The role of interleukin-2 in memory CD8 cell differentiation.

The current literature on the role of interleukin (IL)-2 in memory CD8+ T-cell differentiation indicates a significant contribution of IL-2 during primary and also secondary expansion of CD8+ T cells. IL-2 seems to be responsible for optimal expansion and generation of effector functions following primary antigenic challenge. As the magnitude of T-cell expansion determines the numbers of memory CD8+ T cells surviving after pathogen elimination, these event influence memory cell generation. Moreover, during the contraction phase of an immune respons where most antigen-specific CD8+ T cells disappear by apoptosis, IL-2 signals are able to rescu CD8+ T cells from cell death and provide a durable increase in memory CD8+ T-cell counts. At the memory stage, CD8+ T-cell frequencies can be boosted by administration of exogenous IL-2 Significantly, only CD8+ T cells that have received IL-2 signals during initial priming are able t mediate efficient secondary expansion following renewed antigenic challenge. Thus, IL-2 signals during different phases of an immune response are key in optimizing CD8+ T-cell functions, thereby affecting both primary and secondary responses of these T cells.

Sex chromosomes and male functions: where do new genes go?

The position of a gene in the genome may have important consequences for its function. Therefore, when a new duplicate gene arises, its location may be critical in determining its fate. Our recent work in humans, mouse, and Drosophila provided a test by studying the patterns of duplication in sex chromosome evolution. We revealed a bias in the generation and recruitment of new gene copies involving the X chromosome that has been shaped largely by selection for male germline functions. The gene movement patterns we observed reflect an ongoing process as some of the new genes are very young while others were present before the divergence of humans and mouse. This suggests a continuing redistribution of male-related genes to achieve a more efficient allocation of male functions. This notion should be further tested in organisms employing other sex determination systems or in organisms differing in germline sex chromosome inactivation. It is likely that the selective forces that were detected in these studies are also acting on other types of duplicate genes. As a result, future work elucidating sex chromosome differentiation by other mutational mechanisms will shed light on this important process.

The role of gene duplication in the origin and evolution of new biological functions

Abstract : Gene duplication is an essential source of material for the origin of genetic novelty and the evolution of lineage- or species-specific phenotypic traits. The reverse transcription of source gene mRNA followed by the genomic insertion of the resulting cDNA - retroposition - has provided the human genome with a significant number of gene copies during the last ~63 million years (MYA) of primate evolution. We estimated that at least 1 new functional gene (retrogene) per MYA emerged by retroposition in the primate lineage leading to humans. Using a combination of comparative sequencing and evolutionary simulations, we obtained strong evidence of functionality for 7 primate specific retrogenes. Most of these genes are specifically expressed in testis suggesting that retroposition has contributed with genetic raw material necessary for the evolution ofmale-specific functions in primates. We characterized CDC14Bretro (identified in the previous survey) that originated from the retroposition of a cell cycle gene - CDC14B - in the common ancestor of humans and apes. We demonstrate that CDC14Bretro experienced a period of intense positive selection in the African ape ancestor. By virtue of the amino acid substitutions that occurred during this period CDC 14Bretro adapted to a new subcellular compartment in African apes. Further analyses indicate that this subcellular shift reflects the evolution of anew functional role of CDC 14Bretro. Prompted by this result, we used yeast (Saccharomyces cerevisiae) to investigate on a global scale the extent of functional diversification of duplicate genes through the subcellular adaptation of their encoded proteins. We found that duplicate proteins frequently evolved new cellular localization patterns, either by partitioning of ancestral localizations ("sublocalization"), or more frequently by relocalization to previously unoccupied compartments ("neolocalization"). Interestingly, proteins involved in processes with a wider subcellular distribution more frequently evolved new localization patterns suggesting that subcellular localization changes are dependent on progenitor gene functions. Relocated proteins adapted to their new subcellular environments and evolved new functional roles through changes of their physio-chemical properties, expression levels, and interaction partners. Our work suggests an important role of subcellular adaptation for the emergence of new gene functions.

