Deciphering the principles that govern mutually exclusive expression of Plasmodium falciparum clag3 genes

The product of the Plasmodium falciparum genes clag3.1 and clag3.2 plays a fundamental role in malaria parasite biology by determining solute transport into infected erythrocytes. Expression of the two clag3 genes is mutually exclusive, such that a single parasite expresses only one of the two genes at a time. Here we investigated the properties and mechanisms of clag3 mutual exclusion using transgenic parasite lines with extra copies of clag3 promoters located either in stable episomes or integrated in the parasite genome. We found that the additional clag3 promoters in these transgenic lines are silenced by default, but under strong selective pressure parasites with more than one clag3 promoter simultaneously active are observed, demonstrating that clag3 mutual exclusion is strongly favored but it is not strict. We show that silencing of clag3 genes is associated with the repressive histone mark H3K9me3 even in parasites with unusual clag3 expression patterns, and we provide direct evidence for heterochromatin spreading in P. falciparum. We also found that expression of a neighbor ncRNA correlates with clag3.1 expression. Altogether, our results reveal a scenario where fitness costs and non-deterministic molecular processes that favor mutual exclusion shape the expression patterns of this important gene family

Goal Preferences, Affect, Activity Patterns and Health Outcomes in Women With Fibromyalgia

Some motivational models understand health behavior as a result of the interaction between goal preferences and mood. However, this perspective has not been explored in fibromyalgia. Furthermore, in chronic pain, it has only been explored with regard to negative affect. Thus, our aims were: (1) to develop a Spanish version of the Goal Pursuit Questionnaire (GPQ); (2) to explore the relationships between goal preferences and health outcomes, testing the moderator role of affect and the mediating role of chronic pain activity patterns. We conducted two cross-sectional studies. In Study 1, after a double translation/back-translation process, we interviewed 94 women attending the Fibromyalgia Unit of the Community of Valencia in order to identify the cultural feasibility and the content validity of the GPQ. Study 2 comprised 260 women. We explored the GPQ structure and performed path analyses to test conditional mediation relationships. Eight activities from the original GPQ were changed while maintaining the conceptual equivalence. Exploratory factor analysis showed two factors: ‘Painavoidance goal’ and ‘Mood-management goal’ (37 and 13% of explained variance, respectively). These factors refer to patients’ preference for hedonic goals (pain avoidance or mood-management) over achievement goals. Robust RMSEA fit index of the final models ranged from 0.039 for pain to 0.000 for disability and fibromyalgia impact. Pain avoidance goals and negative affect influenced pain mediated by taskcontingent persistence. They also affected disability mediated by task and excessive persistence. Pain avoidance goals and positive affect influenced fibromyalgia impact mediated by activity avoidance. We also found a direct effect of negative and positive affect on health outcomes. Preference for pain avoidance goals was always related to pain, disability and fibromyalgia impact through activity patterns. Affect did not moderate these relationships and showed direct and indirect paths on health outcomes, mainly by increasing persistence and showing positive affect as an asset and not a risk factor. Intervention targets should include flexible reinforcement of achievement goals relative to pain avoidance goals and positive affect in order to promote task-persistence adaptive activity patterns and decreased activity avoidance

Predicting Abusive Behaviours in Spanish Adolescents’ Relationships: Insights from the Reasoned Action Approach

(1) Background: Partner violence prevention programmes do not produce the expected behavioural changes. Accordingly, experts suggest applying evidence-based behavioural models to identify the determinants of abusive behaviours. In this research, we applied the reasoned action approach (RAA) to predict the performance (boys) and acceptance (girls) of abusive behaviours in adolescents. (2) Method: We designed a questionnaire based on the RAA and performed a crosssectional study. We analysed the predictive capacity of the RAA constructs on intentions with the sample of single adolescents (n = 1112). We replicated the analysis only with those who were in a relationship (n = 587) and in addition analysed the predictive capacity of intention on future behaviour (3 months later). (3) Results: The hierarchical regression analysis performed with the sample of single adolescents showed that the model explained 56% and 47% of the variance of boys’ intentions to perform the controlling and devaluing behaviours, respectively; and 62% and 33% of girls’ intention to accept them. With those in a relationship, the model explained 60% and 53% of the variance of boys’ intentions to perform the controlling and devaluating behaviour, respectively, and 70% and 38% of girls’ intention to accept them. Intention exerted direct effects on boys’ performance of controlling and devaluing behaviours (31% and 34% of explained variance, respectively) and on girls’ acceptance (30% and 7%, respectively). (4) Conclusions: The RAA seems useful to identify the motivational determinants of abusive behaviours, regardless of adolescents´ relationship status, and for their prediction. Perceived social norms emerge as a relevant predictor on which to intervene to produce behavioural changes with both sexe

