Vertebrate centromere architecture: from chromatin threads to functional structures

Centromeres are chromatin structures specialized in sister chromatid cohesion, kinetochore assembly, and microtubule attachment during chromosome segregation. The regional centromere of vertebrates consists of long regions of highly repetitive sequences occupied by the Histone H3 variant CENP-A, and which are flanked by pericentromeres. The three-dimensional organization of centromeric chromatin is paramount for its functionality and its ability to withstand spindle forces. Alongside CENP-A, key contributors to the folding of this structure include components of the Constitutive Centromere-Associated Network (CCAN), the protein CENP-B, and condensin and cohesin complexes. Despite its importance, the intricate architecture of the regional centromere of vertebrates remains largely unknown. Recent advancements in long-read sequencing, super-resolution and cryo-electron microscopy, and chromosome conformation capture techniques have significantly improved our understanding of this structure at various levels, from the linear arrangement of centromeric sequences and their epigenetic landscape to their higher-order compaction. In this review, we discuss the latest insights on centromere organization and place them in the context of recent findings describing a bipartite higher-order organization of the centromere

Análise morfométrica comparada entre Anuros endêmicos do Brasil e a espécie invasora Lithobates catesbeianus

Anfíbios são indicadores ambientais potencialmente confiáveis e eficientes. Estudos referentes a morfologia de leucócitos de anuros são limitados, com poucos estudos morfometricos disponíveis em literatura. O presente estudo empregou técnicas morfometricas para caracterizar leucócitos de anuros Neotropicais brasileiros selecionados e compara-los com a espécie exótica rã-touro (Lithobates catesbeianus), família Ranidae. Esfregaços sanguíneos de 28 espécimes pertencentes a seis gêneros diferentes (Hyla, Phyllomedusa, Hypsiboas, Scinax, Physalaemus e Proceratophrys) foram comparados com amostras de esfregacos de L. catesbeianus. A média do diâmetro dos leucócitos foi calculada por um software de análise de imagens. One-way e teste de Bonferroni foram utilizados para avaliação estatística. Linfócitos, neutrófilos, eosinófilos e basófilos mostraram-se significativamente menores que os valores de referência reportados em outros gêneros de anfíbios, incluindo Lithobathes; por outro lado, a média do diâmetro dos monócitos não demonstrou variação significativa entre os gêneros. Esse e o primeiro estudo de avaliação morfometrica de leucócitos em espécies de anuros brasileiros. Nossos resultados sugerem que a separação geográfica possivelmente influencia a morfometria leucocitaria.Amphibians are potentially reliable and efficient bioindicators. Existing anuran white blood cell morphology studies are limited, with only a few morphometric studies available. We employed morphometric techniques to characterize leukocytes of selected Neotropical anurans from Brazil and compare our findings with the exotic American Bullfrog (Lithobates catesbeianus), genus Ranidae. We compared blood smears of 28 specimens from six different genera (Hyla, Phyllomedusa, Hypsiboas, Scinax, Physalaemus, and Proceratophrys) with samples from L. catesbeianus. Leukocyte average diameter was calculated by an image analysis software. One-way analyses of variance and Bonferroni tests were used on statistical analyses. Lymphocytes, neutrophils, eosinophils, and basophils were significantly smaller than the reference ranges reported for other amphibian genera, including Lithobathes, whereas monocyte diameters did not differ significantly between genera. This is the first study to evaluate leukocyte morphometrics of Brazilian anuran species. Our findings suggest that geographical separation could possibly influence leukocyte morphometry

Spindle checkpoint silencing at kinetochores with submaximal microtubule occupancy

The spindle assembly checkpoint (SAC) ensures proper chromosome segregation by monitoring kinetochore-microtubule interactions. SAC proteins are shed from kinetochores once stable attachments are achieved. Human kinetochores consist of hundreds of SAC protein recruitment modules and bind up to 20 microtubules, raising the question of how the SAC responds to intermediate attachment states. We show that one protein module ('RZZS-MAD1-MAD2') of the SAC is removed from kinetochores at low microtubule occupancy and remains absent at higher occupancies, while another module ('BUB1-BUBR1') is retained at substantial levels irrespective of attachment states. These behaviours reflect different silencing mechanisms: while BUB1 displacement is almost fully dependent on MPS1 inactivation, MAD1 (also known as MAD1L1) displacement is not. Artificially tuning the affinity of kinetochores for microtubules further shows that ∼50% occupancy is sufficient to shed MAD2 and silence the SAC. Kinetochores thus respond as a single unit to shut down SAC signalling at submaximal occupancy states, but retain one SAC module. Thismay ensure continued SAC silencing on kinetochores with fluctuating occupancy states while maintaining the ability for fast SACre-activation

