285 resultados para positive semi-definite matrices


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Prevention of tuberculosis (TB) through vaccination would substantially reduce the global TB burden. Mtb72F/AS02 is a candidate TB vaccine shown to be immunogenic and well tolerated in PPD-negative adults. We evaluated the safety and immunogenicity of Mtb72F/AS02 in Mycobacterium-primed adults (BCG-vaccinated, or infected adults who had received post-exposure chemoprophylaxis or treatment for pulmonary TB disease). In this observer-blind controlled trial, 20 BCG-vaccinated adults and 18 adults previously infected with Mycobacterium tuberculosis (Mtb), were randomized 3:1 to receive three doses of Mtb72F/AS02 or AS02 at one-month intervals, and followed for 6 months post third vaccination. Mtb72F/AS02 was well tolerated in BCG-vaccinated adults, and tended to be more reactogenic in Mtb-infected adults. Adverse events were mainly self-limiting, resolving without sequelae. No serious adverse events were reported. The adverse events in Mtb72F/AS02 vaccinees were not clearly associated with vaccine-induced responses (as assessed by proinflammatory cytokines, total IgE and C-reactive protein levels). No Th2 T-cell responses, or vaccine-induced T-cell responses to Mtb antigens (CFP-10/PPD/ESAT-6) were detected by ICS. In both cohorts, Mtb72F/AS02 induced persistent polyfunctional Mtb72F-specific CD4(+) T-cell responses and anti-Mtb72F humoral responses. IFN-γ was detectable in serum one day post each vaccination. Further evaluation of the candidate vaccine, Mtb72F/AS02, is warranted. Trial registration: ClinicalTrials.gov identifier: NCT00146744.

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Prenatal heart valve interventions aiming at the early and systematic correction of congenital cardiac malformations represent a promising treatment option in maternal-fetal care. However, definite fetal valve replacements require growing implants adaptive to fetal and postnatal development. The presented study investigates the fetal implantation of prenatally engineered living autologous cell-based heart valves. Autologous amniotic fluid cells (AFCs) were isolated from pregnant sheep between 122 and 128 days of gestation via transuterine sonographic sampling. Stented trileaflet heart valves were fabricated from biodegradable PGA-P4HB composite matrices (n = 9) and seeded with AFCs in vitro. Within the same intervention, tissue engineered heart valves (TEHVs) and unseeded controls were implanted orthotopically into the pulmonary position using an in-utero closed-heart hybrid approach. The transapical valve deployments were successful in all animals with acute survival of 77.8% of fetuses. TEHV in-vivo functionality was assessed using echocardiography as well as angiography. Fetuses were harvested up to 1 week after implantation representing a birth-relevant gestational age. TEHVs showed in vivo functionality with intact valvular integrity and absence of thrombus formation. The presented approach may serve as an experimental basis for future human prenatal cardiac interventions using fully biodegradable autologous cell-based living materials.

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Objectives:¦The aim of this study was to estimate the prevalence of subclinical small joint synovitis detected by ultrasonography in patients with axial SpA, and to evaluate their relevance in terms of function or and disease activity.¦Methods:¦Forty axial SpA patients, 40 RA and 20 healthy subjects were evaluated by ultrasonography, using a reproducible semi-quantitative score by B-mode and Doppler, for synovitis, while disease activity and function were assessed using validated instruments (DAS28, BASDAI, BASFI, m-SACRAH and HAQ).¦Results:¦Median B-mode score were respectively 8.2 for axial SpA, 11.5 for RA and 6.0 for healthy subjects, corresponding to a prevalence of clinical significant synovitis of respectively 37.5%, 60% and 11% for a level of significance at > 8 chosen to¦classify as active > 75% of RA patient with DAS28 >2.6 and < 10% of controls. Addtionally, Doppler was positive in 8% of SpA, 30 % of RA and none of the healthy subjects. Echographic synovitis correlated with disease activity (DAS28) and function¦(HAQ, mSACRAH) in RA patients, but no correlation were found for SpA patients with disease activity (BASDAI) or function (BASFI, HAQ, mSACRAH). Cases of synovitis using classification by Doppler positivity were insufficient to allow any¦statistical analysis.¦Conclusions:¦B-mode ultrasonographic evaluation can demonstrate subclinical synovitis in almost 40% of SpA patients, but they do not appear to correlate with disease activity or function on the contrary to what is observed in RA patients, representing potentially different processes

