The predictive value of preoperative B-type natriuretic peptide in children undergooing heart surgery.

Introduction: Low cardiac output syndrome is frequent in childrenafter heart surgery for congenital heart disease and may result in pooroutcome and increased morbidity. In the adult population, preoperativebrain natriuretic peptide (BNP) was shown to be predictive of postoperative complications. In children, the value of preoperative BNP onpostoperative outcome is not so clear. The aim of this study was todetermine the predictive value of preoperative BNP on postoperativeoutcome and low cardiac output syndrome in children after heartsurgery for congenital heart disease.Methods: We examined, retrospectively, the postoperative course of97 pediatric patients (mean age 3.7 years, range 0-14 years old) whounderwent heart surgery in a tertiary care pediatric intensive caresetting. NTproBNP was measured preoperatively in all patients(median 412 pg/ml, range 12-35'000 pg/ml). Patients were divided intothree groups according to their NTproBNP levels (group 1: 0-300 pg/ml, group 2: 300-600 pg/ml, group 3: >600 pg/ml) and then,correlations with postoperative outcomes were examined.Results: We found that patients with a high preoperative BNP requiredmore frequently prolonged (>2 days) mechanical ventilation (33%vs 40% vs 61%, p = 0.045) and stayed more frequently longer than6 days in the intensive care unit (42% vs 50% vs 71%, p = 0.03).However, high preoperative BNP was not correlated with occurrenceof low cardiac output syndrome.Conclusion: Preoperative BNP cannot be used, in children, as areliable and sole predictor of postoperative low cardiac outputsyndrome. However it may help identify, before surgery, those patientsat risk of having a difficult postoperative course.

Banks, government bonds, and default: what do the data say?

We use data from Bankscope to analyze the holdings of public bonds by over 18,000 banks located in 185 countries and the role of these bonds in 18 sovereign debt crises over the period 1998-2012. We find that: (i) banks hold a sizeable share of their assets in government bonds (about 9% on average), particularly in less financially developed countries; (ii) during sovereign crises, banks on average increase their bondholdings by 1% of their assets, but this increase is concentrated among larger and more profitable banks, and; (iii) the correlation between a bank's holdings of public bonds and its future loans is positive in normal times, but turns negative during defaults. A 10% increase in bank bond-holdings during default is associated with a 3.2% reduction in future loans, and bonds bought in normal times account for 75% of this effect. Our results are consistent with the view that there is a liquidity benefit for banks to hold public bonds in normal times, which is critical for understanding bank fragility during sovereign crises.

RHAMM-R3 peptide vaccination in patients with acute myeloid leukemia, myelodysplastic syndrome, and multiple myeloma elicits immunologic and clinical responses.

The receptor for hyaluronic acid-mediated motility (RHAMM) is an antigen eliciting both humoral and cellular immune responses in patients with acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), and multiple myeloma (MM). We initiated a phase 1 clinical trial vaccinating 10 patients with R3 (ILSLELMKL), a highly immunogenic CD8(+) T-cell epitope peptide derived from RHAMM. In 7 of 10 patients, we detected an increase of CD8(+)/HLA-A2/RHAMM R3 tetramer(+)/CD45RA(+)/CCR7(-)/CD27(-)/CD28(-) effector T cells in accordance with an increase of R3-specific CD8(+) T cells in enzyme linked immunospot (ELISpot) assays. In chromium release assays, a specific lysis of RHAMM-positive leukemic blasts was shown. Three of 6 patients with myeloid disorders (1/3 AML, 2/3 MDS) achieved clinical responses: one patient with AML and one with MDS showed a significant reduction of blasts in the bone marrow after the last vaccination. One patient with MDS no longer needed erythrocyte transfusions after 4 vaccinations. Two of 4 patients with MM showed a reduction of free light chain serum levels. Taken together, RHAMM-R3 peptide vaccination induced both immunologic and clinical responses, and therefore RHAMM constitutes a promising target for further immunotherapeutic approaches. This study is registered at http://ISRCTN.org as ISRCTN32763606 and is registered with EudraCT as 2005-001706-37.

