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1.
Nat Immunol ; 24(5): 814-826, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36997670

RESUMO

Missense mutations in PLCG2 can cause autoinflammation with phospholipase C gamma 2-associated antibody deficiency and immune dysregulation (APLAID). Here, we generated a mouse model carrying an APLAID mutation (p.Ser707Tyr) and found that inflammatory infiltrates in the skin and lungs were only partially ameliorated by removing inflammasome function via the deletion of caspase-1. Also, deleting interleukin-6 or tumor necrosis factor did not fully prevent APLAID mutant mice from autoinflammation. Overall, these findings are in accordance with the poor response individuals with APLAID have to treatments that block interleukin-1, JAK1/2 or tumor necrosis factor. Cytokine analysis revealed increased granulocyte colony-stimulating factor (G-CSF) levels as the most distinct feature in mice and individuals with APLAID. Remarkably, treatment with a G-CSF antibody completely reversed established disease in APLAID mice. Furthermore, excessive myelopoiesis was normalized and lymphocyte numbers rebounded. APLAID mice were also fully rescued by bone marrow transplantation from healthy donors, associated with reduced G-CSF production, predominantly from non-hematopoietic cells. In summary, we identify APLAID as a G-CSF-driven autoinflammatory disease, for which targeted therapy is feasible.


Assuntos
Transplante de Medula Óssea , Fator Estimulador de Colônias de Granulócitos , Animais , Camundongos , Citocinas , Interleucina-1 , Fator de Necrose Tumoral alfa/genética , Síndromes de Imunodeficiência/genética , Síndromes de Imunodeficiência/imunologia , Síndromes de Imunodeficiência/metabolismo
2.
Nat Immunol ; 21(12): 1574-1584, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33077975

RESUMO

A classical view of blood cell development is that multipotent hematopoietic stem and progenitor cells (HSPCs) become lineage-restricted at defined stages. Lin-c-Kit+Sca-1+Flt3+ cells, termed lymphoid-primed multipotent progenitors (LMPPs), have lost megakaryocyte and erythroid potential but are heterogeneous in their fate. Here, through single-cell RNA sequencing, we identify the expression of Dach1 and associated genes in this fraction as being coexpressed with myeloid/stem genes but inversely correlated with lymphoid genes. Through generation of Dach1-GFP reporter mice, we identify a transcriptionally and functionally unique Dach1-GFP- subpopulation within LMPPs with lymphoid potential with low to negligible classic myeloid potential. We term these 'lymphoid-primed progenitors' (LPPs). These findings define an early definitive branch point of lymphoid development in hematopoiesis and a means for prospective isolation of LPPs.


Assuntos
Biomarcadores , Proteínas do Olho/metabolismo , Genômica , Células Progenitoras Linfoides/metabolismo , Análise de Célula Única , Animais , Células Cultivadas , Biologia Computacional/métodos , Proteínas do Olho/genética , Perfilação da Expressão Gênica , Genômica/métodos , Hematopoese/genética , Sequenciamento de Nucleotídeos em Larga Escala , Células Progenitoras Linfoides/citologia , Células Progenitoras Linfoides/imunologia , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Proteômica , Análise de Célula Única/métodos
3.
Immunity ; 54(6): 1338-1351.e9, 2021 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-33862015

RESUMO

Despite advances in single-cell multi-omics, a single stem or progenitor cell can only be tested once. We developed clonal multi-omics, in which daughters of a clone act as surrogates of the founder, thereby allowing multiple independent assays per clone. With SIS-seq, clonal siblings in parallel "sister" assays are examined either for gene expression by RNA sequencing (RNA-seq) or for fate in culture. We identified, and then validated using CRISPR, genes that controlled fate bias for different dendritic cell (DC) subtypes. This included Bcor as a suppressor of plasmacytoid DC (pDC) and conventional DC type 2 (cDC2) numbers during Flt3 ligand-mediated emergency DC development. We then developed SIS-skew to examine development of wild-type and Bcor-deficient siblings of the same clone in parallel. We found Bcor restricted clonal expansion, especially for cDC2s, and suppressed clonal fate potential, especially for pDCs. Therefore, SIS-seq and SIS-skew can reveal the molecular and cellular mechanisms governing clonal fate.


