Publications by authors named "Elizabeth Carroll"

50 Publications

Editorial: Next-Generation Genetically-Encoded Fluorescent Sensors.

Front Cell Neurosci 2020 3;14:627792. Epub 2020 Dec 3.

Department of Imaging Physics, Delft University of Technology, Delft, Netherlands.

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http://dx.doi.org/10.3389/fncel.2020.627792DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7744288PMC
December 2020

Experience, circuit dynamics, and forebrain recruitment in larval zebrafish prey capture.

Elife 2020 09 28;9. Epub 2020 Sep 28.

Helen Wills Neuroscience Institute and Graduate Program, University of California Berkeley, Berkeley, United States.

Experience influences behavior, but little is known about how experience is encoded in the brain, and how changes in neural activity are implemented at a network level to improve performance. Here we investigate how differences in experience impact brain circuitry and behavior in larval zebrafish prey capture. We find that experience of live prey compared to inert food increases capture success by boosting capture initiation. In response to live prey, animals with and without prior experience of live prey show activity in visual areas (pretectum and optic tectum) and motor areas (cerebellum and hindbrain), with similar visual area retinotopic maps of prey position. However, prey-experienced animals more readily initiate capture in response to visual area activity and have greater visually-evoked activity in two forebrain areas: the telencephalon and habenula. Consequently, disruption of habenular neurons reduces capture performance in prey-experienced fish. Together, our results suggest that experience of prey strengthens prey-associated visual drive to the forebrain, and that this lowers the threshold for prey-associated visual activity to trigger activity in motor areas, thereby improving capture performance.
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http://dx.doi.org/10.7554/eLife.56619DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7561350PMC
September 2020

Post-COVID-19 inflammatory syndrome manifesting as refractory status epilepticus.

Epilepsia 2020 10 18;61(10):e135-e139. Epub 2020 Sep 18.

Department of Neurology, NYU Langone Medical Center, New York, New York.

There have been multiple descriptions of seizures during the acute infectious period in patients with COVID-19. However, there have been no reports of status epilepticus after recovery from COVID-19 infection. Herein, we discuss a patient with refractory status epilepticus 6 weeks after initial infection with COVID-19. Extensive workup demonstrated elevated inflammatory markers, recurrence of a positive nasopharyngeal SARS-CoV-2 polymerase chain reaction, and hippocampal atrophy. Postinfectious inflammation may have triggered refractory status epilepticus in a manner similar to the multisystemic inflammatory syndrome observed in children after COVID-19.
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http://dx.doi.org/10.1111/epi.16683DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7537028PMC
October 2020

Continuous EEG findings in patients with COVID-19 infection admitted to a New York academic hospital system.

Epilepsia 2020 10 2;61(10):2097-2105. Epub 2020 Sep 2.

Department of Neurology, New York University Grossman School of Medicine and NYU Langone Health, New York, NY, USA.

Objective: There is evidence for central nervous system complications of coronavirus disease 2019 (COVID-19) infection, including encephalopathy. Encephalopathy caused by or arising from seizures, especially nonconvulsive seizures (NCS), often requires electroencephalography (EEG) monitoring for diagnosis. The prevalence of seizures and other EEG abnormalities among COVID-19-infected patients is unknown.

Methods: Medical records and EEG studies of patients hospitalized with confirmed COVID-19 infections over a 2-month period at a single US academic health system (four hospitals) were reviewed to describe the distribution of EEG findings including epileptiform abnormalities (seizures, periodic discharges, or nonperiodic epileptiform discharges). Factors including demographics, remote and acute brain injury, prior history of epilepsy, preceding seizures, critical illness severity scores, and interleukin 6 (IL-6) levels were compared to EEG findings to identify predictors of epileptiform EEG abnormalities.

Results: Of 111 patients monitored, most were male (71%), middle-aged or older (median age 64 years), admitted to an intensive care unit (ICU; 77%), and comatose (70%). Excluding 11 patients monitored after cardiac arrest, the most frequent EEG finding was moderate generalized slowing (57%), but epileptiform findings were observed in 30% and seizures in 7% (4% with NCS). Three patients with EEG seizures did not have epilepsy or evidence of acute or remote brain injury, although all had clinical seizures prior to EEG. Only having epilepsy (odds ratio [OR] 5.4, 95% confidence interval [CI] 1.4-21) or seizure(s) prior to EEG (OR 4.8, 95% CI 1.7-13) was independently associated with epileptiform EEG findings.

Significance: Our study supports growing evidence that COVID-19 can affect the central nervous system, although seizures are unlikely a common cause of encephalopathy. Seizures and epileptiform activity on EEG occurred infrequently, and having a history of epilepsy or seizure(s) prior to EEG testing was predictive of epileptiform findings. This has important implications for triaging EEG testing in this population.
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http://dx.doi.org/10.1111/epi.16667DOI Listing
October 2020

Taking a Strohl Through History: Putting Strohl Back in Guillain-Barré-Strohl Syndrome.

J Neuromuscul Dis 2020 ;7(4):521-522

New York University Langone Health, Department of Neurology, New York City, NY, USA.