Canalização das Remessas de Emigrantes para as Actividades Produtivas via Diáspora Bonds - Caso de Cabo Verde -

As remessas dos emigrantes desde sempre têm sido um fenómeno de grande importância para o desenvolvimento económico dos países em via de desenvolvimento e dos países do desenvolvimento médio, mas a sua utilização nem sempre têm um impacto significativo no crescimento económico dos países. É neste sentido que o presente trabalho visa abordar “Canalização das Remessas de Emigrantes para as Actividades Produtivas via Diáspora Bonds caso de Cabo Verde”, procurando demonstrá-lo através de um estudo de análise de dados e informações recolhidos junto da Bolsa de Valores de Cabo Verde, Banco de Cabo Verde, Instituto de Comunidades e Instituto Nacional das Estatísticas. O objectivo do referido estudo é avaliar a possibilidade da canalização das remessas dos emigrantes nas actividades produtivas, através do produto financeiro, Diáspora Bonds. Os resultados do estudo demonstraram que Diáspora Bonds é um mecanismo de canalização das remessas dos emigrantes nas actividades produtivas, isto porque o estudo revela, que garante a sustentabilidade futura do país, promove a criação da riqueza interna do país, permite a diversificação das fontes de financiamento, e fundamentalmente evidencia um veiculo de captação de fundos nos mercados internacionais a um custo muito mais baixo, por outro lado notou-se que as remessas dos emigrantes as não têm sido utilizada nas actividades produtivas em Cabo Verde, o que isto significa que a maioria dos volumes das remessas destinam-se as despesas do consumo, educação e saúde.

How T cell receptors interact with peptide-MHCs: A multiple steered molecular dynamics study.

The T-cell receptor (TCR) interaction with antigenic peptides (p) presented by the major histocompatibility complex (MHC) molecule is a key determinant of immune response. In addition, TCR-pMHC interactions offer examples of features more generally pertaining to protein-protein recognition: subtle specificity and cross-reactivity. Despite their importance, molecular details determining the TCR-pMHC binding remain unsolved. However, molecular simulation provides the opportunity to investigate some of these aspects. In this study, we perform extensive equilibrium and steered molecular dynamics simulations to study the unbinding of three TCR-pMHC complexes. As a function of the dissociation reaction coordinate, we are able to obtain converged H-bond counts and energy decompositions at different levels of detail, ranging from the full proteins, to separate residues and water molecules, down to single atoms at the interface. Many observed features do not support a previously proposed two-step model for TCR recognition. Our results also provide keys to interpret experimental point-mutation results. We highlight the role of water both in terms of interface resolvation and of water molecules trapped in the bound complex. Importantly, we illustrate how two TCRs with similar reactivity and structures can have essentially different binding strategies. Proteins 2011; © 2011 Wiley-Liss, Inc.

Interplay between T cell receptor binding kinetics and the level of cognate peptide presented by major histocompatibility complexes governs CD8+ T cell responsiveness.

Through a rational design approach, we generated a panel of HLA-A*0201/NY-ESO-1(157-165)-specific T cell receptors (TCR) with increasing affinities of up to 150-fold from the wild-type TCR. Using these TCR variants which extend just beyond the natural affinity range, along with an extreme supraphysiologic one having 1400-fold enhanced affinity, and a low-binding one, we sought to determine the effect of TCR binding properties along with cognate peptide concentration on CD8(+) T cell responsiveness. Major histocompatibility complexes (MHC) expressed on the surface of various antigen presenting cells were peptide-pulsed and used to stimulate human CD8(+) T cells expressing the different TCR via lentiviral transduction. At intermediate peptide concentration we measured maximum cytokine/chemokine secretion, cytotoxicity, and Ca(2+) flux for CD8(+) T cells expressing TCR within a dissociation constant (K(D)) range of ∼1-5 μM. Under these same conditions there was a gradual attenuation in activity for supraphysiologic affinity TCR with K(D) < ∼1 μM, irrespective of CD8 co-engagement and of half-life (t(1/2) = ln 2/k(off)) values. With increased peptide concentration, however, the activity levels of CD8(+) T cells expressing supraphysiologic affinity TCR were gradually restored. Together our data support the productive hit rate model of T cell activation arguing that it is not the absolute number of TCR/pMHC complexes formed at equilibrium, but rather their productive turnover, that controls levels of biological activity. Our findings have important implications for various immunotherapies under development such as adoptive cell transfer of TCR-engineered CD8(+) T cells, as well as for peptide vaccination strategies.

Structure-function characterization and optimization of a plant-derived antibacterial peptide.

