Discontinuation of enfuvirtide in heavily pretreated HIV-infected individuals.

BACKGROUND: Enfuvirtide was shown to be highly effective in treatment- experienced patients. Data on discontinuation of enfuvirtide and switch to new antiretroviral drugs are scarce. We aimed to evaluate the efficacy and the impact of discontinuing and/or switching enfuvirtide on virologic and clinical parameters in clinical practice. METHODS: All HIV-infected individuals participating in the Swiss HIV Cohort Study who were treated with enfuvirtide for at least 4 weeks in combination with an optimized background antiretroviral regimen were included in this study. RESULTS: A total of 151 patients were analyzed. The median baseline CD4 cell count was 108 cells/microL (interquartile range [IQR] 50-206) and HIV RNA was 4.7 log10 copies/mL (IQR 4.1-5.2). Virologic suppression, defined as a viral load below 50 copies/mL at 12 months, was achieved by 57.6% of patients. Overall, a median CD4 cell increase of 121 cells/microL (IQR 50-189) from baseline was noted. Up to 50% of patients discontinued enfuvirtide within the first year of treatment, mainly because of the patient's choice. After discontinuation of enfuvirtide, high rates of virologic failure and clinical progression were observed, notably when CD4 cell count at stopping enfuvirtide was below 100 cells/microL and no switch to new potent antiretroviral drugs such as darunavir, maraviroc, or raltegravir was performed. CONCLUSIONS: Enfuvirtide provides high virologic and immunologic response in treatment-experienced patients in the setting of clinical practice. Enfuvirtide should not be discontinued but should be replaced by new potent antiretrovirals, particularly in case of severe immunosuppression.

Gene expression profiling of isolated tumour cells from anaplastic large cell lymphomas: insights into its cellular origin, pathogenesis and relation to Hodgkin lymphoma.

Anaplastic large cell lymphoma (ALCL) is a main type of T-cell lymphomas and comprises three distinct entities: systemic anaplastic lymphoma kinase (ALK) positive, systemic ALK(-) and cutaneous ALK(-) ALCL (cALCL). Little is known about their pathogenesis and their cellular origin, and morphological and immunophenotypical overlap exists between ALK(-) ALCL and classical Hodgkin lymphoma (cHL). We conducted gene expression profiling of microdissected lymphoma cells of five ALK(+) and four ALK(-) systemic ALCL, seven cALCL and sixteen cHL, and of eight subsets of normal T and NK cells. The analysis supports a derivation of ALCL from activated T cells, but the lymphoma cells acquired a gene expression pattern hampering an assignment to a CD4(+), CD8(+) or CD30(+) T-cell origin. Indeed, ALCL display a down-modulation of many T-cell characteristic molecules. All ALCL types show significant expression of NFkappaB target genes and upregulation of genes involved in oncogenesis (e.g. EZH2). Surprisingly, few genes are differentially expressed between systemic and cALCL despite their different clinical behaviour, and between ALK(-) ALCL and cHL despite their different cellular origin. ALK(+) ALCL are characterized by expression of genes regulated by pathways constitutively activated by ALK. This study provides multiple novel insights into the molecular biology and pathogenesis of ALCL.

A molecular platform for the diagnosis of multidrug-resistant and pre-extensively drug-resistant tuberculosis based on single nucleotide polymorphism mutations present in Colombian isolates of Mycobacterium tuberculosis