Guillain-Barré Syndrome is a popular eponym that comes from a 1916 paper by Drs. Guillain, Barré, and Strohl. These physicians described two soldiers in the French Sixth Army during World War I who developed acute progressive motor weakness. Although Drs. Guillain and Barré have continued to be included in the syndrome's eponym, Dr. Strohl has been forgotten despite having strongly contributed to the original paper. The reasons previously mentioned for Dr. Strohl's absence appear trivial in contemporary practice and thus, his name deserves to be reintroduced to Guillain-Barré-Strohl Syndrome.
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http://dx.doi.org/10.3233/JND-200545DOI Listing
January 2020

Special considerations in the assessment of catastrophic brain injury and determination of brain death in patients with SARS-CoV-2.

J Neurol Sci 2020 10 8;417:117087. Epub 2020 Aug 8.

NYU Langone Medical Center, Department of Neurology, New York, NY 10016, United States of America; NYU Langone Medical Center, Department of Neurosurgery, New York, NY 10016, United States of America.

Introduction: The coronavirus disease 2019 (Covid-19) pandemic has led to challenges in provision of care, clinical assessment and communication with families. The unique considerations associated with evaluation of catastrophic brain injury and death by neurologic criteria in patients with Covid-19 infection have not been examined.

Methods: We describe the evaluation of six patients hospitalized at a health network in New York City in April 2020 who had Covid-19, were comatose and had absent brainstem reflexes.

Results: Four males and two females with a median age of 58.5 (IQR 47-68) were evaluated for catastrophic brain injury due to stroke and/or global anoxic injury at a median of 14 days (IQR 13-18) after admission for acute respiratory failure due to Covid-19. All patients had hypotension requiring vasopressors and had been treated with sedative/narcotic drips for ventilator dyssynchrony. Among these patients, 5 had received paralytics. Apnea testing was performed for 1 patient due to the decision to withdraw treatment (n = 2), concern for inability to tolerate testing (n = 2) and observation of spontaneous respirations (n = 1). The apnea test was aborted due to hypoxia and hypotension. After ancillary testing, death was declared in three patients based on neurologic criteria and in three patients based on cardiopulmonary criteria (after withdrawal of support (n = 2) or cardiopulmonary arrest (n = 1)). A family member was able to visit 5/6 patients prior to cardiopulmonary arrest/discontinuation of organ support.

Conclusion: It is feasible to evaluate patients with catastrophic brain injury and declare brain death despite the Covid-19 pandemic, but this requires unique considerations.
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http://dx.doi.org/10.1016/j.jns.2020.117087DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7414304PMC
October 2020

Catastrophic Intracranial Hemorrhage in Two Critically Ill Patients with COVID-19.

Neurocrit Care 2021 02;34(1):354-358

Department of Neurology, NYU Langone Medical Center, 530 First Avenue HCC-5A, New York, NY, 10016, USA.

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http://dx.doi.org/10.1007/s12028-020-00993-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7250248PMC
February 2021

Anisoplanatic adaptive optics in parallelized laser scanning microscopy.

Opt Express 2020 May;28(10):14222-14236

Inhomogeneities in the refractive index of a biological microscopy sample can introduce phase aberrations, severely impairing the quality of images. Adaptive optics can be employed to correct for phase aberrations and improve image quality. However, conventional adaptive optics can only correct a single phase aberration for the whole field of view (isoplanatic correction) while, due to the highly heterogeneous nature of biological tissues, the sample induced aberrations in microscopy often vary throughout the field of view (anisoplanatic aberration), limiting significantly the effectiveness of adaptive optics. This paper reports on a new approach for aberration correction in laser scanning confocal microscopy, in which a spatial light modulator is used to generate multiple excitation points in the sample to simultaneously scan different portions of the field of view with completely independent correction, achieving anisoplanatic compensation of sample induced aberrations, in a significantly shorter time compared to sequential isoplanatic correction of multiple image subregions. The method was tested in whole Drosophila brains and in larval Zebrafish, each showing a dramatic improvement in resolution and sharpness when compared to conventional isoplanatic adaptive optics.
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http://dx.doi.org/10.1364/OE.389974DOI Listing
May 2020

Mitochondrial mass governs the extent of human T cell senescence.

Aging Cell 2020 02 2;19(2):e13067. Epub 2019 Dec 2.

Translational Medicine and Therapeutics, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK.

The susceptibility of human CD4 and CD8 T cells to senesce differs, with CD8 T cells acquiring an immunosenescent phenotype faster than the CD4 T cell compartment. We show here that it is the inherent difference in mitochondrial content that drives this phenotype, with senescent human CD4 T cells displaying a higher mitochondrial mass. The loss of mitochondria in the senescent human CD8 T cells has knock-on consequences for nutrient usage, metabolism and function. Senescent CD4 T cells uptake more lipid and glucose than their CD8 counterparts, leading to a greater metabolic versatility engaging either an oxidative or a glycolytic metabolism. The enhanced metabolic advantage of senescent CD4 T cells allows for more proliferation and migration than observed in the senescent CD8 subset. Mitochondrial dysfunction has been linked to both cellular senescence and aging; however, it is still unclear whether mitochondria play a causal role in senescence. Our data show that reducing mitochondrial function in human CD4 T cells, through the addition of low-dose rotenone, causes the generation of a CD4 T cell with a CD8 -like phenotype. Therefore, we wish to propose that it is the inherent metabolic stability that governs the susceptibility to an immunosenescent phenotype.
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http://dx.doi.org/10.1111/acel.13067DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6996952PMC
February 2020

Type I IFN signalling is required for cationic adjuvant formulation (CAF)01-induced cellular immunity and mucosal priming.

