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1.
Cell ; 163(6): 1375-87, 2015 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-26638071

RESUMO

TFIIB-related factor 2 (Brf2) is a member of the family of TFIIB-like core transcription factors. Brf2 recruits RNA polymerase (Pol) III to type III gene-external promoters, including the U6 spliceosomal RNA and selenocysteine tRNA genes. Found only in vertebrates, Brf2 has been linked to tumorigenesis but the underlying mechanisms remain elusive. We have solved crystal structures of a human Brf2-TBP complex bound to natural promoters, obtaining a detailed view of the molecular interactions occurring at Brf2-dependent Pol III promoters and highlighting the general structural and functional conservation of human Pol II and Pol III pre-initiation complexes. Surprisingly, our structural and functional studies unravel a Brf2 redox-sensing module capable of specifically regulating Pol III transcriptional output in living cells. Furthermore, we establish Brf2 as a central redox-sensing transcription factor involved in the oxidative stress pathway and provide a mechanistic model for Brf2 genetic activation in lung and breast cancer.


Assuntos
Oxirredução , Fator de Transcrição TFIIIB/química , Fator de Transcrição TFIIIB/metabolismo , Sequência de Aminoácidos , Animais , Cristalografia por Raios X , DNA/química , DNA/metabolismo , Humanos , Camundongos , Modelos Moleculares , Dados de Sequência Molecular , RNA Polimerase III/metabolismo , Saccharomyces cerevisiae , Alinhamento de Sequência , Transdução de Sinais
2.
Nucleic Acids Res ; 52(12): 6994-7011, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38828775

RESUMO

The clinical success of PARP1/2 inhibitors (PARPi) prompts the expansion of their applicability beyond homologous recombination deficiency. Here, we demonstrate that the loss of the accessory subunits of DNA polymerase epsilon, POLE3 and POLE4, sensitizes cells to PARPi. We show that the sensitivity of POLE4 knockouts is not due to compromised response to DNA damage or homologous recombination deficiency. Instead, POLE4 loss affects replication speed leading to the accumulation of single-stranded DNA gaps behind replication forks upon PARPi treatment, due to impaired post-replicative repair. POLE4 knockouts elicit elevated replication stress signaling involving ATR and DNA-PK. We find POLE4 to act parallel to BRCA1 in inducing sensitivity to PARPi and counteracts acquired resistance associated with restoration of homologous recombination. Altogether, our findings establish POLE4 as a promising target to improve PARPi driven therapies and hamper acquired PARPi resistance.


Assuntos
Proteína BRCA1 , DNA Polimerase II , Replicação do DNA , Inibidores de Poli(ADP-Ribose) Polimerases , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Humanos , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , DNA Polimerase II/metabolismo , DNA Polimerase II/genética , Replicação do DNA/efeitos dos fármacos , Dano ao DNA , Linhagem Celular Tumoral , Recombinação Homóloga/genética , Recombinação Homóloga/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética
3.
Proc Natl Acad Sci U S A ; 120(50): e2309472120, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38060560

RESUMO

Ionizable lipid nanoparticles (LNPs) pivotal to the success of COVID-19 mRNA (messenger RNA) vaccines hold substantial promise for expanding the landscape of mRNA-based therapies. Nevertheless, the risk of mRNA delivery to off-target tissues highlights the necessity for LNPs with enhanced tissue selectivity. The intricate nature of biological systems and inadequate knowledge of lipid structure-activity relationships emphasize the significance of high-throughput methods to produce chemically diverse lipid libraries for mRNA delivery screening. Here, we introduce a streamlined approach for the rapid design and synthesis of combinatorial libraries of biodegradable ionizable lipids. This led to the identification of iso-A11B5C1, an ionizable lipid uniquely apt for muscle-specific mRNA delivery. It manifested high transfection efficiencies in muscle tissues, while significantly diminishing off-targeting in organs like the liver and spleen. Moreover, iso-A11B5C1 also exhibited reduced mRNA transfection potency in lymph nodes and antigen-presenting cells, prompting investigation into the influence of direct immune cell transfection via LNPs on mRNA vaccine effectiveness. In comparison with SM-102, while iso-A11B5C1's limited immune transfection attenuated its ability to elicit humoral immunity, it remained highly effective in triggering cellular immune responses after intramuscular administration, which is further corroborated by its strong therapeutic performance as cancer vaccine in a melanoma model. Collectively, our study not only enriches the high-throughput toolkit for generating tissue-specific ionizable lipids but also encourages a reassessment of prevailing paradigms in mRNA vaccine design. This study encourages rethinking of mRNA vaccine design principles, suggesting that achieving high immune cell transfection might not be the sole criterion for developing effective mRNA vaccines.


