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1.
bioRxiv ; 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38895376

RESUMO

Local protein synthesis in axons and dendrites underpins synaptic plasticity. However, the composition of the protein synthesis machinery in distal neuronal processes and the mechanisms for its activity-driven deployment to local translation sites remain unclear. Here, we employed cryo-electron tomography, volume electron microscopy, and live-cell imaging to identify Ribosome-Associated Vesicles (RAVs) as a dynamic platform for moving ribosomes to distal processes. Stimulation via chemically-induced long-term potentiation causes RAV accumulation in distal sites to drive local translation. We also demonstrate activity-driven changes in RAV generation and dynamics in vivo, identifying tubular ER shaping proteins in RAV biogenesis. Together, our work identifies a mechanism for ribosomal delivery to distal sites in neurons to promote activity-dependent local translation.

2.
bioRxiv ; 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38463986

RESUMO

Glutamatergic synapses are the primary site of excitatory synaptic signaling and neural communication in the cerebral cortex. Electron microscopy (EM) studies in non-human model organisms have demonstrated that glutamate synaptic activity and functioning are directly reflected in quantifiable ultrastructural features. Thus, quantitative EM analysis of glutamate synapses in ex vivo preserved human brain tissue has the potential to provide novel insight into in vivo synaptic functioning. However, factors associated with the acquisition and preservation of human brain tissue have resulted in persistent concerns regarding the potential confounding effects of antemortem and postmortem biological processes on synaptic and sub-synaptic ultrastructural features. Thus, we sought to determine how well glutamate synaptic relationships and nanoarchitecture are preserved in postmortem human dorsolateral prefrontal cortex (DLPFC), a region that substantially differs in size and architecture from model systems. Focused ion beam-scanning electron microscopy (FIB-SEM), a powerful volume EM (VEM) approach, was employed to generate high-fidelity, fine-resolution, three-dimensional (3D) micrographic datasets appropriate for quantitative analyses. Using postmortem human DLPFC with a 6-hour postmortem interval, we optimized a tissue preservation and staining workflow that generated samples of excellent ultrastructural preservation and the high-contrast staining intensity required for FIB-SEM imaging. Quantitative analysis of sub-cellular, sub-synaptic and organelle components within glutamate axo-spinous synapses revealed that ultrastructural features of synaptic function and activity were well-preserved within and across individual synapses in postmortem human brain tissue. The synaptic, sub-synaptic and organelle measures were highly consistent with findings from experimental models that are free from antemortem or postmortem effects. Further, dense reconstruction of neuropil revealed a unique, ultrastructurally-complex, spiny dendritic shaft that exhibited features characteristic of neuronal processes with heightened synaptic communication, integration and plasticity. Altogether, our findings provide a critical proof-of-concept that ex vivo VEM analysis provides a valuable and informative means to infer in vivo functioning of human brain.

3.
Curr Med Res Opin ; : 1-7, 2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37752892

RESUMO

OBJECTIVE: The purpose of this analysis was to assess health-related quality of life (HRQoL) in patients treated with zanubrutinib and ibrutinib in the ALPINE trial (NCT03734016). METHODS: HRQoL was measured by the EORTC QLQ-C30 and EQ-5D-5L at baseline, cycle 1, and every third cycle until the end of treatment. Key patient-reported outcome (PRO) endpoints included global health status (GHS), physical and role functioning, as well as symptoms of fatigue, pain, diarrhea, and nausea/vomiting. A mixed model repeated-measure analysis using key PRO endpoints at key clinical cycles (cycles 7 and 13) was performed. RESULTS: 652 patients were randomized to receive zanubrutinib (n = 327) or ibrutinib (n = 325). By cycle 7, GHS scores improved with zanubrutinib versus ibrutinib, and in cycle 13, GHS scores remained higher in the zanubrutinib arm. The zanubrutinib arm experienced clinically meaningful improvements in physical and role functioning, as well as pain and fatigue symptoms at both cycles. Patients in the zanubrutinib arm reported lower diarrhea scores. Nausea/vomiting scores maintained in both arms. EQ-VAS scores showed greater improvement from baseline at both cycle 7 (7.92 versus 3.44) and cycle 13 (7.75 versus 3.92) of treatment with zanubrutinib compared to ibrutinib, respectively. CONCLUSIONS: Patients with R/R CLL/SLL treated with zanubrutinib demonstrated improvement versus ibrutinib in the GHS scale at cycle 7. Other endpoints continued to improve, suggesting treatment with zanubrutinib positively affected HRQoL over time. Given the generally good HRQoL at baseline in both arms, the differences between the arms were not significant.