Vaccine 2020 01 11;38(3):635-643. Epub 2019 Nov 11.

Adjuvant Research Group, School of Biochemistry & Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Ireland; Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Advanced Materials and BioEngineering Research Centre (AMBER), Trinity College Dublin, Ireland. Electronic address:

Despite being in the midst of a global pandemic of infections caused by the pathogen Chlamydia trachomatis, a vaccine capable of inducing protective immunity remains elusive. Given the C. trachomatis mucosal port of entry, a formulation compatible with mucosal administration and capable of eliciting potent genital tract immunity is highly desirable. While subunit vaccines are considered safer and better tolerated, these are typically poorly immunogenic and require co-formulation with immune-potentiating adjuvants. However, of the adjuvants licensed for use in humans, very few drive robust cellular responses, a pre-requisite for protection against C. trachomatis infection. Recently, the cationic adjuvant formulations (CAF) have been shown to induce robust humoral and cellular immunity in pre-clinical models of chlamydia, malaria and tuberculosis (TB). Here, we demonstrate that CAF01 induces potent immune responses when combined with the major outer membrane protein (MOMP) of C. trachomatis following parenteral immunisation and also as part of a heterologous prime/boost regime. We show that a subcutaneous prime with CAF01-adjuvanted recombinant MOMP licenses antigen-specific immunity at distant mucosal sites which can be activated following oral antigen re-encounter in the absence of concomitant adjuvant stimulation. Finally, we shed light on the mechanism(s) through which CAF01 elicits robust antigen-specific immunity to co-formulated MOMP via type I interferon (IFN) signalling.
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http://dx.doi.org/10.1016/j.vaccine.2019.10.047DOI Listing
January 2020

Predation shapes invertebrate diversity in tropical but not temperate seagrass communities.

J Anim Ecol 2020 02 4;89(2):323-333. Epub 2019 Dec 4.

Department of Biology, Temple University, Philadelphia, PA, USA.

The hypothesis that biotic interactions are stronger at lower relative to higher latitudes has a rich history, drawing from ecological and evolutionary theory. While this hypothesis suggests that stronger interactions at lower latitudes may contribute to the maintenance of contemporary patterns of diversity, there remain few standardized biogeographic comparisons of community effects of species interactions. Using marine seagrasses as a focal ecosystem of conservation importance and sessile marine invertebrates as model prey, we tested the hypothesis that predation is stronger at lower latitudes and can shape contemporary patterns of prey diversity. To further advance understanding beyond prior studies, we also explored mechanisms that likely underlie a change in interaction outcomes with latitude. Multiple observational and experimental approaches were employed to test for effects of predators, and the mechanisms that may underlie these effects, in seagrass ecosystems of the western Atlantic Ocean spanning 30° of latitude from the temperate zone to the tropics. In predator exclusion experiments conducted in a temperate and a tropical region, predation decreased sessile invertebrate abundance, richness and diversity on both natural and standardized artificial seagrass at tropical but not temperate sites. Further, predation reduced invertebrate richness at both local and regional scales in the tropics. Additional experiments demonstrated that predation reduced invertebrate recruitment in the tropics but not the temperate zone. Finally, direct observations of predators showed higher but variable consumption rates on invertebrates at tropical relative to temperate latitudes. Together, these results demonstrate that strong predation in the tropics can have consequential impacts on prey communities through discrete effects on early life stages as well as longer-term cumulative effects on community structure and diversity. Our detailed experiments also provide some of the first data linking large-scale biogeographic patterns, community-scale interaction outcomes and direct observation of predators in the temperate zone and tropics. Therefore, our results support the hypothesis that predation is stronger in the tropics, but also elucidate some of the causes and consequences of this variation in shaping contemporary patterns of diversity.
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http://dx.doi.org/10.1111/1365-2656.13133DOI Listing
February 2020

Pathogenic CD8 Epidermis-Resident Memory T Cells Displace Dendritic Epidermal T Cells in Allergic Dermatitis.

J Invest Dermatol 2020 04 10;140(4):806-815.e5. Epub 2019 Sep 10.

The LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark. Electronic address:

The skin is our interface with the outside world, and consequently it is exposed to a wide range of microbes and allergens. Recent studies have indicated that allergen-specific skin-resident memory T (T) cells play a role in allergic contact dermatitis (ACD). However, the composition and dynamics of the epidermal T-cell subsets during ACD are not known. Here we show that exposure of the skin to the experimental contact allergen DNFB results in a displacement of the normally occurring dendritic epidermal T cells (DETC) concomitant with an accumulation of epidermal CD8CD69CD103 T cells in mice. By studying knockout mice, we provide evidence that CD8 T cells are required for the displacement of the DETC and that DETC are not required for recruitment of CD8 T cells to the epidermis following allergen exposure. We demonstrate that the magnitude of the allergic reaction correlates with the number of CD8 epidermal T cells, which again correlates with allergen dose and number of allergen exposures. Finally, in an attempt to elucidate why CD8 epidermal T cells persist in the epidermis, we show that CD8 epidermal T cells have a higher proliferative capability and are bioenergetically more stable, displaying a higher spare respiratory capacity than DETC.
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http://dx.doi.org/10.1016/j.jid.2019.07.722DOI Listing
April 2020

Prevention of surgical site infections after brain surgery: the prehistoric period to the present.

Neurosurg Focus 2019 08;47(2):E2

Departments of1Neurology and.

In this historical vignette, the authors discuss the prevention of surgical site infections (SSIs) after brain surgery from the prehistoric period to the present. Although the mechanism for infection was not fully understood until the 19th century, records demonstrate that as early as 10,000 bc, practitioners used gold, a biocidal material, for cranioplasties and attempted to approximate wounds by tying a patient's hair across the incision. Written records from the Egyptian and Babylonian period depict the process of soaking head dressings in alcohol, an antibacterial agent. In the Greek and Early Byzantine period, Hippocrates argued against the formation of pus in wounds and continued to champion the use of wine in wound management. In the 16th century, intracranial silver drains were first utilized in an effort to prevent postoperative infections. The turning point of SSI prevention was in 1867, when Joseph Lister illustrated the connection between Louis Pasteur's discovery of the fermentation process and the suppuration of wounds. Today, there are ongoing investigations and debates about the optimal techniques to prevent SSI after brain surgery. Although tremendous progress in the field of SSI prevention since the prehistoric period has been made, SSI continues to affect morbidity and mortality after brain surgery.
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http://dx.doi.org/10.3171/2019.5.FOCUS19250DOI Listing
August 2019

Fast Calculation of Computer Generated Holograms for 3D Photostimulation through Compressive-Sensing Gerchberg-Saxton Algorithm.

Methods Protoc 2018 Dec 20;2(1). Epub 2018 Dec 20.

Delft Center for Systems and Control, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands.

The use of spatial light modulators to project computer generated holograms is a common strategy for optogenetic stimulation of multiple structures of interest within a three-dimensional volume. A common requirement when addressing multiple targets sparsely distributed in three dimensions is the generation of a points cloud, focusing excitation light in multiple diffraction-limited locations throughout the sample. Calculation of this type of holograms is most commonly performed with either the high-speed, low-performance random superposition algorithm, or the low-speed, high performance Gerchberg-Saxton algorithm. This paper presents a variation of the Gerchberg-Saxton algorithm that, by only performing iterations on a subset of the data, according to compressive sensing principles, is rendered significantly faster while maintaining high quality outputs. The algorithm is presented in high-efficiency and high-uniformity variants. All source code for the method implementation is available as Supplementary Materials and as open-source software. The method was tested computationally against existing algorithms, and the results were confirmed experimentally on a custom setup for in-vivo multiphoton optogenetics. The results clearly show that the proposed method can achieve computational speed performances close to the random superposition algorithm, while retaining the high performance of the Gerchberg-Saxton algorithm, with a minimal hologram quality loss.
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http://dx.doi.org/10.3390/mps2010002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6481074PMC
December 2018

Holographic two-photon activation for synthetic optogenetics.

Nat Protoc 2019 03 25;14(3):864-900. Epub 2019 Feb 25.

Department of Neuroscience, Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.

Optogenetic tools provide users the ability to photocontrol the activity of cells. Commonly, activation is achieved by expression of proteins from photosynthetic organisms, for example, microbial opsins (e.g., ChR2). Alternatively, a sister approach, synthetic optogenetics, enables photocontrol over proteins of mammalian origin by use of photoswitches, visible light (typically), and genetic modification. Thus, synthetic optogenetics facilitates interrogation of native neuronal signaling mechanisms. However, the poor tissue penetration of visible wavelengths impedes the use of the technique in tissue, as two-photon excitation (2PE) is typically required to access the near-infrared window. Here, we describe an alternative technique that uses 2PE-compatible photoswitches (section 1) for photoactivation of genetically modified glutamate receptors (section 2). Furthermore, for fast, multi-region photoactivation, we describe the use of 2P-digital holography (2P-DH) (section 3). We detail how to combine 2P-DH and synthetic optogenetics with electrophysiology, or with red fluorescence Ca recordings, for all-optical neural interrogation. The time required to complete the methods, aside from obtaining the necessary reagents and illumination equipment, is ~3 weeks.
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http://dx.doi.org/10.1038/s41596-018-0118-2DOI Listing
March 2019

Divergent mechanisms of metabolic dysfunction drive fibroblast and T-cell senescence.

Ageing Res Rev 2018 11 15;47:24-30. Epub 2018 Jun 15.

