Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 163
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Proteome Res ; 23(5): 1844-1858, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38621258

RESUMO

The application of proteomic analysis to forensic skeletal remains has gained significant interest in improving biological and chronological estimations in medico-legal investigations. To enhance the applicability of these analyses to forensic casework, it is crucial to maximize throughput and proteome recovery while minimizing interoperator variability and laboratory-induced post-translational protein modifications (PTMs). This work compared different workflows for extracting, purifying, and analyzing bone proteins using liquid chromatography with tandem mass spectrometry (LC-MS)/MS including an in-StageTip protocol previously optimized for forensic applications and two protocols using novel suspension-trap technology (S-Trap) and different lysis solutions. This study also compared data-dependent acquisition (DDA) with data-independent acquisition (DIA). By testing all of the workflows on 30 human cortical tibiae samples, S-Trap workflows resulted in increased proteome recovery with both lysis solutions tested and in decreased levels of induced deamidations, and the DIA mode resulted in greater sensitivity and window of identification for the identification of lower-abundance proteins, especially when open-source software was utilized for data processing in both modes. The newly developed S-Trap protocol is, therefore, suitable for forensic bone proteomic workflows and, particularly when paired with DIA mode, can offer improved proteomic outcomes and increased reproducibility, showcasing its potential in forensic proteomics and contributing to achieving standardization in bone proteomic analyses for forensic applications.


Assuntos
Proteômica , Espectrometria de Massas em Tandem , Humanos , Proteômica/métodos , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida/métodos , Osso e Ossos/química , Osso e Ossos/metabolismo , Proteoma/análise , Fluxo de Trabalho , Processamento de Proteína Pós-Traducional , Software
2.
J Am Chem Soc ; 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38832750

RESUMO

Dimerized quantum magnets are exotic crystalline materials where Bose-Einstein condensation of magnetic excitations can happen. However, known dimerized quantum magnets are limited to only a few oxides and halides. Here, we unveil 9 dimerized quantum magnets and 11 conventional antiferromagnets in ternary metal borides MTB4 (M = Sc, Y, La, Ce, Lu, Mg, Ca, and Al; T = V, Cr, Mn, Fe, Co, and Ni), where T atoms are arranged in structural dimers. Quantum magnetism in these compounds is dominated by strong antiferromagnetic (AFM) interactions between Cr (Cr and Mn for M = Mg and Ca) atoms within the dimers, with much weaker interactions between the dimers. These systems are proposed to be close to a quantum critical point between a disordered singlet spin-dimer phase, with a spin gap, and the ordered conventional Néel AFM phase. They greatly enrich the materials inventory that allows investigations of the spin-gap phase. Conventional antiferromagnetism in these compounds is dominated by ferromagnetic Mn (Fe for M = Mg and Ca) interactions within the dimers. The predicted stable and nonmagnetic (NM) YFeB4 phase is synthesized and characterized, providing a scarce candidate to study Fe dimers and Fe ladders in borides. The identified quantum, conventional, and NM systems provide a platform with abundant possibilities to tune the magnetic exchange coupling by doping and study the unconventional quantum phase transition and conventional magnetic transitions. This work opens new avenues for studying novel magnetism in borides arising from spin dimers and establishes a theoretical workflow for future searches for dimerized quantum magnets in other families of materials.

