The MYCN inhibitor BGA002 restores the retinoic acid response leading to differentiation or apoptosis by the mTOR block in MYCN-amplified neuroblastoma

BACKGROUND

Neuroblastoma is a deadly childhood cancer, and MYCN-amplified neuroblastoma (MNA-NB) patients have the worst prognoses and are therapy-resistant. While retinoic acid (RA) is beneficial for some neuroblastoma patients, the cause of RA resistance is unknown. Thus, there remains a need for new therapies to treat neuroblastoma. Here we explored the possibility of combining a MYCN-specific antigene oligonucleotide BGA002 and RA as therapeutic approach to restore sensitivity to RA in NB.

METHODS

By molecular and cellular biology techniques, we assessed the combined effect of the two compounds in NB cell lines and in a xenograft mouse model MNA-NB.

RESULTS

We found that MYCN-specific inhibition by BGA002 in combination with RA (BGA002-RA) act synergistically and overcame resistance in NB cell lines. BGA002-RA also reactivated neuron differentiation (or led to apoptosis) and inhibited invasiveness capacity in MNA-NB. Moreover, we found that neuroblastoma had the highest level of mRNA expression of mTOR pathway genes, and that BGA002 led to mTOR pathway inhibition followed by autophagy reactivation in MNA-NB cells, which was strengthened by BGA002-RA. BGA002-RA in vivo treatment also eliminated tumor vascularization in a MNA-NB mouse model and significantly increased survival.

CONCLUSION

Taken together, MYCN modulation mediates the therapeutic efficacy of RA and the development of RA resistance in MNA-NB. Furthermore, by targeting MYCN, a cancer-specific mTOR pathway inhibition occurs only in MNA-NB, thus avoiding the side effects of targeting mTOR in normal cells. These findings warrant clinical testing of BGA002-RA as a strategy for overcoming RA resistance in MNA-NB.

Lamin A and the LINC complex act as potential tumor suppressors in Ewing Sarcoma

Lamin A, a main constituent of the nuclear lamina, is involved in mechanosignaling and cell migration through dynamic interactions with the LINC complex, formed by the nuclear envelope proteins SUN1, SUN2 and the nesprins. Here, we investigated lamin A role in Ewing Sarcoma (EWS), an aggressive bone tumor affecting children and young adults. In patients affected by EWS, we found a significant inverse correlation between LMNA gene expression and tumor aggressiveness. Accordingly, in experimental in vitro models, low lamin A expression correlated with enhanced cell migration and invasiveness and, in vivo, with an increased metastatic load. At the molecular level, this condition was linked to altered expression and anchorage of nuclear envelope proteins and increased nuclear retention of YAP/TAZ, a mechanosignaling effector. Conversely, overexpression of lamin A rescued LINC complex organization, thus reducing YAP/TAZ nuclear recruitment and preventing cell invasiveness. These effects were also obtained through modulation of lamin A maturation by a statin-based pharmacological treatment that further elicited a more differentiated phenotype in EWS cells. These results demonstrate that drugs inducing nuclear envelope remodeling could be exploited to improve therapeutic strategies for EWS.

O-127 The endometrial tissue microbiota of women who did or did not achieve a live birth within 12 months after a first failed IVF/ICSI cycle

Study question

After one failed IVF/ICSI cycle, does the endometrial microbiota composition differ between women who will or will not reach a live birth within 12 months?

Summary answer

The endometrial microbiota composition did not significantly differ in women with one failed IVF/ICSI cycle with or without live birth, but statistical power was low.

What is known already

Evidence for the presence of an indigenous endometrial microbiome is mounting, and its composition may be associated with implantation success. However, a ‘core’ endometrial microbiome has not yet been defined, and its role in embryo implantation is still poorly understood. Further investigation of this topic may allow improvement and personalisation of clinical care for infertile couples. Endometrial microbiome analysis in infertile women has not yet been performed using transcervically obtained endometrial tissue. Using endometrial tissue instead of swabs or fluid may increase the bacterial DNA yield and therefore the precision of microbiome analyses.

Study design, size, duration

Endometrial tissue was obtained from a cohort of 141 infertile women undergoing endometrial scratching within a randomised controlled trial (RCT) (SCRaTCH trial, NL5193/NTR5342). Briefly, women aged 18-44 years with failed implantation after one full IVF/ICSI cycle and planning a subsequent IVF/ICSI cycle, were eligible. Participants were followed-up until 12 months after randomisation, with the primary outcome being live birth, defined as the delivery of at least one live foetus after 24 weeks of gestation.

Participants/materials, setting, methods

Endometrial tissue was obtained with an endometrial biopsy catheter in the midluteal phase of a natural cycle preceding subsequent IVF/ICSI, snap-frozen and stored at -80 °C until use. Total DNA was isolated from these biopsies, followed by 16S rRNA sequencing (V3-V4 region) to determine the endometrial microbiota composition. Positive (mock communities) and negative controls (DNA extraction and PCRs) were included. QIIME2 and DADA2 were used for the data analysis, followed by statistical analysis in R studio.

