Factors associated with latent tuberculosis among asylum seekers in Switzerland: a cross-sectional study in Vaud County.

BACKGROUND: Screening and treatment of latent tuberculosis infection (LTBI) in asylum seekers (AS) may prevent future cases of tuberculosis. As the screening with Interferon Gamma Release Assay (IGRA) is costly, the objective of this study was to assess which factors were associated with LTBI and to define a score allowing the selection of AS with the highest risk of LTBI. METHODS: In across-sectional study, AS seekers recently arrived in Vaud County, after screening for tuberculosis at the border were offered screening for LTBI with T-SPOT.TB and questionnaire on potentially risk factors. The factors associated with LTBI were analyzed by univariate and multivariate regression. RESULTS: Among 393 adult AS, 98 (24.93%) had a positive IGRA response, five of them with active tuberculosis previously undetected. Six factors associated with LTBI were identified in multivariate analysis: origin, travel conditions, marital status, cough, age and prior TB exposure. Their combination leads to a robust LTBI predictive score. CONCLUSIONS: The prevalence of LTBI and active tuberculosis in AS is high. A predictive score integrating six factors could identify the asylum seekers with the highest risk for LTBI.

Association of the Epstein-Barr virus latent membrane protein 1 with lipid rafts is mediated through its N-terminal region.

The latent membrane protein 1 (LMP1) encoded by the Epstein-Barr virus acts like a constitutively activated receptor of the tumor necrosis factor receptor (TNFR) family and is enriched in lipid rafts. We showed that LMP1 is targeted to lipid rafts in transfected HEK 293 cells, and that the endogenous TNFR-associated factor 3 binds LMP1 and is recruited to lipid rafts upon LMP1 expression. An LMP1 mutant lacking the C-terminal 55 amino acids (Cdelta55) behaves like the wild-type (WT) LMP1 with respect to membrane localization. In contrast, a mutant with a deletion of the 25 N-terminal residues (Ndelta25) does not concentrate in lipid rafts but still binds TRAF3, demonstrating that cell localization of LMP1 was not crucial for TRAF3 localization. Moreover, Ndelta25 inhibited WT LMP1-mediated induction of the transcription factors NF-kappaB and AP-1. Morphological data indicate that Ndelta25 hampers WT LMP1 plasma membrane localization, thus blocking LMP1 function.

Impact of clinical practice guidelines on priorisation for intensive care beds allocation in high-risk acute coronary syndrome patients: does age play a role?

QUESTION UNDER STUDY: To assess which high-risk acute coronary syndrome (ACS) patient characteristics played a role in prioritising access to intensive care unit (ICU), and whether introducing clinical practice guidelines (CPG) explicitly stating ICU admission criteria altered this practice. PATIENTS AND METHODS: All consecutive patients with ACS admitted to our medical emergency centre over 3 months before and after CPG implementation were prospectively assessed. The impact of demographic and clinical characteristics (age, gender, cardiovascular risk factors, and clinical parameters upon admission) on ICU hospitalisation of high-risk patients (defined as retrosternal pain of prolonged duration with ECG changes and/or positive troponin blood level) was studied by logistic regression. RESULTS: Before and after CPG implementation, 328 and 364 patients, respectively, were assessed for suspicion of ACS. Before CPG implementation, 36 of the 81 high-risk patients (44.4%) were admitted to ICU. After CPG implementation, 35 of the 90 high-risk patients (38.9%) were admitted to ICU. Male patients were more frequently admitted to ICU before CPG implementation (OR=7.45, 95% CI 2.10-26.44), but not after (OR=0.73, 95% CI 0.20-2.66). Age played a significant role in both periods (OR=1.57, 95% CI 1.24-1.99), both young and advanced ages significantly reducing ICU admission, but to a lesser extent after CPG implementation. CONCLUSION: Prioritisation of access to ICU for high-risk ACS patients was age-dependent, but focused on the cardiovascular risk factor profile. CPG implementation explicitly stating ICU admission criteria decreased discrimination against women, but other factors are likely to play a role in bed allocation.

