bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanisms of Synchrony in Heterogeneous Inhibitory Interneuronal Networks for Type 1 versus Type 2 Excitability
Authors: Tikidji-Hamburyan Ruben A. , Canavier Carmen C. 
Published: October 2019

AbstractPV+ fast spiking basket interneurons are often implicated in gamma rhythms. Here we focus on mechanisms present in purely inhibitory networks. Neurons with type 1 excitability can fire arbitrarily slowly, whereas those with type 2 excitability cannot fire below a minimum frequency. We systematically examine how excitability type affects synchronization of individual spikes to a population rhythm in the presence of heterogeneity and noise, using model neurons of each type with matched F/I curve, input resistance, time constant and action potential shape. Population synchrony in noisy heterogeneous networks is maintained because neurons either fire within a tight time window or skip that cycle. Type 2 neurons with hyperpolarizing inhibition skip cycles due to their intrinsic dynamics; we show here the cycle skipping mechanism for type 1 neurons or type 2 neurons with shunting inhibition is synaptic and not intrinsic. Type 2 neurons are more resistant than type 1 to partial and complete suppression in networks with hyperpolarizing inhibition that exhibit network gamma. Moreover, type 2 neurons are recruited more rapidly and more completely into theta-nested gamma. In contrast, type 1 networks perform better with shunting inhibition on both counts, because the nonlinear dynamics in that case favor suppression of type 2 compared to type 1 neurons. Conductances that control excitability type may provide a therapeutic target to improve spatial and working memory and other tasks that rely on gamma synchrony or phase amplitude coupling.Author SummaryThe collective, synchronized activity of neurons produces brain rhythms. These rhythms are thought to subserve cognitive functions such as attention and memory encoding and retrieval. Faster rhythms are nested in slower rhythms as a putative way of chunking information. A subset of neurons called fast spiking basket cells tend to inhibit other neurons from firing. These neurons play an important role in oscillations, and in the coupling of faster oscillations to slower ones. In some brain regions these neurons can fire arbitrarily slowly (type 1 dynamics) whereas in others they cannot fire below a minimum cutoff frequency (type 2 dynamics). Mathematically, these distinct origins of rhythmic firing are signatures of very different dynamics. Here, we show that these distinct excitability types affect the ability of networks of these neurons to synchronize their fast oscillatory activity, as well as the ability of slower oscillations to modulate these fast oscillations. The exact nature of the inhibitory coupling, which may vary between brain regions, determines which type synchronizes better and is modulated better.
The C. elegans homolog of the Evi1 proto-oncogene, egl-43, coordinates G1 cell cycle arrest with pro-invasive gene expression during anchor cell invasion
Authors: Deng Ting , Daube Michael , Hajnal Alex , Lattmann Evelyn 
Published: October 2019

AbstractCell invasion allows cells to migrate across compartment boundaries formed by basement membranes. Aberrant cell invasion is a first step during the formation of metastases by malignant cancer cells.Anchor cell (AC) invasion in C. elegans is an excellent in vivo model to study the regulation of cell invasion during development. Here, we have examined the function of egl-43, the homolog of the human Evi1 proto-oncogene (also called MECOM), in the invading AC. egl-43 plays a dual role in this process, firstly by imposing a G1 cell cycle arrest to prevent AC proliferation, and secondly, by activating pro-invasive gene expression. We have identified the AP-1 transcription factor fos-1 and the Notch homolog lin-12 as critical egl-43 targets. A positive feedback loop between fos-1 and egl-43 induces pro-invasive gene expression in the AC, while repression of lin-12 Notch expression by egl-43 ensures the G1 cell cycle arrest necessary for invasion. Reducing lin-12 levels in egl-43 depleted animals restored the G1 arrest, while hyperactivation of lin-12 signaling in the differentiated AC was sufficient to induce proliferation.Taken together, our data have identified egl-43 Evi1 as a critical factor coordinating cell invasion with cell cycle arrest.Author summaryCells invasion is a fundamental biological process that allows cells to cross compartment boundaries and migrate to new locations. Aberrant cell invasion is a first step during the formation of metastases by malignant cancer cells.We have investigated how a specialized cell in the Nematode C. elegans, the so-called anchor cell, can invade into an adjacent epithelium. Our work has identified an oncogenic transcription factor that controls the expression of specific target genes necessary for cell invasion, and at the same time inhibits the proliferation of the invading anchor cell.These findings shed light on the mechanisms, by which cells decide whether to proliferate or invade.
Duplication and divergence of the retrovirus restriction geneFv1inMus carolimice allows protection from multiple retroviruses
Authors: Yap Melvyn W. , Young George R. , Varnaite Renata , Morand Serge , Stoye Jonathan P. 
Published: October 2019