3.
Prehosp Emerg Care ; 28(3): 506-512, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37478002

RESUMO

Background/problem: Information transfer between emergency medical services (EMS) and emergency medicine (EM) is at high risk for omissions and errors. EM awareness of prehospital medication administration affects patient management and medication error. In April 2020, we surveyed emergency physicians and emergency department nurse practitioners (NPs) and physician assistants (PAs) regarding the EMS handoff process. Emergency physicians and NPs/PAs endorsed knowing what medications were given, or having received direct verbal handoff from EMS "Often" or "Always" only 20% of the time (n = 71), identifying a need to improve the written handoff process. To assess rates of medication error due to lack of awareness of prehospital administered medications, we measured glucocorticoid redosing in the emergency department (ED) following prehospital dexamethasone administration. In 2020, glucocorticoids were redosed 30% of the time, and our aim was to reduce glucocorticoid redosing to 10% by June 2022. Intervention: We developed and implemented a system innovation where prehospital-administered medications documented in a nursing flowsheet during verbal handoff are pulled directly into the triage note where they are more likely to be reviewed by receiving EM clinicians. Results: Shewhart p-charts were used to evaluate for statistical process change in the process measure of triage note documentation of prehospital medication administration and the outcome measure of glucocorticoid redosing. While the frequency of prehospital dexamethasone administration in the triage note increased, no statistical process change outcome measure of glucocorticoid redosing was observed. However, on repeat survey of EM clinicians in July 2022, 50% now indicated they were aware of prehospital medication administration "Often" or "Always" (n = 61, p = 0.003), 87% maintained they use the triage note as the main source of information regarding prehospital medication administration, and 81% "Always" review the triage note. Conclusions: Innovations that improve accessibility of written documentation of prehospital medication administration were associated with improved subjective assessment of EM clinician awareness of prehospital medications, but not the outcome measure of medication error. Effective error reduction likely requires better system integration between prehospital and EM records.


Assuntos
Serviços Médicos de Emergência , Humanos , Glucocorticoides , Serviço Hospitalar de Emergência , Erros de Medicação , Dexametasona
4.
J Cell Sci ; 134(7)2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33758078

RESUMO

Centriole duplication is tightly controlled to maintain correct centriole number through the cell cycle. Key to this is the regulated degradation of PLK4, the master regulator of centriole duplication. Here, we show that the Rac1 guanine nucleotide exchange factor (GEF) Tiam1 localises to centrosomes during S-phase, where it is required for the maintenance of normal centriole number. Depletion of Tiam1 leads to an increase in centrosomal PLK4 and centriole overduplication, whereas overexpression of Tiam1 can restrict centriole overduplication. Ultimately, Tiam1 depletion leads to lagging chromosomes at anaphase and aneuploidy, which are potential drivers of malignant progression. The effects of Tiam1 depletion on centrosomal PLK4 levels and centriole overduplication can be rescued by re-expression of both wild-type Tiam1 and catalytically inactive (GEF*) Tiam1, but not by Tiam1 mutants unable to bind to the F-box protein ßTRCP (also known as F-box/WD repeat-containing protein 1A) implying that Tiam1 regulates PLK4 levels through promoting ßTRCP-mediated degradation independently of Rac1 activation.


Assuntos
Centríolos , Proteínas Serina-Treonina Quinases , Ciclo Celular , Proteínas de Ciclo Celular/genética , Centrossomo
5.
Thorax ; 78(10): 1019-1027, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-36808087

RESUMO

BACKGROUND: Tracheostomies in children are associated with significant morbidity, poor quality of life, excess healthcare costs and excess mortality. The underlying mechanisms facilitating adverse respiratory outcomes in tracheostomised children are poorly understood. We aimed to characterise airway host defence in tracheostomised children using serial molecular analyses. METHODS: Tracheal aspirates, tracheal cytology brushings and nasal swabs were prospectively collected from children with a tracheostomy and controls. Transcriptomic, proteomic and metabolomic methods were applied to characterise the impact of tracheostomy on host immune response and the airway microbiome. RESULTS: Children followed up serially from the time of tracheostomy up to 3 months postprocedure (n=9) were studied. A further cohort of children with a long-term tracheostomy were also enrolled (n=24). Controls (n=13) comprised children without a tracheostomy undergoing bronchoscopy. Long-term tracheostomy was associated with airway neutrophilic inflammation, superoxide production and evidence of proteolysis when compared with controls. Reduced airway microbial diversity was established pre-tracheostomy and sustained thereafter. CONCLUSIONS: Long-term childhood tracheostomy is associated with a inflammatory tracheal phenotype characterised by neutrophilic inflammation and the ongoing presence of potential respiratory pathogens. These findings suggest neutrophil recruitment and activation as potential exploratory targets in seeking to prevent recurrent airway complications in this vulnerable group of patients.


