New Insights into SARS-CoV-2 and Cancer Cross-Talk: Does a Novel Oncogenesis Driver Emerge?

Since the pandemic’s onset, a growing population of individuals has recovered from SARS-CoV-2 infection and its long-term effects in some of the convalescents are gradually being reported. Although the precise etiopathogenesis of post-acute COVID-19 sequelae (PACS) remains elusive, the mainly accepted rationale is that SARS-CoV-2 exerts long-lasting immunomodulatory effects, promotes chronic low-grade inflammation, and causes irreversible tissue damage. So far, several viruses have been causally linked to human oncogenesis, whereas chronic inflammation and immune escape are thought to be the leading oncogenic mechanisms. Excessive cytokine release, impaired T-cell responses, aberrant activation of regulatory signaling pathways (e.g., JAK-STAT, MAPK, NF-kB), and tissue damage, hallmarks of COVID-19 disease course, are also present in the tumor microenvironment. Therefore, the intersection of COVID-19 and cancer is partially recognized and the long-term effects of the virus on oncogenesis and cancer progression have not been explored yet. Herein, we present an up-to-date review of the current literature regarding COVID-19 and cancer cross-talk, as well as the oncogenic pathways stimulated by SARS-CoV-2.

Decreased cytokine production by mononuclear cells after severe gram-negative infections: early clinical signs and association with final outcome

BACKGROUND

Failure of circulating monocytes for adequate cytokine production is a trait of sepsis-induced immunosuppression; however, its duration and association with final outcome are poorly understood.

METHODS

We conducted a substudy of a large randomised clinical trial. Peripheral blood mononuclear cells (PBMCs) were isolated within the first 24 h from the onset of systemic inflammatory response syndrome in 95 patients with microbiologically confirmed or clinically suspected gram-negative infections. Isolation was repeated on days 3, 7 and 10. PBMCs were stimulated for cytokine production. The study endpoints were the differences between survivors and non-survivors, the persistence of immunosuppression, and determination of admission clinical signs that can lead to early identification of the likelihood of immunosuppression.

RESULTS

PBMCs of survivors produced significantly greater concentrations of tumour necrosis factor-α (TNF-α), interleukin (IL)-6, IL-8, IL-10, interferon-γ and granulocyte-macrophage colony-stimulating factor after day 3. Using ROC analysis, we found that TNF-α production less than 250 pg/ml after lipopolysaccharide stimulation on day 3 could discriminate patients from healthy control subjects; this was associated with a 5.18 OR of having an unfavourable outcome (p = 0.046). This trait persisted as long as day 10. Logistic regression analysis showed that cardiovascular failure on admission was the only independent predictor of defective TNF-α production on day 3.

CONCLUSIONS

Defective TNF-α production is a major trait of sepsis-induced immunosuppression. It is associated with significant risk for unfavourable outcome and persists until day 10. Cardiovascular failure on admission is predictive of defective TNF-α production during follow-up.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01223690 . Registered on 18 October 2010.

Randomized, controlled, multicentre clinical trial of the antipyretic effect of intravenous paracetamol in patients admitted to hospital with infection

Aim

No randomized study has been conducted to investigate the use of intravenous paracetamol (acetaminophen, APAP) for the management of fever due to infection. The present study evaluated a new ready‐made infusion of paracetamol.

Methods

Eighty patients with a body temperature onset ≥38.5°C in the previous 24 h due to infection were randomized to a single administration of placebo (n = 39) or 1 g paracetamol (n = 41), and their temperature was recorded at standard intervals. Rescue medication with 1 g paracetamol was allowed. Serum samples were collected for the measurement of APAP and its metabolites. The primary endpoint was defervescence, defined as a core temperature ≤37.1°C.

Results

During the first 6 h, defervescence was achieved in 15 (38.5%) patients treated with placebo compared with 33 (80.5%) patients treated with paracetamol 1 g (P < 0.0001). The median time to defervescence with paracetamol 1 g was 3 h. Rescue medication was given to 15 (38.5%) and five (12.2%) patients allocated to placebo and paracetamol, respectively (P = 0.007); nine (60.0%) and two (40.0%) of these patients, respectively, experienced defervescence. No further antipyretic medication was needed for patients becoming afebrile with rescue medication. Serum glucuronide‐APAP concentrations were significantly greater in the serum of patients who did not experience defervescence with paracetamol. The efficacy of paracetamol was not affected by serum creatinine. No drug‐related adverse events were reported.

Conclusions

The 1 g paracetamol formulation has a rapid and sustainable antipyretic effect on fever due to infection. Its efficacy is dependent on hepatic metabolism.

Validation of the new Sepsis-3 definitions: proposal for improvement in early risk identification

OBJECTIVES

Sepsis-3 definitions generated controversies regarding their general applicability. The Sepsis-3 Task Force outlined the need for validation with emphasis on the quick Sequential Organ Failure Assessment (qSOFA) score. This was done in a prospective cohort from a different healthcare setting.

METHODS

Patients with infections and at least two signs of systemic inflammatory response syndrome (SIRS) were analysed. Sepsis was defined as total SOFA ≥2 outside the intensive care unit (ICU) or as an increase of ICU admission SOFA ≥2. The primary endpoints were the sensitivity of qSOFA outside the ICU and sepsis definition both outside and within the ICU to predict mortality.

RESULTS

In all, 3346 infections outside the ICU and 1058 infections in the ICU were analysed. Outside the ICU, respective mortality with ≥2 SIRS and qSOFA ≥2 was 25.3% and 41.2% (p <0.0001); the sensitivities of qSOFA and of sepsis definition to predict death were 60.8% and 87.2%, respectively. This was 95.9% for sepsis definition in the ICU. The sensitivity of qSOFA and of ≥3 SIRS criteria for organ dysfunction outside the ICU was 48.7% and 72.5%, respectively (p <0.0001). Misclassification outside the ICU with the 1991 and Sepsis-3 definitions into stages of lower severity was 21.4% and 3.7%, respectively (p <0.0001) and 14.9% and 3.7%, respectively, in the ICU (p <0.0001). Adding arterial pH ≤7.30 to qSOFA increased sensitivity for prediction of death to 67.5% (p 0.004).

CONCLUSIONS

Our analysis positively validated the use of SOFA score to predict unfavourable outcome and to limit misclassification into lower severity. However, qSOFA score had inadequate sensitivity for early risk assessment.