Developing a fast, inexpensive, and specific test that reflects the mutations present in Mycobacterium tuberculosis isolates according to geographic region is the main challenge for drug-resistant tuberculosis (TB) control. The objective of this study was to develop a molecular platform to make a rapid diagnosis of multidrug-resistant (MDR) and extensively drug-resistant TB based on single nucleotide polymorphism (SNP) mutations present in therpoB, katG, inhA,ahpC, and gyrA genes from Colombian M. tuberculosis isolates. The amplification and sequencing of each target gene was performed. Capture oligonucleotides, which were tested before being used with isolates to assess the performance, were designed for wild type and mutated codons, and the platform was standardised based on the reverse hybridisation principle. This method was tested on DNA samples extracted from clinical isolates from 160 Colombian patients who were previously phenotypically and genotypically characterised as having susceptible or MDR M. tuberculosis. For our method, the kappa index of the sequencing results was 0,966, 0,825, 0,766, 0,740, and 0,625 forrpoB, katG, inhA,ahpC, and gyrA, respectively. Sensitivity and specificity were ranked between 90-100% compared with those of phenotypic drug susceptibility testing. Our assay helps to pave the way for implementation locally and for specifically adapted methods that can simultaneously detect drug resistance mutations to first and second-line drugs within a few hours.

Serum sCD163 levels are associated with type 2 diabetes mellitus and are influenced by coffee and wine consumption: results of the Di@bet.es study.

OBJECTIVE Serum levels of soluble TNF-like weak inducer of apoptosis (sTWEAK) and its scavenger receptor CD163 (sCD163) have been linked to insulin resistance. We analysed the usefulness of these cytokines as biomarkers of type 2 diabetes in a Spanish cohort, together with their relationship to food consumption in the setting of the Di@bet.es study. RESEARCH DESIGN AND METHODS This is a cross-sectional, matched case-control study of 514 type 2 diabetes subjects and 517 controls with a Normal Oral Glucose Tolerance Test (NOGTT), using data from the Di@bet.es study. Study variables included clinical and demographic structured survey, food frequency questionnaire and physical examination. Serum concentrations of sTWEAK and sCD163 were measured by ELISA. Linear regression analysis determined which variables were related to sTWEAK and sCD163 levels. Logistic regression analysis was used to estimate odd ratios of presenting type 2 diabetes. RESULTS sCD163 concentrations and sCD163/sTWEAK ratio were 11.0% and 15.0% higher, respectively, (P<0.001) in type 2 diabetes than in controls. Following adjustment for various confounders, the OR for presenting type 2 diabetes in subjects in the highest vs the lowest tertile of sCD163 was [(OR), 2,01 (95%CI, 1,46-2,97); P for trend <0.001]. Coffee and red wine consumption was negatively associated with serum levels of sCD163 (P = 0.0001 and; P = 0.002 for coffee and red wine intake, respectively). CONCLUSIONS High circulating levels of sCD163 are associated with type 2 diabetes in the Spanish population. The association between coffee and red wine intake and these biomarkers deserves further study to confirm its potential role in type 2 diabetes.

CB1 blockade potentiates down-regulation of lipogenic gene expression in perirenal adipose tissue in high carbohydrate diet-induced obesity.

De novo lipogenesis and hypercaloric diets are thought to contribute to increased fat mass, particularly in abdominal fat depots. CB1 is highly expressed in adipose tissue, and CB1-mediated signalling is associated with stimulation of lipogenesis and diet-induced obesity, though its contribution to increasing fat deposition in adipose tissue is controversial. Lipogenesis is regulated by transcription factors such as liver X receptor (LXR), sterol-response element binding protein (SREBP) and carbohydrate-responsive-element-binding protein (ChREBP). We evaluated the role of CB1 in the gene expression of these factors and their target genes in relation to lipogenesis in the perirenal adipose tissue (PrAT) of rats fed a high-carbohydrate diet (HCHD) or a high-fat diet (HFD). Both obesity models showed an up-regulated gene expression of CB1 and Lxrα in this adipose pad. The Srebf-1 and ChREBP gene expressions were down-regulated in HFD but not in HCHD. The expression of their target genes encoding for lipogenic enzymes showed a decrease in diet-induced obesity and was particularly dramatic in HFD. In HCHD, CB1 blockade by AM251 reduced the Srebf-1 and ChREBP expression and totally abrogated the remnant gene expression of their target lipogenic enzymes. The phosphorylated form of the extracellular signal-regulated kinase (ERK-p), which participates in the CB1-mediated signalling pathway, was markedly present in the PrAT of obese rats. ERK-p was drastically repressed by AM251 indicating that CB1 is actually functional in PrAT of obese animals, though its activation loses the ability to stimulate lipogenesis in PrAT of obese rats. Even so, the remnant expression levels of lipogenic transcription factors found in HCHD-fed rats are still dependent on CB1 activity. Hence, in HCHD-induced obesity, CB1 blockade may help to further potentiate the reduction of lipogenesis in PrAT by means of inducing down-regulation of the ChREBP and Srebf-1 gene expression, and consequently in the expression of lipogenic enzymes.