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In Pseudomonas aeruginosa, the small RNA-binding, regulatory protein RsmA is a negative control element in the formation of several extracellular products (e.g., pyocyanin, hydrogen cyanide, PA-IL lectin) as well as in the production of N-acylhomoserine lactone quorum-sensing signal molecules. RsmA was found to control positively the ability to swarm and to produce extracellular rhamnolipids and lipase, i.e., functions contributing to niche colonization by P. aeruginosa. An rsmA null mutant was entirely devoid of swarming but produced detectable amounts of rhamnolipids, suggesting that factors in addition to rhamnolipids influence the swarming ability of P. aeruginosa. A small regulatory RNA, rsmZ, which antagonized the effects of RsmA, was identified in P. aeruginosa. Expression of the rsmZ gene was dependent on both the global regulator GacA and RsmA, increased with cell density, and was subject to negative autoregulation. Overexpression of rsmZ and a null mutation in rsmA resulted in quantitatively similar, negative or positive effects on target genes, in agreement with a model that postulates titration of RsmA protein by RsmZ RNA.

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Invariant Valpha14 (Valpha14i) NKT cells are a murine CD1d-dependent regulatory T cell subset characterized by a Valpha14-Jalpha18 rearrangement and expression of mostly Vbeta8.2 and Vbeta7. Whereas the TCR Vbeta domain influences the binding avidity of the Valpha14i TCR for CD1d-alpha-galactosylceramide complexes, with Vbeta8.2 conferring higher avidity binding than Vbeta7, a possible impact of the TCR Vbeta domain on Valpha14i NKT cell selection by endogenous ligands has not been studied. In this study, we show that thymic selection of Vbeta7(+), but not Vbeta8.2(+), Valpha14i NKT cells is favored in situations where endogenous ligand concentration or TCRalpha-chain avidity are suboptimal. Furthermore, thymic Vbeta7(+) Valpha14i NKT cells were preferentially selected in vitro in response to CD1d-dependent presentation of endogenous ligands or exogenously added self ligand isoglobotrihexosylceramide. Collectively, our data demonstrate that the TCR Vbeta domain influences the selection of Valpha14i NKT cells by endogenous ligands, presumably because Vbeta7 confers higher avidity binding.

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This study on determinants of sexual protection behavior among HIV-positive gay men used the empirically tested information-motivation-behavioral skills (IMB) model. HIV-specific variables were added to the model to determine factors decisive for condom use with steady and casual partners. Data were collected using an anonymous, standardized self-administered questionnaire. Study participants were recruited at HIV outpatient clinics associated with the Eurosupport Study Group and the Swiss HIV Cohort Study. To identify factors associated with condom use, backward elimination regression analyses were performed. Overall, 838 HIV-infected gay men from 14 European countries were included in this analysis. About 53% of them reported at least one sexual contact with a steady partner; 62.5% had sex with a casual partner during the last 6 months. Forty-three percent always used condoms with steady partners and 44% with casual partners. High self-efficacy and subjective norms in favor of condom-use were associated with increased condom use with casual and steady partners, whereas feeling depressed was associated with decreased condom use with casual partners. Condoms were used less often with HIV-positive partners. Self-efficacy as an important behavioral skill to perform protection behavior was influenced by lower perceived vulnerability, higher subjective norms, and more positive safer sex attitudes. The IMB-model constructs appeared to be valid; however, not all the model predictors could be determined as hypothesized. Besides the original IMB constructs, HIV-specific variables, including sexual partners' serostatus and mental health, explained condom use. Such factors should be considered in clinical interventions to promote "positive prevention."

