The management of endoscopic retrograde cholangio- pancreatography-related infections risk: results of an italian survey at regional level.

Background and aim: Among the Endoscopic retrograde cholangiopancreatography (ERCP) adverse events, an increasingly arising problem is the transmission of Multi Drug Resistant (MDR) Bacteria through duodenoscopes. The aim of this survey was to evaluate the current clinical practice of management of ERCP associated infections in Emilia-Romagna, Italy. Methods: An online survey was developed including 12 questions on management of ERCP associated infections risk. The survey was proposed to all 12 endoscopy centers in Emilia Romagna that perform at least > 200 ERCPs per year. Results: 11 centers completed the survey (92%). Among all risk factors of ERCP infections, hospitalization in intensive care units, immunosuppressant therapies, and previous MDR infections have achieved a 80 % minimum of concurrence by our respondents. The majority of them did not have a formalized document in their hospital describing categories and risk factors helpful in the detection of patients undergoing ERCP with an high-level infective risk (9/11, 82%). Most centers (8/11, 72%) do not perform screening in patients at risk of ERCP infections. Post procedural monitoring is performed by 6 of 11 centers (55%). Conclusion: Our survey showed that, at least at regional level, there is a lack of procedures and protocols related to the management of patients at risk of ERCP infections.

Increased frequency of interleukin-4 and reduced frequency of interferon-γ and IL-17-producing CD4+ and CD8+ cells in scleromyxedema.

BACKGROUND: Little is known about the pathogenesis of scleromyxedema, a life-threatening fibromucinosis disease with immunological dysregulation. OBJECTIVES: To investigate on T-cell phenotype, function and cytokine biology in search of new insights supporting the immunopathogenesis of the disease. METHODS: We analysed the frequency of circulating lymphocyte subsets, the T-cell maturation stage, the generation of antigen-specific T-cell lines and T-cell cytokine secretion. RESULTS: The analysis of T-cell maturation stage and the TCR spectratyping findings revealed that scleromyxedema patients showed clear immunological signs of long-lasting immune system activation and stimulation leading to a skewed T-cell repertoire. Moreover, these analyses showed that both CD4+ and CD8+ T cells from scleromyxedema patients have a profound deficiency (even after stimulation) relatively to the production of IFN-γ and IL17 with respect to healthy donor control cells, while they are massively skewed towards IL4 secretion after stimulation. CONCLUSIONS: Our data indicate that a chronic Th2-skewed T-cell response against an unknown target antigen leading to abnormally high IL4 secretion, a pro-fibrotic cytokine, is a main immunological hallmark of scleromyxedema patients. These results, never reported before, may have a translational therapeutic value due to the availability of anti-IL4 agents such as dupilumab.

Impact of multidisciplinary hip fracture program on timing of surgery in elderly patients.

UNLABELLED: The effect of patient characteristics and organizational and system factors on time to surgery were studied using Emilia Romagna Region database and hospital survey. The results showed that the implementation of a Hip Fracture Program significantly increased the probability of early surgery while single intervention had only slight effect INTRODUCTION: The purpose of this study is to evaluate the effect of formal Hip Fracture Program (HFP) on timing of surgery in hip fracture older patients. METHODS: This is a retrospective cohort study based on Emilia Romagna administrative databases. Data on organizational and system factor were also obtained through a hospital survey. A multilevel logistic regression analysis was carried out to assess the effect of covariates on early surgery, taking into account patient level, hospital level, and trust level variability. RESULTS: From 1 January to 31 December 2011, 5,520 subjects over 65 years old underwent surgical repair for hip fracture in Emilia Romagna. The mean waiting time to surgery was 3.4 ± 12.3 days, and the overall percentage of patients operated within 2 days was 52.2%. In the adjusted multilevel logistic model, significant risk factors affecting the timing of surgical intervention at patient level were age, comorbidity, day of admission, and antiplatelet or warfarin therapy while no significant single variables were found at hospital level including dedicated operation theater, hospital volume, dedicated orthogeriatric beds, and geriatrician involvement. The most significant variable was the implementation of HFP at trust level that increased three times the probability of early surgery after adjusting for confounding variables (OR 3.216, 95% CI 0.582-6.539). CONCLUSIONS: Several modifiable organizational factors may affect the proportion of patients with hip fracture undergoing early surgery. This study suggests that the development and the implementation of an evidence-based HFP at trust level are a key point of the strategy of quality of care.