Mapping Nursing language terms of Parkinson's disease

OBJECTIVE Implementing cross-mapping of Nursing language terms with the terminology of NANDA International, contained in records of patients with Parkinson's disease in rehabilitation. METHOD Descriptive study of cross mapping, carried out in three steps. A simple random sample of 67 files of patients who participated in the rehabilitation in the period between March 2009 and April 2013. RESULTS We identified 454 terms of Nursing language that resulted in 54 diagnoses after cross-mapping, present in 11 of the 13 taxonomy domains. The most mapped diagnosis was "Impaired urinary elimination" (59.7%), followed by "Urgent urinary incontinence" (55.2%), "Willingness to self-control improved health" (50.7%), "Constipation" (47.8%) and "Compromised physical mobility" (29.9%). Seven described terms were not mapped due to a corresponding defining characteristic being absent. CONCLUSION It was possible to determine the profile of patients, as well as the complexity of nursing care in the rehabilitation of patients with Parkinson's disease.

Regions of rationality: Maps for bounded agents

An important problem in descriptive and prescriptive research in decision making is to identify regions of rationality, i.e., the areas for which heuristics are and are not effective. To map the contours of such regions, we derive probabilities that heuristics identify the best of m alternatives (m > 2) characterized by k attributes or cues (k > 1). The heuristics include a single variable (lexicographic), variations of elimination-by-aspects, equal weighting, hybrids of the preceding, and models exploiting dominance. We use twenty simulated and four empirical datasets for illustration. We further provide an overview by regressing heuristic performance on factors characterizing environments. Overall, sensible heuristics generally yield similar choices in many environments. However, selection of the appropriate heuristic can be important in some regions (e.g., if there is low inter-correlation among attributes/cues). Since our work assumes a hit or miss decision criterion, we conclude by outlining extensions for exploring the effects of different loss functions.

Approximate knowledge of rationality and correlated equilibria

We extend Aumann's theorem [Aumann 1987], deriving correlated equilibria as a consequence of common priors and common knowledge of rationality, by explicitly allowing for non-rational behavior. Wereplace the assumption of common knowledge of rationality with a substantially weaker one, joint p-belief of rationality, where agents believe the other agents are rational with probability p or more. We show that behavior in this case constitutes a kind of correlated equilibrium satisfying certain p-belief constraints, and that it varies continuously in the parameters p and, for p sufficiently close to one,with high probability is supported on strategies that survive the iterated elimination of strictly dominated strategies. Finally, we extend the analysis to characterizing rational expectations of interimtypes, to games of incomplete information, as well as to the case of non-common priors.

Tabela de vida de fertilidade de Lysiphlebus testaceipes (Cresson, 1880) (Hymenoptera, Aphidiidae) em Schizaphis graminum (Rondani, 1852) (Hemipera, Aphididae)

Life table analyses have been developed to understanding the impact of various sources of intrinsic and extrinsic mortalities on the rate of population growth. The understanding of the population increase of the parasitoids related to their hosts is important in biological control programs. This work had as objective to evaluate the survival and fertility of the parasitoid Lysiphlebus testaceipes (Cresson, 1880) on Schizaphis graminum (Rondani, 1852) as a host under fertility life table. The experiment were carried out in a climatic chamber at 25 ± 1ºC, RH 60 ± 10% and 10h photophase. To determine the immature mortality, the development time and the sex ratio of the parasitoid, 12 females of the parasitoid (less than one day old) and 240 nymphs of S. graminum (3 days old) were used. To evaluate the longevity and fertility of L. testaceipes, 15 females (less than one day old) were used. Nymphs of S. graminum (3 days old) were offered for each parasitoid female daily, until the female died, being in the 1st day - 300 nymphs; 2nd day - 250 nymphs; 3rd day - 200 nymphs; 4th day - 150 and in the other days a number of 50 nymphs. L. testaceipes had an immature mortality of 22,2%, and a development time of males and females of 9.0 and 9.1 days, respectively. The females of L. testaceipes laid, in it first life day, 257.8 eggs, and they survived up until seven days. The net reproduction rate (Ro) and the intrinsic rate of increase (r m) were respectively, 301.9 and 0.513. The finite rate of increase (l) was 1.67 females per day, the mean length of a generation (T) was 11.13 days and the time to duplicate the population (TD) was 1.35 weeks. The parasitoid L. testaceipes have a high potential of population growth on S. graminum as a host under the analyzed conditions.