Main results and the role of chance

During the 12-month follow-up, 61/141 women (43.3%) reached a live birth. While endometrial microbiota profiles of all 141 women were analysed, only samples with ≥100 reads were included in the analysis, resulting in a total of 46 samples (32.6%) that were included in the analysis, which consisted of samples from 25 women who did not have and 21 women who did have a live birth within 12 months. The median number of reads per sample was not significantly different between the two groups (respectively 2,317 (IQR 651-19,031) and 1,335 (IQR 296-3,180), p = 0.29 by Mann-Whitney test). The endometrial microbiota detected, were bacterial genera frequently reported within the vaginal microbiota (e.g. Lactobacillus, Atopobium and Gardnerella). A clear dominance of Lactobacillus (relative abundance 55-100%, n = 22) or an unclassified bacterium genus (relative abundance 52-76%, n = 18) was observed in the majority of the samples; however, this dominance was not associated with the outcome of live birth. In addition, the samples dominated by Lactobacillus genera were mostly dominated by one species of Lactobacillus each (L. crispatus, L. iners, L. gasseri or L. jensenii).

Limitations, reasons for caution

The low biomass and the low ratio of bacterial versus human DNA in endometrial tissue were limiting factors in endometrial microbiota analysis. Furthermore, tissue was obtained transcervically, and contamination with vaginal/cervical microbiota could therefore have occurred. In the SCRaTCH trial no vaginal swabs were taken to serve as internal controls.

Wider implications of the findings

Future endometrial microbiota studies should consider the use of samples with a lower proportion of human DNA to maximize bacterial DNA yield. Furthermore, for endometrial microbiota research, sampling devices avoiding cervicovaginal contamination are desirable and may be developed in the future.

Trial registration number

SCRaTCH trial, NL5193/NTR5342

GSK-3: a multifaceted player in acute leukemias

Glycogen synthase kinase 3 (GSK-3) consists of two isoforms (α and β) that were originally linked to glucose metabolism regulation. However, GSK-3 is also involved in several signaling pathways controlling many different key functions in healthy cells. GSK-3 is a unique kinase in that its isoforms are constitutively active, while they are inactivated mainly through phosphorylation at Ser residues by a variety of upstream kinases. In the early 1990s, GSK-3 emerged as a key player in cancer cell pathophysiology. Since active GSK-3 promotes destruction of multiple oncogenic proteins (e.g., β-catenin, c-Myc, Mcl-1) it was considered to be a tumor suppressor. Accordingly, GSK-3 is frequently inactivated in human cancer via aberrant regulation of upstream signaling pathways. More recently, however, it has emerged that GSK-3 isoforms display also oncogenic properties, as they up-regulate pathways critical for neoplastic cell proliferation, survival, and drug-resistance. The regulatory roles of GSK-3 isoforms in cell cycle, apoptosis, DNA repair, tumor metabolism, invasion, and metastasis reflect the therapeutic relevance of these kinases and provide the rationale for combining GSK-3 inhibitors with other targeted drugs. Here, we discuss the multiple and often conflicting roles of GSK-3 isoforms in acute leukemias. We also review the current status of GSK-3 inhibitor development for innovative leukemia therapy.

B-ALL Complexity: Is Targeted Therapy Still A Valuable Approach for Pediatric Patients?

Simple Summary

B-ALL is the more frequent childhood malignancy. Even though significant improvements in patients’ survival, some pediatric B-ALL have still poor prognosis and novel strategies are needed. Recently, new genetic abnormalities and altered signaling pathways have been described, defining novel B-ALL subtypes.Innovative targeted therapeutic drugs may potentially show a great impact on the treatment of B-ALL subtypes, offering an important chance to block multiple signaling pathways and potentially improving the clinical management of B-ALL younger patients, especially for the new identified subtypes that lack efficient chemotherapeutic protocols. In this review, we shed light on the up-to-date knowledge of the novel childhood B-ALL subtypes and the altered signaling pathways that could become new druggable targets.

Abstract

B-cell acute lymphoblastic leukemia (B-ALL) is a hematologic malignancy that arises from the clonal expansion of transformed B-cell precursors and predominately affects childhood. Even though significant progresses have been made in the treatment of B-ALL, pediatric patients’ outcome has to be furtherly increased and alternative targeted treatment strategies are required for younger patients. Over the last decade, novel approaches have been used to understand the genomic landscape and the complexity of the molecular biology of pediatric B-ALL, mainly next generation sequencing, offering important insights into new B-ALL subtypes, altered pathways, and therapeutic targets that may lead to improved risk stratification and treatments. Here, we will highlight the up-to-date knowledge of the novel B-ALL subtypes in childhood, with particular emphasis on altered signaling pathways. In addition, we will discuss the targeted therapies that showed promising results for the treatment of the different B-ALL subtypes.

Pentraxin 3 in primary percutaneous coronary intervention for ST elevation myocardial infarction is associated with early irreversible myocardial damage : Kinetic profile, relationship to interleukin 6 and infarct size

Background

The inflammatory marker long pentraxin 3 (PTX3) has been shown to be a strong predictor of 30-day and one-year mortality after acute myocardial infarction. The aim of this study was to evaluate the kinetic profile of PTX3 and its relationship with interleukin 6 (IL-6), high-sensitive C-reactive protein (hs-CRP) and infarct size.