Change of annexin binding of monocytes as an expression of cellular response to Candida albicans: down-regulation in severe sepsis

To study the differences of monocyte activation by albicans and non-albicans species of Candida and its change in sepsis, peripheral blood mononuclear cells were isolated from 17 healthy volunteers and 26 patients with severe sepsis/shock, and incubated in the absence/presence of heat-killed (HK) isolates of four different Candida species and purified β-D-glucan from C.albicans. Experiments were repeated in the presence and absence of inhibitors of intracellular activation pathways. Expression of annexin V on cells membranes of monocytes and lymphocytes, cytoplasmic activity of caspase-3, and DNA fragmentation of monocytes were studied. Membrane expression of annexin V on viable monocytes of healthy volunteers decreased significantly after incubation with C.albicans but not with non-albicans species. The decrease was dose-dependent from the Candida inoculum and by the concentration of β-D-glucan. A relationship with inhibition of apoptosis was found as the activity of caspase-3 activity, and the level of DNA fragmentation were also decreased. Incubation in the absence/presence of inhibitors showed that the decrease by annexin V expression resulted by activation of the dectin-1 pathway and Raf-1 by β-D glucan. The decrease of annexin V(+)/PI(-) expression was not shown on monocytes of patients with severe sepsis/shock, where no effect of inhibitors was found. Decrease of annexin V binding on monocytes can be viewed as a selective response to C.albicans partly effected through activation of dectin-1. This response is down-regulated after a septic insult.

Assessment of Global Incidence and Mortality of Hospital-treated Sepsis. Current Estimates and Limitations

RATIONALE

Reducing the global burden of sepsis, a recognized global health challenge, requires comprehensive data on the incidence and mortality on a global scale.

OBJECTIVES

To estimate the worldwide incidence and mortality of sepsis and identify knowledge gaps based on available evidence from observational studies.

METHODS

We systematically searched 15 international citation databases for population-level estimates of sepsis incidence rates and fatality in adult populations using consensus criteria and published in the last 36 years.

MEASUREMENTS AND MAIN RESULTS

The search yielded 1,553 reports from 1979 to 2015, of which 45 met our criteria. A total of 27 studies from seven high-income countries provided data for metaanalysis. For these countries, the population incidence rate was 288 (95% confidence interval [CI], 215-386; τ = 0.55) for hospital-treated sepsis cases and 148 (95% CI, 98-226; τ = 0.99) for hospital-treated severe sepsis cases per 100,000 person-years. Restricted to the last decade, the incidence rate was 437 (95% CI, 334-571; τ = 0.38) for sepsis and 270 (95% CI, 176-412; τ = 0.60) for severe sepsis cases per 100,000 person-years. Hospital mortality was 17% for sepsis and 26% for severe sepsis during this period. There were no population-level sepsis incidence estimates from lower-income countries, which limits the prediction of global cases and deaths. However, a tentative extrapolation from high-income country data suggests global estimates of 31.5 million sepsis and 19.4 million severe sepsis cases, with potentially 5.3 million deaths annually.

CONCLUSIONS

Population-level epidemiologic data for sepsis are scarce and nonexistent for low- and middle-income countries. Our analyses underline the urgent need to implement global strategies to measure sepsis morbidity and mortality, particularly in low- and middle-income countries.

Soluble urokinase plasminogen activator receptor informs on the progression course after multiple injuries

PURPOSE

The purpose of this study is to study the use of soluble urokinase plasminogen activator receptor (suPAR) for the prognosis of multiple organ dysfunction (MOF) after multiple traumas.

METHODS

Serum suPAR was measured within the first 24 h after multiple injuries in 85 patients. Measurements were repeated after 4 d or at sepsis onset.

RESULTS

Odds ratio for trauma-associated MOF was 4.09 (p: 0.026) with admission suPAR greater than 8 ng/ml. More than 40% increases of suPAR were associated with odds ratio 9.33 (p: 0.047) for severe sepsis.

CONCLUSIONS

suPAR is a useful surrogate biomarker for development of MOF and severe sepsis after multiple traumas.

Novel immunotherapeutic strategies for pyelonephritis

Acute pyelonephritis is an infection of the renal parenchyma and renal pelvis. When it is caused by a typical pathogen in an immunocompetent female patient with normal urinary tract, it is considered uncomplicated. In all other cases, sepsis is the most worrisome complication. In the event of sepsis, patients should be hospitalized and treated aggressively with antibiotics, intravenous fluids and agents that enhance the immune response of the host. In this review, we summarize findings from immunomodulatory interventions in experimental studies of acute pyelonephritis and the application of these interventions into clinical practice. Vaccine against bacterial virulence factors and agents aiming to modulate the immune response of the host belong to these interventions and they are discussed.

Defective cytokine production early after multiple traumas: Modulation in severe sepsis

The exact time frame of multiple trauma-induced immunosuppression and the immune mechanisms mediating transition to severe sepsis are largely unknown. Peripheral blood mononuclear cells were isolated from 69 patients with multiple injuries within the first 24h from injury and from 36 healthy volunteers and stimulated for cytokine production. Circulating endotoxins were measured by the kinetic LAL assay. Measurements were repeated the first 24h of sepsis onset. Patients had defective responses for tumour necrosis factor-alpha (TNFα), interleukin (IL)-10, IL-17 and interferon-gamma (IFNγ) using a broad-panel of bacterial stimuli. Production of IFNγ was pronounced for patients with trauma-related multiple organ failure (MOF). Thirty-six patients developed severe sepsis. At that time, production of TNFα was increased compared to baseline. The increase was greater among non-survivors than among survivors. Enhanced TNFα production on sepsis onset was a main finding of patients without endotoxemia. Immunosuppression of both innate and adaptive cytokine responses appears as early as the first 24h from injury. Transition into severe sepsis due to bacterial superinfection is accompanied by enhanced production of TNFα and this is linked with unfavorable outcome.

Esmolol: immunomodulator in pyelonephritis by Pseudomonas aeruginosa

BACKGROUND

Based on previous animal studies showing promising immunomodulatory efficacy esmolol, a selective β1-blocker, it was assumed that administration of esmolol in experimental pyelonephritis by multidrug-resistant Pseudomonas aeruginosa would prolong survival and modulate immune response.

METHODS

Acute pyelonephritis was induced in 80 rabbits and assigned to eight groups receiving normal saline (controls), esmolol, amikacin, or both agents as pretreatment and as treatment. Blood was sampled for measurement of malondialdehyde and tumor necrosis factor alpha. Animals were followed up for survival, and after death quantitative tissue cultures were performed. The in vitro effect of esmolol on bacterial growth and on the oxidative burst of neutrophils of healthy controls and of sepsis patients was studied.

RESULTS

Survival of pretreatment groups administered single esmolol or esmolol and amikacin was prolonged compared with that of controls (P = 0.018 and P = 0.014, respectively); likewise, survival of treatment groups administered single esmolol or both agents was prolonged compared with that of controls (P = 0.007 and P = 0.014, respectively). Circulating malondialdehyde was significantly lower in pretreated animals administered esmolol or esmolol and amikacin compared with that in controls and in treated animals administered both agents compared with in controls (P = 0.020). In these groups, the bacterial load of the lung was significantly lower compared with controls. Serum tumor necrosis factor alpha did not change. Amikacin was increased in serum of esmolol-treated animals at levels which inhibited the in vitro growth of the studied isolate. Esmolol did not modify the in vitro growth of P aeruginosa and the oxidative burst of neutrophils.