Analysis of CD4+ and CD8+ T cells by defined MHC-peptide complexes

MHC class II-peptide multimers are important tools for the detection, enumeration and isolation of antigen-specific CD4+ Τ cells. However, their erratic and often poor performance impeded their broad application and thus in-depth analysis of key aspects of antigen-specific CD4+ Τ cell responses. In the first part of this thesis we demonstrate that a major cause for poor MHC class II tetramer staining performance is incomplete peptide loading on MHC molecules. We observed that peptide binding affinity for "empty" MHC class II molecules poorly correlates with peptide loading efficacy. Addition of a His-tag or desthiobiotin (DTB) at the peptide N-terminus allowed us to isolate "immunopure" MHC class II-peptide monomers by affinity chromatography; this significantly, often dramatically, improved tetramer staining of antigen-specific CD4+ Τ cells. Insertion of a photosensitive amino acid between the tag and the peptide, permitted removal of the tag from "immunopure" MHC class II-peptide complex by UV irradiation, and hence elimination of its potential interference with TCR and/or MHC binding. Moreover, to improve loading of self and tumor antigen- derived peptides onto "empty" MHC II molecules, we first loaded these with a photocleavable variant of the influenza A hemagglutinin peptide HA306-318 and subsequently exchanged it with a poorly loading peptide (e.g. NY-ESO-1119-143) upon photolysis of the conditional ligand. Finally, we established a novel type of MHC class II multimers built on reversible chelate formation between 2xHis-tagged MHC molecules and a fluorescent nitrilotriacetic acid (NTA)-containing scaffold. Staining of antigen-specific CD4+ Τ cells with "NTAmers" is fully reversible and allows gentle cell sorting. In the second part of the thesis we investigated the role of the CD8α transmembrane domain (TMD) for CD8 coreceptor function. The sequence of the CD8α TMD, but not the CD8β TMD, is highly conserved and homodimerizes efficiently. We replaced the CD8α TMD with the one of the interleukin-2 receptor a chain (CD8αTac) and thus ablated CD8α TMD interactions. We observed that ΤΙ Τ cell hybridomas expressing CD8αTacβ exhibited severely impaired intracellular calcium flux, IL-2 responses and Kd/PbCS(ABA) P255A tetramer binding. By means of fluorescence resonance energy transfer experiments (FRET) we established that CD8αTacβ associated with TCR:CD3 considerably less efficiently than CD8αβ, both in the presence and the absence of Kd/PbCS(ABA) complexes. Moreover, we observed that CD8αTacβ partitioned substantially less in lipid rafts, and related to this, associated less efficiently with p56Lck (Lck), a Src kinase that plays key roles in TCR proximal signaling. Our results support the view that the CD8α TMD promotes the formation of CD8αβP-CD8αβ dimers on cell surfaces. Because these contain two CD8β chains and that CD8β, unlike CD8α, mediates association of CD8 with TCR:CD3 as well as with lipid rafts and hence with Lck, we propose that the CD8αTMD plays an important and hitherto unrecognized role for CD8 coreceptor function, namely by promoting CD8αβ dimer formation. We discuss what implications this might have on TCR oligomerization and TCR signaling. - Les multimères de complexes MHC classe II-peptide sont des outils importants pour la détection, le dénombrement et l'isolation des cellules Τ CD4+ spécifiques pour un antigène d'intérêt. Cependant, leur performance erratique et souvent inadéquate a empêché leur utilisation généralisée, limitant ainsi l'analyse des aspects clés des réponses des lymphocytes