Assuntos
Células Dendríticas/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Animais , Diferenciação Celular/genética , Linhagem Celular , Linhagem da Célula/genética , Feminino , Expressão Gênica/genética , Células HEK293 , Humanos , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos Endogâmicos C57BL , Células-Tronco/metabolismo
4.
Genes Dev ; 32(11-12): 849-864, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29907650

RESUMO

Activating JAK2 point mutations are implicated in the pathogenesis of myeloid and lymphoid malignancies, including high-risk B-cell acute lymphoblastic leukemia (B-ALL). In preclinical studies, treatment of JAK2 mutant leukemias with type I JAK2 inhibitors (e.g., Food and Drug Administration [FDA]-approved ruxolitinib) provided limited single-agent responses, possibly due to paradoxical JAK2Y1007/1008 hyperphosphorylation induced by these agents. To determine the importance of mutant JAK2 in B-ALL initiation and maintenance, we developed unique genetically engineered mouse models of B-ALL driven by overexpressed Crlf2 and mutant Jak2, recapitulating the genetic aberrations found in human B-ALL. While expression of mutant Jak2 was necessary for leukemia induction, neither its continued expression nor enzymatic activity was required to maintain leukemia survival and rapid proliferation. CRLF2/JAK2 mutant B-ALLs with sustained depletion or pharmacological inhibition of JAK2 exhibited enhanced expression of c-Myc and prominent up-regulation of c-Myc target genes. Combined indirect targeting of c-Myc using the BET bromodomain inhibitor JQ1 and direct targeting of JAK2 with ruxolitinib potently killed JAK2 mutant B-ALLs.


Assuntos
Janus Quinase 2/genética , Janus Quinase 2/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/fisiopatologia , Animais , Antineoplásicos/farmacologia , Azepinas/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Humanos , Masculino , Camundongos , Mutação , Nitrilas , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Pirazóis/farmacologia , Pirazóis/uso terapêutico , Pirimidinas , Interferência de RNA , Receptores de Citocinas/genética , Transcriptoma , Triazóis/farmacologia
5.
Blood ; 141(26): 3199-3214, 2023 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-36928379

RESUMO

Polycythemia vera (PV) is a myeloproliferative neoplasm driven by activating mutations in JAK2 that result in unrestrained erythrocyte production, increasing patients' hematocrit and hemoglobin concentrations, placing them at risk of life-threatening thrombotic events. Our genome-wide association study of 440 PV cases and 403 351 controls using UK Biobank data showed that single nucleotide polymorphisms in HFE known to cause hemochromatosis are highly associated with PV diagnosis, linking iron regulation to PV. Analysis of the FinnGen dataset independently confirmed overrepresentation of homozygous HFE variants in patients with PV. HFE influences the expression of hepcidin, the master regulator of systemic iron homeostasis. Through genetic dissection of mouse models of PV, we show that the PV erythroid phenotype is directly linked to hepcidin expression: endogenous hepcidin upregulation alleviates erythroid disease whereas hepcidin ablation worsens it. Furthermore, we demonstrate that in PV, hepcidin is not regulated by expanded erythropoiesis but is likely governed by inflammatory cytokines signaling via GP130-coupled receptors. These findings have important implications for understanding the pathophysiology of PV and offer new therapeutic strategies for this disease.


Assuntos
Policitemia Vera , Animais , Camundongos , Policitemia Vera/genética , Policitemia Vera/complicações , Hepcidinas/genética , Estudo de Associação Genômica Ampla , Ferro/metabolismo , Fenótipo , Homeostase
6.
Nature ; 566(7745): 523-527, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30814712

RESUMO

Many physical phenomena create colour: spectrally selective light absorption by pigments and dyes1,2, material-specific optical dispersion3 and light interference4-11 in micrometre-scale and nanometre-scale periodic structures12-17. In addition, scattering, diffraction and interference mechanisms are inherent to spherical droplets18, which contribute to atmospheric phenomena such as glories, coronas and rainbows19. Here we describe a previously unrecognized mechanism for creating iridescent structural colour with large angular spectral separation. Light travelling along different trajectories of total internal reflection at a concave optical interface can interfere to generate brilliant patterns of colour. The effect is generated at interfaces with dimensions that are orders of magnitude larger than the wavelength of visible light and is readily observed in systems as simple as water drops condensed on a transparent substrate. We also exploit this phenomenon in complex systems, including multiphase droplets, three-dimensional patterned polymer surfaces and solid microparticles, to create patterns of iridescent colour that are consistent with theoretical predictions. Such controllable structural colouration is straightforward to generate at microscale interfaces, so we expect that the design principles and predictive theory outlined here will be of interest both for fundamental exploration in optics and for application in functional colloidal inks and paints, displays and sensors.