The repressor element silencing transcription factor (REST)-mediated transcriptional repression requires the inhibition of Sp1.

The terminal differentiation of neuronal and pancreatic beta-cells requires the specific expression of genes that are targets of an important transcriptional repressor named RE-1 silencing transcription factor (REST). The molecular mechanism by which these REST target genes are expressed only in neuronal and beta-cells and are repressed by REST in other tissues is a central issue in differentiation program of neuronal and beta-cells. Herein, we showed that the transcriptional factor Sp1 was required for expression of most REST target genes both in insulin-secreting cells and neuronal-like cells where REST is absent. Inhibition of REST in a non-beta and a non-neuronal cell model restored the transcriptional activity of Sp1. This activity was also restored by trichostatin A indicating the requirement of histone deacetylases for the REST-mediated silencing of Sp1. Conversely, exogenous introduction of REST blocked Sp1-mediated transcriptional activity. The REST inhibitory effect was mediated through its C-terminal repressor domain, which could interact with Sp1. Taken together, these data show that the inhibition of Sp1 by REST is required for the silencing of its target genes expression in non-neuronal and in non-beta-cells. We conclude that the interplay between REST and Sp1 determines the cell-specific expression of REST target genes.

Feasibility and clinical outcomes when using practice guidelines for evaluation of fever in returning travelers and migrants : a validation study.

BACKGROUND: Practice guidelines for examining febrile patients presenting upon returning from the tropics were developed to assist primary care physicians in decision making. Because of the low level of evidence available in this field, there was a need to validate them and assess their feasibility in the context they have been designed for. OBJECTIVES: The objectives of the study were to (1) evaluate physicians' adherence to recommendations; (2) investigate reasons for non-adherence; and (3) ensure good clinical outcome of patients, the ultimate goal being to improve the quality of the guidelines, in particular to tailor them for the needs of the target audience and population. METHODS: Physicians consulting the guidelines on the Internet (www.fevertravel.ch) were invited to participate in the study. Navigation through the decision chart was automatically recorded, including diagnostic tests performed, initial and final diagnoses, and clinical outcomes. The reasons for non-adherence were investigated and qualitative feedback was collected. RESULTS: A total of 539 physician/patient pairs were included in this study. Full adherence to guidelines was observed in 29% of the cases. Figure-specific adherence rate was 54.8%. The main reasons for non-adherence were as follows: no repetition of malaria tests (111/352) and no presumptive antibiotic treatment for febrile diarrhea (64/153) or abdominal pain without leukocytosis (46/101). Overall, 20% of diversions from guidelines were considered reasonable because there was an alternative presumptive diagnosis or the symptoms were mild, which means that the corrected adherence rate per case was 40.6% and corrected adherence per figure was 61.7%. No death was recorded and all complications could be attributed to the underlying illness rather than to adherence to guidelines. CONCLUSIONS: These guidelines proved to be feasible, useful, and leading to good clinical outcomes. Almost one third of physicians strictly adhered to the guidelines. Other physicians used the guidelines not to forget specific diagnoses but finally diverged from the proposed attitudes. These diversions should be scrutinized for further refinement of the guidelines to better fit to physician and patient needs.