5.
Nat Biomed Eng ; 6(5): 593-604, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34992272

RESUMO

The clinical diagnostic evaluation of optic neuropathies relies on the analysis of the thickness of the retinal nerve fibre layer (RNFL) by optical coherence tomography (OCT). However, false positives and false negatives in the detection of RNFL abnormalities are common. Here we show that an algorithm integrating measurements of RNFL thickness and reflectance from standard wide-field OCT scans can be used to uncover the trajectories and optical texture of individual axonal fibre bundles in the retina and to discern distinctive patterns of loss of axonal fibre bundles in glaucoma, compressive optic neuropathy, optic neuritis and non-arteritic anterior ischaemic optic neuropathy. Such optical texture analysis can detect focal RNFL defects in early optic neuropathy, as well as residual axonal fibre bundles in end-stage optic neuropathy that were indiscernible by conventional OCT analysis and by red-free RNFL photography. In a diagnostic-performance study, optical texture analysis of the RNFL outperformed conventional OCT in the detection of glaucoma, as defined by visual-field testing or red-free photography. Our findings show that optical texture analysis of the RNFL for the detection of optic neuropathies is highly sensitive and specific.


Assuntos
Glaucoma , Doenças do Nervo Óptico , Glaucoma/diagnóstico por imagem , Humanos , Fibras Nervosas/patologia , Doenças do Nervo Óptico/diagnóstico por imagem , Retina/diagnóstico por imagem , Tomografia de Coerência Óptica
6.
J Vis Exp ; (174)2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34424247

RESUMO

The underlying causes of heart valve related-disease (HVD) are elusive. Murine animal models provide an excellent tool for studying HVD, however, the surgical and instrumental expertise required to accurately quantify the structure and organization across multiple length scales have stunted its advancement. This work provides a detailed description of the murine dissection, en bloc staining, sample processing, and correlative imaging procedures for depicting the heart valve at different length scales. Hydrostatic transvalvular pressure was used to control the temporal heterogeneity by chemically fixing the heart valve conformation. Micro-computed tomography (µCT) was used to confirm the geometry of the heart valve and provide a reference for the downstream sample processing needed for the serial block face scanning electron microscopy (SBF-SEM). High-resolution serial SEM images of the extracellular matrix (ECM) were taken and reconstructed to provide a local 3D representation of its organization. µCT and SBF-SEM imaging methods were then correlated to overcome the spatial variation across the pulmonary valve. Though the work presented is exclusively on the pulmonary valve, this methodology could be adopted for describing the hierarchical organization in biological systems and is pivotal for the structural characterization across multiple length scales.


Assuntos
Imageamento Tridimensional , Valva Pulmonar , Animais , Camundongos , Microscopia Eletrônica de Varredura , Valva Pulmonar/diagnóstico por imagem , Valva Pulmonar/cirurgia , Manejo de Espécimes , Microtomografia por Raio-X
8.
Lancet ; 397(10272): 366-367, 2021 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-33516329
12.
Ophthalmology ; 127(10): 1322-1330, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32423768