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The present dissertation analyzed the construct of attachment at different time points, specifically focusing on two phases of adoptive family life that have so far received little attention from investigators. Study 1 focused on the first months of adoption, and analyzed the development of the attachment relationship to new caregivers. The sample was composed of a small but homogeneous group (n=6) of Korean-born children, adopted by Italian parents. The Parent Attachment Diary (Dozier & Stovall, 1997) was utilized to assess the child's attachment behavior. We assessed these behavior for the first 3 months after placement into adoption. Results showed a double variability of attachment behavior: within subjects during the 3-months, and between subjects, with just half of the children developing a stable pattern of attachment. In order to test the growth trajectories of attachment behavior, Hierarchical Linear Models (Bryk & Raudenbush, 1992) were also applied, but no significant population trend was identified. Study 2 analyzed attachment among adoptees during the sensitive period of adolescence. Data was derived from an international collection (n= 104, from Belgium Italy, and Romania) of semi-structured clinical interviews (with adolescents and with their adoptive parents), as well as from questionnaires. The purpose of this study was to detect the role played by risk and protective factors on the adoptee's behavioral and socio-emotional outcomes. In addition, we tested the possible interactions between the different attachment representations within the adoptive family. Results showed that pre-adoptive risk predicted the adolescent's adjustment; however, parental representations constituted an important moderator of this relationship. Moreover, the adolescent's security of attachment partially mediated the relationship between age at placement and later behavioral problems. In conclusion, the two present attachment studies highlighted the notable rate of change of attachment behavior over time, which showed its underlying plasticity, and thus the possible reparatory value of the adoption practice. Since parents have been proven to play an important role, especially in adolescence, the post-adoption support acquires even more importance in order to help parents promoting a positive and stable relational environment over time. - L'objectif de cette thèse est de décrire la formation des relations d'attachement chez les enfants et les adolescents adoptés, lors de deux phases particulières de la vie de la famille adoptive, qui ont été relativement peu étudiées. L'Étude 1 analyse les premiers mois après l'adoption, avec le but de comprendre si, et comment, une relation d'attachement aux nouveaux parents se développe. L'échantillon est composé d'un petit groupe (n = 6) d'enfants provenant de Corée du Sud, adoptés par des parents Italiens. A l'aide du Parent Attachment Diary (Dozier & Stovall, 1997), des observations des comportements d'attachement de l'enfant ont été recueillies chaque jour au cours des 3 premiers mois après l'arrivée. Les résultats montrent une double variabilité des comportements d'attachement: au niveau inter- et intra-individuel ; au premier de ces niveaux, seuleme la moitié des enfants parvient à développer un pattern stable d'attachement ; au niveau intra-individuel, les trajectoires de développement des comportements d'attachement ont été testées à l'aide de Modèles Linéaires Hiérarchiques (Bryk et Raudenbush, 1992), mais aucune tendance significative n'a pu être révélée. L'Étude 2 vise à analyser l'attachement chez des enfants adoptés dans l'enfance, lors de la période particulièrement sensible de l'adolescence. Les données sont issues d'un base de données internationale (n = 104, Belgique, Italie et Roumanie), composée d' entretiens cliniques semi-structurées (auprès de l'adolescents et des ses parents adoptifs), ainsi que de questionnaires. Les analyses statistiques visent à détecter la présence de facteurs de risque et de protection relativement à l'attachement et aux problèmes de comportement de l'enfant adopté. En outre, la présence d'interactions entre les représentations d'attachement des membres de la famille adoptive est évaluée. Les résultats montrent que les risques associés à la période pré-adoptive prédisent la qualité du bien-être de l'adolescent, mais les représentations parentales constituent un modérateur important de cette relation. En outre, la sécurité de l'attachement du jeune adopté médiatise partiellement la relation entre l'âge au moment du placement et les problèmes de comportement lors de l'adolescence. En conclusion, à