Assuntos
Proteômica , Traqueostomia , Criança , Humanos , Traqueostomia/efeitos adversos , Qualidade de Vida , Traqueia , Inflamação/etiologia
6.
Sex Health ; 20(6): 531-537, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37743095

RESUMO

BACKGROUND: Traditional school-based sexuality education has a myriad of problems with its successful delivery, including access to comprehensive sexuality curricula, access to trained facilitators, and community and parental fears. As an alternative form of sexuality education, The Sex Wrap podcast is released in weekly episodes of about 20-45min, providing listeners with diverse, evidence-based sexual health information. METHODS: Participants in a larger mixed-methods study evaluating The Sex Wrap were invited to participate in qualitative in-depth interviews to explore their experiences with sexuality education, including The Sex Wrap , and how they relate to information received through the podcast. Seventeen interviews were conducted with listeners of The Sex Wrap , aged 20-25years old. RESULTS: One core category and three axial codes were identified in the interview data. The core category is: sexuality education is an ongoing process that includes learning and unlearning. The three temporally related axial codes are: (1) experiences with formal and informal sexuality education (mostly negative) drove participants to seek more information about sex, (2) participants use The Sex Wrap as a way of exploring and personalising information about sexuality, and (3) participants equipped with comprehensive sexuality education are empowered to educate their peers. CONCLUSIONS: This study suggests that podcast-based interventions, such as The Sex Wrap , can play a key role in young people's process of sexuality education and should be considered for incorporation into other forms of sex education.


Assuntos
Educação Sexual , Saúde Sexual , Humanos , Adolescente , Comportamento Sexual , Sexualidade , Currículo
7.
Antimicrob Agents Chemother ; 66(4): e0195721, 2022 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-35285676

RESUMO

Monoclonal antibody (mAb)-based immunotherapies targeting systemic and deep-seated fungal infections are still in their early stages of development, with no licensed antifungal mAbs currently being available for patients at risk. The cell wall glycoproteins of Candida albicans are of particular interest as potential targets for therapeutic antibody generation due to their extracellular location and key involvement in fungal pathogenesis. Here, we describe the generation of recombinant human antibodies specifically targeting two key cell wall proteins (CWPs) in C. albicans: Utr2 and Pga31. These antibodies were isolated from a phage display antibody library using peptide antigens representing the surface-exposed regions of CWPs expressed at elevated levels during in vivo infection. Reformatted human-mouse chimeric mAbs preferentially recognized C. albicans hyphal forms compared to yeast cells, and increased binding was observed when the cells were grown in the presence of the antifungal agent caspofungin. In J774.1 macrophage interaction assays, mAb pretreatment resulted in the faster engulfment of C. albicans cells, suggesting a role of the CWP antibodies as opsonizing agents during phagocyte recruitment. Finally, in a series of clinically predictive mouse models of systemic candidiasis, our lead mAb achieved improved survival (83%) and a several-log reduction of the fungal burden in the kidneys, similar to the levels achieved for the fungicidal drug caspofungin and superior to the therapeutic efficacy of any anti-Candida mAb reported to date.


Assuntos
Anticorpos Monoclonais , Candida albicans , Animais , Anticorpos Antifúngicos , Anticorpos Monoclonais/farmacologia , Antifúngicos/farmacologia , Antígenos de Fungos , Caspofungina , Parede Celular , Epitopos , Humanos , Camundongos
8.
J Cell Sci ; 132(14)2019 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-31289196

RESUMO

Oriented cell divisions are important for the formation of normal epithelial structures. Dlg1, a tumour suppressor, is required for mitotic spindle orientation in Drosophila epithelia and chick neuroepithelia, but how Dlg1 is localised to the membrane and its importance in mammalian epithelia are unknown. We show that Dlg1 is required in non-transformed mammalian epithelial cells for oriented cell divisions and normal lumen formation. We demonstrate that the MAGUK protein CASK, a membrane-associated scaffold, is the factor responsible for Dlg1 membrane localisation during spindle orientation, thereby identifying a new cellular function for CASK. Depletion of CASK leads to misoriented divisions in 3D, and to the formation of multilumen structures in cultured kidney and breast epithelial cells. Blocking the CASK-Dlg1 interaction with an interfering peptide, or by deletion of the CASK-interaction domain of Dlg1, disrupts spindle orientation and causes multilumen formation. We show that the CASK-Dlg1 interaction is important for localisation of the canonical LGN-NuMA complex known to be required for spindle orientation. These results establish the importance of the CASK-Dlg1 interaction in oriented cell division and epithelial integrity.This article has an associated First Person interview with the first author of the paper.


