Mechanisms of Defect Generation and Clustering in CH3S Self-Assembled Monolayers on Au(111)

Periodic density functional calculations probe that step edges play a key role as source of defects during self-assembly. It is shown that the self-assembly process strongly reduces the energy required to strip an atom from the gold surface, locally increasing the concentration of surface defects. The thermodynamic driving force for the atom stripping is considerably more favorable along step-edge lines within the self-assembly than on the higher-coordinated terrace sites. Furthermore, the clustering of surface defects is considered, and we probe that the formation of aggregates of vacancies in the form of vacancy pits significantly stabilizes the self-assembly on the terraces of gold, where the role of the step edges is expected to be less significant. The high stability of pit-like structures arises from a balance between the corrugation and the enhanced bonding of defect-rich substrates. Our results demonstrate the important role that step edges play during assembly and could be very valuable for discovering defect-free assembled structures.

Scavenger receptors in human airway epithelial cells: role in response to double-stranded RNA

Scavenger receptors and Toll-like receptors (TLRs) cooperate in response to danger signals to adjust the host immune response. The TLR3 agonist double stranded (ds)RNA is an efficient activator of innate signalling in bronchial epithelial cells. In this study, we aimed at defining the role played by scavenger receptors expressed by bronchial epithelial cells in the control of the innate response to dsRNA both in vitro and in vivo. Expression of several scavenger receptor involved in pathogen recognition was first evaluated in human bronchial epithelial cells in steady-state and inflammatory conditions. Their implication in the uptake of dsRNA and the subsequent cell activation was evaluated in vitro by competition with ligand of scavenger receptors including maleylated ovalbumin and by RNA silencing. The capacity of maleylated ovalbumin to modulate lung inflammation induced by dsRNA was also investigated in mice. Exposure to tumor necrosis factor-α increased expression of the scavenger receptors LOX-1 and CXCL16 and the capacity to internalize maleylated ovalbumin, whereas activation by TLR ligands did not. In contrast, the expression of SR-B1 was not modulated in these conditions. Interestingly, supplementation with maleylated ovalbumin limited dsRNA uptake and inhibited subsequent activation of bronchial epithelial cells. RNA silencing of LOX-1 and SR-B1 strongly blocked the dsRNA-induced cytokine production. Finally, administration of maleylated ovalbumin in mice inhibited the dsRNA-induced infiltration and activation of inflammatory cells in bronchoalveolar spaces and lung draining lymph nodes. Together, our data characterize the function of SR-B1 and LOX-1 in bronchial epithelial cells and their implication in dsRNA-induced responses, a finding that might be relevant during respiratory viral infections.

Genetic variants associated with severe pneumonia in A/H1N1 influenza infection

The A/H1N1 influenza strain isolated in Mexico in 2009 caused severe pulmonary illness in a small number of exposed individuals. Our objective was to determine the influence of genetic factors on their susceptibility. We carried out a case-control association study genotyping 91 patients with confirmed severe pneumonia from A/H1N1 infection and 98 exposed but asymptomatic household contacts, using the HumanCVD BeadChip (Illumina, San Diego, CA, USA). Four risk single-nucleotide polymorphisms were significantly (p<0.0001) associated with severe pneumonia: rs1801274 (Fc fragment of immunoglobulin G, low-affinity IIA, receptor (FCGR2A) gene, chromosome 1; OR 2.68, 95% CI 1.69-4.25); rs9856661 (gene unknown, chromosome 3; OR 2.62, 95% CI 1.64-4.18); rs8070740 (RPA interacting protein (RPAIN) gene, chromosome 17; OR 2.67, 95% CI 1.63-4.39); and rs3786054 (complement component 1, q subcomponent binding protein (C1QBP) gene, chromosome 17; OR 3.13, 95% CI 1.89-5.17). All SNP associations remained significant after adjustment for sex and comorbidities. The SNPs on chromosome 17 were in linkage disequilibrium. These findings revealed that gene polymorphisms located in chromosomes 1 and 17 might influence susceptibility to development of severe pneumonia in A/H1N1 infection. Two of these SNPs are mapped within genes (FCGR2A, C1QBP) involved in the handling of immune complexes and complement activation, respectively, suggesting that these genes may confer risk due to increased activation of host immunity.

Efficacy and safety of long-term ezetimibe/simvastatin treatment in patients with familial hypercholesterolemia

AIM

Patients with heterozygous familial hypercholesterolemia (FH) have an increased risk of premature myocardial infarction, stroke, and surgical revascularization, and an increased rate of progression of carotid intima-media thickness (IMT). The most commonly used drugs for cholesterol lowering, statins, have a limited action in these patients. Ezetimibe, a novel compound, selectively inhibits cholesterol uptake and when associated with statins has an additional low-density lipoprotein cholesterol (LDL-C) reducing effect. The aim of this study is to evaluate the effects of long-term combined Ezetimibe/Simvastatin (EZE/SIMVA) therapy (30 months) on the lipidic pattern, inflammatory markers, and carotid IMT in patients with FH subdivided into two groups: one with a history of acute myocardial infarction (IMA) and the other with carotid atherosclerotic plaques but no history of cardiovascular events.

