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result(s) for
"Liu Yang, Lindsay"
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Human Mediodorsal Thalamus in Seizure Propagation
2025
How different thalamic sites are recruited during seizure propagation remains poorly understood. Simultaneous recordings from multiple thalamic sites in patients with focal seizures provide a rare opportunity to investigate the spatiotemporal pattern of thalamic involvement during human epilepsy.
To characterize the recruitment patterns of mediodorsal (MD) thalamic subregion during seizures and their generalization to the contralateral hemisphere.
We analyzed 119 seizures from 23 patients (12 male, age range: 20-57y) undergoing multisite thalamic recordings. In accordance with current clinical standards, we determined the spatial and temporal features of thalamic seizure activity by visually reviewing intracranial EEG recordings from different seizure types in each individual patient.
The procedure of multisite thalamic recordings had no complications. In total, we captured seizures originating from temporal lobes (63%), orbitofrontal (11%), frontotemporal (8%), occipital (8%), lateral frontal (4%), parietal (3%), and cingulate (2%) regions. Seizures were focal (76% in 21 patients), focal-to-bilateral tonic-clonic (FBTC, 9% in nine patients), or only electrographic (15% in six patients). Thalamic engagement was seen in 100% of patients occurring typically early during seizure evolution (83% within 15 seconds of seizure onset). Majority of FBTC seizures (73%) had faster thalamic recruitment, often within the first 5 seconds. The pulvinar (PLV) subregion was the most common first-activated thalamic site, particularly in temporal lobe seizures. Although the MD was involved in most seizures (88.2%), it was rarely the initial or sole thalamic structure engaged and more often followed anterior (ANT) and/or PLV sites. Contralateral propagation occurred in 66% of seizures and was strongly linked to MD involvement: the ipsilateral and contralateral MDs were engaged in about 95% of these cases. When ipsilateral MD engagement was absent, contralateral spread of seizures was uncommon. In majority of seizures (60%) that generalized to the contralateral hemisphere, the ipsilateral MD was involved before or simultaneously with the contralateral cortical sites. Importantly, seizures that first activated the MD originated mainly from the medial temporal lobes, whereas those spreading primarily to the contralateral cortex were mostly neocortical in onset.
The thalamic MD subregion was often involved after the other thalamic sites, but the MD sites, along with the massa intermedia connecting the two thalami, were significantly involved when seizures spread to contralateral hemisphere. Our findings suggest that a single thalamic lead capturing both MD subregions may yield important clinical information about laterality, origin, and generalization of seizures.
Journal Article
Electrophysiological Brain Connectivity and Subjective States Evoked by Electrical Stimulation of the Human Mediodorsal Thalamus
2025
Recent advances in human intracranial EEG (iEEG) have enabled new investigations into the role of the thalamus in human brain functions. In this study, we applied direct intracranial electrical stimulation (iES) to the mediodorsal (MD) subregion of the thalamus using both high-frequency (50 Hz, iES
) and low-frequency (0.5 Hz, iES
) procedures to examine its impact on conscious experience and causal brain connectivity in 30 patients with focal refractory epilepsy (128 electrode contacts; 4 ± 1 MD sites per patient). iES
of the MD elicited reportable changes in conscious experience in 11 of 12 patients (39 sites; 83 stimulations across 27 unique pairs) - predominantly in the visceral, emotional, or somatosensory domains and often described as unpleasant without any lateralization effect. Our connectivity analyses based on iES
revealed that the cingulate and insular cortices produced stronger electrophysiological responses in the MD (inflow connectivity) than did the sites in the prefrontal cortex (PFC) within the same individuals. Moreover, MD stimulation showed its strongest outflow connectivity to the cingulate, insular, and PFC regions, all significantly stronger than to medial temporal lobe (MTL) structures. Notably, inflow from both MTL and insula sites to the MD were significantly stronger than their reverse directions, indicating clear asymmetry in connectivity. These findings provide direct evidence that stimulation of the human thalamus can modulate conscious experience. They also highlight the extensive bidirectional connectivity between the MD and cingulate and insular cortices along with asymmetric connectivity between the MD and MTL and insula sites in the human brain.
