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1.
Cell ; 176(1-2): 56-72.e15, 2019 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-30612743

RESUMO

Local translation regulates the axonal proteome, playing an important role in neuronal wiring and axon maintenance. How axonal mRNAs are localized to specific subcellular sites for translation, however, is not understood. Here we report that RNA granules associate with endosomes along the axons of retinal ganglion cells. RNA-bearing Rab7a late endosomes also associate with ribosomes, and real-time translation imaging reveals that they are sites of local protein synthesis. We show that RNA-bearing late endosomes often pause on mitochondria and that mRNAs encoding proteins for mitochondrial function are translated on Rab7a endosomes. Disruption of Rab7a function with Rab7a mutants, including those associated with Charcot-Marie-Tooth type 2B neuropathy, markedly decreases axonal protein synthesis, impairs mitochondrial function, and compromises axonal viability. Our findings thus reveal that late endosomes interact with RNA granules, translation machinery, and mitochondria and suggest that they serve as sites for regulating the supply of nascent pro-survival proteins in axons.


Assuntos
Endossomos/fisiologia , Biossíntese de Proteínas/fisiologia , Proteínas rab de Ligação ao GTP/metabolismo , Animais , Axônios/metabolismo , Endossomos/metabolismo , Mitocôndrias/genética , Mitocôndrias/metabolismo , RNA/metabolismo , RNA Mensageiro/metabolismo , RNA Mensageiro/fisiologia , Células Ganglionares da Retina/metabolismo , Células Ganglionares da Retina/fisiologia , Ribossomos/metabolismo , Proteínas de Xenopus/metabolismo , Xenopus laevis/metabolismo , Proteínas rab de Ligação ao GTP/genética , Proteínas rab de Ligação ao GTP/fisiologia , proteínas de unión al GTP Rab7
2.
Cell ; 173(3): 720-734.e15, 2018 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-29677515

RESUMO

Reversible phase separation underpins the role of FUS in ribonucleoprotein granules and other membrane-free organelles and is, in part, driven by the intrinsically disordered low-complexity (LC) domain of FUS. Here, we report that cooperative cation-π interactions between tyrosines in the LC domain and arginines in structured C-terminal domains also contribute to phase separation. These interactions are modulated by post-translational arginine methylation, wherein arginine hypomethylation strongly promotes phase separation and gelation. Indeed, significant hypomethylation, which occurs in FUS-associated frontotemporal lobar degeneration (FTLD), induces FUS condensation into stable intermolecular ß-sheet-rich hydrogels that disrupt RNP granule function and impair new protein synthesis in neuron terminals. We show that transportin acts as a physiological molecular chaperone of FUS in neuron terminals, reducing phase separation and gelation of methylated and hypomethylated FUS and rescuing protein synthesis. These results demonstrate how FUS condensation is physiologically regulated and how perturbations in these mechanisms can lead to disease.


Assuntos
Arginina/química , Chaperonas Moleculares/química , Proteína FUS de Ligação a RNA/química , Esclerose Lateral Amiotrófica/metabolismo , Animais , Cátions , Metilação de DNA , Demência Frontotemporal/metabolismo , Degeneração Lobar Frontotemporal/metabolismo , Humanos , Microscopia de Força Atômica , Microscopia de Fluorescência , Ligação Proteica , Domínios Proteicos , Processamento de Proteína Pós-Traducional , Estrutura Secundária de Proteína , Proteína FUS de Ligação a RNA/metabolismo , Tirosina/química , Xenopus laevis
3.
Cell ; 166(1): 181-92, 2016 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-27321671

RESUMO

Local mRNA translation mediates the adaptive responses of axons to extrinsic signals, but direct evidence that it occurs in mammalian CNS axons in vivo is scant. We developed an axon-TRAP-RiboTag approach in mouse that allows deep-sequencing analysis of ribosome-bound mRNAs in the retinal ganglion cell axons of the developing and adult retinotectal projection in vivo. The embryonic-to-postnatal axonal translatome comprises an evolving subset of enriched genes with axon-specific roles, suggesting distinct steps in axon wiring, such as elongation, pruning, and synaptogenesis. Adult axons, remarkably, have a complex translatome with strong links to axon survival, neurotransmission, and neurodegenerative disease. Translationally co-regulated mRNA subsets share common upstream regulators, and sequence elements generated by alternative splicing promote axonal mRNA translation. Our results indicate that intricate regulation of compartment-specific mRNA translation in mammalian CNS axons supports the formation and maintenance of neural circuits in vivo.


