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Abstract Introduction Dyslexia is a widespread Specific Learning Difficulty, and children with dyslexia often face significant psychological difficulties due to their challenges with reading, spelling, and writing. Objective This study examines the psychological functioning of children with dyslexia and compares it with typically developing children. Method This cross-sectional study used the Child Behavior Checklist (CBCL) to evaluate behavioral issues and the State Trait Anxiety Inventory (STAI) to assess anxiety levels. Primary school teachers, who had known the children for at least a year, provided the reports. Data were analyzed using an independent sample t-test. Results Forty children with dyslexia (n = 40) and fifty typically developing children (n = 50) were assessed, in which both groups are predominantly boys (70%, 54%) aged 7–12 years (Mean age:9.3 ± 1.5). The results indicate a significantly greater degree of behavioural problems t(88) = 8.39,p

Liquid-liquid phase separation (LLPS) involving intrinsically disordered protein regions (IDRs) is a major physical mechanism for biological membraneless compartmentalization. The multifaceted electrostatic effects in these biomolecular condensates are exemplified here by experimental and theoretical investigations of the different salt- and ATP-dependent LLPSs of an IDR of messenger RNA-regulating protein Caprin1 and its phosphorylated variant pY-Caprin1, exhibiting, for example, reentrant behaviors in some instances but not others. Experimental data are rationalized by physical modeling using analytical theory, molecular dynamics, and polymer field-theoretic simulations, indicating that interchain ion bridges enhance LLPS of polyelectrolytes such as Caprin1 and the high valency of ATP-magnesium is a significant factor for its colocalization with the condensed phases, as similar trends are observed for other IDRs. The electrostatic nature of these features complements ATP’s involvement in π-related interactions and as an amphiphilic hydrotrope, underscoring a general role of biomolecular condensates in modulating ion concentrations and its functional ramifications.

Abstract Background The influence of social determinants of health (SDH) on sustainable development goals (SDG) has gained attention in recent years. However, there is a scarcity in the availability of valid and reliable instruments to assess the multiple aspects of SDH. Hence, this study was conducted to develop a brief self-reported measure for assessing SDH. Method A cross-sectional survey was conducted among university undergraduate students in Nigeria. The study consisted of 300 participants in the EFA (males 55.7%, females 44.3%) and 430 participants in the CFA (males 54.0%, females 46.0%). Participants were selected using a convenience sampling approach to assess their perceptions regarding SDH. Content Validity Index (CVI), Face Validity Index (FVI), Exploratory Factor Analysis (EFA), Confirmatory Factor Analysis (CFA), Composite Reliability (CR), Average Variance Extracted (AVE), Cronbach’s alpha, and Intraclass Correlation Coefficient (ICC) were computed to determine the psychometric properties of the newly developed SDH scale. Results In the EFA, two factors were extracted (structural determinants of SDH and intermediary determinants of SDH), with all 20 items retained. The total variance explained by the EFA model was 61.8%, and the factor correlation was 0.178. The Cronbach’s alpha values of the two factors were 0.917 and 0.939. In the CFA, the initial model did not fit the data well based on fit indices. After several re-specification of the model, the final re-specified measurement model demonstrated adequate fit factor structure of the SDH scale with two factors and 20 items (CFI = 0.943, TLI = 0.930, SRMR = 0.056, RMSEA = 0.053, RMSEA p-value = 0.220). The CR was 0.797 for structural determinants of SDH and 0.794 for intermediary determinants of SDH. The ICC was 0.938 for structural determinants of SDH and 0.941 for intermediary determinants of SDH. Conclusion The findings indicate that the SDH scale has adequate psychometric properties and can be used to assess the perceived level of SDH. We recommended that this tool be tested in other populations with diverse age groups and other demographic characteristics.