Crushed seeds of the Moringa oleifera tree have been used traditionally as natural flocculants to clarify drinking water. We previously showed that one of the seed peptides mediates both the sedimentation of suspended particles such as bacterial cells and a direct bactericidal activity, raising the possibility that the two activities might be related. In this study, the conformational modeling of the peptide was coupled to a functional analysis of synthetic derivatives. This indicated that partly overlapping structural determinants mediate the sedimentation and antibacterial activities. Sedimentation requires a positively charged, glutamine-rich portion of the peptide that aggregates bacterial cells. The bactericidal activity was localized to a sequence prone to form a helix-loop-helix structural motif. Amino acid substitution showed that the bactericidal activity requires hydrophobic proline residues within the protruding loop. Vital dye staining indicated that treatment with peptides containing this motif results in bacterial membrane damage. Assembly of multiple copies of this structural motif into a branched peptide enhanced antibacterial activity, since low concentrations effectively kill bacteria such as Pseudomonas aeruginosa and Streptococcus pyogenes without displaying a toxic effect on human red blood cells. This study thus identifies a synthetic peptide with potent antibacterial activity against specific human pathogens. It also suggests partly distinct molecular mechanisms for each activity. Sedimentation may result from coupled flocculation and coagulation effects, while the bactericidal activity would require bacterial membrane destabilization by a hydrophobic loop.

Subconjunctival Injection of XG-102, a c-Jun N-Terminal Kinase Inhibitor Peptide, in the Treatment of Endotoxin-Induced Uveitis in Rats.

Abstract Purpose: XG-102, a TAT-coupled dextrogyre peptide inhibiting the c-Jun N-terminal kinase, was shown efficient in the treatment of experimental uveitis. Preclinical studies are now performed to determine optimal XG-102 dose and route of administration in endotoxin-induced uveitis (EIU) in rats with the purpose of clinical study design. METHODS: EIU was induced in Lewis rats by lipopolysaccharides (LPS) injection. XG-102 was administered at the time of LPS challenge by intravenous (IV; 3.2, 35 or 355 μg/injection), intravitreal (IVT; 0.08, 0.2 or 2.2 μg/eye), or subconjunctival (SCJ; 0.2, 1.8 or 22 μg/eye) routes. Controls received either the vehicle (saline) or dexamethasone phosphate injections. Efficacy was assessed by clinical scoring, infiltrating cells count, and expression of inflammatory mediators [inducible nitric oxide synthase (iNOS), cytokine-induced neutrophil chemoattractant-1 (CINC-1)]. The effect of XG-102 on phosphorylation of c-Jun was evaluated by Western blot. RESULTS: XG-102 demonstrated a dose-dependent anti-inflammatory effect in EIU after IV and SCJ administrations. Respective doses of 35 and 1.8 μg were efficient as compared with the vehicle-injected controls, but only the highest doses, respectively 355 and 22 μg, were as efficient as dexamethasone phosphate. After IVT injections, the anti-inflammatory effect of XG-102 was clinically evaluated similar to the corticoid's effect with all the tested doses. Regardless of the administration route, the lowest efficient doses of XG-102 significantly decreased the ration of phospho c-Jun/total c-Jun, reduced cells infiltration in the treated eyes, and significantly downregulated iNOS and CINC-1 expression in the retina. CONCLUSION: These results confirm that XG-102 peptide has potential for treating intraocular inflammation. SCJ injection appears as a good compromise to provide a therapeutic effect while limiting side effects.

Induction of potent antitumor CTL responses by recombinant vaccinia encoding a melan-A peptide analogue.

There is considerable interest in the development of vaccination strategies that would elicit strong tumor-specific CTL responses in cancer patients. One strategy consists of using recombinant viruses encoding amino acid sequences corresponding to natural CTL-defined peptide from tumor Ags as immunogens. However, studies with synthetic tumor antigenic peptides have demonstrated that introduction of single amino acid substitutions may dramatically increase their immunogenicity. In this study we have used a well-defined human melanoma tumor Ag system to test the possibility of translating the immunological potency of synthetic tumor antigenic peptide analogues into recombinant vaccinia viruses carrying constructs with the appropriate nucleotide substitutions. Our results indicate that the use of a mutated minigene construct directing the expression of a modified melanoma tumor Ag leads to improved Ag recognition and, more importantly, to enhanced immunogenicity. Thus, recombinant vaccinia viruses containing mutated minigene sequences may lead to new strategies for the induction of strong tumor-specific CTL responses in cancer patients.