Assuntos
Nanopartículas , Vacinas de mRNA , Músculos , Lipossomos , Transfecção
4.
Lancet Oncol ; 25(5): 563-571, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38621400

RESUMO

BACKGROUND: Enzalutamide and lutetium-177 [177Lu]Lu-prostate-specific membrane antigen (PSMA)-617 both improve overall survival in patients with metastatic castration-resistant prostate cancer. Androgen and PSMA receptors have a close intracellular relationship, with data suggesting complementary benefit if targeted concurrently. In this study, we assessed the activity and safety of enzalutamide plus adaptive-dosed [177Lu]Lu-PSMA-617 versus enzalutamide alone as first-line treatment for metastatic castration-resistant prostate cancer. METHODS: ENZA-p was an open-label, randomised, controlled phase 2 trial done at 15 hospitals in Australia. Participants were men aged 18 years or older with metastatic castration-resistant prostate cancer not previously treated with docetaxel or androgen receptor pathway inhibitors for metastatic castration-resistant prostate cancer, gallium-68 [68Ga]Ga-PSMA-PET-CT (PSMA-PET-CT) positive disease, Eastern Cooperative Oncology Group performance status of 0-2, and at least two risk factors for early progression on enzalutamide. Participants were randomly assigned (1:1) by a centralised, web-based system using minimisation with a random component to stratify for study site, disease burden, use of early docetaxel, and previous treatment with abiraterone acetate. Patients were either given oral enzalutamide 160 mg daily alone or with adaptive-dosed (two or four doses) intravenous 7·5 GBq [177Lu]Lu-PSMA-617 every 6-8 weeks dependent on an interim PSMA-PET-CT (week 12). The primary endpoint was prostate-specific antigen (PSA) progression-free survival, defined as the interval from the date of randomisation to the date of first evidence of PSA progression, commencement of non-protocol anticancer therapy, or death. The analysis was done in the intention-to-treat population, using stratified Cox proportional hazards regression. This trial is registered with ClinicalTrials.gov, NCT04419402, and participant follow-up is ongoing. FINDINGS: 162 participants were randomly assigned between Aug 17, 2020, and July 26, 2022. 83 men were assigned to the enzalutamide plus [177Lu]Lu-PSMA-617 group, and 79 were assigned to the enzalutamide group. Median follow-up in this interim analysis was 20 months (IQR 18-21), with 32 (39%) of 83 patients in the enzalutamide plus [177Lu]Lu-PSMA-617 group and 16 (20%) of 79 patients in the enzalutamide group remaining on treatment at the data cutoff date. Median age was 71 years (IQR 64-76). Median PSA progression-free survival was 13·0 months (95% CI 11·0-17·0) in the enzalutamide plus [177Lu]Lu-PSMA-617 group and 7·8 months (95% CI 4·3-11·0) in the enzalutamide group (hazard ratio 0·43, 95% CI 0·29-0·63, p<0·0001). The most common adverse events (all grades) were fatigue (61 [75%] of 81 patients), nausea (38 [47%]), and dry mouth (32 [40%]) in the enzalutamide plus [177Lu]Lu-PSMA-617 group and fatigue (55 [70%] of 79), nausea (21 [27%]), and constipation (18 [23%]) in the enzalutamide group. Grade 3-5 adverse events occurred in 32 (40%) of 81 patients in the enzalutamide plus [177Lu]Lu-PSMA-617 group and 32 (41%) of 79 patients in the enzalutamide group. Grade 3 events that occurred only in the enzalutamide plus [177Lu]Lu-PSMA-617 group included anaemia (three [4%] of 81 participants) and decreased platelet count (one [1%] participant). No grade 4 or 5 events were attributed to treatment on central review in either group. INTERPRETATION: The addition of [177Lu]Lu-PSMA-617 to enzalutamide improved PSA progression-free survival providing evidence of enhanced anticancer activity in patients with metastatic castration-resistant prostate cancer with risk factors for early progression on enzalutamide and warrants further evaluation of the combination more broadly in metastatic prostate cancer. FUNDING: Prostate Cancer Research Alliance (Movember and Australian Federal Government), St Vincent's Clinic Foundation, GenesisCare, Roy Morgan Research, and Endocyte (a Novartis company).


