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1.
Immunity ; 54(8): 1825-1840.e7, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34270940

RESUMO

Hepatocellular carcinoma (HCC) often develops following chronic hepatitis B virus (HBV) infection and responds poorly to immune checkpoint blockade. Here, we examined the antigen specificities of HCC-infiltrating T cells and their relevance to tumor control. Using highly multiplexed peptide-MHC tetramer staining of unexpanded cells from blood, liver, and tumor tissues from 46 HCC patients, we detected 91 different antigen-specific CD8+ T cell populations targeting HBV, neoantigen, tumor-associated, and disease-unrelated antigens. Parallel high-dimensional analysis delineated five distinct antigen-specific tissue-resident memory T (Trm) cell populations. Intratumoral and intrahepatic HBV-specific T cells were enriched for two Trm cell subsets that were PD-1loTOXlo, despite being clonally expanded. High frequencies of intratumoral terminally exhausted T cells were uncommon. Patients with tumor-infiltrating HBV-specific CD8+ Trm cells exhibited longer-term relapse-free survival. Thus, non-terminally exhausted HBV-specific CD8+ Trm cells show hallmarks of active involvement and effective antitumor response, implying that these cells could be harnessed for therapeutic purposes.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Carcinoma Hepatocelular/imunologia , Memória Imunológica/imunologia , Neoplasias Hepáticas/imunologia , Linfócitos do Interstício Tumoral/imunologia , Antígenos de Neoplasias/imunologia , Carcinoma Hepatocelular/patologia , Vírus da Hepatite B/imunologia , Hepatite B Crônica/imunologia , Proteínas de Grupo de Alta Mobilidade/metabolismo , Humanos , Neoplasias Hepáticas/patologia , Recidiva Local de Neoplasia/imunologia , Recidiva Local de Neoplasia/prevenção & controle , Receptor de Morte Celular Programada 1/metabolismo , Células Tumorais Cultivadas
2.
Nature ; 627(8005): 865-872, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38509377

RESUMO

Disease-associated astrocyte subsets contribute to the pathology of neurologic diseases, including multiple sclerosis and experimental autoimmune encephalomyelitis1-8 (EAE), an experimental model for multiple sclerosis. However, little is known about the stability of these astrocyte subsets and their ability to integrate past stimulation events. Here we report the identification of an epigenetically controlled memory astrocyte subset that exhibits exacerbated pro-inflammatory responses upon rechallenge. Specifically, using a combination of single-cell RNA sequencing, assay for transposase-accessible chromatin with sequencing, chromatin immunoprecipitation with sequencing, focused interrogation of cells by nucleic acid detection and sequencing, and cell-specific in vivo CRISPR-Cas9-based genetic perturbation studies we established that astrocyte memory is controlled by the metabolic enzyme ATP-citrate lyase (ACLY), which produces acetyl coenzyme A (acetyl-CoA) that is used by histone acetyltransferase p300 to control chromatin accessibility. The number of ACLY+p300+ memory astrocytes is increased in acute and chronic EAE models, and their genetic inactivation ameliorated EAE. We also detected the pro-inflammatory memory phenotype in human astrocytes in vitro; single-cell RNA sequencing and immunohistochemistry studies detected increased numbers of ACLY+p300+ astrocytes in chronic multiple sclerosis lesions. In summary, these studies define an epigenetically controlled memory astrocyte subset that promotes CNS pathology in EAE and, potentially, multiple sclerosis. These findings may guide novel therapeutic approaches for multiple sclerosis and other neurologic diseases.


Assuntos
Astrócitos , Encefalomielite Autoimune Experimental , Memória Epigenética , Esclerose Múltipla , Animais , Feminino , Humanos , Masculino , Camundongos , Acetilcoenzima A/metabolismo , Astrócitos/enzimologia , Astrócitos/metabolismo , Astrócitos/patologia , ATP Citrato (pro-S)-Liase/metabolismo , Cromatina/genética , Cromatina/metabolismo , Montagem e Desmontagem da Cromatina , Sequenciamento de Cromatina por Imunoprecipitação , Sistemas CRISPR-Cas , Encefalomielite Autoimune Experimental/enzimologia , Encefalomielite Autoimune Experimental/genética , Encefalomielite Autoimune Experimental/metabolismo , Encefalomielite Autoimune Experimental/patologia , Inflamação/enzimologia , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Esclerose Múltipla/enzimologia , Esclerose Múltipla/genética , Esclerose Múltipla/metabolismo , Esclerose Múltipla/patologia , Análise da Expressão Gênica de Célula Única , Transposases/metabolismo
3.
Nature ; 614(7947): 326-333, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36599367