RESUMO

OBJECTIVE: Evaluation of glaucoma progression with OCT has been centered on the analysis of progressive retinal nerve fiber layer (RNFL) thinning over the parapapillary region and/or progressive ganglion cell inner plexiform layer (GCIPL) thinning over the macula. We investigated (1) whether combining the RNFL and GCIPL as a single layer (i.e., RNFL-GCIPL) for wide-field progression analysis outperforms wide-field progression analysis of the RNFL or the GCIPL, and (2) whether eyes with progressive RNFL-GCIPL thinning are at risk of visual field (VF) progression. DESIGN: Prospective, longitudinal study. PARTICIPANTS: A total of 440 eyes from 236 glaucoma patients; 98 eyes from 49 healthy individuals. METHODS: OCT RNFL/GCIPL/RNFL-GCIPL thickness and VF measurements were obtained at ∼4-month intervals for ≥3 years. Progressive changes of the RNFL/GCIPL/RNFL-GCIPL thicknesses were analyzed over a wide field (12×9 mm2) covering the parapapillary region and the macula with trend-based progression analysis (TPA) controlled at a false discovery rate of 5%. VF progression was determined by the Early Manifest Glaucoma Trial criteria. MAIN OUTCOME MEASURES: Proportions of eyes with progressive RNFL/GCIPL/RNFL-GCIPL thinning; hazard ratios (HRs) for development of VF progression. RESULTS: More eyes showed progressive RNFL-GCIPL thinning (127 eyes; 28.9%, 95% confidence interval [CI]: 23.9%-33.8%) than progressive RNFL thinning (74 eyes; 16.8%, 95% CI: 13.1%-20.6%) and progressive GCIPL thinning (26 eyes; 5.9%, 95% CI: 3.7%-8.1%) in the glaucoma group over the study follow-up. Progressive RNFL-GCIPL thinning was almost always detected before or simultaneously with progressive RNFL thinning or progressive GCIPL thinning. The specificity of TPA (estimated from the healthy group) for detection of progressive RNFL-GCIPL thinning, progressive RNFL thinning, and progressive GCIPL thinning was 83.7% (95% CI: 74.9%-92.4%), 94.9% (95% CI: 90.6%-99.2%), and 96.9% (95% CI: 93.5%-100.0%), respectively. Eyes with progressive RNFL-GCIPL thinning had a higher risk to develop possible (HR: 2.4, 95% CI: 1.2-5.0) or likely (HR: 4.6, 95% CI: 1.5-14.0) VF progression, with adjustment of covariates, compared with eyes without progressive RNFL-GCIPL thinning. CONCLUSIONS: Progression analysis of RNFL-GCIPL thickness reveals a significant portion of progressing eyes that neither progression analysis of RNFL thickness nor GCIPL thickness would identify. Wide-field progression analysis of RNFL-GCIPL thickness is effective to inform the risk of VF progression in glaucoma patients.


Assuntos
Glaucoma/diagnóstico , Pressão Intraocular/fisiologia , Macula Lutea/patologia , Disco Óptico/patologia , Células Ganglionares da Retina/patologia , Tomografia de Coerência Óptica/métodos , Acuidade Visual , Progressão da Doença , Feminino , Seguimentos , Glaucoma/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Fibras Nervosas , Estudos Prospectivos , Campos Visuais
13.
JAMA Ophthalmol ; 138(5): 490-498, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32191274

RESUMO

Importance: Clinical assessment of vision-related disability is hampered by the lack of instruments to assess visual performance in real-world situations. Interactive virtual reality (VR) environments displayed in a binocular stereoscopic VR headset have been designed, presumably simulating day-to-day activities to evaluate vision-related disability. Objective: To investigate the application of VR to identify vision-related disability in patients with glaucoma. Design, Setting, and Participants: In a cross-sectional study, 98 patients with glaucoma and 50 healthy individuals were consecutively recruited from a university eye clinic; all participants were Chinese. The study was conducted between August 30, 2016, and July 31, 2017; data analysis was performed from December 1, 2017, to October 30, 2018. Exposures: Measurements of visual acuity, contrast sensitivity, visual field (VF), National Eye Institute 25-item Visual Function Questionnaire Rasch score, and VR disability scores determined from 5 VR simulations: supermarket shopping, stair and city navigations in daytime, and stair and city navigations in nighttime. Duration required to complete the simulation, number of items incorrectly identified, and number of collisions were measured to compute task-specific and overall VR disability scores. Vision-related disability was identified when the VR disability score was outside the normal age-adjusted 95% confidence region. Main Outcomes and Measures: Virtual reality disability score. Results: In the 98 patients with glaucoma, mean (SD) age was 49.8 (11.6) years and 60 were men (61.2%); in the 50 healthy individuals, mean (SD) age was 48.3 (14.8) years and 16 were men (32.0%). The patients with glaucoma had different degrees of VF loss (122 eyes [62.2%] had moderate or advanced VF defects). The time required to complete the activities by patients with glaucoma vs healthy individuals was longer by 15.2 seconds (95% CI, 5.5-24.9 seconds) or 34.1% (95% CI, 12.4%-55.7%) for the shopping simulation, 72.8 seconds (95% CI, 23.0-122.6 seconds) or 33.8% (95% CI, 10.7%-56.9%) for the nighttime stair navigation, and 38.1 seconds (95% CI, 10.9-65.2 seconds) or 30.8% (95% CI, 8.8%-52.8%) for the nighttime city navigation. The mean (SD) duration was not significantly different between the glaucoma and healthy groups in daytime stair (203.7 [93.7] vs 192.9 [89.1] seconds, P = .52) and city (118.7 [41.5] vs 117.0 [52.3] seconds, P = .85) navigation. For each decibel decrease in binocular VF sensitivity, the risk of collision increased by 15% in nighttime stair (hazard ratio [HR], 1.15; 95% CI, 1.08-1.22) and city (HR, 1.15; 95% CI, 1.08-1.23) navigations. Fifty-eight patients (59.1%) with glaucoma had vision-related disability in at least 1 simulated daily task; a higher proportion of patients had vision-related disability in nighttime city (27 of 88 [30.7%]) and stair (27 of 90 [30.0%]) navigation than in daytime city (7 of 88 [8.0%]) and stair (19 of 96 [19.8%]) navigation. The overall VR disability score was associated with the National Eye Institute 25-item Visual Function Questionnaire Rasch score (R2 = 0.207). Conclusions and Relevance: These findings suggest that vision-related disability is associated with lighting condition and task in patients with glaucoma. Virtual reality may allow eye care professionals to understand the patients' perspectives on how visual impairment imparts disability in daily living and provide a new paradigm to augment the assessment of vision-related disability.