Assuntos
Axônios/metabolismo , Biossíntese de Proteínas , Proteoma/metabolismo , Células Ganglionares da Retina/metabolismo , Processamento Alternativo , Animais , Regulação da Expressão Gênica no Desenvolvimento , Camundongos , Proteoma/análise , RNA Mensageiro/análise , RNA Mensageiro/metabolismo , Ribossomos/metabolismo , Colículos Superiores/metabolismo , Transmissão Sináptica
4.
EMBO J ; 42(14): e113168, 2023 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-37248947

RESUMO

Enhanced expression of the cold-shock protein RNA binding motif 3 (RBM3) is highly neuroprotective both in vitro and in vivo. Whilst upstream signalling pathways leading to RBM3 expression have been described, the precise molecular mechanism of RBM3 cold induction remains elusive. To identify temperature-dependent modulators of RBM3, we performed a genome-wide CRISPR-Cas9 knockout screen using RBM3-reporter human iPSC-derived neurons. We found that RBM3 mRNA and protein levels are robustly regulated by several splicing factors, with heterogeneous nuclear ribonucleoprotein H1 (HNRNPH1) being the strongest positive regulator. Splicing analysis revealed that moderate hypothermia significantly represses the inclusion of a poison exon, which, when retained, targets the mRNA for nonsense-mediated decay. Importantly, we show that HNRNPH1 mediates this cold-dependent exon skipping via its thermosensitive interaction with a G-rich motif within the poison exon. Our study provides novel mechanistic insights into the regulation of RBM3 and provides further targets for neuroprotective therapeutic strategies.


Assuntos
Venenos , Humanos , Proteínas e Peptídeos de Choque Frio/metabolismo , Temperatura Baixa , RNA Mensageiro/genética , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo
5.
J Neurosci ; 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38692734

RESUMO

Aberrant condensation and localisation of the RNA-binding protein (RBP) fused in sarcoma (FUS) occur in variants of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Changes in RBP function are commonly associated with changes in axonal cytoskeletal organisation and branching in neurodevelopmental disorders. Here, we asked whether branching defects also occur in vivo in a model of FUS-associated disease. We use two reported Xenopus models of ALS/FTD (of either sex), the ALS-associated mutant FUS(P525L) and a mimic of hypomethylated FUS, FUS(16R). Both mutants strongly reduced axonal complexity in vivo. We also observed an axon looping defect for FUS(P525L) in the target area, which presumably arises due to errors in stop cue signalling. To assess whether loss of axon complexity also had a cue-independent component, we assessed axonal cytoskeletal integrity in vitro Using a novel combination of fluorescence and atomic force microscopy, we found that mutant FUS reduced actin density in the growth cone, altering its mechanical properties. Therefore, FUS mutants may induce defects during early axonal development.Significance statement This study demonstrates that mutation of the ALS/FTD (amyotrophic lateral sclerosis/frontotemporal dementia)-associated RNA-binding protein Fused in Sarcoma (FUS) can result in changes in axonal development. These changes occur both axon-autonomously in cytoskeletal organisation during axon extension and context-dependently during axonal branching. This indicates pre-symptomatic, developmental changes in axonal organisation may occur in familial disease variants.

6.
Hepatology ; 77(1): 20-32, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-35686937

RESUMO

BACKGROUND AND AIMS: Pruritus is associated with multiple liver diseases, particularly those with cholestasis, but the mechanism remains incompletely understood. Our aim was to evaluate serum IL-31 as a putative biomarker of pruritus in clinical trials of an farnesoid X receptor (FXR) agonist, cilofexor, in patients with NASH, primary sclerosing cholangitis (PSC), and primary biliary cholangitis (PBC). APPROACH AND RESULTS: Serum IL-31 was measured in clinical studies of cilofexor in NASH, PSC, and PBC. In patients with PSC or PBC, baseline IL-31 was elevated compared to patients with NASH and healthy volunteers (HVs). IL-31 correlated with serum bile acids among patients with NASH, PBC, and PSC. Baseline IL-31 levels in PSC and PBC were positively correlated with Visual Analog Scale for pruritus and 5-D itch scores. In patients with NASH, cilofexor dose-dependently increased IL-31 from Week (W)1 to W24. In patients with NASH receiving cilofexor 100 mg, IL-31 was higher in those with Grade 2-3 pruritus adverse events (AEs) than those with Grade 0-1 pruritus AEs. IL-31 weakly correlated with C4 at baseline in patients with NASH, and among those receiving cilofexor 100 mg, changes in IL-31 and C4 from baseline to W24 were negatively correlated. IL-31 messenger RNA (mRNA) was elevated in hepatocytes from patients with PSC and NASH compared to HVs. In a humanized liver murine model, obeticholic acid increased IL-31 mRNA expression in human hepatocytes and serum levels of human IL-31. CONCLUSIONS: IL-31 levels correlate with pruritus in patients with cholestatic disease and NASH, with FXR agonist therapy resulting in higher serum levels in the latter group. IL-31 appears to derive in part from increased hepatocyte expression. These findings have therapeutic implications for patients with liver disease and pruritus.