l'aide de multiples données relatives à l'attachement, ces deux études soulignent son évolution notable au fil du temps, ce qui sous-tend la présence d'une certaine plasticité, et donc la possible valeur réparatrice de la pratique de l'adoption. Comme les parents semblent jouer un rôle important de ce point de vue, surtout à l'adolescence, cela renforce la notion d'un soutien post-adoption, en vue d'aider les parents à la promotion d'un environnement relationnel favorable et stable. - Il presente lavoro è volto ad analizzare l'attaccamento durante le due fasi della vita della famiglia adottiva che meno sono state indagate dalla letteratura. Lo Studio 1 aveva l'obiettivo di analizzare i primi mesi che seguono il collocamento del bambino, al fine di capire se e come una relazione di attaccamento verso i nuovi genitori si sviluppa. Il campione è composto da un piccolo gruppo (n = 6) di bambini provenienti dalla Corea del Sud e adottati da genitori italiani. Attraverso il Parent Attachment Diary (Stovall e Dozier, 1997) sono stati osservati quotidianamente, e per i primi tre mesi, i comportamenti di attaccamento del bambino. I risultati hanno mostrato una duplice variabilità: a livello intraindividuale (nell'arco dei 3 mesi), ed interindividuale, poiché solo la metà dei bambini ha sviluppato un pattern stabile di attaccamento. Per verificare le traiettorie di sviluppo di tali comportamenti, sono stati applicati i Modelli Lineari Gerarchici (Bryk & Raudenbush, 1992), che però non hanno stimato una tendenza significativa all'interno della popolazione. Obiettivo dello Studio 2 è stato quello di esaminare l'attaccamento nelle famiglie i cui figli adottivi si trovavano nella delicata fase adolescenziale. I dati, provenienti da una raccolta internazionale (n = 104, Belgio, Italia e Romania), erano costituiti da interviste cliniche semi-strutturate (con gli adolescenti e i propri genitori adottivi) e da questionari. Le analisi hanno indagato il ruolo dei fattori di rischio sullo sviluppo socio-emotivo e sugli eventuali problemi comportamentali dei ragazzi. Inoltre, sono state esaminate le possibili interazioni tra le diverse rappresentazioni di attaccamento dei membri della famiglia adottiva. I risultati hanno mostrato che il rischio pre-adottivo predice l'adattamento dell'adolescente, sebbene le rappresentazioni genitoriali costituiscano un importante moderatore di questa relazione. Inoltre, la sicurezza dell'attaccamento dell'adolescente media parzialmente la relazione tra età al momento dell'adozione e problemi comportamentali in adolescenza. In conclusione, attraverso i molteplici dati relativi all'attaccamento, i due studi ne hanno evidenziato il cambiamento nel tempo, a riprova della sua plasticità, e pertanto sottolineano il possibile valore riparativo dell'adozione. Dal momento che i genitori svolgono un ruolo importante, soprattutto in adolescenza, il supporto nel post- adozione diventa centrale per aiutarli a promuovere un ambiente relazionale favorevole e stabile nel tempo.

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Summary: Detailed knowledge on tumor antigen expression and specific immune cells is required for a rational design of immunotherapy for patients with tumor invaded liver. In this study, we confirmed that Cancer/Testis (CT) tumor-associated antigens are frequently expressed in hepatocellular carcinoma (HCC) and searched for the presence of CD8+ T cells specific for these antigens. In 2/10 HLA-A2+ patients with HCC, we found that MAGE-A10 and/or SSX-2 specific CD8+ T cells naturally responded to the disease, since they were enriched in tumor lesions but not in non-tumoral liver. Isolated T cells specifically and strongly killed tumor cells in vitro, suggesting that these CTL were selected in vivo for high avidity antigen recognition, providing the rational for specific immunotherapy of HCC, based on immunization with CT antigens such as MAGE-Al 0 and SSX-2. Type 1 NKT cells express an invariant TCR α chain (Vα24.1α18, paired with Vβ11 in human) and share a specific reactivity to αGalactosylceramide (αGC) presented by CD1d. These cells can display paradoxical immuno-regulatory properties including strong anti-tumor effects upon αGC administration in murine models. To understand why NKT cells were not sufficiently protective against tumor development in patients with tumor invaded liver, we characterized the diversity of Vα24/Vβ11 NKT cells in healthy donors (HD) and cancer patients: NKT cells from HD and patients were generally diverse in terms of TCR β chain (Vβ11) variability and NKT cells from HD showed a variable recognition of αGC loaded CD 1 d multimers. Vα24/ Vβ11 NKT cells can