7.
Nano Lett ; 24(21): 6240-6246, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38578061

RESUMO

Monolayer 2D semiconductors, such as WS2, exhibit uniquely strong light-matter interactions due to exciton resonances that enable atomically thin optical elements. Similar to geometry-dependent plasmon and Mie resonances, these intrinsic material resonances offer coherent and tunable light scattering. Thus far, the impact of the excitons' temporal dynamics on the performance of such excitonic metasurfaces remains unexplored. Here, we show how the excitonic decay rates dictate the focusing efficiency of an atomically thin lens carved directly out of exfoliated monolayer WS2. By isolating the coherent exciton radiation from the incoherent background in the focus of the lens, we obtain a direct measure of the role of exciton radiation in wavefront shaping. Furthermore, we investigate the influence of exciton-phonon scattering by characterizing the focusing efficiency as a function of temperature, demonstrating an increased optical efficiency at cryogenic temperatures. Our results provide valuable insights into the role of excitonic light scattering in 2D nanophotonic devices.

8.
Emerg Infect Dis ; 30(6): 1240-1244, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38782018

RESUMO

A 2022 canine gastroenteritis outbreak in the United Kingdom was associated with circulation of a new canine enteric coronavirus closely related to a 2020 variant with an additional spike gene recombination. The variants are unrelated to canine enteric coronavirus-like viruses associated with human disease but represent a model for coronavirus population adaptation.


Assuntos
Infecções por Coronavirus , Surtos de Doenças , Doenças do Cão , Gastroenterite , Filogenia , Animais , Cães , Surtos de Doenças/veterinária , Doenças do Cão/virologia , Doenças do Cão/epidemiologia , Reino Unido/epidemiologia , Gastroenterite/virologia , Gastroenterite/epidemiologia , Gastroenterite/veterinária , Infecções por Coronavirus/veterinária , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , Coronavirus Canino/genética , Coronavirus Canino/classificação , Humanos , Glicoproteína da Espícula de Coronavírus/genética
9.
Cancer ; 130(9): 1577-1589, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38288941

RESUMO

Management of venous thromboembolism (VTE) in patients with primary and metastatic brain tumors (BT) is challenging because of the risk of intracranial hemorrhage (ICH). There are no prospective clinical trials evaluating safety and efficacy of direct oral anticoagulants (DOACs), specifically in patients with BT, but they are widely used for VTE in this population. A group of neuro-oncology experts convened to provide practical clinical guidance for the off-label use of DOACs in treating VTE in patients with BT. We searched PubMed for the following terms: BTs, glioma, glioblastoma (GBM), brain metastasis, VTE, heparin, low-molecular-weight heparin (LWMH), DOACs, and ICH. Although prospective clinical trials are needed, the recommendations presented aim to assist clinicians in making informed decisions regarding DOACs for VTE in patients with BT.


Assuntos
Neoplasias Encefálicas , Neoplasias , Tromboembolia Venosa , Humanos , Anticoagulantes/efeitos adversos , Tromboembolia Venosa/epidemiologia , Hemorragia , Estudos Prospectivos , Neoplasias/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Neoplasias Encefálicas/complicações , Neoplasias Encefálicas/tratamento farmacológico , Administração Oral
10.
Am J Hum Genet ; 108(10): 2006-2016, 2021 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-34626583

RESUMO

Spermatogenesis-associated 5 like 1 (SPATA5L1) represents an orphan gene encoding a protein of unknown function. We report 28 bi-allelic variants in SPATA5L1 associated with sensorineural hearing loss in 47 individuals from 28 (26 unrelated) families. In addition, 25/47 affected individuals (53%) presented with microcephaly, developmental delay/intellectual disability, cerebral palsy, and/or epilepsy. Modeling indicated damaging effect of variants on the protein, largely via destabilizing effects on protein domains. Brain imaging revealed diminished cerebral volume, thin corpus callosum, and periventricular leukomalacia, and quantitative volumetry demonstrated significantly diminished white matter volumes in several individuals. Immunofluorescent imaging in rat hippocampal neurons revealed localization of Spata5l1 in neuronal and glial cell nuclei and more prominent expression in neurons. In the rodent inner ear, Spata5l1 is expressed in the neurosensory hair cells and inner ear supporting cells. Transcriptomic analysis performed with fibroblasts from affected individuals was able to distinguish affected from controls by principal components. Analysis of differentially expressed genes and networks suggested a role for SPATA5L1 in cell surface adhesion receptor function, intracellular focal adhesions, and DNA replication and mitosis. Collectively, our results indicate that bi-allelic SPATA5L1 variants lead to a human disease characterized by sensorineural hearing loss (SNHL) with or without a nonprogressive mixed neurodevelopmental phenotype.