RESUMO

Multiple sclerosis is a chronic inflammatory disease of the central nervous system1. Astrocytes are heterogeneous glial cells that are resident in the central nervous system and participate in the pathogenesis of multiple sclerosis and its model experimental autoimmune encephalomyelitis2,3. However, few unique surface markers are available for the isolation of astrocyte subsets, preventing their analysis and the identification of candidate therapeutic targets; these limitations are further amplified by the rarity of pathogenic astrocytes. Here, to address these challenges, we developed focused interrogation of cells by nucleic acid detection and sequencing (FIND-seq), a high-throughput microfluidic cytometry method that combines encapsulation of cells in droplets, PCR-based detection of target nucleic acids and droplet sorting to enable in-depth transcriptomic analyses of cells of interest at single-cell resolution. We applied FIND-seq to study the regulation of astrocytes characterized by the splicing-driven activation of the transcription factor XBP1, which promotes disease pathology in multiple sclerosis and experimental autoimmune encephalomyelitis4. Using FIND-seq in combination with conditional-knockout mice, in vivo CRISPR-Cas9-driven genetic perturbation studies and bulk and single-cell RNA sequencing analyses of samples from mouse experimental autoimmune encephalomyelitis and humans with multiple sclerosis, we identified a new role for the nuclear receptor NR3C2 and its corepressor NCOR2 in limiting XBP1-driven pathogenic astrocyte responses. In summary, we used FIND-seq to identify a therapeutically targetable mechanism that limits XBP1-driven pathogenic astrocyte responses. FIND-seq enables the investigation of previously inaccessible cells, including rare cell subsets defined by unique gene expression signatures or other nucleic acid markers.


Assuntos
Astrócitos , Encefalomielite Autoimune Experimental , Microfluídica , Esclerose Múltipla , Ácidos Nucleicos , Análise da Expressão Gênica de Célula Única , Animais , Humanos , Camundongos , Astrócitos/metabolismo , Astrócitos/patologia , Regulação da Expressão Gênica , Camundongos Knockout , Esclerose Múltipla/patologia , Microfluídica/métodos , Análise da Expressão Gênica de Célula Única/métodos , Ácidos Nucleicos/análise , Edição de Genes
4.
Nature ; 620(7975): 881-889, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37558878

RESUMO

Dendritic cells (DCs) have a role in the development and activation of self-reactive pathogenic T cells1,2. Genetic variants that are associated with the function of DCs have been linked to autoimmune disorders3,4, and DCs are therefore attractive therapeutic targets for such diseases. However, developing DC-targeted therapies for autoimmunity requires identification of the mechanisms that regulate DC function. Here, using single-cell and bulk transcriptional and metabolic analyses in combination with cell-specific gene perturbation studies, we identify a regulatory loop of negative feedback that operates in DCs to limit immunopathology. Specifically, we find that lactate, produced by activated DCs and other immune cells, boosts the expression of NDUFA4L2 through a mechanism mediated by hypoxia-inducible factor 1α (HIF-1α). NDUFA4L2 limits the production of mitochondrial reactive oxygen species that activate XBP1-driven transcriptional modules in DCs that are involved in the control of pathogenic autoimmune T cells. We also engineer a probiotic that produces lactate and suppresses T cell autoimmunity through the activation of HIF-1α-NDUFA4L2 signalling in DCs. In summary, we identify an immunometabolic pathway that regulates DC function, and develop a synthetic probiotic for its therapeutic activation.