Abstract Background The environmental determinants of health (EDH) have a significant impact on people’s physical, mental, and social wellbeing. Everyone needs access to environmental resources of all types, including food, materials, and energy, to survive. Currently, no valid and reliable instrument exists for evaluating individuals’ perceived levels of EDH. Hence, the purpose of this study was to develop and validate the environmental determinants of health questionnaire (EDH-Q) among undergraduate students in Nigeria. Method We conducted a cross-sectional survey among undergraduate students in Nigeria to assess the psychometric properties of the newly developed Environmental Determinants of Health Questionnaire (EDH-Q). Respondents were selected using a convenience sampling approach to evaluate their perceptions of environmental determinants of health. The Content Validity Index (CVI) and Face Validity Index (FVI) were calculated to ascertain the scale’s content validity and response process validity, respectively. Additionally, exploratory factor analysis (EFA), confirmatory factor analysis (CFA), composite reliability (CR), average variance extracted (AVE), Cronbach’s alpha, and intraclass correlation coefficient (ICC) were computed to assess the scale’s construct validity. Results The study involved 300 respondents in the EFA (males 55.7%, females 44.3%) and 430 respondents in the CFA (males 54.0%, females 46.0%). In the EFA, two constructs were identified (the natural environment and the built environment). The EFA model was able to explain 63.57% of the total cumulative variance, and the factor correlation was 0.671. The whole scale Cronbach’s alpha value was 0.947, while the two constructs’ Cronbach’s alpha values were 0.918 (natural environment) and 0.935 (built environment). In the CFA, six pairs of error covariances were included between items within the same construct to improve the fit indices of the initial proposed measurement model. The final re-specified measurement model showed that the EDH-Q, which has two constructs and 18 items, has adequate construct validity (CFI = 0.948, TLI = 0.938, SRMR = 0.046, RMSEA = 0.052, and RMSEA p-value = 0.344). The CRs were 0.845 (natural environment) and 0.854 (built environment). The ICCs were 0.976 (natural environment) and 0.970 (built environment). Conclusion The results show that the newly created EDH-Q has sufficient construct validity and may be utilized to assess participants’ perceptions of their level of EDH. Researchers should examine this instrument in populations with different age ranges and other demographic characteristics, as the present study only applied it to undergraduate students who may share similar characteristics.

In our series, histology revealed mucin in seven patients, five with previous LE or clinical signs of LE, and only one with a positive lupus band test. During follow-up, one patient with LE antibodies showed recurrent cutaneous LE lesions, and the case was retrospectively concluded as TEN-like LE. In patients without previous LE/SS and no clinical sign of LE, especially those with a trigger drug, the pathophysiology of the LE autoantibodies remains unknown (possibly epitope spreading). [Extracted from the article]

Summary: Background: Acute exanthemas (AEs) are frequently seen; they can be caused by drugs or viruses but often the cause is unknown. Objectives: To describe the clinical, virological and histological aspects of AEs and explore their cytokinic and metagenomic profiles. Methods: This prospective study examined 98 patients with AE, from February to July 2014. Clinical data were recorded in a standardized chart. Virological investigation and skin biopsies were performed. In addition, blood and skin samples were analysed for cytokines and then by a shotgun metagenomic approach. We identified five groups of patients: those with maculopapular exanthemas (MPEs) that were virally induced (group 1); those with drug‐induced MPEs (group 2), those with MPEs that were both viral and drug induced (group 3), those with idiopathic MPEs (group 4) and those with pityriasis rosea (group 5). Results: A virus was identified in 29 cases (human herpesvirus 6, 72%). Cytokinic analysis of the skin (n = 23 MPEs) showed higher levels of interferon‐γ and interleukin‐1 receptor‐α in viral MPEs, higher interleukin‐33 levels in idiopathic MPEs, and higher macrophage inflammatory protein 1α levels in drug‐induced MPEs. By metagenomics analysis (n = 10 MPEs), viruses identified with routine practice methods were not found in group 1 (n = 4 MPEs). However, Enterovirus A was detected in two cases, especially in a group 1 patient for whom metagenomic analysis rectified the diagnosis of the culprit agent. Conclusions: Human herpesvirus 6 was the virus most frequently identified, and histology did not discriminate MPEs. In addition, the level of interleukin‐33 seen in idiopathic MPEs suggests that an environmental factor may be the trigger for these. The results bring into question the utility of routine polymerase chain reaction analysis and viral serology for determining cause in AE. What's already known about this topic? Acute exanthemas, especially maculopapular exanthemas, are a frequent reason for patients consulting emergency and dermatology departments.It is difficult to evaluate the aetiology of acute exanthema based on the clinical aspects.Few data are available on the investigations needed in routine practice, and no prospective series have been published. What does this study add? Our study provides a global and prospective description of acute exanthemas.Cytokine analysis could help to investigate the pathophysiology of idiopathic eruptions.Metagenomic analysis provides new insights about the value of routine practice virological investigations.We show for the first time the feasibility of metagenomics analysis in the skin, which results question the interest of routine PCR and viral sérologies for the exploration of such acute exanthemas. Linked Comment: Shearer et al. Br J Dermatol 2020; 182:268–269. Plain language summary available online [ABSTRACT FROM AUTHOR]