Methods

PTX3, IL-6 and hs-CRP were measured at predefined time points, at baseline (before percutaneous coronary intervention (PCI)), at 12 and 72 hours after PCI in 161 patients with first-time ST elevation myocardial infarction (STEMI).

Results

PTX3 and IL-6 levels increased in the early phase, followed by a gradual decrease between 12 and 72 hours. There were statistically significant correlations between PTX3 and IL-6 in general, for all time points and for changes over time (0–72 hours). In a linear mixed model, PTX3 predicted IL-6 (p < 0.001). PTX3 is also correlated with hs-CRP in general, and at each time point post PCI, except at baseline. PTX3, IL-6 and hs-CRP were all significantly correlated with infarct size in general, and at the peak time point for maximum troponin I. In addition, there was a modest correlation between IL-6 levels at baseline and infarct size at 72 hours after PCI (ρ = 0.23, p = 0.006).

Conclusions

PTX3 had a similar kinetic profile to IL-6, with an early increase and decline, and was statistically significantly correlated with markers of infarct size in STEMI patients post primary PCI. Baseline levels of IL-6 only predicted infarct size at 72 hours post PCI.

The Unfolded Protein Response: A Novel Therapeutic Target in Acute Leukemias

The unfolded protein response (UPR) is an evolutionarily conserved adaptive response triggered by the stress of the endoplasmic reticulum (ER) due, among other causes, to altered cell protein homeostasis (proteostasis). UPR is mediated by three main sensors, protein kinase RNA-like endoplasmic reticulum kinase (PERK), activating transcription factor 6α (ATF6α), and inositol-requiring enzyme-1α (IRE1α). Given that proteostasis is frequently disregulated in cancer, UPR is emerging as a critical signaling network in controlling the survival, selection, and adaptation of a variety of neoplasias, including breast cancer, prostate cancer, colorectal cancer, and glioblastoma. Indeed, cancer cells can escape from the apoptotic pathways elicited by ER stress by switching UPR into a prosurvival mechanism instead of cell death. Although most of the studies on UPR focused on solid tumors, this intricate network plays a critical role in hematological malignancies, and especially in multiple myeloma (MM), where treatment with proteasome inhibitors induce the accumulation of unfolded proteins that severely perturb proteostasis, thereby leading to ER stress, and, eventually, to apoptosis. However, UPR is emerging as a key player also in acute leukemias, where recent evidence points to the likelihood that targeting UPR-driven prosurvival pathways could represent a novel therapeutic strategy. In this review, we focus on the oncogene-specific regulation of individual UPR signaling arms, and we provide an updated outline of the genetic, biochemical, and preclinical therapeutic findings that support UPR as a relevant, novel target in acute leukemias.

Targeting Wnt/β-catenin and PI3K/Akt/mTOR pathways in T-cell acute lymphoblastic leukemia

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological disorder that results from the clonal transformation of T-cell precursors. Phosphatidylinositol 3-kinase (PI3K)/Akt/mechanistic target of rapamycin (mTOR) and canonical Wnt/β-catenin signaling pathways play a crucial role in T-cell development and in self-renewal of healthy and leukemic stem cells. Notably, β-catenin is a transcriptional regulator of several genes involved in cancer cell proliferation and survival. In this way, aberrations of components belonging to the aforementioned networks contribute to T-ALL pathogenesis. For this reason, inhibition of both pathways could represent an innovative strategy in this hematological malignancy. Here, we show that combined targeting of Wnt/β-catenin pathway through ICG-001, a CBP/β-catenin transcription inhibitor, and of the PI3K/Akt/mTOR axis through ZSTK-474, a PI3K inhibitor, downregulated proliferation, survival, and clonogenic activity of T-ALL cells. ICG-001 and ZSTK-474 displayed cytotoxic effects, and, when combined together, induced a significant increase in apoptotic cells. This induction of apoptosis was associated with the downregulation of Wnt/β-catenin and PI3K/Akt/mTOR pathways. All these findings were confirmed under hypoxic conditions that mimic the bone marrow niche where leukemic stem cells are believed to reside. Taken together, our findings highlight potentially promising treatment consisting of cotargeting Wnt/β-catenin and PI3K/Akt/mTOR pathways in T-ALL settings.

Crosstalks of GSK3 signaling with the mTOR network and effects on targeted therapy of cancer