METHODS

All patients enrolled in this study (group A: patients with a history of IMA; group B, patients with carotid lesions but no history of cardiovascular events) were submitted to a 6-week period of isocaloric diet and to a 4-week lipid-lowering wash-out period before study entry. After the wash-out period at baseline (time 0) and then every two months total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C), and apolipoprotein B and A1 were determined. LDL-C levels were calculated. Fibrinogen and hs-CRP at baseline and at 6, 18, and 30 months were determined. All patients were submitted to an ultrasonographic evaluation of the carotid intima-media thickness at baseline, 18 and 30 months. The scheduled duration time of the study was 30 months. At the beginning of the study all patients were assigned to receive the combined EZE/SIMVA treatment 10/20 mg per day. After two months, patients who had not reached the respective LDL-C targets proposed by NCEP ATPIII (<70 mg/dL for patients with a history of IMA and <100 mg/dL for patients with carotid lesions) were assigned to receive EZE/SIMVA 10/40 mg per day and, after four months, patients who had not reached the respective LDL-C targets were assigned to receive EZE/SIMVA 10/80 mg per day.

RESULTS

At the end-point, significant reductions (P<0.001) of about 70% in LDL-C, of 57% in total cholesterol (TC), of 46% in Apo-B, and of 46% in hs-C-reactive protein (hs-CRP) were observed in both groups compared to baseline. Also, triglyceride and fibrinogen levels were significantly (P<0.01) reduced, respectively by 26% and 15% compared to baseline. The EZE/SIMVA association resulted in significant increases in HDL-C (P<0.01) of 11% and in Apo-A1 (P<0.05) by 9% and in significant (P<0.001) reductions of the mean of the carotid IMT in both groups. The EZE/SIMVA treatment was generally well-tolerated, with a safety profile on laboratory parameters. During the 30-month scheduled period of the study, no patient in either group presented any further cardiovascular events.

CONCLUSION

In patients with FH, combined EZE/SIMVA treatment resulted in a significant LDL-C lowering, achieving the goals proposed by NCEP ATP III, in a significant improvement of all the lipidic and inflammatory patterns, and above all in a progressive decrease of the carotid IMT. Although the results of ongoing randomized controlled trials are required before making any definitive conclusions, our results support the hypothesis of stabilizing effect of EZE/SIMVA on the atherosclerotic disease both in primary and in secondary prevention.

Regulation of Th2 responses and allergic inflammation through bystander activation of CD8+ T lymphocytes in early life

Th2-biased immune responses characterizing neonates may influence the later onset of allergic disease. The contribution of regulatory T cell populations in the prevention of Th2-driven pathologies in early life is poorly documented. We investigated the potential of CD8(+) T cells stimulated at birth with alloantigens to modulate the development of allergic airway inflammation. Newborn mice were immunized with semiallogeneic splenocytes or dendritic cells (DCs) and exposed at the adult stage to OVA aeroallergens. DC-immunized animals displayed a strong Th1 and Tc1/Tc2 alloantigen-specific response and were protected against the development of the allergic reaction with reduced airway hyperresponsiveness, mucus production, eosinophilia, allergen-specific IgE and IgG(1), and reduction of lung IL-4, IL-5, IL-10, and IL-13 mRNA levels. By contrast, splenocyte-immunized mice displayed a Th2 and a weak Tc2 alloantigen-specific response and were more sensitive to the development of the allergen-specific inflammation compared with mice unexposed at birth to alloantigens. DC-immunized animals displayed an important increase in the percentage of IFN-gamma-producing CD8(+)CD44(high), CD8(+)CD62L(high), and CD8(+)CD25(+) subsets. Adoptive transfers of CD8(+) T cells from semiallogeneic DC-immunized animals to adult beta(2)m-deficient animals prevented the development of allergic response, in particular IgE, IL-4, and IL-13 mRNA production in an IFN-gamma-dependent manner, whereas transfers of CD8(+) T cells from semiallogeneic splenocyte-immunized mice intensified the lung IL-4 and IL-10 mRNA level and the allergen-specific IgE. These findings demonstrated that neonatal induction of regulatory CD8(+) T cells was able to modulate key parameters of later allergic sensitization in a bystander manner, without recognition of MHC class I molecules.