Cohesion, satisfaction with family bonds, and emotional well-being in families with adolescents

The present paper investigated whether higher cohesion and satisfaction with family bonds were associated with the daily experience of emotional well-being in varying social circumstances. Using a sample of school-age adolescents (N = 95) and both their parents, data were gathered daily over 1 week using a diary approach in addition to self-report instruments. Multilevel analyses revealed higher cohesion to be associated with well-being in fathers and adolescents, but not in mothers. Parents also reported higher well-being when with friends or colleagues than when alone. Moreover, fathers who scored higher on cohesion reported higher well-being when with family members than when alone, whereas adolescents who scored higher on satisfaction with bonds reported lower well-being when with peers or siblings than when alone.

The final N-terminal trimming of a subaminoterminal proline-containing HLA class I-restricted antigenic peptide in the cytosol is mediated by two peptidases.

The proteasome produces MHC class I-restricted antigenic peptides carrying N-terminal extensions, which are trimmed by other peptidases in the cytosol or within the endoplasmic reticulum. In this study, we show that the N-terminal editing of an antigenic peptide with a predicted low TAP affinity can occur in the cytosol. Using proteomics, we identified two cytosolic peptidases, tripeptidyl peptidase II and puromycin-sensitive aminopeptidase, that trimmed the N-terminal extensions of the precursors produced by the proteasome, and led to a transient enrichment of the final antigenic peptide. These peptidases acted either sequentially or redundantly, depending on the extension remaining at the N terminus of the peptides released from the proteasome. Inhibition of these peptidases abolished the CTL-mediated recognition of Ag-expressing cells. Although we observed some proteolytic activity in fractions enriched in endoplasmic reticulum, it could not compensate for the loss of tripeptidyl peptidase II/puromycin-sensitive aminopeptidase activities.

The synthetic Plasmodium falciparum circumsporozoite peptide PfCS102 as a malaria vaccine candidate: a randomized controlled phase I trial.

BACKGROUND: Fully efficient vaccines against malaria pre-erythrocytic stage are still lacking. The objective of this dose/adjuvant-finding study was to evaluate the safety, reactogenicity and immunogenicity of a vaccine candidate based on a peptide spanning the C-terminal region of Plasmodium falciparum circumsporozoite protein (PfCS102) in malaria naive adults. METHODOLOGY AND PRINCIPAL FINDINGS: Thirty-six healthy malaria-naive adults were randomly distributed into three dose blocks (10, 30 and 100 microg) and vaccinated with PfCS102 in combination with either Montanide ISA 720 or GSK proprietary Adjuvant System AS02A at days 0, 60, and 180. Primary end-point (safety and reactogenicity) was based on the frequency of adverse events (AE) and of abnormal biological safety tests; secondary-end point (immunogenicity) on P. falciparum specific cell-mediated immunity and antibody response before and after immunization. The two adjuvant formulations were well tolerated and their safety profile was good. Most AEs were local and, when systemic, involved mainly fatigue and headache. Half the volunteers in AS02A groups experienced severe AEs (mainly erythema). After the third injection, 34 of 35 volunteers developed anti-PfCS102 and anti-sporozoite antibodies, and 28 of 35 demonstrated T-cell proliferative responses and IFN-gamma production. Five of 22 HLA-A2 and HLA-A3 volunteers displayed PfCS102 specific IFN-gamma secreting CD8(+) T cell responses. Responses were only marginally boosted after the 3(rd) vaccination and remained stable for 6 months. For both adjuvants, the dose of 10 microg was less immunogenic in comparison to 30 and 100 microg that induced similar responses. AS02A formulations with 30 microg or 100 microg PfCS102 induced about 10-folds higher antibody and IFN-gamma responses than Montanide formulations. CONCLUSIONS/SIGNIFICANCE: PfCS102 peptide was safe and highly immunogenic, allowing the design of more advanced trials to test its potential for protection. Two or three immunizations with a dose of 30 microg formulated with AS02A appeared the most appropriate choice for such studies. TRIAL REGISTRATION: Swissmedic.ch 2002 DR 1227.

BIRO1, a cell-permeable BH3 peptide, promotes mitochondrial fragmentation and death of retinoblastoma cells.