Our findings provide a functional and causal map of the mediodorsal thalamus (MD) in the human brain. We provide direct evidence that stimulation of the human thalamus can modulate conscious experience. This study also holds clinical and translational value for identifying thalamic pathways involved in the propagation and generalization of seizures, especially seizures involving the medial temporal lobe, as well as for neuromodulation in epilepsy and other neuropsychiatric disorders, as MD stimulation may not be well-tolerated in human subjects.
Journal Article
Genomics and metatranscriptomics of biogeochemical cycling and degradation of lignin-derived aromatic compounds in thermal swamp sediment
2021
Thermal swamps are unique ecosystems where geothermally warmed waters mix with decomposing woody biomass, hosting novel biogeochemical-cycling and lignin-degrading microbial consortia. Assembly of shotgun metagenome libraries resolved 351 distinct genomes from hot-spring (30–45 °C) and mesophilic (17 °C) sediments. Annotation of 39 refined draft genomes revealed metabolism consistent with oligotrophy, including pathways for degradation of aromatic compounds, such as syringate, vanillate,
p
-hydroxybenzoate, and phenol. Thermotolerant
Burkholderiales
, including
Rubrivivax
ssp., were implicated in diverse biogeochemical and aromatic transformations, highlighting their broad metabolic capacity. Lignin catabolism was further investigated using metatranscriptomics of sediment incubated with milled or Kraft lignin at 45 °C. Aromatic compounds were depleted from lignin-amended sediment over 148 h. The metatranscriptomic data revealed upregulation of
des
/
lig
genes predicted to specify the catabolism of syringate, vanillate, and phenolic oligomers in the sphingomonads
Altererythrobacter
ssp. and
Novosphingobium
ssp., as well as in the
Burkholderiales
genus,
Rubrivivax
. This study demonstrates how temperature structures biogeochemical cycling populations in a unique ecosystem, and combines community-level metagenomics with targeted metatranscriptomics to identify pathways with potential for bio-refinement of lignin-derived aromatic compounds. In addition, the diverse aromatic catabolic pathways of
Altererythrobacter
ssp. may serve as a source of thermotolerant enzymes for lignin valorization.
Journal Article
Resistance of SARS-CoV-2 variants to neutralization by monoclonal and serum-derived polyclonal antibodies
by
Errico, John M.
,
Diamond, Michael S.
,
Liu, Jianying
in
631/250/2152/2153/1291
,
631/326/596/4130
,
Animals
2021
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused the global COVID-19 pandemic. Rapidly spreading SARS-CoV-2 variants may jeopardize newly introduced antibody and vaccine countermeasures. Here, using monoclonal antibodies (mAbs), animal immune sera, human convalescent sera and human sera from recipients of the BNT162b2 mRNA vaccine, we report the impact on antibody neutralization of a panel of authentic SARS-CoV-2 variants including a B.1.1.7 isolate, chimeric strains with South African or Brazilian spike genes and isogenic recombinant viral variants. Many highly neutralizing mAbs engaging the receptor-binding domain or N-terminal domain and most convalescent sera and mRNA vaccine-induced immune sera showed reduced inhibitory activity against viruses containing an E484K spike mutation. As antibodies binding to spike receptor-binding domain and N-terminal domain demonstrate diminished neutralization potency in vitro against some emerging variants, updated mAb cocktails targeting highly conserved regions, enhancement of mAb potency or adjustments to the spike sequences of vaccines may be needed to prevent loss of protection in vivo.
A comprehensive analysis of antibody neutralization activity against a panel of authentic isolates and chimeric SARS-CoV-2 variants shows markedly diminished neutralizing activity against the variant B.1.351, first identified in South Africa.
Journal Article
Discovery of lignin-transforming bacteria and enzymes in thermophilic environments using stable isotope probing
2022
Characterizing microorganisms and enzymes involved in lignin biodegradation in thermal ecosystems can identify thermostable biocatalysts. We integrated stable isotope probing (SIP), genome-resolved metagenomics, and enzyme characterization to investigate the degradation of high-molecular weight,
13
C-ring-labeled synthetic lignin by microbial communities from moderately thermophilic hot spring sediment (52 °C) and a woody “hog fuel” pile (53 and 62 °C zones).
13
C-Lignin degradation was monitored using IR-GCMS of
13
CO
2
, and isotopic enrichment of DNA was measured with UHLPC-MS/MS. Assembly of 42 metagenomic libraries (72 Gb) yielded 344 contig bins, from which 125 draft genomes were produced. Fourteen genomes were significantly enriched with
13
C from lignin, including genomes of
Actinomycetes
(
Thermoleophilaceae
,
Solirubrobacteraceae
,
Rubrobacter
sp.),
Firmicutes
(
Kyrpidia
sp.,
Alicyclobacillus
sp.) and
Gammaproteobacteria
(
Steroidobacteraceae
). We employed multiple approaches to screen genomes for genes encoding putative ligninases and pathways for aromatic compound degradation. Our analysis identified several novel laccase-like multi-copper oxidase (LMCO) genes in
13
C-enriched genomes. One of these LMCOs was heterologously expressed and shown to oxidize lignin model compounds and minimally transformed lignin. This study elucidated bacterial lignin depolymerization and mineralization in thermal ecosystems, establishing new possibilities for the efficient valorization of lignin at elevated temperature.
Journal Article
Correlation of SARS-CoV-2 in Wastewater and Individual Testing Results in a Jail, Atlanta, Georgia, USA
2024
Institution-level wastewater-based surveillance was implemented during the COVID-19 pandemic, including in carceral facilities. We examined the relationship between COVID-19 diagnostic test results of residents in a jail in Atlanta, Georgia, USA (average population ≈2,700), and quantitative reverse transcription PCR signal for SARS-CoV-2 in weekly wastewater samples collected during October 2021‒May 2022. The jail offered residents rapid antigen testing at entry and periodic mass screenings by reverse transcription PCR of self-collected nasal swab specimens. We aggregated individual test data, calculated the Spearman correlation coefficient, and performed logistic regression to examine the relationship between strength of SARS-CoV-2 PCR signal (cycle threshold value) in wastewater and percentage of jail population that tested positive for COVID-19. Of 13,745 nasal specimens collected, 3.9% were COVID-positive (range 0%-29.5% per week). We observed a strong inverse correlation between diagnostic test positivity and cycle threshold value (r = -0.67; p<0.01). Wastewater-based surveillance represents an effective strategy for jailwide surveillance of COVID-19.
Journal Article
A roadmap for urban evolutionary ecology
by
Gorton, Amanda J.
,
Verrelli, Brian C.
,
Alberti, Marina
in
citizen science
,
community engagement
,
Ecology
2019
Urban ecosystems are rapidly expanding throughout the world, but how urban growth affects the evolutionary ecology of species living in urban areas remains largely unknown. Urban ecology has advanced our understanding of how the development of cities and towns change environmental conditions and alter ecological processes and patterns. However, despite decades of research in urban ecology, the extent to which urbanization influences evolutionary and eco‐evolutionary change has received little attention. The nascent field of urban evolutionary ecology seeks to understand how urbanization affects the evolution of populations, and how those evolutionary changes in turn influence the ecological dynamics of populations, communities, and ecosystems. Following a brief history of this emerging field, this Perspective article provides a research agenda and roadmap for future research aimed at advancing our understanding of the interplay between ecology and evolution of urban‐dwelling organisms. We identify six key questions that, if addressed, would significantly increase our understanding of how urbanization influences evolutionary processes. These questions consider how urbanization affects nonadaptive evolution, natural selection, and convergent evolution, in addition to the role of urban environmental heterogeneity on species evolution, and the roles of phenotypic plasticity versus adaptation on species’ abundance in cities. Our final question examines the impact of urbanization on evolutionary diversification. For each of these six questions, we suggest avenues for future research that will help advance the field of urban evolutionary ecology. Lastly, we highlight the importance of integrating urban evolutionary ecology into urban planning, conservation practice, pest management, and public engagement.
Journal Article
Structural variants caused by Alu insertions are associated with risks for many human diseases
by
Payer, Lindsay M.
,
Ardeljan, Daniel
,
Burns, Kathleen H.
in
Alu Elements
,
Biological Sciences
,
Case-Control Studies
2017
Interspersed repeat sequences comprise much of our DNA, although their functional effects are poorly understood. The most commonly occurring repeat is the Alu short interspersed element. New Alu insertions occur in human populations, and have been responsible for several instances of genetic disease. In this study, we sought to determine if there are instances of polymorphic Alu insertion variants that function in a common variant, common disease paradigm. We cataloged 809 polymorphic Alu elements mapping to 1,159 loci implicated in disease risk by genome-wide association study (GWAS) (P < 10−8). We found that Alu insertion variants occur disproportionately at GWAS loci (P = 0.013). Moreover, we identified 44 of these Alu elements in linkage disequilibrium (r² > 0.7) with the trait-associated SNP. This figure represents a >20-fold increase in the number of polymorphic Alu elements associated with human phenotypes. This work provides a broader perspective on how structural variants in repetitive DNAs may contribute to human disease.
Journal Article
The chromatin accessibility landscape of primary human cancers
2018
The Cancer Genome Atlas (TCGA) provides a high-quality resource of molecular data on a large variety of human cancers. Corces et al. used a recently modified assay to profile chromatin accessibility to determine the accessible chromatin landscape in 410 TCGA samples from 23 cancer types (see the Perspective by Taipale). When the data were integrated with other omics data available for the same tumor samples, inherited risk loci for cancer predisposition were revealed, transcription factors and enhancers driving molecular subtypes of cancer with patient survival differences were identified, and noncoding mutations associated with clinical prognosis were discovered. Science , this issue p. eaav1898 ; see also p. 401 Chromatin accessibility profiling identifies principles of epigenetic regulation in 23 primary human cancers. We present the genome-wide chromatin accessibility profiles of 410 tumor samples spanning 23 cancer types from The Cancer Genome Atlas (TCGA). We identify 562,709 transposase-accessible DNA elements that substantially extend the compendium of known cis-regulatory elements. Integration of ATAC-seq (the assay for transposase-accessible chromatin using sequencing) with TCGA multi-omic data identifies a large number of putative distal enhancers that distinguish molecular subtypes of cancers, uncovers specific driving transcription factors via protein-DNA footprints, and nominates long-range gene-regulatory interactions in cancer. These data reveal genetic risk loci of cancer predisposition as active DNA regulatory elements in cancer, identify gene-regulatory interactions underlying cancer immune evasion, and pinpoint noncoding mutations that drive enhancer activation and may affect patient survival. These results suggest a systematic approach to understanding the noncoding genome in cancer to advance diagnosis and therapy.
Journal Article
Endovascular thrombectomy with or without intravenous alteplase for acute ischemic stroke due to large vessel occlusion: a systematic review and meta-analysis of randomized trials
by
Prasad, Kameshwar
,
Wang, Xin
,
Zhang, Yi
in
Bias
,
Brain Ischemia - diagnosis
,
Brain Ischemia - therapy
2022
BackgroundAmong patients who had an ischaemic stroke presenting directly to a stroke centre where endovascular thrombectomy (EVT) is immediately available, there is uncertainty regarding the role of intravenous thrombolysis agents before or concurrently with EVT. To support a rapid guideline, we conducted a systematic review and meta-analysis to examine the impact of EVT alone versus EVT with intravenous alteplase in patients who had an acute ischaemic stroke due to large vessel occlusion.MethodsIn November 2021, we searched MEDLINE, Embase, PubMed, Cochrane, Web of Science, clincialtrials.gov and the ISRCTN registry for randomised controlled trials (RCTs) comparing EVT alone versus EVT with alteplase for acute ischaemic stroke. We conducted meta-analyses using fixed effects models and assessed the certainty of evidence using the GRADE approach.ResultsIn total 6 RCTs including 2334 participants were eligible. Low certainty evidence suggests that, compared with EVT and alteplase, there is possibly a small decrease in the proportion of patients independent with EVT alone (risk ratio (RR) 0.97, 95% CI 0.89 to 1.05; risk difference (RD) −1.5%; 95% CI −5.4% to 2.5%), and possibly a small increase in mortality with EVT alone (RR 1.07, 95% CI 0.88 to 1.29; RD 1.2%, 95% CI −2.0% to 4.9%) . Moderate certainty evidence suggests that there is probably a small decrease in symptomatic intracranial haemorrhage (sICH) with EVT alone (RR 0.75, 95% CI 0.52 to 1.07; RD −1.0%; 95%CI −1.8% to 0.27%).ConclusionsLow certainty evidence suggests that there is possibly a small decrease in the proportion of patients that achieve functional independence and a small increase in mortality with EVT alone. Moderate certainty evidence suggests that there is probably a small decrease in sICH with EVT alone. The accompanying guideline provides contextualised guidance based on this body of evidence.PROSPERO registration numberCRD42021249873.
Journal Article