1,290 research outputs found

    Chagas disease reactivation in a heart transplant patient infected by domestic Trypanosoma cruzi discrete typing unit I (TcIDOM)

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    Background Trypanosoma cruzi, causative agent of Chagas disease, displays high intraspecific genetic diversity: six genetic lineages or discrete typing units (DTUs) are currently recognized, termed TcI through TcVI. Each DTU presents a particular distribution pattern across the Americas, and is loosely associated with different transmission cycles and hosts. Several DTUs are known to circulate in Central America. It has been previously suggested that TcI infection is benign and does not lead to chronic chagasic cardiomyopathy (CCC). Findings In this study, we genotyped T. cruzi parasites circulating in the blood and from explanted cardiac tissue of an El Salvadorian patient who developed reactivation Chagas disease while on immunosuppressive medications after undergoing heart transplant in the U.S. as treatment for end-stage CCC. Parasite typing was performed through molecular methods (restriction fragment length polymorphism of polymerase reaction chain amplified products, microsatellite typing, maxicircle sequence typing and low-stringency single primer PCR, [LSSP-PCR]) as well as lineage-specific serology. We show that the parasites infecting the patient belong to the TcI DTU exclusively. Our data indicate that the parasites isolated from the patient belong to a genotype frequently associated with human infection throughout the Americas (TcI DOM ). Conclusions Our results constitute compelling evidence in support of TcI DTU’s ability to cause end-stage CCC and help dispel any residual bias that infection with this lineage is benign, pointing to the need for increased surveillance for dissemination of this genotype in endemic regions, the USA and globally

    Medium-modified DGLAP evolution of fragmentation functions from large to small x

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    The unified description of fragmentation function evolution from large to small x which was developed for the vacuum in previous publications is now generalized to the medium, and is studied for the case in which the complete contribution from the largest class of soft gluon logarithms, the double logarithms, are accounted for and with the fixed order part calculated to leading order. In this approach it proves possible to choose the remaining degrees of freedom related to the medium such that the distribution of produced hadrons is suppressed at large momenta while the production of soft radiation-induced charged hadrons at small momenta is enhanced, in agreement with experiment. Just as for the vacuum, our approach does not require further assumptions concerning fragmentation and is more complete than previous computations of evolution in the medium

    Stressed, but not defenceless: no obvious influence of irradiation levels on antifeeding and antifouling defences of tropical macroalgae

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    The production of defence metabolites is assumed to be costly in metabolic terms. If this holds true, low-light stress should reduce the ability of seaweeds to defend themselves chemically against herbivory and fouling. We investigated the effect of energy limitation on the defensive status of seaweeds by assessing their attractiveness to mesograzers and their activity against a bivalve macrofouler in comparison with non-stressed conspecifics. The macroalgae Codium decorticatum (Woodw.) M. Howe, Osmundaria obtusiloba (C. Agardh) R. E. Norris, Pterocladiella capillacea (S. G. Gmel.) Santel. and Hommer., Sargassum vulgare C. Agardh and Stypopodium zonale (Lamour.) Papenf. collected at the southeastern Brazilian coast were exposed to six levels of irradiation (between 1 and 180 ÎŒmol photons m−2 s−1) for 10–14 days. After this period, algae from all treatment levels were: (a) processed as artificial food and offered to an amphipod community dominated by Elasmopus brasiliensis Dana and (b) extracted to test for differences in settlement rates of the fouling mussel Perna perna L. on filter paper loaded with the crude extracts. Generally, photosynthesis rates and growth were reduced under low light conditions. Attractiveness to herbivores and macrofoulers, however, was insensitive to energy limitation. We discuss possible explanations for the observed absence of a relationship between light availability and algal defence including the change in nutritional value of the algal tissue, the allocation of resources towards defence instead of growth and the absence of costs for defence

    A multi-scale modelling framework combining musculoskeletal rigid-body simulations with adaptive finite element analyses, to evaluate the impact of femoral geometry on hip joint contact forces and femoral bone growth