Identification, using a siRNA screen approach, and molecular characterization of a new Fas pathway modulator: STK11/

Abstract : Apoptosis is an evolutionarily conserved cellular suicide mechanism that can be triggered by activation of various pathways, such as the Fas-Pathway. Upon stimulation by its specific ligand (FasL), present at the surface of Cytotoxic Τ lymphocytes, the death receptor Fas initiates a signaling cascade culminating in the activation of cellular caspases, leading thus to cell death of the target cell (e.g. transformed cell). Dysregulation of apoptosis in general, and of Fas pathway in particular, was shown to contribute to pathogenesis of cancers and many human diseases. Even though, during the last decades the molecular mechanisms of apoptosis have been widely studied, it is important to better understand the mechanisms leading to apoptosis, to improve our understanding of pathological processes, and generate more subtle apoptosis-modulating therapies to fight cancer and other diseases. In order to identify new components of the Fas signaling pathway, a screen based on the mechanism of RNA interference was undertaken. After a first and a second manual whole-kinome screen, we identified several strong positive hits that showed a protection against Fas ligand-induced apoptosis with distinct siRNAs, notably STK11, an interesting tumor suppressor mutated in several sporadic and inherited cancers. The STK11 functional characterization reveals that this kinase represents an apically acting general pro-apoptotic modulator of the extrinsic pathway (FasL, TRAIL, TNF-induced apoptosis), but not of the intrinsic apoptotic pathway. The STK11 action on the Fas pathway was shown to be dependent on its kinase activity, but independent of AMPK, a well-characterized STK11 downstream substrate. Furthermore, STK11 was shown to interact with caspase-8, a major mediator of the extrinsic pathway, and modulate its activity through an unclear mechanism that may involve an STK11-dependant caspase-8 phosphorylation. This modification may allow a proper caspase-8 polyubiquitination and activation in p62 sequestosmes aggregates, but may also increase the activation of caspase-8 at the DISC level. In addition, we observed that STK11 modulate not only the apoptotic pathway induced by Fas engagement, but also FasL-induced JNK and NF- KB, sustaining an upstream role of this kinase in the pathway. In conclusion, our report reveals that STK11 is an important pro-apoptotic modulator of the Fas pathway in particular, and extrinsic pathway in general. Our finding could explain, at least partially, why inactivating mutations of the kinase leads to cancer, by allowing resistance to apoptosis and accordingly evasion of immune surveillance. Résumé : L'apoptose est un mécanisme de suicide cellulaire, conservé dans diverses espèces, et qui au niveau moléculaire est déclenché par différentes voies de signalisation, comme par exemple lors de l'activation du récepteur Fas. La liaison du ligand FasL au récepteur de la mort Fas, induit une cascade de signalisation qui conduit à l'activation des caspases. Les lymphocytes Τ cytotoxiques peuvent utiliser la voie Fas pour induire la mort et se débarrasser de cellules dangereuses pour le reste de l'organisme, tel que les cellules transformées. La dysrégulation de l'apoptose en général, et de la voie Fas en particulier, peut contribuer à diverses maladies telles que le cancer. Même si ces dernières décennies, les mécanismes moléculaires conduisant à l'apoptose ont été extensivement étudiés, il reste néanmoins important de mieux comprendre le phénomène d'apoptose, pour améliorer notre compréhension des processus pathologiques, mais surtout dans le but de développer de nouvelles thérapies ciblant l'apoptose contre le cancer et d'autres pathologies. Pour identifier de nouveau constituants de la voie Fas, un criblage génétique basé sur l'interférence à l'ARN a été entrepris. Après un premier et un deuxième criblage d'une librairie du kinome, nous avons identifié différentes protéines qui pourraient jouer un rôle positif dans la voie Fas, et en particulier la protéine suppresseur de tumeur STK11, qui est fréquemment mutée dans divers cancers sporadiques et héréditaires. La caractérisation fonctionnelle de STK11 a révélé que cette kinase était un modulateur apical de la voie extrinsèque de l'apoptose en général (Fas, TNF, TRAIL), mais pas de la voie intrinsèque. L'action de STK11 sur la voie Fas est dépendante de sa fonction kinase, mais indépendante de l'AMPK, un substrat bien caractérisé de STK11. De plus, STK11 interagît avec la caspase-8, un constituant majeur de la voie Fas, et module son activité, par un mécanisme encore peu clair qui pourrait impliquer une phosphorylation de la caspase-8 par STK11. Cette modification pourrait permettre une activation optimale de la caspase-8 en jouant un rôle dans le processus de polyubiquitination de la caspase-8, phénomène qui semble être important pour l'activation de la caspase-8 dans des agrégats protéiques avec p62, mais qui pourrait aussi augmenter son activation au niveau du DISC. Finalement, nous avons observé que STK11 modulait non seulement la voie apoptotique déclenchée par l'activation de Fas, mais aussi les voies non-apoptotiques de Fas, comme JNK et NF-KB. En conclusion notre étude, révèle que STK11 est un important modulateur pro- apoptotique de la voie Fas, et de la voie extrinsèque en général. Cette découverte pourrait expliquer, du moins partiellement, pourquoi les mutations inactivatrices de STK11 conduisent au cancer, par une augmentation de la résistance à l'apoptose et donc par l'évasion de la surveillance immunitaire.