Assuntos
Colestase , Cirrose Hepática Biliar , Doenças Metabólicas , Hepatopatia Gordurosa não Alcoólica , Humanos , Animais , Camundongos , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Colestase/complicações , Colestase/tratamento farmacológico , Biomarcadores , Doenças Metabólicas/complicações , Prurido/tratamento farmacológico , Prurido/etiologia , Cirrose Hepática Biliar/complicações , Cirrose Hepática Biliar/tratamento farmacológico
7.
Crit Care Med ; 51(12): e253-e263, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-37678209

RESUMO

OBJECTIVES: To identify cytokine signature clusters in patients with septic shock. DESIGN: Prospective observational cohort study. SETTING: Single academic center in the United States. PATIENTS: Adult (≥ 18 yr old) patients admitted to the medical ICU with septic shock requiring vasoactive medication support. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One hundred fourteen patients with septic shock completed cytokine measurement at time of enrollment (t 1 ) and 24 hours later (t 2 ). Unsupervised random forest analysis of the change in cytokines over time, defined as delta (t 2 -t 1 ), identified three clusters with distinct cytokine profiles. Patients in cluster 1 had the lowest initial levels of circulating cytokines that decreased over time. Patients in cluster 2 and cluster 3 had higher initial levels that decreased over time in cluster 2 and increased in cluster 3. Patients in clusters 2 and 3 had higher mortality compared with cluster 1 (clusters 1-3: 11% vs 31%; odds ratio [OR], 3.56 [1.10-14.23] vs 54% OR, 9.23 [2.89-37.22]). Cluster 3 was independently associated with in-hospital mortality (hazard ratio, 5.24; p = 0.005) in multivariable analysis. There were no significant differences in initial clinical severity scoring or steroid use between the clusters. Analysis of either t 1 or t 2 cytokine measurements alone or in combination did not reveal clusters with clear clinical significance. CONCLUSIONS: Longitudinal measurement of cytokine profiles at initiation of vasoactive medications and 24 hours later revealed three distinct cytokine signature clusters that correlated with clinical outcomes.


Assuntos
Choque Séptico , Adulto , Humanos , Estados Unidos/epidemiologia , Estudos Prospectivos , Citocinas
8.
Respirology ; 27(5): 350-356, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35178828

RESUMO

BACKGROUND AND OBJECTIVE: Pleuroscopy with pleural biopsy has a high sensitivity for malignant pleural effusion (MPE). Because MPEs tend to recur, concurrent diagnosis and treatment of MPE during pleuroscopy is desired. However, proceeding directly to treatment at the time of pleuroscopy requires confidence in the on-site diagnosis. The study's primary objective was to create a predictive model to estimate the probability of MPE during pleuroscopy. METHODS: A prospective observational multicentre cohort study of consecutive patients undergoing pleuroscopy was conducted. We used a logistic regression model to evaluate the probability of MPE with relation to visual assessment, rapid on-site evaluation (ROSE) of touch preparation and presence of pleural nodules/masses on computed tomography (CT). To assess the model's prediction accuracy, a bootstrapped training/testing approach was utilized to estimate the cross-validated area under the receiver operating characteristic curve. RESULTS: Of the 201 patients included in the study, 103 had MPE. Logistic regression showed that higher level of malignancy on visual assessment is associated with higher odds of MPE (OR = 34.68, 95% CI = 9.17-131.14, p < 0.001). The logistic regression also showed that higher level of malignancy on ROSE of touch preparation is associated with higher odds of MPE (OR = 11.63, 95% CI = 3.85-35.16, p < 0.001). Presence of pleural nodules/masses on CT is associated with higher odds of MPE (OR = 6.61, 95% CI = 1.97-22.1, p = 0.002). A multivariable logistic regression model of final pathologic status with relation to visual assessment, ROSE of touch preparation and presence of pleural nodules/masses on CT had a cross-validated AUC of 0.94 (95% CI = 0.91-0.97). CONCLUSION: A prediction model using visual assessment, ROSE of touch preparation and CT scan findings demonstrated excellent predictive accuracy for MPE. Further validation studies are needed to confirm our findings.