CONCLUSIONS

It is concluded that esmolol prolonged survival after experimental infection by multidrug-resistant P aeruginosa. Survival benefit may be related with pleiotropic actions connected with modulation of pharmacokinetics and attenuation of inflammation.

Angiopoietin-2 associations with the underlying infection and sepsis severity

Angiopoietin-2 (Ang-2) is an important mediator in sepsis. We have previously shown that endotoxemia levels are related to the underlying infection and affect septic patients' outcome. Based on this background we now investigated if circulating Ang-2 (cAng-2) and monocyte Ang-2 expression in septic patients are associated with the underlying infection and organ failure. We measured cAng-2 in 288 septic patients (121 with sepsis, 167 with severe sepsis/septic shock) at less than 24h post study inclusion (day 1) and on days 3 and 7. Peripheral blood mononuclear cells (PBMCs) were additionally isolated; Ang-2 gene expression was estimated by means of real-time PCR. Levels of cAng-2 were higher under severe sepsis and septic shock, as compared to uncomplicated sepsis; PBMC Ang-2 copies were higher in severe sepsis. On day 1, cAng-2 and Ang-2 gene copies were greater under severe sepsis/septic shock in sufferers from all types of infections with the exception of community-acquired pneumonia and ventilator-associated pneumonia. cAng-2 increased proportionally to the number of failing organs, and was higher under metabolic acidosis and acute coagulopathy as compared to no failing organ. On day 1, copies of Ang-2 were higher in survivors, whereas cAng-2 was higher in non-survivors. In a large cohort of septic patients, cAng-2 kinetics appears associated with the underlying infection and organ failure type.

Thalidomide prolongs survival after experimental musculoskeletal injury, through an effect on mononuclear apoptosis

BACKGROUND

This study was conducted to investigate the effects of intravenous thalidomide administration in an experimental model of musculoskeletal trauma. We hypothesized that because thalidomide inhibits secretion of tumor necrosis factor alpha (TNF-α), survival of animals that received thalidomide would be significantly prolonged.

MATERIAL AND METHODS

After an open fracture of the right femur, 24 rabbits were randomly assigned to control and thalidomide groups. Intravenous therapy with thalidomide was started 30 min after fracture. Hemodynamic monitoring of all animals was performed for 4 h. Survival was recorded and bacterial growth in blood and organs was measured after animal death or sacrifice. Blood was sampled for TNF-α measurement and for isolation of peripheral blood mononuclear cells (PBMCs). Apoptosis of PBMCs was measured by flow cytometry.

RESULTS

Survival was significantly prolonged in the thalidomide group. Apoptosis of PBMCs was increased in the control group compared with the thalidomide group at 24 h. There were no differences in vital signs, blood and tissue cultures, and serum TNF-α concentration between the two groups.

CONCLUSIONS

Intravenous thalidomide prolonged survival in an experimental model of severe musculoskeletal injury in rabbits. Its mechanism of action did not involve TNF-α suppression but prevention of mononuclear apoptosis. In view of these promising results, further research is needed to clarify the immunomodulatory mechanism of action of thalidomide and its potential use for the management of severe trauma.

Comparative efficacy of tigecycline VERSUS vancomycin in an experimental model of soft tissue infection by methicillin-resistant Staphylococcus aureus producing Panton-Valentine leukocidin

Methicillin-resistant Staphylococcus aureus (MRSA) producing Panton-Valentine leukocidin (PVL) is highly virulent. This study aimed to compare the efficacy of tigecycline versus vancomycin in experimental thigh abscess by a PVL-producing MRSA isolate. One hundred and ninety-six Wistar rats were divided into five groups: group A, controls; groups B and C, administered vancomycin starting 1 and 6 h after bacterial challenge respectively; groups D and E, administered tigecycline starting 1 and 6 h after bacterial challenge respectively. Treatment was continued every 12 hours for three consecutive days. Survival was recorded; separate animals were killed for quantitative cultures. Serum samples were collected for estimation of malondialdehyde (MDA). Survival of group D was prolonged compared to all other groups. The bacterial load of blood, liver, spleen and lung was significantly decreased within group D compared to group B at 36 hours. Treatment with tigecycline was accompanied by significant reduction of serum MDA at 24 hours. Tigecycline is comparable to vancomycin for the treatment of soft tissue infections by PVL-producing MRSA.

Intravenous paracetamol as an antipyretic and analgesic medication: the significance of drug metabolism

One prospective, open-label, non-randomized study was conducted in 100 patients to define the antipyretic and analgesic effect of a new intravenous formulation of 1 g of paracetamol; 71 received paracetamol for the management of fever and 29 received paracetamol for pain relief after abdominal surgery or for neoplastic pain. Serial follow-up measurements of core temperature and of pain intensity were done for 6 h. Additional rescue medications were recorded for 5 days. Blood was sampled for the measurement of free paracetamol (APAP) and of glucuronide-APAP and N-sulfate-APAP by an HPLC assay. Defervescence, defined as core temperature below or equal to 37.1°C, was achieved in 52 patients (73.2%) within a median time of 3 h. Patients failing to become afebrile with the first dose of paracetamol became afebrile when administered other agents as rescue medications. Analgesia was achieved in 25 patients (86.4%) within a median time of 2 h. Serum levels of glucuronide-APAP were greater among non-responders to paracetamol. The presented results suggest that the intravenous formulation of paracetamol is clinically effective depending on drug metabolism.

Impact of haplotypes of TNF in the natural course of infective endocarditis

Based on previous findings for the role of single nucleotide polymorphisms (SNPs) of TNF for the predisposition for bloodstream infections, this study investigates the role of these SNPs at the promoter positions -376, -308, -238 in infective endocarditis (IE). In a case-control study, 83 patients with IE and 83 controls were enrolled. Blood genotyping for the presence of G or A alleles of the three SNPs was carried out using restriction fragment length polymorphisms. Haplotypes were calculated. Patients were mostly infected by Staphylococcus aureus (32.5%) and by species of enterococci (14.3%) and streptococci (14.3%). Carriage of the minor frequency A alleles at -238 of the promoter region of TNF was greater than in controls (8.4% versus 1.2%, p 0.003). The presence of any of the three GGA/GAA/AGA haplotypes was more frequent in patients with IE (OR 8.22, 95CI% 1.8-37.4, p 0.001). After multivariate logistic regression analysis, it was found that the only factor related to fatal outcome was carriage of the wild-type GGG haplotype (OR, 3.29, 95CI%, 1.05-10.29, p 0.04). GGA, AGA and GAA haplotypes were more frequent in patients with IE than in controls, suggesting a predisposition for IE and a potential protective role against fatal outcome, as the wild-type GGG haplotype was independently related with death.

Bacterial translocation induces proinflammatory responses and is associated with early death in experimental severe injury

OBJECTIVE

An experimental model of severe injury with great lethality was studied to define the impact of bacterial translocation on survival and on inflammatory response.