Double-stranded RNA exacerbates pulmonary allergic reaction through TLR3: implication of airway epithelium and dendritic cells

Respiratory viral infections have been implicated in exacerbations of allergic asthma, characterized by a Th2-biased immune response. Respiratory viruses target airway epithelial cells and dendritic cells (DCs). Their activation is, at least in part, mediated by the TLR3-dependent recognition of virus-derived dsRNA. To elucidate the role of epithelial cells and DCs and the implication of TLR3/Toll/IL-1R domain-containing adaptor-inducing IFN-beta (TRIF) pathway, we developed a mouse model of lung allergic exacerbation. The effect of intranasal administration of dsRNA in OVA-sensitized wild-type mice and TRIF(-/-) mice was evaluated on airway hyperresponsiveness and pulmonary inflammation. Our data demonstrated that treatment with dsRNA significantly increased the airway hyperresponsiveness, the lung inflammation, and the OVA-specific Th2 response. This was associated with an infiltrate of eosinophils, myeloid DCs, and T lymphocytes. TRIF activation was required for the development of dsRNA-induced exacerbation of the allergic reaction. Intratracheal transfer of IL-4/dsRNA/OVA-pretreated DCs also triggered exacerbation of the allergic reaction, whereas cells primed with dsRNA/OVA had a more limited effect. dsRNA-induced production of CCL20 by airway epithelium was associated with DC recruitment. In vivo and in vitro treatment with dsRNA amplified airway epithelial production of the pro-Th2 chemokines CCL11 and CCL17, their secretion being enhanced by Th2 cytokines. In conclusion, dsRNA derived from respiratory viruses trigger exacerbation of the pulmonary allergic reaction through TLR3/TRIF-dependent pathway. Moreover, Th2 cytokines participate in this process by modulating the response of airway epithelium and DCs to dsRNA.

The Category-Focus Implicit Association Test 1It is journal policy that submissions coauthored by a current editor are handled by a guest editor. We thank Ulrich Wagner, who handled the current manuscript, for his efforts

We propose the Category-Focus IAT (CF-IAT) as an instrument to measure the implicit associations of single concepts. The CF-IAT directs respondents’ attention to a subset of the experimental materials. In a first study using the CF-IAT, Chilean adolescents (N = 49), members of either the indigenous minority (Mapuche) or the nonindigenous majority, completed CF-IATs assessing implicit attitudes toward these groups. Results revealed, in both groups, a neutral implicit evaluation of the ingroup, but a negative implicit evaluation of the outgroup. Process evidence suggests that the CF-IAT’s manipulation of attentional focus was successful.

Perfluorinated contaminants in fur seal pups and penguin eggs from South Shetland, Antarctica

Perfluorinated compounds (PFCs) have emerged as a new class of global environmental pollutants. In this study, the presence of perfluorochemicals (PFCs) in penguin eggs and Antarctic fur seals was reported for the first time. Tissue samples from Antarctic fur seal pups and penguin eggs were collected during the 2003/04 breeding season. Ten PFC contaminants were determined in seal and penguin samples. The PFC concentrations in seal liver were in the decreasing order, PFOS>PFNA>PFHpA>PFUnDA while in Adélie penguin eggs were PFHpA>PFUnDA>PFDA>PFDoDA, and in Gentoo penguin eggs were PFUnDA>PFOS>PFDoDA>PFHpA. The PFC concentrations differed significantly between seals and penguins (p<0.005) and a species-specific difference was found between the two species of penguins (p<0.005). In our study we found a mean concentration of PFOS in seal muscle and liver samples of 1.3 ng/g and 9.4 ng/g wet wt, respectively, and a mean concentration in Gentoo and Adélie penguin eggs of 0.3 ng/g and 0.38 ng/g wet wt, respectively. PFCs detected in penguin eggs and seal pups suggested oviparous and viviparous transfer of PFOS to eggs and off-springs.

Trastuzumab (H) treatment in patients (pts) with metastatic breast cancer (MBC): An observational retrospective study in four hospitals from Bogotá, Colombia (ONCOLGroup study)