Assuntos
Derrame Pleural Maligno , Derrame Pleural , Biópsia , Estudos de Coortes , Humanos , Recidiva Local de Neoplasia , Derrame Pleural Maligno/diagnóstico por imagem , Derrame Pleural Maligno/patologia , Estudos Prospectivos , Toracoscopia
9.
Semin Diagn Pathol ; 39(2): 113-119, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34176697

RESUMO

Acute mediastinitis is a rare infection that carries high morbidity and mortality. They are complications seen most often with deep sternal wound infections from surgeries with median sternotomies, oropharyngeal and odontogenic infections and esophageal perforations. These conditions should be promptly recognized and treated. Mediastinal granulomas are focal, mass-like lesions commonly resulting from prior granulomatous infections. They are regarded as benign, self-resolving lesions however can cause complications by compression of adjacent mediastinal structures. Chronic fibrosing mediastinitis is a rare, diffuse fibroinflammatory process most often seen with granulomatous infections and carries a worse prognosis than mediastinal granulomas especially when adjacent mediastinal structures are compromised. In this review, we discuss the epidemiology, etiology, clinical presentation, treatment and prognosis of acute mediastinitis, mediastinal granulomas, and chronic fibrosing mediastinitis.


Assuntos
Mediastinite , Doença Aguda , Granuloma , Humanos , Mediastinite/diagnóstico , Mediastinite/etiologia , Mediastino , Esclerose
10.
Curr Opin Pulm Med ; 27(4): 229-239, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33973554

RESUMO

PURPOSE OF REVIEW: Robotic bronchoscopy is the newest advanced diagnostic bronchoscopy technology for biopsying peripheral pulmonary lesions; sensitivity for malignancy is currently suboptimal using modalities, such as radial endobronchial ultrasound or electromagnetic navigational bronchoscopy. We review the pitfalls of prior methods and the technological advancements with robotic bronchoscopy. RECENT FINDINGS: The contributors to reduced diagnostic sensitivity with current approaches include limitations in: navigation to the target, confirmation once the target is reached, and tissue acquisition. CT to body divergence with virtual reality methods, such as with electromagnetic navigation, potential false-positive confirmation with radial endobronchial ultrasound because of intraprocedural induced atelectasis, and lack of bronchoscopic and instrument maneuverability are all limitations to improving sensitivity. Robotic bronchoscopy enhances navigation through target pathway selection, allows for further reach in the distal airways, and improves tissue acquisition with more flexible and maneuverable biopsy instruments but lacks a high-fidelity target confirmation system. SUMMARY: Robotic bronchoscopy shows promise in biopsying peripheral lesions. Current published studies focus on diagnostic yield with robotic bronchoscopy. Future studies with long-term follow-up will be needed to assess diagnostic sensitivity for lung cancer and if robotic bronchoscopy is superior to other advanced diagnostic bronchoscopic techniques for peripheral pulmonary lesions.


Assuntos
Neoplasias Pulmonares , Procedimentos Cirúrgicos Robóticos , Broncoscopia , Endossonografia , Humanos , Pulmão/diagnóstico por imagem , Neoplasias Pulmonares/diagnóstico por imagem
11.
RNA Biol ; 18(7): 936-961, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-32988274

RESUMO

It is increasingly recognized that local protein synthesis (LPS) contributes to fundamental aspects of axon biology, in both developing and mature neurons. Mutations in RNA-binding proteins (RBPs), as central players in LPS, and other proteins affecting RNA localization and translation are associated with a range of neurological disorders, suggesting disruption of LPS may be of pathological significance. In this review, we substantiate this hypothesis by examining the link between LPS and key axonal processes, and the implicated pathophysiological consequences of dysregulated LPS. First, we describe how the length and autonomy of axons result in an exceptional reliance on LPS. We next discuss the roles of LPS in maintaining axonal structural and functional polarity and axonal trafficking. We then consider how LPS facilitates the establishment of neuronal connectivity through regulation of axonal branching and pruning, how it mediates axonal survival into adulthood and its involvement in neuronal stress responses.