Formation of membraneless organelles or biological condensates via phase separation and related processes hugely expands the cellular organelle repertoire. Biological condensates are dense and viscoelastic soft matters instead of canonical dilute solutions. To date, numerous different biological condensates have been discovered, but mechanistic understanding of biological condensates remains scarce. In this study, we developed an adaptive single-molecule imaging method that allows simultaneous tracking of individual molecules and their motion trajectories in both condensed and dilute phases of various biological condensates. The method enables quantitative measurements of concentrations, phase boundary, motion behavior, and speed of molecules in both condensed and dilute phases, as well as the scale and speed of molecular exchanges between the two phases. Notably, molecules in the condensed phase do not undergo uniform Brownian motion, but instead constantly switch between a (class of) confined state(s) and a random diffusion-like motion state. Transient confinement is consistent with strong interactions associated with large molecular networks (i.e., percolation) in the condensed phase. In this way, molecules in biological condensates behave distinctly different from those in dilute solutions. The methods and findings described herein should be generally applicable for deciphering the molecular mechanisms underlying the assembly, dynamics, and consequently functional implications of biological condensates.

A key component in the study of antisocial behaviour among adolescents is the presence of callous-unemotional (CU) traits. Among the established tools available to measure CU traits is the Inventory of Callous-Unemotional traits (ICU). To date, there is no validated questionnaire to assess CU traits for the local population. Therefore, there is a need to validate the Malay version of the ICU (M-ICU) so that research can be conducted to explore CU traits among adolescents in Malaysia. The aim of the study is to validate the M-ICU. Two phases of cross-sectional study involving 409 (phase 1 –exploratory factor analysis (EFA), n = 180; phase 2—confirmatory factor analysis (CFA), n = 229) adolescents aged between 13 to 18 years old were conducted from July until October 2020 at six secondary schools in Kuantan district. Participants were selected via multistage random sampling. The ICU was initially translated into Malay language using forward-backward translation procedure by a group of bilingual researchers. Study participants completed the final version of the M-ICU questionnaire and socio-demographic questionnaire. Data was analysed using SPSS version 26 and MPlus software for factor structure validity by performing EFA and CFA. Initial EFA revealed three factors with two items deleted. A further EFA with two factors resulted in the deletion of unemotional factor items. Cronbach’s alpha for overall scale improved from 0.70 to 0.74. CFA supported a two-factor solution with 17 items compared to the original English version that has three factors with 24 items. The findings revealed acceptable fit indices (RMSEA = 0.057, CFI = 0.941, TLI = 0.932, WRMR = 0.968). The study revealed that a two-factor model with 17 items of the M-ICU has good psychometric properties. The scale is valid and reliable to measure CU traits among adolescents in Malaysia.