Assuntos
Proteína 1 Homóloga a Discs-Large/metabolismo , Epitélio/metabolismo , Guanilato Quinases/metabolismo , Mitose , Fuso Acromático/metabolismo , Animais , Membrana Celular/metabolismo , Cães , Células Madin Darby de Rim Canino , Mamíferos , Ligação Proteica
9.
Clin Proteomics ; 18(1): 20, 2021 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-34384350

RESUMO

BACKGROUND: It is not enough to optimize proteomics assays. It is critical those assays are robust to operating conditions. Without robust assays, proteomic biomarkers are unlikely to translate readily into the clinic. This study outlines a structured approach to the identification of a robust operating window for proteomics assays and applies that method to Sequential Window Acquisition of all Theoretical Spectra Mass Spectroscopy (SWATH-MS). METHODS: We used a sequential quality by design approach exploiting a fractional screening design to first identify critical SWATH-MS parameters, then using response surface methods to identify a robust operating window with good reproducibility, before validating those settings in a separate validation study. RESULTS: The screening experiment identified two critical SWATH-MS parameters. We modelled the number of proteins and reproducibility as a function of those parameters identifying an operating window permitting robust maximization of the number of proteins quantified in human serum. In a separate validation study, these settings were shown to give good proteome-wide coverage and high quantification reproducibility. CONCLUSIONS: Using design of experiments permits identification of a robust operating window for SWATH-MS. The method gives a good understanding of proteomics assays and greater data-driven confidence in SWATH-MS performance.

10.
J Health Commun ; 26(2): 121-126, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33736576

RESUMO

It is well documented that social interactions have a crucial impact on all aspects of personal development for adolescents, however few studies have documented how social interactions affect a young person's sense of sexual agency. The aim of the current qualitative study was to examine young people's perceptions of their own sexual agency in relation to their social media attitudes and behaviors. Participants (n = 31) were recruited from a nonprofit organization and asked to complete a one-hour in-depth interview and a demographic survey. Using an inductive method, involving constant comparison, we identified four overarching themes: (a) Participants utilize different social media platforms for distinct purposes and are cognizant of each audience; (b) Based on past experiences, participants have negotiated and created their own rules of engagement for online behavior; (c) Participants have different expectations about how others should act online versus how they act in relation to flirty or sexual messages; (d) Participants were concerned about the authenticity of online identities and are aware of vulnerability in online interactions. Our results highlight the need for sexual health researchers to observe social network etiquette closely through the lens of autonomy and agency.


Assuntos
Comportamento Sexual/psicologia , Mídias Sociais/estatística & dados numéricos , Adolescente , Adulto , Feminino , Humanos , Masculino , Pesquisa Qualitativa , Adulto Jovem
11.
Biochem Soc Trans ; 48(6): 2703-2719, 2020 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-33200195

RESUMO

The Tiam family proteins - Tiam1 and Tiam2/STEF - are Rac1-specific Guanine Nucleotide Exchange Factors (GEFs) with important functions in epithelial, neuronal, immune and other cell types. Tiam GEFs regulate cellular migration, proliferation and survival, mainly through activating and directing Rac1 signalling. Dysregulation of the Tiam GEFs is significantly associated with human diseases including cancer, immunological and neurological disorders. Uncovering the mechanisms and consequences of dysregulation is therefore imperative to improving the diagnosis and treatment of diseases. Here we compare and contrast the subcellular localisation and function of Tiam1 and Tiam2/STEF, and review the evidence for their dysregulation in disease.


Assuntos
Fatores de Troca do Nucleotídeo Guanina/metabolismo , Neoplasias/metabolismo , Proteína 1 Indutora de Invasão e Metástase de Linfoma de Células T/metabolismo , Proteínas rac de Ligação ao GTP/metabolismo , Animais , Adesão Celular , Movimento Celular , Proliferação de Células , Sobrevivência Celular , Humanos , Sistema Imunitário , Doenças do Sistema Nervoso/metabolismo , Neurônios/metabolismo , Domínios Proteicos , Processamento Pós-Transcricional do RNA , Transdução de Sinais , Proteínas rac1 de Ligação ao GTP/metabolismo
12.
Rheumatology (Oxford) ; 59(Suppl 3): iii28-iii32, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32348517