Assuntos
Doença de Alzheimer/genética , Esclerose Lateral Amiotrófica/genética , Axônios/metabolismo , Deficiência Intelectual/genética , Doença de Parkinson/genética , Biossíntese de Proteínas , RNA Mensageiro/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Esclerose Lateral Amiotrófica/metabolismo , Esclerose Lateral Amiotrófica/patologia , Animais , Axônios/patologia , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Deficiência Intelectual/metabolismo , Deficiência Intelectual/patologia , Mutação , Rede Nervosa/crescimento & desenvolvimento , Rede Nervosa/metabolismo , Rede Nervosa/patologia , Proteínas do Tecido Nervoso/classificação , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Plasticidade Neuronal/genética , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo
12.
Crit Care ; 25(1): 333, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34526077

RESUMO

PURPOSE: In acute respiratory distress syndrome (ARDS), dead space fraction has been independently associated with mortality. We hypothesized that early measurement of the difference between arterial and end-tidal CO2 (arterial-ET difference), a surrogate for dead space fraction, would predict mortality in mechanically ventilated patients with ARDS. METHODS: We performed two separate exploratory analyses. We first used publicly available databases from the ALTA, EDEN, and OMEGA ARDS Network trials (N = 124) as a derivation cohort to test our hypothesis. We then performed a separate retrospective analysis of patients with ARDS using University of Chicago patients (N = 302) as a validation cohort. RESULTS: The ARDS Network derivation cohort demonstrated arterial-ET difference, vasopressor requirement, age, and APACHE III to be associated with mortality by univariable analysis. By multivariable analysis, only the arterial-ET difference remained significant (P = 0.047). In a separate analysis, the modified Enghoff equation ((PaCO2-PETCO2)/PaCO2) was used in place of the arterial-ET difference and did not alter the results. The University of Chicago cohort found arterial-ET difference, age, ventilator mode, vasopressor requirement, and APACHE II to be associated with mortality in a univariate analysis. By multivariable analysis, the arterial-ET difference continued to be predictive of mortality (P = 0.031). In the validation cohort, substitution of the arterial-ET difference for the modified Enghoff equation showed similar results. CONCLUSION: Arterial to end-tidal CO2 (ETCO2) difference is an independent predictor of mortality in patients with ARDS.


Assuntos
Dióxido de Carbono/análise , Espaço Morto Respiratório , Síndrome do Desconforto Respiratório/diagnóstico por imagem , Estatística como Assunto/métodos , Adulto , Chicago , Estudos de Coortes , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Curva ROC , Estatística como Assunto/instrumentação , Estatística como Assunto/tendências , Estudos de Validação como Assunto
13.
Crit Care Med ; 48(11): 1645-1653, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32947475

RESUMO

OBJECTIVES: We recently found that distinct body temperature trajectories of infected patients correlated with survival. Understanding the relationship between the temperature trajectories and the host immune response to infection could allow us to immunophenotype patients at the bedside using temperature. The objective was to identify whether temperature trajectories have consistent associations with specific cytokine responses in two distinct cohorts of infected patients. DESIGN: Prospective observational study. SETTING: Large academic medical center between 2013 and 2019. SUBJECTS: Two cohorts of infected patients: 1) patients in the ICU with septic shock and 2) hospitalized patients with Staphylococcus aureus bacteremia. INTERVENTIONS: Clinical data (including body temperature) and plasma cytokine concentrations were measured. Patients were classified into four temperature trajectory subphenotypes using their temperature measurements in the first 72 hours from the onset of infection. Log-transformed cytokine levels were standardized to the mean and compared with the subphenotypes in both cohorts. MEASUREMENTS AND MAIN RESULTS: The cohorts consisted of 120 patients with septic shock (cohort 1) and 88 patients with S. aureus bacteremia (cohort 2). Patients from both cohorts were classified into one of four previously validated temperature subphenotypes: "hyperthermic, slow resolvers" (n = 19 cohort 1; n = 13 cohort 2), "hyperthermic, fast resolvers" (n = 18 C1; n = 24 C2), "normothermic" (n = 54 C1; n = 31 C2), and "hypothermic" (n = 29 C1; n = 20 C2). Both "hyperthermic, slow resolvers" and "hyperthermic, fast resolvers" had high levels of G-CSF, CCL2, and interleukin-10 compared with the "hypothermic" group when controlling for cohort and timing of cytokine measurement (p < 0.05). In contrast to the "hyperthermic, slow resolvers," the "hyperthermic, fast resolvers" showed significant decreases in the levels of several cytokines over a 24-hour period, including interleukin-1RA, interleukin-6, interleukin-8, G-CSF, and M-CSF (p < 0.001). CONCLUSIONS: Temperature trajectory subphenotypes are associated with consistent cytokine profiles in two distinct cohorts of infected patients. These subphenotypes could play a role in the bedside identification of cytokine profiles in patients with sepsis.