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Benzamidas , Dipeptídeos , Compostos Heterocíclicos com 1 Anel , Lutécio , Nitrilas , Feniltioidantoína , Neoplasias de Próstata Resistentes à Castração , Humanos , Masculino , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/patologia , Neoplasias de Próstata Resistentes à Castração/mortalidade , Feniltioidantoína/administração & dosagem , Feniltioidantoína/uso terapêutico , Feniltioidantoína/análogos & derivados , Idoso , Dipeptídeos/uso terapêutico , Dipeptídeos/administração & dosagem , Dipeptídeos/efeitos adversos , Compostos Heterocíclicos com 1 Anel/uso terapêutico , Compostos Heterocíclicos com 1 Anel/administração & dosagem , Compostos Heterocíclicos com 1 Anel/efeitos adversos , Pessoa de Meia-Idade , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Antígeno Prostático Específico/sangue , Intervalo Livre de Progressão , Radioisótopos/uso terapêutico , Idoso de 80 Anos ou mais , Compostos Radiofarmacêuticos
5.
BMC Med Educ ; 24(1): 416, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38627742

RESUMO

BACKGROUND: Professionals are reluctant to make use of machine learning results for tasks like curriculum development if they do not understand how the results were generated and what they mean. Visualizations of peer reviewed medical literature can summarize enormous amounts of information but are difficult to interpret. This article reports the validation of the meaning of a self-organizing map derived from the Medline/PubMed index of peer reviewed medical literature by its capacity to coherently summarize the references of a core psychiatric textbook. METHODS: Reference lists from ten editions of Kaplan and Sadock's Comprehensive Textbook of Psychiatry were projected onto a self-organizing map trained on Medical Subject Headings annotating the complete set of peer reviewed medical research articles indexed in the Medline/PubMed database (MedSOM). K-means clustering was applied to references from every edition to examine the ability of the self-organizing map to coherently summarize the knowledge contained within the textbook. RESULTS: MedSOM coherently clustered references into six psychiatric knowledge domains across ten editions (1967-2017). Clustering occurred at the abstract level of broad psychiatric practice including General/adult psychiatry, Child psychiatry, and Administrative psychiatry. CONCLUSIONS: The uptake of visualizations of published medical literature by medical experts for purposes like curriculum development depends upon validation of the meaning of the visualizations. The current research demonstrates that a self-organizing map (MedSOM) can validate the stability and coherence of the references used to support the knowledge claims of a standard psychiatric textbook, linking the products of machine learning to a widely accepted standard of knowledge.


Assuntos
Algoritmos , Psiquiatria , Adulto , Criança , Humanos , Aprendizado de Máquina
6.
Int J Mol Sci ; 25(4)2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38396985

RESUMO

Retinitis pigmentosa (RP) is a retinal degenerative disease associated with a diversity of genetic mutations. In a natural progression study (NPS) evaluating the molecular changes in Royal College of Surgeons (RCS) rats using lipidomic profiling, RNA sequencing, and gene expression analyses, changes associated with retinal degeneration from p21 to p60 were evaluated, where reductions in retinal ALOX15 expression corresponded with disease progression. This important enzyme catalyzes the formation of specialized pro-resolving mediators (SPMs) such as lipoxins (LXs), resolvins (RvDs), and docosapentaenoic acid resolvins (DPA RvDs), where reduced ALOX15 corresponded with reduced SPMs. Retinal DPA RvD2 levels were found to correlate with retinal structural and functional decline. Retinal RNA sequencing comparing p21 with p60 showed an upregulation of microglial inflammatory pathways accompanied by impaired damage-associated molecular pattern (DAMP) clearance pathways. This analysis suggests that ALXR/FPR2 activation can ameliorate disease progression, which was supported by treatment with an LXA4 analog, NAP1051, which was able to promote the upregulation of ALOX12 and ALOX15. This study showed that retinal inflammation from activated microglia and dysregulation of lipid metabolism were central to the pathogenesis of retinal degeneration in RP, where ALXR/FPR2 activation was able to preserve retinal structure and function.


Assuntos
Araquidonato 15-Lipoxigenase , Degeneração Retiniana , Retinose Pigmentar , Animais , Humanos , Ratos , Araquidonato 15-Lipoxigenase/genética , Araquidonato 15-Lipoxigenase/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Retina/metabolismo , Degeneração Retiniana/patologia , Retinose Pigmentar/metabolismo
7.
Australas Psychiatry ; : 10398562241249579, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38686826

RESUMO

OBJECTIVE: Public services offering gender-affirming care to minors have rapidly expanded across Australia. Despite limited evidence of safety and efficacy, no public information about these services is routinely available. Data from freedom of information requests sent to Australian public gender services for minors is summarised. Gender service numbers increased rapidly in Queensland (2017:190 - 2022:922) and in Victoria (2019:472 - 2023:1290). Limited transparency prevented strong confidence in the number of patients receiving hormone therapy. Staff FTE employed by gender services jumped after 2020 in NSW (to 16.7 across two sites in 2023), Queensland (to 11.4 in 2023), Victoria (to 9.4 in 2022), and WA (to 10.2 in 2023). CONCLUSIONS: Despite low confidence in their safety and efficacy, the number of patients seen by public gender services has expanded rapidly since 2018. Limited transparency makes it difficult to judge the number of patients seen, treatments provided, and outcomes achieved. Safe, effective care of this vulnerable group requires clear treatment goals, and annual reporting.