RESUMO

OBJECTIVES: Takayasu arteritis commonly results in severe arterial injury with stenoses, occlusions and occasionally aneurysms. Arterial disease may compromise organ blood flow and result in significant cardiovascular morbidity and premature mortality. Involvement of the supra-aortic arteries is common, and in its most severe form may compromise cerebral blood supply, resulting in signs of cerebral ischaemia including visual impairment, dysphasia, transient hemiparesis, loss of consciousness and stroke. In addition to combination immunosuppression, the management paradigm for symptomatic cerebral ischaemia includes revascularization. The invasive nature of this surgery, the risk of complications and the relatively high rate of re-stenosis is of concern to patients and their physicians alike. The aim of this study was to determine whether combined immunosuppression with early escalation to biologic therapy improved outcomes and reduced the need for high risk surgical intervention. METHODS: A retrospective review of 145 Takayasu arteritis patients attending Imperial College Healthcare between 2010-2018 was conducted to identify those with cerebral ischaemia secondary to supra-aortic disease and to analyse their treatment and outcomes. RESULTS: Eight patients (5.5%) were identified. Seven patients received long-term combined immunosuppressive therapy and six were prescribed biologics. The data revealed a higher than expected comprehensive response to therapy, with significant falls in disease activity, the cerebral ischaemia score and the prednisolone dose required, over a median follow-up of 37 months. Serial imaging analysis detected no arterial disease progression after the initiation of optimal therapy. Only one patient required surgical intervention for persistent neurological symptoms. CONCLUSION: Early use of biologic therapy in those with supra-aortic Takayasu arteritis presenting with cerebral ischaemia may reduce the numbers of patients requiring surgical intervention and improve outcomes.


Assuntos
Terapia Biológica , Isquemia Encefálica/etiologia , Isquemia Encefálica/terapia , Arterite de Takayasu/complicações , Adulto , Feminino , Humanos , Estudos Retrospectivos , Adulto Jovem
13.
FASEB J ; 33(2): 2796-2808, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30303738

RESUMO

Microcephalin-1 (MCPH1) exists as 2 isoforms that regulate cyclin-dependent kinase-1 activation and chromosome condensation during mitosis, with MCPH1 mutations causing primary microcephaly. MCPH1 is also a tumor suppressor protein, with roles in DNA damage repair/checkpoints. Despite these important roles, there is little information on the cellular regulation of MCPH1. We show that both MCPH1 isoforms are phosphorylated in a cyclin-dependent kinase-1-dependent manner in mitosis and identify several novel phosphorylation sites. Upon mitotic exit, MCPH1 isoforms were degraded by the anaphase-promoting complex/cyclosome-CDH1 E3 ligase complex. Anaphase-promoting complex/cyclosome-CDH1 target proteins generally have D-Box or KEN-Box degron sequences. We found that MCPH1 isoforms are degraded independently, with the long isoform degradation being D-Box dependent, whereas the short isoform was KEN-Box dependent. Our research identifies several novel mechanisms regulating MCPH1 and also highlights important issues with several commercial MCPH1 antibodies, with potential relevance to previously published data.-Meyer, S. K., Dunn, M., Vidler, D. S., Porter, A., Blain, P. G., Jowsey, P. A. Phosphorylation of MCPH1 isoforms during mitosis followed by isoform-specific degradation by APC/C-CDH1.


Assuntos
Ciclossomo-Complexo Promotor de Anáfase/metabolismo , Antígenos CD/metabolismo , Caderinas/metabolismo , Cromatina/metabolismo , Regulação da Expressão Gênica , Mitose , Proteínas do Tecido Nervoso/metabolismo , Ciclossomo-Complexo Promotor de Anáfase/genética , Antígenos CD/genética , Caderinas/genética , Ciclo Celular , Proteínas de Ciclo Celular , Proteínas do Citoesqueleto , Células HEK293 , Células HeLa , Humanos , Proteínas do Tecido Nervoso/genética , Ligação Proteica , Isoformas de Proteínas , Proteólise
14.
J Child Psychol Psychiatry ; 61(3): 294-308, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31373003