be divided in 3 populations, the CD4, DN (CD4-/CD8-) and CD8 NKT cell subsets that show distinct ability of cytokine production. In addition, our functional analysis revealed that DN and CD8 subsets displayed a higher cytolytic potential and a weaker IFNγ release than the CD4 NKT cell subset. NKT cell subsets were variably represented in the blood of HD and cancer patients. However, HD with high NKT cell frequencies displayed an enrichment of the DN and CD8 subsets, and few of them were suggestive of an oligoclonal expansion in vivo. Comparable NKT cell frequencies were found between blood, non-tumoral liver and tumor of patients. In contrast, we identified a gradual enrichment of CD4 NKT cells from blood to the liver and to the tumor, together with a decrease of DN and CD8 NKT cell subsets. Most patient derived NKT cells were unresponsive upon αGalactosylceramide stimulation ex vivo; NKT cells from few patients displayed a weak responsiveness with different cytokine polarization. The NKT cell repertoire was thus different in tumor tissue, suggesting that CD4 NKT cells infiltrating tumors may be detrimental for protection against tumors and instead may favour the tumor growth/recurrence as recently reported in mice. Résumé en français scientifique : Afin de développer le traitement des patients porteurs d'une tumeur dans le foie par immunothérapie, de nouvelles connaissances sont requises concernant l'expression d'antigènes par les tumeurs et les cellules immunitaires spécifiques de ces antigènes. Nous avons vérifié que des antigènes associés aux tumeurs, tels que les antigènes « Cancer-Testis » (CT), sont fréquemment exprimés par le carcinome hepatocéllulaire (CHC). La recherche de lymphocytes T CD8+ spécifiques (CTL) de ces antigènes a révélé que des CTL spécifiques de MAGE-A10 et/ou SSX-2 ont répondu naturellement à la tumeur chez 2/10 patients étudiés. Ces cellules étaient présentes dans les lésions tumorales mais pas dans le foie adjacent. De plus, ces CTL ont démontré une activité cytolytique forte et spécifique contre les cellules tumorales in vitro, ce qui suggère que ces CTL ont été sélectionnés pour une haute avidité de reconnaissance de l'antigène in vivo. Ces données fournissent une base pour l'immunothérapie spécifique du CHC, en proposant de cibler les antigènes CT tels que MAGE-A10 ou SSX-2. Les cellules NKT de type 1 ont une chaîne α de TCR qui est invariante (chez l'homme, Vα24Jα18, apparié avec Vβ11) et reconnaissent spécifiquement l'αGalactosylceramide (αGC) présenté par CD1d. Ces cellules ont des propriétés immuno¬régulatrices qui peuvent être parfois contradictoires et leur activation par l'αGC induit une forte protection anti-tumorale chez la souris: Afin de comprendre pourquoi ces cellules ne sont pas assez protectrices contre le développement des tumeurs dans le foie chez l'homme, nous avons étudié la diversité des cellules NKT Vα24/Vβ11 d'individus sains (IS) et de patients cancéreux. Les cellules NKT peuvent être sous-divisées en 3 populations : Les CD4, DN (CD4- /CD8-) ou CDS, qui ont la capacité de produire des cytokines différentes. Nos analyses fonctionnelles ont aussi révélé que les sous-populations DN et CD8 ont un potentiel cytolytique plus élevé et une production d'IFNγ plus faible que la sous-population CD4. Ces sous-populations sont représentées de manière variable dans le sang des IS ou des patients. Cependant, les IS avec un taux élevé de cellules NKT ont un enrichissement des sous- populations DN ou CDS, et certains suggèrent qu'il s'agit d'une expansion oligo-clonale in vivo. Les patients avaient des fréquences comparables de cellules NKT entre le sang, le foie et la tumeur. Par contre, la sous-population CD4 était progressivement enrichie du sang vers le foie et la tumeur, tandis que les sous-populations DN ou CD8 était perdues. La plupart des cellules NKT des patients ne réagissaient pas lors de stimulation avec l'αGC ex vivo et les cellules NKT de quelques patients répondaient faiblement et avec des polarisations de cytokines différentes. Ces données suggèrent que les cellules NKT CD4, prédominantes dans les tumeurs, sont inefficaces pour la lutte anti-tumorale et pourraient même favoriser la croissance ou la récurrence tumorale. Donc, une mobilisation spécifique des cellules NKT CD4 négatives par immunothérapie pourrait favoriser l'immunité contre des tumeurs chez l'homme. Résumé en français pour un large public Au sein des globules blancs, les lymphocytes T expriment un récepteur (le TCR), qui est propre à chacun d'entre eux et leur permet d'accrocher de manière très spécifique une molécule appelée antigène. Ce TCR est employé par les lymphocytes pour inspecter les