The introduction of therapeutics targeting specific tumor-promoting oncogenic or non-oncogenic signaling pathways has revolutionized cancer treatment. Mechanistic (previously mammalian) target of rapamycin (mTOR), a highly conserved Ser/Thr kinase, is a central hub of the phosphatidylinositol 3-kinase (PI3K)/Akt/mTOR network, one of the most frequently deregulated signaling pathways in cancer, that makes it an attractive target for therapy. Numerous mTOR inhibitors have progressed to clinical trials and two of them have been officially approved as anticancer therapeutics. However, mTOR-targeting drugs have met with a very limited success in cancer patients. Frequently, the primary impediment to a successful targeted therapy in cancer is drug-resistance, either from the very beginning of the therapy (innate resistance) or after an initial response and upon repeated drug treatment (evasive or acquired resistance). Drug-resistance leads to treatment failure and relapse/progression of the disease. Resistance to mTOR inhibitors depends, among other reasons, on activation/deactivation of several signaling pathways, included those regulated by glycogen synthase kinase-3 (GSK3), a protein that targets a vast number of substrates in its repertoire, thereby orchestrating many processes that include cell proliferation and survival, metabolism, differentiation, and stemness. A detailed knowledge of the rewiring of signaling pathways triggered by exposure to mTOR inhibitors is critical to our understanding of the consequences such perturbations cause in tumors, including the emergence of drug-resistant cells. Here, we provide the reader with an updated overview of intricate circuitries that connect mTOR and GSK3 and we relate them to the efficacy (or lack of efficacy) of mTOR inhibitors in cancer cells.

New advances in targeting aberrant signaling pathways in T-cell acute lymphoblastic leukemia

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive disorder characterized by malignant transformation of immature progenitors primed towards T-cell development. Over the past 15 years, advances in the molecular characterization of T-ALL have uncovered oncogenic key drivers and crucial signaling pathways of this disease, opening new chances for the development of novel therapeutic strategies. Currently, T-ALL patients are still treated with aggressive therapies, consisting of high dose multiagent chemotherapy. To minimize and overcome the unfavorable effects of these regimens, it is critical to identify innovative targets and test selective inhibitors of such targets. Major efforts are being made to develop small molecules against deregulated signaling pathways, which sustain T-ALL cell growth, survival, metabolism, and drug-resistance. This review will focus on recent improvements in the understanding of the signaling pathways involved in the pathogenesis of T-ALL and on the challenging opportunities for T-ALL targeted therapies.

The Key Roles of PTEN in T-Cell Acute Lymphoblastic Leukemia Development, Progression, and Therapeutic Response

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive blood cancer that comprises 10–15% of pediatric and ~25% of adult ALL cases. Although the curative rates have significantly improved over the past 10 years, especially in pediatric patients, T-ALL remains a challenge from a therapeutic point of view, due to the high number of early relapses that are for the most part resistant to further treatment. Considerable advances in the understanding of the genes, signaling networks, and mechanisms that play crucial roles in the pathobiology of T-ALL have led to the identification of the key drivers of the disease, thereby paving the way for new therapeutic approaches. PTEN is critical to prevent the malignant transformation of T-cells. However, its expression and functions are altered in human T-ALL. PTEN is frequently deleted or mutated, while PTEN protein is often phosphorylated and functionally inactivated by casein kinase 2. Different murine knockout models recapitulating the development of T-ALL have demonstrated that PTEN abnormalities are at the hub of an intricate oncogenic network sustaining and driving leukemia development by activating several signaling cascades associated with drug-resistance and poor outcome. These aspects and their possible therapeutic implications are highlighted in this review.

Network Model for Optimal Aircraft Location for Human Organ Transportation Activities

BACKGROUND

The efficiency of transport phases is a key factor in successful organ transplant operations. Reliability, safety, and punctuality must be in compliance with the European Union and national frameworks and be consistent with economic, quantitative, and level-of-service parameters. In this study we investigated the optimal numbers and locations of aircraft in the Italian territory by comparing performance indexes related to different time intervals and service design scenarios.

METHODS

An integer linear programming model is described as an optimal service solution for covering the demand for extraregional organ transport by air between June 2015 and May 2016. Restrictions on aircraft utilization and actual length of the missions in cases of incompatible activities are the relevant input data of the model.

RESULTS

Based on mission durations and their origin and destination, the model returns the optimal number and location of aircraft in various scenarios. The performance parameters required by law and the need to guarantee the service from/to the whole territory, together with the transplant figures performed and transplant center locations, have been taken into account to determine the most efficient spatial and numerical allocation.

CONCLUSION

The efficient design of an urgency-based service such as the transportation of organs for transplant purposes is not an easy task. Nevertheless, knowledge of the logistic chain and continuous monitoring and update of data and performance parameters can allow for collection of useful information to guarantee a high-performing service.

Dabigatran versus vitamin k antagonist: an observational across-cohort comparison in acute coronary syndrome patients with atrial fibrillation

Essentials Acute coronary syndrome (ACS) with atrial fibrillation (AF) is a therapeutic challenge. Dual and triple antithrombotic therapy showed a similar thrombotic risk in ACS patients with AF. The omission of aspirin during the first month did not increase the rate of ischemic events. Replacement of vitamin K antagonist by dabigatran leads to an increased thrombotic risk.