RESUMO

Suicide is a leading cause of death among youth worldwide. The purpose of the current review was to examine recent cross-national trends in suicide mortality rates among 10- to 19-year-olds. This study extracted suicide mortality data from the World Health Organization's (WHO) Mortality Database for the most recent year (since 2010) from any country with available high-quality data (as defined by the WHO's guidelines). Data on access to lethal means (firearms, railways) and measures of economic quality (World Bank Income Group) and inequality (Gini coefficients) were obtained from publicly available data sources. Cross-national suicide mortality rates in youth were heterogeneous. The pooled estimate across all ages, sexes, and countries was 3.77/100,000 people. The highest suicide rates were found in Estonia, New Zealand, and Uzbekistan. Suicide rates were higher among older compared with younger adolescents and higher among males than females. The most common suicide methods were hanging/suffocation and jumping/lying in front of a moving object or jumping from a height. Firearm and railway access were related to suicide deaths by firearms and jumping/lying, respectively. Economic quality and inequality were not related to overall suicide mortality rates. However, economic inequality was correlated with a higher ratio of male:female suicides. This study provides a recent update of cross-national suicide trends in adolescents. Findings replicate prior patterns related to age, sex, geographic region, and common suicide methods. New to this review are findings relating suicide method accessibility to suicide mortality rates and the significant association between income inequality and the ratio of male:female suicide. Future research directions include expanding the worldwide coverage to more low- and middle-income countries, examining demographic groupings beyond binary sex and to race/ethnicity within countries, and clarifying factors that account for cross-national differences in suicide trends.


Assuntos
Comportamento do Adolescente , Saúde Global/estatística & dados numéricos , Suicídio Consumado/estatística & dados numéricos , Adolescente , Adulto , Criança , Humanos , Adulto Jovem
15.
Proteomics ; 19(15): e1900156, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31301205

RESUMO

Advances in liquid chromatography-mass spectrometry have facilitated the incorporation of proteomic studies to many biology experimental workflows. Data-independent acquisition platforms, such as sequential window acquisition of all theoretical mass spectra (SWATH-MS), offer several advantages for label-free quantitative assessment of complex proteomes over data-dependent acquisition (DDA) approaches. However, SWATH data interpretation requires spectral libraries as a detailed reference resource. The guinea pig (Cavia porcellus) is an excellent experimental model for translation to many aspects of human physiology and disease, yet there is limited experimental information regarding its proteome. To overcome this knowledge gap, a comprehensive spectral library of the guinea pig proteome is generated. Homogenates and tryptic digests are prepared from 16 tissues and subjected to >200 DDA runs. Analysis of >250 000 peptide-spectrum matches resulted in a library of 73 594 peptides from 7666 proteins. Library validation is provided by i) analyzing externally derived SWATH files (https://doi.org/10.1016/j.jprot.2018.03.023) and comparing peptide intensity quantifications; ii) merging of externally derived data to the base library. This furnishes the research community with a comprehensive proteomic resource that will facilitate future molecular-phenotypic studies using (re-engaging) the guinea pig as an experimental model of relevance to human biology. The spectral library and raw data are freely accessible in the MassIVE repository (MSV000083199).


Assuntos
Proteoma/análise , Espectrometria de Massas em Tandem/métodos , Animais , Cobaias , Peptídeos/análise
16.
Stem Cells ; 36(10): 1535-1551, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30004612

RESUMO

The availability of in vitro models of the human retina in which to perform pharmacological and toxicological studies is an urgent and unmet need. An essential step for developing in vitro models of human retina is the ability to generate laminated, physiologically functional, and light-responsive retinal organoids from renewable and patient specific sources. We investigated five different human-induced pluripotent stem cell (iPSC) lines and showed a significant variability in their efficiency to generate retinal organoids. Despite this variability, by month 5 of differentiation, all iPSC-derived retinal organoids were able to generate light responses, albeit immature, comparable to the earliest light responses recorded from the neonatal mouse retina, close to the period of eye opening. All iPSC-derived retinal organoids exhibited at this time a well-formed outer nuclear like layer containing photoreceptors with inner segments, connecting cilium, and outer like segments. The differentiation process was highly dependent on seeding cell density and nutrient availability determined by factorial experimental design. We adopted the differentiation protocol to a multiwell plate format, which enhanced generation of retinal organoids with retinal-pigmented epithelium (RPE) and improved ganglion cell development and the response to physiological stimuli. We tested the response of iPSC-derived retinal organoids to Moxifloxacin and showed that similarly to in vivo adult mouse retina, the primary affected cell types were photoreceptors. Together our data indicate that light responsive retinal organoids derived from carefully selected and differentiation efficient iPSC lines can be generated at the scale needed for pharmacology and drug screening purposes. Stem Cells 2018;36:1535-1551.


