Mitotic disassembly and reassembly of nuclear pore complexes.

https://bura.brunel.ac.uk/bitstream/2438/22558/1/FullText.pdf

Back to the new beginning: Mitotic exit in space and time.

Changing places: Chromosomal Passenger Complex relocation in early anaphase.

Chromosome mis-segregation during mitosis leads to daughter cells with deviant karyotypes (aneuploidy) and an increased mutational burden through chromothripsis of mis-segregated chromosomes. The rate of mis-segregation and the aneuploidy state are hallmarks of cancer and linked to cancer genome evolution. Errors can manifest as “lagging chromosomes” in anaphase, although the mechanistic origins and likelihood of correction are incompletely understood. Here we combine lattice light sheet microscopy, endogenous protein labelling and computational analysis to define the life history of > 104 kinetochores throughout metaphase and anaphase from over 200 cells. By defining the “laziness” of kinetochores in anaphase, we reveal that chromosomes are at a considerable and continual risk of mis-segregation. We show that the majority of kinetochores are corrected rapidly in early anaphase through an Aurora B dependent process. Moreover, quantitative analyses of the kinetochore life histories reveal a unique dynamic signature of metaphase kinetochore oscillations that forecasts their fate in the subsequent anaphase. We propose that in diploid human cells chromosome segregation is fundamentally error prone, with a new layer of early anaphase error correction required for stable karyotype propagation.

https://biorxiv.org/content/10.1101/2021.03.30.436326v1.full.pdf

Kinetochore life histories reveal the origins of chromosome mis-segregation and correction mechanisms

El estudio busca mapear las caracteristicas y tendencias de la produccion cientifica sobre el cuidado de la salud de los adolescentes en Brasil, Scoping review, realizado en 2018, basado en BVS, Cochrane, SciELO, Ebsco y Web of Science. Se incluyeron articulos originales con los siguientes participantes: adolescentes, profesionales de la salud y/o gerentes. Se revisaron 72 estudios publicados de 2006 a 2017. El analisis identifico siete categorias: salud sexual y reproductiva, factores y comportamientos de riesgo, acciones de atencion y promocion, violencia, salud oral, VIH y salud mental. Concluye que persiste la concepcion de la adolescencia como fase del desarrollo humano y como poblacion en riesgo. Hay una brecha sobre temas como la violencia letal, los determinantes sociales de la salud, asi como la salud mental y digital

/pdf/atencao-a-saude-de-adolescentes-no-brasil-scoping-review-5ak8muj00n.pdf

Atenção à saúde de adolescentes no Brasil: scoping review

Summary Micronuclei are a hallmark of cancer and other human disorders and have recently been implicated in chromothripsis, a series of massive genomic rearrangements that may drive tumor evolution and progression. Here we show that Aurora B kinase mediates a surveillance mechanism that integrates error correction during anaphase with spatial control of nuclear envelope reformation to protect against micronuclei formation during human cell division. Using high-resolution live-cell imaging of human cancer and non-cancer cells we found that anaphase lagging chromosomes are often transient and rarely formed micronuclei. This strong bias against micronuclei formation relied on a midzone-based Aurora B phosphorylation gradient that assisted the mechanical transduction of spindle forces at the kinetochore-microtubule interface required for anaphase error correction, while delaying nuclear envelope reformation on lagging chromosomes, independently of microtubules. Our results uncover a new layer of protection against genomic instability and provide a strategy for the rational design of micronuclei-targeting therapies.

/pdf/an-anaphase-surveillance-mechanism-prevents-micronuclei-2szl2ifvc1.pdf

An anaphase surveillance mechanism prevents micronuclei formation from mitotic errors

Objetivo: Avaliar o conhecimento, atitude e pratica de puerperas adolescentes em Alojamento Conjunto (AC) sobre o aleitamento materno exclusivo. Metodos: Trata-se de uma pesquisa avaliativa do tipo Conhecimento, Atitude e Pratica (CAP), que foi realizada com 81 puerperas adolescentes, na faixa etaria de 13 a 19 anos, em um hospital do municipio de Fortaleza/Ceara, no ano de 2013. Os dados foram analisados atraves do programa Statistical Package for the Social Sciences (SPSS). Resultados: Entre as adolescentes, o conhecimento sobre aleitamento materno mostrou-se adequado para 44 (54,3%) das participantes, sendo considerado adequado para 53(65,4%) no quesito atitude. Acerca da pratica, 50 (61,7%) das adolescentes foram consideradas inadequadas para o aleitamento materno. Conclusao: Observou-se, portanto, que o conhecimento, atitude e pratica atuam diretamente no sucesso do aleitamento materno exclusivo, principalmente na adolescencia, fase na qual se vivencia, muitas vezes, a primeira gravidez. Por ﬁ m, devem-se promover acoes de educacao em saude durante todo pre-natal e alojamento conjunto, por parte dos enfermeiros, a ﬁ m de se enfatizar a importância do aleitamento materno exclusivo, considerando as especiﬁ cidades da adolescencia.

/pdf/conhecimento-atitude-e-pratica-de-puerperas-adolescentes-em-nc7yoti812.pdf

Marcela Ariadne Braga Gomes

Papers

An anaphase surveillance mechanism prevents micronuclei formation from mitotic errors

Conhecimento, atitude e prática de puérperas adolescentes em relaçao ao aleitamento materno