e12016

Background: Breast cancer is the second most common cancer diagnosed in Colombian women, and approximately 26% of MBC are HER-2-positive in our population. The purpose of this study was to assess the characteristics and outcome of pts with HER-2-positive MBC treated with H-based therapy in Bogotá. Methods: This retrospective study included 119 pts treated between 2000 and 2007. Overall response rates (ORR), clinical benefit (CB), time to progression (TTP), and overall survival (OS) were estimated. Most common grade 2/3 toxicities are reported as well as variables that influenced survival. Results: Median age was 62 years (range, 37 to 75). Eighty-seven (73%) pts had recurrent disease and the rest had de novo MBC. Performance status was ≥70% in 114 pts, 66% had ≤2 metastatic sites, and 58% had hormone receptor positive disease. Previous adjuvant therapy before H included antracyclines in 68% and taxanes in 39% of the pts. H was part of the first-line therapy for MBC in 86.5% of the pts, leading to a 54% ORR in 103 evaluable pts. CB was 81% and median TTP was 6.1 months. (range, 1.2 to 26 mo). The most common toxicities in this setting included neutropenia ≥G3 (9%) and neuropathy ≥G3 (7%). H was given as part of second line therapy to 54 (45%) pts, but only 41 had evaluable disease. A 56% ORR was found in this subgroup, 85% CB and 4.7-month median of TTP. Grade ≥G3 hand-foot syndrome was the main toxicity (14%). Median OS after the diagnosis of MBC was 23 months (range, 1.6–93 mo), being longer for pts with HR-positive disease (p = 0.036), in pts with loco-regional relapse (p = 0.029), and in those older than 50 (p = 0.0025). Only two variables independently predicted OS: age (HR: 0.4, 95% CI: 0.35–0.93, p = 0.046) and HR status (HR: 0.7, 95% CI: 0.60–0.86, p = 0.040). Two pts (1.7%) had H-induced heart failure. Conclusions: H in combination with chemotherapeutic agents has been proved to be an effective and safe treatment for HER-2-positive MBC. The results from our series agreed with those reported in the medical literature and guarantee the regular use of H in Colombia.

No significant financial relationships to disclose.

Wood-smoke exposure (WSE) as a predictor of response and survival in erlotinib-treated advanced lung adenocarcinoma (ALA) patients (pts) (ONCOLGroup study)

e19052

Background: There is consistent information suggesting that long-term WSE constitutes a risk factor for lung cancer. More than 50 years of WSE was associated with non-small cell lung cancer (NSCLC). In Colombia the prevalence of WSE in areas having less economic development is approximately 24%. The aim of the study was to evaluate WSE as a predictor of response and survival in ALA pts. Methods: This study included 168 pts with ALA treated between 2002 and 2007 in four referring hospitals of Bogotá. Retrospectively, we estimated overall response rates (ORR), time to progression (TTP) and overall survival (OS) in a subgroup of pts with significant WSE (exposure >5 years for at least 4 hours/day) treated with erlotinib, and compared them with the non-WSE population treated with the same compound. Results: Median age was 66 years (range, 29–96), 53% were female, 39% had never been smokers, 24% of all cohort pts had been considerably exposed to WS and 45 pts had received erlotinib during disease treatment (as 2nd or 3rd line). Sixteen of these pts (F11/M5, PS ≥70% 9 pts) had been exposed to WS and 29 not so (F17/M12, PS ≥70% 22 pts); 10 pts having WSE had been smoking for a mean of 14pk/yr history. ORR to erlotinib was 7% and 32% in pts with and without WSE respectively (p = 0.02). TTP was significantly higher in pts treated with erlotinib with no history of WSE (4.9 mo. vs 1.7 mo., p = 0.034). and in those who had received this compound as second-line (vs erlotinib used as third line, p = 0.044). Among pts with WSE history, OS was 6.6 mo. (range, 5.8–7.3) for those treated with Erlotinib and 12.7 mo. (range, 10.2–17) for those not treated with this compound (p = 0.04). Multivariate analysis was carried out for determining the factors influencing mortality between pts with WSE; only PS (HR: 4.6, 95%CI: 1.2–29, p = 0.050) and gender (HR: 3.6, 95%CI: 2.7–18, p = 0.036) were significant. Conclusions: WSE was associated with a poorer response and survival in ALA pts treated with erlotinib in Colombia.

No significant financial relationships to disclose.

Chitosan-hyaluronic acid nanoparticles loaded with heparin for the treatment of asthma

The purpose of this study was to produce mucoadhesive nanocarriers made from chitosan (CS) and hyaluronic acid (HA), and containing the macromolecular drug heparin, suitable for pulmonary delivery. For the first time, this drug was tested in ex vivo experiments performed in mast cells, in order to investigate the potential of the heparin-loaded nanocarriers in antiasthmatic therapy. CS and mixtures of HA with unfractionated or low-molecular-weight heparin (UFH and LMWH, respectively) were combined to form nanoparticles by the ionotropic gelation technique. The resulting nanoparticles loaded with UFH were between 162 and 217 nm in size, and those prepared with LMWH were 152 nm. The zeta potential of the nanoparticle formulations ranged from +28.1 to +34.6 mV, and in selected nanosystems both types of heparin were associated with a high degree of efficiency, which was approximately 70%. The nanosystems were stable in phosphate buffered saline (PBS), pH 7.4, for at least 24h, and released 10.8% of UFH and 79.7% of LMWH within 12h of incubation. Confocal microscopy experiments showed that fluorescent heparin-loaded CS-HA nanoparticles were effectively internalized by rat mast cells. Ex vivo experiments aimed at evaluating the capacity of heparin to prevent histamine release in rat mast cells indicated that the free or encapsulated drug exhibited the same dose-response behaviour.