Assuntos
Doenças Autoimunes , Sistema Nervoso Central , Células Dendríticas , Subunidade alfa do Fator 1 Induzível por Hipóxia , Ácido Láctico , Humanos , Doenças Autoimunes/imunologia , Doenças Autoimunes/metabolismo , Doenças Autoimunes/prevenção & controle , Autoimunidade , Sistema Nervoso Central/citologia , Sistema Nervoso Central/imunologia , Sistema Nervoso Central/patologia , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/química , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Ácido Láctico/metabolismo , Probióticos/uso terapêutico , Espécies Reativas de Oxigênio/metabolismo , Linfócitos T/imunologia , Retroalimentação Fisiológica , Lactase/genética , Lactase/metabolismo , Análise de Célula Única
5.
Nature ; 611(7937): 801-809, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36266581

RESUMO

Genome-wide association studies have identified risk loci linked to inflammatory bowel disease (IBD)1-a complex chronic inflammatory disorder of the gastrointestinal tract. The increasing prevalence of IBD in industrialized countries and the augmented disease risk observed in migrants who move into areas of higher disease prevalence suggest that environmental factors are also important determinants of IBD susceptibility and severity2. However, the identification of environmental factors relevant to IBD and the mechanisms by which they influence disease has been hampered by the lack of platforms for their systematic investigation. Here we describe an integrated systems approach, combining publicly available databases, zebrafish chemical screens, machine learning and mouse preclinical models to identify environmental factors that control intestinal inflammation. This approach established that the herbicide propyzamide increases inflammation in the small and large intestine. Moreover, we show that an AHR-NF-κB-C/EBPß signalling axis operates in T cells and dendritic cells to promote intestinal inflammation, and is targeted by propyzamide. In conclusion, we developed a pipeline for the identification of environmental factors and mechanisms of pathogenesis in IBD and, potentially, other inflammatory diseases.


Assuntos
Meio Ambiente , Herbicidas , Inflamação , Doenças Inflamatórias Intestinais , Intestinos , Animais , Camundongos , Inflamação/induzido quimicamente , Inflamação/etiologia , Inflamação/imunologia , Inflamação/patologia , Doenças Inflamatórias Intestinais/induzido quimicamente , Doenças Inflamatórias Intestinais/etiologia , Doenças Inflamatórias Intestinais/imunologia , Doenças Inflamatórias Intestinais/patologia , Peixe-Zebra , Aprendizado de Máquina , Bases de Dados Factuais , Modelos Animais de Doenças , Intestinos/efeitos dos fármacos , Intestinos/imunologia , Intestinos/metabolismo , Intestinos/patologia , NF-kappa B , Proteína beta Intensificadora de Ligação a CCAAT , Receptores de Hidrocarboneto Arílico , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/metabolismo , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Herbicidas/efeitos adversos
7.
Eur Heart J ; 45(21): 1920-1933, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38666368

RESUMO

BACKGROUND AND AIMS: Longitudinal change in income is crucial in explaining cardiovascular health inequalities. However, there is limited evidence for cardiovascular disease (CVD) risk associated with income dynamics over time among individuals with type 2 diabetes (T2D). METHODS: Using a nationally representative sample from the Korean National Health Insurance Service database, 1 528 108 adults aged 30-64 with T2D and no history of CVD were included from 2009 to 2012 (mean follow-up of 7.3 years). Using monthly health insurance premium information, income levels were assessed annually for the baseline year and the four preceding years. Income variability was defined as the intraindividual standard deviation of the percent change in income over 5 years. The primary outcome was a composite event of incident fatal and nonfatal CVD (myocardial infarction, heart failure, and stroke) using insurance claims. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated after adjusting for potential confounders. RESULTS: High-income variability was associated with increased CVD risk (HRhighest vs. lowest quartile 1.25, 95% CI 1.22-1.27; Ptrend < .001). Individuals who experienced an income decline (4 years ago vs. baseline) had increased CVD risk, which was particularly notable when the income decreased to the lowest level (i.e. Medical Aid beneficiaries), regardless of their initial income status. Sustained low income (i.e. lowest income quartile) over 5 years was associated with increased CVD risk (HRn = 5 years vs. n = 0 years 1.38, 95% CI 1.35-1.41; Ptrend < .0001), whereas sustained high income (i.e. highest income quartile) was associated with decreased CVD risk (HRn = 5 years vs. n = 0 years 0.71, 95% CI 0.70-0.72; Ptrend < .0001). Sensitivity analyses, exploring potential mediators, such as lifestyle-related factors and obesity, supported the main results. CONCLUSIONS: Higher income variability, income declines, and sustained low income were associated with increased CVD risk. Our findings highlight the need to better understand the mechanisms by which income dynamics impact CVD risk among individuals with T2D.