Introduction-Aims: In the modern days, traditional games have been perceived less preferred than universal games. This study examines the emotional reflection of Malaysians and Immigrants in Malaysia towards Malay traditional games and universal games. Malays (ethnic majority), Malaysian minorities (Chinese and Indian) and immigrants responded to the displayed images of Malay traditional games and universal games using a 9-point rating scale for valence domain of Self-Assessment Manikin. The emotional pleasantness towards Malay traditional games are higher in immigrants than Malaysians. There are emotional similarities between Malays and Malaysian minorities. Socio-cultural factors should be examined in future research to further understand this cultural situation.

The WD40 domain of the SCFCdc4ubiquitin ligase targets substrates via multiple phosphorylated degron motifs. The authors define a second degron-binding WD40 pocket that imparts a negative allosteric effect on binding to the primary pocket, and thereby enables the dynamic exchange of bound degrons.

Biomolecular recognition entails attractive forces for the functional native states and discrimination against potential nonnative interactions that favor alternate stable configurations. The challenge posed by the competition of nonnative stabilization against native-centric forces is conceptualized as frustration. Experiment indicates that frustration is often minimal in evolved biological systems although nonnative possibilities are intuitively abundant. Much of the physical basis of minimal frustration in protein folding thus remains to be elucidated. Here we make progress by studying the colicin immunity protein Im9. To assess the energetic favorability of nonnative versus native interactions, we compute free energies of association of various combinations of the four helices in Im9 (referred to as H1, H2, H3, and H4) by extensive explicit-water molecular dynamics simulations (total simulated time > 300 μs), focusing primarily on the pairs with the largest native contact surfaces, H1-H2 and H1-H4. Frustration is detected in H1-H2 packing in that a nonnative packing orientation is significantly stabilized relative to native, whereas such a prominent nonnative effect is not observed for H1-H4 packing. However, in contrast to the favored nonnative H1-H2 packing in isolation, the native H1-H2 packing orientation is stabilized by H3 and loop residues surrounding H4. Taken together, these results showcase the contextual nature of molecular recognition, and suggest further that nonnative effects in H1-H2 packing may be largely avoided by the experimentally inferred Im9 folding transition state with native packing most developed at the H1-H4 rather than the H1-H2 interface.

The article presents two case studies on febrile erythematous maculopapular rash and diffuse erythema of the trunk and proximal limbs. It mentions first case featured Nikolsky's sign and annular lesions mimicking atypical target lesions and diagnosed with epidermal necrolysis and autoimmune diseases. It also mentions second case associated with livedoid palmar papules, keratotic erythema on the metacarpophalangeal joints and multiple ulcerations.

Deciphering the effects of nonsynonymous mutations on protein structure is central to many areas of biomedical research and is of fundamental importance to the study of molecular evolution. Much of the investigation of protein evolution has focused on mutations that leave a protein's folded structure essentially unchanged. However, to evolve novel folds of proteins, mutations that lead to large conformational modifications have to be involved. Unraveling the basic biophysics of such mutations is a challenge to theory, especially when only one or two amino acid substitutions cause a large-scale conformational switch. Among the few such mutational switches identified experimentally, the one between the GA all-α and GB α+β folds is extensively characterized; but all-atom simulations using fully transferrable potentials have not been able to account for this striking switching behavior. Here we introduce an explicit-chain model that combines structure-based native biases for multiple alternative structures with a general physical atomic force field, and apply this construct to twelve mutants spanning the sequence variation between GA and GB. In agreement with experiment, we observe conformational switching from GA to GB upon a single L45Y substitution in the GA98 mutant. In line with the latent evolutionary potential concept, our model shows a gradual sequence-dependent change in fold preference in the mutants before this switch. Our analysis also indicates that a sharp GA/GB switch may arise from the orientation dependence of aromatic π-interactions. These findings provide physical insights toward rationalizing, predicting and designing evolutionary conformational switches.