A repeated GGA motif is critical for the activity and stability of the riboregulator RsmY of Pseudomonas fluorescens.

The riboregulator RsmY of Pseudomonas fluorescens strain CHA0 is an example of small regulatory RNAs belonging to the global Rsm/Csr regulatory systems controlling diverse cellular processes such as glycogen accumulation, motility, or formation of extracellular products in various bacteria. By binding multiple molecules of the small regulatory protein RsmA, RsmY relieves the negative effect of RsmA on the translation of several target genes involved in the biocontrol properties of strain CHA0. RsmY and functionally related riboregulators have repeated GGA motifs predicted to be exposed in single-stranded regions, notably in the loops of hairpins. The secondary structure of RsmY was corroborated by in vivo cleavage with lead acetate. RsmY mutants lacking three or five (out of six) of the GGA motifs showed reduced ability to derepress the expression of target genes in vivo and failed to bind the RsmA protein efficiently in vitro. The absence of GGA motifs in RsmY mutants resulted in reduced abundance of these transcripts and in a shorter half-life (< or = 6 min as compared with 27 min for wild type RsmY). These results suggest that both the interaction of RsmY with RsmA and the stability of RsmY strongly depend on the GGA repeats and that the ability of RsmY to interact with small regulatory proteins such as RsmA may protect this RNA from degradation.

Quality Assessment of Cardiac Magnetic Resonance Images at 1.5/3.0 T: Description and Validation of Standardized Criteria

PURPOSE: Cardiovascular magnetic resonance (CMR) has become a robust and important diagnostic imaging modality in cardiovascular medicine. However,insufficient image quality may compromise its diagnostic accuracy. No standardized criteria are available to assess the quality of CMR studies. We aimed todescribe and validate standardized criteria to evaluate the quality of CMR studies including: a) cine steady-state free precession, b) delayed gadoliniumenhancement, and c) adenosine stress first-pass perfusion. These criteria will serve for the assessment of the image quality in the setting of the Euro-CMR registry.METHOD AND MATERIALS: First, a total of 45 quality criteria were defined (35 qualitative criteria with a score from 0-3, and 10 quantitative criteria). Thequalitative score ranged from 0 to 105. The lower the qualitative score, the better the quality. The quantitative criteria were based on the absolute signal intensity (delayed enhancement) and on the signal increase (perfusion) of the anterior/posterior left ventricular wall after gadolinium injection. These criteria were then applied in 30 patients scanned with a 1.5T system and in 15 patients scanned with a 3.0T system. The examinations were jointly interpreted by 3 CMR experts and 1 study nurse. In these 45 patients the correlation between the results of the quality assessment obtained by the different readers was calculated.RESULTS: On the 1.5T machine, the mean quality score was 3.5. The mean difference between each pair of observers was 0.2 (5.7%) with a mean standarddeviation of 1.4. On the 3.0T machine, the mean quality score was 4.4. The mean difference between each pair of onservers was 0.3 (6.4%) with a meanstandard deviation of 1.6. The quantitative quality assessments between observers were well correlated for the 1.5T machine: R was between 0.78 and 0.99 (pCONCLUSION: The described criteria for the assessment of CMR image quality are robust and have a low inter-observer variability, especially on 1.5T systems.CLINICAL RELEVANCE/APPLICATION: These criteria will allow the standardization of CMR examinations. They will help to improve the overall quality ofexaminations and the comparison between clinical studies.