Differential allocation and deployment of direct and indirect defences by Vicia sepium along elevation gradients

Dissecting drivers of plant defence investment remains central for understanding the assemblage of communities across different habitats. There is increasing evidence that direct defence strategies against herbivores, including secondary metabolites production, differ along ecological gradients in response to variation in biotic and abiotic conditions. In contrast, intraspecific variation in indirect defences remains unexplored. Here, we investigated variation in herbivory rate, resistance to herbivores, and indirect defences in ant-attracting Vicia species along the elevation gradient of the Alps. Specifically, we compared volatile organic compounds (VOCs) and ant attraction in high and low elevation ecotypes. Consistent with adaptation to the lower herbivory conditions that we detected at higher elevations in the field, high elevation plants were visited by fewer ants and were more susceptible to herbivore attack. In parallel, constitutive volatile organic compound production and subsequent ant attraction were lower in the high elevation ecotypes. We observed an elevation-driven trade-off between constitutive and inducible production of VOCs and ant attraction along the environmental cline. At higher elevations, inducible defences increased, while constitutive defence decreased, suggesting that the high elevation ecotypes compensate for lower indirect constitutive defences only after herbivore attack. Synthesis. Overall, direct and indirect defences of plants vary along elevation gradients. Our findings show that plant allocation to defences are subject to trade-offs depending on local conditions, and point to a feedback mechanism linking local herbivore pressure, predator abundance and the defence investment of plants.

CHARACTERIZATION OF EPSTEIN-BARR VIRUS-ENCODED LATENT MEMBRANE PROTEIN 1

Le virus d'Epstein-Barr (EBV), un virus de la famille des gammaherpesvirus, infecte plus de 95% de la population adulte mondiale. EBV est associé à plusieurs types de cancers dont le lymphome de Hodgkin, le lymphome de Burkitt et le carcinome nasopharyngé. La protéine membranaire de latence 1 (LMP1), l'oncogène principal d'EBV, est une protéine membranaire intégrale composée d'une petite extrémité N-terminale cytoplasmique, six segments transmembranaires (TMs) lié par de petites boucles et un long domaine C-terminale cytoplasmique. Le gène de LMP1, BNLF-1, est très polymorphe et plusieurs variants de la protéine LMP1 ont été décrits. Parmi les variants de LMP1 la majeure différence décrite est leur capacité à activer le facteur de transcription NF-κB. Nous avons défini des polymorphismes permettant aux variants d'avoir une activation accrue de NF-κB comparé au prototype B95-8 LMP1. Tous les polymorphismes cruciaux identifiés dans notre étude se trouvent dans les TMs 4 et 5 de LMP1. Nous avons étudié l'implication de chaque paire de TMs dans l'association à la membrane, l'auto-agrégation, la liaison aux partenaires cellulaires de LMP1 TRAF3 et β-TrCP, ainsi que pour NF-κB. De plus, nous avons décrit un nouveau rôle pour LMP1 consistant à inhiber l'activation contrôlée par MAVS de ISRE et du promoteur d'IFNβ. En résumé, nous avons observé que les différentes paires de TMs, ainsi que les deux boucles intracellulaires, ne sont pas équivalents. Dans l'ensemble, notre étude a montré que les TMs jouent un rôle clé dans les interactions protéine-protéine et la signalisation et qu'ils peuvent être considérés comme des régulateurs essentiels des activités de LMP1.

Comparison of quantiferon-TB gold with tuberculin skin test for detecting latent tuberculosis infection prior to liver transplantation.

Screening for latent tuberculosis infection (LTBI) is recommended prior to organ transplantation. The Quantiferon-TB Gold assay (QFT-G) may be more accurate than the tuberculin skin test (TST) in the detection of LTBI. We prospectively compared the results of QFT-G to TST in patients with chronic liver disease awaiting transplantation. Patients were screened for LTBI with both the QFT-G test and a TST. Concordance between test results and predictors of a discordant result were determined. Of the 153 evaluable patients, 37 (24.2%) had a positive TST and 34 (22.2%) had a positive QFT-G. Overall agreement between tests was 85.1% (kappa= 0.60, p < 0.0001). Discordant test results were seen in 12 TST positive/QFT-G negative patients and in 9 TST negative/QFT-G positive patients. Prior BCG vaccination was not associated with discordant test results. Twelve patients (7.8%), all with a negative TST, had an indeterminate result of the QFT-G and this was more likely in patients with a low lymphocyte count (p = 0.01) and a high MELD score (p = 0.001). In patients awaiting liver transplantation, both the TST and QFT-G were comparable for the diagnosis of LTBI with reasonable concordance between tests. Indeterminate QFT-G result was more likely in those with more advanced liver disease.

Plasticity in sex allocation in the plant Mercurialis annua is greater for hermaphrodites sampled from dimorphic than from monomorphic populations.