Τ CD4+. Dans la première partie de cette thèse, nous montrons que la cause principale de la faible efficacité des multimères de complexes MHC classe II-peptide est le chargement incomplet des molécules MHC par des peptides. Nous montrons également que l'affinité du peptide pour la molécule MHC classe II "vide" n'est pas nécessairement liée au degré du chargement. Grâce à l'introduction d'une étiquette d'histidines (His-tag) ou d'une molécule de desthiobiotine à l'extrémité N-terminale du peptide, des monomères MHC classe II- peptide dits "immunopures" ont pu être isolés par chromatographic d'affinité. Ceci a permis d'améliorer significativement et souvent de façon spectaculaire, le marquage des cellules Τ CD4+ spécifiques pour un antigène d'intérêt. L'insertion d'un acide aminé photosensible entre l'étiquette et le peptide a permis la suppression de l'étiquette du complexe MHC classe- Il peptide "immunopure" par irradiation aux UV, éliminant ainsi de potentielles interférences de liaison au TCR et/ou au MHC. De plus, afin d'améliorer le chargement des molécules MHC classe II "vides" avec des peptides dérivés d'auto-antigènes ou d'antigènes tumoraux, nous avons tout d'abord chargé les molécules MHC "vides" avec un analogue peptidique photoclivable issu du peptide HA306-318 de l'hémagglutinine de la grippe de type A, puis, sous condition de photolyse, nous l'avons échangé avec de peptides à chargement faible (p.ex. NY-ESO-1119-143). Finalement, nous avons construit un nouveau type de multimère réversible, appelé "NTAmère", basé sur la formation chélatante reversible entre les molécules MHC-peptide étiquettés par 2xHis et un support fluorescent contenant des acides nitrilotriacetiques (NTA). Le marquage des cellules Τ CD4+ spécifiques pour un antigène d'intérêt avec les "NTAmères" est pleinement réversible et permet également un tri cellulaire plus doux. Dans la deuxième partie de cette thèse nous avons étudié le rôle du domaine transmembranaire (TMD) du CD8α pour la fonction coréceptrice du CD8. La séquence du TMD du CD8α, mais pas celle du TMD du CD8β, est hautement conservée et permet une homodimérisation efficace. Nous avons remplacé le TMD du CD8α avec celui de la chaîne α du récepteur à l'IL-2 (CD8αTac), éliminant ainsi les interactions du TMD du CD8α. Nous avons montré que les cellules des hybridomes Τ T1 exprimant le CD8αTacβ présentaient une atteinte sévère du flux du calcium intracellulaire, des réponses d'IL-2 et de la liaison des tétramères Kd/PbCS(ABA) P255A. Grâce aux expériences de transfert d'énergie entre molécules fluorescentes (FRET), nous avons montré que l'association du CD8αTacβ avec le TCR:CD3 est considérablement moins efficace qu'avec le CD8αβ, et ceci aussi bien en présence qu'en absence de complexes Kd/PbCS(ABA). De plus, nous avons observé que le CD8αTacβ se distribuait beaucoup moins bien dans les radeaux lipidiques, engendrant ainsi, une association moins efficace avec p56Lck (Lck), une kinase de la famille Src qui joue un rôle clé dans la signalisation proximale du TCR. Nos résultats soutiennent l'hypothèse que le TMD du CD8αβ favorise la formation des dimères de CD8αβ à la surface des cellules. Parce que ces derniers contiennent deux chaînes CD8β et que CD8β, contrairement à CD8α, favorise l'association du CD8 au TCR:CD3 aussi bien qu'aux radeaux lipidiques et par conséquent à Lck, nous proposons que le TMD du CD8α joue un rôle important, jusqu'alors inconnu, pour la fonction coreceptrice du CD8, en encourageant la formation des dimères CD8αβ. Nous discutons des implications possibles sur l'oligomerisation du TCR et la signalisation du TCR.