8.
Br J Dermatol ; 189(Suppl 1): i3-i10, 2023 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-37903072

RESUMO

Immune checkpoint inhibitors (ICIs) have revolutionized treatment strategies in the field of oncology. Their favourable outcomes in terms of efficacy and side-effect profile can be thwarted by the development of immune-related adverse events (irAEs). Cutaneous irAEs are relatively common in patients undergoing immunotherapy and include common inflammatory dermatoses (e.g. eczematous, psoriasiform and lichenoid phenotypes), maculopapular eruptions, pruritus and immunobullous disorders. Most of these reactions can be managed without ICIs having to be stopped completely; however, there are some life-threatening toxicities that dermatologists and oncologists should be aware of. In this review, we focus on how to recognize the commonly associated cutaneous irAEs, touching upon rarer reactions and red flags; finally, we provide guidance on their management.


Assuntos
Exantema , Neoplasias , Dermatopatias , Humanos , Inibidores de Checkpoint Imunológico/efeitos adversos , Neoplasias/tratamento farmacológico , Dermatopatias/induzido quimicamente , Pele , Exantema/etiologia , Imunoterapia/efeitos adversos
9.
Brain ; 145(11): 3816-3831, 2022 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-35696452

RESUMO

Brain voltage-gated sodium channel NaV1.1 (SCN1A) loss-of-function variants cause the severe epilepsy Dravet syndrome, as well as milder phenotypes associated with genetic epilepsy with febrile seizures plus. Gain of function SCN1A variants are associated with familial hemiplegic migraine type 3. Novel SCN1A-related phenotypes have been described including early infantile developmental and epileptic encephalopathy with movement disorder, and more recently neonatal presentations with arthrogryposis. Here we describe the clinical, genetic and functional evaluation of affected individuals. Thirty-five patients were ascertained via an international collaborative network using a structured clinical questionnaire and from the literature. We performed whole-cell voltage-clamp electrophysiological recordings comparing sodium channels containing wild-type versus variant NaV1.1 subunits. Findings were related to Dravet syndrome and familial hemiplegic migraine type 3 variants. We identified three distinct clinical presentations differing by age at onset and presence of arthrogryposis and/or movement disorder. The most severely affected infants (n = 13) presented with congenital arthrogryposis, neonatal onset epilepsy in the first 3 days of life, tonic seizures and apnoeas, accompanied by a significant movement disorder and profound intellectual disability. Twenty-one patients presented later, between 2 weeks and 3 months of age, with a severe early infantile developmental and epileptic encephalopathy and a movement disorder. One patient presented after 3 months with developmental and epileptic encephalopathy only. Associated SCN1A variants cluster in regions of channel inactivation associated with gain of function, different to Dravet syndrome variants (odds ratio = 17.8; confidence interval = 5.4-69.3; P = 1.3 × 10-7). Functional studies of both epilepsy and familial hemiplegic migraine type 3 variants reveal alterations of gating properties in keeping with neuronal hyperexcitability. While epilepsy variants result in a moderate increase in action current amplitude consistent with mild gain of function, familial hemiplegic migraine type 3 variants induce a larger effect on gating properties, in particular the increase of persistent current, resulting in a large increase of action current amplitude, consistent with stronger gain of function. Clinically, 13 out of 16 (81%) gain of function variants were associated with a reduction in seizures in response to sodium channel blocker treatment (carbamazepine, oxcarbazepine, phenytoin, lamotrigine or lacosamide) without evidence of symptom exacerbation. Our study expands the spectrum of gain of function SCN1A-related epilepsy phenotypes, defines key clinical features, provides novel insights into the underlying disease mechanisms between SCN1A-related epilepsy and familial hemiplegic migraine type 3, and identifies sodium channel blockers as potentially efficacious therapies. Gain of function disease should be considered in early onset epilepsies with a pathogenic SCN1A variant and non-Dravet syndrome phenotype.