antigènes associés avec des molécules présentatrices à la surface des autres cellules. Les lymphocytes T CD8 reconnaissent un fragment de protéine (ou peptide), qui est présenté par une des molécules du Complexe Majeur d'Histocompatibilité de classe I et tuent la cellule qui présente ce peptide. Ils sont ainsi bien adaptés pour éliminer les cellules qui présentent un peptide issu d'un virus quand la cellule est infectée. D'autres cellules T CD8 reconnaissent des peptides comme les antigènes CT, qui sont produits anormalement par les cellules cancéreuses. Nous avons confirmé que les antigènes CT sont fréquemment exprimés par le cancer du foie. Nous avons également identifié des cellules T CD8 spécifiques d'antigènes CT dans la tumeur, mais pas dans le foie normal de 2 patients sur 10. Cela signifie que ces lymphocytes peuvent être naturellement activés contre la tumeur et sont capables de la trouver. De plus les lymphocytes issus d'un patient ont démontré une forte sensibilité pour reconnaître l'antigène et tuent spécifiquement les cellules tumorales. Les antigènes CT représentent donc des cibles intéressantes qui pourront être intégrés dans des vaccins thérapeutiques du cancer du foie. De cette manière, les cellules T CD8 du patient lui-même pourront être induites à détruire de manière spécifique les cellules cancéreuses. Un nouveau type de lymphocytes T a été récemment découvert: les lymphocytes NKT. Quand ils reconnaissent un glycolipide présenté par la molécule CD1d, ils sont capables, de manière encore incomprise, d'initier, d'augmenter, ou à l'inverse d'inhiber la défense immunitaire. Ces cellules NKT ont démontré qu'elles jouent un rôle important dans la défense contre les tumeurs et particulièrement dans le foie des souris. Nous avons étudié les cellules NKT de patients atteints d'une tumeur dans le foie, afin de comprendre pourquoi elles ne sont pas assez protectrice chez l'homme. Les lymphocytes NKT peuvent être sous-divisés en 3 populations: Les CD4, les DN (CD4-/CD8-) et les CD8. Ces 3 classes de NKT peuvent produire différents signaux chimiques appelés cytokines. Contrairement aux cellules NKT DN ou CDS, seules les cellules NKT CD4 sont capables de produire des cytokines qui sont défavorables pour la défense anti-tumorale. Par ailleurs nous avons trouvé que les cellules NKT CD4 tuent moins bien les cellules cancéreuses que les cellules NKT DN ou CD8. L'analyse des cellules NKT, fraîchement extraites du sang, du foie et de la tumeur de patients a révélé que les cellules NKT CD4 sont progressivement enrichies du sang vers le foie et la tumeur. La large prédominance des NKT CD4 à l'intérieur des tumeurs suggère que, chez l'homme, ces cellules sont inappropriées pour la lutte anti-tumorale. Par ailleurs, la plupart des cellules NKT de patients n'étaient pas capables de produire des cytokines après stimulation avec un antigène. Cela explique également pourquoi ces cellules ne protègent pas contre les tumeurs dans le foie.

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Usually, the differentiation of inks on questioned documents is carried out by optical methods and thin layer chromatography (TLC). Therefore, spectrometric methods were also proposed in forensic literature for the analysis of dyes. Between these techniques, laser desorption/ionization mass spectrometry (LDI-MS) has demonstrated a great versatility thanks to its sensitivity to blue ballpoint ink dyes and minimal sample destruction. Previous researches concentrated mostly on the LDI-MS positive mode and have shown that this analytical tool offers higher discrimination power than high performance TLC (HPTLC) for the differentiation of blue ballpoint inks. Although LDI-MS negative mode has already been applied in numerous forensic domains like the studies of works of art, automotive paints or rollerball pens, its potential for the discrimination of ballpoint pens was never studied before. The aim of the present paper is therefore to evaluate its potential for the discrimination of blue ballpoint inks. After optimization of the method, ink entries from 33 blue ballpoint pens were analyzed directly on paper in both positive and negative modes by LDI-MS. Several cationic and anionic ink components were identified in inks; therefore, pens were classified and compared according to their formulations. Results show that additional information provided by anionic dyes and pigments significantly increases the discrimination power of positive mode. In fact, it was demonstrated that classifications obtained by the two modes were, to some extent, complementary (i.e., inks with specific cationic dyes not necessarily contained the same anionic components).