Risk of death associated with the use of conventional vs. atypical antipsychotic medications: evaluating the use of the Emilia-Romagna Region database for pharmacoepidemiological studies.

WHAT IS KNOWN AND OBJECTIVE: Since 2005, a mounting base of evidence has identified that conventional antipsychotic medications are associated with an increased risk of mortality among elderly patients when compared to atypical antipsychotics. This study sought to explore the feasibility of using the Emilia-Romagna Region (RER) database for comparative safety analyses by replicating and refining risk estimates of this well-known drug safety example through meta-analysis. METHODS: We identified a cohort of 23 681 Italian RER patients (aged ≥65) who initiated treatment with a conventional or atypical antipsychotic between 1 July 2009 and 30 June 2011. We compared 180-day mortality using Cox proportional hazards models adjusted for risk factors for death, use of other medications and measures of health services utilization intensity, all measured before antipsychotic initiation. We conducted a meta-analysis of studies with similar methods against which to compare our results. RESULTS: Among 14 462 and 9219 patients prescribed conventional and atypical antipsychotics, respectively, we observed 2402 (16·6%) and 821 (8·9%) deaths during follow-up. Conventional antipsychotic initiators were older and generally had higher prevalence of outcome risk factors and higher baseline health service use intensity. The crude hazard ratio (HR) was 1·95 [95% confidence interval (CI), 1·80-2·11], which decreased to 1·47 (95% CI, 1·35-1·60) after full adjustment. We identified seven published studies that examined this association using similar methods. The pooled HR from these studies was 1·34 (95% CI, 1·28-1·39). Including our study, the meta-analysis yielded a summary estimate of 1·35 (95% CI, 1·31-1·40) and did not introduce any heterogeneity (I(2)  = 0%; P = 0·455). WHAT IS NEW AND CONCLUSIONS: Our results support the use of the RER database for pharmacoepidemiological studies and provide an up-to-date and pooled estimate of the magnitude of the association between mortality and conventional vs. atypical antipsychotics.

Intrinsic resistance to selumetinib, a selective inhibitor of MEK1/2, by cAMP-dependent protein kinase A activation in human lung and colorectal cancer cells.

BACKGROUND: MEK is activated in ∼40% colorectal cancer (CRC) and 20-30% non-small cell lung cancer (NSCLC). Selumetinib is a selective inhibitor of MEK1/2, which is currently in clinical development. METHODS: We evaluated the effects of selumetinib in vitro and in vivo in CRC and NSCLC cell lines to identify cancer cell characteristics correlating with sensitivity to MEK inhibition. RESULTS: Five NSCLC and six CRC cell lines were treated with selumetinib and classified according to the median inhibitory concentration (IC(50)) values as sensitive (≤1 µM) or resistant (>1 µM). In selumetinib-sensitive cancer cell lines, selumetinib treatment induced G1 cell-cycle arrest and apoptosis and suppression of tumour growth as xenografts in immunodeficient mice. Evaluation of intracellular effector proteins and analysis of gene mutations showed no correlation with selumetinib sensitivity. Microarray gene expression profiles revealed that the activation of cAMP-dependent protein kinase A (PKA) was associated with MEK inhibitor resistance. Combined targeting of both MEK and PKA resulted in cancer cell growth inhibition of MEK inhibitor-resistant cancer cell lines in vitro and in vivo. CONCLUSION: This study provides molecular insights to explain resistance to an MEK inhibitor in human cancer cell lines.

Antitumour efficacy of MEK inhibitors in human lung cancer cells and their derivatives with acquired resistance to different tyrosine kinase inhibitors.