METHODS

Forty-one rabbits were divided into two groups: A, femur myotomy; and B, myotomy and fracture of the femoral bone. Vital signs and survival were recorded. Serum circulating endotoxins (lipopolysaccharides; LPS) were determined and tissue cultures were performed at necropsy. A subgroup of animals was sacrificed at 48 h post injury; LPS was determined in abdominal aorta and portal vein, apoptosis of spleen cells was assessed by flow cytometry, and ex vivo production of tumor necrosis factor alpha by splenocytes was measured.

RESULTS

Tissue bacterial burden was increased in animals that died early (i.e., within 48 h after injury) versus rabbits that died later. Portal vein LPS at 48 h was increased in group B compared with group A, whereas circulating LPS did not differ. No difference in apoptosis of either lymphocytes or macrophages of the spleen was found in group B compared with group A. Following stimulation with LPS or phytohemagglutinin, tumor necrosis factor α production by splenocytes of group B was greater than that of group A.

CONCLUSIONS

Bacterial translocation primes enhanced proinflammatory responses and it is associated with early death in severe trauma.

Effect of clarithromycin in experimental empyema by multidrug-resistant Pseudomonas aeruginosa

Evidence from a recent randomized study of our group suggests that intravenous clarithromycin resulted in earlier resolution of ventilator-associated pneumonia. The need to understand the mechanism of action of clarithromycin guided to the study of a model of experimental empyema by multidrug-resistant Pseudomonas aeruginosa in 40 rabbits. Animals were randomized into controls (group A); treatment with clarithromycin (group B); treatment with piperacillin/tazobactam (group C); and treatment with both agents (group D). Pleural fluid was collected at regular time intervals for quantitative culture, estimation of cell apoptosis and of concentrations of tumour necrosis factor-alpha (TNFα). After 7 days, animals were euthanized for estimation of tissue growth. Bacterial growth in the pleural fluid of group D was significantly decreased compared with the other groups on day 5. Lung growth of group D was lower than group A. That was also the case of cytokine stimulation by pleural fluid samples on U937 monocytes. It is concluded that administration of clarithromycin enhanced the antimicrobial efficacy of piperacillin/tazobactam and decreased bacterial growth in the pleural fluid and in tissues. It also attenuated the pro-inflammatory phenomena induced by the β-lactam.

Compartmentalization of lipid peroxidation in sepsis by multidrug-resistant gram-negative bacteria: experimental and clinical evidence

Introduction

Recent evidence suggests a link between excess lipid peroxidation and specific organ failures in sepsis. No study has been performed in sepsis by multidrug-resistant (MDR) Gram-negative bacteria.

Methods

Lethal sepsis was induced in rats by the intraperitoneal injection of one MDR isolate of Pseudomonas aeruginosa. Produced malondialdehyde (MDA) was measured in tissues 5 hours after bacterial challenge with the thiobarbiturate assay followed by high-performance liquid chromatography (HPLC) analysis. Results were compared with those from a cohort of patients with ventilator-associated pneumonia (VAP) and sepsis by MDR Gram-negative bacteria. More precisely, serum MDA was measured on 7 consecutive days, and it was correlated with clinical characteristics.

Results

MDA of septic rats was greater in the liver, spleen, and aortic wall, and it was lower in the right kidney compared with sham operated-on animals. Findings were confirmed by the studied cohort. Circulating MDA was greater in patients with hepatic dysfunction and acute respiratory distress syndrome (ARDS) compared with patients without any organ failures. The opposite was found for patients with acute renal dysfunction. No differences were found between patients with ARDS without or with cardiovascular (CV) failure and patients without any organ failure. Serial measurements of MDA in serum of patients indicated that levels of MDA were greater in survivors of hepatic dysfunction and ARDS and lower in survivors of acute renal dysfunction.

Conclusions

Animal findings and results of human sepsis are complementary, and they suggest a compartmentalization of lipid peroxidation in systemic infections by MDR gram-negative bacteria.

Angiopoietin-2 enhances survival in experimental sepsis induced by multidrug-resistant Pseudomonas aeruginosa

Levels of circulating angiopoietin-2 (Ang-2) increase in sepsis, raising the possibility that Ang-2 acts as a modulator in the sepsis cascade. To investigate this, experimental sepsis was induced in male C57BL6 mice by a multidrug-resistant isolate of Pseudomonas aeruginosa; survival was determined along with neutrophil tissue infiltration and release of proinflammatory cytokines. Survival was significantly increased either by pretreatment with recombinant Ang-2 2 h before or treatment with recombinant Ang-2 30 min after bacterial challenge. Likewise, Ang-2 pretreatment protected against sepsis-related death elicited by Escherichia coli; however, Ang-2 failed to provide protection in lipopolysaccharide (LPS)-challenged mice. The survival advantage of Ang-2 in response to P. aeruginosa challenge was lost in tumor necrosis factor (TNF)-deficient mice or neutropenic mice. Infiltration of the liver by neutrophils was elevated in the Ang-2 group compared with saline-treated animals. Serum TNF-α levels were reduced by Ang-2, whereas those of interleukin (IL)-6 and IL-10 remained unchanged. This was accompanied by lower release of TNF-α by stimulated splenocytes. When applied to U937 cells in vitro, heat-killed P. aeruginosa induced the secretion of IL-6 and TNF-α; low levels of exogenous TNF-α synergized with P. aeruginosa. This synergistic effect was abolished after the addition of Ang-2. These results put in evidence a striking protective role of Ang-2 in experimental sepsis evoked by a multidrug-resistant isolate of P. aeruginosa attributed to modulation of TNF-α production and changes in neutrophil migration. The protective role of Ang-2 is shown when whole microorganisms are used and not LPS, suggesting complex interactions with the host immune response.

Serum kinetics of soluble triggering receptor expressed on myeloid cells-1 differs in relation to the type of arthroplasty

CONTEXT

Soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) participates in the inflammatory process.

PURPOSE

To describe changes of sTREM-1 in the serum after hemiarthroplasty (HA) and total hip arthroplasty (THA).

METHODS

Serial blood samples were drawn from 122 patients with hip fracture. Interleukin-6 (IL-6), sTREM-1, and C-reactive protein (CRP) were measured.

RESULTS

IL-6 and CRP were similarly increased after both HA and THA. sTREM-1 was increased early in HA and late after THA. The only parameter that was higher among patients who developed systemic inflammatory response syndrome was IL-6.

CONCLUSIONS

Kinetics of sTREM-1 differs among patients undergoing HA of the hip and those undergoing THA.

Impact of multidrug resistance on experimental empyema by Pseudomonas aeruginosa

BACKGROUND

Pseudomonas aeruginosa is a cause of infections of the lower respiratory tract among patients with chronic lung disorders. It is questionable whether virulence of this species may be influenced by multidrug resistance (MDR).

OBJECTIVES

To define the impact of MDR in experimental lung infection.