William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK. Electronic address:

The impact of cellular senescence during ageing is well established, however senescence is now recognised to play a role in a variety of age related and metabolic diseases, such as cancer, autoimmune and cardiovascular diseases. It is therefore crucial to gain a better understanding of the mechanisms that control cellular senescence. In recent years our understanding of the intimate relationship between cell metabolism, cell signalling and cellular senescence has greatly improved. In this review we discuss the differing roles of glucose and protein metabolism in both senescent fibroblast and CD8 T-cells, and explore the impact cellular metabolism has on the senescence-associated secretory phenotype (SASP) of these cell types.
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http://dx.doi.org/10.1016/j.arr.2018.06.001DOI Listing
November 2018

Copper regulates rest-activity cycles through the locus coeruleus-norepinephrine system.

Nat Chem Biol 2018 07 4;14(7):655-663. Epub 2018 Jun 4.

Department of Chemistry, University of California, Berkeley, CA, USA.

The unusually high demand for metals in the brain, along with insufficient understanding of how their dysregulation contributes to neurological diseases, motivates the study of how inorganic chemistry influences neural circuitry. We now report that the transition metal copper is essential for regulating rest-activity cycles and arousal. Copper imaging and gene expression analysis in zebrafish identifies the locus coeruleus-norepinephrine (LC-NE) system, a vertebrate-specific neuromodulatory circuit critical for regulating sleep, arousal, attention, memory and emotion, as a copper-enriched unit with high levels of copper transporters CTR1 and ATP7A and the copper enzyme dopamine β-hydroxylase (DBH) that produces NE. Copper deficiency induced by genetic disruption of ATP7A, which loads copper into DBH, lowers NE levels and hinders LC function as manifested by disruption in rest-activity modulation. Moreover, LC dysfunction caused by copper deficiency from ATP7A disruption can be rescued by restoring synaptic levels of NE, establishing a molecular CTR1-ATP7A-DBH-NE axis for copper-dependent LC function.
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http://dx.doi.org/10.1038/s41589-018-0062-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6008210PMC
July 2018

Excitation-Wavelength-Dependent Photocycle Initiation Dynamics Resolve Heterogeneity in the Photoactive Yellow Protein from Halorhodospira halophila.

Biochemistry 2018 03 6;57(11):1733-1747. Epub 2018 Mar 6.

Department of Chemistry , University of California, Davis , One Shields Avenue , Davis , California 95616 , United States.

Photoactive yellow proteins (PYPs) make up a diverse class of blue-light-absorbing bacterial photoreceptors. Electronic excitation of the p-coumaric acid chromophore covalently bound within PYP results in triphasic quenching kinetics; however, the molecular basis of this behavior remains unresolved. Here we explore this question by examining the excitation-wavelength dependence of the photodynamics of the PYP from Halorhodospira halophila via a combined experimental and computational approach. The fluorescence quantum yield, steady-state fluorescence emission maximum, and cryotrapping spectra are demonstrated to depend on excitation wavelength. We also compare the femtosecond photodynamics in PYP at two excitation wavelengths (435 and 475 nm) with a dual-excitation-wavelength-interleaved pump-probe technique. Multicompartment global analysis of these data demonstrates that the excited-state photochemistry of PYP depends subtly, but convincingly, on excitation wavelength with similar kinetics with distinctly different spectral features, including a shifted ground-state beach and altered stimulated emission oscillator strengths and peak positions. Three models involving multiple excited states, vibrationally enhanced barrier crossing, and inhomogeneity are proposed to interpret the observed excitation-wavelength dependence of the data. Conformational heterogeneity was identified as the most probable model, which was supported with molecular mechanics simulations that identified two levels of inhomogeneity involving the orientation of the R52 residue and different hydrogen bonding networks with the p-coumaric acid chromophore. Quantum calculations were used to confirm that these inhomogeneities track to altered spectral properties consistent with the experimental results.
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http://dx.doi.org/10.1021/acs.biochem.7b01114DOI Listing
March 2018

Human CD8 EMRA T cells display a senescence-associated secretory phenotype regulated by p38 MAPK.

Aging Cell 2018 02 12;17(1). Epub 2017 Oct 12.

Translational Medicine and Therapeutics, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London, EC1M 6BQ, UK.

Cellular senescence is accompanied by a senescence-associated secretory phenotype (SASP). We show here that primary human senescent CD8 T cells also display a SASP comprising chemokines, cytokines and extracellular matrix remodelling proteases that are unique to this subset and contribute to age-associated inflammation. We found the CD8 CD45RA CD27 EMRA subset to be the most heterogeneous, with a population aligning with the naïve T cells and another with a closer association to the effector memory subset. However, despite the differing processes that give rise to these senescent CD8 T cells once generated, they both adopt a unique secretory profile with no commonality to any other subset, aligning more closely with senescence than quiescence. Furthermore, we also show that the SASP observed in senescent CD8 T cells is governed by p38 MAPK signalling.
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http://dx.doi.org/10.1111/acel.12675DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5770853PMC
February 2018

Ultrafast Charge-Transfer Dynamics in the Iron-Sulfur Complex of Rhodobacter capsulatus Ferredoxin VI.