Promoting unsupervised walking in women with fibromyalgia: a randomized controlled trial

The objective of this study is to test the efficacy of a group motiva-tional plus implementation intentions intervention in promoting adherence to an unsupervised walking program recommended for fibromyalgia, compared to an implementation intentions condition and to an active control condition. A triple-blind, randomized, long-itudinal study with measures at baseline, short (seven weeks post- intervention), mid (12 weeks) and long-term (36 weeks) is performed. Data are analyzed using multilevel longitudinal growth curve two- level modelling. Participants are 157 women with fibromyalgia. In the short-term, adherence to the minimum and to the standard walking program (primary outcome measures) is explained by time (both p <.001), motivational plus implementation intentions intervention (both p <.001) and by their interaction (both p <.001). Regarding the secondary outcomes, only physical function is explained by time (p <.001), motivational plus implementation intentions intervention (p <.05) and by their interaction (p <.05). Motivational plus imple-mentation intentions intervention achieve the promotion of walking as an exercise in the short-term; furthermore, physical function of the women in this condition is better than in the other two intervention groups, which is a relevant outcome from a rehabilitation point of view. However, more studies are needed to maintain the exercise at mid and long-term

Interpretable surface-based detection of focal cortical dysplasias:a Multi-centre Epilepsy Lesion Detection study

One outstanding challenge for machine learning in diagnostic biomedical imaging is algorithm interpretability. A key application is the identification of subtle epileptogenic focal cortical dysplasias (FCDs) from structural MRI. FCDs are difficult to visualize on structural MRI but are often amenable to surgical resection. We aimed to develop an open-source, interpretable, surface-based machine-learning algorithm to automatically identify FCDs on heterogeneous structural MRI data from epilepsy surgery centres worldwide. The Multi-centre Epilepsy Lesion Detection (MELD) Project collated and harmonized a retrospective MRI cohort of 1015 participants, 618 patients with focal FCD-related epilepsy and 397 controls, from 22 epilepsy centres worldwide. We created a neural network for FCD detection based on 33 surface-based features. The network was trained and cross-validated on 50% of the total cohort and tested on the remaining 50% as well as on 2 independent test sites. Multidimensional feature analysis and integrated gradient saliencies were used to interrogate network performance. Our pipeline outputs individual patient reports, which identify the location of predicted lesions, alongside their imaging features and relative saliency to the classifier. On a restricted 'gold-standard' subcohort of seizure-free patients with FCD type IIB who had T1 and fluid-attenuated inversion recovery MRI data, the MELD FCD surface-based algorithm had a sensitivity of 85%. Across the entire withheld test cohort the sensitivity was 59% and specificity was 54%. After including a border zone around lesions, to account for uncertainty around the borders of manually delineated lesion masks, the sensitivity was 67%. This multicentre, multinational study with open access protocols and code has developed a robust and interpretable machine-learning algorithm for automated detection of focal cortical dysplasias, giving physicians greater confidence in the identification of subtle MRI lesions in individuals with epilepsy

Ahora / Ara

La cinquena edició del microrelatari per l’eradicació de la violència contra les dones de l’Institut Universitari d’Estudis Feministes i de Gènere «Purificación Escribano» de la Universitat Jaume I vol ser una declaració d’esperança. Aquest és el moment en el qual les dones (i els homes) hem de fer un pas endavant i eliminar la violència sistèmica contra les dones. Ara és el moment de denunciar el masclisme i els micromasclismes començant a construir una societat més igualitària. Cadascun dels relats del llibre és una denúncia i una declaració que ens encamina cap a un món millor