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    Multi-scale simulations, combining muscle and joint contact force (JCF) from musculoskeletal simulations with adaptive mechanobiological finite element analysis, allow to estimate musculoskeletal loading and predict femoral growth in children. Generic linearly scaled musculoskeletal models are commonly used. This approach, however, neglects subject- and age-specific musculoskeletal geometry, e.g. femoral neck-shaft angle (NSA) and anteversion angle (AVA). This study aimed to evaluate the impact of proximal femoral geometry, i.e. altered NSA and AVA, on hip JCF and femoral growth simulations. Musculoskeletal models with NSA ranging from 120° to 150° and AVA ranging from 20° to 50° were created and used to calculate muscle and hip JCF based on the gait analysis data of a typically developing child. A finite element model of a paediatric femur was created from magnetic resonance images. The finite element model was morphed to the geometries of the different musculoskeletal models and used for mechanobiological finite element analysis to predict femoral growth trends. Our findings showed that hip JCF increase with increasing NSA and AVA. Furthermore, the orientation of the hip JCF followed the orientation of the femoral neck axis. Consequently, the osteogenic index, which is a function of cartilage stresses and defines the growth rate, barely changed with altered NSA and AVA. Nevertheless, growth predictions were sensitive to the femoral geometry due to changes in the predicted growth directions. Altered NSA had a bigger impact on the growth results than altered AVA. Growth simulations based on mechanobiological principles were in agreement with reported changes in paediatric populations

    Resonant Raman scattering off neutral quantum dots

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    Resonant inelastic (Raman) light scattering off neutral GaAs quantum dots which contain a mean number, N=42, of electron-hole pairs is computed. We find Raman amplitudes corresponding to strongly collective final states (charge-density excitations) of similar magnitude as the amplitudes related to weakly collective or single-particle excitations. As a function of the incident laser frequency or the magnetic field, they are rapidly varying amplitudes. It is argued that strong Raman peaks should come out in the spin-density channels, not related to valence-band mixing effects in the intermediate states.Comment: Accepted in Physical Review

    Is methotrexate safe for men with an immune-mediated inflammatory disease and an active desire to become a father? Results of a prospective cohort study (iFAME-MTX)

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    Introduction Current scientific evidence guiding the decision whether men with an active desire to become a father should be treated with methotrexate (MTX) remains controversial. We aimed to prospectively evaluate the testicular toxicity profile of MTX focusing on several markers of male fertility, including semen parameters and sperm DNA fragmentation index (sDFI). As a secondary outcome, we aimed to evaluate whether MTX-polyglutamates can be detected in spermatozoa and seminal plasma and to evaluate the enzymatic activity in spermatozoa of folylpolyglutamate synthetase (FPGS). Methods In a prospective cohort study, men ≄18 years who started therapy with MTX were invited to participate (MTX-starters). Participants were instructed to produce two semen samples (a pre-exposure and a post-exposure sample after 13 weeks). Healthy men ≄18 years were invited to participate as controls. Conventional semen analyses, male reproductive endocrine axis and sDFI were compared between groups. FPGS enzymatic activity and MTX-PG1-5 concentrations were determined by mass spectrometry analytical methods. Results In total, 20 MTX-starters and 25 controls were included. The pre-exposure and postexposure semen parameters of MTX-starters were not statistically significant different. Compared with healthy controls, the conventional semen parameters and the sDFI of MTX-starters were not statistically significant different. These data were corroborated by the marginal accumulation of MTX-PGs in spermatozoa, consistent with the very low FPGS enzymatic activity associated with the expression of an alternative FPGS splice-variant. Discussion Treatment with MTX is not associated with testicular toxicity, consistent with the very low concentration of intracellular MTX-PG. Therefore, therapy with MTX can be safely started or continued in men and with a wish to become a father.</p

    Generation of a gene-corrected human isogenic line (UAMi006-A) from propionic acidemia patient iPSC with an homozygous mutation in the PCCB gene using CRISPR/Cas9 technology

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    Propionic acidemia (PA) is an inherited metabolic disease caused by mutations in the PCCA and PCCB genes. We have previously generated an induced pluripotent stem cell (iPSC) line (UAMi004-A) from a PA patient with the c.1218_1231del14ins12 (p.Gly407Argfs*14) homozygous mutation in the PCCB gene. Here, we report the generation of the isogenic control in which the mutation was genetically corrected using CRISPR/Cas9 technology. Off-target editing presence was excluded and the iPSCs had typical embryonic stem cell-like morphology and normal karyotype that expressed pluripotency markers and maintained their in vitro differentiation potential.Functional Genomics of Muscle, Nerve and Brain Disorder