J Phys Chem Lett 2017 Sep 7;8(18):4498-4503. Epub 2017 Sep 7.

Department of Chemistry, University of California Davis , One Shields Avenue, Davis, California 95616, United States.

Iron-sulfur proteins play essential roles in various biological processes. Their electronic structure and vibrational dynamics are key to their rich chemistry but nontrivial to unravel. Here, the first ultrafast transient absorption and impulsive coherent vibrational spectroscopic (ICVS) studies on 2Fe-2S clusters in Rhodobacter capsulatus ferreodoxin VI are characterized. Photoexcitation initiated populations on multiple excited electronic states that evolve into each other in a long-lived charge-transfer state. This suggests a potential light-induced electron-transfer pathway as well as the possibility of using iron-sulfur proteins as photosensitizers for light-dependent enzymes. A tyrosine chain near the active site suggests potential hole-transfer pathways and affirms this electron-transfer pathway. The ICVS data revealed vibrational bands at 417 and 484 cm, with the latter attributed to an excited-state mode. The temperature dependence of the ICVS modes suggests that the temperature effect on protein structure or conformational heterogeneities needs to be considered during cryogenic temperature studies.
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http://dx.doi.org/10.1021/acs.jpclett.7b02026DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7187928PMC
September 2017

Measuring Behavioral Individuality in the Acoustic Startle Behavior in Zebrafish.

Bio Protoc 2017 Apr;7(7)

Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, USA.

The objective of this protocol is to provide a detailed description for the construction and use of a behavioral apparatus, the zBox, for high-throughput behavioral measurements in larval zebrafish (). The zBox is used to measure behavior in multiple individuals simultaneously. Individual fish are housed in wells of multi-well plates and receive acoustic/vibration stimuli with simultaneous recording of behavior. Automated analysis of behavioral movies is performed with MATLAB scripts. This protocol was adapted from two of our previously published papers (Levitz , 2013; Pantoja , 2016). The zBox provides an easy to setup flexible platform for behavioral experiments in zebrafish larvae.
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http://dx.doi.org/10.21769/BioProtoc.2200DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5526351PMC
April 2017

Neuromodulatory Regulation of Behavioral Individuality in Zebrafish.

Neuron 2016 Aug 7;91(3):587-601. Epub 2016 Jul 7.

Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA; Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA 94720, USA; Bioscience Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. Electronic address:

Inter-individual behavioral variation is thought to increase fitness and aid adaptation to environmental change, but the underlying mechanisms are poorly understood. We find that variation between individuals in neuromodulatory input contributes to individuality in short-term habituation of the zebrafish (Danio Rerio) acoustic startle response (ASR). ASR habituation varies greatly between individuals, but differences are stable over days and are heritable. Acoustic stimuli that activate ASR-command Mauthner cells also activate dorsal raphe nucleus (DRN) serotonergic neurons, which project to the vicinity of the Mauthner cells and their inputs. DRN neuron activity decreases during habituation in proportion to habituation and a genetic manipulation that reduces serotonin content in DRN neurons increases habituation, whereas serotonergic agonism or DRN activation with ChR2 reduces habituation. Finally, level of rundown of DRN activity co-segregates with extent of behavioral habituation across generations. Thus, variation between individuals in neuromodulatory input contributes to individuality in a core adaptive behavior. VIDEO ABSTRACT.
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http://dx.doi.org/10.1016/j.neuron.2016.06.016DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4976045PMC
August 2016

Vocal Fold Paralysis after Esophagectomy for Carcinoma.

Otolaryngol Head Neck Surg 2016 07 3;155(1):122-6. Epub 2016 May 3.

Department of Otolaryngology-Head and Neck Surgery, Loyola University Medical Center, Maywood, Illinois, USA.

Objectives: (1) To recognize factors that contribute to vocal fold paralysis (VFP) after esophagectomy. (2) To describe the morbidity associated with VFP after esophagectomy.

Study Design: Retrospective cohort study.

Setting: Tertiary care academic medical center.

Subjects And Methods: The medical records of 91 patients undergoing esophagectomy for malignancy were reviewed (2008-2014). Twenty-two patients with postoperative VFP were compared with 69 patients without VFP with regard to preoperative variables, surgical approach (transcervical vs other), and postoperative outcomes. A subset analysis of cervical approaches was performed, including those where an otolaryngologist assisted.

Results: There were no significant differences in preoperative variables between patients with and without VFP. Cervical approaches were associated with increased VFP (P < .0001). Recurrent laryngeal nerve (RLN) identification was associated with increased VFP (P = .0001). RLN dissection by head and neck surgeons was associated with decreased VFP (P = .0223). Patients with VFP had longer lengths of stay (P = .0078), higher rates of tracheotomy (P = .0439), and required more outpatient swallow evaluations (P = .0017). Mean time to diagnosis of VFP was 45.6 days (median, 7.5 days).