Assuntos
Paralisia Cerebral/patologia , Epilepsia/patologia , Predisposição Genética para Doença , Variação Genética , Perda Auditiva/patologia , Deficiência Intelectual/patologia , Espasticidade Muscular/patologia , ATPases Associadas a Diversas Atividades Celulares/genética , Adolescente , Adulto , Alelos , Animais , Paralisia Cerebral/etiologia , Paralisia Cerebral/metabolismo , Pré-Escolar , Epilepsia/etiologia , Epilepsia/metabolismo , Feminino , Perda Auditiva/etiologia , Perda Auditiva/metabolismo , Humanos , Lactente , Recém-Nascido , Deficiência Intelectual/etiologia , Deficiência Intelectual/metabolismo , Masculino , Espasticidade Muscular/etiologia , Espasticidade Muscular/metabolismo , Ratos , Adulto Jovem
11.
Am J Physiol Regul Integr Comp Physiol ; 326(1): R53-R65, 2024 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-37955132

RESUMO

To maintain heat balance during exercise, humans rely on skin blood flow and sweating to facilitate whole body dry and evaporative heat exchange. These responses are modulated by the rise in body temperature (thermal factors), as well as several nonthermal factors implicated in the cardiovascular response to exercise (i.e., central command, mechanoreceptors, and metaboreceptors). However, the way these nonthermal factors interact with thermal factors to maintain heat balance remains poorly understood. We therefore used direct calorimetry to quantify the effects of dose-dependent increases in the activation of these nonthermal stimuli on whole body dry and evaporative heat exchange during dynamic exercise. In a randomized crossover design, eight participants performed 45-min cycling at a fixed metabolic heat production (200 W/m2) in warm, dry conditions (30°C, 20% relative humidity) on four separate occasions, differing only in the level of lower-limb compression applied via bilateral thigh cuffs pressurized to 0, 30, 60, or 90 mmHg. This model provoked increments in nonthermal activation while ensuring the heat loss required to balance heat production was matched across trials. At end-exercise, dry heat loss was 2 W/m2 [1, 3] lower per 30-mmHg pressure increment (P = 0.006), whereas evaporative heat loss was elevated 5 W/m2 [3, 7] with each pressure increment (P < 0.001). Body heat storage and esophageal temperature did not differ across conditions (both P ≥ 0.600). Our findings indicate that the nonthermal factors engaged during exercise exert dose-dependent, opposing effects on whole body dry and evaporative heat exchange, which do not significantly alter heat balance.NEW & NOTEWORTHY To maintain heat balance during exercise, humans rely on skin blood flow and sweating to facilitate dry and evaporative heat exchange. These responses are modulated by body temperatures (thermal factors) and several nonthermal factors (e.g., central command, metaboreceptors), although the way thermal and nonthermal factors interact to regulate body temperature is poorly understood. We demonstrate that nonthermal factors exert dose-dependent, opposing effects on dry and evaporative heat loss, without altering heat storage during dynamic exercise.


Assuntos
Regulação da Temperatura Corporal , Temperatura Alta , Humanos , Regulação da Temperatura Corporal/fisiologia , Temperatura Corporal/fisiologia , Sudorese , Termogênese/fisiologia
12.
Langmuir ; 40(1): 211-220, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38154121