Assuntos
Artrogripose , Epilepsias Mioclônicas , Epilepsia , Enxaqueca com Aura , Transtornos dos Movimentos , Espasmos Infantis , Humanos , Epilepsias Mioclônicas/tratamento farmacológico , Epilepsias Mioclônicas/genética , Epilepsias Mioclônicas/diagnóstico , Epilepsia/genética , Epilepsia/diagnóstico , Mutação com Ganho de Função , Canal de Sódio Disparado por Voltagem NAV1.1/genética , Fenótipo , Recém-Nascido , Lactente
10.
Phys Chem Chem Phys ; 25(9): 6562-6585, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36810655

RESUMO

The QM/MM simulation method is provenly efficient for the simulation of biological systems, where an interplay of extensive environment and delicate local interactions drives a process of interest through a funnel on a complex energy landscape. Recent advances in quantum chemistry and force-field methods present opportunities for the adoption of QM/MM to simulate heterogeneous catalytic processes, and their related systems, where similar intricacies exist on the energy landscape. Herein, the fundamental theoretical considerations for performing QM/MM simulations, and the practical considerations for setting up QM/MM simulations of catalytic systems, are introduced; then, areas of heterogeneous catalysis are explored where QM/MM methods have been most fruitfully applied. The discussion includes simulations performed for adsorption processes in solvent at metallic interfaces, reaction mechanisms within zeolitic systems, nanoparticles, and defect chemistry within ionic solids. We conclude with a perspective on the current state of the field and areas where future opportunities for development and application exist.

11.
BMC Public Health ; 23(1): 945, 2023 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-37231468

RESUMO

BACKGROUND: There is extensive evidence for the cost-effectiveness of programmatic and additional tuberculosis (TB) interventions, but no studies have employed the social return on investment (SROI) methodology. We conducted a SROI analysis to measure the benefits of a community health worker (CHW) model for active TB case finding and patient-centered care. METHODS: This mixed-method study took place alongside a TB intervention implemented in Ho Chi Minh City, Viet Nam, between October-2017 - September-2019. The valuation encompassed beneficiary, health system and societal perspectives over a 5-year time-horizon. We conducted a rapid literature review, two focus group discussions and 14 in-depth interviews to identify and validate pertinent stakeholders and material value drivers. We compiled quantitative data from the TB program's and the intervention's surveillance systems, ecological databases, scientific publications, project accounts and 11 beneficiary surveys. We mapped, quantified and monetized value drivers to derive a crude financial benefit, which was adjusted for four counterfactuals. We calculated a SROI based on the net present value (NPV) of benefits and investments using a discounted cash flow model with a discount rate of 3.5%. A scenario analysis assessed SROI at varying discount rates of 0-10%. RESULTS: The mathematical model yielded NPVs of US$235,511 in investments and US$8,497,183 in benefits. This suggested a return of US$36.08 for each dollar invested, ranging from US$31.66-US39.00 for varying discount rate scenarios. CONCLUSIONS: The evaluated CHW-based TB intervention generated substantial individual and societal benefits. The SROI methodology may be an alternative for the economic evaluation of healthcare interventions.


Assuntos
Agentes Comunitários de Saúde , Tuberculose , Humanos , Análise Custo-Benefício , Vietnã/epidemiologia , Cidades , Tuberculose/terapia , Tuberculose/epidemiologia
12.
Health Promot Pract ; 24(1): 121-132, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35382643

RESUMO

"Common-sense" physical activity (PA) interventions for older adults may be more effective if developed in accordance with behavior change theory. One way to achieve this is through retrospectively applying a theoretical behavior change framework to "reverse code" an existing intervention and guide its ongoing development. This study aimed to detail a clear and systematic procedure that applied elements of the Behaviour Change Wheel (BCW) framework to reverse code the Active Ageing Pathway (AAP) intervention. The objectives of the procedure were to characterize the content of the AAP and its links to behavior change theory. The content of the AAP was first deconstructed through the examination of "standard operating procedures" documents, in-person observation, and a series of face-to-face discussions with AAP management. Then, the behavior change techniques (BCT) and BCW intervention functions associated with the AAP's content were identified and coded using the BCT Taxonomy version 1. Forty-one active components were identified within the AAP, which involved numerous professionals, and pertained to a diverse and interlinked range of factors, across various modes of delivery. The components were classified under 20 separate BCT labels, which related to eight of the nine BCW intervention functions. These outcomes were demonstrated to have practical applications for identifying gaps in intervention content as well as for guiding future intervention evaluation. This study supports previous work detailing the usefulness of reverse coding procedures as a tool for developing common-sense interventions, and is the first to do so in the context of a PA intervention for older adults.