EventPointer 3.0: flexible and accurate splicing analysis that includes studying the differential usage of protein-domains

Alternative splicing (AS) plays a key role in cancer: all its hallmarks have been associated with different mechanisms of abnormal AS. The improvement of the human transcriptome annotation and the availability of fast and accurate software to estimate isoform concentrations has boosted the analysis of transcriptome profiling from RNA-seq. The statistical analysis of AS is a challenging problem not yet fully solved. We have included in EventPointer (EP), a Bioconductor package, a novel statistical method that can use the bootstrap of the pseudoaligners. We compared it with other state-of-the-art algorithms to analyze AS. Its performance is outstanding for shallow sequencing conditions. The statistical framework is very flexible since it is based on design and contrast matrices. EP now includes a convenient tool to find the primers to validate the discoveries using PCR. We also added a statistical module to study alteration in protein domain related to AS. Applying it to 9514 patients from TCGA and TARGET in 19 different tumor types resulted in two conclusions: i) aberrant alternative splicing alters the relative presence of Protein domains and, ii) the number of enriched domains is strongly correlated with the age of the patients

An aphasia research agenda - a consensus statement from the collaboration of aphasia trialists.

Coordination of international aphasia research would minimise duplication of effort, support synergistic international activities across languages and multidisciplinary perspectives, and promote high-quality conduct and reporting of aphasia research, thereby increasing the relevance, transparency, and implementation of findings. The Collaboration of Aphasia Trialists (CATs) sought to develop an aphasia research agenda to direct future research activities, based on priorities shared by people with aphasia, family members, and healthcare professionals. Our established international research network spanning 33 countries contributed to this activity. Research literature reporting the priorities of stakeholders was reviewed and synthesised (phase 1). Representatives from Working Groups on Aphasia Assessment & Outcomes, Prognosis & Predictors of Recovery, Effectiveness of Interventions, and Societal Impact & Reintegration participated in a two-day research agenda setting meeting. The CATs expert panel refined research objectives and identified constituent components of research and methodological developments required to address these research components. The objectives and research components were grouped into overarching themes (phase 2). The resultant list was then circulated to more than 180 CATs members for review, revision, and approval. Consensus on the final aphasia research agenda and road-map was reached by CATs executive committee (phase 3). The expert panel identified five overarching research themes: (i) evidence-based interventions for people with aphasia, (ii) effective interventions to support those communicating with people with aphasia, (iii) cross-linguistic assessment and core outcomes for aphasia research, (iv) predictors of language recovery, and (v) clinical implementation of research findings. Within these broad themes, 30 research objectives and 91 individual aphasia research components were identified and sequentially ordered. This agenda builds on research priorities identified by people with aphasia and their families, and includes priorities of healthcare professionals and researchers, and will support the rehabilitation and recovery of people with aphasia. Our internationally relevant research agenda promotes rigour in methodology, considers international applicability, synergistic activities, and sharing of resources and expertise

Cost-effectiveness analysis of pemetrexed versus docetaxel in the second-line treatment of non-small cell lung cancer in Spain: results for the non-squamous histology population

BackgroundThe objective of this study was to conduct a cost-effectiveness evaluation of pemetrexed compared to docetaxel in the treatment of advanced or metastatic non-small cell lung cancer (NSCLC) for patients with predominantly non-squamous histology in the Spanish healthcare setting.MethodsA Markov model was designed consisting of stable, responsive, progressive disease and death states. Patients could also experience adverse events as long as they received chemotherapy. Clinical inputs were based on an analysis of a phase III clinical trial that identified a statistically significant improvement in overall survival for non-squamous patients treated with pemetrexed compared with docetaxel. Costs were collected from the Spanish healthcare perspective.ResultsOutcomes of the model included total costs, total quality-adjusted life years (QALYs), total life years gained (LYG) and total progression-free survival (PFS). Mean survival was 1.03 years for the pemetrexed arm and 0.89 years in the docetaxel arm; QALYs were 0.52 compared to 0.42. Per-patient lifetime costs were € 34677 and € 32343, respectively. Incremental cost-effectiveness ratios were € 23967 per QALY gained and € 17225 per LYG.ConclusionsPemetrexed as a second-line treatment option for patients with a predominantly non-squamous histology in NSCLC is a cost-effective alternative to docetaxel according to the € 30000/QALY threshold commonly accepted in Spain

Subjective response to antipsychotic treatment and compliance in schizophrenia. A naturalistic study comparing olanzapine, risperidone and haloperidol (EFESO Study)