AbstractViruses and their hosts are locked in an evolutionary race where resistance to infection is acquired by the hosts while viruses develop strategies to circumvent these host defenses. Forming one arm of the host defense armory are cell autonomous restriction factors like Fv1. Originally described as protecting laboratory mice from infection by murine leukemia virus (MLV), Fv1s from some wild mice have also been found to restrict non-MLV retroviruses, suggesting an important role in the protection against viruses in nature. To begin to understand how restriction factors evolve, we surveyed theFv1genes of wild mice trapped in Thailand and characterized their restriction activities against a panel of retroviruses. An extra copy of theFv1gene, named Fv7, was found on chromosome 6 of three closely related Asian species of mice (Mus caroli,M. cervicolorandM. cookii). The presence of flanking repeats suggested it arose by LINE-mediated retrotransposition. A high degree of natural variation was observed in bothFv1andFv7, including numerous single nucleotide polymorphisms resulting in altered amino acids, as well as insertions and deletions that changed the length of the reading frames. These genes exhibited a range of restriction phenotypes with activities directed against feline foamy virus (FFV), equine infectious anemia virus (EIAV) and MLV. It seems likely, at least in the case ofM. caroli, that the observed gene duplication confers protection against multiple viruses not possible with a single restriction factor. We suggest that EIAV-, FFV- and MLV-like viruses are endemic within these populations, driving the evolution of theFv1andFv7genes.Author SummaryDuring the passage of time all vertebrates will be exposed to infection by a variety of different kinds of virus. To meet this threat, a variety of genes for natural resistance to viral infection have evolved. The prototype of such so-called restriction factors is encoded by the mouseFv1gene, which acts to block the life cycle of retroviruses at a stage between virus entry into the cell and integration of the viral genetic material into the nuclear DNA. We have studied the evolution of this gene in certain species of wild mice from South East Asia and describe an example where a duplication of theFv1gene has taken place. The two copies of the gene, initially identical, have evolved separately allowing the development of resistance to two rather different kinds of retroviruses, lentiviruses and spumaviruses. Independent selection for resistance to these two kinds of retrovirus suggests that such mice are repeatedly exposed to never-before-reported pathogenic retroviruses of these genera.
Climate teleconnections synchronizePicea glaucamasting and fire disturbance: Evidence for a fire‐related form of environmental prediction
Authors: Ascoli Davide , Hacket‐Pain Andrew , LaMontagne Jalene M. , Cardil Adrián , Conedera Marco , Maringer Janet , Motta Renzo , Pearse Ian S. , Vacchiano Giorgio 
Published: October 2019