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Summary: Severe rashes, called acute exanthemas (AE), are frequently seen in hospital. The most common type is called maculopapular exanthema (MPE), and another type is pityriasis rosea. The main causes of AEs, especially MPEs, are drugs (delayed hypersensitivity) and viruses (such as HIV, human herpesvirus 6 ‐ HHV6, and measles virus), but for some no cause is identified, which is known as ideopathic. There are no guidelines for which tests (viral investigations) should be carried out. The researchers conducted this study to better describe AE, and to explore the value of investigations into the causes of AE, called cytokinic and metagenomic analysis. 98 patients being seen at the Henri Mondor hospital in France were included. Patients were examined by a medic, received tests for viruses, and skin biopsies (tissue samples) were taken. Patients were classified into five groups: viral group (18 people), drug‐induced group (33), drug‐induced and viral (5), idiopathic (32) and pityriasis rosea (10). HHV6 was the most common virus found (74%). Analysis looking at levels of proteins called cytokines showed higher levels of a cytokine called interleukin‐33 in the idiopathic exanthemas (i.e. the ones with an unidentified cause). This could suggest an environmental factor as a trigger. The study showed for the first time the feasibility of metagenomics analysis (studying the genetic material) in the skin, and the results question whether some of the routine virus tests used are always beneficial. This summary relates to the study: Acute exanthemas: a prospective study of 98 adult patients with an emphasis on cytokinic and metagenomic investigation Linked Article: Deschamps et al. Br J Dermatol 2020; 182:355–363 [ABSTRACT FROM AUTHOR]

The bacterial colicin-immunity proteins Im7 and Im9 fold by different mechanisms. Experimentally, at pH 7.0 and 10°C, Im7 folds in a three-state manner via an intermediate but Im9 folding is two-state-like. Accordingly, Im7 exhibits a chevron rollover, whereas the chevron arm for Im9 folding is linear. Here we address the biophysical basis of their different behaviors by using native-centric models with and without additional transferrable, sequence-dependent energies. The Im7 chevron rollover is not captured by either a pure native-centric model or a model augmented by nonnative hydrophobic interactions with a uniform strength irrespective of residue type. By contrast, a more realistic nonnative interaction scheme that accounts for the difference in hydrophobicity among residues leads simultaneously to a chevron rollover for Im7 and an essentially linear folding chevron arm for Im9. Hydrophobic residues identified by published experiments to be involved in nonnative interactions during Im7 folding are found to participate in the strongest nonnative contacts in this model. Thus our observations support the experimental perspective that the Im7 folding intermediate is largely underpinned by nonnative interactions involving large hydrophobics. Our simulation suggests further that nonnative effects in Im7 are facilitated by a lower local native contact density relative to that of Im9. In a one-dimensional diffusion picture of Im7 folding with a coordinate- and stability-dependent diffusion coefficient, a significant chevron rollover is consistent with a diffusion coefficient that depends strongly on native stability at the conformational position of the folding intermediate.

Biologically functional liquid–liquid phase separation of intrinsically disordered proteins (IDPs) is driven by interactions encoded by their amino acid sequences. Little is currently known about the molecular recognition mechanisms for distributing different IDP sequences into various cellular membraneless compartments. Pertinent physics was addressed recently by applying random-phase-approximation (RPA) polymer theory to electrostatics, which is a major energetic component governing IDP phase properties. RPA accounts for charge patterns and thus has advantages over Flory–Huggins (FH) and Overbeek–Voorn mean-field theories. To make progress toward deciphering the phase behaviors of multiple IDP sequences, the RPA formulation for one IDP species plus solvent is hereby extended to treat polyampholyte solutions containing two IDP species plus solvent. The new formulation generally allows for binary coexistence of two phases, each containing a different set of volume fractions $({\phi }_{1},{\phi }_{2})$ for the two different IDP sequences. The asymmetry between the two predicted coexisting phases with regard to their ${\phi }_{1}/{\phi }_{2}$ ratios for the two sequences increases with increasing mismatch between their charge patterns. This finding points to a multivalent, stochastic, ‘fuzzy’ mode of molecular recognition that helps populate various IDP sequences differentially into separate phase compartments. An intuitive illustration of this trend is provided by FH models, whereby a hypothetical case of ternary coexistence is also explored. Augmentations of the present RPA theory with a relative permittivity ${\epsilon }_{{\rm{r}}}(\phi )$ that depends on IDP volume fraction $\phi ={\phi }_{1}+{\phi }_{2}$ lead to higher propensities to phase separate, in line with the case with one IDP species we studied previously. Notably, the cooperative, phase-separation-enhancing effects predicted by the prescriptions for ${\epsilon }_{{\rm{r}}}(\phi )$ we deem physically plausible are much more prominent than that entailed by common effective medium approximations based on Maxwell Garnett and Bruggeman mixing formulas. Ramifications of our findings on further theoretical development for IDP phase separation are discussed.