BACKGROUND: In order to compare the effectiveness of different antipsychotic drugs in the treatment of schizophrenia it is very important to evaluate subjective response and compliance in patient cohorts treated according to routine clinical practice. METHOD: Outpatients with schizophrenia entered this prospective, naturalistic study when they received a new prescription for an antipsychotic drug. Treatment assignment was based on purely clinical criteria, as the study did not include any experimental intervention. Patients treated with olanzapine, risperidone or haloperidol were included in the analysis. Subjective response was measured using the 10-item version of the Drug Attitude Inventory (DAI-10), and treatment compliance was measured using a physician-rated 4 point categorical scale. RESULTS: A total of 2128 patients initiated treatment (as monotherapy) with olanzapine, 417 with risperidone, and 112 with haloperidol. Olanzapine-treated patients had significantly higher DAI-10 scores and significantly better treatment compliance compared to both risperidone- and haloperidol-treated patients. Risperidone-treated patients had a significantly higher DAI-10 score compared to haloperidol-treated patients. CONCLUSION: Subjective response and compliance were superior in olanzapine-treated patients, compared to patients treated with risperidone and haloperidol, in routine clinical practice. Differences in subjective response were explained largely, but not completely, by differences in incidence of EPS

Cost-effectiveness analysis of antimuscarinics in the treatment of patients with overactive bladder in Spain: A decision-tree model

<p>Abstract</p> <p>Background</p> <p>Fesoterodine, a new once daily antimuscarinic, has proven to be an effective, safe, and well-tolerated treatment in patients with overactive bladder (OAB). To date, no analysis has evaluated the economic costs and benefits associated with fesoterodine, compared to antimuscarinics in Spain. The purpose of this analysis was to assess the economic value of OAB treatment with fesoterodine relative to extended release tolterodine and solifenacin, from the societal perspective.</p> <p>Methods</p> <p>The economic model was based on data from two 12-week, randomized, double-blind, and multicenter trials comparing fesoterodine and tolterodine extended released (ER). Treatment response rates for solifenacin were extracted from the published literature. Discontinuation and efficacy were based on the results of a 12-week multinational randomized clinical trial extrapolated to 52 weeks. Changes in health related quality of life were assessed with the King's Health Questionnaire, which was transformed into preference-based utility values. Medical costs included (expressed in € 2010) were antimuscarinics, physician visits, laboratory tests, incontinence pads and the costs of OAB-related comorbidities, fractures, skin infections, urinary tract infections, depression, and nursing home admissions associated with incontinence. Time lost from work was also considered. Univariate sensitivity analyses were also performed.</p> <p>Results</p> <p>At week 12, continents accounted for 50.6%, 40.6% and 47.2% of patients in the fesoterodine, tolterodine, and solifenacin groups, respectively. By week 52, the projected proportions of patients remaining on therapy were 33.1%, 26.5% and 30.8%, respectively. The projected quality- adjusted life years (QALY) gain (compared to baseline) over the 52-week simulation period were 0.01014, 0.00846 and 0.00957, respectively. The overall treatment cost was estimated at €1,937, €2,089 and €1,960 for fesoterodine, tolterodine and solifenacin, respectively. Therefore, treatment with fesoterodine resulted in similar overall costs and greater QALY gain than treatment with either tolterodine or solifenacin. Sensitivity analysis showed that these results were robust to all changes performed.</p> <p>Conclusions</p> <p>The results of this economic analysis suggest that fesoterodine is a cost-effective alternative to tolterodine and solifenacin for the treatment of patients with OAB in Spain. Fesoterodine provides additional health benefits while maintain a similar level of costs being a cost-effective treatment strategy from a societal perspective.</p

Vertebrate centromeres in mitosis are functionally bipartite structures stabilized by cohesin

Centromeres are scaffolds for the assembly of kinetochores that ensure chromosome segregation during cell division. How vertebrate centromeres obtain a three-dimensional structure to accomplish their primary function is unclear. Using super-resolution imaging, capture-C, and polymer modeling, we show that vertebrate centromeres are partitioned by condensins into two subdomains during mitosis. The bipartite structure is found in human, mouse, and chicken cells and is therefore a fundamental feature of vertebrate centromeres. Super-resolution imaging and electron tomography reveal that bipartite centromeres assemble bipartite kinetochores, with each subdomain binding a distinct microtubule bundle. Cohesin links the centromere subdomains, limiting their separation in response to spindle forces and avoiding merotelic kinetochore-spindle attachments. Lagging chromosomes during cancer cell divisions frequently have merotelic attachments in which the centromere subdomains are separated and bioriented. Our work reveals a fundamental aspect of vertebrate centromere biology with implications for understanding the mechanisms that guarantee faithful chromosome segregation