METHODS

Experimental empyema was induced in rabbits by MDR (group A, n = 16) and by susceptible isolates (group B, n = 10). Pleural fluid was sampled for quantitative culture and estimation of cell apoptosis and of tumor necrosis factor-alpha (TNFα) and malondialdehyde (MDA). Survival was recorded. Cytokine production was stimulated in U937 monocytes by samples of pleural fluid. Whole blood of rabbits was incubated with the isolates; induction of apoptosis was assessed.

RESULTS

Survival of group A was prolonged compared to group B. This was accompanied by lower bacterial counts of the inoculated pathogens in pleural fluid and in the lungs of group A compared with group B. Early apoptosis of neutrophils of pleural fluid of group A was lower compared with group B. Pleural fluid concentrations of TNFα and MDA did not differ between the groups. Cytokine production by U937 monocytes after stimulation with pleural fluid was greater in group B than in group A. The susceptible isolate induced apoptosis of neutrophils in vitro at a greater rate than the MDR isolate.

CONCLUSIONS

Experimental empyema by susceptible P. aeruginosa is accompanied by greater mortality compared with MDR P. aeruginosa. This phenomenon may be attributed to the different growth pattern of the pathogens or to their interaction with the innate immune system.

Indication for a role of regulatory T cells for the advent of influenza A (H1N1)-related pneumonia

Regulatory T cells (T(regs) ) have an anti-inflammatory role. A former study in a limited number of patients found that absolute counts of T(regs) increase when infection by the new influenza H1N1 virus is complicated with pneumonia. These results generate the question if H1N1-related pneumonia is associated with a state of hypo-inflammation. A total of 135 patients were enrolled with blood sampling within less than 24 h from diagnosis; 23 with flu-like syndrome; 69 with uncomplicated H1N1-infection; seven with bacterial pneumonia; and 36 with H1N1-related pneumonia. T(regs) and CD14/HLA-DR co-expression were estimated by flow cytometry; concentrations of tumour necrosis factor-alpha (TNF-α), of interleukin (IL)-6 and of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) by an enzyme immunoassay; those of procalcitonin (PCT) by immuno-time-resolved amplified cryptate technology assay. Expression of human leucocyte antigen D-related (HLA-DR) on monocytes was similar between groups; absolute T(reg) counts were greater among patients with H1N1-related pneumonia than flu-like syndrome or H1N1-uncomplicated infection. Serum TNF-α of patients with bacterial pneumonia was greater than those of other groups, but IL-10 was similar between groups. Serum PCT was greater among patients with H1N1-related pneumonia and sTREM-1 among those with H1N1-related pneumonia. Regression analysis revealed that the most important factors related with the advent of pneumonia were the existence of underlying illnesses (P = 0·006) and of T(regs) equal to or above 16 mm(3) (P = 0·013). It is concluded that the advent of H1N1-related pneumonia is related to an early increase of the absolute T(reg) counts. This increase is probably not part of a hypo-inflammatory state of the host.

Efficacy of carbapenems against a metallo-β-lactamase-producing Escherichia coli clinical isolate in a rabbit intra-abdominal abscess model

BACKGROUND

Although metallo-β-lactamases (MBLs) hydrolyse most β-lactams, including carbapenems, MBL-producing Enterobacteriaceae very often remain susceptible to carbapenems in vitro. We studied the in vivo efficacy of imipenem, meropenem, ertapenem and aztreonam against a carbapenem-susceptible MBL-producing clinical Escherichia coli strain in a rabbit intra-abdominal abscess model.

METHODS

Rabbits were inoculated intraperitoneally with 10(8) cfu/mL of VIM-1-positive E. coli and were assigned to receive no treatment (controls) or intravenous imipenem/cilastatin (imipenem) 70 mg/kg/12 h or meropenem 125 mg/kg/12 h or ertapenem 60 mg/kg/12 h or aztreonam 70 mg/kg/12 h. Dosing regimens were chosen on the basis of preliminary pharmacokinetic studies so that T(>MIC) was achieved for ≥50% of the dosing interval for all tested antibiotics. A total of eight doses were administered before sacrifice and the abscesses were harvested and quantitatively cultured.

RESULTS

MICs of imipenem, meropenem, ertapenem and aztreonam for the infecting isolate were 1, ≤0.25, 1.5 and ≤0.25 mg/L, respectively. The log(10) cfu/g (mean ± SD) viable counts in pus were as follows: controls (n = 16), 8.71 ± 1.34 (P < 0.001 versus all other groups); imipenem (n = 15), 4.89 ± 2.42; meropenem (n = 15), 4.24 ± 2.44; ertapenem (n = 16), 3.17 ± 1.85 (P = 0.022 versus imipenem); and aztreonam (n = 15), 3.62 ± 3.05. Mortality among treated rabbits was significantly reduced compared with controls. Four animals in the aztreonam group (26.7%) had culture-negative pus and no mortality was noted among aztreonam-treated animals.

CONCLUSIONS

In the rabbit experimental model, carbapenems were shown to be effective in the treatment of intra-abdominal infection due to an extended-spectrum β-lactamase-negative carbapenem-susceptible VIM-1-producing clinical E. coli strain, but treatment with aztreonam resulted in a more favourable outcome overall.

Eicosapentanoic acid prolongs survival and attenuates inflammatory response in an experimental model of lethal trauma

In an attempt to define the efficacy of intravenously administered n-3 polyunsaturated fatty acids (PUFAs) in an animal model of lethal trauma following femur fracture, an intravenous solution of eicosapentanoic acid (EPA) - one n-3 PUFA - was administered in 25 rabbits; 13 were controls and 12 were treated with EPA 30 min after fracture. Vital signs were recorded and serum concentrations of tumor necrosis factor-alpha (TNFalpha) and respiratory burst of neutrophils were assessed. Survival of controls was 7.7% and of animals treated with EPA 50% (log-rank: 5.162; p: 0.023). Vital signs of both groups did not differ. Oxidative burst of neutrophils was greater among EPA-treated animals compared with controls at 48 h (p: 0.010). Serum levels of TNFalpha of the former group were decreased compared with the latter at 48 h (p: 0.019). Bacterial growth of enterobacteriaceae from liver and spleen after death or euthanasia was lower among EPA-treated rabbits than controls. These results suggest that EPA possesses considerable immunomodulatory activities improving survival in a model of lethal trauma. Restoration of oxidative burst conferring efficient phagocytosis of evading bacteria seems the most probable mechanism of action.

Early alterations of the innate and adaptive immune statuses in sepsis according to the type of underlying infection

Introduction

Although major changes of the immune system have been described in sepsis, it has never been studied whether these may differ in relation to the type of underlying infection or not. This was studied for the first time.

Methods

The statuses of the innate and adaptive immune systems were prospectively compared in 505 patients. Whole blood was sampled within less than 24 hours of advent of sepsis; white blood cells were stained with monoclonal antibodies and analyzed though a flow cytometer.