SUMMARY

Background Dual antithrombotic therapy comprising a vitamin K antagonist (VKA) plus clopidogrel reduces the incidence of major bleeding compared with triple therapy (VKA + clopidogrel + aspirin) in acute coronary syndrome (ACS) patients with atrial fibrillation (AF), with a similar thrombotic risk. The oral thrombin inhibitor dabigatran (150 mg twice a day) showed superiority over VKA in non-valvular AF, but data supporting its use in AF patients presenting with ACS are limited. Objective We sought to evaluate the efficacy of dabigatran vs. VKA in the management of AF patients undergoing percutaneous coronary intervention for an ACS. Methods In this open-label study, 133 consecutive patients received dabigatran plus clopidogrel. Another cohort of 133 patients treated with VKA plus clopidogrel was used as the control group. Results After propensity score adjustment, the cumulative incidence of major adverse cardiovascular events over 24 months was higher with dabigatran vs. VKA (adjusted hazard ratio, 2.28; 95% confidence interval, 1.46-3.56). Similar rates of major bleeding were found (adjusted hazard ratio, 1.17; 95% confidence interval, 0.46-2.96). Conclusions In AF patients presenting with ACS, replacement of VKA by dabigatran concurrently with clopidogrel is associated with an increased thrombotic risk, without a reduction in major bleeding.

[Management of NSTEMI in a hospital without interventional cardiology and without use of GRACE score: Does the clinician appreciation match the GRACE score calculated retrospectively for the coronarography delay?]

PURPOSE

The management of non-ST segment elevation acute coronary syndromes (NSTEACS) remains an issue for mobidity, mortality, and an economic stake. The first aim of the study was to evaluate the additional value of the GRACE score for the compliance with the recommended times to coronary angiography in an hospital without interventional cardiology. We also analysed the in-hospital and 6-month mortality and the predictive factors of compliance for the coronarography delays.

METHODS

Retrospective monocenter cross-sectional study including consecutive patients with chest pain suggestive of a NSTEACS during 1 year. Data of the delay to coronarography were collected and GRACE score was calculated a posteriori.

RESULTS

The time to perform coronary angiography was non-compliant in 49% of cases (27 patients out of 55). The calculation of the GRACE score would have allowed correcting the delay for two patients of our cohort. Clinical appreciation, troponin elevation, ECG modifications were associated with the delay compliance. Age <75 years predisposed to recommended delays. Renal failure and history of coronaropathy were significantly associated with non compliant delays. A non-compliant delay was significantly associated with higher mortality.

CONCLUSION

In our experience, the knowledge of the GRACE score had little impact on the timing of coronary angiography. However, as a predictor of mid and long term mortality, GRACE score remains SCA ST+ useful to intensify surveillance of high-risk patients.

Transport of Human Organs in Italy: Location, Time, and Performances

INTRODUCTION

The outcome of transplantation activities depends on a variety of unpredictable factors. Up-to-date criteria on organ allocation foresee an efficient transport chain along with compliant performance parameters.

METHODS AND OBJECTIVES

The Centro Nazionale Trapianti and the Department of Civil, Chemical, Environmental, and Materials Engineering of the University of Bologna (respectively, CNT and DICAM) have been updating a national database of organ transplantation activities to investigate performance parameters and the main causes of disruption.

RESULTS

Between June 2015 and July 2016, 617 of 1061 organs have been shipped by air (making for 486 flight events), of which 407 were accompanied by medical equipment. Origin/destination and distance matrixes have been drawn for both road and air transport. Each airport node is ranked based on the n° of organs ingoing/outgoing and each route link on its frequency. Performance parameters such as average speed, distance covered, and time have been computed and compared with each organ's cold ischemia time (CIT). Average distance frontiers are rather homogeneous, but much effort is necessary to reduce the number of events performed with approximately 90% or more of CIT spent.

CONCLUSIONS

The monitoring of organ transplantation activities' performance is a standalone action within Europe to support strategic policies to optimize the system. Thus, a clearer awareness on performances and issues related to organ transport has been made possible: analyses show that the higher uncertainty associated with total time of displacement by air is due to the steps which take place by road (length and paths must be optimized) and lung transports generally perform weaker than heart transports due to longer average distances travelled and smaller average speeds, often resulting in a total displacement time greater than 90% of CIT.

Relationship between post-treatment platelet reactivity and ischemic and bleeding events at 1-year follow-up in patients receiving prasugrel

BACKGROUND

Post-treatment platelet reactivity (PR) is associated with ischemic and bleeding events in patients receiving P2Y12 receptor antagonists.

OBJECTIVES

We aimed to study the relationship between post-treatment PR after a 60-mg loading dose (LD) of prasugrel and 1-year thrombotic and bleeding events.

METHOD

Patients were prospectively included in this multicenter study if they had a successful percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) and received prasugrel. The platelet reactivity index (PRI) was measured using the Vasodilator-Stimulated Phosphoprotein index (VASP) after a prasugrel LD. Endpoints included the rate of thrombotic events and bleeding events at 1 year.

RESULTS

Among the 301 patients enrolled, 9 (3%) were lost to follow-up at 1 year. The rates of thrombotic and bleeding events at 1 year were of 7.5% and 6.8%, respectively. Receiver-operating curve (ROC) analysis demonstrated an optimal cut-off value of 53.5% of PRI to predict thrombotic events at 1 year. Using this cut-off value we observed that patients exhibiting high on-treatment platelet reactivity (HTPR) had a higher rate of thrombotic events (22.4% vs. 2.9%; P < 0.001). In parallel the optimal cut-off value of PRI to predict bleeding was 16%. Patients with a PRI ≤ 16% had a higher rate of bleeding events compared with those with a PRI > 16% (15.6% vs. 3.3%; P < 0.001). In multivariate analysis, the PRI predicted both thrombotic and bleeding events (OR: 1.44, 95% confidence interval [CI]: 1.2-1.72; P < 0.001 and OR: 0.75, 95% CI: 0.59-0.96; P = 0.024 [respectively, per 10% increase]).