Molecular recognition by intrinsically disordered proteins (IDPs) commonly involves specific localized contacts and target-induced disorder to order transitions. However, some IDPs remain disordered in the bound state, a phenomenon coined "fuzziness", often characterized by IDP polyvalency, sequence-insensitivity and a dynamic ensemble of disordered bound-state conformations. Besides the above general features, specific biophysical models for fuzzy interactions are mostly lacking. The transcriptional activation domain of the Ewing's Sarcoma oncoprotein family (EAD) is an IDP that exhibits many features of fuzziness, with multiple EAD aromatic side chains driving molecular recognition. Considering the prevalent role of cation-π interactions at various protein-protein interfaces, we hypothesized that EAD-target binding involves polycation- π contacts between a disordered EAD and basic residues on the target. Herein we evaluated the polycation-π hypothesis via functional and theoretical interrogation of EAD variants. The experimental effects of a range of EAD sequence variations, including aromatic number, aromatic density and charge perturbations, all support the cation-π model. Moreover, the activity trends observed are well captured by a coarse-grained EAD chain model and a corresponding analytical model based on interaction between EAD aromatics and surface cations of a generic globular target. EAD-target binding, in the context of pathological Ewing's Sarcoma oncoproteins, is thus seen to be driven by a balance between EAD conformational entropy and favorable EAD-target cation-π contacts. Such a highly versatile mode of molecular recognition offers a general conceptual framework for promiscuous target recognition by polyvalent IDPs.

Experimental studies have shown that some proteins exist in two alternative native-state conformations. It has been proposed that such bi-stable proteins can potentially function as evolutionary bridges at the interface between two neutral networks of protein sequences that fold uniquely into the two different native conformations. Under adaptive conflict scenarios, bi-stable proteins may be of particular advantage if they simultaneously provide two beneficial biological functions. However, computational models that simulate protein structure evolution do not yet recognize the importance of bi-stability. Here we use a biophysical model to analyze sequence space to identify bi-stable or multi-stable proteins with two or more equally stable native-state structures. The inclusion of such proteins enhances phenotype connectivity between neutral networks in sequence space. Consideration of the sequence space neighborhood of bridge proteins revealed that bi-stability decreases gradually with each mutation that takes the sequence further away from an exactly bi-stable protein. With relaxed selection pressures, we found that bi-stable proteins in our model are highly successful under simulated adaptive conflict. Inspired by these model predictions, we developed a method to identify real proteins in the PDB with bridge-like properties, and have verified a clear bi-stability gradient for a series of mutants studied by Alexander et al. (Proc Nat Acad Sci USA 2009, 106:21149-21154) that connect two sequences that fold uniquely into two different native structures via a bridge-like intermediate mutant sequence. Based on these findings, new testable predictions for future studies on protein bi-stability and evolution are discussed.