Assuntos
Doenças Cardiovasculares , Diabetes Mellitus Tipo 2 , Renda , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/complicações , Renda/estatística & dados numéricos , Adulto , Doenças Cardiovasculares/epidemiologia , República da Coreia/epidemiologia , Incidência , Fatores de Risco
8.
Br J Cancer ; 130(1): 43-52, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37903909

RESUMO

BACKGROUND: The TeloVac study indicated GV1001 did not improve the survival of advanced pancreatic ductal adenocarcinoma (PDAC). However, the cytokine examinations suggested that high serum eotaxin levels may predict responses to GV1001. This Phase III trial assessed the efficacy of GV1001 with gemcitabine/capecitabine for eotaxin-high patients with untreated advanced PDAC. METHODS: Patients recruited from 16 hospitals received gemcitabine (1000 mg/m2, D 1, 8, and 15)/capecitabine (830 mg/m2 BID for 21 days) per month either with (GV1001 group) or without (control group) GV1001 (0.56 mg; D 1, 3, and 5, once on week 2-4, 6, then monthly thereafter) at random in a 1:1 ratio. The primary endpoint was overall survival (OS) and secondary end points included time to progression (TTP), objective response rate, and safety. RESULTS: Total 148 patients were randomly assigned to the GV1001 (n = 75) and control groups (n = 73). The GV1001 group showed improved median OS (11.3 vs. 7.5 months, P = 0.021) and TTP (7.3 vs. 4.5 months, P = 0.021) compared to the control group. Grade >3 adverse events were reported in 77.3% and 73.1% in the GV1001 and control groups (P = 0.562), respectively. CONCLUSIONS: GV1001 plus gemcitabine/capecitabine improved OS and TTP compared to gemcitabine/capecitabine alone in eotaxin-high patients with advanced PDAC. CLINICAL TRIAL REGISTRATION: NCT02854072.


Assuntos
Adenocarcinoma , Neoplasias Pancreáticas , Humanos , Gencitabina , Capecitabina/efeitos adversos , Desoxicitidina/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias Pancreáticas/patologia , Adenocarcinoma/induzido quimicamente
9.
BMC Med ; 22(1): 88, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38419017

RESUMO

BACKGROUND: The risk of incident atrial fibrillation (AF) among breast cancer survivors, especially for younger women, and cancer treatment effects on the association remain unclear. This study aimed to investigate the risk of AF among breast cancer survivors and evaluate the association by age group, length of follow-up, and cancer treatment. METHODS: Using data from the Korean Health Insurance Service database (2010-2017), 113,232 women newly diagnosed with breast cancer (aged ≥ 18 years) without prior AF history who underwent breast cancer surgery were individually matched 1:5 by birth year to a sample female population without cancer (n = 566,160) (mean[SD] follow-up, 5.1[2.1] years). Sub-distribution hazard ratios (sHRs) and 95% confidence intervals (CIs) considering death as a competing risk were estimated, adjusting for sociodemographic factors and cardiovascular/non-cardiovascular comorbidities. RESULTS: BCS had a slightly increased AF risk compared to their cancer-free counterparts (sHR 1.06; 95% CI 1.00-1.13), but the association disappeared over time. Younger BCS (age < 40 years) had more than a 2-fold increase in AF risk (sHR 2.79; 95% CI 1.98-3.94), with the association remaining similar over 5 years of follow-up. The increased risk was not observed among older BCS, especially those aged > 65 years. Use of anthracyclines was associated with increased AF risk among BCS (sHR 1.57; 95% CI 1.28-1.92), which was more robust in younger BCS (sHR 1.94; 95% CI 1.40-2.69 in those aged ≤ 50 years). CONCLUSIONS: Our findings suggest that younger BCS had an elevated risk of incident AF, regardless of the length of follow-up. Use of anthracyclines may be associated with increased mid-to-long-term AF risk among BCS.