Mise à jour sur l'hépatite E [An update on hepatitis E].

The hepatitis E virus (HEV) is an RNA virus transmitted via the fecal-oral route or through uncooked animal meat products. Of the 4 known genotypes, genotype 3 is responsible for autochthonous infections in industrialized countries, with a seroprevalence in Switzerland estimated as high as 22%. The majority of infections is asymptomatic but a minority of patients, notably men over 50 or with underlying liver disease, can present with severe acute hepatitis. Chronic hepatitis E with HEV of genotype 3 has been observed in immunosuppressed patients, mostly transplant recipients. Serology is not sufficiently sensitive, especially in immunosuppressed patients, making PCR identification the preferred test for diagnosing active infection. Ribavirin or interferon-alpha can be used to treat chronic hepatitis E if reduction of immunosuppressive treatment does not result in viral elimination.

ATP release due to Thy-1-integrin binding induces P2X7-mediated calcium entry required for focal adhesion formation.

Thy-1, an abundant mammalian glycoprotein, interacts with αvβ3 integrin and syndecan-4 in astrocytes and thus triggers signaling events that involve RhoA and its effector p160ROCK, thereby increasing astrocyte adhesion to the extracellular matrix. The signaling cascade includes calcium-dependent activation of protein kinase Cα upstream of Rho; however, what causes the intracellular calcium transients required to promote adhesion remains unclear. Purinergic P2X7 receptors are important for astrocyte function and form large non-selective cation pores upon binding to their ligand, ATP. Thus, we evaluated whether the intracellular calcium required for Thy-1-induced cell adhesion stems from influx mediated by ATP-activated P2X7 receptors. Results show that adhesion induced by the fusion protein Thy-1-Fc was preceded by both ATP release and sustained intracellular calcium elevation. Elimination of extracellular ATP with Apyrase, chelation of extracellular calcium with EGTA, or inhibition of P2X7 with oxidized ATP, all individually blocked intracellular calcium increase and Thy-1-stimulated adhesion. Moreover, Thy-1 mutated in the integrin-binding site did not trigger ATP release, and silencing of P2X7 with specific siRNA blocked Thy-1-induced adhesion. This study is the first to demonstrate a functional link between αvβ3 integrin and P2X7 receptors, and to reveal an important, hitherto unanticipated, role for P2X7 in calcium-dependent signaling required for Thy-1-stimulated astrocyte adhesion.

Simultaneous determination of antidementia drugs by HPLC-MS: validation data of the method and plasma level determinations in 300 patients

Aims: A rapid and simple HPLC-MS method was developed for the simultaneousdetermination of antidementia drugs, including donepezil, galantamine, rivastigmineand its major metabolite NAP 226 - 90, and memantine, for TherapeuticDrug Monitoring (TDM). In the elderly population treated with antidementiadrugs, the presence of several comorbidities, drug interactions resulting frompolypharmacy, and variations in drug metabolism and elimination, are possiblefactors leading to the observed high interindividual variability in plasma levels.Although evidence for the benefit of TDM for antidementia drugs still remains tobe demonstrated, an individually adapted dosage through TDM might contributeto minimize the risk of adverse reactions and to increase the probability of efficienttherapeutic response. Methods: A solid-phase extraction procedure with amixed-mode cation exchange sorbent was used to isolate the drugs from 0.5 mL ofplasma. The compounds were analyzed on a reverse-phase column with a gradientelution consisting of an ammonium acetate buffer at pH 9.3 and acetonitrile anddetected by mass spectrometry in the single ion monitoring mode. Isotope-labeledinternal standards were used for quantification where possible. The validatedmethod was used to measure the plasma levels of antidementia drugs in 300patients treated with these drugs. Results: The method was validated accordingto international standards of validation, including the assessment of the trueness(-8 - 11 %), the imprecision (repeatability: 1-5%, intermediate imprecision:2 - 9 %), selectivity and matrix effects variability (less than 6 %). Furthermore,short and long-term stability of the analytes in plasma was ascertained. Themethod proved to be robust in the calibrated ranges of 1 - 300 ng/mL for rivastigmineand memantine and 2 - 300 mg/mL for donepezil, galantamine and NAP226 - 90. We recently published a full description of the method (1). We found ahigh interindividual variability in plasma levels of these drugs in a study populationof 300 patients. The plasma level measurements, with some preliminaryclinical and pharmacogenetic results, will be presented. Conclusion: A simpleLC-MS method was developed for plasma level determination of antidementiadrugs which was successfully used in a clinical study with 300 patients.