A new mechanism of antimalarial drug resistance regulated at the epigenetic level

[eng] Malaria is responsible of almost half a million deaths every year. Currently, campaigns for the control and elimination of malaria are implemented in malaria endemic areas. However, drug resistance is one of the major impediments to achieve malaria elimination. In this thesis we have investigated how P. falciparum parasites develop resistance to some toxic compounds by functional variation linked to epigenetic regulation of clag3 genes. These genes present clonally variant expression and determine the formation of the main channel for the transport of solutes at the membrane of the infected RBC: Plasmodium Surface Anion Channel (PSAC). Hence, we hypothesized that P. falciparum parasites can modify the permeability of the membrane to specific solutes by epigenetic regulation of clag3 genes expression; this way, parasites could develop resistance to antimalarial drugs. To test this hypothesis, we have investigated the role of switches in clag3 expression in the acquisition of resistance to the antibiotic BS, the dynamics of clag3 genes expression in human infections and we have tested drugs susceptible to failure by this drug resistance mechanism. First, we show that BS pressure at low concentrations selected for parasites expressing clag3.1, whereas parasites exposed to higher concentrations of BS had repressed the expression of both clag3 genes. We did not find any mutation in the genome of these parasites that could explain the change in their phenotype. Thus, we concluded that parasites can develop resistance to toxic compounds through epigenetic regulation of clag3 genes. Then, we found that parasites collected from patients with uncomplicated malaria predominantly express one of the two paralogues, consistent with the property of mutually exclusive expression, previously described in lab-adapted parasite lines. Adaptation to culture conditions or selection with toxic compound results in isolate-dependent changes in clag3 expression, implying functional differences between the proteins encoded. We also observed that samples collected at day 9 post-infection in human experimental infections (when parasites had been in the peripheral blood for approximately one erythrocytic cycle) showed a mix of parasites expressing either clag3.1 or clag3.2, suggesting that the epigenetic memory of clag3 genes is reset during transmission stages. Finally, we tested whether other drugs, that are suspected to require facilitated transport to reach the cell, could be susceptible of failure by this drug resistance mechanism. We found that the antimalarial compounds T3 and T16 (bis-thiazolium salts) require the product of clag3 genes to enter the infected erythrocyte and that P. falciparum populations can develop resistance to these compounds by selection of parasites with dramatically reduced expression of both genes. The rest of the drugs that we tested might use alternative routes in which clag3 genes are not involved. We have described for the first time an antimalarial drug resistance mechanism regulated at the epigenetic level in P. falciparum parasites. This phenomenon may be of relevance for parasite adaptation to the presence of toxic compounds in human blood, selecting rapidly those parasites that present the less permeable phenotype and developing drug resistance in a single infection.[spa] Actualmente, la resistencia a los medicamentos antimaláricos es uno de los principales impedimentos para lograr la eliminación de la malaria. En esta tesis hemos investigado cómo los parásitos de P. falciparum desarrollan resistencia a algunos compuestos tóxicos por variación funcional relacionada con la regulación epigenética de los genes clag3 (clag3.1 y clag3.2), los cuales presentan expresión clonal variante y mutuamente exclusiva (en condiciones normales sólo uno de los dos genes está en estado activo). clag3 determinan la formación del canal principal para el transporte de solutos a través de la membrana del eritrocito infectado: PSAC. En este trabajo, primero observamos que la aplicación de bajas concentraciones del antibiótico blasticidina en cultivos de P. falciparum resultó en la selección de parásitos que expresan clag3.1, mostrando una IC50 a este compuesto más elevada que aquellas líneas que expresan clag3.2. Por otro lado, parásitos expuestos a concentraciones más altas de blasticidina reprimieron la expresión de ambos clag3 y mostraron altos niveles de resistencia al fármaco. No encontramos ninguna mutación en el genoma de estos parásitos que explicase el cambio de fenotipo, sugiriendo que se trata de un mecanismo regulado a nivel epigenético. El estudio de clag3 en parásitos recolectados de pacientes con malaria no complicada mostró que P. falciparum en infecciones naturales expresa predominantemente uno de los dos parálogos: clag3.2, indicando que este patrón de expresión confiere una ventaja fenotípica en sangre humana. Por otro lado, el análisis de muestras recogidas de infecciones humanas experimentales determinó que la memoria epigenética de los genes clag3 se restablece durante las etapas de transmisión, seleccionándose en pocos ciclos aquellos parásitos que presentan el patrón de expresión más favorable en sangre humana: clag3.2. Finalmente, probamos si otros fármacos que requieren transporte facilitado para llegar a la célula podrían ser susceptibles de fracaso terapéutico a través de este mecanismo de resistencia. Hayamos que los compuestos antipalúdicos T3 y T16 (sales de bis-tiazolio) requieren el producto de los genes clag3 para ingresar en el eritrocito infectado y que poblaciones de P. falciparum puedan desarrollar resistencia a estos compuestos mediante la selección de parásitos con expresión reducida de ambos genes