Abstract Background A new subgroup of HIV-1, designated Group P, was recently detected in two unrelated patients of Cameroonian origin. HIV-1 Group P phylogenetically clusters with SIVgor suggesting that it is the result of a cross-species transmission from gorillas. Until today, HIV-1 Group P has only been detected in two patients, and its degree of adaptation to the human host is largely unknown. Previous data have shown that pandemic HIV-1 Group M, but not non-pandemic Group O or rare Group N viruses, efficiently antagonize the human orthologue of the restriction factor tetherin (BST-2, HM1.24, CD317) suggesting that primate lentiviruses may have to gain anti-tetherin activity for efficient spread in the human population. Thus far, three SIV/HIV gene products (vpu, nef and env) are known to have the potential to counteract primate tetherin proteins, often in a species-specific manner. Here, we examined how long Group P may have been circulating in humans and determined its capability to antagonize human tetherin as an indicator of adaptation to humans. Results Our data suggest that HIV-1 Group P entered the human population between 1845 and 1989. Vpu, Env and Nef proteins from both Group P viruses failed to counteract human or gorilla tetherin to promote efficient release of HIV-1 virions, although both Group P Nef proteins moderately downmodulated gorilla tetherin from the cell surface. Notably, Vpu, Env and Nef alleles from the two HIV-1 P strains were all able to reduce CD4 cell surface expression. Conclusions Our analyses of the two reported HIV-1 Group P viruses suggest that zoonosis occurred in the last 170 years and further support that pandemic HIV-1 Group M strains are better adapted to humans than non-pandemic or rare Group O, N and P viruses. The inability to antagonize human tetherin may potentially explain the limited spread of HIV-1 Group P in the human population.

Abstract Background Xenotropic murine leukemia virus (MLV)-related virus (XMRV) was initially identified in prostate cancer (PCa) tissue, particularly in the prostatic stromal fibroblasts, of patients homozygous for the RNASEL R462Q mutation. A subsequent study reported XMRV antigens in malignant prostatic epithelium and association of XMRV infection with PCa, especially higher-grade tumors, independently of the RNASEL polymorphism. Further studies showed high prevalence of XMRV or related MLV sequences in chronic fatigue syndrome patients (CFS), while others found no, or low, prevalence of XMRV in a variety of diseases including PCa or CFS. Thus, the etiological link between XMRV and human disease remains elusive. To address the association between XMRV infection and PCa, we have tested prostate tissues and human sera for the presence of viral DNA, viral antigens and anti-XMRV antibodies. Results Real-time PCR analysis of 110 PCa (Gleason scores >4) and 40 benign and normal prostate tissues identified six positive samples (5 PCa and 1 non-PCa). No statistical link was observed between the presence of proviral DNA and PCa, PCa grades, and the RNASEL R462Q mutation. The amplified viral sequences were distantly related to XMRV, but nearly identical to endogenous MLV sequences in mice. The PCR positive samples were also positive for mouse mitochondrial DNA by nested PCR, suggesting contamination of the samples with mouse DNA. Immuno-histochemistry (IHC) with an anti-XMRV antibody, but not an anti-MLV antibody that recognizes XMRV, sporadically identified antigen-positive cells in prostatic epithelium, irrespectively of the status of viral DNA detection. No serum (159 PCa and 201 age-matched controls) showed strong neutralization of XMRV infection at 1:10 dilution. Conclusion The lack of XMRV sequences or strong anti-XMRV neutralizing antibodies indicates no or very low prevalence of XMRV in our cohorts. We conclude that real-time PCR- and IHC-positive samples were due to laboratory contamination and non-specific immune reactions, respectively.