Assuntos
Fibrilação Atrial , Neoplasias da Mama , Sobreviventes de Câncer , Humanos , Feminino , Fibrilação Atrial/epidemiologia , Fibrilação Atrial/diagnóstico , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/cirurgia , Sobreviventes , Antraciclinas , Fatores de Risco , Incidência
10.
Magn Reson Med ; 91(2): 541-557, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37753621

RESUMO

PURPOSE: To investigate whether spatiotemporal magnetic field monitoring can correct pronounced eddy current-induced artifacts incurred by strong diffusion-sensitizing gradients up to 300 mT/m used in high b-value diffusion-weighted (DW) EPI. METHODS: A dynamic field camera equipped with 16 1 H NMR field probes was first used to characterize field perturbations caused by residual eddy currents from diffusion gradients waveforms in a 3D multi-shot EPI sequence on a 3T Connectom scanner for different gradient strengths (up to 300 mT/m), diffusion directions, and shots. The efficacy of dynamic field monitoring-based image reconstruction was demonstrated on high-gradient strength, submillimeter resolution whole-brain ex vivo diffusion MRI. A 3D multi-shot image reconstruction framework was developed that incorporated the nonlinear phase evolution measured with the dynamic field camera. RESULTS: Phase perturbations in the readout induced by residual eddy currents from strong diffusion gradients are highly nonlinear in space and time, vary among diffusion directions, and interfere significantly with the image encoding gradients, changing the k-space trajectory. During the readout, phase modulations between odd and even EPI echoes become non-static and diffusion encoding direction-dependent. Superior reduction of ghosting and geometric distortion was achieved with dynamic field monitoring compared to ghosting reduction approaches such as navigator- and structured low-rank-based methods or MUSE followed by image-based distortion correction with the FSL tool "eddy." CONCLUSION: Strong eddy current artifacts characteristic of high-gradient strength DW-EPI can be well corrected with dynamic field monitoring-based image reconstruction.


Assuntos
Artefatos , Processamento de Imagem Assistida por Computador , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imagem de Difusão por Ressonância Magnética/métodos , Encéfalo/diagnóstico por imagem , Imageamento Tridimensional/métodos , Imagem Ecoplanar/métodos
11.
New Phytol ; 242(3): 1068-1083, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38406998

RESUMO

Chromatin configuration is critical for establishing tissue identity and changes substantially during tissue identity transitions. The crucial scientific and agricultural technology of in vitro tissue culture exploits callus formation from diverse tissue explants and tissue regeneration via de novo organogenesis. We investigated the dynamic changes in H3ac and H3K4me3 histone modifications during leaf-to-callus transition in Arabidopsis thaliana. We analyzed changes in the global distribution of H3ac and H3K4me3 during the leaf-to-callus transition, focusing on transcriptionally active regions in calli relative to leaf explants, defined by increased accumulation of both H3ac and H3K4me3. Peptide signaling was particularly activated during callus formation; the peptide hormones RGF3, RGF8, PIP1 and PIPL3 were upregulated, promoting callus proliferation and conferring competence for de novo shoot organogenesis. The corresponding peptide receptors were also implicated in peptide-regulated callus proliferation and regeneration capacity. The effect of peptide hormones in plant regeneration is likely at least partly conserved in crop plants. Our results indicate that chromatin-dependent regulation of peptide hormone production not only stimulates callus proliferation but also establishes pluripotency, improving the overall efficiency of two-step regeneration in plant systems.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Hormônios Peptídicos , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Código das Histonas , Cromatina , Folhas de Planta/fisiologia , Regulação da Expressão Gênica de Plantas
12.
NMR Biomed ; 37(4): e5087, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38168082

RESUMO

The increasing availability of high-performance gradient systems in human MRI scanners has generated great interest in diffusion microstructural imaging applications such as axonal diameter mapping. Practically, sensitivity to axon diameter in diffusion MRI is attained at strong diffusion weightings b , where the deviation from the expected 1 / b scaling in white matter yields a finite transverse diffusivity, which is then translated into an axon diameter estimate. While axons are usually modeled as perfectly straight, impermeable cylinders, local variations in diameter (caliber variation or beading) and direction (undulation) are known to influence axonal diameter estimates and have been observed in microscopy data of human axons. In this study, we performed Monte Carlo simulations of diffusion in axons reconstructed from three-dimensional electron microscopy of a human temporal lobe specimen using simulated sequence parameters matched to the maximal gradient strength of the next-generation Connectome 2.0 human MRI scanner ( ≲ 500 mT/m). We show that axon diameter estimation is accurate for nonbeaded, nonundulating fibers; however, in fibers with caliber variations and undulations, the axon diameter is heavily underestimated due to caliber variations, and this effect overshadows the known overestimation of the axon diameter due to undulations. This unexpected underestimation may originate from variations in the coarse-grained axial diffusivity due to caliber variations. Given that increased axonal beading and undulations have been observed in pathological tissues, such as traumatic brain injury and ischemia, the interpretation of axon diameter alterations in pathology may be significantly confounded.


