Publications by authors named "Lichtman J"

The sense of smell is generated by electrical currents that are influenced by the concentration of ions in olfactory sensory neurons and mucus. In contrast to the extensive morphological and molecular characterization of sensory neurons, there has been little description of the cells that control ion concentrations in the zebrafish olfactory system. Here, we report the molecular and ultrastructural characterization of zebrafish olfactory ionocytes.

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Finding optimal bipartite matchings-e.g., matching medical students to hospitals for residency, items to buyers in an auction, or papers to reviewers for peer review-is a fundamental combinatorial optimization problem.

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Introduction: Macular Telangiectasia type 2 (MacTel), is an uncommon form of late-onset, slowly-progressive macular degeneration. Associated with regional Müller glial cell loss in the retina and the amino acid serine synthesized by Müller cells, the disease is functionally confined to a central retinal region - the MacTel zone.

Methods: We have used high-throughput multi-resolution electron microscopy techniques, optimized for disease analysis, to study the retinas from two women, mother and daughter, aged 79 and 48 years respectively, suffering from MacTel.

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Mapping neuronal networks is a central focus in neuroscience. While volume electron microscopy (vEM) can reveal the fine structure of neuronal networks (connectomics), it does not provide molecular information to identify cell types or functions. We developed an approach that uses fluorescent single-chain variable fragments (scFvs) to perform multiplexed detergent-free immunolabeling and volumetric-correlated-light-and-electron-microscopy on the same sample.

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Connectomics provides essential nanometer-resolution, synapse-level maps of neural circuits to understand brain activity and behavior. However, few researchers have access to the high-throughput electron microscopes necessary to generate enough data for whole circuit or brain reconstruction. To date, machine-learning methods have been used after the collection of images by electron microscopy (EM) to accelerate and improve neuronal segmentation, synapse reconstruction and other data analysis.

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Large-scale electron microscopy (EM) has enabled the reconstruction of brain connectomes at the synaptic level by serially scanning over massive areas of sample sections. The acquired big EM data sets raise the great challenge of image mosaicking at high accuracy. Currently, it simply follows the conventional algorithms designed for natural images, which are usually composed of only a few tiles, using a single type of keypoint feature that would sacrifice speed for stronger performance.

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The hypothalamic suprachiasmatic nucleus (SCN) is the central pacemaker for mammalian circadian rhythms. As such, this ensemble of cell-autonomous neuronal oscillators with divergent periods must maintain coordinated oscillations. To investigate ultrastructural features enabling such synchronization, 805 coronal ultrathin sections of mouse SCN tissue were imaged with electron microscopy and aligned into a volumetric stack, from which selected neurons within the SCN core were reconstructed in silico.

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To fully understand how the human brain works, knowledge of its structure at high resolution is needed. Presented here is a computationally intensive reconstruction of the ultrastructure of a cubic millimeter of human temporal cortex that was surgically removed to gain access to an underlying epileptic focus. It contains about 57,000 cells, about 230 millimeters of blood vessels, and about 150 million synapses and comprises 1.

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Background: An alternative patient-centered appointment-based cardiac rehabilitation (CR) program has led to significant improvements in health outcomes for patients with cardiovascular disease. However, less is known about the effects of this approach on health-related quality of life (HRQoL), particularly for women.

Objective: We examined the effects of a patient-centered appointment-based CR program on HRQoL by sex and examined predictors of HRQoL improvements specifically for women.

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Creating a high-resolution brain atlas in diverse species offers crucial insights into general principles underlying brain function and development. A volume electron microscopy approach to generate such neural maps has been gaining importance due to advances in imaging, data storage capabilities, and data analysis protocols. Sample preparation remains challenging and is a crucial step to accelerate the imaging and data processing pipeline.

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Introduction: Despite evidence supporting the benefits of marriage on cardiovascular health, the impact of marital/partner status on the long-term readmission of young acute myocardial infarction (AMI) survivors is less clear. We examined the association between marital/partner status and 1-year all-cause readmission and explored sex differences among young AMI survivors.

Methods: Data were from the VIRGO study (Variation in Recovery: Role of Gender on Outcomes of Young AMI Patients), which enrolled young adults aged 18-55 years with AMI (2008-2012).

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De novo mutations occur at substantially different rates depending on genomic location, sequence context and DNA strand. The success of methods to estimate selection intensity, infer demographic history and map rare disease genes, depends strongly on assumptions about the local mutation rate. Here we present Roulette, a genome-wide mutation rate model at basepair resolution that incorporates known determinants of local mutation rate.

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Maps of the nervous system that identify individual cells along with their type, subcellular components and connectivity have the potential to elucidate fundamental organizational principles of neural circuits. Nanometer-resolution imaging of brain tissue provides the necessary raw data, but inferring cellular and subcellular annotation layers is challenging. We present segmentation-guided contrastive learning of representations (SegCLR), a self-supervised machine learning technique that produces representations of cells directly from 3D imagery and segmentations.