Results

Expression of HLA-DR was significantly decreased among patients with severe sepsis/shock due to acute pyelonephritis and intraabdominal infections compared with sepsis. The rate of apoptosis of natural killer (NK) cells differed significantly among patients with severe sepsis/shock due to ventilator-associated pneumonia (VAP) and hospital-acquired pneumonia (HAP) compared with sepsis. The rate of apoptosis of NKT cells differed significantly among patients with severe sepsis/shock due to acute pyelonephritis, primary bacteremia and VAP/HAP compared with sepsis. Regarding adaptive immunity, absolute counts of CD4-lymphocytes were significantly decreased among patients with severe sepsis/shock due to community-acquired pneumonia (CAP) and intraabdominal infections compared with sepsis. Absolute counts of B-lymphocytes were significantly decreased among patients with severe sepsis/shock due to CAP compared with sepsis.

Conclusions

Major differences of the early statuses of the innate and adaptive immune systems exist between sepsis and severe sepsis/shock in relation to the underlying type of infection. These results may have a major impact on therapeutics.

In vitro elution of moxifloxacin from cancellous bone allografts

The characteristics of cancellous bone allografts as carriers of moxifloxacin are described. Particles of cancellous bone were compressed into a wire-mesh cylinder and impregnated into a solution of moxifloxacin for different time periods. Five replicas were impregnated for 1 h; another five for 24 h; and another five for 48 h. Impregnated allografts were then transferred into vials containing 5 ml of Mueller-Hinton broth and incubated at 37 degrees C. Broth was replaced daily. Concentrations of moxifloxacin in broth were determined after analysis by an high performance liquid chromatography system. Moxifloxacin was eluted at very high concentrations within the first days. Concentrations remained above 100 microg/ml until day 8 and above 40 microg/ml until day 20. It is concluded that cancellous bone allografts may allow the adequate in vitro elution of moxifloxacin. The latter results support their application in experimental models of osteomyelitis.

Effect of the novel influenza A (H1N1) virus in the human immune system

Background

The pandemic by the novel H1N1 virus has created the need to study any probable effects of that infection in the immune system of the host.

Methodology/Principal Findings

Blood was sampled within the first two days of the presentation of signs of infection from 10 healthy volunteers; from 18 cases of flu-like syndrome; and from 31 cases of infection by H1N1 confirmed by reverse RT-PCR. Absolute counts of subtypes of monocytes and of lymphocytes were determined after staining with monoclonal antibodies and analysis by flow cytometry. Peripheral blood mononuclear cells (PBMCs) were isolated from patients and stimulated with various bacterial stimuli. Concentrations of tumour necrosis factor-alpha, interleukin (IL)-1beta, IL-6, IL-18, interferon (FN)-alpha and of IFN-gamma were estimated in supernatants by an enzyme immunoassay. Infection by H1N1 was accompanied by an increase of monocytes. PBMCs of patients evoked strong cytokine production after stimulation with most of bacterial stimuli. Defective cytokine responses were shown in response to stimulation with phytohemagglutin and with heat-killed Streptococcus pneumoniae. Adaptive immune responses of H1N1-infected patients were characterized by decreases of CD4-lymphocytes and of B-lymphocytes and by increase of T-regulatory lymphocytes (Tregs).

Conclusions/Significance

Infection by the H1N1 virus is accompanied by a characteristic impairment of the innate immune responses characterized by defective cytokine responses to S.pneumoniae. Alterations of the adaptive immune responses are predominated by increase of Tregs. These findings signify a predisposition for pneumococcal infections after infection by H1N1 influenza.

Pharmacokinetics of moxifloxacin in patients undergoing continuous ambulatory peritoneal dialysis

OBJECTIVE

To investigate the effect of continuous ambulatory peritoneal dialysis (CAPD) on plasma and peritoneal fluid concentration and pharmacokinetics of moxifloxacin after administration of one 400 mg dose orally to end-stage renal failure patients undergoing CAPD.

PATIENTS AND METHODS

Blood and peritoneal samples were collected from 8 patients at standard time intervals and concentrations of moxifloxacin were estimated by HPLC analysis with fluorometric and ultraviolet detection. Pharmacokinetic parameters were estimated using standard noncompartmental methods.

RESULTS

Median maximum plasma moxifloxacin concentration was 5.86 mg/L at a median time of 1.25 hours. In serum, median area under the concentration-time curve (AUC(0-->inf)) was 157.95 +/- 100.34 mg.hour/L, median t(1/2) 25.00 hours, median clearance 2.54 L/hour, and median distribution volume 94.90 L. Median peritoneal fluid-to-plasma ratio of moxifloxacin ranged between 0.84 and 1.00, denoting adequate penetration and lack of considerable moxifloxacin removal during CAPD. Maximum moxifloxacin concentration/minimum inhibitory concentration (MIC) and AUC(0-->24)/MIC ratios were above the cutoff points that indicate clinical success.

CONCLUSION

A single 400 mg oral dose of moxifloxacin is safe, presents rapid peritoneal fluid penetration, has similar plasma and peritoneal fluid pharmacokinetics, and should therefore be efficacious in the treatment of CAPD-induced peritonitis.

Pharmacokinetics of Moxifloxacin in Patients Undergoing Continuous Ambulatory Peritoneal Dialysis

Objective

To investigate the effect of continuous ambulatory peritoneal dialysis (CAPD) on plasma and peritoneal fluid concentration and pharmacokinetics of moxifloxacin after administration of one 400 mg dose orally to end-stage renal failure patients undergoing CAPD.

Patients and Methods

Blood and peritoneal samples were collected from 8 patients at standard time intervals and concentrations of moxifloxacin were estimated by HPLC analysis with fluorometric and ultraviolet detection. Pharmacokinetic parameters were estimated using standard noncompartmental methods.

Results

Median maximum plasma moxifloxacin concentration was 5.86 mg/L at a median time of 1.25 hours. In serum, median area under the concentration–time curve (AUC0→inf) was 157.95 ± 100.34 mg·hour/L, median t½ 25.00 hours, median clearance 2.54 L/hour, and median distribution volume 94.90 L. Median peritoneal fluid-to-plasma ratio of moxifloxacin ranged between 0.84 and 1.00, denoting adequate penetration and lack of considerable moxifloxacin removal during CAPD. Maximum moxifloxacin concentration/minimum inhibitory concentration (MIC) and AUC0→24/MIC ratios were above the cutoff points that indicate clinical success.

Conclusion

A single 400 mg oral dose of moxifloxacin is safe, presents rapid peritoneal fluid penetration, has similar plasma and peritoneal fluid pharmacokinetics, and should therefore be efficacious in the treatment of CAPD-induced peritonitis.