BACKGROUND: To study the molecular mechanisms regulating cancer cell resistance to four different tyrosine kinase inhibitors (TKIs): erlotinib, gefitinib, vandetanib and sorafenib. METHODS: An in vitro model of acquired resistance to these TKIs was developed by continuously treating the human lung adenocarcinoma cell line CALU-3 with escalating doses of each drug. Transcriptional profiling was performed with Agilent whole genome microarrays. Western blot analysis, enzyme-linked immunosorbent (ELISA), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell proliferation, migration, invasion and anchorage-independent colony growth assays were conducted in vitro and experiments with established xenografts in athymic nude mice were performed in vivo in parental (P) and TKI-resistant (R) CALU-3 cell lines. RESULTS: As compared with P-CALU-3 cells, in TKI-R CALU-3 cell lines a significant increase in the expression of activated, phosphorylated MET, IGF-1R, AKT, MEK, MAPK and of survivin was observed. Downregulation of E-cadherin and amphiregulin mRNAs and upregulation of vimentin, VE-cadherin, HIF-1α and vascular endothelial growth factor receptor-1 mRNAs were observed in all four TKI-R CALU-3 cell lines. All four TKI-R CALU-3 cells showed increased invasion, migration and anchorage-independent growth. Together, these data suggest epithelial to mesenchymal transition (EMT) in TKI-R CALU-3 cells. Treatment with several agents that target AKT, MET or IGF-1R did not affect TKI-R CALU-3 cell proliferation. In contrast, treatment with MSC19363669B and selumetinib, two selective MEK inhibitors, caused inhibition of cell proliferation, invasion, migration, anchorage-independent growth in vitro and of tumour growth in vivo of all four TKI-R CALU-3 cell lines. CONCLUSION: These data suggest that resistance to four different TKIs is characterised by EMT, which is MEK-inhibitor sensitive in human CALU-3 lung adenocarcinoma.

Updating clinical recommendations for breast, colorectal and lung cancer treatments: an opportunity to improve methodology and clinical relevance.

BACKGROUND: clinical guidelines can improve quality of care summarising available knowledge and proposing recommendations for health care decisions. Being up to date is one of their quality requisites. Little experience is available on when and how guidelines should be updated. We report on the update process of evidence-based clinical recommendations on anticancer drugs. METHODS: three multidisciplinary panels, supported by methodology experts, updated the recommendations. The methodologists were in charge of the qualitative and quantitative synthesis of the evidence. The panels were responsible for the final decision about risk/benefit profile of the drugs and strength of the recommendations. The GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach was used. RESULTS: six recommendations out of 15 were completely updated in 8 months time. In four cases, the strength of the recommendation changed; in two of them, we moved from a weak to a strong positive one. Despite the increased certainty about the positive risk/benefit profile, this was translated in a change in the strength of the recommendation only in one case out of three. Three recommendations were refined making them more clinically specific. CONCLUSIONS: accumulation of evidence is an opportunity for guideline panels to refine methodological rigour, clinical relevance and to foster consensus on recommendations. This requires time and resource investments.

Major histocompatibility complex-independent recognition of a distinctive pollen antigen, most likely a carbohydrate, by human CD8+ alpha/beta T cells.

We have isolated CD8+ alpha/beta T cells from the blood of atopic and healthy individuals which recognize a nonpeptide antigen present in an allergenic extract from Parietaria judaica pollen. This antigen appears to be a carbohydrate because it is resistant to proteinase K and alkaline digestion, is hydrophilic, and is sensitive to trifluoromethane-sulphonic and periodic acids. In addition, on a reverse-phase high performance liquid chromatography column the antigen recognized by CD8(+) T cells separates in a fraction which contains >80% hexoses (glucose and galactose) and undetectable amounts of proteins. Presentation of this putative carbohydrate antigen (PjCHOAg) to CD8+ T cell clones is dependent on live antigen presenting cells (APCs) pulsed for >1 h at 37 degrees C, suggesting that the antigen has to be internalized and possibly processed. Indeed, fixed APCs or APCs pulsed at 15 degrees C were both unable to induce T cell response. Remarkably, PjCHOAg presentation is independent of the expression of classical major histocompatibility complex (MHC) molecules or CD1. CD8+ T cells stimulated by PjCHOAg-pulsed APCs undergo a sustained [Ca2+]i increase and downregulate their T cell antigen receptors (TCRs) in an antigen dose- and time-dependent fashion, similar to T cells stimulated by conventional ligands. Analysis of TCR Vbeta transcripts shows that six independent PjCHOAg-specific T cell clones carry the Vbeta8 segment with a conserved motif in the CDR3 region, indicating a structural requirement for recognition of this antigen. Finally, after activation, the CD8+ clones from the atopic patient express CD40L and produce high levels of interleukins 4 and 5, suggesting that the clones may have undergone a Th2-like polarization in vivo. These results reveal a new class of antigens which triggers T cells in an MHC-independent way, and these antigens appear to be carbohydrates. We suggest that this type of antigen may play a role in the immune response in vivo.

Thymoma-associated immunodeficiency: a syndrome characterized by severe alterations in NK, T and B-cells and progressive increase in naïve CD8+ T Cells.