Assuntos
Imagem de Difusão por Ressonância Magnética , Substância Branca , Humanos , Imagem de Difusão por Ressonância Magnética/métodos , Axônios/patologia , Imageamento por Ressonância Magnética , Microscopia Eletrônica
14.
J Sleep Res ; : e14226, 2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38676409

RESUMO

The glymphatic system is centred around brain cerebrospinal fluid flow and is enhanced during sleep, and the synaptic homeostasis hypothesis proposes that sleep acts on brain microstructure by selective synaptic downscaling. While so far primarily studied in animals, we here examine in humans if brain diffusivity and microstructure is related to time of day, sleep quality and cognitive performance. We use diffusion weighted images from 916 young healthy individuals, aged between 22 and 37 years, collected as part of the Human Connectome Project to assess diffusion tensor image analysis along the perivascular space index, white matter fractional anisotropy, intra-neurite volume fraction and extra-neurite mean diffusivity. Next, we examine if these measures are associated with circadian time of acquisition, the Pittsburgh Sleep Quality Index (high scores correspond to low sleep quality) and age-adjusted cognitive function total composite score. Consistent with expectations, we find that diffusion tensor image analysis along the perivascular space index and orbitofrontal grey matter extra-neurite mean diffusivity are negatively and white matter fractional anisotropy positively correlated with circadian time. Further, we find that grey matter intra-neurite volume fraction correlates positively with Pittsburgh Sleep Quality Index, and that this correlation is driven by sleep duration. Finally, we find positive correlations between grey matter intra-neurite volume fraction and cognitive function total composite score, as well as negative interaction effects between cognitive function total composite score and Pittsburgh Sleep Quality Index on grey matter intra-neurite volume fraction. Our findings propose that perivascular flow is under circadian control and that sleep downregulates the intra-neurite volume in healthy adults with positive impact on cognitive function.

15.
AIDS Behav ; 28(5): 1601-1611, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38261221

RESUMO

Globally and in Malaysia, there are increasing rates of HIV infection among older adults but a corresponding decline in other younger age groups. We aimed to investigate the HIV-related knowledge, perceived risks, attitudes, and risk behaviours among multi-ethnic urban-dwelling older adults in Malaysia. A cross-sectional, questionnaire-based study was conducted among 320 adults aged 50 years and above residing in urban Klang Valley, Malaysia. Participants were recruited via convenience sampling in the community and in the outpatient clinics and pharmacy of University Malaya Medical Centre, Malaysia, from April 2021 to January 2022. The median (IQR) age of participants was 58 (55-64) and 42.5% were males. The median (IQR) knowledge score was 10 (8-12) out of 14. Significant knowledge gaps were noted and ethnic Chinese, higher education levels and better HIV-related attitudes were associated with better scores. The median (IQR) attitude score was 49 (41-55) out of 65. Ethnic Chinese and Indian, knowing people living with HIV (PLHIV), and better HIV-related knowledge were associated with better attitude scores. Many (43.8%) older adults were sexually active however rates of consistent condom use was low (19%) and the majority (89.9%) of participants had low self-perceived risk of HIV. These findings highlight underlying drivers for HIV transmission and delayed treatment among older adults in Malaysia and indicate a need for targeted HIV prevention programs for this population.


Assuntos
Infecções por HIV , Conhecimentos, Atitudes e Prática em Saúde , População Urbana , Humanos , Masculino , Malásia/epidemiologia , Infecções por HIV/prevenção & controle , Infecções por HIV/transmissão , Infecções por HIV/psicologia , Infecções por HIV/epidemiologia , Infecções por HIV/etnologia , Feminino , Pessoa de Meia-Idade , Estudos Transversais , Inquéritos e Questionários , Comportamento Sexual , Assunção de Riscos , Idoso , Fatores de Risco
16.
Nature ; 554(7693): 500-504, 2018 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-29469093