Assuntos
Avaliação da Deficiência , Glaucoma de Ângulo Fechado/diagnóstico , Glaucoma de Ângulo Aberto/diagnóstico , Realidade Virtual , Transtornos da Visão/diagnóstico , Atividades Cotidianas , Adulto , Idoso , Simulação por Computador , Estudos Transversais , Feminino , Glaucoma de Ângulo Fechado/fisiopatologia , Glaucoma de Ângulo Aberto/fisiopatologia , Humanos , Pressão Intraocular/fisiologia , Masculino , Pessoa de Meia-Idade , Perfil de Impacto da Doença , Inquéritos e Questionários , Transtornos da Visão/fisiopatologia , Visão Binocular/fisiologia , Acuidade Visual/fisiologia , Campos Visuais/fisiologia
15.
Bioresour Technol ; 99(17): 7966-70, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18479913

RESUMO

A Klebsiella sp. HE1 strain isolated from hydrogen-producing sewage sludge was examined for its ability to produce H2 and other valuable soluble metabolites (e.g., ethanol and 2,3-butanediol) from sucrose-based medium. The effect of pH and carbon substrate concentration on the production of soluble and gaseous products was investigated. The major soluble metabolite produced from Klebsiella sp. HE1 was 2,3-butanediol, accounting for over 42-58% of soluble microbial products (SMP) and its production efficiency enhanced after increasing the initial culture pH to 7.3 (without pH control). The HE1 strain also produced ethanol (contributing to 29-42% of total SMP) and a small amount of lactic acid and acetic acid. The gaseous products consisted of H2 (25-36%) and CO2 (64-75%). The optimal cumulative hydrogen production (2.7 l) and hydrogen yield (0.92mol H2 mol sucrose(-1)) were obtained at an initial sucrose concentration of 30g CODl(-1) (i.e., 26.7gl(-1)), which also led to the highest production rate for H2 (3.26mmol h(-1)l(-1)), ethanol (6.75mmol h(-1)l(-1)) and 2,3-butanediol (7.14mmol h(-1)l(-1)). The highest yield for H2, ethanol and 2,3-butanediol was 0.92, 0.81 and 0.59molmol-sucrose(-1), respectively. As for the overall energy production performance, the highest energy generation rate was 27.7kJ h(-1)l(-1) and the best energy yield was 2.45kJmolsucrose(-1), which was obtained at a sucrose concentration of 30 and 20g CODl(-1), respectively.


Assuntos
Butileno Glicóis/metabolismo , Etanol/metabolismo , Hidrogênio/metabolismo , Klebsiella/isolamento & purificação , Esgotos/microbiologia , Carbono/farmacologia , Proliferação de Células/efeitos dos fármacos , Elétrons , Fermentação/efeitos dos fármacos , Concentração de Íons de Hidrogênio/efeitos dos fármacos , Ferro/farmacologia , Klebsiella/citologia , Klebsiella/efeitos dos fármacos , Solubilidade/efeitos dos fármacos , Sacarose/farmacologia , Temperatura
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