Assuntos
Exercício Físico , Promoção da Saúde , Humanos , Idoso , Estudos Retrospectivos , Terapia Comportamental/métodos
13.
J Neurosci ; 41(18): 4100-4119, 2021 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-33753548

RESUMO

Understanding how and where in the brain sentence-level meaning is constructed from words presents a major scientific challenge. Recent advances have begun to explain brain activation elicited by sentences using vector models of word meaning derived from patterns of word co-occurrence in text corpora. These studies have helped map out semantic representation across a distributed brain network spanning temporal, parietal, and frontal cortex. However, it remains unclear whether activation patterns within regions reflect unified representations of sentence-level meaning, as opposed to superpositions of context-independent component words. This is because models have typically represented sentences as "bags-of-words" that neglect sentence-level structure. To address this issue, we interrogated fMRI activation elicited as 240 sentences were read by 14 participants (9 female, 5 male), using sentences encoded by a recurrent deep artificial neural-network trained on a sentence inference task (InferSent). Recurrent connections and nonlinear filters enable InferSent to transform sequences of word vectors into unified "propositional" sentence representations suitable for evaluating intersentence entailment relations. Using voxelwise encoding modeling, we demonstrate that InferSent predicts elements of fMRI activation that cannot be predicted by bag-of-words models and sentence models using grammatical rules to assemble word vectors. This effect occurs throughout a distributed network, which suggests that propositional sentence-level meaning is represented within and across multiple cortical regions rather than at any single site. In follow-up analyses, we place results in the context of other deep network approaches (ELMo and BERT) and estimate the degree of unpredicted neural signal using an "experiential" semantic model and cross-participant encoding.SIGNIFICANCE STATEMENT A modern-day scientific challenge is to understand how the human brain transforms word sequences into representations of sentence meaning. A recent approach, emerging from advances in functional neuroimaging, big data, and machine learning, is to computationally model meaning, and use models to predict brain activity. Such models have helped map a cortical semantic information-processing network. However, how unified sentence-level information, as opposed to word-level units, is represented throughout this network remains unclear. This is because models have typically represented sentences as unordered "bags-of-words." Using a deep artificial neural network that recurrently and nonlinearly combines word representations into unified propositional sentence representations, we provide evidence that sentence-level information is encoded throughout a cortical network, rather than in a single region.


Assuntos
Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/fisiologia , Compreensão/fisiologia , Idioma , Redes Neurais de Computação , Semântica , Adulto , Simulação por Computador , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Leitura , Adulto Jovem
14.
EMBO J ; 37(19)2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30177573

RESUMO

Newly synthesised histones are thought to dimerise in the cytosol and undergo nuclear import in complex with histone chaperones. Here, we provide evidence that human H3.1 and H4 are imported into the nucleus as monomers. Using a tether-and-release system to study the import dynamics of newly synthesised histones, we find that cytosolic H3.1 and H4 can be maintained as stable monomeric units. Cytosolically tethered histones are bound to importin-alpha proteins (predominantly IPO4), but not to histone-specific chaperones NASP, ASF1a, RbAp46 (RBBP7) or HAT1, which reside in the nucleus in interphase cells. Release of monomeric histones from their cytosolic tether results in rapid nuclear translocation, IPO4 dissociation and incorporation into chromatin at sites of replication. Quantitative analysis of histones bound to individual chaperones reveals an excess of H3 specifically associated with sNASP, suggesting that NASP maintains a soluble, monomeric pool of H3 within the nucleus and may act as a nuclear receptor for newly imported histone. In summary, we propose that histones H3 and H4 are rapidly imported as monomeric units, forming heterodimers in the nucleus rather than the cytosol.


Assuntos
Núcleo Celular/metabolismo , Histonas/metabolismo , Interfase/fisiologia , Chaperonas Moleculares/metabolismo , Transporte Ativo do Núcleo Celular/fisiologia , Núcleo Celular/genética , Células HeLa , Histonas/genética , Humanos , Chaperonas Moleculares/genética
15.
Int J Obes (Lond) ; 46(9): 1624-1632, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35662271

RESUMO

OBJECTIVE: To analyse the Growing Up in Scotland cohort for predictors of obesity at age 12, present at school entry (age 5-6). METHODS: The initial model included literature-based risk factors likely to be routinely collected in high-income countries (HICs), as well as "Adverse/Protective Childhood Experiences (ACEs/PCEs)". Missing data were handled by Multiple Chained Equations. Variable-reduction was performed using multivariable logistic regression with backwards and forwards stepwise elimination, followed by internal validation by bootstrapping. Optimal sensitivity/specificity cut-offs for the most parsimonious and accurate models in two situations (optimum available data, and routinely available data in Scotland) were examined for their referral burden, and Positive and Negative Predictive Values. RESULTS: Data for 2787 children with full outcome data (obesity prevalence 18.3% at age 12) were used to develop the models. The final "Optimum Data" model included six predictors of obesity: maternal body mass index, indoor smoking, equivalized income quintile, child's sex, child's BMI at age 5-6, and ACEs. After internal validation, the area under the receiver operating characteristic curve was 0.855 (95% CI 0.852-0.859). A cut-off based on Youden's J statistic for the Optimum Data model yielded a specificity of 77.6% and sensitivity of 76.3%. 37.0% of screened children were "Total Screen Positives" (and thus would constitute the "referral burden".) A "Scottish Data" model, without equivalized income quintile and ACEs as a predictor, and instead using Scottish Index of Multiple Deprivation quintile and "age at introduction of solid foods," was slightly less sensitive (76.2%) but slightly more specific (79.2%), leading to a smaller referral burden (30.8%). CONCLUSION: Universally collected, machine readable and linkable data at age 5-6 predict reasonably well children who will be obese by age 12. However, the Scottish treatment system is unable to cope with the resultant referral burden and other criteria for screening would have to be met.