RESUMO

Surfactants provide detergency, foaming, and texture in personal care formulations, yet the micellization of typical industrial primary and cosurfactants is not well understood, particularly in light of the polydisperse nature of commercial surfactants. Synergistic interactions are hypothesized to drive the formation of elongated wormlike self-assemblies in these mixed surfactant systems. Small-angle neutron scattering, rheology, and pendant drop tensiometry are used to examine surface adsorption, viscoelasticity, and self-assembly structure for wormlike micellar formulations comprising cocoamidopropyl betaine, and its two major components laurylamidopropyl betaine and oleylamidopropyl betaine, with sodium alkyl ethoxy sulfates. The tail length of sodium alkyl ethoxy sulfates was related to their ability to form wormlike micelles in electrolyte solutions, indicating that a tail length greater than 10 carbons is required to form wormlike micelles in NaCl solutions, with the decyl homologue unable to form elongated micelles and maintaining a low viscosity even at 20 wt % surfactant loading with 4 wt % NaCl present. For these systems, the incorporation of a disperse ethoxylate linker does not enable shorter chain surfactants to elongate into wormlike micelles for single-component systems; however, it could increase the interactions between surfactants in mixed surfactant systems. For synergy in surfactant mixing, the nonideal regular solution theory is used to study the sulfate/betaine mixtures. Tail mismatch appears to drive lower critical micelle concentrations, although tail matching improves synergy with larger relative reductions in critical micelle concentrations and greater micelle elongation, as seen by both tensiometric and scattering measurements.

13.
Brain ; 146(7): 2897-2912, 2023 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-36516294

RESUMO

Protein quality control pathways have evolved to ensure the fidelity of protein synthesis and efficiently clear potentially toxic protein species. Defects in ribosome-associated quality control and its associated factors have been implicated in the accumulation of aberrant proteins and neurodegeneration. C9orf72 repeat-associated non-AUG translation has been suggested to involve inefficient translation elongation, lead to ribosomal pausing and activation of ribosome-associated quality control pathways. However, the role of the ribosome-associated quality control complex in the processing of proteins generated through this non-canonical translation is not well understood. Here we use reporter constructs containing the C9orf72-associated hexanucleotide repeat, ribosome-associated quality control complex deficient cell models and stain for ribosome-associated quality control markers in C9orf72-expansion carrier human tissue to understand its role in dipeptide-repeat protein pathology. Our studies show that canonical ribosome-associated quality control substrates products are efficiently cleared by the ribosome-associated quality control complex in mammalian cells. Furthermore, using stalling reporter constructs, we show that repeats associated with the C9orf72-expansion induce ribosomal stalling when arginine (R)-rich dipeptide-repeat proteins are synthesized in a length-dependent manner. However, despite triggering this pathway, these arginine-rich dipeptide-repeat proteins are not efficiently processed by the core components of the ribosome-associated quality control complex (listerin, nuclear-export mediator factor and valosin containing protein) partly due to lack of lysine residues, which precludes ubiquitination. Deficient processing by this complex may be implicated in C9orf72-expansion associated disease as dipeptide-repeat protein inclusions were observed to be predominantly devoid of ubiquitin and co-localize with nuclear-export mediator factor in mutation carriers' frontal cortex and cerebellum tissue. These findings suggest that impaired processing of these arginine-rich dipeptide-repeat proteins derived from repeat-associated non-AUG translation by the ribosome-associated quality control complex may contribute to protein homeostasis dysregulation observed in C9orf72-expansion amyotrophic lateral sclerosis and frontotemporal degeneration neuropathogenesis.


Assuntos
Esclerose Lateral Amiotrófica , Demência Frontotemporal , Doenças Neurodegenerativas , Animais , Humanos , Dipeptídeos/genética , Proteína C9orf72/genética , Proteína C9orf72/metabolismo , Esclerose Lateral Amiotrófica/metabolismo , Doenças Neurodegenerativas/genética , Ribossomos , Expansão das Repetições de DNA/genética , Demência Frontotemporal/genética , Mamíferos/genética , Mamíferos/metabolismo
14.
Proc Natl Acad Sci U S A ; 118(25)2021 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-34161263

RESUMO

Epstein-Barr virus (EBV) is a ubiquitous herpesvirus that typically causes asymptomatic infection but can promote B lymphoid tumors in the immune suppressed. In vitro, EBV infection of primary B cells stimulates glycolysis during immortalization into lymphoblastoid cell lines (LCLs). Lactate export during glycolysis is crucial for continued proliferation of many cancer cells-part of a phenomenon known as the "Warburg effect"- and is mediated by monocarboxylate transporters (MCTs). However, the role of MCTs has yet to be studied in EBV-associated malignancies, which display Warburg-like metabolism in vitro. Here, we show that EBV infection of B lymphocytes directly promotes temporal induction of MCT1 and MCT4 through the viral proteins EBNA2 and LMP1, respectively. Functionally, MCT1 was required for early B cell proliferation, and MCT4 up-regulation promoted acquired resistance to MCT1 antagonism in LCLs. However, dual MCT1/4 inhibition led to LCL growth arrest and lactate buildup. Metabolic profiling in LCLs revealed significantly reduced oxygen consumption rates (OCRs) and NAD+/NADH ratios, contrary to previous observations of increased OCR and unaltered NAD+/NADH ratios in MCT1/4-inhibited cancer cells. Furthermore, U-13C6-glucose labeling of MCT1/4-inhibited LCLs revealed depleted glutathione pools that correlated with elevated reactive oxygen species. Finally, we found that dual MCT1/4 inhibition also sensitized LCLs to killing by the electron transport chain complex I inhibitors phenformin and metformin. These findings were extended to viral lymphomas associated with EBV and the related gammaherpesvirus KSHV, pointing at a therapeutic approach for targeting both viral lymphomas.