RESUMO

Memristors are two-terminal passive circuit elements that have been developed for use in non-volatile resistive random-access memory and may also be useful in neuromorphic computing. Memristors have higher endurance and faster read/write times than flash memory and can provide multi-bit data storage. However, although two-terminal memristors have demonstrated capacity for basic neural functions, synapses in the human brain outnumber neurons by more than a thousandfold, which implies that multi-terminal memristors are needed to perform complex functions such as heterosynaptic plasticity. Previous attempts to move beyond two-terminal memristors, such as the three-terminal Widrow-Hoff memristor and field-effect transistors with nanoionic gates or floating gates, did not achieve memristive switching in the transistor. Here we report the experimental realization of a multi-terminal hybrid memristor and transistor (that is, a memtransistor) using polycrystalline monolayer molybdenum disulfide (MoS2) in a scalable fabrication process. The two-dimensional MoS2 memtransistors show gate tunability in individual resistance states by four orders of magnitude, as well as large switching ratios, high cycling endurance and long-term retention of states. In addition to conventional neural learning behaviour of long-term potentiation/depression, six-terminal MoS2 memtransistors have gate-tunable heterosynaptic functionality, which is not achievable using two-terminal memristors. For example, the conductance between a pair of floating electrodes (pre- and post-synaptic neurons) is varied by a factor of about ten by applying voltage pulses to modulatory terminals. In situ scanning probe microscopy, cryogenic charge transport measurements and device modelling reveal that the bias-induced motion of MoS2 defects drives resistive switching by dynamically varying Schottky barrier heights. Overall, the seamless integration of a memristor and transistor into one multi-terminal device could enable complex neuromorphic learning and the study of the physics of defect kinetics in two-dimensional materials.

17.
Nature ; 562(7725): 86-90, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30224747

RESUMO

Topological operations around exceptional points1-8-time-varying system configurations associated with non-Hermitian singularities-have been proposed as a robust approach to achieving far-reaching open-system dynamics, as demonstrated in highly dissipative microwave transmission3 and cryogenic optomechanical oscillator4 experiments. In stark contrast to conventional systems based on closed-system Hermitian dynamics, environmental interferences at exceptional points are dynamically engaged with their internal coupling properties to create rotational stimuli in fictitious-parameter domains, resulting in chiral systems that exhibit various anomalous physical phenomena9-16. To achieve new wave properties and concomitant device architectures to control them, realizations of such systems in application-abundant technological areas, including communications and signal processing systems, are the next step. However, it is currently unclear whether non-Hermitian interaction schemes can be configured in robust technological platforms for further device engineering. Here we experimentally demonstrate a robust silicon photonic structure with photonic modes that transmit through time-asymmetric loops around an exceptional point in the optical domain. The proposed structure consists of two coupled silicon-channel waveguides and a slab-waveguide leakage-radiation sink that precisely control the required non-Hermitian Hamiltonian experienced by the photonic modes. The fabricated devices generate time-asymmetric light transmission over an extremely broad spectral band covering the entire optical telecommunications window (wavelengths between 1.26 and 1.675 micrometres). Thus, we take a step towards broadband on-chip optical devices based on non-Hermitian topological dynamics by using a semiconductor platform with controllable optoelectronic properties, and towards several potential practical applications, such as on-chip optical isolators and non-reciprocal mode converters. Our results further suggest the technological relevance of non-Hermitian wave dynamics in various other branches of physics, such as acoustics, condensed-matter physics and quantum mechanics.

18.
Mol Cell ; 63(6): 1021-33, 2016 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-27618486

RESUMO

Twist has been shown to cause treatment failure, cancer progression, and cancer-related death. However, strategies that directly target Twist are not yet conceivable. Here we reveal that K63-linked ubiquitination is a crucial regulatory mechanism for Twist activation. Through an E3 ligase screen and biochemical studies, we unexpectedly identified that RNF8 functions as a direct Twist activator by triggering K63-linked ubiquitination of Twist. RNF8-promoted Twist ubiquitination is required for Twist localization to the nucleus for subsequent EMT and CSC functions, thereby conferring chemoresistance. Our histological analyses showed that RNF8 expression is upregulated and correlated with disease progression, EMT features, and poor patient survival in breast cancer. Moreover, RNF8 regulates cancer cell migration and invasion and cancer metastasis, recapitulating the effect of Twist. Together, our findings reveal a previously unrecognized tumor-promoting function of RNF8 and provide evidence that targeting RNF8 is an appealing strategy to tackle tumor aggressiveness and treatment resistance.