AbstractSynchronous pulses of seed masting and natural disturbance have positive feedbacks on the reproduction of masting species in disturbance‐prone ecosystems. We test the hypotheses that disturbances and proximate causes of masting are correlated, and that their large‐scale synchrony is driven by similar climate teleconnection patterns at both inter‐annual and decadal time scales.Hypotheses were tested on white spruce (Picea glauca), a masting species which surprisingly persists in fire‐prone boreal forests while lacking clear fire adaptations. We built masting, drought and fire indices at regional (Alaska, Yukon, Alberta, Quebec) and sub‐continental scales (western North America) spanning the second half of the 20th century. Superposed Epoch Analysis tested the temporal associations between masting events, drought and burnt area at the regional scale. At the sub‐continental scale, Superposed Epoch Analysis tested whether El Niño‐Southern Oscillation (ENSO) and its coupled effects with the Atlantic Multidecadal Oscillation (AMO) in the positive phase (AMO+/ENSO+) synchronize drought, burnt area and masting. We additionally tested the consistency of our synchronization hypotheses on a decadal temporal scale to verify whether long‐term oscillations in AMO+/ENSO+ are coherent to decadal variation in drought, burnt area and masting.Analyses demonstrated synchronicity between drought, fire and masting. In all regions the year before a mast event was drier and more fire‐prone than usual. During AMO+/ENSO+ events sub‐continental indices of drought and burnt area experienced significant departures from mean values. The same was observed for large‐scale masting in the subsequent year, confirming 1‐year lag between fire and masting. Sub‐continental indices of burnt area and masting showed in‐phase decadal fluctuations led by the AMO+/ENSO+. Results support the ‘Environmental prediction hypothesis’ for mast seeding.Synthesis. We provide evidence of large‐scale synchronicity between seed masting inPicea glaucaand fire regimes in boreal forests of western North America at both inter‐annual and decadal time scales. We conclude that seed production in white spruce predicts changes in disturbance regimes by sharing the same large‐scale climate drivers with drought and fire. This gives new insides in a mechanism providing a fire‐sensitive species with higher than expected adaptability to changes in climate.
Downregulation of the inflammatory network in senescent fibroblasts and aging tissues of the long‐lived and cancer‐resistant subterranean wild rodent, Spalax
Authors: Odeh Amani , Dronina Maria , Domankevich Vered , Shams Imad , Manov Irena 
Published: October 2019

AbstractThe blind mole rat (Spalax) is a wild, long‐lived rodent that has evolved mechanisms to tolerate hypoxia and resist cancer. Previously, we demonstrated high DNA repair capacity and low DNA damage in Spalax fibroblasts following genotoxic stress compared with rats. Since the acquisition of senescence‐associated secretory phenotype (SASP) is a consequence of persistent DNA damage, we investigated whether cellular senescence in Spalax is accompanied by an inflammatory response. Spalax fibroblasts undergo replicative senescence (RS) and etoposide‐induced senescence (EIS), evidenced by an increased activity of senescence‐associated beta‐galactosidase (SA‐β‐Gal), growth arrest, and overexpression of p21, p16, and p53 mRNAs. Yet, unlike mouse and human fibroblasts, RS and EIS Spalax cells showed undetectable or decreased expression of the well‐known SASP factors: interleukin‐6 (IL6), IL8, IL1α, growth‐related oncogene alpha (GROα), SerpinB2, and intercellular adhesion molecule (ICAM‐1). Apparently, due to the efficient DNA repair in Spalax, senescent cells did not accumulate the DNA damage necessary for SASP activation. Conversely, Spalax can maintain DNA integrity during replicative or moderate genotoxic stress and limit pro‐inflammatory secretion. However, exposure to the conditioned medium of breast cancer cells MDA‐MB‐231 resulted in an increase in DNA damage, activation of the nuclear factor κB (NF‐κB) through nuclear translocation, and expression of inflammatory mediators in RS Spalax cells. Evaluation of SASP in aging Spalax brain and intestine confirmed downregulation of inflammatory‐related genes. These findings suggest a natural mechanism for alleviating the inflammatory response during cellular senescence and aging in Spalax, which can prevent age‐related chronic inflammation supporting healthy aging and longevity.
The efficacy of remote ischemic conditioning in preventing contrast‐induced nephropathy among patients undergoing coronary angiography or intervention: An updated systematic review and meta‐analysis
Authors: Zhan Biming , Zhu Bo , Hu Jianxin , Huang Qianghui , Bao Huihui , Huang Xiao , Cheng Xiaoshu 
Published: October 2019