Plants are notoriously variable in gender, ranging in sex allocation from purely male through hermaphrodite to purely female. This variation can have both a genetic and an adaptive plastic component. In gynodioecious species, where females co-occur with hermaphrodites, hermaphrodites tend to shift their allocation towards greater maleness when growing under low-resource conditions, either as a result of hermaphrodites shifting away from an expensive female function, or because of enhanced siring advantages in the presence of females. Similarly, in the androdioecious plant Mercurialis annua, where hermaphrodites co-exist with males, hermaphrodites also tend to enhance their relative male allocation under low-resource conditions. Here, we ask whether this response differs between hermaphrodites that have been evolving in the presence of males, in a situation analogous to that supposed for gynodioecious populations, vs. those that have been evolving in their absence. We grew hermaphrodites of M. annua from populations in which males were either present or absent under different levels of nutrient availability and compared their reaction norms. We found that, overall, hermaphrodites from populations with males tended to be more female than those from populations lacking males. Importantly, hermaphrodites' investment in pollen and seed production was more plastic when they came from populations with males than without them, reducing their pollen production at low resource availability and increasing their seed production at high resource availability. These results are consistent with the hypothesis that plasticity in sex allocation is enhanced in hermaphrodites that have likely been exposed to variation in mating opportunities due to fluctuations in the frequency of co-occurring males.

Infection latente a M. tuberculosis, mise a jour 2011 [Latent M. tuberculosis infection, update 2011].

It is estimated that one third of the world population is latently infected by Mycobacterium tuberculosis and thus at risk of reactivation. Latent tuberculosis (TB) impact in Switzerland is often overlooked. Diagnosis and prophylaxis are insufficiently undertaken, especially for people at higher risk of reactivation due to immunosuppression. Interferon-gamma release assays replace tuberculosis skin tests for diagnosis of latent infection in adults. It is still recommended to treat prophylactically a case of latent TB infection with 9 months of isoniazid; however therapy with rifampicin for 4 months, currently an alternative option, is linked to improved adherence and favorable cost-benefit ratio.

Testing kin selection with sex allocation data in eusocial hymenoptera

Sex allocation data in eusocial Hymenoptera (ants, bees and wasps) provide an excellent opportunity to assess the effectiveness of kin selection, because queens and workers differ in their relatedness to females and males. The first studies on sex allocation in eusocial Hymenoptera compared population sex investment ratios across species. Female-biased investment in monogyne (= with single-queen colonies) populations of ants suggested that workers manipulate sex allocation according to their higher relatedness to females than males (relatedness asymmetry). However, several factors may confound these comparisons across species. First, variation in relatedness asymmetry is typically associated with major changes in breeding system and life history that may also affect sex allocation. Secondly, the relative cost of females and males is difficult to estimate across sexually dimorphic taxa, such as ants. Thirdly, each species in the comparison may not represent an independent data point, because of phylogenetic relationships among species. Recently, stronger evidence that workers control sex allocation has been provided by intraspecific studies of sex ratio variation across colonies. In several species of eusocial Hymenoptera, colonies with high relatedness asymmetry produced mostly females, in contrast to colonies with low relatedness asymmetry which produced mostly males. Additional signs of worker control were found by investigating proximate mechanisms of sex ratio manipulation in ants and wasps. However, worker control is not always effective, and further manipulative experiments will be needed to disentangle the multiple evolutionary factors and processes affecting sex allocation in eusocial Hymenoptera.

Sex-related and non-sex-related comorbidity subtypes of tic disorders: a latent class approach.

BACKGROUND AND PURPOSE: Recent evidence suggests that there may be more than one Gilles de la Tourette syndrome (GTS)/tic disorder phenotype. However, little is known about the common patterns of these GTS/tic disorder-related comorbidities. In addition, sex-specific phenomenological data of GTS/tic disorder-affected adults are rare. Therefore, this community-based study used latent class analyses (LCA) to investigate sex-related and non-sex-related subtypes of GTS/tic disorders and their most common comorbidities. METHODS: The data were drawn from the PsyCoLaus study (n = 3691), a population-based survey conducted in Lausanne, Switzerland. LCA were performed on the data of 80 subjects manifesting motor/vocal tics during their childhood/adolescence. Comorbid attention-deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder, depressive, phobia and panic symptoms/syndromes comprised the selected indicators. The resultant classes were characterized by psychosocial correlates. RESULTS: In LCA, four latent classes provided the best fit to the data. We identified two male-related classes. The first class exhibited both ADHD and depression. The second class comprised males with only depression. Class three was a female-related class depicting obsessive thoughts/compulsive acts, phobias and panic attacks. This class manifested high psychosocial impairment. Class four had a balanced sex proportion and comorbid symptoms/syndromes such as phobias and panic attacks. The complementary occurrence of comorbid obsessive thoughts/compulsive acts and ADHD impulsivity was remarkable. CONCLUSIONS: To the best of our knowledge, this is the first study applying LCA to community data of GTS symptoms/tic disorder-affected persons. Our findings support the utility of differentiating GTS/tic disorder subphenotypes on the basis of comorbid syndromes.