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Connectomics is a nascent neuroscience field to map and analyze neuronal networks. It provides a new way to investigate abnormalities in brain tissue, including in models of Alzheimer's disease (AD). This age-related disease is associated with alterations in amyloid-β (Aβ) and phosphorylated tau (pTau).

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Primary cilia act as antenna receivers of environmental signals and enable effective neuronal or glial responses. Disruption of their function is associated with circuit disorders. To understand the signals these cilia receive, we comprehensively mapped cilia's contacts within the human cortical connectome using serial-section EM reconstruction of a 1 mm cortical volume, spanning the entire cortical thickness.

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Recent advances in high-resolution connectomics provide researchers with access to accurate petascale reconstructions of neuronal circuits and brain networks for the first time. Neuroscientists are analyzing these networks to better understand information processing in the brain. In particular, scientists are interested in identifying specific small network motifs, i.

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Mapping the complete synaptic connectivity of a mammalian brain would be transformative, revealing the pathways underlying perception, behavior, and memory. Serial section electron microscopy, via membrane staining using osmium tetroxide, is ideal for visualizing cells and synaptic connections but, in whole brain samples, faces significant challenges related to chemical treatment and volume changes. These issues can adversely affect both the ultrastructural quality and macroscopic tissue integrity.

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Background: Medicaid serves as a safety net for low-income US Medicare beneficiaries with limited assets. Approximately 7.7 million Americans aged ≥65 years rely on a combination of Medicare and Medicaid to obtain critical medical services, yet little is known about whether these patients have worse outcomes after stroke than patients with Medicare alone.

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Article Synopsis
  • There is a critical lack of knowledge regarding the long-term outcomes of trauma systems, leading to expanded efforts to assess postdischarge quality metrics, but their application remains unclear.
  • This study aims to explore the effectiveness of using these postdischarge quality metrics as a composite score and to compare its effectiveness with in-hospital mortality indicators for evaluating hospital performance.
  • The research involved analyzing Medicare claims for over 573,000 older adults hospitalized for trauma-related issues, revealing that several quality metrics, particularly readmission rates and patient recovery time, significantly influenced hospital performance evaluations.
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Article Synopsis
  • Detergent-free immunolabeling is effective for combining light and electron microscopy, but is limited by the availability of suitable affinity reagents.
  • The CAptVE method utilizes modified aptamers that have slow off-rates to label cells for fluorescence in electron microscopy images.
  • CAptVE enables labeling of various biomarkers, facilitating the integration of molecular analysis with techniques to map neural circuits in connectomics.
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Article Synopsis
  • The VIRGO study analyzed 3,572 young adults (ages 18-55) who experienced an acute myocardial infarction (AMI), focusing on the effects of obstructive sleep apnea (OSA) on health outcomes, particularly by sex.
  • About 49% of patients were identified as high risk for OSA, but only 4.7% had a prior diagnosis, highlighting a significant gap in awareness.
  • Women at high risk for OSA showed significantly worse physical and mental health outcomes compared to their male counterparts, suggesting they are more adversely affected by the condition following an AMI.
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Background Stress experienced in a marriage or committed relationship may be associated with worse patient-reported outcomes after acute myocardial infarction (AMI), but little is known about this association in young adults (≤55 years) with AMI. Methods and Results We used data from VIRGO (Variation in Recovery: Role of Gender on Outcomes of Young AMI Patients), an observational cohort study that enrolled individuals aged 18 to 55 years with AMI (2008-2012). Marital stress was self-reported 1 month after AMI using the Stockholm Marital Stress Scale (categorized as absent/mild, moderate, and severe).

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Background: Whether stroke patients treated at hospitals with better short-term outcome metrics have better long-term outcomes is unknown. We investigated whether treatment at US hospitals with better 30-day hospital-level stroke outcome metrics was associated with better 1-year outcomes, including reduced mortality and recurrent stroke, for patients after ischemic stroke.

Methods: This cohort study included Medicare fee-for-service beneficiaries aged ≥65 years discharged alive from US hospitals with a principal diagnosis of ischemic stroke from 07/01/2015 to 12/31/2018.

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Analysis of brain structure, connectivity, and molecular diversity relies on effective tissue fixation. Conventional tissue fixation causes extracellular space (ECS) loss, complicating the segmentation of cellular objects from electron microscopy datasets. Previous techniques for preserving ECS in mammalian brains utilizing high-pressure perfusion can give inconsistent results owing to variations in the hydrostatic pressure within the vasculature.

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Mapping neuronal networks that underlie behavior has become a central focus in neuroscience. While serial section electron microscopy (ssEM) can reveal the fine structure of neuronal networks (connectomics), it does not provide the molecular information that helps identify cell types or their functional properties. Volumetric correlated light and electron microscopy (vCLEM) combines ssEM and volumetric fluorescence microscopy to incorporate molecular labeling into ssEM datasets.

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