Assuntos
Obesidade Infantil , Índice de Massa Corporal , Criança , Pré-Escolar , Estudos de Coortes , Humanos , Obesidade Infantil/diagnóstico , Obesidade Infantil/epidemiologia , Obesidade Infantil/prevenção & controle , Estudos Prospectivos , Fatores de Risco
16.
Crit Care ; 26(1): 164, 2022 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-35672834

RESUMO

BACKGROUND: Interleukin (IL)-18 is a marker of inflammasome activation, and high baseline plasma IL-18 is associated with increased mortality in patients with sepsis-induced ARDS. The aim of this analysis was to determine if simvastatin was associated with benefit in patients with ARDS and high plasma IL-18. METHODS: In this secondary analysis of the HARP-2 study, we compared 28-day mortality and response to simvastatin according to baseline plasma IL-18 using cox proportional hazards analysis. Separately, monocyte-derived macrophages from healthy volunteers were pre-incubated with simvastatin or rosuvastatin before stimulation with ATP and LPS, and the effect on secreted IL-18 and IL-1ß compared. RESULTS: 511 patients from HARP-2 had available data. High baseline plasma IL-18 (≥ 800 pg/ml) was associated with increased 28-day mortality (high IL-18 30.6% vs. low IL-18 17.5%; HR 1.89 [95% CI 1.30-2.73]; p = 0.001). Allocation to simvastatin in patients with high baseline plasma IL-18 was associated with a lower probability of 28-day mortality compared with placebo (24.0% vs 36.8%; p = 0.01). Finally, simvastatin, but not rosuvastatin, reduced stimulated macrophage secretion of IL-18 and IL-1ß. CONCLUSION: In patients with high baseline plasma IL-18, simvastatin is associated with a higher probability of survival, and this effect may be due to reduced inflammasome activation. These data suggest that baseline plasma IL-18 may allow a personalised treatment approach by identifying patients with ARDS who could benefit from simvastatin therapy.


Assuntos
Síndrome do Desconforto Respiratório , Sinvastatina , Proteínas de Transporte , Citocinas , Humanos , Inflamassomos , Interleucina-18 , Síndrome do Desconforto Respiratório/tratamento farmacológico , Sinvastatina/farmacologia , Sinvastatina/uso terapêutico
17.
Australas Psychiatry ; 30(1): 18-22, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34570635

RESUMO

OBJECTIVE: To guide the efficient and effective provision of mental health services to clients in Central West and Far North Queensland, we surveyed preferences for face-to-face or in-person contact. METHODS: A clinician-designed survey of contact preferences was offered to 248 clients of mental health services in Far North and Central West Queensland in mid-2020. With the onset of COVID-19, the survey was modified to measure the impact of the pandemic. RESULTS: Just over half of the services' clients participated in the survey (50.4%), of whom more were female (63.2%). Of the participants, 46.3% in Far North and 8.6% in Central West Queensland identified as Indigenous. Strong resistance to telehealth before the pandemic across groups (76%) was moderated during COVID-19 (42.4%), an effect that appeared likely to continue past the pandemic for Central West clients (34.5%). Far North clients indicated their telehealth reluctance would return after the pandemic (77.6%). CONCLUSIONS: Our results suggest that remote Australians strongly prefer in-person mental health care to telehealth. Although the COVID-19 pandemic increased acceptance of telehealth across regions while social distancing continued, there was evidence that Indigenous Australians were more likely to prefer in-person contact after the pandemic.


Assuntos
COVID-19 , Serviços de Saúde Mental , Saúde Mental , Telemedicina , Feminino , Humanos , Masculino , Pandemias , Queensland , Encaminhamento e Consulta , SARS-CoV-2 , Telemedicina/métodos
18.
Langmuir ; 37(31): 9472-9477, 2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34310876

RESUMO

Nanoscale device fabrication requires control over film growth at the atomic scale. Growth conditions must be tuned in consideration of interface parameters like chemical bonding, surface free energy, and lattice matching. In metals, electronic properties may also be utilized for control of physical parameters. Quantum size effects can induce metals to spontaneously form specific shapes and sizes according to their electronic structure. Unfortunately, such electronic growth is generally known only for a few systems and is typically only stable under cryogenic conditions. In this work, we explore a recently discovered class of electronic growth systems in which metal films are grown upon the relatively inert surfaces of van der Waals crystals. In this class of materials, the electronic growth is highly stable at room temperature and actually requires higher temperature annealing to achieve proper equilibrium. We work with the Au/MoS2 system, which shows excellent stability and can readily form discrete and atomically flat nanostructures. Here, we show how the electronic growth modes facilitate the formation of atomically flat films with nanometer scale thickness. The surface roughness of these films was found to be less than a single atom over several square microns, creating nearly perfect surfaces for studies of self-assembled monolayers or other applications.