Assuntos
Temperatura Corporal/fisiologia , Imunidade/imunologia , Sepse/imunologia , Idoso , Bacteriemia/imunologia , Bacteriemia/fisiopatologia , Temperatura Corporal/imunologia , Citocinas/sangue , Feminino , Febre/imunologia , Febre/fisiopatologia , Humanos , Imunidade/fisiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sepse/fisiopatologia , Choque Séptico/imunologia , Choque Séptico/fisiopatologia , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/fisiopatologia
14.
J Evol Biol ; 33(6): 773-782, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32086852

RESUMO

Theory on the evolution of niche width argues that resource heterogeneity selects for niche breadth. For parasites, this theory predicts that parasite populations will evolve, or maintain, broader host ranges when selected in genetically diverse host populations relative to homogeneous host populations. To test this prediction, we selected the bacterial parasite Serratia marcescens to kill Caenorhabditis elegans in populations that were genetically heterogeneous (50% mix of two experimental genotypes) or homogeneous (100% of either genotype). After 20 rounds of selection, we compared the host range of selected parasites by measuring parasite fitness (i.e. virulence, the selected fitness trait) on the two focal host genotypes and on a novel host genotype. As predicted, heterogeneous host populations selected for parasites with a broader host range: these parasite populations gained or maintained virulence on all host genotypes. This result contrasted with selection in homogeneous populations of one host genotype. Here, host range contracted, with parasite populations gaining virulence on the focal host genotype and losing virulence on the novel host genotype. This pattern was not, however, repeated with selection in homogeneous populations of the second host genotype: these parasite populations did not gain virulence on the focal host genotype, nor did they lose virulence on the novel host genotype. Our results indicate that host heterogeneity can maintain broader host ranges in parasite populations. Individual host genotypes, however, vary in the degree to which they select for specialization in parasite populations.


Assuntos
Adaptação Biológica , Evolução Biológica , Interações Hospedeiro-Patógeno/genética , Seleção Genética , Serratia marcescens/patogenicidade , Animais , Caenorhabditis elegans , Serratia marcescens/genética , Software
15.
Development ; 143(7): 1134-48, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-26903505

RESUMO

The transcript encoding translationally controlled tumor protein (Tctp), a molecule associated with aggressive breast cancers, was identified among the most abundant in genome-wide screens of axons, suggesting that Tctp is important in neurons. Here, we tested the role of Tctp in retinal axon development in Xenopus laevis We report that Tctp deficiency results in stunted and splayed retinotectal projections that fail to innervate the optic tectum at the normal developmental time owing to impaired axon extension. Tctp-deficient axons exhibit defects associated with mitochondrial dysfunction and we show that Tctp interacts in the axonal compartment with myeloid cell leukemia 1 (Mcl1), a pro-survival member of the Bcl2 family. Mcl1 knockdown gives rise to similar axon misprojection phenotypes, and we provide evidence that the anti-apoptotic activity of Tctp is necessary for the normal development of the retinotectal projection. These findings suggest that Tctp supports the development of the retinotectal projection via its regulation of pro-survival signalling and axonal mitochondrial homeostasis, and establish a novel and fundamental role for Tctp in vertebrate neural circuitry assembly.