A new mechanism of antimalarial drug resistance regulated at the epigenetic level

Malaria is responsible of almost half a million deaths every year. Currently, campaigns for the control and elimination of malaria are implemented in malaria endemic areas. However, drug resistance is one of the major impediments to achieve malaria elimination. In this thesis we have investigated how P. falciparum parasites develop resistance to some toxic compounds by functional variation linked to epigenetic regulation of clag3 genes. These genes present clonally variant expression and determine the formation of the main channel for the transport of solutes at the membrane of the infected RBC: Plasmodium Surface Anion Channel (PSAC). Hence, we hypothesized that P. falciparum parasites can modify the permeability of the membrane to specific solutes by epigenetic regulation of clag3 genes expression; this way, parasites could develop resistance to antimalarial drugs. To test this hypothesis, we have investigated the role of switches in clag3 expression in the acquisition of resistance to the antibiotic BS, the dynamics of clag3 genes expression in human infections and we have tested drugs susceptible to failure by this drug resistance mechanism. First, we show that BS pressure at low concentrations selected for parasites expressing clag3.1, whereas parasites exposed to higher concentrations of BS had repressed the expression of both clag3 genes. We did not find any mutation in the genome of these parasites that could explain the change in their phenotype. Thus, we concluded that parasites can develop resistance to toxic compounds through epigenetic regulation of clag3 genes. Then, we found that parasites collected from patients with uncomplicated malaria predominantly express one of the two paralogues, consistent with the property of mutually exclusive expression, previously described in lab-adapted parasite lines. Adaptation to culture conditions or selection with toxic compound results in isolate-dependent changes in clag3 expression, implying functional differences between the proteins encoded. We also observed that samples collected at day 9 post-infection in human experimental infections (when parasites had been in the peripheral blood for approximately one erythrocytic cycle) showed a mix of parasites expressing either clag3.1 or clag3.2, suggesting that the epigenetic memory of clag3 genes is reset during transmission stages. Finally, we tested whether other drugs, that are suspected to require facilitated transport to reach the cell, could be susceptible of failure by this drug resistance mechanism. We found that the antimalarial compounds T3 and T16 (bis-thiazolium salts) require the product of clag3 genes to enter the infected erythrocyte and that P. falciparum populations can develop resistance to these compounds by selection of parasites with dramatically reduced expression of both genes. The rest of the drugs that we tested might use alternative routes in which clag3 genes are not involved. We have described for the first time an antimalarial drug resistance mechanism regulated at the epigenetic level in P. falciparum parasites. This phenomenon may be of relevance for parasite adaptation to the presence of toxic compounds in human blood, selecting rapidly those parasites that present the less permeable phenotype and developing drug resistance in a single infection.Actualmente, la resistencia a los medicamentos antimaláricos es uno de los principales impedimentos para lograr la eliminación de la malaria. En esta tesis hemos investigado cómo los parásitos de P. falciparum desarrollan resistencia a algunos compuestos tóxicos por variación funcional relacionada con la regulación epigenética de los genes clag3 (clag3.1 y clag3.2), los cuales presentan expresión clonal variante y mutuamente exclusiva (en condiciones normales sólo uno de los dos genes está en estado activo). clag3 determinan la formación del canal principal para el transporte de solutos a través de la membrana del eritrocito infectado: PSAC. En este trabajo, primero observamos que la aplicación de bajas concentraciones del antibiótico blasticidina en cultivos de P. falciparum resultó en la selección de parásitos que expresan clag3.1, mostrando una IC50 a este compuesto más elevada que aquellas líneas que expresan clag3.2. Por otro lado, parásitos expuestos a concentraciones más altas de blasticidina reprimieron la expresión de ambos clag3 y mostraron altos niveles de resistencia al fármaco. No encontramos ninguna mutación en el genoma de estos parásitos que explicase el cambio de fenotipo, sugiriendo que se trata de un mecanismo regulado a nivel epigenético. El estudio de clag3 en parásitos recolectados de pacientes con malaria no complicada mostró que P. falciparum en infecciones naturales expresa predominantemente uno de los dos parálogos: clag3.2, indicando que este patrón de expresión confiere una ventaja fenotípica en sangre humana. Por otro lado, el análisis de muestras recogidas de infecciones humanas experimentales determinó que la memoria epigenética de los genes clag3 se restablece durante las etapas de transmisión, seleccionándose en pocos ciclos aquellos parásitos que presentan el patrón de expresión más favorable en sangre humana: clag3.2. Finalmente, probamos si otros fármacos que requieren transporte facilitado para llegar a la célula podrían ser susceptibles de fracaso terapéutico a través de este mecanismo de resistencia. Hayamos que los compuestos antipalúdicos T3 y T16 (sales de bis-tiazolio) requieren el producto de los genes clag3 para ingresar en el eritrocito infectado y que poblaciones de P. falciparum puedan desarrollar resistencia a estos compuestos mediante la selección de parásitos con expresión reducida de ambos genes