CONCLUSION

Platelet reactivity measurement after a prasugrel LD predicts both ischemic and bleeding events at 1 year follow-up for ACS patients undergoing PCI.

Mobilization of CD34+ KDR+ endothelial progenitor cells predicts target lesion revascularization

BACKGROUND

Endothelial lesion and regeneration are critical events in the process leading to in-stent restenosis (ISR) after bare metal stent (BMS) percutaneous coronary intervention (PCI).

OBJECTIVES

To prospectively investigate the relationship between biomarkers reflecting endothelial turnover and the occurrence of ISR.

METHODS

We performed a multicenter prospective observational study that included 156 patients undergoing elective PCI with BMS. Endothelial lesion was assessed by the enumeration of circulating endothelial cells (CECs). Endothelial regeneration was evaluated by enumeration of circulating CD34+ progenitor cells (CD34+ PCs) and CD34+ KDR+ endothelial progenitor cells (EPCs). Measurements were performed before PCI, and 6 and 24 h after PCI. Dynamic changes were evaluated by calculating the delta value of each marker. The primary and secondary endpoints of the study were clinical target lesion revascularizations (TLRs) and major adverse cardiovascular events (MACEs) after 6 months of follow-up.

RESULTS

During follow-up, 28 MACEs were recorded, including 27 TLRs. PCI induced a significant rise in the numbers of CECs, CD34+ PCs, and CD34+ KDR+ EPCs. Baseline, 6-h and 24-h levels of these markers did not differ between patients with and without TLR. The delta percentage of CD34+ KDR+ EPCs was significantly reduced in patients with TLR as compared with patients without TLR (- 0.56 ± 8.1 vs. 2.91 ± 6.2; P = 0.015). In multivariate analysis, the delta percentage of CD34+ KDR+ EPCs independently predicted the occurrence of TLR and MACEs (P = 0.02 and P = 0.014, respectively).

CONCLUSION

The endothelial regenerative response to injury induced by PCI, assessed by CD34+ KDR+ EPCs mobilized among progenitor cells, determines the risk of TLR and MACEs in stable coronary artery disease patients.

[Role of angioplasty in the treatment of renal artery stenosis]

Atherosclerotic renal artery stenosis is frequent and is associated with a high incidence of morbidity and mortality, with a strong correlation with coronary artery disease, (Kalra et al., 2005; Cheung et al., 2002; Guo et al., 2007 [1-3]). The atherosclerotic renal artery stenosis is an independent predictive factor of death (Conlon et al., 1998 [4]). The treatment of this lesion does not have strong evidence. A lot of studies in this area suggest the angioplasty is superior in a big majority between surgery, and angioplasty with stent is superior between balloon angioplasty, but some studies fail to prove the superiority of angioplasty versus medical treatment. These studies have sadly a lot of mistakes and nowadays we don't know what is the treatment for our patients in a lot of cases. The angioplasty is indicated when there is a failure of antihypertensive medications for control of blood pressure, when it is associated with a renal insufficiency quickly progressive or when there is a lesion on each renal artery. Other studies must be organized for prove the superiority of angioplasty when there is a real stenosis, maybe with the use of fractional flow reserve.

Inducible ventricular arrhythmias and patency of infarct-related artery in survivors of acute myocardial infarction

BACKGROUND

Patency of infarct-related artery in patients who suffered an acute myocardial infarction (AMI) has been shown to be associated with improved survival. Ventricular tachyarrhythmias induced by programmed electrical stimulation may be predictive of arrhythmic events and sudden death.

HYPOTHESIS

The study was undertaken to assess the possible effect of a patent infarct-related coronary artery on induced ventricular tachyarrhythmias during programmed ventricular stimulation in survivors of AMI.

METHODS

In this prospective study, programmed electrical stimulation was performed before hospital discharge (14 +/- 2 days) in 79 patients who survived an AMI. Patients were subdivided into two groups: Group I with patent infarct-related coronary artery (n = 64) and Group 2 with occluded infarct-related artery (n = 15) at coronary angiography performed at 14 +/- 2 days. These two groups were comparable in terms of mean left ventricular ejection fraction, location of infarct-related artery, number of diseased vessels, peak creatine kinase value, and infarct location.

RESULTS

Ventricular arrhythmias were induced in 21 patients ( 32.6%) of Group I and 4 patients (26.6%) of Group 2. This difference was not statistically significant.

CONCLUSION

This study suggests that ventricular arrhythmias induced by programmed ventricular stimulation in survivors of AMI did not differ whether the infarct-related artery was patent or occluded. Other factors may play a role in electrical instability as assessed by programmed ventricular stimulation.