Assuntos
Linfoma/metabolismo , Linfoma/virologia , Transportadores de Ácidos Monocarboxílicos/antagonistas & inibidores , Linfócitos B/virologia , Linhagem Celular Tumoral , Proliferação de Células , Infecções por Vírus Epstein-Barr/virologia , Glucose/metabolismo , Glutationa/metabolismo , Herpesvirus Humano 4/fisiologia , Herpesvirus Humano 8/fisiologia , Humanos , Ácido Láctico/metabolismo , Linfoma/patologia , Metformina/farmacologia , NAD/metabolismo , Consumo de Oxigênio , Fenformin/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Regulação para Cima
15.
Am J Physiol Heart Circ Physiol ; 325(1): H66-H76, 2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-37172076

RESUMO

Endurance exercise induces cardiovascular adaptations; the athletic phenotypes of the heart and arteries are well characterized, but few studies have investigated the effects of chronic exercise on the venous system. The aim of this study was to describe the anatomy and function of lower-limb deep and superficial veins in athletes compared with controls. Endurance-trained athletes and untrained controls (13 males, 7 females per group) were examined using ultrasound to measure vein diameter and flow, and air plethysmography to assess calf venous volume dynamics and muscle pump function at rest, during a single step, ambulation (10 steps) and after acute treadmill exercise (30 min ∼80% age-predicted heart rate maximum). Diameters of three of the seven deep veins assessed were larger in athletes (P ≤ 0.0167) and more medial calf perforators were detectable (5 vs. 3, P = 0.0039). Calf venous volume was 22% larger in athletes (P = 0.0057), and calf muscle pump ejection volume and ambulatory venous volume after 10 steps were both greater in athletes (20 and 46% respectively, P ≤ 0.0482). Following acute exercise, flow recovery profiles in deep and superficial veins draining the leg were not different between groups, despite athletes performing approximately four times more work. After exercise, venous volume and ejection volume were reduced by ∼20% in athletes with no change in controls (interaction, P ≤ 0.0372) and although ambulatory venous volume reduced, this remained greater in athletes. These findings highlight venous adaptations that compensate for the demands of regular endurance exercise, all of which are suited to enhance flow through the lower-limb venous system.NEW & NOTEWORTHY Although much literature exists describing adaptations to the heart and arteries in response to endurance exercise training, less is known about the effects on the venous system. Characteristics of "the athlete's vein" described here include deep and perforator vein remodeling, improved drainage, and greater calf venous volume at rest and on calf muscle pump activation. Following exercise, athletes demonstrated prompt flow recovery and appropriate volume reductions, and veins beneficially adapt to better tolerate the demands of regular physical activity.


Assuntos
Extremidade Inferior , Veias , Masculino , Feminino , Humanos , Veias/diagnóstico por imagem , Extremidade Inferior/irrigação sanguínea , Ultrassonografia , Pletismografia , Atletas , Resistência Física
16.
Immunol Cell Biol ; 101(10): 923-935, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37721869

RESUMO

The emergence of large language models (LLMs) and assisted artificial intelligence (AI) technologies have revolutionized the way in which we interact with technology. A recent symposium at the Walter and Eliza Hall Institute explored the current practical applications of LLMs in medical research and canvassed the emerging ethical, legal and social implications for the use of AI-assisted technologies in the sciences. This paper provides an overview of the symposium's key themes and discussions delivered by diverse speakers, including early career researchers, group leaders, educators and policy-makers highlighting the opportunities and challenges that lie ahead for scientific researchers and educators as we continue to explore the potential of this cutting-edge and emerging technology.