Assuntos
Células-Tronco Pluripotentes Induzidas/metabolismo , Nutrientes/genética , Organoides/metabolismo , Retina/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Diferenciação Celular , Feminino , Humanos , Masculino , Camundongos , Organoides/citologia , Retina/citologia
17.
Nucleic Acids Res ; 45(10): 5995-6010, 2017 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-28472494

RESUMO

Topoisomerase (topo) IIα and IIß maintain genome stability and are targets for anti-tumor drugs. In this study, we demonstrate that the decatenation checkpoint is regulated, not only by topo IIα, as previously reported, but also by topo IIß. The decatenation checkpoint is most efficient when both isoforms are present. Regulation of this checkpoint and sensitivity to topo II-targeted drugs is influenced by the C-terminal domain (CTD) of the topo II isoforms and by a conserved non-catalytic tyrosine, Y640 in topo IIα and Y656 in topo IIß. Deletion of most of the CTD of topo IIα, while preserving the nuclear localization signal (NLS), enhances the decatenation checkpoint and sensitivity to topo II-targeted drugs. In contrast, deletion of most of the CTD of topo IIß, while preserving the NLS, and mutation of Y640 in topo IIα and Y656 in topo IIß inhibits these activities. Structural studies suggest that the differential impact of the CTD on topo IIα and topo IIß function may be due to differences in CTD charge distribution and differential alignment of the CTD with reference to transport DNA. Together these results suggest that topo IIα and topo IIß cooperate to maintain genome stability, which may be distinctly modulated by their CTDs.


Assuntos
Antígenos de Neoplasias/química , Pontos de Checagem do Ciclo Celular/fisiologia , Instabilidade Cromossômica/fisiologia , DNA Topoisomerases Tipo II/química , Proteínas de Ligação a DNA/química , Sequência de Aminoácidos , Animais , Antígenos de Neoplasias/efeitos dos fármacos , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/fisiologia , Linhagem Celular , Dano ao DNA , DNA Topoisomerases Tipo II/efeitos dos fármacos , DNA Topoisomerases Tipo II/genética , DNA Topoisomerases Tipo II/fisiologia , DNA Complementar/genética , Proteínas de Ligação a DNA/efeitos dos fármacos , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/fisiologia , Resistencia a Medicamentos Antineoplásicos , Fibroblastos , Células HL-60 , Humanos , Camundongos , Mutagênese Sítio-Dirigida , Domínios Proteicos , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Relação Estrutura-Atividade , Inibidores da Topoisomerase II/farmacologia
18.
J Clin Child Adolesc Psychol ; 48(2): 263-272, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30632815

RESUMO

Prior research indicates that adults' implicit identification with death can be used to predict suicidal thoughts and behaviors (STBs) in the community. However, no studies have examined whether this effect is found among adolescents-a group for whom suicide is the 2nd leading cause of death. The current study tested the utility of implicit identification with death, using a Death Implicit Association Test (IAT), for detecting and predicting STBs in adolescents. Participants were 141 adolescents 12-19 years of age (81.6% female, 74.5% White) with a current psychiatric disorder and/or currently receiving outpatient psychiatric treatment. All participants completed the Death IAT and self-report measures of STBs at baseline, as well as self-report measures of STBs at 6-month and 1-year follow-ups. At baseline, stronger implicit identification with death (higher Death IAT score) was related to greater suicide ideation (SI) frequency, severity, and duration, but did not differ based on suicide attempt history. Prospectively, higher Death IAT scores predicted any occurrence (but not frequency) of SI over the subsequent year, but not when controlling for prior SI. Death IAT scores were higher among adolescents with prior attempts who reattempted suicide over the follow-up. Examination of stimuli-level results suggested that Death IAT differences may be driven by responses on trials with specific words, including suicide and die. Implicit identification with death may be a useful behavioral indicator of suicide risk in adolescents. Preliminary findings suggest that the Death IAT may aid in predicting STBs among youth receiving outpatient treatment.