Abstract Background Xenotropic murine leukaemia viruses (MLV-X) are endogenous gammaretroviruses that infect cells from many species, including humans. Xenotropic murine leukaemia virus-related virus (XMRV) is a retrovirus that has been the subject of intense debate since its detection in samples from humans with prostate cancer (PC) and chronic fatigue syndrome (CFS). Controversy has arisen from the failure of some studies to detect XMRV in PC or CFS patients and from inconsistent detection of XMRV in healthy controls. Results Here we demonstrate that Taqman PCR primers previously described as XMRV-specific can amplify common murine endogenous viral sequences from mouse suggesting that mouse DNA can contaminate patient samples and confound specific XMRV detection. To consider the provenance of XMRV we sequenced XMRV from the cell line 22Rv1, which is infected with an MLV-X that is indistinguishable from patient derived XMRV. Bayesian phylogenies clearly show that XMRV sequences reportedly derived from unlinked patients form a monophyletic clade with interspersed 22Rv1 clones (posterior probability >0.99). The cell line-derived sequences are ancestral to the patient-derived sequences (posterior probability >0.99). Furthermore, pol sequences apparently amplified from PC patient material (VP29 and VP184) are recombinants of XMRV and Moloney MLV (MoMLV) a virus with an envelope that lacks tropism for human cells. Considering the diversity of XMRV we show that the mean pairwise genetic distance among env and pol 22Rv1-derived sequences exceeds that of patient-associated sequences (Wilcoxon rank sum test: p = 0.005 and p < 0.001 for pol and env, respectively). Thus XMRV sequences acquire diversity in a cell line but not in patient samples. These observations are difficult to reconcile with the hypothesis that published XMRV sequences are related by a process of infectious transmission. Conclusions We provide several independent lines of evidence that XMRV detected by sensitive PCR methods in patient samples is the likely result of PCR contamination with mouse DNA and that the described clones of XMRV arose from the tumour cell line 22Rv1, which was probably infected with XMRV during xenografting in mice. We propose that XMRV might not be a genuine human pathogen.

Abstract Background Detailed local HIV-1 sequence data are essential for monitoring the HIV epidemic, for maintaining sensitive sequence-based diagnostics, and to aid in designing vaccines. Results Reported here are full envelope sequences derived from 38 randomly selected HIV-1 infections identified at a Gambian clinic between 1991 and 2009. Special care was taken to generate sequences from circulating viral RNA as uncloned products, either by limiting dilution or single genome amplification polymerase chain reaction (PCR). Within these 38 isolates, eight were subtyped as A and 18 as CRF02_AG. A small number of subtype B, C, D viruses were identified. Surprising, however, was the identification of six isolates with subtype J-like envelopes, a subtype found normally in Central Africa and the Democratic Republic of the Congo (DRC), with gag p24 regions that clustered with subtype A sequences. Near full-length sequence from three of these isolates confirmed that these represent a novel circulating recombinant form of HIV-1, now named CRF49_cpx. Conclusions This study expands the HIV-1 sequence database from the Gambia and will provide important data for HIV diagnostics, patient care, and vaccine development.

Le propylthiouracile est un antithyroïdien de synthèse qui peut induire des vascularites à ANCA. Une femme de 27 ans sous PTU depuis 10 ans pour une maladie de Basedow présentait des lésions purpuriques des jambes et de la pointe du nez à type de vascularite. Les ANCA étaient positifs, avec en ELISA des anti-MPO et des anti-PR3. Après arrêt du PTU, l'évolution était favorable. Tous les antithyroïdiens de synthèse, mais plus souvent le PTU, peuvent induire des vascularites à ANCA. Dans la majorité des cas, les anticorps sont dirigés contre la MPO. La double positivité anti-MPO et anti-PR3 est rare. Le mécanisme pourrait passer par une accumulation du PTU dans les neutrophiles, altérant la structure de la MPO et la rendant immunogène. Le PTU peut aussi induire des vascularites sans ANCA ou lupiques, des exanthèmes maculopapuleux ou des urticaires. Beaucoup d'autres médicaments peuvent induire des vascularites à ANCA. Propylthiouracil (PTU) is a synthetic antithyroid drug that can induce ANCA-associated vasculitis. A 27-year-old woman diagnosed with Graves' disease was on PTU for the past 10 years. She developed purpuric lesions of the legs and on the tip of the nose diagnosed as vasculitis. ANCAs were positive, with anti-MPO and anti-PR3 on blood ELISA. After discontinuation of PTU, she was able to fully recover. All synthetic antithyroid drugs can induce ANCA-associated vasculitis, more often PTU. In most cases, antibodies are directed against MPO. Dual anti-MPO and anti-PR3 positivity is possible, but rare. The mechanism could be through an accumulation of PTU in neutrophils, altering the structure of MPO and making it immunogenic. PTU can also induce ANCA-free or lupus vasculitis, maculopapular rashes or urticaria. Many other drugs can induce ANCA-associated vasculitis. [ABSTRACT FROM AUTHOR]