab1- and stimulus-enhanced AP-1 activity, but does not interfere with the induction of the transcription factor NFkappaB. Jab1 activates c-Jun amino-terminal kinase (JNK) activity and enhances endogenous phospho-c-Jun levels, and MIF inhibits these effects. MIF also antagonizes Jab1-dependent cell-cycle regulation by increasing p27Kip1 expression through stabilization of p27Kip1 protein. Consequently, Jab1-mediated rescue of fibroblasts from growth arrest is blocked by MIF. Amino acids 50-65 and Cys 60 of MIF are important for Jab1 binding and modulation. We conclude that MIF may act broadly to negatively regulate Jab1-controlled pathways and that the MIF-Jab1 interaction may provide a molecular basis for key activities of MIF.

COP9 Signalosome Complex↗