Retinoblastoma is the most common pediatric intraocular neoplasm. While retinoblastoma development requires the inactivation of both alleles of the retinoblastoma tumor suppressor gene (RB1) in the developing retina, additional genomic changes are involved in tumor progression, which progressively lead to resistance of tumor cells to death. Therapeutics acting at very downstream levels of death signaling pathways should therefore be interesting in killing retinoblastoma cells. The BH3-only proteins promote apoptosis by modulating the interaction between the pro- and antiapoptotic members of the BCL2 protein family, and this effect can be recapitulated by the BH3 domains. This report analyzes the effect of various BH3 peptides, corresponding to different BH3-only proteins, on two retinoblastoma cell lines, Y79 and WERI-Rb, as well as on the photoreceptor cell line 661W. The BH3 peptide BIRO1, derived from the BCL2L11 death domain, was very effective in promoting Y79 and WERI-Rb cell death without affecting the 661W photoreceptor cells. This cell death was efficient even in absence of BAX and was shown to be caspase independent. While ROS production or AIF release was not detected from mitochondria of treated cells, BIRO1 initiated mitochondria fragmentation in a short period of time following treatment. IMPLICATIONS: The BIRO1 peptide is highly effective at killing retinoblastoma cells and has potential as a peptidomimetic.

Agonist-induced internalization and recycling of the glucagon-like peptide-1 receptor in transfected fibroblasts and in insulinomas.

Glucagon-like peptide-1 (GLP-1) is the most potent stimulator of glucose-induced insulin secretion and its pancreatic beta-cell receptor is a member of a new subfamily of G-protein-coupled receptors which includes the receptors for vasoactive intestinal polypeptide, secretin and glucagon. Here we studied agonist-induced GLP-1 receptor internalization in receptor-transfected Chinese hamster lung fibroblasts using three different approaches. First, iodinated GLP-1 bound at 4 degrees C to transfected cells was internalized with a t 1/2 of 2-3 min following warming up of the cells to 37 degrees C. Secondly, exposure to GLP-1 induced a shift in the distribution of the receptors from plasma membrane-enriched to endosomes-enriched membrane fractions, as assessed by Western blot detection of the receptors using specific antibodies. Thirdly, continuous exposure of GLP-1 receptor-expressing cells to iodinated GLP-1 led to a linear accumulation of peptide degradation products in the medium following a lag time of 20-30 min, indicating a continuous cycling of the receptor between the plasma membrane and endosomal compartments. Potassium depletion and hypertonicity inhibited transferrin endocytosis, a process known to occur via coated pit formation, as well as GLP-1 receptor endocytosis. In contrast to GLP-1, the antagonist exendin-(9-39) did not lead to receptor endocytosis. Surface re-expression following one round of GLP-1 receptor endocytosis occurred with a half-time of about 15 min. The difference in internalization and surface re-expression rates led to a progressive redistribution of the receptor in intracellular compartments upon continuous exposure to GLP-1. Finally, endogenous GLP-1 receptors expressed by insulinoma cells were also found to be internalized upon agonist binding. Together our data demonstrate that the GLP-1 receptor is internalized upon agonist binding by a route similar to that taken by single transmembrane segment receptors. The characterization of the pathway and kinetics of GLP-1-induced receptor endocytosis will be helpful towards understanding the role of internalization and recycling in the control of signal transduction by this receptor.

Soluble MHC-peptide complexes containing long rigid linkers abolish CTL-mediated cytotoxicity.

Soluble MHC-peptide (pMHC) complexes induce intracellular calcium mobilization, diverse phosphorylation events, and death of CD8+ CTL, given that they are at least dimeric and co-engage CD8. By testing dimeric, tetrameric, and octameric pMHC complexes containing spacers of different lengths, we show that their ability to activate CTL decreases as the distance between their subunit MHC complexes increases. Remarkably, pMHC complexes containing long rigid polyproline spacers (&gt; or =80 A) inhibit target cell killing by cloned S14 CTL in a dose- and valence-dependent manner. Long octameric pMHC complexes abolished target cell lysis, even very strong lysis, at nanomolar concentrations. By contrast, an altered peptide ligand antagonist was only weakly inhibitory and only at high concentrations. Long D(b)-gp33 complexes strongly and specifically inhibited the D(b)-restricted lymphocytic choriomeningitis virus CTL response in vitro and in vivo. We show that complications related to transfer of peptide from soluble to cell-associated MHC molecules can be circumvented by using covalent pMHC complexes. Long pMHC complexes efficiently inhibited CTL target cell conjugate formation by interfering with TCR-mediated activation of LFA-1. Such reagents provide a new and powerful means to inhibit Ag-specific CTL responses and hence should be useful to blunt autoimmune disorders such as diabetes type I.