Thymomas are rare tumours that sustain T-lymphopoiesis and trigger a variety of autoimmune diseases and immunodeficiencies, including a fatal hypogammaglobulinemia, namely Goods Syndrome (GS). Due to its rarity, GS has been poorly investigated and immunological features, as well as pathogenetic mechanisms underlying this syndrome, are unclear. We studied 30 thymoma patients by performing an immunological assessment, including immunophenotype and analysis of T cell repertoire (TCR). Development of GS was characterized by a progressive decrease in B, CD4 T and NK lymphocytes. These alterations paired with accumulation of CD8+CD45RA+ T cells that showed a polyclonal repertoire without expansions of specific clonotypes. GS is defined as hypogammaglobulinemia with thymoma. Here, we show for the first time that this syndrome is characterized by a severe loss of CD4+, NK and B cells. Furthermore, the accumulation of CD8+CD45RA+ T lymphocytes parallels these changes; this accumulation may have a role in determining the disease and can be used to monitor clinical stages of immunodeficiency in thymoma.

Anti-epidermal growth factor receptor monoclonal antibodies in cancer therapy.

The epidermal growth factor receptor (EGFR) is a transmembrane tyrosine kinase receptor involved in the proliferation and survival of cancer cells. EGFR is the first molecular target against which monoclonal antibodies (mAb) have been developed for cancer therapy. Here we review the mechanisms underlying the effects of EGFR-specific mAb in cancer therapy. The efficacy of EGFR-specific mAb in cancer occurs thanks to inhibition of EGFR-generated signalling; furthermore, the effects of antibodies on the immune system seem to play an important role in determining the overall anti-tumour response. In this review, attention is focused on cetuximab and panitumumab, two mAb introduced recently into clinical practice for treatment of metastatic colorectal and head and neck cancer which target the external part of EGFR.

Neopterin induces pro-atherothrombotic phenotype in human coronary endothelial cells.

BACKGROUND: Inflammation plays a pivotal role in atherothrombosis. Recent data indicate that serum levels of neopterin, a marker of inflammation and immune modulator secreted by monocytes/macrophages, are elevated in patients with acute coronary syndromes and seem to be a prognostic marker for major cardiovascular events. The aim of the present study was to determine whether neopterin might affect the thrombotic and atherosclerotic characteristics of human coronary artery endothelial cells (HCAECs). METHODS AND RESULTS: In HCAECs, neopterin induced TF-mRNA transcription as demonstrated by real time polymerase chain reaction and expression of functionally active tissue factor (TF) as demonstrated by procoagulant activity assay, and of cellular adhesion molecules (CAMs) as demonstrated by FACS analysis, in a dose-dependent fashion. These neopterin effects were prevented by lovastatin, a HMG-CoA reductase inhibitor. Neopterin-induced TF and CAMs expression was mediated by oxygen free radicals through the activation of the transcription factor, nuclear factor-kappa B (NF-kappaB), as demonstrated by electrophoretic mobility shift assay and by suppression of CAMs and TF expression by superoxide dismutase and by NF-kappaB inhibitor, pyrrolidine-dithio-carbamate ammonium. CONCLUSIONS: These data indicate that neopterin exerts direct effects on HCAECs by promoting CAMs and TF expression and support the hypothesis that neopterin, besides representing a marker of inflammation, might be an effector molecule able to induce a pro-atherothrombotic phenotype in cells of the coronary circulation.

Cytotoxic molecule mRNA expression in chronically rejected human kidney allografts.

The pathogenesis of immunological and nonimmunological components that cause chronic kidney allograft nephropathy (CAN), is not yet completely understood. To explore the possible contribution of alloreactive cytotoxic T cells, we analyzed the transcription of cytotoxic molecules such as granzyme B and perforin using semiquantitative RT-PCR on surgically removed grafts obtained from two groups: group 1 (n = 10) were cases of CAN; group 2 (n = 3) had no CAN. Among group 1 kidneys, granzyme-B was expressed in 7 of 10, whereas perforin was detectable in 9 of 10 cases; their detection was not related to the presence of superimposed signs of acute graft lesions. Cytotoxic molecules were never found in group 2 kidneys. These results show that explanted chronically rejected grafts display cytotoxic molecule transcripts in addition to Th2 type cytokines, such as IL-10, IL-3, and IL-6, suggesting that both cellular and humoral alloreactive mechanisms may play important roles in CAN pathogenesis.

Analysis of the antigen specific T cell repertoires in HIV infection.