AbstractBackgroundNumerous trials have investigated the effect of remote ischemic conditioning (RIC) in preventing contrast‐induced nephropathy (CIN) in patients receiving contrast medium (CM). This meta analysis aims to validate the role of RIC in preventing CIN.MethodsWe searched the PubMed, EMBASE, and Web of Science databases for eligible randomized controlled trials (RCTs) published before April 27, 2019. Two investigators independently extracted basic characteristics from each study. Odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were used to examine the treatment effect.ResultsA total of 18 studies comprising 2,503 patients were included in our meta‐analysis. Compared with conventional therapy, RIC significantly reduced the risk of CIN (OR = 0.43, 95% CI: 0.33, 0.56, p < .05). Subgroup analyses showed that the protective effect of RIC was stronger in the low‐osmolar contrast media group (OR = 0.32; 95% CI: 0.23, 0.45, p < .05) and the nondiabetic group (OR = 0.39; 95% CI: 0.29, 0.53 p < .05). RIC also significantly reduced major adverse cardiovascular events within the first 6 months (OR = 0.39; p < .05), but the influence was not present after long‐term follow‐up.ConclusionsOur meta‐analysis showed that RIC could effectively reduce CIN risk and decrease the short‐term incidence of relevant adverse events. Furthermore, the effects of CIN are more pronounced in nondiabetic patients and with the use of low‐osmolar contrast medium. This meta‐analysis of small trials suggests a possible protective effect of RIC on contrast‐induced nephropathy and favors the performance of a large randomized trial to further investigate this strategy.
Meta‐analysis of the differential effects of habitat fragmentation and degradation on plant genetic diversity
Authors: González Alejandra V. , Gómez‐Silva Valeria , Ramírez María José , Fontúrbel Francisco E. 
Published: October 2019

AbstractGenetic diversity is a key factor for population survival and evolution. However, anthropogenic habitat disturbance can erode it, making populations more prone to extinction. Aiming to assess the global effects of habitat disturbance on plant genetic variation, we conducted a meta‐analysis based on 92 case studies obtained from published literature. We compared the effects of habitat fragmentation and degradation on plant allelic richness and gene diversity (equivalent to expected heterozygosity) and tested whether such changes are sensitive to different life‐forms, life spans, mating systems, and commonness. Anthropogenic disturbance had a negative effect on allelic richness, but not on gene diversity. Habitat fragmentation had a negative effect on genetic variation, whereas habitat degradation had no effect. When we examined the individual effects in fragmented habitats, allelic richness and gene diversity decreased, but this decrease was strongly dependent on certain plant traits. Specifically, common long‐lived trees and self‐incompatible species were more susceptible to allelic richness loss. Conversely, gene diversity decreased in common short‐lived species (herbs) with self‐compatible reproduction. In a wider geographical context, tropical plant communities were more sensitive to allelic richness loss, whereas temperate plant communities were more sensitive to gene diversity loss. Our synthesis showed complex responses to habitat disturbance among plant species. In many cases, the absence of effects could be the result of the time elapsed since the disturbance event or reproductive systems favoring self‐pollination, but attention must be paid to those plant species that are more susceptible to losing genetic diversity, and appropriate conservation should be actions taken.
The use of the orbitofrontal H‐sulcus as a reference frame for value signals
Authors: Troiani Vanessa , Patti Marisa A. , Adamson Kayleigh 
Published: October 2019

AbstractUnderstanding the factors that drive organization and function of the brain is an enduring question in neuroscience. Using functional magnetic resonance imaging (fMRI), structure and function have been mapped in primary sensory cortices based on knowledge of the organizational principles that likely drive a given region (e.g., aspects of visual form in primary visual cortex and sound frequency in primary auditory cortex) and knowledge of underlying cytoarchitecture. The organizing principles of higher‐order brain areas that encode more complex signals, such as the orbitofrontal cortex (OFC), are less well understood. One fundamental component that underlies the many functions of the OFC is the ability to compute the reward or value of a given object. There is evidence of variability in the spatial location of responses to specific categories of objects (or value of said objects) within the OFC, and several reference frames have been proposed to explain this variability, including topographic spatial gradients that correspond to axes of primary versus secondary rewards and positive versus negative reinforcers. One potentially useful structural morphometric reference frame in the OFC is the “H‐sulcus,” a pattern formed by medial orbital, lateral orbital and transverse orbital sulci. In 48 human subjects, we use a structural morphometric tracing procedure to localize functional activation along the H‐sulcus for face and food stimuli. We report the novel finding that food‐selective responses are consistently found within the caudal portion of the medial orbital sulcus, but no consistency within the H‐sulcus for response to face stimuli. These results suggest that sulcogyral anatomy of the H‐sulcus may be an important morphological metric that contributes to the organizing principles of the OFC response to certain stimulus categories, including food.
Update on temporal lobe‐dependent information processing, in health and disease
Authors: Chauvière Laëtitia 
Published: October 2019