Pain-Related Worrying and Goal Preferences Determine Walking Persistence in Women with Fibromyalgia

Physical activity and exercise are relevant behaviors for fibromyalgia health outcomes; however, patients have difficulties undertaking and maintaining an active lifestyle. With a cross-sectional design, this study explored the role of pain-related worrying and goal preferences in the walking persistence of women with fibromyalgia. The sample included 111 women who attended a tertiary health setting. We adapted the Six-Minute Walk Test where participants decided either to stop or continue walking in five voluntary 6 min bouts. Women who were categorized higher in pain-related worrying reported higher preference for pain avoidance goals (t = &minus;2.44, p = 0.02) and performed worse in the walking task (LongRank = 4.21; p = 0.04). Pain avoidance goal preference increased the likelihood of stopping after the first (OR = 1.443), second (OR = 1.493), and third (OR = 1.540) 6 min walking bout, and the risk of ending the walking activity during the 30 min task (HR = 1.02, [1.0&ndash;1.03]). Influence of pain-related worrying on total walking distance was mediated by goal preferences (ab = &minus;3.25). In interventions targeting adherence in physical activity and exercise, special attention is needed for women who are particularly worried about pain to help decrease their preference for short-term pain avoidance goals relative to long-term goals such as being active through walking

Motivational Determinants of Objective Physical Activity in Women with Fibromyalgia Who Attended Rehabilitation Settings

Being physically active has positive effects on fibromyalgia functioning. However, promoting an active lifestyle in these patients continues to be a relevant clinical challenge. Our aim was to test a motivational model to explain light (LPA) and moderate-vigorous physical activity (MVPA). A cross-sectional prospective study was conducted at a tertiary level of care. Participants completed sociodemographic, clinical, motivational (physical activity self-efficacy and goal preferences) and behavioral measures (activity avoidance). LPA and MVPA were measured with triaxial accelerometers, starting the same day of the aforementioned assessment. Out of 211 women, 183 completed this measure. Structural models were performed. Our results show that the best fit indices (CFI = 0.97, SRMR = 0.04) showed a model with direct influence of PA self-efficacy on MVPA (p p p < 0.01). Clinical variables did not have any effect on PA intensities. Thus, the motivational variables showed different paths to explain two PA intensities. Targeting PA self-efficacy in rehabilitation settings is needed to enhance both daily LPA and MVPA intensities