Conclusions: Cervical approaches are associated with increased VFP in patients undergoing esophagectomy for malignancy. When cervical approaches and mobilization are required, the inclusion of an experienced cervical surgeon to identify the RLN may improve the rate of postoperative VFP. Patients with VFP after esophagectomy experience significantly more morbidity. Due to the potential delay in diagnosis and treatment of postoperative VFP, routine assessment of inpatient vocal fold function may be beneficial.
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http://dx.doi.org/10.1177/0194599816644738DOI Listing
July 2016

The Vaccine Adjuvant Chitosan Promotes Cellular Immunity via DNA Sensor cGAS-STING-Dependent Induction of Type I Interferons.

Immunity 2016 Mar 2;44(3):597-608. Epub 2016 Mar 2.

Adjuvant Research Group, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, D02 PN40, Ireland; Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN) & Advanced Materials Bio-Engineering Research Centre (AMBER), Trinity College Dublin, Dublin 2, D02 PN40, Ireland. Electronic address:

The cationic polysaccharide chitosan is an attractive candidate adjuvant capable of driving potent cell-mediated immunity, but the mechanism by which it acts is not clear. We show that chitosan promotes dendritic cell maturation by inducing type I interferons (IFNs) and enhances antigen-specific T helper 1 (Th1) responses in a type I IFN receptor-dependent manner. The induction of type I IFNs, IFN-stimulated genes and dendritic cell maturation by chitosan required the cytoplasmic DNA sensor cGAS and STING, implicating this pathway in dendritic cell activation. Additionally, this process was dependent on mitochondrial reactive oxygen species and the presence of cytoplasmic DNA. Chitosan-mediated enhancement of antigen specific Th1 and immunoglobulin G2c responses following vaccination was dependent on both cGAS and STING. These findings demonstrate that a cationic polymer can engage the STING-cGAS pathway to trigger innate and adaptive immune responses.
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http://dx.doi.org/10.1016/j.immuni.2016.02.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4852885PMC
March 2016

A family of photoswitchable NMDA receptors.

Elife 2016 Mar 1;5. Epub 2016 Mar 1.

Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.

NMDA receptors, which regulate synaptic strength and are implicated in learning and memory, consist of several subtypes with distinct subunit compositions and functional properties. To enable spatiotemporally defined, rapid and reproducible manipulation of function of specific subtypes, we engineered a set of photoswitchable GluN subunits ('LiGluNs'). Photo-agonism of GluN2A or GluN2B elicits an excitatory drive to hippocampal neurons that can be shaped in time to mimic synaptic activation. Photo-agonism of GluN2A at single dendritic spines evokes spine-specific calcium elevation and expansion, the morphological correlate of LTP. Photo-antagonism of GluN2A alone, or in combination with photo-antagonism of GluN1a, reversibly blocks excitatory synaptic currents, prevents the induction of long-term potentiation and prevents spine expansion. In addition, photo-antagonism in vivo disrupts synaptic pruning of developing retino-tectal projections in larval zebrafish. By providing precise and rapidly reversible optical control of NMDA receptor subtypes, LiGluNs should help unravel the contribution of specific NMDA receptors to synaptic transmission, integration and plasticity.
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http://dx.doi.org/10.7554/eLife.12040DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4786437PMC
March 2016

A Common Variant in the Adaptor Mal Regulates Interferon Gamma Signaling.

Immunity 2016 Feb;44(2):368-79

Department of Clinical Medicine, Institute of Molecular Medicine, Trinity College Dublin and St. James's Hospital, D08 W9RT, Dublin, Ireland.

Humans that are heterozygous for the common S180L polymorphism in the Toll-like receptor (TLR) adaptor Mal (encoded by TIRAP) are protected from a number of infectious diseases, including tuberculosis (TB), whereas those homozygous for the allele are at increased risk. The reason for this difference in susceptibility is not clear. We report that Mal has a TLR-independent role in interferon-gamma (IFN-γ) receptor signaling. Mal-dependent IFN-γ receptor (IFNGR) signaling led to mitogen-activated protein kinase (MAPK) p38 phosphorylation and autophagy. IFN-γ signaling via Mal was required for phagosome maturation and killing of intracellular Mycobacterium tuberculosis (Mtb). The S180L polymorphism, and its murine equivalent S200L, reduced the affinity of Mal for the IFNGR, thereby compromising IFNGR signaling in macrophages and impairing responses to TB. Our findings highlight a role for Mal outside the TLR system and imply that genetic variation in TIRAP may be linked to other IFN-γ-related diseases including autoimmunity and cancer.
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http://dx.doi.org/10.1016/j.immuni.2016.01.019DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4760121PMC
February 2016

Photoactivatable genetically encoded calcium indicators for targeted neuronal imaging.

Nat Methods 2015 Sep 13;12(9):852-8. Epub 2015 Jul 13.

Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA.

Circuit mapping requires knowledge of both structural and functional connectivity between cells. Although optical tools have been made to assess either the morphology and projections of neurons or their activity and functional connections, few probes integrate this information. We have generated a family of photoactivatable genetically encoded Ca(2+) indicators that combines attributes of high-contrast photolabeling with high-sensitivity Ca(2+) detection in a single-color protein sensor. We demonstrated in cultured neurons and in fruit fly and zebrafish larvae how single cells could be selected out of dense populations for visualization of morphology and high signal-to-noise measurements of activity, synaptic transmission and connectivity. Our design strategy is transferrable to other sensors based on circularly permutated GFP (cpGFP).
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http://dx.doi.org/10.1038/nmeth.3480DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4597790PMC
September 2015

Two-photon brightness of azobenzene photoswitches designed for glutamate receptor optogenetics.