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Members of the Ly-49 gene family code for class I MHC-specific receptors that regulate NK cell function. Due to a combinatorial distribution of Ly-49 receptors, NK cells display considerable clonal heterogeneity. The acquisition of one Ly-49 receptor, Ly-49A is strictly dependent on the transcriptional trans-acting factor T cell-specific factor-1 (TCF-1). Indeed, TCF-1 binds to two sites in the Ly-49a promoter and regulates its activity, suggesting that the Ly-49a gene is a direct TCF-1 target. TCF-1 deficiency resulted in the altered usage of additional Ly-49 receptors. We show in this study, using TCF-1 beta(2)-microglobulin double-deficient mice, that these repertoire alterations are not due to Ly-49/MHC class I interactions. Our findings rather suggest a TCF-1-dependent, cell autonomous effect on the acquisition of multiple Ly-49 receptors. Besides reduced receptor usage (Ly-49A and D), we also observed no effect (Ly-49C) and significantly expanded (Ly-49G and I) receptor usage in the absence of TCF-1. These effects did not in all cases correlate with the presence of TCF binding sites in the respective proximal promoter. Therefore, besides TCF-1 binding to the proximal promoter, Ly-49 acquisition may also be regulated by TCF-1 binding to more distant cis-acting elements and/or by regulating the expression of additional trans-acting factors. Consistent with the observed differential, positive or negative role of TCF-1 for Ly-49 receptor acquisition, reporter gene assays revealed the presence of an inducing as well as a repressing TCF site in certain proximal Ly-49 promoters. These findings reveal an important role of TCF-1 for the formation of the NK cell receptor repertoire.

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Antipsychotic medication represents the treatment of choice in psychosis according to clinical guidelines. Nevertheless, studies show that half to almost three-quarter of all patients discontinue medication with antipsychotics after some time, a fact which is traditionally ascribed to side-effects, mistrust against the clinician and poor illness insight. The present study investigated whether positive attitudes toward psychotic symptoms (ie, gain from illness) represent a further factor for medication noncompliance. An anonymous online survey was set up in order to prevent conservative response biases that likely emerge in a clinical setting. Following an iterative selection process, data from a total of 113 patients with a likely diagnosis of schizophrenia and a history of antipsychotic treatment were retained for the final analyses (80%). While side-effect profile and mistrust emerged as the most frequent reasons for drug discontinuation, 28% of the sample reported gain from illness (eg, missing voices, feeling of power) as a motive for noncompliance. At least every fourth patient reported the following reasons: stigma (31%), mistrust against the physician/therapist (31%), and rejection of medication in general (28%). Approximately every fifth patient had discontinued antipsychotic treatment because of forgetfulness. On average, patients provided 4 different explanations for noncompliance. Ambivalence toward symptoms and treatment should thoroughly be considered when planning treatment in psychosis. While antipsychotic medication represents the evidence-based cornerstone of the current treatment in schizophrenia, further research is needed on nonpharmacological interventions for noncompliant patients who are willing to undergo intervention but refuse pharmacotherapy.

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The increased incidence over the past decade of bloodstream infections (BSIs) caused by gram-positive bacteria, particularly methicillin-resistant Staphylococcus aureus, highlights the critical need for a consistent approach to therapy. However, there is currently no international consensus on the diagnosis and management of gram-positive BSIs. The Clinical Consensus Conference on Gram-Positive Bloodstream Infections was convened as a session at the 9th International Symposium on Modern Concepts in Endocarditis and Cardiovascular Infections held in 2007. Participants discussed various aspects of the practical treatment of patients who present with gram-positive BSI, including therapeutic options for patients with BSIs of undefined origin, the selection of appropriate empirical therapy, and treatment of complicated and uncomplicated BSIs. The opinions of participants about these key issues are reflected in this article.