Assuntos
Axônios/metabolismo , Biomarcadores Tumorais/genética , Lobo Óptico de Animais não Mamíferos/embriologia , Retina/embriologia , Células Ganglionares da Retina/citologia , Vias Visuais/embriologia , Animais , Blastômeros/citologia , Células Cultivadas , Embrião não Mamífero/embriologia , Marcação In Situ das Extremidades Cortadas , Potencial da Membrana Mitocondrial/fisiologia , Mitocôndrias/fisiologia , Dinâmica Mitocondrial/genética , Morfolinos/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Neurogênese/fisiologia , Ratos , Ratos Endogâmicos F344 , Células Ganglionares da Retina/metabolismo , Proteína Tumoral 1 Controlada por Tradução , Vias Visuais/metabolismo , Xenopus laevis
16.
J Drugs Dermatol ; 16(6): 557-564, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28686773

RESUMO

BACKGROUND: Isotretinoin is an effective treatment for nodulocystic acne. Outside of required pregnancy testing, laboratory monitoring suggested by the manufacturers is vague. Dermatologists, therefore, monitor a variety of tests with variable frequency. Despite intense monitoring, the majority of patients do not have gross laboratory abnormalities that warrant changes in management.

OBJECTIVE: To survey US dermatologists regarding laboratory monitoring practices while prescribing isotretinoin.

METHODS: An online survey sent via e-mail to members of the American Academy of Dermatology.

RESULTS: 12,396 surveys were sent with a response rate of ~19%. At baseline >60% of responders check a CBC, LFTs, and a lipid panel. 74% check a monthly lipid panel and LFTs, while 57% check a monthly CBC. 75% report stopping isotretinoin when AST or ALT values reach 3 times normal; 89% report stopping at 4 times normal. When triglycerides reach 4 times normal, 72% stop the medication.

CONCLUSIONS: There is no consensus on isotretinoin monitoring tests and frequency, though the majority of dermatologists surveyed monitor a lipid panel and LFTs.

J Drugs Dermatol. 2017;16(6):557-564.

.


Assuntos
Fármacos Dermatológicos/uso terapêutico , Dermatologistas , Isotretinoína/uso terapêutico , Acne Vulgar/tratamento farmacológico , Adulto , Fármacos Dermatológicos/administração & dosagem , Fármacos Dermatológicos/efeitos adversos , Feminino , Pesquisas sobre Atenção à Saúde , Humanos , Isotretinoína/administração & dosagem , Isotretinoína/efeitos adversos , Lipídeos/sangue , Monitorização Fisiológica , Padrões de Prática Médica , Gravidez , Inquéritos e Questionários , Estados Unidos
17.
Biol Psychiatry ; 95(9): 888-895, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38103876

RESUMO

BACKGROUND: Genes that encode synaptic proteins or messenger RNA targets of the RNA-binding protein FMRP (fragile X messenger ribonucleoprotein) have been linked to schizophrenia and autism spectrum disorder (ASD) through the enrichment of genetic variants that confer risk for these disorders. FMRP binds many transcripts with synaptic functions and is thought to regulate their local translation, a process that enables rapid and compartmentalized protein synthesis required for development and plasticity. METHODS: We used summary statistics from large-scale genome-wide association studies of schizophrenia (74,776 cases, 101,023 controls) and ASD (18,381 cases, 27,969 controls) to test the hypothesis that the subset of synaptic genes that encode localized transcripts is more strongly associated with each disorder than nonlocalized transcripts. We also postulated that this subset of synaptic genes is responsible for associations attributed to FMRP targets. RESULTS: Schizophrenia associations were enriched in genes encoding localized synaptic transcripts compared to the remaining synaptic genes or to the remaining localized transcripts; this also applied to ASD associations, although only for transcripts observed after stimulation by fear conditioning. The genetic associations with either disorder captured by these gene sets were independent of those derived from FMRP targets. Schizophrenia association was related to FMRP interactions with messenger RNAs in somata, but not in dendrites, while ASD association was related to FMRP binding in either compartment. CONCLUSIONS: Our data suggest that synaptic transcripts capable of local translation are particularly relevant to the pathogenesis of schizophrenia and ASD, but they do not characterize the associations attributed to current sets of FMRP targets.