δ 15N measurement of organic and inorganic substances by EA-IRMS: a speciation-dependent procedure

Little attention has been paid so far to the influence of the chemical nature of the substance when measuring δ 15N by elemental analysis (EA)-isotope ratio mass spectrometry (IRMS). Although the bulk nitrogen isotope analysis of organic material is not to be questioned, literature from different disciplines using IRMS provides hints that the quantitative conversion of nitrate into nitrogen presents difficulties. We observed abnormal series of δ 15N values of laboratory standards and nitrates. These unexpected results were shown to be related to the tailing of the nitrogen peak of nitrate-containing compounds. A series of experiments were set up to investigate the cause of this phenomenon, using ammonium nitrate (NH4NO3) and potassium nitrate (KNO3) samples, two organic laboratory standards as well as the international secondary reference materials IAEA-N1, IAEA-N2-two ammonium sulphates [(NH4)2SO4]-and IAEA-NO-3, a potassium nitrate. In experiment 1, we used graphite and vanadium pentoxide (V2O5) as additives to observe if they could enhance the decomposition (combustion) of nitrates. In experiment 2, we tested another elemental analyser configuration including an additional section of reduced copper in order to see whether or not the tailing could originate from an incomplete reduction process. Finally, we modified several parameters of the method and observed their influence on the peak shape, δ 15N value and nitrogen content in weight percent of nitrogen of the target substances. We found the best results using mere thermal decomposition in helium, under exclusion of any oxygen. We show that the analytical procedure used for organic samples should not be used for nitrates because of their different chemical nature. We present the best performance given one set of sample introduction parameters for the analysis of nitrates, as well as for the ammonium sulphate IAEA-N1 and IAEA-N2 reference materials. We discuss these results considering the thermochemistry of the substances and the analytical technique itself. The results emphasise the difference in chemical nature of inorganic and organic samples, which necessarily involves distinct thermochemistry when analysed by EA-IRMS. Therefore, they should not be processed using the same analytical procedure. This clearly impacts on the way international secondary reference materials should be used for the calibration of organic laboratory standards.