In addition to HIV infection, several acquired immunodeficiencies lead to depletion of CD4 lymphocytes. These include immunosuppression resulting from high dose cancer chemotherapy or induced to control graft rejection, as well as in autoimmune diseases. The consequence of this depletion is an increased susceptibility to opportunistic infections or the inability to control primary infection in the case of HIV infection. In all instances a full or partial immunoreconstitution is desirable. In order to monitor the cellular immune state of a patient, rational information cannot be simply derived from phenotypic quantification of T lymphocytes. Instead loss or recovery of CD4 cells should be monitored by defining the specificity, the function and the clonality of the relevant cell population. Several methods are now available for this type of investigation. Here we describe an approach for the definition of clonal heterogeneity of antigen specific CD4 lymphocytes, a parameter that may help monitor loss or reconstitution in acquired immunodeficiencies. As examples of antigen specific CD4 T cell responses we focused on Pneumocystis carinii and on cytomegalovirus, as prototypic opportunistic pathogens which are responsible for severe infections in AIDS and in other immunosuppressive conditions which arise for instance following transplantation. Specific CD4 T cell lines were generated from normal controls and from seropositives in order to select antigen specific lymphocytes. The cells were subsequently analyzed for clonal diversity according to TCR BV gene family usage and according to TCR CDR3 size heterogeneity (spectratyping).

Analysis of transcripts of genes located within the HLA-D region in B cells from an HLA-severe combined immunodeficiency individual.

The mRNA levels of LMP7, HLA-DMA, and HLA-DMB genes, all located within the HLA-D region, were analyzed in the "bare lymphocyte" line SJO, which had been shown to be characterized by a transcription defect of class II genes (DP, DQ, and DR). This was done using semiquantitative PCR amplification of cDNA generated from total RNA. The results show that the transcription of the LMP7 gene in SJO cells is equivalent to that in the control B-cell line Raji. In contrast, the HLA-DM gene transcripts were not present in the SJO cell line. This observation indicates that the promoter similarity between the classic class II genes and HLA-DM is sufficient for the SJO defect to extend to the DM loci.

Identification of T cells responding to a self-protein modified by an external agent.

An interesting class of immune responses is that in which an environmental agent modifies a self-protein. Heparin induced thrombocytopenia (HIT) is associated with an antibody response in which the immunogen is a self-protein, platelet factor 4 (PF4), modified by an external agent, heparin. We tested the hypothesis that a T cell component exists in HIT, which like the humoral response, also requires the combination of heparin and PF4 to be activated. We identify here, a subset of T cells derived from a subject with severe HIT, which were expanded preferentially in 14-day in vitro cultures specifically in the presence of PF4:heparin complexes. A combination of T cell receptor spectratyping, CDR3 sequencing, and clonotype-specific probe hybridization were used to identify the responding T cells. The three BV17 T cell "clonotypes" thus identified had a CDR3 length of 10 amino acids, used BJ1.2, and displayed a conserved CDR3 sequence motif. These T cells are an example of a cellular response to environmentally altered self and are likely to be directly involved in HIT by functioning as T helper cells. The results are discussed in terms of the possible role of modification of antigen presentation by the external agent in this response.

Effects of somatostatin on plasma ammonia and amino acid profile during fasting and after protein feeding in cirrhotic patients.

The effects of somatostatin on fasting and absorptive plasma ammonia and amino acids were studied in 12 cirrhotic patients. They received a 6 h intravenous infusion of somatostatin (500 micrograms/h) or saline, starting 90 min before protein feeding. During the fasting period somatostatin significantly reduced plasma ammonia (-18%) and total tryptophan (-39%), increased plasma leucine (+19%), isoleucine (+17%), glutamine (+22%), glycine (+13%), arginine (+14%) and lysine (+12%), and prevented the significant fall of phenylalanine (-8%), tyrosine (-6%), alanine (-8%) and threonine (-9%) seen with saline. The percent changes in ammonia and glutamine concentrations were inversely correlated (r = -80; p less than 0.001) After protein ingestion, somatostatin slowed the maximal plasma increase in ammonia and alpha-nitrogens by at least two hours, but their total 5 h plasma response was not reduced, and even, in some instances, significantly increased (valine, leucine, glutamine, alanine and serine) with respect to saline. The results suggest that in fasting cirrhotics somatostatin reduces plasma ammonia, probably through an impaired intestinal ammoniogenesis from circulating precursors, and inhibits the disposal of branched chain, aromatic (except tryptophan) and gluconeogenic amino acids. Furthermore, it delays, but does not reduce, the plasma increase in nitrogen after protein ingestion.

New approaches to an old and vexing problem: improving the results of SEPS: an overview.

