510 research outputs found
Description of hard sphere crystals and crystal-fluid interfaces: a critical comparison between density functional approaches and a phase field crystal model
In materials science the phase field crystal approach has become popular to
model crystallization processes. Phase field crystal models are in essence
Landau-Ginzburg-type models, which should be derivable from the underlying
microscopic description of the system in question. We present a study on
classical density functional theory in three stages of approximation leading to
a specific phase field crystal model, and we discuss the limits of
applicability of the models that result from these approximations. As a test
system we have chosen the three--dimensional suspension of monodisperse hard
spheres. The levels of density functional theory that we discuss are
fundamental measure theory, a second-order Taylor expansion thereof, and a
minimal phase-field crystal model. We have computed coexistence densities,
vacancy concentrations in the crystalline phase, interfacial tensions and
interfacial order parameter profiles, and we compare these quantities to
simulation results. We also suggest a procedure to fit the free parameters of
the phase field crystal model.Comment: 21 page
Urinary and faecal N-methylhistamine concentrations do not serve as markers for mast cell activation or clinical disease activity in dogs with chronic enteropathies
This study sought to correlate faecal and urinary N-methylhistamine (NMH) concentrations with resting versus degranulated duodenal mast cell numbers in dogs with chronic enteropathies (CE), and investigate correlations between intestinal mast cell activation and clinical severity of disease as assessed by canine chronic enteropathy clinical activity index (CCECAI), and between urinary and faecal NMH concentrations, mast cell numbers, and histopathological scores. Twenty-eight dogs with CE were included. Duodenal biopsies were stained with haematoxylin and eosin (H&E), toluidine blue, and by immunohistochemical labelling for tryptase. Duodenal biopsies were assigned a histopathological severity score, and duodenal mast cell numbers were counted in five high-power fields after metachromatic and immunohistochemical staining. Faecal and urinary NMH concentrations were measured by gas chromatographyâmass spectrometry
Local cholesterol metabolism orchestrates remyelination
Cholesterol is an essential component of all cell membranes and particularly enriched in myelin membranes. Myelin membranes are a major target of immune attacks in the chronic neurological disorder multiple sclerosis (MS). During demye- linating insults, cholesterol is released from damaged myelin, increasing local levels of this unique lipid and impeding tissue regeneration. Here, we summarize the current knowledge of cholesterol-dependent processes during demyelination and remyelination, emphasizing cell type-specific responses. We discuss cellular lipid/ cholesterol metabolism during early and late disease phases and highlight the con- cept of lipid-based pharmacological interventions. We propose that knowledge of the interplay between cell type-specific cholesterol handling, inflammation, and bloodâbrain barrier (BBB) integrity will unravel disease processes and facilitate development of strategies for therapies to promote remyelination
Inducible targeting of CNS astrocytes in Aldh1/1-CreERT2 BAC transgenic mice
Background: Studying astrocytes in higher brain functions has been hampered by the lack of genetic tools for the efficient expression of inducible Cre recombinase throughout the CNS, including the neocortex. Methods: Therefore, we generated BAC transgenic mice, in which CreERT2 is expressed under control of the Aldh1l1 regulatory region. Results: When crossbred to Cre reporter mice, adult Aldh1l1-CreERT2 mice show efficient gene targeting in astrocytes. No such Cre-mediated recombination was detectable in CNS neurons, oligodendrocytes, and microglia. As expected, Aldh1l1-CreERT2 expression was evident in several peripheral organs, including liver and kidney. Conclusions: Taken together, Aldh1l1-CreERT2 mice are a useful tool for studying astrocytes in neurovascular coupling, brain metabolism, synaptic plasticity and other aspects of neuron-glia interactions
Photopolymerizable platelet lysate hydrogels for customizable 3D cell culture platforms
3D cell culture platforms have emerged as a setting that resembles in vivo environments replacing the traditional 2D platforms. Over the recent years, an extensive effort has been made on the development of more physiologically relevant 3D cell culture platforms. Extracellular matrix-based materials have been reported as a bioactive and biocompatible support for cell culture. For example, human plasma derivatives have been extensively used in cell culture. Despite all the promising results, in most cases these types of materials have poor mechanical properties and poor stability in vitro. Here plasma-based hydrogels with increased stability are proposed. Platelet lysates are modified by addition of methacryloyl groups (PLMA) that polymerize in controlled geometries upon UV light exposure. The hydrogels could also generate porous scaffolds after lyophilization. The results show that PLMA materials have increased mechanical properties that can be easily adjusted by changing PLMA concentration or modification degree. Cells readily adhere, proliferate, and migrate, exhibiting high viability when encapsulated in PLMA hydrogels. The innovation potential of PLMA materials is based on the fact that it is a complete xeno-free solution for human cell culture, thus an effective alternative to the current gold standards for 3D cell culture based on animal products.publishe
Editorial: Precision medicine approaches in radiotherapy and systemic therapy of brain metastases
Has COVID-19 had a greater impact on female than male oncologists? Results of the ESMO Women for Oncology (W4O) Survey
Coronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Desigualtats; DonaCoronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Desigualdades; MujerCoronavirus SARS-CoV-2; COVID-19; 2019-nCoV Inequalities; WomanBackground
European Society for Medical Oncology Women for Oncology (ESMO W4O) research has previously shown under-representation of female oncologists in leadership roles. As early reports suggested disproportionate effects of the COVID-19 pandemic on women, the ESMO W4O Committee initiated a study on the impact of the pandemic on the lives of female and male oncologists.