Expression and role of BORIS/CTCFL in human cancer stem cells

Le cancer est défini comme la croissance incontrôlée des cellules dans le corps. Il est responsable de 20 % des décès en Europe. Plusieurs expériences montrent que les tumeurs sont issues et se développent grâce à un petit nombre de cellules, que l'on appelle cellules souches cancéreuses (CSC). Ces CSC sont également responsables de l'apparition de métastases et de la résistance aux médicaments anticancéreux. De ce fait, l'identification des gènes qui contribuent aux propriétés de ces CSC (comme la survie des tumeurs, les métastases et la résistance aux médicaments) est nécessaire pour mieux comprendre la biologie des cancers et d'améliorer la qualité des soins des patients avec un cancer. A ce jour, de nombreux marqueurs ont été proposés ainsi que de nouvelles thérapies ciblées contre les CSC. Toutefois, et malgré les énormes efforts de la recherche dans ce domaine, la quasi-totalité des marqueurs de CSC connus à ce jour sont aussi exprimés dans les cellules saines. Ce projet de recherche visait à trouver un nouveau candidat spécifique des CSC. Le gène BORIS (pour Brother of Regulator of Imprinted Sites), nommé aussi CTCFL (CTCF-like), semble avoir certaines caractéristiques de CSC et pourrait donc devenir une cible prometteuse pour le traitement du cancer. BORIS/CTCFL est une protéine nucléaire qui se lie à l'ADN, qui est exprimée dans les tissus normaux uniquement dans les cellules germinales et qui est réactivée dans un grand nombre de tumeurs. BORIS est impliqué dans la reprogrammation épigénétique au cours du développement et dans la tumorigenèse. En outre, des études récentes ont montré une association entre l'expression de BORIS et un mauvais pronostic chez des patients atteints de différents types de cancers. Nous avons développé une nouvelle technologie basée sur les Molecular Beacon pour cibler l'ARNm de BORIS et cela dans les cellules vivantes. Grâce à ce système expérimental, nous avons montré que seule une toute petite sous-population (0,02 à 5%) de cellules tumorales exprimait fortement BORIS. Les cellules exprimant BORIS ont pu être isolées et elles présentaient les caractéristiques de CSC, telles qu'une forte expression de hTERT et des gènes spécifiques des cellules souches (NANOG, SOX2 et OCT4). En outre, une expression élevée de BORIS a été mise en évidence dans des populations enrichies en CSC ('side population' et sphères). Ces résultats suggèrent que BORIS pourrait devenir un nouveau et important marqueur de CSC. Dans des études fonctionnelles sur des cellules de cancer du côlon et du sein, nous avons montré que le blocage de l'expression de BORIS altère largement la capacité de ces cellules à former des sphères, démontrant ainsi un rôle essentiel de BORIS dans l'auto- renouvellement des tumeurs. Nos expériences montrent aussi que BORIS est un facteur important qui régule l'expression de gènes jouant un rôle clé dans le développement et la progression tumorale, tels le gène hTERT et ceux impliqués dans les cellules souches, les CSC et la transition épithélio-mésenchymateuse (EMT). BORIS pourrait affecter la régulation de la transcription de ces gènes par des modifications épigénétiques et de manière différente en fonction du type cellulaire. En résumé, nos résultats fournissent la preuve que BORIS peut être classé comme un gène marqueur de cellules souches cancéreuse et révèlent un nouveau mécanisme dans lequel BORIS jouerait un rôle important dans la carcinogénèse. Cette étude ouvre de nouvelles voies pour mieux comprendre la biologie de la progression tumorale et offre la possibilité de développement de nouvelles thérapies anti-tumorales et anti-CSC avec BORIS comme molécule cible. - Cancer is defined as the uncontrolled growth of cells in the body. It causes 20% of deaths in the European region. Current evidences suggest that tumors originate and are maintained thanks to a small subset of cells, named cancer stems cells (CSCs). These CSCs are also responsible for the appearance of metastasis and therapeutic resistance. Consequently, the identification of genes that contribute to the CSC properties (tumor survival, metastasis and therapeutic resistance) is necessary to better understand the biology of malignant diseases and to improve care management. To date, numerous markers have been proposed to use as new CSC- targeted therapies. Despite the enormous efforts in research, almost all of the known CSCs markers are also expressed in normal cells. This project aimed to find a new CSC-specific candidate. BORIS (Brother of Regulator of Imprinted Sites) or CTCFL (CTCF-like) is a DNA binding protein involves in epigenetic reprogramming in normal development and in tumorigenesis. Recent studies have shown an association of BORIS expression with a poor prognosis in different types of cancer patients. Therefore, BORIS seems to have the same characteristics of CSCs markers and it could be a promising target for cancer therapy. BORIS is normally expressed only in germinal cells and it is re-expressed in a wide variety of tumors. We developed a new molecular beacon-based technology to target BORIS mRNA expressing cells. Using this system, we showed that the BORIS expressing cells are only a small subpopulation (0.02-5%) of tumor cells. The isolated BORIS expressing cells exhibited the characteristics of CSCs, with high expression of hTERT and stem cell genes (NANOG, SOX2 and OCT4). Furthermore, high BORIS expression was observed in the CSC-enriched populations (side population and spheres). These results suggest that BORIS might be a novel and powerful CSCs marker. In functional studies, we observed that BORIS knockdown significantly impairs the capacity to form spheres in colon and breast cancer cells, thus demonstrating a critical role of BORIS in the self-renewal of tumors. The results showed in the functional analysis indicate that BORIS is an important factor that regulates the expression of key-target genes for tumor development and progression, such as hTERT, stem cells, CSCs markers and EMT (epithelial mesenchymal transition)-related marker genes. BORIS could affect the transcriptional regulation of these genes by epigenetic modification and in a cell type dependent manner. In summary, our results support the evidence that BORIS can be classified as a cancer stem cell marker gene and reveal a novel mechanism in which BORIS would play a critical role in tumorigenesis. This study opens new prospective to understand the biology of tumor development and provides opportunities for potential anti-tumor drugs.