Pocket infection complicating inadvertent transarterial permanent pacing. Successful percutaneous explantation

This report describes a patient admitted for the treatment of a pocket infection occurring 5 months after a dual chamber pacemaker implantation. The ventricular lead had been inadvertently placed into the left ventricle through the arterial system. After careful examination using transesophageal echocardiography and left heart angiogram, successful percutaneous extraction was performed without complication.

Capsular polysaccharide induction of apoptosis by intrinsic and extrinsic mechanisms

A purified microbial capsular polysaccharide of Cryptococcus neoformans, glucuronoxylomannan (GXM), induces Fas ligand (FasL) upregulation on macrophages and, as a consequence, apoptosis of lymphocytes. The mechanisms that lead to lymphocyte apoptosis in both in vitro and in vivo systems were investigated by cytofluorimetric analysis and Western blotting experiments. Caspase 8 cleaves caspase 3 in two different pathways: directly as well as indirectly by activation of Bcl-2 interacting domain, which initiates caspase 9 cleavage. Therefore, the caspase 8 and caspase 9 pathways cooperate in an amplification loop for efficient cell death, and noteworthily we provide evidence that they are both activated in one single cell. Furthermore, both activation of GXM-mediated caspase 8 and apoptosis were also found in in vivo systems in an experimental model of murine candidiasis. Collectively, our data show that GXM-induced apoptosis involves, in a single cell, a cross-talk between extrinsic and intrinsic pathways. Such a finding offers opportunities for the therapeutic usage of this polysaccharide in appropriate clinical settings for taming T-cell responses.

Severity of periodontal disease correlates to inflammatory systemic status and independently predicts the presence and angiographic extent of stable coronary artery disease

BACKGROUND

Periodontal disease (PD) has been recognized as a risk factor for systemic diseases, but its involvement in the pathogenesis of coronary artery disease (CAD) remains debated.

OBJECTIVES

We sought to evaluate the potential relations between severity of the PD, inflammatory response and angiographic lesions extent in patients with stable CAD.

DESIGN

A total of 131 subjects referred to our centre for coronary angiography were evaluated for presence and extension of CAD, then divided into two groups, one with presence of lesions (cases, n = 85) and other one with absence of lesions (controls, n = 46). Mean periodontal pocket depth (PPkD), high sensitivity C reactive protein (hs-CRP), serum amyloid A protein (SAA) and fibrinogen levels were measured in all patients.

RESULTS

Cases and controls did not differ according to their baseline characteristics and prevalence of traditional cardiovascular risk factors. PPkD was greater in patients with CAD than in controls (2.24 +/- 1.28 mm vs 1.50 +/- 0.93 mm, P < 0.001 by Student's t-test). Systemic inflammatory response was more pronounced in cases than in controls, with higher values of hs-CRP, SAA and fibrinogen. Furthermore, PPkD values correlated with hs-CRP (r = 0.80, P < 0.001), SAA (r = 0.71, P < 0.001), fibrinogen levels (r = 0.72, P < 0.001) and the American College of Cardiology/American Heart Association angiographic score (r = 0.68, P < 0.001) in cases. Multivariate analysis indicated a persistent independent correlation between PPkD and angiographic score after adjustment for inflammatory markers levels.

CONCLUSION

In the present study, PD lesions predicted presence of CAD stenosis in patients with cardiovascular risk factors. PD severity was correlated to angiographic extent of coronary lesions, independent of systemic inflammatory status. Those results suggest that these patients might benefit from an intensive periodontal therapy to prevent CAD progression.

CD146-based immunomagnetic enrichment followed by multiparameter flow cytometry: a new approach to counting circulating endothelial cells

BACKGROUND

Circulating endothelial cells (CECs) have emerged as non-invasive biomarkers of vascular dysfunction. The most widely used method for their detection is CD146-based immunomagnetic separation (IMS). Although this approach has provided consensus values in both normal and pathologic situations, it remains tedious and requires a trained operator.

OBJECTIVES

Our objective was to evaluate a new hybrid assay for CEC measurement using a combination of pre-enrichment of CD146+ circulating cells and multiparametric flow cytometry measurement (FCM).

PATIENTS AND METHODS

CECs were determined in peripheral blood from 20 healthy volunteers, 12 patients undergoing coronary angioplasty, and 30 renal transplant recipients, and blood spiked with cultured endothelial cells. CD146+ cells were isolated using CD146-coated magnetic nanoparticles and labeled using CD45-fluorescein isothiocyanate and CD146-PE or isotype control antibody and propidium iodide before FCM. The same samples were also processed using CD146-based immunomagnetic separation as the reference method.

RESULTS

The hybrid assay detected CECs, identified as CD45(dim)/CD146(bright)/propidium iodide(+), with high size-related scatter characteristics, and clearly discriminated these from CD45(bright)/CD146(dim) activated T lymphocytes. The method demonstrated both high recovery efficiency and good reproducibility. Both IMS and the hybrid assay similarly identified increased CEC levels in patients undergoing coronary angioplasty and renal transplantation, when compared to healthy controls. In patients, CEC values from these two methods were of the same order of magnitude and highly correlated. Bland-Altman analysis revealed poor statistical agreement between methods, flerrofluid-FCM providing higher values than IMS.