Cumulative dominance and heuristic performance in binary multi-attribute choice

Several studies have reported high performance of simple decision heuristics multi-attribute decision making. In this paper, we focus on situations where attributes are binary and analyze the performance of Deterministic-Elimination-By-Aspects (DEBA) and similar decision heuristics. We consider non-increasing weights and two probabilistic models for the attribute values: one where attribute values are independent Bernoulli randomvariables; the other one where they are binary random variables with inter-attribute positive correlations. Using these models, we show that good performance of DEBA is explained by the presence of cumulative as opposed to simple dominance. We therefore introduce the concepts of cumulative dominance compliance and fully cumulative dominance compliance and show that DEBA satisfies those properties. We derive a lower bound with which cumulative dominance compliant heuristics will choose a best alternative and show that, even with many attributes, this is not small. We also derive an upper bound for the expected loss of fully cumulative compliance heuristics and show that this is moderateeven when the number of attributes is large. Both bounds are independent of the values ofthe weights.

Are tax subsidies for private medical insurance self-financing? Evidence from a microsimulation model for outpatient and inpatient episodes

This paper analyses whether or not tax subsidies to private medicalinsurance are self-financing by means of a structural approach. Weconstruct a simulation routine based on a microeconometric discretechoice model that allows us to evaluate the impact of premium changeson the utilisation of outpatient and inpatient health care services. Wesimulate the 1999 Spanish tax reform that abolished the tax deductionfor expenditures on private health insurance using a representativesample of the Catalan population. Prior to this reform, foregone taxrevenue arising from deductions after the purchase of private insuranceamounted to 69.2 M. per year. In contrast, the elimination of thesubsidies to private policies is estimated to generate an extra costfor the public sector of about 8.9 M. per year.

Causes développementales dans la variabilité de l'efficacité et de la toxicité des antalgiques en pédiatrie [Developmental causes in variability of efficacy and toxicity of analgesics in pediatrics]

The intensity of pain perception and its sensibility to analgesic drugs is highly variable and unpredictable between individuals. Drug disposition varies during development due to the physiological maturation of enzymatic systems and physiological processes responsible for the absorption, distribution, elimination and effect at the site of action. Many of those developmental variables are not yet clearly defined, but their consideration is important for avoiding potential risks of ineffective or toxic treatment. Implications of those developmental changes for day-to-day clinical practice depend on the age of the child, on the type of drug, on the underlying disease and on the potential co-administration of other chemicals.

Draft environmental report on Cape Verde

Faced with recurrent drought and famine during five centuries of human occupation, the small and densely populated Cape Verde Islands have a history of severe environmental problems. The arid climate and steep, rocky terrain provide scant resources for traditional subsistance farming under the best conditions, and in years of low rainfall the failure of rainfed crops causes massive food shortages. Agricultural use of steep slopes where rainfall is highest has led to soil erosion, as has removal of the island's vegetation for fuel and livestock. Pressure on the vegetation is particularly severe in dry years. International aid can provide relief from famine, and the introduction of modern agricultural and conservation techniques can improve the land and increase yield, but it is unlikely that Cape Verde can ever be entirely self -sufficient in food. Ultimately, the solution of Cape Verde's economic and environmental problems will probably require the development of productive urban jobs so the population can shift away from the intensive and destructive use of land for subsistance farming. In the meantime, the people of Cape Verde can best be served by instituting fundamental measures to conserve and restore the land so that it can be used to its fullest potential. The primary environmental problems in Cape Verde today are: 1. Soil degradation. Encouraged by brief but heavy rains and steep slopes, soil erosion is made worse by lack of vegetation. Soils are also low in organic matter due to the practice of completely removing crop plants and natural vegetation for food, fuel or livestock feed. 2. Water shortage. Brief and erratic rainfall in combination with rapid runoff makes surface water scarce and difficult to use. Groundwater supplies can be better developed but capabilities are poorly known and the complex nature of the geological substrate makes estimation difficult. Water is the critical limiting factor to the agricultural capability of the islands. 3. Fuel shortage. Demand for fuel is intense and has resulted in the virtual elimination of native vegetation. Fuelwood supplies are becoming more and more scarce and costly. Development of managed fuelwood plantations and alternate energy sources is required. 4. Inappropriate land use. Much of the land now used for raising crops or livestock is too steep or too arid for these purposes, causing erosion and destruction of vegetation. Improving yield in more appropriate areas and encouraging less damaging uses of the remaining marginal lands can help to alleviate this problem.