AbstractThe past decade has been characterized by a lot of remodeling in the field of learning and memory. Both of them, often associated with neuronal oscillations, an emergent property of brain networks, are governed by temporal lobe (TL) functional connectivity. An impairment of oscillatory mechanisms indeed often leads to TL‐dependent cognitive deficits. While the classical view assigned the TL a major role in spatial information processing, new theories rather confer to the TL a more general function in cognitive processes beyond space representation. The present review covers, both in humans and in animal models, (a) the updated role of the TL in cognitive processes, addressing current debates in the field and proposing a scenario on how TL structures cooperate in order to bind an integrated representation of afferent information, (b) the oscillatory mechanisms underlying these TL‐dependent cognitive functions (theta, gamma, sharp wave ripples) and (c) how TL‐dependent cognition is altered during temporal lobe epilepsy, proposing a scenario on how reorganized TL networks in TLE leads to rhythmopathies and cognitive deficits. Temporal lobe epilepsy (TLE) is a well‐studied neurological disease. Patients do not only suffer from epileptic seizures but also from cognitive and behavioral deficits between their seizures called comorbidities. TLE animal models are therefore used to understand how and when these comorbidities arise and what their underlying mechanisms are.
Bullous pemphigoid associated with dipeptidyl peptidase‐4 inhibitors. A case series and analysis of cases reported in the Spanish pharmacovigilance database
Authors: Reolid Alejandra , Muñoz‐Aceituno Ester , Rodríguez‐Jiménez Pedro , González‐Rojano Esperanza , Llamas‐Velasco Mar , Fraga Javier , Daudén Esteban 
Published: October 2019

AbstractBackgroundBullous pemphigoid (BP) has been associated with dipeptidyl peptidase‐4 inhibitors (DPP4i). Clinical features, outcomes, and risk of BP for new DPP4i (linagliptin, saxagliptin, and alopgliptin) are not well established. Comparison of risk of BP appearance for DPP4i and other oral antidiabetic drugs (OADs) such as sodium glucose cotransporter 2 inhibitors has not been studied to date.ObjectivesTo describe the prevalence, sociodemographic, clinical, and histopathological characteristics, and outcome after drug withdrawal in DPP‐4i‐associated BP cases from our hospital. To review all Spanish spontaneous notifications of BP where DPP4i or OADs were included as suspected drugs and calculate the reporting odds ratios (RORs).MethodsA retrospective observational study was performed examining the association between DDP4i and BP. Clinical features and RORs were analyzed. Data from the Spanish Pharmacovigilance System (SEFV) are included.ResultsIn our center, 28 of 89 patients with BP (31.5%) were under DPP4i treatment; 53.6% were male, and mean age was 80.8 years. BP debuted the first year after DPP4i in 57.2%. BP control was achieved within 3.7 months after drug withdrawal. Regarding SEFV, 22 of 972 spontaneous notifications were related to BP and DPP4i. RORs were superior for DPP4i compared to other OADs. Vildagliptin had the highest ROR.ConclusionsWe present the largest DPP4i‐induced BP case series in a single center, with a detailed study of the sociodemographic, clinical, and histopathological characteristics of each patient, and their treatment and outcome. Vildagliptin had the highest risk. DPP4i‐associated BP does not seem to have specific clinical characteristics.
Thermal processing of rice grains affects the physical properties of their pregelatinised rice flours
Authors: Ma Mengting , He Meng , Xu Yijuan , Li Peng , Li Zijun , Sui Zhongquan , Corke Harold 
Published: October 2019

SummaryWaxy, low‐ and high‐amylose rice were cooked at different temperatures (50, 70, 90 °C) for different times (15, 30, 45 min). The microscopic, rheological and gel textural properties of resultant flours were investigated. There was a coarser and discontinuous honeycomb‐like structure with formation of pores in rice flour with greater cooking degree. TGʹmax was positively correlated with cooking temperature and time. As cooking temperature increased, the Gʹ values of pastes first increased and then decreased, whereas the opposite trend was observed for tan δ. Meanwhile, increased cooking temperature was responsible for increases in n values and caused drops in K and hysteresis area. As cooking time increased, the hardness and gumminess of gels from rice cooked were increased at lower temperature, but were decreased at higher temperature. Overall, cooking temperature was more important in determining the processing properties of rice flours than cooking time.