CONCLUSION

This new hybrid FCM assay constitutes an accurate alternative to visual counting of CECs following CD146-based IMS.

Vasodilator-stimulated phosphoprotein phosphorylation analysis prior to percutaneous coronary intervention for exclusion of postprocedural major adverse cardiovascular events

BACKGROUND

Despite dual antiplatelet therapy, the rate of major adverse cardiovascular events (MACE) after percutaneous coronary angioplasty remains high. Studies have shown interindividual variations in response to clopidogrel. Furthermore, there is an apparent link between clinical outcomes and clopidogrel resistance.

OBJECTIVES

To investigate the value of platelet reactivity index (PRI), assessed by vasodilator-stimulated phosphoprotein (VASP) phosphorylation analysis, for predicting MACE after percutaneous coronary intervention (PCI) with stent implantation.

METHODS

A prospective monocentric study was performed on 144 patients undergoing PCI. PR was evaluated by VASP phosphorylation analysis 24 h after they received a 300-mg loading dose of clopidogrel. MACE were recorded during a 6-month follow-up. Patients were divided into quintiles according to PRI, as assessed by VASP analysis. The receiver operating characteristic (ROC) curve served to determine the optimal cut-off value of VASP analysis to detect MACE.

RESULTS

Of the 144 patients, 34% had stable angina pectoris, 40% silent ischemia, and 26% low-risk non-ST-segment elevation acute coronary syndrome. During the follow-up, 21 MACE were observed. Patients in quintile 1 of VASP analysis had a significantly lower risk of MACE as compared with those among the four higher quintiles (0 vs. 21, P < 0.01). ROC curve analysis of VASP showed an optimal cut-off value of 50% PR to exclude MACE. The negative predictive value of the test was 100%.

CONCLUSIONS

VASP phosphorylation analysis can evaluate the individual response to clopidogrel loading dose prior to PCI and predict postprocedural MACE.

Statins alter oxidant-antioxidant status and lower exercise-induced oxidative stress

Data on effects of statins on resting oxidant-antioxidant status are contradictory and no study has been published on the effects of statins on exercise-induced oxidative stress. We carried out a 6-month longitudinal study in 10 dyslipidemic patients receiving 10 mg/day atorvastatin and 13 healthy sedentary subjects. Thiobarbituric acid reactive substances (TBARS) and reduced ascorbic acid (RAA) were measured in plasma at rest and every 5 minutes after submaximal isometric thumb adduction and handgrip sustained until exhaustion. At inclusion, resting TBARS and RAA levels in controls and patients did not differ and exercise increased TBARS and decreased RAA. Atorvastatin reduced resting TBARS and RAA levels in a time-dependent but lipid-independent manner. The main effect was a post-exercise increase in TBARS, without affecting the post-exercise RAA levels. The reduction in oxidative stress occurred earlier in oxidative muscles involved in thumb adduction. In conclusion, atorvastatin lowers resting oxidant-antioxidant activity: exercise-induced oxidative stress occurs mainly in muscles having a high oxidative capacity.

The lakes of Titan

The surface of Saturn's haze-shrouded moon Titan has long been proposed to have oceans or lakes, on the basis of the stability of liquid methane at the surface. Initial visible and radar imaging failed to find any evidence of an ocean, although abundant evidence was found that flowing liquids have existed on the surface. Here we provide definitive evidence for the presence of lakes on the surface of Titan, obtained during the Cassini Radar flyby of Titan on 22 July 2006 (T16). The radar imaging polewards of 70 degrees north shows more than 75 circular to irregular radar-dark patches, in a region where liquid methane and ethane are expected to be abundant and stable on the surface. The radar-dark patches are interpreted as lakes on the basis of their very low radar reflectivity and morphological similarities to lakes, including associated channels and location in topographic depressions. Some of the lakes do not completely fill the depressions in which they lie, and apparently dry depressions are present. We interpret this to indicate that lakes are present in a number of states, including partly dry and liquid-filled. These northern-hemisphere lakes constitute the strongest evidence yet that a condensable-liquid hydrological cycle is active in Titan's surface and atmosphere, in which the lakes are filled through rainfall and/or intersection with the subsurface 'liquid methane' table.

Microbial immune suppression mediated by direct engagement of inhibitory Fc receptor

A microbial polysaccharide (glucuronoxylomannan (GXM)) exerts potent immunosuppression by direct engagement to immunoinhibitory receptor FcgammaRIIB. Activation of FcgammaRIIB by GXM leads to the recruitment and phosphorylation of SHIP that prevents IkappaBalpha activation. The FcgammaRIIB blockade inhibits GXM-induced IL-10 production and induces TNF-alpha secretion. GXM quenches LPS-induced TNF-alpha release via FcgammaRIIB. The addition of mAb to GXM reverses GXM-induced immunosuppression by shifting recognition from FcgammaRIIB to FcgammaRIIA. These findings indicate a novel mechanism by which microbial products can impair immune function through direct stimulation of an inhibitory receptor. Furthermore, our observations provide a new mechanism for the ability of specific Ab to reverse the immune inhibitory effects of certain microbial products.