19.
BMC Health Serv Res ; 21(1): 1051, 2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34610841

RESUMO

BACKGROUND: Many tuberculosis (TB) patients incur catastrophic costs. Active case finding (ACF) may have socio-protective properties that could contribute to the WHO End TB Strategy target of zero TB-affected families suffering catastrophic costs, but available evidence remains limited. This study measured catastrophic cost incurrence and socioeconomic impact of an episode of TB and compared those socioeconomic burdens in patients detected by ACF versus passive case finding (PCF). METHODS: This cross-sectional study fielded a longitudinal adaptation of the WHO TB patient cost survey alongside an ACF intervention from March 2018 to March 2019. The study was conducted in six intervention (ACF) districts and six comparison (PCF) districts of Ho Chi Minh City, Viet Nam. Fifty-two TB patients detected through ACF and 46 TB patients in the PCF cohort were surveyed within two weeks of treatment initiation, at the end of the intensive phase of treatment, and after treatment concluded. The survey measured income, direct and indirect costs, and socioeconomic impact based on which we calculated catastrophic cost as the primary outcome. Local currency was converted into US$ using the average exchange rates reported by OANDA for the study period (VND1 = US$0.0000436, 2018-2019). We fitted logistic regressions for comparisons between the ACF and PCF cohorts as the primary exposures and used generalized estimating equations to adjust for autocorrelation. RESULTS: ACF patients were poorer than PCF patients (multidimensional poverty ratio: 16 % vs. 7 %; p = 0.033), but incurred lower median pre-treatment costs (US$18 vs. US$80; p < 0.001) and lower median total costs (US$279 vs. US$894; p < 0.001). Fewer ACF patients incurred catastrophic costs (15 % vs. 30 %) and had lower odds of catastrophic cost (aOR = 0.17; 95 % CI: [0.05, 0.67]; p = 0.011), especially during the intensive phase (OR = 0.32; 95 % CI: [0.12, 0.90]; p = 0.030). ACF patient experienced less social exclusion (OR = 0.41; 95 % CI: [0.18, 0.91]; p = 0.030), but more often resorted to financial coping mechanisms (OR = 5.12; 95 % CI: [1.73, 15.14]; p = 0.003). CONCLUSIONS: ACF can be effective in reaching vulnerable populations and mitigating the socioeconomic burden of TB, and can contribute to achieving the WHO End TB Strategy goals. Nevertheless, as TB remains a catastrophic life event, social protection efforts must extend beyond ACF.


Assuntos
Tuberculose , Estudos Transversais , Custos de Cuidados de Saúde , Humanos , Renda , Vietnã/epidemiologia
20.
Proc Natl Acad Sci U S A ; 115(46): 11820-11825, 2018 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-30385636

RESUMO

When oxygen becomes limiting, denitrifying bacteria must prepare for anaerobic respiration by synthesizing the reductases NAR (NO3- → NO2-), NIR (NO2- → NO), NOR (2NO → N2O), and NOS (N2O → N2), either en bloc or sequentially, to avoid entrapment in anoxia without energy. Minimizing the metabolic burden of this precaution is a plausible fitness trait, and we show that the model denitrifier Paracoccus denitrificans achieves this by synthesizing NOS in all cells, while only a minority synthesize NIR. Phenotypic diversification with regards to NIR is ascribed to stochastic initiation of gene transcription, which becomes autocatalytic via NO production. Observed gas kinetics suggest that such bet hedging is widespread among denitrifying bacteria. Moreover, in response to oxygenation, P. denitrificans preserves NIR in the poles of nongrowing persister cells, ready to switch to anaerobic respiration in response to sudden anoxia. Our findings add dimensions to the regulatory biology of denitrification and identify regulatory traits that decrease N2O emissions.


Assuntos
Desnitrificação/fisiologia , Nitratos/metabolismo , Paracoccus denitrificans/metabolismo , Bactérias/metabolismo , Hipóxia/metabolismo , Óxido Nitroso/metabolismo , Oxirredutases/metabolismo , Oxigênio/metabolismo
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