Clarithromycin: Immunomodulatory therapy of experimental sepsis and acute pyelonephritis by Escherichia coli

The potency of clarithromycin as immunomodulator was assessed in an experimental model of sepsis based on acute pyelonephritis by susceptible Escherichia coli. 55 rabbits were utilized; 5 for preliminary pharmacokinetic study and 50 for treatment. The latter were divided into 5 groups of treatment, A: controls; B: clarithromycin pretreatment; C: amikacin pretreatment; D: clarithromycin treatment on presentation of pulmonary oedema; and E; amikacin treatment on presentation of pulmonary oedema. Survival was recorded; tumour necrosis factor-alpha (TNFalpha), and malondialdehyde (MDA) were estimated in serum; activities of caspase-3 in monocyte cytosolic extracts were studied; and bacterial counts made in various organs. Median survival of animals of groups A, B, C, D and E was 1.0, 21.0, 12.5, 2.0 and 5.0 d, respectively. TNFalpha and MDA and monocyte caspase-3 activity of group A increased over time; no increases were detected in groups B and C. Concentrations of MDA and activities of monocytic caspase-3 were decreased after administration of clarithromycin in group D, an effect not occurring in group E. Bacterial load was decreased in renal tissue of group D compared to group A. It is concluded that intravenous clarithromycin might constitute a promising immunomodulator in sepsis even in the advent of pulmonary oedema.

Monocytes as a site of production of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) in the septic host

The role of blood monocytes in the secretion of soluble triggering receptor expressed on myeloiod cells (sTREM-1) was studied in 90 patients with septic syndrome due to ventilator-associated pneumonia. Blood monocytes were isolated on 7 consecutive d after initiation of symptoms. Monocytes were incubated in the absence or presence of LPS and concentrations of sTREM-1 and TNFalpha in cell supernatants and serum were estimated by an enzyme-immunoassay. sTREM-1 and TNFalpha were consistently present at detectable levels in the cell supernatants. LPS induced increased levels of TNFalpha but not of sTREM-1. Supernatants recovered from monocytes on d 1 showed levels of sTREM-1 higher than those recovered on any of the following 6 d (p<0.05); these levels were higher in non-survivors than in survivors. Supernatants recovered from monocytes on d 1 of patients with severe sepsis had elevated concentrations of sTREM-1 compared to patients with septic shock and similar to patients with sepsis. A negative correlation was found between levels of sTREM-1 in the cell supernatants and the percentage of apoptotic monocytes. In essence, the above results suggest that monocytes contribute to the production of sTREM-1 in the event of septic syndrome.

In vitro release of fusidic acid and teicoplanin from cancellous bone allografts

The characteristics of cancellous bone allografts as carriers of fusidic acid and teicoplanin are described. Particles of cancellous bone were compressed into a wiremesh cylinder; five replicas were impregnated for one hour into fusidic acid; and another five for one hour into teicoplanin. Elution was estimated daily. Concentrations of fusidic acid and teicoplanin were determined by a microbiological assay. Both antibiotics were eluted at very high concentrations within the first days. Allografts impregnated in fusidic acid provided concentrations above 20 microg/ml for 20 days. Eluted teicoplanin after day 4 was below 10 microg/ml. It is concluded that cancellous bone allografts may allow adequate in vitro elution of fusidic acid but not of teicoplanin. The latter results support their application in experimental models of osteomyelitis.

Short-term administration of a high oxygen concentration is not injurious in an ex-vivo rabbit model of ventilator-induced lung injury

BACKGROUND

Mechanical ventilation and administration of a high oxygen concentration are simultaneously used in the management of respiratory failure. We conducted this study to evaluate the effect of a high inspired oxygen concentration on ventilator-induced lung injury.

METHODS

Forty sets of isolated/perfused rabbit lungs were randomized for 60 min of pressure-control ventilation at a plateau inspiratory pressure of 25 or 15 cm H(2)O and positive end-expiratory pressure of 3 cm H(2)O while receiving 100% or 21% O(2). The temperature, pH, and partial pressure of CO(2) in the perfusate were maintained the same in all groups (n = 10 for each group). The outcome measures used to assess lung injury included: the change in weight gain and ultrafiltration coefficient, the frequency of vascular failure, the histological lesions and the concentration of tumor necrosis factor-alpha and malondialdehyde in the bronchoalveolar lavage fluid.

RESULTS

The two groups ventilated at the higher inspiratory pressure/tidal volume experienced greater weight gain and increases in the ultrafiltration coefficient, more frequently suffered vascular failure, and presented higher composite scores of histological damage than the two groups ventilated at the lower inspiratory pressure/tidal volume. Hyperoxia was not found to further increase any of the monitored markers of lung injury. No difference was noticed among the four experimental groups in the alveolar lavage fluid levels of tumor necrosis factor-alpha or malondialdehyde.

CONCLUSIONS

These findings suggest that short-term administration of a high oxygen concentration is not a major determinant of ventilator-induced lung injury in this experimental model.

Treatment of experimental osteomyelitis caused by methicillin-resistant Staphylococcus aureus with a synthetic carrier of calcium sulphate (Stimulan) releasing moxifloxacin

The objectives of this study were to assess the efficacy of a synthetic semihydrate form of calcium sulphate (Stimulan) in experimental bone infection caused by methicillin-resistant Staphylococcus aureus (MRSA). Osteomyelitis was induced after inoculation of the test pathogen in the left tibia of 72 New Zealand rabbits assigned to the following groups: 18 control rabbits (Group A); 18 rabbits with Stimulan implanted (Group B); and 36 rabbits with moxifloxacin-impregnated Stimulan implanted (Group C). Rabbits were sacrificed at weekly intervals and cancellous bone was harvested for histopathology and for estimation of bacterial growth and concentrations of moxifloxacin. Bacterial growth from cancellous bone of Group C was significantly lower than the respective growth of Groups A and B on all days of sacrifice. The main histological finding of animals in all three groups was a moderate to intense inflammatory reaction accompanied by fibrosis. The degree of fibrosis was higher in Group C compared with both other groups. Infiltration by giant cells was also observed, which was greater in Group C on Day 42. Antibiotic levels in bone were higher for bone samples closer to the site of implantation. In conclusion, Stimulan admixed with 10% moxifloxacin was very effective in achieving complete eradication of the causative pathogen in experimental osteomyelitis caused by MRSA.

Kinetics of angiopoietin-2 in serum of multi-trauma patients: correlation with patient severity

BACKGROUND

Angiopoietin-2 (Ang-2) is considered a proinflammatory mediator promoting vascular leakage. Its participation in the inflammatory process following multiple injuries was investigated.

METHODS

Blood was sampled on consecutive days from 54 patients with multiple injuries and six healthy volunteers. Ang-2 was estimated in serum by an enzyme immunoassay.

RESULTS

From the enrolled patients, 10 did not develop any complication; 17 developed systemic inflammatory response syndrome (SIRS); 16 developed sepsis and 11 severe sepsis. Among those who did not develop any complication, all survived. Ang-2 was increased on days 4 and 7 of follow-up in patients with SIRS. Ang-2 was highly increased upon advent of sepsis and of severe sepsis. Patients with serum levels below 15,200 pg/ml survived longer compared to those with levels above 15,200 pg/ml (p=0.015). OR for death with serum Ang-2 above 15,200 pg/ml was 4.00 (p=0.037).