Lipodermatosclerosis and chronic ulceration have been longstanding and vexing problems caused by chronic venous insufficiency (CVI). While traditional approaches have been mainly medical with the use of compression, bedrest, and elevation; operative therapy for CVI has now been shown to cause earlier healing with fewer ulcer recurrences. The development of subfascial endoscopic surgery (SEPS) promises a more elegant approach applicable to outpatient or day surgery. However, in a recent trial, early results showed a 22% ulcer recurrence at 30 months, which did not compare favorably with traditional approaches. We have used extrafascial perforator interruption for SEPS recurrence and have now modified our SEPS approach particularly for low-lying ulcers. This overview suggests use of a combination of SEPS with an extrafascial perforator division when skin change relates to retro or submalleolar perforating veins. Several procedures, rather than one intervention may be required in CVI to prevent or divert transmission of venous hypertension to areas of affected skin, including saphenous stripping, staged valveplasty and treatment of iliac occlusions.

Venous ulceration: active approaches to treatment.

Traditional treatment of venous ulceration has been conservative: elevation, wound care, compression, and patient education based on prevention. Conservative treatment will heal most ulcers over time: however, the data reflect a 29% to 59% recurrence rate with optimal care and follow-up. Recurrent ulceration results in significant cost and disability. It is none accepted that limbs with all the signs of severe chronic venous insufficiency (CVI) may have a normal deep venous system. Patients in whom this is the case can be treated surgically with good long-term results. In this article, the specific underlying causes of CVI are noted and diagnostic tests are reviewed. The CEAP (clinical signs, etiology, anatomy, and physiology) classification system is discussed in terms of systematically assessing CVI. Common surgical techniques are related to the underlying pathophysiology, and the nursing care of the patient undergoing surgical intervention is also discussed. The cause of the condition should be investigated, and surgical treatment, when appropriate, should be offered as an alternative to the active symptomatic patient with CVI.

[Microparticulate aerosols and respiratory allergy]. / Microparticolato aerosolico e allergopatie respiratorie.

The assessment of allergenic activity in submicronic particles could explain some unknown aspects of pollinosis pathogenesis. Twenty-five 0.5 discs have been obtained using a high volume sampler (Hi Vol Andersen) equipped with 0.3 micron Whatman paper filters. These discs have been challenged with a concentrated pool of sera of Parietaria allergic patients by RIA in order to evaluate the presence of allergenic activity on filters. Discs of non sampled filters and discs of sampled filters challenged with serum pool of patients sensitized to house dust mites were used as controls. The percentage of bound radioactivity was detected by gamma-counter. The radioactivity bound to sampled discs with Parietaria sera was 2.3 +/- 0.55 (Standard Deviation); radioactivity detected on control discs was comparable to background values detected by counter. These preliminary date might suggest that submicronic particles of Parietaria can retain some allergenic activity.

Cross-talk between toll-like receptor 4 (TLR4) and proteinase-activated receptor 2 (PAR(2) ) is involved in vascular function.

BACKGROUND AND PURPOSE: Proteinase-activated receptors (PARs) and toll-like receptors (TLRs) are involved in innate immune responses. The aim of this study was to evaluate the possible cross-talk between PAR(2) and TLR4 in vessels in physiological condition and how it varies following stimulation of TLR4 by using in vivo and ex vivo models. EXPERIMENTAL APPROACH: Thoracic aortas were harvested from both naïve and endotoxaemic rats for in vitro studies. Arterial blood pressure was monitored in anaesthetized rats in vivo. LPS was used as a TLR4 agonist while PAR(2) activating peptide (AP) was used as a PAR(2) agonist. Aortas harvested from TLR4(-/-) mice were also used to characterize the PAR(2) response. KEY RESULTS: PAR(2) , but not TLR4, expression was enhanced in aortas of endotoxaemic rats. PAR(2) AP-induced vasorelaxation was increased in aortic rings of LPS-treated rats. TLR4 inhibitors, curcumine and resveratrol, reduced PAR(2) AP-induced vasorelaxation and PAR(2) AP-induced hypotension in both naïve and endotoxaemic rats. Finally, in aortic rings from TLR4(-/-) mice, the expression of PAR(2) was reduced and the PAR(2) AP-induced vasodilatation impaired compared with those from wild-type mice and both resveratrol and curcumine were ineffective. CONCLUSIONS AND IMPLICATIONS: Cross-talk between PAR(2) and TLR4 contributes to vascular homeostasis.