Methods
A questionnaire was sent to ESMO members and put on the ESMO website between 8 June 2020 and 2 July 2020. Questions focused on the working (hospital tasks, laboratory tasks, science) and home (household management, childcare, parent care, personal care) lives of oncologists during and after COVID-19-related lockdowns.
Results
Of 649 respondents, 541 completed the questionnaire. Of these, 58% reported that COVID-19 had affected their professional career, 83% of whom said this was in a negative way (85% of women versus 76% of men). Approximately 86% reported that COVID-19 had changed their personal life and 82% their family life. Women were again significantly more affected than men: personal life (89% versus 78%; P = 0.001); family life (84% versus 77%; P = 0.037). During lockdowns, women reported increased time spent on hospital and laboratory tasks compared with men (53% versus 46% and 33% versus 26%, respectively) and a significantly higher proportion of women than men spent less time on science (39% versus 25%) and personal care (58% versus 39%). After confinement, this trend remained for science (42% versus 23%) and personal care (55% versus 36%).
Conclusions
The COVID-19 pandemic has adversely affected the professional and home lives of oncologists, especially women. Reduced research time for female oncologists may have long-lasting career consequences, especially for those at key stages in their career. The gender gap for promotion to leadership positions may widen further as a result of the pandemic.This work was supported by the European Society for Medical Oncology (ESMO)
Autoantibodies against NMDA receptor 1 modify rather than cause encephalitis
The etiology and pathogenesis of âanti-N-methyl-D-aspartate-receptor (NMDAR) encephalitisâ and the role of autoantibodies (AB) in this condition are still obscure. While NMDAR1-AB exert NMDAR-antagonistic properties by receptor internalization, no firm evidence exists to date that NMDAR1-AB by themselves induce brain inflammation/encephalitis. NMDAR1-AB of all immunoglobulin classes are highly frequent across mammals with multiple possible inducers and boosters. We hypothesized that âNMDAR encephalitisâ results from any primary brain inflammation coinciding with the presence of NMDAR1-AB, which may shape the encephalitis phenotype. Thus, we tested whether following immunization with a âcocktailâ of 4 NMDAR1 peptides, induction of a spatially and temporally defined sterile encephalitis by diphtheria toxin-mediated ablation of pyramidal neurons (âDTAâ mice) would modify/aggravate the ensuing phenotype. In addition, we tried to replicate a recent report claiming that immunizing just against the NMDAR1-N368/G369 region induced brain inflammation. Mice after DTA induction revealed a syndrome comprising hyperactivity, hippocampal learning/memory deficits, prefrontal cortical network dysfunction, lasting blood brain-barrier impairment, brain inflammation, mainly in hippocampal and cortical regions with pyramidal neuronal death, microgliosis, astrogliosis, modest immune cell infiltration, regional atrophy, and relative increases in parvalbumin-positive interneurons. The presence of NMDAR1-AB enhanced the hyperactivity (psychosis-like) phenotype, whereas all other readouts were identical to control-immunized DTA mice. Non-DTA mice with or without NMDAR1-AB were free of any encephalitic signs. Replication of the reported NMDAR1-N368/G369-immunizing protocol in two large independent cohorts of wild-type mice completely failed. To conclude, while NMDAR1-AB can contribute to the behavioral phenotype of an underlying encephalitis, induction of an encephalitis by NMDAR1-AB themselves remains to be proven
Challenges in oncology career: are we closing the gender gap? Results of the new ESMO Women for Oncology Committee survey
Discrimination; Gender equity; OncologyDiscriminaciĂł; Equitat de gènere; OncologiaDiscriminaciĂłn; Equidad de gĂŠnero; OncologĂaBackground
Following a European Society for Medical Oncology Women for Oncology (ESMO W4O) survey in 2016 showing severe under-representation of female oncologists in leadership roles, ESMO launched a series of initiatives to address obstacles to gender equity. A follow-up survey in October 2021 investigated progress achieved.