Multiple target tracking using random sets

This paper presents several algorithms for joint estimation of the target number and state in a time-varying scenario. Building on the results presented in [1], which considers estimation of the target number only, we assume that not only the target number, but also their state evolution must be estimated. In this context, we extend to this new scenario the Rao-Blackwellization procedure of [1] to compute Bayes recursions, thus defining reduced-complexity solutions for the multi-target set estimator. A performance assessmentis finally given both in terms of Circular Position Error Probability - aimed at evaluating the accuracy of the estimated track - and in terms of Cardinality Error Probability, aimed at evaluating the reliability of the target number estimates.

Clinical consequences of imatinib plasma concentrations variability in hemato-oncologic patients

Background: Imatinib has revolutionized the treatment of chronic myeloid leukemia (CML) and gastrointestinal stromal tumors (GIST). Considering the large inter-individual differences in the function of the systems involved in its disposition, exposure to imatinib can be expected to vary widely among patients. This observational study aimed at describing imatinib pharmacokinetic variability and its relationship with various biological covariates, especially plasma alpha1-acid glycoprotein (AGP), and at exploring the concentration-response relationship in patients. Methods: A population pharmacokinetic model (NONMEM) including 321 plasma samples from 59 patients was built up and used to derive individual post-hoc Bayesian estimates of drug exposure (AUC; area under curve). Associations between AUC and therapeutic response or tolerability were explored by ordered logistic regression. Influence of the target genotype (i.e. KIT mutation profile) on response was also assessed in GIST patients. Results: A one-compartment model with first-order absorption appropriately described the data, with an average oral clearance of 14.3 L/h (CL) and volume of distribution of 347 L (Vd). A large inter-individual variability remained unexplained, both on CL (36%) and Vd (63%), but AGP levels proved to have a marked impact on total imatinib disposition. Moreover, both total and free AUC correlated with the occurrence and number of side effects (e.g. OR 2.9±0.6 for a 2-fold free AUC increase; p<0.001). Furthermore, in GIST patients, higher free AUC predicted a higher probability of therapeutic response (OR 1.9±0.5; p<0.05), notably in patients with tumor harboring an exon 9 mutation or wild-type KIT, known to decrease tumor sensitivity towards imatinib. Conclusion: The large pharmacokinetic variability, associated to the pharmacokinetic-pharmacodynamic relationship uncovered are arguments to further investigate the usefulness of individualizing imatinib prescription based on TDM. For this type of drug, it should ideally take into consideration either circulating AGP concentrations or free drug levels, as well as KIT genotype for GIST.

Mediate evaluation of replicating a Training Program in Nonverbal Communication in Gerontology

OBJECTIVE Replicating the training program in non-verbal communication based on the theoretical framework of interpersonal communication; non-verbal coding, valuing the aging aspects in the perspective of active aging, checking its current relevance through the content assimilation index after 90 days (mediate) of its application. METHOD A descriptive and exploratory field study was conducted in three hospitals under direct administration of the state of São Paulo that caters exclusively to Unified Health System (SUS) patients. The training lasted 12 hours divided in three meetings, applied to 102 health professionals. RESULTS Revealed very satisfactory and satisfactory mediate content assimilation index in 82.9%. CONCLUSION The program replication proved to be relevant and updated the setting of hospital services, while remaining efficient for healthcare professionals.