Assuntos
Comportamento do Adolescente/psicologia , Atitude Frente a Morte , Ideação Suicida , Tentativa de Suicídio/psicologia , Adolescente , Assistência Ambulatorial , Criança , Feminino , Humanos , Masculino , Transtornos Mentais/terapia , Autorrelato , Adulto Jovem
19.
J Clin Child Adolesc Psychol ; 48(3): 357-392, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31046461

RESUMO

The current review provides an evidence base update of psychosocial treatments for self-injurious thoughts and behaviors (SITBs) in youth. A systematic search was conducted of 2 major scientific databases (PsycInfo and PubMed) and ClinicalTrials.gov for relevant randomized controlled trials (RCTs) published prior to June 2018. The search identified 26 RCTs examining interventions for SITBs in youth: 17 were included in the 2015 review and 9 trials were new to this update. The biggest change since the prior review was the evaluation of Dialectical Behavior Therapy for adolescents (DBT-A) as the first Level 1: Well-established intervention for reducing deliberate self-harm (composite of nonsuicidal and suicidal self-injury) and suicide ideation in youth and Level 2: Probably efficacious for reducing nonsuicidal self-injury and suicide attempts. Five other interventions were rated as Level 2: Probably efficacious for reducing SITBs in youth, with the new addition of Integrated Family Therapy. This evidence base update indicates that there are a few promising treatments for reducing SITBs in youth. Efficacious interventions typically include a significant family or parent training component as well as skills training (e.g., emotion regulation skills). Aside from DBT-A, few treatments have been examined in more than one RCT. Given that replication by independent research groups is needed to evaluate an intervention as Well-established, future research should focus on replicating the five promising interventions currently evaluated as Probably efficacious. In addition, an important future direction is to develop brief efficacious interventions that may be scalable to reach large numbers of youth.


Assuntos
Comportamento Infantil/psicologia , Psicologia/métodos , Comportamento Autodestrutivo/terapia , Tentativa de Suicídio/psicologia , Adolescente , Adulto , Criança , Medicina Baseada em Evidências , Humanos , Comportamento Autodestrutivo/psicologia , Adulto Jovem
20.
Int J Mol Sci ; 20(5)2019 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-30871006

RESUMO

Type II topoisomerase enzymes are essential for resolving DNA topology problems arising through various aspects of DNA metabolism. In vertebrates two isoforms are present, one of which (TOP2A) accumulates on chromatin during mitosis. Moreover, TOP2A targets the mitotic centromere during prophase, persisting there until anaphase onset. It is the catalytically-dispensable C-terminal domain of TOP2 that is crucial in determining this isoform-specific behaviour. In this study we show that, in addition to the recently identified chromatin tether domain, several other features of the alpha-C-Terminal Domain (CTD). influence the mitotic localisation of TOP2A. Lysine 1240 is a major SUMOylation target in cycling human cells and the efficiency of this modification appears to be influenced by T1244 and S1247 phosphorylation. Replacement of K1240 by arginine results in fewer cells displaying centromeric TOP2A accumulation during prometaphase-metaphase. The same phenotype is displayed by cells expressing TOP2A in which either of the mitotic phosphorylation sites S1213 or S1247 has been substituted by alanine. Conversely, constitutive modification of TOP2A by fusion to SUMO2 exerts the opposite effect. FRAP analysis of protein mobility indicates that post-translational modification of TOP2A can influence the enzyme's residence time on mitotic chromatin, as well as its subcellular localisation.


Assuntos
Anáfase/fisiologia , Cromatina/metabolismo , DNA Topoisomerases Tipo II/metabolismo , Metáfase/fisiologia , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Linhagem Celular , Centrômero/metabolismo , Proteínas de Ligação a DNA/metabolismo , Células HEK293 , Humanos , Fosforilação/fisiologia , Processamento de Proteína Pós-Traducional/fisiologia , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/metabolismo , Sumoilação/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA