Faculty Bibliography
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school:SOM
Department/Unit:Neuroscience Institute
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13474
Oxalate degradation rates of oxalobacter formigenes [Meeting Abstract]
Background: Kidney stones commonly affect US adults. In recent years, there has been increasing interest in the human anaerobic colonic bacterium Oxalobacter formigenes because of its ability to metabolize oxalate, and its potential to protect against calcium oxalate kidney stones. Currently, there are two known groups of O. formigenes (Group 1 and Group 2) with only a few isolates from each group characterized. In our experiments, we aimed to isolate O. formigenes from subjects with primary hyperoxaluria (PH), enteric hyperoxaluria (EH) and healthy controls (HC) to compare their metabolic activities. Understanding these differences will help expand our knowledge about this important organism and its effect on oxalate homeostasis in humans.
Method(s): We collected fecal samples from 37 patients via clinical trials at New York University Langone Medical Center and Mayo Clinic with PH, EH and HC. We cultured fecal samples in 25mM oxalate-rich selective media, then isolated O. formigenes by picking characteristic colonies from calcium oxalate agar. We identified and grouped isolates using PCR and Sanger sequencing of the oxc gene. We then tested their oxalate consumption via Oxalate Degradation Assay to compute mean oxalate degradation rates (ODR) for each group of isolates.
Result(s): We isolated 25 O. formigenes colonies from 14 subjects, with all isolates belonging to either HC (n=11) or PH (n= 14) patients, and none from EH patients. Based on oxc sequences, we identified Group 1 (n=17) and Group 2 (n=5) strains, and potentially a new taxonomic group Group 3 (n=3). We were able to regrow 13 (76%) of 17, 1 (20%) of 5, and 1 (33%) of 3 Group 1, 2, and 3 strains, respectively. All 14 PH patient colonies were identified as Group 1, while HC had a mix of all three groups. Mean ODR was significantly higher in Group 1 vs Group 2 isolates (8.5 +/- 3.3 vs 2.8 +/- 1.9 micromole/ hour, p=0.02). Group 3 isolates had intermediate ODR (5.7 +/- 3.1) values. As expected, the ODRs of our Group 1 isolates were similar to the control group 1 strain OXCC13 (11.1 +/- 1.2). Mean ODR between PH, EH and HC did not differ significantly.
Conclusion(s): We were able to isolate and characterize 25 colonies of O. formigenes, including a potential new group of O. formigenes. Group 1 strains appear to be most metabolically active in vitro, and were exclusively present in PH patients
Method(s): We collected fecal samples from 37 patients via clinical trials at New York University Langone Medical Center and Mayo Clinic with PH, EH and HC. We cultured fecal samples in 25mM oxalate-rich selective media, then isolated O. formigenes by picking characteristic colonies from calcium oxalate agar. We identified and grouped isolates using PCR and Sanger sequencing of the oxc gene. We then tested their oxalate consumption via Oxalate Degradation Assay to compute mean oxalate degradation rates (ODR) for each group of isolates.
Result(s): We isolated 25 O. formigenes colonies from 14 subjects, with all isolates belonging to either HC (n=11) or PH (n= 14) patients, and none from EH patients. Based on oxc sequences, we identified Group 1 (n=17) and Group 2 (n=5) strains, and potentially a new taxonomic group Group 3 (n=3). We were able to regrow 13 (76%) of 17, 1 (20%) of 5, and 1 (33%) of 3 Group 1, 2, and 3 strains, respectively. All 14 PH patient colonies were identified as Group 1, while HC had a mix of all three groups. Mean ODR was significantly higher in Group 1 vs Group 2 isolates (8.5 +/- 3.3 vs 2.8 +/- 1.9 micromole/ hour, p=0.02). Group 3 isolates had intermediate ODR (5.7 +/- 3.1) values. As expected, the ODRs of our Group 1 isolates were similar to the control group 1 strain OXCC13 (11.1 +/- 1.2). Mean ODR between PH, EH and HC did not differ significantly.
Conclusion(s): We were able to isolate and characterize 25 colonies of O. formigenes, including a potential new group of O. formigenes. Group 1 strains appear to be most metabolically active in vitro, and were exclusively present in PH patients
EMBASE:633768031
ISSN: 1533-3450
CID: 4755092
The Role Of Multisensory Overlap For Configural Processing Of Food Flavor In Humans: Behavioral Markers And Neural Correlates [Meeting Abstract]
ISI:000493389500196
ISSN: 0379-864x
CID: 4221932
A phase-2 randomized placebo-controlled trial of sirolimus in multiple system atrophy: Protocol, recruitment and preliminary adverse event profile [Meeting Abstract]
Objective: We present the protocol, recruitment numbers, and preliminary adverse event profile of patients enrolled in a single-center phase-2 futility trial using sirolimus for multiple system atrophy (MSA) (ClinicalTrials.gov: NCT03589976).
Background(s): In patients with MSA, autophagy is impaired and misfolded aSyn accumulates in neurons and glia, causing neurodegeneration. Sirolimus, a medication that has been approved by the U.S. Food and Drug Administration for chronic treatment in humans for a variety of disorders for almost 20 years, is a potent activator of autophagy. We hypothesize that treatment with sirolimus might activate autophagy of aSyn resulting in reduced neurodegeneration and slower progression of the neurological deficits in patients with MSA.
Method(s): Single-center, randomized, placebo-controlled, phase-2 futility clinical trial to determine if sirolimus is of sufficient promise to slow the disease progression of patients with MSA, prior to embarking on a large-scale and costly phase-3 study to assess its efficacy. Non-futility will offer strong support for a phase-3 trial to detect clinical efficacy. We will enroll 56 patients with a 3:1 (sirolimus:placebo) randomization. We expect to complete enrollment in 2 years.
Result(s): The first patient was screened and enrolled in September 2018. By May 2019, 35 patients had been screened and 31 had been enrolled and randomized. By October 2019 we expect to have enrolled 43 patients (76% of our final target enrollment). Common adverse events included oral ulcers, abdominal discomfort and diarrhea/loose stools. Recruitment and adverse events will be updated by the time of this abstract presentation.
Conclusion(s): This is the first time sirolimus or analogs are being used clinically with the aim of slowing disease progression in patients with neurodegenerative disorders. Our observations may offer strong support for a phase-3 trial to confirm the efficacy of sirolimus in MSA
Background(s): In patients with MSA, autophagy is impaired and misfolded aSyn accumulates in neurons and glia, causing neurodegeneration. Sirolimus, a medication that has been approved by the U.S. Food and Drug Administration for chronic treatment in humans for a variety of disorders for almost 20 years, is a potent activator of autophagy. We hypothesize that treatment with sirolimus might activate autophagy of aSyn resulting in reduced neurodegeneration and slower progression of the neurological deficits in patients with MSA.
Method(s): Single-center, randomized, placebo-controlled, phase-2 futility clinical trial to determine if sirolimus is of sufficient promise to slow the disease progression of patients with MSA, prior to embarking on a large-scale and costly phase-3 study to assess its efficacy. Non-futility will offer strong support for a phase-3 trial to detect clinical efficacy. We will enroll 56 patients with a 3:1 (sirolimus:placebo) randomization. We expect to complete enrollment in 2 years.
Result(s): The first patient was screened and enrolled in September 2018. By May 2019, 35 patients had been screened and 31 had been enrolled and randomized. By October 2019 we expect to have enrolled 43 patients (76% of our final target enrollment). Common adverse events included oral ulcers, abdominal discomfort and diarrhea/loose stools. Recruitment and adverse events will be updated by the time of this abstract presentation.
Conclusion(s): This is the first time sirolimus or analogs are being used clinically with the aim of slowing disease progression in patients with neurodegenerative disorders. Our observations may offer strong support for a phase-3 trial to confirm the efficacy of sirolimus in MSA
EMBASE:632812812
ISSN: 1619-1560
CID: 4597962
Electrophysiology of Inhibitory Control in the Context of Emotion Processing in Children With Autism Spectrum Disorder
Autism Spectrum Disorder (ASD) is an increasingly common developmental disorder that affects 1 in 59 children. Despite this high prevalence of ASD, knowledge regarding the biological basis of its associated cognitive difficulties remains scant. In this study, we aimed to identify altered neurophysiological responses underlying inhibitory control and emotion processing difficulties in ASD, together with their associations with age and various domains of cognitive and social function. This was accomplished by assessing electroencephalographic recordings during an emotional go/nogo task alongside parent rating scales of behavior. Event related potential (ERP) N200 component amplitudes were reduced in children with ASD compared to typically developing (TD) children. No group differences were found, however, for task performance, P300 amplitude or latency, or N170 amplitude or latency, suggesting that individuals with ASD may only present conflict monitoring abnormalities, as reflected by the reduced N200 component, compared to TD individuals. Consistent with previous findings, increased age correlated with improved task performance scores and reduced N200 amplitude in the TD group, indicating that as these children develop, their neural systems become more efficient. These associations were not identified in the ASD group. Results also showed significant associations between increased N200 amplitudes and improved executive control abilities and decreased autism traits in TD children only. The newly discovered findings of decreased brain activation in children with ASD, alongside differences in correlations with age compared to TD children, provide a potential neurophysiological indicator of atypical development of inhibitory control mechanisms in these individuals.
PMCID:6422887
PMID: 30914937
ISSN: 1662-5161
CID: 3777072
Proceedings of the National Academy of Sciences of the United States of America (PNAS). 2019:116(52):26167-26172.DOI:
From basic brain research to treating human brain disorders INTRODUCTION [Editorial]
ISI:000504656900009
ISSN: 0027-8424
CID: 4259222
Multimodal Hippocampal Subfield Grading For Alzheimer's Disease Classification
ISI:000487586600036
ISSN: 2045-2322
CID: 4155602
Configural Perception Of Odor Mixtures: Functional Early In Life, Convergent Between Species [Meeting Abstract]
ISI:000493389500199
ISSN: 0379-864x
CID: 4221942
Mechanistic investigation of Ca2+ alternans in human heart failure and its modulation by fibroblasts
BACKGROUND:Heart failure (HF) is characterized, among other factors, by a progressive loss of contractile function and by the formation of an arrhythmogenic substrate, both aspects partially related to intracellular Ca2+ cycling disorders. In failing hearts both electrophysiological and structural remodeling, including fibroblast proliferation, contribute to changes in Ca2+ handling which promote the appearance of Ca2+ alternans (Ca-alt). Ca-alt in turn give rise to repolarization alternans, which promote dispersion of repolarization and contribute to reentrant activity. The computational analysis of the incidence of Ca2+ and/or repolarization alternans under HF conditions in the presence of fibroblasts could provide a better understanding of the mechanisms leading to HF arrhythmias and contractile function disorders. METHODS AND FINDINGS/RESULTS:The goal of the present study was to investigate in silico the mechanisms leading to the formation of Ca-alt in failing human ventricular myocytes and tissues with disperse fibroblast distributions. The contribution of ionic currents variability to alternans formation at the cellular level was analyzed and the results show that in normal ventricular tissue, altered Ca2+ dynamics lead to Ca-alt, which precede APD alternans and can be aggravated by the presence of fibroblasts. Electrophysiological remodeling of failing tissue alone is sufficient to develop alternans. The incidence of alternans is reduced when fibroblasts are present in failing tissue due to significantly depressed Ca2+ transients. The analysis of the underlying ionic mechanisms suggests that Ca-alt are driven by Ca2+-handling protein and Ca2+ cycling dysfunctions in the junctional sarcoplasmic reticulum and that their contribution to alternans occurrence depends on the cardiac remodeling conditions and on myocyte-fibroblast interactions. CONCLUSION/CONCLUSIONS:It can thus be concluded that fibroblasts modulate the formation of Ca-alt in human ventricular tissue subjected to heart failure-related electrophysiological remodeling. Pharmacological therapies should thus consider the extent of both the electrophysiological and structural remodeling present in the failing heart.
PMID: 31211790
ISSN: 1932-6203
CID: 3939102
Brain-Derived Neurotrophic Factor and the Attivita plastica dei neuroni: The Neuronal Plasticity as Defined by Ernesto Lugaro (1870-1940)
Many brain functions frequently change across a life span in response to new experience, the rewiring of neural circuits, homeostatic factors, and environmental events. Extracellular signals can promote rapid responses in gene expression and protein synthesis that trigger growth and plasticity in the nervous system. A key component is activity-dependent events and their participation in synaptic function. These responses are required for long-lasting effects in synaptic plasticity associated with learning and memory. The neurotrophin brain-derived neurotrophic factor (BDNF), discovered in 1982, is well established as a prominent molecule responsible for inducing synaptogenesis, dendritic growth, and long-term potentiation. This volume of the Neuromethods Series is dedicated to the methods that have allowed to study the many potential mechanisms whereby BDNF signaling accounts for its many physiological effects.
Copyright
Copyright
EMBASE:628654765
ISSN: 1940-6045
CID: 4021552
Hybrid-state free precession in nuclear magnetic resonance
The dynamics of large spin-1/2 ensembles are commonly described by the Bloch equation, which is characterized by the magnetization's non-linear response to the driving magnetic field. Consequently, most magnetic field variations result in non-intuitive spin dynamics, which are sensitive to small calibration errors. Although simplistic field variations result in robust spin dynamics, they do not explore the richness of the system's phase space. Here, we identify adiabaticity conditions that span a large experiment design space with tractable dynamics. All dynamics are trapped in a one-dimensional subspace, namely in the magnetization's absolute value, which is in a transient state, while its direction adiabatically follows the steady state. In this hybrid state, the polar angle is the effective drive of the spin dynamics. As an example, we optimize this drive for robust and efficient quantification of spin relaxation times and utilize it for magnetic resonance imaging of the human brain.
PMCID:6641569
PMID: 31328174
ISSN: 2399-3650
CID: 3986702