    The role of evidence-based guidelines in the diagnosis and treatment of functional neurological disorder

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    Evidence-based clinical practice guidelines, based on systematic reviews of existing evidence, play an important role in improving and standardizing the quality of patient care in many medical and psychiatric disorders, and could play an important role in the diagnosis and treatment of functional seizures and other functional neurological disorder (FND) subtypes. There are several reasons to think that evidence-based guidelines might be especially beneficial for the management of FND. In particular, the interdisciplinary and multidisciplinary teamwork necessary for the care of people with FND, the current lack of formal clinical training in FND, and the rapidly expanding body of evidence relating to FND all make guidelines based on systematic literature reviews especially valuable. In this perspective piece, we review clinical practice guidelines, their advantages and limitations, the reasons why evidence-based guidelines might be especially beneficial in the diagnosis and treatment of FND, and the steps that must be taken to create such guidelines for FND. We propose that professional organizations such as the American Academy of Neurology and the American Psychiatric Association undertake guideline development, ideally to create a co-authored or jointly endorsed set of guidelines that can set standards for interdisciplinary care for neurologists and mental health clinicians alike

    GeoTraductores: A Collaborative Initiative Democratizing Science Communication in Latin America

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    GeoTraductores is an collaborative initiative between Eos, Planeteando, andGeoLatinas that aims to provide Spanish-speaking communities access to current scientific findings. This goal is accomplished by translating science articles originally published in English on AGU's Eos.org, within their Science News magazine, into Spanish. This cross-organizational initiative has translated, edited, and published over 150 articles, breaking the language barrier for Spanish-speaking communities. Our experience since 2020 has allowed us to tailor an efficient co-production model, which starts with (a) the selection of articles of interest to translate, followed by (b) the translation, reviewing, and editing process by volunteers, and (c) the publication and social media dissemination of the translated article. The tangible impact of GeoTraductores is evident in the substantial surge of visitor traffic to the Eos website between 2020 and 2023, particularly from Latin American countries. Notably, increases exceeding 85% were observed in Colombia, Mexico, and Panama, with 20% or greater growth in Chile, Brazil, Costa Rica, Peru, and Ecuador, confirming the initiative's success in meeting a genuine need. This impact extends globally, with Spain experiencing a 40% increase in visitors. Our co-production model is possible thanks to the contribution of around 40 GeoTraductores, mainly women (85%), who are native Spanish speakers or bilingual (Spanish and English speaking). These early-career scientists, through their volunteer work, enhance their bilingual communication skills while breaking down language barriers in science communication. The Eos-Planeteando-GeoLatinas co-production model fosters science democratization for Latin America while promoting diversity, equity, and inclusion in Earth Sciences, one translation at a time

    Male Sexual Health and Reproduction in Cutaneous Immune-Mediated Diseases: A Systematic Review

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    Introduction: Information about the possible effects of cutaneous immune-mediated diseases (cIMDs) on male sexual function and reproduction is scarce. Factors known to impair sexual health and reproduction, such as inflammation, medication use, and hypogonadism, can be present in a significant proportion of male patients with cIMD. Objectives: To systematically review the literature for the influence of paternal cIMD on many aspects of male sexual and reproductive health, such as sexual function, reproductive hormones, fertility, and pregnancy and offspring outcomes. Methods: A systematic literature search was performed. The searches combined keywords regarding male sexual function and fertility, pregnancy outcomes, and offspring's health with a list of cIMDs. Results: The majority of the identified studies included patients with psoriasis (22 of 27), and sexual function was the most common outcome of interest (20 of 27). For patients diagnosed with psoriasis, the prevalence of male sexual dysfunction reported in these studies ranged from 34 to 81%. Hypogonadism in patients with psoriasis was reported in 2 of 3 studies. Sperm analysis abnormalities in patients with psoriasis were reported in 3 of 4 studies. No information about the effect of paternal disease on pregnancy and offspring outcomes was identified. Conclusions: Disease activity in psoriasis might play an important role in the development of sexual dysfunction, hypogonadism, and abnormal sperm quality. For the other cIMD included in this review, there is insufficient information regarding male sexual and reproductive health to draw firm conclusions. More research is needed to understand the association between cIMD and impaired male sexual and reproductive health
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