CONCLUSIONS

Serum levels of Ang-2 in multi-trauma patients are increased upon advent of septic complications and they are connected with bad prognosis. Its exact role in the process of multiple trauma remains to be defined.

Pharmacokinetics of intravenously administered moxifloxacin in eye compartments: an experimental study

The purpose of this study was to evaluate the pharmacokinetics of intravenously administered moxifloxacin, a fourth-generation fluoroquinolone, in different parts of the non-inflamed eye. Moxifloxacin was administered intravenously at a dose of 20mg/kg moxifloxacin over 30min. Sampling of peripheral blood, aqueous humour and vitreous was performed at standard time intervals post infusion once in each animal. Moxifloxacin levels were estimated by high-performance liquid chromatography with fluorescence detection. Mean serum concentrations were 3.43, 2.74, 1.48 and 1.12microg/mL at 0.5, 3, 6 and 24h after the end of drug infusion, respectively. Respective concentrations in aqueous humour were 2.44, 2.03, 1.30 and 1.09microg/mL and in vitreous body they were 1.68, 1.87, 1.78 and 1.15microg/mL. It is concluded that systemic administration of moxifloxacin in rabbits was accompanied by efficient penetration into both the aqueous humour and the vitreous body at concentrations well above the minimum inhibitory concentration for most causative pathogens of endophthalmitis. Further research is mandatory to clarify the clinical significance of these findings.

Effect of clarithromycin in patients with sepsis and ventilator-associated pneumonia

BACKGROUND

Because clarithromycin provided beneficiary nonantibiotic effects in experimental studies, its efficacy was tested in patients with sepsis and ventilator-associated pneumonia (VAP).

METHODS

Two hundred patients with sepsis and VAP were enrolled in a double-blind, randomized, multicenter trial from June 2004 until November 2005. Clarithromycin (1 g) was administered intravenously once daily for 3 consecutive days in 100 patients; another 100 patients were treated with placebo. Main outcomes were resolution of VAP, duration of mechanical ventilation, and sepsis-related mortality within 28 days.

RESULTS

The groups were well matched with regard to demographic characteristics, disease severity, pathogens, and adequacy of the administered antimicrobials. Analysis comprising 141 patients who survived revealed that the median time for resolution of VAP was 15.5 days and 10.0 days among placebo- and clarithromycin-treated patients, respectively (P = .011); median times for weaning from mechanical ventilation were 22.5 days and 16.0 days, respectively (p = .049). Analysis comprising all enrolled patients showed a more rapid decrease of the clinical pulmonary infection score and a delay for advent of multiple organ dysfunction in clarithromycin-treated patients, compared with those of placebo-treated patients (p = .047). Among the 45 patients who died of sepsis, time to death was significantly prolonged in clarithromycin-treated compared with placebo-treated patients (p = .004). Serious adverse events were observed in 0% and 3% of placebo- and clarithromycin-treated patients, respectively (P = .25).

CONCLUSIONS

Clarithromycin accelerated the resolution of VAP and weaning from mechanical ventilation in surviving patients and delayed death in those who died of sepsis. The mortality rate at day 28 was not altered. Results are encouraging and render new perspectives on the management of sepsis and VAP.

Efficacy of teicoplanin, administered in two different regimens, in the treatment of experimental endocarditis due to Enterococcus faecalis

Using a rabbit model of endocarditis, we studied the efficacy of teicoplanin against a strain of Enterococcus faecalis resistant to ampicillin. Rabbits were randomly assigned to receive no antibiotics, teicoplanin 12 or 18 mg/kg of body weight every 12h, for 9 days. The effect of treatment on bacterial counts of vegetations and survival of the animals was evaluated at the end of treatment and 10 days thereafter. The two treatment regimens of teicoplanin produced peak serum levels 18.51+/-1.84 and 34.66+/-4.19 microg/ml, and trough levels above 10 x MIC of teicoplanin for the infecting organism. Both regimens resulted in significant bacterial reduction in the vegetations as compared to the control group (p<0.001). The drug prevented relapse of the infection 10 days after discontinuation of treatment. By increasing the teicoplanin dosage no additional therapeutic benefit was observed in terms of bacterial killing, sterilization of the vegetations, and survival of the animals, although the higher doses gave numerically superior results. These findings may have meaning for the optimum use of teicoplanin in the treatment of enterococcal endocarditis.

Soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) detection in cancer patients: a prognostic marker for lung metastases from solid malignancies

The aim of the study was to evaluate the serum soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) levels in breast, lung and colorectal cancer patients in correlation with clinical variables.

PATIENTS AND METHODS

A total of 59 patients with a median age of 64 years and histologically confirmed breast 14, colorectal 15 or lung cancer 30 were evaluated. Five patients with breast cancer, 7 patients with colorectal cancer and 8 patients with lung cancer had lung metastases. Blood was collected upon enrolment, centrifuged and the serum kept at -80 degrees C until assayed for sTREM-1. The estimation of sTREM-1 was performed by a crude enzyme immunoabsorbent assay.

RESULTS

High levels of sTREM-1 were observed in 50% of breast cancer, 33.3% of Small Cell Lung carcinoma (SCLC), 26.7% of colorectal cancer and 13.3% of Non Small Cell Lung Carcinoma (NSCLC) patients. sTREM-1 expression showed a correlation to the site of metastases. Higher concentrations were observed in the absence of lung metastases (p=0.019).

DISCUSSION

The novel mediator sTREM-1 may be a prognostic marker for the detection of lung metastases in metastatic and locally advanced solid tumors.

The effect of the type of intraperitoneally implanted prosthetic mesh on the systemic inflammatory response

BACKGROUND

The purpose of this study was to determine any differences in the systemic inflammatory response after the intraperitoneal implantation of three different types of polypropylene mesh.

METHODS

Thirty-two male New Zealand rabbits underwent a 6-cm midline incision and opening of the peritoneal cavity. The animals were randomly divided into four groups. In groups A, B, and C, there was an intraperitoneal placement of polypropylene mesh, titanium-coated polypropylene mesh, and composite polypropylene/e-PTFE mesh, respectively. Group D received a sham operation. Blood was sampled preoperatively and at 6, 24, 48, and 168 h postoperatively to measure white blood cell count (WBC), tumor necrosis factor-alpha (TNF-alpha), and malondialdehyde (MDA).

RESULTS

Statistically significant elevations of WBC, TNF-alpha and MDA were observed in all four groups at 6, 24, and 48 h postoperatively (P<0.05). There were no statistically significant differences in WBC, TNF-alpha, and MDA between groups A, B, and C at any time interval. However, a statistically significant elevation of WBC (P<0.05) and TNF-alpha (P<0.05) was observed between each of the groups with mesh implantation and group D at 24 h postoperatively.

CONCLUSION

Intraperitoneal mesh implantation induces mild systemic inflammatory response regardless of the type of implanted mesh.