Assuntos
Inteligência Artificial , Pesquisa Biomédica , Tecnologia
17.
Microvasc Res ; 146: 104470, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36549373

RESUMO

OBJECTIVES: Evaluate reliability of laser-Doppler flowmetry derived cutaneous vasodilation on the upper and lower limbs during gradual local heating. METHODS: In twenty-eight young adults (21 (SD 3) years, 14 females), absolute cutaneous vascular conductance (CVCabs) and CVC normalized to maximum vasodilation at 44 °C (%CVCmax) were assessed at two adjacent sites on each of the forearm and calf during gradual local skin heating (33-42 °C at 1 °C·5 min-1) for two identical trials (∼1 week apart). Responses were assessed for baseline, the steady-state heating plateau at 42 °C and the span (i.e. plateau-baseline). RESULTS: Between-day reliability was characterized as measurement consistency across trials. Within-day reliability was characterized as within-limb measurement consistency across adjacent skin sites. Between- and within-day absolute reliability (coefficient of variation) generally improved with heating, from poor (>25 %) at baseline to good (<10 %) for %CVCmax and moderate (10-25 %) for CVCabs for plateau and span. However, relative reliability (intraclass correlation coefficient) was generally not acceptable (<0.70) for any condition. Responses were generally consistent for females and males and there were no major forearm and calf differences. CONCLUSIONS: Consistency of CVC estimates improved during gradual local heating with negligible limb and sex differences, which are important considerations for experimental design and interpretation.


Assuntos
Antebraço , Vasodilatação , Humanos , Masculino , Feminino , Adulto Jovem , Vasodilatação/fisiologia , Antebraço/irrigação sanguínea , Fluxometria por Laser-Doppler , Calefação , Reprodutibilidade dos Testes , Pele/irrigação sanguínea , Fluxo Sanguíneo Regional
18.
Br J Dermatol ; 189(6): 674-684, 2023 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-37722926

RESUMO

BACKGROUND: Conventional systemic drugs are used to treat children and young people (CYP) with severe atopic dermatitis (AD) worldwide, but no robust randomized controlled trial (RCT) evidence exists regarding their efficacy and safety in this population. While novel therapies have expanded therapeutic options, their high cost means traditional agents remain important, especially in lower-resource settings. OBJECTIVES: To compare the safety and efficacy of ciclosporin (CyA) with methotrexate (MTX) in CYP with severe AD in the TREatment of severe Atopic Eczema Trial (TREAT) trial. METHODS: We conducted a parallel group assessor-blinded RCT in 13 UK and Irish centres. Eligible participants aged 2-16 years and unresponsive to potent topical treatment were randomized to either oral CyA (4 mg kg-1 daily) or MTX (0.4 mg kg-1 weekly) for 36 weeks and followed-up for 24 weeks. Co-primary outcomes were change from baseline to 12 weeks in Objective Severity Scoring of Atopic Dermatitis (o-SCORAD) and time to first significant flare (relapse) after treatment cessation. Secondary outcomes included change in quality of life (QoL) from baseline to 60 weeks; number of participant-reported flares following treatment cessation; proportion of participants achieving ≥ 50% improvement in Eczema Area and Severity Index (EASI 50) and ≥ 75% improvement in EASI (EASI 75); and stratification of outcomes by filaggrin status. RESULTS: In total, 103 participants were randomized (May 2016-February 2019): 52 to CyA and 51 to MTX. CyA showed greater improvement in disease severity by 12 weeks [mean difference in o-SCORAD -5.69, 97.5% confidence interval (CI) -10.81 to -0.57 (P = 0.01)]. More participants achieved ≥ 50% improvement in o-SCORAD (o-SCORAD 50) at 12 weeks in the CyA arm vs. the MTX arm [odds ratio (OR) 2.60, 95% CI 1.23-5.49; P = 0.01]. By 60 weeks MTX was superior (OR 0.33, 95% CI 0.13-0.85; P = 0.02), a trend also seen for ≥ 75% improvement in o-SCORAD (o-SCORAD 75), EASI 50 and EASI 75. Participant-reported flares post-treatment were higher in the CyA arm (OR 3.22, 95% CI 0.42-6.01; P = 0.02). QoL improved with both treatments and was sustained after treatment cessation. Filaggrin status did not affect outcomes. The frequency of adverse events (AEs) was comparable between both treatments. Five (10%) participants on CyA and seven (14%) on MTX experienced a serious AE. CONCLUSIONS: Both CyA and MTX proved effective in CYP with severe AD over 36 weeks. Participants who received CyA showed a more rapid response to treatment, while MTX induced more sustained disease control after discontinuation.