Assuntos
Transtorno do Espectro Autista , Esquizofrenia , Humanos , Transtorno do Espectro Autista/genética , Transtorno do Espectro Autista/metabolismo , Estudo de Associação Genômica Ampla , Esquizofrenia/genética , Esquizofrenia/metabolismo , Proteína do X Frágil da Deficiência Intelectual/genética , Proteína do X Frágil da Deficiência Intelectual/metabolismo , Neurônios/metabolismo
18.
Diagnostics (Basel) ; 14(2)2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38248073

RESUMO

Atelectasis during bronchoscopy under general anesthesia is very common and can have a detrimental effect on navigational and diagnostic outcomes. While the intraprocedural incidence and anatomic location have been previously described, the severity of atelectasis has not. We reviewed chest CT images of patients who developed atelectasis in the VESPA trial (Ventilatory Strategy to Prevent Atelectasis). By drawing boundaries at the posterior chest wall (A), the anterior aspect of the vertebral body (C), and mid-way between these two lines (B), we delineated at-risk lung zones 1, 2, and 3 (from posterior to anterior). An Atelectasis Severity Score System ("ASSESS") was created, classifying atelectasis as "mild" (zone 1), "moderate" (zones 1-2), and "severe" (zones 1-2-3). A total of 43 patients who developed atelectasis were included in this study. A total of 32 patients were in the control arm, and 11 were in the VESPA arm; 20 patients (47%) had mild atelectasis, 20 (47%) had moderate atelectasis, and 3 (6%) had severe atelectasis. A higher BMI was associated with increased odds (1.5 per 1 unit change; 95% CI, 1.10-2.04) (p = 0.0098), and VESPA was associated with decreased odds (0.05; 95% CI, 0.01-0.47) (p = 0.0080) of developing moderate to severe atelectasis. ASSESS is a simple method used to categorize intra-bronchoscopy atelectasis, which allows for a qualitative description of this phenomenon to be developed. In the VESPA trial, a higher BMI was not only associated with increased incidence but also increased severity of atelectasis, while VESPA had the opposite effect. Preventive strategies should be strongly considered in patients with risk factors for atelectasis who have lesions located in zones 1 and 2, but not in zone 3.

19.
Data Brief ; 54: 110299, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38524840

RESUMO

The dataset includes thermal videos of various hand gestures captured by the FLIR Lepton Thermal Camera. A large dataset is created to accurately classify hand gestures captured from eleven different individuals. The dataset consists of 9 classes corresponding to various hand gestures from different people collected at different time instances with complex backgrounds. This data includes flat/leftward, flat/rightward, flat/contract, spread/ leftward, spread/rightward, spread/contract, V-shape/leftward, V-shape/rightward, and V-shape/contract. There are 110 videos in the dataset for each gesture and a total of 990 videos corresponding to 9 gestures. Each video has data of three different (15/10/5) frame lengths.

20.
J Bronchology Interv Pulmonol ; 31(2): 155-159, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37982602

RESUMO

BACKGROUND: Pleural infections related to indwelling pleural catheters (IPCs) are an uncommon clinical problem. However, management decisions can be complex for patients with active malignancies due to their comorbidities and limited life expectancies. There are limited studies on the management of IPC-related infections, including whether to remove the IPC or use intrapleural fibrinolytics. METHODS: We conducted a retrospective cohort study of patients with active malignancies and IPC-related empyemas at our institution between January 1, 2005 and May 31, 2021. The primary outcome was to evaluate clinical outcomes in patients with malignant pleural effusions and IPC-related empyemas treated with intrapleural tissue plasminogen activator (tPA) and deoxyribonuclease (DNase) compared with those treated with tPA alone or no intrapleural fibrinolytic therapy. The secondary outcome evaluated was the incidence of bleeding complications. RESULTS: We identified 69 patients with a malignant pleural effusion and an IPC-related empyema. Twenty patients received tPA/DNase, 9 received tPA alone, and 40 were managed without fibrinolytics. Those treated with fibrinolytics were more likely to have their IPCs removed as part of the initial management strategy ( P =0.004). The rate of surgical intervention and mortality attributable to the empyema were not significantly different between treatment groups. There were no bleeding events in any group. CONCLUSION: In patients with IPC-related empyemas, we did not find significant differences in the rates of surgical intervention, empyema-related mortality, or bleeding complications in those treated with intrapleural tPA/DNase, tPA alone, or no fibrinolytics. More patients who received intrapleural fibrinolytics had their IPCs removed, which may have been due to selection bias.


Assuntos
Empiema Pleural , Derrame Pleural Maligno , Derrame Pleural , Humanos , Ativador de Plasminogênio Tecidual/uso terapêutico , Fibrinolíticos/uso terapêutico , Empiema Pleural/tratamento farmacológico , Estudos Retrospectivos , Derrame Pleural Maligno/tratamento farmacológico , Derrame Pleural Maligno/complicações , Cateteres de Demora/efeitos adversos , Desoxirribonucleases , Derrame Pleural/terapia
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