Assuntos
Neoplasias da Mama/genética , Proteínas de Ligação a DNA/genética , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica , Células-Tronco Neoplásicas/metabolismo , Proteínas Nucleares/genética , Proteína 1 Relacionada a Twist/genética , Animais , Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Dano ao DNA , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/metabolismo , Progressão da Doença , Transição Epitelial-Mesenquimal , Feminino , Genes Reporter , Humanos , Luciferases/genética , Luciferases/metabolismo , Lisina/metabolismo , Células MCF-7 , Camundongos Nus , Invasividade Neoplásica , Transplante de Neoplasias , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/patologia , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Análise de Sobrevida , Proteína 1 Relacionada a Twist/antagonistas & inibidores , Proteína 1 Relacionada a Twist/metabolismo , Ubiquitina-Proteína Ligases , Ubiquitinação
19.
Aust N Z J Psychiatry ; 58(6): 506-514, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38590033

RESUMO

BACKGROUND: Access to a coordinated range of strengths-based, culturally appropriate community-led primary mental health and Social and Emotional Wellbeing services is critical to the mental health and wellbeing of young Aboriginal and Torres Strait Islander people, and is a policy commitment of the Australian government. However, complex and fragmented service networks and a lack of standardised service data are barriers in identifying what services are available and what care they provide. METHOD: A standardised service classification tool was used to assess the availability and characteristics of Social and Emotional Wellbeing services for young Aboriginal and Torres Strait Islander people in two regions in Queensland, Australia. RESULTS: We identified a complex pattern of service availability and gaps in service provision. Non-Indigenous non-governmental organisations provided a significant proportion of services, particularly 'upstream' support, while Aboriginal Community Controlled Organisations were more likely to provide 'downstream' crisis type care. Most services provided by the public sector were through Child Safety and Youth Justice departments. CONCLUSIONS: Our findings demonstrate the complexity of current networks, and show that non-Indigenous organisations are disproportionately influential in the care received by young Aboriginal and Torres Strait Islander people, despite community goals of self-determination, and government commitment to increasing capacity of Aboriginal Community Controlled Organisations to support their local communities. These findings can be used to support decision making and planning.


Assuntos
Serviços de Saúde do Indígena , Adolescente , Criança , Humanos , Povos Aborígenes Australianos e Ilhéus do Estreito de Torres , Acessibilidade aos Serviços de Saúde , Serviços de Saúde do Indígena/organização & administração , Serviços de Saúde Mental/organização & administração , Serviços de Saúde Mental/normas , Queensland
20.
J Korean Med Sci ; 39(9): e87, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38469963

RESUMO

BACKGROUND: Prolonged length of hospital stay (LOS) is associated with an increased risk of hospital-acquired conditions and worse outcomes. We conducted a nationwide, multicenter, retrospective cohort study to determine whether prolonged hospitalization before developing sepsis has a negative impact on its prognosis. METHODS: We analyzed data from 19 tertiary referral or university-affiliated hospitals between September 2019 and December 2020. Adult patients with confirmed sepsis during hospitalization were included. In-hospital mortality was the primary outcome. The patients were divided into two groups according to their LOS before the diagnosis of sepsis: early- (< 5 days) and late-onset groups (≥ 5 days). Conditional multivariable logistic regression for propensity score matched-pair analysis was employed to assess the association between late-onset sepsis and the primary outcome. RESULTS: A total of 1,395 patients were included (median age, 68.0 years; women, 36.3%). The early- and late-onset sepsis groups comprised 668 (47.9%) and 727 (52.1%) patients. Propensity score-matched analysis showed an increased risk of in-hospital mortality in the late-onset group (adjusted odds ratio [aOR], 3.00; 95% confidence interval [CI], 1.69-5.34). The same trend was observed in the entire study population (aOR, 1.85; 95% CI, 1.37-2.50). When patients were divided into LOS quartile groups, an increasing trend of mortality risk was observed in the higher quartiles (P for trend < 0.001). CONCLUSION: Extended LOS before developing sepsis is associated with higher in-hospital mortality. More careful management is required when sepsis occurs in patients hospitalized for ≥ 5 days.


Assuntos
Hospitalização , Sepse , Adulto , Idoso , Feminino , Humanos , Mortalidade Hospitalar , Tempo de Internação , Prognóstico , Estudos Retrospectivos , Masculino
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