Proc Natl Acad Sci U S A 2015 Feb 4;112(7):E776-85. Epub 2015 Feb 4.

Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720; Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720; and Physical Bioscience Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720

Mammalian neurotransmitter-gated receptors can be conjugated to photoswitchable tethered ligands (PTLs) to enable photoactivation, or photoantagonism, while preserving normal function at neuronal synapses. "MAG" PTLs for ionotropic and metabotropic glutamate receptors (GluRs) are based on an azobenzene photoswitch that is optimally switched into the liganding state by blue or near-UV light, wavelengths that penetrate poorly into the brain. To facilitate deep-tissue photoactivation with near-infrared light, we measured the efficacy of two-photon (2P) excitation for two MAG molecules using nonlinear spectroscopy. Based on quantitative characterization, we find a recently designed second generation PTL, L-MAG0460, to have a favorable 2P absorbance peak at 850 nm, enabling efficient 2P activation of the GluK2 kainate receptor, LiGluR. We also achieve 2P photoactivation of a metabotropic receptor, LimGluR3, with a new mGluR-specific PTL, D-MAG0460. 2P photoswitching is efficiently achieved using digital holography to shape illumination over single somata of cultured neurons. Simultaneous Ca(2+)-imaging reports on 2P photoswitching in multiple cells with high temporal resolution. The combination of electrophysiology or Ca(2+) imaging with 2P activation by optical wavefront shaping should make second generation PTL-controlled receptors suitable for studies of intact neural circuits.
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http://dx.doi.org/10.1073/pnas.1416942112DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4343171PMC
February 2015

Outcomes and long term follow-up after emergent cricothyroidotomy: is routine conversion to tracheostomy necessary?

Am Surg 2011 Dec;77(12):1707-11

Department of Surgery, University of Texas-Southwestern Medical Center, 5323 Harry Hines Boulevard, E5.508A, Dallas, TX 75390-9158, USA.

The purpose of this study is to identify factors associated with survival after cricothyroidotomy (CRIC), and to ascertain long-term outcomes in patients simply decannulated after CRIC versus those revised to tracheostomy. All CRICs between October 1, 1995 and June 20, 2010 were reviewed. Patients were contacted by phone, visited at their last known address, or queried in the Center for Disease Control's National Death Index. DECAN were those CRICs decannulated without revision. TRACH were those revised to a tracheostomy at any point. Ninety-five CRIC patients were identified. In 94 per cent of survivors of initial admission, a Glasgow Coma Score (GCS) of 15 was noted at disposition. Cardiopulmonary resuscitation before or during CRIC performance was strongly associated with all-cause death during index admission, and increasing head Abbreviated Injury Score was associated with lower odds of a neurologically intact survival. Of survivors, 82 per cent of DECAN and 57 per cent of TRACH patients were followed-up with at medians of 48 (interquartile range 19-57) and 53 (20-119) months, respectively. DECAN occurred at a median of 4 days (2-7) whereas TRACH revision occurred at a median of 2 days (1-7). Endoscopy was performed on 36 per cent of DECAN patients and 22 per cent of TRACH patients. Two DECAN patients with acute subglottic edema/stenosis decannulated successfully on days 9 and 15 postinjury and had no problems at 54 and 91 months postinjury. At follow-up, no patient in either group had suffered a clinically evident airway complication. The need for cardiopulmonary resuscitation before or during CRIC portends poorly for neurologically intact survival. Simple decannulation is appropriate for CRIC patients when their need for airway protection has resolved.
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http://dx.doi.org/10.1177/000313481107701248DOI Listing
December 2011

Prestorage leukoreduction abrogates the detrimental effect of aging on packed red cells transfused after trauma: a prospective cohort study.

Am J Surg 2012 Feb 14;203(2):198-204. Epub 2011 Sep 14.

Department of Surgery, Division of Burns/Trauma/Critical Care, University of Texas Southwestern Medical School, Dallas, USA.

Background: The aim of this study was to prospectively duplicate previous retrospective findings showing that prestorage leukoreduction blunts the detrimental effect of aging on banked packed red blood cells transfused after injury.

Methods: Over 19 months, trauma patients transfused with ≥4 U of packed red blood cells and surviving ≥24 hours were followed. The age of each unit was collected.

Results: The cohort consisted of 153 patients. All models showed no association between advancing blood age and the likelihood of developing multiple-organ dysfunction syndrome or infections, regardless of whether the mean age of blood was analyzed as a continuous variable, as a percentage of blood received that was <14 days old, or as a dichotomized value >14 or <14 days old.

Conclusions: This prospective study duplicates previous retrospective findings of an abrogation of the detrimental effects of advancing mean packed red blood cell age on outcomes after trauma by performing prestorage leukoreduction.
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http://dx.doi.org/10.1016/j.amjsurg.2011.05.012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3243822PMC
February 2012