Materials and methods
The W4O questionnaire 2021 expanded on the 2016 survey, with additional questions on the impact of ethnicity, sexual orientation and religion on career development. Results were analysed according to respondent gender and age.
Results
The survey sample was larger than in 2016 (n = 1473 versus 482), especially among men. Significantly fewer respondents had managerial or leadership roles than in 2016 (31.8% versus 51.7%). Lack of leadership development for women and unconscious bias were considered more important in 2021 than in 2016. In 2021, more people reported harassment in the workplace than in 2016 (50.3% versus 41.0%). In 2021, ethnicity, sexual orientation and religion were considered to have little or no impact on professional career opportunities, salary setting or related potential pay gap. However, gender had a significant or major impact on career development (25.5% of respondents), especially in respondents â¤40 years of age and women. As in 2016, highest ranked initiatives to foster workplace equity were promotion of workâlife balance, development and leadership training and flexible working. Significantly more 2021 respondents (mainly women) supported the need for culture and gender equity education at work than in 2016.
Conclusions
Gender remains a major barrier to career progression in oncology and, although some obstacles may have been reduced since 2016, we are a long way from closing the gender gap. Increased reporting of discrimination and inappropriate behaviour in the workplace is a major, priority concern. The W4O 2021 survey findings provide new evidence and highlight the areas for future ESMO interventions to support equity and diversity in oncology career development.This work was supported by the European Society for Medical Oncology (no grant number)
Integrated Molecular-Morphologic Meningioma Classification: A Multicenter Retrospective Analysis, Retrospectively and Prospectively Validated
PURPOSE: Meningiomas are the most frequent primary intracranial tumors. Patient outcome varies widely from benign to highly aggressive, ultimately fatal courses. Reliable identification of risk of progression for individual patients is of pivotal importance. However, only biomarkers for highly aggressive tumors are established (CDKN2A/B and TERT), whereas no molecularly based stratification exists for the broad spectrum of patients with low- and intermediate-risk meningioma.
METHODS: DNA methylation data and copy-number information were generated for 3,031 meningiomas (2,868 patients), and mutation data for 858 samples. DNA methylation subgroups, copy-number variations (CNVs), mutations, and WHO grading were analyzed. Prediction power for outcome was assessed in a retrospective cohort of 514 patients, validated on a retrospective cohort of 184, and on a prospective cohort of 287 multicenter cases.
RESULTS: Both CNV- and methylation family-based subgrouping independently resulted in increased prediction accuracy of risk of recurrence compared with the WHO classification (c-indexes WHO 2016, CNV, and methylation family 0.699, 0.706, and 0.721, respectively). Merging all risk stratification approaches into an integrated molecular-morphologic score resulted in further substantial increase in accuracy (c-index 0.744). This integrated score consistently provided superior accuracy in all three cohorts, significantly outperforming WHO grading (c-index difference P = .005). Besides the overall stratification advantage, the integrated score separates more precisely for risk of progression at the diagnostically challenging interface of WHO grade 1 and grade 2 tumors (hazard ratio 4.34 [2.48-7.57] and 3.34 [1.28-8.72] retrospective and prospective validation cohorts, respectively).
CONCLUSION: Merging these layers of histologic and molecular data into an integrated, three-tiered score significantly improves the precision in meningioma stratification. Implementation into diagnostic routine informs clinical decision making for patients with meningioma on the basis of robust outcome prediction
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