Assuntos
Ciclosporina , Dermatite Atópica , Criança , Humanos , Adolescente , Ciclosporina/efeitos adversos , Metotrexato/efeitos adversos , Dermatite Atópica/tratamento farmacológico , Proteínas Filagrinas , Razão de Chances , Resultado do Tratamento , Índice de Gravidade de Doença , Método Duplo-Cego
19.
J Neurooncol ; 164(3): 701-710, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37804375

RESUMO

BACKGROUND: Patients with primary brain tumors (pPBTs) often exhibit heightened distress. This study assesses how symptoms of anxiety and depression change over time in pPBTs and identifies factors that may predict patients' symptom trajectories. METHODS: Ninety-nine adult pPBTs completed psychosocial assessments at neuro-oncology appointments over 6-18 months. Quality of life was assessed with the Functional Assessment of Cancer Therapy-Brain; symptoms of anxiety and depression were assessed with the Patient-Reported Outcomes Measurement Information System short forms. The prevalence of patients with clinically elevated symptoms and those who experienced clinically meaningful changes in symptoms throughout follow-up were examined. Linear mixed-effects models evaluated changes in symptoms over time at the group level, and latent class growth analysis (LCGA) evaluated changes in symptoms over time at the individual level. RESULTS: At enrollment, 51.5% and 32.3% of patients exhibited clinically elevated levels of anxiety and depression, respectively. Of patients with follow-up data (n = 74), 54.1% and 50% experienced clinically meaningful increases in anxiety and depression scores, respectively. There were no significant changes in anxiety or depression scores over time, but better physical, functional, and brain-cancer well-being predicted lower levels of anxiety and depression (p < 0.001). Five sub-groups of patients with distinct symptom trajectories emerged via LCGA. CONCLUSIONS: pPBTs commonly experience elevated symptoms of anxiety and depression that may fluctuate in clinically meaningful manners throughout the disease. Routine screening for elevated symptoms is needed to capture clinically meaningful changes and identify factors affecting symptoms to intervene on.


Assuntos
Neoplasias Encefálicas , Depressão , Adulto , Humanos , Depressão/diagnóstico , Depressão/etiologia , Depressão/epidemiologia , Qualidade de Vida , Ansiedade/diagnóstico , Ansiedade/etiologia , Ansiedade/psicologia , Prevalência , Neoplasias Encefálicas/complicações , Neoplasias Encefálicas/diagnóstico
20.
Eur J Haematol ; 110(2): 168-176, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36321745

RESUMO

Multi-parametric flow cytometry (MFC) has a well-established role in measurable residual disease (MRD) monitoring in patients with B-lymphoblastic leukemia (B-ALL). However, the optimal time-point (TP) for early MRD testing and associated prognostic impact remain undefined in adult B-ALL patients receiving Hyper-CVAD induction chemotherapy. To evaluate the utility of MRD analysis after one cycle (TP1) in comparison to MRD analysis after two cycles (TP2) of induction treatment with Hyper-CVAD chemotherapy, we studied 49 adult B-ALL patients over a 10-year period (2010-2020) who had available bone marrow samples for morphological and MFC MRD assessments at the two separate TPs. Median times to TP1 and TP2 relative to start of treatment were 21 and 45 days, respectively. When censored at transplant, achievement of MRD negativity at TP1 was not associated with a statistically significant improvement in either event-free survival (EFS) (p = .426) or overall survival (OS) (p = .335) when compared to patients with MRD positivity. In contrast, achieving MRD negativity at TP2 was associated with a statistically significant improvement in both EFS (p = ·005) and OS (p = .047) over patients who remained MRD positive. Multivariate analysis demonstrated that KMT2A-rearrangement and MRD positivity at TP2 were the only significant predictors of outcome, correlating with worse EFS and OS. Therefore, in the absence of residual morphologic disease, MRD analysis after one cycle of Hyper-CVAD induction chemotherapy did not provide additional benefit with regard to risk stratification or correlation with survival outcomes when compared to MRD testing after two cycles of Hyper-CVAD in adult B-ALL patients.


Assuntos
Quimioterapia de Indução , Leucemia-Linfoma Linfoblástico de Células Precursoras B , Humanos , Adulto , Citometria de Fluxo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamento farmacológico , Prognóstico , Neoplasia Residual/diagnóstico
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